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<p>In order to improve the cycle and rate performance of high-nickel LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub>(NCM811) materials, a series of Ce<sup>3</sup>⁺-modified materials (LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1−<i>x</i></sub>Ce<sub><i>x</i></sub>O<sub>2</sub>, <i>x</i> = 0, 1, 2, 5, 10%) were prepared via co-precipitation and high-temperature solid-state method. The influence of different doping amounts on structure, morphology, and electrochemical performance was systematically investigated. XRD and SEM characterizations indicate that Ce<sup>3</sup>⁺ was successfully incorporated into the lattice, inducing controlled lattice expansion and significantly increasing lithium-layer spacing (the<i> c</i>-axis parameter of LNCMCe5 increased from 14.190 to 14.253&#xa0;Å), while effectively suppressing cation mixing (the <i>I</i><sub>003</sub>/<i>I</i><sub>104</sub> ratio rose to 1.312). SEM morphology shows that appropriate doping promotes the formation of uniform, well-defined secondary particles. XPS analysis reveals that the mechanism stems from the “oxygen vacancy synergistic effect” induced by Ce<sup>3</sup>⁺ doping. Electrochemical tests demonstrate that the LNCMCe5 sample with optimal doping (5%) exhibits the best overall performance: It delivers the highest initial discharge capacity (192.5&#xa0;mAh g⁻<sup>1</sup>) at 0.1&#xa0;C, 4.9% higher than the undoped sample; at a high rate of 10&#xa0;C, the capacity retention is dramatically improved by 49.4%; after 150&#xa0;cycles at 0.5&#xa0;C, its capacity retention reaches 94.9%, significantly superior to the 91.1% of the undoped sample. Electrochemical impedance analysis confirms that the lithium-ion diffusion coefficient of the modified material is slightly enhanced (increased from 6.99 × 10<sup>−16</sup>&#xa0;cm<sup>2</sup>&#xa0;s⁻<sup>1</sup> of the undoped sample to 7.19 × 10<sup>−16</sup>&#xa0;cm<sup>2</sup>&#xa0;s⁻<sup>1</sup> of the 5% Ce-doped sample). This study verifies that appropriate Ce<sup>3</sup>⁺ doping effectively improves structural stability and electrochemical performance through multiple synergistic effects, including “enlarging lithium-layer spacing, suppressing cation mixing, and stabilizing grain boundaries.” The results provide theoretical support and practical guidance for the development of high-performance lithium-ion battery cathode materials.</p>

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Doping and Modification of Ce3⁺ on LiNi0.8Co0.1Mn0.1O2 Cathode Materials and Electrochemical Performance Study

  • 期刊论文

  • 发表日期：

    2026年7月30日

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  • Z. R. Zhao,
  • N. Chen,
  • Y. F. Xu,
  • T. Mu,
  • L. Q. Wang,
  • W. Zheng

摘要

In order to improve the cycle and rate performance of high-nickel LiNi0.8Co0.1Mn0.1O2(NCM811) materials, a series of Ce3⁺-modified materials (LiNi0.8Co0.1Mn0.1−xCexO2, x = 0, 1, 2, 5, 10%) were prepared via co-precipitation and high-temperature solid-state method. The influence of different doping amounts on structure, morphology, and electrochemical performance was systematically investigated. XRD and SEM characterizations indicate that Ce3⁺ was successfully incorporated into the lattice, inducing controlled lattice expansion and significantly increasing lithium-layer spacing (the c-axis parameter of LNCMCe5 increased from 14.190 to 14.253 Å), while effectively suppressing cation mixing (the I003/I104 ratio rose to 1.312). SEM morphology shows that appropriate doping promotes the formation of uniform, well-defined secondary particles. XPS analysis reveals that the mechanism stems from the “oxygen vacancy synergistic effect” induced by Ce3⁺ doping. Electrochemical tests demonstrate that the LNCMCe5 sample with optimal doping (5%) exhibits the best overall performance: It delivers the highest initial discharge capacity (192.5 mAh g⁻1) at 0.1 C, 4.9% higher than the undoped sample; at a high rate of 10 C, the capacity retention is dramatically improved by 49.4%; after 150 cycles at 0.5 C, its capacity retention reaches 94.9%, significantly superior to the 91.1% of the undoped sample. Electrochemical impedance analysis confirms that the lithium-ion diffusion coefficient of the modified material is slightly enhanced (increased from 6.99 × 10−16 cm2 s⁻1 of the undoped sample to 7.19 × 10−16 cm2 s⁻1 of the 5% Ce-doped sample). This study verifies that appropriate Ce3⁺ doping effectively improves structural stability and electrochemical performance through multiple synergistic effects, including “enlarging lithium-layer spacing, suppressing cation mixing, and stabilizing grain boundaries.” The results provide theoretical support and practical guidance for the development of high-performance lithium-ion battery cathode materials.