Ultrafast synthesis and luminescence properties of rare earth orthoniobates RENbO4(RE = La, Eu, Gd, Yb, Lu).

Rare earth orthoniobates (RENbO4) are one kind of important functional materials due to its applications in solid-state phosphors, thermal barrier coatings, and microwave dielectric ceramics. The synthesis of rare earth niobates often needs high reaction temperatures (1300 °C-1700 °C) and long processing times (from hours to tens of hours) in solid-state reactions, which can increase the study time of the relationship between structure and properties. In this work, we used ultrafast high-temperature sintering method to synthesize RENbO4(RE = La, Eu, Gd, Yb, Lu), and found specific structure and properties in these materials obtained with specific synthetic techniques. Based on the electronegativity scale, the charge transfer energy of lanthanide ions in the YNbO4crystal was calculated. The rapid synthesis of RENbO4in a vacuum atmosphere generated more oxygen vacancies, and the structures of [REO8] and [NbO6] were distorted. The shortening of the fluorescence lifetime of LaNbO4and EuNbO4was related to the formation of self-trapped excitons facilitated by lattice distortion. The emission peak of LuNbO4at about 530 nm is attributed to the oxygen vacancy in the niobate group. The reported synthetic methods can provide a fast materials screening route for high melting point inorganic materials.

Origin of oxygen-redox and transition metals dissolution in Ni-rich LixNi0.8Co0.1Mn0.1O2 cathode.

Recently, Ni-rich LiNixCoyMn1-x-yO2 (x ≥ 0.8) draw significant research attention as cathode materials in lithium-ion batteries due to their superiority in energy density. However, the oxygen release and the transition metals (TMs) dissolution during the (dis)charging process lead to serious safety issues and capacity loss, which highly prevent its application. In this work, we systematically explored the stability of lattice oxygen and TM sites in LiNi0.8Co0.1Mn0.1O2(NCM811) cathode via investigating various vacancy formations during lithiation/delithiation, and properties such as the number of unpaired spins (NUS), net charges, and d band center were comprehensively studied. In the process of delithiation (x = 1 → 0.75 → 0), the vacancy formation energy of lattice oxygen [Evac(O)] has been identified to follow the order of Evac(O-Mn) > Evac(O-Co) > Evac(O-Ni), and Evac(TMs) shows a consistent trend with the sequence of Evac(Mn) > Evac(Co) > Evac(Ni), demonstrating the importance of Mn to stabilize the structural skeleton. Furthermore, the |NUS| and net charge are proved to be good descriptors for measuring Evac(O/TMs), which show linear correlations with Evac(O) and Evac(TMs), respectively. Li vacancy plays a pivotal role on Evac(O/TMs). Evac(O/TMs) at x = 0.75 vary extremely between the NiCoMnO layer (NCM layer) and the NiO layer (Ni layer), which correlates well with |NUS| and net charge in the NCM layer but aggregates in a small region in the Ni layer due to the effect of Li vacancies. In general, this work provides an in-depth understanding of the instability of lattice oxygen and transition metal sites on the (104) surface of Ni-rich NCM811, which might give new insights into oxygen release and transition metal dissolution in this system.

The protective effects of NE 52-QQ57 against interleukin-33-induced inflammatory response in activated synovial mast cells.

Cytokines-mediated immunity is essential for the pathological development of rheumatoid arthritis (RA). Inhibition of signaling has suggested a potential remedial approach to RA. G protein-coupled receptor 4 (GPR4) has been proven to possess a broad range of physiological functions, but its function in synovial mast cells and RA is less reported. In this study, the protective effects of NE 52-QQ57, a GPR4 antagonist, against interleukin (IL)-33-challenged inflammatory response in activated synovial mast cells were investigated. We report that IL-33 amplified GPR4 expression in HMC-1 mast cells. The GPR4 antagonist NE 52-QQ57 alleviated IL-33-caused secretions of IL-17, interferon-γ, and tumor necrosis factor-α in HMC-1 mast cells. Furthermore, we note that NE 52-QQ57 reduced IL-33-induced expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9. Also, NE 52-QQ57 inhibited cyclooxygenase 2 and prostaglandin E2 expression in IL-33-challenged cells. Also, NE 52-QQ57 ameliorated IL-33-induced oxidative stress by reducing mitochondrial reactive oxygen species and 4-hydroxynonenal. Mechanistically, NE 52-QQ57 mitigated IL-33-induced activation of the p38/nuclear factor-κB signaling pathway. We conclude that targeting GPR4 might be a promising strategy for RA treatment.

