Flexible polypyrrole/TiO2/MXene nanocomposite supercapacitor: A promising energy storage device

Design and development of flexible and high-performance supercapacitors is deemed necessary for portable and wearable electronic devices. In this study, a flexible and high performance PPy/TiO2/Ti3C2TX nanocomposite film as a negative electrode was prepared by electrochemically deposition of PPy/TiO2 on the carbon cloths (CC) as substrate. Then, the prepared PPy/TiO2 nanocomposite film was dipped repeatedly into the few-layered Ti3C2TX nanosheet solution to electrode exhibits a high areal capacitance of 472.0 mF cm−2 at a current density of 3.0 mA cm−2 and outstanding cycling stability of 84 % capacitance retention after 10,000 cycles. Furthermore, an asymmetric supercapacitor was assembled by combining PPy/TiO2/Ti3C2TX as the negative electrode and acid-treatment carbon cloth (TCC) as the positive electrode to increase the potential window of the system. The device exhibited a remarkable specific capacitance of 191.4 mF cm−2 at 1.0 mA cm−2 an excellent energy density of 1.2 mWh cm−3 at a power density of 23.1 mW cm−3, as well as excellent power density of 41.5 mW cm−3 at 0.12 mWh cm−3, and the capacitance retention of 87 % after 13,000 cycles, indicating that the PPy/TiO2/Ti3C2TX nanocomposite film has great potential as an electrode for fabrication of asymmetric supercapacitor.