CA1311266C - Spiral-wound galvanic cell - Google Patents
Spiral-wound galvanic cellInfo
- Publication number
- CA1311266C CA1311266C CA000614199A CA614199A CA1311266C CA 1311266 C CA1311266 C CA 1311266C CA 000614199 A CA000614199 A CA 000614199A CA 614199 A CA614199 A CA 614199A CA 1311266 C CA1311266 C CA 1311266C
- Authority
- CA
- Canada
- Prior art keywords
- electrode
- current collector
- galvanic cell
- shaped
- leaf spring
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/04—Cells with aqueous electrolyte
- H01M6/06—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid
- H01M6/10—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid with wound or folded electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
Abstract
Abstract of the Disclosure A spiral-wound galvanic cell is based upon a lithium system with a nonaqueous electrolyte, and includes a positive electrode, the carrier of which is clamped within the slit of a simple metal splint which serves as the winding mandrel and current collector. Contact with the metal splint is established by a leaf spring associated with the housing cover, which the serves as the positive terminal post for the cell. A high specific contact pressure is developed at this connection by providing the leaf spring with a punched hole which rests on thicker top portions of the metal splint. A small metal plate pressed through the lithium electrode and its separator establishes electrical contact between the lithium electrode and the interior wall of the housing vessel, which then serves as the negative cell pole.
Description
SPIRAL-WOUND GALVANIC CELL
Backqround of the Invention The present invention relates generally to a yalvanic cell with a spiral-shaped electrode body, and more particularly, to an improved center pole conductor for such a cell, and its use S in facilitating the winding procedure.
Spiral-wound galvanic cells are generally produced from windings of band-shaped positive and negative electrodes, with the imposition of a band-shaped separator, toyether with an appropri~te current collector. A metal housing is provided to receive the spiral electrodes, one of which is electrically connected to the metal housing. The other electrode is electrically connected with a cover, which seals the opening of the housing and which serves as a terminal post for the associated electrode.
The conventional process for producing electrode windings of this general type makes use of a winding mandrel, usually a steel needle of about 5 to 7 mm in diameter, having a longitudinal slit which is used to engage the band electrodes.
In most instances, this mandrel is permanently attached to the winding machine. Consequently, in operation, a free space is generally left in the middl~ of the electrode winding after its production, following withdrawal of the mandrel of the winding machine.
This free space, under certain circumstances (e.g., impact stressing of the cell), can lead to a displacement of the windings along the longitudinal axis of the cell, or even a mutual displacement of the electrodes~ Attempts have been made to overcome this problem by using winding ~nandrels formed of plastic rods, whlch are designed to fill the free space in the electrode winding and provide a so-called l'lost nucleus" for permanently positioning the windings (forming the basis for a compact arrangement of the electrodes).
However, in any event, it remains necessary to provide the individual electrodes with separate current-conducting lugs, and to connect the lugs to their external cell poles (advantageously formed by the cell housing and cover). The production o~ such connections (which frequently must take the form of wire bridges) is rather difflcult. What is more, a considerahle transfer resistance can develop in the event of a faulty weld.
DE-C-2 438 296 discloses a somewhat more advantageous arrangement in which at least one electrode is connected to its respective terminal post by means of a terminal collector plate.
; 20 However, such measures are only effective when the electrodes (e.g., a sintered foil strip) are not edged with an active paste, which could come into contact with the plate on the front side of the winding. DE-A-3 412 890, as well as DE-C-3 014 435, disclose wound electrode structures in which a winding core, originally z5 used to produce the set of electrodes, also assumes the role of a terminal collec-tor pole, as a current collector for a first one :
of the electrodes, while the housing serves as the terminal collector for the second electrode. However, the second electrode must t~en form the external side of the winding so that it can rest against the inner wall of the houslng. DE~C-3 014 435 further discloses the placement of a coil C;pring onto the flange-like upper end of the cell's rod~like collector, which presses against the lower side of the metallic cell cover and accordingly establishes an electrical connection between the collector and its external pole. However, during assembly, this spring re~uires special attention, particularly in its positioning on the head of the collector, since there is a danger that the coil spring will fly loose as the result of unintentional squeezing by the tool which is used to manipulate it. Such measures have therefore not proved to be entirely satisfactory.
summary of the Invention It is therefore a primary object of the present invention to provide an improved current collector for a spiral-wound galvanic cell.
It is also an object of the present invention to provide a curren-t collector for a spiral-wowld galvanic cell which is simple in construction, and in its manner of use.
It is also an object of the present invention to provide a current collector for a spiral-wound galvanic cell , -3-~ ' .
which can simultaneously serve as a winding mandrel for producing the cell.
It is also an object of the present invention to provide a current collector for a spiral-wound galvanic cell which can provide a trouble-free electrical connection with the cell's housing cover, to serve as an external cell pole for the associated electrode.
It is also an object of the present invention to provide a spiral-wound galvanic cell having an improved current collector, and which is easy ko assemble.
These and other objects are achieved in accordance with the present invention by providing a current collector for one of the cell's electrodes, preferably the positive electrode, which takes the form of a slit metal needle for receiving the electrode, alony its carrier. The body of the needle is slit so that the electrode is permanently clamped to the current collector~ The top of the needle is closed so that the needle can be firmly grasped by the winding machine. The overall shape and/or thickness of the needle may be varied. However, the length of the slit preferably conforms to the width of the electrode ~and so that there is optimum contact of the carrier with the slit body of the needle, on both side~. In a particularly preferred embodiment o~ the present invention, the slit needle takes the form of a metal splint (much like a cotter pin) with a closed top end which extends into an eye. In such case, the two legs of the splint can be of a di~feren length, if _4_ '~ .
desired.
To establish electrical contact, it is simply sufficient to place the collector or metal splint onto exposed (freed of active material) portions of the carrier for the electrode, which generally takes the form of an expanded metal or fine mesh net of Ni, Ag, Ti, or nonoxidizing steel. An additional spot welding on either, or preferak~ly both sides of the metal splint, above the intervening carrier, is advantageous and therefore also preferred.
