(471a) Molecular Engineering of Hydroxide Ion Conducting Aromatic Polymers and Their Applications in Alkaline Membrane Fuel Cells

Junyoung Han,^† Jong Yeob Jeon,^† Sangtaik Noh,^† Chang Y. Ryu,^† Chulsung Bae*^,†§

^†Department of Chemistry and Chemical Biology, ^§ Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States

Recently, anion exchange membrane (AEM) fuel cell has attracted attention as a clean energy technology device to convert chemical energy into electric energy. AEM fuel cells have several advantages, such as fast kinetics and non-precious metal catalysts.¹ However, AEMs that have desired properties (e.g. high hydroxide conductivity, thermochemical stability at high pH for durable operation, and convenient synthetic process) are not commercially available yet.^2,3 New material developments by designing of new polymer backbones, side chain functional groups and new anion conductive groups have been extensively investigated over the past decade.⁴ Several research groups including us have reported that a long side chain between polymer backbone and quaternary ammonium (QA) end group is helpful for enhancing micro-phase separation based on thermochemical stable backbone.^5-7

In this study, we will present the effects of polymer structures on the membrane morphology, properties and fuel cell performance. To better understand polymer structure–membrane property relationships, aromatic polymers with different QA head groups, tether chain lengths, polymer backbone were prepared and their properties were evaluated. In addition to the fundamental study, how high performance AEMs can be produced in a kilo gram scale by cost effective processes will be presented.

References

1. Y. J. Wang, J. Qiao, R. Baker, J. Zhang, J., Chem. Soc. Rev. 42, 5768, (2013).
2. O. M. M. Page, S. D. Poynton, S. Murphy, A. Lien Ong, D. M. Hillman, C. A. Hancock, M. G. Hale, D. C. Apperley, J. R. Varcoe, RSC Adv. 3, 579 (2013).
3. C. Fujimoto, D.-S. Kim, M. Hibbs, D. Wrobleski, Y. S. Kim, J. Membr. Sci. 423−424, 438 (2012).
4. A. D. Mohanty, C. Y. Ryu, Y. S. Kim, C. Bae, Macromolecules 48, 7085 (2015).
5. H.-S. Dang, P. Jannasch, Macromolecules 48, 5742 (2015).
6. W.-H. Lee, Y. S. Kim, C. Bae, ACS Macro Lett. 4, 814 (2015).
7. W.-H. Lee, A.D. Mohanty, C. Bae, ACS Macro Lett. 4, 453 (2015).