球形Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_2的合成及性能研究

Synthesis and electrochemical properties of Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_2 with spherical structure

采用氨配合氢氧化物共沉淀法合成了前驱体[Ni0.8Co0.1Mn0.1](OH)2,并对其合成工艺进行了研究。经过高温焙烧制备了锂离子电池正极材料Li[Ni0.8Co0.1Mn0.1]O2,研究了焙烧温度对其形貌及性能的影响。实验表明,水浴恒温50℃同时氮气保护下,控制溶液pH=11.0,氨水与金属盐浓度比为0.5:1,搅拌速度为800r/min时,能够合成出粒径均一、高振实密度的球形前驱体;在氧气气氛下,焙烧温度为800℃时,制备出球形形貌、粒径约为12μm的正极材料。其模拟电池在18mA/g的电流密度下首次放电比容量达到187.9mAh/g,循环20次容量保持率为90.0%。

The spherical Li[Ni0.8Co0.1Mn0.1]O2 powders were synthesized by heating the precursor [Ni0.8Co0.1Mn0.1]（OH）2 powders which were prepared via ammonia-hydroxide co-precipitation method.The optimized synthesis condition to obtain the precursor with a homogeneous particle size distribution and a high tap density was as following：50 ℃,pH=11.0,stirring speed=800 r/min,the concentration ratio of ammonia to metal-salt=0.5 and under N2 atmosphere.In addition,the spherical-shaped Li[Ni0.8Co0.1Mn0.1]O2 particles with diameter of 12μm were obtained after firing the precursor under O2 atmosphere.Electrochemical tests show that Li[Ni0.8Co0.1Mn0.1]O2 prepared by this method deliveres an initial specific discharge capacity of 187.9 mAh/g at the current density of 18 mA/g,with a capacity retention rate up to 90.0% after 20 cycles.