Graphene-Wrapped Anatase TiO2 Nanofibers as High-Rate and Long-Cycle-Life Anode Material for Sodium Ion Batteries
Anatase TiO 2 has been suggested as a potential sodium anode material, but the low electrical conductivity of TiO 2 often limits the rate capability, resulting in poor electrochemical properties. To address this limitation, we propose graphene-wrapped anatase TiO 2 nanofibers (rGO@TiO 2 NFs) through...
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Published in | Scientific reports Vol. 5; no. 1; p. 13862 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
10.09.2015
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | Anatase TiO
2
has been suggested as a potential sodium anode material, but the low electrical conductivity of TiO
2
often limits the rate capability, resulting in poor electrochemical properties. To address this limitation, we propose graphene-wrapped anatase TiO
2
nanofibers (rGO@TiO
2
NFs) through an effective wrapping of reduced graphene oxide (rGO) sheets on electrospun TiO
2
NFs. To provide strong electrostatic interaction between the graphene oxide (GO) sheets and the TiO
2
NFs, poly(allylamine hydrochloride) (PAH) was used to induce a positively charged TiO
2
surface by the immobilization of the -NH
3
+
group and to promote bonding with the negatively charged carboxylic acid (-COO
−
) and hydroxyl (-O
−
) groups on the GO. A sodium anode electrode using rGO@TiO
2
NFs exhibited a significantly improved initial capacity of 217 mAh g
−1
, high capacity retention (85% after 200 cycles at 0.2C) and a high average Coulombic efficiency (99.7% from the second cycle to the 200
th
cycle), even at a 5C rate, compared to those of pristine TiO
2
NFs. The improved electrochemical performances stem from highly conductive properties of the reduced GO which is effectively anchored to the TiO
2
NFs. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2045-2322 2045-2322 |
DOI: | 10.1038/srep13862 |