Precursor of Li-ion cathode material, the preparation method thereof and Li-ion cathode material

摘要

Li-ion cathode materials with improved performance characteristics and precursors to prepare such materials are disclosed. The precursors consist of complex, mixed alkali transition metal oxides of the formula Li_xA_y(Mn_aNi_bM_c)O_2+d, where M represents one or more selected from transition metal elements beside Ni and Mn, and the groups IIA and IIIA elements of the periodic table, x is between 1 and 1.4, y is between 0.1 and 0.5, and x+y is between 1.1 and 1.5, a+b+c=1, the value of d depends on the proportions and average oxidation states of the cation elements Li, A, Mn, Ni and M such that the combined positive charge of the cation elements is balanced by the number of oxygen anions, A represents one or more elements selected from Na, K and Cs. The Li-ion cathode materials are produced by exchange of element(s) A for Li under mild conditions to limit the degree of structural reorganization that occurs during the reaction.