The Stability of Organic Solvents and Carbon Electrode in Nonaqueous Li-O2 Batteries

Journal Article · Fri May 18 04:00:00 EDT 2012 · Journal of Power Sources, 215:240-247

DOI:https://doi.org/10.1016/j.jpowsour.2012.05.021· OSTI ID:1047407

Xu, Wu; Hu, Jian Z.; Engelhard, Mark H.; Towne, Silas A.; Hardy, John S.; Xiao, Jie; Feng, Ju; Hu, Mary Y.; Zhang, Jian; Ding, Fei; Gross, Mark E.; Zhang, Jiguang

The effect of different kinds of aprotic organic solvents on the discharge performance and discharge products in Li-O2 batteries was systematically investigated. The discharge products deposited in air cathodes were analyzed by X-ray diffraction, in situ gas chromatography/mass spectroscopy and X-ray photoelectron spectroscopy. We found that a significant amount of Li2O2 can be formed in glyme-based electrolytes during the discharge process, while only small amount of Li2O2 is produced in electrolytes of phosphate, nitrile, ionic liquid and sulfoxide. However, in all the seven types of solvent systems we studied, Li2CO3 and LiF were still formed as byproducts whose compositions are strongly related to the solvents. Li2CO3 is produced not from the carbon air electrode but from oxidation and decomposition of the solvent as we verified by using a 13C-labeled carbon electrode and the solid-state 13C-MAS NMR technique. The formation of Li2CO3 and LiF during discharge will greatly reduce the Coulombic efficiency and cycle life of the Li-air batteries. Therefore, better electrolytes that can ensure the formation of Li2O2 but minimize other reaction products formed on air electrodes of Li-air batteries need to be further investigated.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1047407
• Report Number(s): PNNL-SA-85748; 40125; 44591
• Journal Information: Journal of Power Sources, 215:240-247, Journal Name: Journal of Power Sources, 215:240-247 Vol. 215; ISSN JPSODZ; ISSN 0378-7753
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
AIR
CARBON
CATHODES
DECOMPOSITION
EFFICIENCY
ELECTRODES
ELECTROLYTES
Environmental Molecular Sciences Laboratory
Li-O2 battery
lithium peroxide
electrolyte
organic solvent
discharge product
MOLTEN SALTS
NUCLEAR MAGNETIC RESONANCE
ORGANIC SOLVENTS
OXIDATION
PERFORMANCE
SOLVENTS
SPECTROSCOPY
STABILITY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY