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[Display omitted] Lithium oxides (Li 2 O) possess a considerable theoretical capacity, rendering them highly promising as cathodic pre-lithiation additives. However, its decomposition voltage exceeds the charging cut-off voltage of most cathode materials, hindering its direct use as a cathode sacrificial additive. Herein, we design a facile and safe method to reduce the decomposition energy of Li 2 O at room temperature to offset the irreversible capacity loss by using a core–shell structured Li 2 O-reduced graphene oxide (rGO)-polyethylene glycol (PEG) composite (denoted as Li 2 O-rGO-PEG). The graphene oxide (GO) was heat-treated to remove oxygen functional groups to synthesize rGO, and then reacted with Li 2 O to form a Li 2 O-rGO composite. According to the DFT calculations, the density of states at the Fermi level of Li 2 O-rGO becomes continuous and features a metallic nature, which significantly improves the electrical conductivity of Li 2 O and facilitates electron conduction that modify the delithiation potential of Li 2 O. PEG was used to enhance the cohesive force between rGO and Li 2 O and to protect Li 2 O from atmospheric contamination. Moreover, in order to demonstrate the excellent pre-lithiation ability of Li 2 O-rGO-PEG composite, hard carbon (HC) with low initial coulombic efficiency (ICE) was used as the anode. In the application of LFP (Li 2 O)/HC full cell, Li 2 O was decomposed to Li+ to effectively improve the initial charge capacity from 149.7 to 200 mAh/g and discharge capacity from 104.2 to 147.5 mAh/g, which are 33.6 % and 41.6 % higher than those of the pristine LFP/HC full cell, respectively. The cathode pre-lithiation method proposed in this work is simple and environmentally friendly. The successful utilization of Li 2 O as a pre-lithiation additive effectively addressed the issue of low initial coulombic efficiency of the HC, indicating excellent prospects for practical applications. [ABSTRACT FROM AUTHOR]

This paper reports on a new approach to chlorinating molten salts using vaporized NH4Cl. In separate experiments, chlorination of dissolved Li2O and submerged U metal was demonstrated. Ammonium chloride was thermally decomposed in a quartz glass vaporization chamber with an internal temperature ranging from 295 to 384 °C. These decomposition products were then bubbled into eutectic LiCl–KCl salt via argon carrier gas. The vapor appears to absorb as NH4+/Cl− into the molten LiCl–KCl based on the high dissolved concentration of acid compared literature reported solubility of HCl. In Li2O chlorination experiments, complete reaction was achieved starting with 1 wt% Li2O for reaction times of 24.8 h or less. In U metal chlorination experiments, dissolved U concentrations ranged from 1.75 to 4.17 wt% for reaction times ranging from 3.5 to 21.6 h. The rate limiting step is mass transfer and reaction between the molten salt and U metal pellet. Cyclic voltammetry peak heights were correlated with dissolved U concentration with overall scan results consistent with UCl3 being the dominant form of dissolved U. [ABSTRACT FROM AUTHOR]

Mixed alkaline earth (MgO, CaO) aluminosilicate glass fibers (MCAS) with and without boron are commonly used as reinforcements in plastic composites, and the fundamental understanding of the thermal and mechanical properties is essential to the design of new glass compositions to satisfy the growing demands in applications from renewable energy to lightweight structural components. In this work, a series of Li2O containing low‐boron MCAS fiber glasses have been studied by using molecular dynamic (MD) simulations with recently developed effective partial charge composition dependent boron potentials. Structural characteristics, such as pair distribution function, bond angle distribution, and neutron/X‐ray diffraction structure factors, were calculated, as well as properties such as elastic moduli and vibrational density of states. The addition of Li2O was found to improve the elastic moduli of the fiber glasses in excellent agreement with experimental results we reported earlier. The simulation results showed that the weakened network connectivity and decrease of tri‐/bridging oxygen have positively affected the lowering of liquid temperature, owing to the transformation to more boron Q2 and silicon/aluminon Q3. It is found that higher oxygen packing density, coordinated aluminum/boron species such as [AlO5] and [BO4] units, larger‐membered oxide rings, and intensified connections of [AlOx] and [SiO4] are the main reasons that lead to improved mechanical properties. MD‐based quantitative structure–property relationship analyses were performed and showed excellent correlations to measured properties, indicating that it is a promising approach to understand glass properties and design new glass compositions for functional applications. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the structure of FLiNaK–LaF3 melt with small addition of Li2O through the theoretical approach combining ab initio molecular dynamics and simulation of the isolated structural units. The structure of the melt was studied in detail by calculation of radial distribution functions along with coordination numbers and radii. We found that oxyfluoride intermediate-range structure is formed in the melt. Our observations support the suggestions of other authors on formation of intermediate-range structures in fluoride melts containing metal oxides. Given structure shows long lifetime, the consideration of the isolated specie is valuable. We performed a simulation of ‘gas-phase’ [O2La4Fn] structure in order to calculate its Raman spectrum. It was found that the spectrum of the isolated structure agree in semi-quantitative manner with the vibrational density of states of the oxygen ions in the melt. [ABSTRACT FROM AUTHOR]

