Dynamics Management of Intermediate Water Storage in an Air-Breathing Single-Cell Membrane Electrode Assembly

Area of Science:

• Electrochemistry
• Materials Science
• Mechanical Engineering

Background:

• Proton exchange membrane fuel cells (PEMFCs) are sensitive to membrane hydration.
• Water evaporation in air-breathing PEMFCs (Air PEM FCs) can increase membrane electrode assembly (MEA) resistance.
• Maintaining optimal membrane hydration is crucial for efficient fuel cell operation.

Purpose of the Study:

• To investigate a dead-end hydrogen anode for self-humidification in Air PEM FCs.
• To develop and validate a numerical model for predicting MEA performance based on hydration.
• To assess the feasibility of this system for blimp applications.

Main Methods:

• Development of a dynamic numerical water balance model.
• Experimental validation using humidity measurements, polarization, and electrochemical impedance spectroscopy.
• Testing of a lightweight MEA (12 g) with an integrated dead-end hydrogen storage bag.

Main Results:

• The dead-end anode effectively stores water for self-humidification.
• The validated model accurately predicts MEA resistance and performance.
• Thin membranes and thicker gas diffusion layers enhance membrane hydration and water transfer.

Conclusions:

• A dead-end hydrogen anode offers a viable self-humidification strategy for Air PEM FCs.
• The proposed system is suitable for lightweight, portable fuel cell applications like blimps.
• Optimizing MEA configuration is key to maximizing fuel cell efficiency and longevity.