MoS₂ nanosheets as an efficient matrix for CuFe₂O₄ nanoparticles toward high-performance supercapacitors

Designing advanced electrode nanostructures is crucial for overcoming the limits of conventional supercapacitors and obtaining high energy density while maintaining long-term stability. In this study, a copper ferrite (CuFe₂O₄) and molybdenum disulfide (MoS₂) nanocomposite was created by combining hydrothermal and ultrasonic techniques, and it was employed as an electrode material for high-performance symmetric supercapacitors with an H₂SO₄-based gel electrolyte. The interaction between the layered MoS₂ nanosheets and the spinel CuFe₂O₄ nanoparticles provided abundant active sites, enhanced ion diffusion pathways, and increased electronic conductivity. As a result, the device exhibited a high specific capacitance of 473.75 F g⁻¹ at 10 mV s⁻¹, along with strong rate performance. Electrochemical impedance spectroscopy revealed a low series resistance ( R _s = 3.41 Ω) and charge-transfer resistance ( R _ct = 1.9 Ω), together with a high phase angle of 77.49°, indicating excellent electrical conductivity and rapid ion transport within the MoS₂@CuFe₂O₄ electrode. The relaxation time constant ( τ ₀ ≈ 9.81 s, f ₀ = 0.1019 Hz) further confirmed fast charge-transfer kinetics. Outstanding durability was demonstrated by long-term cycling, maintaining 96.94% capacitance retention after 10,000 cycles with 98% Coulombic efficiency. The device also delivered a high energy density of 58.75 Wh kg⁻¹ at a power density of 750 W kg⁻¹, highlighting its strong practical potential. These results highlight the cooperative combination of MoS₂ conductivity and CuFe₂O₄, making MoS₂@CuFe₂O₄ a promising electrode material for next-generation supercapacitors.