Lithium-sulfur(Li-S) batteries with high energy densities have received increasing attention.However,the electrochemical performance of Li-S batteries is still far from the satisfactory of the practical application,which can be mainly attributed to the shuttling of polysulfides and the slow reaction kinetics of polysulfide conversion.To address this issue,a 3D porous carbon structure constructed by 2D N-doped graphene and 1D carbon nanotubes with embedded Fe3C/Fe nanoparticles(NG@Fe3C/Fe) was designed and prepared by a simple programmed calcination method for the modification of polypropylene(PP) separator.The Fe3C/Fe nanoparticles demonstrate an excellent catalytic conversion and strong chemisorption towards polysulfides,while the unique architecture of N-doped graphene promotes the Li+/electron transfer and the physical adsorption of polysulfides.The electrochemical performance of the Li-S batteries with the NG@Fe3C/Fe-modified separator is significantly improved.A large discharge capacity of 1481 mA·h·g-1 is achieved at 0.2 C(1 C=1675 mA/g),and a high capacity of 601 mA·h·g-1 is maintained after discharged/charged for 500 cycles at a current rate of 1 C.This work provides a new approach for the development of high-performance Li-S batteries through the modification of the PP separator by rationally designed composites with large adsorption capability to polysulfides,good wettability to the electrolyte and high catalytic property.

LIU Yusi;ZHAO Xinghe;LI Sesi;ZHANG Qiang;WANG Kaixue;CHEN Jiesheng

Shanghai Electrochemical Energy Devices Research Center,School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shang-hai 200240,P.R.China

高等学校化学研究（英文版）

[1]LIU Yusi;ZHAO Xinghe;LI Sesi;ZHANG Qiang;WANG Kaixue;CHEN Jiesheng-.Towards High-performance Lithium-Sulfur Batteries:the Modification of Polypropylene Separator by 3D Porous Carbon Structure Embedded with Fe3C/Fe Nanoparticles)[J].高等学校化学研究（英文版）,2022(01):147-154

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