A solid oxide fuel cell (SOFC) is a clean and high-efficiency energy conversion device, which undergoes improvement of performance continuously. The transport of gas species and charges proceed in the porous electrodes. The porous electrodes are also responsible for the removal of exhaust gases. In this paper, a fully coupled 3D single-channel multiphysics computational fluid dynamics (CFD) model was developed based on the finite element method (FEM). The governing equations for momentum, species, charges, and heat transport were solved by a segregated solver. The impact of decreased ionic, electronic, and pore phase tortuosity on the SOFC performance such as fuel utilization, current density, activation overpotential and temperature distribution are analyzed and compared with the base case. In addition to the tortuosity investigation, the volume fraction of the electronic phase in the active layer and the support layer is also investigated using a parametric sweep study. Of all the decreased tortuosity cases, there is an increase in ionic current density and temperature compared with the base case. Except for a decreased pore tortuosity, all other cases led to an increase of electronic current density compared with the base case. The consumption of hydrogen increased for all cases compared with the base case. The activation overpotential increased with decreased electronic phase and pore phase tortuosity, while a decrease of ionic phase tortuosity caused a decrease. Finally, when decreasing all phase tortuosity, both current density, temperature, activation overpotential, and hydrogen consumption increased. For the parametric sweep, there is an optimum electronic phase volume fraction value. This work allows for a better understanding of the relationship between the microstructure and performance of SOFCs. Meanwhile, it provides theoretical guidance for a better porous electrode design.

固体氧化物燃料电池（SOFC）是一种清洁高效的能量转换装置，其性能不断提高。气体物质和电荷的传输在多孔电极中进行。多孔电极还负责去除废气。在本文中，基于有限元方法 (FEM) 开发了一个完全耦合的 3D 单通道多物理场计算流体动力学 (CFD) 模型。动量、种类、电荷和热传输的控制方程由分离求解器求解。分析了离子、电子和孔相弯曲度降低对燃料利用率、电流密度、活化过电位和温度分布等 SOFC 性能的影响，并与基本情况进行了比较。除了曲折调查，还使用参数扫描研究来研究有源层和支撑层中电子相的体积分数。在所有弯曲度降低的情况中，与基本情况相比，离子电流密度和温度有所增加。除了孔隙弯曲度降低外，与基本情况相比，所有其他情况都导致电子电流密度增加。与基本情况相比，所有情况的氢气消耗量都增加了。活化过电位随着电子相和孔相曲折度的降低而增加，而离子相曲折度的降低导致活化过电位降低。最后，当降低全相弯曲度时，电流密度、温度、活化过电位和氢消耗都增加。对于参数化扫描，有一个最佳的电子相体积分数。这项工作有助于更好地了解 SOFC 的微观结构与性能之间的关系。同时，为更好的多孔电极设计提供了理论指导。