储能科学与技术 ›› 2020, Vol. 9 ›› Issue (3): 964-968.doi: 10.19799/j.cnki.2095-4239.2019.0257

• 储能测试与评价 • 上一篇    下一篇

高电压锂离子电池间歇式循环失效分析及改善

孔令丽(), 张克军, 蔡嘉兴, 李福轩   

  1. 天津力神电池股份有限公司，天津 300384
  • 收稿日期:2019-11-11 修回日期:2020-01-03 出版日期:2020-05-05 发布日期:2020-05-11
  • 作者简介:孔令丽（1978—），女，高级工程师，研究方向为锂离子电池，E-mail：kong_lingli@lishen.com。

Analysis and improvement of interval cycle life for high voltage lithium ion batteries

KONG Lingli(), ZHANG Kejun, CAI Jiaxing, LI Fuxuan   

  1. Tianjin Lishen Battery Joint-stock Co. Ltd, Tianjin 300384, China
  • Received:2019-11-11 Revised:2020-01-03 Online:2020-05-05 Published:2020-05-11

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摘要：

本工作通过对比45 ℃间歇式高温循环、45 ℃高温循环和45 ℃存储性能的关系和差异，分析了高电压体系电池间歇式循环的失效原因。研究发现在高温间歇式循环过程中，正极材料发生相变，金属元素溶出，同时释放O2造成电解液的氧化分解:高温高电压状态下正负极CEI膜和SEI膜都会发生重整和修复反应，造成阻抗的增加和循环容量衰减加速。改善正极材料的结构稳定性、稳定正负极界面，可以明显改善电池的高温间歇式循环性能。

关键词: 锂离子电池, 高电压, 间歇式循环, 高温, 胀气

Abstract:

This study analyzes the causes of failure of the interval cycle of a high-voltage system. To this end, it compares the relationships among the interval cycle, high-temperature cycle, and storage performance at 45 ℃. During the high-temperature interval cycle, the cathode material structure is destroyed and the metal element dissolves, releasing O2 that oxidizes and decomposes the electrolyte. The cathode electrolyte interphase and solid electrolyte interface films in the high-temperature and high-voltage state are recombined and repaired, which increases the impedance and accelerates the cycle capacity attenuation. The cell interval cycle life at high temperatures can be obviously increased by improving the structural stability of the cathode material and the cathodeanode interface.

Key words: lithium ion battery, high voltage, interval cycle, high temperature, gassing

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