Connecting the irreversible capacity loss in Li-ion batteries with the electronic insulating properties of solid electrolyte interphase (SEI) components

JOURNAL OF POWER SOURCES

卷:309

Article

Lin, Yu-Xiao¹  Liu, Zhe²  Leung, Kevin³  Chen, Long-Qing²  Lu, Peng⁴  Qi, Yue¹ 

[1] Michigan State Univ, Dept Chem Engn & Mat Sci, E Lansing, MI 48824 USA

[2] Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA

[3] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA

[4] Gen Motors Res & Dev Ctr, Warren, MI 48090 USA

关键词: Electron tunneling model;    Density function theory;    Solid electrolyte interphase;    Lithium ion battery;    Irreversible capacity loss;    Stress and strain;   

DOI  :  10.1016/j.jpowsour.2016.01.078

来源: Elsevier

【 摘 要 】

The formation and continuous growth of a solid electrolyte interphase (SEI) layer are responsible for the irreversible capacity loss of batteries in the initial and subsequent cycles, respectively. In this article, the electron tunneling barriers from Li metal through three insulating SEI components, namely Li2CO3, LiF and Li3PO4, are computed by density function theory (DFT) approaches. Based on electron tunneling theory, it is estimated that sufficient to block electron tunneling. It is also found that the band gap decreases under tension while the work function remains the same, and thus the tunneling barrier decreases under tension and increases under compression. A new parameter, eta, characterizing the average distances between anions, is proposed to unify the variation of band gap with strain under different loading conditions into a single linear function of eta. An analytical model based on the tunneling results is developed to connect the irreversible capacity loss, due to the Li ions consumed in forming these SEI component layers on the surface of negative electrodes. The agreement between the model predictions and experimental results suggests that only the initial irreversible capacity loss is due to the self-limiting electron tunneling property of the SEI. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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