Effect of overcharge on Li(Ni0.5Mn0.3Co0.2)O2 cathodes: NMP-soluble binder. II - Chemical changes in the anode

JOURNAL OF POWER SOURCES

卷:385

Article

Bloom, Ira¹  Bareno, Javier¹  Rago, Nancy Dietz¹  Dogan, Fulya¹  Graczyk, Donald G.²  Tsai, Yifen²  Naik, Seema R.²  Han, Sang-Don¹  Lee, Eungje¹  Du, Zhijia³  Sheng, Yangping³  Li, Jianlin³  Wood, David L., III³  Steele, Leigh Anna⁴  Lamb, Joshua⁴  Spangler, Scott⁴  Grosso, Christopher⁴  Fenton, Kyle⁴ 

[1] Argonne Natl Lab, Chem Sci & Engn Div, 9700 S Cass Ave, Argonne, IL 60439 USA

[2] Argonne Natl Lab, Nucl Engn Div, Analyt Chem Lab, 9700 S Cass Ave, Argonne, IL 60439 USA

[3] Oak Ridge Natl Lab, Energy & Transportat Sci Div, Oak Ridge, TN 37831 USA

[4] Sandia Natl Labs, Power Sources Technol Grp, POB 5800, Albuquerque, NM 87185 USA

关键词: Lithium-ion battery;    Overcharge;    SEI layer;   

DOI  :  10.1016/j.jpowsour.2017.12.015

来源: Elsevier

【 摘 要 】

Cells based on nickel manganese cobalt oxide (NMC)/graphite electrodes, which contained polyvinylidene difluoride (PVDF) binders in the electrodes, were systematically charged to 100, 120, 140, 160, 180, and 250% state of charge (SOC). Characterization of the anodes by inductively-coupled-plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS), and high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) showed several extent-of-overcharge-dependent trends. The concentrations (by wt) of nickel, manganese, and cobalt in the negative electrode increased with SOC, but the metals remained in the same ratio as that of the positive. Electrolyte reaction products, such as LiF:LiPO3, increased with overcharge, as expected. Three organic products were found by HPLC-ESI-MS. From an analysis of the mass spectra, two of these compounds seem to be organophosphates, which were formed by the reaction of polymerized electrolyte decomposition products and PF3 or O = PF3. Their concentration tended to reach a constant ratio. The third was seen at 250% SOC only.

【 授权许可】

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