Patent ID: 8658312

Claim:
A positive electrode for a lithium ion battery, comprising a positive electrode current collector, and a positive electrode active material layer formed on a surface of the positive electrode current collector, wherein the positive electrode active material layer comprises: a lithium-containing nickel oxide represented by the general formula (1): Li x Ni 1−(p+q+r) Co p Al q M r O 2+y , where M is one element selected from the group consisting of transition elements (excluding Ni and Co), Mg, Ca, Zn, and Bi, 0.8≦x≦1.4, −0.1≦y≦0.1, and 0<(p+q+r)≦0.7; and lithium carbonate, the positive electrode active material layer comprises a high concentration region where the lithium carbonate concentration is high, and a low concentration region where the lithium carbonate concentration is low, and the high concentration region covers a range of 2 to 80% of the total thickness of the positive electrode active material layer, the range starting from a surface thereof, and the low concentration region covers the range remaining on the positive electrode current collector side of the positive electrode active material layer.