Lithium Molybdate Research Articles

Lithium-ion comb—artificial self-regulating lithium-storage film on aluminum anode enabling long cycles of batteries

Al anode can increase battery energy density, but its non-wettability and high Li nucleation hindrance cause uneven Li nucleation to deteriorate the anode structure. Herein, we present a novel in-situ synthesis method for the deposition of molybdenum oxide nanospheres (NMO) onto the surface of Al foil, that is, molybdenum oxide/aluminum (M-Al), which demonstrates a two-stage propulsion effect on Li-ion migration to address the issue at hand. The high wettability and low Li nucleation hindrance of the NMO layer drive the first stage of Li-ion migration. NMO acted as a comb to deliver Li ions uniformly with minor volume expansion. Subsequently, the formation of Li2O-rich solid electrolyte interphase (SEI) film with exceptional desolvation capability, facilitated by the NMO layer and electrochemically activated M-Al to Li molybdate/aluminum (Li-M-Al), represents the second stage in the advancement of Li−ion migration. The embedding of lithium ions makes molybdenum oxide evolve into lithium molybdate, thereby enabling Mo to regulate the storage of Li ions through the valence state. Hence, the Li nucleation overpotential of M-Al is decreased by 0.32 V, leading to a significant enhancement in the cycling performance of the Li-M-Al||LiFePO4 (LFP) battery, with a capacity retention rate of 78.5 % after 400 cycles at 1C.

A novel mechanical design of a bolometric array for the CROSS double-beta decay experiment

The CROSS experiment will search for neutrinoless double-beta decay using a specific mechanical structure to hold thermal detectors. The design of the structure was tuned to minimize the background contribution, keeping an optimal detector performance. A single module of the structure holds two scintillating bolometers (with a crystal size of 45 × 45 × 45 mm and a Ge slab facing the crystal's upper side) in the Cu frame, allowing for a modular construction of a large-scale array. Two designs are released: the initial Thick version contains around 15% of Cu over the crystal mass (lithium molybdate, LMO), while this ratio is reduced to ∼ 6% in a finer (Slim) design. Both designs were tested extensively at aboveground (IJCLab, France) and underground (LSC, Spain) laboratories. In particular, at LSC we used a pulse-tube-based CROSS facility to operate a 6-crystal array of LMOs enriched/depleted in 100Mo. The tested LMOs show high spectrometric performance in both designs; notably, the measured energy resolution is 5–7 keV FWHM at 2615 keV γs, nearby the Q-value of 100Mo (3034 keV). Due to the absence of a reflective cavity around LMOs, a low scintillation signal is detected by Ge bolometers: ∼ 0.3 keV (150 photons) for 1-MeV γ(β) LMO-event. Despite that, an acceptable separation between α and γ(β) events is achieved with most devices. The highest efficiency is reached with light detectors in the Thick design thanks to a lower baseline noise width (0.05–0.09 keV RMS) when compared to that obtained in the Slim version (0.10–0.35 keV RMS). Given the pivotal role of bolometric photodetectors for particle identification and random coincidences rejection, we will use the structure here described with upgraded light detectors, featuring thermal signal amplification via the Neganov-Trofimov-Luke effect, as also demonstrated in the present work.

Alleviating the sluggish kinetics of all-solid-state batteries via cathode single-crystallization and multi-functional interface modification

The application of Li-rich Mn-based cathodes, the most promising candidates for high-energy-density Li-ion batteries, in all-solid-state batteries can further enhance the safety and stability of battery systems. However, the utilization of high-capacity Li-rich cathodes has been limited by sluggish kinetics and severe interfacial issues in all-solid-state batteries. Here, a multi-functional interface modification strategy involving dispersed submicron single-crystal structure and multi-functional surface modification layer obtained through in-situ interfacial chemical reactions was designed to improve the electrochemical performance of Li-rich Mn-based cathodes in all-solid-state batteries. The design of submicron single-crystal structure promotes the interface contact between the cathode particles and the solid-state electrolyte, and thus constructs a more complete ion and electron conductive network in the composite cathode. Furthermore, the Li-gradient layer and the lithium molybdate coating layer constructed on the surface of single-crystal Li-rich particles accelerate the transport of Li ions at the interface, suppress the side reactions between cathodes and electrolyte, and inhibit the oxygen release on the cathode surface. The optimized Li-rich cathode materials exhibit excellent electrochemical performance in halide all-solid-state batteries. This study emphasizes the vital importance of reaction kinetics and interfacial stability of Li-rich cathodes in all-solid-state batteries and provides a facile modification strategy to enhance the electrochemical performance of all-solid-state batteries based on Li-rich cathodes.

