Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Desi...Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Designing novel magnetic materials with good magnetocaloric performance is a prerequisite for practical applications.In this study,three gadolinium-transition metal-based high entropy oxides(HEOs)of Gd(Fe_(1/4)Ni_(1/4)Al_(1/4)Cr_(1/4))O_(3),Gd(Fe_(1/5)Ni_(1/5)Al_(1/5)Cr_(1/5)Co_(1/5))O_(3),and Gd(Fe_(1/6)Ni_(1/6)Al_(1/6)Cr_(1/6)Co_(1/6)Mn_(1/6))O_(3)were designed and systematically characterized regarding their structural and cryogenic magnetic properties.These HEOs were confirmed to crystallize into a single-phase perovskite-type orthorhombic structure with a homogeneous microstructure,reveal a second-order magnetic transition at low temperatures,and exhibit significant cryogenic MCEs.The magnetocaloric performances of the present HEOs,identified by magnetic entropy changes,relative cooling power,and temperature-averaged entropy changes,were com-parable with recently reported candidate materials.The present study indicates potential applications for cryogenic magnetic cooling of the present HEOs and provides meaningful clues for designing and exploring HEOs with good cryogenic magnetocaloric performances.展开更多
The lattice distortion effect and cocktail effect of high-entropy oxides(HEOs)will dominate the catalytic effect of the materials,in order to study the influence of the constituent elements of HEOs on the lattice dist...The lattice distortion effect and cocktail effect of high-entropy oxides(HEOs)will dominate the catalytic effect of the materials,in order to study the influence of the constituent elements of HEOs on the lattice distortion effect and cocktail effect,through elemental manipulation of Cr,Cu,and La,high entropy oxides(HEOs)catalyst CrMnFeCoNiO(Cr_(1:1)),CuMnFeCoNiO(Cu_(1:1)),and LaMnFeCoNiO(La_(1:1))were effectively synthesized by the facile co-precipitation approach.With a size of about 10 nm,Cr_(1:1)presented significant modification impacts on enhancing the hydrogen storage capability of MgH_(2).Specifically,MgH_(2)was able to release hydrogen at 200℃with the addition of Cr_(1:1),MgH_(2)+10 wt%Cr_(1:1)showed prompt rate of dehydrogenation which could release 5.56 wt%H_(2)in 20 min at 250℃,and the activation energy of MgH_(2)was lowered to 69.77±3.75 k J·mol^(-1)by adding Cr_(1:1).According to the Chou model fitting,the exceptional kinetic performance of the composite was attributable to a rate-controlling step changed from low-speed surface penetration to high-speed diffusion.Furthermore,MgH_(2)+10wt%Cr_(1:1)was capable of absorbing hydrogen at ambient temperature and the composite could uptake 6 wt%H_(2)within 8 min at the temperature of 150℃.Due to the high entropy effects of HEOs,Cr_(1:1)possessed superior stability,which guarantees the robust cycling qualities of MgH_(2)+10 wt%Cr_(1:1).Meanwhile,microstructure analysis revealed that the active sites with numerous heterogeneous structures were uniformly dispersed on surfaces,exhibiting superior catalytic effects on improving the hydrogen storage performance of MgH_(2).展开更多
High entropy oxides(HEOs) have attracted extensive attention of researchers due to their remarkable properties. The electrocatalytic activity of electrocatalysts is closely related to the reactivity of their surface a...High entropy oxides(HEOs) have attracted extensive attention of researchers due to their remarkable properties. The electrocatalytic activity of electrocatalysts is closely related to the reactivity of their surface atoms which usually shows a positive correlation. Excellenet stability of HEOs leads to their surface atoms with relative poor reactivity, limiting the applications for electrocatalysis. Therefore, it is significant to activate surface atoms of HEOs. Constructing amorphous structure, introducing oxygen defects and leaching are very effective strategies to improve the reactivity of surface atoms. Herein, to remove chemical inert, low-crystallinity(Fe, Co, Ni, Mn, Zn)_(3)O_(4) (HEO-Origin) nanosheets with abundant oxygen vacancies was synthesized, showing an excellent catalytic activity with an overpotential of 265 mV at 10 mA/cm^(2), which outperforms as-synthesized HEO-500℃-air(335 mV). The excellent catalytic performance of HEO-Origin can be attributed to high activity surface atoms, the introduction of oxygen defects efficiently altered electron distribution on the surface of HEO-Origin. Apart from, HEO-Origin also exhibits an outstanding electrochemical stability for oxygen evolution reaction(OER).展开更多
Irradiation makes structural materials of nuclear reactors degraded and failed.However,the damage process of materials induced by irradiation is not fully elucidated,mostly because the charged particles only bombarded...Irradiation makes structural materials of nuclear reactors degraded and failed.However,the damage process of materials induced by irradiation is not fully elucidated,mostly because the charged particles only bombarded the surface of the materials(within a few microns).In this work,we investigated the effects of surface irradiation on the indirect irradiation region of the(Al0.3Cr0.2Fe0.2Ni0.3)3O4 high entropy oxide(HEO)films in detail by plasma surface interaction.The results show that the damage induced by surface irradiation significantly extends to the indirect irradiation region of HEO film where the helium bubbles,dislocations,phase transformation,and the nickel oxide segregation were observed.展开更多
A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields...A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.展开更多
Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition ...Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.展开更多
Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchang...Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.展开更多
