Investigation of structural and electrochemical properties of SrFexCo1-xO3-δ perovskite oxides as a supercapacitor electrode material

In this study, perovskite materials SrFexCo1-xO3-δ (SCF-x, x = 0.2, 0.5, 0.8) were synthesized by sol-gel combustion and investigated as electrode materials for supercapacitors. The crystalline structure and morphology of the synthesized samples were thoroughly investigated using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) analyses. Partial substitution in the B-site of the perovskite structure affects the oxygen vacancy concentration and changes its electrochemical properties. Among the synthesized samples, SCF-0.8 exhibited a faradaic behavior and the highest specific capacitance (433 F·g−1) at 2 A·g−1 current density. This sample also has a lower inherent resistance to ion and electron diffusion. The better electrochemical performance of SCF-0.8 is due to its morphology, perovskite crystal structure, and greater oxygen vacancy concentration. Long charge-discharge cycles were utilized to test the electrochemical stability of SCF-0.8. The specific capacitance reached around 60 % of its initial value after 2500 charge-discharge cycles.