The undesirable dendrite growth induced by non-planar zinc(Zn)deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially im...The undesirable dendrite growth induced by non-planar zinc(Zn)deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries(ZMBs).Herein,we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium(Zn-In)interface in the microchannels.The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities.Meanwhile,electron aggregation accelerates the dissolution of non-(002)plane Zn atoms on the array surface,thereby directing the subsequent homoepitaxial Zn deposition on the array surface.Consequently,the planar dendrite-free Zn deposition and long-term cycling stability are achieved(5,050 h at 10.0 mA cm^(−2) and 27,000 cycles at 20.0 mA cm^(−2)).Furthermore,a Zn/I_(2) full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C,demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.展开更多
Correction to:Nano-Micro Letters(2024)16:112 https://doi.org/10.1007/s40820-024-01327-2 In the supplementary information the following corrections have been carried out:1.Institute of Energy and Climate Research,Mater...Correction to:Nano-Micro Letters(2024)16:112 https://doi.org/10.1007/s40820-024-01327-2 In the supplementary information the following corrections have been carried out:1.Institute of Energy and Climate Research,Materials Synthesis and Processing,Forschungszentrum Jülich GmbH,52425 Jülich,Germany.Corrected:Institute of Energy and Climate Research:Materials Synthesis and Processing(IEK-1),Forschungszentrum Jülich GmbH,52425 Jülich,Germany.展开更多
Based on the high-dimensional(HD) chaotic maps and the sine function, a new methodology of designing new chaotic maps using dimension expansion is proposed. This method accepts N dimensions of any existing HD chaotic ...Based on the high-dimensional(HD) chaotic maps and the sine function, a new methodology of designing new chaotic maps using dimension expansion is proposed. This method accepts N dimensions of any existing HD chaotic map as inputs to generate new dimensions based on the combined results of those inputs. The main principle of the proposed method is to combine the results of the input dimensions, and then performs a sine-transformation on them to generate new dimensions.The characteristics of the generated dimensions are totally different compared to the input dimensions. Thus, both of the generated dimensions and the input dimensions are used to create a new HD chaotic map. An example is illustrated using one of the existing HD chaotic maps. Results show that the generated dimensions have better chaotic performance and higher complexity compared to the input dimensions. Results also show that, in the most cases, the generated dimensions can obtain robust chaos which makes them attractive to usage in a different practical application.展开更多
A plasma-based stable,ultra-wideband electromagnetic（EM） wave absorber structure is studied in this paper for stealth applications.The stability is maintained by a multi-layer structure with several plasma layers an...A plasma-based stable,ultra-wideband electromagnetic（EM） wave absorber structure is studied in this paper for stealth applications.The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately.The plasma in each plasma layer is designed to be uniform,whereas it has a discrete nonuniform distribution from the overall view of the structure.The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption.A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers,by which the wave absorption range is extended to the ultra-wideband.Then,the scattering matrix method（SMM） is employed to analyze the electromagnetic reflection and absorption of the absorber structure.In the simulation,the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case.Then,the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail,verifying the EM wave absorption performance of the absorber.The proposed structure and model are expected to be superior in some realistic applications,such as supersonic aircraft.展开更多
The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼...The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme heterojunction.The apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation efficiency.Interestingly,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)evolution.Moreover,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic matter.Meanwhile,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary contamination.Consid-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.展开更多
Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggi...Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction kinetics.Herein,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon matrix.Thanks to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),respectively.We believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.展开更多
