To meet the requirements of high energy density and fast charge for energy storage systems and electric vehicles, the high-energy and high-power density lithium-ion batteries have attracted numerous attentions.Designing thick-electrode can significantly increase energy density and reduce cost, and is also compatible with various electrode materials, which makes it one of hottest researches for the development of high-energy density lithium-ion batteries.Thick electrodes usually suffer from poor mechanical properties and sluggish reaction kinetics. Therefore, it is very important to construct a thick electrode with good mechanical properties and fast transport network for lithium ion and electron.The electrochemical behavior and key scientific issues of thick electrodes were firstly analyzed in this review, the current strategies for constructing thick electrodes and their advantages were then introduced, and finally the design principles and the development direction of thick electrodes were pointed out.

In recent years, carbon-ceramic matrix composite materials have become a hot topic due to their high temperature resistance, low density, good corrosion resistance, low thermal expansion coefficient, and strong performance design. Biomorphic carbon-ceramic composites have been prepared by introducing the wood-derived pore structure into ceramic matrix.The pore structure, preparation process, properties and application prospects of biomorphic carbon-ceramic matrix composites were reviewed. The importance of designing the microstructure of materials was emphasized, and the key technology in the preparation process of carbon-ceramic matrix composites-infiltration technology were specified, including: chemical vapor infiltration, melt infiltration, sol-gel infiltration, slurry infiltration, polymer precursor infiltration, and molten salt infiltration. The solutions to the existing problems of each technology were proposed. Composite strength and fracture strength of biomass carbon-ceramic matrix composites were reviewed. Suggestions for future research directions on the performance were put forward. It was pointed out that the mechanical properties of materials should be tested under high temperature, strong acid and strong alkali, and alternating cold and heat environments. The potential applications of biomorphic carbon-ceramic matrix composites were discussed in three aspects, including aero-engine blades, automobile exhaust gas purifiers, and catalyst carriers. Existing challenges and practical limitations such as complex molding, strong mechanical properties and thermal stability were outlined. Finally, the improvement of the preparation process and the study of mechanical properties of biomorphic carbon-ceramic matrix composites were prospected, which provides theoretical basis and guidance for the development and application of biomorphic carbon-ceramic matrix composites.

Interface is a key factor affecting the comprehensive performance of magnesium matrix composites, and how to carry out interfacial modulation has been a hot research topic in magnesium matrix composites. Focusing on three types of interface structures of magnesium matrix composites (coherent, semi-coherent and incoherent) and two key issues (interfacial wettability and interfacial reaction) affecting the interface properties, the research progress of interface optimization schemes was reviewed in this paper and the guidelines for the design and regulation of interfacial structures to achieve good interfacial bonding were proposed: good wettability and slight interfacial reaction. In view of the improvement of interface properties of magnesium matrix composites, the addition of rare earth elements can be considered in the future to purify the interface and improve wettability. The matrix and reinforcement are selected according to engineering needs to obtain composite materials with excellent performance in certain aspects. New reinforcement surface coatings will be developed to fully enhance the capabilities of interfacial bonding. First-principles and other computational simulation methods will be used to deeply explore the relationship between interface structure and interface performance.

With the rapid development of the new energy automotive industry, consumers' requirements for the range of electric vehicles have been increasing. The Ni-rich ternary lithium-ion battery has become the most promising power battery in electric vehicles due to its high specific energy, but the battery system still faces the problem of poor performance at low temperature.The research progress on low temperature performance of Ni-rich ternary power battery in recent years was summarized in this review. The influence factors on the low temperature performance of Ni-rich ternary power battery were summarized emphatically. On the one hand, the effects of low temperature performance from thermodynamics were analyzed, including the structural change of the Ni-rich ternary cathode materials and graphite anode materials, electrolytic phase transformation and solvation structure changes, and glass transition of binder. On the other hand, rate controlling step in the low temperature discharge process in the Ni-rich ternary lithium-ion battery was summed up. According to this, main modification measures of low-temperature performance in Ni-rich ternary power battery were summarized. Low temperature electrolyte was designed by optimizing solvents, improving lithium salts and applying new additives. In order to improve the low temperature performance of electrode materials, three methods were mainly employed: substitution, surface modification and smaller material particle size. The remaining shortcomings of the research on low-temperature performance of the battery were summarized, and the research on the low temperature thermodynamic characteristics of batteries is not clear enough. In addition, the research methods for the low temperature kinetic process of batteries are single, and the influence of the reaction sequence in batteries is insufficiently understood.

Additive manufacturing technology as revolutionary manufacturing technology has attracted much attention.This technology transformed traditional processing design and manufacturing concepts and promoted the development of intelligent manufacturing. Intelligent material is a kind of material that has the ability of self-perception, autonomous response, self-healing and adaptation. The combination of intelligent materials and additive manufacturing technology can realize the integrated manufacturing of three-dimensional smart devices with the ability to sense external stimuli or environmental activation. This technology has been widely used in fields such as biomedical devices, flexible electronics, soft robotics, and other fields.Additive manufactured intelligent materials, and the advantages and problems of additive manufactured intelligent materials of metals, polymers, and ceramics were reviewed.As a technical means to realize the organic integration of design, material and structure, additive manufacturing technology will become the key to promote the development of intelligent materials.

