Two-dimensional V4C3MXene as high performance electrodematerials for supercapacitors
Two-dimensional (2D) MXenes such as Ti 3 C 2 , Ti 2 C, Mo 2 C, and Mo 1.33 C have shown excellent electrochemical performances as supercapacitor electrodes, and the exploration of new and/or high-capacity MXene-based supercapacitor electrode materials is an active field. In this work, 2D multi-layered V 4 C 3 MXene has been synthesized by selectively etching Al from V 4 AlC 3 and it shows a high capacitance of 209 F g −1 at 2 mV s −1 , good rate performance, and stable long cyclic performance with capacitance retention rate of 97.23% after 10000 cycles at 10 A g −1 in 1 M H 2 SO 4 . Importantly, the pseudocapacitance (∼100.1 F g −1 ) accounts for about 37% of the total capacity (∼268.5 F g −1 ) for V 4 C 3 MXene electrode. Therefore, the high specific capacitance of V 4 C 3 MXene is not only due to their wide interlayer spacing (∼0.466 nm), large specific surface areas (∼31.35 m 2 g −1 ) and pore volumes (∼0.047 cm 3 g −1 ), and good hydrophilicity but also attributed to the abundant valence states of vanadium (+2, +3, and +4). The high rate performance and excellent cycling stability of V 4 C 3 MXene electrodes are mainly attributed to the high electronic conductivity (1137 S m −1 at 300 K). The present work provides another promising MXene-based supercapacitor electrode material.