Oxidized mixed phase Ti₃C₂T_x MXene nanosheets as a high-performance Li-ion battery anode material

To address the challenge of low electronic and ionic conductivities in lithium-ion batteries (LIBs), we synthesized oxidized mixed-phase Ti₃C₂T_x MXene nanosheets using a wet chemical etching route. This prepared negative electrode demonstrated a reversible specific discharge capacity of 538.49 mAh/g at 0.1C (67 mA/g), which is significantly higher than the pristine MXene and retained 75.46% of its initial capacity during the rate performance test. During its testing for cycling stability, it demonstrated a stable discharge capacity of 383.33 mAh/g after 264 cycles at 0.1C (67 mA/g) and showed an increasing profile with a rosed capacity of 551.98 mAh/g after 404 cycles at 0.4C (268 mA/g). The exceptional electrochemical performance is attributed to the Ti₃C₂T_x MXene architecture, with oxidation of its nanosheets resulting in an increase in exposed Li⁺ sites leading to structural stability. The galvanostatic intermittent titration technique (GITT) was performed for the numerical analysis of Li⁺ mobility. To analyze the effective charge storage mechanism, electrochemical impedance spectroscopy (EIS) was also performed. This MXene electrode is found to be a promising negative electrode with a simple synthesis route demonstrating enhanced electrochemical performance and stability.