ALKALINE STORAGE BATTERY AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To improve the cycle life characteristic at a high temperature after preservation for a long period by containing a specific quantity of a composite oxide having a specific conductivity and stable against an alkaline electrolyte in a positive electrode active material mainly made of nickel hydroxide. SOLUTION: This alkaline storage battery is constituted of a positive electrode, a negative electrode, and an alkaline electrolyte. The positive electrode is provided with an active material mainly made of nickel hydroxide. A composite oxide having the conductivity of 10<-2> S/cm or above at the room temperature (25 deg.C) and stable against the electrolyte made of an alkaline aqueous solution is contained in the positive electrode active material by 2-30wt.% of the total quantity of nickel hydroxide. The composite oxide is powder having the average grain size of about 5μm or below, and the powder is preferably formed into a columnar or fiber-like coagulated body or a sintered body. An alkali solution is added to a solution dissolved with the salt of a transition metal element and the salt of a rare earth element, and the mixture is sintered to synthesize the composite oxide. This storage battery has an excellent capacity recovery factor after long-period preservation and a deep discharge at a high temperature.