Interactions between liquid-water and gas-diffusion layers in polymer-electrolyte fuel cells

Journal Article · Thu Jun 11 00:00:00 EDT 2015 · Procedia Engineering

DOI:https://doi.org/10.1016/j.proeng.2015.05.066· OSTI ID:1208642

Das, Prodip K. ^[1]; Santamaria, Anthony D. ^[2]; Weber, Adam Z. ^[3]

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1. Newcastle Univ., Newcastle upon Tyne (United Kingdom). School of Mechanical and Systems Engineering.
2. Western New England Univ., Springfield, MA (United States)
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Over the past few decades, a significant amount of research on polymer-electrolyte fuel cells (PEFCs) has been conducted to improve performance and durability while reducing the cost of fuel cell systems. However, the cost associated with the platinum (Pt) catalyst remains a barrier to their commercialization and PEFC durability standards have yet to be established. An effective path toward reducing PEFC cost is making the catalyst layers (CLs) thinner thus reducing expensive Pt content. The limit of thin CLs is high gas-transport resistance and the performance of these CLs is sensitive to the operating temperature due to their inherent low water uptake capacity, which results in higher sensitivity to liquid-water flooding and reduced durability. Therefore, reducing PEFC's cost by decreasing Pt content and improving PEFC's performance and durability by managing liquid-water are still challenging and open topics of research. An overlooked aspect nowadays of PEFC water management is the gas-diffusion layer (GDL). While it is known that GDL's properties can impact performance, typically it is not seen as a critical component. In this work, we present data showing the importance of GDLs in terms of water removal and management while also exploring the interactions between liquid-water and GDL surfaces. The critical interface of GDL and gas-flow-channel in the presence of liquid-water was examined through systematic studies of adhesion forces as a function of water-injection rate for various GDLs of varying thickness. GDL properties (breakthrough pressure and adhesion force) were measured experimentally under a host of test conditions. Specifically, the effects of GDL hydrophobic (PTFE) content, thickness, and water-injection rate were examined to identify trends that may be beneficial to the design of liquid-water management strategies and next-generation GDL materials for PEFCs.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Hydrogen Fuel Cell Technologies Office
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1208642
• Journal Information: Procedia Engineering, Vol. 105, Issue C; ISSN 1877-7058
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
polymer-electrolyte fuel cells
liquid-water
water-management
gas-diffusion layers