Research For The Impact Of 6-DOF Vibration Stress On Performance Of Electric Vehicle Power Battery

As advanced technology of energy storage and conversion,power battery has been applied to electric or hybrid electric vehicle(EV or HEV),mirco-gird,mobile device,et al,which is significant for modeling,state of charge(SOC)or state of health(SOH)estimation,the recognition of cell-to-cell variation in the battery pack,monitoring and detecting thermal runaway of battery.Based on operating environment under driving conditions,this research has investigated the performance of power battery six-degree-of-freedom(6-DOF)vibration stress,which includes basic performance,open circuit voltage(OCV)hysteresis and overdischarge characteristics under.In this research,firstly,the battery testing instrument,electrochemical workstation,vibration platform,temperature chamber,thermal collector and so on have been used to establish the experimental bench.Then,according to the working principle of power battery,mechanism of OCV hysteresis and internal short circuit,many experimental tests have been designed and conducted,respectively.The basic performance mainly includes capacity,internal resistance,OCV recovery,thermal conditions,electrochemical impedance spectroscopy(EIS),et al.The OCV hysteresis refers to the phenomenon that the OCV does not duplicate between the charge and discharge process,and the major loop and minor loop are mainly studied in this research.Actually,the overdischarge characteristics are the features of the internal short circuit caused by overdischarged.Finally,the performance of battery is analyzed: the electrochemical analysis method have been applied to describe the impedance conditions of ohmic resistance,charge transfer resistance and Warburg resistance,the mechanism of ageing has been used to analysis of performance degradation.The study involved in this paper is mainly the basic research on the performance of power battery.The results show that the basic performance,OCV hysteresis and overdischarge characteristics are affected by 6-DOF vibration stress in different degree,respectively,which has certain significance for other types of battery performance tests.