Direct inkjet printing of flexible MXene/graphene composite films for supercapacitor electrodes

In this paper, flexible MXene/graphene composite electrodes were successfully fabricated by inkjet printing process using printable graphene-modified MXene-based ink. The results show that the interlayer spacing in the printed MXene-based composite films is increased through the insertion of graphene nanosheets, which effectively reduces the self-stacking effect of MXene. The printed MXene/1 wt% graphene composite electrodes exhibit excellent stability with 89% resistance retention at a 180° bending angle, high volumetric capacitance of 183.5 F cm−3 at a scanning speed of 5 mV s−1, and long cycle life with 75% capacitance retention after 3000 charge-discharge cycles. Moreover, a flexible supercapacitor based on those electrodes demonstrates a competitive energy density of 0.53 μWh cm−2 at a power density of 10 μW cm−2, which provides prospects for the design of next generation flexible and wearable energy storage devices.