The effect of Al₂O₃ on the cycle performance of 1 Ah-class LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811)/graphite lithium-ion cells was studied by exploiting STEM-EELS analysis. Al₂O₃ was coated on NCM811 particles by a mechanochemical process with the coating from 0.5 to 3 wt%. All cells with the Al₂O₃-coated NCM811 cathode demonstrated better cycle performance than that with bare NCM811 independent of the coating amount. Analysis by STEM-EELS for the cells after 200 cycles revealed that the 3 wt%- Al₂O₃-coated NCM811 cathode had a solid solution layer of Al and NCM and also AlF₃ on the surface of NCM particles. Moreover, the Al₂O₃-coated NCM811 cathode showed suppression of the growth of NiO-like layer on the Ni-based cathode material surface to degrade the cell performance. It is, therefore, concluded that the cycle performance was improved mainly by the solid solution and AlF₃ layers to suppress the growth of the surface deposit and NiO-like layer formed by the reaction between NCM and electrolyte solution.

利用STEM-EELS分析研究了Al ₂ O ₃对1 Ah级LiNi _0.8 Co _0.1 Mn _0.1 O ₂（NCM811）/石墨锂离子电池循环性能的影响。通过机械化学方法将Al ₂ O ₃涂覆在NCM811颗粒上，涂层的含量为0.5至3wt％。独立于涂覆量，所有带有Al ₂ O ₃涂层的NCM811阴极的电池都比具有裸露的NCM811的电池具有更好的循环性能。在200个循环后通过STEM-EELS对细胞进行分析，结果表明3 wt％-Al ₂ O ₃涂覆的NCM811阴极在NCM颗粒的表面上具有Al和NCM以及AlF ₃的固溶体层。此外，涂覆有Al ₂ O ₃的NCM811阴极抑制了Ni基阴极材料表面上的NiO状层的生长，从而降低了电池性能。因此，可以得出结论，主要是通过固溶体和AlF ₃层来改善循环性能，从而抑制了由NCM和电解质溶液之间的反应形成的表面沉积物和NiO状层的生长。