Advances in solid oxide fuel cell technologies: lowering the operating temperatures through material innovations

Solid Oxide Fuel Cells (SOFCs) are promising for clean energy generation due to their high efficiency, fuel flexibility and status as a clean energy source with no environmental hazards. However, the challenge of operating these SOFCs at elevated temperatures (800-1000 °C) presents significant hurdles regarding material selection, cost-effectiveness, and device fabrication. Lowering the operational temperature of SOFCs can enhance performance and economic viability. Nevertheless, this pursuit introduces challenges in the form of increased ohmic and polarization resistances, which detrimentally affect electrochemical performance. High ohmic resistance and activation energy at lower temperatures reduce ionic conductivity and impede SOFC device efficiency. Recent advancements in materials and cutting-edge technologies have addressed these issues, particularly in low-temperature operations for SOFC devices. This review article focuses on the latest developments in material selection and advanced technologies that have demonstrated notable improvements in power output and long-term durability at lower operating temperatures, highlighting the significance of high-performing electrolyte and electrode materials with enhanced electrochemical and fast electrocatalytic functionalities to improve cell efficiency. Additionally, the article explores the critical challenges faced by SOFCs at low operating temperatures.