Fabrication of mesoporous carbon hollow spheres intercalated three-dimensional network structure V2O5 nanosheets with enhanced electrochemical performance

Abstract Two-dimensional vanadium pentoxide (V 2 O 5 ) nanosheets has attracted attention for electrochemical energy storage because of the presence of redox active and unique layered structures available for ions diffusion. However, current strategies are largely limited to enhancing the electrochemical kinetics of V 2 O 5 . Combining three-dimensional (3D) V 2 O 5 network with mesoporous carbon hollow spheres (MCHS) is an effective method to improve the electric transport properties of V 2 O 5 because such combinations not only prevent the restacking of V 2 O 5 nanosheets, but also enhance electronic transport. The obtained structure possessed 3D V 2 O 5 nanosheets interconnected with MCHS, producing a 3D hierarchical porous structure MCHS/V 2 O 5 hybrid materials. The continuous 3D porous network not only creates channels for better ions diffusion, electron transport and efficient utilization of active V 2 O 5 and MCHS, but also reduces the internal resistance of electrodes, which leads to superior electrochemical performance of 313 F g −1  at a current density of 0.25 A g −1 , remarkable rate performance with 86.9% capacitance retention in the range of 0.25–10 A g −1 and cycling performance of 81% over 4000 cycles.