In a particularly preferred embodiment of the invention, the current collector is mounted about the midpoint of the carrier, rather than at one end, so that the electrode band which issues from the middle strip of the carrier (which is freed of active material to establish proper contact with the collector) is divided into two cathode segments of about equal length. ~s a result of this, the beginning of the winding for this electrode is developed at the middle of the band, providing advantages both in the winding process as wall as the electrical properties of the resulting electrode.
The slit needle then remains in the wound electrode, after the winding process. rrhis not only represents a lost-nucleus winding needle, but further provides a low-cost grounding compollent which exhibits simplicity as well as trouble~ree mounting.
To establish contact between the current collector of l:l.q~ SCAi'l,ER the present invention and the cell~s housing cover, a leaf spring Sl)llL .'~ ' ~ ,u 111Itr!~ Sr l'~ADt~V'llA VA ll~r~
lZ 51 ~ J --5--r~ol~lr~l ~2151 d~S VJ~-~31 1266 is mounted to the interior side of the housing cover, and pro-trudes downwardly at an angle which causes the leaf spring to rest against -the top of the collector, remaining in position under elastic tension in the assembled cell. Again, the use of a metal splint having an eye in its top side is preferred since the leaf spring can then be provided with a punched aperture having a dia-meter ~lich is smaller than the eye of the metal splint t SO that the aperture of the leaf spring can then rest on the eye of the splint collector such that the punched edge can develop a high specific contact pressure. As a result, even with the strongest shaking of the cell, this arrangement operates to dependably pre-vent a degradation of the resulting electrical contact.
The invention may be broadly summarized as a galvanic cell comprising a spiral-shaped electrode body which is formed from windings of band-~haped positive and negative electrodes with the imposition of a band-shaped separator, a current collector which serves as a winding mandrel and WhiC~I iS electrically con-:~ nected Wit~l a first of said electrodes, wherein said current col-lector is a metal needle having a slit clamped to portions of a carrier of said first electrode, a metal housing for receiving the spira1-shaped electrode body and which is electrically connected with a second one of said electrodes, a cover which seals the opening of the housing and which serves as a terminal post for the electrode which is electrically connected to the current collec-tor, and a contact for bridging the cover and the current collec-tor, wherein said contact takes the form of a leaf spring attached .
''''`'': ~, ' to interior portions of the cover and which rests upon the current collector under elastic tension.
According to another aspect, the invention is a process for producing the galvanic cell described in the immediately pre-ceding paragrap~l comprising the steps of: removing active materi-al from the carrier of said first electrode in a selected region;
placing the current collector into engagement with the selec-ted region of the carrier so that the slit of the metal needle engages the carrier; placing said second electrode over said first elec-trode so that front edge portions of the band-shaped abut the current collector; and rolling said first electrode across said second electrode to form said spiral-shaped electrode body.
For further detail reyarding the improvements oE the present invention, reference is made to the description which is provided below, taken in conjunction with the following illustra-tionsO
Brief Description of the Drawings Figure 1 is an isometric view showing components of an electrode produced with a splint collector according to the pre-sent invention, before winding.
Figure 2 i5 a cross-sectional view showing coiling of the electrode components around the metal splint, at the beginning of the winding procedure.
- 6a -.
Figure 3 is a cross-sectional view of a cell containing a fini~hed electrode winding.
~igure ~ diagrammatically illustrates an alternative winding procedure in accordance ~ith the present invention.
Figure 5 i5 a pArtially sectîoncd, isometric view o~ a galvanic element produced according to the present invention, with the end cap removed to show construction detail.
In the several views provided, like xeference numbers denote similar structure.
Detailed Description of Preferred Embodiments Figure 1 shows the basic components of a spiral-wound electrode structure for a galvanic cell in accordance with the present invention. The electrochemical system employed by the illustrated galvanic cell preferably takes the ~orm of a lithium system with a nonaqueous electrolyte. As cathode-active substances, heavy metal oxides and sulfides such as Ni(VH)2, CuO, CrOx, FeS2 or MnO2, can be used. The cathode paste is produced, for example, from ~nO2 combined with a bonding agent of PTFE
powder and graphite as a conducting medium. This is generally accomplished by means o~ a simple dry-mix process. The cathode band is produced by rolling the dry mixture into a metal net or expanded metal web, as a dry material in a continuous process.
Using this process, the paste material is easily remov~d ~rom the ` carrier at each of the intende~ splint contact points~ even :::
.
. ~
` ~
before it is cut into desired strip lengths. compressed air is suitably employed for this purpose.
This "dry" procedure avoids not only the disadvantayes associated with a wet chemical pas~e preparation, but has the further advantage of developing a greater porosity in the finished rolled electrode. This increased porosity permits the electrode to be loaded with at least a 50% increase in current density, as compared to an electrode produced by the wet process.
The result of this is that with a predetermined (equal) load, an lo electrode produced with a dry-mix process has a greater capacity, consumes less of the carrier material, can employ less separator material, and is associated with less lithium excess. The costs are corresporldinyly lowered.
The band-shaped lithium electrode 1 i5 basically produced in the same manner as other familiar wound cells, and is encased in a tube-shaped sheath of polyethylene or polypropylene ~not shown) with sealed edges. The carrier 2 of the band electrode 1 is exposed, preferably at the middle of the band, by removing the rolled positive paste 3 which then covers the carrier 2, so that the resulting band electrode 1 is comprised of a pair of cathode halves 4, 5. The metal splint 6 is then inserted over the exposed carrier section, establishing frictional contact with the engaged carrier 2. If desired, the splint 6 can be spot welded to the carrier 2 following this placement. Th~ electrode 1 is provided with a notch 7 so that the lower end of the splint 6 can be accessed with a cutting tool 131 ~266 to remove any portions of the splint 6 which may project beyond the winding to be produced, so as to avoid damage to the winding.
