In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the...In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the critical elementary reaction of molybdenum catalysis.However,the relevant density functional theory(DFT)studies are relatively scarce,especially regarding the rational selection of functionals.In this work,14 functionals were employed to investigate the Mo-catalyzed carbonyl oxidative addition step.A benchmark study was carried out to evaluate their performance in structure optimization and energy calculation.Analyses of mean absolute error(MAE)and mean squared error(MSE)indicated that the B3LYP-D3(BJ),TPSSh,and ωB97X-D functionals exhibited superior performance in structure optimization.Using the DLPNO-CCSD(T)functional as the reference,the M06,M06-L,and MN15-L functionals exhibited good performance for energy calculation based on the structures optimized using the B3LYP-D3(BJ)functional.In particular,MN15-L provided the best performance with the smallest MAE and MSE.展开更多
To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produce...To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.展开更多
The increasing global adoption of electric vehicles(EVs)has led to a growing demand for a cost-effective and reliable charging infrastructure.This study presents a novel data-driven approach to assessing EV station pe...The increasing global adoption of electric vehicles(EVs)has led to a growing demand for a cost-effective and reliable charging infrastructure.This study presents a novel data-driven approach to assessing EV station performance by analyzing power consumption efficiency,station utilization rates,no-power session occurrences,and CO_(2)reduction metrics.A dataset of 17,500 charging sessions from 305 stations across a regional network was analyzed to identify operational inefficiencies and opportunities for infrastructure optimization.Results indicate a strong correlation between station utilization and energy efficiency,highlighting the importance of strategic station placement.The findings also emphasize the impact of no-power sessions on network inefficiency and the need for real-time station monitoring.CO_(2)reduction analysis demonstrates that optimizing EV charging performance can significantly contribute to sustainability goals.Based on these insights,this study recommends the implementation of predictive maintenance strategies,real-time user notifications,and diversified provider networks to improve station availability and efficiency.The proposed data-driven framework offers actionable solutions for policymakers,charging network operators,and urban planners to enhance EV infrastructure reliability and sustainability.展开更多
Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,...Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.展开更多
Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon...Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon-based readout circuits in a single step.Based on this,we propose a photodiode based on an n-i-p structure,which removes the buffer layer and further simplifies the manufacturing process of quantum dot image sensors,thus reducing manufacturing costs.Additionally,for the noise complexity in quantum dot image sensors when capturing images,traditional denoising and non-uniformity methods often do not achieve optimal denoising re⁃sults.For the noise and stripe-type non-uniformity commonly encountered in infrared quantum dot detector imag⁃es,a network architecture has been developed that incorporates multiple key modules.This network combines channel attention and spatial attention mechanisms,dynamically adjusting the importance of feature maps to en⁃hance the ability to distinguish between noise and details.Meanwhile,the residual dense feature fusion module further improves the network's ability to process complex image structures through hierarchical feature extraction and fusion.Furthermore,the pyramid pooling module effectively captures information at different scales,improv⁃ing the network's multi-scale feature representation ability.Through the collaborative effect of these modules,the network can better handle various mixed noise and image non-uniformity issues.Experimental results show that it outperforms the traditional U-Net network in denoising and image correction tasks.展开更多
The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase tra...The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase transitions[3-5] and is actively explored on quantum simulation platforms.[6-9] Exploring how the KZ effect fares across different criticalities has proven to be a rewarding pursuit,significantly enriching our understanding of nonequilibrium quantum dynamics.[3-5,10-23]展开更多