MXene has a wide application prospect in energy storage, electromagnetic interference shielding, catalysis, medicine and other fields due to its unique layered structure, high electronic conductivity and rich surface chemical properties.Ti₃C₂T_x, as the earliest discovered MXene material, has the possibility to achieve both high energy density and power density in the field of sodium ion batteries because of its inherent metal conductive characteristics, wide layer spacing and abundant surface functional groups, which is attracted by many researchers. Based on this, the research progress of Ti₃C₂T_x based materials in sodium ion batteries in recent years was reviewed in this paper. Firstly, the structure and electrochemical properties of Ti₃C₂T_x materials with multi-layer and few-layer were summarized by introducing the preparation of Ti₃C₂T_x. Then, combined with the application trend of the study, the influences of layer spacing modification, doping modification and morphology regulation on the sodium storage behavior of the two kinds of Ti₃C₂T_x materials were summarized. The structural design ideas of the two kinds of Ti₃C₂T_x based composites applied to the anode of the sodium ion battery were also analyzed. It was pointed out that the reasonable structural design is vital to the battery performance. Finally, some suggestions for the problems and challenges faced by Ti₃C₂T_x based composites in the field of sodium ion batteries were given.

Resin matrix composites have many advantages such as high specific strength and modulus, good fatigue performance, corrosion resistance, and have become the application and development trend of aero engine components under 400 ℃. Foreign research on resin matrix composites for aero engine started earlier, which have been applied in fan blades, fan casings, outer ducts, nacelles and other components of multi-engine, and developed towards the trend of better structure, higher material performance, lower manufacturing cost and higher automation degree. The development foundation of domestic resin matrix composites is good, but compared with foreign countries the application proportion of resin matrix composites in engines in not high. It is necessary to furthur improve the technical level of design, materials, manufacturing, experiment and engineering ability. In this paper, foreign development status was discussed in the field of structures, materials and processing methods of aero engine composite components, the development trend was analyzed and corresponding suggestions were given, from the aspects of building composites system for aero engine, strengthening application research and design guide, promoting the transformation of pre-research achievements and application of automation technology.

Al-Zn-Mg series aluminum alloys have important applications in aerospace, transportation etc, for their excellent properties of low density and high strength. Further optimizing the microstructure to obtain higher mechanical properties and better corrosion resistance is the development direction of Al-Zn-Mg alloys. Microalloying has become an important means of improving the properties of aluminum alloys, owing to the limited space for alloy composition optimization and heat treatment processes improvement. The effects of microalloying elements on the mechanical properties, hot deformation behavior and corrosion resistance of Al-Zn-Mg alloys were briefly summarized, focusing on the different effects of the second phase particles formed by microalloying elements in different process stages, such as effectively refine grains and strongly hinder the movement of dislocations. The effects of pin grain boundaries, sub-grain boundaries and inhibiting recrystallization during hot deformation were discussed. The internal mechanism of improving the corrosion resistance of the alloy was explained. In addition, the further research direction of microalloying of Al-Zn-Mg aluminum alloy was prospected, understanding the interaction mechanism of microalloying elements and dual alloying-microalloying elements to realize the precise and accurate addition of microalloying elements will be one of the main research contents in the future. Clarifying the regulation effect of microalloying elements on deformation structures and dislocation configurations during hot working will provide a reference for improving the corrosion resistance of alloys.

Hypersonic flight technology is an important direction in the development of aerospace field and plays an important role in national defense security. The thermal protection materials and structures are the key to the safe service of hypersonic vehicles in extreme environments. On one hand, the thermal protection materials and structures must be able to withstand the harsh aerodynamic thermal environment, and on the other hand, they also must reduce its mass to increase the vehicle payload. Therefore, it is necessary to develop thermal protection structures that can combine high temperature resistance, light weight, and load-bearing characteristics at the same time. The manufacturing methods of lightweight C/SiC ceramic matrix composite structures were firstly introduced in this review, then the research on the room temperature and high temperature mechanical behavior, heat transfer mechanism and behavior of the lightweight C/SiC ceramic matrix composite structures were summarized. At last, integrated thermal protection structures with high temperature resistance and lightweight load-bearing were reviewed based on the lightweight C/SiC ceramic matrix composite structures. Finally, the future challenges of the lightweight ceramic matrix composite structures towards thermal protection application were also forecasted in four aspects: new design theory and method, new manufacturing technology, service characteristics and multi-functional integrated design and realization. This review provides some guidance for the research and development of novel thermal protection structures for the next generation hypersonic flight.

The formation mechanisms of the precursor film (PF) at high temperature were reviewed, i.e., surface diffusion mechanism, evaporation-condensation mechanism, subcutaneous infiltration mechanism, and rapid absorption then film overflow mechanism. In the experimental metallic systems, the most possible mechanism is the subcutaneous infiltration mechanism, which is related to the apparent contact angle, contact radius, height of gap between the substrate metal and oxide film. In the metal/ceramic system, the formation of precursor film is usually rapid absorption then film overflow mechanism. The appearance of PF for adsorption mechanism needs to meet the contradiction of relative inertia and high affinity at the liquid/solid interface. Meanwhile, another possible mechanism of precursor film in high temperature reactive wetting system, namely film transport mechanism, is introduced. It was pointed out that the difficulty of studying precursor film lies in the unpredictability and instability of precursor film, and its development direction should be systematic, and the corresponding theoretical model should be established.

The additive friction stir deposition (AFSD) technology is a new solid-state additive manufacturing technology. The metal bars, powders, and wires are used as feedstock. During the additive process, the friction heat generated by the friction between feedstock and the plate and the plastic deformation heat generated by the severe deformation of feedstock form a viscoplastic deposition layer. The deposition layer is stacked layer by layer to form three-dimensional parts. Because of its solid phase characteristics, it has many advantages over fused-based metal additive technologies and has become a research hotspot in the field of additive manufacturing. In this paper, the latest research progress of AFSD technology at home and abroad was reviewed from four aspects of equipment development, microstructure evolution, material flow characteristics and mechanical properties change. The feasibility of the application of this technology in engineering practice was analyzed and the application prospect in the field of metal coating reinforcement for material repair parts of additive manufacturing was forecasted. Finally, it was pointed out that the heat generation mechanism, material flow characteristics, auxiliary optimization process, and intelligent equipment development are the future research directions.