Referring now to Figure 2, the metal splint 6 serves primarily as a winding needle (mandrel). Before winding, the band electrode 1 is folded (together with its paste covering) in an inward direction across the intervening lithium electrode 8, which abuts the windiny needle 6 at the ~ront side edge of its separator casiny 9. To ensure a proper winding, the lenyth of ; the negative band electrode 8, or at least tllat of the separator sleeve 9, must be such that it exceeds the length of the positive electrode 1, when folded, at least by a length equal to the circumference of the finished windiny. This is also true when ; both of the electrodes l, a are rolled up from their ends. In such case, the positive electrode 1, for reasons o~ capacity expansion, must further have what amounts to about a doubled thickness (e.g., about twice an electrode held in the middle o~
the band by the current collector).
The end of the negative electrode 8 is provided with a contact element 10. As shown, this takes the form of a thin, small metal plate, having punched holes 11 which serve to develop pointed burrs 12 (evident in Figure 2) which can penetrate the lithium electrode, including the separator, when the contact element is compressed. During the subsequent positioning of these components in the housing vessel, the burr points 12 protruding from the lower side of the negative electrode 8 will furthPr oper~te to engage (claw) the wall of the cell housing and , _ g _ ,' provide the lithium electrode with a positive electrical connection with the housing wall.
rhe special advantages associated with the division of the cathode band into two band segments, and with the attachment of the splint collector at the middle of the band, come into play during the winding process (which is conventionally supported from beginning to end by a housing jig from which the finished winding can then be ejected and immediately transferred to the waitin~ cell housing). ~s i5 best shown in Figure 2, by dividing the cathode band into two relatively thin halves ~, 5, instead of an equally long but twice as thick electrode plate 1, a greater flexibility in the band is achieved so that both parts can displace each other, and their front ends, carrying with them the interposed lithium electrode ~ enclosed by the separator 9. Once wound, these components are then reliably held by the rolled up splint 6. Moreover, the three-tiered elsctrode arranyement of the resulting winding is gradually built up during the winding process, which facilitates a tighter winding radius and a better utilization of the space of the housing vessel. What is more, the danger of having the active paste peel off is reduced with a thinner cathode, or with a cathode that is wound from its middle.
A further advantage of a "double cathode" wound from the middle is that the cathode will then discharge through the intervening lithium electrode band from both sides of the layered winding, and not just on the power-shielded side.
Figure 3 provides a cross-sectional illustration of the 131 i266 wound cell of the present invention. Centrally located is the positive splint collector 6 (and the winding needle). Extending outw~rdly rro~ the center, in a spiral, are the partial cathode 4, the partial cathode ~, and the lithium elect~ode 8 (packed in the separator sleeve 9). The housing vessel 13 then operates to contain these various components, as previously described. Thus, the two partial cathodes 4, 5 are positioned with their carriers back to back, and with their "layer sides'l turned toward the lithium electrode. Figure 3 also clearly illustrates contact of the lithium electrode 8 with the vessel wall 13 using the contact 10, and the claws 12 of the contact 10 which are pressed thr~ugh the lithium band and the separator casing.
~ eferring now to Figure 4, it is also possible for the band electrode 1 to ba rolled up from its end using the splint col~ector 6 of the present invention. In such case it is advantageous to place the splint collector 6 somewhat inwardly from the end of the band, over the carrier as previously described, and to provide a free end on the separator casing 9 of the counter-electrode 8 (i.e., the Li electrode), the length of ; 20 which preferably corresponds approximately to the short band end of the electrode 1. ~he counter-electrode 8 is then placed on the ~and electrode 1, so that the free end of the separator casing 9 is positioned with its front edge lying along th winding needle 6, ~r abutting against it. The end of the separator is then overlapped by the short end section of the band ~ electrode 1 as it is pivoted 180, and finally clamped between these two parts of t~le band electrode 1. This ensures that the counter-electrode 8 is dependably retracted upon rotation of the needle 6, so that the electrodes are rolled up in trouble~free fashion, one over the other.
Such a winding process is schematically showrl in Figure 4 of the drawings. Figur~ 4a shows the cathode 1 engaged by the winding needle 6, and the lithium electrode 8 in its initial position. Figure 4b shows the winding needle 6 followi~g a completed half revolution rela-tive to Figure 4a. Figure 4c shows the electrode structure following a full revolution of the winding needle 6. Resulting from the displacement of the winding needle 6 from the end of the cathode band, and the peak-shaped form of the illustrated cathode band, trouble-free winding with a tight starting radius is made possible.
Referring now to Figure 5, covering of the cell is simply perPormed making use of a sleeve cowling. To facilitate this, either the interior rim 15 of the cap 14, or th~ exterior wall of the vessel's collar 16, is provided with a plastic coating so that the pressed cap (following electrolyte filling) seals the vessel with a solid force fitting. At the same time, a leaf spring 17 welded to the cap 14, and preferably the punched ; burrs of a hole 18 formed in the leaf spring 17, are brought to rest on the eye 19 of the splint collector 6. Even when placed under a high continuous voltage, this serves to ensure a positive electrical contact between the splint collector 6 and the metal cap 14, which then serves as the positive external pole for the .
~ -12-'~;
resulting cell.
It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrat~d in order to explain the nature of this invention may be made by those skilled in the art within the principle and scope of the invention a5 expressed in the following claims.
,.
, ~ .
~13-'
Backqround of the Invention The present invention relates generally to a yalvanic cell with a spiral-shaped electrode body, and more particularly, to an improved center pole conductor for such a cell, and its use S in facilitating the winding procedure.
