电解质
碳酸乙烯酯
碳酸二甲酯
化学工程
材料科学
碳酸丙烯酯
离子液体
锂(药物)
法拉第效率
化学
无机化学
砜
电化学
碳酸盐
作者
Andreas Hofmann,Matthias Migeot,Eva Thißen,Michael Schülz,Ralf Heinzmann,Sylvio Indris,Thomas Bergfeldt,Boxia Lei,Carlos Ziebert,Thomas Hanemann
出处
期刊:Chemsuschem
[Wiley]
日期:2015-05-07
卷期号:8 (11): 1892-1900
被引量:24
标识
DOI:10.1002/cssc.201500263
摘要
In this study, novel electrolyte mixtures for Li-ion cells are presented with highly improved safety features. The electrolyte formulations are composed of ethylene carbonate/dimethyl sulfone (80:20 wt/wt) as the solvent mixture and LiBF4 , lithium bis(trifluoromethanesulfonyl)azanide, and lithium bis(oxalato)borate as the conducting salts. Initially, the electrolytes are characterized with regard to their physical properties, their lithium transport properties, and their electrochemical stability. The key advantages of the electrolytes are high flash points of >140 °C, which enhance significantly the intrinsic safety of Li-ion cells containing these electrolytes. This has been quantified by measurements in an accelerating rate calorimeter. By using the newly developed electrolytes, which are liquid down to T=-10 °C, it is possible to achieve C-rates of up to 1.5 C with >80 % of the initial specific capacity. During 100 cycles in cell tests (graphite||LiNi1/3 Co1/3 Mn1/3 O2 ), it is proven that the retention of the specific capacity is >98 % of the third discharge cycle with dependence on the conducting salt. The best electrolyte mixture yields a capacity retention of >96 % after 200 cycles in coin cells.
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