Lithium lanthanum zirconium oxide (LLZO) garnet is a solid‐state lithium ion conducting electrolyte promising all‐solid‐state batteries (ASSB) with high charge rates and good energy density due to its chemical stability against lithium metal anodes. LLZO has a high room temperature Li ion conductivity of ∼0.1–1 mS/cm in its cubic phase, but the stability of the cubic phase and ionic conductivity are highly sensitive to lithium stoichiometry. Stabilizing agents such as aluminum oxide and excess lithium are needed to preserve the cubic phase and compensate for lithium volatility. With the range of the end LLZO products spanning powders, porous membranes to dense membranes combined with sintering/calcination that often exceeds 1000°C, it is challenging to maintain an ideal lithium content given its high volatility from a single base powder. This study was designed to elucidate the sensitivities of aluminum doped LLZO powder synthesis and processing along its path to being utilized in a ceramic‐manufacturing optimized ASSB. By utilizing thermogravimetric analysis in conjunction with in situ X‐ray diffraction analysis of solid‐state LLZO synthesis, it was discovered that the sensitivity of the LLZO cubic phase to lithium volatility can be reduced via early incorporation of excess lithium carbonate during initial phase formation in direct combination with controlled surface‐to‐volume ratios of the powders. Isostatically pressed powders of our LLZO sintered at 1100°C for 2 h showed RT ionic conductivity of 0.3–0.4 mS/cm measured via electrochemical impedance spectroscopy, and an improvement in microstructural uniformity with lowered porosity. The improved suppression of lithium volatilization has important implications for the scalable production of LLZO powders and assembly of ASSBs. [ABSTRACT FROM AUTHOR]

Study of spatial spectra and tritium breeding ratio (TBR) in a lithium blanket play a crucial role for the successful operation of a Fusion reactor. In this paper, we have reported the results for the space-dependent fast neutron spectra and tritium production rate (TPR) in cylindrical assemblies of Li2O. The multigroup diffusion equation has been solved using eigenfunction expansion method. The obtained results for scalar spectra, total flux and TPR in Li2O are compared with corresponding values for natural Li. The space dependent scalar spectrum in Li2O has been compared for different configurations (slab, sphere and cylindrical). We find that the shapes of the curves are almost similar, though the neutron flux is found to be highest in the case of cylindrical assembly. This suggests a larger value of total TBR for a cylindrical geometry. Further, the study of space variation of total flux for Li2O and natural Li shows that there is not much change in the shapes and numerical values, however, it falls sharply near the boundary end surface of the assembly for Li2O as compared to natural Li. Similarly, the fall in the TPR curves becomes more rapid for the case of Li2O as compared to natural Li near the boundary end. The calculated results of spatial distributions of TPR for 6Li (n,?)t and 7Li (n,n'a)t reactions are compared with experimentally obtained results for cylindrical slab assemblies. and it is found that agreement is fairly good, both in the case of 7Li and 6Li. [ABSTRACT FROM AUTHOR]

The gas response of layers based on lithium-doped cobalt oxides with different Li2 O/Cox Oy ratios is investigated. The synthesis conditions of oxide composites and the structural analysis of the obtained layers by scanning electron microscopy are presented. It is found that composites with the ratio of the initial components 1:1 have selectivity to formaldehyde, and with the ratio 3:2 — to nitrogen dioxide.

