| 摘要 |
PROBLEM TO BE SOLVED: To provide a cobalt compound good in conductivity and provide a cobalt coating layer high in mechanical strength to provide a high capacity storage battery, by providing a nickel hydroxide higher than bivalent, providing its surface with a higher-valent cobalt compound containing first alkaline cation, and providing the inside with alkaline cation. SOLUTION: A nickel hydroxide compound is coated with a cobalt compound and is heat treated under existence of oxygen and alkaline solution containing first alkaline cation, and thereby, a higher-valent cobalt compound layer good in conductivity is formed on the surface of the nickel hydroxide compound. When this nickel hydroxide compound is oxidized with oxidant, replacement occurs between trivalent cobalt on the surface and atoms in a crystal during conversion of bivalent nickel hydroxide to trivalent nickel hydroxide, and mechanical strength of active material particles is improved. The higher-valent cobalt compound layer is not peeled and coefficient of use of active material is improved. |
