Developing efficient electrocatalysts for oxygen evolution reaction(OER)is imperative to enhance the overall efficiency of electrolysis systems and rechargeable metal-air batteries operating in aqueous solutions.High-...Developing efficient electrocatalysts for oxygen evolution reaction(OER)is imperative to enhance the overall efficiency of electrolysis systems and rechargeable metal-air batteries operating in aqueous solutions.High-entropy materials,featured with their distinctive multi-component properties,have found extensive application as catalysts in electrochemical energy storage and conversion devices.However,synthesizing nanostructured high-entropy compounds under mild conditions poses a significant challenge due to the difficulty in overcoming the immiscibility of multiple metallic constituents.In this context,the current study focuses on the synthesis of an array of nano-sized high entropy sulfides tailored for OER via a facile precursor pyrolysis method at low temperature.The representative compound,Fe Co Ni Cu Mn Sx,demonstrates remarkable OER performance,achieving a current density of 10 m A/cm^(2) at an overpotential of merely 220 m V and excellent stability with constant electrolysis at 100 m A/cm^(2) for over 400 h.The in-situ formed metal(oxy)hydroxide has been confirmed as the real active sites and its exceptional performance can be primarily attributed to the synergistic effects arising from its multiple components.Furthermore,the synthetic methodology presented here is versatile and can be extended to the preparation of high entropy phosphides,which also present favorable OER performance.This research not only introduces promising non-noble electrocatalysts for OER but also offers a facile approach to expand the family of nano high-entropy materials,contributing significantly to the field of electrochemical energy conversion.展开更多
High-entropy oxides(HEOs)have received considerable attention in the past few years due to their unique high configurational entropy and ideal elemental adjustability.HEOs are generally considered to be a special clas...High-entropy oxides(HEOs)have received considerable attention in the past few years due to their unique high configurational entropy and ideal elemental adjustability.HEOs are generally considered to be a special class of oxides containing five or more different metal cations.The attractive synergistic effect makes HEOs promising energy storage and conversion material.However,at present,the knowledge of HEOs and their practical applications on electrochemistry is still scattered without comprehensive report.In this review,we highlight the preparation methods,common crystal structures and their applications in the field of electrochemistry,which can be divided into two main categories:(1)electrochemical energy storage devices,including supercapacitors,lithium-ion batteries,sodium-ion batteries,and other batteries;(2)electrocatalysis reaction system,including hydrogen evolution reaction(HER),oxygen evolution reaction(OER),oxygen reduction reaction(ORR),and electrocatalytic CO_(2)reduction reaction(CO_(2)RR).Finally,the remaining challenges and prospects in the future are envisioned in the related field,which will help to unlock the mysteries of HEOs for energy storage and conversion.展开更多
This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with t...This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.展开更多
Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Sev...Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Several collectors were initially selected through micro-flotation tests,leading to the identification of optimal proportions for a four-component collector system(SHA-OHA-SPA-DBIA in a 4:3:2:1 ratio).Molecular dynamics simulations and surface tension tests were used to investigate the micellar behavior of these collectors in aqueous solution.The adsorption characteristics were quantified using microcalorimetry,enabling the determination of collection entropy and changes in Gibbs free energy.The four-component collector system showed the highest entropy change and the most favorable Gibbs free energy,leading to a cassiterite recovery of above 90%at a concentration of 8.0×10^(5)mol/L.Various analytical techniques were employed to systematically characterize the adsorption mechanism.The findings revealed a positive correlation between the adsorption products formed by the multicomponent collectors on the cassiterite surface and the entropy changes.Industrial-scale testing of the high-entropy collector system produced a tin concentrate with an Sn grade of 6.17%and an Sn recovery of 82.43%,demonstrating its substantial potential for practical applications in cassiterite flotation.展开更多
Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery...Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery of high-entropy alloys(HEAs)comprising multi-principal elements.Owing to the four“core-effects”,these alloys exhibit exceptional properties including better structural stability,high strength and ductility,improved fatigue/fracture toughness,high corrosion and oxidation resistance,superconductiv-ity,magnetic properties,and good thermal properties.Different synthesis routes have been designed and used to meet the properties of interest for particular applications with varying dimensions.How-ever,HEAs are providing new opportunities and challenges for computational modelling of the complex structure-property correlations and in predictions of phase stability necessary for optimum performance of the alloy.Several attempts have been made to understand these alloys by empirical and computa-tional models,and data-driven approaches to accelerate the materials discovery with a desired set of properties.The present review discusses advances and inferences from simulations and models spanning multiple length and time scales explaining a comprehensive set of structure-properties relations.Addi-tionally,the role of machine learning approaches is also reviewed,underscoring the transformative role of computational modelling in unravelling the multifaceted properties and applications of HEAs,and the scope for future efforts in this direction.展开更多
As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise beca...As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.展开更多
High-entropy materials possess high hardness and strong wear resistance,yet the key bottleneck for their practical applications is the poor corrosion resistance in harsh environments.In this work,the high-entropy nitr...High-entropy materials possess high hardness and strong wear resistance,yet the key bottleneck for their practical applications is the poor corrosion resistance in harsh environments.In this work,the high-entropy nitride(HEN)coatings of(MoNbTaTiZr)1-x Nx(x=0-0.47)were fabricated using a hybrid di-rect current magnetron sputtering technique.The research focus was dedicated to the effect of nitrogen content on the microstructure,mechanical and electrochemical properties.The results showed that the as-deposited coatings exhibited a typical body-centered cubic(BCC)structure without nitrogen,while the amorphous matrix with face-centered cubic(FCC)nanocrystalline grain was observed at x=0.17.Further increasing x in the range of 0.35-0.47 caused the appearance of polycrystalline FCC phase in structure.Compared with the MoNbTaTiZr metallic coating,the coating containing nitrogen favored the high hard-ness around 13.7-32.4 GPa,accompanied by excellent tolerance both against elastic and plastic deforma-tion.Furthermore,such N-containing coatings yielded a low corrosion current density of about 10−8-10−7 A/cm^(2) and high electrochemical impedance of 10^(6)Ωcm^(2) in 3.5 wt.%NaCl solution,indicating the supe-rior corrosion resistance.The reason for the enhanced electrochemical behavior could be ascribed to the spontaneous formation of protective passive layers over the coating surface,which consisted of the domi-nated multi-elemental oxides in chemical stability.Particularly,noted that the(MoNbTaTiZr)_(0.83) N0.17 coat-ing displayed the highest hardness of 32.4±2.6 GPa and H/E ratio at 0.09,together with remarkable cor-rosion resistance,proposing the strongest capability for harsh-environmental applications required both good anti-wear and anti-corrosion performance.展开更多
