In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2022-01, No. 35 ( 2022-07-07), p. 1407-1407
Abstract:
Anion exchange membrane fuel cells (AEMFCs) have attracted widespread attention because of the lower cost of using non-precious metal catalysts and high oxygen reduction reaction (ORR) kinetics in alkaline conditions. [1] The previous research focused on the water uptake and OH - conduction properties of anion exchange membranes (AEMs) as thick forms. [2–5] The fuel cell reaction occurs at the triple-phase interface where the junction of ion-conductive ionomer, catalyst, and fuel/oxidant. The ionomer plays an important role to deliver OH - ion between the thick membrane andto electrochemical catalysts in fuel cells. However, the investigation of OH - ion conduction and hydration properties of thin ionomers is important but not sufficient. This work demonstrated the relations between OH - conductivity and water uptake of anion exchange thin films for the first time. [6] The reported poly[(9,9-bis(6′-(N,N,N-trimethylammonium)-hexyl)- 9H -fluorene)- alt -(1,4-benzene)] (PFB + ) [6] was synthesized as a model ionomer. We established in situ methods for measuring OH - conductivity and water uptake of anion exchange thin films [7] because OH - ion easily exchanges for carbon dioxide in the air. The OH - conductivity of 273 nm-thick PFB + thin film form at 25 °C under 95 % relative humidity (RH) is comparable to the reported OH - conductivity value of PFB + bulk membrane. Reduced OH - conductivity and water uptake were observed in 30 nm-thick PFB + film compared to thicker 273 nm-thick PFB + film. This reduced OH - conductivity was caused by the decreased number of water molecules contained in thinner PFB + films. Under the same number of water molecules contained, similar OH - conductivity results can be obtained for both 273 and 30 nm-thick films as shown in Figure. Results show a different trend compared to the case of the proton conductive thin films. [8] References [1] G. Merle, M. Wessling, K. Nijmeijer, J. Memb. Sci. 2011 , 377 , 1–35. [2] J. Y. Jeon, S. Park, J. Han, S. Maurya, A. D. Mohanty, D. Tian, N. Saikia, M. A. Hickner, C. Y. Ryu, M. E. Tuckerman, S. J. Paddison, Y. S. Kim, C. Bae, Macromolecules 2019 , 52 , 2139–2147. [3] J. Chen, M. Guan, K. Li, S. Tang, ACS Appl. Mater. Interfaces 2020 , 12 , 15138–15144. [4] U. Salma, Y. Nagao, Polym. Degrad. Stab. 2020 , 179 , 109299. [5] C. G. Arges, L. Zhang, ACS Appl. Energy Mater. 2018 , 1 , 2991–3012. [6] W. H. Lee, A. D. Mohanty, C. Bae, ACS Macro Lett. 2015 , 4 , 453–457. [7] F. Wang, D. Wang, Y. Nagao, ChemSusChem 2021 , 14 , 2694–2697. [8] Y. Nagao, Sci. Tech. Adv. Mater . 2020 , 21 , 79–91. Figure 1
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2022-01351407mtgabs
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2022
detail.hit.zdb_id:
2438749-6
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