[1]刘 漫,杨锦飞.锂离子电池充放电时电解液性能的分子动力学模拟[J].南京师范大学学报(自然科学版),2020,43(02):43-48.[doi:10.3969/j.issn.1001-4616.2020.02.008]
　Liu Man,Yang Jinfei.Molecular Dynamics Investigation on Electrolyte Properties ofLithium Ion Battery During Charge and Discharge[J].Journal of Nanjing Normal University(Natural Science Edition),2020,43(02):43-48.[doi:10.3969/j.issn.1001-4616.2020.02.008]
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锂离子电池充放电时电解液性能的分子动力学模拟()
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《南京师范大学学报》（自然科学版）[ISSN:1001-4616/CN:32-1239/N]

卷:
第43卷
期数:
2020年02期
页码:
43-48
栏目:
·化学·
出版日期:
2020-05-30

文章信息/Info

Title:
Molecular Dynamics Investigation on Electrolyte Properties ofLithium Ion Battery During Charge and Discharge
文章编号:
1001-4616(2020)02-0043-06
作者:
刘 漫1; 杨锦飞2
(1.北京理工大学化学与化工学院,北京 102488)(2.南京师范大学化学与材料科学学院,江苏 南京 210023)
Author(s):
Liu Man1; Yang Jinfei2
(1.School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China)(2.School of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210023,China)
关键词:
锂离子电池电解液; 电场; 介电常数; 配位数; 接触离子对
Keywords:
lithium ion batteries electrolyte; electric field; dielectric constant; coordination number; ion pair
分类号:
O645.17
DOI:
10.3969/j.issn.1001-4616.2020.02.008
文献标志码:
A
摘要:
探究了锂离子在混合电解液中的微观结构,本文利用分子动力学模拟的方法建立了多元混合电解液溶剂EC-DMC-DEC(ethylene carbonate-dimethyl carbonate-diethyl carbonate)模型,计算分析了零电场以及加电场下电解液混合溶剂的性质. 计算结果表明:无电场时,电解液中没有接触离子对(CIP-contact ion pairs)和离子聚集体(AGG-aggregates)的存在; 而在6V电压下,任何浓度的电解液均存在CIP,降低了锂盐的溶解度. 电场的存在使得电解液溶剂分子的偶极矩与电场方向相一致,溶剂分子排列有序,降低了溶剂的介电常数,促使CIP和AGG的形成以及锂离子配位数的减少. 因此,破坏电场下溶剂分子的有序性、增强溶剂的介电性质对于降低电解液中的离子缔合、改善电解液的性能是至关重要的,这对于今后电解液配方的设计选择有着指导意义.
Abstract:
The model of multi-component mixed electrolyte solvent EC-DMC-DEC(ethylene carbonate-dimethyl carbonate-diethyl carbonate)was established by molecular dynamics simulation for investigating the micro-structure of Li+in the mixed electrolyte. The properties of mixed solvent under zero electric field and electric field were calculated and analyzed. The calculation results show that there is no contact ion pair(CIP)and ion aggregate(AGG)in the electrolyte under 0V electric field. However,CIP exists in electrolyte with different concentration of LiPF6 under 6V electric field,which reduces the solubility of lithium salt. The existence of the electric field makes the dipole moment of the solvent molecule of the electrolyte coincide with the direction of the electric field. The solvent molecules are arranged in order,which lowers the dielectric constant of the solvent,promotes the formation of CIP and AGG and the reduction of the coordination number of lithium ions. Therefore,destroying the order of the solvent molecules under electric field and enhancing the dielectric properties of the solvent are crucial for reducing the ion association and improving the performance of the electrolyte,which serves as a theoretical reference for optimizing LIBs electrolyte properties.

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备注/Memo

备注/Memo:
收稿日期:2019-05-03.
通讯联系人:杨锦飞,教授,博士生导师,研究方向:有机化学. E-mail:yangjinfei@njnu.edu.cn
更新日期/Last Update: 2020-05-15