中国物理B ›› 2024, Vol. 33 ›› Issue (5): 58202-058202.doi: 10.1088/1674-1056/ad3036

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Accurate estimation of Li/Ni mixing degree of lithium nickel oxide cathode materials

Penghao Chen(陈鹏浩)1,2,3, Lei Xu(徐磊)1,3,†, Xiqian Yu(禹习谦)1,2,3,‡, and Hong Li(李泓)1,2,3   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Beijing Frontier Research Center on Clean Energy, Huairou Division, Institute of Physics, Chinese Academy of Sciences, Beijing 101400, China
  • 收稿日期:2023-12-31 修回日期:2024-02-15 接受日期:2024-03-05 出版日期:2024-05-20 发布日期:2024-05-20
  • 通讯作者: Lei Xu, Xiqian Yu E-mail:leixu@iphy.ac.cn;xyu@iphy.ac.cn
  • 基金资助:
    Project supported by the Natural Science Foundation of Beijing (Grant No. Z200013), the Beijing Municipal Science & Technology (Grant No. Z191100004719001), and the National Natural Science Foundation of China (Grant Nos. 52325207 and 22005333).

Accurate estimation of Li/Ni mixing degree of lithium nickel oxide cathode materials

Penghao Chen(陈鹏浩)1,2,3, Lei Xu(徐磊)1,3,†, Xiqian Yu(禹习谦)1,2,3,‡, and Hong Li(李泓)1,2,3   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Beijing Frontier Research Center on Clean Energy, Huairou Division, Institute of Physics, Chinese Academy of Sciences, Beijing 101400, China
  • Received:2023-12-31 Revised:2024-02-15 Accepted:2024-03-05 Online:2024-05-20 Published:2024-05-20
  • Contact: Lei Xu, Xiqian Yu E-mail:leixu@iphy.ac.cn;xyu@iphy.ac.cn
  • Supported by:
    Project supported by the Natural Science Foundation of Beijing (Grant No. Z200013), the Beijing Municipal Science & Technology (Grant No. Z191100004719001), and the National Natural Science Foundation of China (Grant Nos. 52325207 and 22005333).

摘要: Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode materials. However, accurately measuring the Li/Ni mixing degree is difficult due to the preferred orientation of lab-based XRD measurements using Bragg-Brentano geometry. Here, we find that employing spherical harmonics in Rietveld refinement to eliminate the preferred orientation can significantly decrease the measurement error of the Li/Ni mixing ratio. The Li/Ni mixing ratio obtained from Rietveld refinement with spherical harmonics shows a strong correlation with discharge capacity, which means the electrochemical capacity of lithium nickel oxide and high-nickel ternary cathode can be estimated by the Li/Ni mixing degree. Our findings provide a simple and accurate method to estimate the Li/Ni mixing degree, which is valuable to the structural analysis and screening of the synthesis conditions of lithium nickel oxide and high-nickel ternary cathode materials.

关键词: lithium nickel oxide, high-nickel ternary cathode, Li/Ni mixing, spherical harmonics function, discharge capacity

Abstract: Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode materials. However, accurately measuring the Li/Ni mixing degree is difficult due to the preferred orientation of lab-based XRD measurements using Bragg-Brentano geometry. Here, we find that employing spherical harmonics in Rietveld refinement to eliminate the preferred orientation can significantly decrease the measurement error of the Li/Ni mixing ratio. The Li/Ni mixing ratio obtained from Rietveld refinement with spherical harmonics shows a strong correlation with discharge capacity, which means the electrochemical capacity of lithium nickel oxide and high-nickel ternary cathode can be estimated by the Li/Ni mixing degree. Our findings provide a simple and accurate method to estimate the Li/Ni mixing degree, which is valuable to the structural analysis and screening of the synthesis conditions of lithium nickel oxide and high-nickel ternary cathode materials.

Key words: lithium nickel oxide, high-nickel ternary cathode, Li/Ni mixing, spherical harmonics function, discharge capacity

中图分类号:  (Lithium-ion batteries)

  • 82.47.Aa
82.45.Fk (Electrodes)