The performance of LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2 depends largely on the distribution of transition-metal TM ions over the available

lattice sites within the layered rocksalt structure. Despite predictions that the TM ions take on an ordered arrangement described

by a √3 X √3R30° supercell, little experimental evidence is available to confirm this model. However, the observed cation

distribution likely depends on synthesis conditions. Here, we present a study of commercially produced LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2

synthesized at 1000°C before and after charge–discharge cycling. Electron diffraction shows that in-plane ordering is observed to

small extents. After charge–discharge cycling, a transformation toward the cubic spinel structure and significant morphology

changes are observed

Gabrisch, H.

Yazami, R.

Caltech Authors - Main

Electron Diffraction Studies of LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2

After Charge–Discharge Cycling

Electrochemical and Solid-State Letters, 13 7 A88-A90 2010A88
DElectron Diffraction Studies of LiNi1Õ3Mn1Õ3Co1Õ3O2
After Charge–Discharge Cycling
H. Gabrischa,*,z and R. Yazamib,*
aAdvanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
bCalifornia Institute of Technology, Pasadena, California 91125, USA
The performance of LiNi1/3Mn1/3Co1/3O2 depends largely on the distribution of transition-metal TM ions over the available
lattice sites within the layered rocksalt structure. Despite predictions that the TM ions take on an ordered arrangement described
by a 3  3R30° supercell, little experimental evidence is available to confirm this model. However, the observed cation
distribution likely depends on synthesis conditions. Here, we present a study of commercially produced LiNi1/3Mn1/3Co1/3O2
synthesized at 1000°C before and after charge–discharge cycling. Electron diffraction shows that in-plane ordering is observed to
small extents. After charge–discharge cycling, a transformation toward the cubic spinel structure and significant morphology
changes are observed.
© 2010 The Electrochemical Society. DOI: 10.1149/1.3424884 All rights reserved.
Manuscript submitted December 23, 2009; revised manuscript received April 8, 2010. Published May 10, 2010.
1099-0062/2010/137/A88/3/$28.00 © The Electrochemical SocietyOver the past few years, the ternary transition-metal TM oxide
LiNi1/3Mn1/3Co1/3O2 has developed into a strong candidate for ap-
plications in high power rechargeable Li-ion batteries due to its
superior thermal stability and reversible capacity compared to its
LiCoO2 counterpart.1-3 LiNi1/3Mn1/3Co1/3O2 adopts the typical
-NaFeO2 structure that is known of layered LiCoO2 and LiNiO2
and is described by the R3¯m space group space group 166. In
LiCoO2, this structure is often called the “O3” phase, referring to the
octahedral coordination of Co ions and the number of O–Co–O slabs
per unit cell. The crystal structure consists of a cubic close-packed
oxygen lattice Wyckoff position 6a with alternating layers of oc-
tahedral interstitial sites occupied by Li Wyckoff position 3b and
TM TM = Ni, Mn, Co, Wyckoff position 3a. In the coordination
polyhedra description, the structure can be considered as sheets
formed by edge sharing TMO6 octahedra separated by layers of
lithium ions in interstitial octahedral sites.4 TM ions play a signifi-
cant role toward the stability and electrochemical activity in this
compound. Nickel is believed to be the electrochemical active spe-
cies, whereas manganese provides structural stability, and cobalt
supports the ordering of lithium and nickel ions onto their respective
