Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of sec...Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of second-phase particles in Zn-based alloys might induce severe localized degradation via micro-coupling corrosion,thereby compromising the mechanical integrity of the alloy during in vivo tissue regeneration.In this study,high pressure solid solution(HPSS)treatment was conducted at 5 GPa and 380℃ for 1 h to fabricate Zn-0.5 Mn alloys.Microstructural characterization revealed that the HPSS treatment facilitated the formation of a supersaturated solid solution by completely dissolving theζ-MnZn_(13) phase into theα-Zn matrix.The resultant strengthening mechanisms,including supersaturated solid solution strengthening,grain-size strengthening,and dislocation strengthening,collectively enhanced the compressive yield strength(σ_(cys))of the Zn-0.5 Mn alloy to about 183.7 MPa,approximately three times that of the as-cast(AC)Zn-0.5 Mn alloy.Moreover,compared with the AC alloy,the HPSS Zn-0.5 Mn alloy exhibited uniform degradation behavior with a markedly reduced degradation rate.展开更多
Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promisin...Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promising strategy to address this issue.To realize the synergy,herein,Sn whiskers with an in situ oxide layer served as substrates for magnetic-loss-active CoNi nanosheet growth,forming a hierarchical CoNi@SnO_(2)@Sn(CNS)heterostructure.The CNS absorber achieves a minimum reflection loss(RL_(min))value of-62.29 dB with an effective absorption bandwidth(EAB)of 2.2 GHz,covering the entire C-band with 70%absorption at only 2.61 mm thickness.The nanosheet design of CoNi enhances magnetic anisotropy to promote natural resonance,while the conductive Sn core and abundant Sn/SnO_(2) and CoNi/SnO_(2) heterointerfaces facilitate conduction loss and dielectric polarization.When composited into a thermoplastic polyurethane(TPU)matrix,the resulting CNS/TPU-2 film(20 wt%CNS)exhibits an RL_(min) value of-61.04 dB and a 2.5 GHz EAB.Its in-plane and through-plane thermal conductivities reach 2.41 and 0.51 W m^(-1) K^(-1),representing 4.1 and 2.6 times those of pure TPU films,respectively,facilitating heat dissipation from protected devices.This work provides valuable insights into magnetic-dielectric synergy for low-frequency MA of 1D metal-based materials,offering promising potential for 5G communications and flexible electronics.展开更多
Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electro...Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.展开更多
Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as w...Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities.This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties.Special emphasis is placed on reviewing the efforts made by the scientific community in improving the material’s thermodynamic and kinetic properties while maintaining a high hydrogen storage capacity.展开更多
Recent years have witnessed a continuous discovering of new thermoelectric materials which has experienced a paradigm shift from try-and-error efforts to experience-based discovering and first-principles calculation. ...Recent years have witnessed a continuous discovering of new thermoelectric materials which has experienced a paradigm shift from try-and-error efforts to experience-based discovering and first-principles calculation. However, both the experiment and first-principles calculation deriving routes to determine a new compound are time and resources consuming. Here, we demonstrated a machine learning approach to discover new M_(2)X_(3)-type thermoelectric materials with only the composition information. According to the classic Bi_(2)Te_(3) material, we constructed an M_(2)X_(3)-type thermoelectric material library with 720 compounds by using isoelectronic substitution, in which only 101 compounds have crystalline structure information in the Inorganic Crystal Structure Database(ICSD) and Materials Project(MP) database. A model based on the random forest(RF) algorithm plus Bayesian optimization was used to explore the underlying principles to determine the crystal structures from the known compounds. The physical properties of constituent elements(such as atomic mass, electronegativity, ionic radius) were used to define the feature of the compounds with a general formula ^(1)M^(2)M^(1)X^(2)X^(3)X(^(1)M +^(2)M:^(1)X +^(2)X+^(3)X = 2:3). The primary goal is to find new thermoelectric materials with the same rhombohedral structure as Bi_(2)Te_(3) by machine learning.The final trained RF model showed a high accuracy of 91% on the prediction of rhombohedral compounds. Finally, we selected four important features to proceed with the polynomial fitting with the prediction results from the RF model and used the acquired polynomial function to make further discoveries outside the pre-defined material library.展开更多
Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which pr...Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which promotes a further exploration for high temperature(T_(c))superconductors at relatively low pressure.Herein,we performed a systematic theoretical investigation on a series of ternary hydrides with stoichiometry AX_(2)H_(8),which is constructed by interacting molecular XH_(4)(X=B,C,and N)into the fcc metal A lattice under low pressure of 0-150 GPa.We uncovered five compounds which are dynamically stable below 100 GPa,e.g.,AcB_(2)H_(8)(25 GPa),LaB_(2)H_(8)(40 GPa),RbC_(2)H_(8)(40 GPa),CSC_(2)H_(8)(60 GPa),and SrC_(2)H_(8)(65 GPa).Among them,AcB_(2)H_(8),which is energetically stable above 2.5 GPa,exhibits the highest Tcof 32 K at 25 GPa.The superconductivity originates mainly from the coupling between the electron of Ac atoms and the associated low-frequency phonons,distinct from the previous typical hydrides with H-derived superconductivity.Our results shed light on the future exploration of superconductivity among ternary compounds at low pressure.展开更多
