GB331540A - Improvements in the manufacture and production of electrodes for secondary cells, in particular for those which have alkaline electrolytes - Google Patents

Abstract

331,540. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Jan. 4, 1929. Electrodes; connections. - Electrodes for storage batteries consist of supports of porous iron, nickel cobalt, cadmium or ferroso-ferric oxide, the pores of which are filled with active material. The supports may be prepared by the process described in Specification 311.141 in which the metal or metal oxide powders are subjected to pressure and heat while being moulded. The powders are prepa.red by heating metal carbonyls. Plates of ferroso-ferric oxide may be prepared as described in Specification 324,028. The active material may be introduced into the porous metal support by impregnating the latter with solutions of metal salts or compounds such as nitrates and heating. Hydroxides may be introduced by precipitation by means of alkaline solutions or by the alkaline electrolyte itself. By-products may be washed out or removed by electrochemical methods. Nickel or nickel oxides may be introduced into the pores of ferroso-ferric oxide plates by incorporating the former into the latter during manufacture of the plates. In order to prevent the supports from being attacked by the electrolyte the walls of the pores of the supports may be coated with a layer of resistant metal such as nickel or cobalt before the introduction of. the active material. This may be done electrolytically or by impregnating the supports with a solution of a salt of the metal and heating. Connection to the supports may be made by means of wires, bands or rods of iron or nickel welded to the supports by sintering, or grooved frames pressed on to the supports may be used for making connection. Alternatively terminals may be used consisting of the same material as the supports in a more highly sintered and compact form.