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

A method for preparing a precursor to a Li-ion cathode material containing at least Li, A, Ni and Mn and layered phase Li2MnO3 with a composition of LixAy(MnaNibMc)O2+d, where M represents one or more elements 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, and A represents one or more elements selected from Na, K and Cs comprising:

• (1) dissolving soluble salts of Ni, Mn and M in water to obtain a solution of mixed cations;
• (2) combining the solution of mixed cations with a basic solution of lithium hydroxide or lithium carbonate to obtain a solid precipitate;
• and
• (3) mixing the solid precipitate with a combination of lithium carbonate and/or lithium hydroxide and at least one of other carbonates and/or hydroxides of Na, K, and/or Cs, and then firing the mixture.