As solid-oxide fuel cells approach commercialization, enhanced performance is required to achieve widespread adoption. Greater awareness of SOFC technology has resulted in interest from new application sectors, such as the aerospace industry. These new applications bring new complexities and greater demand on cell performance to achieve viability. Cathode materials are an important component in the development of improved cells and stacks by reducing the interfacial resistance of solid oxide fuel cells (SOFCs).

In ongoing programs, cathode materials were evaluated to identify a materials set that increases the power density of SOFCs in two applications: for low temperature, low cost stacks targeted at large commercial markets (such as stationary distributed power or transportation auxiliary power) enhanced lanthanum ferrite based systems have been investigated. For high temperature, high power density systems, modified lanthanum manganite (LSM) cathodes were evaluated in an effort to minimize interfacial resistance, maximize bulk conductivity and enhance cell power density. Recent experiments have investigated the effect of A and B-site doping on the electrical conductivity, thermal expansion, and interfacial resistance of perovskite LSM and LSF cathode materials. Through substitution of dopants such as Ni, Cu, Zn, and Mg on the B-site of these perovskite materials, a set of materials with attractive properties have been identified. Composite materials containing gadolinium doped ceria electrolyte material have also been evaluated. In this presentation, we will describe the status of this work, including results of single-cell SOFC testing cells using optimized materials.