Crosslinked naphthalene-based triblock polymer anion exchange membranes for fuel cells

Abstract

To investigate the influence of main chain structure on the performance of anion exchange membranes (AEMs), crosslinked naphthalene-based block polymer AEMs are synthesized via nucleophilic polycondensation, Williamson reaction, atom transfer radical polymerization (ATRP) reaction, bromination, and quaternization. With a helical structure, the naphthalene-based triblock backbone can provide the ion channels inside AEMs, further enhance the ionic conductivity and dimensional stability. The crosslinked network of long alkyl chains ensures desirable mechanical properties of AEMs. The prepared NAPEK-PVP-X AEMs have a high alkaline stability, a low swelling ratio and a high ionic conductivity. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) are used to confirm the hydrophilic/hydrophobic microphase separated structure of the AEMs. More developed ion transport channels of naphthalene-based AEMs are shown by molecular dynamics (MD) simulations. A power density peak of 160.73 mW cm−2 is obtained by assembling the NAPEK-PVP-10-Q4 AEM into a single cell operating at 60 °C. The study provides a resource for future work on AEMs.