化学结合力载体在锂硫电池中的应用

Chemical Bonding Hosts for Lithium-Sulfur Batteries

在环境问题日益严峻,化石能源日益枯竭的今天,开发具有高比能的二次电池系统显得尤为重要。锂硫电池以其高理论能量密度和低环境影响的优势成为最有潜力的下一代电化学储能系统之一。然而受制于硫的绝缘性质以及由多硫化锂的溶解所引起的穿梭效应,锂硫电池的实用化进程还面临着诸多困难。为弥补常用的碳质载体对稳定硫电极的物理限制作用的不足,近年来对多硫化物具有强烈化学结合作用的载体材料的应用,显著提升了复合硫电极的综合性能,为锂硫电池正极材料的设计提供了新的思路。本文综述了各种具有化学吸附特性的载体材料在复合硫电极中的应用进展,具体包括:基于极性-极性作用固定多硫化物的金属氧化物、改性的碳质材料、能够与硫发生硫化作用的有机聚合物以及对多硫化物具有路易斯酸碱作用的金属有机骨架,重点阐述了这类载体材料与多硫化物的作用机理,并展望锂硫电池的发展方向。

With the ever-increasing environment problems and insufficient fossil energy,the development of high specific energy secondary battery systems is particularly important. Owing to their overwhelming advantages of high theoretical energy density and low environmental impact,lithium-sulfur batteries are considered as ones of the most promising next generation electrochemical energy storage devices. However,due to the insulating property of sulfur and the shuttle effect associated with the dissolution of the intermediate polysulfides,the practical application of lithium-sulfur battery is facing many challenges. To overcome the limited physical forces of the conventional carbonaceous hosts on sulfur electrode stabilization,the recent applications of host materials with strong chemical bondings to polysulfides have significantly enhanced the comprehensive performance of the composite sulfur electrode,and provide new ideas for the cathode designing of lithium-sulfur batteries. This review summarizes the application of various host materials with specific chemisorption properties and elaboratesthe function mechanisms between the high efficient host materials and polysulfide intermediates,such as metal oxide and modified carbonaceous materials based on a polar-polar interaction with polysulfides,functionalized organic polymers that rely on sulfurization to anchor sulfur/polysulfides,and metal organic framworks that exhibit Lewis acid-base interactions with polysulfides. This review prospects the development of the lithiumsulfur battery as well.