▎ 摘　　要

NOVELTY - A nanometer gamma -manganese dioxide-graphene gas gel composite material preparing method involves improving oxidation graphene by hummers method, performing treatment ultrasonically after water dispersion, placing into a sealed container and heating under microwave digestion to obtain graphene hydrogel. The obtained hydrogel is frozen and dried to form graphene gas gel followed by performing ultrasonically after water dispersion, adding divalent manganese salt, stirring uniformly, adding sulfate, performing oxidation reaction at 50-90 degrees C, washing and drying to obtain finished product. USE - Method for preparing nanometer gamma -manganese dioxide-graphene gas gel composite material for a supercapacitor. ADVANTAGE - The method is simple, mild, cost effective and ecofriendly manner, and good capacity property. DETAILED DESCRIPTION - A nanometer gamma -manganese dioxide-graphene gas gel composite material preparing method involves improving oxidation graphene by hummers method, performing ultrasonically after water dispersion, placing into sealed container and heating under 500-900 W microwave digestion for 3-15 minutes to obtain graphene hydrogel. The obtained hydrogel is involved freezing and dried to form graphene gas gel, followed by performing ultrasonically after water dispersion, adding divalent manganese salt, stirring uniformly, adding sulfate, performing oxidation reaction at 50-90 degrees C, washing and drying to obtain finished product.