Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)h...Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)hybrid nanofibers separator to synchronously improve th fast-charging LMB's stability and safety.(1)The separator's surface,enriched with lithiophilic carbonyl and hydroxyl groups,accelerates Li~+ion desolvation,while electrophilic imine groups impede anion movement.This dual mechanism optimizes the Li^(+)-ion flux distribution on th anode,mitigating dendrite formation.(2)The polar PDA modification layer fosters the development of a Li_(3)N/LiF-rich solid electrolyt interface,further enhancing Li anode stability.Consequently,Li//Li symmetric cells with PDA@HA separators exhibit extended cycle life in L plating/stripping tests:5000 h at 1 mA cm^(-2)and 700 h at 20 mA cm^(-2),respectively,outperforming PP separators(80 h and 8 h).In LiFePO_(4)(LFP,^(2.1)mg cm^(-2))//Li full cell evaluation,the PDA@HA separator enables stable operation for 11,000 cycles at 18.2C with 87%capacity retention,significantly outperforming existing fast-charging LMB counterparts in literature.At a high LFP loading of 15.5 mg cm^(-2),the cel maintains 137.6 mAh g^(-1)(2.13 mAh cm^(-2))over 250 cycles at 3C,achieving 98%capacity retention.Moreover,the PDA@HA separato increases threshold temperature for thermal runaway and reduces the exothermic rate,intensifying the battery's thermal safety.This research underscores the importance of functional separator design in improving Li metal anode reversibility,fast-charging performance,and therma safety of LMBs.展开更多
Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified W...Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.展开更多
Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and of...Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and often conflicting requirements of the bulk electrolyte and the electrode-electrolyte interphase.Here,we present a weakly coordinating cationic polymer electrolyte(WCPE)specifically designed to regulate the Li^(+)coordination structure,thereby enabling fast-charging SSLMBs.The WCPE comprises an imidazolium-based polycationic matrix combined with a succinonitrile(SN)-based highconcentration electrolyte.Unlike conventional neutral polymer matrices,the polycationic matrix in the WCPE competes with Li^(+)for interactions with SN,weakening the original coordination between SN and Li^(+).This modulation of SN-Li^(+)interaction improves both Li^(+)conductivity of the WCPE(σ_(Li^(+))=1.29mS cm^(-1))and redox kinetics at the electrode-electrolyte interphase.Consequently,SSLMB cells(comprising LiFePO_(4)cathodes and Li-metal anodes)with the WCPE achieve fast-charging capability(reaching over 80%state of charge within 10 min),outperforming those of previously reported polymer electrolytebased SSLMBs.展开更多
Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite el...Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite element simulations show that incorporating SO_(4)^(2-)into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge cycles.Consequently,the average Na+diffusion coefficient of Na_(3)V_(2)(PO_(4))_(1.95)(SO_(4))_(0.05)O_(2)F(VPS-1) is roughly double that of VP,leading to enhanced rate capability (80 C,75.5 mAh g^(-1)) and cycling stability (111.0 mAh g^(-1)capacity after 1000 cycles at 10 C current density) for VPS-1.VPS-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 min.The assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current,maintaining an average coulombic efficiency of 95.35%.展开更多
As one of the alloy-type lithium-ion electrodes,Bi has outstanding application prospects for large volume capacity(3800 mAh·cm^(-3))and high electronic conductivity(1.4×10^(7)S·m^(-1)).However,the fast-...As one of the alloy-type lithium-ion electrodes,Bi has outstanding application prospects for large volume capacity(3800 mAh·cm^(-3))and high electronic conductivity(1.4×10^(7)S·m^(-1)).However,the fast-charging performance is hindered by significant volume expansion(>218%)and a low rate of phase diffusion.To overcome these two problems,an N-doped carbon nanoflower coating layer was elaborately in-situ reconstructed on a multiple-wall Bi microsphere by hydrothermal methods and subsequent calcination in this study.The carbon nanoflowers greatly increase specific surface area(40.0 m^(2)·g^(-1))and alleviate the volume expansion(130%).In addition,the incorporation of N-doped carbon nanoflowers leads to a gradual enhancement in the Li adsorption energy of Bi during the process of lithium insertion and improves the electrical conductivity.Therefore,the contribution rate of pseudo-capacitance reached 87.5%at the scan rate of 0.8 mV·s^(-1),and the Li-ion diffusion coefficient(D_(Li^(+)))was calculated in the range of 10^(-10)to 10^(-12)cm^(2)·s^(-1).The Bi@CNFs anode provided a high specific volumetric capacity of 2117.0 mAh·cm^(-3)at 5C and a high capacity retention ratio of 93.2%after 800 cycles.The Bi@CNFs//LiFePO_(4)full cell also displayed a stable capacity of 113.9 mAh·g^(-1)and energy density of 296.1 Wh·kg^(-1)after 100 cycles with a Coulombic efficiency of 97.6%.The mechanism of fast-charging lithium storage was verified by distribution of relaxation time analysis and density functional theory calculation.This paper provides a new strategy to increase the pseudo-capacitance and reduce the volume expansion for the preparation of alloy-type fast-charging electrodes.展开更多