Development of oxide solid electrolytes for all-solid-state batteries is attracting increasing attention. In this study, amorphous Li2O–LiI materials are prepared via a mechanochemical process to achieve high lithium ionic conductivity and good compatibility to lithium metal. Amorphous 66.7Li2O·33.3LiI (mol%) electrolyte shows a high ionic conductivity of 3.1 × 10−5 S cm−1 at 25 °C with a relative density of 96 %. An all-solid-state Li symmetric cell (Li/66.7Li2O·33.3LiI/Li) operates without an increase in overvoltage. A simple combination of lithium oxide and lithium iodide exhibits high ionic conductivity, ductility, and stability to lithium metal.

In this work spinel Li4Ti5O12 (LTO) was successfully synthesized via flash sintering technique at a furnace temperature of 580°C within only 5 min for the first time. Phase evolution, microstructures, and electrochemical properties were investigated and compared with conventionally synthesized LTO. The flash sintered LTO shows good crystallinity, high purity, and small particle size. More importantly, it suggests that the flash sintering process could help inhibit lithium volatilization and control the particle size, which is vital to the improvement of the lithium‐ion diffusion process and battery performance. Compared with the conventionally synthesized samples, the flash sintered LTO exhibits higher specific capacities, better cycling stabilities, and rate capabilities. Therefore, flash sintering shows potentials in improving the electrochemical performance of anode materials, and thus suggests an efficient strategy for rapid synthesis of high‐performance anode materials for lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Low first-cycle Coulombic efficiency is especially poor for silicon (Si)-based anodes due to the high surface area of the Si-active material and extensive electrolyte decomposition during the initial cycles forming the solid electrolyte interphase (SEI). Therefore, developing successful prelithiation methods will greatly benefit the development of lithium-ion batteries (LiBs) utilizing Si anodes. In pursuit of this goal, in this study, lithium oxide (Li2O) was added to a LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode using a scalable ball-milling approach to compensate for the initial Li loss at the anode. Different milling conditions were tested to evaluate the impact of particle morphology on the additive performance. In addition, Co3O4, a well-known oxygen evolution reaction catalyst, was introduced to facilitate the activation of Li2O. The Li2O + Co3O4 additives successfully delivered an additional capacity of 1116 mAh/gLi2O when charged up to 4.3 V in half cells and 1035 mAh/gLi2O when charged up to 4.1 V in full cells using Si anodes. [ABSTRACT FROM AUTHOR]

In this study, Cu-doped lithium carbonate (Cu:Li 2 O 2) films are prepared by pulsed direct-current (DC) magnetron sputter using a lithium carbonate and copper oxide mixed target. The oxygen flow rate is varied during the sputtering process to systematically investigate its effect on structural, electrical and optical properties of the films. The experimental results show that all the Cu:Li 2 O 2 films are mainly amorphous as confirmed by X-ray diffraction. Cu incorporation is able to reduce the aggregated clusters of the lithium oxides. At the oxygen flow rate of 20 sccm the film with a Cu content of ∼0.7 at.% has a low p-type resistivity of 0.82 Ω-cm, hole concentration of 1.1 × 1017 cm−3 and the highest mobility of 73 cm2V−1s−1, which is at least twice higher than those of other p-type metal oxides prepared at similarly low temperatures. The film also has a high optical band gap of 2.87 eV. Moreover, the Cu:Li 2 O 2 /ZnO heterojunction demonstrating a clear diode rectification supports the p-type nature of Cu:Li 2 O 2 films. The pulsed DC Cu:Li 2 O 2 films with these remarkable optoelectronic properties demonstrate great potential to be adopted as transparent oxide semiconductors in high-performance optoelectronics. • Low-level Cu incorporation (0.7 at.%) is able to reach optimal film properties. • Cu:Li 2 O 2 films have a high mobility (73 cm2V−1s−1) outperforming other p-type films. • Bandgap of 2.87 eV is wider than other p-type transparent conductive oxides. [ABSTRACT FROM AUTHOR]

