Spatially-resolved lithiation dynamics from operando X-ray diffraction and electrochemical modeling of lithium-ion cells

JOURNAL OF POWER SOURCES

卷:484

Article

Raj, Abhi^1,2  Shkrob, Ilya A.¹  Okasinski, John S.³  Rodrigues, Marco-Tulio Fonseca¹  Chuang, Andrew C.³  Huang, Xiang⁴  Abraham, Daniel P.¹ 

[1] Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USA

[2] Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA

[3] Argonne Natl Lab, Xray Sci Div, Adv Photon Source, Lemont, IL 60439 USA

[4] Argonne Natl Lab, Math & Comp Sci Div, Lemont, IL 60439 USA

关键词: Fast charge;    Concentration gradients;    Heterogeneity;    Graphite;    Layered-oxide;   

DOI  :  10.1016/j.jpowsour.2020.229247

来源: Elsevier

【 摘 要 】

Energy dispersive X-ray diffraction is used to profile the time evolution of ordered LixC6 phases in solid electrodes of lithium-ion cells charged at rates between 0.2 and 4.7C (where 1C corresponds to full discharge in 1 h). The methods for quantifying lithium concentration in these phases from the acquired diffraction patterns are described. Compact expressions for time-dependent concentration gradients in the solid electrodes using orthogonal polynomial expansions are presented. Experimentally, these gradients persisted in lithiated graphite electrodes even after the cells rested at open-circuit for over 9 h. A multiphase electrochemical model of graphite intercalation captured many of the observed behaviors, including the progression of phase transitions and the persistent gradients at zero current. However, the magnitude of concentration gradients in both the oxide cathode and graphite anode is underestimated by the model, even at moderate currents.

【 授权许可】

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