For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered tr...For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered transition metal oxides(LTMOs),which leverage the synergistic properties of two distinct monophasic LTMOs,have garnered significant attention;however,their efficacy under fast-charging conditions remains underexplored.In this study,we developed a high-throughput computational screening framework to identify optimal dopants that maximize the electrochemical performance of LTMOs.Specifically,we evaluated the efficacy of 32 dopants based on P2/O3-type Mn/Fe-based Na_(x)Mn_(0.5)Fe_(0.5)O_(2)(NMFO)cathode material.Multiphase LTMOs satisfying criteria for thermodynamic and structural stability,minimized phase transitions,and enhanced Na^(+)diffusion were systematically screened for their suitability in fast-charging applications.The analysis identified two dopants,Ti and Zr,which met all predefined screening criteria.Furthermore,we ranked and scored dopants based on their alignment with these criteria,establishing a comprehensive dopant performance database.These findings provide a robust foundation for experimental exploration and offer detailed guidelines for tailoring dopants to optimize fast-charging SIBs.展开更多
For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-crit...For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-criteria decisionmaking(MCDM)problem,the current literature lacks a way to unambiguously present criteria and the popular fuzzy analytic network process(ANP)approaches neglect the hesitancy of subjective judgments.To fill these research gaps,an MCDM method based on unified architecture framework(UAF)and interval-valued spherical fuzzy ANP(IVSF-ANP)is proposed in this paper.Firstly,selected viewpoints in UAF are extended to construct criteria models with standardized representation.Secondly,interval-valued spherical fuzzy sets are introduced to ANP to weight interdependent criteria,handling fuzziness and hesitancy in pairwise comparisons.A method of adjusting weights of experts based on their decision similarities is also included in this process to reduce ambiguity brought by multiple experts.Next,performance characteristics are non-linearly transformed regarding to expectations to get final results.This proposition is applied to assess the mission capability of UAV swarms to search and strike surface vessels.Comparative analysis shows that the proposed method is valid and reasonable.展开更多
Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging ...Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.展开更多
High-energy–density lithium-ion batteries(LIBs)that can be safely fast-charged are desirable for electric vehicles.However,sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety is...High-energy–density lithium-ion batteries(LIBs)that can be safely fast-charged are desirable for electric vehicles.However,sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density.Here we hypothesize that a cobalt vanadate oxide,Co_(2)VO_(4),can be attractive anode material for fast-charging LIBs due to its high capacity(~1000 mAh g^(−1))and safe lithiation potential(~0.65 V vs.Li^(+)/Li).The Li+diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15×10^(-10) cm^(2) s^(−1),proving Co_(2)VO_(4) a promising anode in fast-charging LIBs.A hexagonal porous Co2VO4 nanodisk(PCVO ND)structure is designed accordingly,featuring a high specific surface area of 74.57 m^(2) g^(−1) and numerous pores with a pore size of 14 nm.This unique structure succeeds in enhancing Li^(+) and electron transfer,leading to superior fast-charging performance than current commercial anodes.As a result,the PCVO ND shows a high initial reversible capacity of 911.0 mAh g^(−1) at 0.4 C,excellent fast-charging capacity(344.3 mAh g^(−1) at 10 C for 1000 cycles),outstanding long-term cycling stability(only 0.024% capacity loss per cycle at 10 C for 1000 cycles),confirming the commercial feasibility of PCVO ND in fast-charging LIBs.展开更多
Hybrid Na-ion capacitors(NICs)have received considerable interests owing to their low-cost,high-safety,and rapidly charging energy-storage characteristics.The NICs are composed of a capacitor-type cathode and a batter...Hybrid Na-ion capacitors(NICs)have received considerable interests owing to their low-cost,high-safety,and rapidly charging energy-storage characteristics.The NICs are composed of a capacitor-type cathode and a battery-type anode.The major challenge for NICs is to search for suitable electrode materials to overcome the sluggish diffusion of Na^(+)in the anode.Herein,ultrafine vanadium sulfide is encapsulated in carbon fiber(V_(3)S_(4)@CNF)as a self-supported electrode by electrospinning and in situ sulfurization.The carbon cladding and one-dimensional(ID)nanofiber network-like structure could alleviate the volume expansion of V_(3)S_(4)during Na^(+)de-/intercalation process.Consequently,the V_(3)S_(4)@CNF anode exhibited a pseudocapacitive sodium storage in terms of large Na^(+)-storage capacity(476 mAh·g^(-1)at 0.1A·g^(-1)),high-rate capability(290 mAh·g^(-1)at 20.0 A·g^(-1))and excellent cycling stability(95%capacity retention for1500 cycles at 2.0 A·g^(-1))in Na half-cells.By employing V_(3)S_(4)@CNF as the anode and the activated carbon(AC)cathode,the as-assembled NICs could deliver a high energy density of 110 Wh·kg^(-1)at a power density of200 W·kg^(-1).Even at a high power of 10,000 W·kg^(-1),the specific energy is still up to 42 Wh·kg^(-1).展开更多