State of the Art in Crystallization of LiNbO3 and Their Applications.

Lithium niobate (LiNbO3) crystals are important dielectric and ferroelectric materials, which are widely used in acoustics, optic, and optoelectrical devices. The physical and chemical properties of LiNbO3 are dependent on microstructures, defects, compositions, and dimensions. In this review, we first discussed the crystal and defect structures of LiNbO3, then the crystallization of LiNbO3 single crystal, and the measuring methods of Li content were introduced to reveal reason of growing congruent LiNbO3 and variable Li/Nb ratios. Afterwards, this review provides a summary about traditional and non-traditional applications of LiNbO3 crystals. The development of rare earth doped LiNbO3 used in illumination, and fluorescence temperature sensing was reviewed. In addition to radio-frequency applications, surface acoustic wave devices applied in high temperature sensor and solid-state physics were discussed. Thanks to its properties of spontaneous ferroelectric polarization, and high chemical stability, LiNbO3 crystals showed enhanced performances in photoelectric detection, electrocatalysis, and battery. Furthermore, domain engineering, memristors, sensors, and harvesters with the use of LiNbO3 crystals were formulated. The review is concluded with an outlook of challenges and potential payoff for finding novel LiNbO3 applications.

Challenges and perspectives of NASICON-type solid electrolytes for all-solid-state lithium batteries.

NASICON-type (lithium super ionic conductor) solid electrolyte is of great interest because of its high ionic conductivity, wide potential window, and good chemical stability. In this paper, the key problems and challenges of NASICON-type solid electrolyte are described from the aspects of ionic conductivity, electrode interface, and electrochemical stability. Firstly, the migration mechanism of lithium ion is analyzed from the three-dimensional structure of NASICON-type solid electrolyte, and progress in the research of conductivity and stability is summarized. Then, the effective methods to reduce interface impedance and improve the cycle stability of all-solid-state lithium batteries (ASSLBs) with NASICON-type solid electrolyte are introduced. Finally, solutions to improve the conductivity of electrolytes and deal with electrode/electrolyte interface problems are summarized, and the development prospects of ASSLBs are discussed.

Toward materials-by-design: achieving functional materials with physical and chemical effects.

Advances in renewable and sustainable energy technologies critically depend on our ability to rationally design and process target materials with optimized performances. Advanced material design and discovery are ideally involved in material prediction, synthesis and characterization. Control of material crystallization enables the rational design and discovery of novel functional inorganic materials in multi-scale. Material processing can be adjusted by various physical fields and chemical effects at different energy states. Material microstructure, architecture and functionality can thus be modified by multiple design methodologies. In this review, we show typical examples using physical and chemical methods to shape inorganic functional materials and evaluate their specific applications in Na-air batteries, Li-ion batteries and supercapacitors. Furthermore, this review also provides insight into the understanding of synthesis-structure relationship of inorganic functional materials.

Colloidal Supercapattery: Redox Ions in Electrode and Electrolyte.

Redox chemistry is the cornerstone of various electrochemical energy conversion and storage systems, associated with ion diffusion process. To actualize both high energy and power density in energy storage devices, both multiple electron transfer reaction and fast ion diffusion occurred in one electrode material are prerequisite. The existence forms of redox ions can lead to different electrochemical thermodynamic and kinetic properties. Here, we introduce novel colloid system, which includes multiple varying ion forms, multi-interaction and abundant redox active sites. Unlike redox cations in solution and crystal materials, colloid system has specific reactivity-structure relationship. In the colloidal ionic electrode, the occurrence of multiple-electron redox reactions and fast ion diffusion leaded to ultrahigh specific capacitance and fast charge rate. The colloidal ionic supercapattery coupled with redox electrolyte provides a new potential technique for the comprehensive use of redox ions including cations and anions in electrode and electrolyte and a guiding design for the development of next-generation high performance energy storage devices.

Colloidal paradigm in supercapattery electrode systems.

