高压实密度LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2正极材料的制备及性能  

Synthesis and properties of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2 cathode material with high compacted density

作　　者：陈漾[1,2] 唐朝辉[1,2] 熊学[1,2] 李碧平[1,2] 刘志立[1,2] 

机构地区：[1]湖南有色金属研究院,长沙410015 [2]湖南美特新材料科技有限公司,长沙410200

出　　处：《中国有色金属学报》2015年第12期3397-3403,共7页The Chinese Journal of Nonferrous Metals

摘　　要：将Ni_(0.5)Co_(0.2)Mn_(0.3)(OH)_2前驱体、碳酸锂与H_3BO_3按一定配比高效混合,采用固相烧结法制备高压实密度LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2粉体正极材料,探讨H_3BO_3添加量对正极材料物理性能、极片压实密度及电化学性能的影响。使用X射线衍射(XRD)和扫描电镜(SEM)表征材料的物理性能,将正极材料制作成软包装全电池,并对其电化学性能进行测试。结果表明:H_3BO_3具有助熔作用;能增加一次粉体正极材料颗粒的粒径,并提高颗粒致密度,对正极材料的晶体结构没有影响,但对正极材料粒径、pH、比表面积及振实密度等产生影响。将H_3BO_3添加量为0.6%(质量分数)时制备的LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2正极材料制成正极片后,其极限压实密度最高达到3.9 g/cm^3;与采用常规LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2正极材料制成的正极片(压实密度≤3.5 g/cm^3)相比,其体积能量密度提高约11.4%;0.5C首次放电比容量为153.64(mA·h)/g,1C循环首次放电比容量为152.22(mA.h)/g,100次循环容量保持率为96.99%,其综合电化学性能优于常规LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2正极材料的。LiNi（0.5）Co（0.2）Mn（0.3）O2 cathode material with high compacted density was synthesized through solid-state sintering method using LiNi（0.5）Co（0.2）Mn（0.3）O2 precursor,lithium carbonate and H3BO3 at a certain proportion as raw materials.The effects of H3BO3 addition on the physical properties,compacted density and electrochemical properties of the cathode material were studied.The physical properties were investigated by X-ray diffractometry（XRD） and scanning electron microscopy（SEM）.The flexible package batteries were fabricated to inspect the electrochemical properties.The results show that H3BO3 with fluxing action can refine the primary particle size and improve the compact level of the particles.H3BO3 has no influence on the crystal structure,but has impact on the particle size,pH,specific surface area and the tap density.The electrochemical property of LiNi（0.5）Co（0.2）Mn（0.3）O2 with 0.6%H3BO3（mass fraction） is better than that of normal LiNi（0.5）Co（0.2）Mn（0.3）O2 cathode material.The operating limiting compacted density of the electrode increases from 3.5 g/cm^3 to 3.9 g/cm^3,so that the volume energy density improves by about 11.4%.The first discharge specific capacity is 153.64（mA·h）/g and 152.22（mA·h）/gat 0.5C and 1C,respectively.The discharge capacity retention is 96.99%after 100 cycles.

关 键 词：锂离子电池 LiNi(0.5)Co(0.2)Mn(0.3)O2 压实密度 H3BO3 助熔作用 

分 类 号：TM912.9[电气工程—电力电子与电力传动]