The chemical and electrochemical stability of lanthanide nickelates La2 NiO4+δ(LNO),Pr2 NiO4+δ(PNO)and their mixed compounds La(2-x)PrxNiO4+δ(LPNOs)with x=0.5,1 or 1.5 is reported.The aim is to promote these materi...The chemical and electrochemical stability of lanthanide nickelates La2 NiO4+δ(LNO),Pr2 NiO4+δ(PNO)and their mixed compounds La(2-x)PrxNiO4+δ(LPNOs)with x=0.5,1 or 1.5 is reported.The aim is to promote these materials as efficient electrodes for solid oxide fuel cell(SOFC)and/or solid oxide electrolysis cell(SOEC).La2 NiO4+δand La1.5Pr0.5NiO4+δcompounds are chemically very stable as powders over one month in the temperature range 600-800℃,while the other materials rich in praseodymium progressively decompose into various perovskite-deriving components with additional Pr6 O11.Despite their uneven properties,all these materials are quite efficient and sustainable as electrodes on top of gadolinium doped ceria(GDCBL)//yttrium doped zirconia(8 YSZ)electrolyte,for one month at 700℃without polarization.Under polarization(300 mA·cm-2),the electrochemical performances of LNO,PNO and La1.5Pr0.5NiO4+δ(LP5 NO)quickly degrade in SOFC mode,i.e.for the oxygen reduction reaction,while they show durability in SOEC mode,i.e.for the oxide oxidation reaction.展开更多
The rare-earth nickelates(RENiO_(3)) exhibit an exceptional complex electronic phase diagram and multiple electronic phase transitions that enrich promising applications in correlated electronic devices beyond convent...The rare-earth nickelates(RENiO_(3)) exhibit an exceptional complex electronic phase diagram and multiple electronic phase transitions that enrich promising applications in correlated electronic devices beyond conventional semiconductors.Nevertheless,the practical applications of RENiO_(3) are challenged by their intrinsic thermodynamic metastability in material synthesis and high material cost.Therefore,developing an economical strategy to achieve the batch synthesis of RENiO_(3) is of vital importance.In this work,we enlarged the synthesis amount of RENiO_(3) up to 20 g per batch using chloride(KCI) assisted molten salt reaction.By optimizing the reaction conditions,the powder of RENiO_(3) with the cubic shape and average size of ~2μm was effectively synthesized,while their phase purity exceeded 95%.In addition,the cost to synthesize RENiO_(3) was further reduced by using rare-earth extraction intermediate products as the raw materials,instead of using the pure rare-earth precursors.It also achieved wide adjustments in the metal-to-insulator-transition temperature from160 to 420 K without significantly reducing the transition sharpness.By enlarging the synthesis amount and the reducing the cost,it paves the way to the device application of RENiO_(3).展开更多
While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the ...While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the rare-earth elements were rarely concerned.Herein,we demonstrate the material synthesis and MIT properties of RENiO_(3) containing valence variable rare-earth compositions,such as Ce,Pr,Sm,Eu and Tb.The metastable perovskite structure of SmNiO_(3) and EuNiO_(3) with a rare-earth valence states variable towards+2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free energies.This is in contrast to Ce and Tb,in which situations the variable rare-earth valence state towards+4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO_(3).Nevertheless,PrNiO_(3) with MIT properties can be effectively synthesized at lower oxygen pressures,owing to the higher stability to form a fully occupied 6s orbit associated Pr3+compared to the half-filled one related to Pr4+.The present work provides guidance for regulating the MIT properties of RENiO_(3).展开更多
Although the metal to insulator transition(MIT)observed in d-band correlated metal oxides enables promising applications(e.g.,correlated logical devices and Mottronic devices),its present recognition is mainly limited...Although the metal to insulator transition(MIT)observed in d-band correlated metal oxides enables promising applications(e.g.,correlated logical devices and Mottronic devices),its present recognition is mainly limited on the direct current(DC)electrical transports.Up to date,the MIT from the perspective of alternation current(AC)transport and its potential electronic applications remains yet unclear.Herein,we demonstrate the frequency(f_(AC))dependence in the impedance(Z=Z’+iZ″)of typical MIT materials,such as thin film rare-earth nickelates(Re NiO_(3)),across the critical MIT temperature(T_(MIT)).Apart from the abrupt change in the impedance modulus(|Z|)across the critical temperature(T_(MIT))similar to the DC transport,the MIT also triggers non-continuous variation in the impedance phase(θ),and this enables the f_(AC)-regulations in the Z’-T tendencies(Z’=|Z|cosθ).At the critical f_(AC) range(e.g.,104-106 Hz),the con-versing variations in|Z|-T and cosθ-T across T_(MIT) result in non-monotonic delta-shape Z’-T tendency in Sm_(x) Nd_(1-x) NiO_(3),the full width half maximum of which is effectively narrowed compared to the situation with the absence of MIT.Further imparting lower or higher f_(AC) elevate the domination in|Z|-T and cosθ-T,respectively,but also enables abrupt Z’-T tendencies across T_(MIT) showing negative temperature coefficient of resistance(NTCR)or positive temperature coefficient of resistance(PTCR).By introducing f_(AC) as a new freedom,the MIT behavior can be more comprehensively regulated electronically,and this extends the vision in exploring the new electronic applications based on the correlated MIT materials from the AC perspective.展开更多
