Lithium ion battery thermal runaway safety assessment method under vibration working condition

Abstract

The invention provides a lithium ion battery thermal runaway safety assessment method under a vibration condition. The method comprises the following steps: S1, acquiring a vibration characteristic data set; s2, under the vibration working condition of the vibration characteristic data set, performing a cyclic charge-discharge aging test on the tested battery to obtain a plurality of discharge data sets; s3, traversing all the discharge data sets to obtain a test battery discharge capacity change curve; s4, dividing a test battery discharge capacity change curve to obtain at least three aging attenuation stages; s5, calculating a standard attenuation parameter set of each aging attenuation stage; s6, establishing a battery capacity evaluation model; s7, inputting the predicted discharge data into the battery capacity evaluation model to obtain the predicted battery discharge capacity of the ith charge-discharge cycle of the to-be-evaluated battery; s8, analyzing the aging stage of the battery, and obtaining a standard attenuation parameter set; s9, acquiring a real-time parameter data set of the battery in the ith charge-discharge cycle; and S10, judging the current risk stage of the battery.

Description

technical field [0001] The present application relates to the technical field of thermal runaway safety assessment of lithium-ion batteries, and in particular, to a method for assessing thermal runaway safety of lithium-ion batteries under vibration conditions. Background technique [0002] As new energy vehicles gradually replace fuel vehicles as the development direction of future vehicles, the lithium-ion battery industry is developing rapidly. according to. "Made in China 2025" pointed out that the battery energy density will reach 300Wh / kg in 2020; the battery energy density will reach 400Wh / kg in 2025; and the battery energy density will reach 500Wh / kg by 2030. The increase in the energy density of the battery pack and the irreversible reaction heat will increase the risk of thermal runaway. Therefore, it is extremely necessary to make timely safety assessments of battery capacity and thermal runaway. [0003] Most of the existing methods for judging thermal runaway...

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Problems solved by technology

[0005] The purpose of this application is to solve the problem of inaccurate evaluation results caused by only calculating the rate of change of battery voltage and current in evaluating the thermal runaway of lithium-ion batteries in the prior art. Discharge capacity is related, that is, as the battery discharge capacity decreases, the voltage change rate and current change rate increase, and the discharge voltage change rate and discharge current change rate are associated with the remaining service life of the lithium-ion battery to provide a more accurate method. Lithium-ion battery thermal runaway safety assessment method under vibration conditions

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