The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an ...The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an initial Coulombic efficiency(ICE)of 87%as well as excellent cycling performance.More attention is paid to exploration of the relationships between the sodium status on various storage sites at different sodiation states and the ICE by solidstate^(23)Na nuclear magnetic resonance spectroscopy.The adsorbed Na ions contribute the most to the irreversible capacity.The de-solvated Na ions entering the closed pores are reduced to Na atoms and aggregated to Na clusters.Also,this process contributes the most to the reversible capacity and is characteristic of a long plateau in the voltage profile.Intercalation is partially reversible;it is the main source of capacity for slope-type HCs but plays a minor role in the reversible capacity of plateau-type HCs.Therefore,increasing the content of the closed pores can improve the reversible plateau capacity and reducing the open mesopores of HC increases the ICE.These findings provide insights into the structural design and cost-efficient preparation of high-performance HC anode materials for advanced sodium-ion batteries.展开更多
With the introduction of 5G,users and devices can access the industrial network from anywhere in the world.Therefore,traditional perimeter-based security technologies for industrial networks can no longer work well.To...With the introduction of 5G,users and devices can access the industrial network from anywhere in the world.Therefore,traditional perimeter-based security technologies for industrial networks can no longer work well.To solve this problem,a new security model called Zero Trust(ZT)is desired,which believes in“never trust and always verify”.Every time the asset in the industrial network is accessed,the subject is authenticated and its trustworthiness is assessed.In this way,the asset in industrial network can be well protected,whether the subject is in the internal network or the external network.However,in order to construct the zero trust model in the 5G Industrial Internet collaboration system,there are still many problems to be solved.In this paper,we first introduce the security issues in the 5G Industrial Internet collaboration system,and illustrate the zero trust architecture.Then,we analyze the gap between existing security techniques and the zero trust architecture.Finally,we discuss several potential security techniques that can be used to implement the zero trust model.The purpose of this paper is to point out the further direction for the realization of the Zero Trust Architecture(ZTA)in the 5G Industrial Internet collaboration system.展开更多
Material is the basis for manufacturing.Materials innovation has always been the core of disruptive technical revolution.However,it takes 15–20 years or more to place a material on the market after its initial discov...Material is the basis for manufacturing.Materials innovation has always been the core of disruptive technical revolution.However,it takes 15–20 years or more to place a material on the market after its initial discovery.Therefore,the traditional scientific methods of intuition and trial and error cannot keep展开更多
Fast-charging lithium-ion batteries are highly required,especially in reducing the mileage anxiety of the widespread electric vehicles.One of the biggest bottlenecks lies in the sluggish kinetics of the Li^(+)intercal...Fast-charging lithium-ion batteries are highly required,especially in reducing the mileage anxiety of the widespread electric vehicles.One of the biggest bottlenecks lies in the sluggish kinetics of the Li^(+)intercalation into the graphite anode;slow intercalation will lead to lithium metal plating,severe side reactions,and safety concerns.The premise to solve these problems is to fully understand the reaction pathways and rate-determining steps of graphite during fast Li^(+)intercalation.Herein,we compare the Li^(+)diffusion through the graphite particle,interface,and electrode,uncover the structure of the lithiated graphite at high current densities,and correlate them with the reaction kinetics and electrochemical performances.It is found that the rate-determining steps are highly dependent on the particle size,interphase property,and electrode configuration.Insufficient Li^(+)diffusion leads to high polarization,incomplete intercalation,and the coexistence of several staging structures.Interfacial Li^(+)diffusion and electrode transportation are the main rate-determining steps if the particle size is less than 10μm.The former is highly dependent on the electrolyte chemistry and can be enhanced by constructing a fluorinated interphase.Our findings enrich the understanding of the graphite structural evolution during rapid Li^(+)intercalation,decipher the bottleneck for the sluggish reaction kinetics,and provide strategic guidelines to boost the fast-charging performance of graphite anode.展开更多
