Obrovac, Mark N.
Recent Submissions
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Quantitative Measurement of Compositional Inhomogeneity in NMC Cathodes by X-ray Diffraction Postprint
A novel X-ray diffraction (XRD) analysis technique is described for quantitatively measuring compositional inhomogeneity in Li[NixMnyCoz]O2 (NMC) cathode materials and NMC precursors. Single-phase rock salt precursors with ... -
Hydrothermally Deposited Carbon Coatings for Li-Ion Battery Active Materials Postprint
Hydrothermally deposited carbon coatings were evaluated for Li-ion battery materials. The applied coatings were found to be highly uniform and porous, with a density of 1.89 g/ml and a surface area of 370 m2/g. In lithium ... -
Combinatorial Investigations of Ni-Si Negative Electrode Materials for Li-Ion Batteries
Sputtered thin films in the Ni-Si system (0 ≤ x ≤ 0.65 in NixSi1-x) were studied for use as anode materials in Li-ion cells. All compositions were found to be amorphous. The Ni in Ni-Si films was found to suppress the ... -
Lab-scale chemical vapor deposition onto powders
In this paper, a laboratory chemical vapor deposition (CVD) reactor is described, which features an opposing screw rotating fluidized bed. The reactor efficiently concentrates powdered reactants in the reaction zone while ... -
Li-ion Battery Negative Electrodes Based on the FexZn1-x Alloy System (Preprint)
Thin-film Fe-Zn libraries were investigated as negative electrode materials for Li-ion batteries using combinatorial and high-throughput techniques. X-ray diffraction, Mössbauer effect spectroscopy and electron microprobe ... -
Investigation of the NaNixMn1-xO2 (0 ≤ x ≤ 1) System for Na-ion Battery Cathode Materials (Preprint)
Layered NaNixMn1-xO2 (0 ≤ x ≤ 1) oxides were prepared via solid state reactions. Different reaction conditions were required to obtain phase pure samples, depending on the value of x. The 0 ≤ x ≤ 0.1 compositions were ... -
Mössbauer and Electrochemical Investigations of Carbon-Rich Fe1-xCx Films (Preprint)
A thin film binary library of carbon-rich Fe1-xCx (0.47 ≤ x ≤ 0.97) alloys was prepared by combinatorial sputtering of carbon and iron. The sputtered library was characterized by X-ray diffraction and room temperature 57Fe ... -
The Reversible Magnesiation of Pb (Preprint)
Sputtered Pb films have been found to reversibly alloy electrochemically with magnesium in Grignard based electrolytes. The voltage curve shows a single plateau at about 125 mV vs. Mg, corresponding to the formation of ... -
Mixed Transition Metal Titanate and Vanadate Negative Electrode Materials for Na-Ion Batteries (Preprint)
Sodium-ion batteries have the potential to be a low cost, sustainable replacement for lithium-ion batteries in large scale energy storage. The lack of practical negative electrode materials limit the development of Na-ion ... -
A Combinatorial Investigation of Fe-Si-Zn Thin Film Negative Electrodes for Li-ion 2 Batteries (Preprint)
Sodium-ion batteries have the potential to be a low cost, sustainable replacement for lithium-ion batteries in large scale energy storage. The lack of practical negative electrode materials limit the development of Na-ion ... -
A Combinatorial Investigation of Fe-Si-Zn Thin Film Negative Electrodes for Li-ion 1 Batteries (Preprint)
Thin-film Fe-Si-Zn libraries were investigated as negative electrode materials for Li-ion batteries using combinatorial and high-throughput techniques. X-ray diffraction and electron microprobe measurements were used to ... -
Synthesis, Lithium Insertion and Thermal Stability of Si–Mo Alloys
Li insertion was investigated in SixMo100−x (90 ≥ x ≥ 70, Δx = 10) alloys prepared by mechanical ball milling. X-ray diffraction (XRD) and quantitative phase analysis were used to analyze phase compositions of these Si–Mo ... -
Electrochemistry and Thermal Behavior of SiOx Made by Reactive Gas Milling
SiOx with various oxygen contents were synthesized from Si powder by a simple room-temperature ball milling method by controlling the air exposure time during milling. The resulting SiOx consists of nano and amorphous Si ... -
Engineered Particle Synthesis by Dry Particle Microgranulation
Highlights * A method of making monodisperse engineered ∼10-μm particles is introduced * Core-shell, spherical, and tetrahedral particles demonstrated at ∼100% yield * Spherical layered oxides for Li-ion batteries ... -
Polyaniline Electrode Activation in Li Cells
Polyaniline (PANi) can be used as an electroactive organic cathode material in Li-cells with multiple redox states. The theoretical specific capacity of the emeraldine base (PEB) is 150 mAh g−1. In this study, we show how ... -
Spherically Smooth Cathode Particles by Mechanofusion Processing
Surface modification has been shown to be useful for improving the cycling performance of cathode materials. Typically hetero-compositional coatings are applied on cathode particle surfaces using methods, such as aqueous ... -
Quantitative Determination of Carbon Dioxide Content in Organic Electrolytes by Infrared Spectroscopy
CO2 has been shown to be an effective additive to improve the cycling characteristics of silicon negative electrodes for Li-ion batteries. However, a quantitative technique for measuring the CO2 content in electrolyte is ... -
Stabilizing NaCrO2 by Sodium Site Doping with Calcium
Layered cathode materials based on abundant, low cost raw materials have garnered interest in recent years. O3-type NaCrO2 is a promising cathode material as it offers decent energy density and is easy to synthesize. In ... -
An Investigation of the Fe-Mn-Si System for Li-Ion Battery Negative Electrodes
Fe-Mn-Si alloys prepared by ball milling were investigated as negative electrodes for Li-ion batteries. X-ray diffraction and room temperature 57Fe Mössbauer measurements were used to characterize alloy structure, which ... -
Li Insertion in Ball Milled Si-Mn Alloys
Si1-xMnx (0 ≤ x ≤0.5, x=0.05)alloyswereprepared by ball milling and studied as negative electrode materials in Li cells. These alloys were found to be unique amongtransition metals. When x ≤ 0.35, the alloys are essentially ...