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

Abstract

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 À 1 at 80 °C, and a peak power density of 730 mW cm À 2 when integrated into a fuel cell device.

Alkaline Membranes toward Electrochemical Energy Devices: Recent Development and Future Perspectives

“…(a) McMurray coupling reaction for preparing alkaline membranes . (b) Direct insertion polymerization method for preparing alkaline membranes …”

“…Our group recently reported a facile, gentle, and low-cost way, called the McMurray coupling reaction ( Figure 9 a), for the preparation of high-performance alkaline membranes. 102 Furthermore, Fors et al 103 reported a direct coordination–insertion polymerization method of ionic monomers, with the benefits of efficiency and general applicability ( Figure 9 b). This direct insertion polymerization method avoids the postpolymerization modification process in the traditional synthesis method and allows facile access to a broad range of materials.…”