熔融盐法合成高密度锂离子电池正极材料LiNi0.8Co0.2-xAlxO2

Preparation of High-Density LiNi0.8Co0.2-xAlxO2 as Cathode Material for Lithium Ion Battery by Molten Salt Method

摘要:

利用低共熔组成的0.38LiOH-0.62LiNO3混合锂盐体系，与高密度前驱体Ni0.8Co0.2-xAlx(OH)2(0≤x≤0.15)在低温下自混合，无需前期研磨和后续洗涤，直接制备出高密度Co-Al共掺杂的锂离子电池正极材料LiNi0.8Co0.2-xAlxO2(0≤x≤0.15)。X射线衍射分析结果表明，合成的LiNi0.8Co0.2-xAlxO2具有规整的层状α-NaFeO2结构。扫描电镜显示产物颗粒均匀，LiNi0.8Co0.15Al0.05O2的振实密度达2.97 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，LiNi0.8Co0.15Al0.05O2首次放电比容量达167.5 mAh·g-1，且具有良好的循环性能

Abstract:

Co-Al co-doped cathode material LiNi0.8Co0.2-xAlxO2 (0≤x≤0.15) was directly synthesized without artificial grinding and washing by a eutectic molten-salt mixture (0.38LiOH-0.62LiNO3) method. According to this method, the eutectic molten-salt mixture was self-mixed with high tap density precursor Ni0.8Co0.2-xAlx(OH)2 thoroughly at low temperature and then sintered at a certain temperature. The tap-density of LiNi0.8Co0.15Al0.05O2 obtained is 2.97 g·cm-3. According to XRD and SEM, these LiNi0.8Co0.2-x AlxO2 materials have an order α-NaFeO2 layer structure and regular morphology. The charge-discharge tests show that the LiNi0.8Co0.15Al0.05O2 has an initial discharge capacity as high as 167.5 mAh·g-1 and excellent capacity retention in the range from 3.0 V to 4.3 V at a specific current of 0.2 C.