The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics app...The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications,e.g.ocean electric field sensor,bio-sensor,and neuron synapse logical devices.Nevertheless,these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO_(3)with flexibly adjustable rare-earth compositions and electronic structures.Herein,we demonstrate a metal-organic decompositions(MOD)approach that can effectively grow metastable RENiO_(3)covering a large variety of the rare-earth composition without introducing any vacuum process.Unlike the previous chemical growths for RENiO_(3)relying on strict interfacial coherency that limit the film thickness,the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions.Further indicated by positron annihilation spectroscopy,the RENiO_(3)grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers,as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis.This effectively enlarges the magnitude in the resistance regulations in particular for RENiO_(3)with lighter RE,shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering.展开更多
The discovery of Ni-based superconductors has brought new hope to the field of high-temperature superconductivity.Understanding the dimensional characteristics and anisotropy of nickelate superconductors has become a ...The discovery of Ni-based superconductors has brought new hope to the field of high-temperature superconductivity.Understanding the dimensional characteristics and anisotropy of nickelate superconductors has become a central focus in current research.However,the nature of the nickelate superconductivity,especially the transition between 2D and 3D superconductivity,remains debated.In this study,we investigated the magnetic field-dependent electrical transport behaviors of infinite-layer nickelates.The La_(0.8)Sr_(0.2)NiO_(2)films exhibit highly anisotropic superconductivity,which fits well with the 2D Tinkham model,indicating a purely 2D superconducting nature.In contrast,the Nd_(0.8)Sr_(0.2)NiO_(2)films show isotropic behavior with a mixed 2D+3D superconducting characteristics.This“mixed 2D+3D superconducting behavior”is typically associated with the complexity of the electronic band structure in the material.Through a systematic comparison of two model systems with distinct rare-earth orbital contributions,we propose a new perspective based on orbital selectivity.The observed difference likely originates from Nd_(0.8)Sr_(0.2)NiO_(2)incorporates the Nd_(0.8)Sr_(0.2)NiO_(2)orbital,adding a 3D component.Its interaction with the Ni sd_(2)2orbital leads to orbital-selective pairing.Theoretical calculations provide key evidence that the Nd-based system exhibits greater isotropy and 3D character compared to the La-based system.Our study thus suggests that orbital selectivity serves as a critical mechanism governing the superconducting properties,and the distinction between rare-earth elements(such as La and Nd)ultimately influences the dimensional characteristics of superconductivity through this mechanism.展开更多
The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemica...The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemical reactivity of MoO_(4)^(2-)ions in molten CaCl_(2).The eutectic temperature and composition of the system are identified as 1021 K and 4.74 wt.%CaMoO_(4),respectively.Under constant-current electrolysis conditions of−10 mA/cm^(2) at 1123 K,uniform and dense Mo coatings are obtained on Ni plates with up to 90.31%efficiency.Increasing the current density raises the overpotential,leading to refined grains and decreased roughness.The Mo-coated Ni plate exhibits a significant improvement in hardness and corrosion resistance.Microhardness increases from HV 46.00 to HV 215.10 after coating,and the corrosion rate in a 20 wt.%NaCl solution at room temperature decreases to 0.1%that of the bare plate.These findings enhance our understanding of the molten CaCl_(2)–CaMoO_(4) system and emphasize the potential of innovative Mo coating technologies.展开更多
A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca alumina...A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca aluminates)during the impregnation process of the matrix.After cathode activation,the surface Ba:O molar ratio is 0.88:1.00,much higher than the Ba dispenser cathode without Ni doping.The XPS results of the cathode surface showed that the metallic Ba appeared on the activated cathode surface,forming dipoles with oxygen,and effectively reducing the cathode surface work function.The pulse electron emission current density at 1100℃_(b)(brightness temperature)was 18.26 A/cm^(2),and the calculated work function was 1.97 eV.It has a low evaporation rate and the accelerated lifetime test predict a lifetime of over 160000 h.First-principles calculations showed that the charge transfer and dipole moment in the NiW-BaO system were both increased compared to the Ba dispenser cathode,thus improving the emission performance of the Ni-W mixed matrix cathode.展开更多
THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between c...THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to syn...α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.展开更多
Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using iso...Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.展开更多
Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and h...Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and high upkeep costs.Therefore,the development of a specialized front-end filter tailored for direct current water-cooled system is importance.This involves the integration of dimensionally stable anode(DSA)and nickel alloy cathode,valued for their corrosion resistance in seawater,into a novel front-end filter system for Water-cooled applications.This system has the dual capability of generating hydrogen and chlorine for self-cleaning purposes.Implementing a flushing pulse electrolysis mode,it effectively mitigates electrode failure induced by cathodic calcium and magnesium deposition,thereby significantly prolonging electrode lifespan.Laboratory tests comprising system assembly and performance evaluations were conducted,with the system programmed to operate for 5 minutes every 24 hours under continuous flushing by natural seawater to simulate real-world conditions.After more than 11 months of continuous flushing,observations reveal that the DSA mesh and nickel alloy mesh maintain intact structural integrity and normal functioning.Subsequent 1꞉1 physical prototype Sea trial further validated the soundness of the system design and electrolytic control parameters.展开更多
Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of mineral...Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.展开更多
The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts rem...The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.展开更多
Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial c...Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.展开更多
We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O...We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O10shows a paramagnetic metallic behavior with a metal-to-metal phase transition(T^*)at about 162 K,as revealed by both magnetic susceptibility and resistivity.Further magnetoresistance and Hall coefficient results show a negative magnetoresistance at low temperatures and the carrier type of Nd4Ni3O10is dominated by hole-type charge carriers.The significant enhancement of Hall coefficient and resistivity below T*suggests that effective charge carrier density decreases when cooling through the transition temperature.In contrast,Nd4Ni3O8 shows an insulating behavior.In addition,this compound shows a paramagnetic behavior with the similar magnetic moment as that of Nd4Ni3O10derived from the Curie-Weiss fitting.This may suggest that the magnetic moments in both systems are contributed by Nd^3+ ions.By applying pressures up to about 49 GPa,the insulating behavior is still present and becomes even stronger under a high pressure.Our results suggest that the different Ni configurations(Ni^1+/2+ or Ni^2+/3+)and the changes of coordination environment of Ni sites may account for the contrasting behaviors in trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.展开更多
La-Mg-Ni-based hydrogen storage alloys with superlattice structures are the new generation anode material for nickel metal hydride(Ni-MH)batteries owing to the advantages of high capacity and exceptional activation pr...La-Mg-Ni-based hydrogen storage alloys with superlattice structures are the new generation anode material for nickel metal hydride(Ni-MH)batteries owing to the advantages of high capacity and exceptional activation properties.However,the cycling stability is not currently satisfactory enough which plagues its application.Herein,a strategy of partially substituting La with the Y element is proposed to boost the capacity durability of La-Mg-Ni-based alloys.Furthermore,phase structure regulation is implemented simultaneously to obtain the A5 B19-type alloy with good crystal stability specifically.It is found that Y promotes the phase formation of the Pr5 Co19-type phase after annealing at 985℃.The alloy containing Y contributes to the superior rate capability resulting from the promoted hydrogen diffusion rate.Notably,Y substitution enables strengthening the anti-pulverization ability of the alloy in terms of increasing the volume match between[A_(2)B_(4)]and[AB5]subunits,and effectively enhances the anti-corrosion ability of the alloy due to high electronegativity,realizing improved long-term cycling stability of the alloy from 74.2%to 78.5%after cycling 300 times.The work is expected to shed light on the composition and structure design of the La-Mg-Ni-based hydrogen storage alloy for Ni-MH batteries.展开更多
Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish ...Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.展开更多
