Design,preparation,application of advanced array structured materials and their action mechanism analyses for high performance lithium-sulfur batteries

Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.

Research Progress of High Entropy Ceramic Materials

High-entropy materials(HEMs)have better mechanical,thermal,and electrical properties than traditional materials due to their special"high entropy effect".They can also adjust the performance of high entropy ceramics by adjusting the proportion of raw materials,and have broad application prospects in many fields.This article provides a review of the high entropy effect,preparation methods,and main applications of high entropy ceramic materials,especially exploring relevant research on high entropy perovskite ceramics.It is expected to provide reference for the promotion of scientific research and the development of further large-scale applications of high-entropy ceramic materials.

Porous high-entropy rare-earth phosphate(REPO_(4),RE=La,Sm,Eu,Ce,Pr and Gd)ceramics with excellent thermal insulation performance via pore structure tailoring

Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4)(HE(6RE_(1/6))PO_(4))ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents(0–60vol%)on this ceramic properties was systematically investigated.The results show that the porous HE(6RE_(1/6))PO_(4)ceramics with 60vol%starch exhibit the lowest thermal conductivity of 0.061 W·m^(-1)·K^(-1)at room temperature and good pore structure stability with a linear shrinkage of approximately1.67%.Moreover,the effect of large regular spherical pores(>10μm)on its thermal insulation performance was discussed,and an optimal thermal conductivity prediction model was screened.The superior properties of the prepared porous HE(6RE_(1/6))PO_(4)ceramics allow them to be promising insulation materials in the future.

Study on Preparation of Ceramic Material and Its Properties

This paper introduces the classification, properties and application of porous ceramic materials, reviewed preparation of porous ceramics. Taking fly ash and red mud as the main raw material to generate porous ceramics, the paper study the influence of different proportions of raw materials, sintering temperature, porosity of porous ceramic sample rate, bending strength, and microstructure. The results show that, fly ash and red mud proportioning and sintering temperature are the main factors that influence the structure and properties of samples. The4#sample is a kind of high porosity and high strength quality of porous ceramics.

Influence of Inclusion Shape on Thermoelasto-Plastic Optimun Design of Ceramic Metal Functionally Graded Materials

A nonlinear finite element method is applied to observe how inclusion shape influence the thermal response of a ceramic-metal functionally graded material (FGM). The elastic and plastic behaviors of the layers which are two-phase isotropic composites consisting of randomly oriented elastic spheroidal Inclusions and a ductile matrix are predicted by cc mean field method. The prediction results show that inclusion shape has remarkable influence on the overall behavior of the composite. The consequences of the thermal response analysis of the FGM are that the response is dependent on inclusion shape and its composition profile cooperatively and that the plastic behavior of each layer should be taken into account in optimum design of a ceramic-metal FGM.

State of the Art and Prospects in Metal-Organic Framework-Derived Microwave Absorption Materials

Microwave has been widely used in many fields,including communication,medical treatment and military industry;however,the corresponding generated radiations have been novel hazardous sources of pollution threating human’s daily life.Therefore,designing high-performance microwave absorption materials(MAMs)has become an indispensable requirement.Recently,metal-organic frameworks(MOFs)have been considered as one of the most ideal precursor candidates of MAMs because of their tunable structure,high porosity and large specific surface area.Usually,MOF-derived MAMs exhibit excellent electrical conductivity,good magnetism and sufficient defects and interfaces,providing obvious merits in both impedance matching and microwave loss.In this review,the recent research progresses on MOF-derived MAMs were profoundly reviewed,including the categories of MOFs and MOF composites precursors,design principles,preparation methods and the relationship between mechanisms of microwave absorption and microstructures of MAMs.Finally,the current challenges and prospects for future opportunities of MOF-derived MAMs are also discussed.

