FUEL CELLS – SOLID OXIDE FUEL CELLS | Cell Interconnection

Abstract

To build up a useful voltage, a number of solid oxide fuel cells (SOFCs) are electrically connected in series in a stack via interconnects. In addition to functioning as bipolar plates, the interconnects also act as separator plates, physically separating the fuel in the anode from the air or oxygen in the cathode, and at the same time help maintain the structural integrity of the SOFC stack. Depending on the stack operating temperature, both ceramic and metallic materials are used to construct interconnects. Owing to their high-temperature stability, ceramic materials, typically chromites, are used for stacks operating at higher SOFC temperatures of 900–1000 °C. However, at operating temperatures in an intermediate range of 650–800 °C, metallic materials, e.g., high-temperature oxidation-resistant metals/alloys, are preferred to ceramic materials. This article provides a comprehensive review of interconnects, made from both ceramics and metallic alloys, with a focus on recent progress in materials development, as well as on advances in understanding materials degradation and interfacial phenomena under SOFC operating conditions.