Current density distribution in cylindrical Li-Ion cells during impedance measurements

JOURNAL OF POWER SOURCES

卷:314

Article

Osswald, P. J.^1,2  Erhard, S. V.²  Noel, A.²  Keil, R.²  Kindermann, F. M.²  Hoster, H.^1,3  Jossen, A.² 

[1] TUM CREATE Ltd, Singapore, Singapore

[2] Tech Univ Munich, Inst Elect Energy Storage Technol EES, D-80290 Munich, Germany

[3] Univ Lancaster, Energy Lancaster, Lancaster, England

关键词: Lithium-ion battery;    Impedance;    Current density distribution;    Local potential measurements;    Aging;    Cell design;   

DOI  :  10.1016/j.jpowsour.2016.02.070

来源: Elsevier

【 摘 要 】

In this work, modified commercial cylindrical lithium-ion cells with multiple separate current tabs are used to analyze the influence of tab pattern, frequency and temperature on electrochemical impedance spectroscopy. In a first step, the effect of different current tab arrangements on the impedance spectra is analyzed and possible electrochemical causes are discussed. In a second step, one terminal is used to apply a sinusoidal current while the other terminals are used to monitor the local potential distribution at different positions along the electrodes of the cell. It is observed that the characteristic decay of the voltage amplitude along the electrode changes non-linearly with frequency, where high frequent currents experience a stronger attenuation along the current collector than low-frequent currents. In further experiments, the decay characteristic is controlled by the cell temperature, driven by the increasing resistance of the current collector and the enhanced kinetic and transport properties of the active material and electrolyte. Measurements indicate that the ac current distribution depends strongly on the frequency and the temperature. In this context, the challenges for electrochemical impedance spectroscopy as cell diagnostic technique for commercial cells are discussed. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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