The safety aspect of sodium ion batteries for practical applications

Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and cathodes bring about frequent accidents regarding battery fires and explosions and impede the development of high-performance SIBs.Therefore,safety analysis and high-safety battery design have become prerequisites for the development of advanced energy storage systems.The reported reviews that only focus on a specific issue are difficult to provide overall guidance for building high-safety SIBs.To overcome the limitation,this review summarizes the recent research progress from the perspective of key components of SIBs for the first time and evaluates the characteristics of various improvement strategies.By orderly analyzing the root causes of safety problems associated with different components in SIBs(including electrolytes,anodes,and cathodes),corresponding improvement strategies for each component were discussed systematically.In addition,some noteworthy points and perspectives including the chain reaction between security issues and the selection of improvement strategies tailored to different needs have also been proposed.In brief,this review is designed to deepen our understanding of the SIBs safety issues and provide guidance and assistance for designing high-safety SIBs.

Multifunctional applications of gadolinium-doped cerium oxide(Ce_(1-x)Gd_(x)O_(2-■))ceramics:A review

Cerium oxide(CeO_(2)),or ceria,and its doped derivatives have been extensively studied for several decades and are well-known oxides valued for their unique structural properties and wide range of applications.These materials play a crucial role in sustainable development within society.Structural modification through de fect e ngineering of the highly stable cubic fluorite phase enhances the versatility of this doped ceria to a new level.Among the numerous dopants of the CeO_(2)matrix,ceria doped with gadolinium(Gd),known as Ce_(1-x)Gd_(x)O_(2-■)(CGO),is gaining popularity due to its multifunctionality.The introduction of defect-induced vacancies in the oxygen sublattice(V_(o))and a change in the average valence of cerium(Ce^(3+)/Ce^(4+))are primarily responsible for the improved performance compared to pristine CeO_(2).These materials are currently undergoing intensive research for potential use as electrolytes in intermediate-temperature solid oxide fuel cells(IT-SOFCs)and dense oxygen-permeable membranes(OPMs).Additionally,they are being commercially utilized for power generation and oxygen separation.CGO materials are also attracting significant attention in various fields such as optics,photocatalysis,electrostriction,spintronics,gas sensing,electrocatalysis,and biomedical applications.This review paper aims to compile the latest contributions to CGO materials and comprehensively cover their various application areas.The crystal structure,defect equilibrium in Gd^(3+)-doped CeO_(2),the origin of multifunctionality,and the prospects of these materials are also exclusively discussed.

Microstructure,mechanical and wear properties of aluminum borate whisker reinforced aluminum matrix composites

The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker(ABOw)(5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventional powder metallurgy technique. The aluminium powder and the whisker were effectively blended by a semi-powder metallurgy method. The blended powder mixtures were cold compacted and sintered at 600 ℃. The sintered composites were characterized for microstructural features by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and X-ray diffraction(XRD) analysis. Porosity in the composites with variation in ABOw contents was determined. The effect of variation in content of ABOw on mechanical properties, viz. hardness, bending strength and compressive strength of the composites was evaluated. The dry sliding wear behaviour was evaluated at varying sliding distance at constant loads. Maximum flexural strength of 172 MPa and compressive strength of 324 MPa with improved hardness around HV 40.2 are obtained in composite with 10 wt.% ABOw. Further increase in ABOw content deteriorates the properties. A substantial increase in wear resistance is also observed with 10 wt.% ABOw. The excellent combination of mechanical properties of Al-10 wt.%ABOw composites is attributed to good interfacial bonds, less porosity and uniformity in the microstructure.

