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A High‐Kinetics Sulfur Cathode with a Highly Efficient Mechanism for Superior Room‐Temperature Na–S Batteries
Author(s) -
Yan Zichao,
Liang Yaru,
Xiao Jin,
Lai Weihong,
Wang Wanlin,
Xia Qingbing,
Wang Yunxiao,
Gu Qinfen,
Lu Huanming,
Chou ShuLei,
Liu Yong,
Liu Huakun,
Dou ShiXue
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201906700
Subject(s) - cathode , sulfur , materials science , dissolution , chemical engineering , kinetics , carbon fibers , redox , polysulfide , electrocatalyst , diffusion , nanotechnology , electrode , chemistry , electrochemistry , electrolyte , metallurgy , composite material , physics , quantum mechanics , composite number , engineering , thermodynamics
Applications of room‐temperature–sodium sulfur (RT‐Na/S) batteries are currently impeded by the insulating nature of sulfur, the slow redox kinetics of sulfur with sodium, and the dissolution and migration of sodium polysulfides. Herein, a novel micrometer‐sized hierarchical S cathode supported by FeS 2 electrocatalyst, which is grown in situ in well‐confined carbon nanocage assemblies, is presented. The hierarchical carbon matrix can provide multiple physical entrapment to polysulfides, and the FeS 2 nanograins exhibit a low Na‐ion diffusion barrier, strong binding energy, and high affinity for sodium polysulfides. Their combination makes it an ideal sulfur host to immobilize the polysulfides and achieve reversible conversion of polysulfides toward Na 2 S. Importantly, the hierarchical S cathode is suitable for large‐scale production via the inexpensive and green spray‐drying method. The porous hierarchical S cathode offers a high sulfur content of 65.5 wt%, and can deliver high reversible capacity (524 mAh g −1 over 300 cycles at 0.1 A g −1 ) and outstanding rate capability (395 mAh g −1 at 1 A g −1 for 850 cycles), holding great promise for both scientific research and real application.