High-strength aluminum alloys (2××× and 7×××, etc.) are widely used in aerospace, automobile and other fields because of their high specific strength and good machinability. With the development of high thrust-weight ratio engine and automobile lightweight technology, the demand for lightweight structural materials is increasing. Meanwhile, parts also present the "thin-walled, hollow and composite" tendency gradually, and the traditional processing methods of high-strength aluminum alloy are increasingly difficult to meet the requirements. As a common metal additive manufacturing (AM) technology, selective laser melting (SLM) is a great potential manufacturing technology for complex parts. SLM is expected to become an emerging technology to expand the application of high-strength aluminum alloys. However, due to their poor casting and welding properties, high-strength aluminum alloys easily produce the periodic hot cracks and coarse columnar grains during SLM, leading to unsatisfactory mechanical properties. Grain refinement is the key to overcome the inherent hot-tearing crack of SLMed high-strength aluminum alloys. The research progress in microstructure and mechanical property control of SLMed high-strength aluminum alloys in recent years was reviewed. The mechanical properties of alloys with different compositions were summarized. Importantly, the main strategies to suppress hot-crack formation in SLMed high-strength aluminum alloys were highlighted, including optimization of SLM process parameters and grain refinement by microalloying or addition of nanoparticles. It was pointed out that the main issue of SLMed high-strength aluminum alloys was the change of alloy composition on the comprehensive properties and heat treatment process was still unclear. The development trends were forecasted, such as designing new high-strength aluminum alloys and evaluating their comprehensive performances, using post-treatment process and other means to further improve the comprehensive performances of the alloys, and designing special grain refiners for SLM and investigating refinement mechanism.

Collagen, sodium alginate and hyaluronic acid are natural-derived polymer materials with good cell compatibility and bio-safety, which are widely used in cell culture, tissue engineering and drug delivery, and so on. Pure collagen has poor mechanical properties. When preparing collagen and sodium alginate to form a composite hydrogel material, the mechanical properties and porosity of the hydrogel scaffold can be improved by adjusting the degree of cross-linking of sodium alginate and Ca²⁺ mimicking extracellular matrix. The Young's modulus and the sol-gel transition temperature of the hydrogel were characterized by PIUMA nanoindenter and DHR rheometer in this study. Microscopic images of endothelial cells expressing red fluorescent proteins and mesenchymal stem cell expressing green fluorescent proteins were captured with Olympus fluorescence microscope after cell cultured for 0 day, 3 days, 5 days and 7 days in hybrid hydrogel microenvironment, and the images of endothelial cell spheroid growth diffusion after cell cultured for 1 day, 6 days and 9 days. The results show that the hybrid hydrogel is cytocompatible. The Young's modulus of the hydrogel is (600±81) Pa and its sol-gel transition temperature is 23.2℃. In conclusion, type Ⅰ collagen/sodium alginate/hyaluronic acid hydrogel has good cytocompatibility for endothelial cells and mesenchymal stem cells, and can be used as an ideal scaffold material for cell 3D culture. The Young's modulus and sol-gel transition temperature of the hydrogel have no damage to cell viability, which can be used as an in vitro model for studying angiogenesis and has important application prospects in vascular tissue engin-eering.

High-entropy alloys have attracted great attention in various fields due to their high-entropy effect, severe lattice distortion, slow diffusion and special and excellent material performance due to the combination of various alloying elements in equal or near-equal molar proportions. Its high strength and hardness, fatigue resistance, excellent corrosion resistance, radiation resistance, near-zero thermal expansion coefficient, catalytic response, thermoelectric response and photoelectric conversion make high-entropy alloys have potential applications in many aspects. High-throughput computation and machine learning technology have rapidly become powerful tools to explore the huge composition space of high-entropy alloys and comprehensively predict material properties. The basic concepts of high-throughput computing and machine learning were introduced in this paper as well as the advantages of first-principles calculation, thermodynamic/kinetic calculation and machine learning in the research of high-entropy alloys. The application research status of high-entropy alloy composition screening, phase and microstructure calculations and performance prediction were summarized. In the final part, the existing problems, and the solutions and future prospects of this field were summarized, including developing tools for first-principles calculations and machine learning of high-entropy alloys, building high-quality databases for high-entropy alloys and integrating high-throughput computing with machine learning to globally optimize the mechanical property and service performance of high-entropy alloys.

SiC ceramics has been extensively used in heat exchangers because of their excellent mechanical properties, high thermal conductivity, and superior thermal shock, corrosion, and oxidation resistance. However, there is a wide variation in the thermal conductivity of SiC ceramics, depending on the raw materials, molding process, sintering process, and sintering additives. The thermal conductivity of SiC ceramics (≤ 270 W·m^-1·K^-1) is much lower than that of 6H-SiC single crystals (490 W·m^-1·K^-1) because of pores, grain boundaries, impurities, and defects in SiC ceramics. In this work, the important factors affecting the thermal conductivity of SiC ceramics were analyzed, including temperature, pore, crystal structure, and second phase. Further, the preparation processes of high conductivity SiC ceramics were systematically compared based on hot-pressed sintering, spark plasma sintering, pressureless sintering, recrystallization sintering, and reaction sintering. The improvement measures of thermal conductivity of SiC ceramics were summarized, including the optimization of the type and content of sintering aids, high-temperature annealing, and adding a high-thermal-conductivity second phase. Finally, the prospects and research directions of low-cost and high-thermal-conductivity SiC ceramics are proposed.

