储能科学与技术 ›› 2017, Vol. 6 ›› Issue (6): 1273-.doi: 10.12028/j.issn.2095-4239.2017.0062

• 特约文章 • 上一篇    下一篇

无机熔融盐电解质在锂空气电池的应用

陈婉琦，张  旺，尹  微，王  朵，沈  越，黄云辉   

  1. 华中科技大学材料与科学工程学院，湖北 武汉 430074
  • 收稿日期:2017-05-18 修回日期:2017-05-23 出版日期:2017-11-01 发布日期:2017-11-01
  • 通讯作者: 沈越，副教授，主要研究方向为锂空气电池，E-mail：shenyue1213@mail.hust.edu.cn。
  • 作者简介:陈婉琦（1992—），女，硕士研究生，研究方向为锂空气电池，E-mail：chenwanqi2016@163.com
  • 基金资助:
    国家自然科学基金项目（51672098，51361130151），长江学者与大学创新研究团队计划项目（IRT14R18）。

Application of inorganic melting salt electrolyte in lithium-air battery

CHEN Wanqi, ZHANG Wang, YIN Wei, WANG Duo, SHEN Yue, HUANG Yunhui   

  1. School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2017-05-18 Revised:2017-05-23 Online:2017-11-01 Published:2017-11-01

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摘要： 采用双氟磺酰亚氨锂-双氟磺酰亚氨钾-双氟磺酰亚氨铯（LiFSA-KFSA-CsFSA）（LKC）三元无机熔融盐作为锂空气电池电解质。通过电化学阻抗谱（EIS）、燃烧实验和循环伏安法（CV）来考察LKC熔融盐的电化学性质与物理特性。此外，通过充放电测试并结合扫描电子显微镜（SEM）、X射线衍射（XRD）等表征手段来分析LKC熔融盐基锂空气电池的电化学性能。结果表明，LKC熔融盐具有高离子电导率，电化学性质稳定。LKC熔融盐电解质为无机物，不含碳元素，不会燃烧，同时避免了在电池的循环过程中由电解质分解导致副产物碳酸锂的生成。LKC熔融盐基锂空气电池在50 mA/g的电流密度下，电池首圈放电容量为4258 mA·h/g，充电平台为3.83 V，库仑效率约为95%，优于一般有机电解液基锂空气电池。

关键词: 双氟磺酰亚胺盐, 锂空气电池, 熔融盐电解质, 碳酸锂

Abstract:

Ternary molten salt based on bis(fluoroalkylsulfonyl)amide anions (LiFSA-KFSA-CsFSA) as a new class of electrolyte was applied in lithium-air batteries. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and combustion experiments were employed to explore the electrochemical and physical properties of this molten salt electrolyte. The electrochemical performance of molten salt-based lithium air battery was analyzed by means of charge-discharge measurement coupled with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicat that LiFSA-KFSA-CsFSA（LKC）molten salt has much higher ionic conductivity and showed good electrochemical stability. With no carbon component, LKC inorganic molten salt was nonflammable. Furthermore, LKC salt could prevent the formation of insulate and insoluble lithium carbonate originated from electrolyte decomposition during cycling. The lithium-air batteries based on LKC molten salt had an initial discharge capacity of 4 258 mA·h·g1, a charge potential of 3.83 V and the coulombic efficiency was 95% at 50 mA·g1, performing better than the common organic electrolyte-based lithium air battery.

Key words: bis(trifluoromethylsulfonyl)amides, lithium-air battery, molten salt electrolyte, lithium carbonate