This consortium incorporates National-Laboratory investigators related to durability, transport, and performance, and combines them into one highly coordinated effort. The consortium formalized already existing and effective collaborations amongst the National Laboratories that established leadership in PEMFC performance and durability research and development. The consortium coordinates work under in different Thrust Areas including component thrust areas and cross-cutting thrust areas. The six different thrust areas are:
Component Thrust Areas:
- Electrocatalysts and Supports
- Electrode Layers
- Ionomers, Gas Diffusion Layers, Bipolar Plates, Interfaces
Cross-cutting Thrust Areas:
- Modeling and Validation
- Operando Evaluation: Benchmarking, ASTs, and Contaminants
- Component Characterization and Diagnostics
The structure of FC-PAD utilizes multiple cross-cutting thrust areas from theoretical modeling to characterization including benchmarking new materials that are provided to FC-PAD. The FC-PAD structure brings together world-class scientists into one integrated consortium, yet it provides a flexible structure to strategically use the widely varying expertise.
The FC-PAD consortium is examining degradation mechanisms to help develop improved materials and operating strategies. Corrosion of the carbon electrocatalyst support has been measured during drive-cycle operating conditions and increases with increase potential cycling from 0.4 to 0.9 V. Carbon corrosion is one of the major contributors to degradation which leads to changes in the catalyst layer structure and reduces its activity. Reduction in catalyst layer thickness is observed during operation, exacerbated during drive cycles. This reduction can be due to the loss of carbon through carbon corrosion or due to compaction; both effects likely lead to a loss of void volume. Membrane additives which increase membrane life-times, have been measured to migrate into the catalyst layer and appear to be associated with the carbon in the catalyst layers. Low potentials (0.2V) appear to be required to remove membrane fragment adsorbates which decrease catalyst activity. Pt alloy catalysts lose most of their alloying agents during operation; the alloying agents migrated throughout the ionomer. Durability implications of using Pt-X alloy catalysts will be discussed. Results related to the mentioned degradation mechanisms will be presented including characterization from TEM, SEM, XRF, XRD and electrochemical testing.
Consortium members include Argonne National Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, the National Renewable Energy Laboratory and Oak Ridge National Laboratory.
Acknowledgments
This work was funded through the DOE FC-PAD Consortium with thanks to DOE EERE FCTO, Fuel Cell Team Leader: Dimitrios Papageoropoulos