To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration signific...To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.展开更多
Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Prog...Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Program(SPP)on Space Science since 2011.In CSS plan in 2019,eleven space materials science experimental projects were officially approved for execution during the construction of the space station.In the SPP Phase Ⅱ launched in 2018,seven pre-research projects are deployed as the first batch in 2018,and one concept study project in 2019.These pre-research projects will be cultivated as candidates for future selection as space experiment projects on the recovery of scientific experimental satellites in the future.A new apparatus of electrostatic levitation system for ground-based research of space materials science and rapid solidification research has been developed under the support of the National Natural Science Foundation of China.In order to promote domestic academic activities and to enhance the advancement of space materials science in China,the Space Materials Science and Technology Division belong to the Chinese Materials Research Society was established in 2019.We also organized scientists to write five review papers on space materials science as a special topic published in the journal Scientia Sinica to provide valuable scientific and technical references for Chinese researchers.展开更多
To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃...To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃reheating strategy.This method improves the surface properties of NFM without the need for additional coating layers,making it more efficient and suitable for large-scale applications.Pristine NFM(NFM-P)was first synthesized through a high-temperature solid-state method and then modified using this reheating approach(NFM-HT).This strategy significantly enhances air stability and electrochemical performance,yielding an initial discharge specific capacity of 151.46 mAh/g at 0.1C,with a remarkable capacity retention of 95.04%after 100 cycles at 0.5C.Additionally,a 1.7 Ah NFM‖HC(hard carbon)pouch cell demonstrates excellent long-term cycling stability(94.64%retention after 500 cycles at 1C),superior rate capability(86.48%retention at 9C),and strong low-temperature performance(77%retention at-25℃,continuing power supply at-40℃).Notably,even when overcharged to 8.29 V,the pouch cell remained safe without combustion or explosion.This reheating strategy,which eliminates the need for a coating layer,offers a simpler,more scalable solution for industrial production while maintaining outstanding electrochemical performance.These results pave the way for broader commercial adoption of NFM materials.展开更多
MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherent...MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherently laminated crystal structure that Mn+1Xn slabs are intercalated with A element layers.Oriented to the functional requirements of information,intelligence,electrification,and aerospace in the new era,how to accelerate MAX series materials into new quality productive forces?The systematic enhancement of knowledge about MAX series materials is intrinsic to understanding its low-dimensional geometric structure characteristics,and physical and chemical properties,revealing the correlation of composition,structure,and function and further realizing rational design based on simulation and prediction.Diversity also brings complexity to MAX materials research.This review provides substantial tabular information on(Ⅰ)MAX’s research timeline from 1960 to the present,(Ⅱ)structure diversity and classification convention,(Ⅲ)synthesis route exploration,(Ⅳ)prediction based on theory and machine learning,(Ⅴ)properties,and(Ⅵ)functional applications.Herein,the researchers can quickly locate research content and recognize connections and differences of MAX series materials.In addition,the research challenges for the future development of MAX series materials are highlighted.展开更多
Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in...Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in which NH_(3) reduces ZnO and assembles an anti-perovskite Ni_(3)ZnN structure with interstitial nitrogen,significantly boosting hydrogenation efficiency.Nitrogen incorporation expands the lattice parameter,increasing the(111) lattice spacing from 2.04Å in Ni to 2.18Å in Ni_(3)ZnN,with an extended Ni-Ni interatomic distance from 2.49Å to 2.65Å.Additionally,Ni-N coordination shifts the d-band center downward and induces electron deficiency in Ni via charge transfer.These modifications optimize reactant adsorption on the tailored Ni_(3)ZnN structure compared to Ni,leading to a remarkable increase in 1,3-butadiene hydrogenation selectivity from 30.0 % to 92.9 %,along with an enhanced TOF from 0.067 s^(-1) to 0.079 s^(-1).These findings highlight RGMSI as a versatile and effective strategy for designing supported metal catalysts,offering new insights into selective hydrogenation catalysis.展开更多
Commercial carbonate electrolytes suffer from ion transport difficulty in bulk electrolytes and interphase at low temperatures,bringing challenges to the application of lithium-ion batteries(LIBs)at low temperatures.H...Commercial carbonate electrolytes suffer from ion transport difficulty in bulk electrolytes and interphase at low temperatures,bringing challenges to the application of lithium-ion batteries(LIBs)at low temperatures.Herein,the ester solvent of methyl propionate(MP)with low melting point and low viscosity was used to tackle ion transport difficulty in electrolytes.Fluorinated ester was further added to accelerate interfacial transport through intermolecular interactions.The influence of fluorinated esters with different fluorination degrees on the solvation structure of electrolytes and the performance of batteries was further studied.As a result,methyl pentafluoropropionate(M5F)with five fluorine atoms was selected for its optimal interactions with both Li+and MP solvent in the primary solvation structure,contributing to desired solvation structure for fast interfacial transport.The LiFePO4(LFP)||graphite cell with LiFSI-MP-M5F electrolyte exhibited a high cyclability of 85.8%after 120 cycles and retained 81.2%of room-temperature capacity when charged and discharged at−30℃.1 Ah LFP||graphite pouch cell with high cathode loading(20 mg/cm^(2))in LiFSI-MP-M5F electrolyte exhibited 0.85 Ah capacity when charged and discharged at−20℃.This work provides a guidance for electrolyte design by synergistic fluorinated and non-fluorinated solvents for LIBs at low-temperature application.展开更多
Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the effica...Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.展开更多
Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, larg...Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, large thermal expansion coefficient, excellent damage tolerance and moderate mechanical properties are the main requirements of promising TBC materials. In order to improve the efficiency of jet and/or gas turbine engines, which is the key of improved thrust-to-weight ratios and the energysaving, significant efforts have been made on searching for enhanced TBC materials. Theoretically, density functional theory has been successfully used in scanning the structure and properties of materials, and at the same time predicting the mechanical and thermal properties of promising TBC materials for high and ultrahigh temperature applications, which are validated by subsequent experiments. Experimentally,doping and/or alloying are also widely applied to further decrease their thermal conductivities. Now, the strategy through combining theoretical calculations and experiments on searching for next generation thermal insulator materials is widely adopted. In this review, the common used techniques and the recent advantages on searching for promising TBC materials in both theory and experiments are summarized.展开更多
CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@M...CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.展开更多
Nanocarbon materials play a critical role in the development of new or improved technologies and devices for sustainable production and use of renewable energy. This perspective paper defines some of the trends and ou...Nanocarbon materials play a critical role in the development of new or improved technologies and devices for sustainable production and use of renewable energy. This perspective paper defines some of the trends and outlooks in this exciting area, with the effort of evidencing some of the possibilities offered from the growing level of knowledge, as testified from the exponentially rising number of publications, and putting bases for a more rational design of these nanomaterials. The basic members of the new carbon family are fullerene, graphene, and carbon nanotube. Derived from them are carbon quantum dots, nanohorn, nanofiber, nano ribbon, nanocapsulate, nanocage and other nanomorphologies. Second generation nanocarbons are those which have been modified by surface functionalization or doping with heteroatoms to create specific tailored properties. The third generation of nanocarbons is the nanoarchitectured supramolecular hybrids or composites of the first and second genera- tion nanocarbons, or with organic or inorganic species. The advantages of the new carbon materials, relating to the field of sustainable energy, are discussed, evidencing the unique properties that they offer for developing next generation solar devices and energy storage solutions.展开更多
Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their...Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their promising irradiation resistant behavior. Here, we report a new single-phase bodycentered cubic(BCC) structured Ti_2 ZrHfV_(0.5)Mo_(0.2) HEA possessing excellent irradiation resistance, i.e.,scarcely irradiation hardening and abnormal lattice constant reduction after helium-ion irradiation,which is completely different from conventional alloys. This is the first time to report the abnormal XRD phenomenon of metallic alloys and almost no hardening after irradiation. These excellent properties make it to be a potential candidate material used as core components in next-generation nuclear reactors. The particular irradiation tolerance derives from high density lattice vacancies/defects.展开更多
Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process.The m...Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process.The morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction,field-emission gun scanning electron microscopy,transmission electron microscopy and highresolution electron microscopy.The micro-sized Fe3O4 particles exhibit porous structure,while the nano-sized Fe3O4 particles are solid structure.Their electrochemical performance was also evaluated.The nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg-1 and reversible capacity retention of 32.6% over 50 cycles.Interestingly,the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior,with initial discharge capacity of 887.5 mAhg-1 and charge capacity of 684.4 mAhg-1 at the 50th cycle.Therefore,77.1% of the reversible capacity can be maintained over 50 cycles.The micro-sized porous Fe3O4 particles with facile synthesis,good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.展开更多
