Recent advances on electrolyte materials for SOFC: A review

In recent years, solid oxide fuel cells (SOFC) have gained popularity as one of the highly efficient energy conversion devices, which can achieve an efficiency of over 80 % with regeneration. The components of SOFC include an anode, cathode, electrolyte, sealants, and interconnects. In this review, material selection for electrolytes, fundamentals of operation and operating mechanisms, and processing of the materials, are discussed in detail. The major challenge SOFCs face is the hindered O2 migration that converts chemical energy into electrical energy in the solid electrolyte among others. Yttria stabilized zirconia (YSZ) is one of the most explored conventional electrolyte materials for solid oxide fuel cells (SOFC) for high-temperature applications. Nanocrystalline YSZ is regarded as a promising material in terms of high mechanical strength and structural stability in both oxidizing and reducing atmospheres. This enhances its potential and enables its application. Different parameters such as high-temperature operation, thickness, and compatibility with anode and cathode are prime areas of focus. Generally, the two most important aspects of SOFC are: the electrolyte materials and what temperature they operate. This review emphasizes about the history, recent advances, electrolytes materials used in SOFC operated at both high and low temperature and electrolytes for the future.