Electrochemical performances of iron-cobalt oxides nanoparticles loaded crumpled graphene for supercapacitor

Mixed transition metal oxides (MTMOs) have been explored as attractive electrode materials for supercapacitors owing to their higher electronic conductivity and larger specific capacitance compared with simple transition metal oxides. Among MTMOs, cobalt-based binary metal oxides such as Fe-Co oxides have emerged as alternative electrode materials for supercapacitors because they have the advantages of low cost, natural abundance, and environmental friendliness. Recently, graphene-based Fe-Co oxides composites have become of particular interest for their improved electrochemical performance of supercapacitors due to the synergetic effect of both materials. In this study, we present three-dimensional (3D) crumpled graphene (CGR) decorated with Fe-Co oxides nanoparticles to determine which molar ratio of Fe/Co can exhibit higher electrochemical performance. The Fe-Co oxides/CGR composites were synthesized in different molar ratios of Fe/Co via aerosol spray pyrolysis and post heat treatment. Sizes of Fe-Co oxides nanoparticles ranged from 5 to 10 nm when loaded onto 500 nm CGR. The electrochemical properties of the Fe-Co oxides/CGR composites with different molar ratios of Fe/Co were examined. The Fe-Co oxides/CGR electrodes fabricated at the Fe/Co ratio of 0.1 showed the highest performances in the capacitance and electrical conductivity among those electrodes with different molar ratios of Fe/Co. •3D Fe-Co oxides/CGR composites were synthesized in different molar ratios of Fe/Co.•The composites were decorated of oxides nanoparticles on the CGR.•The highest electrochemical performance was found at the Fe/Co ratio of 0.1.