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Gao X, Yamamoto K, Hirai T, Ohta N, Uchiyama T, Watanabe T, Imai H, Sugawara S, Shinohara K, Uchimoto Y. Impact of the Composition of Alcohol/Water Dispersion on the Proton Transport and Morphology of Cast Perfluorinated Sulfonic Acid Ionomer Thin Films. ACS OMEGA 2021; 6:14130-14137. [PMID: 34124435 PMCID: PMC8190810 DOI: 10.1021/acsomega.1c00607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
The dispersion of perfluorinated sulfonic acid ionomers in catalyst inks is an important factor that controls the performance of catalyst layers in membrane electrode assemblies of polymer electrolyte fuel cells. Herein, the effects of water/alcohol compositions on the morphological properties and proton transport are examined by grazing incidence small-angle X-ray scattering, grazing incidence wide-angle X-ray scattering, and electrochemical impedance spectroscopy. The thin films cast by a high water/alcohol ratio Nafion dispersion have high proton conductivity and well-defined hydrophilic/hydrophobic phase separation, which indicates that the proton conductivity and morphology of the Nafion thin films are strongly influenced by the state of dispersion. This finding is expected to further understand the morphology and proton transport properties of Nafion thin films with different water/alcohol ratios, which has implications for the performance of the Pt/Nafion interface.
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Affiliation(s)
- Xiao Gao
- Graduate
School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu-cho, Sakyo-ku, Kyoto 606-8316, Japan
| | - Kentaro Yamamoto
- Graduate
School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu-cho, Sakyo-ku, Kyoto 606-8316, Japan
| | - Tomoyasu Hirai
- Department
of Applied Chemistry, Osaka Institute of
Technology, 5-16-1 Ohmiya, Asahi-ku, Osaka 535-8585, Japan
| | - Noboru Ohta
- Japan
Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo 679-5198, Japan
| | - Tomoki Uchiyama
- Graduate
School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu-cho, Sakyo-ku, Kyoto 606-8316, Japan
| | - Toshiki Watanabe
- Graduate
School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu-cho, Sakyo-ku, Kyoto 606-8316, Japan
| | - Hideto Imai
- Nissan
Analysis and Research Center, 1, Natsushima-cho, Yokosuka-shi, Kanagawa 237-8523, Japan
| | - Seiho Sugawara
- Fuel
Cell Cutting-Edge Research Center Technology Research Association, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Kazuhiko Shinohara
- Fuel
Cell Cutting-Edge Research Center Technology Research Association, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Yoshiharu Uchimoto
- Graduate
School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu-cho, Sakyo-ku, Kyoto 606-8316, Japan
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Abstract
In this comprehensive review, recent progress and developments on perfluorinated sulfonic-acid (PFSA) membranes have been summarized on many key topics. Although quite well investigated for decades, PFSA ionomers' complex behavior, along with their key role in many emerging technologies, have presented significant scientific challenges but also helped create a unique cross-disciplinary research field to overcome such challenges. Research and progress on PFSAs, especially when considered with their applications, are at the forefront of bridging electrochemistry and polymer (physics), which have also opened up development of state-of-the-art in situ characterization techniques as well as multiphysics computation models. Topics reviewed stem from correlating the various physical (e.g., mechanical) and transport properties with morphology and structure across time and length scales. In addition, topics of recent interest such as structure/transport correlations and modeling, composite PFSA membranes, degradation phenomena, and PFSA thin films are presented. Throughout, the impact of PFSA chemistry and side-chain is also discussed to present a broader perspective.
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Affiliation(s)
- Ahmet Kusoglu
- Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, MS70-108B, Berkeley, California 94720, United States
| | - Adam Z Weber
- Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, MS70-108B, Berkeley, California 94720, United States
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