WO2013003846A2 - Surface insulated porous current collectors as dendrite free electrodeposition electrodes - Google Patents

Surface insulated porous current collectors as dendrite free electrodeposition electrodes Download PDF

Info

Publication number
WO2013003846A2
WO2013003846A2 PCT/US2012/045257 US2012045257W WO2013003846A2 WO 2013003846 A2 WO2013003846 A2 WO 2013003846A2 US 2012045257 W US2012045257 W US 2012045257W WO 2013003846 A2 WO2013003846 A2 WO 2013003846A2
Authority
WO
WIPO (PCT)
Prior art keywords
lithium
current collector
metal
insulated
line
Prior art date
Application number
PCT/US2012/045257
Other languages
French (fr)
Other versions
WO2013003846A3 (en
Inventor
Galen D. Stucky
Xiulei Ji
Original Assignee
The Regents Of The University Of California
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Regents Of The University Of California filed Critical The Regents Of The University Of California
Publication of WO2013003846A2 publication Critical patent/WO2013003846A2/en
Publication of WO2013003846A3 publication Critical patent/WO2013003846A3/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00Electroplating characterised by the article coated
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • H01M4/66Selection of materials
    • H01M4/665Composites
    • H01M4/667Composites in the form of layers, e.g. coatings
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • H01M4/70Carriers or collectors characterised by shape or form
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/13Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134Electrodes based on metals, Si or alloys
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/36Selection of substances as active materials, active masses, active liquids
    • H01M4/38Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/381Alkaline or alkaline earth metals elements
    • H01M4/382Lithium
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Definitions