Improving and optimizing the target properties of ceramics via the high entropy strategy has attracted significant attention.Rare earth niobate is a potential thermal barrier coating(TBCs)material,but its poor high-te...Improving and optimizing the target properties of ceramics via the high entropy strategy has attracted significant attention.Rare earth niobate is a potential thermal barrier coating(TBCs)material,but its poor high-temperature phase stability limits its further application.In this work,four sets of TBCs high-entropy ceramics,(Sm_(1/5)Dy_(1/5)Ho_(1/5)Er_(1/5)Yb_(1/5))(Nb_(1/2)Ta_(1/2))O_(4)(5NbTa),(Sm_(1/6)Dy_(1/6)Ho_(1/6)Er_(1/6)Yb_(1/6)Lu_(1/6))(Nb_(1/2)Ta_(1/2))O_(4)(6NbTa),(Sm_(1/7)Gd_(1/7)Dy_(1/7)Ho_(1/7)Er_(1/7)Yb_(1/7)Lu_(1/7))(Nb_(1/2)Ta_(1/2))O_(4)(7NbTa),(Sm_(1/8)Gd_(1/8)Dy_(1/8)Ho_(1/8)Er_(1/8)Tm_(1/8)Yb_(1/8)Lu_(1/8))(Nb_(1/2)Ta_(1/2))O_(4)(8NbTa)are synthesized using a solid-state reaction method at 1650℃for 6 h.Firstly,the X-ray diffractometer(XRD)patterns display that the samples are all single-phase solid solution structures(space group C 2/c).Differential scanning calorimetry(DSC)and the high-temperature XRD of 8NbTa cross-check that the addition of Ta element in 8HERN increases the phase transition temperature above 1400℃,which can be attributed to that the Ta/Nb co-doping at B site introduces the fluctuation of the bond strength of Ta-O and Nb-O.Secondly,compared to high-entropy rare-earth niobates,the introduction of Ta atoms at B site substantially reduce thermal conductivity(re-duced by 44%,800℃)with the seven components high entropy ceramic as an example.The low thermal conductivity means strong phonon scattering,which may originate from the softening acoustic mode and flattened phonon dispersion in 5–8 principal element high entropy rare earth niobium tantalates(5–8NbTa)revealed by the first-principles calculations.Thirdly,the Ta/Nb co-doping in 5–8NbTa systems can further optimize the insulation performance of oxygen ions.The oxygen-ion conductivity of 8NbTa(3.31×10^(−6)S cm^(−1),900℃)is about 5 times lower than that of 8HERN(15.8×10^(−6)S cm^(−1),900℃)because of the sluggish diffusion effect,providing better oxygen barrier capacity in 5–8NbTa systems to inhibit the overgrowth of the thermal growth oxide(TGO)of TBCs.In addition,influenced by lattice dis-tortion and solid solution strengthening,the samples possess higher hardness(7.51–8.15 GPa)and TECs(9.78×10^(−6)K−1^(-1)0.78×10^(−6)K^(−1),1500℃)than the single rare-earth niobates and tantalates.Based on their excellent overall properties,it is considered that 5–8NbTa can be used as auspicious TBCs.展开更多
To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was desi...To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was designed and realized via eutectic high-entropy(EHEA)transformation.Meanwhile,to effectively alleviate the residual stress caused by the notable difference in the thermal expansion coefficient(CTE)between Cantor alloys and Zr-3 alloys,a cladding layer was applied to the HEA surface using laser cladding technology of Nb,followed by brazing to Zr-3 alloys with Zr63.2Cu filler.The cladding layer’s microstructure comprised Nbss and FCC+(Co,Ni)_(2) Nb eutectic structure,resulting from an in-situ reaction between Cantor alloys and Nb.The Nbss and FCC demonstrated good plasticity,and the(Co,Ni)_(2) Nb Laves phase provided increased strength,endowing both good plastic deformation ability and strength of the cladding layer.Notably,the existence of EHEA in the laser cladding layer made the Cantor alloy entropy from 1.61 R to 1.77 R,greatly enhancing its thermal stability and suppressing the grave grain boundary infiltration.Joints produced via laser cladding with Nb-assisted brazing exhibited a complex microstructure(HEA/Nbss+FCC+(Co,Ni)_(2)Nb/(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/(Zr,Nb)_(2)(Cu,Ni,Co,Fe)+(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/Zr-3) and a significantly improved shear strength of 242.8 MPa at 1010℃ for 10 min,42.4%higher than that of directly brazed joints.This improvement was attributed to reduced grain boundary infiltration,alleviated residual stress due to CTE disparity,and eliminated micro-cracks in the brazing seam.This study presents an effective solution for reducing residual stresses and achieving reliable bonding between Cantor alloys and Zr-3 alloys,with potential applications in brazing CoCrFeNi-based HEA and Zr-3 due to the beneficial eutectic reaction between CoCrFeNi and Nb.展开更多
Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated therma...Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.展开更多
In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well...In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well addressed,including phase transition,structural degradation,and voltage platform.High entropy materials have recently gained significant attention from researchers due to their effects on thermodynamics,dynamics,structure,and performance.Researchers have attempted to use these materials in sodium-ion batteries to overcome their problems,making it a modification method.This paper aims to discuss the research status of high-entropy cathode materials for sodium-ion batteries and summarize their effects on sodium-ion batteries from three perspectives:Layered oxide,polyanion,and Prussian blue.The infiuence on material structure,the inhibition of phase transition,and the improvement of ion diffusivity are described.Finally,the advantages and disadvantages of high-entropy cathode materials for sodium-ion batteries are summarized,and their future development has prospected.展开更多
Solid oxide cells(SOCs),which include solid oxide fuel cells(SOFCs),symmetrical solid oxide cells(S-SOCs),and reversible solid oxide cells(R-SOCs),are considered key technologies for driving low-carbon and green revol...Solid oxide cells(SOCs),which include solid oxide fuel cells(SOFCs),symmetrical solid oxide cells(S-SOCs),and reversible solid oxide cells(R-SOCs),are considered key technologies for driving low-carbon and green revolution in the energy sector.Because of their clean,low-cost,and high-efficiency characteristics,SOCs have great potential for energy conversion and storage.However,the further development of SOC technologies faces challenges,such as a lack of long-term operational stability of the cell system,high material cost under high-temperature operating conditions,and limited catalytic effects at low temperatures.Recently,high-entropy materials(HEMs)have demonstrated excellent performance and wide application prospects in catalytic reactions,energy storage,supercapacitors,and other fields owing to their unique atomic arrangement and the four core effects(high mixed entropy stabilization effect,sluggish dif-fusion effect,lattice distortion effect,and“cocktail”effect).HEMs provide a new perspective for solving the aforementioned problems in the field of SOCs.This comprehensive review summarizes the applications of HEMs in the three fundamental components of SOCs:elec-trodes,electrolytes,and interconnects,focusing on the role of HEMs in enhancing catalytic activity and conductivity while mitigating harmful gas poisoning.In addition,this review proposes possible development directions for HEMs in SOCs based on the current re-search progress,providing valuable reference for high-entropy designs aimed at further enhancing the performance of SOCs.展开更多
