高等学校化学学报

• 研究论文 •    

固相烧结法制备锂离子电池正极材料Li2FeP2O7及其电化学性能研究

王任衡1,肖哲1,李艳1,孙一翎1,范姝婷1,郑俊超2,钱正芳1,贺振江2   

  1. 1.深圳大学物理与光电工程学院, 深圳 518060
    2.中南大学冶金与环境学院, 长沙 410083
  • 收稿日期:2020-08-31 出版日期:2021-01-05 发布日期:2021-01-05
  • 基金资助:
    深圳市基础研究基金(批准号(20180123);JCYJ20190808173815205)、 广东省基础与应用基础研究基金(2019A1515012111);国家自然科学基金(51804199);深圳市孔雀团队项目(KQTD20180412181422399);国家重点研发计划(2019YFB2204500)

Synthesis of Li2FeP2O7 Cathode Material at Different Temperatures and Its Electrochemical Performance for Lithium Ion Batteries

WANG Renheng1(), XIAO Zhe1, LI Yan1, SUN Yiling1, FANG Shuting1, ZHENG Junchao2, QIAN Zhengfang1(), HE Zhenjiang2()   

  1. 1.College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China
    2.School of Metallurgy and Environment,Central South University,Changsha 410083,China
  • Received:2020-08-31 Online:2021-01-05 Published:2021-01-05
  • Contact: WANG Renheng,QIAN Zhengfang,HE Zhenjiang E-mail:wangrh@szu.edu.cn;zq001@szu.edu.cn;hzjcsu@csu.edu.cn
  • Supported by:
    the Science and Technology Innovation Commission of Shenzhen City, China(20180123);the Guangdong Basic and Applied Basic Research Foundation of Guangdong Province, China(2019A1515012111);the National Natural Science Foundation of China(51804199);the Shenzhen Science and Technology Program, China(KQTD20180412181422399);the National Key R&D Program of China(2019YFB2204500)

摘要:

介绍了一种先冷冻干燥后固相烧结制备正极材料Li2FeP2O7的方法. 利用X射线衍射(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)和傅里叶变换红外光谱(FTIR)对材料的组成和形态进行表征, 并通过循环伏安曲线(CV)和电化学阻抗谱(EIS)研究了Li2FeP2O7材料的电化学性能. 研究发现, 合成Li2FeP2O7的最佳温度为590 ℃, 此温度下反应较完全且产物杂质较少, 1.6C倍率下的放电比容量达到55 mA·h·g?1, 明显高于其它温度下合成样品的放电比容量. 该温度下合成的Li2FeP2O7还具有低阻抗和较大的交换电流密度, 说明这种合成方式有利于提高锂离子在Li2FeP2O7中的扩散.

关键词: 锂离子电池, 正极, Li2FeP2O7, 固相烧结法

Abstract:

The cathode material Li2FeP2O7 was synthesized via freeze-drying and followed by solid state sintering method. X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR) were used to characterize the structure, composition and morphology of the material. In addition, the electrochemical performance of the Li2FeP2O7 material was investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). It was found that the greatest particle quality could be acquired when the synthesis temperature of Li2FeP2O7 was 590 ℃. The discharge specific capacity reached 55.0 mA·h·g?1 at 1.6C, which was much higher than that of the samples synthesized at other temperatures. The Li2FeP2O7 synthesized at 590 ℃ had a low impedance and a large exchange current density, which facilitated the diffusion of lithium ions and improved the electrochemical performance.

Key words: Lithium ion battery, Cathode, Li2FeP2O7, Solid state sintering method

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