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The 3D ternary Li2GeO3 compound, which could serve as the electrolyte material in Li+-based batteries, exhibits an unusual lattice symmetry (orthorhombic crystal), band structure, charge density distribution and density of states. The essential properties are fully explored through the first-principles method. In the delicate calculations and analyses, the main features of atom-dominated electronic energy spectrum, space-charge distribution, and atom-/orbital-projected density of states are sufficient to identify the critical multi-orbital hybridizations of the chemical bonds: 2s-(2px, 2py, 2pz) and (4s, 4px, 4py, 4pz)-(2s, 2px, 2py, 2pz), respectively, for Li-O and Ge-O. This system possesses a large indirect gap of Eg = 3.77 eV. There exist a lot of significant covalent bonds, with an obvious non-uniformity and anisotropy. In addition, spin-dependent magnetic configurations are completely absent. The theoretical framework could be developed to investigate the important features of anode and cathode materials related to lithium oxide compounds.

Lithium nickelate (LiNiO2) and materials based on it are attractive positive electrode materials for lithium-ion batteries, owing to their large capacity. In this paper, the results of atomic layer deposition (ALD) of lithium&ndash, nickel&ndash, silicon oxide thin films using lithium hexamethyldisilazide (LiHMDS) and bis(cyclopentadienyl) nickel (II) (NiCp2) as precursors and remote oxygen plasma as a counter-reagent are reported. Two approaches were studied: ALD using supercycles and ALD of the multilayered structure of lithium oxide, lithium nickel oxide, and nickel oxides followed by annealing. The prepared films were studied by scanning electron microscopy, spectral ellipsometry, X-ray diffraction, X-ray reflectivity, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction. The pulse ratio of LiHMDS/Ni(Cp)2 precursors in one supercycle ranged from 1/1 to 1/10. Silicon was observed in the deposited films, and after annealing, crystalline Li2SiO3 and Li2Si2O5 were formed at 800 &deg, C. Annealing of the multilayered sample caused the partial formation of LiNiO2. The obtained cathode materials possessed electrochemical activity comparable with the results for other thin-film cathodes.

In recent years, the methods of lithium preparation by metallothermic reduction of its oxide in negative pressure have been developed. Since Li2CO3 was considered as an important raw material for the preparation of Li2O, it is important to clarify the decomposition and melting mechanisms of Li2CO3. The behaviors of decomposition of lithium carbonate under argon, carbon dioxide, and negative pressure were studied by thermogravimetric behavior. Results showed that the decomposition of Li2CO3 can be divided into two steps and the mass loss under different atmospheric conditions is different. The first decomposition temperature of carbonate was 1000 K in argon gas. Decomposition of lithium carbonate was a complex process, including the multiple reactions such as melting of lithium carbonate, dissolution of Li2O and CO2 in Li2CO3, and adsorption of CO2 in Li2O. The first step of the decomposition is reduced, and the second step of the decomposition is increased in carbon dioxide atmosphere or negative pressure, compared with the condition of the argon gas.

The viscosity of lithium borate melts xLi2O-(100-x) B2O3, where 0

Silicon suboxide (SiOx) is a promising anode material for lithium ion batteries (LIBs), due to its high specific capacity, small volume variation and superior cycle performance. Herein, we demonstrated the determining roles of oxygen contents on the behavior of SiOx upon lithium by means of thin-film type electrodes. The SiOx thin-film anodes with different oxygen contents were prepared by sputtering with Cu foil as substrates. XRD and Raman investigations reveal that these SiOx films are amorphous. As anodes, it is found that increasing oxygen contents in SiOx endows an enhanced cycle stability, but does harm to their initial Coulombic efficiency and capacity. Among all the a-SiOx film anodes (x = 0.4, 0.7, 1.1 and 1.5), the SiO0.7 electrode with a thickness of 450 nm exhibits excellent cycle performance and rate capability, with a high initial discharge capacity of 463 μAh cm−2 μm−1 at the current density of 64 μA cm−2 and a high capacity retention of 90% after 300 cycles. This superior performance is ascribed to that the in-situ formed lithium oxide/silicates compounds during discharge effectively alleviates the large volume change of Si components, but also suppresses the electron leakage from the surface of active particles, shutting down the further decomposition of electrolytes and then the formation of thick solid interphase layer. These results will provide inspirations for designing high-performance Si based anodes for lithium ion batteries.

