Study On Combustion Characteristics Of Flame Retardant Electrolyte

Electrolyte is a key component of lithium ion battery,and is also one of the main fuel,when the battery heat out of control,often accompanied by electrolyte splash,spray and toxic gas generation.The heat released by electrolyte combustion accounts for more than 40% of the total heat released by battery fire.In addition,the splashing of electrolyte is easy to lead to the spread of fire.It can be seen that the safety performance of electrolyte plays a crucial role in the overall safety performance of lithium battery.At present,many scholars at home and abroad have made great progress in the study of combustion characteristics of lithium-ion battery electrolyte by means of experiment and simulation.However,as a kind of flammable liquid,there are few researches on the combustion characteristics of electrolyte,especially on the combustion characteristics of flame retardant electrolyte.The main research objective of this paper is to reveal the influence of flame retardants on the combustion characteristics of lithium-ion battery electrolyte,so as to provide reference for the research and development of lithium-ion battery electrolyte,the evaluation method of safety performance of electrolyte and the control of electrolyte fire.In order to achieve this goal,this paper carries out research in three aspects.First of all,the cone calorimeter is the most important experimental instrument in the experimental research in this paper.In order to ensure the scientific nature of the research method in this paper,the heat release rate data calculated by thermal chemistry method based on stoichiometry is compared and analyzed with the heat release rate data of electrolyte measured by the cone calorimeter based on oxygen consumption method.The results show that the heat release rates calculated by the two methods are close to each other,so it is considered that the conical calorimeter is an appropriate method to evaluate the risk of electrolyte combustion and fire.Secondly,the influence of environmental pressure and the mass ratio of organic solvent in the electrolytic liquid system on the combustion characteristics of the electrolyte was explored,and the heat release rate,mass loss rate and flame centerline temperature of the electrolyte at different altitudes were obtained.The experimental results show that with the decrease of ambient pressure,the temperature of the center line of the electrolyte pool fire flame increases and the combustion time increases.Finally,the combustion characteristics of the flame retardant electrolyte were studied by combining the cone calorimeter,flash point tester and water mist extinguishing platform,and the effects of flame retardants on important combustion parameters such as flash point,heat release rate,mass loss rate and total heat release of the electrolyte were analyzed.The influence of flame retardants on the process of water mist extinguishing was analyzed.The experimental results show that the addition of flame retardant to the electrolyte can effectively reduce the heat release rate of the electrolyte pool fire,improve the efficiency of water mist fire extinguishing;different flame retardants play different roles in flame retardancy effect(such as flash point,heat release rate,total heat release,etc.).