With the development of the new energy industry and the depletion of nickel sulfide ore resources,laterite nickel ore has become the main source of primary nickel,and nickel for power batteries has become a new growth...With the development of the new energy industry and the depletion of nickel sulfide ore resources,laterite nickel ore has become the main source of primary nickel,and nickel for power batteries has become a new growth point in consumption.This paper systematically summarizes the processes,parameters,products,recovery rates,environmental indicators,costs,advantages,disadvantages and the latest research progress of mainstream nickel extraction processes from laterite nickel ore.It also provides a comparative analysis of the environmental impact and economic efficiency of different nickel extraction processes.It is found that the current nickel extraction processes from laterite nickel ore globally for commercial production mainly include the RKEF process for producing ferronickel and the HPAL process for producing intermediate products.The former accounts for about 80%of laterite nickel ore production.Compared to each other,the investment cost per ton of nickel metal production capacity for the RKEF is about 43000$,with an operational cost of about 16000$per ton of nickel metal and a total nickel recovery rate of 77%–90%.Its products are mainly used in stainless steels.For the HPAL process,the investment cost per ton of nickel metal production capacity is about 56000$,with an operational cost of about 15000$per ton of nickel metal and a total nickel recovery rate of 83%–90%.Its products are mainly used in power batteries.The significant differences between the two lies in energy consumption and carbon emissions,with the RKEF being 2.18 and 2.37 times that of the HPAL,respectively.Although the use of clean energy can greatly reduce the operational cost and environmental impact of RKEF,if RKEF is converted to producing high Ni matte,its economic and environmental performance still cannot match that of the HPAL and oxygen-enriched side-blown processes.Therefore,it can be inferred that with the increasing demand for nickel in power batteries,HPAL and oxygen-enriched side blowing processes will play a greater role in laterite nickel extraction.展开更多
基金PEREN project(reference:ANR-2011-PREG-016–05)the ECOREVE project(reference:ANR-18-CE05-0036-01)the Agence Nationale de la Recherche(A.N.R.,France)for supporting these scientific works and for the financial support。
文摘The chemical and electrochemical stability of lanthanide nickelates La2 NiO4+δ(LNO),Pr2 NiO4+δ(PNO)and their mixed compounds La(2-x)PrxNiO4+δ(LPNOs)with x=0.5,1 or 1.5 is reported.The aim is to promote these materials as efficient electrodes for solid oxide fuel cell(SOFC)and/or solid oxide electrolysis cell(SOEC).La2 NiO4+δand La1.5Pr0.5NiO4+δcompounds are chemically very stable as powders over one month in the temperature range 600-800℃,while the other materials rich in praseodymium progressively decompose into various perovskite-deriving components with additional Pr6 O11.Despite their uneven properties,all these materials are quite efficient and sustainable as electrodes on top of gadolinium doped ceria(GDCBL)//yttrium doped zirconia(8 YSZ)electrolyte,for one month at 700℃without polarization.Under polarization(300 mA·cm-2),the electrochemical performances of LNO,PNO and La1.5Pr0.5NiO4+δ(LP5 NO)quickly degrade in SOFC mode,i.e.for the oxygen reduction reaction,while they show durability in SOEC mode,i.e.for the oxide oxidation reaction.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFA0718900)the National Natural Science Foundation of China (Nos.52073090 and 62074014)+1 种基金the Fundamental Research Funds for the Central Universities (No.FRF-TP-19-023A3Z)Beijing New-star Plan of Science and Technology (No. Z191100001119071)。
文摘The rare-earth nickelates(RENiO_(3)) exhibit an exceptional complex electronic phase diagram and multiple electronic phase transitions that enrich promising applications in correlated electronic devices beyond conventional semiconductors.Nevertheless,the practical applications of RENiO_(3) are challenged by their intrinsic thermodynamic metastability in material synthesis and high material cost.Therefore,developing an economical strategy to achieve the batch synthesis of RENiO_(3) is of vital importance.In this work,we enlarged the synthesis amount of RENiO_(3) up to 20 g per batch using chloride(KCI) assisted molten salt reaction.By optimizing the reaction conditions,the powder of RENiO_(3) with the cubic shape and average size of ~2μm was effectively synthesized,while their phase purity exceeded 95%.In addition,the cost to synthesize RENiO_(3) was further reduced by using rare-earth extraction intermediate products as the raw materials,instead of using the pure rare-earth precursors.It also achieved wide adjustments in the metal-to-insulator-transition temperature from160 to 420 K without significantly reducing the transition sharpness.By enlarging the synthesis amount and the reducing the cost,it paves the way to the device application of RENiO_(3).
