Local resolved investigation of hydrogen crossover in polymer electrolyte fuel cell

Kurzfassung

In this study, the effects of temperature, pressure and relative humidity (RH) on hydrogen crossover rate from anode to cathode of a PEMFC is investigated. Segmented cells are used to measure the local hydrogen crossover current density (jcrossH2 ) distribution. The results present approximate linear increase of the hydrogen crossover rate with increasing temperature and hydrogen back pressure with rates of 0.038 mA cm�-2 K-�1 and 3.33 mA cm-�2 bar-�1, respectively. Generally, slightly increased H2 crossover is observed in gas inlet areas than cell average. Unlike the approximate linear relationship between temperature or pressure with hydrogen crossover, the effect of relative humidification on hydrogen crossover is more complex with different increasing rate before fully humidification and dramatic decline at excessive humidification. It is demonstrated that segmented cells can be advantageously applied to study local H2 crossover of intact MEAs.