EIS rapid measuring method of lithium-ion battery

Abstract

The invention relates to an EIS rapid measuring method of a lithium-ion battery, and provides an EIS rapid measuring method based on square wave current excitation and Fourier transform. The method includes: selecting a square wave excitation frequency based on an electrochemical reaction characteristic of the lithium-ion battery, determining that the lithium-ion battery is in an appropriate polarized voltage amplitude range, and selecting a sinusoidal alternating current amplitude according to the range; applying a square wave current of a selected frequency point and with a specific amplitude to the lithium-ion battery, performing Fourier transform on the square wave current and a response voltage obtained by sampling, and obtaining the impedance of a specific frequency point; and screening the impedance with a specific frequency based on a frequency spectrum amplitude of Fourier decomposition of the response voltage and an impedance change rule to form the electrochemical impedance spectroscopy of the lithium-ion battery, namely EIS. According to the EIS rapid measuring method, the electrode reaction characteristic of the lithium-ion battery can be accurately described, the EIS of the lithium-ion battery is accurately obtained, the EIS test speed of the lithium-ion battery is fast, the test time is short, and the project is easy to realize.

Description

technical field [0001] The invention relates to the technical field of quick measurement of battery impedance, in particular to a quick measurement method for EIS of a lithium ion battery, in particular to a method for quick measurement of the EIS of a lithium ion battery by using waveforms such as square waves and triangular waves. Background technique [0002] The dual pressure of energy shortage and environmental pollution has boosted the rapid development of electric vehicles. Lithium-ion batteries have become the preferred battery for electric vehicles due to their advantages of high single voltage, high energy density, long life, no memory effect and no pollution. . [0003] The performance detection, state estimation and safety warning of lithium-ion batteries have always been the key problems to be solved during the use of lithium-ion batteries. However, due to the complex operating conditions and limited test data of lithium-ion batteries during use, it is difficult...

AI Technical Summary

Problems solved by technology

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a fast EIS measurement method for lithium-ion batteries, which can improve the problems in the prior art, such as slow sinusoidal current test EIS test, long test time, and difficult engineering implementation.

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