The Y₂O₃-stabilized ZrO₂ (YSZ)/ceria bi-layer electrolyte is a key component in recent solid oxide fuel cells and electrolyzers. An industrially viable route for its effective implementation involves reduced-temperature co-sintering; however, this is a multistep process, often requiring precise control due to the poor sinterability of conventional gadolinia-doped ceria (GDC). Here we demonstrate a bi-layer electrolyte in a single-step 1250 °C co-sintering with Sm_0.2Ce_0.8O_2−δ (SDC) as a key solution, and verify the performance of the resultant bi-layer electrolyte in a Ni–YSZ fuel electrode supported cell. This approach, proven to be scalable, delivers a satisfactory cell performance, such as a fuel cell power density of ∼2.15 W cm⁻² and a steam electrolysis current density of ∼2.95 A cm⁻² at 800 °C. Even without adding the Fe₂O₃ aid to SDC, the YSZ/SDC electrolyte remains reasonably dense, free from resistive phases, and exhibits a higher interdiffusion conductivity than that of the benchmark YSZ/GDC. Furthermore, the strategic addition of Fe₂O₃ improves the shrinkage compatibility of YSZ and SDC, enhancing the integrity of the bi-layer structure. The optimal electrolytes show a remarkable stability across 300 h of typical fuel cell operation. These results suggest important strategic modifications in bi-layer electrolyte compositions and processing.

中文翻译：

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改进的固体氧化物电池双层电解质：Sm0.2Ce0.8O2−δ扩散阻挡层的作用


Y ₂ O ₃稳定的ZrO ₂ (YSZ)/二氧化铈双层电解质是近年来固体氧化物燃料电池和电解槽的关键部件。工业上可行的有效实施途径包括低温共烧结；然而，这是一个多步骤的过程，由于传统氧化钆掺杂二氧化铈（GDC）的烧结性较差，通常需要精确控制。在这里，我们展示了以 Sm _0.2 Ce _0.8 O _{2− δ} (SDC) 作为关键解决方案的单步 1250 °C 共烧结双层电解质，并验证了所得双层电解质在 Ni 中的性能。 –YSZ燃料电极支撑电池。这种方法被证明是可扩展的，可提供令人满意的电池性能，例如在800°C下燃料电池功率密度为～2.15 W cm ^-2 ，蒸汽电解电流密度为～2.95 A cm ^-2 。即使不向SDC添加Fe ₂ O ₃助剂，YSZ/SDC电解质仍然保持相当致密，没有电阻相，并且表现出比基准YSZ/GDC更高的相互扩散电导率。此外，策略性添加Fe ₂ O ₃改善了YSZ 和SDC 的收缩相容性，增强了双层结构的完整性。最佳电解质在 300 小时的典型燃料电池运行过程中表现出卓越的稳定性。 这些结果表明双层电解质成分和加工的重要战略修改。