Browsing Obrovac, Mark N. by Submit Date

Now showing items 1-20 of 45

  • Implications of finite-size and surface effects on nanosize intercalation materials 

    Obrovac, MN, and JR Dahn. 2000. "Implications of finite-size and surface effects on nanosize intercalation materials." Physical Review B 61(10): 6713-6719.
    A Monte Carlo simulation of a two-dimensional lattice gas with free boundaries is used to study the effects of surface and size on the chemical potential-composition curves of intercalation compounds. In particular we are ...

  • Explanation for the 4.8-V plateau LiCrxMn2-xO4 

    Obrovac, MN, Y. Gao, and JR Dahn. 1998. "Explanation for the 4.8-V plateau LiCrxMn2-xO4." Physical Review B 57(10): 5728-5733.
    Using the results of photoelectron spectroscopy (PES) measurements on LiCrxMn2-xO4 we provide an explanation for the origin of the 4.8-V plateau in Li/LiCrxMn2-xO4 cells. PES shows that the d bands derived from Mn 3d e(g) ...

  • Use of carbon black to eliminate surface charging effects in photoelectron spectroscopy measurements of powders 

    Obrovac, MN, Y. Gao, MN Richard, and JR Dahn. 1997. "Use of carbon black to eliminate surface charging effects in photoelectron spectroscopy measurements of powders." Applied Physics Letters 71(16): 2262-2264.
    No abstract available.

  • Structural and Electrochemical Investigation of FexSi1-x Thin Films in Li Cells 

    Zhijia Du, R. A. Dunlap and M. N. Obrovac, Structural and Electrochemical Investigation of FexSi1-x Thin Films in Li Cells, J. Electrochem. Soc., 163 (2016) A2011-A2016.
    FexSi1-x thin films with 0 ≤ x ≤ 0.46 have been prepared by combinatorial sputtering and their electrochemical properties have been studied in Li half-cells. X-ray diffraction showed that all of the films had an amorphous ...

  • Reversible lithium insertion in catalytically graphitized sugar carbon 

    M.N. Obrovac, Xiuyun Zhao, L.T. Burke and R.A. Dunlap, Reversible Lithium Insertion in Catalytically Graphitized Sugar Carbon, Electrochem. Commun., 60 (2015), 221-224
    Highlights • First report of Li insertion in highly ordered catalytically derived graphite. • Fe catalyst combined with hard carbon precursors enable 1200 °C graphitization. • First report of highly ordered graphite ...

  • The Electrochemistry of Amorphous Si-B Thin Film Electrodes in Li Cells 

    Hui Liu, Min Zhu, Zhijia Du and M.N. Obrovac, The Electrochemistry of Amorphous Si-B Thin Film Electrodes in Li Cells, J. Electrochem. Soc., 163 (2016), A192-A196
    Abstract Si1-xBx thin films of 0.071 ≤ x ≤ 0.950 have been synthesized using combinational sputtering. All Si1-xBx film compositions had a highly amorphous structure consisting of amorphous Si and B phases, as characterized ...

  • Combinatorial Study of the Si-Sn-O System as Negative Electrode Materials in Li-Ion Cells 

    Xiuyun Zhao, M.T. Schreiber, L. MacEachern, R.J. Sanderson, R.A. Sanderson, R.A. Dunlap and M.N. Obrovac, Combinatorial Study of the Si-Sn-O System as Negative Electrode Materials in Li-Ion Cells, J. Electrochem. Soc., 163 (2016), A203-A209.
    SixSnyO1-x-y films with 0.45 < x < 0.80, 0.05 < y < 0.35, and 0.05 < (1-x-y) < 0.40 have been prepared using a magnetron sputtering method. All compositions had an amorphous structure and good capacity retention. Reversible ...

  • NixSi1-x Alloys Prepared by Mechanical Milling as Negative Electrode Materials for Lithium Ion Batteries 

    NixSi1-x (0 ≤ x ≤ 0.5, x = 0.05) alloys were prepared by ball milling and studied as anode materials for lithium ion batteries. Nanocrystalline Si/NiSi2 phases were formed for x ≤ 0.25. The NiSi phase was observed for ...

  • Li15Si4 Formation in Silicon Thin Film Negative Electrodes 

    D.S. Iaboni and M.N. Obrovac, Li15Si4 Formation in Silicon Thin Film Negative Electrodes, J. Electrochem. Soc., 163 (2016), A255-A261.
    The conditions for Li15Si4 formation in Si thin film negative electrodes was studied during charge and discharge cycling in lithium cells. It was found that Li15Si4 formation can be suppressed during cycling of Si thin ...

  • The Electrochemical Behavior of Polyimide Binders in Li and Na Cells 

    B. N. Wilkes, Z. L. Brown, L. J. Krause, M. Triemert and M. N. Obrovac, The Electrochemical Behavior of Polyimide Binders in Li and Na Cells, J. Electrochem. Soc., 163 (2016), A364-A372.
    The electrochemistry of aromatic and aliphatic polyimide binders was characterized in composite coatings for Li-ion and Na-ion battery negative electrodes. Aromatic polyimide was found to have a large first lithiation ...