Self-supported nanoarrays have emerged as a promising alternative electrocatalyst for alkaline H_(2)O splitting,owing to their accessible active sites and strongly coupled interfaces with current collectors for improv...Self-supported nanoarrays have emerged as a promising alternative electrocatalyst for alkaline H_(2)O splitting,owing to their accessible active sites and strongly coupled interfaces with current collectors for improved mass transfer and stability.Herein,self-supported crystalline/amorphous NiO/Ni(OH)_(2)nanosheet arrays on nickel foam(NF)are fabricated via an in-situ dissolution-deposition hydrothermal growing of Ni(OH)_(2)nanosheets without additional metal sources assisted by a common Lewis base,EDTA,followed by a rapid calcination at 300℃in air.The as-prepared EDTA-NF-12 h exhibits high OER and HER performance under alkaline conditions,requiring 235 mV and 158 mV,respectively,to reach 10 mA cm^(-2),and the decent performance can be maintained for 24 h without obvious degradation.The dual interfaces,i.e.,the dense crystalline/amorphous interfaces within the NiO/Ni(OH)_(2)nanosheet arrays,as well as the intimate interfaces between nanoarrays and NF,both serve as reaction active sites,facilitate electron transfer,and endow the catalyst with high activity and stability.Furthermore,by applying EDTA-Ni^(2+)and other Lewis bases with varying basicities instead of EDTA,the interfaces with the NF substrate are found to promote the formation of crystalline/amorphous interfaces within the nanosheets.This study offers appealing opportunities for tailoring the electrocatalytic performance of self-supported electrodes via dual interface engineering.展开更多
This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both commo...This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.展开更多
High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs ...High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.展开更多
Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We he...Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We herein report a d-p-f orbital coupling strategy to tackle these critical challenges by incorporating Eu 4f orbitals to activate both metallic(Ni)and non-metallic(Se)sites of Ni Se.The imported Eu atoms could induce essential Ni 3d and Se 4p orbital reconstruction through gradient d-p-f coupling,thereby optimizing the band center alignment between Ni Se and Li PSs.Such electronic reconstruction strengthens both d-p hybridization between Ni and Li PSs and s-p hybridization between Se and Li PSs,which can not only enhance the chemisorption affinity toward Li PSs but also accelerate interfacial charge transfer kinetics,leading to suppressed shuttle effect and boosted Li PSs conversion kinetics.Therefore,the Li-S batteries assembled with Eu incorporated Ni Se deliver exceptional electrochemical performance with a high specific capacity of 896.2 m Ah g^(-1)at 4 C and a retained areal capacity of 5.66 m Ah cm^(-2)under a high sulfur loading of 5.94 mg cm^(-2)after 100 cycles.This work underscores the critical role of rare-earth 4f orbital coupling for modulating the active sites to construct high-efficiency electrocatalysts for Li-S batteries and beyond.展开更多
Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bot...Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bottleneck,severely affecting device stability and long-term operational performance.Herein,we present a multifunctional strategy by incorporating highly thermally conductive Ti_(3)C_(2)T_(X) MXene nanosheets into the perovskite layer to simultaneously enhance thermal management and optoelectronic properties.The Ti_(3)C_(2)T_(X) nanosheets,embedded at perovskite grain boundaries,construct efficient thermal conduction pathways,significantly improving the thermal conductivity and diffusivity of the film.This leads to a notable reduction in the device’s steady-state operating temperature from 42.96 to 39.97 under 100 mW cm^(−2) illumination,thereby alleviating heat-induced performance degradation.Beyond thermal regulation,Ti_(3)C_(2)T_(X),with high conductivity and negatively charged surface terminations,also serves as an effective defect passivation agent,reducing trap-assisted recombination,while simultaneously facilitating charge extraction and transport by optimizing interfacial energy alignment.As a result,the Ti_(3)C_(2)T_(X)-modified PSC achieve a champion PCE of 25.13%and exhibit outstanding thermal stability,retaining 80%of the initial PCE after 500 h of thermal aging at 85 and 30±5%relative humidity.(In contrast,control PSC retain only 58%after 200 h.)Moreover,under continuous maximum power point tracking in N2 atmosphere,Ti_(3)C_(2)T_(X)-modified PSC retained 70%of the initial PCE after 500 h,whereas the control PSC drop sharply to 20%.These findings highlight the synergistic role of Ti_(3)C_(2)T_(X) in thermal management and optoelectronic performance,paving the way for the development of high-efficiency and heat-resistant perovskite photovoltaics.展开更多
Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures ...Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.展开更多
Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we ...Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we found the boosting effects of halogens on organic pollutants formation during thermal processes.In situ electron paramagnetic resonance spectroscopy was used to distinguish the organic free radical intermediates of organic pollutants during thermal processes.The pure chlorine-containing reaction system dominantly induce the formation of highly chlorinated phenoxy radicals,whereas the pure bromine-containing reaction system induce the formation of semiquinone radicals.The results provide clear evidence for the molecular mechanisms by which halogen coexistence boosts pollutants formation.Coexisting halogens made the reactions much more complex.Bromine atom radicals(Br·)can enhance the level of active chlorine atoms radicals(Cl·),then(1)facilitating highly chlorinated organic radicals and toxic pollutants formation,(2)activating polycyclic aromatic hydrocarbons molecules for subsequent ring growth and(3)accelerating oxidation reactions.Combining the identification of organic free radical intermediates and characteristics of products,detailed mechanisms of halogens on the formations of organic pollutants during thermal-related processes were clarified,which can be helpful for their efficient control in the widespread bromines and chlorines co-existence reaction system.展开更多
Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treat...Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treatment of subcutaneous tumors.This study reports the exploration of novel supramolecular halogen-bonded organic frameworks(XOFs)based on[N…Br^(+)…N]halogen bonds through the ligand exchange strategy and their application in photothermal therapy.Through ligand exchange,XOF(Br)-TPy was successfully prepared,and its structure and properties were thoroughly characterized using NMR,XPS,FT-IR,and XRD techniques.Due to their cationic characteristics,these XOFs serve as effective carriers for the photothermal agent IR820.In vitro experiments demonstrated that the IR820@XOF(Br)-TPy composite exhibits excellent photothermal conversion efficiency under NIR irradiation,effectively inducing tumor cell ablation.Furthermore,in vivo studies confirmed the remarkable antitumor efficacy of the composite material in a subcutaneous tumor model.This work demonstrates that the ligand exchange strategy is a versatile and facile approach for constructing XOFs(Br)and provides a novel strategy for developing advanced photothermal therapeutic agents with significant application potential.展开更多
Electrochromic smart windows(ESWs)can significantly reduce building energy consumption,but the high cost hinders large-scale production.The in situ growth of tungsten oxide(WO_(3))films is only by a simple immersion p...Electrochromic smart windows(ESWs)can significantly reduce building energy consumption,but the high cost hinders large-scale production.The in situ growth of tungsten oxide(WO_(3))films is only by a simple immersion process,the silver nanowires(AgNWs)undergo oxidation to Ag^(+)ions through electron loss,and the liberated electrons provide driving force for the deposition of WO_(4)^(2-).Enabled the fabrication of large-area WO_(3)films and ESWs were fabricated under minimal laboratory conditions,demonstrating the economic feasibility,efficient and reliable nature of industrial production.Structural characterization and density functional theory calculations were combined to confirm that AgNWs effectively regulate oxygen vacancies of WO_(3)films and promote the in situ growth process.The optimized WO_(3)exhibits a maximum transmittance modulation of 90.8%and excellent cycling stability of 20,000 cycles.The largescale WO_(3)-based ESWs can save building energy up to 140.0 MJ m^(-2)compared to traditional windows in tropical regions,as verified by simulations more than40 global cities.This research provides a new approach for improving the performance and industrial production of ESW,providing the full understanding and development direction to short the distance of the ESW commercial production.展开更多
Cesium lead iodide perovskites offer promising stability and a bandgap near 1.7 eV,making them suitable as the top cell in tandem solar cells.However,the inorganic perovskite films suffer from a high defect density an...Cesium lead iodide perovskites offer promising stability and a bandgap near 1.7 eV,making them suitable as the top cell in tandem solar cells.However,the inorganic perovskite films suffer from a high defect density and substantial recombination losses,undermining their optoelectronic performances.Here,by activating the aromatic system,we develop 4-methoxybenzoylhydrazine(MeOBH)-modified CsPbI_(3) film with regulated crystallinity,suppressed non-radiative recombination,and improved interfacial energetic alignment.The resultant inorganic perovskite solar cells achieved a power conversion efficiency of 20.95%,along with enhanced phase stability owing to the strong coordination interaction between the lead cation and the hydrazide group.Encapsulated devices retain 90.4% of the initial performance after 624 h of maximum power point operation under the ISOS-L-1I protocol.展开更多
NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was i...NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was investigated. Through electrochemical testing and material characterizations, higher calcination temperatures increase the electrostatic repulsion between oxygen atoms in adjacent layers, resulting in an expansion of Na layer spacing. This structural change enhances the diffusion kinetics of Na^(+), thereby significantly improving the rate performance of NCFM. Furthermore, elevated calcination temperatures facilitate the reduction of oxygen vacancies, leading to improved crystallinity. This enhancement in crystallinity mitigates structural strain during phase transitions, contributing to improved cyclic stability. Consequently, the optimized NCFM shows an initial discharge specific capacity of 143.3 mA·h/g at 0.1C, with a capacity retention rate of 79.28% after 100 cycles at 1C.展开更多
Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted b...Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.展开更多
Sodium-ion batteries(SIBs)have exhibited significant commercial potential,benefiting from the abundance and global distribution of sodium resources.Among the diverse cathode materials under exploration for SIBs,Na_(3)...Sodium-ion batteries(SIBs)have exhibited significant commercial potential,benefiting from the abundance and global distribution of sodium resources.Among the diverse cathode materials under exploration for SIBs,Na_(3)MnTi(PO_(4))_(3)(NMTP)stands out as a highly promising candidate for practical applications,which combines the structural stability and high-voltage characteristics inherent to NASICON-type materials.In recent years,substantial advancements have been achieved in the research of NMTP.However,a comprehensive and up-to-date specialized review dedicated to its research progress and prospects remains lacking.This review,therefore,aims to systematically discuss the development and outlook of NMTP cathode material.Initially,the manuscript delves into the crystal structure and sodium-storage mechanism of NMTP.Subsequently,the synthesis methods,electrochemical properties,and optimization strategies are explored.Finally,the review outlines current challenges and suggests potential future research directions for NMTP.展开更多
Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction...Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.展开更多
基金Project supported by the Fundamental Research Funds for the Central Universities(No.2042025kf0052)。
文摘In molybdenum chemistry,the oxidative addition of o-quinone or 1,2-dicarbonyl compounds to molybdenum has been widely used in Mo-catalyzed C—C bond construction.The carbonyl oxidative addition to Mo(0)or Mo(Ⅱ)is the critical elementary reaction of molybdenum catalysis.However,the relevant density functional theory(DFT)studies are relatively scarce,especially regarding the rational selection of functionals.In this work,14 functionals were employed to investigate the Mo-catalyzed carbonyl oxidative addition step.A benchmark study was carried out to evaluate their performance in structure optimization and energy calculation.Analyses of mean absolute error(MAE)and mean squared error(MSE)indicated that the B3LYP-D3(BJ),TPSSh,and ωB97X-D functionals exhibited superior performance in structure optimization.Using the DLPNO-CCSD(T)functional as the reference,the M06,M06-L,and MN15-L functionals exhibited good performance for energy calculation based on the structures optimized using the B3LYP-D3(BJ)functional.In particular,MN15-L provided the best performance with the smallest MAE and MSE.
基金National Natural Science Foundation of China(12125509,11961141003,12275361,U2267205,12175152,12175121)National Key Research and Development Project(2022YFA1602301)Continuous-support Basic Scientific Research Project。
文摘To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.
文摘The increasing global adoption of electric vehicles(EVs)has led to a growing demand for a cost-effective and reliable charging infrastructure.This study presents a novel data-driven approach to assessing EV station performance by analyzing power consumption efficiency,station utilization rates,no-power session occurrences,and CO_(2)reduction metrics.A dataset of 17,500 charging sessions from 305 stations across a regional network was analyzed to identify operational inefficiencies and opportunities for infrastructure optimization.Results indicate a strong correlation between station utilization and energy efficiency,highlighting the importance of strategic station placement.The findings also emphasize the impact of no-power sessions on network inefficiency and the need for real-time station monitoring.CO_(2)reduction analysis demonstrates that optimizing EV charging performance can significantly contribute to sustainability goals.Based on these insights,this study recommends the implementation of predictive maintenance strategies,real-time user notifications,and diversified provider networks to improve station availability and efficiency.The proposed data-driven framework offers actionable solutions for policymakers,charging network operators,and urban planners to enhance EV infrastructure reliability and sustainability.
文摘Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.
基金Supported by the National key research and development program in the 14th five year plan 2021YFA1200700)the National Natural Science Foundation of China(62535018,62431025,62561160113)the Natural Science Foundation of Shanghai(23ZR1473400).
