摘要
采用加速量热仪(ARC)研究了商业化锂离子电池(LiCoO2/石墨)的热稳定特性,主要考察了开路电压、循环次数以及容量对电池的热稳定性影响。ARC测试结果表明,当电池开路电压由3.8V增至4.4V时,电池的起始放热反应温度由100!降低到73!,并且在同一温度下,电池的自加热速率随电压的升高而增大;在相同条件下,电池的起始放热反应温度几乎不受循环次数(0"400次)及容量大小(710mAh和780mAh)的影响。但是,随着循环次数的增加和电池容量的增大,电池的自加热速率增大。另外,为进一步了解电池内部热量来源,分别对充电到4.2V完整的正负极片进行了热分析。实验结果表明,负极在60!左右开始放热,而正极在110!左右开始热分解,但由于正极热分解释放出大量氧气致使电池内压迅速增大,并最终导致电池热失控。
The commercial Li-ion battery （Li0.5CoO2/graphite） thermal analysis experiments were conducted to investigate the effects of open circuit voltage （OCV）, cycle number and capacity on the thermal stability of lithium-ion battery by accelerating rate calorimeter （ARC）. The results of ARC tests show that the higher OCV, the lower the initial temperature of self-heating （for example, when the OCV is 3.8 V the initial temperature is 100 ℃, while the OCV is 4.4 V, the initial temperature is 73 ℃） and the self-heating rate enhances with the increase of OCV. The initial temperature of self-heating has no obvious change but the self-heating rate enhances with the increase of the cycle number （0-400） and capacity （ 710 mAh vs.780 mAh ）in the same situation. Furthermore, in order to understand the heat generation in the battery, the thermal stability of the full lengths of anode and cathode charged to 4.2 V was also studied. The results show that the initial temperature is about 60 ℃ and 100 ℃ for anode and cathode respectively. But the heat generation and gas from the decomposition of positive material and reaction of that with electrolyte initiates thermal runaway in a Li-ion battery, in thermal or abusive conditions.
出处
《电源技术》
CAS
CSCD
北大核心
2007年第1期23-25,33,共4页
Chinese Journal of Power Sources
关键词
加速量热仪
锂离子电池
热稳定性
安全性
accelerating rate calorimeter
Li-ion battery
thermal stability
safety