With the ever-growing application of lithium-ion batteries(LIBs), their fast-charging technology has attracted great interests of scientists. However, growth of lithium dendrites during fast charge of the bat teries w...With the ever-growing application of lithium-ion batteries(LIBs), their fast-charging technology has attracted great interests of scientists. However, growth of lithium dendrites during fast charge of the bat teries with high energy density may pose great threats to the operation and cause serious safety issues Herein, we prepared a functional separator with an ultra-thin(20 nm) layer of Au nanoparticles deposited by evaporation coating method which could regulate growth direction and morphology of the lithium dendrites, owing to nearly zero overpotential of lithium meal nucleation on lithiated Au. Once the Li den drites are about to form on the graphite anode during fast charging(or lithiation), they plate predomi nantly on the Au deposited separator rather than on the graphite. Such selective deposition does no compromise the electrochemical performance of batteries under normal cycling. More importantly, i enables the better cycling stability of batteries at fast charge condition. The Li/Graphite cells with Au nanoparticles coated separator could cycle stably with a high areal capacity retention of 90.5% over 95 cycles at the current density of 0.72 m A cm^(-2). The functional separator provides an effective strategy to adjust lithium plating position at fast charge to ensure high safety of batteries without a compromise on the energy density of LIBs.展开更多
Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to t...Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.展开更多
Dendrite growth of zinc(Zn)anode at high current density severely affects the fast-charging performance of aqueous zinc metal batteries(AZMBs).While interfacial modification strategies can optimize Zn per formance,cha...Dendrite growth of zinc(Zn)anode at high current density severely affects the fast-charging performance of aqueous zinc metal batteries(AZMBs).While interfacial modification strategies can optimize Zn per formance,challenges such as complicated preparation processes,excessive layer thicknesses,and high voltage hysteresis should be addressed.Herein,we utilize a cost-effective liquid fluorosiloxane,(3,3,3trifluoropropyl)trimethoxysilane,for scalable modification of Zn foil via drop-casting at room tempera ture,resulting in an ultra-thin interphase layer of only 20 nm.The Si-O-Zn bonds formed between flu orosiloxane and Zn ensure interfacial stability,and the Si-O-Si bonds between fluorosiloxane molecule help to homogenize the electric field distribution.Additionally,the abundant highly electronegative flu orine atoms on the anode surface act as zincophilic sites,promoting the uniform deposition of Zn^(2+)Thus,the modified Zn foil(SiFO-Zn)exhibits excellent dendrite suppression,reduced voltage hysteresis and prolonged cycle life at ultra-high current density(40 mA/cm^(2)),achieving a cumulative areal capac ity of 12.9 Ah/cm^(2).Further,the full cell assembled with 10μm-thick Si FO-Zn anode and MnO_(2)cathode achieves 2600 cycles at 5 A/g with minimal capacity degradation,and a large-size(22.5 cm^(-2))pouch cel powers the light-emitting diode even after reverse bending,demonstrating the potential of AZMBs fo fast-charging flexible devices.展开更多
Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics.However,the lithiu...Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics.However,the lithium ion(Li+)-storage performance of the most commercialized lithium cobalt oxide(LiCoO_(2),LCO)cathodes is still far from satisfactory in terms of high-voltage and fast-charging capabilities for reaching the double-high target.Herein,we systematically summarize and discuss high-voltage and fast-charging LCO cathodes,covering in depth the key fundamental challenges,latest advancements in modification strategies,and future perspectives in this field.Comprehensive and elaborated discussions are first presented on key fundamental challenges related to structural degradation,interfacial instability,the inhomogeneity reactions,and sluggish interfacial kinetics.We provide an instructive summary of deep insights into promising modification strategies and underlying mechanisms,categorized into element doping(Li-site,cobalt-/oxygen-site,and multi-site doping)for improved Li+diffusivity and bulkstructure stability;surface coating(dielectrics,ionic/electronic conductors,and their combination)for surface stability and conductivity;nanosizing;combinations of these strategies;and other strategies(i.e.,optimization of the electrolyte,binder,tortuosity of electrodes,charging protocols,and prelithiation methods).Finally,forward-looking perspectives and promising directions are sketched out and insightfully elucidated,providing constructive suggestions and instructions for designing and realizing high-voltage and fast-charging LCO cathodes for next-generation double-high LIBs.展开更多
This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging...This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.展开更多
