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

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 Ti3C2 MXene-based electrodes. However, research on MXenes for supercapacitor applications has been primarily focused on Ti3C2, 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 Ti2C, Mo2C, and Mo1.33C 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, V2C, in three aqueous electrolytes. Excellent specific capacitances were achieved, specifically 487 F/g in 1 M H2SO4, 225 F/g in 1 M MgSO4, 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 V2C MXene for energy storage using aqueous electrolytes.