Propulsion and Power Rapid Response R&D Support Delivery Order 0041: Power Dense Solid Oxide Fuel Cell Systems: High Performance, High Power Density Solid Oxide Fuel Cells - Materials and Load Control

High Performance, High Power Density Solid Oxide Fuel Cells: Materials: The current geometry and materials set of the state-of-the-art anode supported cell (ASC) yields several deficiencies that limit the performance and robustness of the cell/stack under demanding aero based operational requirements. These deficiencies are embodied in poor gas transport through mechanically strong anodes, the limited use of cerium oxide in the anode due to unfavorable thermal expansion, and the poor thermal stability of ultra fine nickel catalyst under higher temperature operation for maximum output. These deficiencies are being addressed with the development of engineered porous substrates, additives to tailor thermal expansion in ceria based anode systems, and methods for complete infiltration of anode catalysts. Novel ceramic anodes were synthesized and fabricated at Montana State University and characterized through electron microscopy, dilatometry, thermal gravimetry, x-ray diffraction, and electrochemical testing. Modified processing techniques have generated a means for preparing controlled pore morphologies over large areas by freeze casting suitable for anode supported cell fabrication. The use of aluminum titanate additives has demonstrated a 30% decrease in thermal expansion in nickel/ceria anodes and the addition of aluminum titanate to nickel/zirconia porous scaffolds has shown to limit nickel coarsening from high temperature exposure. This report provides a physically-based model for design and optimization of a fuel cell powered electric propulsion system for an unmanned aerial vehicle. Components of the system include a solid oxide fuel cell providing power, motor controller, brushless DC motor, and a propeller. The simulation allows an operator to select constraints and explore design trade-offs between components, including fuel cell, controller, motor, and propeller options.
The original document contains color images. All DTIC reproductions will be in black and white. Prepared in cooperation with Universal Technology Corp., Dayton, OH.