Method for preparing cathode material lithium manganate of lithium ion battery

The invention discloses a method for preparing a cathode material lithium manganate of a lithium ion battery, which comprises the following steps of: adding Li(CH3COO).2H2O and Al(NO3)3.9H2O into ethylene glycol monomethyl ether, adding PO(OC4H9)3 and Ti(OC4H9)4 after the Li(CH3COO).2H2O and Al(NO3)3.9H2O are completely dissolved, and continuously stirring the mixed solution to ensure the solution is not precipitated; and adding LiaMn2-bMbO4 powder into the prepared solution, adding H3BO3 with stirring, evaporating to dryness and drying the mixed solution after the stirring, calcining the dried powder in a muffle furnace, naturally cooling the calcined powder and grinding the cooled powder to obtain lithium manganate or doped lithium manganate powder of which surfaces are coated with yLi1+xTi2-x(PO4)3.(1-y)Li3BO3. The cathode material of the lithium ion battery prepared by the method of the invention effectively prevents the lithium manganate from being dissolved, and simultaneously does not influence the int