  • the present invention relates to spatially heterogeneous 3D current collectors and uses thereof.
  • a metallic lithium anode is energetically attractive in that it can theoretically provide a gravimetric capacity of 3861 mA-hg -1 , more than 10 times that of lithiated carbonaceous anodes (339 mA-hg "1 , for LiC6) at a very negative redox potential (- 3.04 V vs. Standard Hydrogen Electrode).
  • LBs Battery- vs. Standard Hydrogen Electrode
  • metallic lithium electrodes were eventually proven unsafe due to the uneven lithium electrodeposition and the growth of dendrites on the surface of a lithium anode.
  • the dendrites are associated with most of the failure mechanisms of LBs and can lead to a battery thermal runaway.
  • Substitution of metallic lithium with Li ions in insertion materials was an initial attempt to address the dendrite safety concern. This substitution came at the serious expense of energy density loss. This approach led to the tremendous success of lithium-ion batteries (LIBs) in powering portable electronics.
  • LIBs lithium-ion batteries
  • LIBs based on topotactic intercalation electrodes have approached the theoretical energy density for such devices.
  • substantially higher energy storage is required to strategically meet many demands including electrified transportation and load-leveling for intermittent renewable energy sources.
  • High energy Li-sulfur and Li-air batteries have been considered candidates to meet the above goals, but have met with difficulties.
  • Approaches other than intercalation chemistry are necessary to address the long-standing dendrite problem while retaining a high energy metallic form of a lithium electrode.
  • this application addresses, among other things, the dendrite formation problem for the lithium electrodes in rechargeable batteries.
  • the present invention comprises surface dendrite-free lithium deposition created by using spatially heterogeneous 3D current collectors.
  • the present invention confines lithium metal deposition inside the 3D current collectors.
  • the present invention employs, inter alia, controlling the conductive electrolyte-facing surface of the 3D current collectors to control or eliminate the dendrite growth, which provides favorable sites for lithium deposition while retarding dendrite growth and infiltrating the interior voids.
  • the present invention comprises introducing an anisotropic spatial heterogeneity in terms of conductivity for the 3D current collectors by insulating the electrolyte-facing surface while keeping the other parts conductive. This embodiment of the present invention reduces or prevents inter-electrode dendrite growth and forces lithium deposition inside the large voids.
  • an insulating layer is deposited by line-of-sight methods onto the electrolyte-facing surface of highly porous current collectors as lithium electrodeposition electrodes.
  • lithium electrodeposition with no electrons available from the insulating electrolyte facing surface, lithium ions from bulk electrolyte have to migrate deeper into the voids inside porous current collectors in order to be reduced.
  • the deposition process comprises essentially a lithium metal infiltration. With the porous volume of the current collector effectively utilized, the lithium plated current collectors or electrodes maintain a constant volume throughout the depositing/stripping cycles with no dendrites formed on the electrolyte-facing surface.
  • the solution for lithium dendrites herein is fundamentally distinct from state of the art technologies.
  • a line-of-sight surface insulated 3D current collector includes: a) a 3D current collector having an line-of-sight surface including openings, and non-line-of-sight surfaces accessible through the openings; and b) an insulating layer coating the line-of-sight surface, where the insulating layer allows access to the non-line-of-sight surfaces via the openings.
  • the 3D current collector can be, but is not limited to, carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous” means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, 3D structures made of conducting ceramics including titanium carbides, vanadium
  • the insulating layer can be, but is not limited to, silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, non- metallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials.
  • PTCT positive temperature coefficient thermistors
  • the insulating layer material can be deposited onto the 3D current collector by a line-of-sight method, which can include, but is not limited to, printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition.
  • a line-of-sight method can include, but is not limited to, printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition.
  • an electrode including the line-of-sight surface insulated 3D current collector is provided.
  • electrodeposition can occur preferentially at the non-line-of-sight surfaces of the 3D current collector or electrode.
  • the electrode can include metallic lithium after electrodeposition.
  • a lithium metal rechargeable battery including the electrode is provided.
  • the lithium metal rechargeable battery includes lithium ion containing positive electrodes to provide lithium ions for the lithium electrodeposition on the spatially heterogeneous current collectors.
  • a battery can be a lithium metal rechargeable battery in certain embodiments.
  • One method is a way of preparing a line-of-sight insulated 3D current collector.
  • the method includes coating an insulating layer onto the line -of- sight surface of a 3D current collector, where the 3D current collector includes openings in the line-of-sight surface and non-line-of-sight surfaces accessible through the openings, and the insulating layer allows access to the non-line-of-sight surfaces via the openings.
  • Another method is a way of performing electrodeposition.
  • the method includes preferentially electrodepositing a metal at non-line-of-sight surfaces of a line-of-sight surface insulated 3D current collector.
  • the metal is lithium.
  • the metals can be sodium, potassium, magnesium, calcium, titanium, vanadium, silicon, tin, zinc, and aluminum.
  • the insulating layer can be coated onto a porous 3D current collector by a line-of-sight method, which can include, but is not limited to, printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of- sight chemical vapor deposition.
  • the 3D current collector can be, but is not limited to, carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous” means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, 3D structures made of conducting ceramics including titanium carbides, vanadium
  • poly(pyrrole)s PPY
  • poly(3,4-ethylenedioxythiophene) PEDOT
  • polythiophenes PT
  • poly(p-phenylene sulfide) PPS
  • the insulating layer can be, but is not limited to, silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, non- metallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials.
  • PTCT positive temperature coefficient thermistors
  • a method of depositing metal on a porous substrate in accordance with one or more embodiments of the present invention comprises coating a first surface of the porous substrate with a layer, wherein the first surface remains porous to the metal to be deposited, placing the first surface with the layer facing an electrode, and depositing the metal on the substrate on a second surface of the substrate distinct from the first surface.
  • Such a method further optionally comprises the metal being lithium, the porous substrate being carbon fiber paper, the metal being electrodeposited on the substrate, the layer being silicon dioxide (Si02), silicon carbide (SiC), or SiC and silicon dioxide (Si02), the layer being deposited in a line-of-sight onto the first surface, the deposition of the metal having a reduced dendrite density compared to a porous substrate lacking the layer, and the layer being coated on the porous substrate using electron beam deposition.
  • An insulated three-dimensional (3D) current collector in accordance with one or more embodiments of the present invention comprises a 3D current collector having a line-of-sight surface comprising openings, and non-line-of-sight surfaces accessible through the openings, and an insulating layer coating the line-of-sight surface, the insulating layer allowing access to the non-line-of-sight surfaces via the openings.
  • Such a current collector further optionally comprises lithium being deposited on the non-line-of-sight surfaces, the lithium being deposited on the non-line-of-sight surfaces electrolytically, the insulated 3D current collector being carbon fiber paper, the insulating layer being silicon dioxide (Si02), silicon carbide (SiC), or SiC and silicon dioxide (Si02), the insulating layer being deposited in a line-of-sight onto the line-of-sight surface, the deposition of the metal having a reduced dendrite density compared to a current collector lacking the insulating layer, and the insulating layer being coated on the insulated three-dimensional (3D) current collector using electron beam deposition.
  • preferentially means that electrodeposition of a metal occurs more at non-line-of-sight surfaces of a 3D current collector than at the coated line-of-sight surface of the 3D current collector.
  • Electrodes include electrodes, electrochemical cells and batteries involving, but not limited to, sodium, potassium, magnesium, calcium, titanium, vanadium, silicon, tin, zinc, and aluminum.
  • Figure 1 is a Schematic illustrating the experimental setup of the
  • Figure 2 is a Schematic showing the vial cell setup for the electrochemical characterization studies in accordance with one or more embodiments of the present invention.
  • FIGS. 3a-3f illustrate Scanning Electron Microscope (SEM) images and corresponding Energy Dispersive X-ray (EDX) maps of the Carbon fiber Paper (CP) samples in accordance with one or more embodiments of the present invention.
  • SEM Scanning Electron Microscope
  • EDX Energy Dispersive X-ray
  • Figures 4a-4d illustrate X-ray Photoelectron Spectroscopy (XPS) spectra of the SiC decorated carbon paper samples made in accordance with one or more embodiments of the present invention.
  • XPS X-ray Photoelectron Spectroscopy
  • Figures 5a-5d illustrate SEM images and corresponding EDX maps on SiC- CP samples made in accordance with one or more embodiments of the present invention.
  • Figure 6 is a panel of SEM images of cross-section areas of the lithium deposited CP and Si0 2 -CP samples made in accordance with one or more embodiments of the present invention
  • Figures 7a-7d illustrate SEM images of the cross-section area of the lithium plated SiC-CP samples made in accordance with one or more embodiments of the present invention.
  • Figure 8 illustrates the coulombic efficiency for the lithium
  • FIG. 9 illustrates lithium depositing/stripping profiles on SiC-CP-2 in accordance with one or more embodiments of the present invention.
  • Figures 10a- lOd illustrate the structures of pristine CP and spatially heterogeneous CP (SH-CP), and the different lithium deposition processes on them in accordance with one or more embodiments of the present invention.
  • Figures 11a and 1 lb illustrate characterizations of CP in accordance with one or more embodiments of the present invention.
  • Figure 11a illustrates a wide angle XRD pattern showing the highly graphitic nature of the carbon fibers
  • Figure l ib illustrates a representative SEM image exhibiting the scaffold morphology of the carbon fiber paper in accordance with one or more embodiments of the present invention.
  • Figures 12a-12d illustrates a SEM image and corresponding EDX maps of the non-Si0 2 side of the Si0 2 -CP in accordance with one or more embodiments of the present invention.
  • Figure 13 shows lithium deposition profiles of CP electrodes at 4 mA cm "2 for two hours in accordance with one or more embodiments of the present invention.
  • Figure 14 is a SEM image of the lithium deposited Si0 2 -CP from a wider view, zoomed out from the part in Figure 7a.
  • Figure 15 is a representative SEM image of the Si0 2 -CP after a lithium deposition for two hours at a current rate of 4 mA cm "2 in accordance with one or more embodiments of the present invention.
  • Figure 16 is a representative SEM image of Si0 2 -CP after a lithium deposition for six hours at a current rate of 4 mA cm "2 in accordance with one or more embodiments of the present invention.
  • Figure 17 illustrates a process chart according to one or more embodiments of the present invention.
  • the related art technologies on lithium metal electrodes have been mainly developed in terms of surface protection of lithium metal electrodes.
  • Various methods have been invented for "wrapping" the lithium metal electrodes with various lithium ion conducting layers/membranes.
  • the wrapping strategy has fundamental disadvantages.
  • a crack-free "wrapping" on the depositing/stripping lithium electrodes which go through large morphological changes repeatedly over 2000 cycles, remains to be a substantial challenge. This worries the battery manufactures and potential consumers. Alloying lithium with other metals induces certain chemical stability of lithium electrodes, but does not solve the dendrite problem or the volumetric change problem.
  • the present invention provides spatially heterogeneous three dimensional (3D) current collectors for lithium electrodeposition to address the dendrite problem.
  • Three dimension current collectors recently have attracted some attention due to the power density enhancement to some electrode materials.
  • the hurdle to infiltrate 3D current collectors by lithium electrodeposition is the conducting external surface which provides favorable sites for cathodic reactions.
  • the present invention introduces anisotropic spatial heterogeneity on to 3D current collectors in terms of conductivity for the lithium deposition.
  • heterogeneity is created by an insulating Si02 layer coated on only one side of carbon fiber papers (CP) by a line-of-sight electron-beam deposition method.
  • the Si02 surface of the current collector facing the electrolyte acts as an insulating "roof, and the interior surface of the carbon fiber paper does the current collecting and provide a large accommodation capacity for lithium deposition without volume changes of the electrode.
  • lithium dendrites are prevented from forming on the insulting external surface of a lithium deposition electrode.
  • Figure 1 illustrates the experimental setup of the magnesiothermic reaction to convert Si0 2 -CP to SiC-CP in accordance with one or more embodiments of the present invention.
  • Si0 2 -CP was placed covering an alumina boat with the Si0 2 decorated side facing magnesium power located in the alumina boat.
  • the reaction experimental setup is schematically shown in Figure 1.
  • the Si0 2 decorated (or coated) side of the carbon paper directly faces hot magnesium vapor during the reaction.
  • magnesiothermic reactions are normally carried out at 650-700 °C.
  • the reaction was conducted at 800 °C for 2 hours with an excess of metallic magnesium source under an argon flow, although other temperatures, times, and pressures can be used without departing from the scope of the present invention.
  • the reacted carbon paper samples were soaked in 2M HC1 overnight in order to remove the formed MgO and possible Mg 2 Si.
  • the SiC decorated paper samples (also referred to as substrates herein) were soaked in 50% (weight) HF aqueous solution overnight to remove silicon.
  • Figure 2 illustrates a vial cell setup for the electrochemical studies in accordance with one or more embodiments of the present invention.
  • Electrochemical characterization studies were carried out in vial cells on an EC-lab VMP3 instrument at room temperature. Typically, only one side of the (Si0 2 -) CP electrode is allowed to expose to the electrolyte.
  • the transparent vial cells were deliberately used for the convenience of in situ visual inspection of the dendrite growth during deposition/stripping cycling, which cannot be readily realized with coin or Swagelok cells.
  • the cells were assembled in an argon-filled glove box.
  • the CP electrode loadings were typically ⁇ 5.8 mg (0.5 cm 2 ).
  • Lithium metal foils were used as a counter/reference electrode.
  • a 1.0 M solution of LiPF 6 in a mixture of EC/EMC (3:7, v/v) was used as the electrolyte.
  • the vial cell setup is schematically shown in Figure 2. The working and counter electrodes were soaked in the electrolyte without any pressure applied on them.
  • Si0 2 -CP SiC-CP
  • SiC-CP SiC-CP
  • the copper foil has the same dimensions as the carbon paper electrode, to avoid an electrolyte exposure on the non-Si0 2 (or non-SiC) side.
  • the copper surface opposite to the CP electrodes was shielded by spin coated and dried Na 2 Si0 3 solution.
  • the pristine CP electrode was assembled in the same manner. Voltage is applied between the carbon paper and the lithium foil electrode to allow for electrolytic migration and deposition of the lithium.
  • Other metals and substrates can be used without departing from the scope of the present invention.
  • the CP exhibits many desirable characteristics as a 3D current collector for lithium deposition, including limited surface area, large void volume, and good conductivity. According to N 2 sorption measurements, the CP used in the present invention exhibits a Brunauer-Emmett-Teller (BET) specific surface area of 5.3 m 2 g "1 and a Barrett- Joyner-Halenda (BJH) specific pore volume of 1.2 cm 3 g "1 . It is well known that the parasite reactions between deposited lithium and aprotic solvents/salt anions are inevitable, and they result in a loss of metallic lithium mass in the formation of the Solid Electrolyte Interface/Interphase (SEI) layer, which is typically several tens of nanometers thick.
  • SEI Solid Electrolyte Interface/Interphase
  • FIGS. 3a-3f illustrate Scanning Electron Microscope (SEM) images and corresponding Energy Dispersive X-ray (EDX) maps of the Carbon Paper (CP) samples in accordance with one or more embodiments of the present invention.
  • SEM Scanning Electron Microscope
  • EDX Energy Dispersive X-ray
  • Figures 11a and 1 lb illustrate characterizations of CP in accordance with one or more embodiments of the present invention.
  • Figure 11a illustrates A wide angle XRD pattern showing the highly graphitic nature of the carbon fibers
  • Figure 11 b illustrates a representative SEM image exhibiting the scaffold morphology of the carbon fiber paper in accordance with one or more embodiments of the present invention.
  • the CP demonstrates a scaffold structure, a smooth surface morphology, and the homogeneity of the Si0 2 deposition on the carbon fibers in accordance with one or more embodiments of the present invention.
  • FIGS. 3 a and 3b illustrate SEM images of the CP in accordance with one or more embodiments of the present invention
  • FIGS. 3 c and 3d illustrate SEM images of the Si0 2 -CP in accordance with one or more embodiments of the present invention.
  • FIGS. 3e and 3f illustrate corresponding silicon and carbon EDX maps of the Si0 2 - CP in accordance with one or more embodiments of the present invention.
  • Figures 12a-12d illustrates a SEM image and corresponding EDX maps of the non-Si0 2 side of the Si0 2 -CP in accordance with one or more embodiments of the present invention.
  • Si02 crystals (99.99%) were electron-beam evaporated by an instrument of Airco Temescal (Model CV-8) onto the CP substrates.
  • CP (Model: 2050 A) was purchased from Fuel Cell Store, Inc.
  • Powder X-ray diffraction (XRD) patterns were collected on a Scintag PADX diffractometer with Cu Ka radiation (45 kV, 35 mA).
