3.5　小结

针对目前缺乏准确的SOFC电极孔隙相曲率预测模型的现状，本章采用3D立方体堆积方法重构电极微观结构并研究了SOFC多孔电极孔隙的曲率，主要结论如下：

①从电极中抽取出代表体元来研究电极性质时，所取的体积边长至少要达到15倍孔隙特征尺寸才能充分代表电极有效性质；

②通过采用成熟的多孔电极扩散模拟手段和几何关系推导，最终获得的传统粉末烧结电极的曲率表达式为：

该式表明曲率是明确依赖于电极孔隙率的，在典型SOFC电极孔隙率范围内，曲率取值为1.3～4。

3D立方体堆积模型提供了一个准确的曲率预测工具，从某种程度上解决了目前曲率值取用不明确的问题，为准确描述电极微观形貌和电极中的传质过程提供了有价值的参考。而为了减小孔隙曲率，在电极烧结过程中增加造孔剂以增加孔隙率是一种方法，但孔隙率和孔隙曲率的调节还应兼顾固体相的导电性能。

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