lattice sites.5 The occupation of the 3a lattice site in the R3¯m struc-
ture with three different TM species gives rise to different cation
ordering schemes, which is likely to affect the electrochemical ac-
tivity and structural stability of the compound. The well-known ten-
dency of Ni ions to exchange sites with Li ions in their respective
layers introduces a local disorder that impairs electrochemical
performance.6 It has also been associated with the formation of a
cubic spinel phase Fd3¯m symmetry, where Li and TM ions occupy
sites in the same interstitial layer.7 First-principle calculations indi-
cate that in-plane ordered LiNi1/3Mn1/3Co1/3O2 where Ni, Co, and
Mn ions are assigned element specific lattice sites in a 3
 3R30° in-plane unit cell Wood’s notation should be stable.8
The available experimental results are not conclusive on a favored
cation arrangement and its evolution with charge–discharge cycling
or aging. For example, experimental evidence for in-plane ordering
has been reported in electron diffraction studies by Yabuuchi et al.
and by Zeng.9,10 For comparison, neutron diffraction and anomalous
X-ray powder diffraction data show random distribution of Mn, Ni,
and Co over 3a sites in the R3¯m structure.11
Previously, we investigated commercial LiNi1/3Mn1/3Co1/3O2 by
electron diffraction before and after long-term aging. We identified
substantial variations in cation ordering in the pristine material and
found indications for growth processes resulting from cation rear-
rangement after aging.12 Inhomogeneous cation distribution in the
* Electrochemical Society Active Member.
z E-mail: heike.gabrisch@gkss.deownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to pristine material converted to a mixture of O3 and spinel phases
after aging or charge to high voltage. In the present study, we inves-
tigate commercial LiNi1/3Mn1/3Co1/3O2 ENAX Inc., generation 2
in the pristine state and after cycling.
Experimental
Commercial LiNi1/3Mn1/3Co1/3O2 and cycled cathodes prepared
of the powder were obtained from ENAX, Inc. generation 2, pow-
der prepared according to the method published in Ref. 9. The
cathodes underwent 520 charge–discharge cycles between 3.0 and
4.3 V and were stopped in the discharged state. The capacity loss
measured after cycling was 15%.
The cycled cathodes were disassembled and the active material
was retrieved from the cathodes for transmission electron micros-
copy TEM specimen preparation. TEM specimens of the virgin
material were prepared of the powder. Electron diffraction and dark-
field imaging were performed with the JEOL 2010 transmission
electron microscope at the University of New Orleans operated at
200 kV. The relative concentrations of Mn, Ni, and Co were deter-
mined in some particles by energy-dispersive spectroscopy. Experi-
mental diffraction patterns were compared to patterns simulated
with the software Desktop Microscopist using unit cells published in
the literature; a list can be found in Ref. 12.
Results and Discussion
Compared to the generation 1 material supplied by the same
company, the generation 2 compound has a more homogeneous
crystal structure.12 The majority of particles in the investigated
LiNi1/3Mn1/3CoO2 ENAX, generation 2 are completely indexed as
an O3 phase, indicating a random distribution of TM ions 22 out of
31 or 71%. Of the remaining particles, three show typical diffrac-
tions of the 3  3R30° unit cell plane ordering, whereas five
particles have spinel type diffraction patterns. A summary of the
cation ordering observed in the analyzed particles is given in Table
I.
Although most particles are single crystalline, 20% of the ana-