How to achieve high-entropy alloys(HEAs)with ultrahigh strength and ductility is a challenging issue.Precipitation strengthening is one of the methods to significantly enhance strength,but unfortunately,ductility will...How to achieve high-entropy alloys(HEAs)with ultrahigh strength and ductility is a challenging issue.Precipitation strengthening is one of the methods to significantly enhance strength,but unfortunately,ductility will be lost.To overcome the strength-ductility trade-off,the strategy of this study is to induce the formation of high-density nanoprecipitates through dual aging(DA),triggering multiple deformation mechanisms,to obtain HEAs with ultrahigh strength and ductility.First,the effect of precold deformation on precipitation behavior was studied using Ni_(35)(CoFe)_(55)V_(5)Nb_(5)(at.%)HEAas the object.The results reveal that the activation energy of recrystallization is 112.2 kJ/mol.As the precold-deformation amount increases from 15%to 65%,the activation energy of precipitation gradually decreases from 178.8 to 159.7 kJ/mol.The precipitation time shortens,the size of the nanoprecipitate decreases,and the density increases.Subsequently,the thermal treatment parameters were optimized,and the DA process was customized based on the effect of precold deformation on precipitation behavior.High-density L1_(2) nanoprecipitates(~3.21×10^(25) m^(-3))were induced in the 65% precold-deformed HEA,which led to the simultaneous formation of twins and stacking fault(SF)networks during deformation.The yield strength(YS),ultimate tensile strength,and ductility of the DA-HEA are~2.0 GPa,~2.2 GPa,and~12.3%,respectively.Compared with the solid solution HEA,the YS of the DA-HEA increased by 1,657 MPa,possessing an astonishing increase of~440%.The high YS stems from the precipitation strengthening contributed by the L1_(2) nanoprecipitates and the dislocation strengthening contributed by precold deformation.The synergistically enhanced ductility stems from the high strain-hardening ability under the dual support of twinning-induced plasticity and SF-induced plasticity.展开更多
High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or mor...High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or more principal elements in nearly equiatom-ic proportions)confer unique advantages such as high configurational entropy,lattice distortion,and synergistic cocktail effects,the fun-damental understanding of structure-property relationships in battery systems remains fragmented across existing studies.This review ad-dresses critical research gaps by proposing a multidimensional design paradigm that systematically integrates synergistic mechanisms spanning cathodes,anodes,electrolytes,and electrocatalysts.We provide an in-depth analysis of HEMs’thermodynamic/kinetic stabiliza-tion principles and structure-regulated electrochemical properties,integrating and establishing quantitative correlations between entropy-driven phase stability and charge transport dynamics.By summarizing the performance benchmarking results of lithium/sodium/potassi-um-ion battery components,we reveal how entropy-mediated structural tailoring enhances cycle stability and ionic conductivity.Notably,we pioneer the systematic association of high-entropy effects to electrochemical interfaces,demonstrating their unique potential in stabil-izing solid-electrolyte interphases and suppressing transition metal dissolution.Emerging opportunities in machine learning-driven com-position screening and sustainable manufacturing are discussed alongside critical challenges,including performance variability metrics and cost-benefit analysis for industrial implementation.This work provides both fundamental insights and practical guidelines for advan-cing HEMs toward next-generation battery technologies.展开更多
Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bott...Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.展开更多
The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carri...The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.展开更多
The interdiffusion coefficients in Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of ...The interdiffusion coefficients in Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of interdiffusion coefficients(HitDIC)software at 1273−1373 K.The results show that the addition of Al,Cu,and Mn to CoCrFeNi high-entropy alloys promotes the diffusion of Co,Cr,and Fe atoms.The comparison of tracer diffusion coefficients indicates that there is no sluggish diffusion in tracer diffusion on the thermodynamic temperature scale for the present Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys.The linear relationship between diffusion entropy and activation energy reveals that the diffusion process of atoms is unaffected by an increase in the number of components as long as the crystal structure remains unchanged.展开更多
Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(...Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.展开更多
High-entropy design is attracting growing interest as it offers unique structures and unprecedented application potential for ma-terials.In this article,a novel high-entropy ferrite(CoNi)_(x/2)(CuZnAl)_((1-x)/3)Fe_(2)...High-entropy design is attracting growing interest as it offers unique structures and unprecedented application potential for ma-terials.In this article,a novel high-entropy ferrite(CoNi)_(x/2)(CuZnAl)_((1-x)/3)Fe_(2)O_(4)(x=0.25,0.34,0.40,0.50)with a single spinel phase of space group Fd3m was successfully developed by the solid-state reaction method.By tuning the Co-Ni content,the magnetic properties of the material,especially the coercivity,changed regularly,and the microwave absorption properties were improved.In particular,the ef-fective absorption bandwidth of the material increased from 4.8 to 7.2 GHz,and the matched thickness decreased from 3.9 to 2.3 mm,while the minimum reflection loss remained below-20 dB.This study provides a practical method for modifying the properties of fer-rites used to absorb electromagnetic waves.展开更多
Introduction High-entropy oxides(HEOs)have attracted much attention in the field of electrochemistry due to their distinctive structural characteristics and unique properties.The multiple-principal elements in HEOs of...Introduction High-entropy oxides(HEOs)have attracted much attention in the field of electrochemistry due to their distinctive structural characteristics and unique properties.The multiple-principal elements in HEOs offer the multiple redox pairs and multiple possible active sites,which can enhance the energy storage capacity and the electrocatalytic performance.Although the notable progress is achieved in the development of HEOs electrodes,their electrochemical properties should be further improved to meet the requirements of high-performance supercapacitors and OER electrocatalysts.The abundant active sites for the Faradic redox reactions and short pathways for charge transportation could be constructed through the design of novel HEOs with advanced microstructures,thus improving the electrochemical properties.As advanced microstructures,a hollow structure has a great promise for energy storage and conversion because it can provide more accessible storage sites,more catalytic centers and a larger electrode/electrolyte contact area.It is thus expected that the construction of hollow structure is an alternative route to significantly promote the electrochemical properties of HEOs electrode materials.However,it is difficult to prepare the HEOs with a hollow structure due to the complexity of the high-entropy system.In this work,a hollow spherical high-entropy perovskite oxide of