基于LLZO的复合电解质对Li-S电池穿梭效应的抑制  

LLZO-based hybrid electrolyte to suppress the shuttle effect of Li-S battery

作　　者：郑鸿鹏[1] 陈挺[1] 徐比翼[1] 田然[1] 刘河洲[1] 段华南[1] 王可[2] 吴勇民[2] 

机构地区：[1]上海交通大学材料科学与工程学院,金属基复合材料国家重点实验室,上海200240 [2]上海空间电源研究所,空间电源技术国家重点实验室,上海200245

出　　处：《储能科学与技术》2016年第5期719-724,共6页Energy Storage Science and Technology

基　　金：国家自然科学基金(11304198);航天先进技术联合研究中心技术创新项目(USCAST-2015-40);上海交通大学材料基因组联合研究中心项目(15X190030002)

摘　　要：相对于传统锂离子电池,锂硫电池具有高比容量、高能量密度、环境友好等特点,因而在作为未来的动力电池和储能电池上被寄予厚望。但是,目前的锂硫电池存在穿梭效应、硫利用率低、充放电体积变化大等问题。本工作主要针对硫的穿梭效应、硫在负极材料沉积等问题开展研究。首先制备出室温离子传导率为6.4×10^(-4) S/cm的含锂石榴石(LLZO)固态电解质;再引入LLZO固态电解质作为隔膜,使用石墨烯气凝胶复合硫正极组装电池进行测试。充放电循环测试结果表明,该电池结构可以解决锂硫电池难以有效充电的问题,获得了接近100%的库仑效率。此外,采用XRD、SEM等检测手段分析了充放电循环后LLZO隔膜的微观物相结构,证明了LLZO能够有效阻挡多硫化物,抑制穿梭效应。Compared with traditional lithium-ion batteries, lithium-sulfur （Li-S） batteries have many advantages such as high specific capacity, high energy density and environment-friendly characteristic, which makes them a promising system for electric vehicles and energy storage. However, the Li-S batteries have been facing problems, such as the shuttle effect, low efficiency, and volume change during cycling. In this paper, we try to suppress the shuttle effect by introducing a LLZO-based hybrid electrolyte. Firstly, we prepare the dense LLZO solid electrolyte with the ionic conductivity of 6.4 × 10^-4 S/cm; then we use the LLZO as the separator, Li anode, and S-C composite cathode to assemble Li-S test cells. The electrochemical test results indicate that the cell can obtain a Coulomb efficiency closely to 100%. The post-test examination shows that element S can only be found on the side of LLZO facing the S-C cathode, not on the side facing the Li anode, suggesting that the LLZO can effectively block the transport of the dissolved polysulfides.

关 键 词：LLZO 锂硫电池 氧化石墨烯 穿梭效应 库仑效率 

分 类 号：TM912[电气工程—电力电子与电力传动]