The invention relates to a preparation method of a high-capacity layered
lithium-rich
manganese-based
oxide, and the method is characterized by comprising the following steps: a) fully mixing a
nickel-containing compound, a
manganese-containing compound I and a
cobalt-containing compound with a
solvent so as to get a solution or suspension; b) adding a precipitator into the solution or suspension obtained in the step a), and filtering to obtain a precipitate; c)
drying the precipitate obtained in the step b) so as to get a precursor; d) uniformly mixing the precursor obtained in the step c), a
manganese-containing compound II, a
doping element M-containing compound and a
lithium-containing compound in proportion so as to get mixed
powder; and e) performing heat treatment on the mixed
powder obtained in the step d) so as to get an ultrahigh-capacity manganese series
lithium transition metal compound
oxide with an expression of Li(Li0.2Mn0.8-
delta-alpha-beta-Ni alpha Co beta M
delta)O2. Compared with the prior art, the preparation method provided by the invention has the advantages of high
utilization rate of raw materials and low production cost, and the prepared lithium-rich manganese-based
oxide has the advantages of excellent charge-
discharge performance and excellent cycle performance.