Molecular simulations of electrolyte structure and dynamics in lithium-sulfur battery solvents
Molecular simulations of electrolyte structure and dynamics in lithium-sulfur battery solvents
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DOI：
10.1016/j.jpowsour.2017.10.081
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发表时间：
2018-01-01
影响因子：
9.2
通讯作者：
Dzubiella, Joachim
中科院分区：
文献类型：
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作者：
Park, Chanbum;Kanduc, Matej;Dzubiella, Joachim
现代锂硫（Li/S）电池系统的性能主要取决于电解质和溶剂的组成。因此，迫切需要高效、足够精确的分子模拟，以获得对分子的基本认识和对实验发展的合理指导。在此，我们构建了具有代表性的由锂-二（三氟甲烷）磺酰亚胺（LiTFSI）和LiNO3电解质在有机溶剂1,2-二甲氧基乙烷（DME）和1,3-二氧基烷（DOL）混合物中构成的锂/硫电池电解质-溶剂体系的分子动力学（MD）计算机模拟模型。我们通过与各种可用的实验参考系统比较结构和动态特征来基准和验证我们的模拟，并证明它们适用于广泛的电解质-溶剂组成。对于最先进的电池溶剂，我们最后计算并讨论了第一层锂溶剂化壳的详细组成，锂扩散的温度依赖性，以及电解质电导率和锂转移数。我们的模型将作为未来有效预测电解质结构和运输的基础，以优化现代锂/硫电池（及相关设备）。
The performance of modern lithium-sulfur (Li/S) battery systems critically depends on the electrolyte and solvent compositions. For fundamental molecular insights and rational guidance of experimental developments, efficient and sufficiently accurate molecular simulations are thus in urgent need. Here, we construct a molecular dynamics (MD) computer simulation model of representative state-of-the art electrolyte-solvent systems for Li/S batteries constituted by lithium-bis(trifluoromethane)sulfonimide (LiTFSI) and LiNO3 electrolytes in mixtures of the organic solvents 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL). We benchmark and verify our simulations by comparing structural and dynamic features with various available experimental reference systems and demonstrate their applicability for a wide range of electrolyte-solvent compositions. For the state-of-the-art battery solvent, we finally calculate and discuss the detailed composition of the first lithium solvation shell, the temperature dependence of lithium diffusion, as well as the electrolyte conductivities and lithium transference numbers. Our model will serve as a basis for efficient future predictions of electrolyte structure and transport in complex electrode confinements for the optimization of modern Li/S batteries (and related devices).