Structure,Properties and Behavior of Kyanite:Use in Refractory Monolithics

1 Introduction Kyanite is an important naturally occurring in-dustrial mineral and is used in the manufacture of avariety of industrial ceramic products; notable exam-ples include refractories and porcelains. It is a high-pressure polymorph of the aluminosilicates of the ne-sosilicate group, which includes kyanite, sillimanite,and andalusite. These three aluminous or alumina-rich minerals are chemically identical with the compo-sition, Al;SiO;, but have different crystal structuresand physical properties. It is, however, their alumina

Deposition and Characterization of (Ba, Sr)RuO3 Oxide Electrode Using TMHD-Based Single Cocktail Source

(Ba, Sr)RuO3 has been paid an attention as a promising electrode for (Ba, Sr)TiO3 dielectric material due to its similarity in structure and chemical composition with BST. In this study, (Ba, Sr)RuO3 conductive oxide film was deposited on a 4 inch p-type Si wafer by metal organic chemical vapor deposition (MOCVD) using single cocktail source for the practical device application. Ba(TMHD)2, Sr(TMHD)2, Ru(TMHD)3 precursors and solvent [1-EtylePiPerdine (C7H15 N) ] as starting materials were mixed together for single cocktail source. A liquid delivery system (LDS) and a vaporization cell were utilized for the delivery and vaporization of single cocktail source, respectively. The source feeding rate was controlled by a liquid mass flow controller (LMFC). Deposition parameters, such as the oxygen flow and the source flow rate,were sensitive to phase formation, resistivity and the composition ratio of (Ba, Sr)RuO3 films. Highly (110)-textured (Ba,Sr)RuO3 film was obtained vhen the Ar/O2 ratio was 200/140 sccm at a source flow rate of 0.05 sccm. The process window of stoichiometric composition of BSR film was observed with varying the source flow rate from 0.05 sccm to 0.1 sccm.

Properties of Ultra-Thin Hafnium Oxide and Interfacial Layer Deposited by Atomic Layer Deposition

Ultra-thin hafnium-oxide gate dielectric films deposited by atomic layer deposition technique using HfCl4 and H2O precursor on a hydrogen-terminated Si substrate were investigated. X-ray photoelectron spectroscopy indicates that the interface layer is Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. The Hf-silicate interfacial layer partially changes into SiOx after high temperature annealing, resulting in a complex HfO2-silicate-SiOx dielectric structure. Electrical measurements confirms that HfO2 on Si is stable up to 700 ℃ for 30 s under N2 ambient.

Modification of the Surface Properties of Core-Shell Semiconductors and Their Effects on the Photodecolorization Activity and Adsorption

Semiconductor-based photocatalysts have been extensively studied for oxidative photodestruction of organic pollutants in wastewaters, releasing non-toxic substances such as Azo dyes. Various synthesized catalyst specimens were characterized to determine the correlation between preparation conditions (catalyst type, dopant, microstructure, preparation routs, optical and physico-chemical properties) on the photocatalytic activity. Some researchers focused on the process parameters to optimize them to reach higher photoactivity. The specific surface areas, crystalline size, charge and pretreatment of the surface have significant effects on the physical and photocatalytic properties of the semiconductors. The surface sites of catalyst (TiO2) were modified by doping ZnS nanoparticles in the form of Core-Shell structure and the photocatalytic activities were determined by using color degradation and hydrogen production tests. The dye adsorption isotherms of photocatalyst were determined using UV-Vis spectroscopy. The specific surface properties were determined from BET, Zeta meter and Particle size analyzer tests. Photocatalytic decolorization of AR and water splitting test were applied to understand the relation between the surface properties and the photocatalytic activity. The result indicated that core-shell prepared samples had different surface suitable sites to cooperate in photocatalytic reaction.