The flexible wearable pressure sensor has unique properties such as high comfort, strong braid ability and the ability to imitate human skin to sensitively perceive and respond to external stimuli. It can be used as the artificial electronic skin which will be widely applied in medical detections, disease diagnosis, human motion tracking and health monitoring, etc. In recent years, the design, construction, performance exploration and development of flexible wearable pressure sensors have attracted extensive attention from researchers. The nanofibrous membranes prepared by electrospinning have the advantages of high porosity, large specific surface area and easy to be functionalized, which make them have extensive applications in the field of flexible sensors. The research and progress of electrospun nanofibers in flexible wearable pressure sensors were reviewed in this paper. The major characteristics of the wearable pressure sensors were briefly introduced, and the advantages of electrospinning technology and electrospinning nanofibers in the preparation of flexible wearable pressure sensors were described. The types and applications of the flexible wearable pressure sensors based on electrospinning in different fields were emphatically discussed. Finally, the low-cost manufacture of flexible wearable pressure sensors with high resolution, high sensitivity and accurate response was briefly summarized and prospected.

Fuel cell, which directly enables the generation of electricity from the conversion of the fuel through an electrochemical reaction at the electrode and electrolyte interface, without going through the heat engine process, is an incredibly powerful renewable energy technology. The electrochemical reaction in fuel cell is not restricted by the Carnot cycle, so it has high energy conversion efficiency. Proton exchange membrane fuel cell (PEMFC), in particular, has been regarded as the most promising candidate for transportations, portable equipment and fixed devices.However, there are still some problems in PEMFC, including high cost, insufficient power and poor stability, which limit the large-scale commercial application of PEMFC. The basic reason behind these problems lies in the key materials, such as cathode catalyst, gas diffusion layer, proton exchange membrane and bipolar plate in fuel cell, which can not meet the requirements of PEMFC commercialization owing to their high cost and low performance. Therefore, in order to achieve large-scale application of PEMFC, advanced cathode catalysts, gas diffusion layers, proton exchange membranes and bipolar plates are needed. For the requirement of low-cost and high-performance advanced materials for PEMFC, the research status of these key materials and main challenges in their practical application were summarized in the review, and the future development direction was pointed out: developing the technology of large-scale preparation of platinum alloy and metal-nitrogen-carbon (M-N-C) compound catalysts, preparation of proton exchange membranes with high proton conductivity and excellent mechanical property, studying the influence of modified gas diffusion layer on PEMFC performance under different working conditions, developing coatings or new metal materials with excellent corrosion resistance and electrical conductivity for bipolar plates.

Nanofluidics is the study on the behavior of fluid flow in a nanoscale-confined channel with at least one characteristic dimension smaller than 100 nm. Nanofluidics can exhibit unique physical phenomena such as ultrafast water transport, surface charges control ion transport that cannot be observed at microscales or in bulk structures. A significant growth of attention in nanofluidics was achieved due to the representative phenomena and effects, which make them potentially useful in osmosis energy generation, nanofluidic diodes or transistors, desalination, biology, and other applications. In the past few years, the fabricating nanofluidic channels is burgeoning throughout the globe and can be widely used for energy conversion due to the rapid advancement of micro- and nanotechnology. This review mainly focused on the research progress of the nanofabrication methods of nanofluidic channels, including nanolithography, microelectromechanical system(MEMS) based techniques, nanofluidic channels based on nanomaterials, and other natural nanofluidic materials. The preparation methods including electron beam lithography, focused ion beam lithography, scanning probe lithography, extreme ultraviolet lithography, interference lithography, and sacrificial layer releasing were discussed in detail. The advantages and disadvantages of each nanofabrication method were pointed out. Following that, the recent application progress of nanofluidics from five aspects was summarized: in salt differenatial energy conversion, responsive ionic gate, sensors of ion detection, sensing of single molecules, and water desalination. Finally, the current challenges were discussed, and the fantastic opportunities and perspectives in the fabrication of nanofluidic channels were prospected, such as high cost, reliability and stability need to beimproved, etc.

Continuous fiber reinforced and toughened ceramic matrix composites (CMCs) are key thermal structural materials in aerospace and other fields. Mechanical connectivity, as one of the most reliable connectivity methods, is an essential method to achieve connectivity of large and complex CMCs components. At present, research on CMCs joints is rapidly developing, but there is few comprehensive review literature on CMCs joints. Based on the research work in the field of CMCs joints in recent years, the preparation and mechanical property characterization methods of CMCs fasteners were summarized in this paper, the damage and failure mechanism of CMCs fasteners were systematically stored and discussed, and focusing on the influencing factors and laws of mechanical properties of CMCs fasteners from the perspective of material properties and external environment. The research work on CMCs mechanical joints was presented, and the damage law, failure mechanism, finite element simulation and reliability of CMCs connectors were prospected.

Advanced oxidation process based on sulfate radical (SO₄^-·) is recognized as one of the effective methods to degrade organic wastewater. In recent years, as an economical and readily available carbon containing material, biochar has been gradually applied in the advanced oxidation field. Biochar and its composite activated persulfate have become a promising system for organic pollutants degradation. The latest research progress of different typical biochar-based catalysts for persulfate activation was analyzed, including pristine biochar, transition metal loaded biochar, non-metallic doping biochar, and metallic and non-metallic co-doping biochar. In addition, the synthesis methods and physicochemical properties were summarized. Furthermore, the activation performance and mechanism of biochar-based catalysts for persulfate and the degradation mechanism of organic pollutants were discussed, respectively. Finally, based on the current research progress, from the perspectives of different biomass sources, metallic and non-metallic co-modified biochar technology and the dynamic change of ecotoxicity in the degradation process, relevant discussions and future suggestions for biochar and its composites were put forward in terms of degradation mechanism exploration, potential catalyst development and practical catalytic system application.

