Analysis of gas transport phenomena in a polymer electrolyte fuel cell by electrochemical pressure impedance spectroscopy

Electrochemical pressure impedance spectroscopy (EPIS) was introduced in view to differentiating transport/transfer phenomena of gas and liquid occurring electrochemical cells. This work aimed at measuring EPIS a 100 cm2 membrane fuel cell upon predominant control from transport, conditions where the presence water is little significant. Operating with pure oxygen allowed observation convection: modulus below 1 μV Pa−1 frequency range mHz–1 Hz, whereas phase shift decrease did not exceed 30° near 200 mHz an MPL-free diffusion layer (GDL). Conversely, occurrence diluted into nitrogen or helium revealed by strong increase up 12–30 500 depending on nature diluting gas, GDL, excess fed oxygen. Corresponding decreased regularly nearly 0° approx. −200° Hz. The its poor management GDL aggravates transport situation porous layers, particular more negative shifts higher high frequency.