Positive Electrode Active Material For Lithium-Ion Battery, Positive Electrode For A Lithium-Ion Battery, Lithium-Ion Battery Using Same, And Precursor To A Positive Electrode Active Material For A Lithium-Ion Battery

Abstract

The present invention provides a positive electrode active material for lithium ion batteries, which realizes a lithium ion battery that is, while satisfying fundamental characteristics of a battery (capacity, efficiency, load characteristics), low in the resistance and excellent in the lifetime characteristics. In the positive electrode active material for lithium ion batteries, the variation in the composition of transition metal that is a main component inside of particles of or between particles of the positive electrode active material, which is defined as a ratio of the absolute value of the difference between a composition ratio inside of the particles of or in a small area between the particles of the transition metal and a composition ratio in a bulk state to the composition ratio in a bulk state of the transition metal, is 5% or less.

What is claimed is: 
     
         1 . A precursor for positive electrode active material for lithium ion batteries, which is composed of secondary particles made of at least lithium and transition metal and formed by flocculating primary particles, wherein the variation in composition of transition metal that is a main component inside of secondary particles or between the secondary particles of the precursor for positive electrode active material, which is defined as a ratio of the absolute value of the difference between a composition ratio inside of the particles of or in a small area between the particles of the transition metal and a composition ratio in a bulk state to the composition ratio in the bulk state of the transition metal, is 5% or less. 
     
     
         2 . The precursor for positive electrode active material for lithium ion batteries of  claim 1 , including lithium and transition metal as main component.