Ti3C2Tx MXene/Alginic Acid-Derived Mesoporous Carbon Nanocomposite as a Potential Electrode Material for Coin-Cell Asymmetric Supercapacitor

Abstract

In this study, we demonstrate a 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°C, 1000°C and 1100°C). Among these, MC-1000 exhibited 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 Fg⁻¹ at 1 Ag⁻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 Fg⁻¹ at 1 Ag⁻¹ and a high energy density of 56 Whkg⁻¹, corresponding to a maximum power density of 10,423 Wkg⁻¹ at 5 Ag⁻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.