Magnesium alloy has been considered as one of the third-generation biomaterials for the regeneration and support of functional bone tissue.As a regeneration implant material with great potential applications,in-situ M...Magnesium alloy has been considered as one of the third-generation biomaterials for the regeneration and support of functional bone tissue.As a regeneration implant material with great potential applications,in-situ Mg_(2)Si phase reinforced Mg-6Zn cast alloy was comprehensively studied and expected to possess excellent mechanical properties via the refining and modifying of Mg_(2)Si reinforcements.The present study demonstrates that the primary and eutectic Mg_(2)Si phase can be greatly modified by the yttrium(Y)addition.The size of the primary Mg_(2)Si phases can be reduced to~20μm with an addition of 0.5 wt.%Y.This phenomenon is mainly attributed to the poisoning effect of the Y element.Moreover,wear resistance and tensile properties of the ternary alloy have also been improved by the Y addition.Mg-6Zn-4Si-0.5Y alloy exhibits optimal tensile properties and wears resistance.The ultimate tensile strength and the elongation of the alloy with 0.5 wt.%Y are 50%and 65%higher than those of the ternary alloy,respectively.Excessive Y addition(1.0 wt.%)deteriorates the tensile properties of Mg-Zn-Si alloy.The improvement of the tensile properties is mainly due to the modification of primary and eutectic Mg_(2)Si phases as well as the solid solution strengthening of the Y atoms.This study provides a certain implication for the application of Mg-Zn-Si alloys containing Y elements as regeneration implants.展开更多
Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using ...Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.展开更多
The original online version of this article (Randrianarivony, M. (June 2014) On DFT Molecular Simulation for Non-Adaptive Kernel Approximation. Advances in Materials Physics and Chemistry, Vol. 4 No. 6, 105-115. http:...The original online version of this article (Randrianarivony, M. (June 2014) On DFT Molecular Simulation for Non-Adaptive Kernel Approximation. Advances in Materials Physics and Chemistry, Vol. 4 No. 6, 105-115. http://dx.doi.org/10.4236/ampc.2014.46013) did not contain any acknowledgment. The author wishes to add the following acknowledgements: Acknowledgements: This work was partially supported by Eurostars Project E!6935 funded by German Federal Ministry of Education and Research.展开更多
In order to understand the influence of ordering behaviors on the thermodynamic and mechanical properties of multi-principal element alloys(MPEAs),the temperature-dependent thermodynamic properties and mechanical prop...In order to understand the influence of ordering behaviors on the thermodynamic and mechanical properties of multi-principal element alloys(MPEAs),the temperature-dependent thermodynamic properties and mechanical properties of FCC_CoNiV MPEAs were comparatively predicted,where the alloys were modeled as the ordered configurations based on our previously predicted site occupying fractions(SOFs),as well as disordered configuration based on traditional special quasi-random structure(SQS).The ordering behavior not only improves the thermodynamic stability of the structure,but also increases the elastic properties and Vickers hardness.For example,at 973 K,the predicted bulk modulus(B),shear modulus(G),Young’s modulus(E),and Vickers hardness(HV)of FCC_CoNiV MPEA based on SOFs configuration are 187.82,79.03,207.93,and 7.58 GPa,respectively,while the corresponded data are 172.58,57.45,155.14,and 4.64 GPa for the SQS configuration,respectively.The Vickers hardness predicted based on SOFs agrees considerably well with the available experimental data,while it is underestimated obviously based on SQS.展开更多
Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of nove...Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of novel device applications.The magnetotransport properties of 2D-Te under varying temperatures and high pressures warrant further study.In this paper,the magnetotransport behavior of 2D-Te under low-temperature and high-pressure conditions is investigated.At room temperature,the magnetoresistance(MR)increases with increasing magnetic field,exhibiting positive MR behavior below 4.3 GPa.During decompression,MR is almost constant with decreasing pressure.MR is more sensitive to pressure at lower temperatures.展开更多
To enhance the power conversion efficiency(PCE)of organic photovoltaic(OPV)cells,the identification of high-performance polymer/macromolecule materials and understanding their relationship with photovoltaic performanc...To enhance the power conversion efficiency(PCE)of organic photovoltaic(OPV)cells,the identification of high-performance polymer/macromolecule materials and understanding their relationship with photovoltaic performance before synthesis are critical objectives.In this study,we developed five algorithms using a dataset of 1343 experimentally validated OPV NFA acceptor materials.The random forest(RF)algorithm exhibited the best predictive performance for material design and screening.Additionally,we explored a newly developed polymer/macromolecule structure expression,polymer-unit fingerprint(PUFp),which outperformed the molecular access system(MACCS)across diverse machine learning(ML)algorithms.PUFp facilitated the interpretability of structure-property relationships,enabling PCE predictions of conjugated polymers/macromolecules formed by the combination of donor(D)and acceptor(A)units.Our PUFp-ML model efficiently preevaluated and classified numerous acceptor materials,identifying and screening the two most promising NFA candidates.The proposed framework demonstrates the ability to design novel materials based on PUFp-ML-established feature/substructure-property relationships,providing rational design guidelines for developing high-performanceOPV acceptors.These methodologies are transferable to donor materials,thereby supporting accelerated material discovery and offering insights for designing innovative OPV materials.展开更多