Spiral-wound galvanic cells are generally produced from windings of band-shaped positive and negative electrodes, with the imposition of a band-shaped separator, toyether with an appropri~te current collector. A metal housing is provided to receive the spiral electrodes, one of which is electrically connected to the metal housing. The other electrode is electrically connected with a cover, which seals the opening of the housing and which serves as a terminal post for the associated electrode.
The conventional process for producing electrode windings of this general type makes use of a winding mandrel, usually a steel needle of about 5 to 7 mm in diameter, having a longitudinal slit which is used to engage the band electrodes.
In most instances, this mandrel is permanently attached to the winding machine. Consequently, in operation, a free space is generally left in the middl~ of the electrode winding after its production, following withdrawal of the mandrel of the winding machine.
This free space, under certain circumstances (e.g., impact stressing of the cell), can lead to a displacement of the windings along the longitudinal axis of the cell, or even a mutual displacement of the electrodes~ Attempts have been made to overcome this problem by using winding ~nandrels formed of plastic rods, whlch are designed to fill the free space in the electrode winding and provide a so-called l'lost nucleus" for permanently positioning the windings (forming the basis for a compact arrangement of the electrodes).
However, in any event, it remains necessary to provide the individual electrodes with separate current-conducting lugs, and to connect the lugs to their external cell poles (advantageously formed by the cell housing and cover). The production o~ such connections (which frequently must take the form of wire bridges) is rather difflcult. What is more, a considerahle transfer resistance can develop in the event of a faulty weld.
DE-C-2 438 296 discloses a somewhat more advantageous arrangement in which at least one electrode is connected to its respective terminal post by means of a terminal collector plate.
; 20 However, such measures are only effective when the electrodes (e.g., a sintered foil strip) are not edged with an active paste, which could come into contact with the plate on the front side of the winding. DE-A-3 412 890, as well as DE-C-3 014 435, disclose wound electrode structures in which a winding core, originally z5 used to produce the set of electrodes, also assumes the role of a terminal collec-tor pole, as a current collector for a first one :
of the electrodes, while the housing serves as the terminal collector for the second electrode. However, the second electrode must t~en form the external side of the winding so that it can rest against the inner wall of the houslng. DE~C-3 014 435 further discloses the placement of a coil C;pring onto the flange-like upper end of the cell's rod~like collector, which presses against the lower side of the metallic cell cover and accordingly establishes an electrical connection between the collector and its external pole. However, during assembly, this spring re~uires special attention, particularly in its positioning on the head of the collector, since there is a danger that the coil spring will fly loose as the result of unintentional squeezing by the tool which is used to manipulate it. Such measures have therefore not proved to be entirely satisfactory.
summary of the Invention It is therefore a primary object of the present invention to provide an improved current collector for a spiral-wound galvanic cell.
It is also an object of the present invention to provide a curren-t collector for a spiral-wowld galvanic cell which is simple in construction, and in its manner of use.
It is also an object of the present invention to provide a current collector for a spiral-wound galvanic cell , -3-~ ' .
which can simultaneously serve as a winding mandrel for producing the cell.
It is also an object of the present invention to provide a current collector for a spiral-wound galvanic cell which can provide a trouble-free electrical connection with the cell's housing cover, to serve as an external cell pole for the associated electrode.
It is also an object of the present invention to provide a spiral-wound galvanic cell having an improved current collector, and which is easy ko assemble.
These and other objects are achieved in accordance with the present invention by providing a current collector for one of the cell's electrodes, preferably the positive electrode, which takes the form of a slit metal needle for receiving the electrode, alony its carrier. The body of the needle is slit so that the electrode is permanently clamped to the current collector~ The top of the needle is closed so that the needle can be firmly grasped by the winding machine. The overall shape and/or thickness of the needle may be varied. However, the length of the slit preferably conforms to the width of the electrode ~and so that there is optimum contact of the carrier with the slit body of the needle, on both side~. In a particularly preferred embodiment o~ the present invention, the slit needle takes the form of a metal splint (much like a cotter pin) with a closed top end which extends into an eye. In such case, the two legs of the splint can be of a di~feren length, if _4_ '~ .
desired.
To establish electrical contact, it is simply sufficient to place the collector or metal splint onto exposed (freed of active material) portions of the carrier for the electrode, which generally takes the form of an expanded metal or fine mesh net of Ni, Ag, Ti, or nonoxidizing steel. An additional spot welding on either, or preferak~ly both sides of the metal splint, above the intervening carrier, is advantageous and therefore also preferred.
In a particularly preferred embodiment of the invention, the current collector is mounted about the midpoint of the carrier, rather than at one end, so that the electrode band which issues from the middle strip of the carrier (which is freed of active material to establish proper contact with the collector) is divided into two cathode segments of about equal length. ~s a result of this, the beginning of the winding for this electrode is developed at the middle of the band, providing advantages both in the winding process as wall as the electrical properties of the resulting electrode.
The slit needle then remains in the wound electrode, after the winding process. rrhis not only represents a lost-nucleus winding needle, but further provides a low-cost grounding compollent which exhibits simplicity as well as trouble~ree mounting.
To establish contact between the current collector of l:l.q~ SCAi'l,ER the present invention and the cell~s housing cover, a leaf spring Sl)llL .'~ ' ~ ,u 111Itr!~ Sr l'~ADt~V'llA VA ll~r~
lZ 51 ~ J --5--r~ol~lr~l ~2151 d~S VJ~-~31 1266 is mounted to the interior side of the housing cover, and pro-trudes downwardly at an angle which causes the leaf spring to rest against -the top of the collector, remaining in position under elastic tension in the assembled cell. Again, the use of a metal splint having an eye in its top side is preferred since the leaf spring can then be provided with a punched aperture having a dia-meter ~lich is smaller than the eye of the metal splint t SO that the aperture of the leaf spring can then rest on the eye of the splint collector such that the punched edge can develop a high specific contact pressure. As a result, even with the strongest shaking of the cell, this arrangement operates to dependably pre-vent a degradation of the resulting electrical contact.
