Flexible and High-Performance MXene/MnO2 Film Electrodes Fabricated by Inkjet Printing: Toward a New Generation Supercapacitive Application

With the deepening of the commercialization of flexible electronic products, it is urgently needed to develop a handleable solution for the applications of printing high-performance and wearable energy storage devices. Herein, flexible, low-cost, and high-performance MXene/manganese dioxide (MnO2) composite film electrodes are reported to meet this urgent expectation. The MXene-based composite film electrodes with different MnO2 content are prepared by inkjet printing using MXene/MnO2 ink. Characterization and test results show that there is a synergistic effect between MXene and MnO2, which can effectively achieve faster electron transfer and shorter diffusion path, thus improving the overall electrochemical performance of the composite. The inkjet-printed MXene/10 wt% MnO2 composite film electrode, with an excellent conductivity of 3400 S m(-1), exhibits an ultrahigh volumetric capacitance of 312 F cm(-3) and retains 130.8% of the initial capacitance after 5000 charge/discharge cycles. Moreover, the fabricated flexible symmetrical supercapacitor shows a superior areal energy density of 0.51 mu Wh cm(-2) at a power density of 12.5 mu W cm(-2). Taken together, inkjet printing technology provides a low-cost, large-area manufacturing route for different MXene-based composites, which are expected to promote the development of novel energy storage technologies that exploit the attractions of MXene.