Patent ID: 8609283
Filing Date: 2013-12-17
Classification: C01G,C01P,H01M,Y02E

Abstract:
1. A positive electrode active material comprising lithium-transition metal composite oxide containing lithium, a principal transition metal M1, and a metallic element M2 different from the principal transition metal M1, wherein, the metallic element M2 has a concentration gradient of the metallic element M2 from the center toward the surface of each particle, molar fraction r (%) satisfies the formula 0.20≦r≦0.80 in the range where the ratio d (%) from the surface to a certain depth satisfies 0.020≦d≦0.050, where ratio d (%)=[(mass of the principal transition metal M1)+(mass of metallic element M2)]/(mass of whole particles), and molar fraction r=(mass of metallic element M2)/[(mass of principal transition metal M1)+(mass of metallic element M2)].