03-type layered metal oxides hold great promise for sodium-ion batteries cathodes owing to their energy density advantage.However,the severe irreversible phase transition and sluggish Na^(+)diffusion kinetics pose sig...03-type layered metal oxides hold great promise for sodium-ion batteries cathodes owing to their energy density advantage.However,the severe irreversible phase transition and sluggish Na^(+)diffusion kinetics pose significant challenges to achieve high-performance layered cathodes.Herein,a boron-doped03-type high entropy oxide Na(Fe_(0.2)Co_(0.15)Cu_(0.05)Ni_(0.2)Mn_(0.2)Ti_(0.2))B_(0.02)O_(2)(NFCCNMT-B_(0.02))is designed and the covalent B-O bonds with high entropy configuration ensure a robust layered structure.The obtained cathode NFCCNMT-B_(0.02)exhibits impressive cycling performance(capacity retention of 95%and 82%after100 cycles and 300 cycles at 1 and 10 C,respectively)and outstanding rate capability(capacity of 83 mAh g^(-1)at 10 C).Furthermore,the NFCCNMT-B_(0.02)demonstrates a superior wide-temperature performance,maintaining the same capacity level(113,4 mAh g^(-1)@-20℃,121 mAh g^(-1)@25℃,and 119 mAh g^(-1)@60℃)and superior cycle stability(90%capacity retention after 100 cycles at 1 C at-20℃).The high-entropy configuration design with boron doping strategy contributes to the excellent sodium-ion storage performance.The high-entropy configuration design effectively suppresses irreversible phase transitions accompanied by small volume changes(ΔV=0.65 A3).B ions doping expands the Na layer distance and enlarges the P3 phase region,thereby enhancing Na^(+)diffusion kinetics.This work offers valuable insights into design of high-performance layered cathodes for sodium-ion batteries operating across a wide temperature.展开更多
The sluggish reaction kinetics of oxygen evolution reaction(OER)and the high price of noble metal catalysts hinder the wide application of water electrolysis for hydrogen generation.High-entropy oxides(HEOs)with multi...The sluggish reaction kinetics of oxygen evolution reaction(OER)and the high price of noble metal catalysts hinder the wide application of water electrolysis for hydrogen generation.High-entropy oxides(HEOs)with multi-components and high entropy stabilized structures have attracted great research interests due to their efficient and durable performance in electrolytic water splitting reactions.However,the development of efficient HEO electrocatalysts are often hindered by the limited surface exposed active sites because high temperature is usually required to form a high entropy stabilized structure.Herein,a flaky high-entropy oxide with a spinel structure,(FeCoNiCrMn)_(3)O_(4),was synthesized by using the sacrificial layered carbon template in situ prepared by the volatile reaction between ammonium sulfate and molten glucose.High-resolution TEM results show the as-prepared(FeCoNiCrMn)_(3)O_(4) flakes are composed of nanosized HEO particles.The nanosized(FeCoNiCrMn)_(3)O_(4) HEO electrocatalysts exhibit excellent OER activity,with an overpotential of 239 mV at 10 mA/cm^(2) and a Tafel slope of 52.4 mV/dec.The electrocatalyst has excellent stability.Even at a high current density of 100 mA/cm^(2),the activity remains unchanged during the stability test for 24 h.The results here shed a new light in the design and fabrication of highly efficient HEO electrocatalysts.展开更多
High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical ...High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical strength,and outstanding catalytic activity.These distinctive characteristics render HEMs highly suitable for various battery components,such as electrodes,electrolytes,and catalysts.This review systematically examines recent advances in the application of HEMs for energy storage,beginning with fundamental concepts,historical development,and key definitions.Three principal categories of HEMs,namely high-entropy alloys,high-entropy oxides,and highentropy MXenes,are analyzed with a focus on electrochemical performance metrics such as specific capacity,energy density,cycling stability,and rate capability.The underlying mechanisms by which these materials enhance battery performance are elucidated in the discussion.Furthermore,the pivotal role of machine learning in accelerating the discovery and optimization of novel high-entropy battery materials is highlighted.The review concludes by outlining future research directions and potential breakthroughs in HEM-based battery technologies.展开更多
Since lithium sulfur(Li-S)energy storage devices are anticipated to power portable gadgets and electric vehicles owing to their high energy density(2600 Wh·kg^(-1));nevertheless,their usefulness is constrained by...Since lithium sulfur(Li-S)energy storage devices are anticipated to power portable gadgets and electric vehicles owing to their high energy density(2600 Wh·kg^(-1));nevertheless,their usefulness is constrained by sluggish sulfur reaction kinetics and soluble lithium polysulfide(LPS)shuttling effects.High electrically conductive bifunctional electrocatalysts are urgently needed for Li-S batteries,and high-entropy oxide(HEO)is one of the most promising electrocatalysts.In this work,we synthesize titanium-containing high entropy oxide(Ti-HEO)(TiFeNiCoMg)O with enhanced electrical conductivity through calcining metal-organic frameworks(MOF)templates at modest temperatures.The resulting single-phase Ti-HEO with high conductivity could facilitate chemical immobilization and rapid bidirectional conversion of LPS.As a result,the Ti-HEO/S/KB cathode(with 70 wt.%of sulfur)achieves an initial discharge capacity as high as~1375 mAh·g^(-1)at 0.1 C,and a low-capacity fade rate of 0.056%per cycle over 1000 cycles at 0.5 C.With increased sulfur loading(~5.0 mg·cm^(-2)),the typical Li-S cell delivered a high initial discharge capacity of~607 mAh·g^(-1)at 0.2 C and showcased good cycling stability.This work provides better insight into the synthesis of catalytic Ti-containing HEOs with enhanced electrical conductivity,which are effective in simultaneously enhancing the LPS-conversion kinetics and reducing the LPS shuttling effect.展开更多
Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg oc-cupancy,high transition metal-oxygen(TM-O)covalency,and lattice energy,which is essential to en-sure efficient and dura...Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg oc-cupancy,high transition metal-oxygen(TM-O)covalency,and lattice energy,which is essential to en-sure efficient and durable oxygen reduction reaction(ORR)process for perovskite lanthanide-transition metal oxides(LaTMO_(3)).However,due to the compositional complexity,clarifying the relevance among the high entropy components,eg occupancy,TM-O properties,and ORR performance still remains a chal-lenge.Herein,adopting the B site entropy-driven strategy,a series of LaTMO_(3)(TM=Cr,Mn,Fe,Co,Ni)with tunable eg occupancy and TM-O bond properties are synthesized,and the correlations between high entropy elements,eg occupancy,TM-O properties,and ORR performances are revealed quantitively based on the crystal field theory and the Phillips-Van Vechten-Levine(P-V-L)valence bond theory.High en-tropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))O_(3)delivers a low overpotential of 493 mV(vs.503 mV for LaMnO_(3))and a minuscule decline by only 1.7%(vs.4.4%for LaMnO_(3))in half wave potential after 10,000 cycles,which can be associated with the tailored eg occupancy(1.06)and the significant enhancement in both TM-O covalency(4%)and lattice energy(691.75 kJ mol^(-1)).This work not only demonstrates the prospects of high entropy LaTMO_(3)in the ORR field but also provides a new perspective for the quantitative analysis of the structure-activity relationship for high entropy oxide ORR catalysts.展开更多
High entropy oxides(HEOs),as a new type of single-phase multielement solid solution materials,have shown many attractive features and promising application prospect in the energy storage fleld.Herein,six-element HEOs(...High entropy oxides(HEOs),as a new type of single-phase multielement solid solution materials,have shown many attractive features and promising application prospect in the energy storage fleld.Herein,six-element HEOs(CoNiZnFeMnLi)_(3)O_(4) and(CoNiZnCrMnLi)_(3)O_(4) with spinel structure are successfully prepared by con-ventional solid-phase method and present outstanding lithium storage performances due to the synergy effect of various electrochemically active elements and the entropy stabilization.By contrast,(CoNiZnFeMnLi)_(3)O_(4) delivers higher initial discharge specific capacity of 1104.3 mAh·g^(−1),better cycle stability(84%capacity retention after 100 cycles at 100 mA·g^(−1)) and rate performance(293 mAh·g^(−1)at 2000 mA·g^(−1))in the half-cell.Moreover,the full-cell assembled with(CoNiZnFeMnLi)_(3)O_(4) and LiCoO_(2)provides a reversible specific capacity of 260.2 mAh·g^(−1)after 100 cycles at 500 mA·g^(−1).Ex situ X-ray diffraction reveals the electrochemical reaction mechanism of HEOs(CoNiZnFeMnLi)_(3)O_(4),and the amorphous phase and the large amount of oxygen vacancies were obtained after the initial discharge process,which are responsible for the excellent cycle and rate performance.This research puts forward fresh insights for the development of advanced energy storage materials for high-performance batteries.展开更多
High-temperature microwave absorbers are significant for military equipment which experiences severe aerodynamic heat.In this work,high-entropy oxide(HEO)(FexCoNiCrMn)mOn with excellent high-temperature microwave abso...High-temperature microwave absorbers are significant for military equipment which experiences severe aerodynamic heat.In this work,high-entropy oxide(HEO)(FexCoNiCrMn)mOn with excellent high-temperature microwave absorption is studied.Driven by the effect of entropy,the composition of the oxide can be transformed from spinel-type phase(FexCoNiCrMn)_(3)O_(4) to corundum-type phase(FexCoNiCrMn)2O3 with the increasing content of iron.Only spinel-type or corundum-type structure composes the oxide when x≤3 or x≥5.But in-situ dual phases can coexist when x equals 4 during phase transition.Interestingly,obliged to abundant heterogeneous interfaces and crystal defects in the dual-phase HEO,magnetic property,dielectric polarization,and microwave loss ability are all well enhanced.The Smith chart analysis demonstrates the impedance matching condition is well improved due to the enhanced loss ability.These findings pave a new way for the adjustment of electromagnetic properties of HEO by entropy-driven phase regulation.Meanwhile,the dual-phase absorber can achieve better than 90%absorption in 9.6-12.4 GHz at 800℃ with a thickness of 2.6 mm,a low thermal diffusivity of 0.0038 cm^(2)/s at 900℃,and excellent high-temperature stability,which indicates it’s promising as a high-temperature microwave absorber.展开更多
A new class of high-entropy oxide glasses 20LaO_(3/2)-20TiO_(2)-20NbO_(5/2)-20WO_(3)-20MO_(3/2)(M=B/Ga/In)were designed and successfully fabricated by aerodynamic containerless processing.The results show that one can...A new class of high-entropy oxide glasses 20LaO_(3/2)-20TiO_(2)-20NbO_(5/2)-20WO_(3)-20MO_(3/2)(M=B/Ga/In)were designed and successfully fabricated by aerodynamic containerless processing.The results show that one can control the properties and increase the functionality of glass by changing the type of M.The Vicker's hardness reaches the highest value of 6.45 GPa for glass M=B.The best thermal stability and the glass forming ability,measured using the glass-transition temperature T_(g) and the temperature gap ΔT respectively,are found in glass M=In,with T_(g)=740℃ and ΔT=72℃.The optical properties show that the as-prepared glasses exhibit good transparency and high refractive index.Especially for glass M=In,its transmittance reaches almost 78% from visible to IR region,and the value is nearly unchanged after electron beam irradiation,indicating good irradiation resistance of this high-entropy oxide glass.Furthermore,the glass M=In has the highest refractive index(n_(d)=2.46) and low wavelength dispersion(v_(d)=45.6).These results demonstrate that the conceptual design of high-entropy materials is adaptable to high performance oxide glasses,which should be promising host materials for optical applications such as smart phones with digital cameras and endoscopes.展开更多
