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Lithium oxalyldifluoroborate/carbonate electrolytes for LiFePO4/artificial graphite lithium-ion cells
- Source :
- Journal of Power Sources. 195:5344-5350
- Publication Year :
- 2010
- Publisher :
- Elsevier BV, 2010.
-
Abstract
- The electrolytes based on lithium oxalyldifluoroborate (LiODFB) and carbonates have been systematically investigated for LiFePO 4 /artificial graphite (AG) cells, by ionic conductivity test and various electrochemical tests, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge test. The conductivity of nine electrolytes as a function of solvent composition and LiODFB salt concentration has been studied. The coulombic efficiency of LiFePO 4 /Li and AG/Li half cells with these electrolytes have also been compared. The results show that 1 M LiODFB EC/PC/DMC (1:1:3, v/v) electrolyte has a relatively higher conductivity (8.25 mS cm −1 ) at 25 °C, with high coulombic efficiency, good kinetics characteristics and low interface resistance. With 1 M LiODFB EC/PC/DMC (1:1:3, v/v) electrolyte, LiFePO 4 /AG cells exhibit excellent capacity retention ∼92% and ∼88% after 100 cycles at 25 °C and at elevated temperatures up to 65 °C, respectively; The LiFePO 4 /AG cells also have good rate capability, the discharge capacity is 324.8 mAh at 4 C, which is about 89% of the discharge capacity at 0.5 C. However, at −10 °C, the capacity is relatively lower. Compared with 1 M LiPF 6 EC/PC/DMC (1:1:3, v/v), LiFePO 4 /AG cells with 1 M LiODFB EC/PC/DMC (1:1:3, v/v) exhibited better capacity utilization at both room temperature and 65 °C. The capacity retention of the cells with LiODFB-based electrolyte was much higher than that of LiPF 6 -based electrolyte at 65 °C, while the capacity retention and the rate capacity of the cells is closed to that of LiPF 6 -based electrolyte at 25 °C. In summary, 1 M LiODFB EC/PC/DMC (1:1:3, v/v) is a promising electrolyte for LiFePO 4 /AG cells.
- Subjects :
- Renewable Energy, Sustainability and the Environment
Inorganic chemistry
Energy Engineering and Power Technology
chemistry.chemical_element
Electrolyte
Conductivity
Electrochemistry
Dielectric spectroscopy
chemistry
Ionic conductivity
Lithium
Electrical and Electronic Engineering
Physical and Theoretical Chemistry
Cyclic voltammetry
Faraday efficiency
Subjects
Details
- ISSN :
- 03787753
- Volume :
- 195
- Database :
- OpenAIRE
- Journal :
- Journal of Power Sources
- Accession number :
- edsair.doi...........7333277c2c11cb9ae8a2f4ef9edf7d28