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Strong Surface‐Bound Sulfur in Carbon Nanotube Bridged Hierarchical Mo 2 C‐Based MXene Nanosheets for Lithium–Sulfur Batteries
Author(s) -
Lv LiPing,
Guo ChaoFei,
Sun Weiwei,
Wang Yong
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201804338
Subject(s) - sulfur , electrochemistry , materials science , mxenes , carbon nanotube , lithium (medication) , chemical engineering , carbon fibers , conductivity , electrode , nanotube , composite number , nanotechnology , chemistry , composite material , medicine , endocrinology , engineering , metallurgy
In this work, hydroxyl‐functionalized Mo 2 C‐based MXene nanosheets are synthesized by facilely removing the Sn layer of Mo 2 SnC. The hydroxyl‐functionalized surface of Mo 2 C suppresses the shuttle effect of lithium polysulfides (LiPSs) through strong interaction between Mo atoms on the MXenes surface and LiPSs. Carbon nanotubes (CNTs) are further introduced into Mo 2 C phase to enlarge the specific surface area of the composite, improve its electronic conductivity, and alleviate the volume change during discharging/charging. The strong surface‐bound sulfur in the hierarchical Mo 2 C‐CNTs host can lead to a superior electrochemical performance in lithium–sulfur batteries. A large reversible capacity of ≈925 mAh g − 1 is observed after 250 cycles at a current density of 0.1 C (1 C = 1675 mAh g −1 ) with good rate capability. Notably, the electrodes with high loading amounts of sulfur can also deliver good electrochemical performances, i.e., initial reversible capacities of ≈1314 mAh g −1 (2.4 mAh cm −2 ), ≈1068 mAh g −1 (3.7 mAh cm −2 ), and ≈959 mAh g −1 (5.3 mAh cm −2 ) at various areal loading amounts of sulfur (1.8, 3.5, and 5.6 mg cm −2 ) are also observed, respectively.