CAJ | 학술논문

采用溶胶?凝胶法合成锂离子电池正极材料 Li1.2(Mn0.54Ni0.16Co0.08)O2，并用AlF3对这种材料进行表面包覆改性。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨率透射电子显微镜(HRTEM)等表征材料的结构和形貌。结果表明，合成的 Li1.2(Mn0.54Ni0.16Co0.08)O2具有典型的层状α-NaFeO2结构， AlF3均匀包覆在Li1.2(Mn0.54Ni0.16Co0.08)O2材料表面，包覆层厚度为5~7 nm。电化学测试表明，包覆AlF3后材料的电化学性能得到提高，在1C倍率下，包覆的AlF3材料的首次放电容量为208.2 mA·h/g，50次循环后容量保持率为72.4%，而未包覆AlF3的材料的首次放电容量和容量保持率分别为191.7 mA·h/g和51.6%。
채용용효?응효법합성리리자전지정겁재료 Li1.2(Mn0.54Ni0.16Co0.08)O2，병용AlF3대저충재료진행표면포복개성。채용X사선연사(XRD)、소묘전자현미경(SEM)、고분변솔투사전자현미경(HRTEM)등표정재료적결구화형모。결과표명，합성적 Li1.2(Mn0.54Ni0.16Co0.08)O2구유전형적층상α-NaFeO2결구， AlF3균균포복재Li1.2(Mn0.54Ni0.16Co0.08)O2재료표면，포복층후도위5~7 nm。전화학측시표명，포복AlF3후재료적전화학성능득도제고，재1C배솔하，포복적AlF3재료적수차방전용량위208.2 mA·h/g，50차순배후용량보지솔위72.4%，이미포복AlF3적재료적수차방전용량화용량보지솔분별위191.7 mA·h/g화51.6%。
Li-rich layered transitional metal oxide Li1.2(Mn0.54Ni0.16Co0.08)O2 was prepared by sol?gel method and further modified by AlF3 coating via a wet process. The bare and AlF3-coated Li1.2(Mn0.54Ni0.16Co0.08)O2 samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and high resolution transmission electron microscope (HRTEM). XRD results show that the bare and AlF3-coated samples have typical hexagonalα-NaFeO2 structure, and AlF3-coated layer does not affect the crystal structure of the bare Li1.2(Mn0.54Ni0.16Co0.08)O2. Morphology measurements present that the AlF3layer with a thickness of 5?7 nm is coated on the surface of the Li1.2(Mn0.54Ni0.16Co0.08)O2 particles.Galvanostatic charge?discharge tests at various rates show that the AlF3-coated Li1.2(Mn0.54Ni0.16Co0.08)O2 has an enhanced electrochemical performance compared with the bare sample. At 1C rate, it delivers an initial discharge capacity of 208.2 mA·h/g and a capacity retention of 72.4% after 50 cycles, while those of the bare Li1.2(Mn0.54Ni0.16Co0.08)O2 are 191.7 mA·h/g and 51.6 %, respectively.