大倍率充放电循环对锂离子电池特性及热安全性能的影响  

Influence of high rate charge and discharge cycle on the electronic performance and thermal safety of lithium ion battery

作　　者：李东琪 张青松[1] 郑少帅 LI Dong-qi;ZHANG Qing-song;ZHENG Shao-shuai(Key Laboratory of Civil Aviation Thermal Hazards Prevention and Emergency Response,Civil Aviation University of China,Tianjin300300,China)

机构地区：[1]中国民航大学民航热灾害防控与应急重点实验室,天津300300

出　　处：《兰州理工大学学报》2023年第3期30-35,共6页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金民航联合基金(U2033204);天津市教委科研计划项目(2021KJ061)。

摘　　要：锂离子电池广泛应用于电动汽车及各类储能设备.通过不同充放电倍率下循环老化及热失控实验,研究了大倍率充放电对单体锂离子电池性能与热安全性的影响.结果表明:大倍率充放电循环下,单体锂离子电池的实际容量出现了衰减,衰减程度与充放电倍率呈正相关.恒流比呈阶梯式衰减,但库伦效率仍处于99%~100%,表明锂离子电池的可逆性能正常.随着倍率增加,热失控触发时间、燃爆压力、喷射火焰温度呈先增大后减小的趋势,燃爆时电池表面平均温度为655.8℃,接近金属铝的熔点温度,燃爆喷射粉末产物主要以金属铝、石墨、锂钴氧化物为主.Lithium-ion batteries are widely used in electric vehicles and various energy storage devices.In this paper,cyclic aging and thermal runaway experiments under different charge-discharge rates were carried out,and the effects of large-rate charging and discharging on the performance and thermal safety of single lithium-ion batteries were studied.The results showed that the actual capacity of single lithium-ion battery is attenuated under the large-rate charge-discharge cycle,and the degree of attenuation is positively relevant to the charge-discharge rate.With the charge-discharge rate increasing,the constant current ratio is stepwise attenuation,but the coulombic efficiency still maintains in the range of 99%-100%,indicating that the reversible performance of lithium-ion batteries is normal.With the increase of the magnification,the thermal runaway trigger time,explosion pressure and jet flame temperature first increase and then decrease.The average surface temperature of the battery during explosion is 655.8℃,which is close to the melting point of aluminum.The explosion injection powder products are mainly metal aluminum,graphite and lithium cobalt oxide.

关 键 词：锂离子电池 大电流充放电 循环老化 热失控 

分 类 号：TB39[一般工业技术—材料科学与工程]