储能科学与技术 ›› 2020, Vol. 9 ›› Issue (3): 813-817.doi: 10.19799/j.cnki.2095-4239.2019.0239

• 储能材料与器件 • 上一篇    下一篇

高镍三元锂离子电池循环衰减分析及改善

张欣(), 孔令丽, 高腾跃, 李海涛, 姚晓辉, 李福轩   

  1. 天津力神电池股份有限公司，天津 300384
  • 收稿日期:2019-10-23 修回日期:2019-10-28 出版日期:2020-05-05 发布日期:2019-11-04
  • 作者简介:张欣（1985—），女，硕士，主要从事锂离子动力软包电池体系研发，E-mail：in@lishen.com.cn。

Analysis and improvement of cycle performance for Ni-rich lithium ion battery

ZHANG Xin(), KONG Lingli, GAO Tengyue, LI Haitao, YAO Xiaohui, LI Fuxuan   

  1. Tianjin Lishen Battery Joint-Stock Co. Ltd, Tianjin 300384, China
  • Received:2019-10-23 Revised:2019-10-28 Online:2020-05-05 Published:2019-11-04

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摘要：

本文针对NCM811/石墨体系电池高温循环衰减快的问题，通过XRD、SEM、ICP等手段系统分析了循环前后电池材料的结构和形貌变化。结果表明，高温循环后正极材料Li/Ni离子混排度增加，层状结构受到破坏，二次颗粒内部开裂、粉化，导致电解液消耗、内阻增加，是导致电池循环性能衰减的主要因素。通过对正极材料进行掺杂改性，高温循环性能得到显著提升，45 ℃循环1000次，容量保持率87%。

关键词: 高镍三元, 高温循环, 衰减机理, 金属溶出

Abstract:

To investigate the fast-decay problem of Li(Ni0.8Co0.1Mn0.1)O2/graphite system cells in high-temperature cycling, the structures and morphologies of the cathode and anode were systematically analyzed in fresh and cycled cells. The characterizations were performed by X-ray diffraction, scanning electron microscopy, and inductively coupled plasma spectroscopy. After cycling, the Li/Ni cation mixing degree increased and the cathode materials cracked from the inside (even pulverized at 45 ℃). These processes reduced both the electrolyte consumption and internal resistance of the cell and hence degraded the cycling performance. After doping the cathode material, the high-temperature cycling performance can be significantly improved, with a capacity retention of 87% after 1000 cycles at 45 ℃.

Key words: Ni-rich cathode, high temperature cycle performance, failure mechanism, metal dissolution

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