Shevtsov Andrey, Han Haixiang, Morozov Anatolii, Carozza Jesse C, Savina Aleksandra A, Shakhova Iaroslava, Khasanova Nellie R, Antipov Evgeny V, Dikarev Evgeny V, Abakumov Artem M
Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Nobel str. 3, 143026 Moscow, Russia.
Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
Nanomaterials (Basel). 2020 Sep 18;10(9):1870. doi: 10.3390/nano10091870.
The LiNiMnCoO Li-rich NMC positive electrode (cathode) for lithium-ion batteries has been coated with nanocrystals of the LiMnCoO high-voltage spinel cathode material. The coating was applied through a single-source precursor approach by a deposition of the molecular precursor LiMnCo(thd) (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) dissolved in diethyl ether, followed by thermal decomposition at 400 °C inair resulting in a chemically homogeneous cubic spinel. The structure and chemical composition of the coatings, deposited on the model SiO spheres and Li-rich NMC crystallites, were analyzed using powder X-ray diffraction, electron diffraction, high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy-dispersive X-ray (EDX) mapping. The coated material containing 12 wt.% of spinel demonstrates a significantly improved first cycle Coulombic efficiency of 92% with a high first cycle discharge capacity of 290 mAhg. The coating also improves the capacity and voltage retention monitored over 25 galvanostatic charge-discharge cycles, although a complete suppression of the capacity and voltage fade is not achieved.
用于锂离子电池的富锂NMC正极（阴极）LiNiMnCoO已涂覆有LiMnCoO高压尖晶石阴极材料的纳米晶体。通过单源前驱体方法进行涂覆，即将溶解在乙醚中的分子前驱体LiMnCo(thd)（thd = 2,2,6,6-四甲基-3,5-庚二酮酸酯）进行沉积，然后在400℃空气中热分解，得到化学均匀的立方尖晶石。使用粉末X射线衍射、电子衍射、高角度环形暗场扫描透射电子显微镜（HAADF-STEM）和能量色散X射线（EDX）映射分析了沉积在模型SiO球和富锂NMC微晶上的涂层的结构和化学成分。含有12 wt.%尖晶石的涂覆材料显示出显著提高的首次循环库仑效率，达到92%，首次循环放电容量高达290 mAhg。尽管没有完全抑制容量和电压衰减，但涂层也改善了在25次恒电流充放电循环中监测到的容量和电压保持率。
