Performance Evaluationof Poly(Vinylidene Fluoride)-Vinyl Benzyl Trimethyl Ammonium Chloride Copolymer as Anion ExchangeMembranes for Fuel Cell Applications

In recent years, poly(vinylidene fluoride) (PVDF) and its family of copolymers have started to gain increasing attention as potential systems to produce chemically and mechanically stable anion exchange membranes (AEMs). Here, a novel anion exchange membrane has been synthesized by chemical grafting of a vinyl benzyl trimethylammonium chloride monomer to the PVDF backbone. The resulting PVDF-VB copolymer was investigated under three ionic forms, i.e., Cl^–, HCO₃^–, and OH^–, comparing the swelling capability, mechanical robustness, transport properties, and ionic conductivity. In its hydroxylated form, the PVDF-VB membrane exhibited efficient OH^– transport under both long and short ranges and achieved a conductivity value of 20 mS/cm at 80 °C and 90% RH. For the first time, the single H₂–O₂ fuel cell performance of PVDF-VB was investigated, resulting in a beginning-of-life OCV of 1.04 with a peak power density of 118 mW cm^–2 at 70 °C.