Facile electrostatic coprecipitation of f-SWCNT/Co3O4 nanocomposite as supercapacitor material

Abstract

A facile electrostatic co-precipitation route has been employed to prepare f-SWCNT/Co3O4 nano-composite. The prepared samples have been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and BET. Application of the prepared samples has been evaluated as supercapacitor material in 6 M KOH solution using cyclic voltammetry in different potential scan rates, ranging from 5 to 50 mV s−1, and electrochemical impedance spectroscopy (EIS). The specific capacitance of f-SWCNT/Co3O4 has been calculated to be as high as 343 F g−1, much higher than that of obtained for pure Co3O4 nanoparticles (77 F g−1). Moreover, the composite material has shown better rate capability (55 % capacitance retention) in various scan rates in comparison with the pure oxide (40 % retention). The composite material also showed excellent cycling performance (92 % capacitance retention) over 5,000 continuous cycles. EIS results show that the composite material benefits form much lower charge transfer resistance, compared with Co3O4 nanoparticles.