基金Project supported by the National Key Research and Development Program of China(2021YFA0718900)the National Natural Science Foundation of China(62074014,52073090)。
文摘While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the rare-earth elements were rarely concerned.Herein,we demonstrate the material synthesis and MIT properties of RENiO_(3) containing valence variable rare-earth compositions,such as Ce,Pr,Sm,Eu and Tb.The metastable perovskite structure of SmNiO_(3) and EuNiO_(3) with a rare-earth valence states variable towards+2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free energies.This is in contrast to Ce and Tb,in which situations the variable rare-earth valence state towards+4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO_(3).Nevertheless,PrNiO_(3) with MIT properties can be effectively synthesized at lower oxygen pressures,owing to the higher stability to form a fully occupied 6s orbit associated Pr3+compared to the half-filled one related to Pr4+.The present work provides guidance for regulating the MIT properties of RENiO_(3).
基金financially supported by the National Key Re-search and Development Program of China(No.2021YFA0718900)the National Natural Science Foundation of China(Nos.62074014 and 52073090)the Beijing New-star Plan of Science and Tech-nology(No.Z191100001119071).
文摘Although the metal to insulator transition(MIT)observed in d-band correlated metal oxides enables promising applications(e.g.,correlated logical devices and Mottronic devices),its present recognition is mainly limited on the direct current(DC)electrical transports.Up to date,the MIT from the perspective of alternation current(AC)transport and its potential electronic applications remains yet unclear.Herein,we demonstrate the frequency(f_(AC))dependence in the impedance(Z=Z’+iZ″)of typical MIT materials,such as thin film rare-earth nickelates(Re NiO_(3)),across the critical MIT temperature(T_(MIT)).Apart from the abrupt change in the impedance modulus(|Z|)across the critical temperature(T_(MIT))similar to the DC transport,the MIT also triggers non-continuous variation in the impedance phase(θ),and this enables the f_(AC)-regulations in the Z’-T tendencies(Z’=|Z|cosθ).At the critical f_(AC) range(e.g.,104-106 Hz),the con-versing variations in|Z|-T and cosθ-T across T_(MIT) result in non-monotonic delta-shape Z’-T tendency in Sm_(x) Nd_(1-x) NiO_(3),the full width half maximum of which is effectively narrowed compared to the situation with the absence of MIT.Further imparting lower or higher f_(AC) elevate the domination in|Z|-T and cosθ-T,respectively,but also enables abrupt Z’-T tendencies across T_(MIT) showing negative temperature coefficient of resistance(NTCR)or positive temperature coefficient of resistance(PTCR).By introducing f_(AC) as a new freedom,the MIT behavior can be more comprehensively regulated electronically,and this extends the vision in exploring the new electronic applications based on the correlated MIT materials from the AC perspective.
基金financially supported by the National Key Research and Development Program of China(No.2021YFA0718900)National Natural Science Foundation of China(Nos.62074014,52073090,and 52103284)。
文摘The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications,e.g.ocean electric field sensor,bio-sensor,and neuron synapse logical devices.Nevertheless,these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO_(3)with flexibly adjustable rare-earth compositions and electronic structures.Herein,we demonstrate a metal-organic decompositions(MOD)approach that can effectively grow metastable RENiO_(3)covering a large variety of the rare-earth composition without introducing any vacuum process.Unlike the previous chemical growths for RENiO_(3)relying on strict interfacial coherency that limit the film thickness,the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions.Further indicated by positron annihilation spectroscopy,the RENiO_(3)grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers,as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis.This effectively enlarges the magnitude in the resistance regulations in particular for RENiO_(3)with lighter RE,shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering.
