Research On Thermal Runaway Of Vehicle Lithium-ion Battery Based On Data Analysis

With the vigorous promotion and popularization of new energy vehicles in recent years,spontaneous combustion accidents of new energy vehicles have also occurred frequently.This paper takes the power battery of a pure electric vehicle that spontaneously ignites during driving as the research object.First,it reads the CAN message generated during the work of the car in the CANoe development environment of the bus,and observes the total current of the power battery and the temperature of the characteristic point.The changes of the parameters such as the cell voltage during the operation of the car,combined with the characteristics and causes of auto spontaneous combustion accidents at home and abroad in recent years,made a preliminary guess on the triggers of this spontaneous combustion accident from three aspects: mechanical trigger,electrical trigger,and thermal trigger.Secondly,various data in the CAN message are exported from the CANoe environment,and the battery cell voltage and battery characteristic point temperature and other data are sorted out with the help of the My SQL database management system,and the battery cell voltage and battery characteristic point temperature are plotted.The heat map of the parameters determines the diffusion path of the battery thermal runaway in the battery pack and the location of the monomer that triggers the thermal runaway through the observation of the thermal map.Finally,the battery cell voltage and the temperature of the battery characteristic point were visualized with the help of the 3D drawing tool of Matlab software,and the voltage fluctuation and temperature change of the battery cell voltage in each time period were analyzed,and the inconsistency of the battery cell was ignored In the case of the battery,the short-circuit resistance in the battery was estimated by establishing a short-circuit model in the battery,and the main cause of the spontaneous combustion accident was speculated.This article takes real electric vehicle working data as a research basis and makes a comprehensive observation in the CANoe development environment of the bus,and analyzes the induced battery thermal runaway incentives with a certain degree of reliability.The visualization of working data makes the process of battery thermal runaway more intuitive,and provides ideas for the improvement of battery thermal runaway diagnostic technology that is in urgent need of improvement;the research induced thermal runaway causes and their diffusion methods provide the design of thermal runaway early warning system Basis,and help car users improve their own car habits and reduce the occurrence of spontaneous combustion accidents in electric vehicles.