Hierarchical architecture of PANI@TiO2/Ti3C2Tx ternary composite electrode for enhanced electrochemical performance

Abstract

A hierarchical structure of PANI@TiO2/Ti3C2Tx ternary composite for high performance electrochemical capacitors was prepared by a hydrothermal treatment combining with in situ polymerization process. Layered Ti3C2Tx was used as both an active material with large surface area and a framework providing more paths for ion insertion/extraction. The introduction of PANI nanoflakes and TiO2 nanoparticles can offer an enhanced performance due to their good pseudocapacitance behavior and increased surface area of active materials. The hierarchical PANI@TiO2/Ti3C2Tx ternary composite exhibits high specific capacitance of 188.3 F g−1 at 10 mV s−1, which is about twice higher than that of TiO2/Ti3C2Tx, and 435.4 F cm−2 at 0.5 A g−1 in KOH solution. Furthermore, it also shows remarkable cycle stability, remaining at 94% of the initial value even after 8000 cycles at a current density of 1 A g−1. The enhanced electrochemical performance can be attributed to the hierarchical architecture and the synergistic effect of combining PANI nanoflakes with TiO2/Ti3C2Tx composite. This work propels a novel way of using MXene matrix to prepare hierarchical structure composite for next-generation electrochemical capacitors electrode.