Patent ID: 8865349

Claim:
A method of producing a positive electrode active material, the method comprising: preparing lithium manganese phosphate LiMnPO 4 or a compound LiMn 1-x M x PO 4 wherein 0<x<1 and M is at least one metal element selected from the group consisting of Co, Ni, Fe, Zn, Cu, Ti, Sn, Zr, V, and Al, containing LiMnPO 4 as a solid solution composition using a manganese source containing a manganese powder; mixing carbon particles with lithium manganese phosphate LiMnPO 4 or the compound LiMn 1-x M x PO 4 containing lithium manganese phosphate LiMnPO 4 as a solid solution composition, and heat treating the obtained mixture under an inert gas atmosphere.