Comprehensive understanding of electrical conductivity measurements of gas diffusion media of PEM fuel cells

Knowledge of the electrical resistivity of components in polymer electrolyte membrane (PEM) fuel cells is important. Generally, the electrical properties are dependent on the solid material of which the layers are composed as well as their physical structure (e.g. fiber alignment and geometry and porosity). Further, the electrical resistance between the layers affects the overall electrical properties of the cell. In this work, a comprehensive overview of techniques available to measure the electrical properties of the gas diffusion media of PEM fuel cells is given. Although the discussion covers the measurement of both in- and through- plane properties, attention is particularly given to the through-plane properties. Problems associated with measuring the electrical properties in the through-plane direction of highly porous and thin materials are hence discussed. Suggested solutions are finally given. The discussion is carried forward using measured properties.