In 2015,a team led by S.Curtarolo and J.P.Maria transplanted the concept of“high-entropy”from alloys into the ceramic domain,giving rise to a new class of materials named“high-entropy ceramics”(HECs,also known as...In 2015,a team led by S.Curtarolo and J.P.Maria transplanted the concept of“high-entropy”from alloys into the ceramic domain,giving rise to a new class of materials named“high-entropy ceramics”(HECs,also known as“compositionally complex ceramics”)[1,2].A variety of novel HECs,including high-entropy oxides(HEOs),high-entropy diborides,high-entropy carbides,highentropy nitrides(HENs),and high-entropy carbonitrides,have been developed since then[3].The short-range chemical complexity in these materials,resulting from diverse species occupying identical crystallographic sites,implies a configurational disorder that can lead to unprecedented properties surpassing those of their non-disordered counterparts.Consequently,HECs have garnered great research interest over the past decade due to their exceptional thermal,mechanical,electrical,magnetic,optical,catalytic,electrochemical,and corrosion and radiation resistance properties,along with certain biological characteristics[4e6].The boundless compositional space,unique microstructures,and versatile performance also render them very promising in broad applications ranging from structural components for engines and nuclear reactors to electronic and energy storage devices.To bring the recent advances in HECs to a wide audience,we organized this special issue in the Journal of Materiomics(JMAT).展开更多
In this study,compositionally complex cobaltites with the general formula BaLnCo_(2)O_(6−δ)with three to eight different lanthan-ides at the Ln-site were synthesized using the solid-state reaction method and studied....In this study,compositionally complex cobaltites with the general formula BaLnCo_(2)O_(6−δ)with three to eight different lanthan-ides at the Ln-site were synthesized using the solid-state reaction method and studied.Analysis of entropy metrics and configurational en-tropy calculations indicated that these compounds are medium entropy oxides.All of these crystallize as tetragonal double perovskites from the space group P4/mmm.The unit cell parameters are controlled by the average ionic radius,not the configurational entropy.On the other hand,the oxygen non-stoichiometry is consistently higher than in the case of low entropy double perovskite cobaltites.The total electrical conductivity of all materials in studied conditions is well above 50 S/cm,peaking at 1487 S/cm for BaLa_(1/3)Nd_(1/3)Gd_(1/3)Co_(2)O_(6−δ)at 300℃.The electrical conductivity decreases with the number of substituents.展开更多
High-entropy oxides(HEOs),with their multi-principal-element compositional diversity,have emerged as promising candidates in the realm of energy materials.This review encapsulates the progress in harnessing HEOs for e...High-entropy oxides(HEOs),with their multi-principal-element compositional diversity,have emerged as promising candidates in the realm of energy materials.This review encapsulates the progress in harnessing HEOs for energy conversion and storage applications,encompassing solar cells,electrocatalysis,photocatalysis,lithium-ion batteries,and solid oxide fuel cells.The critical role of theoretical calculations and simulations is underscored,highlighting their contribution to elucidating material stability,deciphering structure-activity relationships,and enabling performance optimization.These computational tools have been instrumental in multi-scale modeling,high-throughput screening,and integrating artificial intelligence for material design.Despite their promise,challenges such as fabrication complexity,cost,and theoretical computational hurdles impede the broad application of HEOs.To address these,this review delineates future research perspectives.These include the innovation of cost-effective synthesis strategies,employment of in situ characterization for micro-chemical insights,exploration of unique physical phenomena to refine performance,and enhancement of computational models for precise structure-performance predictions.This review calls for interdisciplinary synergy,fostering a collaborative approach between materials science,chemistry,physics,and related disciplines.Collectively,these efforts are poised to propel HEOs towards commercial viability in the new energy technologies,heralding innovative solutions to pressing energy and environmental challenges.展开更多
基金supported by the National Natural Science Foundation of China(No.52171174).The authors acknowledge Dr.Chao Zhang from the Instrumentation Service Center for Physical Sciences at Westlake University for magnetization measurements.
文摘Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Designing novel magnetic materials with good magnetocaloric performance is a prerequisite for practical applications.In this study,three gadolinium-transition metal-based high entropy oxides(HEOs)of Gd(Fe_(1/4)Ni_(1/4)Al_(1/4)Cr_(1/4))O_(3),Gd(Fe_(1/5)Ni_(1/5)Al_(1/5)Cr_(1/5)Co_(1/5))O_(3),and Gd(Fe_(1/6)Ni_(1/6)Al_(1/6)Cr_(1/6)Co_(1/6)Mn_(1/6))O_(3)were designed and systematically characterized regarding their structural and cryogenic magnetic properties.These HEOs were confirmed to crystallize into a single-phase perovskite-type orthorhombic structure with a homogeneous microstructure,reveal a second-order magnetic transition at low temperatures,and exhibit significant cryogenic MCEs.The magnetocaloric performances of the present HEOs,identified by magnetic entropy changes,relative cooling power,and temperature-averaged entropy changes,were com-parable with recently reported candidate materials.The present study indicates potential applications for cryogenic magnetic cooling of the present HEOs and provides meaningful clues for designing and exploring HEOs with good cryogenic magnetocaloric performances.
