| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive electrode active material useful for a lithium secondary battery indicating a battery resistance lower than conventional at a freezing point.SOLUTION: A positive electrode active material useful for a lithium secondary battery containing at least one kind of elements composed of a group consisting of nickel, cobalt and manganese, and having a layer structure satisfies the following requirements (1)-(3) entirely. (1) The primary particle size is 0.1-1 μm, and the secondary particle size is 1-10 μm. (2) In the powder X-ray diffraction measurement using a CuKα ray, the crystallite size at a peak in a range of 2&thetas;=18.7±1° is 100-1200Å, and the crystallite size at a peak in a range of 2&thetas;=44.6±1° is 100-700Å, and (3) In a pore distribution obtained by a method of mercury penetration, there is a pore peak in a range of 10-200nm, and the pore volume in that range is 0.01-0.05 cm/g. |
