MgF2包覆对正极材料LiNi1/3Co1/3Mn1/3O2性能的影响

通过浸渍法在正极材料LiNi1/3Co1/3Mn1/3O2的表面包覆MgF2，通过XRD、SEM、交流阻抗（EIS）分析、充放电测试研究了不同量MgF2包覆对LiNi1/3Co1/3Mn1/3O2正极材料的结构与电化学性能的影响。结果表明，MgF2以非晶态形式包覆于LiNi1/3Co1/3Mn1/3O2材料颗粒的表面，当包覆量为3%（物质的量分数，下同）时，三元正极材料具有优良的电化学性能，在3.0~4.6 V充放电范围内0.1C充放电倍率下，首次放电比容量为196.3 mA·h/g，1C循环50次后容量保持率为95.7%，55 ℃高温下1C循环50次后容量保持率为93.3%。

Effect of MgF2-coating on performance of LiNi1/3Co1/3Mn1/3O2 cathode materials

MgF2-coated LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by impregnation method.The effects of amounts of MgF2 coating on the structure，morphology，and electrochemical properties of LiNi1/3Co1/3Mn1/3O2  were analyzed by XRD，SEM，charge-discharge tests，and electrochemical impedance spectra（EIS），respectively.Results showed that the uncrystalline MgF2 uniformly distributed on the surface of the LiNi1/3Co1/3Mn1/3O2  particles.The sample with 3%（amount-of-substance frac- tion，same below） MgF2 coating showed excellent electrochemical properties.Between 3.0~4.6 V，at 0.1C，the sample of above-mentioned exhibited a initial discharge capacity of 196.3 mA·h/g.At 1C，it maintained 95.7% of the initial capacity af- ter 50 cycles，and 93.3% capacity retention after 50 cycles at 55 ℃.