Recently, with the development of research techniques, researchers have discovered numerous new phenomena in nanowires with potential applications. Clearly depicting the structure-activity relationship between nanowire structure and mechanical properties has important guiding significance for the design, service and performance optimization of nanodevices. Firstly, several typical in-situ testing methods of mechanical properties of nanowires were summarized. Secondly, the mechanical properties such as elasticity and strength of various nanowires in tensile tests were introduced. The size-dependent plastic deformation of nanowires was described. In addition, the unique mechanical behavior of nanomaterials in the in-situ tests was discussed. In the future, it is necessary to systematically study the effect of electron beam irradiation on the deformation behavior of nanowires during in situ electron microscopy characterization and to investigate the mechanical properties exhibited by nanowires under complex external field environments. Thus, a complete set of theoretical guidance systems can be established, which is an important development direction in the field of in situ characterization of nanomaterial properties.

Thermoplastic polyether ether ketone (PEEK) composites are widely used in aerospace field due to their excellent fracture toughness, impact resistance and material versatility. Sizing agent as the core auxiliary product of carbon fiber has an important impact on the interface of composites. Limited by the decomposition temperature, the traditional thermosetting sizing agents are difficult to meet the use of PEEK composites, which restricts the development and application of high-performance PEEK composites. Therefore, it is of great significance to develop a matching carbon fiber sizing agent for PEEK composites. In this paper, the interfacial properties of composites and the action mechanism of sizing agent were analyzed and introduced; the research progress and results of modified PEEK, polyimide precursor and polyetherimide sizing agents were focused, and different systems of sizing agents were analyzed and summarized.Finally, the relevant suggestions on carbon fiber sizing agents for PEEK composites were put forward while the environmental and multi-function developments for sizing agents were prospected.

Pure copper/copper alloy has excellent thermal and electrical conductivity, which is an important industrial material. Laser powder bed fusion, which represents the laser additive manufacturing technology, has excellent design freedom and forming accuracy, and is the mainstream development direction of additive manufacturing. Compared with traditional processing and manufacturing technology, the laser powder bed fusion of pure copper/copper alloy can give better play to the excellent performance of copper, and has broad application prospects in the fields of high thermal conductivity/electrical conductivity such as electrical and electronic, automotive, aerospace and other fields. The current research status of laser powder bed fusion of laser high-reflective materials represented by pure copper/copper alloys, the important problems they face, and the analysis of corresponding solutions were reviewed in this paper. On this basis, combined with the team's experience in the laser powder bed fusion process of pure copper/copper alloy, it was pointed out that the use of blue, green and other short-wavelength lasers for the powder bed laser fusion of pure copper/copper alloy and other highly reflective materials is a future study hot spots and development directions.

The electrically conductive silicon carbide (SiC) ceramics that can be machined by electrical discharge machining, can not only overcome the highlight shortcomings of traditional high resistivity-grade SiC ceramics in machinability, but also maintain its other excellent properties. It has outstanding advantages to replace traditional high resistivity-grade SiC ceramics in the field of structural ceramics. In this paper, the nitrogen doping principle of electrically conductive SiC ceramics was illustrated, and then the powder sintering methods, sintering additives, thermoelectric and mechanical properties were summarized. Meanwhile, in order to provide guidance for the control of electrical properties, the electrical properties-related factors were discussed. In the end, the main challenges of nitrogen-doped electrically conductive SiC ceramics were pointed out, and the future interests were suggested to focus on the development of new sintering technology and additive, as well as clarifying the control mechanism of electrical properties, thereby establishing the technical foundation for fabrication of high-performance conductive SiC ceramics with controllable electrical resistivity.

Two-dimensional Ce-MOFs nanosheets were successfully constructed by using ceric ammonium nitrate as metal salt and 1, 3, 5-tris(4-carboxyphenyl)benzene (H₃BTB) as organic ligand, together with the use of acetic acid as modulator.Acetic acid modulator shows significant effects on the morphology and crystallinity of Ce-MOFs. Ce-MOFs microspheres synthesized without acetic acid as modulator (named Ce-BTB-H₀) are composed of highly cross-linked small nanosheets with low crystallinity and surface areas. On the contrary, Ce-MOFs synthesized with acetic acid (named Ce-BTB-H₆₀) consist of dispersed nanosheets, and show improved crystallinity and higher surface areas than that of Ce-BTB-H₀. Using blue LED as light source and oxygen as oxidant, two-dimensional Ce-MOFs nanosheets enable decarboxylation oxygenation of a variety of substituted phenylacetic acid to their corresponding benzaldehydes and benzyl alcoholsunder irradiation of blue LED in oxygen atmosphere at room temperature.Moreover, Ce-BTB-H₆₀nanosheets show better photocatalytic performance due to their higher crystallinity, larger specific surface area and improved dispersity than that of Ce-BTB-H₀.

Solid state lithium battery is expected to be one of the next generation of battery systems with high energy density in the field of high energy. Based on the constructure characteristics and related formation mechanism of interface between solid polymer electrolyte and lithium anode, the impact of interface contact, interface chemistry and electrochemical reaction, and moreover, the growing process of lithium dendrite and other problems on the interface stability and compatibility were systematically discussed in this review.Thus, the application of doping modification, structure design, and other methods for the interfaces between polymer matrix and lithium anode were also emphasized. In addition, the common interface characterization methods and their applications on the interface between solid polymer electrolyte and lithium anode were also reviewed. Finally, based on the relevant strategies of designing and constructing a stable polymer solid electrolyte-lithium anode interface, the development prospects of interface optimization methods such as doping and core layer design were analyzed and prospected in this paper.

