Electrochemical simplified model of lithium ion battery and parameter acquisition method thereof

Abstract

The invention discloses an electrochemical simplified model of a lithium ion battery and a parameter acquisition method thereof, and relates to a mechanism model of the lithium ion battery. The electrochemical simplified model of the lithium ion battery is as follows: Uapp is terminal voltage of the lithium ion battery; Up and Un are positive and negative open-circuit potentials; t is time, and t+ is a cation migration number; ysurf and xsurf are the concentrations of lithium ions on the solid-phase surfaces of the positive electrode and the negative electrode; R is an ideal gas constant; f is a Faraday constant; t is the working temperature of the lithium ion battery; c0 is the initial lithium ion concentration in the electrolyte; mp and mn are intermediate variables and have no specificphysical significance; [delta]c1 and [delta]c2 are the change amounts of the lithium ion concentrations at the positive and negative current collectors relative to the initial lithium ion concentration c0 in the electrolyte; Rohm is the equivalent ohmic internal resistance of the lithium ion battery; I is an external current, and it is stipulated that discharge is positive and charge is negative.According to the invention, accurate simulation of batteries made of different lithium cobalt oxide materials at 4C multiplying power and below terminal voltage can be realized.

Description

technical field [0001] The invention relates to a mechanism model of a lithium-ion battery, in detail, an electrochemical simplified model of a lithium-ion battery with high simulation accuracy under a large magnification condition and a method for obtaining parameters thereof. Background technique [0002] The outstanding features of lithium-ion batteries are high voltage, high energy density, good cycle performance, small self-discharge, no memory effect, and environmental protection. They are the main energy storage devices for large-scale equipment or systems. The safety, reliability and economic performance of the battery restrict its further promotion and use. From the perspective of application level, the battery management system is of great significance to give full play to the performance of the battery. [0003] The lithium-ion battery mechanism model can accurately describe the complex physical and chemical processes inside the battery, and has the ability to si...

AI Technical Summary

Problems solved by technology

After actual use and experimental verification, it is known that this method has the problem of poor simulation accuracy of the lithium-ion battery mechanism model under high-magnification conditions.

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