Introduction of 1D rGO nanoribbons as spacers between 2D MXenes for a high-performance electrode for supercapacitors.

Two-dimensional (2D) transition-metal carbide TiCT (MXene) possesses good electrical conductivity, high specific surface areas and metal oxide-like surfaces, which make it ideal for application in supercapacitors with both high energy density and power density. However, similar to other 2D materials, the issue of self-stacking leads to narrower ion-transport channels, along with a drastic reduction in active sites, thus severely limiting the performance of MXene-based electrodes. To address this problem, this work proposes to introduce one-dimensional (1D) reduced graphene oxide (rGO) nanoribbons as spacers between MXene nanosheets to construct a composite structure for inhibiting self-stacking. As expected, owing to the steric effect and high aspect ratio of rGO nanoribbons, the fabricated MXene/rGO hybrid electrode, with the addition of 5 wt% graphene oxide (GO), exhibits a greatly improved specific capacitance (397.4 F g at 5 mV s) and an unparalleled rate capability (with a capacitance retention of 52.9% at 2000 mV s). This work sheds significant light on the development of MXene-based materials for advanced energy storage devices.