A One-Dimensional Model of a PEM Fuel Cell with the Cathode Catalyst Layer Hydrophobically Treated for Water Management
A One-Dimensional Model of a PEM Fuel Cell with the Cathode Catalyst Layer Hydrophobically Treated for Water Management
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具有用于水管理的经过疏水处理的阴极催化剂层的 PEM 燃料电池的一维模型
DOI：
10.1149/1945-7111/ac9bdf
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发表时间：
2022
影响因子：
3.9
通讯作者：
Van Nguyen, Trung
中科院分区：
文献类型：
--
作者：
Li, Yuanchao;Van Nguyen, Trung
带有疏水处理的阴极催化层(CL)的质子交换膜燃料电池在70℃时，当加湿空气时，∼峰值功率增加了220%。为了解释增加的原因，建立了一个数学模型，重点研究了阴极催化层中的氧-水两相传输现象。这表明治疗对CL有两方面的影响。首先，与气孔接触的离聚体层的界面变得更加疏水，有助于减少液态水的覆盖率，加快CL的排水速度，从而在高电流密度下获得更好的性能。其次，它还影响离聚体中的水合程度，导致离聚体上和催化剂聚团中离聚体中的氧浓度较高，从而在整个极化曲线上具有更高的性能。对模型拟合实验数据有显著影响的属性是CL的毛细压力属性、催化剂团聚体中的疏水离聚体比率以及氧在Nafion®相中的溶解/扩散系数。结合疏水气体扩散材料和疏水化学发光材料的实例研究表明，该模型可以同时实现膜的自增湿(净水通量为零)和峰值功率提高(∼为15%)，为未来材料的发展提供了方向。
A PEM fuel cell with a hydrophobically treated cathode catalyst layer (CL) demonstrates∼ 220% peak power increase with humidified air at 70 C. To understand the reasons of the increase, a mathematical model was developed focusing on the oxygen-water two-phase transport phenomena in the CL. It suggests the treatment affects the CL in two ways. First, the interface of the ionomer layer exposed to the gas pores becomes more hydrophobic, facilitating less liquid water coverage and faster water drainage from the CL and resulting in better performance at high current densities. Second, it also affects the hydration level in the ionomer phase resulting in higher oxygen concentration in the ionomer phase on and in the catalyst agglomerates, leading to higher performance over the whole polarization curve. The properties having significant influence on the model fitting the experimental data are the capillary pressure property of the CL, the hydrophobic ionomer ratio in the catalyst agglomerate, and the oxygen solubility/diffusivity in the Nafion® phases. With this experimentally verified model, additional case studies combining the hydrophobic gas diffusion material with the hydrophobic CL demonstrate that the membrane's self-humidification (zero-net-water flux) and peak power enhancement (∼ 15%) can be reached simultaneously, providing direction for the future materials development.