Na metal anode, benefiting from its high theoretical capacity and lowest electrochemical potential, ~sone of the most favorable candidates for future Na-based batteries with high energy density. Dendritegrowth, volume...Na metal anode, benefiting from its high theoretical capacity and lowest electrochemical potential, ~sone of the most favorable candidates for future Na-based batteries with high energy density. Dendritegrowth, volume change and high reactivity are the formidable challenges in terms of good cycling perfor-mance and high Coulombic efficiency as well as an expected safety guarantee of Na metal anode for thepractical application. Solid electrolyte interphase （SEI） layer as an indispensable component of a battery,its formation and stability play the critical role in the feasibility of Na metal anode. In this review, wefirst discuss the current consideration and challenges of Na metal anode, and then summarize severalstrategies to suppress dendrite growth and improve electrochemical performance, including interface en-gineering, electrolyte composition, electrode construction, and so on. Finally, the conclusion and futureperspective of potential development on Na metal anode are proposed.展开更多
Safety requirements stimulate Na-based batteries to evolve from high-temperature Na–S batteries to room-temperature Na-ion batteries(NIBs).Even so,NIBs may still cause thermal runaway due to the external unexpected a...Safety requirements stimulate Na-based batteries to evolve from high-temperature Na–S batteries to room-temperature Na-ion batteries(NIBs).Even so,NIBs may still cause thermal runaway due to the external unexpected accidents and internal high activity of electrodes or electrolytes,which has not been comprehensively summarized yet.In this review,we summarize the significant advances about the failure mechanisms and related strategies to build safer NIBs from the selection of electrodes,electrolytes and the construction of electrode/electrolyte interfaces.Considering the safety risk,the thermal behaviors are emphasized which will deepen the understanding of thermal stability of different NIBs and accelerate the exploitation of safe NIBs.展开更多
All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significa...All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.展开更多
The low ionic conductivity of solid-state electrolytes(SSEs)and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium ba...The low ionic conductivity of solid-state electrolytes(SSEs)and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium batteries(SSSBs).Herein,sodium(Na)super ionic conductor(NASICON)-type SSEs with a nominal composition of Na_(3+2x)Zr_(2-x)MgxSi_(2)PO_(12) were synthesized using a facile two-step solid-state method,among which Na_(3.3)Zr_(1.85)Mg_(0.15)Si_(2)PO_(12)(x=0.15,NZSP-Mg_(0.15))showed the highest ionic conductivity of 3.54mS∙cm^(-1) at 25℃.By means of a thorough investigation,it was verified that the composition of the grain boundary plays a crucial role in determining the total ionic conductivity of NASICON.Furthermore,due to a lack of examination in the literature regarding whether NASICON can provide enough anodic electrochemical stability to enable high-voltage SSSBs,we first adopted a high-voltage Na_(3)(VOPO_(4))2F(NVOPF)cathode to verify its compatibility with the optimized NZSP-Mg_(0.15) SSE.By comparing the electrochemical performance of cells with different configurations(low-voltage cathode vs high-voltage cathode,liquid electrolytes vs SSEs),along with an X-ray photoelectron spectroscopy evaluation of the after-cycled NZSP-Mg_(0.15),it was demonstrated that the NASICON SSEs are not stable enough under high voltage,suggesting the importance of investigating the interface between the NASICON SSEs and high-voltage cathodes.Furthermore,by coating NZSP-Mg_(0.15) NASICON powder onto a polyethylene(PE)separator(PE@NASICON),a 2.42 A∙h non-aqueous Na-ion cell of carbon|PE@NASICON|NaNi_(2/9)Cu_(1/9)Fe_(1/3)Mn_(1/3)O_(2) was found to deliver an excellent cycling performance with an 88%capacity retention after 2000 cycles,thereby demonstrating the high reliability of SSEs with NASICON-coated separator.展开更多
