Poly(Ethylene Piperidinium)s for Anion Exchange Membranes

The lack of anion exchange membranes (AEMs) that possess both high hydroxide conductivity and stable mechanical and chemical properties poses a major challenge to the development of high-performance fuel cells. Improving one side of the balance between conductivity and stability usually means sacrificing the other. Herein, we used facile, high-yield chemical reactions to design and synthesize a piperidinium polymer with a polyethylene backbone for AEM fuel cell applications. To improve the performance, we introduced ionic crosslinking into high-cationic-ratio AEMs to suppress high water uptake and swelling while further improving the hydroxide conductivity. Remarkably, PEP80-20PS achieved a hydroxide conductivity of 354.3 mS cm(-1) at 80 & DEG;C while remaining mechanically stable. Compared with the base polymer PEP80, the water uptake of PEP80-20PS decreased by 69 % from 813 % to 350 %, and the swelling decreased substantially by 85 % from 350.0 % to 50.2 % at 80 & DEG;C. PEP80-20PS also showed excellent alkaline stability, 84.7 % remained after 35 days of treatment with an aqueous KOH solution. The chemical design in this study represents a significant advancement toward the development of simultaneously highly stable and conductive AEMs for fuel cell applications.

Automated summary

The lack of anion exchange membranes (AEMs) with both high hydroxide conductivity and stable mechanical and chemical properties is a major challenge for high-performance fuel cells. In this study, a piperidinium polymer with a polyethylene backbone was designed and synthesized for AEM fuel cell applications using facile, high-yield chemical reactions. Ionic crosslinking was introduced to suppress high water uptake and swelling while improving hydroxide conductivity. The designed AEMs exhibited excellent stability and conductivity, with a hydroxide conductivity of 354.3 mS cm(-1) and reduced water uptake and swelling.