PANI-MnO2 and Ti3C2Tx (MXene) as electrodes for high-performance flexible asymmetric supercapacitors

Polyaniline (PANI) and manganese dioxide (MnO2) are forward-looking electrode materials due to their high specific capacitance. But poor cyclic stability of PANI and low power density of MnO2 limit their development. In this paper, PANI and MnO2 were synthesized on carbon cloth (CC) by electrochemical polymerization with the addition of LiClO4. The capacitance of CC/PANI-MnO2 increases to 634.0 F g−1 (380.4 C g−1) at 1 A g−1. And its decent electrochemical performances can be ascribed to the synergistic effect of PANI and MnO2. Moreover, an asymmetric supercapacitor based on CC/PANI-MnO2 as positive electrode and CC/MXene as negative electrode were assembled to broaden the potential range. The device has capacitance of 21.1 F g−1 at 0.5 A g−1 and the capacitance retention of 83% after 4000 cycles. The device shows an energy density of 47.25 μWh cm−2 at a power density of 2.40 mW cm−2. Furthermore, the ductility of the device was explored to resist the bending and stretching from external forces. The research of flexible asymmetric supercapacitors herein further improves the practical application of energy storage devices.