Two-dimensional vanadium carbide (V2C) MXene as electrode for supercapacitors with aqueous electrolytes.

Abstract Recently, a large family of 2D materials called MXenes have attracted much attention in the field of supercapacitors, thanks to the excellent performance demonstrated by Ti 3 C 2 MXene-based electrodes. However, research on MXenes for supercapacitor applications has been primarily focused on Ti 3 C 2 , even though there are more than 20 other members of this large family of materials already available. Studies on other MXenes are emerging, with promising results already achieved by Ti 2 C, Mo 2 C, and Mo 1.33 C in aqueous electrolytes. Yet, many other MXenes remain unexplored in aqueous supercapacitor applications. In this work, we report on the electrochemical behavior of a vanadium carbide MXene, V 2 C, in three aqueous electrolytes. Excellent specific capacitances were achieved, specifically 487 F/g in 1 M H 2 SO 4 , 225 F/g in 1 M MgSO 4 , and 184 F/g in 1 M KOH, which are higher than previously reported values for few micrometer-thick delaminated MXene electrodes. This work shows the promise of V 2 C MXene for energy storage using aqueous electrolytes. Graphical abstract Unlabelled Image Highlights • A flexible freestanding film was prepared from MXene V 2 C nanosheets. • V 2 C MXene was investigated as electrode for supercapacitors with three aqueous electrolytes. • The best performance, 487 F/g, was obtained in 1 M H 2 SO 4. • V 2 C exhibited higher specific capacitance than previously reported MXenes. [ABSTRACT FROM AUTHOR]