Among decades of development, electrochemical energy storage systems are now sorely in need of a new design paradigm at the nano size and ion level to satisfy the higher energy and power demands. In this review paper, we introduce a new colloidal electrode paradigm for supercapattery that integrates multiple-scale forms of matter, i.e. ion clusters, colloidal ions, and nanosized materials, into one colloid system, coupled with multiple interactions, i.e. electrostatic, van der Waals forces, and chemical bonding, thus leading to the formation of many redox reactive centers. This colloidal electrode not only keeps the original ionic nature in colloidal materials, but also creates a new attribute of high electroactivity. Colloidal supercapattery is a perfect application example of the novel colloidal electrode, leading to higher specific capacitance than traditional electrode materials. The high electroactivity of the colloidal electrode mainly comes from the contribution of exposed reactive centers, owing to the confinement effect of carbon and a binder matrix. Systematic and thorough research on the colloidal system will significantly promote the development of fundamental science and the progress of advanced energy storage technology.

Structural design of graphene for use in electrochemical energy storage devices.

There are many practical challenges in the use of graphene materials as active components in electrochemical energy storage devices. Graphene has a much lower capacitance than the theoretical capacitance of 550 F g(-1) for supercapacitors and 744 mA h g(-1) for lithium ion batteries. The macroporous nature of graphene limits its volumetric energy density and the low packing density of graphene-based electrodes prevents its use in commercial applications. Increases in the capacity, energy density and power density of electroactive graphene materials are strongly dependent on their microstructural properties, such as the number of defects, stacking, the use of composite materials, conductivity, the specific surface area and the packing density. The structural design of graphene electrode materials is achieved via six main strategies: the design of non-stacking and three-dimensional graphene; the synthesis of highly packed graphene; the production of graphene with a high specific surface area and high conductivity; the control of defects; functionalization with O, N, B or P heteroatoms; and the formation of graphene composites. These methodologies of structural design are needed for fast electrical charge storage/transfer and the transport of electrolyte ions (Li(+), H(+), K(+), Na(+)) in graphene electrodes. We critically review state-of-the-art progress in the optimization of the electrochemical performance of graphene-based electrode materials. The structure of graphene needs to be designed to develop novel electrochemical energy storage devices that approach the theoretical charge limit of graphene and to deliver electrical energy rapidly and efficiently.

Morphology engineering of high performance binary oxide electrodes.

Advances in materials have preceded almost every major technological leap since the beginning of civilization. On the nanoscale and microscale, mastery over the morphology, size, and structure of a material enables control of its properties and enhancement of its usefulness for a given application, such as energy storage. In this review paper, our aim is to present a review of morphology engineering of high performance oxide electrode materials for electrochemical energy storage. We begin with the chemical bonding theory of single crystal growth to direct the growth of morphology-controllable materials. We then focus on the growth of various morphologies of binary oxides and their electrochemical performances for lithium ion batteries and supercapacitors. The morphology-performance relationships are elaborated by selecting examples in which there is already reasonable understanding for this relationship. Based on these comprehensive analyses, we proposed colloidal supercapacitor systems beyond morphology control on the basis of system- and ion-level design. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Enhancing the electrochemical performance of the LiMn(2)O(4) hollow microsphere cathode with a LiNi(0.5)Mn(1.5)O(4) coated layer.

Spinel cathode materials consisting of LiMn2 O4 @LiNi0.5 Mn1.5 O4 hollow microspheres have been synthesized by a facile solution-phase coating and subsequent solid-phase lithiation route in an atmosphere of air. When used as the cathode of lithium-ion batteries, the double-shell LiMn2 O4 @LiNi0.5 Mn1.5 O4 hollow microspheres thus obtained show a high specific capacity of 120 mA h g(-1) at 1 C rate, and excellent rate capability (90 mAhg(-1) at 10 C) over the range of 3.5-5 V versus Li/Li(+) with a retention of 95 % over 500 cycles.

Ex situ identification of the Cu+ long-range diffusion path of a Cu-based anode for lithium ion batteries.

An ex situ observation was made by XRD patterns, SEM and TEM images, as well as cyclic voltammogram curves of CuO/Cu integrated anodes for lithium ion batteries. For the first time, the existence of a Cu(+) ion long-range transfer path was identified at the potential widow of 1.30-1.60 V during both charging and discharging processes. Both SEM and TEM images show that these nanowires networks hanging CuO nanoparticles provide a Cu(+) diffusion path within our designed CuO/Cu integrated anode. This work provides new insights into the conversion reaction of inorganic anode materials, and can favor the development of high-performance conversion anodes for lithium-ion batteries.