  • Electrochemistry of Catalytically Graphitized Ball Milled Carbon in Li Batteries 

    High carbon Fe-C composites with starting concentrations of 10, 20, 30, and 40 wt% Fe (2.3 - 12.5 atomic % Fe) were prepared by ball milling followed by annealing. Increasing the Fe concentration and annealing temperature ...

  • The Electrochemical Reaction Mechanism of Tin Phosphide with Sodium 

    Lituo Zheng, R.A. Dunlap and M.N. Obrovac, The Electrochemical Reaction Mechanism of Tin Phosphide with Sodium, J. Electrochem. Soc., 163 (2016), A1188-1191.
    The sodiation mechanism of Sn4P3 was studied by ex-situ X-ray diffraction and Mössbauer effect spectroscopy. These results show that Sn4P3 is initially amorphized during sodiation, and suggest that upon further sodiation ...

  • Electrochemistry of CuxSi1−x Alloys in Li Cells 

    Zhijia Du, Hui Liu, S.N. Ellis, R.A. Dunlap, M. Zhu and M.N. Obrovac, Electrochemistry of CuxSi1−x Alloys in Li Cells, J. Electrochem. Soc., 163 (2016), A1275-1279.
    The structure and electrochemistry in lithium cells of sputtered thin films and ball milled alloys in the Cu-Si system (0 ≤ x ≤ 0.60 in CuxSi1−x) were investigated. Both thin films and ball milled Cu-Si alloys showed the ...

  • Phenolic Resin as an Inexpensive High Performance Binder for Li-Ion Battery Alloy Negative Electrodes 

    T.D. Hatchard, P. Bissonnette and M.N. Obrovac, Phenolic Resin as an Inexpensive High Performance Binder for Li-Ion Battery Alloy Negative Electrodes, J. Electrochem. Soc., 163 (2016) A2035-A2039.
    Phenolic resin was evaluated as a binder material for Li-ion battery negative electrodes containing Si-based alloys. Phenolic resin was found to have a large first lithiation capacity of about 1200 mAh/g, which is suspected ...

  • Honeycomb Compound Na3Ni2BiO6 as Positive Electrode Material in Na Cells 

    Lituo Zheng and M.N. Obrovac, Honeycomb Compound Na3Ni2BiO6 as Positive Electrode Material in Na Cells, J. Electrochem. Soc., 163 (2016) A2362-A2367.
    Honeycomb compound Na3Ni2BiO6 was synthesized and studied as positive electrode material in sodium cells for the first time. This material exhibits a reversible capacity of ∼80 mAh/g and an average voltage of ∼3.1 V, ...

  • Electrochemical Activity of Nano-NiSi2 in Li Cells 

    Zhijia Du, T.D. Hatchard, P. Bissonnette, R. A. Dunlap and M. N. Obrovac, Electrochemical Activity of Nano-NiSi2 in Li Cells, J. Electrochem. Soc., 163 (2016) A2456-A2460.
    Crystalline and nanocrystalline NiSi2 were studied as negative electrode materials in Li cells. Crystalline NiSi2 was found to be inactive toward lithiation/delithiation. However, it was found that NiSi2 becomes active ...

  • Rapid mechanochemical synthesis of amorphous alloys 

    T.D. Hatchard, A. Genkin and M.N. Obrovac, Rapid Mechanochemical Synthesis of Amorphous Alloys, AIP Advances, 7 (2017) 045201.
    A rapid method for preparing amorphous alloys has been developed utilizing a SPEX high energy ball mill. Parameters such as ball size, mass of balls and milling time, were systematically optimized to prepare amorphous ...

  • Lithium Insertion in Nanostructured Si1-xTix Alloys 

    Yukun Wang, Simeng Cao, Mariya Kalinina, Lituo Zheng, Linjun Li, Min Zhu and M.N. Obrovac, Lithium Insertion in Nanostructured Si1-xTix Alloys, J. Electrochem. Soc., 164 (2017) A3006-A3010.
    Nanostructured Si1-xTix alloys (0 ≤ x ≤ 0.3) prepared by ball milling were studied as negative electrode materials in Li cells. The alloys comprised a nanocrystalline andamorphousSiphaseandananocrystallineC49TiSi2 phase. ...

  • All-Dry Synthesis of Single Crystal NMC Cathode Materials for Li-Ion Batteries 

    Lituo Zheng, J. Craig Bennett and M. N. Obrovac. All-Dry Synthesis of Single Crystal NMC Cathode Materials for Li-Ion Batteries. Journal of The Electrochemical Society (2020), 167 (13), 130536.
    Single crystal (SC) cathode materials with a layered structure are considered to be state-of-the-art for lithium ion batteries. However, their production involves many steps and can produce large amounts of wastewater. ...

  • LiF as an Alloy Component or Slurry Additive in Si-Alloy Anodes 

    Robert S. Young, Benjamin Scott, Congxiao Wei and M. N. Obrovac. LiF as an Alloy Component or Slurry Additive in Si-Alloy Anodes. J. Electrochem. Soc. (2020), 167 (16), 160524.
    Electrolyte additives are commonly used to improve electrochemical performance in Li-ion cells. The use of solids as electrolyte additives is far less common. Here, Si40'(FeSi2)(60−x)'(LiF)(x)' (' = volume percent) alloys ...