In this paper, a wet chemical method is used to coat LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode material by Li₂O-2B₂O₃ (LBO) layer for Lithium-ion batteries (LIBs). For performance optimization, the effects of different contents (thicknesses) of LBO coating layers on NCM811 particle surface on the morphologies, structures, compositions, and electrochemical properties of the corresponding LIBs are studied using XRD, SEM, TEM, and electrochemical measurements. Coin LIBs are assembled with such coated NCM811 cathode materials for performance validation. Results show that LBO coating layer does not change the original lattice structure of the bulk material, it can only adhere to the surface of the bulk material. After coating, NCM811 shows a good crystallinity and the ordered layered structure. TEM images show that the thickness of LBO coating is increased with increasing LBO content, and that the appropriate LBO coating thickness and uniform coating state are conducive to the improvement of the electrochemical properties of NCM811 cathode materials. Particularly, NCM811 with LBO coating content of 1000 ppm shows the best performance compared to other coating contents. In this case, the coating thickness is relatively uniform, which is about 40～100 nm, giving a good first charge-discharge capacity of 214.1mAh/g, and a high Coulomb efficiency of 90.06%. After 50 cycles, the capacity retention rate of LIBs still keeps as high as 99.64%. Therefore, LBO coating can improve the performance of NCM811 and then the lithium-ion batteries.

本文采用湿化学法通过Li ₂ O-2B ₂ O ₃涂覆正极材料LiNi _0.8 Co _0.1 Mn _0.1 O ₂（NCM811）。锂离子电池（LIB）的（LBO）层。为了优化性能，使用XRD，SEM，TEM和电化学测量研究了NCM811颗粒表面上LBO涂层的不同含量（厚度）对相应LIB的形态，结构，组成和电化学性质的影响。硬币型LIB与此类涂覆的NCM811阴极材料组装在一起以进行性能验证。结果表明，LBO涂层不会改变散装材料的原始晶格结构，它只能粘附到散装材料的表面。涂覆后，NCM811显示出良好的结晶度和有序的分层结构。TEM图像显示LBO涂层的厚度随LBO含量的增加而增加，适当的LBO涂层厚度和均匀的涂层状态有利于改善NCM811正极材料的电化学性能。特别是，LBO涂层含量为1000 ppm的NCM811与其他涂层含量相比，表现出最好的性能。在这种情况下，涂层厚度相对均匀，约为40〜100 nm，具有良好的首次充放电容量214.1mAh / g，库仑效率高达90.06％。经过50个循环后，LIB的容量保持率仍保持高达99.64％。因此，LBO涂层可以改善NCM811的性能，进而改善锂离子电池的性能。LBO涂层含量为1000 ppm的NCM811与其他涂层含量相比表现出最佳性能。在这种情况下，涂层厚度相对均匀，约为40〜100 nm，具有良好的首次充放电容量214.1mAh / g，库仑效率高达90.06％。经过50个循环后，LIB的容量保持率仍保持高达99.64％。因此，LBO涂层可以改善NCM811的性能，进而可以改善锂离子电池的性能。LBO涂层含量为1000 ppm的NCM811与其他涂层含量相比表现出最佳性能。在这种情况下，涂层厚度相对均匀，约为40〜100 nm，具有良好的首次充放电容量214.1mAh / g，库仑效率高达90.06％。经过50个循环后，LIB的容量保持率仍保持高达99.64％。因此，LBO涂层可以改善NCM811的性能，进而可以改善锂离子电池的性能。