Lithium battery pack thermal abuse safety risk assessment method based on multi-physics field simulation

Abstract

The invention relates to a lithium battery pack thermal abuse safety risk assessment method based on multi-physics field simulation, and the method comprises the steps: determining the configuration and geometric structure of a lithium battery pack, constructing a thermal abuse-oriented lithium battery pack multi-physics field simulation model and a thermal abuse safety assessment model, carrying out the sampling of random parameters, and calculating the thermal abuse safety risk of the lithium battery pack. And carrying out corresponding multi-physical field simulation and thermal safety analysis to obtain a thermal safety boundary and a thermal runaway delay period, carrying out distribution fitting on results, and carrying out thermal safety risk assessment based on a stress intensity interference model. According to the method, the influence of random uncertainty caused by the multi-field multi-cell coupling effect, the load working condition, the production process level, degradation and other factors on the thermal safety is considered at the same time, the thermal safety of the lithium battery pack can be accurately evaluated, and the thermal abuse safety boundary and the risk probability are given out.

Description

[0001] Technical field [0002] The invention relates to the field of thermal safety of lithium batteries, in particular to a method for evaluating thermal abuse safety risk of lithium battery packs based on multi-physics simulation. Background technique [0003] Lithium-ion batteries have been widely used in automotive power, energy storage and other systems due to their high energy / power density and long cycle life. However, in recent years, frequent safety accidents such as lithium battery fires, combustion, and explosions have hindered the in-depth development and application of lithium batteries. Therefore, the safety of lithium batteries is very important. For lithium-ion batteries, thermal runaway is one of the main reasons for the occurrence of safety accidents. Studying the thermal safety of lithium-ion batteries and accurately evaluating the safety boundary of lithium-ion batteries under thermal excitation is of great significance for preventing the occurrence of li...

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Problems solved by technology

[0005] However, there are still the following deficiencies: 1) the existing lithium battery thermal safety analysis methods are mainly aimed at single or single physical fields, and cannot fully and accurately evaluate the thermal safety of lithium battery packs under the coupling of multiple physical fields; 2) the existing The thermal safety assessment of lithium batteries based on physical simulation is deterministic, and the dispersion and random uncertainty of each battery cell are not fully considered

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