Facile synthesis of NiCo₂O₄/rGO microspheres with high-performance for supercapacitor

NiCo₂O₄/rGO microspheres were synthesized by a hydrothermal reaction followed by a spray drying process. The existence of a rGO coating layer was responsible for a conductivity improvement and fast charge transport kinetics. Furthermore, an elastic matrix of rGO reinforced the structure stability and accommodated the volume expansion of the NiCo₂O₄ particles. Based on the above advantages, the NiCo₂O₄/rGO presented excellent electrochemical performance, such as an impressive specific capacitance (702 F g⁻¹ at 0.5 A g⁻¹) and notable cycling stability, maintaining 98.3% of the initial specific capacitance after 10000 charge-discharge cycles at 0.5 A g⁻¹. This simplified method is not only potentially beneficial for spinel-type hybrid electrode materials but also potentially suitable for mass production.