La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Ni_(0.2)Cu_(0.2))O_(3)(HS-HEPs)was prepared by microwave solvothermal process and subsequent calcination treatment.The as-prepared HS-HEPs exhibited the excellent electrochemical performance when used as an electrode material for supercapacitors and OER electrocatalysts due to the advantages resulted from the combination of high-entropy perovskite and special hollow structure.Methods HS-HEPs were prepared by microwave solvothermal process and subsequent calcination treatment.Typically,0.134 mmol Cr(NO_(3))_(3)·6H_(2)O,0.134 mmol Mn(NO_(3))_(2)·4H_(2)O,0.134 mmol Fe(NO_(3))_(3)·9H_(2)O,0.134 mmol Ni(NO_(3))_(2)·6H_(2)O,0.134 mmol Cu(NO_(3))_(2)·3H_(2)O,and 0.5 mmol La(NO_(3))_(3)·6H_(2)O were dissolved in 30 mL ethanol under stirring for 1 h to obtain the homogeneous solution.Afterwards,60 mg of carbon spheres were added in the solution under ultrasonic treatment for 30 min.The resulting mixture was transferred to a 50 mL microwave digestion vessel.The vessel was heated in a microwave oven at a power of 210 W for 10 min.Subsequently,the obtained mixture was centrifuged,washed with deionized water,and dried in a vacuum drying oven at 70℃for 12 h.Finally,the obtained precursor powder was calcinated in a tube furnace with a heating rate of 3℃/min at 650℃for 2 h to acquire HS-HEPs.The crystalline structure of the sample was determined by X-ray diffraction(XRD,D8 Davinci,Bruker Co.,Germany).The morphology and microstructure of sample were characterized by field-emission scanning electron microscopy(FESEM,S-4800,Hitachi Co.Ltd.,Japan)equipped with energy dispersive X-ray spectroscopy(EDS)and transmission electron microscopy(TEM,2100F,JEOL Co.,Japan).The X-ray photoelectron spectra were obtained by a X-ray photoelectron spectrometry(XPS,ESCALab 250,Thermo VG Co.,USA).The supercapacitor and OER performance of the sample were measured on a CHI 660E electrochemical workstation(Shanghai Chenhua Instrument Co.,China).Results and discussion The as-prepared samples display a cubic perovskite crystalline structure and a hollow sphere morphology.According to the XPS analysis,the variable oxidation states of Cr,Fe and Mn present in the HS-HEPs,which benefits the Faradaic redox reactions and increases the capacitance.In addition,the existence of high concentration of oxygen vacancies in HS-HEPs is beneficial to enhancing the capacitance and OER activity.Based on the GCD curve,the specific capacitance of HS-HEPs is estimated to be 406 F/g at 1 A/g.After GCD cycles of 5000 at a current density of 5 A/g,65%capacitance is retained,implying a good long-term electrochemical stability.An asymmetric supercapacitor device(HS-HEPs//AC)with a two electrode configuration is assembled.A maximum energy density of 39.4 W·h/kg is achieved at power density of 746 W/kg.The OER activity of HS-HEPs is evaluated by a linear sweep voltammetry(LSV)polarization curve in 1 mol/L KOH aqueous solution using a standard three-electrode system.The overpotential of HS-HEPs is identified as 347 mV versus RHE for achieving a current density of 10 mA/cm^(2),which is smaller than that of commercial IrO2(372 mV).The HS-HEPs possess the excellent electrochemical performance,which can be ascribed to the high specific surface area,abundant active sites,and high oxygen vacancy content,resulting from the combination of high-entropy perovskite and special hollow structure.Conclusions High-entropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Ni_(0.2)Cu_(0.2))O_(3)hollow spheres with a perovskite crystalline structure were prepared by microwave solvothermal process and subsequent calcination treatment.The HS-HEPs possessed the excellent electrochemical performance,which could be ascribed to the high specific surface area,abundant active sites,and high oxygen vacancy content,resulting from the combination of high-entropy perovskite and special hollow structure.Based on the electrochemical performance,HS-HEPs could be used as supercapacitor electrode material and OER electrocatalysts.This work could provide a strategy to design and prepare high-entropy oxides with a hollow sphere structure,having promising applications in energy storage and conversion.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22209183,22225902,U22A20436)the Advanced Talents of Jiangsu University,China(No.23JDG027)。
文摘Developing efficient electrocatalysts for oxygen evolution reaction(OER)is imperative to enhance the overall efficiency of electrolysis systems and rechargeable metal-air batteries operating in aqueous solutions.High-entropy materials,featured with their distinctive multi-component properties,have found extensive application as catalysts in electrochemical energy storage and conversion devices.However,synthesizing nanostructured high-entropy compounds under mild conditions poses a significant challenge due to the difficulty in overcoming the immiscibility of multiple metallic constituents.In this context,the current study focuses on the synthesis of an array of nano-sized high entropy sulfides tailored for OER via a facile precursor pyrolysis method at low temperature.The representative compound,Fe Co Ni Cu Mn Sx,demonstrates remarkable OER performance,achieving a current density of 10 m A/cm^(2) at an overpotential of merely 220 m V and excellent stability with constant electrolysis at 100 m A/cm^(2) for over 400 h.The in-situ formed metal(oxy)hydroxide has been confirmed as the real active sites and its exceptional performance can be primarily attributed to the synergistic effects arising from its multiple components.Furthermore,the synthetic methodology presented here is versatile and can be extended to the preparation of high entropy phosphides,which also present favorable OER performance.This research not only introduces promising non-noble electrocatalysts for OER but also offers a facile approach to expand the family of nano high-entropy materials,contributing significantly to the field of electrochemical energy conversion.
基金the Macao Science and Technology Development Fund(FDCT)for funding(FDCT-MOST joint project nos.0026/2022/AMJ,0098/2020/A2,and 006/2022/ALC of the Macao Centre for Research and Development in Advanced Materials(2022-2024))the Natural Science Foundation of Guangdong Province(No.2023A1515010765)+4 种基金the Shenzhen-Hong Kong-Macao Science and Technology Plan Project(Category C)(No.SGDX20220530111004028)the Science and Technology Program of Guangdong Province of China(No.2023A0505030001)the National Natural Science Foundation of China(No.52102264)the Leading Edge Technology of Jiangsu Province(No.BK20220009)the Macao Young Scholars Program(No.AM2022009).
文摘High-entropy oxides(HEOs)have received considerable attention in the past few years due to their unique high configurational entropy and ideal elemental adjustability.HEOs are generally considered to be a special class of oxides containing five or more different metal cations.The attractive synergistic effect makes HEOs promising energy storage and conversion material.However,at present,the knowledge of HEOs and their practical applications on electrochemistry is still scattered without comprehensive report.In this review,we highlight the preparation methods,common crystal structures and their applications in the field of electrochemistry,which can be divided into two main categories:(1)electrochemical energy storage devices,including supercapacitors,lithium-ion batteries,sodium-ion batteries,and other batteries;(2)electrocatalysis reaction system,including hydrogen evolution reaction(HER),oxygen evolution reaction(OER),oxygen reduction reaction(ORR),and electrocatalytic CO_(2)reduction reaction(CO_(2)RR).Finally,the remaining challenges and prospects in the future are envisioned in the related field,which will help to unlock the mysteries of HEOs for energy storage and conversion.
