In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride ...In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.展开更多
Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive n...Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive nature of titanium,metallic titanium production involves extensive procedures and high costs.Considering its advantages and limitations,the European Union has classified titanium metal as a critical raw material(CRM)of low category.The Kroll process is predominantly used to produce titanium;however,molten salt electrolysis(MSE)is currently being explored for producing metallic titanium at a low cost.Since 2000,electrolytic titanium production has undergone a wave of technological advancements.However,because of the intermediate and disproportionation reactions in the electrolytic titanium production process,the process efficiency and titanium purity according to industrial standards could not be achieved.Consequently,metallic titanium production has gradually diversified into employing technologies such as thermal reduction,MSE,and titanium alloy preparation.This study provides a comprehensive review of research advances in titanium metal preparation technologies over the past two decades,highlighting the challenges faced by the existing methods and proposing potential solutions.It offers useful insights into the development of low-cost titanium preparation technologies.展开更多
Molten salt reactors,being the only reactor type among Generation Ⅳ advanced nuclear reactors that utilize liquid fuels,offer inherent safety,high-temperature,and low-pressure operation,as well as the capability for ...Molten salt reactors,being the only reactor type among Generation Ⅳ advanced nuclear reactors that utilize liquid fuels,offer inherent safety,high-temperature,and low-pressure operation,as well as the capability for online fuel reprocessing.However,the fuel-salt flow results in the decay of delayed neutron precursors(DNPs)outside the core,causing fluctuations in the effective delayed neutron fraction and consequently impacting the reactor reactivity.Particularly in accident scenarios—such as a combined pump shutdown and the inability to rapidly scram the reactor—the sole reliance on negative temperature feedback may cause a significant increase in core temperature,posing a threat to reactor safety.To address these problems,this paper introduces an innovative design for a passive fluid-driven suspended control rod(SCR)to dynamically compensate for reactivity fluctuations caused by DNPs flowing with the fuel.The control rod operates passively by leveraging the combined effects of gravity,buoyancy,and fluid dynamic forces,thereby eliminating the need for an external drive mechanism and enabling direct integration within the active region of the core.Using a 150 MWt thorium-based molten salt reactor as the reference design,we develop a mathematical model to systematically analyze the effects of key parameters—including the geometric dimensions and density of the SCR—on its performance.We examine its motion characteristics under different core flow conditions and assess its feasibility for the dynamic compensation of reactivity changes caused by fuel flow.The results of this study demonstrate that the SCR can effectively counteract reactivity fluctuations induced by fuel flow within molten salt reactors.A sensitivity analysis reveals that the SCR’s average density exerts a profound impact on its start-up flow threshold,channel flow rate,resistance to fuel density fluctuations,and response characteristics.This underscores the critical need to optimize this parameter.Moreover,by judiciously selecting the SCR’s length,number of deployed units,and the placement we can achieve the necessary reactivity control while maintaining a favorable balance between neutron economy and heat transfer performance.Ultimately,this paper provides an innovative solution for the passive reactivity control in molten salt reactors,offering significant potential for practical engineering applications.展开更多
The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study intro...The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of t...Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of the graphite used in the fuel element for these reactors being susceptible to molten salt infiltration,carbon black(CB)was added to increase the density of the graphite,and a fuel element(TRISO(tri-structural isotropic)fuel particles were randomly distributed in the modified graphite matrix)was prepared by cold isostatic pressing process.An out-of-pile performance study shows that the densification and pore structure of the modified graphite matrix were improved,as was the resistance to molten salt infiltration.The median pore size of the modified graphite was reduced from 673 to 433 nm and the threshold pressure for molten salt(FLiBe,66%(molar fraction)LiF and 34%BeF_(2))infiltration was increased from 0.88 to 1.37 MPa.The isotropic CB made the graphite matrix less anisotropic,while its thermal conductivity and compressive strength were reduced due to the difficult graphitization of CB.Fuel elements containing 20%(volume fraction)TRISO particles were prepared.Numerical simulations show that the power and temperature distribution of the fuel were in line with the design requirements.The modified graphite matrix had a higher density,smaller pores,a lower anisotropy and a greater resistance to FLiBe infiltration.展开更多
Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the character...Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the characteristics of corncob CO_(2)-gasification in molten salt environments is thoroughly investigated,and the approach of introducing Fe_(2)O_(3) as catalyst to enhance the syngas yield is proposed.The results showed that the molten salts significantly promoted the conversion of corncob into gaseous products with very low tar and char yield.Compared to O_(2) and H_(2)O atmospheres,utilizing CO_(2) as gasifying agent enhanced the yield of gaseous products during the corncob gasification,especially the yields of CO and H_(2).The introduction of Fe_(2)O_(3) as a catalyst could further increase the yield of gaseous products and the cold gas efficiency(CGE),and the yield of syngas was increased into 2258.3 ml·g^(−1) with a high CGE of 105.8%in 900℃.The findings evidenced that CO_(2) gasification in the molten salt environment with Fe_(2)O_(3) addition can promote the cracking of tar,increasing the syngas yield significantly.Moreover,the energy required to drive the gasification process was calculated,and the total energy consumption was calculated as 16.83 GJ·t^(−1).The study opened up a new solution for the biomass gasification,exhibiting a great potential in distributed energy or chemical systems.展开更多
A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosi...A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosion resistance of 347H stainless steel in molten salt were investigated by analyzing the phase composition,microstructure and chemical composition of the corrosion products.The results show that the grain refinement induced by element Mo imparts the stainless steel with optimal corrosion resistance at a medium grain size.Furthermore,the formation of MoC significantly enhances the intergranular corrosion resistance of the stainless steel.The stainless steel exhibits uniform corrosion in the nitrate solution.The corrosion layer displays a dual-layer structure,and the corrosion products protecting matrix are present in both the inner and outer layers.The outer layer consists of a mixture of Fe oxides(Fe_(2)O_(3),Fe_(3)O_(4)),NaFeO_(2),and a minor amount of MgFe_(2)O_(4).Conversely,the inner layer is primarily composed of a spinel layer(FeCr_(2)O_(4),MgCr_(2)O_(4))and a thin Cu_(2)O layer.The oxidation of Cu in the inner layer leads to the formation of a dense Cu_(2)O layer,effectively impeding O_(2)-plasma infiltration into the matrix.展开更多
The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology ...The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology and constitution of Ir film were examined by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. It is found that the reduction mechanism of Ir（III） is a three-electron step and electro reaction is a reversible diffusion controlled process; the diffusion coefficients of Ir（III） at 1083, 1113, 1143 and 1183 K are 1.56×10-4, 2.23×10-4, 2.77×10-4 and 4.40×10-4 cm2/s, respectively, while the activation energy of the electrode reaction is 102.95 kJ/mol. The compacted Ir film reveals that the applied potential greatly affects the deposition of Ir, the thickness of Ir film deposited at the potential of reduction peak is the highest, the temperature of the molten salt also exerts an influence on deposition, the film formed at a lower temperature is thinner, but more micropores would occur on film when the temperature went too high.展开更多
Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chem...Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.展开更多
This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential ox...This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential oxidation pathway of molybdenum into high-valence ions(Mo^(6+),Mo^(5+),Mo^(4+))under vary-ing electrolysis potentials.Electrochemical Impedance Spectroscopy(EIS)demonstrated that the dissolu-tion is governed by both charge transfer and diffusion mechanisms,with reduced impedance at higher potentials facilitating molybdenum dissolution.The reduction behavior of dissolved molybdenum ions was further explored using cyclic voltammetry(CV)and square wave voltammetry(SWV),confirming a multi-step reduction process controlled by diffusion and high reversibility.Nucleation studies using chronoamperometry established that molybdenum deposition follows an instantaneous nucleation mech-anism.Morphological analysis of cathodic deposits revealed that current density significantly influences particle size,transitioning from nano-sized spherical particles to larger equiaxed crystals with increasing current density.These findings provide a comprehensive understanding of molybdenum’s electrochemical properties in molten salts,offering valuable insights for optimizing electrolysis processes and advancing molybdenum-based material production.展开更多
Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare eart...Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare earth(RE)elements(especially Dy)are unevenly distributed globally.Therefore,an environmental-friendly recycling method for RE elements with a highly precise separation of Dy and Nd from end-of-life magnets is required to realize a carbon-neutral society.As an alternative to traditional hydrometallurgical RE separation techniques with a high environmental load,we designed a novel,highly efficient,and precise process for the separation and recycling of RE elements from magnet scrap.As a result,over 90%of the RE elements were efficiently extracted from the magnets using MgCl_(2)and evaporation loss was selectively suppressed by adding CaF_(2).The extracted RE elements were electrolytically separated based on the formation potential differences of the RE alloys.Nd and Dy metals with purities greater than 90%were estimated to be recovered at rates of 96%and 91%,respectively.Almost all the RE in the scraps could be separated and recycled as RE metals,and the byproducts were easily removed.Thus,this process is expected to be used on an industrial scale to realize a carbon-neutral society.展开更多
Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise ...Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise development path to accelerate deployment time.Uncertainty and sensitivity analyses of accidents guide nuclear reactor design and safety analyses.Uncertainty analysis can ascertain the safety margin,and sensitivity analysis can reveal the correlation between accident consequences and input parameters.Loss of forced cooling(LOFC)represents an accident scenario of the SM-MSR,and the study of LOFC could offer useful information to improve physical thermohydraulic and structural designs.Therefore,this study investigates the uncertainty of LOFC consequences and the sensitivity of related parameters.The uncertainty of the LOFC consequences was analyzed using the Monte Carlo method,and multiple linear regression was employed to analyze the sensitivity of the input parameters.The uncertainty and sensitivity analyses showed that the maximum reactor outlet fuel salt temperature was 725.5℃,which is lower than the acceptable criterion,and five important parameters influencing LOFC consequences were identified.展开更多
Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spot...Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spots,and inclusions.These defects are intricately linked to the electromagnetic effects,temperature distribution,and fluid dynamics during the melting process.The self-induced magnetic field created by the electric current,along with the axial magnetic field applied to stabilize the arc,significantly influences the solidification of titanium alloy ingots.A mathematical model optimized for the integrated analysis of multiple fields—electromagnetic,fluid,and thermal—was developed for the VAR solidification process of titanium alloys.The influence mechanism of electromagnetic field on the macroscopic solidification process of titanium alloy was investigated.The findings indicate the presence of two competing forces within the VAR molten pool,namely,thermal buoyancy and the Lorentz force.Introducing a coupled self-induced magnetic field and elevating the current to 15 kA led to an increase in the molten pool depth by 42.9%and a reduction in the thickness of the mushy zone by 25.2%.The application of a constant axial magnetic field enhances a unidirectional momentum buildup within the molten pool,thereby enhancing the flow velocity and cooling efficiency of melt.展开更多
The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechan...The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechanical loading with the plastic strain up to 10%.After immersion in molten salt for 300 h,all the samples exhibited a corrosion-induced Cr depletion layer.The depth of the Cr depletion layer increased by 40% for the alloy with helium ion irradiation and 10% plastic deformation,compared with that for the only corroded sample.Moreover,the proportion of large-sized helium bubbles increased with plastic deformation.These results indicate that the coupling effects of irradiation and tensile deformation accelerate the corrosion of the GH3535 alloy.In addition,in a molten salt environment,an unexpected outward migration behavior of helium bubbles was observed under different plastic deformation.Helium bubbles migrated closer to the surface as the strain increased up to 3%,while the migration depth declined when the strain reached 10%.This is ascribed to the interaction between deformation-induced dislocations and helium bubbles.展开更多
Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifesp...Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifespan has brought about a significant recycling dilemma.The traditional hydrometallurgical or pyrometallurgical strategies are not capable to maximize the output value of spent LIBs and minimize the potential environmental hazards.Herein,to alternate the tedious and polluting treatment processes,we propose a high-temperature molten-salt strategy to directly regenerate spent cathodes of LIBs,which can also overcome the barrier of the incomplete defects'restoration with previous low-temperature molten salts.The high-energy and stable medium environment ensures a more thorough and efficient relithiation reaction,and simultaneously provides sufficient driving force for atomic rearrangement and grains secondary growth.In consequence,the regenerated ternary cathode(R-NCM)exhibits significantly enhanced structural stability that effectively suppresses the occurrence of cracks and harmful side reactions.The R-NCM delivers excellent cycling stability,retaining 81.2%of its capacity after 200 cycles at 1 C.This technique further optimizes the traditional eutectic molten-salt approach,broadening its applicability and improving regenerated cathode performance across a wider range of conditions.展开更多
Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon...Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon materials based on organic compounds pyrolysis is high energy-consuming and high-emission,which is not conducive to addressing the climate crisis and achieving the goal of carbon neutrality.Molten salt electrolysis technology enables the direct capture and reduction of CO_(2)to produce solid carbon,resulting in significant environmental benefits while achieving carbon emissions reduction.The molten salt also has a purification function,enabling the production of high-purity carbon materials.The kinetics of the electrochemical reduction process can be easily controlled,and the co-reduction of multiple elements provides convenience for the in-situ optimization of carbon material structure and the expansion of its applications.Therefore,this review focuses on the thermodynamics&kinetics processes of molten salt capture and electrochemical reduction of CO_(2)to prepare carbon materials.It further reviews the recent research progress on the preparation of carbon materials for pollutant removal based on molten salt electrochemical processes for the first time.Finally,we analyze the advantages and challenges of the current molten salt electrochemical processes and offers prospects for future research directions.展开更多
Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle a...Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.展开更多
Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain b...Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.展开更多
The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional ...The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional double-plate radial diffuser is ill-suited for a single-medium TEST’s full tank storage due to its unidirectional fluid inflow.There has been a notable lack of optimization analysis of diffusers.Two innovative tubular diffuser designs with reduced cross-sectional areas have been introduced:the annular-arranged diffuser(AAD)and the cross-arranged diffuser(CAD).To elucidate the impact of diffuser designs on energy storage efficiency,a 3D transient computational fluid dynamics(CFD)model was established to simulate a thermocline formation under two diffuser types.The model was validated against experimental data.Results showed that the thermocline of AAD was 11.39%thinner than that of a traditional double-plate diffuser.In the process of charging and discharging,the time-varying thermocline and factors influencing thermocline thickness were analyzed.Results indicate that in the mixed dominant region,increased turbulent kinetic energy correlates with reduced thermocline thickness.Notably,the AAD’s stable thermocline was 4.23%and 5.41%thinner than the CAD’s during charging and discharging,respectively,making the AAD preferable for engineering applications.The effects of tube diameter and orifice opening angle on temperature stratification performance were also examined.The findings suggest that an inclined impact jet and large-diameter tubes are more conducive to temperature stratification.Moreover,an orifice diameter optimization method was developed,which can decrease the thermocline by 6.78%.展开更多
文摘In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.
基金financial support from the Yunnan Province Key Industries Science and Technology Special Project for Colleges and UniversitiesChina(No.FWCY-QYCT2024006)+6 种基金National Natural Science Foundation of China(Nos.52104351 and 52364051)Science and Technology Major Project of Yunnan Province,China(No.202202AG050007)the Yunnan Fundamental Research ProjectsChina(No.202401AT070314)the Key Technology Research and Development Program of Shandong Province,China(No.2023CXGC010903)Central Guidance Local Scientific and Technological Development Funds,China(No.202407AB110022)Yunnan Province Xingdian Talent Support Plan Project,China。
文摘Titanium exhibits outstanding properties,particularly,high specific strength and resistance to both high and low temperatures,earning it a reputation as the metal of the future.However,because of the highly reactive nature of titanium,metallic titanium production involves extensive procedures and high costs.Considering its advantages and limitations,the European Union has classified titanium metal as a critical raw material(CRM)of low category.The Kroll process is predominantly used to produce titanium;however,molten salt electrolysis(MSE)is currently being explored for producing metallic titanium at a low cost.Since 2000,electrolytic titanium production has undergone a wave of technological advancements.However,because of the intermediate and disproportionation reactions in the electrolytic titanium production process,the process efficiency and titanium purity according to industrial standards could not be achieved.Consequently,metallic titanium production has gradually diversified into employing technologies such as thermal reduction,MSE,and titanium alloy preparation.This study provides a comprehensive review of research advances in titanium metal preparation technologies over the past two decades,highlighting the challenges faced by the existing methods and proposing potential solutions.It offers useful insights into the development of low-cost titanium preparation technologies.
