Abstract:

Ni-rich ternary cathode material LiNi_0.8Co_0.1Mn_0.1O₂ for lithium-ion battery was synthesized by a high-temperature solid-state reaction method, and its process conditions were optimized. The structural and morphological features of LiNi_0.8Co_0.1Mn_0.1O₂ cathode material prepared were investigated with X-ray diffraction and scanning electron microscopy. Its electrochemical properties were analyzed. The results showed that under the oxygen atmosphere, the molar ratio of lithium to metal elements was 1.05:1, the sintering time was 15 h and the sintering temperature was 750℃, the optimal synthesis conditions were obtained. The initial discharge capacity of the sample was 174.9 mA·h·g^-1 at 1C, the specific capacity was 158.5 mA·h·g^-1 after 50 cycles, and the capacity retention rate was 90.62%, which showed good cycle stability. The results of XRD and SEM showed that the sample sintered in oxygen atmosphere had a good layered structure with a small degree of cationic mixing and a good spherical shape. The particles were uniformly distributed in the range of 10-20 μm. The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the electrochemical performance of the cathode materials was improved by optimization conditions.

Key words: LiNi_0.8Co_0.1Mn_0.1O₂, synthesis, high-temperature solid-state, electrochemistry, stability, lithium-ion battery

摘要：

采用高温固相法合成锂离子电池富镍三元材料LiNi_0.8Co_0.1Mn_0.1O₂，对其工艺条件进行优化，对产物进行X射线衍射（XRD（，扫描电镜（SEM（以及电化学性能分析。结果表明：在氧气气氛下，锂与金属元素摩尔比为1.05:1、烧结时间15 h、烧结温度750℃为最佳合成工艺条件。按最佳工艺合成的样品在1C首次放电容量高达174.9 mA·h·g^-1，50次循环后比容量为158.5 mA·h·g^-1，容量保持率为90.62%，表现出良好的循环稳定性。XRD和SEM表征表明，在氧气气氛下烧结的样品有良好的层状结构，阳离子混排程度小，具有较好的类球形，粒径均匀分布在10~20 μm。循环伏安（CV（和电化学阻抗（EIS（结果表明，工艺条件的优化有助于提高正极材料的电化学性能。

关键词: LiNi_0.8Co_0.1Mn_0.1O₂, 合成, 高温固相, 电化学, 稳定性, 锂离子电池