A Novel Hierarchical Porous 3D Structured Vanadium Nitride/Carbon Membranes for High-performance Supercapacitor Negative Electrodes

Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon（VN/C） membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g-1 at 0.5 A g-1 and an excellent rate capability with capacitance retention of 50.5% at 30 A g-1. For the asymmetric device fabricated using Ni（OH）2//VN/C membranes, a high energy density of 43.0 Wh kg-1 at a power density of800 W kg-1 was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g-1 after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.