Sm3+ doped lead alumino-borate glasses containing ZnO, Li2O and BaO were synthesized and characterized for their structural and spectroscopic properties using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), optical absorption and luminescence measurements. The FTIR spectra, optical band gap and the values of density indicate formation of more BO4 units and a compact structure for the glass containing ZnO. Using optical absorption spectra, three phenomenological Judd-Ofelt parameters Ωλ (λ = 2, 4, 6) have been evaluated to determine the local structure and bonding in the vicinity of Sm3+ ions; the parameters are found to follow the trend Ω4> Ω6> Ω2. The parameter Ω2, which indicates the covalency of Sm O bond is found to be maximum for the glass containing zinc oxide followed by glasses with barium oxide and lithium oxide, in the decreasing order. . This result points towards a higher asymmetry and a less centro-symmetric coordination environment around the Sm3+ ions site for glass containing ZnO. The positive values of bonding parameter δ indicate a covalent nature of the Sm O bond for the glasses under study. The photoluminescence spectra recorded under an excitation of 402 nm exhibited four emission bands centered at about 562 nm, 597 nm, 642 nm and 706 nm corresponding to the transitions 4G5/2 → 6H5/2, 6H7/2, 6H9/2 and 6H11/2, respectively. The intensity of potential emission bands and radiative parameters such as branching ratio (βR) and stimulated emission cross-section ( σ ) are found to be higher for the glass containing zinc oxide. However, all other prepared glasses are also found to be efficient lasing materials showing suitability for the development of photonic materials emitting radiations in the reddish-orange range. The values of Figure of Merit (FOM) point towards a possible use of the prepared glasses as optical amplifier devices.

An elevated lithium battery Batteries based on lithium metal and oxygen could offer energy densities an order of magnitude larger than that of lithium ion cells. But, under normal operation conditions, the lithium oxidizes to form peroxide or superoxide. Xia et al. show that, at increased temperatures, the formation of lithium oxide is favored, through a process in which four electrons are transferred for each oxygen molecule (see the Perspective by Feng et al. ). Reversible cycling is achieved through the use of a thermally stable inorganic electrolyte and a bifunctional catalyst for both oxygen reduction and evolution reactions. Science , this issue p. 777 ; see also p. 758

A battery device with graphene platelets as anode, lithium nickel manganese oxide as cathode, and solid-state electrolyte consisting of layers of lithium phosphorous oxynitride and lithium lanthanum titanate is assembled on the stainless steel substrate. The battery in a polymer enclosure is subjected to several electrical tests consisting of charge and discharge cycles at different current and voltage levels. Thermal conductivity of the cathode layer is determined at the end of charge-discharge cycles using transient thermoreflectance. The microstructure and composition of the cathode layer and the interface between the cathode, the anode, and the electrolyte are characterized using scanning electron microscopy and elemental mapping. The decrease in the thermal conductivity of the same cathode observed after each set of electrical test cycles is correlated with the volume changes and formation of low ionic and thermal conductivity lithium oxide and lithium oxychloride at the interface and along porous regions. The interface between the metal current collector and the cathode is also found to be responsible for the increase in thermal resistance. The results indicate that changes in the thermal conductivity of the electrodes provide a measure of the resistance to heat transfer and degradation of ionic transport in the cathode accompanying the charge–discharge cycles in the batteries.

