Nickel active material for use in alkali storage cells and its manufacturing method

• Main Authors: YAMAWAKI, AKIFUMI, BABA, YOSHITAKA, HAMAMATSU, TAKEO, TADOKORO, MOTOO
• Format: Patent
• Language: English; French; German
• Published: 06.05.1999
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

A nickel active material for an alkali storage cell whose surface is covered with a cobalt compound, wherein the diffusion and permeation into the nickel hydroxide mother particles of cobalt compound during excessive discharging, which act to reduce the active material efficiency and the excessive discharging characteristics, are prevented. This is achieved by having a covering layer, including one or more of the following metal compounds; an aluminum compound, a magnesium compound, an indium compound and a zinc compound, in addition to a cobalt compound, formed on the surface of a mother particle of nickel hydroxide, and by heat treating the covered mother particles in the presence of alkali and oxygen so as to convert the cobalt compound into a compound of cobalt where an oxidization number of cobalt is greater than 2.