V. Focused Fundamental Research - EERE - U.S. Department of ...

V.B.4 Stabilized Spinels and Nano Olivines (U. Texas)
Manthiram – U. Texas
of trace amounts of impurity phases. Further fine tuning of
the conditions to eliminate the minor impurity phases and
characterization of the samples by electron microscopy and
electrochemical measurements are currently in progress.
Figure V - 22: XRD patterns of (a) triclinic, (b) orthorhombic, and (c) tetragonal LiVOPO4.
Conclusions and Future Directions
Substitution of M n+ in the high-voltage spinel
cathodes LiMn 1.5 Ni 0.42 M 0.08 O 4 (M = Al, Cr, Fe, Co, Zn,
and Ga) eliminates the Li x Ni 1-x O impurity phase, increases
the Mn 3+ content, and suppresses the ordering between
Mn 4+ and Ni 2+ , resulting in improved cyclability and rate
capability. Characterization of the samples by TOF-SIMS
reveals a segregation of Al, Cr, Fe, and Ga to the surface,
which leads to a robust cathode-electrolyte interface and
superior cycle life at elevated temperatures due to the
suppression of SEI layer formation. Also, synthesis of the
undoped LiMn 1.5 Ni 0.5 O 4 in various morphologies by novel
synthesis approaches and their characterization reveal that
the variations in performance is due to the differences in
the Mn 3+ content. Samples with higher Mn 3+ content show
better performance. Our future work is focused on
adopting the synthesis approaches developed to obtain the
doped samples with high tap density and assessing the role
of morphology on electrochemical performances.
With the 4 V spinels, the oxyfluorides exhibit better
thermal stability than the corresponding oxides. Also, the
cathodes with lower lithium content in the charged state or
with higher capacity exhibit better thermal stability.
The metastable LiFe 1-x (VO) x PO 4 (0 ≤ x ≤ 0.25) and
the three crystallographic modifications of LiVOPO 4 have
been obtained by a novel microwave-solvothermal process.
Our future work is focused on comparing the properties of
the three forms of LiVOPO 4 as well as exploring the
microwave-solvothermal process for other polyanion
cathodes based on silicates and Nasicon-type phosphates.
FY 2011 Publications/Presentations
Journal Articles
1. T. Muraliganth, K. R. Stroukoff, and A. Manthiram,
“Microwave-Solvothermal Synthesis of
Nanostructured Li 2 MSiO 4 /C (M = Mn and Fe)
Cathodes for Lithium-Ion Batteries,” Chemistry of
Materials, 22, 5754-5761 (2010).
2. S. Yoon and A. Manthiram, “Nanostructured Sn-Ti-C
Composite Anodes for Lithium Ion Batteries,”
Electrochimica Acta 56, 3029-3035 (2011).
3. A. Manthiram, “Materials Challenges and
Opportunities of Lithium-ion Batteries,” Journal of
Physical Chemistry Letters, 2, 176-184 (2011).
4. K. R. Stroukoff and A. Manthiram, “Thermal Stability
of Spinel Li 1.1 Mn 1.9-y M y O 4-z F z (M = Ni, Al, and Li, 0
≤ y ≤ 0.3, and 0 ≤ z ≤ 0.2) Cathodes for Lithium Ion
Batteries,” Journal of Materials Chemistry 21, 10165­
10170 (2011).
5. K. L. Harrison and A. Manthiram, “Microwaveassisted
Solvothermal Synthesis and Characterization
of Metastable LiFe 1-x (VO) x PO 4 Cathodes,” Inorganic
Chemistry 50, 3613-3620 (2011).
6. D.W. Shin and A. Manthiram, “Surface-segregated,
high-voltage spinel LiMn 1.5 Ni 0.42 Ga 0.08 O 4 cathodes
with superior high-temperature cyclability for lithiumion
batteries,” Electrochemistry Communications 13,
1213-1216 (2011).
Presentations
1. A. Manthiram and T. Muraliganth, “Electrochemical
Behavior and Shifts in the Redox Potentials of Olivine
LiM 1-y M y PO 4 (M = Fe, Mn, and Co) Solid Solutions,”
218 th Meeting of the Electrochemical Society Meeting,
Las Vegas, NV, October 10 – 15, 2010.
2. A. Manthiram, “Nanotechnology for Electrical Energy
Storage,” Nano Monterey 2010: Applications of
Nanotechnology to New Energy Sources, Monterey,
Mexico, November 18 – 19, 2010 (plenary talk).
3. A. Manthiram, T. Muraliganth, A. Vadivel Murugan,
and K. L. Harrison, “Microwave-assisted
Solvothermal Synthesis of Nanostructured Materials
for Lithium-ion Batteries,” 2010 Fall Meeting of the
Materials Research Society, Boston, MA, November
28 – December 3, 2010 (invited).
Energy Storage R &D 486 FY 2011 Annual Progress Report