基金the financial support from the National Natural Science Foundation of China(Grant No.51801078)。
文摘The lattice distortion effect and cocktail effect of high-entropy oxides(HEOs)will dominate the catalytic effect of the materials,in order to study the influence of the constituent elements of HEOs on the lattice distortion effect and cocktail effect,through elemental manipulation of Cr,Cu,and La,high entropy oxides(HEOs)catalyst CrMnFeCoNiO(Cr_(1:1)),CuMnFeCoNiO(Cu_(1:1)),and LaMnFeCoNiO(La_(1:1))were effectively synthesized by the facile co-precipitation approach.With a size of about 10 nm,Cr_(1:1)presented significant modification impacts on enhancing the hydrogen storage capability of MgH_(2).Specifically,MgH_(2)was able to release hydrogen at 200℃with the addition of Cr_(1:1),MgH_(2)+10 wt%Cr_(1:1)showed prompt rate of dehydrogenation which could release 5.56 wt%H_(2)in 20 min at 250℃,and the activation energy of MgH_(2)was lowered to 69.77±3.75 k J·mol^(-1)by adding Cr_(1:1).According to the Chou model fitting,the exceptional kinetic performance of the composite was attributable to a rate-controlling step changed from low-speed surface penetration to high-speed diffusion.Furthermore,MgH_(2)+10wt%Cr_(1:1)was capable of absorbing hydrogen at ambient temperature and the composite could uptake 6 wt%H_(2)within 8 min at the temperature of 150℃.Due to the high entropy effects of HEOs,Cr_(1:1)possessed superior stability,which guarantees the robust cycling qualities of MgH_(2)+10 wt%Cr_(1:1).Meanwhile,microstructure analysis revealed that the active sites with numerous heterogeneous structures were uniformly dispersed on surfaces,exhibiting superior catalytic effects on improving the hydrogen storage performance of MgH_(2).
基金supported by the National Natural Science Foundation of China(Nos.U19A2017,21902047,51402100,21825201,21573066,and 21905088)the Provincial Natural Science Foundation of Hunan(Nos.2020JJ5044,2022JJ10006)。
文摘High entropy oxides(HEOs) have attracted extensive attention of researchers due to their remarkable properties. The electrocatalytic activity of electrocatalysts is closely related to the reactivity of their surface atoms which usually shows a positive correlation. Excellenet stability of HEOs leads to their surface atoms with relative poor reactivity, limiting the applications for electrocatalysis. Therefore, it is significant to activate surface atoms of HEOs. Constructing amorphous structure, introducing oxygen defects and leaching are very effective strategies to improve the reactivity of surface atoms. Herein, to remove chemical inert, low-crystallinity(Fe, Co, Ni, Mn, Zn)_(3)O_(4) (HEO-Origin) nanosheets with abundant oxygen vacancies was synthesized, showing an excellent catalytic activity with an overpotential of 265 mV at 10 mA/cm^(2), which outperforms as-synthesized HEO-500℃-air(335 mV). The excellent catalytic performance of HEO-Origin can be attributed to high activity surface atoms, the introduction of oxygen defects efficiently altered electron distribution on the surface of HEO-Origin. Apart from, HEO-Origin also exhibits an outstanding electrochemical stability for oxygen evolution reaction(OER).
基金National Key Research and Development Program of China(Grant No.2017YFB0405702)the National Natural Science Foundation of China(Grant No.11775150).
文摘Irradiation makes structural materials of nuclear reactors degraded and failed.However,the damage process of materials induced by irradiation is not fully elucidated,mostly because the charged particles only bombarded the surface of the materials(within a few microns).In this work,we investigated the effects of surface irradiation on the indirect irradiation region of the(Al0.3Cr0.2Fe0.2Ni0.3)3O4 high entropy oxide(HEO)films in detail by plasma surface interaction.The results show that the damage induced by surface irradiation significantly extends to the indirect irradiation region of HEO film where the helium bubbles,dislocations,phase transformation,and the nickel oxide segregation were observed.
基金financially supported by the National Natural Science Foundation of China(No.52201173)the S&T Program of Hebei(No.22567627H)+3 种基金the Natural Science Foundation of Hebei Province(No.E2021501017)Henan key Laboratory of Aeronautical Materials and Application Technology Open fund(No.ZHKF-230113)Hebei Key Laboratory of Dielectric and Electrolyte Functional Material,Northeastern University at Qinhuangdao(HKDEFM2021301)the Fundamental Research Funds for the Central Universities(No.2024GFYD002,N2323021)
文摘A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.
基金supported by the National Natural Science Foundation of China(No.52002094)Shenzhen Science and Technology Program(Nos.JCYJ20210324121411031,JSGG202108021253804014 and RCBS20210706092218040)Shenzhen Steady Support Plan(Nos.GXWD20221030205923001 and GXWD20201230155427003-20200824103000001).
文摘Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.
文摘Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction(OER)in anion exchange membrane water electrolysis.Here,homogeneous high entropy oxide(HEO)film is in-situ fabricated on nickel foam(NF)substrate via magnetron sputtering technology without annealing process in air,which is composed of many spinel-structured(FeCoNiCrMo)_(3)O_(4) grains with an average particle size of 2.5 nm.The resulting HEO film(abbreviated as(FeCoNiCr-Mo)_(3)O_(4))exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm^(–2) and steadily operates at 100 mA cm^(–2) for 200 h with a decay of only 272μV h^(–1),which is far better than that of commercial IrO_(2) catalyst(290 mV,1090μV h^(–1)).Tetramethylammonium cation(TMA^(+))probe experiment,activation energy analysis and theoretical calculations unveil that the OER on(FeCoNiCrMo)_(3)O_(4) follows an adsorbate evolution mechanism pathway,where the energy barrier of rate-determining step for OER on(FeCoNiCrMo)_(3)O_(4) is substantially lowered.Also,methanol molecular probe experiment suggests that a weakened ^(*)OH bonding on the(FeCoNiCrMo)_(3)O_(4) surface and a rapid deprotonation of ^(*)OH,further enhancing its OER performance.This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER,accelerating the practical process of water electrolysis for H2 production.
