Study on the electrochemical performance of TiO2 coating on high nickel NCM811
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摘要: 高镍材料具有较好的电化学性能，但其存在着表面稳定性较差的问题，通过钛酸四丁酯在NCM811材料表面水解生成TiO2，改善了高镍材料的表面稳定性。利用SEM和TEM对改性后的材料进行表面分析，结果表明，实验成功将TiO2层均匀地包覆在高镍NCM811表面，并且发现，在表面包覆过程中，还发生了体相掺杂。利用表面包覆和体相掺杂的共同作用，在1C放电的条件下，循环200圈后，材料的容量保持率从81.40%提升至92.39%，改善了材料的电化学性能。Abstract: High nickel materials have good electrochemical performance, but there is a problem of poor surface stability. In this study, tetrabutyl titanate was hydrolyzed on the surface of NCM811 material to generate TiO2. SEM and TEM analysis results indicate that the TiO2 layer can be uniformly coated on the surface of high nickel NCM811 using the proposed method. By utilizing the combined effect of surface coating and bulk doping, the capacity retention rate of the material increased from 81.40% to 92.39% after 200 cycles under 1C discharge condition, and the electrochemical performance of NCM811 material was improved.
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Key words:
- high nickel material /
- ternary material /
- surface coating /
- titania /
- cyclic performance
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图 1 NCM811包覆TiO2的制备方法图示
Figure 1. Preparation method diagram of NCM811 coated with TiO2
图 2 不同量钛酸四丁酯涂层产品的SEM图像
Figure 2. SEM images of coated products with different amounts of tetrabutyl titanate
图 4 NCM被TiO2包覆前后的SEM图对比
Figure 4. Comparison of SEM images of NCM before and after TiO2 coating
图 5 NCM被TiO2包覆前后TEM图对比
Figure 5. Comparison of TEM images of NCM before and after TiO2 coating
图 6 NCM811原始样和 TiO2包覆后样品的XRD图谱
Figure 6. XRD patterns of NCM811 original sample and TiO2 coated sample
图 7 NCM811与T-NCM811的C80测试热流曲线
Figure 7. C80 test heat flow curve of NCM811 and T-NCM811
图 8 NCM811和T-NCM811在不同循环下的充放电分布。
Figure 8. Charge and discharge distribution of NCM811and T-NCM811 under different cycles
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