Molecular simulations of electrolyte structure and dynamics in lithium-sulfur battery solvents

JOURNAL OF POWER SOURCES

卷:373

Article

Park, Chanbum^1,2  Kanduc, Matej¹  Chudoba, Richard^1,2  Ronneburg, Arne^1,2  Risse, Sebastian¹  Ballauff, Matthias^1,2  Dzubiella, Joachim^1,2 

[1] Helmholtz Zentrurn Berlin Mat & Energie, Inst Weiche Mat & Funkt Mat, Hahn Meitner Pl 1, D-14109 Berlin, Germany

[2] Humboldt Univ, Inst Phys, Newtonstr 15, D-12489 Berlin, Germany

关键词: Battery;    Electrolyte;    Molecular dynamics;    Conductivity;    Solvation;    Ion pairing;   

DOI  :  10.1016/j.jpowsour.2017.10.081

来源: Elsevier

【 摘 要 】

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).

【 授权许可】

Free