Pure lithium (Li) surfaces are difficult to maintain in fusion devices due to rapid oxide formation, therefore, parameterizing and understanding the mechanisms of hydrogen (H, D) retention in lithium oxide (Li2O) in addition to pure Li is crucial for Li plasma-facing material applications. To compare H retention in Li and Li2O films, measurements were made as a function of surface temperature (90–520 K) under ultrahigh vacuum (UHV) conditions using temperature programmed desorption (TPD). In both cases, the total retention dropped with surface temperature, from 95% at 90 K to 35% at 520 K Li2O films retained H in similar amounts as pure Li. Molecular Dynamics (MD) modeling was used to elucidate the mechanisms of H retention, and results were consistent with experiments in terms of both retention fraction and the drop of retention with temperature.

To develop reactive catalysts for oxidative coupling of methane at low temperatures, different alkali-metal oxides are adopted in this study to modify the surface of SnO2. In comparison with the unmodified SnO2, the reaction performance of all of the modified catalysts can be significantly improved, among which lithium oxide shows the best promotional effects, and the optimal catalyst is achieved with a Sn/Li molar ratio of 5:5. With this catalyst, the highest C2 product yield of 16 % is achieved at 750 °C. The XPS and CO2-TPD results reveal that for those catalysts with evident enhanced OCM reaction performance, the coexistence of a suitable amount of surface alkaline and electrophilic oxygen sites is indispensable. Furthermore, with the catalysts modified by different amounts of lithium oxide, the C2 yield at different temperatures is nearly proportional to the amounts of both surface intermediate alkaline sites and electrophilic oxygen species. Therefore, it is concluded that the abundance and the concerted interaction of these two types of surface active sites are the major factors determining the reaction performance of the SnO2 based catalysts. Last, but not least, the optimized catalyst, which has a Sn/Li molar ratio of 5:5 and also contains equal amounts of SnO2 and Li2SnO3 crystalline phases, exhibits much better reaction performance than Mn/Na2WO4/SiO2, the most promising catalyst at present, in the low-temperature region (below 750 °C). After all, this may give people some new insight into developing new types of OCM catalysts that can operate at low temperatures and thereby facilitate the industrialization process of this important chemical engineering reaction.

Electrochemical reduction of CO2 to value-added carbon and oxygen in molten carbonates is a promising approach to the efficient and economical utilization of CO2. Fully understanding the electrode kinetics is crucial to scaling up the process. Herein, the reduction kinetics were studied by cyclic voltammetry, linear sweep voltammetry and potentiostatic electrolysis. The electrolytic products prepared at selected potentials were characterized by X-ray diffraction. It was found that the cathode surface was partially covered by insoluble lithium oxide and that the sluggish diffusion of the O2– ion was the rate-determining step during carbon deposition at 723 K. When the temperature is increased to 923 K, the reaction kinetics are accelerated around 100-fold with a limiting current density of 1.5 A/cm2. Knowledge of this mechanism should prove useful in the design of a pilot cell based on molten salt CO2 capture and electrochemical transformation (MSCC-ET) technology. Keywords: Carbon dioxide utilization, Molten carbonates, Electrochemical reduction, Electrode kinetics, Rate-determining step

Recently, the high demand for the development of improved energy storage devices has brought the focus on tin oxide nanoparticles due to their ability to intercalate lithium. In order to strengthen the potential of the technological applications of Li doped SnO2, the synthesis of nanoparticles by a soft chemistry method with a highly homogeneous controlled size, high crystallinity and concentration of effectively incorporated Li over the range of 10 to 30 cat% is reported in this study. Li doped SnO2 nanoparticles were prepared with sizes between 4 nm (for undoped material) and 11 nm (for the 30 cat% Li doped nanoparticles). The samples were thoroughly characterized using different complementary techniques to determine the defect structure and electronic surface properties, whose knowledge is of the utmost relevance for achieving the desirable properties needed for implementation in different applications. The results indicate that lithium is incorporated mainly in substitutional sites in the rutile structure of tin oxide. On increasing the lithium content in the nanoparticles, the amount of oxygen vacancies reduced and a shift in the Fermi level, which was pinned at the surface defects, toward the maximum of the valence band was obtained. In the samples with the highest Li content, the local environment of lithium at the nanoparticle surface resembled the environment of Li in lithium oxide. Several intra-gap recombination defect levels were detected in the visible range, which are related to intrinsic tin oxide defects such as vacancies in different configurations. In addition, a defect level at 3.1 eV is also exhibited with increasing intensity in Li doped nanoparticles.