基金supported by Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020261)Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA02010000)the Young Potential Program of Shanghai Institute of Applied Physics,Chinese Academy of Sciences(No.SINAP-YXJH-202412).
文摘Molten salt reactors,being the only reactor type among Generation Ⅳ advanced nuclear reactors that utilize liquid fuels,offer inherent safety,high-temperature,and low-pressure operation,as well as the capability for online fuel reprocessing.However,the fuel-salt flow results in the decay of delayed neutron precursors(DNPs)outside the core,causing fluctuations in the effective delayed neutron fraction and consequently impacting the reactor reactivity.Particularly in accident scenarios—such as a combined pump shutdown and the inability to rapidly scram the reactor—the sole reliance on negative temperature feedback may cause a significant increase in core temperature,posing a threat to reactor safety.To address these problems,this paper introduces an innovative design for a passive fluid-driven suspended control rod(SCR)to dynamically compensate for reactivity fluctuations caused by DNPs flowing with the fuel.The control rod operates passively by leveraging the combined effects of gravity,buoyancy,and fluid dynamic forces,thereby eliminating the need for an external drive mechanism and enabling direct integration within the active region of the core.Using a 150 MWt thorium-based molten salt reactor as the reference design,we develop a mathematical model to systematically analyze the effects of key parameters—including the geometric dimensions and density of the SCR—on its performance.We examine its motion characteristics under different core flow conditions and assess its feasibility for the dynamic compensation of reactivity changes caused by fuel flow.The results of this study demonstrate that the SCR can effectively counteract reactivity fluctuations induced by fuel flow within molten salt reactors.A sensitivity analysis reveals that the SCR’s average density exerts a profound impact on its start-up flow threshold,channel flow rate,resistance to fuel density fluctuations,and response characteristics.This underscores the critical need to optimize this parameter.Moreover,by judiciously selecting the SCR’s length,number of deployed units,and the placement we can achieve the necessary reactivity control while maintaining a favorable balance between neutron economy and heat transfer performance.Ultimately,this paper provides an innovative solution for the passive reactivity control in molten salt reactors,offering significant potential for practical engineering applications.
基金supported by the Yunnan Province Basic Research General Program,China(No.202201BE070001-002)the Major Science and Technology Projects in Yunnan Province,China(No.202402AF 080005).
文摘The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
文摘Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of the graphite used in the fuel element for these reactors being susceptible to molten salt infiltration,carbon black(CB)was added to increase the density of the graphite,and a fuel element(TRISO(tri-structural isotropic)fuel particles were randomly distributed in the modified graphite matrix)was prepared by cold isostatic pressing process.An out-of-pile performance study shows that the densification and pore structure of the modified graphite matrix were improved,as was the resistance to molten salt infiltration.The median pore size of the modified graphite was reduced from 673 to 433 nm and the threshold pressure for molten salt(FLiBe,66%(molar fraction)LiF and 34%BeF_(2))infiltration was increased from 0.88 to 1.37 MPa.The isotropic CB made the graphite matrix less anisotropic,while its thermal conductivity and compressive strength were reduced due to the difficult graphitization of CB.Fuel elements containing 20%(volume fraction)TRISO particles were prepared.Numerical simulations show that the power and temperature distribution of the fuel were in line with the design requirements.The modified graphite matrix had a higher density,smaller pores,a lower anisotropy and a greater resistance to FLiBe infiltration.
基金supported by the National Natural Science Foundation of China(52066007,22279048)the Major Science and Technology Project of Yunnan Province(202202AG050017).
文摘Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the characteristics of corncob CO_(2)-gasification in molten salt environments is thoroughly investigated,and the approach of introducing Fe_(2)O_(3) as catalyst to enhance the syngas yield is proposed.The results showed that the molten salts significantly promoted the conversion of corncob into gaseous products with very low tar and char yield.Compared to O_(2) and H_(2)O atmospheres,utilizing CO_(2) as gasifying agent enhanced the yield of gaseous products during the corncob gasification,especially the yields of CO and H_(2).The introduction of Fe_(2)O_(3) as a catalyst could further increase the yield of gaseous products and the cold gas efficiency(CGE),and the yield of syngas was increased into 2258.3 ml·g^(−1) with a high CGE of 105.8%in 900℃.The findings evidenced that CO_(2) gasification in the molten salt environment with Fe_(2)O_(3) addition can promote the cracking of tar,increasing the syngas yield significantly.Moreover,the energy required to drive the gasification process was calculated,and the total energy consumption was calculated as 16.83 GJ·t^(−1).The study opened up a new solution for the biomass gasification,exhibiting a great potential in distributed energy or chemical systems.
