Reactions in the Rechargeable Lithium鈥揙2 Battery with Alkyl Carbonate Electrolytes

详细信息    查看全文

• 作者：Stefan A. Freunberger ; Yuhui Chen ; Zhangquan Peng ; John M. Griffin ; Laurence J. Hardwick ; Fanny Bard茅 ; Petr Nov谩k ; Peter G. Bruce
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：May 25, 2011
• 年：2011
• 卷：133
• 期：20
• 页码：8040-8047
• 全文大小：999K
• 年卷期：v.133,no.20(May 25, 2011)
• ISSN：1520-5126

文摘

The nonaqueous rechargeable lithium鈥揙₂ battery containing an alkyl carbonate electrolyte discharges by formation of C₃H₆(OCO₂Li)₂, Li₂CO₃, HCO₂Li, CH₃CO₂Li, CO₂, and H₂O at the cathode, due to electrolyte decomposition. Charging involves oxidation of C₃H₆(OCO₂Li)₂, Li₂CO₃, HCO₂Li, CH₃CO₂Li accompanied by CO₂ and H₂O 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鈥揙₂ cells. Oxidation of C₃H₆(OCO₂Li)₂ involves terminal carbonate groups leaving behind the OC₃H₆O moiety that reacts to form a thick gel on the Li anode. Li₂CO₃, HCO₂Li, CH₃CO₂Li, and C₃H₆(OCO₂Li)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.