熔融盐法合成高密度锂离子电池正极材料LiNi0.8Co0.2-xTixO2

Preparation of High Density LiNi0.8Co0.2-xTixO2 as Cathode Material for Lithium Ion Battery by a Molten Salt Method

摘要:

利用具有低共熔组成的LiOH-LiNO3混合锂盐体系，与高密度前驱体掺杂Co的Ni(OH)2，TiO2粉末混合，经3阶段温度烧结制备出高密度Co-Ti共掺杂的锂离子电池正极材料LiNi0.8Co0.2-xTixO2（0≤x≤0.1）。XRD分析表明，合成的LiNi0.8Co0.2-xTixO2具有规整的层状α-NaFeO2结构。LiNi0.8Co0.2-xTixO2颗粒均匀，平均粒度为1~5 μm，随掺Ti量的增加而减小，LiNi0.8Co0.15Ti 0.05O2的振实密度达3.17 g·cm-3。电性能测试表明，在0.2 C放电倍率和3.0~4.3 V的电压范围内，LiNi0.8Co0.15Ti0.05O2首次放电比容量达169 mAh·g-1，且具有良好的循环性能和高倍率放电性能。

Abstract:

Co-Ti co-doped cathode material LiNi0.8Co0.2-xTixO2 (0≤x≤0.1) with a high tamping-density for Li ion battery was prepared by a molten-salt synthesis method using eutectic molten salt 0.62LiNO3-0.38LiOH, high-density precursor Co-doped Ni(OH)2 and TiO2 powder. X-ray diffraction analysis shows that the synthesized material has a well-developed layered α-NaFeO2 structure. LiNi0.8Co0.2-xTixO2 has homogeneous particles with average sizes of 1-5 μm and the particles become smaller with Ti content increasing. The tamping-density of LiNi0.8Co0.15Ti0.05O2 reaches to 3.17 g·cm-3. Charge-discharge tests show that LiNi0.8Co0.15Ti0.05O2 has an initial discharge capacity as high as 169 mAh·g-1 and excellent capacity retention in the range 3.0-4.3 V at a specific current of 0.2 C.