| 摘要 |
PROBLEM TO BE SOLVED: To reduce drop in discharging capacity in charging-discharging cycles and suppress increase in inner pressure of a battery or leakage of an alkaline electrolyte by using solid solution powder of γ type nickel oxy hydroxide and manganese as a positive electrode active material, and adding conductor powder prepared by partially covering the particle surface of carbon powder with oxy oxide or oxy hydroxide of cobalt to the solid solution powder. SOLUTION: As the positive electrode active material of a sealed alkaline storage battery in which a power generating element body occupies 75% or more of battery can inner volume, γ type nickel oxy hydroxide having a valency of nickel in full charged state of 3.4-3.8 is used, and as the solid solution powder, solid solution ratio of manganese represented by definition of the expression of manganese solid solution ratio (%) = the number of manganese atoms/(the total number of atoms of manganese and nickel)}×100 is preferable to be 5-50%. Conductor powder prepared by partially covering the particle surface of carbon powder with manganese oxy hydroxide or cobalt oxy hydroxide is added by 3-12 wt.% to γtype nickel oxy hydroxide is used for the solid solution powder. |
