物理化学学报 >> 2010, Vol. 26 >> Issue (03): 567-572.doi: 10.3866/PKU.WHXB20100247

电化学 上一篇    下一篇

Al掺杂量对正极材料LiNi1/3Co2/3-xAlxO2结构和电化学性能的影响

常照荣, 郁旭, 汤宏伟, 魏文强, 代冬梅   

  1. 河南师范大学化学与环境科学学院, 河南 新乡 453007
  • 收稿日期:2009-09-03 修回日期:2009-11-13 发布日期:2010-03-03
  • 通讯作者: 常照荣 E-mail:czr_56@163.com

Influence of Al Doping Content on the Structure and Electrochemical Properties of LiNi1/3Co2/3-xAlxO2

CHANG Zhao-Rong, YU Xu, TANG Hong-Wei, WEI Wen-Qiang, DAI Dong-Mei   

  1. College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007, Henan Province, P. R. China
  • Received:2009-09-03 Revised:2009-11-13 Published:2010-03-03
  • Contact: CHANG Zhao-Rong E-mail:czr_56@163.com

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摘要：

以共沉淀法合成的前驱体Ni1/3Co2/3-xAlx(OH)2与低共熔锂盐0.38LiOH·H2O-0.62LiNO3制备了锂离子电池正极材料LiNi1/3Co2/3-xAlxO2(x=1/12, 1/6, 1/3, 1/2, 7/12). 采用X射线衍射(XRD)、扫描电镜(SEM)和电化学性能测试对其结构、形貌和电化学性质进行表征. 结果表明, LiNi1/3Co2/3-xAlxO2在1/12≤x≤1/3范围内可以保持单一的六方层状α-NaFeO2结构, 当Al掺杂量(x)高于1/3 时, 会出现杂相. 其中, LiNi1/3Co1/3Al1/3O2结晶程度最高, 阳离子混排效应最小, 并且颗粒小而均匀, 振实密度可以达到2.88 g·cm-3, 首次放电容量为151.5 mAh·g-1, 循环50次后放电容量保持在91.4%, 在1C和2C倍率下放电容量仍可达到133.7和120.9 mAh·g-1.

关键词: 锂离子电池, 正极材料, 掺杂, LiNi1/3Co2/3-xAlxO2

Abstract:

The layerd cathode materials LiNi1/3Co2/3-xAlxO2 (x=1/12, 1/6, 1/3, 1/2, 7/12) for lithiumion battery has been successfully synthesized using eutectic lithium salts of 0.38LiOH·H2O-0.62LiNO3 mixed with Ni1/3Co1/3Al1/3(OH)2 as a precursor. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical performance tests. Results show that the LiNi1/3Co2/3 -xAlxO2 can be maintained as a well-layered α-NaFeO2 structure in the range of 1/12≤x≤1/3. At x>1/3, a miscellaneous phase is present. The LiNi1/3Co1/3Al1/3O2 products have the highest crystallinity, the least cation mixing effect and the most uniform particle size with a tap-density of 2.88 g·cm-3. Additionally, the initial discharge capacity of the product was 151.5 mAh·g -1 and after 50 cycles, 91.4%of the initial discharge capacity was maintained. The reversible capacities of the products are 133.7 and 120.9 mAh·g-1 at 1C and 2C discharge rates, respectively.

Key words: Lithium ion battery, Cathode material, Doping, LiNi1/3Co2/3-xAlxO2