ELECTROREDUCTION OF NICKEL(II) CHLORIDE, COBALT(II) FLUORIDE AND MOLYBDENUM(VI) OXIDE MIXTURES IN A HEAT ACTIVATED BATTERY

The discharge characteristics of the elements of a thermally activated chemical current source (HAB) containing NiCl2–CoF2–MoO3 mixtures as a positive electrode are investigated. It is established that molybdenum oxide stabilizes the discharge plateau and increases the discharge voltage at temperatures above 530°C. The discharge curve has a stepwise character. The number of steps of the discharge curve is determined by the operating conditions of HAB. The low-voltage stage (less than 0.4 V) corresponds to the reduction of lithium molybdates, which are formed by the interaction of molybdenum oxide with the reduction products of transition metal halides. A study of the cathode reduction products by the methods of XRD, STA and SEM was carried out. It is established that during the discharge of the HAB element, the initial components of the cathode mixture are restored to metals that form a dendritic matrix. The DSC curves of the salt fraction formed during electrochemical reactions have a number of thermal effects corresponding to the temperatures of joint melting of a triple mixture of lithium halides LiF–LiCl–LiBr and eutectic dual systems LiF–LiCl, LiCl–Li2O, in which transition metal halides and lithium molybdates are dissolved.

Li2100deplMoO4 Scintillating Bolometers for Rare-Event Search Experiments

We report on the development of scintillating bolometers based on lithium molybdate crystals that contain molybdenum that has depleted into the double-β active isotope 100Mo (Li2100deplMoO4). We used two Li2100deplMoO4 cubic samples, each of which consisted of 45-millimeter sides and had a mass of 0.28 kg; these samples were produced following the purification and crystallization protocols developed for double-β search experiments with 100Mo-enriched Li2MoO4 crystals. Bolometric Ge detectors were utilized to register the scintillation photons that were emitted by the Li2100deplMoO4 crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc Underground Laboratory (Spain). We observed that the Li2100deplMoO4 scintillating bolometers were characterized by an excellent spectrometric performance (∼3–6 keV of FWHM at 0.24–2.6 MeV γs), moderate scintillation signal (∼0.3–0.6 keV/MeV scintillation-to-heat energy ratio, depending on the light collection conditions), and high radiopurity (228Th and 226Ra activities are below a few µBq/kg), which is comparable with the best reported results of low-temperature detectors that are based on Li2MoO4 using natural or 100Mo-enriched molybdenum content. The prospects of Li2100deplMoO4 bolometers for use in rare-event search experiments are briefly discussed.

Twelve-crystal prototype of Li2MoO4 scintillating bolometers for CUPID and CROSS experiments

An array of twelve 0.28 kg lithium molybdate (LMO) low-temperature bolometers equipped with 16 bolometric Ge light detectors, aiming at optimization of detector structure for CROSS and CUPID double-beta decay experiments, was constructed and tested in a low-background pulse-tube-based cryostat at the Canfranc underground laboratory in Spain. Performance of the scintillating bolometers was studied depending on the size of phonon NTD-Ge sensors glued to both LMO and Ge absorbers, shape of the Ge light detectors (circular vs. square, from two suppliers), in different light collection conditions (with and without reflector, with aluminum coated LMO crystal surface). The scintillating bolometer array was operated over 8 months in the low-background conditions that allowed to probe a very low, μBq/kg, level of the LMO crystals radioactive contamination by 228Th and 226Ra.

Structural, dielectric, optical, and electrochemical performance of Li4Mo5O17 for ULTCC applications

Lithium molybdates are of great interest in ultra-low temperature cofired ceramics (ULTCC) technology due to their low processing temperature. In this study, a ULTCC Li4Mo5O17 was prepared via a solid state route. X-ray diffraction and Raman spectroscopy analysis revealed the formation of single phase triclinic structure. The variation in relative permittivity and dielectric loss of the sample with the change in frequency is explained using the polaron model. At the excitation of 514 nm, excitonic and deep-level (impurities, oxygen, and lithium vacancies) emissions were observed which contribute to the lossy nature of Li4Mo5O17. The experimentally calculated direct optical band gap energy of ∼ 3.1 eV is consistent with the energy gap (∼ 3.07 eV) predicted through density functional theory. The electrochemical study showed that the sample exhibits a high specific capacitance of ∼ 252.5 F/g at a low scan rate of 5 mV/s.