The invention may be broadly summarized as a galvanic cell comprising a spiral-shaped electrode body which is formed from windings of band-~haped positive and negative electrodes with the imposition of a band-shaped separator, a current collector which serves as a winding mandrel and WhiC~I iS electrically con-:~ nected Wit~l a first of said electrodes, wherein said current col-lector is a metal needle having a slit clamped to portions of a carrier of said first electrode, a metal housing for receiving the spira1-shaped electrode body and which is electrically connected with a second one of said electrodes, a cover which seals the opening of the housing and which serves as a terminal post for the electrode which is electrically connected to the current collec-tor, and a contact for bridging the cover and the current collec-tor, wherein said contact takes the form of a leaf spring attached .
''''`'': ~, ' to interior portions of the cover and which rests upon the current collector under elastic tension.
According to another aspect, the invention is a process for producing the galvanic cell described in the immediately pre-ceding paragrap~l comprising the steps of: removing active materi-al from the carrier of said first electrode in a selected region;
placing the current collector into engagement with the selec-ted region of the carrier so that the slit of the metal needle engages the carrier; placing said second electrode over said first elec-trode so that front edge portions of the band-shaped abut the current collector; and rolling said first electrode across said second electrode to form said spiral-shaped electrode body.
For further detail reyarding the improvements oE the present invention, reference is made to the description which is provided below, taken in conjunction with the following illustra-tionsO
Brief Description of the Drawings Figure 1 is an isometric view showing components of an electrode produced with a splint collector according to the pre-sent invention, before winding.
Figure 2 i5 a cross-sectional view showing coiling of the electrode components around the metal splint, at the beginning of the winding procedure.
- 6a -.
Figure 3 is a cross-sectional view of a cell containing a fini~hed electrode winding.
~igure ~ diagrammatically illustrates an alternative winding procedure in accordance ~ith the present invention.
Figure 5 i5 a pArtially sectîoncd, isometric view o~ a galvanic element produced according to the present invention, with the end cap removed to show construction detail.
In the several views provided, like xeference numbers denote similar structure.
Detailed Description of Preferred Embodiments Figure 1 shows the basic components of a spiral-wound electrode structure for a galvanic cell in accordance with the present invention. The electrochemical system employed by the illustrated galvanic cell preferably takes the ~orm of a lithium system with a nonaqueous electrolyte. As cathode-active substances, heavy metal oxides and sulfides such as Ni(VH)2, CuO, CrOx, FeS2 or MnO2, can be used. The cathode paste is produced, for example, from ~nO2 combined with a bonding agent of PTFE
powder and graphite as a conducting medium. This is generally accomplished by means o~ a simple dry-mix process. The cathode band is produced by rolling the dry mixture into a metal net or expanded metal web, as a dry material in a continuous process.
Using this process, the paste material is easily remov~d ~rom the ` carrier at each of the intende~ splint contact points~ even :::
.
. ~
` ~
before it is cut into desired strip lengths. compressed air is suitably employed for this purpose.
This "dry" procedure avoids not only the disadvantayes associated with a wet chemical pas~e preparation, but has the further advantage of developing a greater porosity in the finished rolled electrode. This increased porosity permits the electrode to be loaded with at least a 50% increase in current density, as compared to an electrode produced by the wet process.
The result of this is that with a predetermined (equal) load, an lo electrode produced with a dry-mix process has a greater capacity, consumes less of the carrier material, can employ less separator material, and is associated with less lithium excess. The costs are corresporldinyly lowered.
The band-shaped lithium electrode 1 i5 basically produced in the same manner as other familiar wound cells, and is encased in a tube-shaped sheath of polyethylene or polypropylene ~not shown) with sealed edges. The carrier 2 of the band electrode 1 is exposed, preferably at the middle of the band, by removing the rolled positive paste 3 which then covers the carrier 2, so that the resulting band electrode 1 is comprised of a pair of cathode halves 4, 5. The metal splint 6 is then inserted over the exposed carrier section, establishing frictional contact with the engaged carrier 2. If desired, the splint 6 can be spot welded to the carrier 2 following this placement. Th~ electrode 1 is provided with a notch 7 so that the lower end of the splint 6 can be accessed with a cutting tool 131 ~266 to remove any portions of the splint 6 which may project beyond the winding to be produced, so as to avoid damage to the winding.
Referring now to Figure 2, the metal splint 6 serves primarily as a winding needle (mandrel). Before winding, the band electrode 1 is folded (together with its paste covering) in an inward direction across the intervening lithium electrode 8, which abuts the windiny needle 6 at the ~ront side edge of its separator casiny 9. To ensure a proper winding, the lenyth of ; the negative band electrode 8, or at least tllat of the separator sleeve 9, must be such that it exceeds the length of the positive electrode 1, when folded, at least by a length equal to the circumference of the finished windiny. This is also true when ; both of the electrodes l, a are rolled up from their ends. In such case, the positive electrode 1, for reasons o~ capacity expansion, must further have what amounts to about a doubled thickness (e.g., about twice an electrode held in the middle o~
the band by the current collector).
The end of the negative electrode 8 is provided with a contact element 10. As shown, this takes the form of a thin, small metal plate, having punched holes 11 which serve to develop pointed burrs 12 (evident in Figure 2) which can penetrate the lithium electrode, including the separator, when the contact element is compressed. During the subsequent positioning of these components in the housing vessel, the burr points 12 protruding from the lower side of the negative electrode 8 will furthPr oper~te to engage (claw) the wall of the cell housing and , _ g _ ,' provide the lithium electrode with a positive electrical connection with the housing wall.
rhe special advantages associated with the division of the cathode band into two band segments, and with the attachment of the splint collector at the middle of the band, come into play during the winding process (which is conventionally supported from beginning to end by a housing jig from which the finished winding can then be ejected and immediately transferred to the waitin~ cell housing). ~s i5 best shown in Figure 2, by dividing the cathode band into two relatively thin halves ~, 5, instead of an equally long but twice as thick electrode plate 1, a greater flexibility in the band is achieved so that both parts can displace each other, and their front ends, carrying with them the interposed lithium electrode ~ enclosed by the separator 9. Once wound, these components are then reliably held by the rolled up splint 6. Moreover, the three-tiered elsctrode arranyement of the resulting winding is gradually built up during the winding process, which facilitates a tighter winding radius and a better utilization of the space of the housing vessel. What is more, the danger of having the active paste peel off is reduced with a thinner cathode, or with a cathode that is wound from its middle.
