US267319A - Aeon bernstein - Google Patents

Description

(No Model.)

A. BERIL\ISTEI1\I.v GALVANI'C BATTERY-V NO. 267,319. Patented Nov. 14, 188g N, PETERS. mwumogmpner. wnhmgrm uAc.

NrTn STATES PATENT FFICE GA LVAN C BATTERY.

SFECIFICATION forming part of Letters Patent No. 267,319, dated November 14, 1882. Application filed September 27, 188i (No model.)

To all whom it may concern Be it known that I, ARoN BERNsTn1N.doc tor of philosophy, residing in Berlin, Kingdom ofPrussia, German Empire, have invented new and useful Improvementsin GalvanicElements, of which the following is aspecification.

My invention relates togalvanic elements the positive electrode whereof consists of an amalgam of an alkali metal; and its object is to render such elements more eflcient and to protect the said metal against the oxidizing inliuence of the air.

It is known that by the employment of an amalgamated alkali metal-for instance, potassium or sodiumas electrode a galvanic element ot' considerable energy may be produced. Nevertheless elements of this kind have hitherto not found any practical use, as, on one hand, the amalgam speedily oxidizes, while on the other hand certain arrangements introduced in order to obviate this inconvenience give rise to an excessive internal resistance. Such elements, may, however, be rendered tit for practical purposes in the following manner: The sodium or potassium amalgam, to which a conducting-wire of copper or other suitable metal is attached, is brought into asmall bag or an envelope, consisting of any cloth which is not affected by the exciting-fluid to be employed. As such cloth may be used linen, cotton, or other sufliciently-close fabrics made of vegetable bers. The bag or envelope is drawn tightly together around the conducting-wire by a string, and it is by preference at this point coated with stearine, paraftine, rosin, or other similar substance, in order to prevent its upper end from being soaked by liquid. Finally, the envelope is impregnated with a solution of caustic soda or potash containing in one hundred parts from thirty to t'ty parts, by weight, of the alkali, whereupon it is dried. The fabric thereby becomes so close that it will efficiently protect the amalgam against oxidation by the atmospheric air, (which is specially of importance while the element is not in use,) whereas, on the other hand, it ,presents but slight resistance to the galvanic current.

The plate of amalgam thus prepared and enveloped, and which forms the positive electrode ofthe element., is brought in close contact with the negative electrode and immersed with the same in the exciting-liquid. 'In case copper is used as negative electrode, the liquid to be employed may consist,as in Daniells battery, of a concentrated solution of sulphate of copper, to which crystals of the same salt are added, in order to keep np its full degree of concentration.

If it be desired to use a carbon plate, the saine is rst moistened with diluted nitric acid, and thereupon plunged, together with the enveloped plate of amalgam, into a weak solution of caustic soda. Various other materials, may, however, be applied as negative electrode, and

other solutions as exciting-liquids, provided that the latter do not affect the envelope of the amalgam plate.

In respect to the form of the element, the horizontal arrangement of the electrodes has proved to be very advantageous. Supposing, for instance, a carbon plate or a plate of copper having small feet be laid, with the enveloped amalgam plate on top thereof', into a ilat vessel of glass or guttaperca, Src., and the latter then be so far filled with liquid that only the lower surface of the amalgam becomes wet, an element is obtained which is of but small bulk in comparison with its efficiency,and,be sides, the close contact between the electrodes and the envelope or diaphragm which is required for the purpose of reducing as much as possible the internal resistance ofthe element is thus attained in the simplest manner. In order to facilitate the access of the liquid to the surfaces in contact with each other, it is advantageous to drill several holes into the copper plate. Such an arrangement is shown insection in the accompanying drawings, in which A represents the jar or vessel; B, the negative plate; C, the positive plate; a, the bag, inclosing plate C; b, the exciting-liquid, and c c the conductors. The combination of two or more such elements to a battery does not require any explanation, as the same is carried out in the usual manner.

I claim as my inventionl. In a galvanic element, a positive electrode consisting of the amalgam of an alkali metal, in combination with an envelope serv- ICO ing as diaphragm and made of :L fabric not infected by the exciting-liquid-such as a, fabric of vegetable fibersand which is impregnated with zi caustic alkaline solution, sub- 5 stnntinlly as and for the purpose described.

2. A galvanic element composed of a Het negative electrode, and a positive electrode consisting of a plate of amfilgemated alkali metal and inclosed in :in envelope having the 1o nature and prepared as described, both electrodes being placed horizontally and so as to be both in contact with the said envelope, substantially as specified.

In testimony WhereofI havesigned my name to this specification inthe presence of nwo sub- 15 seribing witnesses.

ARON BERNSTEIN.

Witnesses:

HENRY SPRINGMANN, B. ROI.

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