Studies on Design and Properties of Metal-supported Solid Oxide Fuel Cell: Electrode material, Cell and Stack

Abstract

The purpose of the research is to study and develop the core technologies related to electrode material, cell and stack for commercialization of metal-supported solid oxide fuel cell (SOFC). High performance cell, through the material study, should be preferentially fabricated to develop the high performance metal-supported SOFC system, and based on metal-supported cell technology, the research and development related to metal-supported SOFC stack should be progressed. In this study, the following researches were conducted: 1) Design and properties of electrode material for metal-supported SOFC, 2) Analysis of reaction mechanism for electrode material, 3) Design and properties of metal-supported cell, 4) Design and fabrication of metal-supported SOFC stack. Samarium (Sm) oxide based cathode materials are recognized as material which has excellent electrochemical property for SOFC. The synthesized Sm-based cathode materials were studied with respect to the electrochemical properties and thermal stability in terms of compositions, crystal structures, microstructure and sinterability. The analysis and understanding of oxygen reduction mechanism of cathode is very important for design and development of high performance cathode material for metal-supported SOFC. However, the mechanism for the MIEC cathode reaction has not clearly clarified. In this study, an oxygen reduction reaction of a porous-structured cathode involving an important MIEC cathode material, $Sm_{0.5}Sr_{0.5}CoO_{3-\delta}$, and its composite cathode, $Sm_{0.5}Sr_{0.5}CoO_{3-\delta}$ / $Sm_{0.2}Ce_{0.8}O_{1.9}$ (6:4), was investigated in terms of the oxygen partial pressure, the temperature and the frequency via impedance spectroscopy. From these results, In present research, two approaches related to cathode formation for metal-supported cell were investigated and discussed; 1) Sintered cathode materials which have stability in reducing atmosphere, 2) In-situ cathode materials which can be appl...