  • Scanning electron microscopy (SEM) images were acquired on a FEI XL40 Sirion FEG digital scanning electron microscope.
  • the electrodes taken from the vial cells were washed by dry tetrahydrofuran (THF) in an argon-filled glove box to remove the residual electrolytes and later on dried under vacuum at room temperature. Nitrogen sorption isotherms were measured at -196 °C on a Micromeritics Tristars 3000 analyzer. Before measurements, the samples were degassed on a vacuum line at 150 °C overnight.
  • Figure 12a illustrates an illustrative SEM image which confirms a line-of- sight deposition of Si0 2 achieved on the CP by electron beam deposition.
  • Other methods of deposition of Si02 or other materials, onto CP or other equivalent structures, can be used without departing from the scope of the present invention.
  • Figures 12b-12d are corresponding EDX maps showing the energy dispersion for silicon, carbon, and a background element (titanium is shown), respectively.
  • the Si0 2 e-beam evaporation coating was used in accordance with one or more embodiments of the present invention to selectively insulate the line-of-sight (also the electrolyte-facing surface) of the 3D current collector.
  • the line-of-sight process is confirmed in our case by the fact that the silicon energy dispersive X-ray (EDX) map on the non-Si0 2 side of the carbon paper displayed very weak signals close to the background noise (see Figures 12b-12d).
  • the CP After the Si0 2 deposition, the CP turns from gray to a dark-brown color.
  • the SEM image and the corresponding silicon EDX map reveal the homogeneity of the Si0 2 coating as shown in Figures 3c and 3e.
  • the present invention shows that the surface of the carbon fibers when the present invention is applied stays smooth with a pinhole-free Si0 2 deposition as shown in Figure 3d. This indicates impermeability to lithium ions from the electrolyte during lithium deposition. Silicon Carbide Formation on Carbon Paper
  • Figures 4a-4d illustrate X-ray Photoelectron Spectroscopy (XPS) spectra of the SiC decorated carbon paper samples made in accordance with one or more embodiments of the present invention.
  • the present invention formed a SiC coating on the carbon fibers as well, in order to resist the potential HF etching in the electrolytes. It is challenging to form SiC coating on the CP by conventional methods due to its high formation temperatures. Magnesiothermic reactions have been applied in converting a nanoporous silica film into a silicon film.
  • the present invention used a
  • the deconvo luted carbon [Is] signal exhibits the characteristic peak assigned to SiC at 282.5 eV.
  • the Si [2p] signal can be assigned to metallic silicon at 99.0 eV and SiC at 100.1 eV,
  • Figure 4c illustrates a C [Is] signal of SiC-CP-2 deconvo luted into
  • Figure 4d illustrates a Si [2p] signal of SiC-CP-2 centered at 100.1 eV without any contribution from metallic silicon.
  • Figures 5a-5d illustrate SEM images and corresponding EDX maps on SiC-
  • SiC-CP- 1 The CP sample after the magnesiothermic reaction and HF etching is referred to as SiC-CP- 1.
  • Figures 5a and 5b are SEM images that reveal the rough surface morphology of SiC-CP, in contrast to that of the pristine (uncoated or un-decorated) CP and the Si0 2 -CP shown in Figures 3a-3f.
  • Figure 5b is an enlarged image of the inset shown in Figure 5 a.
  • the corresponding silicon EDX map remains intense and homogeneous on the surface of CP as shown in Figure 5c.
  • the roughness is not continuous, indicating an incomplete coverage of SiC on the carbon fiber surface.
  • the Si0 2 coating and magnesiothermic conversion were repeated once upon the SiC-CP-1, although this process could be repeated more than once without departing from the scope of the present invention.
  • the obtained sample is referred to as SiC-CP-2.
  • the line-of- sight surface morphology of SiC-CP-2 is now completely roughened, suggestive of a much better SiC coverage on the designated area of CP.
  • SiC-CP-2 XPS was used to characterize HF etched SiC-CP-2.
  • the minor C [Is] component at 282.5 assigned to the SiC phase from SiC-CP-1 turns into a major component in the C [Is] signal from SiC-CP-2, which confirms a better SiC coverage of SiC-CP-2 than Si-CP- 1.
  • SiC-CP-2 displays a Si [2p] signal centered at 100.1 eV that can be assigned to the SiC phase, without any contribution from metallic silicon.
  • Figure 13 illustrates lithium deposition profiles of CP electrodes at 4 mA cm " 2 for two hours in accordance with one or more embodiments of the present invention.
  • Si0 2 -CP current collector line 1302 are shown.
  • the present invention carried out lithium depositing on pristine CP, Si0 2 -CP,
  • SiC-CP-1 and SiC-CP-2 as working electrodes.
  • the present invention minimized the lithium intercalation reactions into the CP samples and focused on the lithium depositing behavior.
  • a high current density of ⁇ 4 mA cm “2 (330 mA g _1 cp , based on 0.012 g cm "2 for CP) was applied between the working electrode and a lithium counter/reference electrode during the depositing process.
  • This current density represents one of the highest values reported for lithium deposition studies, compared to current densities of less than 1 mA cm "2 in most previous studies.
  • the deposition process was carried out for two hours, and the deposition capacity was set to be 28.8 C cm "2 (or 660 mA-h g _1 cp ).
  • the present invention illustrates one of the largest quantity of lithium deposition compared to previous dendrite -related studies, including those with protection layers in the related art.
  • the deposition on Si0 2 -CP was also done for six hours to approach the limit of the accommodation capacity.
  • the potentials of both CP and Si0 2 -CP electrodes rapidly dropped below 0.0 V vs. Li + /Li, indicating that metallic lithium deposition on the carbon fiber surface had started.
  • Lithium intercalation into carbon is thermodynamically favorable; however, at potentials below 0.0 V vs. Li /Li, lithium plating on carbon surface is kinetically more facile. This leads to the fact that lithium-ion batteries on electric vehicles have to be charged for hours to prevent lithium plating.
  • the deposition and stripping current density was set to be 2 mA cm “2 (or 165 mA g _1 C p), and lithium of 14.4 C cm “2 (or 330 mA g _1 cp) was deposited.
  • the cut-off potential was set to be 3.0 V versus Li + /Li for lithium stripping.
  • Figure 8 illustrates the coulombic efficiency for the lithium
  • Figure 8 reveals the superior disposition performance of the methods and apparatuses of the present invention.
  • Figure 8 is an image of the vial cell containing SiC-CP-2 working electrode and lithium foil counter electrode, taken after 15 cycles, showing the dendrite-free surface of SiC-CP-2 current collector and mossy lithium phase formed around the lithium counter electrode. Note that the low coulombic efficiency in the first cycle is due to SEI formation on the carbon surface, which is widely observed for carbon electrodes in the first discharge/charge cycle.
  • SiC-CP-2 displays a very stable lithium stripping/deposition efficiency of -94% starting with the second cycle. This is one of the highest lithium-cycling efficiencies reported for aprotic organic electrolytes. It is worth stressing that the high efficiency is achieved at a current rate of 2 mA cm “2 and a deep lithium deposition of 14.4 C cm “2 in a carbonate based organic electrolyte, in contrast to previously reported lower efficiencies of around 70%> to 90%> typically obtained by using current rates less than 1 mA cm “2 , a lithium deposition less than 2 C cm “2 , and certain surface protection methods in favorable organic electrolytes. Note that the internal surface area of a 3D current collector is much larger than its footprint area, which is a significant advantage than 2D ones. This could be an important factor that leads to the high coulombic efficiency.
  • the lithium cycling efficiency is strongly influenced by the morphology of the deposited lithium.
  • the high cycling efficiency obtained here corroborates the ex-situ SEM observation that deposited lithium is closely packed in the voids of the 3D current collectors. This clearly illustrates the superiority of the lithium deposition into 3D current collectors as in the present invention that is facilitated by a spatially heterogeneous structure.
  • the lithium counter electrode was covered by isolated mossy lithium
  • the SiC-CP-2 current collector retained a dendrite-free surface.
  • Figure 9 illustrates lithium depositing/stripping profiles on SiC-CP-2 in accordance with one or more embodiments of the present invention.
  • Figure 9 shows the first 15 deposition/stripping cycle profiles plotted on voltage versus time, at a current density of 2 mA cm “2 and a lithium deposition of 14.4 C cm “2 (330 mA-h g " 1 caAon paper ).
  • a lithium cycling efficiency of up to 99.2% can be achieved with ionic liquid based or polymer based electrolytes in the related art.
  • these high efficiencies were obtained at lower current densities and lower lithium deposition rates than those of the present invention.
  • the morphology of the deposited lithium is still highly dendritic.
  • the present invention does not suffer from these infirmities of the related art.
  • Figures 6a-6f illustrate SEM images of cross-section areas of the lithium deposited CP and Si0 2 -CP samples made in accordance with one or more
  • Figure 6a is representative SEM image of lithium deposited on pristine CP.
  • Figure 6b is an enlarged image of the inset of Figure 6a.
  • Figure 6c is representative SEM image showing the surface morphology of the lithium deposited CP and existence of formed dendrites.
  • Figure 6d illustrates a representative SEM image of the lithium deposited Si0 2 -CP made in accordance with one or more embodiments of the present invention.
  • Figures 6e and 6f are enlarged images of inset a and inset ⁇ of Figure 6d. All the images here were taken with the paper specimen stage tilted by 45°. Note that the dendrites readily apparent in Figures 6a-6c are not present in figures 6d-6f.
  • Figures 7a-7d illustrate SEM images of the cross-section area of the lithium plated SiC-CP samples made in accordance with one or more embodiments of the present invention.
  • Figure 7a is an overview image of the cross-section area of SiC-CP-1.
  • Figure 7b is an enlarged image of inset a shown in Figure 7a.
  • Figure 7c is an enlarged image of inset ⁇ of Figure 7a.
  • Figure 7d is a representative SEM image of carbon fibers in the line-of-sight surface of lithium deposited SiC-CP-2. All the images were taken with the paper specimen stage tilted by 45°.
  • the deposited electrodes were examined ex-situ by SEM in order to investigate the "geographical" distribution of the deposited lithium metal.
  • the SEM specimen stage was tilted by 45° in order to show both the cross-section and the adjacent face area of the lithium metal deposited CP electrodes.
  • the cross-section of lithium metal deposited CP electrode displays a uniform morphology of carbon fibers as shown in Figures 6a and 6b. It is evident that lithium metal deposition did not infiltrate the voids of pristine CP.
  • Figure 6c reveals a representative area on the CP surface with large lithium metal dendrites over 20 ⁇ in size and small lithium metal crystals homogeneously distributed.
  • the pristine CP electrode functions essentially as a two-dimensional current collector.
  • the voids near the bottom of the Si0 2 -CP were well infiltrated by lithium metal deposition.
  • the surface morphology of the Si0 2 decorated area near the cross-section remains very smooth and free of deposited lithium crystallites or dendrites, as shown in Figure 6f. This indicates that the Si0 2 coating is impermeable to lithium ions and has successfully created an insulating roof for the 3D current collector.
  • Figure 14 is a SEM image of the lithium deposited Si0 2 -CP from a wider view, zoomed out from the part in Figure 7a.
  • a zoom-out view under SEM confirms that the surface of deposited Si0 2 - CP is completely free of lithium dendrites and that the voids near the top surface are also free of lithium infiltration as shown in Figure 14.
  • the lithium metal deposition into the Si0 2 -CP fills up the voids from the non-silica to the silica side, which is facilitated by the conducting copper foil support on the non-Si0 2 surface of the electrode and, more importantly, by the anisotropic structure of the current collector.
  • the surface is free of dendrites and the voids near the top surface are free of lithium infiltration.
  • the image was taken with the paper specimen stage tilted by 45°.
  • Figure 15 is a representative SEM image of the Si0 2 -CP after a lithium deposition for two hours at a current rate of 4 mA cm "2 in accordance with one or more embodiments of the present invention.
  • lithium deposition occurs on the conducting carbon surface which is oppositely oriented towards the Si0 2 coated electrode surface.
  • the top part of the carbon fiber coated with a Si0 2 layer is free of lithium deposition, and the bottom part without Si0 2 is covered with lithium deposition.
  • the image was taken with the paper specimen stage tilted by 45°.
  • Figure 16 is a representative SEM image of Si0 2 -CP after a lithium deposition for six hours at a current rate of 4 mA cm "2 in accordance with one or more embodiments of the present invention.
  • the deposited lithium provided a capacity of 71.3 C cm “2 (or 1980 mA-h g _1 C p), which is near (79%) 90 C cm “2 (2500 mA-h g _1 C p), the theoretical accommodation capacity calculated based on the specific pore volume and lithium metal density.
  • Further deposition on a fully infiltrated 3D current collector may result in the dendrite growth on the filled paper top surface. Therefore, it is important to prevent an over- infiltration during the deposition cycle in practical scenarios.
  • the spatially controlled lithium deposition resembles in some degree the single-crystal growth of calcium carbonate in the assembly process that generates the abalone cell. Compared to the deposition on pristine CP, the surface Si0 2 coating effectively realizes the proposed function of a spatially heterogeneous structure.
  • Figures 10a- lOd illustrate the structures of pristine CP and spatially
  • heterogeneous CP (SH-CP)
  • the different lithium deposition processes on them in accordance with one or more embodiments of the present invention.
  • Figure 10a illustrates pristine CP.
  • Figure 10b illustrates SH-CP, where anisotropic spatial heterogeneity is achieved after a line-of-sight deposition of Si0 2 onto the carbon fibers. Areas 2 indicate a Si0 2 or SiC coating, and black areas 4 represent uncovered conducting carbon surface.
  • Figure 10c illustrates the situation of lithium deposition on CP, mostly on the line-of-sight surface, as shown by spheres 6, which represent the lithium atoms.
  • Figure 6d illustrates lithium
  • Lithium electrodeposition does not take place on the insulating line-of-sight surface, but is driven by the electric field towards voids of the current collector.
  • insulating/conducting properties of the CP can be obtained after the Si0 2 electron- beam deposition.
  • the same spatial heterogeneity can be maintained by converting Si0 2 into SiC atop the carbon paper surface.
  • This anisotropic spatial heterogeneity is essential in order to achieve surface dendrite-free lithium deposition on the Si0 2 -CP or SiC-CP current collectors, as schematically shown in Figure lOd.
  • the electrode With the large porous volume of the current collector effectively utilized by lithium deposition, the electrode maintains a constant volume upon deposition.
  • due to the scaffold-like structure of the carbon paper disintegration of deposited lithium cannot occur inside the paper in the presence of nearby 3D electric contacts at a high depositing rate.
  • the stable lithium cycling efficiency of 94% achieved in SiC-CP-2 in a carbonate based organic electrolyte further demonstrates the superiority of the anisotropic spatial heterogeneity of the 3D current collector.
  • Figure 17 illustrates a process chart according to one or more embodiments of the present invention.
  • Box 1700 illustrates coating a first surface of the porous substrate with a layer, wherein the first surface remains porous to the metal to be deposited.
  • Box 1702 illustrates placing the first surface with the layer facing an electrode.
  • Box 1704 illustrates depositing the metal on the substrate on a second surface of the substrate distinct from the first surface.
  • the teachings of the present invention address the dendrite formation problem in a fundamentally new concept via rationally designed current collectors with heterogeneous properties.
  • 3D architectures such as carbon cloth, carbon nanotube infiltrated papers and those made with copper, aluminum or conducting ceramics should show similar performances and are contemplated within the scope of the present invention.
  • Other systems with metallic electrodes, e.g. sodium, magnesium, calcium, aluminum or zinc batteries may be benefited from this method as well, and are also contemplated within the scope of the present invention.
  • an insulated 3D current collector in accordance with one or more embodiments of the present invention can comprise carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous” means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium
  • poly(pyrrole)s PPY
  • poly(3,4-ethylenedioxythiophene) PEDOT
  • polythiophenes PT
  • poly(p-phenylene sulfide) PPS
  • the 3D current collector of one or more embodiments of the present invention can comprise a layer that is insulating or non-insulating, and, where insulating, can comprise silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non- metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, nonmetallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials, and can be applied or deposited by a line-
  • a method of preparing an insulated 3D current collector in accordance with one or more embodiments of the present invention comprises coating an insulating layer onto an line-of-sight surface of a 3D current collector, wherein the 3D current collector comprises openings in the line-of-sight surface and non-line-of-sight surfaces accessible through the openings, and the insulating layer allows access to the non-line-of-sight surfaces via the openings.
  • a method of electrodeposition in accordance with one or more embodiments of the present invention comprises preferentially electrodepositing a metal at non-line-of- sight surfaces of an insulated 3D current collector.
  • Such methods further optionally comprise the insulated 3D current collector comprises a 3D current collector having a line-of-sight surface comprising openings, the non-line-of-sight surfaces being accessible through the openings, and an insulating layer coating the line-of-sight surface, the insulating layer allowing access to the non- line-of-sight surfaces via the openings, where the line-of-sight surface is coated by a line-of-sight method, and the line-of-sight method is printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition.
  • Such methods further optionally comprise the insulating layer being silicon oxide, graphene oxide, silicon carbide, hafnium oxide, lithium phosphorous oxynitride (LIPON), zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, nonmetallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials, and further optionally comprise the 3D current collector being carbon fiber paper, carbon cloth, carbon nanotube coated paper, graph

