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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (14): 1399-1403. 上一篇    下一篇

研究论文

梯度式升温脱水制备LiBF4及其表征

周园*,1，张昕岳1,2,3，年洪恩1，庞玉娜1,2，王宏斌1,2   

  1. (1中国科学院青海盐湖研究所 西宁810008)
    (2中国科学院研究生院 北京100039)
    (3中国科学院化学研究所 北京100190)
  • 投稿日期:2009-09-15 修回日期:2010-02-05 发布日期:2010-03-19
  • 通讯作者: 周园 E-mail:zhouy@isl.ac.cn
  • 基金资助:

    中国科学院知识创新工程重要方向项目（项目编号 KZCXZ-YW-343）

Preparation and Characterization of LiBF4 by Gradient Heating Dehydration

Zhou Yuan*,1 Zhang Xinyue1,2,3 Nian Hongen1 Pang Yuna1,2 Wang Hongbin1,2   

  • Received:2009-09-15 Revised:2010-02-05 Published:2010-03-19

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用水溶液法以硼酸、氢氟酸和碳酸锂为原料制备出LiBF4水溶液, 经浓缩、结晶、梯度式升温脱水得到锂离子电池电解质盐LiBF4, 应用X射线衍射(XRD)、红外图谱、热分析对其进行了表征. 研究结果表明: 梯度式升温脱水避免了传统的迅速升温导致的部分水合物熔融包裹在晶体表面而妨碍内部晶体脱水, 自制LiBF4与商品LiBF4的XRD图谱吻合, 并与粉末衍射文件(PDF)卡片00-040-1431符合, 确认为无水LiBF4, 属六方晶系, 空间群为P3121; LiBF4红外谱图分析中, 1050 cm－1处的吸收峰分裂为两个分别处于1055和1038 cm－1的吸收峰, 属于T2振动模式的ν3 (as)振动, 在650 cm－1处出现中等强度吸收峰, 属T2振动模式的δ3 (s)振动; LiBF4的TG-DTG图谱中314.31 K处有一微弱分解峰, 在516.48 K处出现强分解峰, 失重率为72.33%, 其分解过程可视为LiBF4分解为LiF和BF3.

关键词: LiBF4, 电解质, 锂离子电池, 锂盐, 水溶液法

(1 Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008)
(2 Graduate School of Chinese Academy of Sciences, Beijing 100039)
(3 Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190) Abstract LiBF4 was prepared via aqueous solution process and its properties were examined by X-ray diffraction (XRD), IR, and thermogravimetry and differential thermogravimetry (TG-DTG). H3BO3, HF and Li2CO3 were used as starting materials to prepare LiBF4 solution, followed by concentrating, crystallizing and dehydrating to obtain LiBF4. The incomplete dehydration caused by traditional rapid heating was avoided through gradient heating dehydration. The obtained LiBF4 crystal belongs to the hexagonal system with space group P3121, confirmed by its XRD spectrum which conformed to powder diffraction file (PDF) card 00-040-1431. The infrared absorption bands of the obtained LiBF4 were observed, one band located at 1050 cm－1, and splitted off two bands which are located at 1055 and 1038 cm－1; the other band located at 650 cm－1; attributed to ν3 (as) vibration and δ3 (s) vibration, respectively. In TG-DTG spectrum, a weak decomposition peak was observed at 341.31 K and a strong decomposition peak appeared at 516.48 K, the weight loss rate was 72.33%. The decomposition was regarded as the LiBF4 decomposed into LiF and BF3.

Key words: LiBF4, electrolyte, lithium-ion battery, lithium salt, aqueous solution process