Dynamic fuel cell gas humidification system

Water management is one of the crucial factors regarding the performance and durability of low temperature PEM fuel cells. Amongst other factors, the water balance in an operating fuel cell can be influenced by the humidification of the reaction gases. For transient response investigations of the fuel cell behavior under fast humidification changes a system is needed which is able to humidify the supplied gases in a highly dynamic and reproducible way. Exact knowledge of the water content of the supplied gases is of utmost importance to study humidification effects. In this contribution, a dynamic fuel cell humidification system is presented. Reliability of the concept is proven by using three different methods: straightforward dew point measurements, electrochemical impedance spectroscopy (EIS) and in situ neutron radiography. The test setup is able to provide dew point temperatures with a tolerance range of 1–3 K leading to a highly reproducible fuel cell performance and water content of the complete cell.

► An accurate and reliable humidification system for PEM fuel cells is presented.
► Relative gas humidity of the gas stream was verified in three different ways.
► Electrochemical impedance spectroscopy and neutron radiography were used for analysis.
► A high reproducibility of the humidification level of the fuel cells was proven.