Abstract

Device, apparatus and method involving a line-of-sight surface insulated 3D current collector. The line-of-sight surface insulated 3D current collector includes a 3D current collector having a line-of-sight surface having openings, and non-line-of- sight surfaces accessible through the openings, and includes an insulating layer coating the line-of-sight surface, where the insulating layer allows access to the non- line-of-sight surfaces via the openings. The insulated 3D current collector can be used in electrodes, electrochemical cells and rechargeable batteries where electrodeposition of a metal occurs during the charging process. Methods of making the insulated 3D current collector and methods of electrodeposition using the insulated 3D current collector are provided.

Description

SURFACE INSULATED POROUS CURRENT COLLECTORS AS DENDRITE FREE ELECTRODEPOSITION ELECTRODES
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPEMENT
This invention was made with Government support under Grant No. DMR- 0805148 from the National Science Foundation. The Government has certain rights in this invention.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. Section 119(e) of U.S. Provisional Patent Application Serial No. 61/503,322, filed on June 30, 2011, by Galen D. Stucky and Xiulei Ji, entitled "SURFACE INSULATED POROUS
CURRENT COLLECTORS AS DENDRITE FREE ELECTRODEPOSITION ELECTRODES," which application is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to spatially heterogeneous 3D current collectors and uses thereof.
2. Description of the Related Art.
A metallic lithium anode is energetically attractive in that it can theoretically provide a gravimetric capacity of 3861 mA-hg-1, more than 10 times that of lithiated carbonaceous anodes (339 mA-hg"1, for LiC6) at a very negative redox potential (- 3.04 V vs. Standard Hydrogen Electrode). The earliest rechargeable Lithium Batteries (LBs), produced in the 1970s and 1980s, used lithium metal as the negative electrode in prototypes and commercial products. Despite the high energy density, metallic lithium electrodes were eventually proven unsafe due to the uneven lithium electrodeposition and the growth of dendrites on the surface of a lithium anode.
The dendrites are associated with most of the failure mechanisms of LBs and can lead to a battery thermal runaway. Substitution of metallic lithium with Li ions in insertion materials was an initial attempt to address the dendrite safety concern. This substitution came at the serious expense of energy density loss. This approach led to the tremendous success of lithium-ion batteries (LIBs) in powering portable electronics.
After two decades of optimization, LIBs based on topotactic intercalation electrodes have approached the theoretical energy density for such devices. However, substantially higher energy storage is required to strategically meet many demands including electrified transportation and load-leveling for intermittent renewable energy sources. High energy Li-sulfur and Li-air batteries have been considered candidates to meet the above goals, but have met with difficulties. Approaches other than intercalation chemistry are necessary to address the long-standing dendrite problem while retaining a high energy metallic form of a lithium electrode.
The major efforts have been devoted to altering the surface chemistry of lithium metal anodes by a wide variety of protection layers. Reactions between lithium metal and electrolyte additives or sol-gel precursors were employed to form a solid electrolyte interphase (SEI) layer. Polymer films and carbon films were also investigated as protective coatings. Impermeable multi-layer structures, composed of an outer glass-ceramic layer, and an inner layer made of Li3N or polymers in contact with lithium metal, can give rise to water- stable lithium metal electrodes. The surface protection approaches improve the compatibility of lithium metal anodes with electrolytes. However, the intrinsic uneven electrodeposition still results in large stress buildup beneath the protection layers, and the possibility of defects in protection layers and dendrite extrusions cannot be excluded. Furthermore, protected lithium electrodes still suffer hazardous volume changes during operation when the thickness of a lithium layer is not negligible. Further, nearly all of the approaches were made using flat lithium foil/film or 2D metal foil current collectors. Although designed electrode materials with function precisely controlled have shown great potential, rationally designed current collectors have rarely been taken into account in solving the dendrite problem.
SUMMARY
In some embodiments, this application addresses, among other things, the dendrite formation problem for the lithium electrodes in rechargeable batteries.
During electrochemical reduction (deposition) of lithium ions into the metallic phases onto a current collector, dendrites are usually observed due to the uneven current density distribution on different sites of the current collector. This application utilizes the 3D structure of porous current collectors to accommodate plated lithium while inhibiting lithium plating, by coating an insulating layer on the electrolyte facing surface of the porous current collector. In the present application, use of the word "insulating" means being non-conductive both electronically and ionically.
The present invention comprises surface dendrite-free lithium deposition created by using spatially heterogeneous 3D current collectors. The present invention confines lithium metal deposition inside the 3D current collectors. The present invention employs, inter alia, controlling the conductive electrolyte-facing surface of the 3D current collectors to control or eliminate the dendrite growth, which provides favorable sites for lithium deposition while retarding dendrite growth and infiltrating the interior voids. The present invention comprises introducing an anisotropic spatial heterogeneity in terms of conductivity for the 3D current collectors by insulating the electrolyte-facing surface while keeping the other parts conductive. This embodiment of the present invention reduces or prevents inter-electrode dendrite growth and forces lithium deposition inside the large voids.
In particular embodiments, an insulating layer is deposited by line-of-sight methods onto the electrolyte-facing surface of highly porous current collectors as lithium electrodeposition electrodes. During lithium electrodeposition, with no electrons available from the insulating electrolyte facing surface, lithium ions from bulk electrolyte have to migrate deeper into the voids inside porous current collectors in order to be reduced. The deposition process comprises essentially a lithium metal infiltration. With the porous volume of the current collector effectively utilized, the lithium plated current collectors or electrodes maintain a constant volume throughout the depositing/stripping cycles with no dendrites formed on the electrolyte-facing surface. The solution for lithium dendrites herein is fundamentally distinct from state of the art technologies.
In one aspect, a line-of-sight surface insulated 3D current collector is provided. The insulated 3D current collector includes: a) a 3D current collector having an line-of-sight surface including openings, and non-line-of-sight surfaces accessible through the openings; and b) an insulating layer coating the line-of-sight surface, where the insulating layer allows access to the non-line-of-sight surfaces via the openings. The 3D current collector can be, but is not limited to, carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous" means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, 3D structures made of conducting ceramics including titanium carbides, vanadium carbides, manganese carbides, iron carbides, zirconium carbides, tungsten carbides, molybdenum carbides, titanium nitrides, vanadium nitrides, manganese nitrides, iron nitrides, zirconium nitrides, tungsten nitrides, molybdenum nitrides, silicon nitrides, iron phosphide, titanium oxide, molybdenum oxides, indium doped tin oxide or zinc oxide, 3D structures made of conducting polymers including polyanilines (PANI), poly(pyrrole)s (PPY), poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophenes (PT), poly(p-phenylene sulfide) (PPS). The insulating layer can be, but is not limited to, silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, non- metallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials. In particular embodiments, the insulating layer material can be deposited onto the 3D current collector by a line-of-sight method, which can include, but is not limited to, printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition.
In another aspect, an electrode including the line-of-sight surface insulated 3D current collector is provided. When used as part of an electrodeposition process, electrodeposition can occur preferentially at the non-line-of-sight surfaces of the 3D current collector or electrode. Thus, in certain embodiments, the electrode can include metallic lithium after electrodeposition.
In a further aspect, a lithium metal rechargeable battery including the electrode is provided. In some embodiments, the lithium metal rechargeable battery includes lithium ion containing positive electrodes to provide lithium ions for the lithium electrodeposition on the spatially heterogeneous current collectors.
In another aspect, a battery can be a lithium metal rechargeable battery in certain embodiments.
In additional aspects, methods involving the line-of-sight insulated 3D current collectors are provided. One method is a way of preparing a line-of-sight insulated 3D current collector. The method includes coating an insulating layer onto the line -of- sight surface of a 3D current collector, where the 3D current collector includes openings in the line-of-sight surface and non-line-of-sight surfaces accessible through the openings, and the insulating layer allows access to the non-line-of-sight surfaces via the openings. Another method is a way of performing electrodeposition. The method includes preferentially electrodepositing a metal at non-line-of-sight surfaces of a line-of-sight surface insulated 3D current collector.
In some embodiments of this method, the metal is lithium. In some other embodiments, the metals can be sodium, potassium, magnesium, calcium, titanium, vanadium, silicon, tin, zinc, and aluminum. In the methods, the insulating layer can be coated onto a porous 3D current collector by a line-of-sight method, which can include, but is not limited to, printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of- sight chemical vapor deposition. The 3D current collector can be, but is not limited to, carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous" means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, 3D structures made of conducting ceramics including titanium carbides, vanadium carbides, manganese carbides, iron carbides, zirconium carbides, tungsten carbides, molybdenum carbides, titanium nitrides, vanadium nitrides, manganese nitrides, iron nitrides, zirconium nitrides, tungsten nitrides, molybdenum nitrides, silicon nitrides, iron phosphide, titanium oxide, molybdenum oxides, indium doped tin oxide or zinc oxide, 3D structures made of conducting polymers including polyanilines (PANI),
poly(pyrrole)s (PPY), poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophenes (PT), poly(p-phenylene sulfide) (PPS).
The insulating layer can be, but is not limited to, silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, non- metallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials.
A method of depositing metal on a porous substrate in accordance with one or more embodiments of the present invention comprises coating a first surface of the porous substrate with a layer, wherein the first surface remains porous to the metal to be deposited, placing the first surface with the layer facing an electrode, and depositing the metal on the substrate on a second surface of the substrate distinct from the first surface.
Such a method further optionally comprises the metal being lithium, the porous substrate being carbon fiber paper, the metal being electrodeposited on the substrate, the layer being silicon dioxide (Si02), silicon carbide (SiC), or SiC and silicon dioxide (Si02), the layer being deposited in a line-of-sight onto the first surface, the deposition of the metal having a reduced dendrite density compared to a porous substrate lacking the layer, and the layer being coated on the porous substrate using electron beam deposition.
An insulated three-dimensional (3D) current collector in accordance with one or more embodiments of the present invention comprises a 3D current collector having a line-of-sight surface comprising openings, and non-line-of-sight surfaces accessible through the openings, and an insulating layer coating the line-of-sight surface, the insulating layer allowing access to the non-line-of-sight surfaces via the openings.
Such a current collector further optionally comprises lithium being deposited on the non-line-of-sight surfaces, the lithium being deposited on the non-line-of-sight surfaces electrolytically, the insulated 3D current collector being carbon fiber paper, the insulating layer being silicon dioxide (Si02), silicon carbide (SiC), or SiC and silicon dioxide (Si02), the insulating layer being deposited in a line-of-sight onto the line-of-sight surface, the deposition of the metal having a reduced dendrite density compared to a current collector lacking the insulating layer, and the insulating layer being coated on the insulated three-dimensional (3D) current collector using electron beam deposition.
The term "preferentially" as used in the present application means that electrodeposition of a metal occurs more at non-line-of-sight surfaces of a 3D current collector than at the coated line-of-sight surface of the 3D current collector.
Although embodiments involving lithium electrodes and batteries are described in the Examples below, other systems with metal electrodes or non-metallic electrodes involving electrodeposition are also contemplated. Such systems include electrodes, electrochemical cells and batteries involving, but not limited to, sodium, potassium, magnesium, calcium, titanium, vanadium, silicon, tin, zinc, and aluminum.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Figure 1 is a Schematic illustrating the experimental setup of the
magnesiothermic reaction to convert Si02-CP to SiC-CP in accordance with one or more embodiments of the present invention.
Figure 2 is a Schematic showing the vial cell setup for the electrochemical characterization studies in accordance with one or more embodiments of the present invention.
Figures 3a-3f illustrate Scanning Electron Microscope (SEM) images and corresponding Energy Dispersive X-ray (EDX) maps of the Carbon fiber Paper (CP) samples in accordance with one or more embodiments of the present invention.
