Polymer geometry and Li+ conduction in poly(ethylene oxide)

JOURNAL OF COMPUTATIONAL PHYSICS

卷:227

Article

Gitelman, L.²  Israeli, M.¹  Averbuch, A.¹  Nathan, M.³  Schuss, Z.⁴  Golodnitsky, D.⁵ 

[1] Tel Aviv Univ, Sch Comp Sci, IL-69978 Tel Aviv, Israel

[2] Technion Israel Inst Technol, Fac Appl Math, IL-32000 Haifa, Israel

[3] Tel Aviv Univ, Sch Elect Engn, IL-69978 Tel Aviv, Israel

[4] Tel Aviv Univ, Sch Math Sci, Dept Appl Math, IL-69978 Tel Aviv, Israel

[5] Tel Aviv Univ, Sch Chem, IL-69978 Tel Aviv, Israel

关键词: lithium battery;    polymer molecule;    Brownian motion;    simulation;    conductivity;    PEO;   

DOI  :  10.1016/j.jcp.2008.06.006

来源: Elsevier

【 摘 要 】

We study the effect of molecular shape on Li+ conduction in dilute and concentrated polymer electrolytes (Lil:P(EO)(n)(3 <= n <= 100)). We model the transport-diffusion of interacting Li+ ions in the helical PEO molecule as Brownian motion in a field of electrical force. Our model demonstrates that ionic conductivity of the amorphous PE structure is increased by mechanical stretching due to the unraveling of loops in the polymer molecule and to increased order. The enhancement of the ionic conductivity in the stretch direction, observed in our Brownian simulations, is in agreement with experimental results. We find an up to 40-fold increase in the Lil P(EO)(7) conductivity, which is also in agreement with experimental results. The good agreement with experiment ends much credibility to our physical model of conductivity. (c) 2008 Elsevier Inc. All rights reserved.

【 授权许可】

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