GB529394A - Improvements in air-depolarised primary cells - Google Patents

Abstract

529,394. Batteries. GORDON, C. J. May 17, 1939, No. 14716. [Class 53] In an air-depolarized cell having electrodes of gas carbon and magnesium, the carbon surface facing the negative electrode is treated by removing its skin so as to expose the pores, and forcing into the pores a carbon substance of higher conductivity than gas carbon. In the cell described, a number of parallel connected magnesium rods 1 is arranged around a perforated tube 10, of paper or cardboard, inside a carbon cylinder 3, the intervening spaces being filled with wood wool 2 and the lower part of the cell being closed by a waxed cardboard bottom 8. The magnesium rods are connected to a terminal 5 and a clamping ring 4 serves as terminal for the carbon electrode. Before assembly, the inner surface of the carbon is scraped to remove the hard face and to expose the pores. Acetylene soot or oil carbon is then sprinkled on the inner surface and pressure is applied by means of a roller until the whole surface is covered with the soot well worked into the pores. A few crystals of potassium bromide are placed at the bottom of the cell and when the cell is required for use water is added which is rendered conductive by the potassium bromide and is absorbed by the wood wool. in contact with the electrodes. During use of the cell the increased volume required by the production of magnesium dioxide is accommodated by the crushing of the central cardboard tube. The magnesium ,rods may be made of an alloy containing aluminium and manganese. Specifications 423,301, 423,353, 423,738, 437,821, 441,894, 443,983 are referred to.