網印 La0.6Sr0.4Co0.2Fe0.8O3 塗層對2205DSS 高溫電性之影響

Effect of LSCF Protective Coating on the Electrical Properties of 2205DSS at High Temperature

本研究使用 2205 雙相不銹鋼 （2205DSS） 作為固態氧化物燃料電池（SOFC） 的雙極板材料，並以網印方式披覆La0.6Sr0.4Co0.2Fe0.8O3 （LSCF） 塗層，以及分別添加30 wt%、20 wt%、10 wt%、5 wt% Ag 於LSCF 中，再經氮氣氣氛高溫燒結後，探討2205LSCF 的高溫電性行為及Ag 於高溫電性的作用。實驗結果顯示，2205LSCF 在1000°C 氮氣氣氛燒結，LSCF 相穩定且塗層與合金底材附著性良好。塗層與合金底材界面間僅生成較低電阻、單層且薄的Cr-Mnspinel 氧化物。500~750°C 的電性量測結果顯示，2205LSCF 的ASR 值皆低於披覆La0.7Sr0.3MnO3 （LSM） 的2205DSS 的ASR 值，2205DSS 網印LSCF 塗層的導電性優於LSM 塗層。在長時間的ASR 值量測，2205LSCF 於750°C 長時間的ASR 值低於2205LSM 於800°C 長時間的ASR 值。網印方式披覆LSCF塗層於2205DSS，適合作為金屬雙極板的保護材料。添加不同含量Ag 的2205（LSCF-Ag） 於500 ~ 750°C 的ASR 值皆大於2205LSCF 於500 ~ 750°C 的ASR 值。因此使用網印方式披覆 （LSCF-Ag） 塗層，並不適合作為保護金屬雙極板的保護層材料。

Duplex stainless steel (2205DSS) is being considered as a potentialinterconnect material for SOFC. The protection layers, LSCF and LSCF-Ag, were chosen, and the electrical properties and oxidation resistance ofcoating layers on 2205DSS were examined. The LSCF layer was coatedon 2205DSS (2205LSCF) by screen printing and was sintered at 1000°C.LSCF was sintered in N2 atmosphere without decomposition, and only athin oxide layer formed between LSCF and the alloy. The area specific resistancemeasurements from 500°C to 750°C were conducted, and the result showed that the area specific resistance (ASR) of 2205LSCF wasless than that of LSM-coated specimens, because LSCF has higherelectronic conductivity. The results of ASR measurement at 750°C as afunction of holding time implied that the lower ASR of 2205LSCF was dueto the formation of Cr-Mn spinel only. The incorporation of Ag in theLSCF layer was found to be an ineffective way to reduce ASR over theentire range from 500°C to 750°C. It is concluded that screen printedLSCF-coated 2205DSS is adequate for metallic interconnects.