What happens inside a fuel cell? Developing an experimental functional map of fuel cell performance

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• Fuel cell performance is complex, influenced by mass transport, energy transfer, and electrochemical reactions.
• Spatial heterogeneity in fuel cells arises from reactant consumption, water management, and flow plate design, making bulk measurements insufficient.
• Spatially resolved measurements are crucial for monitoring and optimizing fuel cell performance.

Purpose of the Study:

• To explore in situ techniques for studying fuel cells.
• To present novel experimental methods for creating an 'experimental functional map' of fuel cell performance.
• To validate numerical and analytical fuel cell models.

Main Methods:

• Mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance, and CO poisoning distribution in proton-exchange membrane fuel cells (PEFCs).
• Laser Doppler anemometry (LDA) for mapping reactant flow in gas channels.
• Temperature mapping, reference electrode placement, Raman spectroscopy, and microstructural analysis for solid oxide fuel cells (SOFCs).

Main Results:

• Development of an 'experimental functional map' to visualize internal fuel cell processes.
• Demonstration of techniques applicable to both PEFCs and SOFCs.
• Acquisition of a unique understanding of internal fuel cell operations across various conditions.

Conclusions:

• The combination of spatially resolved techniques provides unprecedented insight into fuel cell internal workings.
• These methods are essential for accurate fuel cell monitoring, optimization, and model validation.
• This approach enables a comprehensive understanding of fuel cell performance heterogeneity.