Patent ID: 7638236

Claim:
A lithium ion battery comprising: a positive electrode for the lithium ion battery comprising: a conductive collector; a positive electrode active material layer being in contact with the collector, the positive electrode active material layer having a compound containing at least one selected from the group consisting of cobalt (Co), nickel (Ni), and manganese (Mn) as a component; and a cover layer made of an inorganic compound with lithium ion conductivity provided on at least part of a surface of the positive electrode active material layer, wherein the cover layer has a chemical composition expressed by general formula: Li a MO b N c wherein M is at least one element selected from the group consisting of Si, B, Ge, Al, C, Ga, and S, and a, b, and c satisfy 0.6≦a≦1.0, 1.05≦b≦1.99, and 0.01≦c≦0.5; 1.6≦a≦2.0, 2.05≦b≦2.99, and 0.01≦c≦0.5; 1.6≦a≦2.0, 3,05≦b≦3.99, and 0.01≦c≦0.5; or 4.6≦a≦5.0, 3.05≦b≦3.99, and 0.01≦c≦0.5; an electrolyte conducting lithium ions provided separately from the cover layer; and a negative electrode reversibly storing and releasing lithium ions, wherein the cover layer is formed between the positive electrode active material layer and the electrolyte.