Lithium manganese oxide material and preparation method thereof

The invention discloses a lithium manganese oxide material and a preparation method thereof, in particular to a high-crystallinity lithium manganese oxide material and a preparation method thereof, wherein the high-crystallinity lithium manganese oxide material is used for coating a lithium ion battery. The lithium manganese oxide material is obtained by being coated on a lithium manganese oxide precursor with the one-time crystal particle of 0.01-20mum and has the general formula of LiaMn2-b-cMbGcO4-d-eXdZe, wherein M and X are doped elements, G and Z are coating elements of which the concentration is distributed in a decreasing gradient from outside to inside, a is not less than 0.9 and is not more than 1.2, b is not less than 0 and is not more than 0.2, c is more than 0 and is not more than 0.2, d is not less than 0 and is not more than 0.2, and e is not less than 0 and is not more than 0.2. The material serves as the positive pole material of the lithium ion battery, has better normal-temperature and high