Notch is a very important geometry with widespread applications in engineering structural components. Finding a universal equation to predict the effect of notch on strength of materials is of much significance for st...Notch is a very important geometry with widespread applications in engineering structural components. Finding a universal equation to predict the effect of notch on strength of materials is of much significance for structural design and materials selection. In the present work, we tried to find this universal equation from experimental results of metallic glasses （MGs） and other materials as well as theoretical derivations based on a universal fracture criterion （Qu and Zhang, Sci. Rep. 3 （2013） 1117）. Experimental results showed that the notch effect of the studied MG was affected by the notch geometry characterized by the stress concentration factor Kt. As Kt becomes smaller, the notch strength ratio （NSR, which is the ratio of nominal ultimate tensile strength （UTS） of the notched sample to UTS of the unnotched sample） increases. By comparing MGs with other materials like brittle ceramics and ductile for ductile metals but smaller for brittle effect on strength of materials： NSR = equation was found to be consistent with crystalline metals, we find that when Kt is same, the NSR is larger ceramics. Theoretically, we derived a universal equation for notch M/Kt, where M is a constant related to materials. This universal the experimental results.展开更多
Vanadium pentoxide （V205） exhibits high theoretical capacities when used as a cathode in lithium ion batteries （LIBs）, but its application is limited by its structural instability as well as its low lithium and el...Vanadium pentoxide （V205） exhibits high theoretical capacities when used as a cathode in lithium ion batteries （LIBs）, but its application is limited by its structural instability as well as its low lithium and electronic conductivities. A porous composite of V2Os-SnO2/carbon nanotubes （CNTs） was prepared by a hydrothermal method and followed by thermal treatment. The small particles of V205, their porous structure and the coexistence of SnO2 and CNTs can all facilitate the diffusion rates of the electrons and lithium ions. Electrochemical impedance spectra indicated higher ionic and electric conductivities, as compared to commercial V205. The VzOs-SnOz/CNTs composite gave a reversible discharge capacity of 198 mAh.g- 1 at the voltage range of 2.05-4.0 V, measured at a current rate of 200 mA.g-1, while that of the commercial V205 was only 88 mAh.g-1, demonstrating that the porous V2Os-SnOz/CNTs composite is a promising candidate for high-performance lithium secondary batteries.展开更多
Two low-cost synthesis routes have been developed to fabricate carbon-coated Li4Ti5O12 by using H2TiO3 instead of anatase TiO2 as Ti source through solid-state reaction process. One route is a direct solid mixture of ...Two low-cost synthesis routes have been developed to fabricate carbon-coated Li4Ti5O12 by using H2TiO3 instead of anatase TiO2 as Ti source through solid-state reaction process. One route is a direct solid mixture of H2TiO3, Li2CO3 and pitch followed by high-temperature solid-state reaction. The other includes mixture of H2TiO3 and Li2CO3 with pitch dissolved in furanidine under vacuum and the same solid-state reaction procedure is followed after the mixture is totally dried. Microstructural investigations indicate that H2TiO3 exhibits secondary aggregates morphology with primary particle sizes of 10-20 nm. Carbon-coating layers with thickness of 2-3 nm have been observed on Li4Ti5O12 synthesized by the two routes. Cyclic performance, rate capability and electrochemical impedance spectrum of the two Li4Ti5O12/C composites have been performed, which indicate that Li4Ti5O12/C obtained by furanidine-assisted mixture exhibits better electrochemical performance than Li4Ti5O12/C synthesized by direct solid mixture. The possible reasons have been discussed. The low-cost synthesis routes of Li4Ti5O12/C using H2TiO3 as Ti source are expected to be more competitive than the traditional one for practical applications.展开更多
Thermal resistance of low-melting-temperature alloy （LMTA） thermal interface materials （TIMs） was measured by laser flash method before and after different stages of heating. The results showed that the thermal pe...Thermal resistance of low-melting-temperature alloy （LMTA） thermal interface materials （TIMs） was measured by laser flash method before and after different stages of heating. The results showed that the thermal performance of the LMTA TIMs was degraded during the heating process. It is suggested that the degradation may mainly be attributed to the interfacial reaction between the Cu and the molten LMTAs. Due to the fast growth rate of intermetallic compound （IMC） at the solid-liquid interface, a thick brittle IMC is layer formed at the interface, which makes cracks easy to initiate and expand. Otherwise, the losses of indium and tin contents in the LMTA during the interfacial reaction will make the melting point of the TIM layer increase, and so, the TIM layer will not melt at the operating temperature.展开更多
Nickel/cobalt-layered double hydroxides(Ni Co-LDH) have been attracted increasing interest in the applications of anode materials for lithium ion battery(LIB), but the low cycle stability and rate performance are stil...Nickel/cobalt-layered double hydroxides(Ni Co-LDH) have been attracted increasing interest in the applications of anode materials for lithium ion battery(LIB), but the low cycle stability and rate performance are still limited its practice applications. To achieve high performance LIB, the surface-confined strategy has been applied to design and fabricate a new anode material of NiCo-LDH nanosheet anchored on the surface of Ti3C2 MXene(Ni Co-LDH/Ti3C2). The ultra-thin, bended and wrinkled α-phase crystal with an interlayer spacing of 8.1 ? can arrange on the conductive substrates Ti3C2 MXene directly, resulting in high electrolyte diffusion ability and low internal resistance. Furthermore, chemical bond interactions between the highly conductive Ti3C2 MXene and Ni Co-LDH nanosheets can greatly increase the ion and electron transport and reduce the volume expansion of NiCo-LDH during Li ion intercalation. As expected,the discharge capacity of 562 m Ah g-1 at 5.0 A g-1 for 800 cycles without degradation can be achieved,rate capability and cycle performance are better than that of NiCo-LDH(~100 mAh g-1). Furthermore, the density function theory(DFT) calculations were performed to demonstrate that Ni Co-LDH/Ti3C2 system can be used as a highly desirable and promising anode material for lithium ion battery.展开更多
