Fabrication And Electrochemical Performance Of Graphene/cobalt Oxide Composites

Graphene, a kind of two-dimensional carbon material, is composed of sp2 bonded carbon atoms, which exhibits excellent electrochemical performance. These excellent abilities make graphene to be the current research hotspots in the field of energy storage.In this study, we designed two kinds of graphene/cobalt oxide composites nanostructure. The mainly research contents are below:1.The needle-like Co(CO3)0.5(OH)?0.11H2 O /GO composites precursor was firstly obtained by hydrothermal method. Then, the needle-like composites precursor was annealed in the inert environment, leading to Co3O4 /GNS composites. We explored the capacitor performance of Co3O4 /GNS composites by the three electrode, and found that the capacity of needle-like composites was still retained over 70% of the initial capacity after 4000 cycles at 2 mol/L KOH.2.The nanorod Co5(OH)2(CH3COO)8?2H2O /GO compsites with the size of 1~3 μm were synthesized by recrystallization method. Then these composites were annealed in the vacuum environment, finally the nanocrystal with the size 2~20 nm CoO /GNS composites were obtained. Then, we measured the lithium battery performance and found that these composites could still maintain 626.3 mAh/g after 104 cycles at the current density of 500 mA/g, while the capacity of CoO /Co was only 146.5 mAh/g.All in all, the synthesis of the graphene/ cobalt oxide could effectively improve the conductivity of the cobalt oxide, on the contrary, the nanocrystal cobalt oxide could also hinder the aggregation of the graphene sheets. Meanwhile, these composites show both the advantages of graphene and cobalt oxide, which are benefit to enhance the electrochemical performance of the supercapacitor and lithium ion battery.