Development of a new class of stable and adaptable free-standing fibre mats with high room-temperature hydroxide-ion conductivity

For alkaline anion-exchange membrane electrolysers and fuel cells to become a technological reality, hydroxide-ion (OH^-) conducting membranes that are flexible, robust, affording high OH^- conductivity, and synthesised in a low-cost and scalable way must be developed. In this paper, we engineer a stable, self-supporting, and flexible fibre mat using a low-cost ZIF-8 metal-organic framework composited with ionic liquid tetrabutylammonium hydroxide and widely used polyacrylonitrile as polymeric backbone. We obtain mats with a high intrinsic OH^- conductivity for a metal-organic framework-based material already at room temperature, without added ion-conductor polymers. This approach will contribute to the development of low-cost and tuneable ion-conducting membranes.