Highly performed electrochemical activities of hybrid supercapacitors based on CeO2-Sm2O3 nanocomposites

The highly performed electrochemical energy storage systems have been required to rectify the reduction of sustainable energies in recent times. Herein, we investigate a facile hydrothermal synthesis of binary cerium oxide-samarium oxide nanocomposites (CeO2-Sm2O3 NCs) and study their electrochemical performance of Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS) analysis. The structure, chemical bonds, and morphology of the synthesized nanocomposites have been analyzed by XRD, FTIR, SEM with EDX, and HR-TEM with SAED pattern. From the CV study, the binary CeO2-Sm2O3 NCs reveal 397.50 C/g of higher specific capacity compared to individual CeO2 (72.85 C/g) and Sm2O3 (122.80 C/g). The Trasatti and Dunn's method manifests the outer (Co), total (CT), and inner (Ci) capacities of 165.05, 531.91, and 366.86 C/g for the prepared binary CeO2-Sm2O3 NCs. The stability of CeO2-Sm2O3 NCs delivers 97.84% excellent retention and 101.21% coulombic efficiency over 3000 cycles. Furthermore, the hybrid supercapacitor (CeO2-Sm2O3//AC) device has been developed and their electrochemical behaviors were analyzed in two electrode setup. The constructed device manifests a higher specific capacity of 139.97 C/g at 0.5 A/g current density, better retention of 86.92% and coulombic efficiency of 100.02% at 5 A/g over 3000 cycles, the higher energy density of 32.85 Wh/kg, and a higher power density of 4223.91 W/kg respectively.