MATERIAL FOR ALKALINE SECONDARY BATTERY NEGATIVE ELECTRODE BY COBALT/TUNGSTEN ALLOY PLATING AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To improve discharge characteristics and reduce the weight and size of a negative electrode itself by forming a cobalt/tungsten alloy plating layer including a specific rate of tungsten on surfaces of a material. SOLUTION: A cobalt/tungsten alloy plating layer including tungsten of, preferably 4.2 to 26 wt.%, and more preferably, 16 to 25 wt.%, is formed on surfaces of a material when it starts to be used as a negative electrode of a secondary battery. As a method therefor, a tungsten compound, such as tungstic acid and sodium tungstate, is added to and dissolved in an acidic cobalt plating bath or an alkaline cobalt plating bath, then a specified metallic material is electroplated therein, thus the alloy plating layer is formed thereon. As the material, a metal, conductive fiber, or a conductive plastic is used, and as the metal suitable, high-purity iron, high-purity nickel, or the like, including no constituents which hinder battery performance, is used.