Identifying air-stable two-dimensional(2D)ferromagnetism with high Curie temperature(T_(c))is highly desirable for its potential applications in next-generation spintronics.However,most of the work reported so far mai...Identifying air-stable two-dimensional(2D)ferromagnetism with high Curie temperature(T_(c))is highly desirable for its potential applications in next-generation spintronics.However,most of the work reported so far mainly focuses on promoting one specific key factor of 2D ferromagnetism(T_(c)or air stability),rather than comprehensive promotion of both of them.Herein,ultrathin Cr_(1-x)Te crystals grown by chemical vapor deposition(CVD)show thickness-dependent T_(c)up to 285 K.The out-of-plane ferromagnetic order is well preserved down to atomically thin limit(2.0 nm),as evidenced by anomalous Hall effect observed in non-encapsulated samples.Besides,the CVD-grown Cr_(1-x)Te nanosheets present excellent ambient stability,with no apparent change in surface roughness or electrical transport properties after exposure to air for months.Our work provides an alternative platform for investigation of intrinsic 2D ferromagnetism and development of innovative spintronic devices.展开更多
Li metal has been recognized as the most promising anode materials for next-generation high-energy-density batteries,however,the inherent issues of dendrite growth and huge volume fluctuations upon Li plating/strippin...Li metal has been recognized as the most promising anode materials for next-generation high-energy-density batteries,however,the inherent issues of dendrite growth and huge volume fluctuations upon Li plating/stripping normally result in fast capacity fading and safety concerns.Functionalized Cu current collectors have so far exhibited significant regulatory effects on stabilizing Li metal anodes(LMAs),and hold a great practical potential owing to their easy fabrication,low-cost and good compatibility with the existing battery technology.In this review,a comprehensive overview of Cu-based current collectors,including planar modified Cu foil,3D architectured Cu foil and nanostructured 3D Cu substrates,for Li metal batteries is provided.Particularly,the design principles and strategies of functionalized Cu current collectors associated with their functionalities in optimizing Li plating/stripping behaviors are discussed.Finally,the critical issues where there is incomplete understanding and the future research directions of Cu current collectors in practical LMAs are also prospected.This review may shed light on the critical understanding of current collector engineering for high-energy-density Li metal batteries.展开更多
The envelope of a hypersonic vehicle is affected by severe fluctuating pressure, which causes the airborne antenna to vibrate slightly. This vibration mixes with the transmitted signals and thus introduces additional ...The envelope of a hypersonic vehicle is affected by severe fluctuating pressure, which causes the airborne antenna to vibrate slightly. This vibration mixes with the transmitted signals and thus introduces additional multiplicative phase noise. Antenna vibration and signal coupling effects as well as their influence on the lock threshold of the hypersonic vehicle carrier tracking system of the Ka band are investigated in this study. A vibration model is initially established to obtain phase noise in consideration of the inherent relationship between vibration displacement and electromagnetic wavelength. An analytical model of the Phase-Locked Loop（PLL）, which is widely used in carrier tracking systems, is established. The coupling effects on carrier tracking performance are investigated and quantitatively analyzed by imposing the multiplicative phase noise on the PLL model. Simulation results show that the phase noise presents a Gaussian distribution and is similar to vibration displacement variation. A large standard deviation in vibration displacement exerts a significant effect on the lock threshold. A critical standard deviation is observed in the PLL of Binary Phase Shift Keying（BPSK） and Quadrature Phase Shift Keying（QPSK） signals. The effect on QPSK signals is more severe than that on BPSK signals. The maximum tolerable standard deviations normalized by the wavelength of the carrier are 0.04 and 0.02 for BPSK and QPSK signals,respectively. With these critical standard deviations, lock thresholds are increased from à12 andà4 d B to 3 and à2 d B, respectively.展开更多
A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current...A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current Li-S batteries. The proposed hybrid structure showing high surface area （870 m^2.g^-1） and high B-dopant content （6.51 wt.%） simultaneously offers both physical confinement and chemical absorption of polysulfides. On one hand, the abundant-pore structure ensures high sulfur loading, facilitates fast charge transfer, and restrains polysulfide migration during cycling. On the other hand, our density functional theory calculations demonstrate that the B dopant is capable of chemically binding polysulfides. As a consequence of such dual polysulfide confinement, the BPCS-G/S cathode prepared with 70 wt.% sulfur loading presents a high reversible capacity of 1,174 mAh.g^-1 at 0.02 C, a high rate capacity of 396 mAh·g^-1 at 5 G and good cyclability over 500 cycles with only 0.05% capacity decay per cycle. The present work provides an efficient and cost-effective platform for the scalable synthesis of high-performance carbon-based materials for advanced Li-S batteries.展开更多
