In situ synthesis of NiMoO4 cathode with high cycle stability and high specific capacitance for supercapacitors on nickel foam via gamma irradiation

To enhance the capacitive performance of supercapacitors, NiMoO4 electrode materials were synthesized by applying a molybdenum source to the nickel foam (NF) surface using irradiation technology. The morphology, microstructure, and electrochemical properties of the materials were optimized by varying the absorbed dose. The in situ synthesized NiMoO4 on an NF surface is an effective anode material for supercapacitors, demonstrating impressive energy storage capabilities. Its specific capacitance reaches 586.1 C/g at a current density of 1 A/g. It maintains a specific capacitance of 361.5 C/g at 15 A/g, resulting in a performance retention of 85.6%. Furthermore, the material retains a specific capacitance of 533.4 C/g with a capacity retention rate of 91.6% after 10 000 charge/discharge cycles, indicating strong cycling stability. The NiMoO4 electrode material was combined with activated carbon (AC) to create a hybrid supercapacitor, NiMoO4//AC. This device, operating at a maximum voltage of 1.7 V, exhibited a high energy density of 44.5 Wh/kg at a power density of 800.0 W/kg. The specific capacitance of the device remained at 93.2% after 5 000 charge/discharge cycles at a current density of 10 A/g. This study demonstrated that NiMoO4 electrode materials, prepared via irradiation, possess excellent electrochemical properties and significant application potential, offering a novel approach for designing high-efficiency, low-cost supercapacitor electrodes.