Patent ID: 7078127

Claim:
A method for producing a positive electrode material of the formula (I), Li 1+X Mn 2−y M y O 4 (I) wherein M is Mg, Al, Cr, Fe, Co, or Ni, 0≦x≦0.4, and 0≦y≦0.2 comprising steps of: (A) mixing salts of Li, Mn and M with at least a solvent to form an initial solution, wherein the mole ratio of Li, Mn, and M ions contained in their respective salts is (1+x):(2−y):y; (B) adding at least a chelate into said initial solution to form a suspension, wherein the mole ratio of said chelate to Li ion in said Li salt ranges from 1:1 to 5:1; (C) filtering said suspension to obtain a co-precipitate; and (D) calcining and heating said co-precipitate.