PNNL

Abstract

Planar SOFC stack performance requires reliable uniform contact to carry the electrical current between the series-connected cells. On the cathode side, the contact layer must survive the oxidizing environment to maintain a durable bond between the ceramic electrode and the metallic interconnect. Stable, but expensive, noble metals have been used for contact materials; hence, less expensive alternatives are being investigated including ceramics with additions to aid low temperature sintering. Since the contact layer may be the final fabrication step completed in situ during the stack assembly process, heat treatment temperatures are limited when a metallic interconnect is used to prevent unacceptable oxide scale growth. Ceramic contact materials are desirable due to compatibility with the cathode and good oxidation resistance, but densification is generally poor at the expected heat treatment range (