From concept to commercialization:A review of tubular solid oxide fuel cell technology

The reduced sealing difficulty of tubular solid oxide fuel cells(SOFCs)makes the stacking of tubular cell groups relatively easy,and the thermal stress constraints during stack operation are smaller,which helps the stack to operate stably for a long time.The special design of tubular SOFC structures can completely solve the problem of high-temperature sealing,especially in the design of multiple single-cell series integrated into one tube,where each cell tube is equivalent to a small electric stack,with unique characteristics of high voltage and low current output,which can significantly reduce the ohmic polarization loss of tubular cells.This paper provides an overview of typical tubular SOFC structural designs both domestically and internationally.Based on the geometric structure of tubular SOFCs,they can be divided into bamboo tubes,bamboo flat tubes,single-section tubes,and single-section flat tube structures.Meanwhile,this article provides an overview of commonly used materials and preparation methods for tubular SOFCs,including commonly used materials and preparation methods for support and functional layers,as well as a comparison of commonly used preparation methods for microtubule SOFCs,It introduced the three most important parts of building a fuel cell stack:manifold,current collector,and ceramic adhesive,and also provided a detailed introduction to the power generation systems of different tubular SOFCs,Finally,the development prospects of tubular SOFCs were discussed.

Low-Cost Preparation of Boron Nitride Ceramic Powders

The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composition, structure and surface morphology of the products were investigated through FT-IR, XRD and SEM. The results show that the products ceramize and crystallize gradually with the increase of the temperature. When the molar ratio and reaction temperature are 3：2 and 850 ℃, respectively, the products have high purity, compact structure and nice shape. The oxidation treatment at 450 ℃ will not impair the composition and structure of boron nitride but effectively remove the impurities.

Plastic Deformation of Nano-TiO_2 Ceramics Prepared by Different Methods

The comparative study of the tensile plastic deformation of nano(n)-TiO2 ceramic prepared byphysical gas condensation (P) and chemical hydrolysis precipitation (C) methods was conductedby a gas pressure forming technique at 750~800℃. The results show that n-TiO2 (P) possessesexcellent property of tensile pIastic deformation comparing with n-TiO2(C). The reason for thisis attributed to the surface cleanness and soft agglomeration of n-TiO2 (P) particfe prepared inreIatively cIean vacuum condition.

SnO_(2)nanostructured materials used as gas sensors for the detection of hazardous and flammable gases:A review

SnO_(2)has been extensively used in the detection of various gases.As a gas sensing material,SnO_(2)has excellent physical-chemical properties,high reliability,and short adsorption-desorption time.The application of the traditional SnO_(2)gas sensor is limited due to its higher work-temperature,low gas response,and poor selectivity.Nanomaterials can significantly impact gas-sensitive properties due to the quantum size,surface,and small size effects of nanomaterials.By applying nanotechnology to the preparation of SnO_(2),the SnO_(2)nanomaterial-based sensors could show better performance,which greatly expands the application of SnO_(2)gas sensors.In this review,the preparation method of the SnO_(2)nanostructure,the types of gas detected,and the improvements of SnO_(2)gas-sensing performances via elemental modification are introduced as well as the future development of SnO_(2)is discussed.

Study of Dielectric Constant of (1-x) Zn.xMg.TiO3(ZMT) Ceramic Material at MicrowaveFrequencies as a Function of Composition x andProcessing Temperature

In this paper measurement of real part of permittivity and loss tangent of (1-x) Zn.xMg.TiO3 (ZMT) material in powder form in S-band of microwave frequencies is presented and the associated accuracy estimated. This approach is based on the measurement of transmitted power from the cavity at and off resonance. Details of the design and fabrication of the rectangular cavity and the input and output coupling are given. The variation of dielectric properties of (1-x) Zn.xMg.TiO3 (ZMT) with x-value and calcination temperature (for x = 0.1) is presented. The effect of doping of V2O5 is also studied. The results of present work may provide useful design guidelines for development of microwave compo-nents including dielectric resonator antennas.

The preparation and properties of N-doped carbon materials and their use for sodium storage

Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.

Rapid communication Preparation of TiO_2 nanometer thin films with high photocatalytic activity by reverse micellar method

Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.

Research Progress of Ceramic Metallization Technology

Due to the wide application of ceramics in electronic device packaging,the performance of ceramic metallization layer directly determines the performance of the whole package device.This paper introduces the main preparation methods of ceramic metallization,discusses the influence of Mo powder size,metallization formula,sintering temperature and other factors on the performance of ceramic metallization layer prepared by activated Mo-Mn method,and introduces several kinds of methods that can be tested to test the performance of ceramic metallized sealing samples.A new research direction of Ceramic Metallization Technology in the advanced field is put forward.

