Structure Design And Analysis Of A Battery Pack Module

The safety of new energy vehicle power battery has always been the focus of attention.During the charging and discharging process of lithium ion battery,due to the self-reaction will cause the battery to expand and shrink,the existing battery pack module structure has serious safety hidden trouble.Therefore,it is very important to design a battery pack module which can adapt to the expansion of the core.The research work of this paper mainly starts from the following aspects:The safety of new energy vehicle power battery has always been the focus of attention.During the charging and discharging process of lithium ion battery,due to the self-reaction will cause the battery to expand and shrink,the existing battery pack module structure has serious safety hidden trouble.Therefore,it is very important to design a battery pack module which can adapt to the expansion of the core.The research work of this paper mainly starts from the following aspects:A new type of battery pack module structure with the functions of anti-freeze,heat insulation and explosion-proof core is proposed.This paper focuses on the structure of the end-side plate connection and solves the cracking phenomenon of the end-side plate connection caused by the expansion of the core.Through experiments,the relationship model of charge-discharge cycle times and pressure is constructed,and then the finite element model is established to simulate the law of expansion force change.Based on the analysis of the expansion force and core temperature cloud diagram of the three modules,the optimal arrangement of the battery pack module insulation pad is proposed. the finite element model of battery pack module structure based on HyperMesh is established.according to the safety requirements of GBT31467 national standard for battery pack module,25 g?15ms of semi-sinusoidal impact waveform and random vibration load are applied to the module.and the results show that the maximum stress of the unit(the most dangerous place)at the bottom edge of the side plate is 91.03 Mpa,which is less than the allowable value.Therefore,the structure design of the battery pack module meets the national standard.According to the national standard,a half cylinder with a radius of 75 mm is used to carry out vibration shock test on the battery pack module.The test results show that the designed battery module safety index conforms to the national standard(no leakage,good structure,insulation resistance is not less than 500?/V,leakage current is not more than 1 mA,after extrusion module does not explode,do not catch fire).Through this research,a new type of battery pack module structure meets the national standard and solves the safety problems caused by thermal expansion and vibration shock.The research results provide theoretical basis and technical support for the design of other battery pack modules.