Figures 4a-4d illustrate X-ray Photoelectron Spectroscopy (XPS) spectra of the SiC decorated carbon paper samples made in accordance with one or more embodiments of the present invention.
Figures 5a-5d illustrate SEM images and corresponding EDX maps on SiC- CP samples made in accordance with one or more embodiments of the present invention.
Figure 6 is a panel of SEM images of cross-section areas of the lithium deposited CP and Si02-CP samples made in accordance with one or more embodiments of the present invention
Figures 7a-7d illustrate SEM images of the cross-section area of the lithium plated SiC-CP samples made in accordance with one or more embodiments of the present invention.
Figure 8 illustrates the coulombic efficiency for the lithium
depositing/stripping cycling process on the SiC-CP-2 current collector in accordance with one or more embodiments of the present invention. Figure 9 illustrates lithium depositing/stripping profiles on SiC-CP-2 in accordance with one or more embodiments of the present invention.
Figures 10a- lOd illustrate the structures of pristine CP and spatially heterogeneous CP (SH-CP), and the different lithium deposition processes on them in accordance with one or more embodiments of the present invention.
Figures 11a and 1 lb illustrate characterizations of CP in accordance with one or more embodiments of the present invention. Figure 11a illustrates a wide angle XRD pattern showing the highly graphitic nature of the carbon fibers, and Figure l ib illustrates a representative SEM image exhibiting the scaffold morphology of the carbon fiber paper in accordance with one or more embodiments of the present invention.
Figures 12a-12d illustrates a SEM image and corresponding EDX maps of the non-Si02 side of the Si02-CP in accordance with one or more embodiments of the present invention.
Figure 13 shows lithium deposition profiles of CP electrodes at 4 mA cm"2 for two hours in accordance with one or more embodiments of the present invention.
Figure 14 is a SEM image of the lithium deposited Si02-CP from a wider view, zoomed out from the part in Figure 7a.
Figure 15 is a representative SEM image of the Si02-CP after a lithium deposition for two hours at a current rate of 4 mA cm"2 in accordance with one or more embodiments of the present invention.
Figure 16 is a representative SEM image of Si02-CP after a lithium deposition for six hours at a current rate of 4 mA cm"2 in accordance with one or more embodiments of the present invention.
Figure 17 illustrates a process chart according to one or more embodiments of the present invention. DETAILED DESCRIPTION
In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Overview
The related art technologies on lithium metal electrodes have been mainly developed in terms of surface protection of lithium metal electrodes. Various methods have been invented for "wrapping" the lithium metal electrodes with various lithium ion conducting layers/membranes. The wrapping strategy has fundamental disadvantages. A crack-free "wrapping" on the depositing/stripping lithium electrodes which go through large morphological changes repeatedly over 2000 cycles, remains to be a substantial challenge. This worries the battery manufactures and potential consumers. Alloying lithium with other metals induces certain chemical stability of lithium electrodes, but does not solve the dendrite problem or the volumetric change problem.
The present invention provides spatially heterogeneous three dimensional (3D) current collectors for lithium electrodeposition to address the dendrite problem. Three dimension current collectors recently have attracted some attention due to the power density enhancement to some electrode materials. The hurdle to infiltrate 3D current collectors by lithium electrodeposition is the conducting external surface which provides favorable sites for cathodic reactions. In order to solve this problem, the present invention introduces anisotropic spatial heterogeneity on to 3D current collectors in terms of conductivity for the lithium deposition. The spatial
heterogeneity is created by an insulating Si02 layer coated on only one side of carbon fiber papers (CP) by a line-of-sight electron-beam deposition method. The Si02 surface of the current collector facing the electrolyte acts as an insulating "roof, and the interior surface of the carbon fiber paper does the current collecting and provide a large accommodation capacity for lithium deposition without volume changes of the electrode. Most importantly, lithium dendrites are prevented from forming on the insulting external surface of a lithium deposition electrode.
Experimental and Vial Cell Setups
Figure 1 illustrates the experimental setup of the magnesiothermic reaction to convert Si02-CP to SiC-CP in accordance with one or more embodiments of the present invention.
To prepare the SiC-CP samples, Si02-CP was placed covering an alumina boat with the Si02 decorated side facing magnesium power located in the alumina boat. The reaction experimental setup is schematically shown in Figure 1.
Typically, the Si02 decorated (or coated) side of the carbon paper directly faces hot magnesium vapor during the reaction.
Note that magnesiothermic reactions are normally carried out at 650-700 °C.
In our study, to overcome the low reactivity of highly graphitic CP fibers, the reaction was conducted at 800 °C for 2 hours with an excess of metallic magnesium source under an argon flow, although other temperatures, times, and pressures can be used without departing from the scope of the present invention. The reacted carbon paper samples were soaked in 2M HC1 overnight in order to remove the formed MgO and possible Mg2Si. Before lithium deposition, the SiC decorated paper samples (also referred to as substrates herein) were soaked in 50% (weight) HF aqueous solution overnight to remove silicon.
Figure 2 illustrates a vial cell setup for the electrochemical studies in accordance with one or more embodiments of the present invention.
Electrochemical characterization studies were carried out in vial cells on an EC-lab VMP3 instrument at room temperature. Typically, only one side of the (Si02-) CP electrode is allowed to expose to the electrolyte.
The transparent vial cells were deliberately used for the convenience of in situ visual inspection of the dendrite growth during deposition/stripping cycling, which cannot be readily realized with coin or Swagelok cells. The cells were assembled in an argon-filled glove box. The CP electrode loadings were typically ~ 5.8 mg (0.5 cm2). Lithium metal foils were used as a counter/reference electrode. A 1.0 M solution of LiPF6 in a mixture of EC/EMC (3:7, v/v) was used as the electrolyte. The vial cell setup is schematically shown in Figure 2. The working and counter electrodes were soaked in the electrolyte without any pressure applied on them. Si02-CP (SiC-CP) was attached onto a copper foil at the edges by dried Na2Si03 solution. The copper foil has the same dimensions as the carbon paper electrode, to avoid an electrolyte exposure on the non-Si02 (or non-SiC) side. The copper surface opposite to the CP electrodes was shielded by spin coated and dried Na2Si03 solution. The pristine CP electrode was assembled in the same manner. Voltage is applied between the carbon paper and the lithium foil electrode to allow for electrolytic migration and deposition of the lithium. Other metals and substrates can be used without departing from the scope of the present invention.
Illustrating Examples of Dendrite- Free Growth
The present invention may be better understood by referring to the accompanying examples, which are intended for illustration purposes only and should not in any sense be construed as limiting the scope of the invention.
Physical characterizations of CP and Si02 coated CP
CP exhibits many desirable characteristics as a 3D current collector for lithium deposition, including limited surface area, large void volume, and good conductivity. According to N2 sorption measurements, the CP used in the present invention exhibits a Brunauer-Emmett-Teller (BET) specific surface area of 5.3 m2 g"1 and a Barrett- Joyner-Halenda (BJH) specific pore volume of 1.2 cm3 g"1. It is well known that the parasite reactions between deposited lithium and aprotic solvents/salt anions are inevitable, and they result in a loss of metallic lithium mass in the formation of the Solid Electrolyte Interface/Interphase (SEI) layer, which is typically several tens of nanometers thick.
Figures 3a-3f illustrate Scanning Electron Microscope (SEM) images and corresponding Energy Dispersive X-ray (EDX) maps of the Carbon Paper (CP) samples in accordance with one or more embodiments of the present invention.
Figures 11a and 1 lb illustrate characterizations of CP in accordance with one or more embodiments of the present invention. Figure 11a illustrates A wide angle XRD pattern showing the highly graphitic nature of the carbon fibers, and Figure 11 b illustrates a representative SEM image exhibiting the scaffold morphology of the carbon fiber paper in accordance with one or more embodiments of the present invention.
Current collectors of a 3D structure with a relatively low surface area help limit the reactivity of the deposited lithium towards electrolytes. On the other hand, a large void volume is desirable to achieve a high deposition accommodation capacity. The well-resolved peaks in the wide angle X-ray diffraction (XRD) pattern as shown in Figure 1 la reveal a highly graphitic structure of the carbon fibers in CP. Measured by the four-point method, the graphitic CP exhibits a high conductivity of 31 S cm"1 at room temperature, which is an order of magnitude higher than its amorphous counterparts. The CP is typically 200 (±25) μιη thick, slightly thicker than the commercial LIB anode layer (-150 μιη) composed of a copper foil current collector (18 μιη) and a carbon electrode paste.
Scanning electron microscopy (SEM) images as shown in Figures 3a and 1 lb reveal a scaffold-like morphology of CP which is constructed by carbon fibers that are 10 to 20 μιη in diameter and contains interconnected voids sized from ~50 μιη to -100 μιη. The surface of carbon fibers appears fairly smooth at a 20,000x
magnification as shown in Figures 3 a and 3b. This provides a spacious volume for deposited lithium to grow into large crystals.
As shown in the figures, the CP demonstrates a scaffold structure, a smooth surface morphology, and the homogeneity of the Si02 deposition on the carbon fibers in accordance with one or more embodiments of the present invention. FIGS. 3 a and 3b illustrate SEM images of the CP in accordance with one or more embodiments of the present invention, FIGS. 3 c and 3d illustrate SEM images of the Si02-CP in accordance with one or more embodiments of the present invention. FIGS. 3e and 3f illustrate corresponding silicon and carbon EDX maps of the Si02- CP in accordance with one or more embodiments of the present invention.
Line-Of-Sight Coating Process
Figures 12a-12d illustrates a SEM image and corresponding EDX maps of the non-Si02 side of the Si02-CP in accordance with one or more embodiments of the present invention.
Si02 crystals (99.99%) were electron-beam evaporated by an instrument of Airco Temescal (Model CV-8) onto the CP substrates. CP (Model: 2050 A) was purchased from Fuel Cell Store, Inc.
Powder X-ray diffraction (XRD) patterns were collected on a Scintag PADX diffractometer with Cu Ka radiation (45 kV, 35 mA). Scanning electron microscopy (SEM) images were acquired on a FEI XL40 Sirion FEG digital scanning electron microscope. Prior to the SEM measurements, the electrodes taken from the vial cells were washed by dry tetrahydrofuran (THF) in an argon-filled glove box to remove the residual electrolytes and later on dried under vacuum at room temperature. Nitrogen sorption isotherms were measured at -196 °C on a Micromeritics Tristars 3000 analyzer. Before measurements, the samples were degassed on a vacuum line at 150 °C overnight.
Figure 12a illustrates an illustrative SEM image which confirms a line-of- sight deposition of Si02 achieved on the CP by electron beam deposition. Other methods of deposition of Si02 or other materials, onto CP or other equivalent structures, can be used without departing from the scope of the present invention. Figures 12b-12d are corresponding EDX maps showing the energy dispersion for silicon, carbon, and a background element (titanium is shown), respectively.
As a line-of-sight process, the Si02 e-beam evaporation coating was used in accordance with one or more embodiments of the present invention to selectively insulate the line-of-sight (also the electrolyte-facing surface) of the 3D current collector. The line-of-sight process is confirmed in our case by the fact that the silicon energy dispersive X-ray (EDX) map on the non-Si02 side of the carbon paper displayed very weak signals close to the background noise (see Figures 12b-12d).
After the Si02 deposition, the CP turns from gray to a dark-brown color. The SEM image and the corresponding silicon EDX map reveal the homogeneity of the Si02 coating as shown in Figures 3c and 3e. The present invention shows that the surface of the carbon fibers when the present invention is applied stays smooth with a pinhole-free Si02 deposition as shown in Figure 3d. This indicates impermeability to lithium ions from the electrolyte during lithium deposition. Silicon Carbide Formation on Carbon Paper
Figures 4a-4d illustrate X-ray Photoelectron Spectroscopy (XPS) spectra of the SiC decorated carbon paper samples made in accordance with one or more embodiments of the present invention. Further, the present invention formed a SiC coating on the carbon fibers as well, in order to resist the potential HF etching in the electrolytes. It is challenging to form SiC coating on the CP by conventional methods due to its high formation temperatures. Magnesiothermic reactions have been applied in converting a nanoporous silica film into a silicon film. The present invention used a
magnesiothermic reaction to convert Si02 layer atop the carbon surface into SiC. X- ray photon spectra (XPS) measurements on the reacted CP were conducted.
As Figure 4a shows, the deconvo luted carbon [Is] signal exhibits the characteristic peak assigned to SiC at 282.5 eV. As revealed in Figure 4b, the Si [2p] signal can be assigned to metallic silicon at 99.0 eV and SiC at 100.1 eV,
respectively, and Si02 signal contribution is not observed. The atomic ratio between SiC and metallic Si is 47.2 to 52.8. The XPS results suggest that the carbon atomic diffusion did not permeate the Si02/Si layer during the magnesiothermic reaction.
Figure 4c illustrates a C [Is] signal of SiC-CP-2 deconvo luted into
components including a major contribution from SiC (blue curve) at 282.5 eV.
Figure 4d illustrates a Si [2p] signal of SiC-CP-2 centered at 100.1 eV without any contribution from metallic silicon.
SiC-CP SEM Images and EDX Maps