MOFs基碳材料对水体中抗生素的吸附去除

近年来,金属有机框架(metal-organic frameworks,MOFs)所衍生的多孔碳材料得益于其优异的孔隙结构和丰富的表面官能团,对水体中的抗生素表现出优异的吸附能力。并且,MOFs基碳材料制备合成方法简单且多样。为提高该类材料的吸附性能,现今研究人员主要研究集中在MOFs前体选择、制备条件优化、微观形貌调控及表面官能团修饰等方面。文中以MOFs基碳材料含有的元素种类及含量为依据,详细列举和分析了通过不同方法制备的MOFs基碳材料,通过模型拟合深入分析其对水体中抗生素吸附过程和机理,讨论影响吸附过程的不同因素,并对制备高性能MOFs基碳材料提出了见解。

Ti_(3)SiC_(2)陶瓷材料制备方法研究进展

作为MAX相家族重要成员,钛硅化碳Ti_(3)SiC_(2)除了具有耐高温、抗氧化性能外,还具有与金属类似的优异导电性、导热性和可加工性,在电接触材料、热交换器构件材料、润滑材料等领域展现出较大的应用潜力,成为当前一种备受关注的新型陶瓷材料。现有的Ti_(3)SiC_(2)制备方法主要有无压烧结、热压烧结、热等静压、放电等离子烧结、前驱体转换陶瓷、反应熔体浸渗法、熔盐法、化学气相沉积、物理气相沉积等。本文首先阐述了Ti_(3)SiC_(2)材料的结构与性能,然后重点综述了国内外Ti_(3)SiC_(2)陶瓷材料的制备方法,最后展望了Ti_(3)SiC_(2)陶瓷材料的应用前景。

单晶高镍三元正极材料的制备及改性研究进展

介绍了单晶高镍三元正极材料的结构特点,总结了单晶高镍三元正极材料常见的制备工艺,并探讨了近年来材料性能改善的主要策略,可为高性能单晶高镍三元正极材料的规模化生产提供借鉴和参考。

磁流变弹性体及其振动控制应用综述

磁流变弹性体是将磁性颗粒(微米级)分散到聚合物弹性体中制备而成的一种磁控智能材料,其不仅拥有颗粒增强复合材料的优异力学特性,还具备迅速、连续且可逆的磁控特性,在智能传感、电磁屏蔽及缓冲减振等领域具有广泛的前景。为了促进磁流变弹性体及其振动控制技术的发展,综述了磁流变弹性体的材料组成,制备方法。总结了磁流变弹性体在振动控制领域的应用现状及对应用前景进行了展望。

绿茶中联苯菊酯和氯氟氰菊酯残留检测质量控制基体标准物质的研制

目的:制备一批绿茶中联苯菊酯和氯氟氰菊酯基体标准物质。方法:以绿茶为研究对象,通过喷洒联苯菊酯和氯氟氰菊酯,样品经粉碎、过筛、均质、装瓶,通过均匀性、稳定性检验后,由3家实验室联合定值确定量值,并进行不确定度评估。结果:绿茶中联苯菊酯和氯氟氰菊酯的量值分别为(0.185±0.0197),(0.207±0.0466)mg/kg,k=2,置信区间为95%。结论:研制出的绿茶中联苯菊酯和氯氟氰菊酯基体标准物质足够均匀,足够稳定,定值结果可靠。

纳米铝热剂的制备及老化研究进展

纳米铝热剂含能材料因其比表面积大、体积能量密度高、高反应速率等特点,在各领域中得到广泛应用。为了使纳米铝热剂组分之间混合均匀以及性能改变,产生了多种形式的制备方法。随着纳米铝热剂的应用多样化,它在长期储存过程中的贮存性能有待进一步观察,防止其在环境或其他应力条件下失效或者意外发火。因此,开展对纳米铝热剂的制备方法以及在存储过程中的老化性能研究非常有必要。本文综述了纳米铝热剂的制备方法和老化研究,并总结了制备方法的优缺点和老化研究的方法、性能评估、机理研究和抑制措施,以期望对纳米铝热剂的应用具有借鉴意义,并在此基础上进一步优化纳米铝热剂的制备方法、老化研究。