This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic mo...This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.展开更多
Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as t...Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as the research objects.Emergency rescue capability training was conducted from March 2023 to June 2023,once a month.The students’mastery of emergency rescue before and after the intervention was analyzed.Survey questionnaires were distributed to all college students to understand their channels and willingness to acquire emergency rescue knowledge.Results:A total of 886 valid questionnaires were collected in this study.The highest proportion of knowledge about China’s general emergency telephone number and how to dial the emergency rescue hotline was 100.00%.Among the strategies for dealing with cardiac arrest in CPR,the highest proportion was 336.34%.Among the four major first aid techniques of hemostasis,bandaging,fixation,transportation,the highest proportion of knowledge about the use of rubber band signs was 31.71%.Among the first aid techniques for heatstroke,poisoning,fire,and sharp instrument injuries,the principle of emergency treatment for severe gas poisoning had the highest proportion of 41.42%,showing significant differences.College students mainly acquire knowledge of emergency rescue capability through TV programs,health education lectures,and the internet.Around 61.40%of college students hope to learn more about prevention and control knowledge.Conclusion:After the intervention of emergency rescue capability,the emergency rescue capability of college students in this university has been significantly improved,showing a strong training effect,which is worthy of promotion.展开更多
To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials an...To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.展开更多
An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual cry...An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.展开更多
A comprehensive model is proposed to evaluate the damage capability of laser system in ground-air defense environments.This model takes into account the laser system's heavy reliance on weather conditions and the ...A comprehensive model is proposed to evaluate the damage capability of laser system in ground-air defense environments.This model takes into account the laser system's heavy reliance on weather conditions and the stringent requirements for beam pointing accuracy.It initiates by simulating the laser spot characteristics on target in ground-to-air environments,factoring in the effects of atmospheric turbulence,absorption and scattering through slant transmission paths.Subsequently,a calculation method based on the thermal damage effect of the target material is introduced to quantify the damage ability of the laser system.To further enhance the model's applicability,a method for calculating the laser damage probability based on random crossover theory has been introduced,which takes into account the error of the Acquisition,Tracking and Pointing(ATP)system to estimate the likelihood of successful damage in operation applications.Theoretical analysis and simulation results validate the effectiveness of the proposed model in calculating and analyzing the damage capability of laser system in ground-air defense environments.This model offers valuable decision-making insights for users of laser systems operating in lowaltitude atmospheric conditions.Furthermore,it furnishes essential data support for the development and validation of laser systems,ensuring their effectiveness in real-world applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52202328,52372099,52271222)the Shanghai Sailing Program(22YF1455500)。
文摘Severe lithium dendrite growth and elevated thermal runaway risks pose significant hurdles for fast-charging lithium metal batteries(LMBs)This study reports a polydopamine-functionalized hydroxyapatite/aramid(PDA@HA)hybrid nanofibers separator to synchronously improve th fast-charging LMB's stability and safety.(1)The separator's surface,enriched with lithiophilic carbonyl and hydroxyl groups,accelerates Li~+ion desolvation,while electrophilic imine groups impede anion movement.This dual mechanism optimizes the Li^(+)-ion flux distribution on th anode,mitigating dendrite formation.(2)The polar PDA modification layer fosters the development of a Li_(3)N/LiF-rich solid electrolyt interface,further enhancing Li anode stability.Consequently,Li//Li symmetric cells with PDA@HA separators exhibit extended cycle life in L plating/stripping tests:5000 h at 1 mA cm^(-2)and 700 h at 20 mA cm^(-2),respectively,outperforming PP separators(80 h and 8 h).In LiFePO_(4)(LFP,^(2.1)mg cm^(-2))//Li full cell evaluation,the PDA@HA separator enables stable operation for 11,000 cycles at 18.2C with 87%capacity retention,significantly outperforming existing fast-charging LMB counterparts in literature.At a high LFP loading of 15.5 mg cm^(-2),the cel maintains 137.6 mAh g^(-1)(2.13 mAh cm^(-2))over 250 cycles at 3C,achieving 98%capacity retention.Moreover,the PDA@HA separato increases threshold temperature for thermal runaway and reduces the exothermic rate,intensifying the battery's thermal safety.This research underscores the importance of functional separator design in improving Li metal anode reversibility,fast-charging performance,and therma safety of LMBs.
