Membrane Electrode Assemblies (MEAs) have evolved significantly in recent years to become a complex piece of technology. Currently, MEAs incorporate a variety of catalyst types and supports which need to be integrated into layers for both anode and cathode electrodes. In addition, the additives used in the membrane have also become more complex, to mitigate gas crossover and degradation that can be caused by metal ion impurities, thus enabling the deployment of thinner membranes (<15 mm). Further, different approaches to maximising the power per cost lead to different power density requirements. For example, the performance target set by the US-DOE is 1.0 W/cm², whereas in EU funded program GAIA¹ the target is a demanding 1.8 W/cm². This forces MEA developers to carefully design each component to enable mass commercialization.

This presentation will document recent advances at JM in the design of MEAs for the transportation industry, with an emphasis on the integration of scaled-up alloy catalysts in cathode layers. Results from advanced catalyst characterisation using state of the art TEM and XPS facilities will be provided; these results have helped identify the mechanisms that compromise catalyst stability and activity and have allowed the synthesis of new materials and layers that will enable thrifting of Pt to levels that will help mass commercialization. In addition, with the help of 1D testing and the use of simulation tools such as OpenFCST, insights will be provided into proton and oxygen transport limitations at high current densities. Finally, a detailed analysis will also be provided that highlights the importance of understanding catalyst and ionomer surface compositions to give high kinetic activity whilst also enabling high performance at high current densities in H₂/Air, in order to reach 1.8 W/cm².

References

1. GAIA, Grant Agreement Number 826097, http://www.gaia-fuelcell.eu/

Acknowledgements

1. The GAIA project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No 826097. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme, Hydrogen Europe and Hydrogen Europe Research.