lyzed particles in the pristine material are polycrystals. In most
cases, the polycrystalline particles consist of two crystals indexed as
an O3 phase that are related by a twin boundary 4 out of 5. An
example is shown in Fig. 1, where diffraction patterns of each crys-
tal Fig. 1c and d are shown together with the pattern obtained from
the whole particle Fig. 1b. The pattern in Fig. 1b is a superposition
of the patterns shown in Fig. 1c and d. The image in Fig. 1a is taken
in the dark-field condition using the 1¯011¯ reflection of the diffrac-
tion pattern shown in Fig. 1d that corresponds to the bright, larger
crystal in Fig. 1a.
During cycling, the amount of polycrystals and the fraction of
particles with a long-range order remain approximately constant. A
significant change is observed in the amount of spinel phase thatECS license or copyright; see http://www.ecsdl.org/terms_use.jsp
A89Electrochemical and Solid-State Letters, 13 7 A88-A90 2010
Dincreases at the expense of the O3 phase from 16% before cycling to
47% after cycling. Energy-dispersive analysis shows only small
variations in the ratio of Mn:Co:Ni. In all analyzed spectra, includ-
ing those representative of the spinel phase, the values for Mn, Co,
and Ni were within the ranges Mn: 0.29–0.35, Co: 0.28–0.35, and
Ni: 0.32–0.36.
The intensity of spinel reflections in the pristine and cycled ma-
terials spans a wide range. A comparison is shown in Fig. 2, where
the typical spinel reflections are barely visible in Fig. 2a, whereas
they have an intensity identical to that of the fundamental reflections
in Fig. 2c. The intensity variations in the typical spinel diffractions
correspond to a gradual change in the cation ordering between the
two limiting phases: layered and cubic.
The most striking observation in the cycled particles is the
change in morphology in some particles. An example showing sev-
eral such damaged particles is given in Fig. 3. Apparently, the par-
ticles disintegrate during cycling and form a lamellar morphology
consisting of 5–10 nm thick lamellas that are stacked along the
0001 direction. An example of this morphology that we call
“mille-feuille” is shown in Fig. 4, together with its diffraction pat-
tern. The diffraction pattern can be indexed as an O3 phase, but faint
Table I. Analysis of commercial LiNi1Õ3Mn1Õ3Co1Õ3O2: The num-
bers reflect the count of diffraction patterns in each category.
Some particles were polycrystals, the total number of analyzed
patterns is given in brackets at the top of each column. Twenty-
five pristine particles and 15 cycled particles were analyzed.
Classification Pristine 31 Cycled 17
O3 22 6
Spinel 5 8
3  3R30° 3 2
Other 1 1
Figure 1. Image and diffraction patterns taken from a pristine, commercial
polycrystalline particle. a Dark field image taken with a reflection unique
for the bright part in the image. b Corresponding diffraction pattern; the
reflection used for imaging is marked by the pointer. c and d The dif-
fraction patterns of the two crystals.ownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to contributions of spinel and 3  3R30° ordering are also visible.
A comparison between the directions in the diffraction pattern and in
the image illustrates that the lamellas are separated between 0001
planes, where bonding between adjacent layers is weak. A closer
look at the corresponding diffraction pattern in Fig. 4b shows that
the shape of fundamental reflections is not circular but streaked
along the 0001 direction. Streaking indicates the presence of pla-
nar defects such as platelike precipitates or stacking faults oriented
perpendicular to the streaking direction here, the defects lie in the
