物理化学学报 >> 2011, Vol. 27 >> Issue (11): 2593-2599.doi: 10.3866/PKU.WHXB20111104

电化学和新能源 上一篇    下一篇

纳米MgO掺杂改善LiNi1/3Co1/3Mn1/3O2正极材料

李节宾1,2, 徐友龙1, 熊礼龙1, 王景平1   

  1. 1. 西安交通大学电子陶瓷与器件教育部重点实验室, 国际电介质研究中心, 西安 710049;
    2. 陕西应用物理化学研究所, 西安 710061
  • 收稿日期:2011-06-07 修回日期:2011-08-03 发布日期:2011-10-27
  • 通讯作者: 徐友龙 E-mail:ylxuxjtu@mail.xjtu.edu.cn

Improvement of LiNi1/3Co1/3Mn1/3O2 Cathode Materials by Nano-MgO Doping

LI Jie-Bin1,2, XU You-Long1, XIONG Li-Long1, WANG Jing-Ping1   

  1. 1. International Center for Dielectric Research, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, P. R. China;
    2. Shaanxi Applied Physics and Chemistry Research Institute, Xi'an 710061, P. R. China
  • Received:2011-06-07 Revised:2011-08-03 Published:2011-10-27
  • Contact: XU You-Long E-mail:ylxuxjtu@mail.xjtu.edu.cn

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摘要： 将氢氧化物共沉淀法制备的(Ni1/3Co1/3Mn1/3)(OH)2在500°C热处理5 h 得到具有尖晶石结构、纳米尺寸的氧化物M3O4 (M=Ni1/3Co1/3Mn1/3). 将其与LiOH及不同量的纳米MgO混合均匀, 并在850°C热处理24 h制备了Li(Ni1/3Co1/3Mn1/3)1-xMgxO2 (x=0, 0.01, 0.02, 0.03, 0.04, 0.05)正极材料. 随着Mg掺杂量的增大, 正极材料的晶胞参数增大; 少量的Mg掺杂增大了锂离子的扩散系数, 而过度掺杂却使锂离子扩散系数有所降低, 其中Li(Ni1/3Co1/3Mn1/3)0.98Mg0.02O2的锂离子扩散系数最大, 其脱出和嵌入扩散系数分别为DLi-dein=29.20×10-11 cm2·s-1和DLi-in=4.760×10-11 cm2·s-1; 其以3C倍率充放电的平均放电比容量为139.3 mAh·g-1, 比未掺杂的原粉约高9.5 mAh·g-1; 另外其循环性能也得到了大幅度改善.

关键词: 锂离子电池, 正极材料, LiNi1/3Co1/3Mn1/3O2, Mg掺杂, 锂离子扩散系数

Abstract: Nano-sized M3O4 (M=Ni1/3Co1/3Mn1/3) powder with a spinel structure was prepared by sintering co-precipitated M(OH)2 at 500°C for 5 h. The so-obtained M3O4 was then mixed with LiOH and different amounts of nano-MgO. The mixture was sintered at 850°C for 24 h to synthesize Li(Ni1/3Co1/3Mn1/3)1-xMgxO2 (x=0, 0.01, 0.02, 0.03, 0.04,0.05) cathode materials. The lattice parameters increased while the diffusion coefficients of Li+ ion showed an increasing and then decreasing trend with an increase in the amount of Mg substitution. Li(Ni1/3Co1/3Mn1/3)0.98Mg0.02O2 had the highest Li+ ion diffusion coefficients, which were 29.20× 10-11 cm2·s-1 for Li+ de-intercalation and 4.760×10-11 cm2·s-1 for Li+ intercalation. Its discharge capacity at 3C rate was 139.3 mAh·g-1, which is 9.5 mAh·g-1 higher than that of the pristine material. Furthermore, its cycle performance was also improved significantly compared with the un-doped counterpart.

Key words: Lithium ion battery, Cathode material, LiNi1/3Co1/3Mn1/3O2, Mg-doping, Diffusion coefficient of Li+ ion

MSC2000: 

  • O646