Materials and Microstructure in Solid Oxide Electrolysis Cells: Linking Performance and Durability

Solid oxide electrolysis cells (SOECs) represent a transformative technology for the efficient production of green hydrogen and syngas from water and carbon dioxide, leveraging high operating temperatures to enhance reaction kinetics and thermodynamic efficiency. This review provides a comprehensive overview of the critical correlations between material properties, electrode microstructure, and overall SOEC performance. We delve into the impact of triple-phase boundary density, electronic/ionic conductivity, and surface chemistry on cell efficiency and current densities. Furthermore, the paper highlights significant performance improvements achieved over time, including higher current densities, reduced operating temperatures, and enhanced long-term durability, alongside major breakthroughs such as industrial-scale demonstrations, high-pressure operation, direct CO2 electrolysis, and the development of reversible solid oxide cells. Understanding these advancements and the underlying material science challenges is crucial for accelerating the commercialization of SOEC technology for a sustainable energy future.