A Goldilocks Approach to Water Management: Amphiphilic Porous Transport Layers for Unitized Reversible Fuel Cells

Published

March 14, 2023

Author(s)

Siddharth Komini Babu, Abdurrahman Yilmaz, Md Aman Uddin, Jacob LaManna, Elias Baltic, David Jacobson, Ugur Pasaogullari, Jacob Spendelow

Abstract

Unitized reversible fuel cells (URFCs) are a promising option for both local and grid-scale energy storage, and could help facilitate the deployment of intermittent renewable power sources. URFCs consist of a single cell that operates in both fuel cell (FC) and water electrolyzer (WE) mode for power generation and energy storage, respectively. Rapid transport of O2 and H2O is needed to provide high performance in both operating modes, but cell design is complicated by conflicting water management requirements: electrolyzers perform best with high liquid water saturation, whereas fuel cells perform best when liquid water saturation is as low as possible while still maintaining effective ionomer hydration. Conventional Ti-based porous transport layers (PTLs) for the oxygen electrode are hydrophilic, making them suitable for WE mode, but prone to flooding in FC mode. Hydrophobic treatment can improve liquid water removal from the PTL, helping FC performance but hurting WE performance due to water starvation. A novel amphiphilic PTL that uses Nafion channels to provide hydrophilic pathways through an otherwise hydrophobic PTL, enabling optimal performance in both FC and WE mode, is presented in this work. Neutron radiography measurements of water content in both operating modes confirm that the amphiliphilic PTL enables high performance due to its improved water management capabilities.

Citation

Energy and Environmental Science

Pub Type

Journals

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Keywords

reversible fuel cell, electrolysis, hydrogen, neutron imaging

Citation

Komini Babu, S. , Yilmaz, A. , Uddin, M. , LaManna, J. , Baltic, E. , Jacobson, D. , Pasaogullari, U. and Spendelow, J. (2023), A Goldilocks Approach to Water Management: Amphiphilic Porous Transport Layers for Unitized Reversible Fuel Cells, Energy and Environmental Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935308 (Accessed March 21, 2025)