摘要
随着便携式电子设备、新能源电动汽车和储能电网的快速发展,人类对经济高效的电化学储能(EES)系统的需求越来越大。锂硫电池由于成本低、取材广、效率高、质量轻、硫元素零污染等优势,已成为当前EES系统中应用范围最广的储能器件之一。然而,因正极硫的利用率低、锂枝晶生长、体积膨胀和长链多硫化物的穿梭效应等问题,严重制约了其商业化进程。因此,寻找新的硫宿主材料迫在眉睫。本工作通过开发煤基氧化石墨烯复合材料试图解决上述问题,设计了一种含氧官能团的煤基氧化石墨烯,对多硫化物的空间限域或物理捕捉。并通过煤基石墨烯(G)和被氧化后的煤基氧化石墨烯(GO),组装成完整的扣式锂硫电池;实现了在高倍率3 C条件下进行500次长循环,比容量从初始622.5 mAh/g维持到448.2 mAh/g,比容量保持率为72%,比容量的衰减率为0.056%,经过多次验证,得出含有丰富功能基团的煤基氧化石墨烯能够为中间产物多硫化锂提供更丰富的极性位点,在一定程度上显示出更高的亲硫性,再经过一系列的电化学表征来证明该材料在锂硫电池中的优势,为锂硫电池的进一步发展提供借鉴和方法。
With the rapid development of portable electronic devices,new energy electric vehicles,and energy storage grids,the demand for developing economical and efficient electrochemical energy storage(EES)systems has increased.Lithium-sulfur batteries have become one of the most widely used EES system because of their low cost,wide range of materials,high efficiency,light weight,and zero sulfur pollution.However,their commercialization process has been seriously restricted due to the low utilization rate of positive sulfur,the growth of lithium dendrites,volume expansion,and the shuttle effect of long chain polysulfide.Therefore,there is a need for new sulfur host materials.This paper is devoted to the development of coal-based graphene oxide(GO)composites to solve the above problems.Herein,a coal-based GO containing oxygen functional group is designed to capture the spatial limit or physical range of polysulfide and used to assemble a complete button lithiumsulfur battery.After 500 long cycles at a high rate of 3 C,the specific capacity changes from the initial 622.5 mAh/g to 448.2 mAh/g,the specific capacity retention rate is 72%,and the specific capacity decay rate is 0.056%.Our findings show that coal-based GO containing rich functional groups can provide more abundant polar sites for the intermediate lithium polysulfide,showing higher sulfur affinity to a certain extent.After a series of electrochemical characterizations to prove the advantages of this material in lithium sulfur batteries,to provide reference and methods for the further development of lithium sulfur batteries.
作者
谭超
王超
TAN Chao;WANG Chao(College of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,Guangdong,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2023年第4期1025-1033,共9页
Energy Storage Science and Technology
基金
国家自然科学基金重点国际(地区)合作研究项目(500190118)。
关键词
氧化石墨烯
功能基团
锂硫电池
多硫化锂
graphene oxide
functional group
lithium-sulfur batteries
lithium polysulfide