基金Science and Technology Program Project of Gansu Province(21ZD3GB001)。
文摘A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosion resistance of 347H stainless steel in molten salt were investigated by analyzing the phase composition,microstructure and chemical composition of the corrosion products.The results show that the grain refinement induced by element Mo imparts the stainless steel with optimal corrosion resistance at a medium grain size.Furthermore,the formation of MoC significantly enhances the intergranular corrosion resistance of the stainless steel.The stainless steel exhibits uniform corrosion in the nitrate solution.The corrosion layer displays a dual-layer structure,and the corrosion products protecting matrix are present in both the inner and outer layers.The outer layer consists of a mixture of Fe oxides(Fe_(2)O_(3),Fe_(3)O_(4)),NaFeO_(2),and a minor amount of MgFe_(2)O_(4).Conversely,the inner layer is primarily composed of a spinel layer(FeCr_(2)O_(4),MgCr_(2)O_(4))and a thin Cu_(2)O layer.The oxidation of Cu in the inner layer leads to the formation of a dense Cu_(2)O layer,effectively impeding O_(2)-plasma infiltration into the matrix.
文摘The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology and constitution of Ir film were examined by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. It is found that the reduction mechanism of Ir（III） is a three-electron step and electro reaction is a reversible diffusion controlled process; the diffusion coefficients of Ir（III） at 1083, 1113, 1143 and 1183 K are 1.56×10-4, 2.23×10-4, 2.77×10-4 and 4.40×10-4 cm2/s, respectively, while the activation energy of the electrode reaction is 102.95 kJ/mol. The compacted Ir film reveals that the applied potential greatly affects the deposition of Ir, the thickness of Ir film deposited at the potential of reduction peak is the highest, the temperature of the molten salt also exerts an influence on deposition, the film formed at a lower temperature is thinner, but more micropores would occur on film when the temperature went too high.
基金financially supported by the National Postdoctoral Program for Innovative Talents, China (No. BX2021327)the National Natural Science Foundation of China (Nos. 22206194 and U2267222)+1 种基金the Ningbo Natural Science Foundation of China (No. 2023J337)the Yongjiang Talent Introduction Programme, China (No. 2 021A-161-G)。
文摘Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.
基金financially supported by the National Natural Science Foundation of China for Distinguished Young Scholar(No.52025042)the Open Fund of State Key Laboratory of Advanced Metallurgy(No.KF24-12)。
文摘This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential oxidation pathway of molybdenum into high-valence ions(Mo^(6+),Mo^(5+),Mo^(4+))under vary-ing electrolysis potentials.Electrochemical Impedance Spectroscopy(EIS)demonstrated that the dissolu-tion is governed by both charge transfer and diffusion mechanisms,with reduced impedance at higher potentials facilitating molybdenum dissolution.The reduction behavior of dissolved molybdenum ions was further explored using cyclic voltammetry(CV)and square wave voltammetry(SWV),confirming a multi-step reduction process controlled by diffusion and high reversibility.Nucleation studies using chronoamperometry established that molybdenum deposition follows an instantaneous nucleation mech-anism.Morphological analysis of cathodic deposits revealed that current density significantly influences particle size,transitioning from nano-sized spherical particles to larger equiaxed crystals with increasing current density.These findings provide a comprehensive understanding of molybdenum’s electrochemical properties in molten salts,offering valuable insights for optimizing electrolysis processes and advancing molybdenum-based material production.
基金supported by a Grant-in-Aid from the Japan Society for the Promotion of Science(JSPS)Fellows(19J20301).