Low reversion of lithium oxide (Li2O) and the tin (Sn) coarsening causing irreversible capacity loss is the main reason for the poor cycle performance in tin dioxide (SnO2) based composites. In this research, a novel sandwiched spherical tin dioxide/graphene with a three-dimensional interconnected closed pore structure is synthesized. The microstructural characterization shows that the spherical graphene with submicron sized diameters interconnects with each other forming an interconnected flexible conductive network, whereas a large number of SnO2 nanoparticles (approximately 5 nm) are limited homogeneously in between the interlayers of the sphere-like graphene shell. The sandwich structure of the SnO2/graphene and the closed graphene sphere can provide double protection for the SnO2. When it is used as an anode material for energy storage, the generated Li2O can remain in close contact with Sn to make the conversion reaction (SnO2 + 4Li+ + 2e- ↔ Sn + Li2O) highly reversible in situ and the reversibility even does not diminish markedly after 100 cycles. A high reversible specific capacity of 914.8 mA h g-1 is expressed in the sandwiched spherical SnO2/graphene composite at 100 mA g-1 after 100 cycles, which is significantly higher than that of a SnO2/graphene aerogel with an open pore structure.

An active anode material for Li-ion batteries was synthesized using a simple mechanochemical process to minimize the large change in Si volume observed during charge-discharge operation and to compensate for the associated irreversible loss of Li or irreversible capacity loss, which are obstacles to achieve high-performance electrochemical properties during charge-discharge. The composite was mechanochemically milled with Si, lithium oxide, and copper oxide as raw materials; the composite contains Si nanoparticles, amorphous silicon monoxide, and Si-Li or Si-Cu alloy compounds, and it exhibits improved electrochemical properties. In particular, this composite achieved a better capacity retention, higher coulombic efficiency (over 100%), and longer cycling performance than Si alone, indicating considerable optimization of the electrical and ionic conductivity in the composite. The developed method allowed for control of the Li content to compensate for the lack of Li ions in the composite, and the cycling performance was optimized using the Cu alloy, oxide, and Li compounds within the composite.

Compounds of lithium oxide, hydroxide and carbonate, mixed with silver, were prepared for use as a cathode in caesium-sputter ion source. The intention was to determine the procedure which would produce the highest intensity negative lithium beams over extended period and with maximum stability. The chemical composition and properties of the samples were analysed using mass-spectrometry, optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analyses (EDX) and Raman spectroscopy. These analyses showed that the chemical transformations with components resulted from pressing, storage and bake out were qualitatively in agreement with expectations. Intensive negative lithium ion beams >1 μA were delivered using cathodes fabricated from materials with multicomponent chemical composition when the following conditions were met: (i) use of components with moderate enthalpy of formation; (ii) low moisture content at final stage of cathode production and (iii) small concentration of water molecules in hydrate phase in the cathode mixture.

The physical, optical, and gamma ray shielding behavior of the four Bi2O3-Li2O-P2O5 glasses with varying Li2O and Bi2O3 compositions have been explored. The glass density increases from 2.44 to 3.85 g cm-3 with bismuth oxide content. The molar volume follows the same trend as density and the overall molar volume of these glasses increases, which in turn directly affects the oxygen packing density (OPD). Optical band gap energies decrease after lithium oxide is replaced with bismuth oxide. The values of M lie between 0.3485 and 0.3209 indicates that glasses under investigation are non-metallic. Radiation shielding evaluation using EpiXS software and Phy-X/PSD program shows comparable mass attenuation coefficients (MACs) but with relatively higher percent differences at energies near the K-edge energies of O (0.538 keV) and Bi (90.5 keV). The MACs of the glasses rise when Li2O oxide is replaced with Bi2O3 oxide. The half-value layer (HVL) results showed the difference in the radiation shielding capabilities of the four glasses is more apparent at high energies. An increase in MAC and a decrease in HVL imply that adding Bi2O3 to the glass improves its radiation attenuation properties.

