Highly conductive branched poly(aryl piperidinium) anion exchange membranes with robust chemical stability

Jia Jun Wang; Wei Ting Gao; Yvonne Shuen Lann Choo; Zhi Hong Cai; Qiu Gen Zhang; Ai Mei Zhu; Qing Lin Liu

doi:10.1016/j.jcis.2022.08.183

Highly conductive branched poly(aryl piperidinium) anion exchange membranes with robust chemical stability

J Colloid Interface Sci. 2023 Jan;629(Pt A):377-387. doi: 10.1016/j.jcis.2022.08.183. Epub 2022 Sep 5.

Authors

Jia Jun Wang¹, Wei Ting Gao¹, Yvonne Shuen Lann Choo¹, Zhi Hong Cai¹, Qiu Gen Zhang¹, Ai Mei Zhu¹, Qing Lin Liu²

Affiliations

¹ Department of Chemical & Biochemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China.
² Department of Chemical & Biochemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China. Electronic address: qlliu@xmu.edu.cn.

PMID: 36087553
DOI: 10.1016/j.jcis.2022.08.183

Abstract

Poly(aryl piperidinium) (PAP) anion exchange membranes (AEMs) furnish an important avenue for the commercialization of anion exchange membrane fuel cells (AEMFCs), but their ionic conductivity and alkali resistance still need to be improved. Here, we report the synthesis of PAP AEMs with a branched structure by the acid-catalyzed reaction and compare them with the main-chain AEMs. The experimental results show that the branched AEMs have higher OH^- conductivity and alkaline resistance than the poly(terphenyl piperidine) (PTPQ1) AEM. The alkaline stability and OH^- conductivity of the AEMs were further improved by a flexible multi-cation crosslinker. The results show that the branched poly(p-terphenyl triphenylmethane 1-methyl piperidine) membrane crosslinked by multi-cation (PTTPQ4-40) shows an excellent OH^- conductivity (155.3 mS cm^-1) at 80 °C. The OH^- conductivity of the PTTPQ4-40 membrane was maintained at 92.1% after soaking in 2 M NaOH for 1080 h at 80 °C. In addition, the peak power density (PPD) of the crosslinked PTTPQ4-40 membrane can reach 656.7 mW cm^-2. Compared to the PTPQ1 AEM, the PPD of the crosslinked PTTPQ4-40 AEM is increased by 38.6% in H₂-O₂. All of the results confirm that the PTTPQ4-40 AEM has excellent fuel cell application prospects.

Keywords: Anion exchange membranes; Branched structure; Free volume; Superacid catalysis.