Two-dimensional heterostructures of V2O5 and reduced graphene oxide as electrodes for high energy density asymmetric supercapacitors†
In this article, we report the synthesis of electrode materials based on two-dimensional (2D) heterostructures of V2O5 nanosheets (V2O5 NS) and reduced graphene oxide (rGO) electrodes for asymmetric supercapacitor applications. Specifically, the 2D V2O5 and rGO/V2O5 nanosheet electrodes showed a specific capacitance of 253 F g−1 and 635 F g−1, respectively at a current density of 1 A g−1. The capacitance of the heterostructures is almost 2.5 times higher than the 2D V2O5 nanosheets alone. The corresponding energy density of 39 Wh kg−1 and 79.5 Wh kg−1 were achieved for the two electrodes at a power density of 900 W kg−1 in an asymmetric supercapacitor configuration. The energy and power density using the nanosheet heterostructure are, to our knowledge, higher than any of those that were previously reported for asymmetric supercapacitors using V2O5 electrodes.