In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.Th...In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.The annealing at 300℃ for 2 h did not change the grain size significantly;however,a slight growth of Mg_(2)Ca precipitates was observed.When the annealing temperature increased up to 400℃ for 2 h,full recrystallization of the alloy occurred;the grains and precipitates grew noticeably.Those changes were responsible for decreasing the corrosion and the tribocorrosion resistance of the alloy.Due to lowered resistance to the corrosion medium,the cell viability was also reduced.Although MG63 cells on the annealed specimens developed filopodia,cell-to-cell communication was not observed.展开更多
This study was undertaken to understand the effects of incorporating a trace amount(0.1 at.%)of Ti and/or Mn with low diffusivities on the thermal stability of the precipitation morphologies of the T-Al6Mg11Zn11 phase...This study was undertaken to understand the effects of incorporating a trace amount(0.1 at.%)of Ti and/or Mn with low diffusivities on the thermal stability of the precipitation morphologies of the T-Al6Mg11Zn11 phase in a heat-resistant Al-Mg-Zn-Cu-Ni quinary alloy in terms of the locations of the added solute elements.In the Ti-added alloy,solute Ti was concentrated in the center of the dendriticα-Al phase via a peritectic reaction during solidification.The Ti distribution was retained even after so-lution treatment at 480℃.In contrast,in the Mn-added alloy,Mn appeared localized around granular intermetallic phases(or formed Mn-rich phases),resulting in a slight amount of solute Mn in theα-Al matrix.Solute Mn slightly affected the precipitation morphology of the T-phase at 200 or 300℃.Nevertheless,much finer precipitates were observed in theα-Al matrix(resulting in finer precipitation morphology)with higher solute Ti concentration,indicating suppressed growth and coarsening of the T-phase precipitates by solute Ti.Introducing both Ti and Mn enhanced local coarsening of the precipi-tates inside the dendriticα-Al phases with higher Ti solute concentrations.The coexistence of solute Ti and Mn promoted the formation of a significantly coarsened stable Al18Mg3(Ti,Mn)2 phase accompanied by the decomposition of initial fine T-phase precipitates,leading to mechanical degradation of the alloy in a high-temperature environment for a long period.These results provide new insights into element selection for the design of heat-resistant Al alloys with superior high-temperature creep performances.展开更多
L1_(2)precipitates are known to significantly enhance the strength and ductility of single-phase face-centered cubic(FCC)medium-or high-entropy alloys(M/HEAs).However,further improvements in mechanical properties rema...L1_(2)precipitates are known to significantly enhance the strength and ductility of single-phase face-centered cubic(FCC)medium-or high-entropy alloys(M/HEAs).However,further improvements in mechanical properties remain untapped,as alloy design has historically focused on systems with specific CrCoNi-or FeCoCrNi-based FCC matrix and Ni_(3)Al L1_(2)phase compositions.This study introduces novel Co-Ni-Mo-Al alloys with L1_(2)precipitates by systematically altering Al content,aiming to bridge this research gap by revealing the strengthening mechanisms.The(CoNi)_(81)Mo_(12)Al_(7)alloy achieves yield strength of 1086 MPa,tensile strength of 1520 MPa,and ductility of 35%,demonstrating an impressive synergy of strength,ductility,and strain-hardening capacity.Dislocation analysis via transmission electron microscopy,supported by generalized stacking fault energy(GSFE)calculations using density functional theory(DFT),demonstrates that Mo substitution for Al in the L1_(2)phase alters dislocation behavior,promoting the formation of multiple deformation modes,including stacking faults,super-dislocation pairs,Lomer-Cottrell locks,and unusual nano-twin formation even at low strains.These behaviors are facilitated by the low stacking fault energy(SFE)of the FCC matrix,overlapping of SFs,and dislocation dissociation across anti-phase boundaries(APBs).The increased energy barrier for superlattice intrinsic stacking fault(SISF)formation compared to APBs,due to Mo substitution,further influences dislocation activity.This work demonstrates a novel strategy for designing high-performance M/HEAs by expanding the range of FCC matrix and L1_(2)compositions through precipitation hardening.展开更多
The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron mi...The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and tensile test.It is found that,as-cast Mg-8Li-3Al-(1,2,3)Sn alloys consist ofα-Mg+β-Li duplex matrix,MgLiAl2 and Li2Mg Sn phases.Increasing Sn content leads to grain refinement ofα-Mg dendrites and increase in content of Li2MgSn phase.During hot extrusion,complete dynamic recrystallization(DRX)takes place inβ-Li phase while incomplete DRX takes place inα-Mg phase.As Sn content is increased,the volume fraction of DRXedα-Mg grains is increased and the average grain size of DRXedα-Mg grains is decreased.Increasing Sn content is beneficial to strength but harmful to ductility for as-cast Mg-8Li-3Al-(1,2,3)Sn alloys.Tensile properties of Mg-8Li-3Al-(1,2,3)Sn alloys are improved significantly via hot extrusion and Mg-8Li-3Al-2Sn alloy exhibits the best tensile properties.展开更多
