EFFECT OF ND2O3 AND FE2O3 ADDITION ON GADOLINIA DOPED CERIA (GDC) SOLID ELECTROLYTE SYSTEM FOR INTERMEDIATE TEMPERATURE-SOLID OXIDE FUEL CELL (IT-SOFC) APPLICATIONS

• Main Author: Faisal Akbar, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66354
• Institution: Institut Teknologi Bandung

Solid Oxide Fuel Cell (SOFC) is a type of fuel cell or electrochemical device that can transform chemical energy from a fuel into electrical energy with high efficiency. However, SOFC still has several operational issues, particularly the high operating temperature. Therefore, it is necessary to reduce the operating temperature of SOFC. Gadolinia Doped Ceria (GDC) is a solid electrolyte contender for intermediate-temperature SOFCs. Nevertheless, more development of this solid electrolyte is required to improve its ionic conductivity. In this research, we investigate the addition of Nd2O3 and Fe2O3 to GDC solid electrolytes to boost ionic conductivity. Solid electrolytes with the composition of Ce0,9Gd0,1MxO1,9 (M = Nd, Fe) (x = 0%; 2.5%; 5%, and 7.5%) were synthesized using mixed oxide method and formed into pellets with a diameter of 1 cm. The pellets were sintered at 1200????C and 1400????C for 4 hours in an argon environment then the Electrochemical Impedance Spectroscopy (EIS) test was performed at 450- 650????C. The results showed that the addition of Nd2O3 and Fe2O3 totally dissolved in the ceria structure and produced single-phase cubic fluorite CeO2. GDC solid electrolyte with Fe2O3 addition produces higher densification than Nd2O3 addition, where the value reaches 75% in the sample sintered at 1400oC. However, the addition of Nd2O3 further increased the value of ionic conductivity and decreased the activation energy of the GDC solid electrolyte compared to the addition of Fe2O3. The highest ionic conductivity and the lowest activation energy were obtained in the sample with 2.5% Nd2O3 at 650????C operating temperature, with the values achieved at 1.2 mS/cm and 0.41 eV, respectively. Therefore, it can be concluded that Nd2O3 is the more effective material to improve the performance of solid electrolyte GDC.