One of the most promising anode materials for Li-ion batteries, Li4Ti5O12, has attracted attention because it is a zero-strain Li insertion host having a stable insertion potential. In this study, we suggest two different synthetic processes to prepare Li4Ti5O12 using anatase TiO2 nanoprecursors. TiO2 powders, which have extraordinarily large surface areas of more than 250 m2 g-1, were initially prepared through the urea-forced hydrolysis/precipitation route below 100°C. For the synthesis of Li4Ti5O12, LiOH and Li2CO3 were added to TiO2 solutions prepared in water and ethanol media, respectively. The powders were subsequently dried and calcined at various temperatures. The phase and morphological transitions from TiO2 to Li4Ti5O12 were characterized using X-ray powder diffraction and transmission electron microscopy. The electrochemical performance of nanosized Li4Ti5O12 was evaluated in detail by cyclic voltammetry and galvanostatic cycling. Furthermore, the high-rate performance and long-term cycle stability of Li4Ti5O12 anodes for use in Li-ion batteries were discussed

Hwang, In-Sung

Jin, Yun-Ho

Kim, Dong-Wan

Min, Kyung-Mi

Park, Kyung-Soo

Seo, Seung-Deok

Shim, Hyun-Woo

Nanoscale Research Letters

English

PubMed

Springer - Publisher Connector

NANO EXPRESS Open Access
Facile synthesis of nano-Li4 Ti5O12 for high-rate
Li-ion battery anodes
Yun-Ho Jin, Kyung-Mi Min, Hyun-Woo Shim, Seung-Deok Seo, In-Sung Hwang, Kyung-Soo Park and
Dong-Wan Kim*
Abstract
One of the most promising anode materials for Li-ion batteries, Li4Ti5O12, has attracted attention because it is a
zero-strain Li insertion host having a stable insertion potential. In this study, we suggest two different synthetic
processes to prepare Li4Ti5O12 using anatase TiO2 nanoprecursors. TiO2 powders, which have extraordinarily large
surface areas of more than 250 m2 g-1, were initially prepared through the urea-forced hydrolysis/precipitation
route below 100°C. For the synthesis of Li4Ti5O12, LiOH and Li2CO3 were added to TiO2 solutions prepared in water
and ethanol media, respectively. The powders were subsequently dried and calcined at various temperatures. The
phase and morphological transitions from TiO2 to Li4Ti5O12 were characterized using X-ray powder diffraction and
transmission electron microscopy. The electrochemical performance of nanosized Li4Ti5O12 was evaluated in detail
by cyclic voltammetry and galvanostatic cycling. Furthermore, the high-rate performance and long-term cycle
stability of Li4Ti5O12 anodes for use in Li-ion batteries were discussed.
Introduction
Li4Ti5O12 is one of the most promising anode materials
for Li-ion batteries even though it has lower specific capa-
city (175 mAh g-1) than does graphite (372 mAh g-1). One
of the unique properties of Li4Ti5O12 is the negligible lat-
tice change in the Li-ion insertion/desertion process,
which provides good high-rate cycling stability [1]. The
electrochemical properties of Li4Ti5O12 are dependent on
its method of preparation. The conventional solid-state,
sol-gel [2], hydrothermal [3], spray pyrolysis [4], and com-
bustion [5] methods have been proposed for Li4Ti5O12
synthesis. Among these, the solid-state process is a simple
method that is well suited for production scale-up. How-
ever, the solid-state process using TiO2 as a starting pre-
cursor requires lengthy heating with Li salts at high
temperatures in order to obtain highly crystalline
Li4Ti5O12 [6]. As a result, particle size control is more dif-
ficult than that in hydrothermal or sol-gel method, and
the resultant larger particles lead to poor capacity reten-
tion and rate capability.
Herein, we demonstrate the preparation of highly
crystalline nanosized Li4Ti5O12 [nano-Li4Ti5O12] with a
uniform particle size via a urea-mediated wet process, in
which a TiO2 precursor with a large surface area is initi-
ally formed, followed by wet and solid-state processes
with different Li sources, LiOH and Li2CO3, respec-
