Poly(arylene pyridine)s: New alternative materials for high temperature polymer electrolyte fuel cells

Abstract

Developing high-performance and low-cost high temperature polymer exchange membranes (HT-PEMs) is a huge challenge to fuel cells. Here, two poly(arylene pyridine)s (PTAP and PBAP) are synthesized through a simple one-step Friedel–Crafts polymerization of 4-acetylpyridine and para-terphenyl/biphenyl. Both PTAP and PBAP exhibit superior organic solubility and excellent thermal stability. Owing to pyridine groups, PBAP and PTAP membranes display excellent phosphoric acid (PA) absorption capability. The PTAP membrane achieves a PA uptake of 220% after immersing in 85 wt% PA solution at 100 °C, and a high conductivity of 0.102 S cm−1 at 180 °C. Specially, PBAP and PTAP also possess remarkable chemical stability. After 450 h Fenton test, the PTAP membrane still exhibits a high PA uptake of 200% and high conductivity of 0.086 S cm−1. A single H2-O2 cell based on the PTAP/220% membrane shows a peak power density of 743 mW cm−2 at 180 °C without any back pressure, which also displays excellent durability under 200 mA cm−2 and 400 mA cm−2 at 160 °C. Thus, this work develops a facile, cost effective and up-scalable synthetic route of alternative HT-PEM under mild conditions, comparing with the state-of-the-art polybenzimidazole (PBI) membrane.