Erratum to: Crystal Growth and Heat Capacity of Lithium Molybdate Tungstates

Erratum to: Crystal Growth and Heat Capacity of Lithium Molybdate Tungstates

Computational Analysis of Radiative Heat Transfer in Czochralski Furnace and 3D Anisotropic Thermal Stress in Li2MoO4 Bulk Crystal (Crystal Research and Technology 10/2022)

Crystal Research and TechnologyVolume 57, Issue 10 2270019 Cover PictureFree Access Computational Analysis of Radiative Heat Transfer in Czochralski Furnace and 3D Anisotropic Thermal Stress in Li2MoO4 Bulk Crystal (Crystal Research and Technology 10/2022) First published: 07 October 2022 https://doi.org/10.1002/crat.202270019AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Li2MoO4 Crystals In article number 2200097, Faiza Mokhtari and co-workers compute 3D thermal stress in lithium molybdate (LMO) single crystals for different cases using anisotropic and temperature dependent properties. Radiative heat transfer between the furnace elements and inside the semitransparent oxide crystal are considered separately then simultaneously to deeply analyse their roles in heat transfer, power consumption and stress generation. The effect of the LMO melt opacity on thermal stress is studied and related to temperature gradients in the crystal and at the melt free surface. A good agreement is found with experimental observations. Volume57, Issue10October 20222270019 RelatedInformation

Crystal Growth and Heat Capacity of Lithium Molybdate Tungstates

Crystal Growth and Heat Capacity of Lithium Molybdate Tungstates

Optimization of cryogenic calorimetric detection with lithium molybdate crystals for AMoRE-II experiments

The AMoRE collaboration is preparing for the second phase of the experiment, AMoRE-II, which will exploit a 100 kg of 100Mo isotopes to search for neutrinoless double beta decay from the isotope. Most of the 100Mo isotopes will be contained in the lithium molybdate (Li2MoO4) crystals, which will act as absorbers of cryogenic calorimeters coupled to MMC (metallic magnetic calorimeter) sensors. The detector array will have a total mass of approximately 200 kg with hundreds of detector modules. Hence, considerable effort has been taken to optimize the lithium molybdate crystal detector in terms of the detector performance and preparation procedure to build many detector modules in a reasonable schedule without compromising the detector performance. We found some critical experimental conditions to improve the energy resolution in a series of test experiments. In this paper, we discuss the effect of surface treatment and thermal link connection in improving the energy resolution from 14–15 keV to below 7 keV at 2.615 MeV, 208Tl gamma line, which is near the Q-value of the decay of 100Mo, 3.034MeV. We also report the high discrimination power for the separation of alpha particles using the simultaneous scintillation light detection with a test performed in the cryogen-free dilution refrigerator.

Cosmogenic background study for a ^{100}Mo-based bolometric demonstration experiment at China JinPing underground Laboratory

We perform simulation study for a 10-kg ^{100}Mo-based bolometeric demonstration experiment for neutrinoless double-beta decay (0nu beta beta ) search at China JinPing underground Laboratory (CJPL). Cosmogenic production of radionuclides in ^{100}Mo-enriched lithium molybdate crystals and copper components of the detector system are studied using Geant4 toolkit based on the simulated cosmic ray data from the CRY library. Background energy spectra of the cosmogenic radionuclides including ^{56}Co, ^{82}Rb and ^{88}Y which are harmful for the ^{100}Mo-based 0nu beta beta experiment are investigated. We then evaluate the total cosmogenic background level in the ^{100}Mo 0nu beta beta search energy region of interest (ROI) for the demonstration experiment. After one year of cooling down underground, the residual background contribution is found to be 1.8 times 10^{-6} cts/kg/keV/yr and 3.3times 10^{-4} cts/kg/keV/yr from crystals and copper components, respectively. Furthermore, underground cosmogenic activation of copper and lithium molybdate crystal is calculated based on the simulation spectra of neutron and proton in CJPL. The underground cosmogenic background is found to be negligible in the ROI.

Mechanical properties of Li2MoO4 single crystals

Mechanical properties of lithium molybdate single crystals, Li2MoO4, are studied from room temperature to 650 °C. Density functional theory calculations gave the seven elastic constants of the rhombohedral crystal at 0 K. Brillouin light scattering experiments delivered comparable values at room temperature, and measurements up to 650 °C show a linear decrease in the constants with temperature. Nano-indentation results were typical of a brittle material with a low Young modulus and allowed deriving Young's moduli, for c (63 GPa) and m (48 GPa) faces, in agreement with those computed from measured elastic constants. Compressive rupture tests were performed. At 650 °C, the rupture stress was in the range 2–7.5 MPa. No clear evidence of a plastic regime was observed before cracking, even at temperatures close to the melting point.

