Direct Insertion Polymerization of Ionic Monomers: Rapid Production of Anion Exchange Membranes

• Published in: Angewandte Chemie 2023-07, Vol.135 (30), p.n/a
• Main Authors: Hsu, Jesse H., Peltier, Cheyenne R., Treichel, Megan, Gaitor, Jamie C., Li, Qihao, Girbau, Renee, Macbeth, Alexandra J., Abruña, Héctor D., Noonan, Kevin J. T., Coates, Geoffrey W., Fors, Brett P.
• Format: Article
• Language: English
• Subjects: Anion exchange; Anion exchanging; Cationic polymerization; Cations; Chemical synthesis; Chemistry; Conductivity; Copolymerization; Fuel Cells; Fuel technology; Insertion; Membranes; Monomers; Polymerization; Polymers; Polynorbornene; Stability
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202304778

The limited number of methods to directly polymerize ionic monomers currently hinders rapid diversification and production of ionic polymeric materials, namely anion exchange membranes (AEMs) which are essential components in emerging alkaline fuel cell and electrolyzer technologies. Herein, we report a direct coordination‐insertion polymerization of cationic monomers, providing the first direct synthesis of aliphatic polymers with high ion incorporations and allowing facile access to a broad range of materials. We demonstrate the utility of this method by rapidly generating a library of solution processable ionic polymers for use as AEMs. We investigate these materials to study the influence of cation identity on hydroxide conductivity and stability. We found that AEMs with piperidinium cations exhibited the highest performance, with high alkaline stability, hydroxide conductivity of 87 mS cm−1 at 80 °C, and a peak power density of 730 mW cm−2 when integrated into a fuel cell device. We developed a direct coordination‐insertion polymerization of cation‐containing monomers, allowing facile access to a broad range of materials. Demonstrating the utility of this method, we produced a diverse library of ionic polymers for use as anion exchange membranes and investigated the influence of cation identity on hydroxide conductivity and alkaline stability.