7 xxx welding wire was self-made by spray forming ingots drawn to series welding wires products,and then TIG butt welding test is used for 5 mm thick 7075 high-strength aluminium alloy.After welding,the stress relief+...7 xxx welding wire was self-made by spray forming ingots drawn to series welding wires products,and then TIG butt welding test is used for 5 mm thick 7075 high-strength aluminium alloy.After welding,the stress relief+solid-solution aging heat treatment(T6)were performed to joints,and the mechanical properties and microstructure of the joints before and after heat treatment were comparative analyzed.The results show that the properties of the heat-affected zone(HAZ)of the joint before heat treatment decreas,and the joint is softened.The welded joints tensile strength is 271.8 MPa,the elongation is 5.6%,and the average hardness of the weld is 118.4 HV.The second phase particles such asη(Mg Zn2),S(Al2 Cu Mg),Al13 Fe4 are distributed in a network layer,with no apparent element segregation.After heat treatment,the structure of each area of the joint is coarsened,and a small amount of Fe-containing impurity phases are distributed.Theηand S phases are dissolved in the matrix.The hardness of each area of the joint is increased to 155 HV,and the softening zone is disappeared,this leads the joint elongation close to 16.9%.The tensile strength is increased to 511.8 MPa,reaching 94%of the base metal tensile strength.展开更多
Hydrogen dissolved in metals as a result of internal and external hydrogen can affect the mechanical properties of the metals, principally through the interactions between hydrogen and material defects. Multiple pheno...Hydrogen dissolved in metals as a result of internal and external hydrogen can affect the mechanical properties of the metals, principally through the interactions between hydrogen and material defects. Multiple phenomena such as hydrogen dissolution, hydrogen diffusion, hydrogen redistribution and hydrogen interactions with vacancies, dislocations, grain boundaries and other phase interfaces are involved in this process. Consequently, several hydrogen embrittlement(HE) mechanisms have been successively proposed to explain the HE phenomena, with the hydrogen-enhanced decohesion mechanism, hydrogenenhanced localized plasticity mechanism and hydrogen-enhanced strain-induced vacancies being some of the most important. Additionally, to reduce the risk of HE for engineering structural materials in service, surface treatments and microstructural optimization of the alloys have been suggested. In this review, we report on the progress of the studies on HE in metals, with a particular focus on steels. It focuses on four aspects:(1) hydrogen diffusion behavior;(2) hydrogen characterization methods;(3) HE mechanisms;and(4) the prevention of HE. The strengths and weaknesses of the current HE mechanisms and HE prevention methods are discussed, and specific research directions for further investigation of fundamental HE mechanisms and methods for preventing HE failure are identified.展开更多
Rechargeable aluminum-ion batteries(AIBs)are a new generation of low-cost and large-scale electrical energy storage systems.However,AIBs suffer from a lack of reliable cathode materials with insufficient intercalation...Rechargeable aluminum-ion batteries(AIBs)are a new generation of low-cost and large-scale electrical energy storage systems.However,AIBs suffer from a lack of reliable cathode materials with insufficient intercalation sites,poor ion-conducting channels,and poor diffusion dynamics of large chloroaluminate anions(AlCl4−and Al2Cl7−).To address these issues,surfacemodified graphitic carbon materials[i.e.,acidtreated expanded graphite(AEG)and base-etched graphite(BEG)]are developed as novel cathode materials for ultra-fast chargeable AIBs.AEG has more turbostratically ordered structure covered with abundant micro-to nano-sized pores on the surface structure and expanded interlayer distance(d002=0.3371 nm)realized by surface treatment of pristine graphite with acidic media,which can be accelerated the diffusion dynamics and efficient AlCl4−ions(de)-intercalation kinetics.The AIB system employing AEG exhibits a specific capacity of 88.6 mAh g^(−1)(4 A g^(−1))and~80 mAh g^(−1) at an ultra-high current rate of 10 A g^(−1)(~99.1%over 10,000 cycles).BEG treated with KOH solution possesses the turbostratically disordered structure with high density of defective sites and largely expanded d-spacing(d002=0.3384 nm)for attracting and uptaking more AlCl4−ions with relatively shorter penetration depth.Impressively,the AIB system based on the BEG cathode delivers a high specific capacity of 110 mAh g^(−1)(4 A g^(−1))and~91 mAh g^(−1)(~99.9%over 10,000 cycles at 10 A g^(−1)).Moreover,the BEG cell has high energy and power densities of 247 Wh kg^(−1) and 44.5 kW kg^(−1).This performance is one of the best among the AIB graphitic carbon materials reported for chloroaluminate anions storage performance.This finding provides great significance for the further development of rechargeable AIBs with high energy,high power density,and exceptionally long life.展开更多
基金Project(52401064)supported by the National Natural Science Foundation of ChinaProject(24B0172)supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(XDCX2024Y273)supported by the Postgraduate Scientific Research Innovation Project of Xiangtan University,China。
文摘Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of second-phase particles in Zn-based alloys might induce severe localized degradation via micro-coupling corrosion,thereby compromising the mechanical integrity of the alloy during in vivo tissue regeneration.In this study,high pressure solid solution(HPSS)treatment was conducted at 5 GPa and 380℃ for 1 h to fabricate Zn-0.5 Mn alloys.Microstructural characterization revealed that the HPSS treatment facilitated the formation of a supersaturated solid solution by completely dissolving theζ-MnZn_(13) phase into theα-Zn matrix.The resultant strengthening mechanisms,including supersaturated solid solution strengthening,grain-size strengthening,and dislocation strengthening,collectively enhanced the compressive yield strength(σ_(cys))of the Zn-0.5 Mn alloy to about 183.7 MPa,approximately three times that of the as-cast(AC)Zn-0.5 Mn alloy.Moreover,compared with the AC alloy,the HPSS Zn-0.5 Mn alloy exhibited uniform degradation behavior with a markedly reduced degradation rate.
基金supported by the National Natural Science Foundation of China(52171033,52431003,U23A20574)the Fundamental Research Funds for the Central Universities(2242025K20004)the SEU Innovation Capability Enhancement Plan for Doctoral Students(CXJH_SEU 24148,CXJH_SEU 25036).