Characterization of Li₂MoO₄/BaTiO₃ All-Ceramic Films on Organic Substrate Printed Capacitors at 45 MHz–10 GHz

This article presents novel all-ceramic composite films used as a screen-printed capacitors on polymer surface and their characterization at 45-MHz to 10-GHz frequency range. All-ceramic composite paste is based on lithium molybdate (Li₂MoO₄), barium titanate (BaTiO₃), and water manufactured by the room temperature fabrication (RTF) method. For the determination of the permittivity and the loss tangent of the materials, ceramic thick films are printed on the top of an interdigital-shaped microwave capacitors using pastes with 0, 10, and 20 vol.&#x0025; of BaTiO₃ filler in Li₂MoO₄ followed by a drying process at 120 &#x00B0;C. The electrical properties of the capacitors, capacitance, and quality value are derived from measured <inline-formula> <tex-math notation="LaTeX">${S}$ </tex-math></inline-formula>-parameter results, whereas the electrical properties of the ceramic thick-film materials, real, and imaginary values of permittivity are derived from the measured results through computer simulations. The electrical properties of the ceramic material, such as moderate permittivity and moderately low-loss tangent, could be adjusted by changing the volume fraction of the BaTiO₃ filler to match the demands of different areas of applications. The obtained results are verified with five samples of each ceramic composition. The results show the capacitance values of 0.30 pF for an uncoated capacitor and 0.55, 0.67, and 0.95 pF with coatings of Li₂MoO₄ with 0, 10, and 20 vol.&#x0025; of BaTiO₃ composites, respectively, at 2.5-GHz frequency. The calculated relative permittivity (<inline-formula> <tex-math notation="LaTeX">$\varepsilon _{r}$ </tex-math></inline-formula>) values for the same materials are 3.70, 5.23, and 6.43, and loss tangent values are 0.035, 0.027, and 0.036 at 2.5 GHz. These novel all-ceramic capacitor composite materials are applicable for the RF components used in telecommunication applications in the frequency range of 45 MHz&#x2013;10 GHz, thus widening the technology roadmap in terms of material choices for different applications, especially high thermal resistant materials.

Thermoluminescence characteristics of a novel Li2MoO4 phosphor: Heating rate, dose response and kinetic parameters

Lithium molybdate (Li2MoO4) phosphor was synthesized by a gel combustion method and its thermoluminescence properties were studied with the irradiation of beta. Various Heating Rate (VHR), Initial Rise (IR), and Computerized Glow Curve Deconvolution (CGCD) methods were used to determine the kinetic parameters (activation energy E (eV), frequency factor s (s−1), and kinetic order b) of the visible glow peaks. According to the kinetic study, the TL glow curve is made up of seven separate peaks with activation energies of 1.05, 0.76, 0.40, 0.60, 0.78, 1.81 and 1.25 eV and these peaks follow general-order kinetics. The results clearly showed that undoped Li2MoO4 has a potential to be considered in dosimetric applications where high doses have to be monitored as in the case of clinical dosimetry.

Lithium molybdate composited with carbon nanofibers as a high-capacity and stable anode material for lithium-ion batteries

Transition metal molybdates have been studied as anode materials for high-performance lithium-ion batteries, owing to their high theoretical capacity and low cost, as well as the multivalent states of molybdenum. However, their electrochemical performance is hindered by poor conductivity and large volume changes during charge and discharge. Here, we report lithium molybdate (Li2MoO4) composited with carbon nanofibers (Li2MoO4@CNF) as an anode material for lithium-ion batteries. Li2MoO4 shows a shot-rod nanoparticle morphology that is tightly wound in the fibrous CNF. Compared with bare Li2MoO4, the Li2MoO4@CNF composite demonstrates superior high specific capacity and cycling stability, which are attributed to the reversible Li-ion intercalation in the LixMoyOz amorphous phase during charge and discharge. The capacity of the Li2MoO4@CNF anode material can reach 830 mAh g-1 in the second cycle and 760 mAh g-1 after 100 cycles at a charge/discharge current density of 100 mA g-1, which is much better than the bare Li2MoO4. This work provides a simple method to prepare a high-capacity and stable lithium molybdate anode material for lithium-ion batteries.

