Temperature-dependent cycling performance and ageing mechanisms of C6/LiNi1/3Mn1/3Co1/3O2 batteries

JOURNAL OF POWER SOURCES

卷:396

Article

Li, Dongjiang^1,2  Li, Hu¹  Danilov, Dmitri^2,3  Gao, Lu³  Zhou, Jiang⁴  Eichel, Ruediger-A^2,5  Yang, Yong¹  Notten, Peter H. L.^2,3,6 

[1] Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China

[2] Forschungszentrum Julich, Fundamental Electrochem IEK 9, D-52425 Julich, Germany

[3] Eindhoven Univ Technol, NL-5600 MB Eindhoven, Netherlands

[4] Tianjin Lishen Battery Joint Stock Co Ltd, Tianjin 300384, Peoples R China

[5] Rhein Westfal TH Aachen, D-52074 Aachen, Germany

[6] Univ Technol Sydney, Sydney, NSW 2007, Australia

关键词: Layered-oxid cathode materials;    Solid-Electrolyte-Interface;    Cathode-Electrolyte-Interface;    Capacity loss;    Electromotive force;    Derivative voltage analysis;   

DOI  :  10.1016/j.jpowsour.2018.06.035

来源: Elsevier

【 摘 要 】

Ageing mechanisms of NMC-based Li-ion (C-6/LiNi1/3Mn1/3Co1/3O2) batteries have been investigated under various cycling conditions. The electromotive force (EMF) curves are regularly determined by mathematical extrapolation of voltage discharge curves. The irreversible capacity losses determined from the EMF curves have been investigated as a function of time and cycle number. Parasitic side reactions, occurring at the cathode and anode, determine the charge-discharge efficiency (CDE) and discharge-charge efficiency (DCE), respectively. The recently developed non-destructive voltage analysis method is also applied to the present battery chemistry. The decline of the second plateau of the dV(EMF)/dQ curves upon cycling is considered to be an indicator of graphite degradation whereas the development of the third peak in these derivative curves is considered to be an indicator for electrode voltage slippage. X-ray Photoelectron Spectroscopy (XPS) measurements confirm the deposition of transition-metal elements at the graphite electrode, indicating dissolution of these metals from the cathode. Furthermore, XPS analyses confirm the existence of a Cathode-Electrolyte-Interface (CEI) layer. The outer CEI layer is composed of various compounds, such as carbonate-related Li salts, LiF and NiF2, etc., while the inner CEI layer is dominantly composed of fluoride-related compounds, such as NiF2. Finally, a cathode degradation model including transition-metal dissolution and electrolyte decomposition is proposed.

【 授权许可】

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