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Simultaneous Polymerization Enabled the Confinement of Size‐Adjustable TiO 2 Nanocrystals in S‐Doped Carbons for High‐Rate Anode Materials
Author(s) -
Gao Pengyuan,
Lu Yun,
Deng Shuyi,
Cui Xun,
Zhang Qing,
Yang Yingkui
Publication year - 2019
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201900247
Subject(s) - materials science , nanocrystal , chemical engineering , anode , carbonization , anatase , carbon fibers , polymerization , nanoparticle , heteroatom , nanocomposite , electrochemistry , nanotechnology , composite material , electrode , photocatalysis , polymer , composite number , organic chemistry , catalysis , chemistry , scanning electron microscope , ring (chemistry) , engineering
Homogeneous confinement of metal oxide nanoparticles into the heteroatom‐doped carbon matrix is highly desirable but remains challenging to develop high‐performance anode materials. Herein, a facile simultaneous polymerization of 2‐thiophenemethanol (ThM) and titanium ethoxide (TTEO) is proposed to incorporate ultrafine anatase TiO 2 nanocrystals into the continuous S‐doped carbon framework by carbonizing the as‐produced TiO 2 /poly(2‐thiophenemethanol) composites. This in situ crafting process spatially suppresses the growth of TiO 2 by the polymerization of ThM, thus producing size‐adjustable TiO 2 nanocrystals (5–50 nm) by tailoring the ratio of TTEO to ThM. It is found that smaller TiO 2 nanocrystals are generated using the lower TTEO‐to‐ThM ratio. When used as lithium‐ion batteries (LIBs) anode, TiO 2 /S‐doped carbon (TSC) shows larger reversible capacity, superior rate capability, and better cycling stability compared to pure TiO 2 . A typical TSC with the smallest TiO 2 nanocrystals (8 nm) shows the reversible capacity as high as 386 mAh g −1 at 50 mA g −1 , and retains 55% of initial capacity at 500 mA g −1 , and 96.8% capacity after 500 cycles at 1000 mA g −1 . The excellent electrochemical performance is attributed to the shortened ion diffusion path of ultrafine TiO 2 and the improved electronic conductivity, structural stability, and surface/interface nature by the S‐doped carbon matrix.