[Display omitted] In lithium-ion batteries (LIBs), as a promising energy storage device, materials with fast lithium (Li) transport are required for high-power applications such as electric vehicles. Thus, a deeper understanding of Li transport in components of LIBs is crucial for improving their rate capability. In this study, the Li transport in lithium oxide (Li 2 O), as one of the key components of the solid electrolyte interphase (SEI) layer, was examined by a multiscale computational approach ranging from density functional theory (DFT) to Monte Carlo simulations. The DFT calculations were used to investigate the recombination of Frenkel pairs, their first-principles total energies, and the Li diffusion mechanisms. The effect of atomic configurations on both first-principles total energies and diffusion barrier energies was formulated by periodic and local cluster expansions. These formalisms were then incorporated into the Monte Carlo and Kinetic Monte Carlo (KMC) simulations to calculate the diffusion coefficient of Li. Our calculations revealed that the vacancy-mediated jump along the 〈 100 〉 direction in the antifluorite structure of Li 2 O possesses the lowest barrier energy compared to other diffusion mechanisms. The KMC simulations indicated that the diffusion coefficient of Li better converged with the direct experimental measurement when the recombination of Frenkel pairs was integrated into the simulations. At a temperature of 300 K, the KMC simulation yielded a Li diffusion coefficient of 3.8 × 10 - 12 cm 2 / s in Li 2 O. This is only one order of magnitude larger than indirect experimental measurement, suggesting the accuracy of our formalism. Thus, our formalism for studying Li transport in Li 2 O will pave the path to a rational design of inorganic SEI in the future development of LIBs. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are playing a vital role in recent technology to compensate the energy crises facing by industries. Lithium based oxides materials are extensively used as an electrode material due to their high energy density. The zinc (Zn2+) ion substituted nickel rich lithium cobalt oxide nanomaterials having formula Li 2 [Ni 6 Zn x Co 2−x ]O 10 were prepared with various concentrations of zinc (x = 0.00, 0.50, 1.00, 1.50, 2.00) using sol-gel wet chemical route. All samples were annealed at temperature of 700 °C for 3 h in a muffle furnace. X-ray diffraction (XRD) analysis confirmed the hexagonal structure of the prepared nanomaterials. The crystallite size was determined through Scherrer's and Williamson Hall (W–H) method. The effects of Zn2+ ion substitution on surface morphology, grain size and their distribution were investigated using scanning electron microscope (SEM). Dielectric properties of synthesized nanomaterials were also investigated within the applied frequency range from 1 MHz to 3 GHz at room temperature. A significant impact of zinc on dielectric response was observed. The different polarizations mechanisms were discussed with effect of frequency. The relaxation mechanism with hopping phenomena were also discussed at higher frequencies. The prepared materials were also investigated by employing a vibrating sample magnetometer (VSM) for their magnetic properties. The narrow magnetic hysteresis loop suggested that the prepared material is soft magnetic in nature with all concentrations of Zn2+. Finally, the prepared nanomaterials are suitable for energy storage and microwave device applications. [Display omitted] •Zn substitution in Nickel Rich Lithium Oxide Li 2 [Ni 6 Zn x Co 2−x ]O 10 nanomaterials fabricated via sol-gel auto-combustion route. • The effect of Zinc on structural, dielectric, and magnetic properties was investigated. • Frequency dependent dielectric, impedance, electric modulus, and Ac conductivity were investigated in microwave region. • Saturation magnetization, coercivity, retentivity, and anisotropy constant were determined. [ABSTRACT FROM AUTHOR]

Low first-cycle Coulombic efficiency is especially poor for silicon (Si)-based anodes due to the high surface area of the Si-active material and extensive electrolyte decomposition during the initial cycles forming the solid electrolyte interphase (SEI). Therefore, developing successful prelithiation methods will greatly benefit the development of lithium-ion batteries (LiBs) utilizing Si anodes. In pursuit of this goal, in this study, lithium oxide (Li2O) was added to a LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode using a scalable ball-milling approach to compensate for the initial Li loss at the anode. Different milling conditions were tested to evaluate the impact of particle morphology on the additive performance. In addition, Co3O4, a well-known oxygen evolution reaction catalyst, was introduced to facilitate the activation of Li2O. The Li2O + Co3O4 additives successfully delivered an additional capacity of 1116 mAh/gLi2O when charged up to 4.3 V in half cells and 1035 mAh/gLi2O when charged up to 4.1 V in full cells using Si anodes.

