储能科学与技术 ›› 2020, Vol. 9 ›› Issue (1): 82-87.doi: 10.12028/j.issn.2095-4239.2019.0182

• 储能材料与器件 • 上一篇    下一篇

实用化软包装锂硫电池电解液的研究

廖红英1(), 王维坤2(), 孟蓉1, 金朝庆2, 王安邦2()   

  1. 1. 北京化学试剂研究所有限责任公司,北京 102607
    2. 防化研究院,北京 100191
  • 收稿日期:2019-08-08 修回日期:2019-08-22 出版日期:2020-01-05 发布日期:2020-01-10
  • 通讯作者: 王维坤,王安邦 E-mail:hongyingliao@163.com;wangweikun2002@163.com;wab_wang2000@aliyun.com
  • 作者简介:廖红英(1976—),女,硕士,教授级高工,研究方向为电化学及电池材料,E-mail:hongyingliao@163.com

Research on electrolytes for Li-S soft packing batteries

LIAO Hongying1(), WANG Weikun2(), MENG Rong1, JIN Zhaoqing2, WANG Anbang2()   

  1. 1. Beijing Institute of Chemical Reagents Co. , Ltd. , Beijing 102607, China
    2. Institute of Chemical Defense, Beijing 100191, China
  • Received:2019-08-08 Revised:2019-08-22 Online:2020-01-05 Published:2020-01-10
  • Contact: Weikun WANG,Anbang WANG E-mail:hongyingliao@163.com;wangweikun2002@163.com;wab_wang2000@aliyun.com

摘要:

锂硫电池因其高能量密度而备受关注。电池性能与极片的含硫量、载硫量及电解液用量等因素密切相关,锂硫电池体系的复杂性导致多数情况下以扣式电池进行评价的数据失真。本文用1.8 A·h锂硫软包装电池在电解液与硫质量比为3.5∶1条件下,采用线性伏安扫描法(LSV)和恒流充放电法,研究了两种醚类电解液中电解质锂盐分别为双(三氟甲基磺酰)亚胺锂(LiTFSI)、六氟磷酸锂(LiPF6)和四氟硼酸锂(LiBF4)、溶剂比例为乙二醇二甲醚(DME):1,3-二氧五环(DOL)为1∶1(体积比)和2∶1(体积比)时对锂硫软包电池的首次充放电、放电中值电压、循环性能和充放电效率的影响。结果表明,LiTFSI和LiPF6均适用于锂硫软包电池,LiBF4不适用,LiPF6 /DME∶DOL=2∶1(体积比)的体系更有利于锂硫电池的容量发挥,对电池循环也有更佳效果。文章基于软包装电池的研究结果具有较高的实用化参考价值。

关键词: 锂硫软包电池, 电解液, 六氟磷酸锂

Abstract:

Lithium-sulfur batteries have attracted considerable attention due to their high energy density. Their battery performance is closely related to the sulfur loading, sulfur content of the cathode, and amount of electrolyte. The complexity of the lithium-sulfur battery systems causes data distortion with coin cells. Literature reports on the performance evaluation of soft-packed batteries are rare. Six ether-based electrolytes were studied by linear sweep voltammetry and galvanostatic charge-discharge methods along with the physicochemical parameters, conductivity, and viscosity. The electrolyte lithium salts were lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPF6), and lithium tetrafluoroborate (LiBF4). The mixed solvent volume ratios of 1,2-dimethoxyethane (DME) to 1, 3-dioxane ring (DOL) were 1∶1 and 2∶1. The effects of six electrolytes on the first charge-discharge cycle, median discharge voltage, cycling performance, and charge-discharge efficiency were analyzed using an electrolyte/sulfur ratio of 3.5∶1 with 1.8 A·h lithium-sulfur soft-packed batteries. The results denoted that LiPF6 was suitable for lithium-sulfur batteries as well as the conventional LiTFSI and mixed solvents in case of DME∶DOL = 2∶1, exhibiting better discharging capacity and a more effective cycling performance. The results based on Li-S soft-packed batteries are of high practical value.

Key words: Li-S soft packing batteries, electrolytes, lithium hexafluorophosphate

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