The U.S. Advanced Battery Consortium (USABC) has established performance targets for various automotive platforms including hybrid, plug-in hybrid, and electric vehicle modes. A 15-year calendar-life capability at a given reference temperature is typically included as part of these targets, thus necessitating the need for accelerated aging protocols to screen candidate technologies. Accelerated aging typically consists of calendar-life testing at elevated temperatures to increase degradation rates. From the acquired data, and a given life model, battery life estimations are conducted at the reference temperature and compared with the 15-year target. The Idaho National Laboratory has been calendar-life aging a set of lithium-ion cells at various temperatures for several years based on the USABC Hybrid Electric Vehicle (HEV) Power Assist targets. This presentation will show calendar-life estimations at various levels of battery degradation compared with the actual measured results. This work was prepared as an account of work sponsored by an agency of the United States Government under US DOE Contract DE-AC07-05ID14517.
- Review accelerated aging protocols
- Review battery life estimation methodology (models / statistical analysis, etc.)
- Compare battery life prediction with measured data at various levels of battery degradation
- Address key questions:
- How accurate is the life model at given levels of battery degradation?
- How long should aging be conducted to improve accuracy of the estimation?
- Summary / Conclusion