Crystallization of amorphous anodized TiO2 nanotube arrays.

Anodized TiO2 nanotube arrays (TNTAs) prepared by anodization have garnered widespread attention due to their unique structure and properties. In this study, we prepared TNTAs of varying lengths by controlling the anodization time. Among them, the nanotubes anodized for 2 h have an inner diameter of approximately 92 nm and a wall thickness of approximately 12 nm. Then we subjected amorphous TNTAs prepared by the anodization method to annealing treatments, systematically analyzing the evolution of morphology and structure with varying annealing temperatures. As the annealing temperature increases, the amorphous successively undergoes transitions to the anatase phase and then to the rutile phase. During the transition to the anatase phase, the structure of the nanotube array remains intact, with the complete preservation of the tubular array structure. However, during the transition to the rutile phase, the tubular array structure is destroyed. To address why the tubular array remains undamaged during the amorphous-to-anatase transition, we subjected amorphous TNTAs to annealing at 300 °C for different durations. Raman spectroscopy was employed for fit analysis, providing insights into the evolution of the molecular structure during the anatase phase transition. Finally, TNTAs annealed at different temperatures were incorporated into lithium-ion batteries. By combining XRD for semi-quantitative phase content and anatase particle size calculations, we established a correlation between structure and electrochemical performance. The results indicate a significant improvement in electrochemical performance for an amorphous-anatase structure obtained through annealing at 300 °C, providing insights for the design of high-performance energy storage materials.

Facile synthesis of transition-metal oxide nanocrystals embedded in hollow carbon microspheres for high-rate lithium-ion-battery anodes.

Charged up: A general soft-template route for the synthesis of uniform hollow carbon microspheres embedded with transition-metal oxide nanocrystals (OHCMs) has been developed (see figure). The obtained OHCMs possess a microsized spherical shape, embedded transition-metal oxide nanocrystals, and fully encapsulating conductive carbon shells, which endow the resulting anode materials with high specific capacities, rate capabilities, electrode densities, and cycle stabilities.

A chemical reaction controlled mechanochemical route to construction of CuO nanoribbons for high performance lithium-ion batteries.

We reported a chemical reaction controlled mechanochemical route to synthesize mass CuO nanosheets by manual grinding in a mortar and pestle, which does not require any solvent, complex apparatus and techniques. The activation of chemical reactions by milling reactants was thus proved, and the energy from mechanical grinding promotes the fast formation of CuO nanoribbons. The resultant materials have preferential nanoscale ribbon-like morphology that can show large capacity and high cycle performance as lithium-ion battery anodes. After 50 cycles, the discharge capacity of CuO nanoribbon electrodes is 614.0 mA h g(-1), with 93% retention of the reversible capacity. The thermodynamic reactions of the CuO battery showed size-dependent characterization. The microstructures of CuO nanosheets and reaction routes can be controlled by the ratio of NaOH/CuAc2 according to the chemical reactions involved. The intact nanoribbon structure, thin-layer, and hierarchical structures endow present CuO materials with high reversible capacity and excellent cycling performances. The simple, economical, and environmentally friendly mechanochemical route is of great interest in modern synthetic chemistry.

[Frequency correction in terahertz absorption spectroscopy].

Measurement errors in frequency domain always appear when testing samples' terahertz (THz) absorption spectrum using terahertz time-domain spectroscopy (THz-TDS) system, which is supposed to be attributed to the sampling accuracy of the high speed electro-optic sampling system In order to make the measurement have a high accuracy, the method of error correction was studied in the present article. Carbon monoxide in gas phase was employed as our standard sample, and its absorption spectrum at the pressure of 2.0 x 10(5) Pa was measured experimentally. Comparing the obtained absorption frequencies with the corresponding standard data in JPL database, we got the error values, and their distribution law shows that the values have a linear correlation with the standard absorption frequency. Based on this, the error correction model was built. Using the model to correct the experimental data, the result shows the maximum error after correction is reduced to 3.36 GHz, which is two orders of magnitude lower than the error before correction. This states that the model can be used to correct the error of the THz spectrum caused by high speed electro-optic sampling system. At last, the authors draw a conclusion that the THz-TDS system is supposed to be corrected by the terahertz spectrum of carbon monoxide before measurement, in this way, the terahertz spectrum of sample can have a high accuracy. The study contributes to the material identification and the construction of molecular spectroscopy database in THz region.

