Designed formation of 2D/2D hierarchical V2CTx MXene/NiV layered double hydroxide heterostructure with boosted electrochemical performance for asymmetric supercapacitors

Designing exceptional hierarchical structure of nanocomposites has far-reaching significance for improving the electrochemical performance. Herein, a new 2D/2D hierarchical structure of V2CTx MXene/NiV layered double hydroxide (V2CTx/NiV-LDH) composite was successfully constructed by in-situ synthesis method. The introduction of V2CTx MXene with high electrical conductivity can suppress the aggregation of NiV-LDH nanosheets and relieve the volume change, which significantly improves the electrical conductivity of the composites and provides more active sites. The synergistic effect of NiV-LDH and V2CTx effectively enhances the charge storage capacity. The specific capacitance of V2CTx/NiV-LDH-10 electrode at 1 A g-1 is 1658.19 F g-1. Meanwhile, V2CTx/NiV-LDH-10 exhibits excellent stability with 80.95 % capacity retention after 10,000 cycles. Moreover, the asymmetric supercapacitor based on V2CTx/NiV-LDH-10 (positive electrode) and AC (negative electrode) assembled achieves a maximum energy density of 54.19 Wh kg- 1 at a power density of 750 W kg- 1. The results show that V2CTx/NiV-LDH-10 is a promising electrode candidate material for green energy storage.