Highly conductive and stable anion‐exchange membranes based on crosslinked poly(arylene ether sulfone)‐block‐poly(phenylene oxide) Networks

Abstract

In the field of the developments of next-generation polymer electrolyte membranes, high conductivity is often regarded as the first important performance requirement. There is still a huge challenge to face, which is hard to achieve the balance between high ion conductivity (mainly related to ion-exchange capacity [IEC]) and good mechanical-dimensional stability (represented by swelling ratio [SR]). Here, a family of crosslinked block polyelectrolytes consisting of hydrophobic rigid poly(arylene ether sulfone) segments to ensure enough dimensional stability and hydrophilic poly(phenylene oxide) segments bearing long-flexible chains with high-density multications to serve as crosslinker and carrier for ion transport are prepared. The polyelectrolyte with an IEC of 3.04 mmol g −1 exhibits a high hydroxide conductivity of 126 mS cm −1 and a low SR of 8.6% at 80 C. No obvious degradation below 200 C is observed, and maximum tensile strength reaches 28.4 MPa. As a conclusion, these crosslinked membranes based on well-designed block polyelectrolytes exhibit an excellent combination of high ion conductivity and good mechanicaldimensional stability to meet the performance requirements for the application of anion-exchange membranes.

Beneficial use of hyperbranched polymer in cross‐linked anion exchange membranes for fuel cells

“…In our previous studies, to prepare highly conductive AEMs with mechanically strength, several useful approaches including the synthesis of high-IEC naphthalene-based poly(arylene ether ketone), 44 and the constructions of cross-linked polymeric networks with a well-designed architecture [45][46][47] have been developed. Here, we prepared some cross-linked bicomponent networks containing a high-molecular-weight linear PPO as a framework to maintain mechanical strength and flexibility and a hyperbranched poly(4-vinylbenzyl chloride) (HVBC) as a functional component to provide the local high-density ionic groups for OH À transport.…”