Influence of Biomimetic Apatite Coating on the Biobehavior of TiO_(2)Scaffolds

Immersion of scaffolds in Simulated Body Fluid(10SBF)is a standardized method for evaluating their bioactivity,simulating in vivo conditions where apatite deposits can be formed on the surface of scaffold,facilitating bone integration and ensuring their suitability for bone implant purposes,ultimately contributing to long-term implant success.The effect of apatite deposition on bioactivity and cell behavior of TiO_(2)scaffolds was studied.Scaffolds were soaked in 10SBF for different durations to form HAP layer on their surface.The results proved the development of a hydroxyapatite film resembling the mineral composition of bone Extracellular Matrix(ECM)on the TiO_(2)scaffolds.The XRD test findings showed the presence of hydroxyapatite layer similar to bone at the depth of 10 nm.A decrease in the specific surface area(18.913 m^(2)g^(−1)),the total pore volume(0.045172 cm^(3)g^(−1)(at p/p0=0.990)),and the mean pore diameter(9.5537 nm),were observed by BET analysis which confirmed the formation of the apatite layer.It was found that titania scaffolds with HAP coating promoted human osteosarcoma bone cell(MG63)cell attachment and growth.It seems that immersing the scaffolds in 10SBF to form HAP coating before utilizing them for bone tissue engineering applications might be a good strategy to promote bioactivity,cell attachment,and implant fixation.

用差热分析测定玻璃析晶过程的核化速率曲线

本方法通过对玻璃试样 DTA 数据的处理,改进了玻璃晶化过程中成核速率随温度变化曲线的测定方法。此法比用光学显微镜,对试样中可见晶粒进行计数的传统方法,更快速而简便。本实验确认,Li_2O·2SiO_2玻璃的成核速率曲线(I-T)和晶体生长速度曲线(U-T)不重叠。该系统的 DTA 曲线中,晶体放热峰的高度δT可看成是试样中晶核数量的大小。实验还证明,在确定成核温度范围和成核速率达最大值的最佳温度方面,峰高δT随温度变化的曲线可以代替成核速率 I 随温度变化的曲线。由固体相变理论推出的结论,证明了本实验方法的可行性。

Nanotopography Impact in Shallow Trench Isolation Chemical Mechanical Polishing-Dependence on Slurry Characteristics

The nanotopography of the surface of silicon wafers has become an important issue in ULSI device manufacturing since it affects the post-chemical mechanical polishing (post-CMP) uniformity of the thickness deviation of dielectric films. In this study, the nanotopography impact was investigated in terms of its dependence on the characteristics of ceriabased slurries, such as the abrasive size, the grain size of the polycrystalline abrasive and the surfactant added to the slurry. It was found that the magnitude of the post-CMP oxide thickness deviation due to nanotopography increased with the surfactant concentration in the case of smaller abrasives but was almost independent of the concentration in the case of larger abrasives. The grain size of the polycrystalline abrasive did not affect the nanotopography impact.

Preparation,crystallization,microstructure and dielectric properties of lead bismuth titanate borosilicate glass ceramics

Various bulk and transparent glasses were prepared by rapid melt quenching technique in the glass system 55[(Pb_(x)Bi_(1-x))TiO_(3)]-44[2Si_(O)2B_(2)O_(3)]-La2O3(x=0-0.7).The X-ray diffraction(XRD)studies of the glass samples confirmed the amorphous nature.The differential thermal analyses(DTA)were carried out from room temperature to 900℃with a heating rate of 10℃/min.The DTA patterns of the samples showed one or more exothermic sharp peaks shifting towards lower temperature side with increasing concentration of bismuth oxide(BiO).On the basis of DTA results,the solid solution of bismuth titanum oxide(Bi_(2)Ti_(2)O_(7))/lead bismuth titanium oxide(Pb3Bi4Ti6O21)was precipitated in borosilicate glassy matrix as a major phase.The glasses were subjected to 4 h and 8 h heat treatment schedules to convert into glass ceramics.XRD analysis of these glass ceramic samples showed that the major crystalline phase of the entire glass ceramic samples with 0≤x≤0.5 is found to have cubic crystal structure,while it is tetragonal for glass ceramic sample with x=0.7.The scanning electron microscopy(SEM)micrographs indicated the uniform distribution of Bi_(2)Ti_(2)O_(7)and Pb3Bi4Ti6O21 crystallites in the glassy matrix.

