Proton conductivity study of a fuel cell membrane with nanoscale resolution.

The present work demonstrates that EC-AFM is a very useful new tool for identification and spatially resolved characterization of proton conductivity at the membrane surface in comparison with topography, however it does not provide insight into the 3D pore structure within the membrane. The results are consistent with those of conventional macroscopic measurements, confirming the reliability of the method. It will allow careful analysis of the homogeneity, the nature and the consequences of microphase separation as well as the effect of humidity on novel alternative membranes, and it will thus be essential for tailored developments of new materials for fuel-cell membranes. The present initial work is followed up with further experiments which provide a more complete understanding of the proton conductivity of the polymers, determine the influence of relative humidity on the size of conductive regions and investigate the reproducibility of the results.

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