Enhanced electrochemical performance of molten salt synthesized V2CTx MXene@VOx composite in Zn ion aqueous electrolytes

The development of MXenes using Lewis acidic salts for etching (MS-MXenes) in molten salts presents a novel, fluorine-free method attracting considerable interest. However, the behavior of various MS-MXenes and their derivatives in aqueous environments remains largely unexplored. Particularly, vanadium-based MXenes demonstrate intriguing properties in Zn ion aqueous electrolytes. Herein, a fluorine-free V 2 CT x MXene@VO x is synthesized by molten salt etching under an argon atmosphere. The electrochemical properties of V 2 CT x @VO x are tested in various aqueous electrolytes, including Zn(TFSI) 2 , ZnSO 4 , ZnBr 2 , ZnAc 2 , and ZnCl 2 solutions. The V 2 CT x @VO x shows high redox capacities in all these Zn ion electrolytes, with the peak performance observed in 1 M ZnBr 2 , achieving a maximum capacity of 172 mAh g −1 at 1 mV s −1 . This performance rivals that of V 2 CT x MXene prepared through wet-chemical methods. These results underscore the potential of MS-MXenes materials in aqueous energy storage applications.