Details

Autor(en) / Beteiligte

• Zhang, Jun
• Lenser, Christian
• Menzler, Norbert H.
• Guillon, Olivier

Titel

Comparison of solid oxide fuel cell (SOFC) electrolyte materials for operation at 500 °C

Ist Teil von

• Solid state ionics, 2020-01, Vol.344, p.115138, Article 115138

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Solid oxide fuel cells (SOFCs) operating at low temperature (~500 °C) enable new fields of application, such as auxiliary power units (APUs) or power generation for mobile applications. However, the state-of-the-art electrolyte material currently used in intermediate-temperature SOFCs (yttria-stabilized zirconia (YSZ)) does not provide sufficiently high ionic conductivity for low temperature applications. When looking for alternatives, the conductivity values for each material found in widely cited literature can be confusing, as the reported values are sometimes in conflict with each other. Therefore, we present a systematic comparison of the conductivity of the three most popular, commercially available electrolyte materials, i.e., YSZ, scandia-stabilized zirconia (ScSZ), and gadolinium-doped ceria (GDC). By using electrochemical impedance spectroscopy (EIS) to characterize the ionic conductivities, we find that at 500 °C, GDC has a higher ionic conductivity (5.8 × 10−3 S cm−1) than ScSZ (2.5 × 10−3 S cm−1) and YSZ (1.1 × 10−3 S cm−1). The properties of the starting powders, powder processing and the microstructure after sintering were considered. This conductivity comparison can be used as a guide when deciding on electrolyte materials for different SOFC applications, especially when the fabrication of different thickness of the electrolyte layer has to be considered and rectify misleading information in the literature. •Comprehensive ionic conductivity comparison is done for YSZ, ScSZ and GDC.•YSZ, ScSZ and GDC each have an optimal operation temperature in SOFC applications.•A brick layer model is used to predict the dependence of electrolyte resistance on grain size.