| 摘要 |
A positive electrode active material having a lithium-excess lithium-transition metal composite oxide particle represented by the chemical formula Li1.2Mn0.54Ni0.13Co0.13O2. The lithium-excess lithium-transition metal composite oxide particle has an inner portion (1) having a layered structure and a surface adjacent portion (2) having a crystal structure gradually changing from a layered structure to a spinel structure from the inner portion (1) toward the outermost surface portion (3). The layered structure and the spinel structure have an identical ratio of the amount of Mn and the total amount of Ni and Co. |