Figures 5a-5d illustrate SEM images and corresponding EDX maps on SiC-
CP samples made in accordance with one or more embodiments of the present invention.
It is well known that silicon phase can be lithiated and potentially acts as plating sites during lithium deposition. Therefore, the SiC decorated CP samples were etched in an HF solution (50% weight) overnight. The CP sample after the magnesiothermic reaction and HF etching is referred to as SiC-CP- 1.
Figures 5a and 5b are SEM images that reveal the rough surface morphology of SiC-CP, in contrast to that of the pristine (uncoated or un-decorated) CP and the Si02-CP shown in Figures 3a-3f. Figure 5b is an enlarged image of the inset shown in Figure 5 a. The corresponding silicon EDX map remains intense and homogeneous on the surface of CP as shown in Figure 5c. Importantly, the roughness is not continuous, indicating an incomplete coverage of SiC on the carbon fiber surface.
In order to achieve the aimed spatial heterogeneity in accordance with one or more embodiments of the present invention, the Si02 coating and magnesiothermic conversion were repeated once upon the SiC-CP-1, although this process could be repeated more than once without departing from the scope of the present invention. The obtained sample is referred to as SiC-CP-2. As shown in Figure 5d, the line-of- sight surface morphology of SiC-CP-2 is now completely roughened, suggestive of a much better SiC coverage on the designated area of CP.
XPS was used to characterize HF etched SiC-CP-2. As Figures 4a and 4c show, the minor C [Is] component at 282.5 assigned to the SiC phase from SiC-CP-1 turns into a major component in the C [Is] signal from SiC-CP-2, which confirms a better SiC coverage of SiC-CP-2 than Si-CP- 1. As shown in Figure 4d, SiC-CP-2 displays a Si [2p] signal centered at 100.1 eV that can be assigned to the SiC phase, without any contribution from metallic silicon.
Lithium Deposition/Stripping Profiles
Figure 13 illustrates lithium deposition profiles of CP electrodes at 4 mA cm" 2 for two hours in accordance with one or more embodiments of the present invention. The deposition profile pristine CP current collector line 1300 and the
Si02-CP current collector line 1302 are shown.
The present invention carried out lithium depositing on pristine CP, Si02-CP,
SiC-CP-1 and SiC-CP-2 as working electrodes. For spatially heterogeneous CPs, only the insulated side was exposed to the electrolyte. The present invention minimized the lithium intercalation reactions into the CP samples and focused on the lithium depositing behavior. Hence, a high current density of ~ 4 mA cm"2 (330 mA g_1 cp, based on 0.012 g cm"2 for CP) was applied between the working electrode and a lithium counter/reference electrode during the depositing process. This current density represents one of the highest values reported for lithium deposition studies, compared to current densities of less than 1 mA cm"2 in most previous studies. The deposition process was carried out for two hours, and the deposition capacity was set to be 28.8 C cm"2 (or 660 mA-h g_1 cp).
The present invention illustrates one of the largest quantity of lithium deposition compared to previous dendrite -related studies, including those with protection layers in the related art. The deposition on Si02-CP was also done for six hours to approach the limit of the accommodation capacity. As shown in Figure 13, after several minutes of cathodic reactions on the working electrodes, the potentials of both CP and Si02-CP electrodes rapidly dropped below 0.0 V vs. Li+/Li, indicating that metallic lithium deposition on the carbon fiber surface had started. Lithium intercalation into carbon is thermodynamically favorable; however, at potentials below 0.0 V vs. Li /Li, lithium plating on carbon surface is kinetically more facile. This leads to the fact that lithium-ion batteries on electric vehicles have to be charged for hours to prevent lithium plating.
Repeated deposition/stripping on SiC-CP-2 were conducted to investigate the reversibility of the dendrite-free deposition. The deposition and stripping current density was set to be 2 mA cm"2 (or 165 mA g_1 Cp), and lithium of 14.4 C cm"2 (or 330 mA g_1cp) was deposited. The cut-off potential was set to be 3.0 V versus Li+/Li for lithium stripping. By deep deposition/stripping processes, the 3D current collectors were placed in a more dendrite favored scenario to test the efficacy of the spatial heterogeneity concept.
Figure 8 illustrates the coulombic efficiency for the lithium
depositing/stripping cycling process on the SiC-CP-2 current collector in accordance with one or more embodiments of the present invention.
Figure 8 reveals the superior disposition performance of the methods and apparatuses of the present invention. In the inset of Figure 8 is an image of the vial cell containing SiC-CP-2 working electrode and lithium foil counter electrode, taken after 15 cycles, showing the dendrite-free surface of SiC-CP-2 current collector and mossy lithium phase formed around the lithium counter electrode. Note that the low coulombic efficiency in the first cycle is due to SEI formation on the carbon surface, which is widely observed for carbon electrodes in the first discharge/charge cycle.
SiC-CP-2 displays a very stable lithium stripping/deposition efficiency of -94% starting with the second cycle. This is one of the highest lithium-cycling efficiencies reported for aprotic organic electrolytes. It is worth stressing that the high efficiency is achieved at a current rate of 2 mA cm"2 and a deep lithium deposition of 14.4 C cm"2 in a carbonate based organic electrolyte, in contrast to previously reported lower efficiencies of around 70%> to 90%> typically obtained by using current rates less than 1 mA cm"2, a lithium deposition less than 2 C cm"2, and certain surface protection methods in favorable organic electrolytes. Note that the internal surface area of a 3D current collector is much larger than its footprint area, which is a significant advantage than 2D ones. This could be an important factor that leads to the high coulombic efficiency.
The lithium cycling efficiency is strongly influenced by the morphology of the deposited lithium. The high cycling efficiency obtained here corroborates the ex-situ SEM observation that deposited lithium is closely packed in the voids of the 3D current collectors. This clearly illustrates the superiority of the lithium deposition into 3D current collectors as in the present invention that is facilitated by a spatially heterogeneous structure. As shown in the inset of Figure 8, at the end of the 15th cycle, the lithium counter electrode was covered by isolated mossy lithium
accumulated over the deep deposition/stripping cycling; however, in sharp contrast, the SiC-CP-2 current collector retained a dendrite-free surface.
Figure 9 illustrates lithium depositing/stripping profiles on SiC-CP-2 in accordance with one or more embodiments of the present invention.
Figure 9 shows the first 15 deposition/stripping cycle profiles plotted on voltage versus time, at a current density of 2 mA cm"2 and a lithium deposition of 14.4 C cm"2 (330 mA-h g" 1 caAon paper).
A lithium cycling efficiency of up to 99.2% can be achieved with ionic liquid based or polymer based electrolytes in the related art. However, these high efficiencies were obtained at lower current densities and lower lithium deposition rates than those of the present invention. Despite the high efficiencies achieved in these superior electrolytes, even at the lower current densities and lithium deposition rates that were used, the morphology of the deposited lithium is still highly dendritic. The present invention does not suffer from these infirmities of the related art.
Ex-situ SEM studies after lithium deposition
Figures 6a-6f illustrate SEM images of cross-section areas of the lithium deposited CP and Si02-CP samples made in accordance with one or more
embodiments of the present invention.
To illustrate the superior performances of the Si02-CP made in accordance with one or more embodiments of the present invention than the pristine CP in terms of dendrite control and lithium infiltration into the paper voids, Figure 6a is representative SEM image of lithium deposited on pristine CP. Figure 6b is an enlarged image of the inset of Figure 6a. Figure 6c is representative SEM image showing the surface morphology of the lithium deposited CP and existence of formed dendrites. Figure 6d illustrates a representative SEM image of the lithium deposited Si02-CP made in accordance with one or more embodiments of the present invention. Figures 6e and 6f are enlarged images of inset a and inset β of Figure 6d. All the images here were taken with the paper specimen stage tilted by 45°. Note that the dendrites readily apparent in Figures 6a-6c are not present in figures 6d-6f.
Figures 7a-7d illustrate SEM images of the cross-section area of the lithium plated SiC-CP samples made in accordance with one or more embodiments of the present invention.
As with Figures 6d-6f, the SEM images of the SiC-CP samples also show superior performance over the pristine CP. Figure 7a is an overview image of the cross-section area of SiC-CP-1. Figure 7b is an enlarged image of inset a shown in Figure 7a. Figure 7c is an enlarged image of inset β of Figure 7a. Figure 7d is a representative SEM image of carbon fibers in the line-of-sight surface of lithium deposited SiC-CP-2. All the images were taken with the paper specimen stage tilted by 45°.
The cross-section of the lithium deposited SiC-CP-1 is shown in Figure 7a. It is evident that lithium infiltration took place in the voids, as shown in Figure 7b. However, some plated lithium phase can be observed on the SiC decorated surface (Figure 7c), due to the discontinuity of the nano-crystalline SiC coating on the SiC- CP- 1. On the SiC-CP-2, with a complete SiC coverage, it is confirmed that the SiC double coated area is dendrite-free, as shown in Figure 7d. This indicates that a HF resisting spatial heterogeneity has been created in the SiC-CP-2.
The deposited electrodes were examined ex-situ by SEM in order to investigate the "geographical" distribution of the deposited lithium metal. The SEM specimen stage was tilted by 45° in order to show both the cross-section and the adjacent face area of the lithium metal deposited CP electrodes. The cross-section of lithium metal deposited CP electrode displays a uniform morphology of carbon fibers as shown in Figures 6a and 6b. It is evident that lithium metal deposition did not infiltrate the voids of pristine CP. Figure 6c reveals a representative area on the CP surface with large lithium metal dendrites over 20 μιη in size and small lithium metal crystals homogeneously distributed. The pristine CP electrode functions essentially as a two-dimensional current collector.
In sharp contrast, as shown by the SEM images of Figures 6d-6f, the voids near the bottom of the Si02-CP were well infiltrated by lithium metal deposition. The deposited lithium metal crystals, closely packed, exhibit particle sizes in the range of 10 to 20 μηι as shown in Figure 6e. The surface morphology of the Si02 decorated area near the cross-section remains very smooth and free of deposited lithium crystallites or dendrites, as shown in Figure 6f. This indicates that the Si02 coating is impermeable to lithium ions and has successfully created an insulating roof for the 3D current collector.
Figure 14 is a SEM image of the lithium deposited Si02-CP from a wider view, zoomed out from the part in Figure 7a.
A zoom-out view under SEM, confirms that the surface of deposited Si02- CP is completely free of lithium dendrites and that the voids near the top surface are also free of lithium infiltration as shown in Figure 14. The lithium metal deposition into the Si02-CP fills up the voids from the non-silica to the silica side, which is facilitated by the conducting copper foil support on the non-Si02 surface of the electrode and, more importantly, by the anisotropic structure of the current collector. The surface is free of dendrites and the voids near the top surface are free of lithium infiltration. The image was taken with the paper specimen stage tilted by 45°.
Figure 15 is a representative SEM image of the Si02-CP after a lithium deposition for two hours at a current rate of 4 mA cm"2 in accordance with one or more embodiments of the present invention.
During lithium deposition, with no electrons available from the Si02 surface, lithium ions driven by the electric field migrated deeper into the voids inside the porous current collector where they were reduced. As Figure 15 shows, lithium deposition occurs on the conducting carbon surface which is oppositely oriented towards the Si02 coated electrode surface.
The top part of the carbon fiber coated with a Si02 layer is free of lithium deposition, and the bottom part without Si02 is covered with lithium deposition. The image was taken with the paper specimen stage tilted by 45°.
Figure 16 is a representative SEM image of Si02-CP after a lithium deposition for six hours at a current rate of 4 mA cm"2 in accordance with one or more embodiments of the present invention.
After lithium deposition for six hours, the Si02-CP was nearly fully
infiltrated by deposited lithium, as revealed by the solid edge part of the paper under the ex situ SEM investigation shown in Figure 16. The paper face surface is free of dendrites and the voids originally in the carbon paper edge are nearly filled. The image was taken with the paper specimen stage tilted by 45°.
The deposited lithium provided a capacity of 71.3 C cm"2 (or 1980 mA-h g_1 Cp), which is near (79%) 90 C cm"2 (2500 mA-h g_1 Cp), the theoretical accommodation capacity calculated based on the specific pore volume and lithium metal density. Further deposition on a fully infiltrated 3D current collector may result in the dendrite growth on the filled paper top surface. Therefore, it is important to prevent an over- infiltration during the deposition cycle in practical scenarios. The spatially controlled lithium deposition resembles in some degree the single-crystal growth of calcium carbonate in the assembly process that generates the abalone cell. Compared to the deposition on pristine CP, the surface Si02 coating effectively realizes the proposed function of a spatially heterogeneous structure.
Discussion
Figures 10a- lOd illustrate the structures of pristine CP and spatially
heterogeneous CP (SH-CP), and the different lithium deposition processes on them in accordance with one or more embodiments of the present invention.
Figure 10a illustrates pristine CP. Figure 10b illustrates SH-CP, where anisotropic spatial heterogeneity is achieved after a line-of-sight deposition of Si02 onto the carbon fibers. Areas 2 indicate a Si02 or SiC coating, and black areas 4 represent uncovered conducting carbon surface. Figure 10c illustrates the situation of lithium deposition on CP, mostly on the line-of-sight surface, as shown by spheres 6, which represent the lithium atoms. Figure 6d illustrates lithium
