通过控制结晶法制备高密度类球形Ni0.85Co0.06Mn0.06Al0.03(OH)2前驱体,与LiOH·H2O均匀混合后,在820 ℃于氧气气氛下进行高温煅烧,最终合成高压实富镍正极材料LiNi085Co0.06Mn0.06Al0.03O2.通过扫描电子显微镜(SEM)表征前驱体、正极材料及正极片的形貌;X射线衍射(XRD)表明材料具有良好的六方单相层状α-NaFeO2结构,能谱仪(EDS)分析表明材料颗粒中各组分含量呈均匀分布.制备的LiNi0.85Co0.06Mn0.06Al0.03O2正极材料具有良好的加工性能和很高的压实密度,极片压实密度达到了3.82 g·cm-3.以该极片组装的模拟电池具有良好的电化学性能,尤其具有优异的倍率性能,在电压区间2.8～4.3 V和0.2C电流密度充放电条件下,首次放电比容量为211.7 mAh· g-1,首次充放电效率88.9％,5C大倍率充放电条件下容量仍达到180.2 mAh·g-1,循环200周容量保持率为80.4％.%High density spherical precursor Ni0.85Co0.06Mn0.06Al0.03(OH)2 was obtained by controlled crystallization method.A uniform mixture of Ni0.85Co0.06Mn0.06Al0.03(OH)2 and LiOH· H2O was sintered under 820 ℃ in O2 atmosphere to synthesize Ni-rich layered LiNi0.85Co0.06Mn0.06Al0.03O2 cathode material with high compacted density.SEM was used to characterize the morphology of the precursor,cathode material and positive electrode disk.XRD showed that the product possessed a well-layered α-NaFeO2 structure.EDS spectra show the elements in the material are distributed evenly.The material prepared by high temperature sintering shows good processing performance andhigh compacted density of 3.82 g·cm-3.The cells with the material as cathode display excellent electro-chemical performance,especially rate capability:an initial discharge capacity of 211.7 mAh·g-1 at 0.2C between 2.8 and 4.3 V with an initial coulombic efficiency of 88.9％,a discharge capacity of 180.2 mAh·g-1 at 5C and a capacity retention rate of 80.4％ after 200 cycles.
展开▼
