Electrodeposition of Cobalt-Copper Oxides Decorated with Conductive Polymer for Supercapacitor Electrodes with High Stability

Here, we report about the synthesis of Cobalt-Copper (CC) mixed oxides prepared by electrodeposition and thermal annealing, and coated with PEDOT:PSS (CCP) for supercapacitor electrodes. The electrodes' morphology and electrochemical performance were investigated by combining XRD, XPS, SEM, cyclic voltammetry, and galvanostatic charge/discharge tests. The initial capacity of the CC electrode was 26 mAh/g at a scan rate of 5 mV/s with a coulombic efficiency of 92 %. The CC electrode featured a capacity retention of 81 % at a constant current density of 1 A/g after 5000 cycles. CCP electrodes slightly reduced the specific capacity but increased both coulombic efficiency and cyclic stability. CCP1 electrode featured a specific capacity of 21 mAh/g at 5 mV/s scan rate with better coulombic efficiency 95 % along with capacity retention of 92.3 % over 5000 cycles. Increasing the amount of PEDOT:PSS lowered the CC electrodes' specific capacity, but significantly improved the capacity retention up to 100 %.