基金financially supported by the National Natural Science Foundation of China(No.52071073,52177208,and52171202)Hebei Province“333 talent project”(No.C20221012)+1 种基金the Science and Technology Project of Hebei Education Department(BJK2023005)Hebei Province Graduate Innovation Funding Program CXZZBS2024177。
文摘03-type layered metal oxides hold great promise for sodium-ion batteries cathodes owing to their energy density advantage.However,the severe irreversible phase transition and sluggish Na^(+)diffusion kinetics pose significant challenges to achieve high-performance layered cathodes.Herein,a boron-doped03-type high entropy oxide Na(Fe_(0.2)Co_(0.15)Cu_(0.05)Ni_(0.2)Mn_(0.2)Ti_(0.2))B_(0.02)O_(2)(NFCCNMT-B_(0.02))is designed and the covalent B-O bonds with high entropy configuration ensure a robust layered structure.The obtained cathode NFCCNMT-B_(0.02)exhibits impressive cycling performance(capacity retention of 95%and 82%after100 cycles and 300 cycles at 1 and 10 C,respectively)and outstanding rate capability(capacity of 83 mAh g^(-1)at 10 C).Furthermore,the NFCCNMT-B_(0.02)demonstrates a superior wide-temperature performance,maintaining the same capacity level(113,4 mAh g^(-1)@-20℃,121 mAh g^(-1)@25℃,and 119 mAh g^(-1)@60℃)and superior cycle stability(90%capacity retention after 100 cycles at 1 C at-20℃).The high-entropy configuration design with boron doping strategy contributes to the excellent sodium-ion storage performance.The high-entropy configuration design effectively suppresses irreversible phase transitions accompanied by small volume changes(ΔV=0.65 A3).B ions doping expands the Na layer distance and enlarges the P3 phase region,thereby enhancing Na^(+)diffusion kinetics.This work offers valuable insights into design of high-performance layered cathodes for sodium-ion batteries operating across a wide temperature.
基金The authors acknowledge support from the National Natural Science Foundation of China(NSFC)(Grant No.22109147 and 52371144)Institute of Materials,China Academy of Engineering Physics(No.TP01201701).
文摘The sluggish reaction kinetics of oxygen evolution reaction(OER)and the high price of noble metal catalysts hinder the wide application of water electrolysis for hydrogen generation.High-entropy oxides(HEOs)with multi-components and high entropy stabilized structures have attracted great research interests due to their efficient and durable performance in electrolytic water splitting reactions.However,the development of efficient HEO electrocatalysts are often hindered by the limited surface exposed active sites because high temperature is usually required to form a high entropy stabilized structure.Herein,a flaky high-entropy oxide with a spinel structure,(FeCoNiCrMn)_(3)O_(4),was synthesized by using the sacrificial layered carbon template in situ prepared by the volatile reaction between ammonium sulfate and molten glucose.High-resolution TEM results show the as-prepared(FeCoNiCrMn)_(3)O_(4) flakes are composed of nanosized HEO particles.The nanosized(FeCoNiCrMn)_(3)O_(4) HEO electrocatalysts exhibit excellent OER activity,with an overpotential of 239 mV at 10 mA/cm^(2) and a Tafel slope of 52.4 mV/dec.The electrocatalyst has excellent stability.Even at a high current density of 100 mA/cm^(2),the activity remains unchanged during the stability test for 24 h.The results here shed a new light in the design and fabrication of highly efficient HEO electrocatalysts.
基金supported by the Fujian Provincial Science and Technology Planning Project(No.2022HZ027006,No.2024HZ021023)National Natural Science Foundation of China(No.U22A20118).
文摘High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical strength,and outstanding catalytic activity.These distinctive characteristics render HEMs highly suitable for various battery components,such as electrodes,electrolytes,and catalysts.This review systematically examines recent advances in the application of HEMs for energy storage,beginning with fundamental concepts,historical development,and key definitions.Three principal categories of HEMs,namely high-entropy alloys,high-entropy oxides,and highentropy MXenes,are analyzed with a focus on electrochemical performance metrics such as specific capacity,energy density,cycling stability,and rate capability.The underlying mechanisms by which these materials enhance battery performance are elucidated in the discussion.Furthermore,the pivotal role of machine learning in accelerating the discovery and optimization of novel high-entropy battery materials is highlighted.The review concludes by outlining future research directions and potential breakthroughs in HEM-based battery technologies.
基金the following financial supports:the National Natural Science Foundation of China(Nos.52372289 and 52102368)Guangdong Science and Technology Bureau(Grant Nos.2019B090908001 and 2020A0505090011)+4 种基金Guangdong Special Fund for Key Areas(20237DZX3042)Shenzhen STI(Grant No.SGDX20190816230615451)Shenzhen Stable Support Project,Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices(Grant No.2019B121205001)Otto Poon Charitable Foundation(Grant Nos.847W,CDBC,CDBW)HKPolyU Postdoctoral Fellowships(Grant No.W28H).