With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretica...With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretical capacity and low redox potential.However,the commercial application of LMAs is impeded by the uncontrolled growth of lithium dendrites.Such dendrite growth may result in internal short circuits,detrimental side reactions,and the formation of dead lithium.Therefore,the growth of lithium metal must be controlled.This article summarizes our recent efforts in inhibiting such dendrite growth,decreasing the detrimental side reactions,and elongating the LMA lifespan by optimizing the electrolyte structure and by designing appropriate current collectors.After identifying that the unstable solid electrolyte inter-face(SEI)film is responsible for the potential dropping in carbonate electrolytes,we developed LiPF_(6)-LiNO_(3) dual-salt electrolyte and lithium bis(fluorosulfonyl)imide(LiFSI)-carbonate electrolyte to stabilize the SEI film of LMAs.In addition,we achieved controlled lithium depos-ition by designing the structure and material of the current collectors,including selective lithium deposition in porous current collectors,lithio-philic metal guided lithium deposition,and iron carbide induced underpotential lithium deposition in nano-cavities.The limitations of the cur-rent strategies and prospects for future research are also presented.展开更多
As a new electrochemical power system,safety(especially thermal safety)of Na-ion batteries(NIBs)is the key towards large-scale industrialization and market application.Thus,research on the thermal stability of NIBs is...As a new electrochemical power system,safety(especially thermal safety)of Na-ion batteries(NIBs)is the key towards large-scale industrialization and market application.Thus,research on the thermal stability of NIBs is helpful to evaluate the safety properties and to provide effective strategies to prevent the occurrence of battery safety failure.Thermal stability of the high-power 26650 cylindrical NIBs using Cu-based layered oxide cathode and hard carbon anode is studied.The high power NIBs can achieve fast charge and discharge at 5–10 C rate and maintain 80%capacity after 4729 cycles at 2 C/2 C rate,where the unit C denotes a measure of the rate at which a battery is charge-discharged relative to its maximum capacity.The results of accelerating rate calorimeter and differential scanning calorimetry(ARC-DSC)test results show that NIBs have a higher initial decomposition temperature(≥110℃)and a lower maximum thermal runaway temperature(≤350℃)than those of Li-ion batteries(LIBs),exhibiting a favorable thermal stability.It should be noted that the heat generation of cathode accounts for a large proportion of the total heat generation while the thermal stability of the anode determines the initial thermal runaway temperature,which is similar to LIBs.Finally,the whole temperature characteristics of the NIBs in the range of−60℃–1000℃are summarized,which provide guidance for the safety design and applications of NIBs.展开更多
Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalati...Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalation compounds with intriguing staging structures,which however are still unclear,especially in their nanostructure and dynamic transition mechanism.Herein,the nature of the staging structure and evolution of the lithium(Li)‐intercalated graphite was revealed by cryogenic‐transmission electron microscopy and other methods at the nanoscale.The intercalated Li‐ions distribute unevenly,generating local stress and dislocations in the graphitic structure.Each staging compound is found macroscopically ordered but microscopically inhomogeneous,exhibiting a localized‐domains structural model.Our findings uncover the correlation between the long‐range ordered structure and short‐range domains,refresh the insights on the staging structure and transition of Li‐intercalated/deintercalated graphite,and provide effective ways to enhance the reaction kinetic in rechargeable batteries by defect engineering.展开更多
In network-connected UAV(NCUAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anony...In network-connected UAV(NCUAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anonymous attestation(DAA) is an attractive cryptographic scheme that provides an elegant balance between platform authentication and anonymity. However, because of the low-level computing capability and limited transmission bandwidth in UAV, the existing DAA schemes are not suitable for NC-UAV communication systems. In this paper, we propose an enhanced DAA scheme with mutual authentication(MA-DAA scheme), which meets the security requirements of NC-UAV communication systems. The proposed MA-DAA scheme, which is based on asymmetric pairings, bundles the identities of trusted platform module(TPM) and Host to solve the malicious module changing attacks. Credential randomization, batch proof and verification, and mutual authentication are realized in the MA-DAA scheme. The computational workload in TPM and Host is reduced in order to meet the low computation and resource requirements in TPM and Host.The entire scheme and protocols are presented,and the security and efficiency of the proposed MA-DAA scheme are proved and analyzed.Our experiment results also confirm the high efficiency of the proposed scheme.展开更多
