Carbon nanotubes modified V-Ti3C2Tx/poly(3,4-ethylenedioxythiophene) composite as a high-performance electrode for supercapacitor

Abstract

Poly (3,4-ethylenedioxythiophene) (PEDOT) is an electrically conductive polymer that is highly conductive and oxidatively stable. However, its poor cycling stability and small specific capacitance limit its application as an electrode material for supercapacitors. In this work, carbon nanotubes (CNTs) modified V-Ti₃C₂T_x/poly(3,4-ethylenedioxythiophene) composite (CVT/PEDOT) was prepared by obtaining vanadium-doped Ti₃C₂T_x (V-Ti₃C₂T_x) using a simple hydrothermal method, and then polymerizing 3,4-ethylene-dioxythiophene monomers (EDOT) on the surface of carbon nanotubes modified V-Ti₃C₂T_x. The incorporation of CNTs with V-Ti₃C₂T_x results in better stability of CVT/PEDOT. The synergistic effect of the three components make the CVT/PEDOT composite have good electrochemical performance and excellent cycling stability as an electrode material for supercapacitor. The specific capacitance of CVT/PEDOT at a current density of 1 A g⁻¹ is up to 263 F g⁻¹, and the capacitance retention is 86 % after 5000 cycles at a current density of 10 A g⁻¹, which is superior to that of the V-Ti₃C₂T_x/PEDOT composite. The energy density of CVT/PEDOT is 15.26 Wh kg⁻¹ at a power density of 600 W kg⁻¹, which is higher than those of previously reported PEDOTs and other PEDOT-based composites. So, the CVT/PEDOT composite can be a potential candidate for electrode materials of supercapacitor.