Twisted van der Waals homo-and hetero-structures have aroused great attentions due to their unique physical properties,providing a new platform to explore the novel two-dimensional(2D)condensed matter physics.The robu...Twisted van der Waals homo-and hetero-structures have aroused great attentions due to their unique physical properties,providing a new platform to explore the novel two-dimensional(2D)condensed matter physics.The robust dependence of phonon vibrations and electronic band structures on the twist angle has been intensively observed in transition metal dichalcogenide(TMD)homo-structures.However,the effects of twist angle on the lattice vibrational properties in the TMD heterostructures have not caused enough attention.Here,we report the distinct evolutions of Raman scattering and the underlying interlayer interactions in the twisted WS_(2)/MoS_(2) heterostructures.The shifts and linewidths of E_(2g)(Γ)and A_(1g)(Γ)phonon modes are found to be twist angle dependent.In particular,analogous to that of the twisted TMD homostructures,the frequency separations between E_(2g)(Γ)and A_(1g)(Γ)modes of MoS_(2) and WS_(2) in the twisted heterostructures varying with twist angle correlate with the interlayer mechanical coupling,essentially originating from the spacing-related repulsion between sulfur atoms.Moreover,the opposite shift behaviors and broadening of A_(1g)(Γ)modes caused by charge transfer are also observed in the twisted heterostructures.The calculated interlayer distances and band alignment of twisted WS_(2)/MoS_(2) through density functional theory further evidence our interpretations on the roles of the interlayer mechanical coupling and charge transfer in variations of Raman features.Such understanding and controlling of interlayer interaction through the stacking orientation are significant for future optoelectronic device design based on the newly emerged 2D heterostructures.展开更多
The development of inexpensive and efficient Pt-free electrocatalysts for the hydrogen evolution reaction(HER)is greatly crucial for water electrolysis.Tungsten carbide(WC)exhibiting a Pt-like electronic structure rep...The development of inexpensive and efficient Pt-free electrocatalysts for the hydrogen evolution reaction(HER)is greatly crucial for water electrolysis.Tungsten carbide(WC)exhibiting a Pt-like electronic structure represents an attractive alternative,although its overall performance is limited by the strong W-H bond that impedes hydrogen desorption.Here,we employed an in-situ interface engineering strategy to construct high-performance and cost effective electrocatalysts comprising WC/tungsten phosphide(WP)heterostructures that were anchored on N,P-codoped carbon(WC/WP@NPC)via a one-step pyrolysis of a melamine polyphosphate/WO_(3) hybrid in an inert atmosphere.Owing to the crystal structure compatibility and electron-rich property of WP,it optimizes the electronic structure and hydrogen adsorption configuration of WC,thus significantly weakening the W-H bond with a thermoneutral Gibbs free energy of hydrogen adsorption(ΔG_(H^(*)))of−0.05 eV.Additionally,NPC ensures fast electron transport and structural stability of the WC/WP@NPC ternary architecture.These synergistically lead to outstanding HER performances of the catalyst in acidic and alkaline media.Our finding offers a new strategy for designing Pt-alternative electrocatalysts with outstanding electrochemical performances for high-efficiency water splitting and other applications.展开更多
Despite red phosphorous(P)-based anodes hold great promise for advanced lithium-ion batteries due to their high theoretical capacity, their practical application is hindered by poor electronic conductivity and drastic...Despite red phosphorous(P)-based anodes hold great promise for advanced lithium-ion batteries due to their high theoretical capacity, their practical application is hindered by poor electronic conductivity and drastic volume changes during charge-discharge processes. In order to tackle these issues, herein, a facile grinding method was developed to embed sub-micro-and nano-sized red P particles in N,P-codoped hierarchical porous carbon(NPHPC). Such a unique structure enables P@NPHPC long-cyclic stability(1120 mAh g^-1 after 100 cycles at 100 mA g^-1) and superior rate performance(248 mA h g^-1 at 6400 mA g^-1). It is believed that our method holds great potential in scalable synthesis of P@carbon composites for future practical applications.展开更多
Developing host has been recognized a potential countermeasure to circumvent the intrinsic drawbacks of Li metal anode(LMA),such as uncontrolled dendrite growth,unstable solid electrolyte interface,and infinite volume...Developing host has been recognized a potential countermeasure to circumvent the intrinsic drawbacks of Li metal anode(LMA),such as uncontrolled dendrite growth,unstable solid electrolyte interface,and infinite volume fluctuations.To realize proper Li accommodation,particularly bottom-up deposition of Li metal,gradient designs of host materials including lithiophilicity and/or conductivity have attracted a great deal of attention in recent years.However,a critical and specialized review on this quickly evolving topic is still absent.In this review,we attempt to comprehensively summarize and update the related advances in guiding Li nucleation and deposition.First,the fundamentals regarding Li deposition are discussed,with particular attention to the gradient design principles of host materials.Correspondingly,the progress of creating diferent gradients in terms of lithiophilicity,conductivity,and their hybrid is systematically reviewed.Finally,future challenges and perspective on the gradient design of advanced hosts towards practical LMAs are provided,which would provide a useful guidance for future studies.展开更多
基金supported by the National Research Foundation of Korea Grant funded by the Korean government(MSIP)(No.2018R1A6A1A03025708).
