Stable lithium electrodeposition in salt-reinforced electrolytes

JOURNAL OF POWER SOURCES

卷:279

Article

Lu, Yingying¹  Tu, Zhengyuan²  Shu, Jonathan³  Archer, Lynden A.¹ 

[1] Cornell Univ, Sch Chem & Biomol Engn, Ithaca, NY 14853 USA

[2] Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA

[3] Cornell Univ, Cornell Ctr Mat Res, Ithaca, NY 14853 USA

关键词: Lithium-metal battery;    Lithium bromide;    Dendrite;    Liquid electrolyte;    Electrodeposition;   

DOI  :  10.1016/j.jpowsour.2015.01.030

来源: Elsevier

【 摘 要 】

Development of high-energy lithium-based batteries that are safe remains a challenge due to the nonuniform lithium electrodeposition during repeated charge and discharge cycles. We report on the effectiveness of lithium bromide (LiBr) salt additives in a common liquid electrolyte (i.e. propylene carbonate (PC)) on the stability of lithium electrodeposition. From galvanostatic cycling measurements, we find that the presence of LiBr in PC provides more than 20-fold enhancement in cell lifetime over the control LiTFSI/PC electrolyte. Batteries containing 30 mol% LiBr additive in the electrolytes are able to cycle stably for at least 1.8 months with no observations of cell failure. From galvanostatic polarization measurements, an electrolyte containing 30 mol% LiBr shows a maximum improvement in lifetime. The formation of uneven lithium electrodeposits is significantly suppressed by the Br-containing SEI layers, evidenced by impedance spectra, post-mortem SEM and XPS analyses. The study also concludes that good solubility of halogenated salts is not necessary for achieving the observed improvements in cell lifetime. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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