We report results of systematic, holistic, diagnostic, and cell studies to elucidate the mechanistic role of the experimentally determined influence of the anode gas-diffusion layer (GDL) on the performance of ultra-thin electrode polymer-electrolyte fuel cells, which can further enable fuel-cell market penetration. Measurements of product water balance and in situ neutron imaging of operational membrane-electrode-assembly water profiles demonstrate how improved performance is due to a novel anode GDL fiber-density modulated structure at the micrometer scale that removes water preferentially out of the anode, a key strategy to manage water in these cells. The banded structure results in low transport-resistance pathways, which affect water-droplet removal from the GDL surface. This interfacial effect is unexpectedly shown to be critical for decreasing overall water holdup throughout the cell. These studies demonstrate a new material paradigm for understanding and controlling fuel-cell water management and related high-power technologies or electrodes where multiphase flow occurs.

我们报告系统，整体，诊断和电池研究的结果，以阐明实验确定的阳极气体扩散层（GDL）对超薄电极聚合物电解质燃料电池性能的影响的机理作用。使燃料电池市场渗透。产品水平衡和原位测量可操作的膜电极组件水剖面的中子成像表明，微米级的新型阳极GDL纤维密度调节结构可优先从阳极中去除水，这是管理这些电池中水的关键策略，从而如何改善性能。带状结构导致低的运输阻力途径，这影响了水滴从GDL表面的去除。出乎意料地表明，这种界面效应对于降低整个电池的总持水率至关重要。这些研究证明了一种新的材料范式，用于理解和控制发生多相流的燃料电池水管理以及相关的大功率技术或电极。