储能科学与技术 ›› 2018, Vol. 7 ›› Issue (3): 459-464.doi: 10.12028/j.issn.2095-4239.2018.0032

• 高比能量动力锂离子电池专刊 • 上一篇    下一篇

高比能NMC811/SiO-C软包电池循环失效分析

梁大宇, 包婷婷, 高田慧, 张健   

  1. 合肥国轩高科动力能源有限公司工程研究总院, 安徽 合肥 230011
  • 收稿日期:2018-03-05 修回日期:2018-04-03 出版日期:2018-05-01 发布日期:2018-05-01
  • 通讯作者: 梁大宇(1988-),男,工程师,研究方向为锂离子动力电池,E-mail:liangdayu@gotion.com.cn
  • 作者简介:梁大宇(1988-),男,工程师,研究方向为锂离子动力电池,E-mail:liangdayu@gotion.com.cn
  • 基金资助:
    国家重点研发计划项目（2016YFB010030）。

Analysis of cycling performance failure of NMC811/SiO-C pouch cells with high specific energy

LIANG Dayu, BAO Tingting, GAO Tianhui, ZHANG Jian   

  1. Institute of Engineering Research, Hefei Guoxuan High-tech Power Energy Co. Ltd., Hefei 230011, Anhui, China
  • Received:2018-03-05 Revised:2018-04-03 Online:2018-05-01 Published:2018-05-01

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摘要： NMC811/SiO-C电池由于电极材料克容量高，工作平台电压高成为实现高比能量密度的一个重要途径，然而在实际应用中其循环寿命差的问题一直难以解决。本工作通过电化学阻抗谱（EIS）、X射线衍射光谱、傅里叶红外变换光谱（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等多种分析表征手段对循环前后电极材料进行了表征测试与分析，系统研究了NMC811/SiO-C电池长期循环失效的原因，结果表明：NMC811正极材料在循环过程中结构保持完整，金属溶出现象轻微；而SiO-C负极材料在循环过程中膨胀粉化，并且不断消耗电解液和形成更厚的SEI膜，最终导致负极克容量衰减严重，是全电池常温循环性能很差的主要原因。

关键词: NMC811/SiO-C电池, 失效机理, 表征分析

Abstract: NMC811/SiO-C cell is one of the most potential battery systems with high specific capacity, however, it is difficult to improve its poor cycling performance in practical application. To analysis the cycling failure mechanism of NMC811/SiO-C cell, electrode characterizations have been carried out by electrochemical impedance spectroscopy (EIS), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM),transmission electron microscope (TEM). The result showed that NMC811 cathode material can keep stable crystal structure and yield dissolving of metal ions during cycling, while SiO-C anode material suffered from structure cracking and displayed increasing consumption of electrolyte as well as growing SEI layer thickness. The changes in electrodes cause the serious specific capacity degradation and the poor cycling performance of NMC811/SiO-C pouch cells.

Key words: NMC811/SiO-C, failure mechanism, characterization analysis

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