The influence of cations on lithium ion coordination and transport in ionic liquid electrolytes: a MD simulation study.
The influence of cations on lithium ion coordination and transport in ionic liquid electrolytes: a MD simulation study.
复制标题
DOI：
10.1039/c5cp05111h
复制
发表时间：
2016-01
期刊：
影响因子：
--
通讯作者：
V. Lesch;Zhe Li;D. Bedrov;O. Borodin;A. Heuer
中科院分区：
文献类型：
--
作者：
V. Lesch;Zhe Li;D. Bedrov;O. Borodin;A. Heuer
用原子分子动力学(MD)模拟方法比较了1-乙基-3-甲基咪唑双(三氟甲磺酰基)亚胺([EMIM][TFSI])和N-甲基-N-丙基吡咯烷亚胺(bis-(trifluoromethanesulfonyl)imide([pyr13][TFSI]))两种离子液体电解质(ILE)的结构和动力学性质随锂盐浓度的变化关系。利用了多体可极化的Apple&P力场。考察了阴离子极化对Li(+)第一配位壳层结构的影响。特别是，TFSI阴离子(OTFSI)的氧极化率从1.36ä(3)降低到1.00ä(3)，导致TFSI阴离子与Li(+)的双齿配位比例增加。虽然基于[pyr13][TFSI]的离子交换体系的整体动力学比基于[EMIM][TFSI]的ILE慢，但在基于pyr13的体系中，TFSI阴离子进出Li(+)的第一配位壳层的交换速度更快。这些体系的Li(+)离子迁移数也较高。这些趋势可能与TFSI与IL阳离子相互作用的差异有关，PYR13的相互作用比EMIM强。
The dynamical and structural properties in two ionic liquid electrolytes (ILEs) based on 1-ethyl-3-methylimidazolium bis-(trifluoromethanesulfonyl)-imide ([emim][TFSI]) and N-methyl-N-propylpyrrolidinium bis-(trifluoromethanesulfonyl)imide([pyr13][TFSI]) were compared as a function of lithium bis-(trifluoromethanesulfonyl)-imide (LiTFSI) salt concentrations using atomistic molecular dynamics (MD) simulations. The many-body polarizable APPLE&P force field has been utilized. The influence of anion polarization on the structure of the first coordination shell of Li(+) was examined. In particular, the reduction of the oxygen of the TFSI anion (OTFSI) polarizability from 1.36 Å(3) to 1.00 Å(3) resulted in an increased fraction of the TFSI anion bidentate coordination to the Li(+). While the overall dynamics in [pyr13][TFSI]-based ILEs was slower than in [emim][TFSI]-based ILEs, the exchange of TFSI anions in and out of the first coordination shell of Li(+) was found to be faster in pyr13-based systems. The Li(+) ion transference number is higher for these systems as well. These trends can be related to the difference in interaction of TFSI with the IL cation which is stronger for pyr13 than for emim.