The invention discloses a preparation method of a layered
lithium-rich
manganese base
oxide of a positive material of a
lithium ion battery. The preparation method comprises the following steps of: slowly adding
transition metal brine solution, alkali liquor and
ammonia water which conform to a stoichiometric ratio into a stirring reactor respectively; stirring and heating; aging, filtering, washing and
drying the obtained precipitate to obtain a
nickel cobalt and
manganese composite precursor; proportioning and mixing with a
lithium source according to the stoichiometric ratio; adding a fluxing agent of a certain proportion and uniformly mixing in a mechanical mode; placing mixed
powder in a furnace for
sintering; cooling to
room temperature; fully washing with water; and removing remaining fluxing agent to obtain the layered lithium-rich
manganese base
oxide Li1+xNialphaCobetaMngammaO2 (wherein x is greater than 0 and is less than or equal to 0.33, alpha is greater than or equal to 0 and is less than 1, beta is greater than or equal to 1 and is less than 1, gamma is greater than 0 and is less than 1, and alpha and beta are not zero simultaneously.). According to the preparation method, the
heating efficiency is greatly increased, the
energy consumption is reduced, and meanwhile, the electrochemical performance of the material is improved; the prepared spherical layered lithium-rich manganese base
oxide has no doped phase; and a product has a uniform average particle
diameter and superior circulation performance.