Tightly connected MnO2-graphene with tunable energy density and power density for supercapacitor applications

MnO2 nanoparticles uniformly distributed and tightly anchored on graphene are prepared using an ethanol-assisted graphene-sacrifice reduction method, producing composite electrodes with tunable energy density (up to 12.6 Wh kg(-1)) and power density (up to 171 kW kg(-1)) via rational design of the oxide/graphene ratio.