基金financially supported by the National Natural Science Foundation of China(Nos.21171018 and 51271021)the State Key Laboratory for Advanced Metals and Materials。
文摘This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.
基金supported by Yunnan Science and Technology Leading Talent Project(No.202305AB350005)。
文摘Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Several collectors were initially selected through micro-flotation tests,leading to the identification of optimal proportions for a four-component collector system(SHA-OHA-SPA-DBIA in a 4:3:2:1 ratio).Molecular dynamics simulations and surface tension tests were used to investigate the micellar behavior of these collectors in aqueous solution.The adsorption characteristics were quantified using microcalorimetry,enabling the determination of collection entropy and changes in Gibbs free energy.The four-component collector system showed the highest entropy change and the most favorable Gibbs free energy,leading to a cassiterite recovery of above 90%at a concentration of 8.0×10^(5)mol/L.Various analytical techniques were employed to systematically characterize the adsorption mechanism.The findings revealed a positive correlation between the adsorption products formed by the multicomponent collectors on the cassiterite surface and the entropy changes.Industrial-scale testing of the high-entropy collector system produced a tin concentrate with an Sn grade of 6.17%and an Sn recovery of 82.43%,demonstrating its substantial potential for practical applications in cassiterite flotation.
基金the Science and Engineering Re-search Board(SERB),India for providing the financial assistance to support this work(Project No.SRG/2020/002449).
文摘Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery of high-entropy alloys(HEAs)comprising multi-principal elements.Owing to the four“core-effects”,these alloys exhibit exceptional properties including better structural stability,high strength and ductility,improved fatigue/fracture toughness,high corrosion and oxidation resistance,superconductiv-ity,magnetic properties,and good thermal properties.Different synthesis routes have been designed and used to meet the properties of interest for particular applications with varying dimensions.How-ever,HEAs are providing new opportunities and challenges for computational modelling of the complex structure-property correlations and in predictions of phase stability necessary for optimum performance of the alloy.Several attempts have been made to understand these alloys by empirical and computa-tional models,and data-driven approaches to accelerate the materials discovery with a desired set of properties.The present review discusses advances and inferences from simulations and models spanning multiple length and time scales explaining a comprehensive set of structure-properties relations.Addi-tionally,the role of machine learning approaches is also reviewed,underscoring the transformative role of computational modelling in unravelling the multifaceted properties and applications of HEAs,and the scope for future efforts in this direction.
基金supported by the National Key R&D Program of China(2022YFB4004000)National Natural Science Foundation of China(U24A20542,52472210,22279057)+3 种基金Natural Science Foundation of Jiangsu Province(BK20221312)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1465)Cultivation Program for the Excellent Doctoral Dissertation of Nanjing Tech University(2023-09)the grant of Hydrogen Energy Laboratory(No.FEUZ-2024-0009)。
文摘As global energy demand increases and environmental standards tighten,the development of efficient,eco-friendly energy conversion and storage technologies becomes crucial.Solid oxide cells(SOCs)show great promise because of their high energy conversion efficiency and wide range of applications.Highentropy materials(HEMs),a novel class of materials comprising several principal elements,have attracted significant interest within the materials science and energy sectors.Their distinctive structural features and adaptable functional properties offer immense potential for innovation across various applications.This review systematically covers the basic concepts,crystal structures,element selection,and major synthesis strategies of HEMs,and explores in detail the specific applications of these materials in SOCs,including its potential as air electrodes,fuel electrodes,electrolytes,and interconnects(including barrier coatings).By analyzing existing studies,this review reveals the significant advantages of HEMs in enhancing the performance,anti-poisoning,and stability of SOCs;highlights the key areas and challenges for future research;and looks into possible future directions.
基金supported by the National Science Fund for Distinguished Young Scholars of China(No.52025014)Zhejiang Provincial Natural Science Foundation of China(Nos.LZJWY23E090001 and LD24E010003)the Natural Science Foundation of Ningbo(No.2022J305).
文摘High-entropy materials possess high hardness and strong wear resistance,yet the key bottleneck for their practical applications is the poor corrosion resistance in harsh environments.In this work,the high-entropy nitride(HEN)coatings of(MoNbTaTiZr)1-x Nx(x=0-0.47)were fabricated using a hybrid di-rect current magnetron sputtering technique.The research focus was dedicated to the effect of nitrogen content on the microstructure,mechanical and electrochemical properties.The results showed that the as-deposited coatings exhibited a typical body-centered cubic(BCC)structure without nitrogen,while the amorphous matrix with face-centered cubic(FCC)nanocrystalline grain was observed at x=0.17.Further increasing x in the range of 0.35-0.47 caused the appearance of polycrystalline FCC phase in structure.Compared with the MoNbTaTiZr metallic coating,the coating containing nitrogen favored the high hard-ness around 13.7-32.4 GPa,accompanied by excellent tolerance both against elastic and plastic deforma-tion.Furthermore,such N-containing coatings yielded a low corrosion current density of about 10−8-10−7 A/cm^(2) and high electrochemical impedance of 10^(6)Ωcm^(2) in 3.5 wt.%NaCl solution,indicating the supe-rior corrosion resistance.The reason for the enhanced electrochemical behavior could be ascribed to the spontaneous formation of protective passive layers over the coating surface,which consisted of the domi-nated multi-elemental oxides in chemical stability.Particularly,noted that the(MoNbTaTiZr)_(0.83) N0.17 coat-ing displayed the highest hardness of 32.4±2.6 GPa and H/E ratio at 0.09,together with remarkable cor-rosion resistance,proposing the strongest capability for harsh-environmental applications required both good anti-wear and anti-corrosion performance.
基金support from Yunnan Major Scientific and Technological Projects(No.202302AG050010)Yunnan Fundamental Research Projects(Nos.202101AW070011 and202101BE070001–015)+1 种基金National Natural Science Foundation of China(No.52303295)Project Funds of“Xingdian Talent Support Program”.
