Characteristic analysis and modeling on PEMFC degradation associated with low frequency ripple current effects

This work deals with a diagnosis of cathode flooding and membrane drying associated with a low frequency ripple current of a polymer electrolyte membrane fuel cell (PEMFC) based in impedance measurement on single cells. Through direct measurement of the impedance curve of a single cell obtained after cycling for hours at variable frequencies, it has been found that impedance magnitude of a fuel cell injecting a low frequency ripple current increased when compared with those injecting a high frequency ripple current. The study develops these investigations one step further by showing impedance measurement on single cells during operation in flooding and drying modes concerning a low frequency ripple current. In particular, it is shown that a low frequency ripple current more accelerates the PEMFC degradation associated with two PEMFC failures.