▎ 摘　　要

Exploration of new MXene-based materials with excellent electrical conductivity and a high redox-active surface as high electrochemical performance supercapacitor electrodes is a very promising field. However, it remains challenging to have electrode materials that feature ultrahigh specific capacitance. In this work, NiO nanoflowers uniformly grow onto a V4C3TX substrate to form a core-shell hierarchical V4C3TX@NiO heterostructure, and then the heterostructure is incorporated into a 3D interconnected porous hydrogel via a hydrothermal graphene oxide (GO)-gelation method at low temperatures. Due to the synergistic effect among each components as well as the significant prevention of the aggregation of V4C3TX, the free-standing V4C3TX@NiO-reduced graphene oxide (RGO) heterostructured hydrogel electrodes exhibit an ultrahigh specific capacitance of up to 1009.5 F g(-1) at 1 A g(-1), in comparison to those of V4C3TX@NiO (665.3 F g(-1)) and V4C3TX (184 F g(-1)), excellent cycling stability (capacity retention rate is 97.4% for the device after 10 000 cycles at 10 A g(-1)), and a maximum energy density of 61.13 W h kg(-1) at a power density of 526.32 W kg(-1). This work highlights the unique potential of V4C3TX-based heterostructured hydrogels as inspired electrode materials for low-cost supercapacitor devices.