文摘Near-infrared image sensors are widely used in fields such as material identification,machine vision,and autonomous driving.Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with sil⁃icon-based readout circuits in a single step.Based on this,we propose a photodiode based on an n-i-p structure,which removes the buffer layer and further simplifies the manufacturing process of quantum dot image sensors,thus reducing manufacturing costs.Additionally,for the noise complexity in quantum dot image sensors when capturing images,traditional denoising and non-uniformity methods often do not achieve optimal denoising re⁃sults.For the noise and stripe-type non-uniformity commonly encountered in infrared quantum dot detector imag⁃es,a network architecture has been developed that incorporates multiple key modules.This network combines channel attention and spatial attention mechanisms,dynamically adjusting the importance of feature maps to en⁃hance the ability to distinguish between noise and details.Meanwhile,the residual dense feature fusion module further improves the network's ability to process complex image structures through hierarchical feature extraction and fusion.Furthermore,the pyramid pooling module effectively captures information at different scales,improv⁃ing the network's multi-scale feature representation ability.Through the collaborative effect of these modules,the network can better handle various mixed noise and image non-uniformity issues.Experimental results show that it outperforms the traditional U-Net network in denoising and image correction tasks.
文摘The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase transitions[3-5] and is actively explored on quantum simulation platforms.[6-9] Exploring how the KZ effect fares across different criticalities has proven to be a rewarding pursuit,significantly enriching our understanding of nonequilibrium quantum dynamics.[3-5,10-23]
基金the foundation of Guangdong Engineering Technology Research Center for Hydrogen Energy and Fuel Cells,the Guangdong Provincial Department of Education Innovation Project(No.2022KQNCX056)the Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515110354 and 2021A1515110582)。
文摘Self-supported nanoarrays have emerged as a promising alternative electrocatalyst for alkaline H_(2)O splitting,owing to their accessible active sites and strongly coupled interfaces with current collectors for improved mass transfer and stability.Herein,self-supported crystalline/amorphous NiO/Ni(OH)_(2)nanosheet arrays on nickel foam(NF)are fabricated via an in-situ dissolution-deposition hydrothermal growing of Ni(OH)_(2)nanosheets without additional metal sources assisted by a common Lewis base,EDTA,followed by a rapid calcination at 300℃in air.The as-prepared EDTA-NF-12 h exhibits high OER and HER performance under alkaline conditions,requiring 235 mV and 158 mV,respectively,to reach 10 mA cm^(-2),and the decent performance can be maintained for 24 h without obvious degradation.The dual interfaces,i.e.,the dense crystalline/amorphous interfaces within the NiO/Ni(OH)_(2)nanosheet arrays,as well as the intimate interfaces between nanoarrays and NF,both serve as reaction active sites,facilitate electron transfer,and endow the catalyst with high activity and stability.Furthermore,by applying EDTA-Ni^(2+)and other Lewis bases with varying basicities instead of EDTA,the interfaces with the NF substrate are found to promote the formation of crystalline/amorphous interfaces within the nanosheets.This study offers appealing opportunities for tailoring the electrocatalytic performance of self-supported electrodes via dual interface engineering.
基金Project(2023YFB4606200)supported by the National Key Research and Development Program of ChinaProject(2023-SSRF-HZ-503114-2)supported by Shanghai Synchrotron Radiation Facility,Instrument BL16U2,China。
文摘This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.
基金supported by the National Natural Science Foundation of China(Grant Nos.52202282,52402054,22471283,and 52202327)Natural Science Foundation of Tianjin City(Grant Nos.22JCYBJC00040,24JCQNJC00970)。
文摘High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20250050)the National Natural Science Foundation of China(22472111,12275189)+4 种基金the National Key Research Program of China(2022YFA1503101)the Postdoctoral Fellowship Program of CPSF(GZC20250614)Jiangsu Funding Program for Excellent Postdoctoral Talent(2025ZB299)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 Project。
文摘Lithium-sulfur(Li-S)batteries hold great promise for high-energy–density energy storage applications but are plagued by the severe shuttle effect and sluggish conversion kinetics of lithium polysulfides(Li PSs).We herein report a d-p-f orbital coupling strategy to tackle these critical challenges by incorporating Eu 4f orbitals to activate both metallic(Ni)and non-metallic(Se)sites of Ni Se.The imported Eu atoms could induce essential Ni 3d and Se 4p orbital reconstruction through gradient d-p-f coupling,thereby optimizing the band center alignment between Ni Se and Li PSs.Such electronic reconstruction strengthens both d-p hybridization between Ni and Li PSs and s-p hybridization between Se and Li PSs,which can not only enhance the chemisorption affinity toward Li PSs but also accelerate interfacial charge transfer kinetics,leading to suppressed shuttle effect and boosted Li PSs conversion kinetics.Therefore,the Li-S batteries assembled with Eu incorporated Ni Se deliver exceptional electrochemical performance with a high specific capacity of 896.2 m Ah g^(-1)at 4 C and a retained areal capacity of 5.66 m Ah cm^(-2)under a high sulfur loading of 5.94 mg cm^(-2)after 100 cycles.This work underscores the critical role of rare-earth 4f orbital coupling for modulating the active sites to construct high-efficiency electrocatalysts for Li-S batteries and beyond.
