Two-dimensional heterostructures of V2O5 and reduced graphene oxide as electrodes for high energy density asymmetric supercapacitors

Abstract

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.