Patent ID: 7241532

Claim:
A positive-electrode material for a secondary lithium battery, which comprises: secondary particles of a lithium/transition metal composite oxide containing boron and/or bismuth, and wherein the atomic ratio of the sum of boron and bismuth to the sum of the metallic elements other than lithium, boron, and bismuth in surface portions of the secondary particles ranges from 8 times to 70 times the atomic ratio of the sum of boron and bismuth to the sum of the metallic elements other than lithium, boron, and bismuth throughout the entirety of each of the secondary particles, and wherein the lithium/transition metal composite oxide has a lamellar crystal structure and is represented by the following formula (3): Li x Ni α Mn β Q (1−α−β) Bi v B w O 2 (3) wherein Q represents at least one element selected from the group consisting of Al, Fe, Ga, Sn, V, Cr, Co, Cu, Zn, Mg, Ti, Ge, Nb, Ta, Zr, and Ca; and x, α, β, v, and w respectively represent numbers satisfying the relationships 0<x≦1.2, 0.7≦α/β≦9, 0≦(1−α−β)≦0.5 , 0≦v≦0.1 and 0≦w≦0.1 (provided that at least one of v and w is not 0).