Neda Kalantari

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 combustionmethod and were investigated as an electrodematerial for a supercapacitor device. The morphology,crystalline structure and electrochemical performance of thes amples were studied in detail.The activepoints,where the electrochemical redox reaction take splace to store faradaicenergy, are the oxygen vacancies on the surface of perovskiteoxides.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 per formance. Based on the results of structural analysis, LBFM-0.2has thehighest concentrationofoxygenva cancies; thus, it showed a high erelectrochemical performance compared to other samples.The supercapacitors prepared with this electrodematerial should have an acceptably high specificcapacitance of 685F.g 1 at a currentdensity of 2.0A.g 1.The partial substitution of Mnn+at the B-siteincreases the oxidation state of Fe cations and the mobility of oxygen ions through the oxygenvacan cysites.The electrochemical stability of LBFM 0.2,wasevaluatedbyapplying longcharge-dischargecycles.After3000charge-dischargecycles, thesuper capacitor was able to maintain about 94% of its initial capacity.