基金supported by Hengyang City,Hunan Province Science and Technology Innovation Project(No.202250045319)the National Natural Science Foundation of China(Nos.11375084,21808125)the Scientific Research Planning Project of Jilin Provincial Education Department(No.JJKH20241249KJ)。
文摘Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.
基金supported by the Basic Science Research Program(RS-2024-00344021,RS-2023-00261543,and RS-202300257666)through the National Research Foundation of Korea(NRF),the National Research Council of Science(000)Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(RS-2024-00420590,HRD Program for Industrial Innovation)The computational resources were provided by KITSI(KSC-2024-CRE-0143)。
文摘Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and often conflicting requirements of the bulk electrolyte and the electrode-electrolyte interphase.Here,we present a weakly coordinating cationic polymer electrolyte(WCPE)specifically designed to regulate the Li^(+)coordination structure,thereby enabling fast-charging SSLMBs.The WCPE comprises an imidazolium-based polycationic matrix combined with a succinonitrile(SN)-based highconcentration electrolyte.Unlike conventional neutral polymer matrices,the polycationic matrix in the WCPE competes with Li^(+)for interactions with SN,weakening the original coordination between SN and Li^(+).This modulation of SN-Li^(+)interaction improves both Li^(+)conductivity of the WCPE(σ_(Li^(+))=1.29mS cm^(-1))and redox kinetics at the electrode-electrolyte interphase.Consequently,SSLMB cells(comprising LiFePO_(4)cathodes and Li-metal anodes)with the WCPE achieve fast-charging capability(reaching over 80%state of charge within 10 min),outperforming those of previously reported polymer electrolytebased SSLMBs.
基金National Natural Science Foundation of China (52372224 and 52072299)Major Project of Shaanxi Coal Joint Fund of Shaanxi Provincial Science and Technology Department (2019JLZ-07)。
文摘Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite element simulations show that incorporating SO_(4)^(2-)into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge cycles.Consequently,the average Na+diffusion coefficient of Na_(3)V_(2)(PO_(4))_(1.95)(SO_(4))_(0.05)O_(2)F(VPS-1) is roughly double that of VP,leading to enhanced rate capability (80 C,75.5 mAh g^(-1)) and cycling stability (111.0 mAh g^(-1)capacity after 1000 cycles at 10 C current density) for VPS-1.VPS-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 min.The assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current,maintaining an average coulombic efficiency of 95.35%.
基金supported by the project of the National Natural Science Foundation of China(NSFC,Nos.5216040127,52164048 and U1802256)Central Guidance for Local Science and Technology Development Funds(No.202107AB110011)the Analysis and Test Funds of Kunming University of Science and Technology(No.2021M0202230188).
文摘As one of the alloy-type lithium-ion electrodes,Bi has outstanding application prospects for large volume capacity(3800 mAh·cm^(-3))and high electronic conductivity(1.4×10^(7)S·m^(-1)).However,the fast-charging performance is hindered by significant volume expansion(>218%)and a low rate of phase diffusion.To overcome these two problems,an N-doped carbon nanoflower coating layer was elaborately in-situ reconstructed on a multiple-wall Bi microsphere by hydrothermal methods and subsequent calcination in this study.The carbon nanoflowers greatly increase specific surface area(40.0 m^(2)·g^(-1))and alleviate the volume expansion(130%).In addition,the incorporation of N-doped carbon nanoflowers leads to a gradual enhancement in the Li adsorption energy of Bi during the process of lithium insertion and improves the electrical conductivity.Therefore,the contribution rate of pseudo-capacitance reached 87.5%at the scan rate of 0.8 mV·s^(-1),and the Li-ion diffusion coefficient(D_(Li^(+)))was calculated in the range of 10^(-10)to 10^(-12)cm^(2)·s^(-1).The Bi@CNFs anode provided a high specific volumetric capacity of 2117.0 mAh·cm^(-3)at 5C and a high capacity retention ratio of 93.2%after 800 cycles.The Bi@CNFs//LiFePO_(4)full cell also displayed a stable capacity of 113.9 mAh·g^(-1)and energy density of 296.1 Wh·kg^(-1)after 100 cycles with a Coulombic efficiency of 97.6%.The mechanism of fast-charging lithium storage was verified by distribution of relaxation time analysis and density functional theory calculation.This paper provides a new strategy to increase the pseudo-capacitance and reduce the volume expansion for the preparation of alloy-type fast-charging electrodes.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2022R1F1A1074339)。
文摘For the advancement of fast-charging sodium-ion batteries(SIBs),the synthesis of cutting-edge cathode materials with superior structural stability and enhanced Na+diffusion kinetics is imperative.Multiphase layered transition metal oxides(LTMOs),which leverage the synergistic properties of two distinct monophasic LTMOs,have garnered significant attention;however,their efficacy under fast-charging conditions remains underexplored.In this study,we developed a high-throughput computational screening framework to identify optimal dopants that maximize the electrochemical performance of LTMOs.Specifically,we evaluated the efficacy of 32 dopants based on P2/O3-type Mn/Fe-based Na_(x)Mn_(0.5)Fe_(0.5)O_(2)(NMFO)cathode material.Multiphase LTMOs satisfying criteria for thermodynamic and structural stability,minimized phase transitions,and enhanced Na^(+)diffusion were systematically screened for their suitability in fast-charging applications.The analysis identified two dopants,Ti and Zr,which met all predefined screening criteria.Furthermore,we ranked and scored dopants based on their alignment with these criteria,establishing a comprehensive dopant performance database.These findings provide a robust foundation for experimental exploration and offer detailed guidelines for tailoring dopants to optimize fast-charging SIBs.
