Recent Advances and Future Perspectives on Symmetrical Solid Oxide Cells: From Materials to Stack Fabrication

The urgent need to reduce fossil fuel consumption and carbon emissions has driven the development of clean and efficient energy conversion technologies. Symmetrical solid oxide cells (SSOCs) have emerged as a promising electrochemical energy conversion device that is capable of reversibly converting chemical energy and electrical energy. Compared with conventional solid oxide cells, SSOCs employ identical electrode materials on both sides of the electrolyte, which simplifies cell fabrication, improves structural compatibility, and enhances operational flexibility while mitigating issues such as sulfur poisoning and carbon deposition. In SSOCs, the electrode composition, microstructure, and cell fabrication methods play crucial roles in determining the energy conversion efficiency and overall output performance. This review summarizes recent progress in SSOC technology, including the design and development of symmetric electrode materials, electrolyte selection, and cell fabrication and assembly strategies. It aims to provide a comprehensive understanding of the thermodynamics and kinetics of SSOCs and promote the development and practical application of SSOCs in clean energy systems.