文摘Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promising strategy to address this issue.To realize the synergy,herein,Sn whiskers with an in situ oxide layer served as substrates for magnetic-loss-active CoNi nanosheet growth,forming a hierarchical CoNi@SnO_(2)@Sn(CNS)heterostructure.The CNS absorber achieves a minimum reflection loss(RL_(min))value of-62.29 dB with an effective absorption bandwidth(EAB)of 2.2 GHz,covering the entire C-band with 70%absorption at only 2.61 mm thickness.The nanosheet design of CoNi enhances magnetic anisotropy to promote natural resonance,while the conductive Sn core and abundant Sn/SnO_(2) and CoNi/SnO_(2) heterointerfaces facilitate conduction loss and dielectric polarization.When composited into a thermoplastic polyurethane(TPU)matrix,the resulting CNS/TPU-2 film(20 wt%CNS)exhibits an RL_(min) value of-61.04 dB and a 2.5 GHz EAB.Its in-plane and through-plane thermal conductivities reach 2.41 and 0.51 W m^(-1) K^(-1),representing 4.1 and 2.6 times those of pure TPU films,respectively,facilitating heat dissipation from protected devices.This work provides valuable insights into magnetic-dielectric synergy for low-frequency MA of 1D metal-based materials,offering promising potential for 5G communications and flexible electronics.
基金the financial support from the National Natural Science Foundation of China(52172110,52472231,52311530113)Shanghai"Science and Technology Innovation Action Plan"intergovernmental international science and technology cooperation project(23520710600)+1 种基金Science and Technology Commission of Shanghai Municipality(22DZ1205600)the Central Guidance on Science and Technology Development Fund of Zhejiang Province(2024ZY01011)。
文摘Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.
文摘Over the last decade’s magnesium and magnesium based compounds have been intensively investigated as potential hydrogen storage as well as thermal energy storage materials due to their abundance and availability as well as their extraordinary high gravimetric and volumetric storage densities.This review work provides a broad overview of the most appealing systems and of their hydrogenation/dehydrogenation properties.Special emphasis is placed on reviewing the efforts made by the scientific community in improving the material’s thermodynamic and kinetic properties while maintaining a high hydrogen storage capacity.
基金the National Key Research and Development Program of China (No. 2018YFB0703600)Shenzhen Key Projects of Long-Term Support Plan (No. 20200925164021002)。
文摘Recent years have witnessed a continuous discovering of new thermoelectric materials which has experienced a paradigm shift from try-and-error efforts to experience-based discovering and first-principles calculation. However, both the experiment and first-principles calculation deriving routes to determine a new compound are time and resources consuming. Here, we demonstrated a machine learning approach to discover new M_(2)X_(3)-type thermoelectric materials with only the composition information. According to the classic Bi_(2)Te_(3) material, we constructed an M_(2)X_(3)-type thermoelectric material library with 720 compounds by using isoelectronic substitution, in which only 101 compounds have crystalline structure information in the Inorganic Crystal Structure Database(ICSD) and Materials Project(MP) database. A model based on the random forest(RF) algorithm plus Bayesian optimization was used to explore the underlying principles to determine the crystal structures from the known compounds. The physical properties of constituent elements(such as atomic mass, electronegativity, ionic radius) were used to define the feature of the compounds with a general formula ^(1)M^(2)M^(1)X^(2)X^(3)X(^(1)M +^(2)M:^(1)X +^(2)X+^(3)X = 2:3). The primary goal is to find new thermoelectric materials with the same rhombohedral structure as Bi_(2)Te_(3) by machine learning.The final trained RF model showed a high accuracy of 91% on the prediction of rhombohedral compounds. Finally, we selected four important features to proceed with the polynomial fitting with the prediction results from the RF model and used the acquired polynomial function to make further discoveries outside the pre-defined material library.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074154,12174160,and 11722433)the funding from the Six Talent Peaks Project+1 种基金333 High-level Talents Project of Jiangsu Provincethe Innovation and Entrepreneurship Training Programme for University Students in Jiangsu Province(Grant No.202210320140Y)。
文摘Recently,many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure.However,the extreme pressure required is indeed a challenge for practical application,which promotes a further exploration for high temperature(T_(c))superconductors at relatively low pressure.Herein,we performed a systematic theoretical investigation on a series of ternary hydrides with stoichiometry AX_(2)H_(8),which is constructed by interacting molecular XH_(4)(X=B,C,and N)into the fcc metal A lattice under low pressure of 0-150 GPa.We uncovered five compounds which are dynamically stable below 100 GPa,e.g.,AcB_(2)H_(8)(25 GPa),LaB_(2)H_(8)(40 GPa),RbC_(2)H_(8)(40 GPa),CSC_(2)H_(8)(60 GPa),and SrC_(2)H_(8)(65 GPa).Among them,AcB_(2)H_(8),which is energetically stable above 2.5 GPa,exhibits the highest Tcof 32 K at 25 GPa.The superconductivity originates mainly from the coupling between the electron of Ac atoms and the associated low-frequency phonons,distinct from the previous typical hydrides with H-derived superconductivity.Our results shed light on the future exploration of superconductivity among ternary compounds at low pressure.
基金supported by Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJD430004)the Fund of the Jiangsu CHINA-ISRAEL Industrial Technology Research Institute and Changzhou Sci&Tech Program(Nos.CJ20190042,CJ20200046).