基金supported by the National Natural Science Foundation of China(62073267,61903305)the Fundamental Research Funds for the Central Universities(HXGJXM202214)。
文摘For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-criteria decisionmaking(MCDM)problem,the current literature lacks a way to unambiguously present criteria and the popular fuzzy analytic network process(ANP)approaches neglect the hesitancy of subjective judgments.To fill these research gaps,an MCDM method based on unified architecture framework(UAF)and interval-valued spherical fuzzy ANP(IVSF-ANP)is proposed in this paper.Firstly,selected viewpoints in UAF are extended to construct criteria models with standardized representation.Secondly,interval-valued spherical fuzzy sets are introduced to ANP to weight interdependent criteria,handling fuzziness and hesitancy in pairwise comparisons.A method of adjusting weights of experts based on their decision similarities is also included in this process to reduce ambiguity brought by multiple experts.Next,performance characteristics are non-linearly transformed regarding to expectations to get final results.This proposition is applied to assess the mission capability of UAV swarms to search and strike surface vessels.Comparative analysis shows that the proposed method is valid and reasonable.
基金financially supported by Guangdong Basic and Applied Basic Research Foundation (No.2020A1515110762)。
文摘Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.
基金supported by the National Key Research and Development Project(2018YFE0124800)the National Nature Science Foundation of China(51702157,51873086,51673096).
文摘High-energy–density lithium-ion batteries(LIBs)that can be safely fast-charged are desirable for electric vehicles.However,sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density.Here we hypothesize that a cobalt vanadate oxide,Co_(2)VO_(4),can be attractive anode material for fast-charging LIBs due to its high capacity(~1000 mAh g^(−1))and safe lithiation potential(~0.65 V vs.Li^(+)/Li).The Li+diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15×10^(-10) cm^(2) s^(−1),proving Co_(2)VO_(4) a promising anode in fast-charging LIBs.A hexagonal porous Co2VO4 nanodisk(PCVO ND)structure is designed accordingly,featuring a high specific surface area of 74.57 m^(2) g^(−1) and numerous pores with a pore size of 14 nm.This unique structure succeeds in enhancing Li^(+) and electron transfer,leading to superior fast-charging performance than current commercial anodes.As a result,the PCVO ND shows a high initial reversible capacity of 911.0 mAh g^(−1) at 0.4 C,excellent fast-charging capacity(344.3 mAh g^(−1) at 10 C for 1000 cycles),outstanding long-term cycling stability(only 0.024% capacity loss per cycle at 10 C for 1000 cycles),confirming the commercial feasibility of PCVO ND in fast-charging LIBs.
基金financially supported by the National Natural Science Foundation of China(No.22279122)Zhejiang Provincial Natural Science Foundation of China(No.LZ22B030004)the Foundation of State Key Laboratory of Coal Conversion(No.J22-23-909)。
文摘Hybrid Na-ion capacitors(NICs)have received considerable interests owing to their low-cost,high-safety,and rapidly charging energy-storage characteristics.The NICs are composed of a capacitor-type cathode and a battery-type anode.The major challenge for NICs is to search for suitable electrode materials to overcome the sluggish diffusion of Na^(+)in the anode.Herein,ultrafine vanadium sulfide is encapsulated in carbon fiber(V_(3)S_(4)@CNF)as a self-supported electrode by electrospinning and in situ sulfurization.The carbon cladding and one-dimensional(ID)nanofiber network-like structure could alleviate the volume expansion of V_(3)S_(4)during Na^(+)de-/intercalation process.Consequently,the V_(3)S_(4)@CNF anode exhibited a pseudocapacitive sodium storage in terms of large Na^(+)-storage capacity(476 mAh·g^(-1)at 0.1A·g^(-1)),high-rate capability(290 mAh·g^(-1)at 20.0 A·g^(-1))and excellent cycling stability(95%capacity retention for1500 cycles at 2.0 A·g^(-1))in Na half-cells.By employing V_(3)S_(4)@CNF as the anode and the activated carbon(AC)cathode,the as-assembled NICs could deliver a high energy density of 110 Wh·kg^(-1)at a power density of200 W·kg^(-1).Even at a high power of 10,000 W·kg^(-1),the specific energy is still up to 42 Wh·kg^(-1).