0001 planes. In Fig. 5, a cycled particle is shown that does not
have the mille-feuille morphology but has pronounced streaking in
the diffraction pattern. Therefore, it is not clear that the observed
Figure 2. Electron diffraction patterns showing spinel reflections of increas-
ing intensity from a to c corresponding to a gradual change in cation
rearrangement.
Figure 3. TEM image showing an agglomerate of LiNi1/3Mn1/3Co1/3O2 par-
ticles with a mille-feuille morphology observed after charge–discharge cy-
cling.ECS license or copyright; see http://www.ecsdl.org/terms_use.jsp
A90 Electrochemical and Solid-State Letters, 13 7 A88-A90 2010
Dmorphology change is responsible for the observed streaking. Pos-
sibly, stacking faults or monoatomic layers form on the 0001
planes that give rise to streaking. With continued cycling, these de-
fects may contribute to the observed morphology change. In another
study, we observed similar morphology changes in chemically
Figure 4. Image and diffraction pattern illustrating the orientation relation-
ship between the lamella in the mille-feuille morphology and the diffraction
pattern.
Figure 5. Image and diffraction pattern of a cycled particle. Pronounced
streaking along the 0001 direction is observed in the diffraction pattern.
ownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to delithiated LixNi1/3Mn1/3Co1/3O2 particles after long-time anneal,
indicating that the underlying processes can take place during aging
of a battery and do not require continued Li extraction and insertion
to be published. Altogether, we observed streaking in 6 out of 15
particles analyzed after cycling but only in 1 out of 22 of the pristine
material.
Conclusions
Commercial LiNi1/3Mn1/3Co1/3O2 synthesized at approximately
1000°C shows long-range ordering in about 10% of the analyzed
diffraction patterns, a fraction that remains stable over charge–
discharge cycling. The pristine material consists of 70% of particles
with random TM ion distribution on the 3a lattice sites; however,
after 520 charge–discharge cycles, a portion of these have trans-
formed to spinel, so that 47% spinel phase is observed after cy-
cling. The mille-feuille morphology is observed frequently after cy-
cling. Streaking in the diffraction pattern of cycled particles
indicates that microscopic defects have formed on the 0001 planes.
Acknowledgment
This work was supported through the Louisiana Board of Re-
gents, LEQSF2007012_ENH-PKSFI-PRS-04. We thank ENAX,
Inc. of Japan for providing LiNi1/3Mn1/3Co1/3O2 powder and cycled
cathodes.
References
1. T. Ohzuku and Y. Makimura, Chem. Lett., 7, 642 2001.
2. I. Belharouak, Y. K. Sun, J. Liu, and K. Amine, J. Power Sources, 123, 247
2003.
3. J. W. Wen, H. J. Liu, H. Wu, and C. H. Chen, J. Mater. Sci., 42, 7696 2007.
4. X. Luo, X. Wang, L. Liao, X. Wang, S. Gamboa, and P. J. Sebastian, J. Power
Sources, 161, 601 2006.
5. M. S. Whittingham, Chem. Rev. (Washington, D.C.), 104, 4271 2004.
6. T. Nedoseykina, S.-S. Kim, and Y. Nitta, Electrochim. Acta, 52, 1467 2006.
7. Y. Hinuma, Y. S. Meng, K. Kang, and G. Ceder, Chem. Mater., 19, 1790 2007.
8. Y. Koyama, Y. Makimura, I. Tanaka, H. Adachi, and T. Ohzuku, J. Electrochem.
Soc., 151, A1499 2004.
9. N. Yabuuchi, Y. Koyama, N. Nakayama, and T. Ohzuku, J. Electrochem. Soc., 152,
A1434 2005.
10. Y. W. Zeng, J. Power Sources, 183, 316 2008.
11. P. S. Whitfield, I. J. Davidson, L. M. D. Cranswick, I. P. Swainson, and P. W.
Stephens, Solid State Ionics, 176, 463 2005.
12. H. Gabrisch, T. Yi, and R. Yazami, Electrochem. Solid-State Lett., 11, A1192008.
ECS license or copyright; see http://www.ecsdl.org/terms_use.jsp


