PEO/LITFSI固态电解质的离子传输与压力构效关系  

Relationship of ion transport and pressure in PEO/LITFSI solid electrolytes

作　　者：陈兵兵 赵井文[1] 马君[1] 崔光磊[1] CHEN Bingbing;ZHAO Jinwen;MA Jun;CUI Guanglei(Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences,Qingdao 266101,Shandong,China)

机构地区：[1]中国科学院青岛生物能源与过程研究所,山东青岛266101

出　　处：《储能科学与技术》2018年第3期431-436,共6页Energy Storage Science and Technology

基　　金：国家自然科学基金项目(51502319)

摘　　要：采用聚氧化乙烯/双三氟甲烷磺酰亚胺锂(PEO/LITFSI)固态电解质为研究对象,首次通过分子动力学方法模拟了压力对固态电解质模型构象和扩散系数的影响,揭示了外界压力与PEO/LITFSI中离子传输的构效关系。PEO聚合物链迴转半径和径向分布函数的模拟结果表明,压力升高将会导致PEO聚合物链呈现折叠现象,并且锂离子与TFSI-之间的相互作用变强,从而阻碍了锂离子在固态电解质中的传输。锂离子总均方位移的模拟结果进一步阐明了外界压力对锂离子扩散系数的影响:随着压力升高,离子扩散系数逐渐降低,离子的传输能力下降,但压力影响幅度小于锂盐浓度的影响。本工作将为固态电解质在高压力环境下的应用提供理论基础和指导。The relationship of ion transport and pressure in poly(ethylene oxide)/lithium salts(PEO/LITFSI)solid polymer electrolyte with different lithium salts concentration is firstly simulated by molecular dynamics(MD)method.Our simulation results demonstrate that the PEO polymer chains fold with the increased pressure,which will increase the interaction between lithium ions and TFSI anions and thus hinders the lithium ions transport in PEO/LITFSI solid electrolyte.Moreover,the molecular simulation results show a reduced lithium-ion diffusion coefficient and decreased ion transport ability in PEO/LITFSI under increased pressure.The present study will offer a theoretical basis for the applications of these solid electrolytes in high pressure environment.

关 键 词：PEO/LITFSI 压力 扩散 分子模拟 

分 类 号：TM911[电气工程—电力电子与电力传动]