Co2SnO4/activated carbon composite electrode for supercapacitor

A new kind of Co2SnO4-based electrode materials for supercapacitor was synthesized by co-precipitation method. The microstructure and surface morphology of Co2SnO4 were characterized by X-ray diffraction and scanning electron microscopy, respectively. Cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy were employed for the determination of specific capacitance and the equivalent series resistance of Co2SnO4/activated carbon composite electrode in KCl solution. It was shown that the composite electrode with 25 wt% Co2SnO4 had excellent specific capacitance up to 285.3 F g−1 at the current density of 5 mA cm−2. In addition, the composite electrode exhibited excellent long-term stability and, after 1000 cycles, 70.6% of initial capacitance was retained. Regarding the low cost, easy preparation, steady performance and environment friendliness, Co2SnO4/activated carbon composite electrode could have potentially promising application for supercapacitor. -- Highlights: ► Crystalline Co2SnO4 was synthesized by co-precipitation method. ► The specific capacitance of Co2SnO4/AC composite electrode was up to 285.3 F g−1. ► Co2SnO4/AC composite electrode showed excellent electrochemical reversibility. ► Co2SnO4/AC composite electrode showed long cycle life and high stability.