A further advantage of a "double cathode" wound from the middle is that the cathode will then discharge through the intervening lithium electrode band from both sides of the layered winding, and not just on the power-shielded side.
Figure 3 provides a cross-sectional illustration of the 131 i266 wound cell of the present invention. Centrally located is the positive splint collector 6 (and the winding needle). Extending outw~rdly rro~ the center, in a spiral, are the partial cathode 4, the partial cathode ~, and the lithium elect~ode 8 (packed in the separator sleeve 9). The housing vessel 13 then operates to contain these various components, as previously described. Thus, the two partial cathodes 4, 5 are positioned with their carriers back to back, and with their "layer sides'l turned toward the lithium electrode. Figure 3 also clearly illustrates contact of the lithium electrode 8 with the vessel wall 13 using the contact 10, and the claws 12 of the contact 10 which are pressed thr~ugh the lithium band and the separator casing.
~ eferring now to Figure 4, it is also possible for the band electrode 1 to ba rolled up from its end using the splint col~ector 6 of the present invention. In such case it is advantageous to place the splint collector 6 somewhat inwardly from the end of the band, over the carrier as previously described, and to provide a free end on the separator casing 9 of the counter-electrode 8 (i.e., the Li electrode), the length of ; 20 which preferably corresponds approximately to the short band end of the electrode 1. ~he counter-electrode 8 is then placed on the ~and electrode 1, so that the free end of the separator casing 9 is positioned with its front edge lying along th winding needle 6, ~r abutting against it. The end of the separator is then overlapped by the short end section of the band ~ electrode 1 as it is pivoted 180, and finally clamped between these two parts of t~le band electrode 1. This ensures that the counter-electrode 8 is dependably retracted upon rotation of the needle 6, so that the electrodes are rolled up in trouble~free fashion, one over the other.
Such a winding process is schematically showrl in Figure 4 of the drawings. Figur~ 4a shows the cathode 1 engaged by the winding needle 6, and the lithium electrode 8 in its initial position. Figure 4b shows the winding needle 6 followi~g a completed half revolution rela-tive to Figure 4a. Figure 4c shows the electrode structure following a full revolution of the winding needle 6. Resulting from the displacement of the winding needle 6 from the end of the cathode band, and the peak-shaped form of the illustrated cathode band, trouble-free winding with a tight starting radius is made possible.
Referring now to Figure 5, covering of the cell is simply perPormed making use of a sleeve cowling. To facilitate this, either the interior rim 15 of the cap 14, or th~ exterior wall of the vessel's collar 16, is provided with a plastic coating so that the pressed cap (following electrolyte filling) seals the vessel with a solid force fitting. At the same time, a leaf spring 17 welded to the cap 14, and preferably the punched ; burrs of a hole 18 formed in the leaf spring 17, are brought to rest on the eye 19 of the splint collector 6. Even when placed under a high continuous voltage, this serves to ensure a positive electrical contact between the splint collector 6 and the metal cap 14, which then serves as the positive external pole for the .
~ -12-'~;
resulting cell.
It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrat~d in order to explain the nature of this invention may be made by those skilled in the art within the principle and scope of the invention a5 expressed in the following claims.
,.
, ~ .
~13-'
Claims (19)
1. A galvanic cell comprising a spiral-shaped electrode body which is formed from windings of band-shaped positive and negative electrodes with the imposition of a band-shaped separa-tor, a current collector which serves as a winding mandrel and which is electrically connected with a first of said electrodes, wherein said current collector is a metal needle having a slit clamped to portions of a carrier of said first electrode, a metal housing for receiving the spiral-shaped electrode body and which is electrically connected with a second one of said electrodes, a cover which seals the opening of the housing and which serves as a terminal post for the electrode which is electrically connected to the current collector, and a contact for bridging the cover and the current collector, wherein said contact takes the form of a leaf spring attached to interior portions of the cover and which rests upon the current collector under elastic tension.
2. The galvanic cell of claim 1 wherein the current collec-tor is a metal splint having a closed top end which is shaped into an eye.
3. The galvanic cell of claim 2 wherein the leaf spring includes an aperture having a diameter which is smaller than the eye of the metal splint, so that the aperture of the leaf spring rests against the eye of the metal splint under high specific contact pressure.
4. The galvanic cell of claim 1 wherein the leaf spring includes means for positioning the current collector within said galvanic cell.
5. The galvanic cell of claim 4 wherein said positioning means is an aperture formed in the leaf spring for engaging end portions of the current collector.
6. A galvanic cell comprising a spiral-shaped electrode body which is formed from windings of band-shaped positive and negative electrodes with the imposition of a band-shaped separa-tor, a current collector which serves as a winding mandrel and which is electrically connected with a first of said electrodes, wherein said current collector is a metal needle having a slit clamped to portions of a carrier of said first electrode, a metal housing for receiving the spiral-shaped electrode body and which is electrically connected with a second one of said electrodes, a cover which seals the opening of the housing and which serves as a terminal post for the electrode which is electrically connected to the current collector, and a flexible contact for bridging the cover and the current collector having means for positioning the current collector within the galvanic cell, wherein said contact takes the form of a leaf spring attached to interior portions of the cover and which rests upon the current collector under elastic tension.
7. The galvanic cell of claim 6 wherein the current collec-tor is a metal splint having a closed top end which is shaped into an eye.
