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In situ chemical polymerisation of pyrrole in Nafion®‐115 membranes produces a composite material that shows a decrease in methanol crossover compared with the non‐modified material, and a good protonic conduction (area resistance of 0.65 Ω cm2). Pyrrole is impregnated from an appropriate solvent, and the choice of oxidising agent (hydrogen peroxide, ammonium peroxodisulfate) provides two types of modified membrane. Membrane characterisation using infrared spectroscopy shows the presence of pyrrole oligomers and polymer, but the proton conductivity is lower than that of the Nafion®‐115 membrane by only a factor 2–3. Methanol transport measurements in 2 mol dm–3 methanol with and without application of an electric field show ca. 30% lower crossover for the pyrrole‐modified membranes. In single cell hydrogen – oxygen fuel cell tests, the pyrrole‐modified Nafion® prepared using hydrogen peroxide oxidant gave higher open circuit voltage and current density, in particular at > 80 °C, than non‐modified Nafion®‐115.

Small angle neutron scattering experiments were performed on a proton exchange membrane fuel cell in order to determine the transversal water concentration profile, within the polymer electrolyte. This is determined under state-of-art operating conditions. From the scattering spectra, different concentration profiles were deduced and discussed in terms of a competition between electro-osmosis and back diffusion. For steady states, the balance between these driving forces is modified by the current density. It is also demonstrated that this equilibrium is laterally nonuniform in the fuel cell. This is especially pronounced between the gas inlets and outlets, in a co-flow geometry.

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In spite of significant achievements in alkaline exchange membrane fuel cells (AEMFCs) in recent years, they are still lagging behind proton exchange membrane fuel cells (PEMFCs) due to performance instability. Among the relevant operational parameters of AEMFC, the researchers have found that poor water management within the cell was the main reason for failure of the system. In the past five years, numerous modeling and experimental works were reported proposing different strategies to improve water management of AEMFC. The achievable power output in AEMFCs is then comparable with that of PEMFCs or even more. Efforts have to be continued, but AEMFCs can become a strong competitor in the market place. This review paper discusses the strategies and developments impacting water management of AEMFCs providing knowledge source for upcoming studies.

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