文摘The undesirable dendrite growth induced by non-planar zinc(Zn)deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries(ZMBs).Herein,we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium(Zn-In)interface in the microchannels.The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities.Meanwhile,electron aggregation accelerates the dissolution of non-(002)plane Zn atoms on the array surface,thereby directing the subsequent homoepitaxial Zn deposition on the array surface.Consequently,the planar dendrite-free Zn deposition and long-term cycling stability are achieved(5,050 h at 10.0 mA cm^(−2) and 27,000 cycles at 20.0 mA cm^(−2)).Furthermore,a Zn/I_(2) full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C,demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.
文摘Correction to:Nano-Micro Letters(2024)16:112 https://doi.org/10.1007/s40820-024-01327-2 In the supplementary information the following corrections have been carried out:1.Institute of Energy and Climate Research,Materials Synthesis and Processing,Forschungszentrum Jülich GmbH,52425 Jülich,Germany.Corrected:Institute of Energy and Climate Research:Materials Synthesis and Processing(IEK-1),Forschungszentrum Jülich GmbH,52425 Jülich,Germany.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61161006 and 61573383)
文摘Based on the high-dimensional(HD) chaotic maps and the sine function, a new methodology of designing new chaotic maps using dimension expansion is proposed. This method accepts N dimensions of any existing HD chaotic map as inputs to generate new dimensions based on the combined results of those inputs. The main principle of the proposed method is to combine the results of the input dimensions, and then performs a sine-transformation on them to generate new dimensions.The characteristics of the generated dimensions are totally different compared to the input dimensions. Thus, both of the generated dimensions and the input dimensions are used to create a new HD chaotic map. An example is illustrated using one of the existing HD chaotic maps. Results show that the generated dimensions have better chaotic performance and higher complexity compared to the input dimensions. Results also show that, in the most cases, the generated dimensions can obtain robust chaos which makes them attractive to usage in a different practical application.
基金supported in part by the National Basic Research Program of China (grant no.2014CB340205)in part by the Science and Technology on Space Physics Laboratory Fundsin part by the Fundamental Research Funds for the Central Universities (20101156180)
文摘A plasma-based stable,ultra-wideband electromagnetic（EM） wave absorber structure is studied in this paper for stealth applications.The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately.The plasma in each plasma layer is designed to be uniform,whereas it has a discrete nonuniform distribution from the overall view of the structure.The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption.A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers,by which the wave absorption range is extended to the ultra-wideband.Then,the scattering matrix method（SMM） is employed to analyze the electromagnetic reflection and absorption of the absorber structure.In the simulation,the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case.Then,the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail,verifying the EM wave absorption performance of the absorber.The proposed structure and model are expected to be superior in some realistic applications,such as supersonic aircraft.
基金supported by the Natural Science Foundation of Shenzhen(No.GXWD20201230155427003-20200802110025006)the National Natural Science Foundation of China(Nos.52170157 and 52111530188)+3 种基金the Major Program of Jiangxi Provincial Depart-ment of Science and Technology(No.2022KSG01004)the Natural Science Foundation of Shenzhen(No.JCYJ20220531095408020)the Start-up Grant Harbin Institute of Technology(Shenzhen)(No.IA45001007)the Start-up Talent Grant at Harbin Institute of Technology(Shenzhen)(No.HA11409066).
文摘The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme heterojunction.The apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation efficiency.Interestingly,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)evolution.Moreover,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic matter.Meanwhile,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary contamination.Consid-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.
基金supported by the National Natural Science Foundation of China(22279104,51902261,and 61935017)the National Key Research and Development Program of China(2020YFA0709900)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2020A1515110604)the Natural Science Basic Research Program of Shaanxi(2021JQ-107)the Natural Science Foundation of Ningbo(202003N4053 and 202003N4046)the Provincial Innovation and Entrepreneurship Training Program for College Students(S202110699517).
