当前位置: X-MOL 学术Energy Environ. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Comprehensive investigation of novel pore-graded gas diffusion layers for high-performance and cost-effective proton exchange membrane electrolyzers
Energy & Environmental Science ( IF 32.4 ) Pub Date : 2017-07-24 00:00:00 , DOI: 10.1039/c7ee01240c
P. Lettenmeier 1, 2, 3, 4 , S. Kolb 1, 2, 3, 4 , N. Sata 1, 2, 3, 4 , A. Fallisch 4, 5, 6 , L. Zielke 7, 8, 9, 10, 11 , S. Thiele 7, 8, 9, 10, 11 , A. S. Gago 1, 2, 3, 4 , K. A. Friedrich 1, 2, 3, 4, 12
Affiliation  

Hydrogen produced by water electrolysis is a promising storage medium for renewable energy. Reducing the capital cost of proton exchange membrane (PEM) electrolyzers without losing efficiency is one of its most pressing challenges. Gas diffusion layers (GDL), such as felts, foams, meshes and sintered plates, are key stack components, but these are either inefficient or expensive. This study presents a new type of GDL produced via vacuum plasma spraying (VPS), which offers a large potential for cost reduction. With this technology, it is possible to introduce a gradient in the pore-size distribution along the thickness of the GDL by varying the plasma parameters and titanium powder particle sizes. This feature was confirmed by cross-section scanning electron microscopy (SEM). X-ray computed tomography (CT) and mercury intrusion porosimetry allowed determining the porosity, pore radii distribution, and pore entry distribution. Pore radii of ca. 10 μm could be achieved in the layers of the GDL close to the bipolar plate, while those in contact with the electrodes were in the range of 5 μm. The thermally sprayed Ti-GDLs allowed achieving PEM electrolyzer performances comparable to those of the state-of-the-art sintered plates and far superior than those of meshes. Moreover, a numerical model showed that the reduced capillary pressure and tortuosity eliminates mass transport limitations at 2 A cm−2. The results presented herein demonstrate a promising solution to reduce the cost of one of the most expensive components of the stack.

中文翻译:

高性能和高性价比的质子交换膜电解槽的新型孔隙梯度气体扩散层的综合研究

水电解产生的氢气是可再生能源的有前途的存储介质。减少质子交换膜(PEM)电解器的资本成本而不损失效率是其最紧迫的挑战之一。气体扩散层(GDL),例如毛毡,泡沫,筛网和烧结板,是关键的烟囱组件,但是它们要么效率低下要么昂贵。这项研究提出了一种通过真空等离子喷涂(VPS),具有降低成本的巨大潜力。利用这种技术,可以通过改变等离子体参数和钛粉的粒径,沿GDL的厚度在孔径分布中引入梯度。通过横截面扫描电子显微镜(SEM)证实了这一特征。X射线计算机断层扫描(CT)和压汞法可确定孔隙度,孔隙半径分布和孔隙入口分布。孔隙半径在靠近双极板的GDL层中可以达到10μm,而与电极接触的层在5μm的范围内。热喷涂的Ti-GDL可以实现PEM电解槽的性能,可与最新的烧结板相媲美,并且远远优于筛孔。此外,数值模型表明,降低的毛细管压力和曲折度消除了在2 A cm -2处的传质限制。本文介绍的结果证明了一种有希望的解决方案,可以降低堆叠中最昂贵的组件之一的成本。
更新日期:2017-08-11
down
wechat
bug