Preparation and application of piperidinium-functionalized cross-linked polynorbornene-based anion-exchange membranes

Abstract

Anion-exchange membranes (AEMs) with cross-linked vinyl-addition polynorbornene (VA-PNB) backbones have proved to be outstanding candidates for water electrolysis due to their high hydroxide conductivity and alkaline stability. Herein, we introduced piperidinium cations into the VA-PNB network to produce high performance AEMs (D-2-Pip) through a simple fabrication process. The resulting membrane exhibited a desirable combination of mechanical robustness, high-dimensional stability (swelling ratio of 24%), and remarkable hydroxide conductivity (138 mS cm⁻¹ at 80 °C). It demonstrated exceptional alkaline stability, retaining over 98% of its initial conductivity after 1320 hours in 1 M KOH at 80 °C. The membrane was successfully applied in anion-exchange membrane water electrolyzers (AEMWEs), achieving a high current density of 1.93 A cm⁻² at 2.0 V and outstanding operational durability for over 1400 hours. This study demonstrates the promising potential of the D-2-Pip AEM for efficient and stable clean energy conversion applications.