A SINGLE MANIFOLD, RADIAL FLOW SOLID OXIDE FUEL CELL

THIS RESEARCH IS STUDYING A NEW PLANAR SOLID OXIDE FUEL CELL (SOFC) GEOMETRY THAT FEATURES A SINGLE MANIFOLD FOR RADIAL FUEL FLOW THROUGH THE ANODE AND OXYGEN DIFFUSION THROUGH THE CATHODE. THE DESIGN USES ONLY ONE SEAL PER CELLIN THE FUEL MANIFOLD, IS MADE USING SIMPLE, LOW COST CERAMICFABRICATION TECHNIQUES, AND CAN USE AUTOMATED STACK MANUFACTURING TECHNIQUES TO PRODUCE A LOW COST SOFC SYSTEM. THE DESIGN IS A VARIATION OF THE INTERSCIENCE RADIAL FLOW (IRF) FUEL CELL USING OXYGEN DIFFUSION TO PROVIDE OXIDANT RATHER THAN FORCED CONVECTION. THE TWO KEY PHYSICAL CHARACTERISTICS OF SINGLE MANIFOLD IRF DESIGN (SMIRF) ARE POROUS, PARTICULATE ELECTRODES AND THE SINGLE MANIFOLD. PARTICULATE ELECTRODES ELIMINATE PROBLEMS CAUSED BY THERMAL EXPANSION COEFFICIENT MISMATCHES BY ALLOWING THE SEPARATOR, SEALS, AND ELECTROLYTE TO EXPAND AT DIFFERENT RATES, AND CHANGE POSITION WITH RESPECT TO THE ELECTRODE WITHOUT LOSINGELECTRICAL CONTACT. SIMPLE, INEXPENSIVE MANUFACTURING TECHNIQUES CAN BE USED, SUCH AS TAPE CASTING AND STAMPING. THE SINGLE MANIFOLD DESIGN ALLOWS INTERNAL MANIFOLDING OF THE FUEL STREAM ONLY, REQUIRING ONLY ONE SEAL PER CELL. THUS, EXHAUST MANIFOLDS ARE NEEDED. PREVIOUS EXPERIMENTS USING SINGLE CELL IRFS HAVE PROVED THE FEASIBILITY OF USING PARTICULATE ELECTRODES WITH FORCED CONVECTION OF BOTH FUEL AND OXIDANT. PHASE I INCLUDES STUDIES TO VERIFY THE FEASIBILITY OF OXYGEN DIFFUSION-BASED FUEL CELL OPERATION. RESEARCH IS BEING CONDUCTED TO STUDY OXYGEN DIFFUSION-BASED,SINGLE MANIFOLD, FUEL CELLS WITH COMPUTER MODELS; TO TEST AND IMPROVE THE MODEL WITH SINGLE CELL EXPERIMENTS; AND TO COMPARE THE RESULTS WITH FORCED CONVECTION EXPERIMENTS.