文摘Magnesium alloy has been considered as one of the third-generation biomaterials for the regeneration and support of functional bone tissue.As a regeneration implant material with great potential applications,in-situ Mg_(2)Si phase reinforced Mg-6Zn cast alloy was comprehensively studied and expected to possess excellent mechanical properties via the refining and modifying of Mg_(2)Si reinforcements.The present study demonstrates that the primary and eutectic Mg_(2)Si phase can be greatly modified by the yttrium(Y)addition.The size of the primary Mg_(2)Si phases can be reduced to~20μm with an addition of 0.5 wt.%Y.This phenomenon is mainly attributed to the poisoning effect of the Y element.Moreover,wear resistance and tensile properties of the ternary alloy have also been improved by the Y addition.Mg-6Zn-4Si-0.5Y alloy exhibits optimal tensile properties and wears resistance.The ultimate tensile strength and the elongation of the alloy with 0.5 wt.%Y are 50%and 65%higher than those of the ternary alloy,respectively.Excessive Y addition(1.0 wt.%)deteriorates the tensile properties of Mg-Zn-Si alloy.The improvement of the tensile properties is mainly due to the modification of primary and eutectic Mg_(2)Si phases as well as the solid solution strengthening of the Y atoms.This study provides a certain implication for the application of Mg-Zn-Si alloys containing Y elements as regeneration implants.
文摘Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.
文摘The original online version of this article (Randrianarivony, M. (June 2014) On DFT Molecular Simulation for Non-Adaptive Kernel Approximation. Advances in Materials Physics and Chemistry, Vol. 4 No. 6, 105-115. http://dx.doi.org/10.4236/ampc.2014.46013) did not contain any acknowledgment. The author wishes to add the following acknowledgements: Acknowledgements: This work was partially supported by Eurostars Project E!6935 funded by German Federal Ministry of Education and Research.
基金financially supported by the State Administration for Market Regulation,China(No.2021MK050)the National Natural Science Foundation of China(Nos.50971043,51171046,21973012)+3 种基金the Key Research and Development Program of China(Nos.2022YFB3807200,CISRI-21T62450ZD)the Natural Science Foundation of Fujian Province,China(Nos.2021J01590,2020J01351,2018J01754,2020J01474)the Student Research and Training Program(SRTP) of Fuzhou University,China(No.29320)Fujian Provincial Department of Science & Technology,China(No.2021H6011)。
文摘In order to understand the influence of ordering behaviors on the thermodynamic and mechanical properties of multi-principal element alloys(MPEAs),the temperature-dependent thermodynamic properties and mechanical properties of FCC_CoNiV MPEAs were comparatively predicted,where the alloys were modeled as the ordered configurations based on our previously predicted site occupying fractions(SOFs),as well as disordered configuration based on traditional special quasi-random structure(SQS).The ordering behavior not only improves the thermodynamic stability of the structure,but also increases the elastic properties and Vickers hardness.For example,at 973 K,the predicted bulk modulus(B),shear modulus(G),Young’s modulus(E),and Vickers hardness(HV)of FCC_CoNiV MPEA based on SOFs configuration are 187.82,79.03,207.93,and 7.58 GPa,respectively,while the corresponded data are 172.58,57.45,155.14,and 4.64 GPa for the SQS configuration,respectively.The Vickers hardness predicted based on SOFs agrees considerably well with the available experimental data,while it is underestimated obviously based on SQS.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(Grant No.12304067)+1 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2021QA087 and ZR2021QA092)the Special Construction Project Fund for Shandong Province Taishan Scholars。
文摘Two-dimensional tellurium(2D-Te)exhibits strong spin-orbit coupling and a chiral structure.Studying its magnetotransport properties is crucial for the development of spintronic technologies and the exploration of novel device applications.The magnetotransport properties of 2D-Te under varying temperatures and high pressures warrant further study.In this paper,the magnetotransport behavior of 2D-Te under low-temperature and high-pressure conditions is investigated.At room temperature,the magnetoresistance(MR)increases with increasing magnetic field,exhibiting positive MR behavior below 4.3 GPa.During decompression,MR is almost constant with decreasing pressure.MR is more sensitive to pressure at lower temperatures.
基金support was provided by the National Natural Science Foundation of China(92463310,92163212,52473235,52472213,22179062,52125202,and U24A2065)National Key R&D Program of China(2022YFA1203400)+3 种基金High Level of Special Funds(G03050K002)Guangdong Provincial Key Laboratory of Computational Science and Material Design(2019B030301001)the Natural Science Foundation of Jiangsu Province(BK20230035)Computing resources were supported by the Center for Computational Science and Engineering at Southern University of Science and Technology.
文摘To enhance the power conversion efficiency(PCE)of organic photovoltaic(OPV)cells,the identification of high-performance polymer/macromolecule materials and understanding their relationship with photovoltaic performance before synthesis are critical objectives.In this study,we developed five algorithms using a dataset of 1343 experimentally validated OPV NFA acceptor materials.The random forest(RF)algorithm exhibited the best predictive performance for material design and screening.Additionally,we explored a newly developed polymer/macromolecule structure expression,polymer-unit fingerprint(PUFp),which outperformed the molecular access system(MACCS)across diverse machine learning(ML)algorithms.PUFp facilitated the interpretability of structure-property relationships,enabling PCE predictions of conjugated polymers/macromolecules formed by the combination of donor(D)and acceptor(A)units.Our PUFp-ML model efficiently preevaluated and classified numerous acceptor materials,identifying and screening the two most promising NFA candidates.The proposed framework demonstrates the ability to design novel materials based on PUFp-ML-established feature/substructure-property relationships,providing rational design guidelines for developing high-performanceOPV acceptors.These methodologies are transferable to donor materials,thereby supporting accelerated material discovery and offering insights for designing innovative OPV materials.