Anisotropic Pr-Fe-B films with soft-magnetic layer （Fe） and/or antiferromagnetic layer （Mn, FeMn or MnO） were prepared by direct-current （DC） magnetron sputtering on Si （100） substrates heated at 650℃. The in...Anisotropic Pr-Fe-B films with soft-magnetic layer （Fe） and/or antiferromagnetic layer （Mn, FeMn or MnO） were prepared by direct-current （DC） magnetron sputtering on Si （100） substrates heated at 650℃. The influence of four types＇ different structures on the magnetic properties of Pr-Fe-B films was investigated. The phase and magnetic properties were characterized by means of X-ray diffraction （XRD） and superconducting quantum interference device （SQUID）. Addition of anti-ferromagnetic layer enhances both the coercivity and the remanence ratios of Pr-Fe-B films with suitable structures. The interface number increases and the antiferromagnetic-ferromagnetic exchange interaction is likely to become stronger, which affect the improvement of magnetic properties. To further understand the influence of structures with soft-magnetic Fe layer and/or antifer- romagnetic FeMn layer on the magnetic properties of Pr-Fe-B hard-magnetic films, the thickness of Pr-Fe-B layer was designed to decrease from 600 to 50 nm. The improvement of magnetic properties becomes obvious in Mo（50 nm）/Pr-Fe-B（25 nm）Mo（2 nm）FeMn（20 nm）Mo （2 nm）Pr-Fe-B（25 nm）/Mo（50 rim） film.展开更多
The deformation, damage, fracture, plasticity and melting phenomenon induced by shear fracture were investigated and summarized for Zr-, Cu-, Ti- and Mg-based bulk metallic glasses （BMGs） and their composites. The s...The deformation, damage, fracture, plasticity and melting phenomenon induced by shear fracture were investigated and summarized for Zr-, Cu-, Ti- and Mg-based bulk metallic glasses （BMGs） and their composites. The shear fracture angles of these BMG materials often display obvious differences under compression and tension, and follow either the Mohr-Coulomb criterion or the unified tensile fracture criterion. The compressive plasticity of the composites is always higher than the tensile plasticity, leading to a significant inconsistency. The enhanced plasticity of BMG composites containing ductile dendrites compared to monolithic glasses strongly depends on the details of the microstructure of the composites. A deformation and damage mechanism of pseudo-plasticity, related to local cracking, is proposed to explain the inconsistency of plastic deformation under tension and compression. Besides, significant melting on the shear fracture surfaces was observed. It is suggested that melting is a common phenomenon in these materials with high strength and high elastic energy, as it is typical for BMGs and their composites failing under shear fracture. The melting mechanism can be explained by a combined effect of a significant temperature rise in the shear bands and the instantaneous release of the large amount of elastic energy stored in the material.展开更多
Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.H...Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.However,serious sodium polysulfide shutting and sluggish reaction kinetics lead to rapid capacity decay and poor Coulombic efficiency.Recently,catalytic materials capable of adsorbing and catalyzing the conversion of polysulfides are profiled as a promising method to improve electrochemical performance.In this review,the research progress is summarized that the application of catalytic materials in RT Na-S battery.For the role of catalyst on the conversion of sulfur species,specific attention is focused on the influence factors of reaction rate during different redox processes.Various catalytic materials based on lightweight and high conductive carbon materials,including heteroatom-doped carbon,metals and metal compounds,single-atom and heterostructure,promote the reaction kinetic via lowered energy barrier and accelerated charge transfer.Additionally,the adsorption capacity of the catalytic materials is the key to the catalytic effect.Particular attention to the interaction between polysulfides and sulfur host materials is necessary for the exploration of catalytic mechanism.Lastly,the challenges and outlooks toward the desired design of efficient catalytic materials for RT Na-S battery are discussed.展开更多
基金supported by the National Key R&D Program of China(Nos.2022YFB3504804 and 2023YFF0718303)the National Natural Science Foundation of China(Nos.51871219,52071324,52031014,and 52401255)+1 种基金Science and Technology Project of Shenyang City(No.22-101-0-27)Liaoning Institute of Science and Technology Doctoral Initiation Fund Project(No.2307B19).
文摘To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.
基金Supports by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(XDA15013200,XDA15013700,XDA15013800,XDA15051200)the China’s Manned Space Station Project(TGJZ800-2-RW024)and the National Natural Science Foundation of China(51327901)。
文摘Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Program(SPP)on Space Science since 2011.In CSS plan in 2019,eleven space materials science experimental projects were officially approved for execution during the construction of the space station.In the SPP Phase Ⅱ launched in 2018,seven pre-research projects are deployed as the first batch in 2018,and one concept study project in 2019.These pre-research projects will be cultivated as candidates for future selection as space experiment projects on the recovery of scientific experimental satellites in the future.A new apparatus of electrostatic levitation system for ground-based research of space materials science and rapid solidification research has been developed under the support of the National Natural Science Foundation of China.In order to promote domestic academic activities and to enhance the advancement of space materials science in China,the Space Materials Science and Technology Division belong to the Chinese Materials Research Society was established in 2019.We also organized scientists to write five review papers on space materials science as a special topic published in the journal Scientia Sinica to provide valuable scientific and technical references for Chinese researchers.
