Hydrothermally Synthesized rGO-Coated NiCo2O4/MoS2 Cubes as High-Performance Positive Electrode for Asymmetric Supercapacitors

Abstract

A novel hierarchical NiCo₂O₄/MoS₂@rGO composite was synthesized to improve the electrochemical properties of supercapacitors. The nanocomposite combines the enhance capacity of NiCo₂O₄, the excellent ion storage capability of MoS₂, and the conductive support of rGO, addressing challenges related to energy density, cycle life performance. The NiCo₂O₄/MoS₂@rGO nanocomposite exhibits an impressive specific capacitance of 1696 F g⁻¹ at 1 A g⁻¹, and the resulting asymmetric supercapacitor (NiCo₂O₄/MoS₂@rGO//AC) demonstrates an increased energy density of 56.45 Wh kg⁻¹ and a power density of 750 W kg⁻¹. Moreover, the composite retains 95.2% of its initial capacitance over 10,000 cycles at 1 A g⁻¹, showing exceptional cycling performance. These improvements are due to the synergistic interaction of NiCo₂O₄, MoS₂, and rGO, where MoS₂ serves as an effective ion buffer, enhancing ion diffusion and transport, while rGO improves conductivity and structural stability. The NiCo₂O₄/MoS₂@rGO composite exhibits great promise for advanced asymmetric supercapacitor applications, offering large energy capacity, rapid charge/discharge performance, and exceptional longevity.