文摘Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare earth(RE)elements(especially Dy)are unevenly distributed globally.Therefore,an environmental-friendly recycling method for RE elements with a highly precise separation of Dy and Nd from end-of-life magnets is required to realize a carbon-neutral society.As an alternative to traditional hydrometallurgical RE separation techniques with a high environmental load,we designed a novel,highly efficient,and precise process for the separation and recycling of RE elements from magnet scrap.As a result,over 90%of the RE elements were efficiently extracted from the magnets using MgCl_(2)and evaporation loss was selectively suppressed by adding CaF_(2).The extracted RE elements were electrolytically separated based on the formation potential differences of the RE alloys.Nd and Dy metals with purities greater than 90%were estimated to be recovered at rates of 96%and 91%,respectively.Almost all the RE in the scraps could be separated and recycled as RE metals,and the byproducts were easily removed.Thus,this process is expected to be used on an industrial scale to realize a carbon-neutral society.
基金supported by the Youth Innovation Promotion Association(YIPA)(No.E329290101)of the Chinese Academy of Sciences。
文摘Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise development path to accelerate deployment time.Uncertainty and sensitivity analyses of accidents guide nuclear reactor design and safety analyses.Uncertainty analysis can ascertain the safety margin,and sensitivity analysis can reveal the correlation between accident consequences and input parameters.Loss of forced cooling(LOFC)represents an accident scenario of the SM-MSR,and the study of LOFC could offer useful information to improve physical thermohydraulic and structural designs.Therefore,this study investigates the uncertainty of LOFC consequences and the sensitivity of related parameters.The uncertainty of the LOFC consequences was analyzed using the Monte Carlo method,and multiple linear regression was employed to analyze the sensitivity of the input parameters.The uncertainty and sensitivity analyses showed that the maximum reactor outlet fuel salt temperature was 725.5℃,which is lower than the acceptable criterion,and five important parameters influencing LOFC consequences were identified.
基金financially supported by the National Natural Science Foundation of China(Nos.52422408 and 52171031)the Excellent Youth Fund of Liaoning Natural Science Foundation(No.2023JH3/10200001)the Liaoning Xingliao Talents-Top-notch Young Talents Project(No.XLYC2203064).
文摘Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spots,and inclusions.These defects are intricately linked to the electromagnetic effects,temperature distribution,and fluid dynamics during the melting process.The self-induced magnetic field created by the electric current,along with the axial magnetic field applied to stabilize the arc,significantly influences the solidification of titanium alloy ingots.A mathematical model optimized for the integrated analysis of multiple fields—electromagnetic,fluid,and thermal—was developed for the VAR solidification process of titanium alloys.The influence mechanism of electromagnetic field on the macroscopic solidification process of titanium alloy was investigated.The findings indicate the presence of two competing forces within the VAR molten pool,namely,thermal buoyancy and the Lorentz force.Introducing a coupled self-induced magnetic field and elevating the current to 15 kA led to an increase in the molten pool depth by 42.9%and a reduction in the thickness of the mushy zone by 25.2%.The application of a constant axial magnetic field enhances a unidirectional momentum buildup within the molten pool,thereby enhancing the flow velocity and cooling efficiency of melt.
基金supported by the National Natural Science Foundation of China(Nos.12425511,12375280,U2341261,U23B2072 and 12305293).
文摘The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechanical loading with the plastic strain up to 10%.After immersion in molten salt for 300 h,all the samples exhibited a corrosion-induced Cr depletion layer.The depth of the Cr depletion layer increased by 40% for the alloy with helium ion irradiation and 10% plastic deformation,compared with that for the only corroded sample.Moreover,the proportion of large-sized helium bubbles increased with plastic deformation.These results indicate that the coupling effects of irradiation and tensile deformation accelerate the corrosion of the GH3535 alloy.In addition,in a molten salt environment,an unexpected outward migration behavior of helium bubbles was observed under different plastic deformation.Helium bubbles migrated closer to the surface as the strain increased up to 3%,while the migration depth declined when the strain reached 10%.This is ascribed to the interaction between deformation-induced dislocations and helium bubbles.
基金support by National Natural Science Foundation of China(22379166)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2022JJ10089)Central South University Innovation-Driven Research Programme(2023CXQD034).
