Manganese doped La0.8Ba0.2FeO3 perovskite oxide as an efficient electrode material for supercapacitor

In this study, L0.8Ba0.2Fe1-xMnxO3 (LBFM-x, x = 0.0, 0.2, 0.5, 0.8) perovskite materials were synthesized by a Sol-Gel combustion method and were investigated as an electrode material for a supercapacitor device. The morphology, crystalline structure and electrochemical performance of the samples were studied in detail. The active points, where the electrochemical redox reaction takes place to store faradaic energy, are the oxygen vacancies on the surface of perovskite oxides. Partial substitution in the B-site of the perovskite structure, which is directly related to the oxygen vacancy in BO6 octahedral, is effective in optimizing the electrochemical performance. Based on the results of structural analysis, LBFM-0.2 has the highest concentration of oxygen vacancies; thus, it showed a higher electrochemical performance compared to other samples. The supercapacitors prepared with this electrode material should have an acceptably high specific capacitance of 685 F.g−1 at a current density of 2.0 A.g−1. The partial substitution of Mnn+ at the B-site increases the oxidation state of Fe cations and the mobility of oxygen ions through the oxygen vacancy sites. The electrochemical stability of LBFM-0.2, was evaluated by applying long charge-discharge cycles. After 3000 charge-discharge cycles, the supercapacitor was able to maintain about 94 % of its initial capacity.