(Invited) Reducing the Operating Temperature of Protonic Ceramic Fuel Cells to

Abstract

Protonic ceramic fuel cells (PCFCs) show significant promise for highly efficient and durable power generation. Intermediate-temperature PCFC operation (500–650 °C) enables significantly higher efficiency than low temperature (50–100 °C) polymer electrolyte membrane-based fuel cells and can approach that of high-temperature (700–900 °C) and intermediate-temperature (600 °C) oxygen-ion solid oxide fuel cells (SOFCs). Reduced operating temperatures (versus SOFCs) relax stack and balance-of-plant constraints, potentially lowering the fuel cell manufacturing cost while also improving the reliability, thermal cycling tolerance, and dynamic response. In the last decade, there have been several astonishing demonstrations of high-performance PCFCs. A peak power density of >1.5 W/cm2 has been demonstrated at 600-650 °C. However, PCFCs that operate at 500-650 °C haven’t led to revolutionary changes to the scaleup and commercialization of PCFCs yet, which is due to the operating temperatures are still too high to allow using low-cost interconnects, cheap endplates, and gasket sealant. Although reduced operating temperatures improve the fuel cell durability, PCFCs that operate at 500-650 °C require similar components to HT-SOFCs to build the stacks. Therefore, the operating temperature of PCFCs should be further reduced to <400 °C and the corresponding performance needs to be significantly enhanced to create a new scenario of power generation. At Kansas State University, we have made significant achievements on reducing the operating temperature of PCFCs. Herein, we will present how we rationally design and manufacture PCFCs that achieve remarkable performance and durability at <400 °C.