| Project Information |
| Project ID: | FEAA066 |
| Project Title: | Reliability of Materials and Components for Solid Oxide Fuel Cells - ORNL |
| FE Program: | Adv. Power - Fuel Cells, Solid Oxide |
| Research Type: | To Be Provided |
| Funding Memorandum: | Field Office Work Agreement |
| Project Performer |
| Performer Type: | DOE/National Laboratory |
| Performer: | Oak Ridge National Laboratory (ORNL)
P.O. Box 2008
1 Bethel Valley Road |
| Project Team Members: |
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| Project Location |
| City: | Oak Ridge |
| State: | Tennessee |
| Zip Code: | 37830-8050 |
| Congressional District: | 03 |
| Responsible FE Site: | NETL |
| Project Point of Contact |
| Name: | Lara-Curzio, Edgar |
| Telephone: | (865) 574-1749 |
| Fax Number: | |
| Email Address: | http://www.ornl.gov |
| Fossil Energy Point of Contact |
| Name: | Shultz, Travis |
| Telephone: | (304) 285-1370 |
| Location: | NETL |
| Email Address: | Travis.Shultz@NETL.DOE.GOV |
| Project Dates |
| Start Date: | 10/01/2008 |
| End Date: | 09/30/2010 |
| Contract Specialist |
| Name: | Loudin, Edward |
| Telephone: | (304) 285-4341 |
| Cost & Funding Information |
| Total Est. Cost: | $4,900,000 |
| DOE Share: | $4,900,000 |
| Non DOE Share: | $0 |
| Project Description |
A methodology will be developed and applied for predicting the life and reliability of ceramic components for solid oxide fuel cells. Mechanical data will be generated to screen and rank candidate materials and provide input for design and basic life prediction purposes. Failure mechanisms for solid oxide fuel cells will be investigated.
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| Project Background |
Solid Oxide Fuel Cells (SOFC) use a ceramic, solid-phase electrolyte, which eliminates problems associated with managing liquid electrolytes. Furthermore, to achieve adequate ionic conductivity in ceramic electrolytes, the system must operate at high temperatures, which leads to higher efficiency but also results in higher rates of material degradation. One of the leading candidate materials for use in SOFC electrolytes is yttria-stabilized zirconia (YSZ) because of its excellent ionic conductivity at high temperatures, but other candidate materials exist. Furthermore, current state-of-the-art SOFC electrodes utilize composites of electrical- and ionic-conducting ceramics (e.g. LSM/YSZ for the cathode) and ceramic-metal composites (e.g. Ni/YSZ for the anode).
Although fuel cells have been around since the 1830's and have been used successfully in short-term duration applications in the space program, their future use in distributed power applications will require demonstration of reliable operation for periods of time that will be measured in tens of thousand of hours. As design methodologies emerge for SOFCs, designers need to be aware of the innate features of the ceramic materials that will be incorporated in these designs. To minimize ohmic losses, most SOFC designs are based on the use of electrolytes that are tens of microns thick at which point the electrolyte cannot longer be self-supporting. Manufacturing techniques therefore involve the engineering of multilayer anode/electrolyte/cathode assemblies to provide the required support. Predictions of service life and reliability of SOFCs will require a fundamental understanding of damage initiation and progression in the thin multilayer ceramic structure at high temperature, taking into account the effects of the manufacturing processes and the chemical environment.
Hesitation to incorporate ceramic components in engineering designs often stems from: (1) limited data and lack of basic understanding of failure processes in these materials; (2) limited standardized test techniques to allow comparisons of materials behavior and collection of engineering data; and (3) inadequate models and statistical techniques for life prediction and reliability analyses. However, significant progress has been made in recent years in these three areas. For example, standardized test methods for the mechanical evaluation of ceramics have been developed by national and international standards organizations (ASTM, ISO, CEN and JFC). The precision of these test methods has been assessed through national and international round-robin testing programs (e.g. through ASTM, VAMAS) and design methodologies and software packages are currently available (e.g., NASA's CARES/LIFE and AlliedSignal's CERAMIC/ERICA) for predicting the reliability and service life of ceramic components. These probabilistic design methodologies are based on the development of a thorough understanding of the failure mechanisms of the material and component. They are also based on well established relationships between the inherent population of defects in the material, their evolution with time, and the material's probabilistic distribution of strengths, and on combining that information with a stress analysis of the component.
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| Project Milestones |
| This information is currently unavailable. |
| Project Accomplishments |
| Title: | Significant Accomplishment Nov. 2004 |
| Date: | 11/30/2004 |
Description | Noteworthy finding: Elastic properties and strength of 8-YSZ not significantly affected by heating rates up to 50C/sec.
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