Patent ID: 8178238
Filing Date: 2012-05-15
Classification: H01M,Y02E

Abstract:
1. A positive-electrode active material for a lithium-ion secondary battery comprising an average composition expressed by the following formula (1): 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, cobalt Co, nickel Ni, copper Cu, zinc Zn, gallium Ga, yttrium Y, zirconium Zr, molybdenum Mo, silver Ag, tungsten W, indium In, tin Sn, lead Pb, and antimony Sb, X represents a halogen element, and x, y, z, a, and b satisfy 0.2<x≦1.2, 0≦y≦0.1, 0.015≦z0.05, 1.8≦b≦2.2, and 0≦a≦1.0, respectively, wherein the concentration of cerium Ce is higher in a vicinity of a surface of the positive-electrode active material as composed to an inside thereof.