Planar SOFC Stack with Low-Cost Multi-Layer Ceramic Interconnect

Abstract

The SOFCo-EFS stack utilizes a multi-layer ceramic (MLC) interconnect that is designed to have a close thermal expansion match with zirconia-based cells. The MLC interconnect is fabricated using multiple layers of YSZ tape, with each layer containing conductive vias to provide for electrical current flow through the interconnect. Fuel and air supply to cells are accomplished through the use of flow passages in the layers. This paper provides an update on the development status for the MLC interconnects and stacks, with emphasis on low-cost conductor materials for the vias. Separate low-cost materials have been developed for the airside and fuel-side vias, and successfully implemented into 10 cm interconnects. Planar stacks have been assembled using electrolyte-supported cells and tested. Special instrumentation was used for these stacks in order to separate area specific resistance (ASR) contribution from each component.