title: Flexible copper-stabilized sulfur-carbon nanofibers with excellent electrochemical performance for Li-S batteries.
abstract: By rational design, we fabricated a flexible and free-standing copper-immobilized sulfur-porous carbon nanofiber (denoted as S@PCNFs-Cu) electrode by simply impregnating sulfur into electrospun derived Cu embedded porous carbon nanofibers (PCNFs-Cu). The PCNF film with a 3D interconnected structure is used as a conducting matrix to encapsulate sulfur. In addition, the introduction of Cu leads to the formation of a chemical bond between Cu and S, preventing the dissolution of polysulfide during cycling. The micropores and mesopores of PCNF hosts provide free space to accommodate the volume change of S and polysulfide. When used as a cathode material for Li-S batteries, the S@PCNFs-Cu (S content: 52 wt%) exhibits much better electrochemical performance compared to the Cu-free S@PCNF electrode. The S@PCNFs-Cu displays high reversible capacity (680 mA h g(-1) after 100 cycles at 50 mA g(-1)), excellent rate capability (415 mA h g(-1) at 1 A g(-1)) and super Coulombic efficiency of 100%. This strategy of stabilizing S with a small amount of copper nanoparticles can be a very promising method to prepare free-standing cathode material for high-performance Li-S batteries.
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, Anhui, Hefei 230026, China. yanyumse@ustc.edu.cn.
authors.forename: Linchao
authors.initials: L
authors.lastname: Zeng
authors.forename: Yu
authors.initials: Y
authors.lastname: Jiang
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Weihan
authors.initials: W
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu