Improvement in primary cells

596,224. Batteries. MALLORY & CO., Inc., P. R. Aug. 30, 1944, No. 16523. Convention date, Dec. 10, 1943. [Class 53] One terminal of a dry cell consists of the metal container 17 with which one electrode is in contact, the other terminal consisting of an insulated metal closing member 18 in direct contact with the other electrode. In the construction shown in Fig. 3, the electrode in contact with the container 17, which is made of iron or steel, consists of a compressed layer 16 of graphite and mercuric oxide or cupric oxide, the bottom and lower parts of the inside wall of the container being painted with a graphite suspension to improve the contact. The electrode 10 in contact with the closing member 18 consists of a strip of corrugated zinc wound into a spiral with a strip of paper and enclosed in a sleeve 12 of polystyrene or other material The zinc strip projects beyond the paper strip at the upper end and the paper extends below the zinc at the lower end 11. The electrolyte is a solution of potassium hydroxide and is absorbed in the paper with which the zinc strip is rolled. Absorption of the electrolyte is carried out before the electrode is placed in the cell by standing it in a bath of electrolyte, the zinc being amalgamated at the same time by placing a quantity of mercury on the top of the roll. The top of the cell consists of an amalgamated zinc disc 18 fitted into a neoprene ring 20 which is held in position by the turned-over edge 21 of the container. A wire 23 is soldered to the disc 18. A porous ceramic disc may be placed between the depolarizer 16 and the lower end 11 of the paper separator. In a modification both electrodes are rolled into a spiral with an intervening insulating sheet. One electrode is of zinc the other consisting of a strip of plain steel or a steel mesh strip pasted with a depolarizing composition of mercuric oxide and graphite mixed with a binder. The pasted strip is baked and pressed between rollers. The rolled electrodes and separator are impregnated with electrolyte and placed in a steel container, the steel electrode extending below the zinc and separating sheet and making contact with the bottom of the container. The zinc projects at the top and makes contact with the closing disc as described in connection with Fig. 3. In another construction the zinc electrode is made by spraying zinc or zinc amalgam on to a strip of paper, cloth or regenerated cellulose. Specifications 579,849 and 596,225 are referred to.