ZnCo₂O₄/CuS/rGO ternary nanocomposites with enhanced capacitance and stability for advanced supercapacitors
摘要
The development of efficient and stable electrode materials is essential for advancing next-generation supercapacitors. In this study, ternary ZnCo₂O₄/CuS/rGO nanocomposites were successfully fabricated using a straightforward hydrothermal approach. The resulting hybrid exhibits a layered, sheet-like structure with a high specific surface area of 78.4 m² g⁻¹ and mesopores averaging 3 nm, providing plentiful active sites and promoting rapid ion transport. Electrochemical evaluation shows that the ZnCo₂O₄/CuS/rGO electrode achieves a high specific capacitance of 953 F g⁻¹ (158.8 mAh g− 1) at 1 A g⁻¹, nearly doubling the performance of the binary ZnCo₂O₄/CuS material, which exhibits the specific capacitance of 508 F g⁻¹ (84.6 mAhg− 1) at 1 A g⁻¹). The composite also demonstrates outstanding stability, retaining 95.5% of its initial capacitance and a coulombic efficiency of ~ 101.5% after 5000 cycles. The assembled asymmetric supercapacitor delivers an energy density of 65 Wh kg⁻¹ at 877 W kg⁻¹, while maintaining 35 Wh kg⁻¹ at 3117 W kg⁻¹, confirming its high-rate capability and robust performance. These findings demonstrate that ZnCo₂O₄/CuS/rGO is an excellent electrode material for high-performance energy storage devices since it is both inexpensive and long-lasting.