Ti₂CT_x–MXene aerogel based ultra–stable Zn–ion supercapacitor

Zn–ion supercapacitors (ZISCs) have emerged as a potential technology for energy storage applications because of their rich natural resources, eco–friendly nature, and excellent safety. However, the development of ZISC is in its early stages, and work on cathode materials is still required to significantly improve the charge storage ability. Herein, ZISC is assembled by combining zinc metal anode and Ti₂CT_x–MXene aerogel (MXene–A) as a cathode (denoted by MXene–A//Zn). The MXene–A cathode material provides high structural stability, an abundance of active sites, and an excess of open channels, which allow rapid ion diffusion. The MXene–A//Zn exhibits a high specific capacitance of 233.5 F/g at 1 A/g, with capacitance retention of 98.3% after 5000 cycles and Coulombic–efficiency close to 99%. The MXene–A//Zn exhibited outstanding charge performance, and the capacitive mechanism is predominant in total charge (73.6% at 4 mV/s). Additionally, the MXene–A//Zn demonstrates a maximum energy density of 129.83 W h/kg at a power density of 1000.8 W/kg. This work introduces a novel approach to the design of energy storage devices with enhanced electrochemical performance.