Electrochemical and Solid-State Letters, 13 7 A88-A90 2010A88
D
Electron Diffraction Studies of LiNi1Õ3Mn1Õ3Co1Õ3O2
After Charge–Discharge Cycling
H. Gabrischa,*,z and R. Yazamib,*
aAdvanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA
bCalifornia Institute of Technology, Pasadena, California 91125, USA
The performance of LiNi1/3Mn1/3Co1/3O2 depends largely on the distribution of transition-metal TM ions over the available
lattice sites within the layered rocksalt structure. Despite predictions that the TM ions take on an ordered arrangement described
by a 3  3R30° supercell, little experimental evidence is available to confirm this model. However, the observed cation
distribution likely depends on synthesis conditions. Here, we present a study of commercially produced LiNi1/3Mn1/3Co1/3O2
synthesized at 1000°C before and after charge–discharge cycling. Electron diffraction shows that in-plane ordering is observed to
small extents. After charge–discharge cycling, a transformation toward the cubic spinel structure and significant morphology
changes are observed.
© 2010 The Electrochemical Society. DOI: 10.1149/1.3424884 All rights reserved.
Manuscript submitted December 23, 2009; revised manuscript received April 8, 2010. Published May 10, 2010.
1099-0062/2010/137/A88/3/$28.00 © The Electrochemical SocietyOver the past few years, the ternary transition-metal TM oxide
LiNi1/3Mn1/3Co1/3O2 has developed into a strong candidate for ap-
plications in high power rechargeable Li-ion batteries due to its
superior thermal stability and reversible capacity compared to its
LiCoO2 counterpart.
1-3 LiNi1/3Mn1/3Co1/3O2 adopts the typical
-NaFeO2 structure that is known of layered LiCoO2 and LiNiO2
and is described by the R3̄m space group space group 166. In
LiCoO2, this structure is often called the “O3” phase, referring to the
octahedral coordination of Co ions and the number of O–Co–O slabs
per unit cell. The crystal structure consists of a cubic close-packed
oxygen lattice Wyckoff position 6a with alternating layers of oc-
tahedral interstitial sites occupied by Li Wyckoff position 3b and
TM TM = Ni, Mn, Co, Wyckoff position 3a. In the coordination
polyhedra description, the structure can be considered as sheets
formed by edge sharing TMO6 octahedra separated by layers of
lithium ions in interstitial octahedral sites.4 TM ions play a signifi-
cant role toward the stability and electrochemical activity in this
compound. Nickel is believed to be the electrochemical active spe-
cies, whereas manganese provides structural stability, and cobalt
supports the ordering of lithium and nickel ions onto their respective
lattice sites.5 The occupation of the 3a lattice site in the R3̄m struc-
ture with three different TM species gives rise to different cation
ordering schemes, which is likely to affect the electrochemical ac-
tivity and structural stability of the compound. The well-known ten-
dency of Ni ions to exchange sites with Li ions in their respective
layers introduces a local disorder that impairs electrochemical
performance.6 It has also been associated with the formation of a
cubic spinel phase Fd3̄m symmetry, where Li and TM ions occupy
sites in the same interstitial layer.7 First-principle calculations indi-
cate that in-plane ordered LiNi1/3Mn1/3Co1/3O2 where Ni, Co, and
Mn ions are assigned element specific lattice sites in a 3
 3R30° in-plane unit cell Wood’s notation should be stable.8
The available experimental results are not conclusive on a favored
cation arrangement and its evolution with charge–discharge cycling
or aging. For example, experimental evidence for in-plane ordering
has been reported in electron diffraction studies by Yabuuchi et al.
and by Zeng.9,10 For comparison, neutron diffraction and anomalous
X-ray powder diffraction data show random distribution of Mn, Ni,
and Co over 3a sites in the R3̄m structure.11
Previously, we investigated commercial LiNi1/3Mn1/3Co1/3O2 by
electron diffraction before and after long-term aging. We identified
substantial variations in cation ordering in the pristine material and
found indications for growth processes resulting from cation rear-
rangement after aging.12 Inhomogeneous cation distribution in the
* Electrochemical Society Active Member.
z E-mail: heike.gabrisch@gkss.deownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to pristine material converted to a mixture of O3 and spinel phases
after aging or charge to high voltage. In the present study, we inves-
tigate commercial LiNi1/3Mn1/3Co1/3O2 ENAX Inc., generation 2
in the pristine state and after cycling.
Experimental
Commercial LiNi1/3Mn1/3Co1/3O2 and cycled cathodes prepared
