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Hierarchical Sulfur‐Based Cathode Materials with Long Cycle Life for Rechargeable Lithium Batteries
Author(s) -
Wang Jiulin,
Yin Lichao,
Jia Hao,
Yu Haitao,
He Yushi,
Yang Jun,
Monroe Charles W.
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201300742
Subject(s) - nanosheet , faraday efficiency , materials science , graphene , sulfur , nanoparticle , chemical engineering , composite number , lithium (medication) , cathode , porosity , pyrolysis , lithium–sulfur battery , nanotechnology , electrochemistry , composite material , electrode , chemistry , metallurgy , medicine , endocrinology , engineering
Composite materials of porous pyrolyzed polyacrylonitrile–sulfur@graphene nanosheet (pPAN–S@GNS) are fabricated through a bottom‐up strategy. Microspherical particles are formed by spray drying of a mixed aqueous colloid of PAN nanoparticles and graphene nanosheets, followed by a simple heat treatment with elemental sulfur. The pPAN–S primary nanoparticles are wrapped homogeneously and loosely within a three‐dimensional network of graphene nanosheets (GNS). The hierarchical pPAN–S@GNS composite shows a high reversible capacity of 1449.3 mAh g −1 sulfur or 681.2 mAh g −1 composite in the second cycle; after 300 cycles at a 0.2 C charge/discharge rate the capacity retention is 88.8 % of its initial reversible value. Additionally, the coulombic efficiency (CE) during cycling is near 100 %, apart from in the first cycle, in which CE is 81.1 %. A remarkable capacity of near 700 mAh g −1 sulfur is obtained, even at a high discharge rate of 10 C. The superior performance of pPAN–S@GNS is ascribed to the spherical secondary GNS structure that creates an electronically conductive 3D framework and also reinforces structural stability.