Electrochemical Properties of Bismuth (Bi) Doped Lanthanum Cobalt Iron (LCF) Oxide Material as Cathode at Different Sintering Temperatures

Abstract

To reduce carbon dioxide emissions, which create global warming and climate change, the world is moving toward renewable energy sources. Solid oxide fuel cells are one of the most effective energy generation technologies because of their high energy conversion and minimal influence on the environment. In this research work, we are synthesized the bismuth doped lanthanum cobalt iron oxide Bix (La0.6Co0.3Fe0.1)1-x (BLCF), where x= 0.1, 0.2, 0.3, & 0.4 cathode materials are prepared by sol-gel method and sintered (700-900) oC. The cathodes materials are characterized with various techniques such as for oxidation reduction reaction (ORR) by Electrochemical Impedance Spectroscopy (EIS), to examine the functional groups by Fourier Transformation Infrared Spectroscopy (FTIR), structural and vibratory properties through Raman Spectroscopy, energy band gaps by Uv-Vis Spectroscopy. The electrical conductivity and electrochemical performance are also studying at different temperatures. The composition Bi0.4(La0.36Co0.18Fe0.06)-oxide shows maximum oxidation reduction reaction (ORR) and good electronic behavior. The maximum conductivity is obtained Bi0.4(La0.36Co0.18Fe0.06)-oxide at 700 °C in air atmosphere and having the value 2.75 S/cm. FTIR spectra of cathodes materials B(LCF) show the peaks at 653, 994, 1097, and 3600-3855 cm-1 having different modes and bond (stretching of C-C) , Co-O, O-H bonding and vibrational peaks). Raman spectra represent the prominent bands at 310, 418, 635, 993 cm-1 related to the La-O vibration, Fe-O vibration, Co-O vibration, and Ag and normal modes. Band gap values decreased with increase in the temperatures and 4.00 eV at 700 °C and 3.53 eV at 900 °C, which indicate the semiconductor nature of the prepared materials. These results revealed that the BLCF cathode materials show high conductivity at intermediate temperatures. This makes it useful for SOFC application.