基金supported by the National Natural Science Foundation of China(Grant No.52525208)the Sichuan Science and Technology Program(Grant No.2024ZYD0164)+2 种基金the Key Research and Development Program from the Ministry of Science and Technology(Grant No.2023YFA1406301)the National Natural Science Foundation of China(Grant Nos.12274061,and 12204090)the Technology Department of Sichuan Province(Grant No.2023NSFSC1336)。
文摘The discovery of Ni-based superconductors has brought new hope to the field of high-temperature superconductivity.Understanding the dimensional characteristics and anisotropy of nickelate superconductors has become a central focus in current research.However,the nature of the nickelate superconductivity,especially the transition between 2D and 3D superconductivity,remains debated.In this study,we investigated the magnetic field-dependent electrical transport behaviors of infinite-layer nickelates.The La_(0.8)Sr_(0.2)NiO_(2)films exhibit highly anisotropic superconductivity,which fits well with the 2D Tinkham model,indicating a purely 2D superconducting nature.In contrast,the Nd_(0.8)Sr_(0.2)NiO_(2)films show isotropic behavior with a mixed 2D+3D superconducting characteristics.This“mixed 2D+3D superconducting behavior”is typically associated with the complexity of the electronic band structure in the material.Through a systematic comparison of two model systems with distinct rare-earth orbital contributions,we propose a new perspective based on orbital selectivity.The observed difference likely originates from Nd_(0.8)Sr_(0.2)NiO_(2)incorporates the Nd_(0.8)Sr_(0.2)NiO_(2)orbital,adding a 3D component.Its interaction with the Ni sd_(2)2orbital leads to orbital-selective pairing.Theoretical calculations provide key evidence that the Nd-based system exhibits greater isotropy and 3D character compared to the La-based system.Our study thus suggests that orbital selectivity serves as a critical mechanism governing the superconducting properties,and the distinction between rare-earth elements(such as La and Nd)ultimately influences the dimensional characteristics of superconductivity through this mechanism.
基金supported by Research Center for Industries of the Future(No.WU2022C034)at Westlake University,China。
文摘The molten CaCl_(2)−CaMoO_(4) system was investigated,and the electrodeposition of protective Mo coatings on Ni plates was demonstrated.The results confirm the high solubility of solid CaMoO_(4) and the electrochemical reactivity of MoO_(4)^(2-)ions in molten CaCl_(2).The eutectic temperature and composition of the system are identified as 1021 K and 4.74 wt.%CaMoO_(4),respectively.Under constant-current electrolysis conditions of−10 mA/cm^(2) at 1123 K,uniform and dense Mo coatings are obtained on Ni plates with up to 90.31%efficiency.Increasing the current density raises the overpotential,leading to refined grains and decreased roughness.The Mo-coated Ni plate exhibits a significant improvement in hardness and corrosion resistance.Microhardness increases from HV 46.00 to HV 215.10 after coating,and the corrosion rate in a 20 wt.%NaCl solution at room temperature decreases to 0.1%that of the bare plate.These findings enhance our understanding of the molten CaCl_(2)–CaMoO_(4) system and emphasize the potential of innovative Mo coating technologies.
基金supported by the National Natural Science Foundation of China(Nos.U2341209 and 52130407).
文摘A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca aluminates)during the impregnation process of the matrix.After cathode activation,the surface Ba:O molar ratio is 0.88:1.00,much higher than the Ba dispenser cathode without Ni doping.The XPS results of the cathode surface showed that the metallic Ba appeared on the activated cathode surface,forming dipoles with oxygen,and effectively reducing the cathode surface work function.The pulse electron emission current density at 1100℃_(b)(brightness temperature)was 18.26 A/cm^(2),and the calculated work function was 1.97 eV.It has a low evaporation rate and the accelerated lifetime test predict a lifetime of over 160000 h.First-principles calculations showed that the charge transfer and dipole moment in the NiW-BaO system were both increased compared to the Ba dispenser cathode,thus improving the emission performance of the Ni-W mixed matrix cathode.
