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Author Dimitrievska, M.; Shea, P.; Kweon, K.E.; Bercx, M.; Varley, J.B.; Tang, W.S.; Skripov, A.V.; Stavila, V.; Udovic, T.J.; Wood, B.C. pdf  url
doi  openurl
  Title Carbon Incorporation and Anion Dynamics as Synergistic Drivers for Ultrafast Diffusion in Superionic LiCB11H12 and NaCB11H12 Type A1 Journal article
  Year (down) 2018 Publication Advanced energy materials Abbreviated Journal Adv Energy Mater  
  Volume 8 Issue 15 Pages 1703422  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The disordered phases of LiCB11H12 and NaCB11H12 possess superb superionic conductivities that make them suitable as solid electrolytes. In these materials, cation diffusion correlates with high orientational mobilities of the CB11H12- anions; however, the precise relationship has yet to be demonstrated. In this work, ab initio molecular dynamics and quasielastic neutron scattering are combined to probe anion reorientations and their mechanistic connection to cation mobility over a range of timescales and temperatures. It is found that anions do not rotate freely, but rather transition rapidly between orientations defined by the cation sublattice symmetry. The symmetry-breaking carbon atom in CB11H12- also plays a critical role by perturbing the energy landscape along the instantaneous orientation of the anion dipole, which couples fluctuations in the cation probability density directly to the anion motion. Anion reorientation rates exceed 3 x 10(10) s(-1), suggesting the underlying energy landscape fluctuates dynamically on diffusion-relevant timescales. Furthermore, carbon is found to modify the orientational preferences of the anions and aid rotational mobility, creating additional symmetry incompatibilities that inhibit ordering. The results suggest that synergy between the anion reorientational dynamics and the carbon-modified cation-anion interaction accounts for the higher ionic conductivity in CB11H12- salts compared with B12H122-.  
  Address  
  Corporate Author Thesis  
  Publisher WILEY-VCH Verlag GmbH & Co. Place of Publication Weinheim Editor  
  Language Wos 000434031400026 Publication Date 2018-02-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1614-6832; 1614-6840 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.721 Times cited 20 Open Access OpenAccess  
  Notes ; This work was performed in part under the auspices of the U.S. Department of Energy at Lawrence Livermore National Laboratory (LLNL) under Contract No. DE-AC52-07NA27344 and funded by Laboratory Directed Research and Development Grant 15-ERD-022. Computing support came from the LLNL Institutional Computing Grand Challenge program. This work was also performed in part within the assignment of the Russian Federal Agency of Scientific Organizations (program “Spin” No. 01201463330). The authors gratefully acknowledge support from the Russian Foundation for Basic Research under Grant No. 15-03-01114 and the Ural Branch of the Russian Academy of Sciences under Grant No. 15-9-2-9. A.V.S. gratefully acknowledges travel support from CRDF Global in conjunction with this work under Grant No. FSCX-15-61826-0. M.D. gratefully acknowledges research support from the Hydrogen Materials-Advanced Research Consortium (HyMARC), established as part of the Energy Materials Network under the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office, under Contract No. DE-AC36-08GO28308. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy National Nuclear Security Administration under Contract No. DE-AC04-94AL85000. This work utilized facilities supported in part by the National Science Foundation under Agreement No. DMR-1508249. The views, opinions, findings, and conclusions stated herein are those of the authors and do not necessarily reflect those of CRDF Global, or the United States Government or any agency thereof. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. ; Approved Most recent IF: 16.721  
  Call Number UA @ lucian @ c:irua:152045 Serial 5015  
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Author Sathiya, M.; Jacquet, Q; Doublet, M.L; Karakulina, O.M.; Hadermann, J.; Tarascon, J.-M. pdf  url
doi  openurl
  Title A Chemical Approach to Raise Cell Voltage and Suppress Phase Transition in O3 Sodium Layered Oxide Electrodes Type A1 Journal article
  Year (down) 2018 Publication Advanced energy materials Abbreviated Journal Adv. Energy Mater.  