We propose a novel electrolyte additive, 5-acetylthiophene-2-carbonitrile (ATCN) with three functional groups (thiophene, nitrile and carbonyl), to in situ construct a stable cathode interface film that can significantly improve the cycling stability of LiCoO2 cathode under high-voltage. Adding 0.2% of ATCN into a base electrolyte, the capacity retention of LiCoO2/Li cell under 4.5 V is enhanced from 53% to 91% after 200 cycles at 1 C, and the cycle number of commercial LiCoO2/graphite pouch cell (34 Ah) with 10% capacity loss at 0.5 C under a cut-off voltage of 4.45 V is increased from 550 to 800. Experimental characterizations and theoretical calculations reveal that ATCN is preferentially oxidized on LiCoO2 cathode and utilizes its decomposition intermediates to convert the detrimental components, the hydrogen fluoride and water present in the electrolyte, and the lithium oxide and carbonate resulting from the electrolyte decomposition, into a unique film texture comprised of underneath compacted lithium salts and outer thiophene polymers. The as-constructed film significantly improves the cathode/electrolyte interface stability and the cycling stability of the cell. Such an effective strategy to address the interface instability has never been reported before and paves a new path to improve the energy density of commercial lithium-ion batteries via enhancing cut-off charge voltage.

We identify that reversible formation/decomposition of lithium oxide, pulverization of Fe3O4 nanoparticles, and electrolyte reactions, are contributors to the enhanced capacity observed in the Fe3O4 electrode upon long cycling. Introducing three-dimensional graphene foam to form a composite with Fe3O4 nanoparticles largely increases the capacity (~ 1220 mA h g−1 vs. ~ 690 mA h g−1) and promotes the cycling induced capacity enhancement (an earlier capacity rise and a faster rising rate) of the Fe3O4 electrode. Together with Fe3O4 nanoparticles, the presence of graphene effectively promotes the electrolyte reactions and reversible formation/decomposition of lithium oxide. At the same time, activation of GF also occurs in the presence of Fe3O4 nanoparticles, further increases the capacity of the nanocomposite.

The tritium breeding materials require small particle size to reduce the diffusion distance of generated tritium in the intercrystalline. In addition, the essential resource, especially enriched Li-6, has to be recovered from the used tritium breeding material. For the hands-on operation during the recovery process, the activation level of the used breeder is strictly limited in order to reduce the impurities of long-lived radioactive nuclides in the tritium breeding material. In this study, lithium oxide (Li2O) and titanium dioxide (TiO2) were used as starting materials in the synthesis of Li2TiO3 powder. The starting materials were mixed by wet ball-milling process. The mixed powders were synthesized by heat treatment. The average particle size of synthesized Li2TiO3 powder was approximately 150 nm. And, the long-lived radioactive nuclides, such as aluminum (Al) and cobalt (Co), were not accumulated in the synthesized Li2TiO3 powder during the synthesis process. The Li2TiO3 pebbles were fabricated by slurry droplet wetting method using the synthesized Li2TiO3 nano-powder. The particle size, crush load, and porosity of fabricated Li2TiO3 pebbles using the synthesized nano-powder were investigated.