PEO-based solid polymer electrolytes are considered as a promising solid electrolyte in the field of solid-state lithium batteries.PEO/LiClO₄ solid polymer electrolyte(SPE) was prepared through electrostatic spinning technology, in order to meet the demand of industrial production. The effects of spinning voltage, spinning solution concentration and lithium salt content on the morphology and diameter of the fiber were studied.The morphology of SPE fiber was observed by scanning electron microscope and the diameter of SPE fiber was analysed by Image J.Furthermore, the composition, structure and properties of solid polymer electrolyte fiber membranes prepared by electrospinning were studied by DSC, XRD, FTIR-ATR and tensile testing.The results show that the PEO/LiClO₄ solid polymer electrolyte membrane prepared by electrostatic spinning method has good fiber morphology, when the spinning voltage is 15 kV, and the concentration of PEO/LiClO₄ spinning solution is 6%, and the molar ratio ([EO]: [Li⁺]) is 10:1.Meanwhile, the average diameter of the fibers is 557 nm, giving relatively uniform distribution.When[EO]: [Li⁺]=10:1, the melting point of PEO in the SPE fiber membrane is only 53.8℃, with the crystallinity as low as 18.9%. And the ionic conductivity of the prepared SPE exhibits as high as 5.16×10^-5 S·cm^-1 at 30℃.Moreover, the prepared electrospun SPE has good electrochemical stability and interfacial stability.

As one of the most common transition metal oxides, manganese oxides have many advantages and show great potential in many fields. Its catalytic activity, adsorption capacity, stability, and other properties of manganese oxides can be adjusted by changing its crystal, morphology, pore structure and oxygen vacancies. To improve the MnO_X activity performance, various preparation methods have been developed to adjust its crystal structure and morphology structure. In this work, the relationship between the structure of different crystalline manganese dioxides (α, β, γ, δ, λ) and their catalytic activity/adsorption performance activity was studied. The preparation methods on the morphologies structure (nanorods, nanosheets, nanoflowers, nanospheres) of MnO_X materials were comprehensively summarized. Then, the typical application performance of manganese oxides materials in the energy file (catalytic conversion of biomass, electrochemistry) and environment (decomposition of gas pollutants, adsorption of heavy metals, degradation of organic pollutants) were summarized. Finally, the problems such as complicated action mechanism and poor stability of MnO_X were analyzed.MnO_X still has great application potential in the fields of environment and energy in the future.

Cobalt (Co) based oxygen reduction catalysts have become one of the important choices to replace platinum based oxygen reduction catalysts because of their low price, high reserves and easy availability. ECP600 JD was pretreated with nitric acid, mixed with cobalt acetate tetrahydrate, and then pyrolyzed at 800 ℃ in ammonia atmosphere to prepare Co-N/C oxygen reduction catalyst. The infrared spectrum test, alkali neutralization titration and specific surface area measurement show that the number of oxygen-containing functional groups on the surface of ECP600 JD increases, the pore size of ECP600 JD remains unchanged, but the proportion of mesopores increases after nitric acid acidification pretreatment. XRD and TEM tests show that Co_5.47N is formed from ECP600 JD and cobalt acetate tetrahydrate after ammonia heat treatment, the Co-N/C catalyst is dispersed evenly without agglomeration. Electrochemical tests show that after pretreatment, the electrocatalytic performance of the prepared Co-N/C catalyst for oxygen reduction reaction (ORR) is better. Under alkaline conditions, the current density reaches 4.2 times that before pretreatment, and belongs to four electron transfer in catalytic kinetics.

Porous tantalum metal has good biocompatibility and osteoconductivity, with a lower modulus of elasticity and a higher coefficient of friction to avoid stress-shielding compared with traditional implant metal materials. In addition, its porous structure, similar to that of human cancellous bone. Porous tantalum has received increasing attention in recent years due to its advantages in mechanical properties and excellent biological properties, and has been developed and applied in the treatment of various bone defects. With the progress of the preparation methods of porous tantalum materials and the proposal of various modification methods, the prosperity of porous tantalum in clinical applications has been further demonstrated. In this paper, the application of porous tantalum implant in bone defects treatment was reviewed, considering its preparation technology, cytotoxicity, osseointegration properties, and current clinical applications. Furthermore, the developments of porous tantalum including surface modification for establishing composite systems, optimization of preparation processes and personalized preparation techniques are expected to facilitate the clinical application of porous tantalum implants in the treatment of bone defects.

The nano-SiC/AlSi7Mg mixed powder was prepared by mechanical mixing method. The specimens of nano-SiC particle reinforced AlSi7Mg composite were fabricated by selective laser melting (SLM). The relative density, phase and microstructure were observed and analyzed, and the microhardness and tensile properties were tested. The results show that the relative densities of SLM nano-SiC/AlSi7Mg composite are increased firstly and then decreased with the increase of scanning speed and scanning space, and the maximum relative density reaches 99.75%. The microstructure of specimens is similar to that of SLM-formed Al-Si alloys, and the network-structured Si phase is uniformly embedded in the α-Al matrix. There are nano-SiC agglomerates and Mg₂Si phase in the α-Al matrix, which has a similar distribution to Si. Compared with AlSi7Mg, the microstructure of specimens is changed from columnar to equiaxed grain, and the grains are significantly refined (the average grain size is 1.36 μm). Due to the addition of SiC, grain refinement strengthening and solid solution strengthening are produced, and the hardness and strength of composite are significantly improved. The hardness, tensile strength and yield strength reach 137.3HV, 448.3 MPa and 334.7 MPa, respectively. However, the elongation is reduced to 3.9%, and the fracture mode is mainly brittle fracture.

