A method, device and medium for testing AC impedance spectroscopy

Abstract

The invention discloses an alternating-current impedance spectrum testing method and a device and a medium. The method comprises the following steps: outputting a trigger signal so as to apply an excitation current to a tested battery, then, collecting the response voltage of the tested battery; establishing a corresponding battery model according to the excitation current and the response voltage; applying a model excitation current to the battery model for simulation to obtain a model prediction voltage under the frequency, repeating the above process, obtaining corresponding model prediction voltages under model excitation current of different frequencies, finally calculating the model excitation current and the obtained multiple model prediction voltages to obtain battery impedance under multiple frequencies, and further calculating to obtain a battery alternating current impedance spectrum. By applying the technical scheme, the real sampling frequency of the repetition period is reduced, the time for obtaining the alternating-current impedance spectrum is greatly shortened, the detection precision of the alternating-current impedance spectrum is improved, and the anti-interference capability in the test process is enhanced.

Description

technical field [0001] The present application relates to the field of electrochemistry, in particular to an AC impedance spectroscopy test method, device and medium. Background technique [0002] AC impedance spectroscopy is a measurement method in the frequency domain. It can obtain more kinetic information than other conventional electrochemical methods to study the electrode system through impedance spectroscopy testing in a wide frequency range. AC impedance spectroscopy can study the characteristics of the electrode process, including ohmic characteristics, electrochemical polarization characteristics and concentration polarization characteristics, and at the same time provide support for testing the battery state of charge (SOC) and battery state of health (SOH). AC impedance spectroscopy has a wide range of applications in the field of electrochemistry, especially in the field of lithium-ion batteries, such as conductivity, chemical diffusion coefficient, growth and ...

AI Technical Summary

Problems solved by technology

However, in order to ensure the accuracy of the measurement, it is necessary to sample and measure the response voltage many times during the charging and discharging process of the battery, which leads to the problems of long detection time and low efficiency.

[0004] In view of this, in the prior art, the identification parameters under the working state of the battery are directly used to establish the battery model, and then the battery model is simulated at different frequencies, and the sampling process is realized through simulation. Although the problem of long detection time can be solved, the In the process, the battery parameters are fixed, so the AC impedance spectrum obtained according to the battery model is a theoretical spectrum with fixed parameters, ignoring the influence of the ambient temperature in the parameter identification process, resulting in inaccurate measurement results

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