V. Focused Fundamental Research - EERE - U.S. Department of ...
V. Focused Fundamental Research - EERE - U.S. Department of ...
V. Focused Fundamental Research - EERE - U.S. Department of ...
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Thackeray – ANL<br />
V.B.9 Layered Cathode Materials (ANL)<br />
(a)<br />
(b)<br />
Figure V - 50: (a) Surface coordination numbers; (b) Mn oxidation states <strong>of</strong> LiMn2O4<br />
Conclusions and Future Directions<br />
Conclusions<br />
· All milestones set for this project in FY2011 were<br />
met.<br />
· The voltage-fade phenomenon in high-capacity<br />
xLi 2 MnO 3 (1-x)LiMO 2 (M=Mn, Ni, Co) electrodes<br />
was evaluated.<br />
· A new approach to synthesize composite electrode<br />
structures from a Li 2 MnO 3 precursor was identified<br />
with promising results; this project will form the basis<br />
<strong>of</strong> a new cathode project in FY2012.<br />
· Progress was made in stabilizing the surface, and<br />
improving the rate capability, <strong>of</strong> xLi 2 MnO 3 (1<br />
x)LiMO 2 electrodes using sonochemical reactions.<br />
· Simulation <strong>of</strong> the surface structure <strong>of</strong> LiMn 2 O 4 shows<br />
that near-surface manganese ions strongly prefer the<br />
trivalent state, which provided further insight into<br />
dissolution phenomena associated, for example, with<br />
Ni-substituted LiMn 2 O 4 electrodes.<br />
Future Work<br />
(See New Cathode Project V.B.14.)<br />
· Exploit novel processing methods using Li 2 MnO 3 as a<br />
precursor to synthesize and optimize various<br />
composite electrode structures (composition and<br />
performance) with the goal <strong>of</strong> reaching/exceeding the<br />
energy and power goals required for 40-mile PHEVs<br />
and EVs. In particular, focus on ‘layered-layered’<br />
,‘layered-layered-spinel’- and new ‘layered-rocksalt’<br />
xLi 2 MnO 3 (1-x)MO systems.<br />
· Focus on the stabilization <strong>of</strong> both surface and bulk<br />
structures. Use complementary experimental and<br />
theoretical approaches to improve the surface<br />
stability, rate capability and cycle life <strong>of</strong> high capacity<br />
Mn-rich oxide electrodes at high potentials.<br />
· Further explore sonication to fabricate and evaluate<br />
stable surface architectures.<br />
· Continue EFRC-related work and interact with DOE’s<br />
energy storage centers.<br />
FY 2011 Publications/Patents/Presentations<br />
Publications<br />
1. K. A. Walz, C. S. Johnson, J. Genthe, L. C. Stoiber,<br />
W. A. Zeltner, M. A. Anderson and M. M. Thackeray,<br />
Elevated Temperature Cycling Stability and<br />
Electrochemical Impedance <strong>of</strong> LiMn 2 O 4 Cathodes<br />
with Nanoporous ZrO 2 and TiO 2 Coatings, J. Power<br />
Sources, 195, 4943 (2010).<br />
2. A. Rockett, Y. W. Chung, H. Blaichek, S. Butterfield,<br />
R. R. Chance, C. Ferekides, M. Robinson, S. W.<br />
Snyder and M. M. Thackeray, Transformative<br />
<strong>Research</strong> Issues and Opportunities in Alternative<br />
Energy Generation and Storage, Current Opinion in<br />
Solid State & Materials Science, 15, 8-15 (2011).<br />
3. R. Benedek and M. M. Thackeray. Simulation <strong>of</strong> the<br />
Surface Structure <strong>of</strong> Lithium Manganese Oxide<br />
Spinel, Phys. Rev. B, 83 (19): Art. No. 195439 (May<br />
31 2011).<br />
4. J. R. Croy, S.-H. Kang, M. Balasubramanian and M.<br />
M. Thackeray, A New Approach to Fabricating<br />
Li 2 MnO 3 -based Composite Cathode Structures for<br />
Lithium Batteries, Electrochem. Comm., 13, 1063<br />
1066 (2011).<br />
Patents<br />
1. M. M. Thackeray, S.-H. Kang, M. Balasubramaian<br />
and J. R. Croy, Electrode Structures and Surfaces for<br />
Li Batteries, US Patent Application, Serial No.<br />
13/044038 (9 March 2011).<br />
FY 2011 Annual Progress Report 511 Energy Storage R&D
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