Modeling charge polarization voltage for large lithium-ion batteries in electric vehicles
Abstract: Polarization voltage
of the lithium-ion battery is an important parameter that has direct influence
on battery performance. The paper aims to analyze the impedance characteristics
of the lithium-ion battery based on EIS data.
Design/methodology/approach: The effects of currents, initial SOC of the
battery on charge polarization voltage are investigated, which is approximately
linear function of charge current. The change of charge polarization voltage is
also analyzed with the gradient analytical method in the SOC domain. The charge
polarization model with two RC networks is presented, and parts of model
parameters like Ohmic resistance and charge transfer impedance are estimated by
both EIS method and battery constant current testing method.
Findings: This paper reveals that the Ohmic resistance accounts for much
contribution to battery total polarization compared to charge transfer
impedance.
Practical implications: Experimental results demonstrate the efficacy of
the model with the proposed identification method, which provides the
foundation for battery charging optimization.
Originality/value: The paper analyzed the impedance characteristics of
the lithium-ion battery based on EIS data, presented a charge polarization
model with two RC networks, and estimated parameters like Ohmic resistance and
charge transfer impedance.
Author: Yan Jiang, Caiping
Zhang, Weige Zhang, Wei Shi, Qiujiang Liu
Journal Code: jptindustrigg130097
