▎ 摘　　要

NOVELTY - Composite carbon material comprises graphene and activated carbon, where surface of the activated carbon is filled with graphene. USE - Composite carbon material used for seawater desalination. ADVANTAGE - The composite carbon material has a large specific surface area, a clear pore structure, good ion transmission channel, and has a simple preparation process, high product yield, low cost, high resource utilization rate, mass-produced later and high capacitance, and improves the performance of the deionization capacitor and efficiency of seawater desalination. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a composite carbon material, which involves: (A) washing, drying and pulverizing biomass carbon source and placing in a potassium hydroxide solution to prepare a mixed solution; (B) heating the mixed solution at 1-3 megapascal and at 100-120 degrees C for 2-3 hours to obtain a solid, and washing and drying the solid; (C) heating activated carbon to 800-1000 degrees C for 2-3 hours under argon atmosphere, washing and drying to obtain activated carbon; (D) mixing graphite, potassium persulfate and phosphorus pentoxide and then heating to a temperature of 80-95 degrees C for a period of 5-8 hours for pre-oxidation at a mass ratio of 1:0.5-1.5:0.5-1.5; (E) mixing the pre-oxidized graphite, concentrated sulfuric acid, and potassium permanganate and then heating to a temperature of 30-40 degrees C for 3-6 hours to obtain graphene oxide; (F) subjecting graphene oxide and activated carbon to ultrasonic reaction at a mass ratio of 1:0.4-0.8 under the conditions of 150-250 watt for 2-4 hours to obtain a semi-finished product; and (G) subjecting the semi-finished product and glutathione to reduction reaction at a mass ratio of 1:0.4-0.8 to obtain a composite material.