Empowering Electrochemistry: Degradation of Fuel Cell Membrane Electrode Assemblies from Buses Operated More than 25,000 h

We’re proud to spotlight the innovative work of Harsh Srivastav, Arthur Dizon, Adam Weber, Rangachary Mukundan, and their team at Lawrence Berkeley National Laboratory.

The team monitored degradation of membrane electrode assemblies (MEA) from fuel cell buses using in situ polarization curves and electrochemical impedance spectroscopy (EIS), conducted on Scribner 850 and 840 test stations equipped with 885 potentiostats and automatic backpressure control units. This work was performed as part of the Million Mile Fuel Cell Truck consortium with ex situ characterization conducted at Oak Ridge National Laboratory and beginning of life MEAs provided by Nimbus Power Systems.

Key Highlights:

• After surpassing 25,000 hours of operation, MEA degradation resulted in just a 50 mV drop at 1 A cm⁻²
• Performance loss was primarily due to electrochemical surface area (ECSA) reduction, driven by Pt particle growth and partial Pt migration into the membrane
• Uniform catalyst-layer thinning was observed across the cell, possibly aided by high catalyst loading
• Stack hardware and balance-of-plant components may have contributed to overall system degradation observed in the fuel cell buses

Why It Matters:

These findings demonstrate the potential for long-lifetime MEAs in fuel cell vehicles—if operated under optimal conditions—marking a promising step forward for hydrogen-powered transportation.

Kudos to the team for advancing our understanding of fuel cell durability in real-world applications.