Nitrogen‐Doped Hollow Carbon Polyhedrons with Carbon Nanotubes Surface Layers as Effective Sulfur Hosts for High‐Rate, Long‐Lifespan Lithium–Sulfur Batteries. Issue 24 (22nd December 2020)

• Record Type: Journal Article
• Authors: Fan, Bin; Zhao, Dengke; Zhou, Wei; Xu, Wei; Liang, Xinghua; He, Guoqiang; Wu, Zexing; Li, Ligui
• Is Part Of: ChemElectroChem. Volume 7:Issue 24(2020)
• Page Start: 4990
• Page End: 4998
• Publication Date: 2020-12-22
• Subjects: Lithium-sulfur batteries -- Hollow carbon polyhedrons -- CNTs -- Nitrogen doping -- Rate performance; Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.202001310
• Languages: English
• ISSNs: 2196-0216

Abstract

Abstract: Effectively confining lithium polysulfides inside porous material matrix with a high electrical conductivity represents a judicious way to extend lifespan and enhance rate performance of lithium‐sulfur (Li‐S) batteries. Herein, nitrogen‐doped hollow carbon polyhedrons with a thin CNTs conductive surface layer (CNTs/HNC) were prepared by directly pyrolyzing the CNTs coated ZIF‐8 polyhedrons crystallite precursors, and subsequently served as sulfur hosts in Li‐S batteries. The resulted product CNTs/HNC‐800 comprises a nitrogen content of 4.94 at.% as well as a high electrical conductivity of 8.43×10 −1 S cm −1, which help to effectively adsorb/confine lithium polysulfides and substantially improve the rate capacity of Li‐S batteries. With a sulfur loading of 1.60 mg cm −2, the S@CNTs/HNC based cathode shows a discharge capacity of 870.7 mAh g −1 at 1.0 C, and can maintain 76.4 % of its initial capacity after 500 charge‐discharge cycles, corresponding to a capacity fade rate of only 0.047 % per cycle. While with a higher sulfur loading of 2.46 mg cm −2, a discharge capacity of 649.7 mAh g −1 can be achieved at 0.5 C, along with a capacity fade rate of merely 0.044 % per cycle during 200 cycles. When sulfur loading is further increased to 5.39 mg cm −2, it can also maintain a considerable initial discharge capacity of 812 mAh g −1 at 0.1 C. This work enriches the ways to prepare complicate nano structured sulfur hosts for long‐life and high‐rate Li‐S batteries. Abstract : Welcoming carbon : Nitrogen‐doped hollow carbon polyhedrons with highly conductive carbon nanotubes surface layers can serve as efficient sulfur hosts for high‐rate long‐life Li‐S batteries.