COATED NICKEL HYDROXIDE POWDER FOR ALKALI SECONDARY BATTERY POSITIVE ELECTRODE ACTIVE MATERIAL, AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide coated nickel hydroxide powder suitable for an alkali secondary battery positive electrode active material, which enables the suppression of delamination of a coating when making a paste therefrom.SOLUTION: Coated nickel hydroxide powder for an alkali secondary battery positive electrode active material comprises: core particles made of nickel hydroxide; and a cobalt compound covering the surface of each core particle. As to the coated nickel hydroxide powder, the turbidity measured by an integrating sphere type turbidimeter is 30 degrees or less, which was determined according to the following steps of: putting 10 g of the coated nickel hydroxide powder and 10-30 mL of water in a hermetically sealable, preferably circular or rectangular column-like cylindrical cell; shaking the cylindrical cell for 16 hours with a horizontal reciprocating type shaker of 200-280 times/min; then, re-dispersing a delaminated material deposited on the surface of an inner wall of the cylindrical cell in 20 mL of an aqueous solution containing 0.2-0.8 mass% of formic acid; and measuring the turbidity of a liquid dispersion obtained by the re-dispersion.