8. The galvanic cell of claim 7 wherein the positioning means is an aperture formed in the leaf spring and having 2 dia-meter which is smaller than the eye of the metal splint, so that the aperture of the leaf spring rests against the eye of the metal splint under high specific contact pressure.
9. A process for producing the galvanic cell of claim 1, comprising the steps of:
removing active material from the carrier of said first electrode in a selected region;
placing the current collector into engagement with the selected region of the carrier so that the slit of the metal needle engages the carrier;
placing said second electrode over said first electrode so that front edge portions of the band-shaped separator abut the current collector; and rolling said first electrode across said second elec-trode to form said spiral-shaped electrode body.
removing active material from the carrier of said first electrode in a selected region;
placing the current collector into engagement with the selected region of the carrier so that the slit of the metal needle engages the carrier;
placing said second electrode over said first electrode so that front edge portions of the band-shaped separator abut the current collector; and rolling said first electrode across said second elec-trode to form said spiral-shaped electrode body.
10. The process of claim 9 which further comprises the step of spot welding the current collector to the carrier.
11. The process of claim 10 wherein said current collector is spot-welded to the carrier above the intervening slit.
12. The process of claim 9 wherein said region is located at the midpoint of said first electrode.
13. The process of claim 12 wherein said second electrode has a length which exceeds the length of said first electrode by the circumference of the finished electrode body.
14. The process of claim 9 wherein said region is located on said first electrode at a position which is slightly displaced from an end thereof.
15. The process of claim 14 which further comprises the steps of:
providing a free end on the separator of said second electrode;
placing said second electrode so that the free end of the separator abuts the current collector;
turning said first electrode, with the free separator end, so that in a first half-rotation of the current collector, the separator end is clamped between said first electrode and an end segment separated from said first electrode by said region;
and further turning said current collector so that said second electrode is drawn along with the separator end, and so that said first electrode is rolled across said second electrode.
providing a free end on the separator of said second electrode;
placing said second electrode so that the free end of the separator abuts the current collector;
turning said first electrode, with the free separator end, so that in a first half-rotation of the current collector, the separator end is clamped between said first electrode and an end segment separated from said first electrode by said region;
and further turning said current collector so that said second electrode is drawn along with the separator end, and so that said first electrode is rolled across said second electrode.
16. The process of claim 9 wherein said first electrode is a positive electrode.
17. The process of claim 16 wherein said positive electrode has an active material comprising MnO2.
18. The process of claim 16 wherein said second electrode is a negative lithium electrode.
19. The process of claim 18 wherein an electrical connection is developed between the lithium electrode and the cell housing by a contact plate having structure-engaging projections.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3902648A DE3902648A1 (en) | 1989-01-30 | 1989-01-30 | GALVANIC ELEMENT |
| DEP3902648.5 | 1989-01-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1311266C true CA1311266C (en) | 1992-12-08 |
Family
ID=6373051
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000614199A Expired - Fee Related CA1311266C (en) | 1989-01-30 | 1989-09-28 | Spiral-wound galvanic cell |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US5021306A (en) |
| EP (1) | EP0380803B1 (en) |
| JP (1) | JPH02234346A (en) |
| CA (1) | CA1311266C (en) |
| DE (2) | DE3902648A1 (en) |
| ES (1) | ES2042956T3 (en) |
| HK (1) | HK1894A (en) |
| MX (1) | MX173987B (en) |
Families Citing this family (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100207254B1 (en) * | 1995-07-28 | 1999-07-15 | 전주범 | Electrode plate of winding assembly for lithium battery |
| US5655797A (en) * | 1995-12-21 | 1997-08-12 | Edstrom Industries, Inc. | Sanitary fitting |
| US6020084A (en) * | 1998-02-17 | 2000-02-01 | Alcatel | Electrochemical cell design with a hollow core |
| EP1033768B1 (en) | 1999-03-04 | 2002-09-18 | Wilson Greatbatch Ltd. | Wound cell stack design for enhanced battery performance |
| JP4423699B2 (en) * | 1999-05-27 | 2010-03-03 | ソニー株式会社 | Semiconductor laser device and manufacturing method thereof |
| US6245457B1 (en) | 1999-06-11 | 2001-06-12 | Alcatel | Bussing structure in an electrochemical cell |
| JP3951526B2 (en) * | 1999-11-26 | 2007-08-01 | 松下電器産業株式会社 | Cylindrical storage battery |
| US7467089B2 (en) * | 2001-09-05 | 2008-12-16 | Roth Daniel L | Combined speech and handwriting recognition |
| US7809574B2 (en) * | 2001-09-05 | 2010-10-05 | Voice Signal Technologies Inc. | Word recognition using choice lists |
