International Society for Industrial Process Tomography

Investigation of the Dielectric Properties of Lithium-ion Battery Slurry by Electrical Impedance Spectra-tomography Method

Zhilong WANG^1*, Tong ZHAO², Masanori KANZAWA¹ and Masahiro TAKEI¹

¹Division of Artificial Systems Science, Graduate School of Mechanical Engineering, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan

²Faculty of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, 710048 Xi'an, China

^*Email: xalg088@163.com

ABSTRACT

The dielectric properties (resistance, reactance and conductivity) of Lithium-ion battery (LIB) slurry were experimentally and numerically investigated by using impedance spectra-tomography (EIST) method. In the experiment, an EIST measurement system was developed for LIB slurry, which mainly includes Field－Programmable Gate Array (FPGA), multiplexer, switch circuit and EIST sensor. Moreover, LIB slurry was stirred with a mixer under different rotation speeds n=0rpm and n=100rpm. By using this EIST system, frequency-dependent dielectric properties of LIB slurry are able to be obtained. In the numerical simulation, the dielectric properties of LIB slurry were acquired under four different multi-component configurations and three different measurement frequencies (f=1KHz, 250KHz, 500KHz). Both the experiment and the simulation are used Tikhonov algorithm get the reconstructed images of LIB slurry under those different conditions. The numerical simulation results are verified by the experiment results. As a result, the following conclusion points are able to be obtained. Firstly, with increasing of n, resistance and reactance of LIB slurry are decreased, while conductivity of LIB slurry is increased. Secondly, from the reconstructed images of the experiment and simulation, it is obvious that high frequency is able to show clear distribution of dielectric properties for LIB slurry, which has the potential to be used for real-time LIB slurry manufacture process. Thirdly, in the case that frequency didn’t have influence on the reconstructed images of dielectric properties, the LIB slurry is homogenous, which is capable of ensure the high performance LIB.

Keywords Dielectric properties, electrical impedance spectra-tomography (EIST), Lithium-ion battery (LIB) slurry, Reconstructed image

Industrial Application General