skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Band Diagram and Rate Analysis of Thin Film Spinel LiMn 2 O 4 Formed by Electrochemical Conversion of ALD-Grown MnO

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. Department of Chemical and Biological Engineering, University of Colorado, Boulder CO 80309 USA
  2. Leupold-Institut für Angewandte Naturwissenschaften, Westsächsische Hochschule, 08012 Zwickau Germany
  3. Department of Chemical and Biological Engineering, University of Colorado, Boulder CO 80309 USA; Department of Chemistry and Biochemistry, University of Colorado, Boulder CO 80309 USA; National Renewable Energy Laboratory, Golden CO 80401 USA
  4. Department of Chemistry and Biochemistry, University of Colorado, Boulder CO 80309 USA; Department of Mechanical Engineering, University of Colorado, Boulder CO 80309 USA
  5. Department of Chemical and Biological Engineering, University of Colorado, Boulder CO 80309 USA; Department of Chemistry and Biochemistry, University of Colorado, Boulder CO 80309 USA
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Next Generation of Materials by Design: Incorporating Metastability (CNGMD)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1388813
DOE Contract Number:
AC36-99GO10337
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advanced Functional Materials; Journal Volume: 26; Journal Issue: 43; Related Information: CNGMD partners with National Renewable Energy Laboratory (lead); Colorado School of Mines; Harvard University; Lawrence Berkeley National Laboratory; Massachusetts Institute of Technology; Oregon State University; SLAC National Accelerator Laboratory
Country of Publication:
United States
Language:
English
Subject:
solar (photovoltaic), solar (fuels), solid state lighting, phonons, thermoelectric, hydrogen and fuel cells, defects, charge transport, optics, materials and chemistry by design, synthesis (novel materials)