基金the National Natural Science Foundation of China(Nos.62374029,22175029,62474033,and W2433038)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220550)+2 种基金the Sichuan Science and Technology Program(No.2024NSFSC0250)the Natural Science Foundation of Shenzhen Innovation Committee(JCYJ20210324135614040)the Fundamental Research Funds for the Central Universities of China(No.ZYGX2022J032).
文摘Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bottleneck,severely affecting device stability and long-term operational performance.Herein,we present a multifunctional strategy by incorporating highly thermally conductive Ti_(3)C_(2)T_(X) MXene nanosheets into the perovskite layer to simultaneously enhance thermal management and optoelectronic properties.The Ti_(3)C_(2)T_(X) nanosheets,embedded at perovskite grain boundaries,construct efficient thermal conduction pathways,significantly improving the thermal conductivity and diffusivity of the film.This leads to a notable reduction in the device’s steady-state operating temperature from 42.96 to 39.97 under 100 mW cm^(−2) illumination,thereby alleviating heat-induced performance degradation.Beyond thermal regulation,Ti_(3)C_(2)T_(X),with high conductivity and negatively charged surface terminations,also serves as an effective defect passivation agent,reducing trap-assisted recombination,while simultaneously facilitating charge extraction and transport by optimizing interfacial energy alignment.As a result,the Ti_(3)C_(2)T_(X)-modified PSC achieve a champion PCE of 25.13%and exhibit outstanding thermal stability,retaining 80%of the initial PCE after 500 h of thermal aging at 85 and 30±5%relative humidity.(In contrast,control PSC retain only 58%after 200 h.)Moreover,under continuous maximum power point tracking in N2 atmosphere,Ti_(3)C_(2)T_(X)-modified PSC retained 70%of the initial PCE after 500 h,whereas the control PSC drop sharply to 20%.These findings highlight the synergistic role of Ti_(3)C_(2)T_(X) in thermal management and optoelectronic performance,paving the way for the development of high-efficiency and heat-resistant perovskite photovoltaics.
基金financially supported by National Natural Science Foundation of China(Grant Nos.12141203,52202083,W2421013)the Natural Science Foundation Project of Shaanxi Province(Grant No.2024JC-YBMS-450)+1 种基金the Sichuan Science and Technology Program(Grant No.2024YFHZ0265)the Open Project of High-end Equipment Advanced Materials and Manufacturing Technology Laboratory(Grant No.2023KFKT0005)。
文摘Designing materials with both structural load-bearing capacity and broadband electromagnetic(EM)wave absorption properties remains a significant challenge.In this work,SiOC/SiC/SiO_(2)composite with gyroid structures were prepared through digital light processing(DLP)3D printing,polymer-derived ceramics(PDCs),chemical vapor infiltration(CVI),and oxidation technologies.The incorporation of the CVISiC phase effectively increases the dissipation capability,while the synergistic interaction between the gyroid structure and SiO_(2)phase significantly improves impedance matching performance.The SiOC/SiC/SiO_(2)composite achieved a minimum reflection loss(RL min)of-62.2 d B at 4.3 mm,and the effective absorption bandwidth(EAB)covered the X-band,with a thickness range of 4.1 mm-4.65 mm.The CST simulation results explain the broadband and low-frequency absorption characteristics,with an EAB of 8.4 GHz(9.6-18 GHz)and an RL min of-21.5 dB at 5 GHz.The excellent EM wave attenuation performance is associated primarily with polarization loss,conduction loss,the gyroid structure's enhancement of multiple reflections and scattering of EM waves,and the resonance effect between the structural units.The SiOC/SiC/SiO_(2)composite also demonstrated strong mechanical properties,with a maximum compressive failure strength of 31.6 MPa in the height direction.This work opens novel prospects for the development of multifunctional structural wave-absorbing materials suitable for broadband microwave absorption and load-bearing properties.