基金the financial support provided by the Longzihu New Energy Laboratory Joint Fund of Henan Province(2023008)the Energy Storage Mater.and Processes Key Laboratory of Henan Province Open Fund(2021003)+1 种基金the Collaborative Innovation Team Project Fund of Industry-University-Research(32214085)the financial support received from Zhejiang Vast Na Technology Co.,Ltd.(24110380)。
文摘To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃reheating strategy.This method improves the surface properties of NFM without the need for additional coating layers,making it more efficient and suitable for large-scale applications.Pristine NFM(NFM-P)was first synthesized through a high-temperature solid-state method and then modified using this reheating approach(NFM-HT).This strategy significantly enhances air stability and electrochemical performance,yielding an initial discharge specific capacity of 151.46 mAh/g at 0.1C,with a remarkable capacity retention of 95.04%after 100 cycles at 0.5C.Additionally,a 1.7 Ah NFM‖HC(hard carbon)pouch cell demonstrates excellent long-term cycling stability(94.64%retention after 500 cycles at 1C),superior rate capability(86.48%retention at 9C),and strong low-temperature performance(77%retention at-25℃,continuing power supply at-40℃).Notably,even when overcharged to 8.29 V,the pouch cell remained safe without combustion or explosion.This reheating strategy,which eliminates the need for a coating layer,offers a simpler,more scalable solution for industrial production while maintaining outstanding electrochemical performance.These results pave the way for broader commercial adoption of NFM materials.
基金financial support by the Development Plan of Science and Technology of Jilin Province(No.YDZJ202201ZYTS305)the Natural Science Foundation of Jilin Province(No.YDZJ202401316ZYTS)the Innovation Laboratory Development Program of Education Department of Jilin Province and Industry and Information Technology Department of Jilin Province,China(The Joint Laboratory of MAX/MXene Materials).
文摘MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherently laminated crystal structure that Mn+1Xn slabs are intercalated with A element layers.Oriented to the functional requirements of information,intelligence,electrification,and aerospace in the new era,how to accelerate MAX series materials into new quality productive forces?The systematic enhancement of knowledge about MAX series materials is intrinsic to understanding its low-dimensional geometric structure characteristics,and physical and chemical properties,revealing the correlation of composition,structure,and function and further realizing rational design based on simulation and prediction.Diversity also brings complexity to MAX materials research.This review provides substantial tabular information on(Ⅰ)MAX’s research timeline from 1960 to the present,(Ⅱ)structure diversity and classification convention,(Ⅲ)synthesis route exploration,(Ⅳ)prediction based on theory and machine learning,(Ⅴ)properties,and(Ⅵ)functional applications.Herein,the researchers can quickly locate research content and recognize connections and differences of MAX series materials.In addition,the research challenges for the future development of MAX series materials are highlighted.
基金the financial support provided by the National Natural Science Foundation of China (Nos.22072164,22472180,22002173)Energy Revolution S&T Program of Yulin Innovation Institute of Clean Energy (No.E411030705)+2 种基金Natural Science Foundation of Liaoning Province (No.2022-MS004)China Postdoctoral Science Foundation (No.2020M680999)the Research Fund of Shenyang National Laboratory for Materials Science。
文摘Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in which NH_(3) reduces ZnO and assembles an anti-perovskite Ni_(3)ZnN structure with interstitial nitrogen,significantly boosting hydrogenation efficiency.Nitrogen incorporation expands the lattice parameter,increasing the(111) lattice spacing from 2.04Å in Ni to 2.18Å in Ni_(3)ZnN,with an extended Ni-Ni interatomic distance from 2.49Å to 2.65Å.Additionally,Ni-N coordination shifts the d-band center downward and induces electron deficiency in Ni via charge transfer.These modifications optimize reactant adsorption on the tailored Ni_(3)ZnN structure compared to Ni,leading to a remarkable increase in 1,3-butadiene hydrogenation selectivity from 30.0 % to 92.9 %,along with an enhanced TOF from 0.067 s^(-1) to 0.079 s^(-1).These findings highlight RGMSI as a versatile and effective strategy for designing supported metal catalysts,offering new insights into selective hydrogenation catalysis.
基金supported by the National Key R&D Program of China(No.2022YFB3803400)National Natural Science Foundation of China(Nos.52102054,52020105010,51927803,52188101 and 52072378)+1 种基金Liaoning Province Science and Technology Planning Project(No.2022-BS-007)Fujian Science and Technology Program(No.2023T3025).
文摘Commercial carbonate electrolytes suffer from ion transport difficulty in bulk electrolytes and interphase at low temperatures,bringing challenges to the application of lithium-ion batteries(LIBs)at low temperatures.Herein,the ester solvent of methyl propionate(MP)with low melting point and low viscosity was used to tackle ion transport difficulty in electrolytes.Fluorinated ester was further added to accelerate interfacial transport through intermolecular interactions.The influence of fluorinated esters with different fluorination degrees on the solvation structure of electrolytes and the performance of batteries was further studied.As a result,methyl pentafluoropropionate(M5F)with five fluorine atoms was selected for its optimal interactions with both Li+and MP solvent in the primary solvation structure,contributing to desired solvation structure for fast interfacial transport.The LiFePO4(LFP)||graphite cell with LiFSI-MP-M5F electrolyte exhibited a high cyclability of 85.8%after 120 cycles and retained 81.2%of room-temperature capacity when charged and discharged at−30℃.1 Ah LFP||graphite pouch cell with high cathode loading(20 mg/cm^(2))in LiFSI-MP-M5F electrolyte exhibited 0.85 Ah capacity when charged and discharged at−20℃.This work provides a guidance for electrolyte design by synergistic fluorinated and non-fluorinated solvents for LIBs at low-temperature application.
