Advances and challenges in symmetrical solid oxide electrolysis cells: materials development and resource utilization

Solid oxide electrolysis cells (SOECs) have emerged as a promising technology for efficient hydrogen production and syngas conversion to low-carbon fuels. Among various SOEC configurations, symmetrical solid oxide electrolysis cells (S-SOECs) offer unique advantages due to their simplicity, reduced operational steps, and reversible operation. The symmetric electrodes enable the production of hydrogen and oxygen during electrolysis, while the generated gases can be harnessed for electricity generation during fuel cell operation. This reversible operation not only minimizes the number of components necessary for the system but also decreases the overall cost of the technology. This review provides a comprehensive overview of the advancements in S-SOEC research, with a primary focus on materials development. We discuss the current challenges associated with material limitations and explore the potential for utilizing syngas products as a resource. Finally, we propose future research directions to further improve the performance and durability of S-SOECs, paving the way for widespread implementation of this versatile technology.