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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (18): 1850-1854. 上一篇    下一篇

研究论文

PEO基锂硫二次聚合物电池

李亚娟*,1，詹晖*,2，黄可龙1，周运鸿2   

  1. (1中南大学化学化工学院 长沙 410083)
    (2武汉大学化学与分子科学学院 武汉 430072)
  • 投稿日期:2009-08-25 修回日期:2010-03-08 发布日期:2010-05-27
  • 通讯作者: 李亚娟 E-mail:yajuanlee@hotmail.com
  • 基金资助:

    中国博士后基金(No. 20080440989)；中南大学博士后基金

All Solid State Lithium Sulfur Rechargeable Battery with PEO-based Polymer Electrolytes

Li Yajuan*,1 Zhan Hui*,2 Huang Kelong1 Zhou Yunhong2   

  1. (1 Institute of Chemistry and Chemical Engineering, Central South University, Changsha 410083)
    (2 College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072)
  • Received:2009-08-25 Revised:2010-03-08 Published:2010-05-27

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被引次数

5 | 1

分别对单质硫和PABTH (polyanthra [1 ,9 ,8 -b,c,d,e][4 ,10 ,5 -b ,c ,d ,e ]bis-[1,6,6a(6a-SⅣ)trithia]pentalene)在PEO (polyethylene oxide)基聚合物电解质中的电化学性能进行了研究. 研究发现单质硫和PABTH在PEO基聚合物电解质中都存在放电产物溶解现象, 说明醚基电解液即使以聚合物形式存在(如PEO基聚合物电解质)也不能有效抑制硫电极放电产物的溶解损失. 因此, 必须设计合成具有特定结构的电解质溶剂, 以抑制硫电极放电产物的溶解. 另外, 硫及有机硫化物在PEO基聚合物电解质中的利用率较低, 这主要是由于硫及有机硫化物不是离子导体, Li＋在硫及有机硫化物中的扩散系数较低, 同时, 传输Li＋的PEO分子量较大, Li＋不能被有效传输至材料颗粒的内部. 因此, 全固态聚合物电解质不适合锂硫二次电池, 液态小分子电解质溶剂更有利于锂硫二次电池发挥其高比容量.

关键词: 锂硫二次电池, 容量衰减, 聚合物电解质, PEO, 溶剂分子设计

The electrochemical performances of S8 and polyanthra [1 ,9 ,8 -b,c,d,e][4 ,10 ,5 -b ,c ,d , e ]bis-[1,6,6a(6a-SIV)trithia]pentalene (PABTH) in PEO-based polymer electrolyte are studied. It s found that there are phenomena of the solution of reduction products in the discharging process for Li/PEO-based polymer electrolyte/S8 cell and Li/PEO-based polymer electrolyte/PABTH cell. It suggests that ether-based electrolytes even in the form of polymer (such as PEO-based Polymer Electrolytes) can t alleviate the loss of active material in sulfur electrode for the dissolution of its reduction products. For alleviating the solution of reduction production, designing electrolyte solvent with a special structure is necessary. Moreover, preliminary investigation on discharge capacity of the Li/PEO-based polymer electrolyte/S8 cell and PABTH/ PEO20LiTFSI/Li cell show that the utilization of the active material is lower than that in liquid electrolyte. It due to that sulfur and PABTH isn t ionic conductor, and the diffusivity values of Li＋ in sulfur and PABTH are very low. PEO molecular with a large volume can t penetrate into particle of sulfur and PABTH carrying Li＋, this is another main reason. From this point of view, electrolyte solvent with a small volume is favorable to the utilization of sulfur and PABTH.

Key words: rechargeable lithium sulfur battery, capacity fade, polymer electrolyte, PEO-based, molecular design of electrolyte solvent