Facile synthesis of cobalt/nickel tungstate and its application in hybrid supercapacitor

In this paper, cobalt/nickel tungstate materials (CoWO4@NiWO4-A) have been synthetized by co-precipitation in alkaline condition, and the electrochemical behaviors of the samples were investigated. The as-prepared composites have been systematically characterized by powder X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller analysis. The pseudocapacitive performances of composite electrode materials were investigated by the electrochemical tests. The CoWO4@NiWO4-A showed good electrochemical performances. In addition, a hybrid supercapacitor (HSC) was assembled by using the CoWO4@NiWO4-A as the positive electrode and activated carbon (AC) as negative electrode. The HSC exhibited an energy density of 11.96 Wh/kg at a power density of 1090 W/kg. In addition, the HSC displayed good cyclic stability after 5000 continuous charge-discharge tests. Therefore, this work provides a candidate electrode materials for supercapacitors.