基金funded by the National Centre for Research and Development in Poland, project V4-JAPAN/2/15 “Development of Advanced Magnesium Alloys for Multifunctional Applications in Extreme Environments,” under statutory work at the Faculty of Material Science and Engineering Warsaw University of Technology in Polandthe International Visegrad Fund (project no. JP39421, V4Japan Joint Research Program)+3 种基金the support of the International Visegrad Fund (project V4Japan Joint Research Program, Ref. JP3936)the National Research, Development and Innovation Office (contract no. 2019-2.1.7-ERA-NET-2021-00030)Support by the Ministry of Education, Youth and Sports of the Czech Republic in the framework of Visegrad Group (V4)-Japan Joint Research Program-Advanced Materials under grant no. 8F21011 is gratefully acknowledged by K.M., D.D., and A.Fthe support from the Department of Metal and Corrosion Engineering, University of Chemical Technology, Prague, Czech Republic, while performing the tribocorrosion measurements
文摘In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.The annealing at 300℃ for 2 h did not change the grain size significantly;however,a slight growth of Mg_(2)Ca precipitates was observed.When the annealing temperature increased up to 400℃ for 2 h,full recrystallization of the alloy occurred;the grains and precipitates grew noticeably.Those changes were responsible for decreasing the corrosion and the tribocorrosion resistance of the alloy.Due to lowered resistance to the corrosion medium,the cell viability was also reduced.Although MG63 cells on the annealed specimens developed filopodia,cell-to-cell communication was not observed.
基金support from the Global Institute for Materials Research Tohoku(Proposal No.202302-RDKGE-0084)JSPS KAKENHI(Grant No.24H00378).
文摘This study was undertaken to understand the effects of incorporating a trace amount(0.1 at.%)of Ti and/or Mn with low diffusivities on the thermal stability of the precipitation morphologies of the T-Al6Mg11Zn11 phase in a heat-resistant Al-Mg-Zn-Cu-Ni quinary alloy in terms of the locations of the added solute elements.In the Ti-added alloy,solute Ti was concentrated in the center of the dendriticα-Al phase via a peritectic reaction during solidification.The Ti distribution was retained even after so-lution treatment at 480℃.In contrast,in the Mn-added alloy,Mn appeared localized around granular intermetallic phases(or formed Mn-rich phases),resulting in a slight amount of solute Mn in theα-Al matrix.Solute Mn slightly affected the precipitation morphology of the T-phase at 200 or 300℃.Nevertheless,much finer precipitates were observed in theα-Al matrix(resulting in finer precipitation morphology)with higher solute Ti concentration,indicating suppressed growth and coarsening of the T-phase precipitates by solute Ti.Introducing both Ti and Mn enhanced local coarsening of the precipi-tates inside the dendriticα-Al phases with higher Ti solute concentrations.The coexistence of solute Ti and Mn promoted the formation of a significantly coarsened stable Al18Mg3(Ti,Mn)2 phase accompanied by the decomposition of initial fine T-phase precipitates,leading to mechanical degradation of the alloy in a high-temperature environment for a long period.These results provide new insights into element selection for the design of heat-resistant Al alloys with superior high-temperature creep performances.
基金financially supported by the National Research Foundation of Korea grant funded by the Korea government(MSIT)(Nos.NRF-2022R1A5A1030054,NRF-RS-2024-00345498,and NRFRS-2023-00281508)by Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(HRD Program for Industrial Innovation-No P0023676)+1 种基金funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-No 519607530funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(Grant Agreement No 865855).
文摘L1_(2)precipitates are known to significantly enhance the strength and ductility of single-phase face-centered cubic(FCC)medium-or high-entropy alloys(M/HEAs).However,further improvements in mechanical properties remain untapped,as alloy design has historically focused on systems with specific CrCoNi-or FeCoCrNi-based FCC matrix and Ni_(3)Al L1_(2)phase compositions.This study introduces novel Co-Ni-Mo-Al alloys with L1_(2)precipitates by systematically altering Al content,aiming to bridge this research gap by revealing the strengthening mechanisms.The(CoNi)_(81)Mo_(12)Al_(7)alloy achieves yield strength of 1086 MPa,tensile strength of 1520 MPa,and ductility of 35%,demonstrating an impressive synergy of strength,ductility,and strain-hardening capacity.Dislocation analysis via transmission electron microscopy,supported by generalized stacking fault energy(GSFE)calculations using density functional theory(DFT),demonstrates that Mo substitution for Al in the L1_(2)phase alters dislocation behavior,promoting the formation of multiple deformation modes,including stacking faults,super-dislocation pairs,Lomer-Cottrell locks,and unusual nano-twin formation even at low strains.These behaviors are facilitated by the low stacking fault energy(SFE)of the FCC matrix,overlapping of SFs,and dislocation dissociation across anti-phase boundaries(APBs).The increased energy barrier for superlattice intrinsic stacking fault(SISF)formation compared to APBs,due to Mo substitution,further influences dislocation activity.This work demonstrates a novel strategy for designing high-performance M/HEAs by expanding the range of FCC matrix and L1_(2)compositions through precipitation hardening.