基金supported by the National Key R&D Program of China(2021YFA1502802)the National Natural Science Foundation of China(U21B2092,22202213,22402210,22502215,22502214,22572200,and 22579171)+4 种基金the International Partnership Program of Chinese Academy of Sciences(172GJHZ2022028MI)the Shenyang Bureau of Science and Technology(24-213-3-25)the Natural Science Foundation of Liaoning Province(2025BS0153)Zhongke Technology Achievement Transfer and Transformation Center of Henan Province 2025119The XAS experiments were conducted in Beijing Synchrotron Radiation Facility(BSRF)and Shanghai Synchrotron Radiation Facility(SSRF).
文摘Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
基金supported by the National Natural Science Foundation of China (No. 51602188)the Program for Professor of Special Appointment (Eastern Scholar)by Shanghai Municipal Education Commission (No. TP2015040)
文摘Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, large thermal expansion coefficient, excellent damage tolerance and moderate mechanical properties are the main requirements of promising TBC materials. In order to improve the efficiency of jet and/or gas turbine engines, which is the key of improved thrust-to-weight ratios and the energysaving, significant efforts have been made on searching for enhanced TBC materials. Theoretically, density functional theory has been successfully used in scanning the structure and properties of materials, and at the same time predicting the mechanical and thermal properties of promising TBC materials for high and ultrahigh temperature applications, which are validated by subsequent experiments. Experimentally,doping and/or alloying are also widely applied to further decrease their thermal conductivities. Now, the strategy through combining theoretical calculations and experiments on searching for next generation thermal insulator materials is widely adopted. In this review, the common used techniques and the recent advantages on searching for promising TBC materials in both theory and experiments are summarized.
基金supported by the Fundamental Research Funds for the Central Universities (No 30919011410)。
文摘CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.
基金the financial support by MOST (2011CBA00504)NSFC (21133010, 50921004, 212111074) of China
文摘Nanocarbon materials play a critical role in the development of new or improved technologies and devices for sustainable production and use of renewable energy. This perspective paper defines some of the trends and outlooks in this exciting area, with the effort of evidencing some of the possibilities offered from the growing level of knowledge, as testified from the exponentially rising number of publications, and putting bases for a more rational design of these nanomaterials. The basic members of the new carbon family are fullerene, graphene, and carbon nanotube. Derived from them are carbon quantum dots, nanohorn, nanofiber, nano ribbon, nanocapsulate, nanocage and other nanomorphologies. Second generation nanocarbons are those which have been modified by surface functionalization or doping with heteroatoms to create specific tailored properties. The third generation of nanocarbons is the nanoarchitectured supramolecular hybrids or composites of the first and second genera- tion nanocarbons, or with organic or inorganic species. The advantages of the new carbon materials, relating to the field of sustainable energy, are discussed, evidencing the unique properties that they offer for developing next generation solar devices and energy storage solutions.
基金supported by the National Natural Science Foundation of China (Nos. 11605271, 51471044, 51525401, 51771201 and 51401208)Support Plan for Innovation of High-level Talents (Top and Leading Talents, 2015R013)Support Plan for Innovation of High-level Talents (Youth Technology Stars, 2016RQ005)
文摘Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their promising irradiation resistant behavior. Here, we report a new single-phase bodycentered cubic(BCC) structured Ti_2 ZrHfV_(0.5)Mo_(0.2) HEA possessing excellent irradiation resistance, i.e.,scarcely irradiation hardening and abnormal lattice constant reduction after helium-ion irradiation,which is completely different from conventional alloys. This is the first time to report the abnormal XRD phenomenon of metallic alloys and almost no hardening after irradiation. These excellent properties make it to be a potential candidate material used as core components in next-generation nuclear reactors. The particular irradiation tolerance derives from high density lattice vacancies/defects.