deposition in SH-CP. Lithium electrodeposition does not take place on the insulating line-of-sight surface, but is driven by the electric field towards voids of the current collector.
As schematically shown in Figure 10b, spatially heterogeneous
insulating/conducting properties of the CP can be obtained after the Si02 electron- beam deposition. The same spatial heterogeneity can be maintained by converting Si02 into SiC atop the carbon paper surface. This anisotropic spatial heterogeneity is essential in order to achieve surface dendrite-free lithium deposition on the Si02-CP or SiC-CP current collectors, as schematically shown in Figure lOd. With the large porous volume of the current collector effectively utilized by lithium deposition, the electrode maintains a constant volume upon deposition. Moreover, due to the scaffold-like structure of the carbon paper, disintegration of deposited lithium cannot occur inside the paper in the presence of nearby 3D electric contacts at a high depositing rate. The stable lithium cycling efficiency of 94% achieved in SiC-CP-2 in a carbonate based organic electrolyte further demonstrates the superiority of the anisotropic spatial heterogeneity of the 3D current collector.
Process Chart
Figure 17 illustrates a process chart according to one or more embodiments of the present invention.
Box 1700 illustrates coating a first surface of the porous substrate with a layer, wherein the first surface remains porous to the metal to be deposited.
Box 1702 illustrates placing the first surface with the layer facing an electrode.
Box 1704 illustrates depositing the metal on the substrate on a second surface of the substrate distinct from the first surface.
References
The following publications are incorporated by reference herein in their entirety:
[I] T. Nagaura, K. Tozawa, Prog. Batteries Solar Cells 9 (1990) 209-217.
[2] J.S. Dunning, W.H. Tiedemann, L. Hsueh, D.N. Bennion, J. Electrochem. Soc.
118(1971) 1886-1890.
[3] M.S. Whittingham, US Patent 4009052 (1977).
[4] G.-A. Nazri, G. Pistoia, (eds) Kluwer Academic Publishers, (2004).
[5] I. Epelboin, M. Froment, M. Garreau, J. Thevenin, D. Warin, Proc-
Electrochem. Soc. 80-4 (1980) 417-429.
[6] R. Bhattacharyya, B. Key, H. Chen, A.S. Best, A.F. Hollenkamp, CP. Grey,
Nature Mater. 9 (2010) 504-510.
[7] Y. Cohen, D. Aurbach, J. Phys. Chem. B 104 (2000) 12282-12291.
[8] D. Aubach, Y. Cohen, J. Electrochem. Soc. 143 (1996) 3525-3532.
[9] A. Teyssot, C. Belhomme, R. Bouchet, M. Rosso, S. Lascaud, M. Armand, J.
Electroanal. Chem. 584 (2005) 70-74.
[10] D.W. Murphy, F. J. DiSalvo, J. N. Carides, J.V. Waszczak, Mat. Res. Bull. 13
(1978) 1395-1402.
[I I] M. Lazzari, B. Scrosati, J. Electrochem. Soc. 127 (1980) 773-774.
[12] J.B. Goodenough, Y. Kim, Chem. Mater. 22 (2010) 587-603. [13] B.L. Ellis, K.T. Lee, L.F. Nazar, Chem. Mater. 22 (2010) 691-714.
[14] Y.J. Lee, H. Yi, W.-J. Kim, K. Kang, D.S. Yun, M.S. Strano, G. Ceder, A.M.
Belcher, Science 324 (2009) 1051-1055.
[15] H. L. Zhang, D. E. Morse, J. Mater. Chem. 19 (2009) 9006-9011.
[16] B. Scrosati, J. Garche J. Power. Sources 195 (2010) 2419-2430.
[17] X. Ji, K.T. Lee, L.F. Nazar, Nature Mater. 8 (2009) 500-506.
[18] K.M. Abraham, Z. Jiang, J. Electrochem. Soc. 143 (1996) 1-5.
[19] E. Yoo, H. Zhou, ACS Nano 5 (2011) 3020-3026.
[20] X. Ji, S. Evers, R. Black, L.F. Nazar, Nature Commun. x:x
doi: 10.1038/ncommsl293 (2011).
[21] J.-S. Lee, S.T. Kim, R. Cao, N.-S. Choi, M. Liu, K.T. Lee, J. Cho, Adv.
Energy Mater. 1 (2011) 34-50.
[22] J.-N. Chazalviel, Phys. Rev. A 42 (1990) 7355-7367.
[23] M. Rosso, T. Gobron, C. Brissot, J.-N. Chazalviel, S. Lascaud, J. Power
Sources 97-98 (2001) 804-806.
[24] M. Armand, W. Gorecki, R. Andreani, B. Scrosati Ed., Second Int. Symp. on
Polymer Electrolytes, Elsevier, London, (1990) p. 91.
[25] L. Sannier, R. Bouchet, L. Santinacci, S. Grugeon, J.-M. Tarascon, J.
Electrochem. Soc. 151 (2004) A873-A879.
[26] L. Sannier, R. Bouchet, M. Rosso, J-M. Tarascon J. Power Sources 158 (2006)
564-570.
[27] N. Byrne, P. C. Howlett, D. R. MacFarlane, M. Forsyth, Adv. Mater. 17
(2005) 2497-2501.
[28] G.T. Kim, G.B. Appetecchi, M. Montanino, F. Alessandrini, S. Passerini, ECS Trans. 25 (2010) 127-138.
[29] H. Ota, Y. Sakata, Y. Otake, K. Shima, M. Ue, J. Yamaki, J. Electrochem.Soc.
15 (2004) A1778-A1788. [30] K. Kanamura, S. Shiraishi, Z. Takehara, J. Electrochem. Soc. 141 (1994) L108-L110.
[31] F. Marchioni, K. Star, E. Menke, T. Buffeteau, L. Servant, B. Dunn, F. Wudl,
Langmuir, 23 (2007) 11597-11602.
[32] G.A. Umeda, E. Menke, M. Richard, K.L. Stamm, F. Wudl, B. Dunn, J.
Mater. Chem. 21 (2011) 1593-1599.
[33] C. Liebenow, K. Luhder, J. Appl. Electrochem. 26 (1996) 689-692.
[34] Y.M. Lee, N.-S. Choi, J.H. Park, J.-K. Park, J. Power Sources 119-121 (2003)
964-972.
[35] J.B. Bates, N.J. Dudney, G.R. Gruzalski, R.A. Zuhr, A. Choudhury, C.F.
Luck, J. Power Sources 43-44 (1993) 103-110.
[36] S.J. Visco, F.Y. Tsang, US Patent 6214061 (2001).
[37] S.J. Visco, E. Nomon, B. Katz, L.C.D. Jongle, M.Y. Chu, Abstract #53, The 12th
International Meeting on Lithium Batteries, Nara, Japan, (2004).
[38] S.J. Visco, Y.S. Nimon, B.D. Katz, US Patent 7390591 (2008).
[39] T.A. Skotheim, C.J. Sheehan, Y.V. Mikhaylik, J. Affmito, US Patent 6936381
(2005) .
[40] S.J. Visco, Y.S. Nimon, B.D. Katz, US Patent 7282302 (2007).
[41] J. Elezgaray, C. Leger, F. Argoul, Phys. Rev. Letts. 84 (2000) 3129-3132.
[42] K. Okita, K. Ikeda, H. Sano, Y. Iriyama, H. Sakaebe, J. Power Sources 196 (2011) 2135-2142.
[43] Y.J. Lee, Y. Lee, D. Oh, T. Chen, G. Ceder, A.M. Belcher, Nano Lett. 10 (2010) 2433-2440.
[44] P. L. Taberna, S. Mitra, P. Poizot, P. Simon, J.-M. Tarascon, Nature Mater. 5
(2006) 567-573.
[45] M.S.Yazici, D. Krassowski, J. Prakash, J. Power Sources 141 (2005) 171-176. [46] C. Arbizzani, M. Lazzari, M. Mastragostino, J. Electrochem. Soc. 152 (2010) A289-A294.
[47] L.H.S. Gasparotto, A. Prowald, N. Borisenko, S. Zein El Abedin, A. Garsuch, F. Endres, J. Power Sources 196 (2011) 2879-2883.
[48] B. Markovsky, F. Amalraj, H. E. Gottlieb, Y. Gofer, S.K. Martha, D. Aurbach, J. Electrochem. Soc. 157 (2010) A423-A429.
[49] D. Aurbach, I. Weissman, A. Schechter, Langmuir 12 (1996) 3991-4007.
[50] R. Moshtev, B. Johnson, J. Power Sources 91 (2000) 86-91.
[51] D.M. Mattox, Vacuum Deposition, Reactive Evaporation and Gas
Evaporation, in ASM Handbook, ASM Publ. 5, Surface Engineering (1994)
556-572.
[52] E.K. Richman, C.B. Kang, T. Brezesinski, S.H. Tolbert, Nano Lett. 8 (2008) 3075-3079.
[53] Y. Shi, F. Zhang, Y.-S. Hu, X. Sun, Y. Zhang, H. I. Lee, L. Chen, G. D.
Stucky,
J. Am. Chem. Soc. 132 (2010) 5552-5553.
[54] H. Honbo, K. Takei, Y. Ishii, T. Nishida, J. Power Sources 189 (2009) 337- 343.
[55] K. Eberman, P. M. Gomadam, G. Jain, E. Scott, ECS Trans. 25 (2010) 47-58.
[56] C. M. Zaremba, A. M. Belcher, M. Fritz, Y. Li, S. Mann, P. K. Hansma, D.
E. Morse, J. S. Speck, G. D. Stucky, Chem. Mater. 8 (1996) 679-690.
[57] M. Winter, J. O. Besenhard, M. E. Spahr, Pe. Novak, Adv. Mat. 10 (1998)
725-763.
[58] H. Ota, Y. Sakata, Y. Otake, K. Shima, M. Ue, J. Yamaki, J. Electrochem.
Soc. 151 (2004) A1778-A1788.
[59] H. Ota, X. Wang, E. Yasukawa, J. Electrochem. Soc. 151 (2004) A427-A436.
[60] D. Aurbach, A. Zaban, A. Schechter, Y. Ein-Eli, E. Zinigrad, B. Markovsky, J.
Electrochem. Soc. 142 (1995) 2873-2882. [61] S. Shiraishi, K. Kanamura, Z. Takehara, J. Electrochem. Soc. 146 (1999) 1633-1639.
[62] D. Aurbach, E. Zinigrad, H. Teller, P. Dan, J. Electrochem. Soc. 147
(2000)1274-1279.
Conclusion
The teachings of the present invention address the dendrite formation problem in a fundamentally new concept via rationally designed current collectors with heterogeneous properties. Although described with respect to Carbon Paper, other 3D architectures such as carbon cloth, carbon nanotube infiltrated papers and those made with copper, aluminum or conducting ceramics should show similar performances and are contemplated within the scope of the present invention. Other systems with metallic electrodes, e.g. sodium, magnesium, calcium, aluminum or zinc batteries may be benefited from this method as well, and are also contemplated within the scope of the present invention.
As such, although described with respect to carbon fiber paper, an insulated 3D current collector in accordance with one or more embodiments of the present invention can comprise carbon fiber paper, carbon fiber cloth, carbon nanotube cloth, carbon nanotube coated cellulose paper, graphene coated cellulose paper, 3D carbon nanotube structures, 3D graphene structures, macroporous porous carbon films wherein "macroporous" means pores sized over 50 nm, mesoporous porous carbon films wherein "mesoporous means pores sized between 2 nm to 50 nm, macroporous carbon monoliths, mesoporous carbon monoliths, 3D porous metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, 3D structures made of conducting ceramics including titanium carbides, vanadium carbides, manganese carbides, iron carbides, zirconium carbides, tungsten carbides, molybdenum carbides, titanium nitrides, vanadium nitrides, manganese nitrides, iron nitrides, zirconium nitrides, tungsten nitrides, molybdenum nitrides, silicon nitrides, iron phosphide, titanium oxide, molybdenum oxides, indium doped tin oxide or zinc oxide, 3D structures made of conducting polymers including polyanilines (PANI),
poly(pyrrole)s (PPY), poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophenes (PT), poly(p-phenylene sulfide) (PPS), or other materials.
Further, the 3D current collector of one or more embodiments of the present invention can comprise a layer that is insulating or non-insulating, and, where insulating, can comprise silicon oxide, graphene oxide, silicon carbide, hafnium oxide, zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non- metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, nonmetallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials, and can be applied or deposited by a line-of-sight method or other methods, including printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition. The present invention also comprises devices, or parts of devices such as electrodes, comprising the insulated 3D current collector of the present invention, which can be applied using
an electrodeposition process, where electrodeposition occurs preferentially at the non- line-of-sight surfaces. Such devices can comprise a rechargeable battery, such as a lithium battery, and can further comprise lithium ion containing positive electrodes to provide lithium ions for the lithium electrodeposition on the electrode. A method of preparing an insulated 3D current collector in accordance with one or more embodiments of the present invention comprises coating an insulating layer onto an line-of-sight surface of a 3D current collector, wherein the 3D current collector comprises openings in the line-of-sight surface and non-line-of-sight surfaces accessible through the openings, and the insulating layer allows access to the non-line-of-sight surfaces via the openings.
A method of electrodeposition in accordance with one or more embodiments of the present invention comprises preferentially electrodepositing a metal at non-line-of- sight surfaces of an insulated 3D current collector.
Such methods further optionally comprise the insulated 3D current collector comprises a 3D current collector having a line-of-sight surface comprising openings, the non-line-of-sight surfaces being accessible through the openings, and an insulating layer coating the line-of-sight surface, the insulating layer allowing access to the non- line-of-sight surfaces via the openings, where the line-of-sight surface is coated by a line-of-sight method, and the line-of-sight method is printing, spray coating, electron beam deposition, ion beam deposition, sputtering, thermal evaporation, spin coating, stamping, or line-of-sight chemical vapor deposition.
Such methods further optionally comprise the insulating layer being silicon oxide, graphene oxide, silicon carbide, hafnium oxide, lithium phosphorous oxynitride (LIPON), zeolite, metal organic-ligand complexes, insulating organic materials including polyethylene oxides, polyethylene glycols, carbon hydrates, cellulose or biomass, metal sulfates, carbon nitride, non-metallic metal nitrides, metal phosphates, non-metallic metal phosphides, metal carbonates, non-metallic metal carbides, metal chlorates, metal fluorides, metal iodides, nonmetallic metal arsenides, metal hydroxides, metal sulfides, metal bromides, metal selenides, metal borates, positive temperature coefficient thermistors (PTCT) including metal titanates, metal chromates, insulating ceramics, or other insulating polymeric materials, and further optionally comprise the 3D current collector being carbon fiber paper, carbon cloth, carbon nanotube coated paper, graphene structures, porous carbon films, porous carbon monoliths, or 3D metallic structures made of metals including copper, aluminum, nickel, silver, gold, platinum, titanium, tantalum, iron, niobium, zirconium, chromium, molybdenum, zinc, vanadium, tungsten or beryllium, or alloy s/intermetallics including stainless steel, copper alloys, cobalt alloys, nickel alloys, aluminum alloys or titanium alloys, or 3D structures made of conducting ceramics including titanium carbides, vanadium carbides, manganese carbides, iron carbides, zirconium carbides, tungsten carbides, molybdenum carbides, titanium nitrides, vanadium nitrides, manganese nitrides, iron nitrides, zirconium nitrides, tungsten nitrides, molybdenum nitrides, silicon nitrides, iron phosphide, titanium oxide, molybdenum oxides, indium doped tin oxide or zinc oxide, or 3D structures made of conducting organic materials including conducting polymers.
Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the invention and the following claims, and the full range of equivalents of the claims.
This concludes the description of the preferred embodiment of the present invention. The foregoing description of one or more embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many
modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto and the full range of equivalents of the claims. The attached claims are presented merely as one aspect of the present invention. The Applicant does not disclaim any claim scope of the present invention through the inclusion of this or any other claim language that is presented or may be presented in the future. Any disclaimers, expressed or implied, made during prosecution of the present application regarding these or other changes are hereby rescinded for at least the reason of recapturing any potential disclaimed claim scope affected by these changes during prosecution of this and any related applications. Applicant reserves the right to file broader claims in one or more continuation or divisional applications in accordance within the full breadth of disclosure, and the full range of doctrine of equivalents of the disclosure, as recited in the original specification.

