Nanorod-Structured NiCo ₂ O ₄ /Moss-Like Ni(OH) ₂ Composites with Enhanced Capacitive Performance for Photorechargeable Devices

during prolonged cycling. The results show that the composite electrodes exhibit a specific capacitance of 2170.22 F/g (301.42 mAh/g) at 1 A/g and a capacitance retention of 82.3% at 20 A/g, with the assembled supercapacitor maintaining 91.94% of its initial capacitance after 6000 cycles at 2 A/g. Benefiting from the improved performance, particularly the rate capability, the resulting photorechargeable supercapacitors achieve a solar-to-electrochemical energy efficiency of 16.21%. This study provides a nanostructure engineering strategy for improving the capacitive behaviors of materials, advancing high-performance photorechargeable devices.