The influence of poly(3,4‐ethylenedioxythiophene) modification on the transport properties and fuel cell performance of Nafion‐117 membranes

Abstract

AbstractNafion‐117/PEDOT composite membranes were synthesized by in situ chemical polymerization of 3,4‐ethylenedioxythiophene (EDOT) using ammonium persulfate as an oxidant. The polymerization of EDOT in Nafion membranes for various EDOT/oxidant treatment sequences was studied for the first time. PEDOT introduction leads to a slight decrease in both the ion‐exchange capacity and water uptake of the composite membranes, as well as to an increase in cationic transport. Membranes initially treated with an oxidant exhibit better conductivity and lower hydrogen permeability. The effect of both modification of Nafion‐117 membranes by PEDOT and hot‐pressing of hydrogen‐oxygen membrane‐electrode assemblies (MEAs) on the performance of proton‐exchange membrane fuel cells was studied. The maximum power density of the fabricated MEAs increases 1.5‐fold: from 510 (for a pristine Nafion‐117 membrane) to 810 mW cm−2 (for a membrane modified by PEDOT). The current density at a voltage of 0.4 V reaches 1248 and 2246 mA cm−2, respectively.