AlSi10Mg alloy has excellent characteristics such as high specific strength and good wear resistance. The composition of AlSi10Mg alloy is close to the eutectic point, thus it has good forming property and has been widely used in selective laser melting processing. However, for this moment, only the conventional annealing strategy is employed in the selective laser melted AlSi10Mg component, which greatly limits their further applications. In this work, the effects of several annealing on the microstructure and tensile properties of selective laser melted AlSi10Mg alloys were investigated. The results show that the as-fabricated sample presents a mixed structure of columnar α-Al and eutectic Al-Si structure along building direction, which possesses a strong texture of α-Al 〈100〉. The single molten pool consists of fine grain region, coarse grain region and heat affected region. The as-fabricated sample shows ultimate strength of 389.5 MPa with 4% elongation to failure. During the heat treatment, the eutectic Si is broken and spheroidized along with precipitation of supersaturated Al(Si). When the annealing temperature increases from 200 ℃ to 500 ℃, the silicon particle suffers the Ostwald ripening for size increase of 23 times. The samples heat treated at 300 ℃ and 500 ℃ show the ultimate strength of 287.0 MPa and 268.0 MPa, and elongation of 10.3% and 17.2%, respectively.

Metal foam composite is a kind of lightweight composite with low density, high strength, high shielding performance, high damping performance and other characteristics. It has a wide range of application prospects in aerospace, drilling trap floats, artificial bone and other fields, which has attracted people's attention. In this paper, based on the research of the existing literature, the fabrication methods of metal foam composites were introduced, the effect of microstructure on the properties of metal foam composites was analyzed, the progress of mechanical properties, damping properties, shielding properties and heat insulation and their mechanisms of metal foam composites and their applications in relevant fields were reviewed, which provides a theoretical basis for the development of metal foam composites in the future, and the new fabrication technology, modeling research, sandwich structure of metal foam composites and the fabrication of high performance foam hollow sphere composite were also prospected.

With graphite oxide (GO) as the main raw material, combining with carboxymethyl cellulose (CMC), hydrothermal reduction combined ice template method was used to prepare graphene/carboxymethyl cellulose composite aerogel (HGA/CMC), through drying under the environmental pressure and hydrophobic modification. The HGA/CMC was characterized through SEM, FT-IR, XPS and microcomputer controlled electronic universal testing machine, which proves the successful combination between GO and CMC and the effective hydrophobic modification. HGA/CMC can absorb pure oil because of its abundant pore structure, the adsorption capacity of oil is 70.28-172.78 g·g^-1, and the higher the oil density is, the greater the oil mass can be adsorbed by aerogel per unit mass. Furthermore, HGA/CMC shows good selective adsorption capacity for floating oil on water, heavy oil on water bottom and emulsified oil in water. HGA/CMC can be recycled by mechanical extrusion, and its adsorption capacity loss is only 15% after 10 times of extrusion regeneration. It is an oily wastewater treatment material with application potential.

Titanium and its alloys are promising biomedical metallic materials due to their high specific strength, low Young's modulus, nonmagnetic, excellent biocompatibility and corrosion resistance. A new generation of metastable β-type Ti alloys with non-toxic Nb, Mo, Ta, Zr and Sn alloying elements and low Young's modulus has become the key research direction of Ti alloys for biomedical applications. The basic characteristics and development history of biomedical titanium alloys were reviewed. Taking Ti-Nb based biomedical titanium alloys as an example, the composition design method, alloying principle, research status and preparation technology of new metastable β-type biomedical titanium alloys were introduced. Finally, it was pointed out that the further reduction of elastic modulus and improving the comprehensive properties including strength, fatigue performance, and functional properties are the key development directions of β-type Ti alloys for biomedical applications. In the future, in-depth research should be placed on the interaction mechanism of alloying elements, chemical composition design approach, microstructure and mechanical properties regulation methods, as well as micromechanical mechanisms.

In response to the China's target of carbon peaking before 2030 and carbon neutralization before 2060, the steam parameters like steam temperature and pressure of thermal power generation need to be further increased to improve its thermal efficiency and reduce carbon emissions, which challenges the safety operation of thermal power plant. It is an important factor that the synergistic effect of high-temperature fireside corrosion and stress leads to the failure of alloys used for boiler, which is quite distinctive from the conventional stress corrosion cracking (SCC) since promising materials such as Ni-based superalloys are not sensitive to SCC tendency under the service condition of fireside corrosion coupled stress. Unfortunately, those impacts are often studied independently. The fireside corrosion mechanism and the stress failure of alloys were summarized in this paper, and the influential factors were pointed out from the materials (metal types, alloy elements and metal surface state) and the environments (temperature, corrosion atmosphere and coal-ash composition) that affect the corrosion performance of alloys. Furthermore, the failure mechanism of alloys from the perspective of the interaction between corrosion and stress was reviewed. On the one hand, the corrosion products deteriorate the creep rupture life of materials; additionally, the defects caused by stress will change the corrosion process of materials. Therefore, this paper focuses on the influence of the synergistic effect of high-temperature fireside corrosion and stress on the material performance, which is indicative for the design and performance of candidate materials for boiler environment of thermal power plants. As an example, the failure of Super304H under the fireside corrosion, creep and the synergism of fireside corrosion and stress were discussed. Finally, the prospect of future investigations on the interaction of fireside corrosion and stress was put forward, including the interaction between fireside corrosion and stress and the failure mechanism of materials under the synergistic effect.