tively. After subsequent heat treatment, the electroche-
mical performance of the resultant Li4Ti5O12 as an
anode for Li-ion batteries is evaluated and discussed.
Experimental procedure
Preparation of TiO2 precursor
TiO2 nanoparticles with an anatase structure were pre-
pared using the urea-mediated precipitation method [7],
in which 0.015 M titanium trichloride (20% in 3% hydro-
chloric acid, TiCl3, Alfa Aesar, Ward Hill, MA, USA) and
3.0 M urea (99.3%, (NH2)2CO, Alfa Aesar, Ward Hill, MA,
USA) were dissolved in deionized [DI] water at room tem-
perature. The solution was heated at 90°C to 100°C for 4 h
with magnetic stirring. Precipitates were obtained by cen-
trifugation and repeated washing (five times with DI water
and once with anhydrous ethanol). The powders were
dried at 100°C for several hours in a vacuum oven.
Preparation of Li4Ti5O12
Wet process
Stoichiometric amounts of the prepared TiO2 nanopow-
der were dispersed in DI water by sonication for 2 h.
* Correspondence: dwkim@ajou.ac.kr
Department of Materials Science and Engineering, Ajou University, Suwon
443-749, South Korea
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
© 2012 Jin et al; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution
License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.
A stoichiometric amount of LiOH (98%, Sigma-Aldrich,
St. Louis, MO, USA) was then dissolved in the solution
with stirring. The resulting white-colored suspensions
were heated at 110°C to evaporate water. Finally, the
powder was calcined at various temperatures in air to
afford Li4Ti5O12.
Solid-state process
For the solid-state process, Li2CO3 (99%, Sigma-Aldrich,
St. Louis, MO, USA) was chosen as the Li source. The
stoichiometric mixture was agitated for 24 h with a zirco-
nia ball in absolute ethanol, dried, and calcined at various
temperatures in air.
Characterization of TiO2 precursors and Li4Ti5O12
nanoparticles
The powders were characterized by X-ray powder dif-
fraction [XRD] (D/max-2500 V, Rigaku, Tokyo, Japan),
Brunauer-Emmett-Teller [BET] (Belsorp-mini II, BEL
Japan Inc., Osaka, Japan) surface area determination,
high-resolution transmission electron microscopy
[HRTEM] (JEM-3000F, JEOL, Tokyo, Japan) at an accel-
erating voltage of 300 kV, and field-emission scanning
electron microscopy [FESEM] (JSM-6700F, JEOL,
Tokyo, Japan).
Electrochemical analysis
A mixture consisting of 70 wt.% of the active materials,
15 wt.% Super P carbon black (MMM Carbon, Brussels,
Belgium), and 15 wt.% Kynar 2801 binder (PVDF-HFP,
Arkema Inc., King of Prussia, PA, USA) was dissolved in
1-methyl-2-pyrrolidinone (Sigma-Aldrich, St. Louis, MO,
USA) solvent for uniform dispersion of the active materi-
als on a Cu foil to obtain positive electrodes. Then, the
solvent was evaporated in a vacuum oven at 100°C. A
Swagelok-type cell was assembled in an Ar-filled glove box
in order to protect the cell from oxidation and moisture. A
Li metal foil (negative electrode) and the prepared mixture
(positive electrode) were saturated with a liquid electrolyte
obtained by dissolving 1 M LiPF6 in ethylene carbonate
and dimethyl carbonate (1:1 by volume, Techno Semi-
chem Co., Ltd., Sungnam, South Korea). Li4Ti5O12 pow-
ders were analyzed by the galvanostatic discharge/charge
cycling method and cyclic voltammetry [CV] measure-
ments with a battery cycler (WBCS 3000, WonATech,
Seoul, South Korea). Each cell was cycled through a
voltage range of 1.0 to 2.5 V versus Li/Li+.
Results and discussion
The XRD pattern (Figure 1a) for precursor powders
indicated that they comprised anatase-phase TiO2 (Joint
Committee of Powder Diffraction System [JCPDS] #21-
1272). The TiO2 morphology was found to be flower-
like clusters of 50 nm in size, which comprised tiny
aggregated nanorods (Figure 1b). For this reason, the
powder had an extremely large surface area, 267 m2 g-1,
as confirmed by BET surface area measurements. In
addition, the electron diffraction (selected area electron
diffraction [SAED]) pattern of the selected area coin-
cided with that of anatase TiO2, as shown in the inset of
Figure 1b.
In order to obtain nano-Li4Ti5O12 with a sufficiently large
surface area, the TiO2 powders prepared as mentioned
above were used as precursors. After mixing the TiO2 pre-
cursor with LiOH and Li2CO3 through wet and solid-state
processes, respectively, both mixtures were calcined at
700°C and 800°C and were found to mainly comprise the
cubic Li4Ti5O12 phase (JCPDS #49-0207; Figure 2). How-
ever, the Li4Ti5O12 powders prepared through the wet pro-
cess had an undesirable (Li-inactive) secondary phase,
Li2TiO3 (JCPDS #33-0831), even after calcination at 800°C
as confirmed by the XRD peak at 2θ = 35.6°. As opposed to
the powders prepared by the wet process, those prepared
through the solid-state process showed an almost pure
Li4Ti5O12 phase with negligible secondary phases.
Figures 3a, b show the typical FESEM and HRTEM
images of the Li4Ti5O12 powders prepared through the
solid-state process. Small and uniformly sized Li4Ti5O12
particles (50 to 100 nm) were obtained even if the calcina-
tion temperature was 700°C, which could be attributed to
the unique TiO2 nanoprecursors with extremely large sur-
face areas. These Li4Ti5O12 powders were further investi-
gated by HRTEM, as shown in Figure 3c. The typical
HRTEM image was recorded from a single particle with
lattice fringes of approximately 0.496 nm, which corre-
sponded to the (111) interplanar spacing in Li4Ti5O12. The
presence of single-phase Li4Ti5O12 was also confirmed
from the SAED patterns shown in the inset of Figure 3c.
Nanostructured electrode materials help in enhancing
the performance of Li-ion batteries by providing higher
electrode/electrolyte contact areas, shorter Li+ diffusion
lengths (L) in the intercalation host (smaller time constant
(τ); τ = L2/2D, where D is the coupled diffusion coefficient
for Li+ and e-), and better accommodation of the Li-ion
insertion/extraction strain [8,9]. Figure 4 shows the elec-
trochemical activity of nano-Li4Ti5O12 powders that were
prepared through the solid-state process. These CV mea-
surements were carried out during the first cycle using a
half cell with Li metal foil as the negative electrode, oper-
ating at 0.3 mV/s. Clear cathodic and anodic peaks
appeared at approximately 1.46 and 1.7 V, respectively, for
the Li intercalation/deintercalation, in accordance with the
pair of peaks reported for Li4Ti5O12 powders [10]. The fol-
lowing electrochemical reaction of Li4Ti5O12 with Li has
been suggested [11]:
Li4Ti5O12 + 3 Li+ + 3 e− ↔ Li7Ti5O12.
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
Page 2 of 6
Figure 4b shows the galvanostatic cycling characteris-
tics of nano-Li4Ti5O12 powders that were prepared
through the solid-state process. The first discharge capa-
city was 154 mAh g-1 over a voltage window of 1.0 to
2.5 V at a current rate of 1 C (175 mAh g-1; here, C is
defined as three Li ions per hour and per formula unit
of Li4Ti5O12 on the basis of the above equation). The
reversible capacities were observed to be 135, 133, 131,
130, and 128 mAh g-1 after 100, 200, 300, 400, and 500
cycles, respectively. Indeed, it is interesting to note that
the nano-Li4Ti5O12 electrode in this study shows super-
ior long-term cyclability and negligible variation in
reversible capacity upon cycling (0.013% fading per cycle
between 100 and 500 cycles).
Figure 5 shows the rate capability of the nano-
Li4Ti5O12 powders that were prepared through the solid-
state process, for up to 20 C. The cells were charged and
discharged at 1 C for the first 10 cycles, and then, the
Figure 1 Characterization of TiO2 products. (a) A typical XRD pattern. (b) A TEM image of TiO2 precursor powders. The inset in (b) shows
SAED patterns. (By Jin YH et al.).
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
Page 3 of 6
Figure 2 XRD patterns of Li4Ti5O12 powders. Li4Ti5O12 prepared through wet and solid-state processes and subsequently calcined at 700°C
and 800°C for 4 h. (By Jin YH et al.).
 
