▎ 摘　　要

NOVELTY - Preparation of three-dimensional graphene/manganese dioxide composite material involves preparing three-dimensional graphene nanomaterial, and depositing cauliflower-like delta -manganese dioxide nanomaterial on the graphene nanomaterial at a low temperature. USE - Preparation of three-dimensional graphene/manganese dioxide composite material used as supercapacitor in micro-vibration energy harvesting system (claimed). ADVANTAGE - The method enables preparation of three-dimensional graphene/manganese dioxide composite material with excellent cycle performance. The three-dimensional graphene/manganese dioxide composite material has specific capacitance of 328 F/g, which is improved when compared with the specific capacitance (245 F/g) of pure graphene electrode material. The specific capacitance of three-dimensional graphene/manganese dioxide composite material is 92.2% of the original, after 2000 cycles.