The hygrothermal aging of T800 carbon fiber/epoxy resin composites in seawater environment were studied. The prepared specimens were immersed in artificial seawater 70 ℃, 3.5% NaCl solution for 30, 60 and 90 days for corrosion. The mechanical properties of the materials were analyzed by mass change, surface morphology before and after aging, infrared spectroscopy, dynamic mechanical properties, compression test and interlayer shear test. The results show that the moisture absorption rate of T800 carbon fiber/epoxy resin matrix composites in 3.5% NaCl solution is 0.39%, 0.47%, 0.53%. Good adhesion between unaging sample fiber and matrix, and the damage of the interface between the fiber and the matrix become more serious with the increase of time after aging in 3.5% NaCl solution. The glass transition temperature(T_g) is decreased from 189.16 ℃ to 177.54, 171.88 ℃ and 168.06 ℃ after 30, 60 and 90 days aging. After aging with 3.5%NaCl solution, the maximum compressive failure load of specimens for 30, 60 and 90 days is decreased by 3.2%, 8.4% and 15.3%, respectively, and the compressive strength is decreased by 3.0%, 8.2% and 15.9%, respectively. The maximum interlaminar shear failure load is reduced by 3.0%, 9.2% and 14.9%, and the shear strength is reduced by 3.0%, 9.7% and 16.4%, respectively.

As the core of electric energy conversion, power devices have been developed rapidly in new electronic fields such as spacecraft, renewable energy vehicles, high-speed trains and submarine communication cables. The new generation of power devices have put forward higher, faster and more efficient requirements for advanced electronic packaging. However, the significant reduction of the solder joint size of chip interconnection leads to a sharp increase in the formation of intermetallic compounds (IMCs) within the solder joint, which poses a challenge to the reliability of the solder joint. In packaging structure, diffusion barrier layer plays an important role in the generation of intermetallic compounds. Therefore, the development of high reliability diffusion barrier layer has become one of the research concerns in the field of advanced electronic packaging. Herein, the research progress of diffusion barrier in advanced electronic packaging field in recent years was summarized based on different materials including elementary substance, binary compound, ternary compound, composite material and multi-layers. On this basis, three diffusion blocking mechanisms were summarized, including grain refinement of IMCs, segregation of alloying elements and suppression of Kirkendall voids. In the meanwhile, the failure mechanism of the barrier layer was analyzed.The effect of diffusion barrier on solder joint reliability was discussed. Finally, it was pointed out that the existing diffusion barrier research is still in the stage of manufacturing process and material performance exploration, and in the future, in-depth and systematic research can be carried out on high-entropy alloys, multi-physics coupling effects, failure and diffusion barrier mechanism disclosure.

Nickel-based superalloys have attracted significant attention due to their outstanding high-temperature strength, corrosion resistance, and oxidation resistance, and are widely used in aerospace and other fields. This article provides a comprehensive review of the preparation methods, common grades, and microstructure and properties of additive manufactured nickel-based superalloys, summarizes the current issues, and proposes future areas for exploration. Nickel-based superalloys prepared by metal additive manufacturing technology have excellent performance, can achieve precise forming of complex components, and have minimal material waste during the manufacturing process. They are expected to become an important production process for nickel-based superalloys components in fields such as aerospace. Common methods for additive manufacturing of nickel-based superalloys include laser powder bed melting, directed energy deposition, and arc additive manufacturing. Powder bed melting is widely used for manufacturing high-precision and complex parts, but it has a relatively slow manufacturing speed and higher equipment and material costs. Directed energy deposition has higher degrees of freedom and flexibility and can be used to prepare functional gradient materials, but it has lower accuracy. Arc additive manufacturing has lower equipment and material costs and is suitable for rapid manufacturing of large parts, but the surface roughness of the alloy produced by this method is poor and requires additional processing or post-treatment. Nickel-based superalloys widely studied in the additive manufacturing process include IN625, Hastelloy X, and other solid solution strengthened alloys, as well as IN718, CM247LC, IN738LC, and other precipitation strengthened superalloys. Compared with traditional casting and forging methods, the unique layer-by-layer forming and rapid cooling and heating process of additive manufacturing result in a coarse columnar grain structure and a unique microstructure with a large number of fine grains. It also forms unique melt pool structures and dislocation cell structures. However, the alloys obtained by additive manufacturing generally require heat treatment to control grain structure and precipitated phases, which affects the mechanical properties of the alloy. In addition, the mechanical properties of additive manufactured nickel-based superalloys are also related to specific preparation methods and alloy types. Although additive manufacturing has been widely used in the preparation of nickel-based superalloys, there are still issues such as anisotropy in microstructure and properties, high sensitivity to alloy cracking, and a lack of corresponding specifications and standards. In the future, further exploration is needed in areas such as heat treatment, customization and development of specialized alloys, investigation of the process-structure-function relationship, and computational modeling.

With the development of electric vehicles, higher requirements for battery energy density are put forward. High nickel/SiO_x-C batteries with high energy density have become the first choice for long-range electric vehicles. However, high nickel/SiO_x-C batteries have the problem of rapid capacity decay in practical use. Non-destructive electrochemical analysis and post-mortem analysis were used to detect the changes in battery capacity and internal resistance during the cycle. The changes in the structure, material morphology and surface composition of positive and negative electrodes before and after the battery cycle were compared, revealing the mechanism of cycling failure of high nickel/SiO_x-C batteries. The results show that the capacity decay of the battery presents three stages: the stationary period, the rapid decay period and the extreme decay period. After cycling, the polarization of the battery is more serious, and the polarization internal resistance of the battery, the surface film resistance of the negative electrode and the charge transfer resistance increase significantly. Through differential curve analysis combined with disassembly analysis, it is found that the high nickel cathode material has less attenuation, and the silica carbon anode material has more attenuation and active lithium-ion loss. The expansion and cracking of silicon oxide particles, the loss of negative electrode active material, and the continuous growth of solid electrolyte interface film on the negative electrode surface consuming too much active lithium are the main reasons for the rapid decline of battery capacity.