  Volume Issue Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Sodium ion batteries (NIBs) are one of the versatile technologies for lowcost rechargeable batteries. O3-type layered sodium transition metal oxides (NaMO2, M = transition metal ions) are one of the most promising positive electrode materials considering their capacity. However, the use of O3 phases is limited due to their low redox voltage and associated multiple phase transitions which are detrimental for long cycling. Herein, a simple strategy is proposed to successfully combat these issues. It consists of the introduction of a larger, nontransition metal ion Sn4+ in NaMO2 to prepare a series of NaNi0.5Mn0.5−y SnyO2 (y = 0–0.5) compositions with attractive electrochemical performances, namely for y = 0.5, which shows a single-phase transition from O3 ⇔ P3 at the very end of the oxidation process. Na-ion NaNi0.5Sn0.5O2/C coin cells are shown to deliver an average cell voltage of 3.1 V with an excellent capacity retention as compared to an average stepwise voltage of ≈2.8 V and limited capacity retention for the pure NaNi0.5Mn0.5O2 phase. This study potentially shows the way to manipulate the O3 NaMO2 for facilitating their practical use in NIBs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000430163100013 Publication Date 2018-01-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 21.875 Times cited 28 Open Access OpenAccess  
  Notes M.S. and Q.J. contributed equally to this work. The authors thank Dr. Daniel Alves Dalla Corte and Sujoy Saha for electronic conductivity measurements and Prof. Dominique Larcher for fruitful discussions. Q.J. thanks the ANR “Deli-Redox” for Ph.D. funding. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. TGA analysis by Matthieu Courty, LRCS, Amiens, is greatly acknowledged. J.H. and O.M.K. acknowledge funding from FWO Vlaanderen project G040116N. Approved Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:149515 Serial 4907  
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Author Lutz, L.; Corte, D.A.D.; Chen, Y.; Batuk, D.; Johnson, L.R.; Abakumov, A.; Yate, L.; Azaceta, E.; Bruce, P.G.; Tarascon, J.-M.; Grimaud, A. pdf  doi
openurl 
  Title The role of the electrode surface in Na-Air batteries : insights in electrochemical product formation and chemical growth of NaO2 Type A1 Journal article
  Year (down) 2018 Publication Advanced energy materials Abbreviated Journal Adv Energy Mater  
  Volume 8 Issue 4 Pages 1701581  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The Na-air battery, because of its high energy density and low charging overpotential, is a promising candidate for low-cost energy storage, hence leading to intensive research. However, to achieve such a battery, the role of the positive electrode material in the discharge process must be understood. This issue is herein addressed by exploring the electrochemical reduction of oxygen, as well as the chemical formation and precipitation of NaO2 using different electrodes. Whereas a minor influence of the electrode surface is demonstrated on the electrochemical formation of NaO2, a strong dependence of the subsequent chemical precipitation of NaO2 is identified. In the origin, this effect stems from the surface energy and O-2/O-2(-) affinity of the electrode. The strong interaction of Au with O-2/O-2(-) increases the nucleation rate and leads to an altered growth process when compared to C surfaces. Consequently, thin (3 mu m) flakes of NaO2 are found on Au, whereas on C large cubes (10 mu m) of NaO2 are formed. This has significant impact on the cell performance and leads to four times higher capacity when C electrodes with low surface energy and O-2/O-2(-) affinity are used. It is hoped that these findings will enable the design of new positive electrode materials with optimized surfaces.  
  Address  
  Corporate Author Thesis  
  Publisher WILEY-VCH Verlag GmbH & Co. Place of Publication Weinheim Editor  
  Language Wos 000424152200009 Publication Date 2017-09-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1614-6832; 1614-6840 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.721 Times cited 13 Open Access Not_Open_Access  
  Notes ; L.L. thanks ALISTORE-ERI for his PhD grant. P.G.B. is indebted to the EPSRC for financial support, including the Supergen Energy Storage grant. ; Approved Most recent IF: 16.721  
  Call Number UA @ lucian @ c:irua:149269 Serial 4951  
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