文摘Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction kinetics.Herein,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon matrix.Thanks to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),respectively.We believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.
基金J.X.W.acknowledges financial support from the National Natural Science Foundation of China(No.92064005)Beijing National Laboratory for Molecular Sciences(No.BNLMS201914)+4 种基金thanks S.S.D.in Tianjin Key Laboratory of Molecular Optoelectronic Sciences for her instrumental assistance on PPMS(Dynacool-9T)H.T.Y.acknowledges the support from the National Natural Science Foundation of China(Nos.91750101,21733001,52072168,and 51861145201)the National Key Basic Research Program of China(No.2018YFA0306200)the Fundamental Research Funds for the Central Universities(Nos.021314380078,021314380104,and 021314380147)Jiangsu Key Laboratory of Artificial Functional Materials。
文摘Identifying air-stable two-dimensional(2D)ferromagnetism with high Curie temperature(T_(c))is highly desirable for its potential applications in next-generation spintronics.However,most of the work reported so far mainly focuses on promoting one specific key factor of 2D ferromagnetism(T_(c)or air stability),rather than comprehensive promotion of both of them.Herein,ultrathin Cr_(1-x)Te crystals grown by chemical vapor deposition(CVD)show thickness-dependent T_(c)up to 285 K.The out-of-plane ferromagnetic order is well preserved down to atomically thin limit(2.0 nm),as evidenced by anomalous Hall effect observed in non-encapsulated samples.Besides,the CVD-grown Cr_(1-x)Te nanosheets present excellent ambient stability,with no apparent change in surface roughness or electrical transport properties after exposure to air for months.Our work provides an alternative platform for investigation of intrinsic 2D ferromagnetism and development of innovative spintronic devices.
基金This work was supported by the National Natural Science Foundation of China(Nos.22279104,51902261 and 61935017)the National Key Research and Development Program of China(No.2020YFA0709900)the Singapore Ministry of Education AcRF Tier 1:2020-T1-001-031,RG4/20,the 111 project(D18023)from Zhengzhou University.
文摘Li metal has been recognized as the most promising anode materials for next-generation high-energy-density batteries,however,the inherent issues of dendrite growth and huge volume fluctuations upon Li plating/stripping normally result in fast capacity fading and safety concerns.Functionalized Cu current collectors have so far exhibited significant regulatory effects on stabilizing Li metal anodes(LMAs),and hold a great practical potential owing to their easy fabrication,low-cost and good compatibility with the existing battery technology.In this review,a comprehensive overview of Cu-based current collectors,including planar modified Cu foil,3D architectured Cu foil and nanostructured 3D Cu substrates,for Li metal batteries is provided.Particularly,the design principles and strategies of functionalized Cu current collectors associated with their functionalities in optimizing Li plating/stripping behaviors are discussed.Finally,the critical issues where there is incomplete understanding and the future research directions of Cu current collectors in practical LMAs are also prospected.This review may shed light on the critical understanding of current collector engineering for high-energy-density Li metal batteries.
基金co-supported by the National Basic Research Program of China (No. 2014CB340205)the Natural Science Foundation of Shaanxi Provincial Department of Education (No. 2016JM6016)the National Natural Science Foundation of China (No. 61473228)
文摘The envelope of a hypersonic vehicle is affected by severe fluctuating pressure, which causes the airborne antenna to vibrate slightly. This vibration mixes with the transmitted signals and thus introduces additional multiplicative phase noise. Antenna vibration and signal coupling effects as well as their influence on the lock threshold of the hypersonic vehicle carrier tracking system of the Ka band are investigated in this study. A vibration model is initially established to obtain phase noise in consideration of the inherent relationship between vibration displacement and electromagnetic wavelength. An analytical model of the Phase-Locked Loop（PLL）, which is widely used in carrier tracking systems, is established. The coupling effects on carrier tracking performance are investigated and quantitatively analyzed by imposing the multiplicative phase noise on the PLL model. Simulation results show that the phase noise presents a Gaussian distribution and is similar to vibration displacement variation. A large standard deviation in vibration displacement exerts a significant effect on the lock threshold. A critical standard deviation is observed in the PLL of Binary Phase Shift Keying（BPSK） and Quadrature Phase Shift Keying（QPSK） signals. The effect on QPSK signals is more severe than that on BPSK signals. The maximum tolerable standard deviations normalized by the wavelength of the carrier are 0.04 and 0.02 for BPSK and QPSK signals,respectively. With these critical standard deviations, lock thresholds are increased from à12 andà4 d B to 3 and à2 d B, respectively.
