PEO基锂硫二次聚合物电池  

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

作　　者：李亚娟[1] 詹晖[2] 黄可龙[1] 周运鸿[2] 

机构地区：[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

出　　处：《化学学报》2010年第18期1850-1854,共5页Acta Chimica Sinica

基　　金：高等学校博士学科点基金(No.20090162120011);中国博士后基金(No.20080440989);湖南省科技计划(No.2009GK3079)基金资助项目

摘　　要：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(polye thylene 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.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, prelimi- nary 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.

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 

分 类 号：TM912[电气工程—电力电子与电力传动]