文摘Improving and optimizing the target properties of ceramics via the high entropy strategy has attracted significant attention.Rare earth niobate is a potential thermal barrier coating(TBCs)material,but its poor high-temperature phase stability limits its further application.In this work,four sets of TBCs high-entropy ceramics,(Sm_(1/5)Dy_(1/5)Ho_(1/5)Er_(1/5)Yb_(1/5))(Nb_(1/2)Ta_(1/2))O_(4)(5NbTa),(Sm_(1/6)Dy_(1/6)Ho_(1/6)Er_(1/6)Yb_(1/6)Lu_(1/6))(Nb_(1/2)Ta_(1/2))O_(4)(6NbTa),(Sm_(1/7)Gd_(1/7)Dy_(1/7)Ho_(1/7)Er_(1/7)Yb_(1/7)Lu_(1/7))(Nb_(1/2)Ta_(1/2))O_(4)(7NbTa),(Sm_(1/8)Gd_(1/8)Dy_(1/8)Ho_(1/8)Er_(1/8)Tm_(1/8)Yb_(1/8)Lu_(1/8))(Nb_(1/2)Ta_(1/2))O_(4)(8NbTa)are synthesized using a solid-state reaction method at 1650℃for 6 h.Firstly,the X-ray diffractometer(XRD)patterns display that the samples are all single-phase solid solution structures(space group C 2/c).Differential scanning calorimetry(DSC)and the high-temperature XRD of 8NbTa cross-check that the addition of Ta element in 8HERN increases the phase transition temperature above 1400℃,which can be attributed to that the Ta/Nb co-doping at B site introduces the fluctuation of the bond strength of Ta-O and Nb-O.Secondly,compared to high-entropy rare-earth niobates,the introduction of Ta atoms at B site substantially reduce thermal conductivity(re-duced by 44%,800℃)with the seven components high entropy ceramic as an example.The low thermal conductivity means strong phonon scattering,which may originate from the softening acoustic mode and flattened phonon dispersion in 5–8 principal element high entropy rare earth niobium tantalates(5–8NbTa)revealed by the first-principles calculations.Thirdly,the Ta/Nb co-doping in 5–8NbTa systems can further optimize the insulation performance of oxygen ions.The oxygen-ion conductivity of 8NbTa(3.31×10^(−6)S cm^(−1),900℃)is about 5 times lower than that of 8HERN(15.8×10^(−6)S cm^(−1),900℃)because of the sluggish diffusion effect,providing better oxygen barrier capacity in 5–8NbTa systems to inhibit the overgrowth of the thermal growth oxide(TGO)of TBCs.In addition,influenced by lattice dis-tortion and solid solution strengthening,the samples possess higher hardness(7.51–8.15 GPa)and TECs(9.78×10^(−6)K−1^(-1)0.78×10^(−6)K^(−1),1500℃)than the single rare-earth niobates and tantalates.Based on their excellent overall properties,it is considered that 5–8NbTa can be used as auspicious TBCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52275321 and 52205348)the Shandong Natural Science Foundation(Grant No.ZR2023JQ021)+3 种基金the Taishan Scholars Foundation of Shandong Province(No.tsqn 201812128)the Innovation Scientists and Technicians Troop Projects of Henan Province(No.204200510031)the Heilongjiang Touyan Innovation Team Program(No.HITTY-20190013)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(Nos.NRF-2021R1A2C3006662 and NRF-2022R1A5A1030054).
文摘To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was designed and realized via eutectic high-entropy(EHEA)transformation.Meanwhile,to effectively alleviate the residual stress caused by the notable difference in the thermal expansion coefficient(CTE)between Cantor alloys and Zr-3 alloys,a cladding layer was applied to the HEA surface using laser cladding technology of Nb,followed by brazing to Zr-3 alloys with Zr63.2Cu filler.The cladding layer’s microstructure comprised Nbss and FCC+(Co,Ni)_(2) Nb eutectic structure,resulting from an in-situ reaction between Cantor alloys and Nb.The Nbss and FCC demonstrated good plasticity,and the(Co,Ni)_(2) Nb Laves phase provided increased strength,endowing both good plastic deformation ability and strength of the cladding layer.Notably,the existence of EHEA in the laser cladding layer made the Cantor alloy entropy from 1.61 R to 1.77 R,greatly enhancing its thermal stability and suppressing the grave grain boundary infiltration.Joints produced via laser cladding with Nb-assisted brazing exhibited a complex microstructure(HEA/Nbss+FCC+(Co,Ni)_(2)Nb/(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/(Zr,Nb)_(2)(Cu,Ni,Co,Fe)+(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/Zr-3) and a significantly improved shear strength of 242.8 MPa at 1010℃ for 10 min,42.4%higher than that of directly brazed joints.This improvement was attributed to reduced grain boundary infiltration,alleviated residual stress due to CTE disparity,and eliminated micro-cracks in the brazing seam.This study presents an effective solution for reducing residual stresses and achieving reliable bonding between Cantor alloys and Zr-3 alloys,with potential applications in brazing CoCrFeNi-based HEA and Zr-3 due to the beneficial eutectic reaction between CoCrFeNi and Nb.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB4000604)the National Natural Science Foundation of China (No. 52271220)+2 种基金the 111 Project (No. B12015)the Fundamental Research Funds for the Central UniversitiesHaihe Laboratory of Sustainable Chemical Transformations, Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials, Science Research and Technology Development Project of Guilin (No. 20210102-4)
文摘Novel hydrogen storage materials have propelled progress in hydrogen storage technologies.Magnesium hydride(MgH_(2))is a highly promising candidate.Nevertheless,several drawbacks,including the need for elevated thermal conditions,sluggish dehydrogena-tion kinetics,and high thermodynamic stability,limit its practical application.One effective method of addressing these challenges is cata-lyst doping,which effectively boosts the hydrogen storage capability of Mg-based materials.Herein,we review recent advancements in catalyst-doped MgH_(2) composites,with particular focus on multicomponent and high-entropy catalysts.Structure-property relationships and catalytic mechanisms in these doping strategies are also summarized.Finally,based on existing challenges,we discuss future research directions for the development of Mg-based hydrogen storage systems.
基金the National Natural Science Foundation of China Key Program(No.U22A20420)Changzhou Leading Innovative Talents Introduction and Cultivation Project(No.CQ20230109)for supporting our work。
文摘In recent years,sodium-ion batteries(SIBs)have become one of the hot discussions and have gradually moved toward industrialization.However,there are still some shortcomings in their performance that have not been well addressed,including phase transition,structural degradation,and voltage platform.High entropy materials have recently gained significant attention from researchers due to their effects on thermodynamics,dynamics,structure,and performance.Researchers have attempted to use these materials in sodium-ion batteries to overcome their problems,making it a modification method.This paper aims to discuss the research status of high-entropy cathode materials for sodium-ion batteries and summarize their effects on sodium-ion batteries from three perspectives:Layered oxide,polyanion,and Prussian blue.The infiuence on material structure,the inhibition of phase transition,and the improvement of ion diffusivity are described.Finally,the advantages and disadvantages of high-entropy cathode materials for sodium-ion batteries are summarized,and their future development has prospected.
