Synthesis of Bismuth Doped Lanthanum Cobalt Iron Oxide Material as Cathode for Application of Solid Oxide Fuel Cell

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 due to their high energy conversion and low environmental impact. In this project, we are synthesized the bismuth doped lanthanum cobalt iron oxide cathode material. The proposed materials are bismuth doped lanthanum cobalt iron oxide (Bix (La0.5Co0.45 Fe0.05)1-x (BLCF)), where x=0.1, 0.2, 0.3 & 0.4 are prepared by sol gel technique. Different characteristics of cathode materials Bix (La0.5Co0.45Fe0.05)1-x are study in this project are X-ray diffraction (XRD), Raman spectroscopy, Fourier Transformation Infrared Spectroscopy (FTIR) and DC-conductivity by four probe methods. The Bi0.1 (La0.45Co0.405Fe0.045) XRD pattern shows that material has composite phase. The phase of Bismuth Iron oxide (average crystalline size 63.63 nm) has an orthorhombic structure (ICSD card No 96-900-8149), Bismuth Lanthanum Oxide (average crystalline size 50.65) has an orthorhombic crystal structure (ICSD card No 96-100-1472) and Lanthanum Cobalt Oxide (average crystalline size 26.42 nm) having orthorhombic crystal structure (ICSD card No 96-200-2266). In Bi0.2 (La0.4Co0.36Fe0.04) XRD pattern Lanthanum Bismuth Oxide (ICSD card No 96-901-5834) and Bismuth Cobalt Iron Oxide (ICSD card No 96-433-6779) having hexagonal structure with crystalline size 93.4 and 76.1 nm. The 3rd sample Bi0.3 (La0.35Co0.315Fe0.035) XRD pattern shows Bismuth Cobalt Iron oxide (ICSD card No 96- 433-6780), Lanthanum Cobalt Oxide (ICSD card No 96-200-2266) and Bismuth Lanthanum Oxide (ICSD card No 96-100-1471) having monoclinic, orthorhombic, orthorhombic structure with crystalline size 67.7, 65.8 and 76.3 nm. The XRD pattern of Bi0.4 (La0.3Co0.27Fe0.03) shows that Bismuth Lanthanum Oxide (ICSD card No 96-100-1471), Bismuth Iron Oxide (ICSD card No 96-900-8149) and Cobalt Oxide (ICSD card No 96-900- 5888) have orthorhombic, orthorhombic and cubic with crystalline size 56.2, 61.3 and 91.8 respectively. Raman spectra of all samples [Bi (LCF)] show prominent bands at 128, 281, 320, 374, 486, 595, 621, 645 and 980 cm-1 related to La sit vibration, Fe-O vibration, O-B-O O, CoFeO, Co O, Ag symmetry, stretching vibrations and Ag and Bg normal modes. FTIR spectra of all xi samples [Bi (LCF)] show the peaks at 1060, 1098, 1117, 1426 and 3500 to 3800 cm-1 having different modes and bond (stretching of C-C, Bi O-H, Co precipitation O= C = O stretching vibrations and vibrational peaks). We use DC four-probe methods to measure conductivity of material at different temperature (300-600) ℃. The sample Bi0.4 (La0.3Co0.27Fe0.03) shows the maximum conductivity (6.9 S/cm) at temperature 650 °C. We use EIS techniques to find the ORR of cathode material at (350 to 650 ℃) in air atmosphere. The sample Bi0.4 (La0.3Co0.27Fe0.03) shows the maximum ORR and good electronic behavior.