基金the financial supports from the National Natural Science Foundation of China (No. 52103360)the Basic and Applied Basic Research Foundation of Guangdong Province, China (No. 2020A1515111104)+1 种基金the Key-Area Research and Development Program of Guangdong Province (No. 2018B090905002)the technical support of Sinoma Institute of Materials Research (Guangzhou) Co., Ltd. (China)。
基金Project(51601076)supported by the National Natural Science Foundation of ChinaProject(17KJA430005)supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,ChinaProject(2019M650096)supported by China Postdoctoral Science Foundation。
文摘The effects of Sn content on microstructure and tensile properties of as-cast and as-extruded Mg-8Li-3Al-(1,2,3)Sn(wt.%)alloys were investigated by X-ray diffractometry(XRD),optical microscopy(OM),scanning electron microscopy(SEM)and tensile test.It is found that,as-cast Mg-8Li-3Al-(1,2,3)Sn alloys consist ofα-Mg+β-Li duplex matrix,MgLiAl2 and Li2Mg Sn phases.Increasing Sn content leads to grain refinement ofα-Mg dendrites and increase in content of Li2MgSn phase.During hot extrusion,complete dynamic recrystallization(DRX)takes place inβ-Li phase while incomplete DRX takes place inα-Mg phase.As Sn content is increased,the volume fraction of DRXedα-Mg grains is increased and the average grain size of DRXedα-Mg grains is decreased.Increasing Sn content is beneficial to strength but harmful to ductility for as-cast Mg-8Li-3Al-(1,2,3)Sn alloys.Tensile properties of Mg-8Li-3Al-(1,2,3)Sn alloys are improved significantly via hot extrusion and Mg-8Li-3Al-2Sn alloy exhibits the best tensile properties.
文摘7 xxx welding wire was self-made by spray forming ingots drawn to series welding wires products,and then TIG butt welding test is used for 5 mm thick 7075 high-strength aluminium alloy.After welding,the stress relief+solid-solution aging heat treatment(T6)were performed to joints,and the mechanical properties and microstructure of the joints before and after heat treatment were comparative analyzed.The results show that the properties of the heat-affected zone(HAZ)of the joint before heat treatment decreas,and the joint is softened.The welded joints tensile strength is 271.8 MPa,the elongation is 5.6%,and the average hardness of the weld is 118.4 HV.The second phase particles such asη(Mg Zn2),S(Al2 Cu Mg),Al13 Fe4 are distributed in a network layer,with no apparent element segregation.After heat treatment,the structure of each area of the joint is coarsened,and a small amount of Fe-containing impurity phases are distributed.Theηand S phases are dissolved in the matrix.The hardness of each area of the joint is increased to 155 HV,and the softening zone is disappeared,this leads the joint elongation close to 16.9%.The tensile strength is increased to 511.8 MPa,reaching 94%of the base metal tensile strength.
基金the National Natural Science Foundation of China(No.51505477)the Guangdong Provincial Key S&T Special Project(Nos.2017B020235001 and 20198010943001)+1 种基金the Guangdong Education Department Fund(No.2016KQNCX005)basic start-up fund of Sun-Yat Sen University(45000-18841218)。
文摘Hydrogen dissolved in metals as a result of internal and external hydrogen can affect the mechanical properties of the metals, principally through the interactions between hydrogen and material defects. Multiple phenomena such as hydrogen dissolution, hydrogen diffusion, hydrogen redistribution and hydrogen interactions with vacancies, dislocations, grain boundaries and other phase interfaces are involved in this process. Consequently, several hydrogen embrittlement(HE) mechanisms have been successively proposed to explain the HE phenomena, with the hydrogen-enhanced decohesion mechanism, hydrogenenhanced localized plasticity mechanism and hydrogen-enhanced strain-induced vacancies being some of the most important. Additionally, to reduce the risk of HE for engineering structural materials in service, surface treatments and microstructural optimization of the alloys have been suggested. In this review, we report on the progress of the studies on HE in metals, with a particular focus on steels. It focuses on four aspects:(1) hydrogen diffusion behavior;(2) hydrogen characterization methods;(3) HE mechanisms;and(4) the prevention of HE. The strengths and weaknesses of the current HE mechanisms and HE prevention methods are discussed, and specific research directions for further investigation of fundamental HE mechanisms and methods for preventing HE failure are identified.
基金This work was supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(No.NRF-2019R1I1A3A01046928)the“Human Resources Program in Energy Technology”of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(No.20204010600100).
文摘Rechargeable aluminum-ion batteries(AIBs)are a new generation of low-cost and large-scale electrical energy storage systems.However,AIBs suffer from a lack of reliable cathode materials with insufficient intercalation sites,poor ion-conducting channels,and poor diffusion dynamics of large chloroaluminate anions(AlCl4−and Al2Cl7−).To address these issues,surfacemodified graphitic carbon materials[i.e.,acidtreated expanded graphite(AEG)and base-etched graphite(BEG)]are developed as novel cathode materials for ultra-fast chargeable AIBs.AEG has more turbostratically ordered structure covered with abundant micro-to nano-sized pores on the surface structure and expanded interlayer distance(d002=0.3371 nm)realized by surface treatment of pristine graphite with acidic media,which can be accelerated the diffusion dynamics and efficient AlCl4−ions(de)-intercalation kinetics.The AIB system employing AEG exhibits a specific capacity of 88.6 mAh g^(−1)(4 A g^(−1))and~80 mAh g^(−1) at an ultra-high current rate of 10 A g^(−1)(~99.1%over 10,000 cycles).BEG treated with KOH solution possesses the turbostratically disordered structure with high density of defective sites and largely expanded d-spacing(d002=0.3384 nm)for attracting and uptaking more AlCl4−ions with relatively shorter penetration depth.Impressively,the AIB system based on the BEG cathode delivers a high specific capacity of 110 mAh g^(−1)(4 A g^(−1))and~91 mAh g^(−1)(~99.9%over 10,000 cycles at 10 A g^(−1)).Moreover,the BEG cell has high energy and power densities of 247 Wh kg^(−1) and 44.5 kW kg^(−1).This performance is one of the best among the AIB graphitic carbon materials reported for chloroaluminate anions storage performance.This finding provides great significance for the further development of rechargeable AIBs with high energy,high power density,and exceptionally long life.
