3.5　小結

針對目前缺乏準確的SOFC電極孔隙相曲率預測模型的現狀，本章采用3D立方體堆積方法重構電極微觀結構并研究了SOFC多孔電極孔隙的曲率，主要結論如下：

①從電極中抽取出代表體元來研究電極性質時，所取的體積邊長至少要達到15倍孔隙特征尺寸才能充分代表電極有效性質；

②通過采用成熟的多孔電極擴散模擬手段和幾何關系推導，最終獲得的傳統粉末燒結電極的曲率表達式為：

該式表明曲率是明確依賴于電極孔隙率的，在典型SOFC電極孔隙率范圍內，曲率取值為1.3～4。

3D立方體堆積模型提供了一個準確的曲率預測工具，從某種程度上解決了目前曲率值取用不明確的問題，為準確描述電極微觀形貌和電極中的傳質過程提供了有價值的參考。而為了減小孔隙曲率，在電極燒結過程中增加造孔劑以增加孔隙率是一種方法，但孔隙率和孔隙曲率的調節還應兼顧固體相的導電性能。

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