| 摘要 |
PROBLEM TO BE SOLVED: To provide a cathode active material for a lithium ion battery improved in battery characteristics such as battery lifetime by satisfactorily suppressing cracking of particles and improved in a coating property and fixability of a cathode mixture using the cathode active material during battery production.SOLUTION: A cathode active material for a lithium ion battery is represented by a composition formula of LiNiMO(M is a metal and conditions of 0.9≤x≤1.2, 0<y≤0.7 and -0.1≤α≤0.1 are satisfied), an average particle diameter D50 is 7 μm or more and 12 μm or less, an average mechanical strength in loading one of secondary particles in the cathode active material to a preset load 49 mN at a load speed of 2.67 mM/sec by a diamond indenter is 10 MPa or more and 60 MPa or less, and average displacement in defining a moving distance of the indenter from a position where the indenter is abutted to the particle and starts pressing to a position of pressure rupture as displacement is 0.2 μm or more and 1 μm or less. |
