Fuel Cells – Solid Oxide Fuel Cell | Membranes

The high-temperature membranes or membrane-electrode assemblies (MEAs) for solid oxide cell (SOC) consist of a thin electrolyte with a high ionic conductivity, an air electrode made of mixed oxide, and a cermet fuel or steam electrode. Different types of MEAs are currently under development: electrolyte-supported cells, anode-supported cells, or metal-supported cells. The commonly oxygen ion conducting electrolyte is made of stabilized zirconia, however, stabilized ceria and lanthanum gallate also are used. Furthermore, high temperature proton conducting electrolytes have been successfully developed recently and utilized in MEA production.
The ionic conductivity of electrolytes and the factors that influence their durability are comprehensively described in this article. The short overview of different electrolytes, electrode materials and their interactions as well as the stability of electrochemically active interfaces is provided. The area specific resistance (ASR) of MEAs depends strongly on the thickness of the electrolyte and its chemical compatibility toward electrode material. The costs of single cell, as well as ASR, should be reduced to obtain high specific power density (kWel L−1) and material efficiency (kWel kg−1) and to reduce the specific cell, stack and system costs (in €kWel−1).