| 摘要 |
Provided is a lithium-ion battery positive electrode active material with which particle cracks are effectively suppressed, thereby improving battery characteristics such as, for example, battery life, and a positive electrode mixture using the positive active material becomes excellent in coating properties and fixing properties during battery fabrication. The lithium-ion battery positive electrode active material is represented by a composition formula of LixNi1-yMyO2+α, where, M is a metal, 0.9 ≤ x ≤ 1.2, 0 ˂ y ≤ 0.7, and -0.1 ≤α≤ 0.1. The lithium-ion battery positive electrode active material has an average particle diameter (D50) of 7 μm to 12 μm, inclusive. In a micro-compression test, the lithium-ion battery positive electrode active material has an average mechanical strength of 10 MPa to 60 Mpa, inclusive, and an average displacement of 0.2 μm to 1 μm, inclusive, said average mechanical strength being obtained when one of the secondary particles of the positive electrode active material is loaded by a diamond indenter at a loading rate of 2.67 mN/s up to a set load of 49 mN, said average displacement being obtained when the distance of the indenter moving from a position where the indenter touches the particle and starts pressing to a position where pressure cracks have occurred is defined as displacement. |