High performance piezoelectric composite fabricated at ultra low temperature

This work presents the next leap in piezoelectric all-ceramic composites fabricated at ultra low temperatures. The “Upside-down” composite method is further developed and instead of the water-soluble lithium molybdate used in our earlier study, an organotitanate based precursor gel is used as a binder. Utilizing heat and pressure the precursor transforms into titanium oxide which, together with lead zirconate titanate particles, forms a high-performance piezoelectric composite. The two-step fabrication method is based only on mixing and uniaxial hot-pressing sequences. The all-ceramic samples are fabricated at ultra low temperatures 275–350 °C with exceptionally high fractions of filler (filler to matrix 84:16 vol ratio) resulting in low porosity and showing excellent dielectric and piezoelectric properties. The charge coefficient d33 ∼150 pC N−1 and the voltage coefficient, g33 ∼52 mVm N−1 obtained with the developed composite outperforms many other known composites (80% and 70% higher than achieved with lithium molybdate bound upside-down composite, respectively) and are comparable even to some bulk piezoceramics and low permittivity polymer-ceramic piezocomposites. The sensor properties of the developed composite and the feasibility of the material from the application point of view are successfully demonstrated by utilizing sample elements in a charge mode acceleration sensor and sensitivities comparable to commercial devices are achieved.

In Situ Electrochemical Activation Derived Lix MoOy Nanorods as the Multifunctional Interlayer for Fast Kinetics Li-S batteries.

Li-S batteries (LSBs) have attracted worldwide attention owing to their characteristics of high theoretical energy density and low cost. However, the commercial promotion of LSBs is hindered by the irreversible capacity decay and short cycling life caused by the shuttle effect of lithium-polysulfides (LiPSs). Herein, a hybrid interlayer consisting of MoO3 , conductive Ni foam, and Super P is prepared to prevent the shuttle effect and catalyze the LiPSs conversion. MoO3 with a reversible lithiation/delithiation behavior between Li0.042 MoO3 and Li2 MoO4 within 1.7-2.8V versus Li/Li+ combines the Li+ insertion and LiPSs immobilization and efficiently improve the LSBs redox kinetics. Benefiting from the reversible Li+ insertion/extraction in lithium molybdate (Lix MoOy ) and the highly conductive Ni foam substrate, the sulfur cathode coupled with such electrochemical activation derived catalytic interlayer exhibits a high initial discharge capacity of 1100.1 mAh g-1 at a current density of 1 C with a low decay rate of 0.09% cycle-1 . Good capacity retention can still be obtained even the areal sulfur loading is increased to 13.28mg cm-2 .

Conventional Czochralski growth of large Li2MoO4 single crystals

Lithium molybdate single crystals up to one kilogram have been grown by a conventional Czochralski process. The growth configuration (geometry, coil, crucible, insulation casing) was optimized by numerical simulation of heat and mass transfer. Dislocations are shown to belong to the basal glide system. Their density (≤104 cm−2) and luminescence properties indicate crystal quality similar to that of previously reported crystals grown by Czochralski technique. Numerical simulation of thermo-elastic stresses suggest that the crack observed in one of these crystals is rather due to a mechanical accident than to internal stresses during growth.

Lattice engineering to alleviate microcrack of LiNi0.9Co0.05Mn0.05O2 cathode for optimization their Li+ storage functionalities

Intrinsic structural degradation and unstable surface chemical properties are bottlenecks of the Ni-rich cathode material for commercial application, which mainly originates from the lattice distortion and residual lithium. In this work, an effective molybdenum lattice engineering method to simultaneously enhance the intrinsic structural stability and the surface chemical properties of LiNi0.9Co0.05Mn0.05O2 cathode material is developed. The molybdenum on transition-metal sites visibly alleviates lattice distortion initiating microcracks by anchoring in the crystal lattice, meanwhile, the interface chemical stability is also significantly improved by consuming residual lithium to form the lithium molybdate oxide fast ion conductor coating layer. Therefore, the molybdenum-modified LiNi0.9Co0.05Mn0.05O2 delivers a remarkable Li+ storage functionalities (202.8 mAh g−1 with 90% capacity retention after 100 cycles), much higher than the pristine LiNi0.9Co0.05Mn0.05O2 (78% capacity retention after 100 cycles). In addition, the Density-Functional Theory (DFT) calculations announce that the Li+ migration the energy barrier of molybdenum-modified LiNi0.9Co0.05Mn0.05O2 is decreased, thus showing an ultrahigh discharge capacity of 166.4 mAh g−1 even at 8C rate. This strategy is very promising to provide a new insight into lattice engineering of cations doping effect, highlight the importance of lattice engineering in optimizing their energy functionalities.