Facile Preparation of MXene Decorated PANI/Lignosulfonate Nanocomposite Film Electrodes for Electrochemical Supercapacitors

Abstract MXenes are a large family of two‐dimensional transition‐metal carbides, nitrides, and carbonitrides with large surface area and metal conductivity. They have not been widely used as electrodes in the field of supercapacitors because of their low specific capacity, poor chemical stability, and tendency towards self‐stacking. Herein, a three‐component nanocomposite film electrode has been successfully achieved, consisting of MXene nanosheets, polyaniline (PANI), and lignosulfonate (LGS). The PANI‐LGS nanocomposite was prepared through the oxidative polymerization of PANI in the presence of LGS, and then MXene decorated PANI/LGS (labeled as MPL) nanocomposite films were facilely self‐assembled via a vacuum‐assisted filtration by using the dispersion. Compared with pure PANI and PANI‐LGS, the MPL nanocomposite film electrode possesses better conductivity, showing a high specific capacitance of 559 F/g at a scan rate of 5 mV/s and a capacity retention rate of 92.2 % after 1000 cycles at a current density of 10 A/g. This study demonstrates that the doping of LGS and MXene can significantly improve the electrochemical performance of PANI‐based composite materials. Thus, the convenient preparation and excellent electrochemical performance of MPL show great potentials in the application of high‐performance electrodes for supercapacitors.