The effect of partial substitution of noble metal (Pd) at the B site of La0.6Sr0.4FeO3 as a supercapacitor electrode material

Sol-gel combustion was used to produce the perovskite-type La_0.6Sr_0.4FeO₃ (LSF) and La_0.6Sr_0.4Fe_0.9Pd_0.1O₃ (LSFP) materials and assessed as supercapacitor electrodes. The synthesized materials' crystal structure, morphology, and electrochemical performance were thoroughly analyzed. The partial substitution of Pd in the B site of the LSF structure affected the electrochemical properties of this compound and improved its performance. In fact, the greatest effect of Pd substitution was on the content of oxygen vacancies, which are known as the active sites of the perovskite surface in the supercapacitor cell. The specific capacitance obtained for the sample containing Pd was about 80 F.g^-1 at a current density of 1 A.g^-1 in 1M KOH. In addition, this sample had a decreased intrinsic resistance to ion and electron diffusion. The remarkable structural and morphological features of LSFP contribute to its superior electrochemical performance. At a power density of 1000 W.kg^-1 and a current density of 1 A.g^-1, an LSFP symmetrical cell had an energy density of 44.45 W.h.kg^-1.