基金supported by the Industrial Foresight Projects and Common Key Technologies of Zhenjiang(No.GY2024028)The authors also acknowledged the support of the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology(No.XTCX202404).
文摘Solid oxide cells(SOCs),which include solid oxide fuel cells(SOFCs),symmetrical solid oxide cells(S-SOCs),and reversible solid oxide cells(R-SOCs),are considered key technologies for driving low-carbon and green revolution in the energy sector.Because of their clean,low-cost,and high-efficiency characteristics,SOCs have great potential for energy conversion and storage.However,the further development of SOC technologies faces challenges,such as a lack of long-term operational stability of the cell system,high material cost under high-temperature operating conditions,and limited catalytic effects at low temperatures.Recently,high-entropy materials(HEMs)have demonstrated excellent performance and wide application prospects in catalytic reactions,energy storage,supercapacitors,and other fields owing to their unique atomic arrangement and the four core effects(high mixed entropy stabilization effect,sluggish dif-fusion effect,lattice distortion effect,and“cocktail”effect).HEMs provide a new perspective for solving the aforementioned problems in the field of SOCs.This comprehensive review summarizes the applications of HEMs in the three fundamental components of SOCs:elec-trodes,electrolytes,and interconnects,focusing on the role of HEMs in enhancing catalytic activity and conductivity while mitigating harmful gas poisoning.In addition,this review proposes possible development directions for HEMs in SOCs based on the current re-search progress,providing valuable reference for high-entropy designs aimed at further enhancing the performance of SOCs.
基金supported by the National Key Research and Development Project(No.2023YFA1600082)the National Natural Science Foundation of China(Nos.U2141207,52001083,52171111)+3 种基金Natural Science Foundation of Heilongjiang(No.YQ2023E026)the Fundamental Research Funds for the Central Universities(No.3072022JIP1002)Key Laboratory Found of the Ministry of Industry and Information Technology(No.GXB202201)Youth Talent Project of China National Nuclear Corporation(No.CNNC2021YTEP-HEU01).
文摘How to achieve high-entropy alloys(HEAs)with ultrahigh strength and ductility is a challenging issue.Precipitation strengthening is one of the methods to significantly enhance strength,but unfortunately,ductility will be lost.To overcome the strength-ductility trade-off,the strategy of this study is to induce the formation of high-density nanoprecipitates through dual aging(DA),triggering multiple deformation mechanisms,to obtain HEAs with ultrahigh strength and ductility.First,the effect of precold deformation on precipitation behavior was studied using Ni_(35)(CoFe)_(55)V_(5)Nb_(5)(at.%)HEAas the object.The results reveal that the activation energy of recrystallization is 112.2 kJ/mol.As the precold-deformation amount increases from 15%to 65%,the activation energy of precipitation gradually decreases from 178.8 to 159.7 kJ/mol.The precipitation time shortens,the size of the nanoprecipitate decreases,and the density increases.Subsequently,the thermal treatment parameters were optimized,and the DA process was customized based on the effect of precold deformation on precipitation behavior.High-density L1_(2) nanoprecipitates(~3.21×10^(25) m^(-3))were induced in the 65% precold-deformed HEA,which led to the simultaneous formation of twins and stacking fault(SF)networks during deformation.The yield strength(YS),ultimate tensile strength,and ductility of the DA-HEA are~2.0 GPa,~2.2 GPa,and~12.3%,respectively.Compared with the solid solution HEA,the YS of the DA-HEA increased by 1,657 MPa,possessing an astonishing increase of~440%.The high YS stems from the precipitation strengthening contributed by the L1_(2) nanoprecipitates and the dislocation strengthening contributed by precold deformation.The synergistically enhanced ductility stems from the high strain-hardening ability under the dual support of twinning-induced plasticity and SF-induced plasticity.
基金supported by National Natural Science Foundation of China(No.5227130161).
文摘High-entropy materials(HEMs),an innovative class of materials with complex stoichiometry,have recently garnered consider-able attention in energy storage applications.While their multi-element compositions(five or more principal elements in nearly equiatom-ic proportions)confer unique advantages such as high configurational entropy,lattice distortion,and synergistic cocktail effects,the fun-damental understanding of structure-property relationships in battery systems remains fragmented across existing studies.This review ad-dresses critical research gaps by proposing a multidimensional design paradigm that systematically integrates synergistic mechanisms spanning cathodes,anodes,electrolytes,and electrocatalysts.We provide an in-depth analysis of HEMs’thermodynamic/kinetic stabiliza-tion principles and structure-regulated electrochemical properties,integrating and establishing quantitative correlations between entropy-driven phase stability and charge transport dynamics.By summarizing the performance benchmarking results of lithium/sodium/potassi-um-ion battery components,we reveal how entropy-mediated structural tailoring enhances cycle stability and ionic conductivity.Notably,we pioneer the systematic association of high-entropy effects to electrochemical interfaces,demonstrating their unique potential in stabil-izing solid-electrolyte interphases and suppressing transition metal dissolution.Emerging opportunities in machine learning-driven com-position screening and sustainable manufacturing are discussed alongside critical challenges,including performance variability metrics and cost-benefit analysis for industrial implementation.This work provides both fundamental insights and practical guidelines for advan-cing HEMs toward next-generation battery technologies.
基金supported by the National Natural Science Foundation of China(Nos.52371128,52304378,52101031 and 92163107).
文摘Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.
基金support from National Natural Science Foundation of China(NSFC,Grant numbers U22A20185,U21A20128,52175302 and 52305353)Aeronautical Science Foundation(ASFC-20230036077001)Fundamental Research Funds for the Central Universities(2022FRFK060009,HIT.DZI1.2023012).
文摘The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.
基金supported by the National Natural Science Foundation of China(No.52374372)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.23KJB430042)+3 种基金the Jiangsu Province Large Scientific Instruments Open Sharing Autonomous Research Filing Project,China(No.TC2023A037)the Yangzhou City−Yangzhou University Cooperation Foundation,China(No.YZ2022183)High-end Talent Support Program of Yangzhou University,China,Qinglan Project of Yangzhou University,ChinaLvyangjinfeng Talent program of Yangzhou,China.
文摘The interdiffusion coefficients in Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of interdiffusion coefficients(HitDIC)software at 1273−1373 K.The results show that the addition of Al,Cu,and Mn to CoCrFeNi high-entropy alloys promotes the diffusion of Co,Cr,and Fe atoms.The comparison of tracer diffusion coefficients indicates that there is no sluggish diffusion in tracer diffusion on the thermodynamic temperature scale for the present Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys.The linear relationship between diffusion entropy and activation energy reveals that the diffusion process of atoms is unaffected by an increase in the number of components as long as the crystal structure remains unchanged.