文摘Since lithium sulfur(Li-S)energy storage devices are anticipated to power portable gadgets and electric vehicles owing to their high energy density(2600 Wh·kg^(-1));nevertheless,their usefulness is constrained by sluggish sulfur reaction kinetics and soluble lithium polysulfide(LPS)shuttling effects.High electrically conductive bifunctional electrocatalysts are urgently needed for Li-S batteries,and high-entropy oxide(HEO)is one of the most promising electrocatalysts.In this work,we synthesize titanium-containing high entropy oxide(Ti-HEO)(TiFeNiCoMg)O with enhanced electrical conductivity through calcining metal-organic frameworks(MOF)templates at modest temperatures.The resulting single-phase Ti-HEO with high conductivity could facilitate chemical immobilization and rapid bidirectional conversion of LPS.As a result,the Ti-HEO/S/KB cathode(with 70 wt.%of sulfur)achieves an initial discharge capacity as high as~1375 mAh·g^(-1)at 0.1 C,and a low-capacity fade rate of 0.056%per cycle over 1000 cycles at 0.5 C.With increased sulfur loading(~5.0 mg·cm^(-2)),the typical Li-S cell delivered a high initial discharge capacity of~607 mAh·g^(-1)at 0.2 C and showcased good cycling stability.This work provides better insight into the synthesis of catalytic Ti-containing HEOs with enhanced electrical conductivity,which are effective in simultaneously enhancing the LPS-conversion kinetics and reducing the LPS shuttling effect.
基金supported by the Key R&D Program of Shanxi Province(Nos.202102030201006 and 202202070301016)the National Natural Science Foundation of China(No.52072256)+3 种基金the Shanxi Science and Technology Major Project(No.20201101016)the Natural Science Foundation of Shanxi Province(Nos.20210302124105 and 20210302124308)the Centralized Guided Local Science and Technology Development Funds Project(No.YDZJSX2021B005)the Shanxi Provincial Science and Technology Innovation Base Construction Project(No.YDZJSX2022B003).
文摘Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg oc-cupancy,high transition metal-oxygen(TM-O)covalency,and lattice energy,which is essential to en-sure efficient and durable oxygen reduction reaction(ORR)process for perovskite lanthanide-transition metal oxides(LaTMO_(3)).However,due to the compositional complexity,clarifying the relevance among the high entropy components,eg occupancy,TM-O properties,and ORR performance still remains a chal-lenge.Herein,adopting the B site entropy-driven strategy,a series of LaTMO_(3)(TM=Cr,Mn,Fe,Co,Ni)with tunable eg occupancy and TM-O bond properties are synthesized,and the correlations between high entropy elements,eg occupancy,TM-O properties,and ORR performances are revealed quantitively based on the crystal field theory and the Phillips-Van Vechten-Levine(P-V-L)valence bond theory.High en-tropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))O_(3)delivers a low overpotential of 493 mV(vs.503 mV for LaMnO_(3))and a minuscule decline by only 1.7%(vs.4.4%for LaMnO_(3))in half wave potential after 10,000 cycles,which can be associated with the tailored eg occupancy(1.06)and the significant enhancement in both TM-O covalency(4%)and lattice energy(691.75 kJ mol^(-1)).This work not only demonstrates the prospects of high entropy LaTMO_(3)in the ORR field but also provides a new perspective for the quantitative analysis of the structure-activity relationship for high entropy oxide ORR catalysts.
基金the National Natural Science Foundation of China(Nos.51902046,51871046,52071073,51771046 and 51971055)Natural Science Foundation of Hebei Province(Nos.E2019501097,E2018501091 and E2020501004)+1 种基金the Science and Technology Project of Hebei Province(No.15271302D)Funds for the Central Universities(N2123032)。
文摘High entropy oxides(HEOs),as a new type of single-phase multielement solid solution materials,have shown many attractive features and promising application prospect in the energy storage fleld.Herein,six-element HEOs(CoNiZnFeMnLi)_(3)O_(4) and(CoNiZnCrMnLi)_(3)O_(4) with spinel structure are successfully prepared by con-ventional solid-phase method and present outstanding lithium storage performances due to the synergy effect of various electrochemically active elements and the entropy stabilization.By contrast,(CoNiZnFeMnLi)_(3)O_(4) delivers higher initial discharge specific capacity of 1104.3 mAh·g^(−1),better cycle stability(84%capacity retention after 100 cycles at 100 mA·g^(−1)) and rate performance(293 mAh·g^(−1)at 2000 mA·g^(−1))in the half-cell.Moreover,the full-cell assembled with(CoNiZnFeMnLi)_(3)O_(4) and LiCoO_(2)provides a reversible specific capacity of 260.2 mAh·g^(−1)after 100 cycles at 500 mA·g^(−1).Ex situ X-ray diffraction reveals the electrochemical reaction mechanism of HEOs(CoNiZnFeMnLi)_(3)O_(4),and the amorphous phase and the large amount of oxygen vacancies were obtained after the initial discharge process,which are responsible for the excellent cycle and rate performance.This research puts forward fresh insights for the development of advanced energy storage materials for high-performance batteries.
