▎ 摘　　要

NOVELTY - A graphene composite multilayer porous spherical lithium manganate electrode material comprises graphene with sheet structure uniformly dispersed around the lithium manganate particles. The lithium manganate comprises multilayer porous spherical structure formed by stacking primary particles with particle size of 100-200 nm. The stacked multilayer porous lithium manganate electrode material has particle size of 1-5 mu m. USE - Graphene composite multilayer porous lithium manganate electrode material is used for rechargeable lithium-ion battery (claimed). ADVANTAGE - The graphene composite multilayer porous lithium manganate electrode material with excellent magnification characteristics and cycle stability is prepared by economical method. The rechargeable lithium-ion battery comprising the graphene composite multilayer porous lithium manganate electrode material has high energy density and power density. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) lithium-ion battery, which has positive electrode, a negative electrode, electrolyte, diaphragm and shell. The material of positive electrode contains graphene composite multilayer porous spherical lithium manganate electrode material. The negative electrode material comprises lithium metal or lithium-embedded active material. The diaphragm comprises polyethylene, polypropylene microporous membrane and/or glass fiber membrane. The electrolyte comprises soluble lithium salt organic solution; and (2) preparation of graphene composite multilayer porous spherical lithium manganate electrode material, which involves dissolving cetyltrimethylammonium bromide and ammonium bicarbonate in deionized water to form mixed solution (s1), dissolving manganese sulfate in deionized water to form mixed solution (s2), placing mixed solution (s1) in oil bath at 40-60 degrees C, dripping mixed solution (s1) to mixed solution (s2), adjusting pH of mixture to 7-8, to obtain turbid solution, washing turbid solution with water and centrifuging and drying mixture to obtain manganese carbonate primary powder, calcining primary manganese carbonate powder at 600-800 degrees C, to obtain precursor of manganese oxide, adding manganese dihydride and lithium salt to precursor, grinding mixture with absolute ethanol, placing uniformly ground mixture in tube furnace at 500-600 degrees C for 2-6 hours under oxygen atmosphere and calcining mixture at 600-800 degrees C for 8-15 hours, to obtain multilayer porous lithium manganate, dispersing graphene in deionized water, adding multilayer porous lithium manganate, stirring mixture, centrifugally and drying mixture.