Adsorbents for the absorption of CO2 (Li2ZrO3, Li4SiO4, CaSiO3, MgO, and Li2O) are synthesized and deposited on silicon carbide. The adsorbents are effective in the range of medium (300–400°C) and high (450–750°C) temperatures, have a high capacity for the dynamic absorption of CO2, and an enhanced rate of absorption. [ABSTRACT FROM AUTHOR]

The components and structures of the solid-electrolyte interphase (SEI) are critical for stable cycling of lithium metal batteries (LMBs). LiF has been widely studied as the dominant component of SEI, but Li 2 O, which has a much lower diffusion barrier for Li + , has rarely been investigated as the dominant component of SEI. The effect of Li 2 O-dominated SEI on electrochemical performance still remains elusive. Herein, an ultrastrong coordinated cosolvation diluent, 2,3-difluoroethoxybenzene (DFEB), is designed to modulate solvation structure and tailor Li 2 O-dominated SEI for stable LMBs. In the DFEB-based LHCE (DFEB-LHCE), DFEB intensively participates in the first solvation shell and synergizes with FSI - to tailor an Li 2 O-dominated inorganic-rich SEI which is different from the LiF-dominated SEI formed in conventional LHCE. Benefiting from this special SEI architecture, a high Coulombic efficiency (CE) of 99.58% in Li||Cu half cells, stable voltage profiles, and dense and uniform lithium deposition, as well as effective inhibition of Li dendrite formation in the symmetrical cell, are achieved. More importantly, the DFEB-LHCE can be matched with various cathodes such as LFP, NCM811, and S cathodes, and the Li||LFP full cell using DFEB-LHCE possesses 85% capacity retention after 650 stable cycles with 99.9% CE. Especially the 1.5 Ah practical lithium metal pouch cell achieves an excellent capacity retention of 89% after 250 cycles with a superb average CE of 99.93%. This work unravels the superiority of the Li 2 O-dominated SEI and the feasibility of tailoring SEI components through modulation of solvation structures.

The safety and cycle life of lithium-ion batteries (LIBs) are largely determined by the solid electrolyte interphase (SEI) formed on the surface of the anode. However, there is still a lack of understanding regarding the structure and properties of the individual SEI components. Among others, lithium oxide (Li 2 O), lithium carbonate (Li 2 CO 3 ), and lithium fluoride (LiF) are known to be the main components of the inorganic SEI layer in conventional LIBs, but their intrinsic protective roles remain controversial. Herein, we present the transformational effects of their amorphous phase on the mechanical and transport characteristics, based on first-principles calculations. Our studies clearly demonstrate that their amorphous phases exhibit significantly improved Li-ion conductivity when compared to the crystalline structures. Additionally, among them, amorphous LiF emerges as a frontrunner for fast Li + ion transportation, reversing the conventionally understood hierarchy. Under ambient conditions, the amorphous phases of LiF, Li 2 O, and Li 2 CO 3 are thermodynamically unstable and tend to undergo recrystallization. However, this work highlights that exceptionally ductile and resilient amorphous phases can form if SEI formation and growth would involve some admixing of lithiophilic impurities like nitrogen (N) within the host matrices.

This work utilizes in situ transmission electron microscopy–based nanopillar compression to investigate the effect of electrochemical cycling on the mechanical properties of LiCoO2. The ultimate strength of LiCoO2 in the pristine state, and after 1 and 11 cycles are 5.62 ± 0.22 GPa, 3.91 ± 1.22 GPa, and 2.27 ± 1.07 GPa, respectively. The reduced average yield strengths and the large standard deviations of cycled samples, relative to the pristine powder, are hypothesized to result from nonuniform accumulation of Li+ site‐point defects during cycling; either H+ or Li+ vacancies. Density functional theory calculations support our hypothesized link between a nonuniform Li site‐point defect distribution in the cathode and reduction in the materials cohesive strength. Cycling lithium cobalt oxide reduces its strength as a result of point defect accumulation. [ABSTRACT FROM AUTHOR]

