| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive active material having an increased real discharge capacity by chemically or electrochemical oxidizing a metal hydroxide in solution containing Li salt and setting an average oxidizing number in a specified range. SOLUTION: In a metal hydroxide M (OH)2 , M is a metal optionally selected from Co, Ni and Mn, and this is oxidized in a solution containing Li salt to obtain an active material where an average oxidizing number is higher than 3 and lower than 4. Specifically, powder of Ni0.9 Co0.1 (OH)2 having a particle size of 5 to 50 μm is treated by sodium peroxodisulfate at 80 deg.C in lithium hydroxide solution of 4.5 M. In another example, powder of Ni0.85 Co0.1 Mn0.05 (OH)2 having a particle size of 5 to 50 μm is anode-oxidized at 80 deg.C in lightium hydroxide solution of 4.5 M. By a positive electrode active material thus obtained, a lithium battery having a greatly increased discharge capacity, high stability and high safety is provided. |
