锂离子电池正极材料LiNi_(0·4)Co_(0·2)Mn_(0·4)O_2的合成、表征及电化学性能  

Preparation,Characterization and Electrochemical Performance of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) as Cathode Materials in Lithium Ion Battery

作　　者：李劼[1] 郑建明[1] 郭晓健[1] 龚正良[1] 杨勇[1] 

机构地区：[1]厦门大学化学系固体表面物理化学国家重点实验室,厦门361005

出　　处：《高等学校化学学报》2006年第7期1311-1314,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20473068;29985310)资助

摘　　要：以过渡金属乙酸盐和氢氧化锂为原料，应用共沉淀或流变相预处理高温烧结法优化并制备出LiNi0．4Co0．2Mn0．4O2正极材料．X射线衍射技术（XRD）及Rietveld结构精修、扫描电子显微技术（SEM）、综合热分析（TG—DSC）表征结果和电化学测试结果表明，该材料具有单一层状结构，颗粒大小均匀，热稳定性好，首次放电比容量高达208．7mA·h／g（2．0—4．6V，0．1C），电化学性能优异．非原位（ex situ）XRD测定结果表明，材料充至高电位下发生的不可逆相变造成了材料的循环容量衰减．Cathode material of LiNi0.4Co0.2Mn0.4O2 was prepared by mixed hydroxide or rheological reaction method at 850 ℃ within 15 h. The materials were characterized by XRD with Rietveld refinement, SEM, TGDSC and electrochemical tests. The results showed that it has R-3m layered structure, with a high capacity and good thermal property. It delivered a specific capacity as high as 208.7 mA ·h/g（2. 0-4. 6 V, 0. 1 C）. Phase change of LiNi0.4Co0.2Mn0.4O2（0 〈x 〈 1 ） in charge-discharge process will affect the cyclic stability of the materials, especially in the first 10 circles.

关 键 词：LiNi0.4Co0.2Mn0.4O2 热稳定性 循环容量衰减 

分 类 号：O646[理学—物理化学]