储能科学与技术 ›› 2013, Vol. 2 ›› Issue (6): 603-609.doi: 10.3969/j.issn.2095-4239.2013.06.007

• 研究及进展 • 上一篇    下一篇

LiNi0.8Co0.2O2正极材料的空气气氛烧结合成与电化学性能

陈凯, 刘兴泉, 马慎思, 寇丹, 张峥   

  1. 电子科技大学微电子与固体电子学院,电子薄膜与集成器件国家重点实验室,四川 成都 610054
  • 收稿日期:2013-05-03 修回日期:2013-06-24 出版日期:2013-12-19 发布日期:2013-12-19
  • 通讯作者: 刘兴泉,教授,E-mail:lxquan2000@sina.com.
  • 作者简介:陈凯(1988--),男,硕士研究生,研究方向为新型储能与能量转换材料
  • 基金资助:
    国家自然科学基金项目(21071026)

Synthesis of LiNi0.8Co0.2O2 cathode material through sintering in an air environment and electrochemical properties characterization

CHEN Kai, LIU Xingquan, MA Shensi, KOU Dan, ZHANG Zheng   

  1. State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,Sichuan,China
  • Received:2013-05-03 Revised:2013-06-24 Online:2013-12-19 Published:2013-12-19

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摘要： 制备锂离子电池正极材料LiNi0.8Co0.2O2通常需要在纯氧气气氛下进行烧结.本工作以硫酸镍,硫酸钴和氢氧化钠为原料,采用并流共沉淀法制备了高密度Ni0.8Co0.2(OH)2前驱体,再采用高温固相反应法在空气中烧结制备了锂离子电池LiNi0.8Co0.2O2正极材料.采用X射线衍射(XRD),扫描电镜(SEM),恒流充放电测试(ECT),循环伏安(CV)与比表面积(BET)测试等方法对目标样品进行了表征,详细考察了烧结条件对材料结构,微观形貌及电化学性能的影响.结果表明,锂/(钴+镍)摩尔比为1.13∶1时,在管式炉中和空气气氛下于第一段烧结温度700 ℃保温9 h,于第二段烧结温度750 ℃保温12 h,合成的材料比表面积适中(0.78 m2/g),具有规则的六边形α-NaFeO2层状结构,晶粒分布均匀,电化学性能最优.在0.5 C充放电倍率下和2.7~4.3 V电压范围内,其首次放电比容量达到153.0 mA·h/g,循环20次后放电比容量仍为150.7 mA·h/g,容量保持率达到98.5%,显示了优异的循环稳定性能,可用做高能量密度动力电池正极材料.

关键词: 锂离子电池, 正极材料, LiNi0.8Co0.2O2, 空气气氛, 共沉淀法, 固相合成, 电化学性能

Abstract: The work reported in this paper is on LiNi0.8Co0.2O2 cathode material for lithium-ion batteries applications. A high-density precursor, Ni0.8Co0.2(OH)2, was prepared first by concurrent co-precipitation using nickel sulfate, cobalt sulfate and sodium hydroxide as raw materials. The cathode material was made by high temperature solid state reaction in an air environment. The s as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and constant current electrochemical test (ECT), and the impact of sintering time on the structure, surface morphology and electrochemical properties was investigated. The LiNi0.8Co0.2O2 sample made with n(Li)∶n(Ni+Co)=1.13∶1 and sintered in the air at 700 ℃ for 9 h and then 750 ℃ for 12 h shows optimal electrochemical performance, giving an initial discharge capacity of 153.0 mA·h/g, a capacity of 150.7 mA·h/g at 20th discharge and a capacity retention so high as 98.5% at the rate of 0.5 C from 2.7 V to 4.3 V. These results demonstrate excellent cyclic stability of the material and good potential for use as the cathode material of high power density power batteries.

Key words: lithium-ion batteries, cathode material, LiNi0.8Co0.2O2, air atmosphere, co-precipitation method, solid state synthesis, electrochemical properties

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