A LOW COST RADIAL FLOW SOLID OXIDE FUEL CELL

THIS RESEARCH STUDIES A NEW PLANAR SOLID OXIDE FUEL CELL (SOFC) GEOMETRY THAT FEATURES RADIAL FLOW OF FUEL AND OXIDANT STREAMS THROUGH PARTICULATE ELECTRODES (THE INTERSCIENCE RADIAL FLOW (IRF) FUEL CELL). THE TWO KEY PHYSICAL CHARACTERISTICS OF IRF DESIGN ARE THE POROUS, PARTICULATE ELECTRODES AND THE RADIAL DESIGN. PARTICULATE ELECTRODES ELIMINATE PROBLEMS CAUSED BY MISMATCHES IN THE THERMAL EXPANSION COEFFICIENT, BY ALLOWING THE SEPARATOR, SEALS, AND ELECTROLYTE TO EXPAND AT DIFFERENT RATES AND CHANGE POSITION WITH RESPECT TO THE ELECTRODE, WITHOUT LOSING ELECTRICAL CONTACT. NOVEL AND IMPROVED MATERIALS CAN BE INCORPORATED AND OPTIMIZED FOR ELECTRICAL AND CATALYTIC PROPERTIES RATHER THAN FOR THERMAL EXPANSION PROPERTIES. SIMPLE, INEXPENSIVE MANUFACTURING TECHNIQUES CAN BE USED, SUCH AS TAPE CASTING AND STAMPING. THE RADIAL DESIGN ALLOWS INTERNAL MANIFOLDING OF THE FUEL AND OXIDANT INLET STREAMS, WHICH MINIMIZES THE REQUIRED SEAL AREA. NO EXHAUST MANIFOLDS ARE NEEDED. PREVIOUS EXPERIMENTS USING SINGLE CELLS HAVE PROVED THE FEASIBILITY OF USING PARTICULATE ELECTRODES. SEALING PROBLEMS, IDENTIFIED IN STACK TESTS, CAN BE CORRECTED BY OPTIMIZED SEALS. SEAL MATERIALS MUST BE OPTIMIZED FOR PHYSICAL PROPERTIES SUCH AS SOFTENING TEMPERATURE, VISCOSITY, ADHESION TO SURFACES, AND WETTING OF SURFACES, AND FOR GEOMETRIC FACTORS SUCH AS INITIAL HEIGHT AND WIDTH, AND DIMENSIONAL CHANGE WITH THERMAL EXPANSION. THE PHASE I RESEARCH IS IDENTIFYING THE BEST SEAL MATERIALS FOR THE PROCESS AND WILL OPTIMIZE BOTH THE MATERIALS PROPERTIES AND THE GEOMETRIC PROPERTIES FOR STACK OPERATIONS.