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

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 80degree celsius. 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 25degree celsius 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 80degree celsius 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 H-2/O-2 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.

Automated summary

By constructing a semi-interpenetrating network structure, anion exchange membranes (AEMs) with balanced ion conductivity, mechanical strength, and alkali stability were created. The AEMs exhibited excellent comprehensive properties, making them promising candidates for anion exchange membrane fuel cells (AEMFCs).