Self-assembled VN/Ti3C2Tx composites for asymmetric supercapacitors
MXenes have gained significant recognition due to their outstanding electrical conductivity, abundant surface functional groups, and distinctive two-dimensional layered structure. However, restacking of nanoflakes hinders the electrochemical performance of Ti3C2Tx-based supercapacitors. Herein, a Ti3C2Tx/VN composite is fabricated using a one-step in situ nitriding method. The presence of VN within the Ti3C2Tx nanoflakes results in an increased interlayer spacing, providing additional electrochemically active sites for charge storage. In addition, the Ti3C2Tx nanosheets form a continuous metallic skeleton that suppresses the formation of soluble salts from VN during charging and discharging resulting in better cycling stability. As the negative electrode in supercapacitors, Ti3C2Tx/VN demonstrates an outstanding specific capacity of 382.1 F g−1 at a current density of 1 A g−1 and exceptional cycling endurance, retaining 93.5% of its capacity after 5000 cycles. An asymmetric supercapacitor comprising Co3O4 and Ti3C2Tx/VN as the positive and negative electrodes, respectively, shows high energy and power densities of 69.1 W h kg−1 (1 A g−1) and 7.6 kW kg−1 (8 A g−1). The results reveal a promising strategy to design composite anodes with high energy and power densities for supercapacitors.
危险品化学品经营许可证（带存储）