Metal Sulfide/Mxene Based Nanostructured Electrode Materials for High-Performance Supercapacitors

Abstract

2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, due to their unique layered structure, high surface area, remarkable chemical stability, and electrical conductivity for energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, the low capacity of MXene electrodes limits their further application in ECs. In this study we developed the electrode materials comprised of titanium carbide MXene (Ti3C2Tx) decorated with MWCNTs and Metal Sulfide, which are both 2D layered materials that contribute to the fast ion diffusion in the interdigitated electrode architecture. The nanocomposite samples have been characterized by XRD, SEM, TEM, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. Due to the synergistic effect between Metal sulfide and Ti3C2 matrix, the nanocomposite exhibits a superior capacitance and shows excellent cycling stability with capacitance up to several hundred cycles. These results show that pseudocapacitive MXene based negative electrodes exhibits excellent properties in asymmetric electrochemical capacitors, leading to an increased energy density.