固態氧化物燃料電池（Solid oxide fuel cell，SOFC）操作溫度約800℃，金屬連接板在此高溫長時間之運轉過程中易生成氧化膜，其氧化膜是由不同成分的氧化物所組成，且氧化膜厚度可能不是均勻的，隨著長時間操作其氧化膜會有增生現象，造成導電率下降而影響SOFC 的整體效率。如何減緩連接板氧化層的生長速率，首先必需了解氧化層本身的特性及生成機制，然後設法增加金屬材料本身的抗氧化能力或藉由披覆保護性塗層來阻礙氧離子擴散進入連接板表面以減少氧化物生成。本研究選擇三種肥粒鐵系不鏽鋼分別為，Crofer22 APU、ZMG 232、中鋼ZMG 232做為材料並以網印法塗覆LSCF：結果如下 1. 肥粒鐵系不鏽鋼經800℃空氣氧化後其氧化膜是由（Mn,Cr3）O4 spinel與Cr2O3所構成。許多文獻提到連接板中添加微量的Al、Si元素可增加抗氧化能力；但經過實驗分析後發覺，添加Al、Si元素並無明顯阻抗氧化物生成的能力。 2. LSCF經1000℃持溫50分鐘燒結後，LSCF成穩定的相且塗層與金屬連接板間附著性良好，經800℃空氣氧化後的氧化皮膜厚度皆較未塗覆時低，這也意謂此塗層材料可有效阻礙氧離子擴散通過塗層到Crofer22 APU界面，以降低氧化皮膜成長。將已塗覆LSCF連接板放入800℃加熱爐進行電性量測（Area-specific Resistance, ASR），證實LSCF擁有良好的導電性。在經由WDS分析後顯示塗覆材料中有部份的Cr存在，其原因為cobaltite結構（輝鈷礦）容易吸附Cr元素所導致。 The operation temperature of the solid oxide fuel cell (SOFC) is about 800℃. Metal coupling plates performing under these conditions are prone to producing thin oxide films with increasing time. The film possesses different oxide structures and compositions, the film could also be non- homogeneous. The oxide film thickness grows with time; causing a decrease in conductivity, therefore influences the total efficiency of the SOFC. In order to reduce the growth rate of oxide layer, one must first understand the nature and growing mechanisms of the film. One can reduce the formation of oxides by using protective coatings on the surface to impede oxygen ions diffusing into the surface or by increasing the metal material’s anti-oxidation abilities. This research chooses three types of ferritic stainless steels, Crofer22 APU, ZMG 232 and China Steel ZMG 232, respectively as the basic experimental materials and uses screen printing LSCF. The results are as follow: 1. The oxide films of the ferritic stainless steels, oxidized in 800℃ air, are composed of (Mn,Cr3)O4 spinel and Cr2O3. According to many references , adding trace elements Al and Si into the coupling plates can increase the material’s anti-oxidation abilities. However, after experimental analyses, there is no obvious increase in its ability to impede oxide formation after Al and Si were added. 2. LSCF possesses a stable phase and the coating layer has good adhesion with the metal coupling plates after sintering at 1000℃ for 50 minutes. Also the oxidation layer thickness of the coated specimens is thinner than uncoated ones after oxidizing in 800℃ air. The results indicate that the coatings can effectively stop the oxygen ions passing though the coating to the Crofer22 APU interface and reduce oxide film growth. We prove that LSCF has a good conductivity by placing plates coated with LSCF and performing Area-specific Resistance(ASR) test at 800℃. WDS analysis indicates that the coatings partially consists of Cr, this is due to its cobaltite structure which easily adheres Cr.
