PURPOSE: To maintain high capacity density and increase charge-discharge cycle life by adding cadmium hydroxide so that a weight ratio of it to nickel hydroxide is 2∼15% to an active mass in a sponge-like metal positive electrode.
CONSTITUTION: An active mass paste mainly comprising nickel hydroxide is filled in a sponge-like nickel substrate to form a positive electrode. The active mass paste comprises nickel hydroxide, metal nickel powder, metal cobalt powder, and cadmium hydroxide which its adding ratio is 2∼15wt% to nickel hydroxide. In the figure, the battery constructed by adding no cadmium hydroxide in its active mass shows that discharge duration gradually increases with the number of charge-discharge cycles, then suddenly decreases. The battery b which the adding amount of cadmium hydroxide to nickel hydroxide is 1wt% shows slightly similar tendency to the battery a. The batteries c and d having adding ratios of 2wt% and 5wt% respectively show less variation in discharge duration. Therefore, minimum requiring amount of cadmium hydroxide is 2.0wt% or more to nickel hydroxide.
TSUDA SHINGO
MATSUMOTO ISAO
YAMAGA MINORU
| JPS5413225U | 1979-01-27 | |||
| JPS5321424U | 1978-02-23 |