A facile strategy for fabricating hierarchical nanocomposites of V2O5 nanowire arrays on a three-dimensional N-doped graphene aerogel with a synergistic effect for supercapacitors

Abstract

As one of the most promising candidates for supercapacitor electrodes, vanadium pentoxide (V₂O₅) usually suffers from poor electronic conductivity and small ionic diffusivity. The key to solving these problems is to synthesize electrode materials with suitable architectures and a delicate design. Here we introduce a facile strategy to construct hierarchical nanocomposites by combining one-dimensional (1D) V₂O₅ nanowires with a 3D N-doped graphene aerogel (NGA). The V₂O₅ nanowire arrays (NWAs) are aligned vertically on the graphene substrate and wonderfully incorporated into the 3D NGA matrix. The key to forming this 3D architecture is to incorporate nitrogen atoms into the 3D graphene aerogel and the analysis of combined simulation and experiment as a proof-of-concept is conducted. Such a design offers distinct advantages for V₂O₅-based materials for supercapacitors. As a consequence, they deliver an ultrahigh specific capacitance of 710 F g⁻¹ (at a current density of 0.5 A g⁻¹) and exhibit outstanding rate performance and good cycling behavior (after 20 000 cycles 95% retention of specific capacitance). This study will open a way to guide the fabrication of nanocomposites by combining different dimensional nanomaterials.