Joseph Teprovich

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• Doctor of Philosophy
• Professor (Associate) at California State University, Northridge

We have developed a LiBH4-C-60 nanocomposite that displays fast lithium ionic conduction in the solid state. The material is a homogeneous nanocomposite that contains both LiBH4 and a hydrogenated fullerene species. In the presence of C-60, the lithium ion mobility of LiBH4 is significantly enhanced in the as-prepared state when compared to pure Li...

Our investigation of the chemical and physical properties of the alkali-metal dodecahydro-closo-dodecaborate, Li2B12H12, determined that it is a bi-functional material that can be used as a solid state electrolyte in lithium ion batteries and as a luminescent down conversion dye in scalable transparent displays. A series of electrochemical measurem...

In this work, we evaluate the electrochemical properties of MBH4-C60 (M = Li⁺, Na⁺) nanocomposites for potential use as a solid-state electrolyte in alkali-ion batteries. The enhancement of ionic conductivity for MBH4 was achieved through the addition of C60 and partial dehydrogenation, resulting in an electrolyte with significantly higher ionic co...

Abstract A major challenge in the pursuit of higher‐energy‐density lithium batteries for carbon‐neutral‐mobility is electrolyte compatibility with a lithium metal electrode. This study demonstrates the robust and stable nature of a closo‐borate based gel polymer electrolyte (GPE), which enables outstanding electrochemical stability and capacity ret...

In this work, we evaluated two closo-borate salts (Li2B12H12 and Li2B12F12) in propylene carbonate from theoretical and experimental perspectives to understand how the coordination environment influences their spectroscopic and electrochemical properties. The coordination environments of the closo-borate salts were modeled via density functional th...

Metal hydrides with a high hydrogen content have long been considered for materials-based hydrogen storage and but are now attracting attention as potential high-temperature superconductors. ¹ Recently, we showed that cryo-milling lanthanum improves hydrogen diffusion, yielding a higher hydrogen-to-metal ratio of lanthanum hydride up to LaH 4 . ² A...

Porphyrins play pivotal roles in many crucial biological processes including photosynthesis. However, there is still a knowledge gap in understanding electronic and excited state implications associated with functionalization of the porphyrin ring system. These effects can have electrochemical and spectroscopic signatures that reveal the complex na...

In this study, the use of a closo-borate salt as an electrolyte for lithium-ion batteries (LIB) was evaluated in a series of solvent systems. The lithium closo-borate salts are a unique class of halogen-free salts that have the potential to offer some advantages over the halogenated salts currently employed in commercially available LIB due to thei...

There is a need to develop high capacity and stable anode materials for the next generation of lithium ion batteries that will power consumer electronics and of automobiles of the future. This report describes a systematic experimental and theoretical evaluation of a series of hydrogenated fullerenes (C60Hx) for use as high capacity anodes in lithi...

We reply to the comment raised by M. Paskevicius et al. on our paper characterizing the properties of the Li 2 B 12 H 12 .

In this study, we propose a new methodology for lithium hydride electrolysis which can be extended for the extraction of hydrogen isotopes from molten lithium. This new process utilizes a ceramic lithium ion conductor that can be directly immersed in molten lithium to facilitate the electrochemical extraction of hydrogen isotopes in the molten stat...

Small-angle neutron scattering (SANS) combined with powder neutron diffraction (PND) were employed to study phase formation upon absorption/desorption of hydrogen gas in Li- and Na-intercalated fullerides. The comparative system analysis, addressing changes in the sample phase compositions and morphology of powders, revealed higher degree of comple...

Concentrated solar power (CSP) has been gaining significant attention as a method to produce electricity, but requires a suitable thermal energy storage (TES) system for continuous operation when the sun is unavailable. Thermochemical energy storage systems based on metal hydrides have advantages due to their high energy densities, potential for co...

In this study, we analyze and compare the physical and electrochemical properties of an all solid-state cell utilizing LiBH4 as the electrolyte and aluminum as the active anode material. The system was characterized by galvanostatic lithiation/delithiation, cyclic voltammetry (CV), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS)...

