锂离子电池安全性实验研究

Experiment Research on Safety Characteristics of Lithium-ion Batteries

为研究锂离子电池受到穿刺时的安全性,针对3种典型18650型锂离子电池(1种为钴酸锂正极,2种为三元锂正极)开展不同正极材料和能量密度的锂离子电池穿刺实验,从表面温度、温升速率、侧壁破裂程度等3个方面分析其安全性。研究表明:钴酸锂比三元锂离子电池热失控温升速率快,最高表面温度高,侧壁破裂的风险小;高能量密度的锂离子电池较低能量密度的锂离子电池穿刺热失控的荷电状态阀值低,温升速率快;对于锂离子电池的正极材料来说,能量密度对锂离子电池的安全性影响更大。

In order to study the safety performance of lithium-ion batteries when punctured,aiming at three types of typical 18650 lithium-ion batteries,one of which is a lithium cobalt oxide cathode and two of which are ternary material cathodes,the puncture experiments of lithium-ion batteries with different cathode materials and different energy density were carried out,and the safety performance of lithium-ion batteries was analyzed from three aspects of surface temperature,temperature rise rate,and side wall rupture degree.The results show that lithium cobalt oxide batteries have a faster rate of the thermal runaway temperature rise,a higher maximum surface temperature,and a lower risk of the sidewall rupture than those of ternary lithium-ion batteries;that the SOC threshold of the puncture thermal runaway of lithium-ion batteries with a high-energy-density is lower than that of lithium-ion batteries with a low-energy-density,while the temperature rise rate is faster;and that the energy density has a greater impact on the safety performance of lithium-ion batteries for anode materials of lithium-ion batteries.