基金supported by the National Key Research and Development Program of China(No.2023YFC3707004)the National Natural Science Foundation of China(Nos.22376204,22076201 and 92143201)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB0750400,XDB0750100 and XDB0750000)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2019 QZKK0605).
文摘Halogens are common in industrial thermal processes and can induce formation of toxic organic pollutants.Currently,the specific effects of coexisting halogens on toxic pollutant formation are unclear.In this study,we found the boosting effects of halogens on organic pollutants formation during thermal processes.In situ electron paramagnetic resonance spectroscopy was used to distinguish the organic free radical intermediates of organic pollutants during thermal processes.The pure chlorine-containing reaction system dominantly induce the formation of highly chlorinated phenoxy radicals,whereas the pure bromine-containing reaction system induce the formation of semiquinone radicals.The results provide clear evidence for the molecular mechanisms by which halogen coexistence boosts pollutants formation.Coexisting halogens made the reactions much more complex.Bromine atom radicals(Br·)can enhance the level of active chlorine atoms radicals(Cl·),then(1)facilitating highly chlorinated organic radicals and toxic pollutants formation,(2)activating polycyclic aromatic hydrocarbons molecules for subsequent ring growth and(3)accelerating oxidation reactions.Combining the identification of organic free radical intermediates and characteristics of products,detailed mechanisms of halogens on the formations of organic pollutants during thermal-related processes were clarified,which can be helpful for their efficient control in the widespread bromines and chlorines co-existence reaction system.
基金supported by the National Natural Science Foundation of China(Nos.22371218,82271518,21801194)Xianyang Bureau of Science and Technology(No.L2024-QCY-ZYYJJQ-260)+2 种基金The Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University(No.JCRCFZ-2022-030)Guiding Projects of Traditional Chinese Medicine in 2023~2024 by Hubei Provincial Administration of Traditional Chinese Medicine(No.ZY2023F038)the support of the Core Facility of Wuhan University and the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University。
文摘Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treatment of subcutaneous tumors.This study reports the exploration of novel supramolecular halogen-bonded organic frameworks(XOFs)based on[N…Br^(+)…N]halogen bonds through the ligand exchange strategy and their application in photothermal therapy.Through ligand exchange,XOF(Br)-TPy was successfully prepared,and its structure and properties were thoroughly characterized using NMR,XPS,FT-IR,and XRD techniques.Due to their cationic characteristics,these XOFs serve as effective carriers for the photothermal agent IR820.In vitro experiments demonstrated that the IR820@XOF(Br)-TPy composite exhibits excellent photothermal conversion efficiency under NIR irradiation,effectively inducing tumor cell ablation.Furthermore,in vivo studies confirmed the remarkable antitumor efficacy of the composite material in a subcutaneous tumor model.This work demonstrates that the ligand exchange strategy is a versatile and facile approach for constructing XOFs(Br)and provides a novel strategy for developing advanced photothermal therapeutic agents with significant application potential.
基金the National Natural Science Foundation of China(grant No.52163022,62305076)Sichuan Science and Technology Program(2024ZYD0196)+1 种基金China Postdoctoral Science Foundation(2023M740505)Sichuan Postdoctoral Science Special Foundation(No.TB2023010)。
文摘Electrochromic smart windows(ESWs)can significantly reduce building energy consumption,but the high cost hinders large-scale production.The in situ growth of tungsten oxide(WO_(3))films is only by a simple immersion process,the silver nanowires(AgNWs)undergo oxidation to Ag^(+)ions through electron loss,and the liberated electrons provide driving force for the deposition of WO_(4)^(2-).Enabled the fabrication of large-area WO_(3)films and ESWs were fabricated under minimal laboratory conditions,demonstrating the economic feasibility,efficient and reliable nature of industrial production.Structural characterization and density functional theory calculations were combined to confirm that AgNWs effectively regulate oxygen vacancies of WO_(3)films and promote the in situ growth process.The optimized WO_(3)exhibits a maximum transmittance modulation of 90.8%and excellent cycling stability of 20,000 cycles.The largescale WO_(3)-based ESWs can save building energy up to 140.0 MJ m^(-2)compared to traditional windows in tropical regions,as verified by simulations more than40 global cities.This research provides a new approach for improving the performance and industrial production of ESW,providing the full understanding and development direction to short the distance of the ESW commercial production.