Figure 3 FESEM and HRTEM images. (a) FESEM image of a typical Li4Ti5O12. (b) Low-magnification HRTEM image of Li4Ti5O12. (c) HRTEM
image of Li4Ti5O12 powders prepared through the solid-state process and subsequently calcined at 700°C for 4 h. The inset in (c) shows SAED
patterns. (By Jin YH et al.).
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
Page 4 of 6
 Figure 4 Electrochemical performance of Li4Ti5O12. (a) A cyclic voltammogram of Li4Ti5O12. (b) Charge-discharge profiles of Li4Ti5O12
powders prepared through the solid-state process and subsequently calcined at 700°C for 4 h. (By Jin YH et al.).
Figure 5 Rate capability of Li4Ti5O12. Cycling behavior at different C values for Li4Ti5O12 powders prepared through the solid-state process and
subsequently calcined at 700°C and 800°C for 4 h. Solid and open circles indicate discharge and charge capacities, respectively. (By Jin YH et al.).
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
Page 5 of 6
rate was increased in stages to 20 C. At a rate of 20 C, the
capacity of the nano-Li4Ti5O12 powders was still high:
112 mAh g-1. This outstanding performance at high rates
was much better than that afforded by any of the various
types of Li4Ti5O12 nanostructures such as nanowires and
nanoparticles [3,12,13]. In particular, the nano-Li4Ti5O12
powders calcined at 700°C exhibited better long-term
cyclability as well as superior rate capabilities than those
calcined at 800°C (Figure 5), possibly a result of the
nanosize effect of the small particle size and large surface
area.
Conclusion
In summary, spinel-type nano-Li4Ti5O12 particles were
synthesized by a solid-state process from a large-sur-
face-area TiO2 precursor and subsequent calcination at
700°C. The average particle size of these nano-Li4Ti5O12
particles was 50 to 100 nm. High Li electroactivity was
confirmed by CV experiments. The nano-Li4Ti5O12 par-
ticles calcined at 700°C showed a high Li storage capa-
city of 128 mAh g-1 after 500 cycles at 1 C and superior
cycle performance (112 mAh g-1) even at a high rate of
20 C. The enhanced reversible capacity and cycling per-
formance were attributed to the formation of highly
crystalline, uniform nanoparticles, which make this
nano-Li4Ti5O12 a potential host material for high-pow-
der Li-ion batteries.
Acknowledgements
This work was supported by the National Research Foundation of Korea
(NRF) grant funded by the Korean government (MEST; No. 2010-0029617 &
2011-0005776) and was completed with Ajou University Research Fellowship
of 2011 (S-2011-G0001-00070).
Authors’ contributions
Y-HJ carried out the TiO2 and Li4Ti5O12 sample preparation and drafted the
manuscript. K-MM and H-WS fulfilled the electrochemical analyses. S-DS, I-
SH, and K-SP participated in the microstructural analysis. D-WK designed the
study, led the discussion of the results, and participated in writing the
manuscript. All authors read and approved the final manuscript.
Competing interests
The authors declare that they have no competing interests.
Received: 2 September 2011 Accepted: 5 January 2012
Published: 5 January 2012
References
1. Jiang C, Ichihara M, Honma I, Zhou H: Effect of particle dispersion on high
rate performance of nano-sized Li4Ti5O12 anode. Electrochimica Acta 2007,
52:6470.
2. Kavana L, Grätzel M: Facile synthesis of nanocrystalline Li4Ti5O12 (spinel)
exhibiting fast Li insertion. Electrochem Solid-State Lett 2002, 5:A39.
3. Li J, Tang J, Zhang Z: Controllable formation and electrochemical
properties of one-dimensional nanostructured spinel Li4Ti5O12.
Electrochem Commun 2005, 7:894.
4. Ju SH, Kang YC: Characteristics of spherical-shaped Li4Ti5O12 anode
powders prepared by spray pyrolysis. J Phys Chem Solids 2009, 70:40.
5. Yuan T, Cai R, Wang K, Ran R, Liu S, Shao Z: Combustion synthesis of
high-performance Li4Ti5O12 for secondary Li-ion battery. Ceram Int 2009,
35:1757.
6. Ferg E, Gummow RJ, de Kock A, Thackeray MM: Spinel anodes for lithium-
ion batteries. J Electrochem Soc 1994, 141:L147.
7. Jin YH, Lee SH, Shim HW, Ko KH, Kim DW: Tailoring high-surface-area
nanocrystalline TiO2 polymorphs for high-power Li ion battery
electrodes. Electrochimica Acta 2010, 55:7315.
8. Kunduraci M, Amatucci GG: The effect of particle size and morphology on
the rate capability of 4.7 V LiMn1.5+δNi0.5-δO4 spinel lithium-ion battery
cathodes. Electrochimica Acta 2008, 53:4193.
9. Ren Y, Armstrong AR, Jiao F, Bruce PG: Influence of size on the rate of
mesoporous electrodes for lithium batteries. J Am Chem Soc 2010,
132:996.
10. Woo SW, Dokko K, Kanamura K: Preparation and characterization of three
dimensionally ordered macroporous Li4Ti5O12 anode for lithium
batteries. Electrochimica Acta 2007, 53:79.
11. Ohsuku T, Ueda A, Yamamoto N: Zero-strain insertion material of Li[Li1/
3Ti5/3]O4 for rechargeable lithium cells. J Electrochem Soc 1995, 142:1431.
12. Lee DK, Shim HW, An JS, Cho CM, Cho IS, Hong KS, Kim DW: Synthesis of
heterogeneous Li4Ti5O12 nanostructured anodes with long-term cycle
stability. Nanoscale Res Lett 2010, 5:1585.
13. Lee SS, Byun KT, Park JP, Kim SK, Kwak HY, Shim IW: Preparation of
Li4Ti5O12 nanoparticles by a simple sonochemical method. Dalton Trans
2007, 37:4182.
doi:10.1186/1556-276X-7-10
Cite this article as: Jin et al.: Facile synthesis of nano-Li4 Ti5O12 for high-
rate Li-ion battery anodes. Nanoscale Research Letters 2012 7:10.
Submit your manuscript to a 
journal and benefi t from:
7 Convenient online submission
7 Rigorous peer review
7 Immediate publication on acceptance
7 Open access: articles freely available online
7 High visibility within the fi eld
7 Retaining the copyright to your article
    Submit your next manuscript at 7 springeropen.com
Jin et al. Nanoscale Research Letters 2012, 7:10
http://www.nanoscalereslett.com/content/7/1/10
Page 6 of 6


