In this review article, new systems being investigated for application in solid oxide fuel cells are discussed. For the electrode materials, materials with the perovskite or related structures continue to dominate the field, due to the need for high electronic conductivity. Research in this field is being directed toward compositions allowing high ionic conductivity in addition to their electronic contribution. In contrast, research on new electrolyte materials has shown a diverse range of structure-types, with an apparent tendency toward structures containing cations in lower coordination environments, particularly tetrahedral. In both the electrode and electrolyte area, materials allowing the incorporation of oxygen excess into interstitial sites have shown promising results, warranting further investigations of materials that will allow this type of defect chemistry.
- molecular shape