Porous PTFE supported bis(siloxane imidazole) functionalized Norbornyl copolymer composite anion exchange membrane for alkaline fuel cells

Abstract

Anion exchange membrane plays a vital role in alkaline anion exchange membrane fuel cell (AEMFC). In this work, a combination strategy of organic–inorganic nanocomposite technology and compounding with PTFE matrix was adopted, which effectively improve the dimensional stability and mechanical properties of AEMs. TGA test results showed that the AEMs had excellent thermal stability with initial thermal decomposition temperature higher than 260°C. SEM showed that the functionalized norbornyl copolymer CL‐aP(NB‐MGE‐b‐NB‐MHE) penetrated into the micropores structure of PTFE, and they had good interface bonding morphology. Composite AEMs had excellent swelling resistance, and the highest swelling ratio was only 7.53% at 80°C. PTFE/CL40‐aP(NB‐MGE‐b‐NB‐MHE) had the highest ionic conductivity (74.40 mS cm−1, 80°C). After immersing in 1 M NaOH solution for 500 h at 60°C, the initial ionic conductivity could be maintained above 90%. The open‐circuit voltage of PTFE/CL40‐aP(NB‐MGE‐b‐NB‐MHE) in H2/O2 fuel cell tests was 1.01 V, and the peak power density reached 182 mW cm−2 at the current density of 398 mA cm−2.