基金The National Natural Science Foundation of China(Grant No.12462006)Beijing Institute of Structure and Environment Engineering Joint Innovation Fund(No.BQJJ202414).
文摘THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金the National Natural Science Foundation of China(Nos.22150410339,W2432012,22301233 and 22171218)the Ministry of Science and Technology China(No.wgxz2022188)。
文摘α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.
基金supported by the National Natural Science Foundation of China(Nos.22271007,W2431014)Peking University Shenzhen Graduate School+2 种基金State Key Laboratory of Chemical OncogenomicsShenzhen Key Laboratory of Chemical GenomicsShenzhen Bay Laboratory.
文摘Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.
基金Supported by the Project of Design of Anti-corrosion and Anti-fouling Solutions for Offshore Wind Power Water-Cooled Systems(No.E428161)the National Natural Science Foundation of China(No.42176047)。
文摘Water-cooled system have significantly enhanced the power generation efficiency of offshore wind turbines.However,these innovative systems are susceptible to substantial biological fouling,maintenance challenges,and high upkeep costs.Therefore,the development of a specialized front-end filter tailored for direct current water-cooled system is importance.This involves the integration of dimensionally stable anode(DSA)and nickel alloy cathode,valued for their corrosion resistance in seawater,into a novel front-end filter system for Water-cooled applications.This system has the dual capability of generating hydrogen and chlorine for self-cleaning purposes.Implementing a flushing pulse electrolysis mode,it effectively mitigates electrode failure induced by cathodic calcium and magnesium deposition,thereby significantly prolonging electrode lifespan.Laboratory tests comprising system assembly and performance evaluations were conducted,with the system programmed to operate for 5 minutes every 24 hours under continuous flushing by natural seawater to simulate real-world conditions.After more than 11 months of continuous flushing,observations reveal that the DSA mesh and nickel alloy mesh maintain intact structural integrity and normal functioning.Subsequent 1꞉1 physical prototype Sea trial further validated the soundness of the system design and electrolytic control parameters.
基金funded by geological survey project of China Geological Survey(DD20211404)。
文摘Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.
基金financially supported by the Sichuan Science and Technology Program (Grant No. 2025NSFSC0139)the China Postdoctoral Science Foundation (Grant No.2023MD734228)+10 种基金funding from Generalitat de Catalunya 2021SGR00457supported by MCIN with funding from European Union NextGenerationEU(PRTR-C17.I1)by Generalitat de Catalunya (In-CAEM Project)the support from the project AMaDE(PID2023-149158OB-C43)funded by MCIN/AEI/10.13039/501100011033/by “ERDF A way of making Europe”by the “European Union”supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.:CEX2021-001214-S)funded by the CERCA Programme/Generalitat de Catalunyaperformed in the framework of Universitat Autònoma de Barcelona Materials Science PhD programfunding from the CSC-UAB PhD scholarship program. ICN2 is founding member of e-DREAM[87]
文摘The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.
基金financially supported by the Ten-thousand Talents Programthe K. C. Wong Pioneer Talent Program+3 种基金China Three Gorges Corporation (WWKY-2021–0027)Inner Mongolia Science and Technology Plan (2021ZD0033)the National Natural Science Foundation of China (52202121)funded by China Petroleum&Chemical Corporation (123091)
文摘Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.
基金supported by the National Key R&D Program of China(Grant Nos.2016YFA0300401,and 2016YFA0401704)the National Natural Science Foundation of China(Grant Nos.A0402/11534005,and A0402/11674164)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000)。
文摘We report the crystal structures and physical properties of trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.Measurements of magnetization and electrical resistivity display contrasting behaviors in the two compounds.Nd4Ni3O10shows a paramagnetic metallic behavior with a metal-to-metal phase transition(T^*)at about 162 K,as revealed by both magnetic susceptibility and resistivity.Further magnetoresistance and Hall coefficient results show a negative magnetoresistance at low temperatures and the carrier type of Nd4Ni3O10is dominated by hole-type charge carriers.The significant enhancement of Hall coefficient and resistivity below T*suggests that effective charge carrier density decreases when cooling through the transition temperature.In contrast,Nd4Ni3O8 shows an insulating behavior.In addition,this compound shows a paramagnetic behavior with the similar magnetic moment as that of Nd4Ni3O10derived from the Curie-Weiss fitting.This may suggest that the magnetic moments in both systems are contributed by Nd^3+ ions.By applying pressures up to about 49 GPa,the insulating behavior is still present and becomes even stronger under a high pressure.Our results suggest that the different Ni configurations(Ni^1+/2+ or Ni^2+/3+)and the changes of coordination environment of Ni sites may account for the contrasting behaviors in trilayer nickelates Nd4Ni3O10and Nd4Ni3O8.