Facile synthesis of nano-Li TiO for high-rate Li-ion battery anodes

Abstract
          One of the most promising anode materials for Li-ion batteries, Li4Ti5O12, has attracted attention because it is a zero-strain Li insertion host having a stable insertion potential. In this study, we suggest two different synthetic processes to prepare Li4Ti5O12 using anatase TiO2 nanoprecursors. TiO2 powders, which have extraordinarily large surface areas of more than 250 m2 g-1, were initially prepared through the urea-forced hydrolysis/precipitation route below 100°C. For the synthesis of Li4Ti5O12, LiOH and Li2CO3 were added to TiO2 solutions prepared in water and ethanol media, respectively. The powders were subsequently dried and calcined at various temperatures. The phase and morphological transitions from TiO2 to Li4Ti5O12 were characterized using X-ray powder diffraction and transmission electron microscopy. The electrochemical performance of nanosized Li4Ti5O12 was evaluated in detail by cyclic voltammetry and galvanostatic cycling. Furthermore, the high-rate performance and long-term cycle stability of Li4Ti5O12 anodes for use in Li-ion batteries were discussed.</jats:p

Yun-Ho Jin

Kyung-Mi Min

Hyun-Woo Shim

Seung-Deok Seo

In-Sung Hwang

Kyung-Soo Park

Dong-Wan Kim

Crossref

Facile synthesis of nano-Li4 Ti5O12 for high-rate Li-ion battery anodes

Amatucci GG: The effect of particle size and morphology on the rate capability of 4.7 V LiMn1.5+δNi0.5-δO4 spinel lithium-ion battery cathodes. Electrochimica Acta

Controllable formation and electrochemical properties of one-dimensional nanostructured spinel Li4Ti5O12. Electrochem Commun

DW: Synthesis of heterogeneous Li4Ti5O12 nanostructured anodes with long-term cycle stability. Nanoscale Res Lett

DW: Tailoring high-surface-area nanocrystalline TiO2 polymorphs for high-power Li ion battery electrodes. Electrochimica Acta

Effect of particle dispersion on high rate performance of nano-sized Li4Ti5O12 anode. Electrochimica Acta

Grätzel M: Facile synthesis of nanocrystalline Li4Ti5O12 (spinel) exhibiting fast Li insertion. Electrochem Solid-State Lett

Kang YC: Characteristics of spherical-shaped Li4Ti5O12 anode powders prepared by spray pyrolysis.

PG: Influence of size on the rate of mesoporous electrodes for lithium batteries.

Preparation and characterization of three dimensionally ordered macroporous Li4Ti5O12 anode for lithium batteries. Electrochimica Acta

Thackeray MM: Spinel anodes for lithiumion batteries.

Z: Combustion synthesis of high-performance Li4Ti5O12 for secondary Li-ion battery. Ceram Int

Zero-strain insertion material of Li[Li1/ 3Ti5/3]O4 for rechargeable lithium cells.

file:///data/core-remote/dit/data/Springer-OA/pdf/1b5/aHR0cDovL2xpbmsuc3ByaW5nZXIuY29tLzEwLjExODYvMTU1Ni0yNzZYLTctMTAucGRm.pdf

Facile synthesis of nano-Li4 Ti5O12 for high-rate Li-ion battery anodes

Abstract

Similar works

Full text

Available Versions

Springer - Publisher Connector

Crossref