Lithium Solvation and Mobility in Ionic Liquid Electrolytes with Asymmetric Sulfonyl-Cyano Anion
Lithium Solvation and Mobility in Ionic Liquid Electrolytes with Asymmetric Sulfonyl-Cyano Anion
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具有不对称磺酰基-氰基阴离子的离子液体电解质中的锂溶剂化和迁移率
DOI：
10.1021/acs.jced.2c00294
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发表时间：
2022
影响因子：
--
通讯作者：
Gurkan, Burcu
中科院分区：
文献类型：
--
作者：
Penley, Drace;Wang, Xiaoyu;Lee, Yun-Yang;Garaga, Mounesha N.;Ghahremani, Raziyeh;Greenbaum, Steve;Maginn, Edward J.;Gurkan, Burcu
采用拉曼、核磁共振（NMR）扩散法和分子动力学（MD）模拟研究了Li+在N-甲基-正丁基吡咯烷氰基（三氟甲磺酰基）酰亚胺[PYR 14][CTFSI]和[Li][CTFSI]（0 ≤xLi≤ 0.7）离子液体电解质中的溶剂化结构和输运性质.当x Li < 0.3时，Li+配位由氰基主导。AsxLi增加，游离氰基位点变得有限，导致通过磺酰基的配位增加。对称阴离子双（三氟甲磺酰基）酰亚胺（[TFSI]）和双氰胺（[DCA]）的1：1混合物产生与具有[CTFSI]的IL相似的物理性质。然而，阴离子不对称性被示出为增加Li盐溶解度和促进Li+转移。计算得到[CTFSI]的Li+-氰基配位寿命比[DCA]的短，表明来自磺酰基的竞争削弱了其与Li+的溶剂化作用.这导致具有[CTFSI]的电解质的更高的Li+转移。对于这些电解质在能量存储中的应用，用IL电解质组装的Li-LiFePO_4半电池（xLi= 0.3，0.5，和0.7）在0.1C倍率和90 °C下表现出140 mAh/g的标称容量，其中具有xLi = 0.7 IL电解质的电池表现出61%的容量。100次循环后的容量保持率和由于增加的电化学稳定性而具有的优良的上级倍率性能。
The solvation structure and transport properties of Li+in ionic liquid (IL) electrolytes based onn-methyl-n-butylpyrrolidinium cyano(trifluoromethanesulfonyl)imide [PYR14][CTFSI] and [Li][CTFSI] (0 ≤xLi≤ 0.7) were studied by Raman and Nuclear Magnetic Resonance (NMR) diffusometry, and molecular dynamics (MD) simulations. AtxLi< 0.3, Li+coordination is dominated by the cyano group. AsxLiis increased, free cyano-sites become limited, resulting in increased coordination via the sulfonyl group. The 1:1 mixture of the symmetric anions bis(trifluoromethanesulfonyl)imide ([TFSI]) and dicyanamide ([DCA]) results in similar physical properties as the IL with [CTFSI]. However, anion asymmetry is shown to increase Li-salt solubility and promote Li+transference. The lifetimes of Li+-cyano coordination for [CTFSI] are calculated to be shorter than those for [DCA], indicating that the competition from the sulfonyl group weakens its solvation with Li+. This resulted in higher Li+transference for the electrolyte with [CTFSI]. In relation to the utility of these electrolytes in energy storage, the Li–LiFePO4half cells assembled with IL electrolyte (xLi= 0.3, 0.5, and 0.7) demonstrated a nominal capacity of 140 mAh/g at 0.1C rate and 90 °C where the cell withxLi= 0.7 IL electrolyte demonstrated 61% capacity retention after 100 cycles and superior rate capability owing to increased electrochemical stability.
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影响因子：
3.9
作者：
Ashley M. Heist;Sehee Lee
通讯作者：
Ashley M. Heist;Sehee Lee
影响因子：
8.4
作者：
Gao, Xinpei;Wu, Fanglin;Passerini, Stefano
通讯作者：
Passerini, Stefano
影响因子：
9.2
作者：
Giffin, Guinevere A.;Moretti, Arianna;Passerini, Stefano
通讯作者：
Passerini, Stefano
影响因子：
5.7
作者：
Kirby, Brian J.;Jungwirth, Pavel
通讯作者：
Jungwirth, Pavel
影响因子：
3.3
作者：
Nuernberg, Pinchas;Lozinskaya, Elena, I;Schoenhoff, Monika
通讯作者：
Schoenhoff, Monika