of the powder were obtained from ENAX, Inc. generation 2, pow-
der prepared according to the method published in Ref. 9. The
cathodes underwent 520 charge–discharge cycles between 3.0 and
4.3 V and were stopped in the discharged state. The capacity loss
measured after cycling was 15%.
The cycled cathodes were disassembled and the active material
was retrieved from the cathodes for transmission electron micros-
copy TEM specimen preparation. TEM specimens of the virgin
material were prepared of the powder. Electron diffraction and dark-
field imaging were performed with the JEOL 2010 transmission
electron microscope at the University of New Orleans operated at
200 kV. The relative concentrations of Mn, Ni, and Co were deter-
mined in some particles by energy-dispersive spectroscopy. Experi-
mental diffraction patterns were compared to patterns simulated
with the software Desktop Microscopist using unit cells published in
the literature; a list can be found in Ref. 12.
Results and Discussion
Compared to the generation 1 material supplied by the same
company, the generation 2 compound has a more homogeneous
crystal structure.12 The majority of particles in the investigated
LiNi1/3Mn1/3CoO2 ENAX, generation 2 are completely indexed as
an O3 phase, indicating a random distribution of TM ions 22 out of
31 or 71%. Of the remaining particles, three show typical diffrac-
tions of the 3  3R30° unit cell plane ordering, whereas five
particles have spinel type diffraction patterns. A summary of the
cation ordering observed in the analyzed particles is given in Table
I.
Although most particles are single crystalline, 20% of the ana-
lyzed particles in the pristine material are polycrystals. In most
cases, the polycrystalline particles consist of two crystals indexed as
an O3 phase that are related by a twin boundary 4 out of 5. An
example is shown in Fig. 1, where diffraction patterns of each crys-
tal Fig. 1c and d are shown together with the pattern obtained from
the whole particle Fig. 1b. The pattern in Fig. 1b is a superposition
of the patterns shown in Fig. 1c and d. The image in Fig. 1a is taken
in the dark-field condition using the  1̄011̄ reflection of the diffrac-
tion pattern shown in Fig. 1d that corresponds to the bright, larger
crystal in Fig. 1a.
During cycling, the amount of polycrystals and the fraction of
particles with a long-range order remain approximately constant. A
significant change is observed in the amount of spinel phase thatECS license or copyright; see http://www.ecsdl.org/terms_use.jsp
A89Electrochemical and Solid-State Letters, 13 7 A88-A90 2010
D
increases at the expense of the O3 phase from 16% before cycling to
47% after cycling. Energy-dispersive analysis shows only small
variations in the ratio of Mn:Co:Ni. In all analyzed spectra, includ-
ing those representative of the spinel phase, the values for Mn, Co,
and Ni were within the ranges Mn: 0.29–0.35, Co: 0.28–0.35, and
Ni: 0.32–0.36.
The intensity of spinel reflections in the pristine and cycled ma-
terials spans a wide range. A comparison is shown in Fig. 2, where
the typical spinel reflections are barely visible in Fig. 2a, whereas
they have an intensity identical to that of the fundamental reflections
in Fig. 2c. The intensity variations in the typical spinel diffractions
correspond to a gradual change in the cation ordering between the
two limiting phases: layered and cubic.
The most striking observation in the cycled particles is the
change in morphology in some particles. An example showing sev-
eral such damaged particles is given in Fig. 3. Apparently, the par-
ticles disintegrate during cycling and form a lamellar morphology
consisting of 5–10 nm thick lamellas that are stacked along the
0001 direction. An example of this morphology that we call
“mille-feuille” is shown in Fig. 4, together with its diffraction pat-
tern. The diffraction pattern can be indexed as an O3 phase, but faint
Table I. Analysis of commercial LiNi1Õ3Mn1Õ3Co1Õ3O2: The num-
bers reflect the count of diffraction patterns in each category.
Some particles were polycrystals, the total number of analyzed
patterns is given in brackets at the top of each column. Twenty-
five pristine particles and 15 cycled particles were analyzed.
Classification Pristine 31 Cycled 17
O3 22 6
Spinel 5 8
3  3R30° 3 2
Other 1 1
Figure 1. Image and diffraction patterns taken from a pristine, commercial
polycrystalline particle. a Dark field image taken with a reflection unique
for the bright part in the image. b Corresponding diffraction pattern; the
reflection used for imaging is marked by the pointer. c and d The dif-
