中国物理B ›› 2025, Vol. 34 ›› Issue (10): 108201-108201.doi: 10.1088/1674-1056/ae0436

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Oxygen activation-triggered thermal instability in Li(Ni0.8Co0.1Mn0.1)O2 cathode

Supeng Chen(陈苏鹏)1,†, Yingli Li(李英丽)1,†, Yande Li(李彦德)2,†, Keqiang Li(李克强)1, Peirong Li(李培荣)1, Jianwei Meng(孟建伟)3, Zilong Zhao(赵子龙)4,‡, Yuanyuan Pan(潘圆圆)1,§, Qinghao Li(李庆浩)1,¶, and Pengfei Yu(于鹏飞)3,#   

  1. 1 College of Physics, Qingdao University, Qingdao 266071, China;
    2 National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China;
    3 Center for Transformative Science, ShanghaiTech University, Shanghai 201210, China;
    4 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
  • 收稿日期:2025-08-03 修回日期:2025-08-28 接受日期:2025-09-08 出版日期:2025-09-25 发布日期:2025-10-24
  • 通讯作者: Zilong Zhao, Yuanyuan Pan, Qinghao Li, Pengfei Yu E-mail:zhaozl@sari.ac.cn;panyuanupc@126.com;qhli@qdu.edu.cn;yupf1@shanghaitech.edu.cn
  • 基金资助:
    This project was supported by the Science and Technology Commission of Shanghai Municipality (Grant No. 22560780300), the National Natural Science Foundation of China (Grant Nos. 22309097 and 52130202), the Shandong Provincial Natural Science Foundation (Grant Nos. 2023KJ228 and ZR2021QE061), the Youth Innovation Technology Project of Higher Education Institutions in Shandong Province (Grant No. 2022KJ139), and the Shanghai Soft X-ray Free-Electron Laser Facility beamline project. The authors thank beamline 20U (31124.02.SSRF.BL20U2) of SSRF and UXS of sXFEL for the XES measurements, and beamline BL02B (31124.02.SSRF.BL02B02) of SSRF for the sXAS measurements.

Oxygen activation-triggered thermal instability in Li(Ni0.8Co0.1Mn0.1)O2 cathode

Supeng Chen(陈苏鹏)1,†, Yingli Li(李英丽)1,†, Yande Li(李彦德)2,†, Keqiang Li(李克强)1, Peirong Li(李培荣)1, Jianwei Meng(孟建伟)3, Zilong Zhao(赵子龙)4,‡, Yuanyuan Pan(潘圆圆)1,§, Qinghao Li(李庆浩)1,¶, and Pengfei Yu(于鹏飞)3,#   

  1. 1 College of Physics, Qingdao University, Qingdao 266071, China;
    2 National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China;
    3 Center for Transformative Science, ShanghaiTech University, Shanghai 201210, China;
    4 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
  • Received:2025-08-03 Revised:2025-08-28 Accepted:2025-09-08 Online:2025-09-25 Published:2025-10-24
  • Contact: Zilong Zhao, Yuanyuan Pan, Qinghao Li, Pengfei Yu E-mail:zhaozl@sari.ac.cn;panyuanupc@126.com;qhli@qdu.edu.cn;yupf1@shanghaitech.edu.cn
  • Supported by:
    This project was supported by the Science and Technology Commission of Shanghai Municipality (Grant No. 22560780300), the National Natural Science Foundation of China (Grant Nos. 22309097 and 52130202), the Shandong Provincial Natural Science Foundation (Grant Nos. 2023KJ228 and ZR2021QE061), the Youth Innovation Technology Project of Higher Education Institutions in Shandong Province (Grant No. 2022KJ139), and the Shanghai Soft X-ray Free-Electron Laser Facility beamline project. The authors thank beamline 20U (31124.02.SSRF.BL20U2) of SSRF and UXS of sXFEL for the XES measurements, and beamline BL02B (31124.02.SSRF.BL02B02) of SSRF for the sXAS measurements.

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摘要： Ni-rich layered LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ (NCM811) is a leading cathode candidate for the next generation of lithium-ion batteries because of its high energy density. In practice, NCM811 exhibits poor thermal stability that can lead to thermal runaway, which is a critical bottleneck for the practical application of this promising material. The fundamental factors underlying thermal failure and the relationship between surface and bulk degradation, however, remain unclear. In this work, we track the evolution of the atomic and electronic structures of high-voltage delithiated NCM811 using x-ray diffraction (XRD), transmission electron microscopy (TEM), and synchrotron-based soft x-ray absorption spectroscopy (sXAS). Oxygen hole states formed upon delithiation are thermodynamically unstable and lead to O$_2$ release upon heating. This O$_2$ release occurs prior to phase transitions and therefore constitutes the primary cause of thermal failure in NCM811 cathodes. Although surface oxygen is inherently less stable, the presence of similar oxygen hole states at the surface and in the bulk causes surface and bulk degradation to proceed almost simultaneously. These findings delineate the degradation pathway of NCM811 during thermal runaway and provide rational guidelines for material design and optimization.

关键词: Ni-rich cathode, thermal decay, oxygen hole, soft x-ray spectroscopy

Abstract: Ni-rich layered LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ (NCM811) is a leading cathode candidate for the next generation of lithium-ion batteries because of its high energy density. In practice, NCM811 exhibits poor thermal stability that can lead to thermal runaway, which is a critical bottleneck for the practical application of this promising material. The fundamental factors underlying thermal failure and the relationship between surface and bulk degradation, however, remain unclear. In this work, we track the evolution of the atomic and electronic structures of high-voltage delithiated NCM811 using x-ray diffraction (XRD), transmission electron microscopy (TEM), and synchrotron-based soft x-ray absorption spectroscopy (sXAS). Oxygen hole states formed upon delithiation are thermodynamically unstable and lead to O$_2$ release upon heating. This O$_2$ release occurs prior to phase transitions and therefore constitutes the primary cause of thermal failure in NCM811 cathodes. Although surface oxygen is inherently less stable, the presence of similar oxygen hole states at the surface and in the bulk causes surface and bulk degradation to proceed almost simultaneously. These findings delineate the degradation pathway of NCM811 during thermal runaway and provide rational guidelines for material design and optimization.

Key words: Ni-rich cathode, thermal decay, oxygen hole, soft x-ray spectroscopy

中图分类号:  (Lithium-ion batteries)

  • 82.47.Aa
82.45.Fk (Electrodes) 78.70.Dm (X-ray absorption spectra) 68.60.Dv (Thermal stability; thermal effects)