▎ 摘　　要

NOVELTY - Preparing three-dimensional graphene-coated mesoporous graphene composite material comprises e.g. (a) dispersing nickel salt and graphene oxide at certain mass ratio in mixed solution of ethylenediaminetetraacetic acid and triethylamine in dimethylformamide to obtain graphene oxide/nickel (ethylenediaminetetraacetic acid) complex, and (b) subjecting calcined graphene/nickel (ethylenediaminetetraacetic acid) complex to two-step temperature controlled high temperature calcination, etching metal nickel particles with acid solution of iron (III) chloride, filtering, washing, filtering and drying. USE - The composite material is useful in super capacitors, capacitive desalination, lithium-ion batteries, sodium batteries and other fields. ADVANTAGE - The composite material has high specific surface area, simple preparation method, and low cost. DETAILED DESCRIPTION - Preparing three-dimensional graphene-coated mesoporous graphene composite material comprises (a) dispersing nickel salt and graphene oxide at certain mass ratio in mixed solution of ethylenediaminetetraacetic acid and triethylamine in dimethylformamide, where mass ratio between ethylenediaminetetraacetic acid and triethylamine is 10:1-30:1, stirring and centrifugating by removing dimethylformamide to obtain graphene oxide/nickel (ethylenediaminetetraacetic acid) complex, where mass ratio between nickel salt and ethylenediaminetetraacetic acid is 5:1-1:1; mass ratio between ethylenediaminetetraacetic acid and graphene oxide is 15:1-3:1, and (b) subjecting calcined graphene/nickel (ethylenediaminetetraacetic acid) complex to two-step temperature controlled high temperature calcination under inert gas protection, where first calcination temperature is 300-500 degrees C, second step calcination temperature is 600-1200 degrees C, insulation time is 1-3 hours, heating rate is 0.5-5 degrees C/minutes, inert gas flow rate is 50-150 ml/minutes to obtain three-dimensional graphene-coated mesoporous graphene/nickel complex, etching metal nickel particles with acid solution of 3-6 mol/l iron (III) chloride, filtering, washing, and filtering and drying to obtain three-dimensional graphene-coated mesoporous graphene composite material.