Zn3V2O7(OH)2<middle dot>2H2O/MXene cathode with fast ion diffusion for highly durable zinc ion batteries

V-based materials are considered promising candidates as cathode materials for zinc ion batteries (ZIBs). However, the inherent low conductivity of V-based compounds leads to the sluggish diffusion kinetics of Zn2+ and serious cycling capacity degradation of ZIBs. Herein, 1D Zn3V2O7(OH)(2)<middle dot>2H(2)O (ZVO) nanowires were grown on monodisperse 2D Ti3C2Tx MXene nanosheets via a facile microwave-assisted method. The introduction of Ti3C2Tx MXenes effectively improved the conductivity and hydrophilicity of ZVO. Furthermore, the Zn2+ diffusion coefficient of ZVO/Ti3C2Tx composites was enhanced to 10(-7)-10(-8) cm(2) s(-1), which was superior to that of pure ZVO nanowires (10(-8)-10(-10) cm(2) s(-1)) and other previously reported typical V-based cathodes. The ZIBs based on the ZVO/Ti3C2Tx cathode possessed an excellent discharge specific capacity of 215.2 mAh g(-1) at 0.1 A g(-1) and cycling stability (84% retention over 14 000 cycles at 10 A g(-1)). Moreover, the flexible Zn//ZVO/Ti3C2Tx ZIBs using a gel electrolyte still exhibited good cycling stability and rate performance.