Fabrication of a fibrous MnO2@MXene/CNT electrode for high-performance flexible supercapacitor

Abstract As shining stars of 2-dimensional materials, transition metal carbides (MXene) and transition metal oxides have attracted much interest in various energy fields due to their excellent conductive and electrochemical properties. However, big challenge still remains in the accessibility of high-performance fibrous electrodes for flexible supercapacitors. In this paper, MnO2 nanorods are loaded on MXene sheets to obtain MnO2@MXene composites by a facile hydrothermal method, which are subsequently coated on carbon nanotube fibers (CNTFs). With a fine control on morphology, the resulting MnO2@MXene/CNTF electrode exhibits a high specific capacitance of 181.8 F/g at 1 A/g, a capacitance retention of 91% after 5000 charge-discharge cycles, as well as superb flexibility, i.e., neglected capacitance loss at a bending angle of 180°. The as-fabricated flexible composite fiber opens a new door for transition metal carbides and transition metal oxides with great potential in flexible electronics.