高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (6): 1258-1264.doi: 10.7503/cjcu20180773

• 物理化学 • 上一篇    下一篇

腈基功能化有机硅电解液添加剂对LiFePO4电池低温性能的影响

赵欣悦, 汪靖伦, 闫晓丹, 张灵志()   

  1. 中国科学院广州能源研究所, 中国科学院可再生能源重点实验室, 广州 510640
  • 收稿日期:2018-11-19 出版日期:2019-06-10 发布日期:2019-03-27
  • 作者简介:

    联系人简介: 张灵志, 男, 博士, 研究员, 博士生导师, 主要从事有机光电材料和纳米材料方面的研究. E-mail: lzzhang@ms.giec.ac.cn

  • 基金资助:
    国家自然科学基金(批准号: 51602312)、 广东省科技计划项目(批准号: 2015B010135008)和广州市科技计划项目(批准号: 201509010018)资助.

Effect of Nitrile Group Functionalized Organosilicon as Electrolyte Additive on Low-temperature Performance of LiFePO4 Battery

ZHAO Xinyue, WANG Jinglun, YAN Xiaodan, ZHANG Lingzhi()   

  1. Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
  • Received:2018-11-19 Online:2019-06-10 Published:2019-03-27
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.51602312), the Guangdong Provincial Project for Science and Technology, China(No.2015B010135008) and the Guangzhou Municipal Project for Science and Technology, China(No.201509010018).

摘要:

合成了一种腈基功能化有机硅化合物3-氰乙基-二乙氧基-甲基硅烷(DESCN), 并对其化学结构和电化学窗口进行了表征. 采用恒流充放电、 扫描电子显微镜(SEM)、 X射线光电子能谱(XPS)及电化学阻抗谱(EIS)等方法研究了DESCN添加剂对LiFePO4电池低温性能的影响. 结果表明, DESCN化合物能够在电极表面参与形成更薄、 更均匀且致密的固体电解质界面(SEI)膜, 抑制电解液副反应的发生, 减小界面膜阻抗, 有利于低温下电极/电解液界面的Li+扩散和电荷转移, 从而提高LiFePO4电池的低温性能.

关键词: 有机硅, 腈基, 电解液添加剂, 低温性能, 锂离子电池

Abstract:

A nitrile group functionalized organosilicon compound, 3-(diethoxy-methyl-silanyl)-propionitrile(DESCN) was synthesized and its chemical structure and electrochemical window were characterized. The effects of DESCN on the low-temperature performance of LiFePO4 cell were investigated by charge-discharge cycling test, scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and electrochemical impedance spectroscopy(EIS) and so on. It is revealed that adding 2%DESCN could improve the low-temperature performance of LiFePO4 cell. At -20 ℃, the cell exhibits a high discharge capacity of 73 mA·h/g and are stable after 50 cycles. DESCN involved in the formation of stable solid electrolyte interface(SEI) film to inhibit electrolyte decomposition and decrease the battery resistance, which facilitate Li+ diffusion and electron transportation at electrode/electrolyte interface at low-temperature.

Key words: Organosilicon, Nitrile group, Electrolyte additive, Low-temperature performance, Lithium-ion battery

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