期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 145, 期 4, 页码 2473-2484出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.2c118072473J
关键词
-
Electrolytes in lithium-ion batteries must contain a stable solid electrolyte interphase (SEI) to ensure battery performance. The electric double layer (EDL) structure near charged surfaces is important in determining the species for SEI formation. A new model was used to study the effect of EDL on SEI formation in carbonate-based and ether-based electrolytes. The role of fluoroethylene carbonate (FEC) as an SEI modifier differs in these electrolytes due to the competition between FEC and the anion in the EDL.
Electrolytes, consisting of salts, solvents, and additives, must form a stable solid electrolyte interphase (SEI) to ensure the performance and durability of lithium(Li)-ion batteries. However, the electric double layer (EDL) structure near charged surfaces is still unsolved, despite its importance in dictating the species being reduced for SEI formation near a negative electrode. In this work, a newly developed model was used to illustrate the effect of EDL on SEI formation in two essential electrolytes, the carbonate-based electrolyte for Li-ion batteries and the ether-based electrolyte for batteries with Li-metal anodes. Both electrolytes have fluoroethylene carbonate (FEC) as a common additive to form the beneficial F-containing SEI component (e.g., LiF). However, the role of FEC drastically differs in these electrolytes. FEC is an effective SEI modifier for the carbonate-based electrolyte by being the only F-containing species entering the EDL and being reduced, as the anion (PF6-) will not enter the EDL. For the ether-based electrolyte, both the anion (TFSI-) and FEC can enter the EDL and be reduced. The competition of the two species within the EDL due to the surface charge and temperature leads to a unique temperature effect observed in prior experiments: the FEC additive is more effective in modulating SEI components at a low temperature (-40 degrees C) than at room temperature (20 degrees C) in the ether-based electrolyte. These collective quantitative agreements with experiments emphasize the importance of incorporating the effect of the EDL in multicomponent electrolyte reduction reactions in simulations/experiments to predict/control the formation of the SEI layer.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据