Enhancement of Proton Conductivity Performance in High Temperature Polymer Electrolyte Membrane, Processed the Adding of Pyridobismidazole

Kehua Lin; Chengxiang Wang; Zhiming Qiu; Yurong Yan

doi:10.3390/polym14071283

Enhancement of Proton Conductivity Performance in High Temperature Polymer Electrolyte Membrane, Processed the Adding of Pyridobismidazole

Polymers (Basel). 2022 Mar 22;14(7):1283. doi: 10.3390/polym14071283.

Authors

Kehua Lin¹, Chengxiang Wang¹, Zhiming Qiu¹, Yurong Yan¹

Affiliation

¹ School of Materials Science and Engineering, South China University of Technology, 391 Wushan Road, Guangzhou 510641, China.

Abstract

A pyridobisimidazole unit was introduced into a polymer backbone to obtain an increased doping level, a high number of interacting sites with phosphoric acid and simple processibility. The acid uptake of poly(pyridobisimidazole) (PPI) membrane could reach more than 550% (ADL = 22), resulting in high conductivity (0.23 S·cm^-1 at 180 °C). Along with 550% acid uptake, the membrane strength still held 10 MPa, meeting the requirement of Proton Exchange Membrane (PEM). In the Fenton Test, the PPI membrane only lost around 7% weight after 156 h, demonstrating excellent oxidative stability. Besides, PPI possessed thermal stability with decomposition temperature at 570 °C and mechanical stability with a glass transition temperature of 330 °C.

Keywords: fuel cell; imidazole; proton exchange membrane; pyridine.