The invention relates to a monocrystal
lithium-rich
manganese-based multi-component positive
electrode material and a preparation method. The molecular formula of the material is xLi<2>MnO<3>.(1-x)LiMO<2>, wherein x is greater than 0 and less than 1; and M is one or more of Mn, Ni, Co, Mg or Al. The preparation method comprises the following steps of 1) weighing soluble
nickel salt, soluble
cobalt salt, soluble
manganese salt, soluble
magnesium salt and soluble aluminum salt based on stoichiometric ratio of elements and dissolving into deionized water to form a solution A with
metal ion concentration of 0.2-4mol / L; 2) configuring a mixed water solution B of
sodium carbonate and
sodium bicarbonate, wherein the concentration of
carbanion is 0.2-4mol / L; 3) dropwise adding the solution A and the solution B to a
beaker and stirring constantly to obtain precipitate, and performing aging on the precipitate for 4-24h; 4) performing filtering, washing and
drying on the obtained precipitate to obtain a
carbonate precursor; and 5) performing smashing and ball
grinding on the
carbonate precursor and then mixing with a
lithium-containing compound, and carrying out calcining in two sections in an
oxygen-rich
atmosphere to obtain the monocrystal
lithium-rich
manganese-based multi-component positive
electrode material with relatively high tap density. The preparation process is simple and industrialization can be achieved easily; and the
prepared material is stable in
crystal structure, high in volume ratio and
energy density, and long in cycle life.