文摘A hybrid structure consisting of boron-doped porous carbon spheres and graphene （BPCS-G） has been designed and synthesized toward solving the polysulfide- shuttle problem, which is the most critical issue of current Li-S batteries. The proposed hybrid structure showing high surface area （870 m^2.g^-1） and high B-dopant content （6.51 wt.%） simultaneously offers both physical confinement and chemical absorption of polysulfides. On one hand, the abundant-pore structure ensures high sulfur loading, facilitates fast charge transfer, and restrains polysulfide migration during cycling. On the other hand, our density functional theory calculations demonstrate that the B dopant is capable of chemically binding polysulfides. As a consequence of such dual polysulfide confinement, the BPCS-G/S cathode prepared with 70 wt.% sulfur loading presents a high reversible capacity of 1,174 mAh.g^-1 at 0.02 C, a high rate capacity of 396 mAh·g^-1 at 5 G and good cyclability over 500 cycles with only 0.05% capacity decay per cycle. The present work provides an efficient and cost-effective platform for the scalable synthesis of high-performance carbon-based materials for advanced Li-S batteries.
基金This work was mainly supported by the National Key R&D Program of China(Grant No.2018YFA0703700)the Ministry of Education,Singapore,MOE Tier 1 RG93/19,NRF-CRP-21-2018-0007,MOE2018-T2-2-072,and MOE2019T2-1-004+11 种基金C.X.C.also thanks the support of the National Natural Science Foundation of China(Grant No.61774040)the Shanghai Municipal Science and Technology Commission(Grant No.18JC1410300)the Fudan University-CIOMP Joint Fund(Grant No.FC2018-002)the National Young 1000 Talent Plan of China,and the Shanghai Municipal Natural Science Foundation(No.16ZR1402500)J.Z.S.appreciates the support of the Fundamental Research Funds for the Central Universities of ChinaNational Natural Science Foundation of China under Grant No.61904151Natural Science Foundation of Shaanxi under Grant No.2020JM-108the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-020)Z.L.acknowledges the support of MOE Tier 1 grant RG164/15,Tier 2 grant MOE2016-T2-2-153,and MOE2015-T2-2-007Singapore National Research Foundation under NRF award No.NRF-NRFF2013-08W.H.Y.acknowledges the support of the National Natural Science Foundations of China(Grant No.61704040)This research was also supported by Zhejiang Provincial Natural Science Foundation of China(Grant No.LGG19F040003).
文摘Twisted van der Waals homo-and hetero-structures have aroused great attentions due to their unique physical properties,providing a new platform to explore the novel two-dimensional(2D)condensed matter physics.The robust dependence of phonon vibrations and electronic band structures on the twist angle has been intensively observed in transition metal dichalcogenide(TMD)homo-structures.However,the effects of twist angle on the lattice vibrational properties in the TMD heterostructures have not caused enough attention.Here,we report the distinct evolutions of Raman scattering and the underlying interlayer interactions in the twisted WS_(2)/MoS_(2) heterostructures.The shifts and linewidths of E_(2g)(Γ)and A_(1g)(Γ)phonon modes are found to be twist angle dependent.In particular,analogous to that of the twisted TMD homostructures,the frequency separations between E_(2g)(Γ)and A_(1g)(Γ)modes of MoS_(2) and WS_(2) in the twisted heterostructures varying with twist angle correlate with the interlayer mechanical coupling,essentially originating from the spacing-related repulsion between sulfur atoms.Moreover,the opposite shift behaviors and broadening of A_(1g)(Γ)modes caused by charge transfer are also observed in the twisted heterostructures.The calculated interlayer distances and band alignment of twisted WS_(2)/MoS_(2) through density functional theory further evidence our interpretations on the roles of the interlayer mechanical coupling and charge transfer in variations of Raman features.Such understanding and controlling of interlayer interaction through the stacking orientation are significant for future optoelectronic device design based on the newly emerged 2D heterostructures.