This work utilizes in situ transmission electron microscopy–based nanopillar compression to investigate the effect of electrochemical cycling on the mechanical properties of LiCoO2. The ultimate strength of LiCoO2 in the pristine state, and after 1 and 11 cycles are 5.62 ± 0.22 GPa, 3.91 ± 1.22 GPa, and 2.27 ± 1.07 GPa, respectively. The reduced average yield strengths and the large standard deviations of cycled samples, relative to the pristine powder, are hypothesized to result from nonuniform accumulation of Li+ site‐point defects during cycling; either H+ or Li+ vacancies. Density functional theory calculations support our hypothesized link between a nonuniform Li site‐point defect distribution in the cathode and reduction in the materials cohesive strength. Cycling lithium cobalt oxide reduces its strength as a result of point defect accumulation. [ABSTRACT FROM AUTHOR]

The catalytic performance for the oxidative coupling of methane (OCM) over chloride-containing Li/SnO2 was investigated experimentally and the mechanism of OCM was further suggested. Cl− ions exerted remarkable influence on the catalytic performance of Li/SnO2, with that at 750 °C displaying the highest catalytic activity (18.5% C2 yield) for OCM. The prepared catalysts were characterized with N2 physisorption, X-ray diffraction, O2-temperature programmed desorption, X-ray photoelectron spectroscopy and H2 temperature programmed reduction measurement to elucidate the effect of Cl− ions on its properties and catalytic performance. The results showed that the enhanced OCM catalytic activity of the chloride-containing Li/SnO2 catalysts compared with pure Li/SnO2 catalyst may originate from the higher concentration of anion vacancies, more rapid oxygen mobility and improved redox ability of tin. In addition, characterization by CO2-temperature programmed desorption, infrared spectroscopy and O2 frequency pulse reactions results illustrated that adding Cl− ions improved performance of Li/SnO2, which not only reduced strong basic sites to prevent the formation of poisoning carbonate, but also facilitated the formed chloromethane to convert quickly to ethylene. [ABSTRACT FROM AUTHOR]

• The structures of FLiNaK–Li 2 O and FLiNaK–Li 2 O–CeF 3 melts were studied by ab initio molecular dynamics. • A variety of instantaneous local structure configurations is observed. • The most probable groupings in the FLiNaK–Li 2 O melt are [OLi 5 K], [OLi 5 K 2 ] and [OLi 4 NaK 2 ] • The FLiNaK–Li 2 O–CeF 3 melt contain [OCe 2 Li 2 ], [OCe 2 Li 2 K], [OCe 2 Li 3 ] and [OCe 3 Li] structural units. • The most stable structures are [OLi n ] (n = 4, 5) and [OCe n ] (n = 1, 2, 3), depending on the composition of the melt. Oxide impurities affect the performance of the molten mixtures applicable in molten salt reactors. To reveal the underlying reasons of changes in physicochemical properties, the in-depth investigations on microscopic structure of melts are demanded. In this study, the FLiNaK and FLiNaK–CeF 3 molten mixtures with small addition of Li 2 O were simulated within the ab initio theory to obtain the local structure patterns. The emphasis is placed on oxygen-based groupings since these are expected to be the most stable. In order to estimate the stability, the calculation of ion pair lifetimes was performed. It is shown that the most probable ion groupings existing in the FLiNaK–Li 2 O melt are [OLi 5 K], [OLi 5 K 2 ] and [OLi 4 NaK 2 ], while the FLiNaK–Li 2 O–CeF 3 melt contain [OCe 2 Li 2 ], [OCe 2 Li 2 K], [OCe 2 Li 3 ] and [OCe 3 Li] units predominantly. Within the groupings, the most stable ion pairs are O-Li or O-Ce, depending on the melt composition. [ABSTRACT FROM AUTHOR]

The iron catalyst precursor promoted with Al2O3, CaO, and Li2O was obtained applying the fusing method. Lithium oxide forms two phases in this iron catalyst: a chemical compound with iron oxide (Li2Fe3O4) and a solid solution with magnetite. The catalyst promoted with lithium oxide was not fully reduced at 773 K, while the catalyst containing potassium was easily reducible at the same conditions. After reduction at 873 K the activity of the catalyst promoted with lithium oxide was 41% higher per surface than the activity of the catalyst promoted with potassium oxide. The concentration of free active sites on the surface of the catalyst containing lithium oxide after full reduction was greater than the concentration of free active sites on the surface of the catalyst promoted with potassium oxide.

