US1978624A - Primary cell - Google Patents

Description

Oct. 30, 1934. H. coLLosEus PRIMARY CELL Filed July 14. 1932 lll lfm garbo ef Hepa/awfzerf mmorgfr'um Patented Oct. 30, 1934 UNITED STATES PRIMARY CELL Heinrich Colloseus, Berlin, Germany Application July 14, 1932, Serial No. 622.484

In Germany 3Claim8.

Galvanic dry-cells of the Leclanch type are generally provided with an electrolyte of ammonium chloride which not only iills the intermediate space between the zinc anode and the 5 depolarizing material but also impregnat'es the depolarizing material, an addition oi solid ammonium chloride being sometimes made to the depolarizing material. 'I'hese cells possess a good electrical capacity, but their capacity for being stored is restricted, this being due to the reet that the zinc is attacked by the ammonium chloride solution even when the cell is at rest. It has also been proposed to use solutions oi magnesium chloride or manganous chloride or a mixture thereof as the electrolyte, the said salts serving, to the exclusion oi ammonium chloride, both for impregnating the depolarizing material and for iilling the intermediate space between the latterand the zinc vessel-like anode. Such cells have a good capacity for being stored on account of the zinc being less rapidly attacked by the said salts. On the other hand they exhibit a somewhat lower electrical capacity, which is chiefly to be ascribed to the precipitation of hydroxides of magnesium or manganese on orin the depolarizing material during discharge.

The present invention has for its object to pro- -vide a cell of the Leclanch type which possesses a good capacity for being stored and a large initial electrical capacity. This is achieved by using concentrated magnesium chloride solution, with or without an addition of manganous chloride solution, as the electrolyte between the zinc and the depolarizing material, and by adding ammonium chloride in solid or dissolved form to the depolarizing material. p

The manner in which the invention may be applied is illustrated in the accompanying drawing, in which Figure 1 is a vertical sectional view of one form of cell constructed in accordance with the principles of the invention; and

Figure 2 is a similar view illustrating a modied type ot cell.

In the form o! the invention shown iii Figure 1, a suitable container 10 ot vitreous or other inert y material constitutes a support for the carbon electrode 11, this electrode including a depolarizer and ammonium chloride. The container is partly filled with a solution oi concentrated magnesium chloride and is closed by a centrally disposed cap l2 iltting within the carbon electrode and Bupporting a zinc electrode 13.

In the arrangement shown in Figure 2, the outer container 16 is formed of4 zinc .to constitute one o! the electrodes, the construction being otherwise generally similar to that shown in Figure 1.

It has proved that cells so constituted have not ce only a very good initial electrical capacity but also August 8, 1931 (Cl. 13B-103) good powers of sustaining storage and of recovery. The danger of the formation of complex zinc compounds which immediately set the cell out oi action is largely avoided, as experience has shown, because diilusion of the sal ammoniac from the depolarizing material into the electrolyte takes place very slowly only and during use oi the cell only. 'Ihis phenomenon is due to the tact that -sal ammoniac is practically completely insoluble in concentrated magnesium chloride solution, so that there is no tendency at all for the sal ammoniac to pass in substantial quantities from the depolarizing material into the external electrolyte. In this manner it is possible to combine the advantage of the sal ammoniac cell in respect oi large initial electrical capacity with the considerable powers of sustaining storage and of. recovery of cells whereof the external electrolyte consists essentially o! concentrated magnesium chloride solution.

On the other hand, 'as compared with cells not 4 containing sal ammoniac, the advantage is also achieved that precipitation ot hydroxides oi the metals dissolved as salts in the electrolyte cannotoccur during the operation of the cell in the presence ot the sal ammoniac.

Experiments have shown that the electrical capacity of such cells on continuous discharge is considerably increased, as compared with otherwise equal magnesium chloride cells not containing sal ammoniac, without the capacity for sustaining storage being materially impaired.

I claimz- El. Primary cell ofthe Leclanche type, comprising electrodes, an electrolyte consisting oi a concentrated solution ot magnesium chloride, and a depolariaing material containing ammonium chloride.

y 2. Primary cell oi the Leclanch type, comprising electrodes, an electrolyte consisting of a concentrated solution o! magnesium chloride with an, addition of manganous chloride solution, and a'. depolarlzing material containing ammonium chloride.

3. Primary dry-cell of the Leclanch-tyiiefcom- "A prising electrodes including a zinc anode in the form oi' a vessel, a depolarising material containing an addition of ammonium chloride and an external electrolyte free from ammonium chloride and consisting of a concentrated solution of magnesium chloride.

. HEINRICH COILOSEUB.

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