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Honeycomb‐Like Spherical Cathode Host Constructed from Hollow Metallic and Polar Co 9 S 8 Tubules for Advanced Lithium–Sulfur Batteries
Author(s) -
Dai Chunlong,
Lim JinMyoung,
Wang Minqiang,
Hu Linyu,
Chen Yuming,
Chen Zhaoyang,
Chen Hao,
Bao ShuJuan,
Shen Bolei,
Li Yi,
Henkelman Graeme,
Xu Maowen
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201704443
Subject(s) - polysulfide , cathode , materials science , dissolution , sulfur , lithium (medication) , electrochemistry , chemical engineering , redox , kinetics , composite number , conductivity , metal , electrode , nanotechnology , inorganic chemistry , composite material , chemistry , electrolyte , metallurgy , medicine , physics , quantum mechanics , engineering , endocrinology
The practical application of lithium‐sulfur (Li‐S) batteries remains remote because of rapid capacity fade caused by the low conductivity of sulfur, dissolution of intermediate lithium polysulfides, severe volumetric expansion, and slow redox kinetics of polysulfide intermediates. Here, to address these obstacles, a new sulfiphilic and highly conductive honeycomb‐like spherical cathode host constructed from hollow metallic and polar Co 9 S 8 tubes is designed. Co 9 S 8 can effectively bind polar polysulfides for prolonged cycle life, due to the strong chemisorptive capability for immobilizing the polysulfide species. The hollow structure, as the sulfur host, can further prevent polysulfide dissolution and offer sufficient space to accommodate the necessary volume expansion. Well‐aligned tubular arrays provide a conduit for rapid conduction of electrons and Li‐ions. More importantly, the experimental results and theoretical calculations show that Co 9 S 8 plays an important catalytic role in improving the electrochemical reaction kinetics. When used as cathode materials for Li–S batteries, the S@Co 9 S 8 composite cathode exhibits high capacity and an exceptional stable cycling life demonstrated by tests of 600 cycles at 1 C with a very low capacity decay rate of only ≈0.026% per cycle.