| 摘要 |
The present invention provides a positive electrode active material for lithium ion battery having good rate characteristics. The positive electrode active material for lithium ion battery has a layer structure expressed by a composition formula: Li x (Ni y M 1- y)O z , wherein M represents Mn and Co, x represents 0.9 to 1.2, y represents 0.6 to 0.9, and z represents 1.8 to 2.4. The positive electrode active material has a particle size ratio D50P/D50 of 0.60 or more, wherein D50 is the average secondary particle size of the positive electrode active material powder, and D50P is the average secondary particle size of the positive electrode active material powder after pressing at 100 MPa. The positive electrode active material contains 3% or less particles having a particle size of 0.4 µm or less in terms of the volume ratio after pressing at 100 MPa. |
