Highly Anion Conductive Cellulose Realized by One-Step, Facile, and Effective Introduction of Ammonium and Phenyl Alkyl Groups

Abstract

Anion exchange membranes (AEMs) have attracted attention due to their applications in water electrolyzers, metal–air batteries, and redox flow batteries. However, developing AEMs with cost-effective and environmentally friendly methods is highly challenging. Herein, we demonstrate that a novel, one-step molecular modification of cellulose (powder, degreasing cotton, and natural cotton) provides AEMs very effectively. By controlling the feed molar ratio of reactants, cellulose AEMs (QC-1) having wide varieties of ion exchange capacity (0.63–1.54 mmol g–1) and degree of substitution (0.52–1.39) were successfully prepared. QC-1 achieved one of the highest OH–conductivity values (∼42.6 mS cm–1) among reported cellulose-based AEMs. QC-1 showed good alkaline stability and moderate mechanical properties, which were applicable to a solid-state zinc–air battery (ZAB). The result would open a new era of AEM development, and in the future, green AEMs will further enhance the sustainability of clean energy conversion and storage devices.