Galvanostatic interruption of lithium insertion into magnetite: Evidence of surface layer formation

JOURNAL OF POWER SOURCES

卷:321

Article

Brady, Nicholas W.¹  Knehr, K. W.¹  Cama, Christina A.²  Lininger, Christianna N.¹  Lin, Zhou²  Marschilok, Amy C.^2,4  Takeuchi, Kenneth J.^2,4  Takeuchi, Esther S.^2,3,4  West, Alan C.¹ 

[1] Columbia Univ, Dept Chem Engn, New York, NY 10027 USA

[2] SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA

[3] Brookhaven Natl Lab, Energy Sci Directorate, Upton, NY 11973 USA

[4] SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA

关键词: Lithium ion batteries;    Voltage recovery;    Multi-scale model;    Avrami model;    SEI;   

DOI  :  10.1016/j.jpowsour.2016.04.117

来源: Elsevier

【 摘 要 】

Magnetite is a known lithium intercalation material, and the loss of active, nanocrystalline magnetite can be inferred from the open-circuit potential relaxation. Specifically, for current interruption after relatively small amounts of lithium insertion, the potential first increases and then decreases, and the decrease is hypothesized to be due to a formation of a surface layer, which increases the solid-state lithium concentration in the remaining active material. Comparisons of simulation to experiment suggest that the reactions with the electrolyte result in the formation of a thin layer of electrochemically inactive material, which is best described by a nucleation and growth mechanism. Simulations are consistent with experimental results observed for 6, 8 and 32-nm crystals. Furthermore, simulations capture the experimental differences in lithiation behavior between the first and second cycles. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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