Synthesis of an MXene/polyaniline composite with excellent electrochemical properties

Abstract

As a family member of MXenes, Ti3C2Tx has received worldwide interest due to its excellent electrochemical energy storage properties. However, freestanding Ti3C2Tx films synthesized by direct assembly of two-dimensional (2D) sheets have relatively low specific capacitance and rate capability due to the low ion transport efficiency between Ti3C2Tx (MXene) sheets. Here, we demonstrate an effective method to improve the electrochemical performance of MXene-based electrodes by incorporating MXene sheets with conducting polymers. A Ti3C2Tx/polyaniline (MXene/PANI) composite was fabricated by chemical oxidative polymerization of aniline monomers on the surface of Ti3C2Tx sheets. Benefiting from the highly conductive open structure, efficient ion and electron transport and high electrochemical activity of Ti3C2Tx and PANI, the MXene/PANI electrode presents a maximum specific capacitance of 556.2 F g-1 at a current density of 0.5 A g-1, an impressive rate capability (high capacitance retention of 78.7% at 5 A g-1) and excellent cycling stability with a high capacitance retention of 91.6% after 5000 cycles at 5 A g-1. Therefore, this paper provides a facile and effective method to achieve high performance MXene-based electrode materials for supercapacitors.