MEMS-based thin-film solid-oxide fuel cells

Abstract

Thin-film solid-oxide fuel cells (TF-SOFCs) fabricated using microelectromechanical systems (MEMS) processing techniques not only help lower the cell operating temperature but also provide a convenient platform for studying cathodic losses. Utilizing these platforms, cathode kinetics can be enhanced dramatically by engineering the microstructure of the cathode/electrolyte interface by increasing the surface grain-boundary density. Nanoscale secondary ion mass spectrometry and high-resolution transmission electron microscopy studies have shown that oxygen exchange at electrolyte surface grain boundaries is facilitated by a high population of oxide-ion vacancies segregating preferentially to the grain boundaries. Furthermore, three-dimensional structuring of TF-SOFCs enabled by various lithography methods also helps increase the active surface area and enhance the surface exchange reaction. Although their practical prospects are yet to be verified, MEMS-based TF-SOFC platforms hold the potential to provide high-performance for low-temperature SOFC applications.