Solid oxide fuel cells have been paid a lot of attention as a new energy source for the next generation due to their high fuel utilization. The operating temperature of solid oxide fuel cells is in the range of 800-1000 ?, which is referred to as high temperature fuel cells for these cells. Their high operating temperatures lead to heat generation, which can be used with heat, which also increases the efficiency of the cell. However, problems have hindered their industrialization, which is long-term sustainability as well as production costs, both due to the high working temperature of these cells. Recent studies have proposed new to reduce operating temperatures, which open opportunities of Solid oxide fuel cells in variety of application use. Electrolyte, anode and cathode are the three key components of Solid oxide fuel cell. Perovskite-type (ABO 3 ) materials have excellent conductivity and catalytic properties at intermediate temperature. These materials can be used as the cathodes of Solid oxide fuel cell. In this investigation, perovskite oxide cathode, Lanthanum ferrite doped with strontium and manganese La 0.6 Sr 0.4 Fe 0.8 Mn 0.2 O 3- ? was used because of its has high electronic conductivity and catalytic property. La 0.6 Sr 0.4 Fe 0.8 Mn 0.2 O 3- ? was synthesized by the sol–gel method. The structural, electrical and electrochemical properties of La 0.6 Sr 0.4 Fe 0.8 Mn 0.2 O 3- ? were tested via X-ray diffraction ,scanning electron microcopy ,four-probe direct current techniques and impedance spectra. The X-ray pattern shows that sample had a Rombohedrah perovskite structure. Small polaron hopping was responsible mechanism in conductivity. The activation energy for carrier formation in La 0.6 Sr 0.4 Fe 0.8 Mn 0.2 O 3- ? was 0.18 eV. Also resisthvity of sample has beenmeasured at the different temperature ranges and in presence of Oxygen/Argon atmosphere. By using electrical relaxation technique and some approximations, ionic diffusion coefficient and activation energy for ionic conductivity has been calculated. The results demonstrated that by increasing temperature the value of D chem is enhanced and activation energy for ionic conductivity was 0.70 eV. Impedance spectra of symmetrical cell at different temperatures (600-800?) measured by the electrochemical station. The area specific resistance decreas with increase in the measurement temperature. According to the results, it can be said that the cathode material has been shown to function at an intermediate temperature.
