Bilayered Electrolyte for Intermediate-Low Temperature Solid Oxide Fuel Cell: A Review

Fuel cell is an energy converter device that generates electricity through electrochemical reaction between hydrogen and oxygen. An example of fuel cell is the solid oxide fuel cell (SOFC) which uses a ceramics based solid electrolyte. Due to the use of ceramics, SOFC normally operates at high temperatures up to 1000°C. This high operating temperature makes SOFC known for its efficient energy conversion capability and excellent fuel flexibility. However, despite the advantages, the extreme temperatures limit the uses of SOFC. High operation temperature leads to long term operational issues in durability and cell degradation. Yttria stabilized zirconia, YSZ is a commonly used material for electrolyte in high temperature SOFCs. However, YSZ electrolyte is unable to perform well when the operating temperature is reduced to intermediate-low zones below 800°C. Thus, development of new materials for SOFC components is needed whereby the production of electrolyte materials becomes one of the main scopes for research in intermediate-low temperature SOFCs. Apart from the synthesis of new materials, another approach in increasing the ionic conductivity of intermediate-low temperature SOFC is through the fabrication of a bilayered electrolyte. As such, this review article focuses on the potential of bilayered electrolyte for intermediate-low temperature SOFCs.