基金supported by the National Natural Science Foundation of China (Grand No. 50872032)the financial support from the Hundred Talents Program of the Chinese Academy of Sciencesthe National Basic Research Program of China(Grant No. 2010CB631006)
文摘Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process.The morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction,field-emission gun scanning electron microscopy,transmission electron microscopy and highresolution electron microscopy.The micro-sized Fe3O4 particles exhibit porous structure,while the nano-sized Fe3O4 particles are solid structure.Their electrochemical performance was also evaluated.The nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg-1 and reversible capacity retention of 32.6% over 50 cycles.Interestingly,the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior,with initial discharge capacity of 887.5 mAhg-1 and charge capacity of 684.4 mAhg-1 at the 50th cycle.Therefore,77.1% of the reversible capacity can be maintained over 50 cycles.The micro-sized porous Fe3O4 particles with facile synthesis,good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China under Grant Nos. 51331007 and 51301174
文摘Notch is a very important geometry with widespread applications in engineering structural components. Finding a universal equation to predict the effect of notch on strength of materials is of much significance for structural design and materials selection. In the present work, we tried to find this universal equation from experimental results of metallic glasses （MGs） and other materials as well as theoretical derivations based on a universal fracture criterion （Qu and Zhang, Sci. Rep. 3 （2013） 1117）. Experimental results showed that the notch effect of the studied MG was affected by the notch geometry characterized by the stress concentration factor Kt. As Kt becomes smaller, the notch strength ratio （NSR, which is the ratio of nominal ultimate tensile strength （UTS） of the notched sample to UTS of the unnotched sample） increases. By comparing MGs with other materials like brittle ceramics and ductile for ductile metals but smaller for brittle effect on strength of materials： NSR = equation was found to be consistent with crystalline metals, we find that when Kt is same, the NSR is larger ceramics. Theoretically, we derived a universal equation for notch M/Kt, where M is a constant related to materials. This universal the experimental results.
基金supported by the National Natural Science Foundation of China (No. 51001098)the Institute of Metal Research of CAS (No. 09NBA211A1)
文摘Vanadium pentoxide （V205） exhibits high theoretical capacities when used as a cathode in lithium ion batteries （LIBs）, but its application is limited by its structural instability as well as its low lithium and electronic conductivities. A porous composite of V2Os-SnO2/carbon nanotubes （CNTs） was prepared by a hydrothermal method and followed by thermal treatment. The small particles of V205, their porous structure and the coexistence of SnO2 and CNTs can all facilitate the diffusion rates of the electrons and lithium ions. Electrochemical impedance spectra indicated higher ionic and electric conductivities, as compared to commercial V205. The VzOs-SnOz/CNTs composite gave a reversible discharge capacity of 198 mAh.g- 1 at the voltage range of 2.05-4.0 V, measured at a current rate of 200 mA.g-1, while that of the commercial V205 was only 88 mAh.g-1, demonstrating that the porous V2Os-SnOz/CNTs composite is a promising candidate for high-performance lithium secondary batteries.
基金supported by the National Natural Science Foundation of China (No.50872032)
文摘Two low-cost synthesis routes have been developed to fabricate carbon-coated Li4Ti5O12 by using H2TiO3 instead of anatase TiO2 as Ti source through solid-state reaction process. One route is a direct solid mixture of H2TiO3, Li2CO3 and pitch followed by high-temperature solid-state reaction. The other includes mixture of H2TiO3 and Li2CO3 with pitch dissolved in furanidine under vacuum and the same solid-state reaction procedure is followed after the mixture is totally dried. Microstructural investigations indicate that H2TiO3 exhibits secondary aggregates morphology with primary particle sizes of 10-20 nm. Carbon-coating layers with thickness of 2-3 nm have been observed on Li4Ti5O12 synthesized by the two routes. Cyclic performance, rate capability and electrochemical impedance spectrum of the two Li4Ti5O12/C composites have been performed, which indicate that Li4Ti5O12/C obtained by furanidine-assisted mixture exhibits better electrochemical performance than Li4Ti5O12/C synthesized by direct solid mixture. The possible reasons have been discussed. The low-cost synthesis routes of Li4Ti5O12/C using H2TiO3 as Ti source are expected to be more competitive than the traditional one for practical applications.
基金supported by the National Basic Research Program of China (No.2010CB631006)the National Natural Science Foundation of China (No.51171191)
文摘Thermal resistance of low-melting-temperature alloy （LMTA） thermal interface materials （TIMs） was measured by laser flash method before and after different stages of heating. The results showed that the thermal performance of the LMTA TIMs was degraded during the heating process. It is suggested that the degradation may mainly be attributed to the interfacial reaction between the Cu and the molten LMTAs. Due to the fast growth rate of intermetallic compound （IMC） at the solid-liquid interface, a thick brittle IMC is layer formed at the interface, which makes cracks easy to initiate and expand. Otherwise, the losses of indium and tin contents in the LMTA during the interfacial reaction will make the melting point of the TIM layer increase, and so, the TIM layer will not melt at the operating temperature.
