Research on CuxSy/CoSz/graphene supercapacitor electrode materials

Abstract

Multilayer graphene was prepared in this study by microwave burst method. Cu9S5/CoS/graphene and CuS/CoS2/graphene composites were obtained by hydrothermal method to regulate the molecular structure and combination of Cu and Co metal sulfides on graphene substrate. Graphite oxide was doped by hydrothermal method, and then Cu9S5/CoS/graphene composite was prepared by microwave explosion method. Raman, SEM and TEM were used to characterize the self-made graphene. Results showed that the multilayer graphene had a bag-like structure which was beneficial to anchor sulfide. Three graphene-based composites were characterized by scanning electron microscopy, X-ray diffraction, energy spectrum analysis and electrochemical properties. Moreover, results showed that CuS/CoS2/graphene had the best electrochemical performance, and its specific capacity reached 324 F/g when the current density was 1 A · g–1, which was much higher than that of the other two samples. Capacity retention rate, interfacial charge transfer resistance and electrolyte diffusion resistance also have advantages.