Bimetallic CoS-CuCo2O4 composite microstructure decorated on Ni foam as highly efficient electrode material for advanced supercapacitor applications

Abstract

In this article, a composite material consisting of metal sulfide (CoS) and bimetallic oxide (CuCo2O4) was prepared by hydrothermal and ultrasonication methods. As prepared CoS-CuCo2O4 composite and its pure counterparts i.e., CoS and CuCo2O4 were characterized by different physiochemical characterization techniques. XRD analysis of CoS-CuCo2O4 showed presence of both CoS and CuCo2O4 phases. FT-IR analysis displayed different vibrational modes from CoS and CoS-CuCo2O4. Morphological investigations revealed unique microstructure of CoS-CuCo2O4 composite consisting of sheet like assembly and asymmetric particles. As supercapacitor electrode, CoS-CuCo2O4 exhibited high specific capacitance of 1116.4 F/g at 5 mV/s and 1073.3 F/g at 1 A/g, in a three-electrode setup. A high rate performance of 80.9 % was achieved for CoS-CuCo2O4 electrode. The impedance performance was assessed by EIS analysis which showed low Warburg resistance for CoS-CuCo2O4. The value of RES for CoS-CuCo2O4 was obtained as 0.14 Ω that was lower than that of CoS (0.81 Ω) and CuCo2O4 (5.72 Ω). In addition, CoS-CuCo2O4 showed excellent cyclic stability (89.3 %) up to 3000 cycles. As obtained findings indicated that CoS-CuCo2O4 has the capacity to be applied as efficient material for supercapacitor applications.