基金Rachadapisek Sompoch project,Chulalongkorn University(CU_GR_62_14_62_02)the Energy Conservation and Promotion Fund Office,Ministry of Energy+2 种基金the NSFC(grant 51421091)National Science Foundation for Distinguished Young Scholars for Hebei Province of China(grant E2016203376)Asahi Glass Foundation。
文摘Nickel/cobalt-layered double hydroxides(Ni Co-LDH) have been attracted increasing interest in the applications of anode materials for lithium ion battery(LIB), but the low cycle stability and rate performance are still limited its practice applications. To achieve high performance LIB, the surface-confined strategy has been applied to design and fabricate a new anode material of NiCo-LDH nanosheet anchored on the surface of Ti3C2 MXene(Ni Co-LDH/Ti3C2). The ultra-thin, bended and wrinkled α-phase crystal with an interlayer spacing of 8.1 ? can arrange on the conductive substrates Ti3C2 MXene directly, resulting in high electrolyte diffusion ability and low internal resistance. Furthermore, chemical bond interactions between the highly conductive Ti3C2 MXene and Ni Co-LDH nanosheets can greatly increase the ion and electron transport and reduce the volume expansion of NiCo-LDH during Li ion intercalation. As expected,the discharge capacity of 562 m Ah g-1 at 5.0 A g-1 for 800 cycles without degradation can be achieved,rate capability and cycle performance are better than that of NiCo-LDH(~100 mAh g-1). Furthermore, the density function theory(DFT) calculations were performed to demonstrate that Ni Co-LDH/Ti3C2 system can be used as a highly desirable and promising anode material for lithium ion battery.
基金financially supported by the National Key Basic Research Program of China (No. 2010CB934603)the National Nature Science Foundation of China (Nos. 50931006 and 50971123)
文摘Anisotropic Pr-Fe-B films with soft-magnetic layer （Fe） and/or antiferromagnetic layer （Mn, FeMn or MnO） were prepared by direct-current （DC） magnetron sputtering on Si （100） substrates heated at 650℃. The influence of four types＇ different structures on the magnetic properties of Pr-Fe-B films was investigated. The phase and magnetic properties were characterized by means of X-ray diffraction （XRD） and superconducting quantum interference device （SQUID）. Addition of anti-ferromagnetic layer enhances both the coercivity and the remanence ratios of Pr-Fe-B films with suitable structures. The interface number increases and the antiferromagnetic-ferromagnetic exchange interaction is likely to become stronger, which affect the improvement of magnetic properties. To further understand the influence of structures with soft-magnetic Fe layer and/or antifer- romagnetic FeMn layer on the magnetic properties of Pr-Fe-B hard-magnetic films, the thickness of Pr-Fe-B layer was designed to decrease from 600 to 50 nm. The improvement of magnetic properties becomes obvious in Mo（50 nm）/Pr-Fe-B（25 nm）Mo（2 nm）FeMn（20 nm）Mo （2 nm）Pr-Fe-B（25 nm）/Mo（50 rim） film.
基金financially supported by the National Natural Science Foundation of China(NSFC)under Gtrant No.50401019the“Hun-dred of Talent Project"by Chinese Academy of Sciences+1 种基金National Outstanding Young Scientist Foundation for Z.F.Zhang under Grant No.50625103the financial support of the Alexander-von-Humboldt(AvH)Foundation.
文摘The deformation, damage, fracture, plasticity and melting phenomenon induced by shear fracture were investigated and summarized for Zr-, Cu-, Ti- and Mg-based bulk metallic glasses （BMGs） and their composites. The shear fracture angles of these BMG materials often display obvious differences under compression and tension, and follow either the Mohr-Coulomb criterion or the unified tensile fracture criterion. The compressive plasticity of the composites is always higher than the tensile plasticity, leading to a significant inconsistency. The enhanced plasticity of BMG composites containing ductile dendrites compared to monolithic glasses strongly depends on the details of the microstructure of the composites. A deformation and damage mechanism of pseudo-plasticity, related to local cracking, is proposed to explain the inconsistency of plastic deformation under tension and compression. Besides, significant melting on the shear fracture surfaces was observed. It is suggested that melting is a common phenomenon in these materials with high strength and high elastic energy, as it is typical for BMGs and their composites failing under shear fracture. The melting mechanism can be explained by a combined effect of a significant temperature rise in the shear bands and the instantaneous release of the large amount of elastic energy stored in the material.
基金financial support from National Natural Science Foundation of China(Nos.52020105010,51972313,51927803,52072378,51902316 and 51525206)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010602)+2 种基金LiaoNing Revitalization Talents Program(No.XLYC1908015)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y201942)the Special Projects of the Central Government in Guidance of Local Science and Technology Development(No.2020JH6/10500024)。
文摘Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.However,serious sodium polysulfide shutting and sluggish reaction kinetics lead to rapid capacity decay and poor Coulombic efficiency.Recently,catalytic materials capable of adsorbing and catalyzing the conversion of polysulfides are profiled as a promising method to improve electrochemical performance.In this review,the research progress is summarized that the application of catalytic materials in RT Na-S battery.For the role of catalyst on the conversion of sulfur species,specific attention is focused on the influence factors of reaction rate during different redox processes.Various catalytic materials based on lightweight and high conductive carbon materials,including heteroatom-doped carbon,metals and metal compounds,single-atom and heterostructure,promote the reaction kinetic via lowered energy barrier and accelerated charge transfer.Additionally,the adsorption capacity of the catalytic materials is the key to the catalytic effect.Particular attention to the interaction between polysulfides and sulfur host materials is necessary for the exploration of catalytic mechanism.Lastly,the challenges and outlooks toward the desired design of efficient catalytic materials for RT Na-S battery are discussed.
