无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (6): 85-92.doi: 10.19964/j.issn.1006-4990.2024-0593

• 研究与开发 • 上一篇    下一篇

磷酸三甲酯-混盐阻燃电解液性能研究

王一人1,2,3(), 朵兴红1,2,3,4()   

  1. 1.青海民族大学化学与材料科学学院,青海 西宁 810007
    2.青海省纳米材料与技术重点实验室,青海 西宁 810007
    3.青海省应用物理化学重点实验室,青海 西宁 810007
    4.青海省基础化学实验教学示范中心,青海 西宁 810007
  • 收稿日期:2024-11-07 出版日期:2025-06-10 发布日期:2025-06-25
  • 通讯作者: 朵兴红(1980— ),女,博士,副教授,主要研究方向为化学工程、功能材料等;E-mail:wlkdxh@tju.edu.cn
  • 作者简介:王一人(1999— ),女,硕士,研究方向为电池电解液;E-mail:755874970@qq.com
  • 基金资助:
    国家自然科学基金项目(NSFC 51963018);青海民族大学高层次人才项目(2019XJG01);天津大学-青海民大自主创新基金合作项目(30587);青海民大研究生创新计划项目(12M2024040)

Study on trimethyl phosphate-mixed salt flame retardant electrolytes performance

WANG Yiren1,2,3(), DUO Xinghong1,2,3,4()   

  1. 1. School of Chemistry and Material Science,Qinghai Minzu University,Xi′ning 810007,China
    2. Qinghai Provincial Key Laboratory of Nanomaterials and Technology,Xi′ning 810007,China
    3. Qinghai Provincial Key Laboratory of Applied Physical Chemistry,Xi′ning 810007,China
    4. Qinghai Provincial Demonstration Center for Basic Chemistry Experimental Teaching,Xi′ning 810007,China.
  • Received:2024-11-07 Published:2025-06-10 Online:2025-06-25

摘要:

电解液对锂离子电池能量密度和稳定性极为关键,但商业电解液常用的锂盐六氟磷酸锂(LiPF6)在60 ℃以上的高温环境下易发生分解,增加了电池在极端高温下燃烧或爆炸的风险。研究开发了一系列新型阻燃电解液体系,该体系采用六氟磷酸锂(LiPF6)和二氟磷酸锂(LiPO2F2)作为锂盐,以碳酸乙烯酯(EC)和碳酸二乙酯(DEC)为混合溶剂,并添加磷酸三甲酯(TMP)作为阻燃添加剂。通过自熄时间和红外光谱分析来评估其阻燃性能,利用差示扫描-热重实验分析其热稳定性,同时,通过电化学充放电测试、循环性能测试、阻抗测试来分析其电化学性能。研究结果显示,添加质量分数为3%的TMP后电解液燃烧不会蔓延,显出优异的阻燃性能;电解液中锂盐LiPO2F2的加入提升了电解液的热稳定性;结果表明,电解液 (LiPF6+LiPO2F2)+(EC+DEC)+3%TMP组成的LiCoO2/Li电池在25 ℃、0.5C倍率下首次放电比容量达到132.9 mA·h/g,库仑效率为99.63%;在80 ℃、1.0C倍率下循环100次后,放电比容量为110.8 mA·h/g,容量保持率为92.49%。

关键词: 锂离子电池, 电解液, 阻燃添加剂, 协同效应, 高温

Abstract:

The electrolyte is crucial to the energy density and stability of lithium-ion batteries.However,the lithium salt commonly used in commercial electrolytes,lithium hexafluorophosphate(LiPF6),is prone to decomposition at temperatures above 60 ℃,which increases the risk of combustion or explosion of the battery under extreme high temperatures.A series of novel flame-retardant electrolyte systems were developed,which used lithium hexafluorophosphate(LiPF6) and lithium difluorophosphate(LiPO2F2) as lithium salts,with ethylene carbonate(EC) and diethyl carbonate(DEC) as mixed solvents,and trimethyl phosphate(TMP) as a flame-retardant additive.The flame-retardant performance was evaluated by self-extinguishing time and infrared spectroscopy analysis,the thermal stability was analyzed by differential scanning calorimetry-thermogravimetric(DSC-TG) experiments,and the electrochemical performance was assessed through electrochemical charge-discharge testing,cycle performance testing,and impedance testing.The results showed that the electrolyte with 3% TMP added did not spread when burned,demonstrating excellent flame-retardant properties.The addition of the lithium salt LiPO2F2 to the electrolyte had improved the thermal stability of the electrolyte.The results indicated that the electrolyte(LiPF6+LiPO2F2)+(EC+DEC)+3%TMP in a LiCoO2/Li battery achieved a first discharge specific capacity of 132.9 mA·h/g and a coulombic efficiency of 99.63% at 25 ℃ and 0.5C rate.After 100 cycles at 80 ℃ and 1.0C rate,the discharge specific capacity was 110.8 mA·h/g,with a capacity retention rate of 92.49%.

Key words: lithium-ion batteries, electrolyte, flame retardant additive, synergistic effect, high temperature

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