Well understanding the role fluxing agents in the CaO-Al 2 O 3 -based slag system is essential to devise new mold fluxes for heat-resistant steel as well as for further improvement of data for viscosities and structure properties of the molten fluxes. The role of Li 2 O in CaO-Al 2 O 3 -Li 2 O-Ce 2 O 3 slag system was investigated through measuring viscosity combined with the FTIR spectra analysis. It was noted that Li 2 O show obvious effect of decreasing viscosity in the CaO-Al 2 O 3 -based slag system. The viscosity of the CaO-Al 2 O 3 -Li 2 O-Ce 2 O 3 slag melts decreased with increasing Li 2 O content. The relationship between the viscosity and the slag structure was discussed. Under the condition of increasing Li 2 O addition from 10 to 14 mass%, the relative ratio of [AlO 4 ]-tetrahedrons and [AlO 6 ]-octahedrons remain constant. The O 2– dissociated from Li 2 O just cut the network formed by [AlO 4 ]-tetrahedrons. The depolymerization of [AlO 4 ]-tetrahedrons from Q 4 units to Q 3 and Q 2 units was the main reason of the decrease of the viscosity. When the content of Li 2 O increased from 14 to 18 mass%, more and more O 2– dissociated from Li 2 O reacted with [AlO 4 ]-tetrahedrons to form [AlO 6 ]-octahedrons. The decrease of viscosity was mainly induced by the increase of free oxygen and the formation of [AlO 6 ]-octahedrons, which acts as a network modifier.

The structural and morphological changes occurred during the molten salt treatment of ilmenite (FeTiO3) are investigated by a variety of techniques including X-ray diffraction, scanning and transmission electron microscopy, as well as Raman and photoelectron spectroscopy. The phase evolution of ilmenite in molten LiCl under humid atmosphere leads to the facile formation of Li-containing phases such as Li0.8Ti2.2O4 and LiFeO2. Moreover, graphene nanosheets are successfully incorporated in the molten salt produced material through ball milling, and the Li-storage performance of the electrode made of the hybrid material is investigated. Unlike ilmenite, the hybrid structure exhibit an excellent electrochemical performance with a stable capacity of around 300 mAh g−1 after 500 successive discharge/charge cycles. This enhanced electrochemical performance is attributed to the presence of lithium oxide in the molten salt product that reduces the overall volume changes taking place during the lithiation/delithiation of the material, increasing the structural stability of the electrode. Furthermore, the presence of graphene nanosheets not only provides the electrical conductivity for the electrode, but also contributes to the structural stability of electrode by agglomerating the nanoparticles formed during cycling of the electrode. This article suggests a green and low-cost approach for the facile conversion of ilmenite into materials applicable for energy storage systems.

Author(s): Xiao, Y; Jun, KJ; Wang, Y; Miara, LJ; Tu, Q; Ceder, G | Abstract: The key component in lithium solid-state batteries (SSBs) is the solid electrolyte composed of lithium superionic conductors (SICs). Lithium oxide SICs offer improved electrochemical and chemical stability compared with sulfides, and their recent advancements have largely been achieved using materials in the garnet- and NASICON (sodium superionic conductor)- structured families. In this work, using the ion-conduction mechanisms in garnet and NASICON as inspiration, a common pattern of an “activated diffusion network” and three structural features that are beneficial for superionic conduction: a 3D percolation Li diffusion network, short distances between occupied Li sites, and the “homogeneity” of the transport path are identified. A high-throughput computational screening is performed to search for new lithium oxide SICs that share these features. From this search, seven candidates are proposed exhibiting high room-temperature ionic conductivity evaluated using ab initio molecular dynamics simulations. Their structural frameworks including spinel, oxy-argyrodite, sodalite, and LiM(SeO3)2 present new opportunities for enriching the structural families of lithium oxide SICs.

Lithium oxide Li2O was synthesized by two green synthesis methods using two plants saffron and turmeric. Then the Li2O colloidal is deposite on p-type porous Si substrate p-PSi and n-type porous silicon substrate n-PSi to fabricate Al/Li2O/p-PSi/pSi/Al heterojunction and Al/Li2O/n-Psi/nSi/Al heterojunction. The morphological studies were measured by X-Ray Diffraction XRD getting an average crystallite size 34.7 nm for green synthesized saffron and 31.36 nm average crystallite size in case of green synthesized turmeric. Scanning Electron Microscopy SEM was about 80 nm size in case of saffron and about 55 nm. Fourier Transformation Infra-Red FT-IR was nearly the same in both cases. Optical measurement UV-visible occurred by calculating the transmittance and absorbance spectra and finally IV-in dark and IV under illumination were measured for the application of a heterojunction as a solar cell.