fraction patterns of the two crystals.ownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to contributions of spinel and 3  3R30° ordering are also visible.
A comparison between the directions in the diffraction pattern and in
the image illustrates that the lamellas are separated between 0001
planes, where bonding between adjacent layers is weak. A closer
look at the corresponding diffraction pattern in Fig. 4b shows that
the shape of fundamental reflections is not circular but streaked
along the 0001 direction. Streaking indicates the presence of pla-
nar defects such as platelike precipitates or stacking faults oriented
perpendicular to the streaking direction here, the defects lie in the
0001 planes. In Fig. 5, a cycled particle is shown that does not
have the mille-feuille morphology but has pronounced streaking in
the diffraction pattern. Therefore, it is not clear that the observed
Figure 2. Electron diffraction patterns showing spinel reflections of increas-
ing intensity from a to c corresponding to a gradual change in cation
rearrangement.
Figure 3. TEM image showing an agglomerate of LiNi1/3Mn1/3Co1/3O2 par-
ticles with a mille-feuille morphology observed after charge–discharge cy-
cling.ECS license or copyright; see http://www.ecsdl.org/terms_use.jsp
A90 Electrochemical and Solid-State Letters, 13 7 A88-A90 2010
D
morphology change is responsible for the observed streaking. Pos-
sibly, stacking faults or monoatomic layers form on the 0001
planes that give rise to streaking. With continued cycling, these de-
fects may contribute to the observed morphology change. In another
study, we observed similar morphology changes in chemically
Figure 4. Image and diffraction pattern illustrating the orientation relation-
ship between the lamella in the mille-feuille morphology and the diffraction
pattern.
Figure 5. Image and diffraction pattern of a cycled particle. Pronounced
streaking along the 0001 direction is observed in the diffraction pattern.
ownloaded 28 May 2010 to 131.215.193.213. Redistribution subject to delithiated LixNi1/3Mn1/3Co1/3O2 particles after long-time anneal,
indicating that the underlying processes can take place during aging
of a battery and do not require continued Li extraction and insertion
to be published. Altogether, we observed streaking in 6 out of 15
particles analyzed after cycling but only in 1 out of 22 of the pristine
material.
Conclusions
Commercial LiNi1/3Mn1/3Co1/3O2 synthesized at approximately
1000°C shows long-range ordering in about 10% of the analyzed
diffraction patterns, a fraction that remains stable over charge–
discharge cycling. The pristine material consists of 70% of particles
with random TM ion distribution on the 3a lattice sites; however,
after 520 charge–discharge cycles, a portion of these have trans-
formed to spinel, so that 47% spinel phase is observed after cy-
cling. The mille-feuille morphology is observed frequently after cy-
cling. Streaking in the diffraction pattern of cycled particles
indicates that microscopic defects have formed on the 0001 planes.
Acknowledgment
This work was supported through the Louisiana Board of Re-
gents, LEQSF2007012_ENH-PKSFI-PRS-04. We thank ENAX,
Inc. of Japan for providing LiNi1/3Mn1/3Co1/3O2 powder and cycled
cathodes.
References
1. T. Ohzuku and Y. Makimura, Chem. Lett., 7, 642 2001.
2. I. Belharouak, Y. K. Sun, J. Liu, and K. Amine, J. Power Sources, 123, 247
2003.
3. J. W. Wen, H. J. Liu, H. Wu, and C. H. Chen, J. Mater. Sci., 42, 7696 2007.
4. X. Luo, X. Wang, L. Liao, X. Wang, S. Gamboa, and P. J. Sebastian, J. Power
Sources, 161, 601 2006.
5. M. S. Whittingham, Chem. Rev. (Washington, D.C.), 104, 4271 2004.
6. T. Nedoseykina, S.-S. Kim, and Y. Nitta, Electrochim. Acta, 52, 1467 2006.
7. Y. Hinuma, Y. S. Meng, K. Kang, and G. Ceder, Chem. Mater., 19, 1790 2007.
8. Y. Koyama, Y. Makimura, I. Tanaka, H. Adachi, and T. Ohzuku, J. Electrochem.
Soc., 151, A1499 2004.
9. N. Yabuuchi, Y. Koyama, N. Nakayama, and T. Ohzuku, J. Electrochem. Soc., 152,
A1434 2005.
10. Y. W. Zeng, J. Power Sources, 183, 316 2008.
11. P. S. Whitfield, I. J. Davidson, L. M. D. Cranswick, I. P. Swainson, and P. W.
Stephens, Solid State Ionics, 176, 463 2005.
12. H. Gabrisch, T. Yi, and R. Yazami, Electrochem. Solid-State Lett., 11, A1192008.
ECS license or copyright; see http://www.ecsdl.org/terms_use.jsp


English

https://authors.library.caltech.edu/18557/1/Gabrisch2010p10169Electrochem_Solid_St.pdf

Electron Diffraction Studies of LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2 After Charge–Discharge Cycling

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