Enhanced Cycling Stability of Rechargeable Li-O2 Batteries Using High Concentration Electrolytes

Journal Article · Tue Jan 26 04:00:00 EST 2016 · Advanced Functional Materials

DOI:https://doi.org/10.1002/adfm.201503697· OSTI ID:1239475

Liu, Bin; Xu, Wu; Yan, Pengfei; Sun, Xiuliang; Bowden, Mark E.; Read, Jeffrey; Qian, Jiangfeng; Mei, Donghai; Wang, Chong M.; Zhang, Jiguang

The electrolyte stability against reactive reduced-oxygen species is crucial for the development of rechargeable Li-O2 batteries. In this work, we systematically investigated the effect of lithium salt concentration in 1,2-dimethoxyethane (DME)-based electrolytes on the cycling stability of Li-O2 batteries. Cells with high concentration electrolyte illustrate largely enhanced cycling stability under both the full discharge/charge (2.0-4.5 V vs. Li/Li+) and the capacity limited (at 1,000 mAh g-1) conditions. These cells also exhibit much less reaction-residual on the charged air electrode surface, and much less corrosion to the Li metal anode. The density functional theory calculations are conducted on the molecular orbital energies of the electrolyte components and the Gibbs activation barriers for superoxide radical anion to attack DME solvent and Li+-(DME)n solvates. In a highly concentrated electrolyte, all DME molecules have been coordinated with salt and the C-H bond scission of a DME molecule becomes more difficult. Therefore, the decomposition of highly concentrated electrolyte in a Li-O2 battery can be mitigated and both air-cathodes and Li-metal anodes exhibits much better reversibility. As a results, the cyclability of Li-O2 can be largely improved.

• 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: 1239475
• Report Number(s): PNNL-SA-112653; 48877; 48379; VT1201000
• Journal Information: Advanced Functional Materials, Journal Name: Advanced Functional Materials Journal Issue: 4 Vol. 26; ISSN 1616-301X
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory
Li-O2 battery
high concentration electrolyte
lithium-metal
air-electrode
stability
protection