GB646800A - Alkaline primary cells - Google Patents

Abstract

646,800. Batteries. RUBEN, S. July 31, 1947, Nos. 20755, 20756 and 20757. Convention dates, May 21, 1946, June 5, 1946, and July 11, 1946. [Class 53] A primary cell having an immobilized alkaline electrolyte, a zinc anode of large area and a cathode surrounded by depolarizer has a negative terminal formed by a part of the container which is formed of a metal insoluble in the electrolyte. Fig. 1 shows a cell having a steel container 10 enclosing a depolarizer 11 covered by a porous layer 12 above which is a rolled corrugated zinc anode 13 interwound with porous paper. The cell is closed by a metal disc 15 which makes contact with the anode 13 and forms the negative terminal. Disc 15 is separated from container 10 by an insulating washer 16. The disc 15 may be of copper which may be amalgamated, or silverplated copper, of of an alloy of copper with cadmium or zinc. The electrolyte consists of a solution of potassium hydroxide containing zinc oxide in solution and the depolarizer may consist of a mixture of mercuric oxide with graphite. The anode roll 13 is impregnated with electrolyte and amalgamated by placing mercury on top of the roll while standing on a suction-plate. The layer 12 may consist of parchment paper, an organic film of nylon, plasticized polyvinyl chloride, fibrous sheet such as asbestos or a pressed disc of powdered glass, magnesium silicate or hydroxide or ceramic material. Figs. 3 and 4 show in sectional plan and elevation a cell in which the zinc anode 21 is in the form of a corrugated and perforated sheet bent into a cylinder which makes contact with the inner surface of the container 20 which forms the negative terminal. The container 20 is of copper or a copper alloy and may be plated with silver or amalgamated with mercury. Copper alloys that may be used are those with cadmium, magnesium or zinc. The container may also be made of magnesium or amalgamated cadmium. The cathode consists of a steel rod 24 surrounded by a mixture of mercuric oxide and graphite 23 and is provided with a mica &c. washer 26, 27 at each end. The electrolyte 22 consists of a solution of potassium hydroxide containing zincate and converted into a jelly by sodium carboxy-methylcellulose. Fig. 5 shows a further modification in which the negative terminal comprises a cup 40 of magnesium or silverplated copper containing amalgamated zinc pellets or zinc shot 42 upon which is a slab of jelly electrolyte 43. The positive terminal consists of an iron or steel cup 46 enclosing a compressed depolarizer 49 such as a mixture of mercuric oxide and graphite. Cups 40, 46 are separated by an insulating washer and ring 44, 45. Instead of the jelly electrolyte 43, a porous layer of paper &c. impregnated with jelly or liquid electrolyte may be used. Specifications 596,224, 596,225, 610,719 and 646,799 are referred to.