锂硫电池电解质研究进展  

Review of Electrolyte for Lithium Sulfur Battery

作　　者：金朝庆[1] 谢凯[1] 洪晓斌[1] 

机构地区：[1]国防科技大学航天科学与工程学院材料科学与工程系,长沙410073

出　　处：《化学学报》2014年第1期11-20,共10页Acta Chimica Sinica

摘　　要：锂硫电池由于其高能量密度(理论高达2600 Wh/kg)、低成本、环境友好等优点而广受关注.但是锂硫电池仍存在正极活性物质利用率低、循环性能差等问题.造成这些问题的主要原因是易溶于有机电解液的中间产物聚硫锂Li2Sn(4≤n≤8)和不溶于有机电解液的硫化锂造成的.简要介绍了锂硫电池体系的主要问题,并结合本研究小组的研究,对锂硫电池用电解质体系从有机电解液组成、电解液添加剂、聚合物电解质和无机固体电解质等方面进行了详细的综述,最后对电解质的发展前景进行了展望.Of the high energy density chemical power systems currently being considered, lithium/sulfur （Li/S） batteries which use elemental sulfur as the cathode and lithium metal as the anode, are attracting increased attention in recent decades. Li/S batteries have a high energy density （2600 Wh/kg in theoretical, about 400 Wh/kg in practice nowadays）, consist of abundant raw materials, are low cost and environmentally friendly. Although the rechargeable Li/S batteries possess more advantages over the conventional lithium ion batteries, the practical use faces with a variety of problems such as low utiliza- tion of sulfur and bad cycle life. Central to the operation of Li/S batteries are polysulfide anions （S2-, 4≤n ≤8）], which are intermediate products generated during the electrochemical reduction process. These anions have high solubility in organic electrolytes. On the one hand, these anions typically diffuse to the lithium anode according to a concentration gradient and directly react with the anode. This diffusion causes an internal shuttle phenomenon and significantly corrodes the anode, which decreases active material utilization during the discharge process and reduces its cycle life. On the other hand, there are residual Li2S2 and/or Li2S on the surface of sulfur cathode and Li anode even at 1000 depth of charge. The formation of Li2S2 and Li2S increasing with cycling results in active material loss. These drawbacks have seriously retarded industrial production of Li/S batteries. In this paper, combining with the works of our research team, the main research directions and the latest development of the electrolyte to enhance the cycle performance of Li-S batteries are reviewed from the aspects of the composition of the liquid electrolyte, the additives in liquid electrolyte, the polymer electrolyte and the inorganic electro- lyte. At the meanwhile, the principle, the preparation of electrolyte, the influence on the performance of Li-S batteries, and oroblem in each research are analyzed. Finally

关 键 词：锂硫电池 有机电解液 离子液体电解质 电解液添加剂 有机电解质 无机电解质 

分 类 号：TM912[电气工程—电力电子与电力传动]