物理化学学报 >> 2007, Vol. 23 >> Issue (Supp): 40-45.doi: 10.3866/PKU.WHXB2007Supp10

研究论文 上一篇    下一篇

高容量锂离子电池正极材料LiNi0.8Co0.2-xMgxO2

侯宪全; 江卫军; 其鲁; 韩立娟   

  1. 中信国安盟固利新能源科技有限公司, 北京 102200; 北京大学化学与分子工程学院应用化学系, 新能源材料与技术实验室 北京 100871
  • 收稿日期:1900-01-01 修回日期:1900-01-01 发布日期:2008-01-04
  • 通讯作者: 其鲁 E-mail:qilu@pku.edu.cn

Synthesis and Properties of Layered LiNi0.8Co0.2-xMgxO2 Cathode Material

HOU Xian-Quan; JIANG Wei-Jun; QI Lu; HAN Li-Juan   

  1. CITIC Guoan Mengguli New Engery Technology Co. Ltd., Beijing 102200, P. R. China; New Energy Material and Technology Laboratory, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:1900-01-01 Revised:1900-01-01 Published:2008-01-04
  • Contact: QI Lu E-mail:qilu@pku.edu.cn

摘要: 以共沉淀法合成了高容量锂离子电池用正极材料LiNi0.8Co0.2-xMgxO2 (x=0.02, 0.03, 0.04). 对合成的层状材料采用X射线衍射(XRD)、扫描电镜(SEM)、热重(TG)和差示扫描热量(DSC)进行了结构、形貌和热分析. 分析结果表明, 所得生成物为球形颗粒, 结构为α-NaFeO2型层状结构, 生成物中无杂相. 在电压范围为3.0-4.3 V, 放电电流密度为0.5 mA·cm-2 时, 对材料的电化学性能进行了测试. 首次放电容量最高可达184.8 mAh·g-1; 循环50次后, 容量保持率为94.2%. DSC结果表明, 无机金属离子Mg掺杂后材料基本保持高容量, 同时相变得到抑制, 材料的稳定性和循环性能提高.

关键词: 锂离子电池, 正极材料, 高容量, 掺杂

Abstract: LiNi0.8Co0.2-xMgxO2 (x=0.02, 0.03, 0.04) cathode materials were synthesized by co-precipitation method. The materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetry (TG), and differential scanning calorimetry (DSC). The results showed that the spherical products, without impurities, had a typical α-NaFeO2 layered structure. In the range of 3.0-4.3 V, at 0.5 mA·cm-2 of the current density, the first specific capacity was 184.8 mAh·g-1. After 50 cycles, the capacity retention was 94.2%. The DSC result showed that after the doping with Mg2+, the phase transition of LiNi0.8Co0.2-xMgxO2 was inhibited without distinct capacity fall. At the same time, the stability and cycling character was improved obviously.

Key words: Lithiumion secondary battery, Cathode material, High capacity, Doping