3D porous MXene induced by zinc-assisted electrodeposition for flexible all-solid-state supercapacitors

The MXene Ti3C2Tx shows good promise for use in energy storage applications. 2D MXene sheets exhibit serious restacking problems, so these MXene sheets are assembled into 3D macro structures to develop MXene-based functional materials. However, existing methods for the macro assembly of 3D MXenes usually require high temperatures and high-concentration MXene solutions, which exacerbate the oxidation of MXene and result in poor surface utilization. In this paper, a simple and rapid zinc-assisted electrodeposition strategy utilizing a low-concentration MXene solution was used to successfully prepare Ti3C2Tx MXene hydrogel. This self-assembled 3D porous structure inhibits MXene layer stacking, shortens the electrolyte ion transport/diffusion pathways, and exposes a higher number of electrochemically active sites. As a supercapacitor electrode, Zn-Ti3C2Tx exhibits good capacitance (352 F g-1 at 2 mV s-1) and excellent rate performance (73.3% at 1 V s-1). The assembled Zn-Ti3C2Tx/carbon cloth all-solid symmetric supercapacitor (ASSC) device exhibits excellent energy density (11.65 Wh kg-1) under a power density of 104.85 W kg-1. This research offers new ideas for designing porous MXene-based materials.