• 文献标题:   High-Performance Lithium-Sulfur Batteries with a Self-Supported, 3D Li2S-Doped Graphene Aerogel Cathodes
  • 文献类型:   Article
  • 作  者:   ZHOU GM, PAEK E, HWANG GS, MANTHIRAM A
  • 作者关键词:  
  • 出版物名称:   ADVANCED ENERGY MATERIALS
  • ISSN:   1614-6832 EI 1614-6840
  • 通讯作者地址:   Univ Texas Austin
  • 被引频次:   113
  • DOI:   10.1002/aenm.201501355
  • 出版年:   2016

▎ 摘  要

Lithium-sulfur (Li-S) batteries are being considered as the next-generation high-energy-storage system due to their high theoretical energy density. However, the use of a lithium-metal anode poses serious safety concerns due to lithium dendrite formation, which causes short-circuiting, and possible explosions of the cell. One feasible way to address this issue is to pair a fully lithiated lithium sulfide (Li2S) cathode with lithium metal-free anodes. However, bulk Li2S particles face the challenges of having a large activation barrier during the initial charge, low active-material utilization, poor electrical conductivity, and fast capacity fade, preventing their practical utility. Here, the development of a self-supported, high capacity, long-life cathode material is presented for Li-S batteries by coating Li2S onto doped graphene aerogels via a simple liquid infiltration-evaporation coating method. The resultant cathodes are able to lower the initial charge voltage barrier and attain a high specific capacity, good rate capability, and excellent cycling stability. The improved performance can be attributed to the (i) cross-linked, porous graphene network enabling fast electron/ion transfer, (ii) coated Li2S on graphene with high utilization and a reduced energy barrier, and (iii) doped heteroatoms with a strong binding affinity toward Li2S/lithium polysulfides with reduced polysulfi de dissolution based on first-principles calculations.