▎ 摘　　要

NOVELTY - A secondary battery consists of a positive electrode including a positive electrode active material (100) and a rectangular parallelepiped convex portion (103) on the surface of positive electrode active material. USE - Secondary battery used for vehicles and electronic device (all claimed). Uses semiconductor device, display device, light-emitting device, power storage device, and electro-optical device. ADVANTAGE - The battery has excellent capacity, long-term reliability, safe in operating, and has reduced weight. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a manufacture of the positive electrode active material, which involves mixing lithium source, a cobalt source to performs heating (A) for producing a composite oxide (I), mixing composite oxide (I), magnesium source, and fluorine source to perform heating (B) for producing composite oxide (II), mixing composite oxide (II), nickel source, and aluminum source to perform heating (C) for producing composite oxide (III), mixing composite oxide (III), zirconium source and yttrium source with an alcohol as a solvent, and fabricating a positive electrode active material. The heating is done at a temperature of 720-950 degrees C for 2-10 hours. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the positive electrode active material. Positive electrode active material (100) Convex portion (103)