基金financially supported by the National Ten Thousand Talent Program (H.C.)。
文摘Cesium lead iodide perovskites offer promising stability and a bandgap near 1.7 eV,making them suitable as the top cell in tandem solar cells.However,the inorganic perovskite films suffer from a high defect density and substantial recombination losses,undermining their optoelectronic performances.Here,by activating the aromatic system,we develop 4-methoxybenzoylhydrazine(MeOBH)-modified CsPbI_(3) film with regulated crystallinity,suppressed non-radiative recombination,and improved interfacial energetic alignment.The resultant inorganic perovskite solar cells achieved a power conversion efficiency of 20.95%,along with enhanced phase stability owing to the strong coordination interaction between the lead cation and the hydrazide group.Encapsulated devices retain 90.4% of the initial performance after 624 h of maximum power point operation under the ISOS-L-1I protocol.
基金supported by the National Natural Science Foundation of China(No.12175089)the Key Research and Development Program of Yunnan Province,China(No.202103AF140006)+2 种基金Basic Research Programs of Yunnan Provincial Science and Technology Department,China(Nos.202001AW070004,202301AS070051,202401AV070008)Yunnan Industrial Innovative Talents Program for“Xingdian Talent Support Plan”,China(No.KKXY202252001)Yunnan Major Scientific and Technological Projects,China(No.202202AG050003)。
文摘NaCu_(0.2)Fe_(0.3)Mn_(0.5)O_(2) (NCFM) cathode material was synthesized using a simple solid-state reaction, and the effect of calcination temperature on its interlayer spacing and oxygen vacancies concentration was investigated. Through electrochemical testing and material characterizations, higher calcination temperatures increase the electrostatic repulsion between oxygen atoms in adjacent layers, resulting in an expansion of Na layer spacing. This structural change enhances the diffusion kinetics of Na^(+), thereby significantly improving the rate performance of NCFM. Furthermore, elevated calcination temperatures facilitate the reduction of oxygen vacancies, leading to improved crystallinity. This enhancement in crystallinity mitigates structural strain during phase transitions, contributing to improved cyclic stability. Consequently, the optimized NCFM shows an initial discharge specific capacity of 143.3 mA·h/g at 0.1C, with a capacity retention rate of 79.28% after 100 cycles at 1C.
基金supported by the National Key R&D Program of China(2023YFB2406000)the National Natural Science Foundation of China(22479057,52172201,51732005)。
文摘Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.
基金National Natural Science Foundation of China Key Program,Grant/Award Number:U22A20420Jiangsu Provincial Double-Innovation Doctor,Grant/Award Number:JSSCBS20230439+1 种基金Natural Science Foundation of Jiangsu Provincial,Grant/Award Number:BK20240972Key project of Jiangsu Provincial Basic Research Program,Grant/Award Number:BK20243032。
文摘Sodium-ion batteries(SIBs)have exhibited significant commercial potential,benefiting from the abundance and global distribution of sodium resources.Among the diverse cathode materials under exploration for SIBs,Na_(3)MnTi(PO_(4))_(3)(NMTP)stands out as a highly promising candidate for practical applications,which combines the structural stability and high-voltage characteristics inherent to NASICON-type materials.In recent years,substantial advancements have been achieved in the research of NMTP.However,a comprehensive and up-to-date specialized review dedicated to its research progress and prospects remains lacking.This review,therefore,aims to systematically discuss the development and outlook of NMTP cathode material.Initially,the manuscript delves into the crystal structure and sodium-storage mechanism of NMTP.Subsequently,the synthesis methods,electrochemical properties,and optimization strategies are explored.Finally,the review outlines current challenges and suggests potential future research directions for NMTP.
基金funded by the Innovative Research Group Project of the National Natural Science Foundation of China(52121004)the Research Development Fund(No.RDF-21-02-060)by Xi’an Jiaotong-Liverpool University+1 种基金support received from the Suzhou Industrial Park High Quality Innovation Platform of Functional Molecular Materials and Devices(YZCXPT2023105)the XJTLU Advanced Materials Research Center(AMRC).
文摘Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.
