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化学学报 ›› 2008, Vol. 66 ›› Issue (8): 890-896. 上一篇    下一篇

研究论文

高密度非球形和球形LiNi1/3Mn1/3Co1/3O2的合成和性能比较

常照荣*,1，陈中军1，吴锋2，汤宏伟1，朱志红1   

  1. (1河南师范大学化学与环境科学学院 新乡 453007)
    (2北京理工大学化工与环境学院 北京 100080)
  • 投稿日期:2007-06-21 修回日期:2007-09-20 发布日期:2008-04-28
  • 通讯作者: 常照荣

Comparison of Synthesis and Properties of the Spherical and Non-Spherical LiNi1/3Mn1/3Co1/3O2 with High Tap-Density

CHANG Zhao-Rong*,1 CHEN Zhong-Jun1 WU Feng2 TANG Hong-Wei1 ZHU Zhi-Hong1   

  1. (1 College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007)
    (2 College of Chemical Engineering and Environmental, Beijing Institute of Technology, Beijing 100080)
  • Received:2007-06-21 Revised:2007-09-20 Published:2008-04-28
  • Contact: CHANG Zhao-Rong

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利用二次干燥法和共沉淀法分别制备出了非球形的Ni1/3Co1/3Mn1/3OOH前驱体和球形Ni1/3Co1/3Mn1/3(OH)2前驱体, 并分别和LiNO3混合烧结合成高密度非球形和球形的锂离子正极材料Li(Ni1/3Co1/3Mn1/3)O2. XPS分析表明, 二次干燥法制备的非球形Ni1/3Co1/3Mn1/3OOH前驱体其过渡金属Ni, Co和Mn的价态分别是＋2, ＋3和＋4, 而共沉淀法制备的球形Ni1/3Co1/3Mn1/3(OH)2前驱体其各金属价态为＋2; X射线衍射分析表明, 非球形的Ni1/3Co1/3Mn1/3OOH前驱体比球形的前驱体具有较高的活性, 能够在低温下合成出Li(Ni1/3Co1/3Mn1/3)O2, 而且制备的产物结晶度高, 具有规整的层状α-NaFeO2结构, 扫描电镜显示制备的非球形产物颗粒均匀, 颗粒间隙小, 振实密度高达2.95 g•cm－3, 远高于球形的振实密度2.35 g•cm－3; 充放电实验表明, 由非球形前驱体制备的Li(Ni1/3Co1/3Mn1/3)O2其充放电性能和循环性能以及体积比容量均高于球形正极材料.

关键词: 锂离子电池, 正极材料, LiNi1/3Mn1/3Co1/3O2, 高密度

Non-spherical Ni1/3Co1/3Mn1/3OOH and spherical Ni1/3Co1/3Mn1/3(OH)2 precursor powders were synthesized using a two step drying method and a co-precipitation method, respectively. And then high tap-density non-spherical and spherical Li(Ni1/3Co1/3Mn1/3)O2 powders were prepared from their precursors, which were sintered with LiNO3. XPS studies indicated that the predominant oxidation states of Ni, Co and Mn in the non-spherical precursor were ＋2, ＋3 and ＋4, respectively. However, those in the spherical precursor were all ＋2. And the XRD studies showed that the activity of non-spherical Ni1/3Co1/3Mn1/3OOH was higher than that of spherical Ni1/3Co1/3Mn1/3(OH)2, and furthermore, the non-spherical Li(Ni1/3Co1/3Mn1/3)O2 could be synthesized at a low temperature, which had a well-ordered layered α-NaFeO2 structure with a small amount of cation mixture. SEM showed that the synthesized non-spherical particles are uniform in size. The tap-density is up to 2.95 g•cm－3, which is higher than that of spherical powders (2.35 g•cm－3). Charge and discharge capacity experiments showed that the non-spherical cathodes delivered higher discharge capacity and better charge-discharge cycling property than the spherical powders.

Key words: lithium ion battery, cathode material, LiNi1/3Mn1/3Co1/3O2, high tap-density