Flexible Ti3C2Tx MXene/V2O5 composite films for high-performance all-solid supercapacitors

Designing and synthesizing flexible self-supporting materials with high electrical conductivity and flexibility are the key to the development of wearable energy storage devices. Herein, a strategy to prepare Ti3C2Tx MXene/V2O5 (MV) films as flexible electrode materials for supercapacitors by vacuum-assisted filtration of a mixture of MXene nanosheets and V2O5 nanofibers is reported. The introduction of V2O5 nanofibers effectively suppresses the self-stacking phenomenon of MXene nanosheets, and simultaneously regulates the thickness of the MV films by controlling the amount of V2O5 nanofibers. Benefiting from the efficient intercalation of V2O5 nanofibers, the Ti3C2Tx MXene/V2O5 (20 mg) (MV2) film as electrode shows good capacitive performance (319.1 F g‐1, 0.5 A g‐1) and cycling stability (70.4 %, 5000 cycles, 3 A g‐1). Furthermore, the MV2//MV2 symmetric supercapacitor (SSC) and the MV2//MnO2 asymmetric supercapacitor (ASC) are assembled, which separately have 72.1 % and 83.9 % capacitance retention after 8000 charge/discharge cycles at 2 A g‐1. The SSC exhibits an energy density of 18.43 Wh kg‐1 at 603.2 W kg‐1 power density, and the ASC provides an energy density of 20.83 Wh kg‐1 at 374.94 W kg‐1 power density, indicating their good energy storage capacity. This study provides a new strategy to improve the electrochemical properties and flexibility of Ti3C2Tx and a reliable method for its application in flexible wearable devices.