Deep eutectic solvent-supported poly(vinyl) alcohol electrospun anion-exchange membrane for potential application in alkaline fuel cells

Abstract

This research introduces a new method to synthesize poly(vinyl) alcohol (PVA)-based deep eutectic solvent (DES)-supported anion-exchange membranes (AEMs) for alkaline fuel cell (AFC) applications. The fabrication method involved the modification of a PVA-based crosslinked nanofiber mat with DES prepared by mixing choline chloride (ChCl) and ethylene glycol (EG) in a 1:3 molar ratio. Various concentrations of glutaraldehyde (GA) solution were used to cross-link of the PVA fibers. The composite AEM developed using DES was designated as DES3@PVA4 and showed improved performance with a high hydroxide conductivity of 1.05 mS/cm at 60 °C, which is higher than that of the unmodified AEM (0.77 ± 0.01 mS/cm at 60 °C). The absence of swelling, enhanced elongation at break, and improved alkaline stability were further confirmed for the DES-modified AEM; the ionic conductivity remained stable after one month of soaking in 1 M potassium hydroxide solution. These results demonstrate that DES-enhanced PVA-based AEMs can be used for AFCs with improved conductivity, flexibility, mechanical strength, and alkaline stability compared to conventional AEMs.