In this work we demonstrate how hydrogen can be utilized to fine tune the emission gap of C60 through the formation of direct CH bonds in sodium and lithium intercalated systems (M6C60Hx). Upon hydrogenation, a shift in the emission spectrum to shorter wavelengths (higher energy) is observed relative to alkali metal free fulleranes (C60Hx) and pure...

Herein the photophysical properties of hydrogenated fullerenes (fulleranes) synthesized by direct hydrogenation utilizing hydrogen pressure (100 bar) and elevated temperatures (350 °C) are compared to the fulleranes C60H18 and C60H36 synthesized by amine reduction and the Birch reduction, respectively. Through spectroscopic measurements and density...

In nuclear facilities utilizing plutonium, polymeric materials are subjected to long-term, close-contact, and continuous α radiation exposure, which can lead to compounding material degradation and eventual failure. Herein we model the attenuation of α particles by linear-low-density polyethylene (LLDPE), polyvinyl alcohol (PVA) thin films, and C60...

Recently, there has been increasing interest in thermal energy storage (TES) systems for concentrated solar power (CSP) plants, which allow for continuous operation when sunlight is unavailable. Thermochemical energy storage materials have the advantage of much higher energy densities than latent or sensible heat materials. Furthermore, thermochemi...

The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can o...

In this study, alkali doped fullerenes synthesized by two different solvent assisted mixing techniques are compared for their hydrogen uptake activity. In particular, we investigated the interaction of hydrogen with lithium and sodium doped fullerenes via physisorption. In addition, we present the first mass spectrometric evidence for the formation...

The conversion reaction of AlH3, LiAlH4, and NaAlH4 complex hydrides with lithium has been examined electrochemically. All compounds undergo a conversion reaction in which one equivalent of LiH is formed for each equivalent of hydrogen contained in the hydride material. Decomposition of the hydrides follows different paths depending of the nature o...

Thermal energy storage systems based on metal hydride pairs using high efficiency materials are evaluated. The low temperature metal hydrides NaAlH4 and Na3AlH6 were cycled to determine stability of hydrogen capacity over extended cycling. Addition of aluminum and expanded natural graphite were found to enhance the cycling stability of NaAlH4. Pote...

In this report we describe and compare the hydrogen storage properties of lithium and sodium doped fullerenes prepared via a solvent-assisted mixing process. For the preparation of these samples either NaH or LiH was utilized as the alkali metal source to make material based on either a Na6C60 or Li6C60. Both of the alkali-doped materials can rever...

Reversible hydrogen storage in a LiBH4:C60 nanocomposite (70:30 wt %) synthesized by solvent-assisted mixing has been demonstrated. During the solvent-assisted mixing and nanocomposite formation, a chemical reaction occurs in which the C60 cages are significantly modified by polymerization as well as by hydrogenation (fullerane formation) in the pr...

Herein is presented a novel, straightforward route to the synthesis of an alkali metal-doped fullerene as well as a detailed account of its reversible and enhanced hydrogen sorption properties in comparison to pure C60. This work demonstrates that a reaction of sodium hydride with fullerene (C60) results in the formation of a sodium-doped fullerene...

The anelastic spectra of Li6C60Hx and Na6C60Hx have been measured for the first time. The spectra of composite materials obtained by mixing of LiH and NaH with C-60 in a solvent still show the structural phase transition around 260 K and preserve the buckyball dynamics of pure fullerenes but do not show the spectral features of the hydrides. This o...

Addition of tert-butylisocyanide or 2,6-dimethylphenylisocyanide to a solution of trialkylaluminum or trialkylgallium results in formation of complexes R(3)M·C≡N(t)Bu (M = Al, R = Me (1), Et (2), (i)Bu (3), (t)Bu (4); M = Ga, R = (t)Bu (9)) or R(3)M·C≡N(2,6-Me(2)C(6)H(3)) (M = Al, R = Me (5), Et (6), (i)Bu (7), (t)Bu (8); M = Ga, R = (t)Bu (10)), r...

