Reactions in the rechargeable lithium-O2 battery with alkyl carbonate electrolytes

Stefan A Freunberger; Yuhui Chen; Zhangquan Peng; John M Griffin; Laurence J Hardwick; Fanny Bardé; Petr Novák; Peter G Bruce

doi:10.1021/ja2021747

Reactions in the rechargeable lithium-O2 battery with alkyl carbonate electrolytes

J Am Chem Soc. 2011 May 25;133(20):8040-7. doi: 10.1021/ja2021747. Epub 2011 May 4.

Authors

Stefan A Freunberger¹, Yuhui Chen, Zhangquan Peng, John M Griffin, Laurence J Hardwick, Fanny Bardé, Petr Novák, Peter G Bruce

Affiliation

¹ School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK.

PMID: 21524112
DOI: 10.1021/ja2021747

Abstract

The nonaqueous rechargeable lithium-O(2) battery containing an alkyl carbonate electrolyte discharges by formation of C(3)H(6)(OCO(2)Li)(2), Li(2)CO(3), HCO(2)Li, CH(3)CO(2)Li, CO(2), and H(2)O at the cathode, due to electrolyte decomposition. Charging involves oxidation of C(3)H(6)(OCO(2)Li)(2), Li(2)CO(3), HCO(2)Li, CH(3)CO(2)Li accompanied by CO(2) and H(2)O evolution. Mechanisms are proposed for the reactions on discharge and charge. The different pathways for discharge and charge are consistent with the widely observed voltage gap in Li-O(2) cells. Oxidation of C(3)H(6)(OCO(2)Li)(2) involves terminal carbonate groups leaving behind the OC(3)H(6)O moiety that reacts to form a thick gel on the Li anode. Li(2)CO(3), HCO(2)Li, CH(3)CO(2)Li, and C(3)H(6)(OCO(2)Li)(2) accumulate in the cathode on cycling correlating with capacity fading and cell failure. The latter is compounded by continuous consumption of the electrolyte on each discharge.