【摘要】 采用溶胶-凝胶法合成正极材料层状Li1.1[Ni1/3Co1/3Mn(1/3-x)Mgx]O2-yFy(0≤x≤0.04,0≤y≤0.04)。通过原子吸收光谱(AAS)、X射线衍射(XRD)、扫描电镜(SEM)和电化学测试等手段研究了掺杂元素对材料结构和电化学性能的影响。结果表明,镁氟掺杂后的样品具有单相的典型六方晶系结构,合成材料颗粒分布比较均匀。在充放电倍率为0.1 C和电压范围为3.0￣4.3 V的条件下,与未掺杂样品相比,Li1.1[Ni1/3Co1/3Mn(1/3-0.04)Mg0.04]O2-0.04F0.04具有较高的放电比容量和容量保持率。其首次放电比容量和库仑效率分别为158 mAh/g和91.3%,20个循环后容量保持率达92.1%。Li1.1[Ni1/3Co1/3Mn(1/3-0.04)Mg0.04]O2-0.04F0.04是一种有前景的锂离子电池新型正极材料。更多还原

【Abstract】 The cathode-active materials layered Li1.1[Ni1/3Co1/3Mn(1/3-x)Mgx]O2-yFy(0≤x≤0.04,0≤y≤0.04) were synthesized by sol-gel method.The influence of doping elements on the structural and electrochemical properties of the as-prepared samples was investigated by atomic absorption spectroscopy(AAS),X-ray diffraction(XRD),scanning electron microscope(SEM) and electrochemical experiments.The studies showed that as-prepared materials have a typical hexagonal structure with a single phase,the particle sizes of the samples are distributed uniformly.Li1.1-[Ni1/3Co1/3Mn(1/3-0.04)Mg0.04]O2-0.04F0.04 shows an improved cathodic behavior and discharge capacity retention compared to Li1.1(Ni1/3Co1/3Mn1/3)O2 at 0.1 C rate in the voltage range of 3.0-4.3V.The Li1.1[Ni1/3Co1/3Mn(1/3-0.04)Mg0.04]O2-0.04F0.04 electrode delivered an initial discharge capacity of 158 mAh/g during the first charge and discharge cycle and the first coulombic efficiency was 91.3 %,and the capacity retention at the 20th cycle was 92.1 %.The outstanding electrochemical properties of Li1.1[Ni1/3Co1/3Mn(1/3-0.04)Mg0.04]O2-0.04F0.04 make it a promising cathode material for lithiumion batteries.更多还原