An innovative carbon template-induced approach to a graphene-like MnO2 nanomesh with enhanced pseudocapacitance performance

Abstract

Exfoliated two-dimensional layered materials have gained renewed interest in the application of energy storage and conversion. In particular for pseudocapacitive materials, the ultrathin structure can resolve the disadvantage of their low proton/ion conductivity. Compared with the generally used liquid exfoliation, we first present an ingenious approach to directly realize a self-assembled mono/few-layered MnO₂ nanomesh architecture by a simple in situ redox reaction between KMnO₄ solution and a sacrificial carbon template. Electron microscopy, X-ray diffraction and spectroscopy results strongly suggest that the interconnected MnO₂ nanosheets are separated into the individual layers. The synthesized graphene-like MnO₂ nanomesh electrode exhibits a substantially increased specific capacitance (516.7 F g⁻¹) with excellent cycle stability and coulombic efficiency, which is among the highest reported values of a pure MnO₂ electrode with similar loading mass and demonstrates the promising potential supercapacitor and battery applications.