高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

1,3-二氧戊环基LiCF3SO3电解液对锂硫电池正极材料单质硫的电化学性能影响

苑克国, 王安邦, 余仲宝, 王维坤, 杨裕生
   

  1. 防化研究院军用化学电源研发中心, 北京 100083
  • 收稿日期:2005-08-24 修回日期:1900-01-01 出版日期:2006-09-10 发布日期:2006-09-10
  • 通讯作者: 王安邦

Effects of LiCF3SO3 Dioxolane-based Electrolytes on the Electrochemical Properties of the Sulfur Cathode for Rechargeable Li/S Batteries

YUAN Ke-Guo, WANG An-Bang, YU Zhong-Bao, WANG Wei-Kun, YANG Yu-Sheng   

  1. Center of Military Chemical Power Sources, Institute of Chemical Defense, Beijing 100083, China
  • Received:2005-08-24 Revised:1900-01-01 Online:2006-09-10 Published:2006-09-10
  • Contact: WANG An-Bang

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摘要： 测试了二元和多元溶剂组分的1,3-二氧戊环基LiCF3SO3电解液的粘度、离子电导率和单质硫的溶解度. 研究结果表明, 由较强的给电子能力溶剂组成的低粘度电解液较容易提高单质硫的氧化还原反应活性和可逆性能, 有利于提高单质硫在2.10 V附近的低放电平台电位和放电比容量. DOL-DME LiCF3SO3电解液能够较好地改善单质硫电极的表面钝化层结构, 促进电活性物质离子扩散和降低界面电荷传递阻抗, 从而表现出很好的放电倍率特性. 在室温下充放电流密度分别为0.1和0.2
mA/cm2时, 单质硫的首次放电比容量为792 mA·h/g, 第29次放电比容量达到412 mA·h/g.

关键词: 电解液, 锂硫电池, 单质硫, 正极材料, 溶剂

Abstract: In order to study the effects of electrolytes on the electrochemical properties of sulfur cathode for rechargeable lithium sulfur batteries, viscosities, ionic conductivities and sulfur solubilities of binary and multiple solvent 1 mol/L LiCF3SO3 electrolytes based on 1,3-dioxolane(DOL) were measured. The results from cyclic voltammograms and various discharge profiles indicated that the electrolyte with the lower viscosity and the higher donor number could favor to improve the redox reaction activity and reversibility of the sulfur cathode, and correspondingly to improve the low discharge voltage plateau and the discharge rate. Furthermore, an electrolyte with the lower viscosity preferred to improve the surface layer microstructure of the sulfur electrode, to increase the ionic diffusion rate of electroactive species and to decrease the charge transfer resistance. At the charge/discharge current density of 0.1/0.2 mA/cm2, sulfur cathode achieved an initial discharge specific capacity of 792 mA·h/g and the specific capacity of 412 mA·h/g of the 29th discharge.

Key words: Electrolyte, Lithium sulfur battery, Elemental sulfur, Cathode material, Solvent

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