Electrochemical and physical analysis of a Li-ion cell cycled at elevated temperature
Laboratory-size LiNi0.8Co0.15Al0.05O2/graphite lithium-ion pouch cells were cycled over 100 percent DOD at room temperature and 60 degrees C in order to investigate high-temperature degradation mechanisms of this important technology. Capacity fade for the cell was correlated with that for the individual components, using electrochemical analysis of the electrodes and other diagnostic techniques. The high-temperature cell lost 65 percent of its initial capacity after 140 cycles at 60 degrees C compared to only 4 percent loss for the cell cycled at room temperature. Cell ohmic impedance increased significantly with the elevated temperature cycling, resulting in some of loss of capacity at the C/2 rate. However, as determined with slow rate testing of the individual electrodes, the anode retained most of its original capacity, while the cathode lost 65 percent, even when cycled with a fresh source of lithium. Diagnostic evaluation of cell components including XRD, Raman, CSAFM and suggest capacity loss occurs primarily due to a rise in the impedance of the cathode, especially at the end-of-charge. The impedance rise may be caused in part by a loss of the conductive carbon at the surface of the cathode and/or by an organic film on the surface of the cathode that becomes non-ionically conductive at low lithium content.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Energy Efficiency and Renewable Energy. Office of Transportation Technologies (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 825482
- Report Number(s):
- LBNL-50101; JPSODZ; R&D Project: 674501; TRN: US200423%%288
- Journal Information:
- Journal of Power Sources, Vol. 112, Issue 1; Other Information: Journal Publication Date: 10/24/2002; PBD: 21 Jun 2002; ISSN 0378-7753
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diagnostic Evaluation of Detrimental Phenomena in High-PowerLithium-Ion Batteries
Thermal and electrochemical characterization of MCMB/LiNi{sub 1/3}Co{sub l/3}Mn{sub l/3}O{sub 2} using LiBoB as an electrolyte additive.