▎ 摘　　要

NOVELTY - An ultra-thin manganese dioxide nanosheet graphene composite material preparing method involves carrying out chemical vapor deposition of foamed graphene flexible substrate by flattening a foam nickel to 0.2 mm thick, and cutting with an electrode chip diameter (R) of 12mm using electrode cutting machine, using hydrochloric acid cleaning to remove the oxide layer, immersing 15 electrode wafer in a tube furnace and heat-treating by introducing hydrogen and argon followed by introducing methane, cooling and etching nickel foam. Ultra-thin manganese dioxide nanosheet array growth is carried out. USE - Method for preparing an ultra-thin manganese dioxide nanosheet graphene composite material for super capacitor. ADVANTAGE - The method enables preparing the composite material with good flexibility and higher energy density, low internal resistance, safety and no pollution, and does not need a conductive adhesive. DETAILED DESCRIPTION - An ultra-thin manganese dioxide nanosheet graphene composite material preparing method involves carrying out chemical vapor deposition of foamed graphene flexible substrate by flattening a foam nickel to 0.2 mm thick, and cutting with an electrode chip diameter (R) of 12mm using electrode cutting machine, using 1 M hydrochloric acid cleaning to remove the oxide layer, immersing 15 electrode wafer in a tube furnace and heat-treating at 1000 degrees C by introducing 50 sccm hydrogen and 280 sccm argon for 20 min followed by introducing 2.5 sccm methane for 20 min, cooling to room temperature and etching nickel foam to obtain independent self-supporting flexible electrode substrate. Ultra-thin manganese dioxide nanosheet array growth is carried out by immersion pretreatment of 10 ml concentrated hydrochloric acid on the electrode wafer, and mixing 2.5 mmol potassium permanganate and 1 ml concentrated hydrochloric acid in 45 ml deionized water with stirring for 10 min to obtain a mixed solution. The mixed solution is transferred to 100 ml hydrothermal reactor to the filling rate of 90%, followed by putting 3 pieces of pretreated electrode wafer, carrying out hydrothermal reaction for 20 min-3 hours at 85 degrees C, washing using de-ionized water after reacting the electrode wafer, and drying for 24h at 80 degrees C, and growing thin manganese dioxide annaoarray composite material on the three-dimensional graphene.