Interface engineering of self-supported Ni3S2/MoS2@MXene heterostructure on nickel foam for advanced asymmetric supercapacitor with superior energy density

Abstract

High-performance electrode materials with strong conductivity and robust interfacial coupling are essential for next-generation supercapacitors. Herein, we demonstrate a binder-free in situ growth of an Ni₃S₂/MoS₂ heterostructure on an MXene-modified nickel foam, forming abundant electrochemically active interfaces. The hierarchical nanosheet heterostructure promotes fast ion and electron transport, while the conductive MXene framework enhances charge-transfer kinetics and mechanical integrity. As a result, the Ni₃S₂/MoS₂@MXene/NF electrode delivers a high specific capacitance of 2310 F g⁻¹ at a current density of 1 A g⁻¹, with good capacitance retention of ∼70% after 4000 cycles. Electrochemical impedance spectroscopy reveals a low charge-transfer resistance and fast ion diffusion, confirming the rapid kinetics achieved through interfacial engineering. The assembled asymmetric supercapacitor, using Ni₃S₂/MoS₂@MXene/NF as the positive electrode and activated carbon/NF as the negative electrode, achieves a specific capacitance of 131.25 F g⁻¹ at a current density of 1 A g⁻¹ and a remarkable energy density of 46.66 Wh kg⁻¹ at a power density of 2880 W kg⁻¹ while retaining 81.15% of its initial capacitance at a higher current density of 10 A g⁻¹. These results highlight the great potential of the Ni₃S₂/MoS₂@MXene hybrid architecture for developing high-performance energy storage devices. This work establishes an effective approach for designing multifunctional hybrid electrodes and offers new opportunities for the development of next-generation energy storage devices.