基金supported by the National Key Research and Development Program(2019YFC0810703)the National Natural Science Foundation of China(22071133)the China Postdoctoral Science Foundation(2020M680581)。
文摘With the ever-growing application of lithium-ion batteries(LIBs), their fast-charging technology has attracted great interests of scientists. However, growth of lithium dendrites during fast charge of the bat teries with high energy density may pose great threats to the operation and cause serious safety issues Herein, we prepared a functional separator with an ultra-thin(20 nm) layer of Au nanoparticles deposited by evaporation coating method which could regulate growth direction and morphology of the lithium dendrites, owing to nearly zero overpotential of lithium meal nucleation on lithiated Au. Once the Li den drites are about to form on the graphite anode during fast charging(or lithiation), they plate predomi nantly on the Au deposited separator rather than on the graphite. Such selective deposition does no compromise the electrochemical performance of batteries under normal cycling. More importantly, i enables the better cycling stability of batteries at fast charge condition. The Li/Graphite cells with Au nanoparticles coated separator could cycle stably with a high areal capacity retention of 90.5% over 95 cycles at the current density of 0.72 m A cm^(-2). The functional separator provides an effective strategy to adjust lithium plating position at fast charge to ensure high safety of batteries without a compromise on the energy density of LIBs.
基金supported by the National Natural Science Foundation of China (No.92372123)the Natural Science Foundation of Guangdong Province (No.2022B1515020005)the Department of Science and Technology of Guangdong Province (No.2020B0101030005)
文摘Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.
基金supported by the National Natural Science Foundation of China(Nos.22075048,52201201)Shaanxi Yanchang Petroleum Co.,Ltd.(No.18529),Yiwu Research Institute of Fudan University(No.20-1-06)+2 种基金the Shanghai International Collaboration Research Project(No.19520713900)the State Key Laboratory of Molecular Engineering of Polymers(Fudan University,No.K2024-36)the State Key Lab of Advanced Metals and Materials(No.2022Z-11)。
文摘Dendrite growth of zinc(Zn)anode at high current density severely affects the fast-charging performance of aqueous zinc metal batteries(AZMBs).While interfacial modification strategies can optimize Zn per formance,challenges such as complicated preparation processes,excessive layer thicknesses,and high voltage hysteresis should be addressed.Herein,we utilize a cost-effective liquid fluorosiloxane,(3,3,3trifluoropropyl)trimethoxysilane,for scalable modification of Zn foil via drop-casting at room tempera ture,resulting in an ultra-thin interphase layer of only 20 nm.The Si-O-Zn bonds formed between flu orosiloxane and Zn ensure interfacial stability,and the Si-O-Si bonds between fluorosiloxane molecule help to homogenize the electric field distribution.Additionally,the abundant highly electronegative flu orine atoms on the anode surface act as zincophilic sites,promoting the uniform deposition of Zn^(2+)Thus,the modified Zn foil(SiFO-Zn)exhibits excellent dendrite suppression,reduced voltage hysteresis and prolonged cycle life at ultra-high current density(40 mA/cm^(2)),achieving a cumulative areal capac ity of 12.9 Ah/cm^(2).Further,the full cell assembled with 10μm-thick Si FO-Zn anode and MnO_(2)cathode achieves 2600 cycles at 5 A/g with minimal capacity degradation,and a large-size(22.5 cm^(-2))pouch cel powers the light-emitting diode even after reverse bending,demonstrating the potential of AZMBs fo fast-charging flexible devices.
基金supported by the National Key Research and Development Program of China(2022YFA1504100)the National Natural Science Foundation of China(22125903,51872283,and 22005298)+4 种基金Dalian Innovation Support Plan for High Level Talents(2019RT09)Dalian National Laboratory For Clean Energy(DNL),Chinese Academy of Sciences(CAS),DNL Cooperation Fund,CAS(DNL202016 and DNL202019)Dalian Institute of Chemical Physics(DICP I2020032)Exploratory Research Project of Yanchang Petroleum International Limited and DICP(yc-hw-2022ky-01)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2021002 and 2021009).
