Lithium ion battery overcharge thermal-runaway modeling method

Abstract

The invention provides a lithium ion battery overcharge thermal-runaway modeling method and belongs to the field of batteries. The lithium ion battery overcharge thermal-runaway modeling method comprises the steps that a heat-insulating overcharge thermal-runaway experiment is firstly conducted on a first lithium ion battery, and the temperature, voltage and internal resistance of the first lithium ion battery at different moments are recorded; then, a second lithium ion battery same as the first lithium ion battery is disassembled, and relation curves including positive and negative voltages of the second lithium ion battery and the stoichiometric number of lithium ions are respectively obtained; stage division is conducted on the overcharge thermal-runaway process of the first lithium ion battery, internal chemical reactions of the batteries corresponding to different stages are determined, and finally a mathematical model of the first lithium ion battery in the heat-insulating overcharge thermal-runaway experiment process is established. The lithium ion battery overcharge thermal-runaway modeling method simultaneously simulates the change rules of the voltage and temperature in the overcharge thermal-runaway process, accurately simulates overcharge thermal-runaway behaviors of the lithium ion batteries and guarantees the battery system safety.

Description

technical field [0001] The invention belongs to the field of batteries, and in particular relates to a modeling method for overcharging thermal runaway of a lithium-ion battery. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density / power density and long service life, and are currently the most widely used chemical power source for vehicles. However, in recent years, thermal runaway accidents of battery systems of electric vehicles have emerged one after another, endangering people's lives and property, and at the same time hitting the public's confidence in electric vehicles. [0003] Overcharging is one of the most common battery abuse situations, which means that the battery is still being charged with current after reaching the charging cut-off voltage, usually caused by the failure of the battery management system. During the overcharging process, a series of chemical reactions will occur inside the battery. These reactions...

AI Technical Summary

Problems solved by technology

However, so far, there is no model capable of simulating the voltage and temperature changes in the real battery overcharge thermal runaway process

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