Positive electrode active material, nonaqueous electrolyte battery and method for manufacturing positive electrode active material

摘要

A positive electrode active material includes: a secondary particle obtained upon aggregation of a primary particle that is a lithium complex oxide particle in which at least nickel (Ni) and cobalt (Co) are solid-solved as transition metals, wherein an average composition of the whole of the secondary particle is represented by the following formula (1):
LixCoyNizM1-y-zOb-aXa   Formula (1)
wherein an existent amount of cobalt (Co) becomes large from a center of the primary particle toward the surface thereof; and an existent amount of cobalt (Co) in the primary particle existing in the vicinity of the surface of the secondary particle is larger than an existent amount of cobalt (Co) in the primary particle existing in the vicinity of the center of the secondary particle.

主权项

1. A positive electrode active material comprising:
a secondary particle obtained upon aggregation of a primary particle that is a lithium complex oxide particle in which at least nickel (Ni) and cobalt (Co) are solid-solved as transition metals, wherein an average composition of the whole of the secondary particle is represented by:
LixCoyNizM1-y-zOb-aXa wherein
M represents at least one element selected from the group consisting of boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba), tungsten (W), indium (In), strontium (Sr), tin (Sn), lead (Pb) and antimony (Sb); X represents a halogen atom; and x, y, z, a and b are values falling within the ranges of (0.8