Method for forecasting service life of lithium ion battery based on capacity attenuation mechanism decomposition analysis

Abstract

The invention discloses a method for forecasting service life of a lithium ion battery based on capacity attenuation mechanism decomposition analysis. The method comprises the following steps: step one, establishing an equilibrium potential equation of a lithium ion battery to be tested by subtracting equilibrium potentials of positive and negative electrodes with combination of test data of the lithium ion battery to be tested, and then carrying out polarization modification to obtain the equilibrium potential equation; step two, establishing a multi-attenuation-mode decomposition model based on different attenuation mechanisms of the lithium ion battery, establishing a multi-attenuation-mode fitting equation of the lithium ion battery to be tested through a short-term aging test and forecasting attenuation trend; and step three, substituting a forecasting result of the multi-attenuation-mode fitting equation into the equilibrium potential equation of the lithium ion battery to be tested, and forecasting residual capacity. Through the service life forecasting method for carrying out decomposition analysis of different attenuation modes based on different capacity attenuations of the lithium ion battery, the problem that simple extrapolation is carried out according to the experiment test data or the attenuation of the service life of the lithium ion battery is simply ascribed to the single electrochemical mechanism is solved.

Description

technical field [0001] The invention belongs to the field of lithium ion battery life prediction and relates to a lithium ion battery life prediction method based on capacity decay mechanism decomposition analysis. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high energy density, long cycle life, and low self-discharge, and are widely used in portable electronic devices, electric vehicles, new energy power generation and energy storage, and space fields. [0003] Compared with other types of secondary batteries, lithium-ion batteries have better life characteristics, better room temperature storage performance and cycle performance. The storage life of lithium-ion batteries at room temperature can reach 6-8 years, and the long-storage life of lithium-ion batteries developed for long-term storage life characteristics can even reach 10-15 years; and used for electric vehicle power battery systems and energy storage battery sy...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of being out of touch with the attenuation mechanism in the process of predicting the remaining capacity of lithium-ion batteries, and to establish a method that can accurately predict the remaining capacity of lithium-ion batteries.

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