LiCoO_2包覆LiNi_(0.78)Co_(0.2)Zn_(0.02)O_2锂离子电池正极材料  

LiCoO_2-coated LiNi_(0.78)Co_(0.2)Zn_(0.02)O_2 cathode material for lithium-ion battery

作　　者：宋振业[1] 顾大明[1] 陈志刚[2] 

机构地区：[1]哈尔滨工业大学应用化学系,哈尔滨150001 [2]黑龙江工程学院电子工程系,哈尔滨150050

出　　处：《哈尔滨工业大学学报》2007年第3期481-484,共4页Journal of Harbin Institute of Technology

基　　金：黑龙江省自然科学基金资助项目(E2004-24);哈尔滨市科技攻关项目(2004AA5CG077)

摘　　要：采用共沉淀法制备了LiCoO2包覆LiNi0．78Co0．2Zn0．02O2锂离子电池正极材料，对材料进行XRD、SEM的分析结果表明，该材料具类α-NaFeO2（R-3m）结构，而且微观颗粒大小均匀．电化学测试结果表明，用LiCoO2进行表面包覆后比未包覆材料的初期放电比容量略有降低，但是材料的循环性能明显提高．包覆材料的首次恒流（60mA·cm^2，3．0～4．2V，vs．Li^＋／Li）充、放电比容量分别为243．63mAh·g^-1和204．58mAh·g^-1。首次循环效率为83．97％，200次循环后比容量仍为197．06mAh·g^-1，不可逆容量损失仅为7．52mAh·g^-1，容量保持率达到96．0％以上，具有很好的循环性能．The LiCoOE-Coated LiNi0.78Co0.2Zn0.02O2 cathode material was synthesized with co-precipitation method. The XRD pattern and the SEM photo of the material indicate that the layered crystal structure of the material with α-NaFeO2 type （space group R -3 m） is perfect and its morphology is well-distributed. The galvanostatic charge-discharge（60 mA · cm^2 ,3.0- 4.2 V, vs. Li^＋/Li ）test show that the first discharge specific capacity of the LiCoO2 coated material is lower than the uncoated material slightly, but the cyclic stability of the coated material is improved greatly and its first charge-discharge specific capacities are 243.63 mAh/g and 204. 58 mAh/g respectively. The discharge capacity can still retain 197.06 mAh g^-1 at the 200^th cycle and its irreversible loss is only 7.52 mAh g^- 1 with a discharge capacity retention ratio above 96.0%. The coated ma- terial exhibits a good cycle-property.

关 键 词：共沉淀 LICOO2 包覆 LiNi0.78Co0.2Zn0.02O2 循环性能 

分 类 号：O614[理学—无机化学]