POROUS GRAPHENE-MANGANESE DIOXIDE NANOWIRES COMPOSITE FILM FOR HIGH VOLUMETRIC PERFORMANCE SUPERCAPACITORS

Mingxuan Han, Hao Wang, Di Yu, Lili Jiang, Yu Zhang

ABSTRACT:We report a novel strategy to prepare densely packed porous graphene and MnO2 nanowires composite film (PGNs-MnO2 NWs) through graphene etching process, hydrothermal method and subsequent vacuum-assisted filtration method. The ion diffusion ability of the PGNs-MnO2 NWs film is greatly enhanced due to the contribution of cross-plane diffusion from porous graphene and in-plane diffusion from MnO2 nanowires-graphene sandwiched structure. Based on its high surface area, fast ion diffusion and high film density, the PGNs-MnO2 NWs film electrode exhibits high volumetric specific capacitance of 206 F cm-3 at 5 mV s-1 in 1 M Na2SO4 aqueous solution. The capacitance remains 99.5% after 2000 cycles of the cyclic voltammetry method. The strategy provides a facile and effective method to achieve high performance electrode materials for supercapacitor.

Keywords:Porous graphene, Manganese dioxide nanowires, Composite film, Volumetric performance, Supercapacitors.