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Designing Tailored Gas Diffusion Layers with Pore Size Gradients via Electrospinning for Polymer Electrolyte Membrane Fuel Cells
ACS Applied Energy Materials ( IF 5.4 ) Pub Date : 2020-02-03 00:00:00 , DOI: 10.1021/acsaem.9b02371
Manojkumar Balakrishnan 1 , Pranay Shrestha 1 , Nan Ge 1 , ChungHyuk Lee 1 , Kieran F. Fahy 1 , Roswitha Zeis 2, 3 , Volker P. Schulz 4 , Benjamin D. Hatton 5 , Aimy Bazylak 1
Affiliation  

We present electrospinning as a versatile technique to design and fabricate tailored polymer electrolyte membrane (PEM) fuel cell gas diffusion layers (GDLs) with a pore-size gradient (increasing from catalyst layer to flow field) to enhance the high current density performance and water management behavior of a PEM fuel cell. The novel graded electrospun GDL exhibits highly robust performance over a range of inlet gas relative humidities (RH). At relatively dry (50% RH) inlet conditions that exacerbate ohmic losses, the graded GDL lowers ohmic resistance and improves high current density performance compared to a uniform GDL with larger pores and fiber diameters. Specifically, the graded GDL facilitates a beneficial degree of liquid water retention at the catalyst layer/GDL interface due to the high capillary pressure inherent in its microstructure, thereby improving membrane hydration. Additionally, enhanced graphitization and connectivity of the graded electrospun fibers improves heat dissipation from the catalyst layer interface compared to the GDL with larger fiber diameters, thereby reducing membrane dehydration. When the inlet RH is raised to fully humid (100% RH) conditions, the graded GDL mitigates liquid water accumulation and lowers mass transport resistance. Specifically, the pore size gradient directs the removal of liquid water from the GDL, resulting in superior performance at high current densities.

中文翻译:

通过电纺设计聚合物电解质膜燃料电池孔尺寸梯度的量身定制的气体扩散层。

我们介绍静电纺丝作为一种通用技术,以设计和制造定制的聚合物电解质膜(PEM)燃料电池气体扩散层(GDL),其孔径梯度(从催化剂层到流场逐渐增加)以增强高电流密度性能和水PEM燃料电池的管理行为。新型分级电纺GDL在一系列进气相对湿度(RH)范围内均表现出高度耐用的性能。在相对干燥(相对湿度为50%)的入口条件下,这会加剧欧姆损失,与具有较大孔和纤维直径的均一GDL相比,渐变GDL降低了欧姆电阻并提高了高电流密度性能。特别,由于其微观结构固有的高毛细管压力,分级的GDL有助于在催化剂层/ GDL界面处保持液态水的有益程度,从而改善了膜的水合作用。另外,与具有较大纤维直径的GDL相比,梯度电纺纤维的增强的石墨化和连通性改善了从催化剂层界面的散热,从而减少了膜的脱水。当入口RH升高到完全潮湿(100%RH)的条件时,分级的GDL减轻了液态水的积聚并降低了传质阻力。具体而言,孔径梯度可指导从GDL中除去液态水,从而在高电流密度下具有出色的性能。与纤维直径较大的GDL相比,梯度电纺纤维增强的石墨化和连通性改善了从催化剂层界面的散热,从而减少了膜的脱水。当入口RH升高到完全潮湿(100%RH)的条件时,分级的GDL减轻了液态水的积聚并降低了传质阻力。具体而言,孔径梯度可指导从GDL中除去液态水,从而在高电流密度下具有出色的性能。与纤维直径较大的GDL相比,梯度电纺纤维增强的石墨化和连通性改善了从催化剂层界面的散热,从而减少了膜的脱水。当入口RH升高到完全潮湿(100%RH)的条件时,分级的GDL减轻了液态水的积聚并降低了传质阻力。具体而言,孔径梯度可指导从GDL中除去液态水,从而在高电流密度下具有出色的性能。
更新日期:2020-02-03
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