基金financially supported by the National Natural Science Foundation of China(51902261,61935017)the Joint Research Funds of the Department of Science&Technology of Shaanxi Province and NPU(2020GXLH-Z-024)+3 种基金the Natural Science Basic Research Program of Shaanxi Province(2021JQ-096,2021JQ-107)the Natural Science Foundation of Ningbo(202003N4053,202003N4046)the Fundamental Research Funds for the Central Universities(31020180QD094,31020180QD116,G2021KY05106)the Start-up Funding from NPU。
文摘The development of inexpensive and efficient Pt-free electrocatalysts for the hydrogen evolution reaction(HER)is greatly crucial for water electrolysis.Tungsten carbide(WC)exhibiting a Pt-like electronic structure represents an attractive alternative,although its overall performance is limited by the strong W-H bond that impedes hydrogen desorption.Here,we employed an in-situ interface engineering strategy to construct high-performance and cost effective electrocatalysts comprising WC/tungsten phosphide(WP)heterostructures that were anchored on N,P-codoped carbon(WC/WP@NPC)via a one-step pyrolysis of a melamine polyphosphate/WO_(3) hybrid in an inert atmosphere.Owing to the crystal structure compatibility and electron-rich property of WP,it optimizes the electronic structure and hydrogen adsorption configuration of WC,thus significantly weakening the W-H bond with a thermoneutral Gibbs free energy of hydrogen adsorption(ΔG_(H^(*)))of−0.05 eV.Additionally,NPC ensures fast electron transport and structural stability of the WC/WP@NPC ternary architecture.These synergistically lead to outstanding HER performances of the catalyst in acidic and alkaline media.Our finding offers a new strategy for designing Pt-alternative electrocatalysts with outstanding electrochemical performances for high-efficiency water splitting and other applications.
基金supported by the National Key Basic Research Program of China (2015CB932200)the National Natural Science Foundation of China (61704076)+2 种基金the Natural Science Foundation of Jiangsu Province (BK20171018)Jiangsu Specially-Appointed Professor Program (54935012)the support from the Fundamental Research Funds for the Central Universities (31020180QD094)
文摘Despite red phosphorous(P)-based anodes hold great promise for advanced lithium-ion batteries due to their high theoretical capacity, their practical application is hindered by poor electronic conductivity and drastic volume changes during charge-discharge processes. In order to tackle these issues, herein, a facile grinding method was developed to embed sub-micro-and nano-sized red P particles in N,P-codoped hierarchical porous carbon(NPHPC). Such a unique structure enables P@NPHPC long-cyclic stability(1120 mAh g^-1 after 100 cycles at 100 mA g^-1) and superior rate performance(248 mA h g^-1 at 6400 mA g^-1). It is believed that our method holds great potential in scalable synthesis of P@carbon composites for future practical applications.
基金This work was financially supported by the National Natural Science Foundation of China(51902261 and 61935017)the National Key Research and Development Program of China(2020YFA0709900)+4 种基金the Joint Research Funds of the Department of Science&Technology of Shaanxi Province and NPU(2020GXLH-Z-024)the Natural Science Basic Research Program of Shaanxi(2021JQ-107)Guangdong Basic and Applied Basic Research Foundation(2020A1515110604)the Natural Science Foundation of Ningbo(202003N4053)the Fundamental Research Funds for the Central Universities(31020180QD116 and G2021KY05106).
文摘Developing host has been recognized a potential countermeasure to circumvent the intrinsic drawbacks of Li metal anode(LMA),such as uncontrolled dendrite growth,unstable solid electrolyte interface,and infinite volume fluctuations.To realize proper Li accommodation,particularly bottom-up deposition of Li metal,gradient designs of host materials including lithiophilicity and/or conductivity have attracted a great deal of attention in recent years.However,a critical and specialized review on this quickly evolving topic is still absent.In this review,we attempt to comprehensively summarize and update the related advances in guiding Li nucleation and deposition.First,the fundamentals regarding Li deposition are discussed,with particular attention to the gradient design principles of host materials.Correspondingly,the progress of creating diferent gradients in terms of lithiophilicity,conductivity,and their hybrid is systematically reviewed.Finally,future challenges and perspective on the gradient design of advanced hosts towards practical LMAs are provided,which would provide a useful guidance for future studies.