Citation Formats

Young, Matthias J., Schnabel, Hans-Dieter, Holder, Aaron M., George, Steven M., and Musgrave, Charles B.. Band Diagram and Rate Analysis of Thin Film Spinel LiMn 2 O 4 Formed by Electrochemical Conversion of ALD-Grown MnO. United States: N. p., 2016. Web. doi:10.1002/adfm.201602773.
Young, Matthias J., Schnabel, Hans-Dieter, Holder, Aaron M., George, Steven M., & Musgrave, Charles B.. Band Diagram and Rate Analysis of Thin Film Spinel LiMn 2 O 4 Formed by Electrochemical Conversion of ALD-Grown MnO. United States. doi:10.1002/adfm.201602773.
Young, Matthias J., Schnabel, Hans-Dieter, Holder, Aaron M., George, Steven M., and Musgrave, Charles B.. 2016. "Band Diagram and Rate Analysis of Thin Film Spinel LiMn 2 O 4 Formed by Electrochemical Conversion of ALD-Grown MnO". United States. doi:10.1002/adfm.201602773.
@article{osti_1388813,
title = {Band Diagram and Rate Analysis of Thin Film Spinel LiMn 2 O 4 Formed by Electrochemical Conversion of ALD-Grown MnO},
author = {Young, Matthias J. and Schnabel, Hans-Dieter and Holder, Aaron M. and George, Steven M. and Musgrave, Charles B.},
abstractNote = {},
doi = {10.1002/adfm.201602773},
journal = {Advanced Functional Materials},
number = 43,
volume = 26,
place = {United States},
year = 2016,
month = 9
}
  • Nanoscale spinel lithium manganese oxide is of interest as a high-rate cathode material for advanced battery technologies among other electrochemical applications. In this work, the synthesis of ultrathin films of spinel lithium manganese oxide (LiMn 2O 4) between 20 and 200 nm in thickness by room-temperature electrochemical conversion of MnO grown by atomic layer deposition (ALD) is demonstrated. The charge storage properties of LiMn 2O 4 thin films in electrolytes containing Li +, Na +, K +, and Mg 2+ are investigated. A unified electrochemical band-diagram (UEB) analysis of LiMn 2O 4 informed by screened hybrid density functional theory calculationsmore » is also employed to expand on existing understanding of the underpinnings of charge storage and stability in LiMn 2O 4. It is shown that the incorporation of Li + or other cations into the host manganese dioxide spinel structure (λ-MnO 2) stabilizes electronic states from the conduction band which align with the known redox potentials of LiMn 2O 4. Furthermore, the cyclic voltammetry experiments demonstrate that up to 30% of the capacity of LiMn 2O 4 arises from bulk electronic charge-switching which does not require compensating cation mass transport. As a result, the hybrid ALD-electrochemical synthesis, UEB analysis, and unique charge storage mechanism described here provide a fundamental framework to guide the development of future nanoscale electrode materials for ion-incorporation charge storage.« less
  • LiMn{sub 2}O{sub 4} thin films with different crystallizations were respectively grown at high, medium and low temperatures by pulsed laser deposition (PLD). Structures, morphologies and electrochemical properties of these three types of thin films were comparatively studied. Films grown at high temperature ({>=}873 K) possessed flat and smooth surfaces and were highly crystallized with different textures and crystal sizes depending on the deposition pressure of oxygen. However, films deposited at low temperature (473 K) had rough surfaces with amorphous characteristics. At medium temperature (673 K), the film was found to consist mainly of nano-crystals less than 100 nm with relativelymore » loose and rough surfaces, but very dense as observed from the cross-section. The film deposited at 873 K and 100 mTorr of oxygen showed an initial discharge capacity of 54.3 {mu}Ah/cm{sup 2} {mu}m and decayed at 0.28% per cycle, while the amorphous film had an initial discharge capacity of 20.2 {mu}Ah/cm{sup 2} {mu}m and a loss rate of 0.29% per cycle. Compared with the highly crystallized and the amorphous films, nano-crystalline film exhibited higher potential, more capacity and much better cycling stability. As high as 61 {mu}Ah/cm{sup 2} {mu}m of discharge capacity can be achieved with an average decaying rate of only 0.032% per cycle up to 500 cycles. The excellent performance of nano-crystalline film was correlated to its microstructures in the present study. - Graphical abstract: LiMn{sub 2}O{sub 4} thin films with different crystal size were grown at high, medium and low temperatures by PLD. Cyclic voltammograms of LiMn{sub 2}O{sub 4} thin film electrodes deposited at different temperatures show that the excellent performance of nano-crystalline film was correlated to its microstructures.« less
  • Electrical conductivity of LiMn{sub 2}O{sub 4}, which is a promising cathode active material for lithium ion batteries, was monitored in situ during electrochemical lithium extraction and reinsertion reactions in 1 M LiClO{sub 4} propylene carbonate solution. The in-situ conductivity measurement was achieved by means of an interdigitated microarray electrode coated with a uniform and dense film of LiMn{sub 2}O{sub 4}. The conductivity of Li{sub 1{minus}x}Mn{sub 2}O{sub 4} was found to exhibit a peak-shaped profile as a function of lithium content. The conductivity of Cr{sup 3+}-doped spinel, LiMn{sub 1.95}Cr{sub 0.05}O{sub 4}, decreased monotonically with decreasing lithium content. These results are discussedmore » by considering the effects of phase transformation on the conductivity of these materials.« less
  • LiMn{sub 2}O{sub 4}-based spinels are of great interest as positive electrode materials for lithium-ion batteries. The authors describe here what is believed to be the first synthesis of these materials using the Pechini process, a low temperature synthetic method that often yields inorganic oxides of excellent phase purity and well-controlled stoichiometry. Using this process, it has been possible to synthesize phase-pure crystalline spinel LiMn{sub 2}O{sub 4} by calcining the appropriate polymeric precursors in air at 250 C for several hours. The influence of different firing temperatures and the effect of substituting a small amount of Mn with Ni have alsomore » been explored. Electrochemical studies show that the Pechini-synthesized materials appear to offer not only high quality performance but also significant analytical advantages which allows one to understand the structural mechanism of Li intercalation.« less
  • The preparation and characterization of spinel LiMn{sub 2}O{sub 4} having small average particle sizes (<4.0 {micro}m) and narrow particle size distribution are reported. They were obtained by heating a 1:4 Li{sub 2}CO{sub 3}/MnCO{sub 3} mixture at 650 to 850 C in oxygen. Particle size control of the product was achieved by controlling the particle sizes of the precursor materials and the heating conditions. Heating the Li{sub 2}CO{sub 3}/4MnCO{sub 3} mixture results in the formation of Mn{sub 2}O{sub 3} initially, which then reacts with Li{sub 2}CO{sub 3} to form spinel LiMn{sub 2}O{sub 4} according to: 2Li{sub 2}CO{sub 3} + 4 Mn{submore » 2}O{sub 3} + O{sub 2} {yields} 2CO{sub 2}. The LiMn{sub 2}O{sub 4} cathodes have shown excellent rechargeability as well as superior rate capability in Li/polymer electrolyte/LiMn{sub 2}O{sub 4} cells cycled between 3.0 and 4.3 V. Specific capacities between 0.75 and 0.83 /Li per LiMn{sub 2}O{sub 4} were obtained for more than fifty cycles. The LiMn{sub 2}O{sub 4} cathodes can be reversibly cycled between 2.4 and 3.5 V but with declining capacity. For the LiMn{sub 2}O{sub 4} prepared at 650 C, cycling in the 3 V region has little effect on its subsequent performance in the 4 V region, while for the LiMn{sub 2}O{sub 4} prepared at higher temperatures, such cycling causes the 4 V capacity to decline.« less