Hybrid Solid Oxide Cell Enables Efficient and Robust High-Temperature CO2 Electrolysis

Electrocatalytic conversion of CO2 into chemicals and fuels offers a promising route toward a circular carbon economy. High-temperature CO2 electroreduction in solid oxide electrolysis cells (SOECs) delivers high selectivity and energy efficiency, but balancing mechanical robustness and electrochemical performance remains challenging. Here, we address this challenge by introducing a hybrid ionic-conductor architecture that spatially decouples electrocatalysis, ionic transport, and mechanical support into function-specific layers. The resulting cell combines high mechanical robustness (fracture load > 7 N) with 1.5–3.0-fold higher CO2-to-CO activity than state-of-the-art SOECs over 600–800 °C. Stable operation is maintained for over 1000 h at 1.0 A cm–2. Furthermore, we demonstrate scalability with a single-cell area of 100 cm2, achieving total currents up to 120 A and powers up to 200 W. This work establishes an effective strategy for developing mechanically resilient, efficient, and scalable energy conversion devices.