▎ 摘　　要

NOVELTY - A graphene/manganese dioxide composite material preparing method involves reducing a graphene oxide into graphene. The graphene is uniformly fixed on an electrode surface. Thickness of a graphene coating layer is controlled. Manganese acetate and sodium sulfate are taken as a manganese precursor and a supporting electrolyte. Acidity of the electrolyte is adjusted and controlled potential electrolysis is performed. Manganese dioxide is electrically deposited on a graphene surface. Particle size and distribution density of the manganese dioxide are controlled to prepare the composite material. USE - Method for electrochemically preparing a graphene/manganese dioxide composite material that is utilized as an electrode or a supercapacitor assembly. ADVANTAGE - The method enables improving the capacity and cyclic charging and discharging characteristics of the supercapacitor assembly. DETAILED DESCRIPTION - A graphene/manganese dioxide composite material preparing method involves taking sodium carbonate as a supporting electrolyte and reducing a graphene oxide into graphene by a controlled potential electrolysis method. The graphene is uniformly fixed on a surface of an electrode. Thickness of a graphene coating layer is precisely controlled according to the concentration of the graphene oxide, potential, temperature and time during electro-deposition. Manganese acetate and sodium sulfate are taken as a manganese precursor and a supporting electrolyte. Acidity of the electrolyte is adjusted by sulfuric acid and controlled potential electrolysis is performed. Manganese dioxide is electrically deposited on the graphene surface. Particle size and the distribution density of the manganese dioxide are precisely controlled to prepare the graphene/manganese dioxide composite material. An INDEPENDENT CLAIM is also included for a method for using a graphite/manganese dioxide composite material, which involves utilizing acetonitrile or ethanol solution as an ionic liquid electrolyte of a supercapacitor assembly, where the concentration of the ionic liquid is 0.1-10 mole/l. DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram illustrating a method for electrochemically preparing a graphene/manganese dioxide composite material. '(Drawing includes non-English language text)'