Interfacial-Engineered NiZn-MOF@MXene Core-shell Heterostructure for High-Performance Asymmetric Supercapacitors

The development of efficient energy storage devices simultaneously delivering high energy density, rapid charge transport, and long-term stability remains a major challenge for next-generation electronics. Herein, a hierarchical NiZn-MOF@MXene core-shell heterostructure is synthesized through a facile hydrothermal strategy and explored as an electrode material for high-performance asymmetric supercapacitors. The integration of redox-active bimetallic NiZn metal-organic framework (MOF) with conductive Ti₃C₂T_x MXene nanosheets provides abundant electroactive sites while facilitating rapid electron transport and efficient ion diffusion. The core-shell architecture effectively suppresses the restacking of MXene layers and exposes abundant electrochemically active sites. As a result, the electrode delivers a high specific capacitance of 1827 F/g at 1 A/g and excellent cycling stability with 92.4% retention after 10000 cycles in a three-electrode configuration. The assembled NiZn-MOF@MXene//activated carbon asymmetric supercapacitor operates within a voltage window of 1.6 V, achieving an energy density of 84.9 Wh/kg at a power density of 3200 W/kg, while maintaining 90.5% capacitance retention after 10000 cycles. The superior performance arises from the synergistic interaction between Ni/Zn redox centers and the conductive MXene framework, which improves charge-transfer kinetics and structural stability. These results highlight an effective strategy for designing advanced MOF-MXene hybrid electrodes for next-generation high-performance energy storage systems.