Study Of Tipical Safety Issues Of Lithium-ion Battery Used In Electric Vehicles

With the rapid development of new energy vehicles, lithium ion battery are used widespread, and consequent safety issues become serious. Once accidents, such as burning and explosion, occur in lithium ion battery, severe financial loss and grate harm to the whole society is inevitable. Therefore, the study of safety issues and further presentation of method for fault diagnosis are full of meaning. This study can reduce the frequency of occurrence of accidents and faults in batteries, and preventive or lessen harm caused by safety issues.In order to discuss typical safety issues of cells for electric vehicle, at the beginning of this article, functional mechanism and inner structures are analyzed, and several existing protection measures are studied. These parts are the theoretical basis to design and analyze safety experiment. In addition, with the purpose of cell sorting before safety experiment, a circuit of internal resistance measurement are designed and realized.Secondly, four typical safety issues under abuse are discussed deeply, and safety experiment are finished accordingly. After analyzing the experiment results, related fault prognosis methods and preventive advices are presented.Finally, a simulation model for battery pack is established. Based on simulation experiments and practical experiments, prognosis for connection faults in battery packs of serial and parallel and inner short in parallel battery packs, which lays the foundation for forecasting faults of battery pack and then avoiding them.