The invention belongs to the technical field of
lithium ion batteries, and provides a modified
lithium-rich
manganese-based positive
electrode material and a preparation method and application thereof. The modified
lithium-rich
manganese-based positive
electrode material comprises a lithium-rich
manganese-based matrix material inner core and a
coating layer
coating the surface of the lithium-rich manganese-based matrix material inner core; a
cobalt element is doped in the lithium-rich manganese-based matrix material, the chemical general formula of the lithium-rich manganese-based matrix material is Li < 1 + a > (Ni < x > Co < y > Mn < 1-a-x-y >) < 1-a > O < 2 >, a is more than 0 and less than 1, x is more than 0, and y is more than or equal to 0.005 and less than or equal to 0.015; the
raw material of the
coating layer comprises polyanion
metaphosphate, and the
metaphosphate is a three-dimensional lattice-shaped
crystal. According to the invention, trace
cobalt element is doped in the core of the lithium-rich manganese-based matrix material and is cooperatively matched with the coating of
metaphosphate, so that the problems of Li / Ni mixed arrangement phenomenon, serious interface
side reaction and the like of the lithium-rich manganese-based
cathode material are solved, and the electrochemical performance is more comprehensively and effectively improved.