Preparation of Flexible N-Doped Carbon Nanotube/MXene/PAN Nanocomposite Films with Improved Electrochemical Properties

Flexible supercapacitors show broader application prospects in the electronics field due to excellent electrochemical performance and mechanical flexibility. However, impeded by the structural stability of the electrode, it is still challenging to expand their applications. In this study, flexible nitrogen-doped carbon nanotube (N-CNT)/Ti3C2Tx (MXene)/polyacrylonitrile (PAN) nanocomposite films as electrode of supercapacitors were prepared by vacuum filtration and electrospinning methods. The introduction of carbon nanotubes expanded the layer spacing of MXene and further inhibited the stacking of the nanosheets. The expansion of the layer spacing provided channels for ion transport and also enabled MXene to expose more active sites to provide major contributions to electrochemical performance. Therefore, the N-CNT/MXene/PAN film electrode exhibited a high area specific capacitance of 669.27 mF cm–2 and a high mass specific capacitance of 446.18 F g–1 at 5 mV s–1. In addition, it displayed a cycling stability with a retention of 90.9% after 4000 cycles, which was superior to recently reported electrodes. Meanwhile, the composite films possessed desirable flexibility and small capacity loss at different bent angles. The facile synthetic strategy may open up new research ideas for developing flexible electrodes with excellent electrochemical performance.