(680i) Comb Shaped Anion Conductive Ionomer Films for Electrochemical Energy Storage Devices

Electricity generation continues to grow over the course of time, but an increase energy consumption occurs as result of this process. The United States energy consumption is predicted to increase 56% by 2040. It is very important to come up with cheaper and more sustainable options. One of the options is to study batteries as energy sources. Batteries have contributed to many energy storage applications over two centuries. Vanadium redox flow (VRF) batteries have attracted significant attention due to its energy efficiency and low cost. They consist of a negative and positive electrolyte tank, pumps, and current collecting plates connected by an ion exchange membrane separator.¹ In a membrane based redox flow battery system, an ion-exchange membrane is usually used as the electrolyte separator.^2,3 The most commonly used ion-exchange membrane is Nafion, a type of thermoplastic polymer that is known for its excellent chemical and thermochemical stability. However, Nafion has been criticized for its environmental impact, low efficiency, and high cost.⁴

The main purpose of this project is to investigate poly(arylene ether sulfone)-based multiblock anion conductive ionomers as a potential alternative for VRF batteries. The quaternary ammonium containing ionomer films at an ion exchange capacity (IEC) of 2.76 meq/g showed a hydroxide conductivity of over 50 mS/cm. The maximum swelling observed for these multiblock ionomers was 33.6% at an IEC of 2.86 meq/g, which was much lower than the swelling observed in random copolymers with much smaller IECs. In order to study the effect of hydrophobic side chains attached to the ionomer backbone, a strategy to improve phase separation in ionomer films, a series of flexible side chain containing multiblock ionomers were also synthesized. In this presentation, emphasis will be put on the properties of these side chain containing poly(arylene ether sulfone)-based multiblock ionomers. The data will be presented in relation to electrochemical applications. This will be preceded by a brief overview of the recent development in anion conductive ionomers.

References:

1. Parasuraman, A., Lim, T. M., Menictas, C. & Skyllas-Kazacos, M. Review of material research and development for vanadium redox flow battery applications. Electrochim. Acta 101, 27–40 (2013).
2. Li, X., Zhang, H. H., Mai, Z., Zhang, H. H. & Vankelecom, I. Ion exchange membranes for vanadium redox flow battery (VRB) applications. Energy Environ. Sci. 4, 1147 (2011).
3. Schwenzer, B. et al. Membrane development for vanadium redox flow batteries. ChemSusChem 4, 1388–1406 (2011).
4. Iojoiu, C., Maréchal, M., Chabert, F. & Sanchez, J. Y. Mastering sulfonation of aromatic polysulfones: Crucial for membranes for fuel cell application. Fuel Cells 5, 344–354 (2005).