储能科学与技术 ›› 2022, Vol. 11 ›› Issue (6): 1806-1815.doi: 10.19799/j.cnki.2095-4239.2021.0562

• 化工与储能专刊 • 上一篇    下一篇

软包锂离子电池真空环境下循环性能特性

刘杭鑫1,2(), 陈现涛1,2(), 孙强1,2, 赵晨曦1,2   

  1. 1.中国民用航空飞行学院民机火灾与安全工程四川省重点实验室
    2.民航安全工程学院,四川 广汉 618307
  • 收稿日期:2021-10-26 修回日期:2021-11-29 出版日期:2022-06-05 发布日期:2022-06-13
  • 通讯作者: 陈现涛 E-mail:hangxinliu@163.com;chenxiantao@ cafuc.edu.cn
  • 作者简介:刘杭鑫(1998—),男,硕士研究生,从事机载锂电池适航安全技术与锂电池热安全等方面研究,E-mail: hangxinliu@163.com
  • 基金资助:
    国家重点研发计划项目(2018YFC0809500);民用航空火灾科学省部级重点实验室建设项目(14002600100018J028)

Cycle performance characteristics of soft pack lithium-ion batteries under vacuum environment

LIU Hangxin1,2(), CHEN Xiantao1,2(), SUN Qiang1,2, ZHAO Chenxi1,2   

  1. 1.Sichuan Provincial Key Laboratory of Civil Aircraft Fire and Safety Engineering, Civil Aviation Flight Academy of China
    2.Civil Aviation Safety Engineering College, Guanghan 618307, Sichuan, China
  • Received:2021-10-26 Revised:2021-11-29 Online:2022-06-05 Published:2022-06-13
  • Contact: CHEN Xiantao E-mail:hangxinliu@163.com;chenxiantao@ cafuc.edu.cn

摘要:

为研究飞行器和轨道空间站等低气压真空环境下,锂离子电池的循环安全性能。实验采用商用Li(NiCoMn)O2软包锂电池,在球舱近似真空压力下,进行0.5 C倍率循环充放电实验,并与常压环境下进行对比分析。研究发现:真空循环后,电池出现严重的大面积不可恢复形变和褶皱且厚度增加。随着循环次数增加,容量加速衰减,循环10次后容量低于80 %。但恢复常压后,出现少部分容量的恢复;真空下扩大了充放电过程中的膨胀与收缩效应,加速了容量的衰减同时也造成部分容量的假性损失;电池周期性升温和降温速率加快,周期内温度不均匀性加剧,最大温差可达12.9 ℃,充放电的热稳定性和安全性变差,同时潜在的热灾害危害性变大。通过微分容量分析发现,低压真空环境下,所产生的活性锂的损耗和电极材料结构的损伤是降低电池循环充放性能的重要因素。

关键词: 软包锂离子电池, 真空环境, 循环安全性能, 不可逆形变, 容量衰减, 热稳定性

Abstract:

To investigate the cycle safety performance of batteries under low-pressure conditions, such as those found on the space station, aircrafts were used. The pouch batteries Li(NiCoMn)O2 were cycled at 0.5 ℃ at a pressure of 0 kPa in a low-pressure cabin. After the experiment, the cycle characteristics changed greatly compared with the standard pressure environment. With the increase in cycles, severe large-scale areas of unrecoverable deformation occurred on the batteries, and the thickness increased. Furthermore, the capacity decreased rapidly, and it was >80% after 10 cycles. However, when the pressure is increased from 0 kPa to 95 kPa, a small portion of the cycle capacity is recovered. Under vacuum pressure, the processes of expansion and contraction within the battery during charging and discharging are accelerated. It hastens capacity attenuation and causes false loss of some capacity due to massive internal and external pressures. Besides, the battery periodic heating and cooling accelerates, and the temperature inhomogeneity deteriorates within the cycle. Therefore, the maximum temperature difference between the charge and the discharge is 12.9 ℃. Obviously, the battery's thermal stability and safety deteriorate, whereas the potential thermal hazard during charging and discharging increases under low-pressure conditions. Capacity differential analysis demonstrates that the loss of active lithium and the destruction of the electrode material structure are essential factors that decrease the cyclic charging and discharging performance of the battery in a low-pressure vacuum environment.

Key words: soft pack lithium-ion battery, vacuum pressure condition, cycle safety performance, irreversible deformation, capacity attenuation, thermal stability

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