Polymorphs of Nb2O5 Compound and Their Electrical Energy Storage Applications.

Niobium pentoxide (Nb2O5), as an important dielectric and semiconductor material, has numerous crystal polymorphs, higher chemical stability than water and oxygen, and a higher melt point than most metal oxides. Nb2O5 materials have been extensively studied in electrochemistry, lithium batteries, catalysts, ionic liquid gating, and microelectronics. Nb2O5 polymorphs provide a model system for studying structure-property relationships. For example, the T-Nb2O5 polymorph has two-dimensional layers with very low steric hindrance, allowing for rapid Li-ion migration. With the ever-increasing energy crisis, the excellent electrical properties of Nb2O5 polymorphs have made them a research hotspot for potential applications in lithium-ion batteries (LIBs) and supercapacitors (SCs). The basic properties, crystal structures, synthesis methods, and applications of Nb2O5 polymorphs are reviewed in this article. Future research directions related to this material are also briefly discussed.

Smart Materials Prediction: Applying Machine Learning to Lithium Solid-State Electrolyte.

Traditionally, the discovery of new materials has often depended on scholars' computational and experimental experience. The traditional trial-and-error methods require many resources and computing time. Due to new materials' properties becoming more complex, it is difficult to predict and identify new materials only by general knowledge and experience. Material prediction tools based on machine learning (ML) have been successfully applied to various materials fields; they are beneficial for modeling and accelerating the prediction process for materials that cannot be accurately predicted. However, the obstacles of disciplinary span led to many scholars in materials not having complete knowledge of data-driven materials science methods. This paper provides an overview of the general process of ML applied to materials prediction and uses solid-state electrolytes (SSE) as an example. Recent approaches and specific applications to ML in the materials field and the requirements for building ML models for predicting lithium SSE are reviewed. Finally, some current obstacles to applying ML in materials prediction and prospects are described with the expectation that more materials scholars will be aware of the application of ML in materials prediction.

Omni-functional crystal: Advanced methods to characterize the composition and homogeneity of lithium niobate melts and crystals.

Lithium niobate (LN) is a type of multifunctional dielectric and ferroelectric crystal that is widely used in acoustic, optical, and optoelectronic devices. The performance of pure and doped LN strongly depends on various factors, including its composition, microstructure, defects, domain, and homogeneity. The structure and composition homogeneity can affect both the chemical and physical properties of LN crystals, including their density, Curie temperature, refractive index, and piezoelectric and mechanical properties. In terms of practical demands, both the composition and microstructure characterizations these crystals must range from the nanometer scale up to the millimeter and wafer scales. Therefore, LN crystals require different characterization technologies when verifying their quality for various device applications. Optical, electrical, and acoustic technologies have been developed, including x-ray diffraction, Raman spectroscopy, electron microscopy, and interferometry. To obtain detailed structural information, advanced sub-nanometer technologies are required. For general industrial demands, fast and non-destructive technologies are preferable. This review outlines the advanced methods used to characterize both the composition and homogeneity of LN melts and crystals from the micro- to wafer scale.

Targeting 4-1BB for tumor immunotherapy from bench to bedside.

Immune dysfunction has been proposed as a factor that may contribute to disease progression. Emerging evidence suggests that immunotherapy aims to abolish cancer progression by modulating the balance of the tumor microenvironment. 4-1BB (also known as CD137 and TNFRS9), a member of tumor necrosis factor receptor superfamily, has been validated as an extremely attractive and promising target for immunotherapy due to the upregulated expression in the tumor environment and its involvement in tumor progression. More importantly, 4-1BB-based immunotherapy approaches have manifested powerful antitumor effects in clinical trials targeting 4-1BB alone or in combination with other immune checkpoints. In this review, we will summarize the structure and expression of 4-1BB and its ligand, discuss the role of 4-1BB in the microenvironment and tumor progression, and update the development of drugs targeting 4-1BB. The purpose of the review is to furnish a comprehensive overview of the potential of 4-1BB as an immunotherapeutic target and to discuss recent advances and prospects for 4-1BB in cancer therapy.