Durability Working Group
The Durability Working Group meets twice per year to exchange information, create synergies, and collaboratively develop both an understanding of and tools for studying degradation mechanisms of polymer electrolyte fuel cell stacks. Its members include principle investigators and supporting personnel from U.S. Department of Energy (DOE)—funded durability projects. More information on DOE durability activities can be found in the Multi-Year Research, Development, and Demonstration Plan.
DOE durability targets for stationary and transportation fuel cells are 40,000 hours and 5,000 hours, respectively, under realistic operating conditions. In the most demanding applications, realistic operating conditions include impurities in the fuel and air, starting and stopping, freezing and thawing, and humidity and load cycles that result in stresses on the chemical and mechanical stability of the fuel cell materials, components, and interfaces. Degradation-exacerbating conditions resulting from cyclic operation include hydrogen starvation, differential pressure imbalance, oxidation-reduction cycling, and oxygen ingress to the anode, resulting in high cathode potentials. Significant progress has been made in determining the degradation mechanisms of fuel cell components and developing improved materials. However, as stated in the 2008 DOE Fuel Cell Solicitation, there is a need for further research and development in the following areas:
- Fundamental materials degradation mechanisms.
- Impact of microstructure on performance and durability.
- Component microstructure stability in the three-phase region of reactant gas, electrolyte, and catalyst.
- Interface stability (plate/GDL, GDL/electrode, catalyst/support, electrode/membrane).
- Bipolar plate and GDL interactions and effect of (hydrophobicity and structural) stability on water management and flow field stability.
- Correlation of durability to local cell operating conditions.
- Effects of cell/stack operating parameters (current density, temperature, relative humidity).
- Correlation of performance drop to changes in structure and/or chemistry.
- Kinetic and materials models of the aging process.
- Effect of material degradation and structural changes on water management.
- Experimental data for water management models: degradation of hydrophobic materials properties (contact angle, porosity, permeability, cell resistance, etc.) with known automotive cycle stressors (e.g., freeze).
- Effects of degradation of other components (e.g., seal, bipolar plates, membranes, impurities) on components responsible for water management.
In addition to the understanding of cell degradation mechanism studies, as stated in the 2008 DOE solicitation, there is also a need for the development and demonstration of accelerated testing protocol. The Fuel Cell Technical Team of the U.S. DRIVE have established accelerated stress test (AST) protocols in order to isolate and elucidate component degradation mechanisms. However, there is a need for the development of ex situ stress tests and to demonstrate the correlation between ex situ tests with in situ real-time degradation of fuel cell systems.
The Durability Working Group has proposed accelerated stress tests for ex situ, rotating disk electrode (RDE) screening studies of catalyst durability, as described in a recent webinar (see slides 35-39). The Energy Department is soliciting comments to the RDE protocols in a Request for Information that is open until July 12, 2013, at 5:00 p.m. Eastern Time.
The goal of the Durability Working Group, through close cooperation and coordination of the activities of the DOE Fuel Cell Technologies Office-funded durability projects, is to address the gaps in understanding as identified by DOE to enable fuel cell systems to meet DOE durability targets.
The DOE Fuel Cell Technologies Office's durability R&D activities and accomplishments are summarized at these websites:
The Durability Working Group held its kick-off meeting on June 9, 2010. The group meets twice a year to discuss coordination of the projects, experimental results, and computational results with discussions centered around fuel cell degradation mechanisms.
Technical Targets for Fuel Cell Durability
The Department of Energy and the Fuel Cell Technical Team of the US DRIVE have developed a set of targets and test protocols for polymer electrolyte fuel cell stack durability. These targets are contained in the Multi-Year RD&D Plan, Fuel Cell Section.
The Durability Working Group holds two meetings per year: one members-only meeting in the fall and the other an open meeting in conjunction with the DOE Annual Merit Review. The next meeting will be held in Fall 2013.
- Durability Working Group Meeting, Washington, DC, February 2013
- Durability Working Group Meeting, Honolulu, HI, October 2012
- Durability Working Group Meeting, Washington, DC, May 2012
- Durability Working Group Meeting, Boston, MA, October 2011
- Durability Working Group Meeting, Washington, DC, May 2011
- Durability Working Group Meeting, Las Vegas, NV, October 2010
- Durability Working Group Kick-off Meeting, Washington, DC, June 2010
The following people can be contacted for more information about the Durability Working Group.
Donna Lee Ho
DOE Fuel Cell Technologies
Fuel Cell Team
U.S. Department of Energy, EE-2H
1000 Independence Avenue
Washington, DC 20585-0121
Dr. Deborah Myers
Argonne National Laboratory
9700 S. Cass Avenue
Argonne, IL 60439
Dr. Rod Borup
MPA-11, MS D429
P.O. Box 1663
Los Alamos, NM 87545