基金the financial support by the National Nat-ural Science Foundation of China(Nos.52201282,52071281,52371239)the China Postdoctoral Science Foundation(No.2023M742945)+4 种基金Hebei Provincial Postdoctoral Science Foundation(No.B2023003023)the Science Research Project of Hebei Education Department(No.BJK2022033)the Natural Science Foundation of Hebei Province(No.C2022203003)the Inner Mongolia Science and Technology Major Project(No.2020ZD0012)the Baotou Science and Technology Planning Project(No.XM2022BT09).
文摘La-Mg-Ni-based hydrogen storage alloys with superlattice structures are the new generation anode material for nickel metal hydride(Ni-MH)batteries owing to the advantages of high capacity and exceptional activation properties.However,the cycling stability is not currently satisfactory enough which plagues its application.Herein,a strategy of partially substituting La with the Y element is proposed to boost the capacity durability of La-Mg-Ni-based alloys.Furthermore,phase structure regulation is implemented simultaneously to obtain the A5 B19-type alloy with good crystal stability specifically.It is found that Y promotes the phase formation of the Pr5 Co19-type phase after annealing at 985℃.The alloy containing Y contributes to the superior rate capability resulting from the promoted hydrogen diffusion rate.Notably,Y substitution enables strengthening the anti-pulverization ability of the alloy in terms of increasing the volume match between[A_(2)B_(4)]and[AB5]subunits,and effectively enhances the anti-corrosion ability of the alloy due to high electronegativity,realizing improved long-term cycling stability of the alloy from 74.2%to 78.5%after cycling 300 times.The work is expected to shed light on the composition and structure design of the La-Mg-Ni-based hydrogen storage alloy for Ni-MH batteries.
基金Institute of Technology Research Fund Program for Young Scholars21C Innovation Laboratory Contemporary Amperex Technology Co.,Limited,Ninde, 352100, China (21C–OP-202314)。
文摘Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.
基金This research was jointly supported by the China Geological Survey Project(DD20211404)the Natural Science Foundation of Inner Mongolia Autonomous Region(2019LH05028).
文摘With the development of the new energy industry and the depletion of nickel sulfide ore resources,laterite nickel ore has become the main source of primary nickel,and nickel for power batteries has become a new growth point in consumption.This paper systematically summarizes the processes,parameters,products,recovery rates,environmental indicators,costs,advantages,disadvantages and the latest research progress of mainstream nickel extraction processes from laterite nickel ore.It also provides a comparative analysis of the environmental impact and economic efficiency of different nickel extraction processes.It is found that the current nickel extraction processes from laterite nickel ore globally for commercial production mainly include the RKEF process for producing ferronickel and the HPAL process for producing intermediate products.The former accounts for about 80%of laterite nickel ore production.Compared to each other,the investment cost per ton of nickel metal production capacity for the RKEF is about 43000$,with an operational cost of about 16000$per ton of nickel metal and a total nickel recovery rate of 77%–90%.Its products are mainly used in stainless steels.For the HPAL process,the investment cost per ton of nickel metal production capacity is about 56000$,with an operational cost of about 15000$per ton of nickel metal and a total nickel recovery rate of 83%–90%.Its products are mainly used in power batteries.The significant differences between the two lies in energy consumption and carbon emissions,with the RKEF being 2.18 and 2.37 times that of the HPAL,respectively.Although the use of clean energy can greatly reduce the operational cost and environmental impact of RKEF,if RKEF is converted to producing high Ni matte,its economic and environmental performance still cannot match that of the HPAL and oxygen-enriched side-blown processes.Therefore,it can be inferred that with the increasing demand for nickel in power batteries,HPAL and oxygen-enriched side blowing processes will play a greater role in laterite nickel extraction.