文摘Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifespan has brought about a significant recycling dilemma.The traditional hydrometallurgical or pyrometallurgical strategies are not capable to maximize the output value of spent LIBs and minimize the potential environmental hazards.Herein,to alternate the tedious and polluting treatment processes,we propose a high-temperature molten-salt strategy to directly regenerate spent cathodes of LIBs,which can also overcome the barrier of the incomplete defects'restoration with previous low-temperature molten salts.The high-energy and stable medium environment ensures a more thorough and efficient relithiation reaction,and simultaneously provides sufficient driving force for atomic rearrangement and grains secondary growth.In consequence,the regenerated ternary cathode(R-NCM)exhibits significantly enhanced structural stability that effectively suppresses the occurrence of cracks and harmful side reactions.The R-NCM delivers excellent cycling stability,retaining 81.2%of its capacity after 200 cycles at 1 C.This technique further optimizes the traditional eutectic molten-salt approach,broadening its applicability and improving regenerated cathode performance across a wider range of conditions.
基金supported by the National Natural Science Foundation of China(Nos.52200143,51979011 and 52276208)the Natural Science Foundation of Hubei Province(No.2024AFB546)the Fundamental Research Funds for Central Public Welfare Research Institutes(Nos.CKSF2023302/CL and CKSF2023314/CL).
文摘Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon materials based on organic compounds pyrolysis is high energy-consuming and high-emission,which is not conducive to addressing the climate crisis and achieving the goal of carbon neutrality.Molten salt electrolysis technology enables the direct capture and reduction of CO_(2)to produce solid carbon,resulting in significant environmental benefits while achieving carbon emissions reduction.The molten salt also has a purification function,enabling the production of high-purity carbon materials.The kinetics of the electrochemical reduction process can be easily controlled,and the co-reduction of multiple elements provides convenience for the in-situ optimization of carbon material structure and the expansion of its applications.Therefore,this review focuses on the thermodynamics&kinetics processes of molten salt capture and electrochemical reduction of CO_(2)to prepare carbon materials.It further reviews the recent research progress on the preparation of carbon materials for pollutant removal based on molten salt electrochemical processes for the first time.Finally,we analyze the advantages and challenges of the current molten salt electrochemical processes and offers prospects for future research directions.
基金supported by the National Key R&D Program of China(2023YFA1508001)the National Natural Science Foundation of China(22272120 and U2202251)+2 种基金the Fundamental Research Funds for the Central Universities(2042022kf1174)the Hainan Province Science and Technology Special Fund(ZDYF2023SHFZ120 and ZDYF2021SHFZ058)the Research Foundation of Marine Science and Technology Collaborative Innovation Center of Hainan University(XTCX2022HYB01)。
文摘Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.
基金financially supported by the National Natural Science Foundation of China under the Grant No.22209075。
文摘Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.
基金supported by the National Natural Science Foundation of China(No.52375274)the Zhejiang Provincial Natural Science Foundation of China(No.LD21E050003)+1 种基金the Key R&D Program of Zhejiang Province(No.2023C01229)the Central Government Fund for Regional Science and Technology Development of China(No.2023ZY1033).
文摘The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional double-plate radial diffuser is ill-suited for a single-medium TEST’s full tank storage due to its unidirectional fluid inflow.There has been a notable lack of optimization analysis of diffusers.Two innovative tubular diffuser designs with reduced cross-sectional areas have been introduced:the annular-arranged diffuser(AAD)and the cross-arranged diffuser(CAD).To elucidate the impact of diffuser designs on energy storage efficiency,a 3D transient computational fluid dynamics(CFD)model was established to simulate a thermocline formation under two diffuser types.The model was validated against experimental data.Results showed that the thermocline of AAD was 11.39%thinner than that of a traditional double-plate diffuser.In the process of charging and discharging,the time-varying thermocline and factors influencing thermocline thickness were analyzed.Results indicate that in the mixed dominant region,increased turbulent kinetic energy correlates with reduced thermocline thickness.Notably,the AAD’s stable thermocline was 4.23%and 5.41%thinner than the CAD’s during charging and discharging,respectively,making the AAD preferable for engineering applications.The effects of tube diameter and orifice opening angle on temperature stratification performance were also examined.The findings suggest that an inclined impact jet and large-diameter tubes are more conducive to temperature stratification.Moreover,an orifice diameter optimization method was developed,which can decrease the thermocline by 6.78%.