| US7505911B2 (en) * | 2001-09-05 | 2009-03-17 | Roth Daniel L | Combined speech recognition and sound recording |
| US7526431B2 (en) * | 2001-09-05 | 2009-04-28 | Voice Signal Technologies, Inc. | Speech recognition using ambiguous or phone key spelling and/or filtering |
| US7444286B2 (en) * | 2001-09-05 | 2008-10-28 | Roth Daniel L | Speech recognition using re-utterance recognition |
| DE10159231A1 (en) * | 2001-12-03 | 2003-06-18 | Nbt Gmbh | Galvanic element with winding electrode set |
| US6670071B2 (en) * | 2002-01-15 | 2003-12-30 | Quallion Llc | Electric storage battery construction and method of manufacture |
| US6677076B2 (en) * | 2002-01-15 | 2004-01-13 | Quallion Llc | Electric storage battery construction and method of manufacture |
| US20060035147A1 (en) * | 2003-01-15 | 2006-02-16 | Quallion Llc | Battery |
| US8080329B1 (en) | 2004-03-25 | 2011-12-20 | Quallion Llc | Uniformly wound battery |
| US20090081532A1 (en) * | 2007-09-21 | 2009-03-26 | David Aaron Kaplin | Electrochemical cell with improved internal contact |
| US7618742B2 (en) * | 2005-01-28 | 2009-11-17 | Eveready Battery Co., Inc. | Electrochemical cell with improved internal contact |
| JP5011732B2 (en) * | 2006-01-20 | 2012-08-29 | ソニー株式会社 | battery |
| US20070235716A1 (en) * | 2006-03-22 | 2007-10-11 | Emir Delic | Electrode |
| US20080026293A1 (en) * | 2006-07-26 | 2008-01-31 | Eveready Battery Company, Inc. | Lithium-iron disulfide cylindrical cell with modified positive electrode |
| US20080026288A1 (en) * | 2006-07-26 | 2008-01-31 | Eveready Battery Company, Inc. | Electrochemical cell with positive container |
| US20100273036A1 (en) * | 2006-10-17 | 2010-10-28 | Eveready Battery Company, Inc. | Lithium-Iron Disulfide Cell Design with Core Reinforcement |
| WO2008109699A2 (en) * | 2007-03-06 | 2008-09-12 | Emotiv Systems Pty Ltd | Electrode headset |
| US7960201B2 (en) * | 2009-01-29 | 2011-06-14 | Emcore Solar Power, Inc. | String interconnection and fabrication of inverted metamorphic multijunction solar cells |
| EP2489087B1 (en) * | 2009-10-14 | 2016-08-24 | Energizer Brands, LLC | Lithium-iron disulfide cell design |
| DE102011004932A1 (en) * | 2011-03-01 | 2012-09-06 | Varta Microbattery Gmbh | Spirally wound electrode, galvanic element and manufacture thereof |
| CN103531746B (en) * | 2013-09-24 | 2016-01-06 | 北京鼎能开源电池科技股份有限公司 | A kind of clear powder method of electrodes of lithium-ion batteries |
| CN109037720B (en) * | 2018-06-28 | 2020-07-28 | 大族激光科技产业集团股份有限公司 | Winding needle device of winding machine |
| US11862983B1 (en) | 2019-03-28 | 2024-01-02 | Roger W. Graham | Earth energy systems and devices |
| CN110987959A (en) * | 2019-12-16 | 2020-04-10 | 广州量子激光智能装备有限公司 | Online burr detection method |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT123428B (en) * | 1927-05-30 | 1931-06-25 | Austro Daimler Puchwerke Ag | Suspension for motor vehicles with swinging half axles. |
| US3202549A (en) * | 1961-05-01 | 1965-08-24 | Union Carbide Corp | Leak-resistant dry cells |
| SE351945B (en) * | 1971-03-16 | 1972-12-11 | Svenska Ackumulator Ab | |
| BE791609A (en) * | 1971-11-26 | 1973-05-21 | Accumulateurs Fixes | CYLINDRICAL ELECTRIC BATTERY |
| US3775182A (en) * | 1972-02-25 | 1973-11-27 | Du Pont | Tubular electrochemical cell with coiled electrodes and compressed central spindle |
| FR2328296A1 (en) * | 1975-10-17 | 1977-05-13 | Accumulateurs Fixes | Axially strong cylindrical electrochemical cell - has electrode edges as supports preventing container collapsing under axial compression |
| US4091181A (en) * | 1977-09-01 | 1978-05-23 | Union Carbide Corporation | Rechargeable galvanic cell |
| JPS5834694Y2 (en) * | 1979-04-16 | 1983-08-04 | 三洋電機株式会社 | battery |
| JPS5830073A (en) * | 1981-08-18 | 1983-02-22 | Matsushita Electric Ind Co Ltd | Manufacture of battery |
| JPS5866270A (en) * | 1981-10-15 | 1983-04-20 | Matsushita Electric Ind Co Ltd | Manufacturing method for spiral electrode body |
| JPS6023964A (en) * | 1983-07-15 | 1985-02-06 | Hitachi Maxell Ltd | Manufacture of spiral electrode |
| JPS62147661A (en) * | 1985-12-23 | 1987-07-01 | Sanyo Electric Co Ltd | Manufacture of spiral electrode |
| JPS6345758A (en) * | 1986-08-13 | 1988-02-26 | Toshiba Battery Co Ltd | Cylindrical nonaqueous electrolyte battery |
| JPS63164170A (en) * | 1986-12-26 | 1988-07-07 | Toshiba Battery Co Ltd | Manufacture of cylindrical nonaqueous electrolyte cell |
-
1989
- 1989-01-30 DE DE3902648A patent/DE3902648A1/en not_active Withdrawn
- 1989-09-28 CA CA000614199A patent/CA1311266C/en not_active Expired - Fee Related
- 1989-11-15 US US07/436,650 patent/US5021306A/en not_active Expired - Fee Related
- 1989-12-20 ES ES89123516T patent/ES2042956T3/en not_active Expired - Lifetime
- 1989-12-20 DE DE8989123516T patent/DE58904976D1/en not_active Expired - Fee Related
- 1989-12-20 EP EP89123516A patent/EP0380803B1/en not_active Expired - Lifetime
-
1990
- 1990-01-16 MX MX019145A patent/MX173987B/en unknown
- 1990-01-30 JP JP2018116A patent/JPH02234346A/en active Pending
-
1994
- 1994-01-06 HK HK18/94A patent/HK1894A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| ES2042956T3 (en) | 1993-12-16 |
| US5021306A (en) | 1991-06-04 |
| HK1894A (en) | 1994-01-14 |
| EP0380803A2 (en) | 1990-08-08 |
| EP0380803A3 (en) | 1991-07-17 |
| MX173987B (en) | 1994-04-13 |
| DE58904976D1 (en) | 1993-08-26 |
| JPH02234346A (en) | 1990-09-17 |
| DE3902648A1 (en) | 1990-08-09 |
| EP0380803B1 (en) | 1993-07-21 |
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