Homogenization of current density of PEM fuel cells by in-plane graded distributions of platinum loading and GDL porosity
Homogenization of current density of PEM fuel cells by in-plane graded distributions of platinum loading and GDL porosity
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DOI：
10.1016/j.ces.2018.08.029
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发表时间：
2018-12
影响因子：
4.7
通讯作者：
L. Xing;Yan Wang;P. Das;K. Scott;W. Shi
中科院分区：
文献类型：
--
作者：
L. Xing;Yan Wang;P. Das;K. Scott;W. Shi
本文对质子交换膜燃料电池阴极催化剂层（CL）内铂负载量的不均匀性和气体扩散层（GDL）内的孔隙率进行了数值研究。研究了它们沿面内（纵向）方向的沿着分布以及它们之间的相互作用对电池性能和电流密度均匀性的影响。通过一系列不同条件下的实验结果验证了数学模型的正确性。铂负载量和GDL孔隙率对性能的强烈相互作用被揭示，并且由于电化学反应速率和物种传输速率之间的相关性，GDL孔隙率对最佳铂梯度存在显著影响。当阴极入口处的初始铂载量和GDL孔隙率高时，单独增加出口附近的铂载量不能改善电池性能和电流密度均匀性。系统地控制铂负载和GDL孔隙率的梯度实现了膜电极组件内电流密度的更均匀分布。
This paper presents a numerical study of the inhomogeneous platinum loading within the catalyst layer (CL) and porosity inside the gas diffusion layer (GDL) at the cathode of a proton exchange membrane fuel cell. Their distributions along the in-plane (longitudinal) direction and the effect of their interactions on the cell performance and current density uniformity are investigated. The mathematic model is validated by a series of experimental results at various conditions. A strong interaction of platinum loading and GDL porosity on performance is revealed, and a significant impact of GDL porosity on the optimal platinum gradients exists, due to the correlations between the electrochemical reaction rate and species transport rate. When the initial platinum loading and GDL porosity are high at the cathode inlet, individually increasing the platinum loading near the outlet cannot improve the cell performance and current density uniformity. Systematically controlling the gradients of platinum loading and GDL porosity achieves a more uniform distribution of current density within the membrane electrode assembly.