Herein, we present a new system for the generation of hydrogen for use in portable power systems utilizing a two-step process that involves the thermal decomposition of α-AlH3 (10 wt % H2) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H2. This study focuses on the use of promoter additives (PA) to cataly...

Herein, we present a lithium-doped fullerane (Li(x)-C(60)-H(y)) that is capable of reversibly storing hydrogen through chemisorption at elevated temperatures and pressures. This system is unique in that hydrogen is closely associated with lithium and carbon upon rehydrogenation of the material and that the weight percent of H(2) stored in the mater...

Carbonaceous nanomaterials utilized as scaffolds, catalysts, and additives in conjunction with complex metal hydrides have shown remarkable hydrogen sorption properties. Our studies have confirmed fullerene-C60 is an excellent catalyst for temperature induced hydrogen desorption for both NaAlH4 and LiAlH4. Fullerene-containing complex metal hydride...

In previous work, a reversible cycle that uses electrolysis and catalytic hydrogenation of spent Al(s) for the regeneration of alane (AlH3) was reported. In this study, the electrochemical synthesis of alane is improved. Advances in the electrochemical regeneration of alane have been achieved via the use of lithium aluminum hydride (LiAlH4) and lit...

LiBH_4 doped with 1.6 mol % well-dispersed C_(60) is studied with solid-state nuclear magnetic resonance (NMR). Variable-temperature hydrogen NMR shows large changes between the data upon first heating and after exposure to 300 °C. After heating, a large fraction on the order of 50% of the hydrogen signal appears in a motionally narrowed peak, simi...

Mechanistic studies show the importance of iodide displacement by additives that accelerate reactions of samarium diiodide. The key feature important for acceleration of reaction rate is the use of proton donors and other additives that have a high enough affinity for Sm(II) to displace iodide yet do not saturate the coordination sphere inhibiting...

The interaction between water-soluble Keplerate polyoxometalate {Mo(72)Fe(30)} macroions and small countercations is explored by laser light scattering, anomalous small-angle X-ray scattering (ASAXS), and isothermal titration calorimetry (ITC) techniques. The macroions are found to be able to select the type of associated counterions based upon the...

Ultrasound (20kHz) Was used to prepare samarium(11) diiodide (SMl(2)), samarium(II) dibromide (SmBr(2)), and samarium(II) triflate (SmOTf)(2). The method described herein provides a straightforward and rapid approach to the synthesis of Sm(II) compounds not accessible by other means. Of particular importance is the fact that this approach can be us...

The cover picture shows the sonochemical preparation of samarium diiodide, samarium dibromide, and samarium triflate. The use of high intensity ultrasound (20 kHz) provides a straightforward and rapid approach to the synthesis of SmII compounds, some of which are not accessible by other means. Of particular importance is the fact that this approach...

Three's a crowd: Initial coordination of diethylene glycol to SmI 2 liberates THF or iodide, thus providing open coordination sites for substrates and enhancing reactivity. Concentrations of diethylene glycol that lead to coordinative saturation of SmI2 (see structure) reduce its reactivity. Replacement of a hydroxy proton with a methyl group decre...

Kronjuwelen: Kronenether und SmI2 bilden in Acetonitril einen Komplex, der das SmII-Ion gegen Wechselwirkungen mit dem Solvens und Substraten abschirmt. Daher nimmt die solvensinduzierte Lumineszenzlöschung ab und die Lebensdauer des angeregten Zustands zu. Folglich ist es möglich, durch geschickte Wahl von Ligand und Solvens sehr stabile lumineszi...

803-646-8876. This article reviews and discusses research activities and results of our studies on catalytic carbon nanostructures and the formation of novel nanocomposites that can reversibly store hydrogen. Carbon nanomaterials have been utilized as catalysts, additives, agents for ball milling and scaffolds, in conjunction with hydrides and comp...