Novel Dead-Ended Anode Design for Self-Regulating Humidification in an Air-Breathing H2-PEM Fuel Cell

A novel design of anode chamber has been implemented in an air-breathing a PEM fuel cell allowing for stable long-term operation under strictly stoichiometric H 2 consumption with 100% fuel utilization. The developed model allows for selective exchange of water between the anode and the external environment by means of a gas-tight polymer. The gas-tight drying film provides a suitable way for excess water removal from the anode. The present study analyzes in detail the operation of this anode configuration. Electrochemical impedance spectroscopy and polarization hysteresis curves have been used to explore the cell behavior under different environmental conditions of temperature and relative humidity controlled by means of a climate chamber. The results are compared with those obtained for a similar cell assembled with a conventional anode operating under continuous flow and dead-ended anode under periodical purge. The stable long-term operation of the 2W cell with this novel design ensures 100% efficiency in fuel utilization.