氧化钇包覆LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2的结构和电化学性能  

Structure and electrochemical performance of yttrium oxide coated LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2

作　　者：许军娜 陈晓青[2] 高雄 周友元 肖可颂 黄承焕 习小明[4] XU Jun-na;CHEN Xiao-qing;GAO Xiong;ZHOU You-yuan;XIAO Ke-song;HUANG Cheng-huan;XI Xiao-ming(Kingray New Materials Science and Technology Co., Ltd., Changsha 410012, China;School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;Hunan Changyuan LiCo Co., Ltd., Changsha 410205, China;Changsha Research Institute of Mining and Metallurgy Co., Ltd., Changsha 410012, China)

机构地区：[1]金瑞新材料科技股份有限公司,长沙410012 [2]中南大学化学化工学院,长沙410083 [3]湖南长远锂科有限公司,长沙410205 [4]长沙矿冶研究院有限责任公司,长沙410012

出　　处：《中国有色金属学报》2018年第3期528-535,共8页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2016YFB0100400);国家自然科学基金资助项目(51474037)~~

摘　　要：以氧化钇溶胶为包覆前驱物,利用氧化钇和正极材料表面带电状态不同制备氧化钇包覆LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2。采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)及电化学测试等手段对LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2包覆前后的物相结构、表面形貌及电化学性能进行研究。结果表明:氧化钇包覆并未影响LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2的晶体结构,氧化钇以颗粒状分布在正极材料表面,氧化钇包覆层厚度在15~25nm,氧化钇在正极材料表面分布比较均匀。与未包覆LiNi_(0.5)Co_(0.2)Mn_(0.3)O_2相比,氧化钇包覆后,材料在高电压下的循环稳定性有所提高,最佳包覆量为0.4%。氧化钇包覆有效降低材料在充放电过程中的极化和电荷转移电阻。Yttrium oxide coated LiNi_（0.5）Co_（0.2）Mn_（0.3）O_2 was successfully prepared based on the different surface potentials between the cathode material and yttrium oxide using yttrium oxide sol as coating precursor. The crystal structure, morphology and electrochemical properties of uncoated and yttrium oxide coated LiNi_（0.5）Co_（0.2）Mn_（0.3）O_2 were investigated by X-ray diffractometry（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and electrochemical measurements. The results indicate that the crystal structure is not affected by yttrium oxide coating, the yttrium oxide particles homogenously distribute on the surface of cathode materials and the thickness of coating layer is 15-25nm. Comparing with the uncoated LiNi_（0.5）Co_（0.2）Mn_（0.3）O_2, the cycle performance of the cathode material improves after yttrium oxide coating and the optimum coating amount is 0.4%. The charge transfer resistance and the polarization are suppressed after coating during the charge-discharge processes.

关 键 词：氧化钇 表面包覆 LiNi0.5Co0.2Mn0.3O2 电化学性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]