▎ 摘　　要

NOVELTY - The preparation method of graphene/ternary composite material involves (a) mixing nickel ion solution, cobalt ion solution and manganese ion solution to obtain metal ion mixed solution (A), (b) weighing graphene oxide solution, then adding nitrogen source and evenly stirring, then adding metal ion mixed solution (A) and ultrasonically dispersing to obtain uniform solution, transferring uniform solution to high pressure reaction vessel, reacting to obtain hydrogel, vacuum drying hydrogel to obtain metal ion doped high-density graphene oxide composite material (B), and (c) adding lithium salt to ethyl methyl carbonate to form solvent, then adding high-density graphene oxide composite material (B) as working electrode, platinum electrode as counter electrode, and saturated calomel as reference electrode, placing high-density graphene oxide composite material (B) in solvent by electrochemical deposition to deposit lithium salt on the surface. USE - The method is useful for preparing graphene/ternary composite material for lithium ion battery. ADVANTAGE - The method enables preparation of graphene/ternary composite material with excellent gram capacity and conductivity. The graphene/ternary composite material improves the multiplying power performance and cycle performance of lithium ion battery. DETAILED DESCRIPTION - The preparation method of graphene/ternary composite material involves (a) mixing nickel ion solution, cobalt ion solution and manganese ion solution in molar ratio of (0.7-0.9):(0.05-0.15):(0.05-0.15) to obtain 0.01-0.1 mol/l metal ion mixed solution (A), (b) weighing 1-10 mg/ml graphene oxide solution, then adding nitrogen source and evenly stirring, then adding metal ion mixed solution (A) and ultrasonically dispersing to obtain uniform solution, transferring uniform solution to high pressure reaction vessel, reacting at 150-200 degrees C for 2-12 hours to obtain hydrogel, vacuum drying hydrogel at 30-80 degrees C for 24-96 hours to obtain metal ion doped high-density graphene oxide composite material (B), (c) adding lithium salt to ethyl methyl carbonate to form solvent having lithium salt concentration of 0.1 mol/l, then adding high-density graphene oxide composite material (B) as working electrode, platinum electrode as counter electrode, and saturated calomel as reference electrode, placing high-density graphene oxide composite material (B) in solvent by electrochemical deposition to deposit lithium salt on the surface to obtain ternary material precursor (C) containing high-density graphene oxide, and (c) sintering ternary material precursor (C) containing high-density graphene oxide in an argon and hydrogen atmosphere in ratio of 1:1 at heating rate of 5 degrees C/minute to 300-400 degrees C for 1-3 hours, again heating at heating rate of 5 degrees C/minute to 800-900 degrees C for 2-12 hours, then cooling to room temperature in argon atmosphere, crushing and grading. The composite material comprises ternary material and internally doped graphene 1-10 wt.%.