Abstract Closed Li O 2 batteries consisting of electrolytes derived from molten salt have emerged as attractive energy-storage cells because of their unique oxygen-supply mechanism to form a stable Li 2 O discharge product without requiring an oxygen-gas-reservoir. However, the formation of stable Li 2 O discharge product increases the overpotential during the charging process, which compromises the cell performance because of the resulting parasitic reaction. In this study, we demonstrate a potent approach to reversibly operate an oxygen-gas-reservoir-free Li O 2 battery by using chemically impregnated nickel oxide (NiO) nanoparticles as a catalyst on the carbon electrode. The efficient bottom-up process for decorating NiO on a carbon material in binary molten electrolyte enables not only to significantly reduce the loading level of the catalyst but also to enhance the electrochemical performance with preventing the detrimental parasitic reaction in the oxygen-gas-reservoir-free Li O 2 cell. In particular, using the in situ gas analysis with electrochemical measurements, the 20 wt% NiO added to the carbon cathode is sufficient to reduce the charging potential without generation of parasitic gas evolution. Highlights • Oxygen gas tank free Li O 2 battery is demonstrated by using nitrate molten salt. • Chemically impregnated nickel oxide cathode enables to reduce the over potential. • Gas analysis results suggest the reliable electrochemical reaction. [ABSTRACT FROM AUTHOR]

In an effort to verify a previous striking report that ethanol could be oxidized selectively to ethylene oxide, ethanol oxidation on Ag, Cu, or Au nanoparticles supported on Li 2 O/γ-Al 2 O 3 or γ-Al 2 O 3 was examined between 100 and 400 °C. Ag and Cu catalysts were found to be highly selective to acetaldehyde (>95% on Ag below 325 °C and on Cu below 250 °C). On Au, selectivities to acetaldehyde were lower, with higher selectivity to ethyl acetate and acetic acid. No ethylene oxide was observed under any conditions. Our results, including selectivity variations among these metals, are consistent with previous studies of ethanol oxidation over coinage metals supported on γ-Al 2 O 3 , with no changes in primary product identity and minor changes in selectivity upon addition of Li 2 O. Unfortunately, these results are in direct contradiction to previous work reporting the desirable direct conversion of ethanol to ethylene oxide on Ag, Cu, and Au on Li 2 O/γ-Al 2 O 3 . [ABSTRACT FROM AUTHOR]

Abstract: Lithium and sodium aluminosilicates are important glass‐forming systems for commercial glass‐ceramics, as well as being important model systems for ion transport in battery studies. In addition, uncontrolled crystallization of LiAlSiO4 (eucryptite) in high‐Li2O compositions, analogous to the more well‐known problem of NaAlSiO4 (nepheline) crystallization, can cause concerns for long‐term chemical durability in nuclear waste glasses. To study the relationships between glass structure and crystallization, nine glasses were synthesized in the LixNa1‐xAlSiO4 series, from x = 0 to x = 1. Raman spectra, nuclear magnetic resonance (NMR) spectroscopy (Li‐7, Na‐23, Al‐27, Si‐29), and X‐ray diffraction were used to study the quenched and heat‐treated glasses. It was found that different LiAlSiO4 and NaAlSiO4 crystal phases crystallize from the glass depending on the Li/Na ratio. Raman and NMR spectra of quenched glasses suggest similar structures regardless of alkali substitution. Li‐7 and Na‐23 NMR spectra of the glass‐ceramics near the endmember compositions show evidence of several differentiable sites distinct from known LixNa1‐xAlSiO4 crystalline phases, suggesting that these measurements can reveal subtle chemical environment differences in mixed‐alkali systems, similar to what has been observed for zeolites. [ABSTRACT FROM AUTHOR]

