Effect of carbon blacks filler addition on electrochemical behaviors of Co3O4/graphene nanosheets as a supercapacitor electrodes

A series of cobalt oxide/graphene nanocomposites have been successfully synthesized by adding carbon blacks filler. We have introduced carbon blacks to act as a structural modifier in fabricating graphene based composites. The composites were prepared by ultrasonication and microwave-assisted methods. Microstructure measurements showed that carbon blacks could be conductive links among layers of graphene and cobalt oxide particles (5–7 nm in size), which was deposited on the edge surfaces of nanosheets. This composite could function as a stable structured blocks for preventing an aggolomeration of graphene layers. The electrochemical properties are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS). The prepared nanocomposites showed the superior capacitive performance with good rate capability, large specific capacitance, and excellent cyclic performance. Among various samples, Co3O4/GNS–CB (15 wt.%) showed the largest specific capacitance of 341 F g−1 at a scan rate of 10 mV s−1 in 6 M KOH electrolyte. Therefore, the prepared composite could be potential electrode materials for supercapacitors.

A series of cobalt oxide/graphene nanocomposites have been successfully synthesized by adding carbon blacks additive. We have introduced carbon blacks to act as a structural modifier in fabricating graphene based composites. Scheme of the formation of composites consisting of cobalt oxide and carbon blacks added graphene nanosheets is shown. The prepared nanocomposites showed the superior capacitive performance with good rate capability, large specific capacitance, and excellent cyclic performance.Figure optionsDownload as PowerPoint slideHighlights
► Cobalt oxide/graphene composites have been prepared by adding carbon blacks.
► Carbon blacks addition improved electrode structural stability and charge–discharge cycle stability.
► Composites showed the better capacitive performance such as rate capability, specific capacitance, and cycle performance.
► Carbon blacks could prevent graphene-based composites from an aggregation and improve an electrical conductivity.