| CPC H01M 4/525 (2013.01) [H01M 4/131 (2013.01); H01M 4/366 (2013.01); H01M 4/505 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); Y02E 60/10 (2013.01)] | 15 Claims |

|
1. A positive electrode active material, comprising:
a bulk particle consisting of a plurality of primary particles that are lithium composite oxides enabling lithium intercalation and deintercalation,
wherein a first concentration gradient section in which the concentration of at least one of metal elements constituting the primary particles in the bulk particle increases in a direction (transverse direction) perpendicular to a direction (longitudinal direction) toward a surface region of the bulk particle from a core region of the bulk particle, and a second concentration gradient section in which the concentration of at least one of metal elements constituting the primary particles in the bulk particle decreases in a direction (transverse direction) perpendicular to a direction (longitudinal direction) toward a surface region of the bulk particle from a core region of the bulk particle, are present in the bulk particle,
wherein the first concentration gradient and the second concentration gradient section are laterally arranged along a circumferential surface of the bulk particle.
|