Electrostatic self-assembly of WO3/Ti3C2Tx MXene composite as anode for lithium-ion batteries

The limited theoretical capacity exhibited by commercial graphite electrodes in lithium-ion batteries (LIBs) necessitates the exploration and development of innovative anode materials that possess superior rate performance, reversible specific capacity, and extended cycle life. Research has found that MXene exhibits metallic conductivity and a unique two-dimensional layered structure, which has attracted great interest and attention in electrochemical energy storage. Tungsten trioxide (WO₃) is a low-cost n-type semiconductor material. When utilized as the anode material in lithium-ion batteries, the active sites generated by it can enhance the electrochemical properties of the batteries. In this study, WO₃/MXene hybrids were synthesized using an efficient electrostatic self-assembly technique. This composite material combines the advantages of both WO₃ and MXene, facilitating rapid electron and ion transport at the interface while effectively mitigating structural alterations during the cycling process. When utilized as the anode material for lithium-ion storage, the WO₃/MXene composite demonstrates enhanced reversible capacity and exceptional cycling stability. It demonstrates a reversible specific capacity of 318.5 mA h g^-1 after 100 cycles at 100 mA g^-1 and experiences an increase in specific capacity from 191.8 mA h g^-1 to 302.9 mA h g^-1 after 400 cycles at 200 mA g^-1. After elucidating the enhancement mechanism through a range of tests, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), we conclude that the WO₃/MXene composite is a promising candidate as an anode material for lithium-ion batteries.