基金support provided by the National Key R&D Program of China(No.2024YFE0101500)the National Natural Science Foundation of China(No.52272257)the Natural Science Foundation of Jiangsu Province(No.BK20240109).
文摘Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.
基金supported by the National Natural Science Foundation of China(No.52371231)the Key Research and Development Program of Shanxi Province,China(No.202102030201006)+1 种基金the Central Government Guides Local Science and Technology Development Special Fund Project(No.YDZJSX2022B003),the Natural Science Foundation of Shanxi Province,China(No.202203021212205)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi,China(No.2022L074).
文摘High-entropy design is attracting growing interest as it offers unique structures and unprecedented application potential for ma-terials.In this article,a novel high-entropy ferrite(CoNi)_(x/2)(CuZnAl)_((1-x)/3)Fe_(2)O_(4)(x=0.25,0.34,0.40,0.50)with a single spinel phase of space group Fd3m was successfully developed by the solid-state reaction method.By tuning the Co-Ni content,the magnetic properties of the material,especially the coercivity,changed regularly,and the microwave absorption properties were improved.In particular,the ef-fective absorption bandwidth of the material increased from 4.8 to 7.2 GHz,and the matched thickness decreased from 3.9 to 2.3 mm,while the minimum reflection loss remained below-20 dB.This study provides a practical method for modifying the properties of fer-rites used to absorb electromagnetic waves.
文摘Introduction High-entropy oxides(HEOs)have attracted much attention in the field of electrochemistry due to their distinctive structural characteristics and unique properties.The multiple-principal elements in HEOs offer the multiple redox pairs and multiple possible active sites,which can enhance the energy storage capacity and the electrocatalytic performance.Although the notable progress is achieved in the development of HEOs electrodes,their electrochemical properties should be further improved to meet the requirements of high-performance supercapacitors and OER electrocatalysts.The abundant active sites for the Faradic redox reactions and short pathways for charge transportation could be constructed through the design of novel HEOs with advanced microstructures,thus improving the electrochemical properties.As advanced microstructures,a hollow structure has a great promise for energy storage and conversion because it can provide more accessible storage sites,more catalytic centers and a larger electrode/electrolyte contact area.It is thus expected that the construction of hollow structure is an alternative route to significantly promote the electrochemical properties of HEOs electrode materials.However,it is difficult to prepare the HEOs with a hollow structure due to the complexity of the high-entropy system.In this work,a hollow spherical high-entropy perovskite oxide of La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Ni_(0.2)Cu_(0.2))O_(3)(HS-HEPs)was prepared by microwave solvothermal process and subsequent calcination treatment.The as-prepared HS-HEPs exhibited the excellent electrochemical performance when used as an electrode material for supercapacitors and OER electrocatalysts due to the advantages resulted from the combination of high-entropy perovskite and special hollow structure.Methods HS-HEPs were prepared by microwave solvothermal process and subsequent calcination treatment.Typically,0.134 mmol Cr(NO_(3))_(3)·6H_(2)O,0.134 mmol Mn(NO_(3))_(2)·4H_(2)O,0.134 mmol Fe(NO_(3))_(3)·9H_(2)O,0.134 mmol Ni(NO_(3))_(2)·6H_(2)O,0.134 mmol Cu(NO_(3))_(2)·3H_(2)O,and 0.5 mmol La(NO_(3))_(3)·6H_(2)O were dissolved in 30 mL ethanol under stirring for 1 h to obtain the homogeneous solution.Afterwards,60 mg of carbon spheres were added in the solution under ultrasonic treatment for 30 min.The resulting mixture was transferred to a 50 mL microwave digestion vessel.The vessel was heated in a microwave oven at a power of 210 W for 10 min.Subsequently,the obtained mixture was centrifuged,washed with deionized water,and dried in a vacuum drying oven at 70℃for 12 h.Finally,the obtained precursor powder was calcinated in a tube furnace with a heating rate of 3℃/min at 650℃for 2 h to acquire HS-HEPs.The crystalline structure of the sample was determined by X-ray diffraction(XRD,D8 Davinci,Bruker Co.,Germany).The morphology and microstructure of sample were characterized by field-emission scanning electron microscopy(FESEM,S-4800,Hitachi Co.Ltd.,Japan)equipped with energy dispersive X-ray spectroscopy(EDS)and transmission electron microscopy(TEM,2100F,JEOL Co.,Japan).The X-ray photoelectron spectra were obtained by a X-ray photoelectron spectrometry(XPS,ESCALab 250,Thermo VG Co.,USA).The supercapacitor and OER performance of the sample were measured on a CHI 660E electrochemical workstation(Shanghai Chenhua Instrument Co.,China).Results and discussion The as-prepared samples display a cubic perovskite crystalline structure and a hollow sphere morphology.According to the XPS analysis,the variable oxidation states of Cr,Fe and Mn present in the HS-HEPs,which benefits the Faradaic redox reactions and increases the capacitance.In addition,the existence of high concentration of oxygen vacancies in HS-HEPs is beneficial to enhancing the capacitance and OER activity.Based on the GCD curve,the specific capacitance of HS-HEPs is estimated to be 406 F/g at 1 A/g.After GCD cycles of 5000 at a current density of 5 A/g,65%capacitance is retained,implying a good long-term electrochemical stability.An asymmetric supercapacitor device(HS-HEPs//AC)with a two electrode configuration is assembled.A maximum energy density of 39.4 W·h/kg is achieved at power density of 746 W/kg.The OER activity of HS-HEPs is evaluated by a linear sweep voltammetry(LSV)polarization curve in 1 mol/L KOH aqueous solution using a standard three-electrode system.The overpotential of HS-HEPs is identified as 347 mV versus RHE for achieving a current density of 10 mA/cm^(2),which is smaller than that of commercial IrO2(372 mV).The HS-HEPs possess the excellent electrochemical performance,which can be ascribed to the high specific surface area,abundant active sites,and high oxygen vacancy content,resulting from the combination of high-entropy perovskite and special hollow structure.Conclusions High-entropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Ni_(0.2)Cu_(0.2))O_(3)hollow spheres with a perovskite crystalline structure were prepared by microwave solvothermal process and subsequent calcination treatment.The HS-HEPs possessed the excellent electrochemical performance,which could be ascribed to the high specific surface area,abundant active sites,and high oxygen vacancy content,resulting from the combination of high-entropy perovskite and special hollow structure.Based on the electrochemical performance,HS-HEPs could be used as supercapacitor electrode material and OER electrocatalysts.This work could provide a strategy to design and prepare high-entropy oxides with a hollow sphere structure,having promising applications in energy storage and conversion.