基金financially supported by the Shanghai Sailing Program(No.21YF1454600)。
文摘High-temperature microwave absorbers are significant for military equipment which experiences severe aerodynamic heat.In this work,high-entropy oxide(HEO)(FexCoNiCrMn)mOn with excellent high-temperature microwave absorption is studied.Driven by the effect of entropy,the composition of the oxide can be transformed from spinel-type phase(FexCoNiCrMn)_(3)O_(4) to corundum-type phase(FexCoNiCrMn)2O3 with the increasing content of iron.Only spinel-type or corundum-type structure composes the oxide when x≤3 or x≥5.But in-situ dual phases can coexist when x equals 4 during phase transition.Interestingly,obliged to abundant heterogeneous interfaces and crystal defects in the dual-phase HEO,magnetic property,dielectric polarization,and microwave loss ability are all well enhanced.The Smith chart analysis demonstrates the impedance matching condition is well improved due to the enhanced loss ability.These findings pave a new way for the adjustment of electromagnetic properties of HEO by entropy-driven phase regulation.Meanwhile,the dual-phase absorber can achieve better than 90%absorption in 9.6-12.4 GHz at 800℃ with a thickness of 2.6 mm,a low thermal diffusivity of 0.0038 cm^(2)/s at 900℃,and excellent high-temperature stability,which indicates it’s promising as a high-temperature microwave absorber.
基金Project supported by the National Natural Science Foundation of China (51972048)the Fundamental Research Funds for the Central Universities (N2123003)。
文摘A new class of high-entropy oxide glasses 20LaO_(3/2)-20TiO_(2)-20NbO_(5/2)-20WO_(3)-20MO_(3/2)(M=B/Ga/In)were designed and successfully fabricated by aerodynamic containerless processing.The results show that one can control the properties and increase the functionality of glass by changing the type of M.The Vicker's hardness reaches the highest value of 6.45 GPa for glass M=B.The best thermal stability and the glass forming ability,measured using the glass-transition temperature T_(g) and the temperature gap ΔT respectively,are found in glass M=In,with T_(g)=740℃ and ΔT=72℃.The optical properties show that the as-prepared glasses exhibit good transparency and high refractive index.Especially for glass M=In,its transmittance reaches almost 78% from visible to IR region,and the value is nearly unchanged after electron beam irradiation,indicating good irradiation resistance of this high-entropy oxide glass.Furthermore,the glass M=In has the highest refractive index(n_(d)=2.46) and low wavelength dispersion(v_(d)=45.6).These results demonstrate that the conceptual design of high-entropy materials is adaptable to high performance oxide glasses,which should be promising host materials for optical applications such as smart phones with digital cameras and endoscopes.
文摘In 2015,a team led by S.Curtarolo and J.P.Maria transplanted the concept of“high-entropy”from alloys into the ceramic domain,giving rise to a new class of materials named“high-entropy ceramics”(HECs,also known as“compositionally complex ceramics”)[1,2].A variety of novel HECs,including high-entropy oxides(HEOs),high-entropy diborides,high-entropy carbides,highentropy nitrides(HENs),and high-entropy carbonitrides,have been developed since then[3].The short-range chemical complexity in these materials,resulting from diverse species occupying identical crystallographic sites,implies a configurational disorder that can lead to unprecedented properties surpassing those of their non-disordered counterparts.Consequently,HECs have garnered great research interest over the past decade due to their exceptional thermal,mechanical,electrical,magnetic,optical,catalytic,electrochemical,and corrosion and radiation resistance properties,along with certain biological characteristics[4e6].The boundless compositional space,unique microstructures,and versatile performance also render them very promising in broad applications ranging from structural components for engines and nuclear reactors to electronic and energy storage devices.To bring the recent advances in HECs to a wide audience,we organized this special issue in the Journal of Materiomics(JMAT).
基金support of these studies from Gdańsk University of Technology by the DEC-3/2/IDUB/Ⅲ.1a/Ra/2023 and DEC-1/1/2024/IDUB/Ⅲ.4c/Tc grants under the Radium and Technetium-‘Excellence Initiative-Research University’programs.
文摘In this study,compositionally complex cobaltites with the general formula BaLnCo_(2)O_(6−δ)with three to eight different lanthan-ides at the Ln-site were synthesized using the solid-state reaction method and studied.Analysis of entropy metrics and configurational en-tropy calculations indicated that these compounds are medium entropy oxides.All of these crystallize as tetragonal double perovskites from the space group P4/mmm.The unit cell parameters are controlled by the average ionic radius,not the configurational entropy.On the other hand,the oxygen non-stoichiometry is consistently higher than in the case of low entropy double perovskite cobaltites.The total electrical conductivity of all materials in studied conditions is well above 50 S/cm,peaking at 1487 S/cm for BaLa_(1/3)Nd_(1/3)Gd_(1/3)Co_(2)O_(6−δ)at 300℃.The electrical conductivity decreases with the number of substituents.
基金financial support from the Key Research and Development Program of Yunnan Province(Grant No.202302AF080002)。
文摘High-entropy oxides(HEOs),with their multi-principal-element compositional diversity,have emerged as promising candidates in the realm of energy materials.This review encapsulates the progress in harnessing HEOs for energy conversion and storage applications,encompassing solar cells,electrocatalysis,photocatalysis,lithium-ion batteries,and solid oxide fuel cells.The critical role of theoretical calculations and simulations is underscored,highlighting their contribution to elucidating material stability,deciphering structure-activity relationships,and enabling performance optimization.These computational tools have been instrumental in multi-scale modeling,high-throughput screening,and integrating artificial intelligence for material design.Despite their promise,challenges such as fabrication complexity,cost,and theoretical computational hurdles impede the broad application of HEOs.To address these,this review delineates future research perspectives.These include the innovation of cost-effective synthesis strategies,employment of in situ characterization for micro-chemical insights,exploration of unique physical phenomena to refine performance,and enhancement of computational models for precise structure-performance predictions.This review calls for interdisciplinary synergy,fostering a collaborative approach between materials science,chemistry,physics,and related disciplines.Collectively,these efforts are poised to propel HEOs towards commercial viability in the new energy technologies,heralding innovative solutions to pressing energy and environmental challenges.
