Rescaling of metal oxide nanocrystals for energy storage having high capacitance and energy density with robust cycle life
Abstract
Nanocrystals are promising structures, but they are too large for achieving maximum energy storage performance. We show that rescaling 3-nm particles through lithiation followed by delithiation leads to high-performance energy storage by realizing high capacitance close to the theoretical capacitance available via ion-to-atom redox reactions. Reactive force-field (ReaxFF) molecular dynamics simulations support the conclusion that Li atoms react with nickel oxide nanocrystals (NiO-n) to form lithiated core–shell structures (Ni:Li_2O), whereas subsequent delithiation causes Ni:Li_2O to form atomic clusters of NiO-a. This is consistent with in situ X-ray photoelectron and optical spectroscopy results showing that Ni^(2+) of the nanocrystal changes during lithiation–delithiation through Ni^0 and back to Ni^(2+). These processes are also demonstrated to provide a generic route to rescale another metal oxide. Furthermore, assembling NiO-a into the positive electrode of an asymmetric device enables extraction of full capacitance for a counter negative electrode, giving high energy density in addition to robust capacitance retention over 100,000 cycles.
Additional Information
© 2015 National Academy of Sciences. Contributed by William A. Goddard III, May 20, 2015 (sent for review December 9, 2014) Published online before print June 15, 2015, doi: 10.1073/pnas.1503546112. This research was supported by the Global Frontier R&D Program (2013M3A6B1078865) on Center for Hybrid Interface Materials funded by the Ministry of Science, Information and Communication Technology and Future Planning, and the National Research Foundation of Korea (2011-0028737, 2012M1A2A2671813). The work at the Molecular Foundry was supported by the US Department of Energy (DOE) under Contract DE-AC02-05CH11231. D.J.M. was supported by DOE Advanced Research Projects Agency-Energy under the same contract. Support for T.C. and W.A.G. was provided by National Science Foundation (CBET-1067848). Author contributions: H.M.J. and J.K.K. designed research; H.M.J., K.M.C., R.Z., I.W.O., and J.K.K. performed research; D.K.L. and I.W.O. contributed new reagents/analytic tools; T.C. and W.A.G. analyzed data; and H.M.J., K.M.C., T.C., D.J.M., W.A.G., and J.K.K. wrote the paper. The authors declare no conflict of interest. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1503546112/-/DCSupplemental.Attached Files
Published - PNAS-2015-Jeong-7914-9.pdf
Supplemental Material - pnas.1503546112.sapp.pdf
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Additional details
- PMCID
- PMC4491738
- Eprint ID
- 58263
- Resolver ID
- CaltechAUTHORS:20150615-151220941
- 2013M3A6B1078865
- Ministry of Science, Information and Communication Technology and Future Planning (Korea)
- 2011-0028737
- National Research Foundation of Korea
- 2012M1A2A2671813
- National Research Foundation of Korea
- DE-AC02-05CH11231
- Department of Energy (DOE)
- CBET-1067848
- NSF
- Created
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2015-06-15Created from EPrint's datestamp field
- Updated
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2022-06-01Created from EPrint's last_modified field