Silicon has been the subject of an extensive research effort aimed at developing new anode materials for lithium ion batteries due to its large specific and volumetric capacity. However, commercial use is limited by a number of degradation problems, many of which are related to the large volume change the material undergoes during cycling in combination with limited lithium-diffusivity. Silicon rich silicon oxides (SiOx), which converts into active silicon and inactive lithium oxide during the initial lithiation, have attracted some attention as a possible solution to these issues. In this work we present an investigation of silicon rich amorphous silicon nitride (a-SiNx) as an alternative convertible anode material. Amorphous SiN0.89 thin films deposited by plasma enhanced chemical vapour deposition show reversible reactions with lithium when cycled between 0.05 and 1.0 V vs. Li+/Li. This material delivers a reversible capacity of approximately 1,200 mAh/g and exhibits excellent cycling stability, with 41 nm a-SiN0.89 thin film electrodes showing negligible capacity degradation over more than 2,400 cycles.

Development of solid-state electrolyte (SSE) thin films is a key toward the fabrication of all-solid-state batteries (ASSBs). However, it is challenging for conventional deposition techniques to deposit uniform and conformal SSE thin films in a well-controlled fashion. In this study, atomic layer deposition (ALD) was used to fabricate lithium silicate thin films as a potential SSE for ASSBs. Lithium silicates thin films were deposited by combining ALD Li2O and SiO2 subcycles using lithium tert-butoxide, tetraethylorthosilane, and H2O as precursors. Uniform and self-limiting growth was achieved at temperatures between 225 and 300 °C. X-ray absorption spectroscopy analysis disclosed that the as-deposited lithium silicates were composed of SiO4 tetrahedron structure and lithium oxide as the network modifier. X-ray photoelectron spectroscopy confirmed the chemical states of Li in the thin films were the same with that in standard lithium silicate. With one to one subcycle of Li2O and SiO2 the thin films had a...

The results of designing and studying of potassium-aluminoborate glass activated by chromium and lithium ions are discussed. Changes in the absorption and luminescence spectra of glass after the isothermal treatment are demonstrated. X-ray diffraction data showed the presence of Li(Al7B4O17) and Cr2O3 nanocrystals with an average size of 20 and 15 nm, respectively. Analysis of the luminescence spectra showed that the Cr3+ ions are in a crystalline environment. The luminescence quantum yield was 20–50%, which indicates the prospects for using such materials as a basis for fiber amplifiers in information transmission systems and laser biomedical technologies.

A reactional mechanism describing the hydrolysis of lithium hydride (LiH) under moist atmosphere is proposed and modeled. It involves the formation of lithium oxide (Li2O) at low vapor pressure and both lithium oxide and lithium hydroxide (LiOH) at higher vapor pressures, with diffusion of water in these layers. A numerical model based on this mechanism is implemented with COMSOL Multiphysics to simulate the hydrolysis of LiH particles in open system (constant water vapor pressure). Kinetic parameters such as rate constant of reactions and diffusion coefficient of water in Li2O and LiOH are first fitted against experimental data. The best agreements are obtained when the diffusion coefficient of water is 10 times higher in LiOH than in Li2O. The resulting model accurately predicts the hydrolysis rates experimentally measured for a wide range of water vapor pressures (0.3–17 Pa). The hydrolysis mechanisms are compatible with a Li2O production limited by water diffusion and a LiOH production governed by the kinetics. Finally, simulation suggest that the thickness of the Li2O layer does not depends much on the water vapor pressure whereas that of LiOH increases drastically at high water vapor pressures.