The prospect and challenges of sodium-ion batteries for low-temperature conditions

In recent years,considerable attention has been focused on the development of sodium-ion batteries(SIBs)because of the natural abundance of raw materials and the possibility of low cost,which can alleviate the concerns of the limited lithium resources and the increasing cost of lithium-ion batteries.With the growing demand for reliable electric energy storage devices,requirements have been proposed to further increase the comprehensive performance of SIBs.Especially,the low-temperature tolerance has become an urgent technical obstacle in the practical application of SIBs,because the low operating temperature will lead to sluggish electrochemical reaction kinetics and unstable interfacial reactions,which will deteriorate the performance and even cause safety issues.On the basis of the charge-storage mechanism of SIBs,optimization of the composition and structure of electrolyte and electrode materials is crucial to building SIBs with high performance at low temperatures.In this review,the recent research progress and challenges were systematically summarized in terms of electrolytes and cathode and anode materials for SIBs operating at low temperatures.The typical full-cell configurations of SIBs at low temperatures were introduced to shed light on the fundamental research and the exploitation of SIBs with high performance for practical applications.

A rapid solid-state synthesis of electrochemically active Chevrel phases （Mo6T8; T = S, Se） for rechargeable magnesium batteries

High energy mechanical milling （HEMM） of a stoichiometric mixture of molybdenum and metal chalcogenides （CuT and MOT2; T = S, Se） followed by heat treatment at elevated temperatures was successfully applied to synthesize Chevrel phases （Cu2Mo6T8; T = S, Se） as positive electrodes for rechargeable magnesium batteries. Differential scanning calorimetry （DSC）, thermogravimetric analyses （TGA）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were used to understand the phase formation following milling and heat treatment. CuS and Mo were observed to react at 714-800 K and formed an intermediate ternary Chevrel phase （Cu1.83Mo3S4）, which further reacted with residual Mo and MoS2 to form the desired Cu2MosSs. Quantitative XRD analysis shows the formation of a -96%-98% Chevrel phase at 30 min following the milling and heat treatment. The electrochemical performance of de-cuprated Mo6S8 and Mo6Ses phases were evaluated by cyclic voltammetry （CV）, galvanostatic cycling, and electrochemical impedance spectroscopy （EIS）. The results of the CV and galvanostatic cycling data showed the expected anodic/cathodic behavior and a stable capacity after the first cycle with the formation of MgxMo6T8 （T = S, Se; 1 ≤ x 〈 2）. EIS at -0.1 V intervals for the Mo6Ss electrode during the first and second cycle shows that partial Mg-ion trapping resulted in an increase in charge transfer resistance Re. In contrast, the interfacial resistance Ri remained constant, and no significant trapping was evident during the galvanostatic cycling of the Mo6,Se8 electrode. Importantly, the ease of preparation, stable capacity, high Coulombic efficient35 and excellent rate capabilities render HEMM a viable route to laboratory-scale production of Chevrel phases for use as positive electrodes for rechargeable magnesium batteries.

Role of MgF2 addition on high energy ball milled kalsilite:Implementation as dental porcelain with low temperature frit

Porcelain fused to metal(PFM)has received great attention over the last few years due to its importance in the dentistry.Kalsilite(K_(2)O·Al_(2)O_(3)·SiO_(2))is a high thermal expansion porcelain,suitable for bonding to metals.However,kalsilite is a metastable phase which gets converted into crystalline leucite upon heating.In the current work feasibility of developing stable kalsilite phase,dispersion of MgF2 in it as an additive and using mechanochemical synthesis are studied.Micro fine dental material has been formulated by mixing prepared kalsilite with low temperature frit(LTF)in different ratio.The crystalline phases evolved in fired powders are characterized by powder X-ray diffraction(XRD)technique.Kalsilite with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion(CTE),flexural strength,apparent porosity(AP),bulk density(BD)and microstructure.Results indicate that MgF_(2) addition and high milling duration help in kalsilite stabilization.Temperature also plays an important role in this stabilization,and at 1100℃single phase kalsilite formation is observed.Present outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.