Ti3C2Tx MXene/dopamine-modified polypyrrole flexible composite electrodes with application in energy storage devices

Ti3C2Tx MXene is a new 2D material with great potential for supercapacitor applications. Here, we propose a straightforward strategy to fabricate the composite electrode based on MXene. Firstly, the addition of dopamine-modified polypyrrole (DA-PPy) nanofibers prevents the MXene restacking during the fabrication process of the films by vacuum-assisted filtration and makes it easier for the rapid and reversible intercalation/deintercalation of ions. And then, the DA-PPy nanofibers provide more conductive channels for the charge carriers and effectively improve the electrochemical performance of the composite films. The composite electrode yielded the highest specific capacitance of 384.9 F g−1 at 1 A g−1 with 86.7 % capacitance retention after 3000 cycles at 2 A g−1. The CV curves of the supercapacitor assembled with the composite electrode and the conductive carbon cloth maintain an approximately rectangular shape, displaying the relatively ideal capacitive behavior. In addition, the MXene/DA-PPy film shows potential for triboelectric nanogenerator (TENG) applications. The MXene/DA-PPy 9–1 film was combined with the triboelectric layer to fabricate the flexible single-electrode type TENG, demonstrating its potential as the practical power source that can power small electronics, and be a promising candidate for energy storage applications.