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Degradation of Commercial Lithium-Ion Cells as a Function of Chemistry and Cycling Conditions

Journal of the Electrochemical Society

Preger, Yuliya P.; Barkholtz, Heather M.; Fresquez, Armando J.; Campbell, Daniel L.; Juba, Benjamin W.; Kustas, Jessica K.; Ferreira, Summer R.; Chalamala, Babu C.

Energy storage systems with Li-ion batteries are increasingly deployed to maintain a robust and resilient grid and facilitate the integration of renewable energy resources. However, appropriate selection of cells for different applications is difficult due to limited public data comparing the most commonly used off-the-shelf Li-ion chemistries under the same operating conditions. This article details a multi-year cycling study of commercial LiFePO4 (LFP), LiNixCoyAl1-x-yO2 (NCA), and LiNixMnyCo1-x-yO2 (NMC) cells, varying the discharge rate, depth of discharge (DOD), and environment temperature. The capacity and discharge energy retention, as well as the round-trip efficiency, were compared. Even when operated within manufacturer specifications, the range of cycling conditions had a profound effect on cell degradation, with time to reach 80% capacity varying by thousands of hours and cycle counts among cells of each chemistry. The degradation of cells in this study was compared to that of similar cells in previous studies to identify universal trends and to provide a standard deviation for performance. All cycling files have been made publicly available at batteryarchive.org, a recently developed repository for visualization and comparison of battery data, to facilitate future experimental and modeling efforts.

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TYPE Journal Article YEAR 2020
DOIOSTIScopus

A database for comparative electrochemical performance of commercial 18650-format lithium-ion cells

Journal of the Electrochemical Society

Barkholtz, Heather B.; Fresquez, Armando J.; Chalamala, Babu C.; Ferreira, Summer R.

Lithium-ion batteries are a central technology to our daily lives with widespread use in mobile devices and electric vehicles. These batteries are also beginning to be widely used in electric grid infrastructure support applications which have stringent safety and reliability requirements. Typically, electrochemical performance data is not available for modelers to validate their simulations, mechanisms, and algorithms for lithium-ion battery performance and lifetime. In this paper, we report on the electrochemical performance of commercial 18650 cells at a variety of temperatures and discharge currents. We found that LiFePO4 is temperature tolerant for discharge currents at or below 10 A whereas LiCoO2, LiNixCoyAl1-x-yO2, and LiNi0.80Mn0.15Co0.05O2 exhibited optimal electrochemical performance when the temperature is maintained at 15◦C. LiNixCoyAl1-x-yO2 showed signs of lithium plating at lower temperatures, evidenced by irreversible capacity loss and emergence of a high-voltage differential capacity peak. Furthermore, all cells need to be monitored for self-heating, as environment temperature and high discharge currents may elicit an unintended abuse condition. Overall, this study shows that lithium-ion batteries are highly application-specific and electrochemical behavior must be well understood for safe and reliable operation. Additionally, data collected in this study is available for anyone to download for further analysis and model validation.

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TYPE Journal Article YEAR 2017
DOIDOIOSTIScopusOSTIScopus
Results 1–25 of 35
Results 1–25 of 35