GB190703711A - Method of Producing Electroactive Cement-like Substances of Iron and Nickel Hydrates for Forming Electrodes, and Accumulators Constructed with such Electrodes. - Google Patents

Abstract

3711. Jungner, E. W. Feb. 15, 1906, [date applied for under Patents Act, 1901]. Secondary batteries.-Relates to the production of active cement-like hydrates of nickel and iron for accumulator electrodes. In examples, pulverized iron or nickel is mixed with a small amount of sulphur, the mixture is made into a paste with an electrolyte, for example ammonium chloride or sulpburic acid solution, the paste is moulded into bricks and these are exposed to the air ; nitric acid or other oxidizing-agent may be added to the electrolyte used. The surface of the iron particles may be coated with another metal such as mercury, copper, nickel, or bismuth, copper amalgam being preferred. Thus, iron particles are immersed in an acid solution of copper sulphate and mercury sulphate, and after coating are washed by decantation and then washed with alcohol, or are dried in vacuo to prevent oxidation ; or the powdered metals may be added to the cement paste. In another example, amalgamated iron powder is mixed with sulphur, and the mixture is made into a paste with alcohol and pressed between perforated iron plates, which are folded or bent together at the edges. After evaporation of the alcohol, the electrode is immersed in a solution of ammonium chloride and sulphuric acid ; it is then embedded in moist sawdust and allowed to rust. In another example, a layer of paste consisting of iron powder mixed with sulphur and a solution of ammonium chloride and sulphuric acid, is spread on an iron wire net or perforated plate, and the electrode is pressed and allowed to rust in moist sawdust. It is advantageous to immerse the electrode in a solution of some binding - agent which is not attached by alkali, for instance solutions of rubber in carbon disulphide, or collodion in ether, or viscose or shellac solution, &c. After evaporation of the solvent, the electrode is made the cathode in an alkaline bath, and when gases have begun to develop, the electrode is removed and pressed ; copper, nickel, &c. carriers may be substituted for iron carriers. Nickel electrodes may be made similarly and treated by anode-electrolysis. The surface of the carrier may be previously oxidized, say, by electrolysis. Plates thus prepared are used in alkaline accumulators with separating-partitions of a porous material, such as asbestos or artificial silk.