LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料的制备与倍率性能研究  

Preparation and Rate Capability Study of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 as Cathode Material

作　　者：王海燕[1] 唐爱东[1] 黄可龙[1] 荆涛[1] 赵薇[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《无机化学学报》2008年第4期593-599,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金项目资助(No50542004);中南大学2006年研究生学位论文创新选题和米塔尔创新选题(06MX04)

摘　　要：在碳酸盐共沉淀法中引入超声波技术,合成锂镍钴锰前驱体,然后通过高温煅烧制备了LiNi1/3Co1/3Mn1/3O2正极材料,采用扫描电镜(SEM)、X射线能谱(EDS)、X射线衍射(XRD)、差示量热扫描(DSC)、循环伏安法(CV)及充放电测试等手段对材料进行了表征。结果表明,材料在700～1000℃下均能形成六方层状α-NaFeO2结构,其晶体有序化程度随着煅烧温度的升高而升高。SEM分析显示材料颗粒分散非常均匀,平均粒径约200nm。在2.8～4.3V,0.1C下,900℃煅烧得到的材料首次放电比容量达156.3mAh.g-1。而在1C、2C、5C,10C下,其放电比容量仍分别为137.8、129.3、114.4、95.5mAh·g-1,在前5次循环后容量基本保持不变,在1C下前40次循环的容量保持率为96%。该材料显示了良好的倍率性能。DSC结果表明,在同样充电至4.2V的条件下,LixNi1/3Co1/3Mn1/3O2的热稳定性能优于LixMn2O4和LixCoO2。LiNi1/3Co1/3Mn1/3O2 was prepared by a carbonate co-precipitation method combined with an ultrasonic technique, followed by a high temperature solid state reaction. Related characters were investigated by scanning electron macroscopy （SEM）, energy dispersive spectroscopy （EDS）, X-ray diffraction （XRD）, differential scanning calorimetry （DSC）, cyclic voltammetry （CV） and charge-discharge cycling. It＇s found that the material could form a hexagonal structure （α-NaFeO2）, calcined at 700-1 000 ℃ and the ordering degree of crystal increased with the increasing of calcined temperature. The particle size was about 200 nm and its distribution was uniform, as observed by SEM. Initial discharge capacity of 156.3 mAh·g^-1 of LiNi1/3Co1/3Mn1/3O2 prepared at 900 ℃ was obtained between 2.8 and 4.3 V, at 0.1C-rate. The initial dischange capacity of 137.8, 129.3, 114.4, 95.5 mAh·g^-1 was observed at 1C, 2C, 5C, 10C, respectively. The electrode showed good rate capability since little capacity fade appeared after 5 cycles at different rates even at 10C and 96% of initial discharge capacity was maintained after 40 cycles at 1C. Besides, thermal stability of LiNi1/3Co1/3Mn1/3O2（4.2 V） showed by DSC was better than that of LixMn2O4 and LixCoO2.

关 键 词：LINI1/3CO1/3MN1/3O2 碳酸盐共沉淀法 超声波技术 制备 倍率性能 

分 类 号：O614.111[理学—无机化学] O614.81[理学—化学]