Claims

WHAT IS CLAIMED IS:
1. A method of depositing metal on a porous substrate, comprising:
coating a first surface of the porous substrate with a layer, wherein the first surface remains porous to the metal to be deposited;
placing the first surface with the layer facing an electrode; and
depositing the metal on the substrate on a second surface of the substrate distinct from the first surface.
2. The method of claim 1, wherein the metal is lithium.
3. The method of claim 2, wherein the substrate is carbon fiber paper.
4. The method of claim 3, wherein the metal is electrodeposited on the substrate.
5. The method of claim 1, wherein the layer is silicon dioxide (Si02).
6. The method of claim 1, wherein the layer is silicon carbide (SiC).
7. The method of claim 7, wherein the layer further comprises silicon dioxide (Si02).
8. The method of claim 1, wherein the layer is deposited in a line-of-sight onto the first surface.
9. The method of claim 2, wherein the deposition of the metal has a reduced dendrite density compared to a porous substrate lacking the layer.
10. The method of claim 1, wherein the layer is coated on the porous substrate using electron beam deposition.
11. An insulated three-dimensional (3D) current collector comprising: a 3D current collector having a line-of-sight surface comprising openings and non-line-of-sight surfaces accessible through the openings; and
an insulating layer coating the line-of-sight surface, the insulating layer allowing access to the non-line-of-sight surfaces via the openings.
12. The insulated three-dimensional (3D) current collector of claim 11, wherein lithium is deposited on the non-line-of-sight surfaces.
13. The insulated three-dimensional (3D) current collector of claim 12, wherein the lithium is deposited on the insulated three-dimensional (3D) current collector electrolytically.
14. The insulated three-dimensional (3D) current collector of claim 11, wherein the insulated 3D current collector is carbon fiber paper.
15. The insulated three-dimensional (3D) current collector of claim 11, wherein the insulating layer is silicon dioxide (Si02).
16. The insulated three-dimensional (3D) current collector of claim 11, wherein the insulating layer is silicon carbide (SiC).
17. The insulated three-dimensional (3D) current collector of claim 16, wherein the insulating layer further comprises silicon dioxide (Si02).
18. The insulated three-dimensional (3D) current collector of claim 11 , wherein the insulating layer is deposited in a line-of-sight onto the line-of-sight surface.
19. The insulated three-dimensional (3D) current collector of claim 12, wherein the insulated three-dimensional (3D) current collector has a reduced dendrite density compared to a current collector lacking the insulating layer.
20. The insulated three-dimensional (3D) current collector of claim 11, wherein the insulating layer is coated on the insulated three-dimensional (3D) current collector using electron beam deposition.
PCT/US2012/045257 2011-06-30 2012-07-02 Surface insulated porous current collectors as dendrite free electrodeposition electrodes WO2013003846A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201161503322P 2011-06-30 2011-06-30
US61/503,322 2011-06-30

Publications (2)

Publication Number Publication Date
WO2013003846A2 true WO2013003846A2 (en) 2013-01-03
WO2013003846A3 WO2013003846A3 (en) 2014-05-08

Family

ID=47424830

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2012/045257 WO2013003846A2 (en) 2011-06-30 2012-07-02 Surface insulated porous current collectors as dendrite free electrodeposition electrodes

Country Status (1)

Country Link
WO (1) WO2013003846A2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105280925A (en) * 2014-07-16 2016-01-27 辉能科技股份有限公司 Cathode Electrode
CN105280883A (en) * 2014-07-16 2016-01-27 辉能科技股份有限公司 Lithium Metal Electrode
JP2020501305A (en) * 2016-12-06 2020-01-16 ナショナル インスティテュート オブ フォレスト サイエンスNational Institute Of Forest Science Paper current collector, method for producing the same, and electrochemical element including the same
CN111167496A (en) * 2020-01-09 2020-05-19 南开大学 Visible light catalytic material and preparation method and application thereof
CN112133872A (en) * 2020-09-05 2020-12-25 武汉科技大学 Graphene-loaded Cu/VN quantum dot heterojunction material and preparation method and application thereof
CN114628635A (en) * 2022-04-28 2022-06-14 南京邮电大学 Lithium metal battery cathode and manufacturing method thereof
CN116247190A (en) * 2023-05-10 2023-06-09 赣州吉锐新能源科技股份有限公司 Method for preparing porous nano silicon-based composite anode material by using photovoltaic sawdust slurry

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4565753A (en) * 1985-04-03 1986-01-21 Gte Government Systems Corporation Electrochemical cell having wound electrode structures
US20020085968A1 (en) * 1997-03-07 2002-07-04 William Marsh Rice University Method for producing self-assembled objects comprising single-wall carbon nanotubes and compositions thereof
US20020182508A1 (en) * 1998-09-03 2002-12-05 Polyplus Battery Company Coated lithium electrodes
US20050150620A1 (en) * 2001-10-09 2005-07-14 Mitsubishi Rayon Co., Ltd. Carbon fiber paper and porous carbon electrode substratefor fuel cell therefrom
US20060177732A1 (en) * 2001-07-25 2006-08-10 Polyplus Battery Company Battery cell with barrier layer on non-swelling membrane
US20090068553A1 (en) * 2007-09-07 2009-03-12 Inorganic Specialists, Inc. Silicon modified nanofiber paper as an anode material for a lithium secondary battery
US20090169943A1 (en) * 2005-07-07 2009-07-02 Fujfilm Corporation Solid electrolyte multilayer membrane, method and apparatus of producing the same, membrane electrode assembly, and fuel cell
US20110003229A1 (en) * 2008-02-29 2011-01-06 Angstrom Power Incorporated Electrochemical cell and membranes related thereto

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4565753A (en) * 1985-04-03 1986-01-21 Gte Government Systems Corporation Electrochemical cell having wound electrode structures
US20020085968A1 (en) * 1997-03-07 2002-07-04 William Marsh Rice University Method for producing self-assembled objects comprising single-wall carbon nanotubes and compositions thereof
US20020182508A1 (en) * 1998-09-03 2002-12-05 Polyplus Battery Company Coated lithium electrodes
US20060177732A1 (en) * 2001-07-25 2006-08-10 Polyplus Battery Company Battery cell with barrier layer on non-swelling membrane
US20050150620A1 (en) * 2001-10-09 2005-07-14 Mitsubishi Rayon Co., Ltd. Carbon fiber paper and porous carbon electrode substratefor fuel cell therefrom
US20090169943A1 (en) * 2005-07-07 2009-07-02 Fujfilm Corporation Solid electrolyte multilayer membrane, method and apparatus of producing the same, membrane electrode assembly, and fuel cell
US20090068553A1 (en) * 2007-09-07 2009-03-12 Inorganic Specialists, Inc. Silicon modified nanofiber paper as an anode material for a lithium secondary battery
US20110003229A1 (en) * 2008-02-29 2011-01-06 Angstrom Power Incorporated Electrochemical cell and membranes related thereto

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105280925A (en) * 2014-07-16 2016-01-27 辉能科技股份有限公司 Cathode Electrode
CN105280883A (en) * 2014-07-16 2016-01-27 辉能科技股份有限公司 Lithium Metal Electrode
EP2978052A1 (en) * 2014-07-16 2016-01-27 Prologium Holding Inc. Anode electrode
US9755228B2 (en) 2014-07-16 2017-09-05 Prologium Holding Inc. Lithium metal electrode
US10483534B2 (en) 2014-07-16 2019-11-19 Prologium Holding Inc. Lithium metal anode electrode
JP2020501305A (en) * 2016-12-06 2020-01-16 ナショナル インスティテュート オブ フォレスト サイエンスNational Institute Of Forest Science Paper current collector, method for producing the same, and electrochemical element including the same
CN111167496A (en) * 2020-01-09 2020-05-19 南开大学 Visible light catalytic material and preparation method and application thereof
CN111167496B (en) * 2020-01-09 2020-12-25 南开大学 Visible light catalytic material and preparation method and application thereof
CN112133872A (en) * 2020-09-05 2020-12-25 武汉科技大学 Graphene-loaded Cu/VN quantum dot heterojunction material and preparation method and application thereof
CN114628635A (en) * 2022-04-28 2022-06-14 南京邮电大学 Lithium metal battery cathode and manufacturing method thereof
CN114628635B (en) * 2022-04-28 2023-11-03 南京邮电大学 Lithium metal battery negative electrode and manufacturing method thereof
CN116247190A (en) * 2023-05-10 2023-06-09 赣州吉锐新能源科技股份有限公司 Method for preparing porous nano silicon-based composite anode material by using photovoltaic sawdust slurry

Also Published As

Publication number Publication date
WO2013003846A3 (en) 2014-05-08

Similar Documents

Publication Publication Date Title
Ji et al. Spatially heterogeneous carbon-fiber papers as surface dendrite-free current collectors for lithium deposition
Wang et al. Dendrite-free Na metal plating/stripping onto 3D porous Cu hosts
Xu et al. A high-performance Li-ion anode from direct deposition of Si nanoparticles
Mckerracher et al. Comparison of carbon materials as cathodes for the aluminium-ion battery
US10147966B2 (en) Metal sulfide composite materials for batteries
WO2013003846A2 (en) Surface insulated porous current collectors as dendrite free electrodeposition electrodes
Xie et al. Iron supported C@ Fe 3 O 4 nanotube array: a new type of 3D anode with low-cost for high performance lithium-ion batteries
Memarzadeh et al. Silicon nanowire core aluminum shell coaxial nanocomposites for lithium ion battery anodes grown with and without a TiN interlayer
Han et al. Bilayered nanoporous graphene/molybdenum oxide for high rate lithium ion batteries
EP3449519A1 (en) Metal alloy layers on substrates, methods of making same, and uses thereof
Sun et al. Self-standing oxygen-deficient α-MoO3-x nanoflake arrays as 3D cathode for advanced all-solid-state thin film lithium batteries
Cheng et al. Electrically conductive ultrananocrystalline diamond-coated natural graphite-copper anode for new long life lithium-ion battery
Lu et al. Cotton pad derived 3D lithiophilic carbon host for robust Li metal anode: In-situ generated ionic conductive Li3N protective decoration
Wang et al. Direct growth of mesoporous Sn-doped TiO 2 thin films on conducting substrates for lithium-ion battery anodes
Osaka et al. New Si–O–C composite film anode materials for LIB by electrodeposition
CN110476283B (en) Protective layer for metal electrode battery
US11569527B2 (en) Lithium battery
Bian et al. Mesoporous C-coated SnO x nanosheets on copper foil as flexible and binder-free anodes for superior sodium-ion batteries
Jing et al. Sandwich-like strontium fluoride graphene-modified separator inhibits polysulfide shuttling and lithium dendrite growth in lithium–sulfur batteries
Ensafi et al. Metal (Ni and Bi) coated porous silicon nanostructure, high-performance anode materials for lithium ion batteries with high capacity and stability
Hong et al. Cost-effective approach for structural evolution of Si-based multicomponent for Li-ion battery anodes
Pan et al. Binder and carbon-free SbSn-P nanocomposite thin films as anode materials for sodium-ion batteries
Cheng et al. An interconnected silver coated carbon cloth framework as a host to reduce lithium nucleation over-potential for dendrite-free lithium metal anodes
WO2016063281A1 (en) High-capacity silicon nanowire based anode for lithium-ion batteries
Lim et al. Operando electrochemical pressiometry probing interfacial evolution of electrodeposited thin lithium metal anodes for all-solid-state batteries

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12804841

Country of ref document: EP

Kind code of ref document: A2

122 Ep: pct application non-entry in european phase

Ref document number: 12804841

Country of ref document: EP

Kind code of ref document: A2