▎ 摘　　要

NOVELTY - Porous graphene-coated graphite nano composite material comprises porous graphene and graphite where porous graphene is coated on the surface of the graphite. USE - Method for preparing porous graphite-coated graphite nano composite material used as negative electrode material of lithium ion battery. ADVANTAGE - The method enables to prepare porous graphite coated nano composite material in simple manner and exhibits high capacity, good multiplying power property and cyclical stability, material resource is rich, cost effective and easy large-scale production. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing porous graphene-coated graphite nano composite material, which involves: (A) preparing graphene oxide dispersion liquid, and adding a metal salt to graphene dispersion to obtain mixed solution according to mass ratio of graphene and metal salt is 1:100-1:0.01; (B) placing obtained mixed solution in an ultrasonicator for ultrasonic treatment for 0 minutes to 1 hour, then stirred for 1-24 hours by a magnetic stirrer, and then lyophilized to obtain graphene metal salt mixture; (C) placing obtained graphene metal salt mixture in an inert atmosphere and carbonizing at 100-1000 degrees C to obtain carbonized sample with reaction time of 0 minutes to 10 hours; (D) treating carbonized sample with an acid solution where concentration of hydrochloric acid is 0.01-10 mol/L, and treatment time is 30 minutes to 8 hours, after washing with deionized water to neutrality, freeze-drying to obtain porous graphene powder; and (E) mixing obtained porous graphene powder with graphite in mass ratio of 1:100-1:0.01 in solid phase, placing mixed material in inert atmosphere and carbonizing at 100-1000 degrees C where reaction time is 0 minutes to 10 hours to obtaine desired product.