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 (Li 2 O) in addition to pure Li is crucial for Li plasma-facing material applications. To compare H retention in Li and Li 2 O 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 Li 2 O 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. [ABSTRACT FROM AUTHOR]

Crystallization temperatures (liquidus and solidus) in the LiCl-Li 2 O and (LiCl-KCl)-Li 2 O systems with the KCl content of 10 and 20 mol.% were obtained with independent methods of thermal analysis using cooling curves, isothermal saturation, and differential scanning calorimetry. The linear sweep voltammetry was applied to control the time of the equilibrium establishment in the molten system after the Li 2 O addition, which depended on the composition of the base melt and the concentration of Li 2 O. The fragments of the binary LiCl-Li 2 O and quazi-binary [LiCl-KCl(10 mol.%)]-Li 2 O and [LiCl-KCl(20 mol.%)]-Li 2 O phase diagrams in the Li 2 O concentration range from 0 to 12 mol.% were obtained. The KCl presence in the LiCl-KCl-Li 2 O molten mixture in the amount of 10 and 20 mol.% reduces the liquidus temperature by 30 and 80°, respectively, but the region of the homogeneous molten state of the system is considerably narrowed, which complicates its practical application. The Li 2 O solubility in the molten LiCl, LiCl-KCl(10 mol.%) and LiCl-KCl(20 mol.%) decreases with increasing the KCl content and is equal to 11.5, 7.7 and 3.9 mol.% at 650°С, respectively. The LiCl-KCl melt with 10 mol.% KCl can be recommended for practical use as a medium for the SNF pyro-chemical reprocessing at temperature below 700 °C. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Li7La3Zr2O12 ( LLZO) has been reported to react in humid air to form Li2 CO3 on the surface, which decreases ionic conductivity. To study the reaction mechanism, 0.5-mol Ta-doped LLZO (0.5Ta- LLZO) pellets are exposed in dry (humidity ~5%) and humid air (humidity ~80%) for 6 weeks, respectively. After exposure in humid air, the formation of Li2 CO3 on the pellet surface is confirmed experimentally and the room-temperature ionic conductivity is found to drop from 6.45×10−4 S cm−1 to 3.61×10−4 S cm−1. Whereas for the 0.5Ta- LLZO samples exposed in dry air, the amount of formed Li2 CO3 is much less and the ionic conductivity barely decreases. To further clarify the reaction mechanism of 0.5Ta- LLZO pellets with moisture, we decouple the reactions between 0.5Ta- LLZO with water and CO2 by immersing 0.5Ta- LLZO pellets in deionized water for 1 week and then exposing them to ambient air for another week. After immersion in deionized water, Li+/H+ exchange occurs and Li OH H2O forms on the surface, which is a necessary intermediate step for the Li2 CO3 formation. Based on these observations, a reaction model is proposed and discussed. [ABSTRACT FROM AUTHOR]

Li7La3Zr2O12 ( LLZO) has been reported to react in humid air to form Li2 CO3 on the surface, which decreases ionic conductivity. To study the reaction mechanism, 0.5-mol Ta-doped LLZO (0.5Ta- LLZO) pellets are exposed in dry (humidity ~5%) and humid air (humidity ~80%) for 6 weeks, respectively. After exposure in humid air, the formation of Li2 CO3 on the pellet surface is confirmed experimentally and the room-temperature ionic conductivity is found to drop from 6.45×10−4 S cm−1 to 3.61×10−4 S cm−1. Whereas for the 0.5Ta- LLZO samples exposed in dry air, the amount of formed Li2 CO3 is much less and the ionic conductivity barely decreases. To further clarify the reaction mechanism of 0.5Ta- LLZO pellets with moisture, we decouple the reactions between 0.5Ta- LLZO with water and CO2 by immersing 0.5Ta- LLZO pellets in deionized water for 1 week and then exposing them to ambient air for another week. After immersion in deionized water, Li+/H+ exchange occurs and Li OH H2O forms on the surface, which is a necessary intermediate step for the Li2 CO3 formation. Based on these observations, a reaction model is proposed and discussed. [ABSTRACT FROM AUTHOR]