文摘Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics.However,the lithium ion(Li+)-storage performance of the most commercialized lithium cobalt oxide(LiCoO_(2),LCO)cathodes is still far from satisfactory in terms of high-voltage and fast-charging capabilities for reaching the double-high target.Herein,we systematically summarize and discuss high-voltage and fast-charging LCO cathodes,covering in depth the key fundamental challenges,latest advancements in modification strategies,and future perspectives in this field.Comprehensive and elaborated discussions are first presented on key fundamental challenges related to structural degradation,interfacial instability,the inhomogeneity reactions,and sluggish interfacial kinetics.We provide an instructive summary of deep insights into promising modification strategies and underlying mechanisms,categorized into element doping(Li-site,cobalt-/oxygen-site,and multi-site doping)for improved Li+diffusivity and bulkstructure stability;surface coating(dielectrics,ionic/electronic conductors,and their combination)for surface stability and conductivity;nanosizing;combinations of these strategies;and other strategies(i.e.,optimization of the electrolyte,binder,tortuosity of electrodes,charging protocols,and prelithiation methods).Finally,forward-looking perspectives and promising directions are sketched out and insightfully elucidated,providing constructive suggestions and instructions for designing and realizing high-voltage and fast-charging LCO cathodes for next-generation double-high LIBs.
基金State Grid Henan Power Company Science and Technology Project‘Key Technology and Demonstration Application of Multi-Domain Electric Vehicle Aggregated Charging Load Dispatch’(5217L0240003).
文摘This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.
基金supported by the National Natural Science Foundation of China(Nos.62103052 and No.52175214)。
文摘This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.
文摘Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as the research objects.Emergency rescue capability training was conducted from March 2023 to June 2023,once a month.The students’mastery of emergency rescue before and after the intervention was analyzed.Survey questionnaires were distributed to all college students to understand their channels and willingness to acquire emergency rescue knowledge.Results:A total of 886 valid questionnaires were collected in this study.The highest proportion of knowledge about China’s general emergency telephone number and how to dial the emergency rescue hotline was 100.00%.Among the strategies for dealing with cardiac arrest in CPR,the highest proportion was 336.34%.Among the four major first aid techniques of hemostasis,bandaging,fixation,transportation,the highest proportion of knowledge about the use of rubber band signs was 31.71%.Among the first aid techniques for heatstroke,poisoning,fire,and sharp instrument injuries,the principle of emergency treatment for severe gas poisoning had the highest proportion of 41.42%,showing significant differences.College students mainly acquire knowledge of emergency rescue capability through TV programs,health education lectures,and the internet.Around 61.40%of college students hope to learn more about prevention and control knowledge.Conclusion:After the intervention of emergency rescue capability,the emergency rescue capability of college students in this university has been significantly improved,showing a strong training effect,which is worthy of promotion.
基金supported by the National Natural Science Foundation of China(Nos.22178221,22208221)the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)+2 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)the Scientific Foundation for Youth Scholars of Shenzhen University(868-000001032522,827-0001004)the Instrumental Analysis Center of Shenzhen University for the assistance with the Electron Microscope technical support。
文摘To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.
基金supported by the Natural Science Foundation of Hunan Province(No.2024JJ7392)the National Natural Science Foundation of China(No.52463002)+1 种基金Educational Commission of Hunan Province(No.22A0383)Special Funds for Construction of Innovative Provinces in Hunan Province(No.2020SK2028).
文摘An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.
基金co-supported by the National Social Science Foundation of China(No.2022-SKJJ-C-037)the Ministerial-level Funding Project,China(JY2023A016)。
文摘A comprehensive model is proposed to evaluate the damage capability of laser system in ground-air defense environments.This model takes into account the laser system's heavy reliance on weather conditions and the stringent requirements for beam pointing accuracy.It initiates by simulating the laser spot characteristics on target in ground-to-air environments,factoring in the effects of atmospheric turbulence,absorption and scattering through slant transmission paths.Subsequently,a calculation method based on the thermal damage effect of the target material is introduced to quantify the damage ability of the laser system.To further enhance the model's applicability,a method for calculating the laser damage probability based on random crossover theory has been introduced,which takes into account the error of the Acquisition,Tracking and Pointing(ATP)system to estimate the likelihood of successful damage in operation applications.Theoretical analysis and simulation results validate the effectiveness of the proposed model in calculating and analyzing the damage capability of laser system in ground-air defense environments.This model offers valuable decision-making insights for users of laser systems operating in lowaltitude atmospheric conditions.Furthermore,it furnishes essential data support for the development and validation of laser systems,ensuring their effectiveness in real-world applications.
