SYNTHESIS AND CHARACTERIZATION OF GdBaCo2O5+? CATHODE, Ce0,9Gd0,1O2?? ELECTROLYTE AND Sr2Mg0,2Mn0,8MoO6-? ANODE FOR SOLID OXIDE FUEL CELL FABRICATION

• Main Author: Puspita, Indri
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34921
• Institution: Institut Teknologi Bandung

The fuel cell is an electrochemical cell that works to change the chemical into electrical energy. One type of fuel cell is the solid oxide fuel cell (SOFC) that use solid oxides as electrolyte. The use of high operating temperatures of SOFC (~1000 °C) raises the problem such as limited materials that can work in high operating temperatures, short operation time and high production cost. Research in the field of SOFC is currently focused on developing the components of the cell that is able to work well at intermediate operating temperatures (500 – 800 °C). One of the Intermediate Temperature-SOFC (IT-SOFC) which has been fabricated is GBCO/GDC/Ni-GDC. Based on research that has been done previously, the anode material Sr2Mg1-xMnxMoO6-? with x = 0.2 composition is known to produce the highest electrical conductivity. Therefore, the fabrication of SOFC research carried out using cell components GdBaCo2O5+? (GBCO)/Ce0.9Gd0.1O2-? (GDC)/Sr2Mg0.2Mn0.8MoO6-? (SMMO) is expected to improve the performance of SOFC. A fuel cell unit consists of three components, namely the cathode, electrolyte and anode. Cathode and electrolyte respectively synthesized by using solid phase reaction method, while the anode was synthesized using sol-gel method. Diffractograms were analyzed with the Le Bail method to obtain cell parameters. X-ray diffraction results showed that the GBCO compound form a single phase, orthorhombic structure with space group Pmmm. Electronic conductivity measurements GBCO compounds with four-point probes method shows that there is a metal-insulator phase transition at temperature of 100 °C. So that the region above this transition temperature can be used as a good electronic conductor. Conditions to be met by a cathode of which is high electronic and ionic conductivity. At temperature 500 °C GBCO give a high electronic conductivity that is equal to 304.11 S.cm-1. The result of SEM analysis of surface and cross section GBCO compound showed the presence of pores that enable oxygen gas sufficient to flow into the electrolyte. X-ray diffraction analysis showed that GDC compound is in a single phase, cubic structure with space group Fm-3m. Ionic conductivity was studied by impedance spectroscopy using a source of alternating voltage (AC). Ionic conductivity measured at a temperature of 500 °C of 1.27 x 10-2 S.cm-1. The morphology of the dense electrolyte greatly affects the performance of SOFC. The result of SEM analysis of surface and cross section showing the structure of the compound GDC meeting to prevent the leakage of oxygen gas. The result of X-ray diffraction for compounds SMMO sintered at 1250 °C temperature indicate the presence of three phases, namely SMMO as the main phase with monoclinic structure and space group P21/n as well as secondary and tertiary phases of SrMoO4 and MnO2 as has been reported in previous studies. SOFC fabrication is performed using slurry coating method produced a good contact between the layers of electrolyte and anode-cathode-electrolyte layer with visibility of grain boundaries. The thickness of the electrolyte produced after refined by using powder carborundum reach 640 ?m. Cathode layer thickness reached 49.33 ?m, whereas at the anode thickness reaches only 22.89 ?m. Thus, it can be said that the slurry coating method with the addition of ?-terpineol organic compounds used in this study represents a fairly accurate method for SOFC fabrication