A brief review of heterostructure electrolytes for high-performance solid oxide fuel cells at reduced temperatures

Solid oxide fuel cells (SOFCs), which are widely viewed as the next-generation energy conversion devices, provide environmentally friendly power generation by direct conversion of chemical energy with high efficiency and less pollutant emissions. However, their high operating temperatures limit their usability in applications, such as distributed generation of electricity and heat, power plants, and transportation. At reduced temperatures, the electrolytes and electrodes used in SOFCs experience sluggish oxygen transport kinetics. Therefore, the development of materials with high oxygen ion conduction and unique cell designs is needed to achieve higher performance. This article provides an overview of the recent progress on solid oxide electrolyte materials, unique cell designs featuring bilayer electrolytes, and resulting microstructures at lower operating temperatures.