Lithium ion battery health state prediction method

Abstract

The invention provides a lithium ion battery health state prediction method. The lithium ion battery health state prediction method comprises the steps of: placing a lithium ion battery in a constant-temperature environment, and performing constant-current charging and discharging circulation on the lithium ion battery after standing for a period of time; after each charge-discharge cycle is performed for preset times, placing the lithium ion battery in a room-temperature environment for standing for preset time, and performing primary capacity calibration on the lithium ion battery; carryingout constant-current discharging on the battery at a certain multiplying power, measuring the alternating-current impedance of the lithium ion battery once after the state-of-charge value of the lithium ion battery is reduced to a set value, and establishing a dynamic impedance spectrum; establishing the equivalent circuit of the lithium ion battery according to the dynamic impedance spectrum, andfitting the dynamic impedance spectrum of the lithium ion battery according to the equivalent circuit to obtain fitting data; extracting the fitting data as an input parameter, and substituting the fitting data into a BP neural network model to obtain the health state of the lithium ion battery; by adopting the scheme, the health state detection reliability is improved, the prediction error is reduced, the prediction time is shortened, the data is simple and easy to obtain, and online detection can be achieved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery health state prediction, and in particular relates to a lithium-ion battery health state prediction method. Background technique [0002] Lithium-ion batteries have been developed and innovated for many years since they were invented. They have high energy density and long cycle life, and are now widely used in smart grids and electric vehicles. However, the actual operating environment of electric vehicles is very Maintain stable electrochemical performance throughout the life cycle, but the composition of the battery system is complex, and various electrochemical and thermodynamic processes are involved in the operation. Long-term stability is a huge challenge for lithium-ion batteries, and more importantly, practical Long-term safety and reliability during use is the prerequisite for large-scale and long-term application of large-capacity lithium-ion batteries in electric vehicles. ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to propose a method for predicting the state of health of a lithium-ion battery aimed at solving the existing deficiencies in the above-mentioned technologies.

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