A Ti3C2Tx MXene/alginic acid-derived mesoporous carbon nanocomposite as a potential electrode material for coin-cell asymmetric supercapacitors

In this study, we demonstrate MXene (Ti3C2Tx)-based coin-cell asymmetric supercapacitor (coin-cell ASC) exhibiting high energy density and high power density along with good capacitance. We synthesized mesoporous carbon (MC) by annealing alginic acid at varying temperatures (900 degrees C, 1000 degrees C and 1100 degrees C). Among the prepared samples, MC-1000 exhibited a highly porous structure and a higher surface area. We then developed a Ti3C2Tx/MC (MC-1000) nanocomposite using a simple and efficient solvothermal method. The synthesized nanocomposite displayed the layered morphology of MXene alongside the amorphous characteristics of carbon, indicating a strong interaction between the two materials. Notably, the Ti3C2Tx/MC-9 nanocomposite features a higher number of pores and a larger surface area than either MXene or MC-1000, significantly enhancing its capacitive performance. We evaluated the performance using a three-electrode system, revealing an impressive specific capacitance (Csp) of 1629 F g-1 at 1 A g-1, with a retention of 99.9% even after 35 000 cycles. Furthermore, the fabricated coin-cell ASC using (MC-1000//Ti3C2Tx/MC-9) electrodes demonstrated a Csp of 80.3 F g-1 at 1 A g-1 and a high energy density of 56 W h kg-1, corresponding to a maximum power density of 10 423 W kg-1 at 5 A g-1. The key factors contributing to the enhanced electrochemical performance include the strong connection between MXene and MC-1000, along with the large specific surface area and high porosity of the electrode materials.