Study on Water Content and Water Saturation of Proton Exchange Membrane Fuel Cell under Dynamic Conditions

Membrane water and liquid water of Proton exchange membrane fuel cell (PEMFC) have hysteresis, overshoot and uneven distribution under dynamic conditions. These characteristics lead to dehydration or water flooding which affect the performance and working life of PEMFC. In this paper, a three-dimensional non-isothermal two-phase model of PEMFC was established, considering the transport of water content and the liquid water saturation. The model was simulated under 0.8 V → 0.5 V → 0.8 V. The results showed: At 0.8 V → 0.5 V, the lag time of average water content in ACL was 25 s, and the location of the lowest water content was inlet in centerline between ACL and MEM. At 0.5 V → 0.8 V, the lag time and the overshoot of average water saturation in CCL were 45 s and 9.5%, and the location of the highest water saturation moved from inlet to outlet at the edge of interface between CCL and MEM.