Semi-interpenetrating network anion exchange membranes based on flexible polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene and rigid Poly(vinylbenzyl chloride) for fuel cell applications

• Published in: Polymer (Guilford) 2023-10, Vol.285, p.126377, Article 126377
• Main Authors: Han, Juanjuan, Liu, Chifeng, Lu, Yuyang, Zheng, Xiumeng, Li, Wanting, Liu, Yi, Yang, Xiaohong, Ren, Zhandong, Hu, Meixue, Xiao, Li, Zhuang, Lin
• Format: Article
• Language: English
• Subjects: Anion exchange membrane; Fuel cell; Semi-interpenetrating network
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2023.126377

Balancing ion conductivity, mechanical strength, and alkali stability is a significant challenge in the application of anion exchange membranes (AEMs) in anion exchange membrane fuel cells (AEMFCs). In this study, rigid poly(4-vinylbiphenyl chloride) (PVB) and flexible polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) are selected as the polymer backbones to create semi-interpenetrating network (SIPN) AEMs. To achieve high ionic conductivity, quaternary ammonium groups are grafted onto each PVB structural unit, and TMHDA reacts with CMSEBS to construct a cross-linking network while also generating quaternary ammonium groups. This approach, along with well-defined micro-morphology, result in SIPN-SEBS/PVB-10 exhibiting an impressive ionic conductivity of 105.7 mS cm−1 at 80 °C. The SIPN structure, formed by the linear quaternary ammonium PVB and cross-linked SEBS, enhances the compatibility between the rigid and flexible components, resulting in good tensile strength (>14.5 Mpa) and elongation at break (>31.8%) for SIPN-SEBS/PVB AEMs at 25 °C in the wet state. Furthermore, SIPN-SEBS/PVB AEMs exhibit excellent chemical stability, in addition to the restricted swelling behavior, which can be attributed to the stable PVB and SEBS main chains. After immersion in a 1 M NaOH solution at 80 °C for 30 days, the degradation of backbones and cations in all membranes is less than 10% and 20%, respectively. Moreover, the peak power density of SIPN-SEBS/PVB-10 in an H2/O2 single fuel cell reaches an impressive value of 379 mW cm−2. Based on these excellent properties, the developed SIPN AEMs hold great promise as candidates for AEMFCs. Structure diagram and photos of SIPN-SEBS/PVB AEMs. And the single fuel cell performance by using SIPN-SEBS/PVB-10 as the separator. [Display omitted] •A new perspective is offered on the development of AEMs with high performance.•Semi-interpenetrating network AEMs is achieved using linear QPVB and cross-linked cQSEBS.•A peak power density of 379 mW cm−2 is presented.