Patent ID: 8323830

Claim:
An electrode composite material of a lithium ion battery, comprising an electrode active material particle and a protective film coated on a surface of the electrode active material particle, wherein a composition of the protective film is selected from the group consisting of Al x M y PO 4 , Al x M y (PO 3 ) 3 , and a combination thereof; M represents at least one chemical element selected from the group consisting of Cr, Zn, Mg, Zr, Mo, V, Nb, and Ta, a valence of M is represented by k, wherein 0<x<1, 0<y<1 and 3x+ky=3, and a molar ratio of an aluminum element, an M element, and a phosphorous element in the Al x M y PO 4 or Al x M y (PO 3 ) 3 is set by (Mol Al +Mol Metal ):Mol p =about 1:2.5 to about 1:4, Mol Al is the amount of substance of the aluminum element, Mol Metal is the amount of substance of the M element, and Mol p is the amount of substance of the phosphorous element.