Enabling Ti₂C MXene on carbon cloth as binder-free anode for distinguished lithium-ion and sodium-ion storage

Two-dimensional transition metal carbides and nitrides (MXenes) hold promise as electrode materials for alkali metal ion batteries on account of some fascinating peculiarities. However, the high temperature required in the synthesis of the MAX phase severely hinders its further development. Herein, MAX phase (Ti₂AlC) is first grown on carbon cloth (CC) by molten salt method at a milder temperature, then the hierarchical structure that Ti₂C sheets arrayed on the carbon fibers can be obtained after HF treatment, demonstrating 269 mA h g⁻¹ after 400 cycles at 1 mA cm⁻² for lithium-ion storage and 206 mA h g⁻¹ after 100 cycles at 0.1 mA cm⁻² for sodium-ion storage when served as freestanding anode. Meanwhile, in-situ and ex-situ characterization techniques are employed to monitor the possible phase transitions in the electrochemical process. In addition, the kinetics for carrier diffusion in the electrochemical process is also studied. This work endows edification for configuration of MXene-based freestanding electrode.