当前位置:文档之家 > 石墨烯包覆炭硫复合物正极材料的制备及其电化学性能

石墨烯包覆炭硫复合物正极材料的制备及其电化学性能

文章编号:1007-8827(2014)04-0309-07

石墨烯包覆炭硫复合物正极材料的制备及其电化学性能

李芳菲1,2,吕伟1,牛树章1,2,李宝华1

(1.清华大学深圳研究生院下一代动力与储能电池和炭功能材料工程实验室,广东深圳518055;

2.清华大学材料学院先进材料教育部重点实验室,北京100084)

摘要:利用石墨烯作为新型的阻挡层,设计并制备出具有核壳结构的石墨烯包覆多孔炭/硫复合材料,抑制锂硫电池中的 穿梭效应 ,以提高正极材料的循环性能㊂该结构利用多孔炭材料作为储存硫的载体,而石墨烯作为阻挡层可以限制充放电过程中形成的多硫化物向体相电解液中的扩散,从而实现对正极材料的容量和循环性能的提高㊂此外,提出一种简便的组装方法来实现石墨烯在多孔炭/硫复合材料表面的包覆㊂利用氧化石墨烯在液相还原过程中官能团的去除来降低亲水性,从而使其自发地包覆在不亲水的多孔炭/硫复合材料表面,形成石墨烯包覆的核壳结构㊂

关键词:锂硫电池;核壳结构;还原氧化石墨烯;炭硫复合

中图分类号:TB332文献标识码:A

收稿日期:2014-06-15;修回日期:2014-08-11

基金项目:国家重点基础研究发展计划(2014CB932400);国家自然科学基金(51202121,51232005);NSAF联合基金(U1330123);深圳市科技计划项目(JC201005310705A,JCYJ20120619152808478,JCYJ20130402145002382);广东省创新研发团队计划(2009010025).

通讯作者:李宝华,副研究员.E-mail:libh@http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html

作者简介:李芳菲,硕士研究生,E-mail:lbj19561109@http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html

Preparation and electrochemical performance

of a graphene-wrapped carbon/sulphur composite cathode

LI Fang-fei1,2,LU Wei1,NIU Shu-zhang1,2,LI Bao-hua1

(1.Engineering Laboratory for Next Generation Power and Energy Storage Batteries,

Engineering Laboratory for Functionalized Carbon Materials,Graduate School at Shenzhen,Tsinghua University,Shenzhen518055,China;

http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html boratory of Advanced Materials,School of Materials,Tsinghua University,Beijing100084,China)

Abstract:Graphene is used as a barrier film to suppress the shuttle effect and to improve the performance of activated carbon-sulphur hybrid cathode materials in a lithium-sulphur battery by forming a core-shell structure.Graphene wraps around the activated carbon-sulphur hybrid to form a core-shell structure,in which the porous carbon framework stores most of the sulphur and the gra-phene layer suppresses the movement of the soluble polysulfide in the electrolyte during charge-discharge,resulting in an improve-ment of capacity and cyclic stability during long-term cycling.Such a core-shell structure is formed by changing the hydrophilicity of graphene oxide during reduction,in which the hydrophobic graphene closely wraps around the hydrophobic carbon surface. Keywords: Lithium-sulphurbattery;Core-shell structure;Reduced graphene oxide;Carbon-sulphur compound Foundation item:National Key Basic Research Program of China(2014CB932400);National Natural Science Foundation of China (51202121,51232005);NSAF(U1330123);Shenzhen Technical Plan Project(JC201005310705A,

JCYJ20120619152808478,JCYJ20130402145002382);Guangdong Province Innovation R&D Team Plan for En-

ergy and Environmental Materials(2009010025).

Corresponding author:LI Bao-hua,Associate Professor.E-mail:libh@http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html

Author introduction:LI Fang-fei,Master candidate.E-mail:lbj19561109@http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html

English edition available online ScienceDirect(http://www.doczj.com/doc/8ed2da51dc36a32d7375a417866fb84ae45cc38c.html /science/journal/18725805).

DOI:10.1016/S1872-5805(14)60140-2

1 Introduction

In recent years,enormous effort has been
made to develop batteries with a higher capacity and energy density to meet the requirement for all-electric vehi-cles and green energy storage[1].Lithium-sulphur battery,newly emerged a few decades ago,occurs to people with its super high discharge capacity (1675mAh/g)and theoretical energy density

In recent years,enormous effort has been made to develop batteries with a higher capacity and energy density to meet the requirement for all-electric vehi-cles and green energy storage[1].Lithium-sulphur battery,newly emerged a few decades ago,occurs to people with its super high discharge capacity (1675mAh/g)and theoretical energy density

第29卷第4期

2014年8月新型炭材料

NEW CARBON MATERIALS Vol.29 No.4 Aug.2014