Litchi-Skin-Like NiMoP₂ Microspheres Supported on MOF-Derived Carbon Layer as High Performance Composite Positive...

Developing ideal positive electrodes with excellent performance and structural stability for supercapacitors is crucial in enhancing the application potential. Herein, we successfully fabricate a composite structure of NiMoP₂@C on nickel foam (NF) (NMP@C/NF), which is formed by loading a litchi-skin-like morphology NiMoP₂ microspheres onto MOF-derived carbon layer with the two-step electrodeposition method. The carbon layer acts as a structurally stable framework, and its synergistic effect with active materials suppresses volume expansion while enhancing electron transport efficiency. Meanwhile, the heterogeneous interface between crystalline/amorphous phases optimizes redox reaction kinetics, and the unique morphology composed of multi-scale components increases the accessible surface area for redox reactions. As a result, the NMP@C/NF obtains a high specific capacitance of 2224.8 F g^-1 at 1 A g^-1, and the capacitance retention rate is 94.97% after 8000 cycles. The asymmetric supercapacitor (ASC) assembled with NMP@C/NF positive electrode and active carbon negative electrode generates an energy density of 52.52 Wh kg^-1 at a power density of 784.55 W kg^-1, and its capacitance retention rate reaches up to 78% after 8000 cycles. This study provides promising pathway for the rational design of high-performance and environmentally friendly positive electrodes for supercapacitors.