Fast and low-consumption granular NiCo-LDH/graphene nanosheet composites for high-performance supercapacitor electrodes

In this work, graphene nanosheets (rGNS) were prepared by rapidly reducing graphene oxide (GO) at room temperature. The cobalt organic framework (Co-MOF) was etched with nickel nitrate, and nickel–cobalt layered double hydroxides (NiCo-LDH)/rGNS was synthesized using rGNS as the growth substrate. Scanning electron microscopy shows that the material grows in a morphology of granular particles on the rGNS substrate. A three-electrode system was used to study the electrochemical properties of the material. Adjusting the reaction time of ion exchange can greatly improve the electrochemical performance of the materials. The results show that the performance of the materials is optimal when the reaction time is 120 min. The specific capacitance of NiCo-LDH/rGNS at 1 A/g reaches 2179 F/g, which is about twice that of NiCo-LDH, and only reduced by 19% at 10 A/g. When the reaction lasted for 120 min, NiCo-LDH/rGNS still maintained 88% of the initial specific capacitance after 3000 cycles. The strategy of the electrode material is fast, low consumption, and has good electrochemical performance. It is expected to become a potential application material for commercial applications.