摘要 |
A positive electrode active material for a lithium ion battery includes a material represented by chemical formula LiMPO4 where M includes at least one of iron, manganese, cobalt, and nickel. Particles of the positive electrode active material have a diameter d in the range of 10 nm to 200 nm, the diameter d being determined by observation under a transmission electron microscope. A ratio d/D of the diameter d to a crystallite diameter D is in the range of 1 to 1.35, the crystallite diameter D being determined from a half width measured by X-ray diffraction. The positive electrode active material is coated with carbon, an amount of the carbon being in the range of 1 weight percent to 10 weight percent. |