Stainless-steel porous substrates for metal-supported solid oxide fuel cells require protective coatings to prevent chromium poisoning of the cathode. In this study, CuNi0.2Mn1.8O4 powders were synthesized by the glycine nitrate combustion synthesis process and protective coatings were deposited on porous SUS 430 substrates by electrophoretic deposition and densified using a two-step annealing procedure. It was found that an AC signal of 500 Hz, ±20 V voltage amplitude with a 60/40 duty ratio (coating deposition to removal time ratio), combined with a stirring rate of 200 RPM, resulted in a ∼ 2 μm relatively uniform coating throughout the surfaces of the porous structure. The conductivity of CuNi0.2Mn1.8O4 decreased and the activation energy of small polaron hopping increased with increasing Cr doping concentration. The diffusivity of Cr in CuNi0.2Mn1.8O4 at 700°C was determined to be 7.93 × 10−20 m2/s. It is predicted that the surface of a 2 μm CuNi0.2Mn1.8O4 coating will not exceed the solubility limit of Cr even after 50,000 h of operation, highlighting the excellent gettering property of the coating. A model was developed that indicated that at 700 °C, the coating layer contribution to the area specific resistance is more dominant during the first 250 h, after which the contribution of the Cr2O3 layer becomes more significant. Compared to the uncoated sample, the ASR of the coated metal support is expected to be less than 1/10th of that of an uncoated sample after 50,000 h of operation. These results show that AC-EPD CuNi0.2Mn1.8O4 coatings not only mitigates chromium poisoning in SOFC stacks but also maintains robust electrical conductivity, thereby promising enhanced long-term cell performance.

中文翻译：

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保护性 Ni 掺杂 Cu[sbnd]Mn 尖晶石互连涂层的加工和性能


用于金属负载固体氧化物燃料电池的不锈钢多孔基板需要保护涂层，以防止阴极的铬中毒。本研究采用甘氨酸硝酸盐燃烧合成工艺合成了 CuNi0.2Mn1.8O4 粉末，通过电泳沉积将保护涂层沉积在多孔 SUS 430 基材上，并使用两步退火程序进行致密化。研究发现，500 Hz 的交流信号、±20 V 电压幅值和 60/40 的占空比（涂层沉积与去除时间之比），再加上 200 RPM 的搅拌速率，导致整个多孔结构表面的涂层相对均匀。CuNi0.2Mn1.8O4 的电导率随着 Cr 掺杂浓度的增加而降低，小极化子跳跃的活化能增加。在 700°C 时 CuNi0.2Mn1.8O4 中 Cr 的扩散率为 7.93 × 10−20 m2/s。据预测，即使在运行 50,000 小时后，2 μm CuNi0.2Mn1.8O4 涂层的表面也不会超过 Cr 的溶解度极限，突出了涂层优异的吸气性能。开发了一个模型，表明在 700 °C 时，涂层层对面积比电阻的贡献在前 250 h 更为主要，之后 Cr2O3 层的贡献变得更加显着。与未涂层样品相比，涂层金属载体的 ASR 预计在运行 50,000 小时后将小于未涂层样品的 1/10。这些结果表明，AC-EPD CuNi0.2Mn1.8O4 涂层不仅可以减轻 SOFC 堆栈中的铬中毒，还可以保持强大的导电性，从而有望增强电池的长期性能。