Nano-sized caiboxylales Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries.Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off volt...Nano-sized caiboxylales Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries.Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs.Li＋/Li.potentially improving the safety of the batteries.In addition,good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.展开更多
In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configurat...In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configuration and optimization. Based on the most promising battery energy storage technology, this paper introduces the current status of the grid technology, the application of large-scale energy storage technology and the supporting role of battery energy storage for GEI. Based on several key technologies of large-scale battery energy storage system, preliminary analysis of the standard system construction of energy storage system is made, and the future prospect is put forward.展开更多
Organic materials, especially the carbonyl compounds, are promising anode materials for room temperature sodium-ion batteries owing to their high reversible capacity, structural diversity as well as eco-friendly synth...Organic materials, especially the carbonyl compounds, are promising anode materials for room temperature sodium-ion batteries owing to their high reversible capacity, structural diversity as well as eco-friendly synthesis from bio-mass. Herein, we report a novel anthraquinone derivative, C_(14)H_6 O_4 Na_2 composited with carbon nanotube(C_(14)H_6 O_4 Na_2-CNT), used as an anode material for sodium-ion batteries in etherbased electrolyte. The C_(14)H_6 O_4 Na_2-CNT electrode delivers a reversible capacity of 173 mAh g^(-1) and an ultra-high initial Coulombic efficiency of 98% at the rate of 0.1 C. The capacity retention is 82% after 50 cycles at 0.2 C and a good rate capability is displayed at 2 C.Furthermore, the average Na insertion voltage of 1.27 V vs. Na^+/Na makes it a unique and safety battery material, which would avoid Na plating and formation of solid electrolyte interface. Our contribution provides new insights for designing developed organic anode materials with high initial Coulombic efficiency and improved safety capability for sodium-ion batteries.展开更多
The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been ...The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and E The strong and localized Coulomb attraction between Li and F atoms breaks the C-F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.展开更多
Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suita...Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suitable cathode materials hinder the wide commercialization of SIBs.Given this aspect,in this work,a new layered oxide with 4d metal Tin was synthesized and investigated as cathode material for SIBs.Two optimized sodium-deficient O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2and O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2were selected for comprehensive investigation,both of which exhibited high operating voltage of around 3.45 V with smooth charge/discharge curves.In comparison,O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2shows a higher reversible capacity(65 m A h/g,0.1 C),better rate capability and cycling stability than that of O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2(50 mA h/g,0.1 C),indicating that a small amount of Mn-substitution can improve the electrochemical performance.This work presents a new possibility of discovering potential cathode candidates by exploring the Tin-based layered oxides.展开更多
The one-time pad(OTP)is an applicationlayer encryption technique to achieve the informationtheoretic security,and the physical-layer secret key generation(SKG)technique is a promising candidate to provide the random k...The one-time pad(OTP)is an applicationlayer encryption technique to achieve the informationtheoretic security,and the physical-layer secret key generation(SKG)technique is a promising candidate to provide the random keys for OTP.In this paper,we propose a joint SKG and OTP encryption scheme with the aid of a reconfigurable intelligent surface(RIS)to boost secret key rate.To maximize the efficiency of secure communication,we divide the process of secure transmission into two stages:SKG and then encrypted packet transmission.Meanwhile,we design an optimal algorithm for allocating time slots for SKG to maximize SKG efficiency without security risk.Furthermore,we design a key updating protocol based on our SKG scheme for OTP encryption.Simulation results verify that our scheme can generate keys securely and efficiently,and significantly improve the secure communication performance in an intelligent IoT system.展开更多
Na-ion batteries(NIBs) have been attracting growing interests in recent years with the increasing demand of energy storage owing to their dependence on more abundant Na than Li. The exploration of the industrializatio...Na-ion batteries(NIBs) have been attracting growing interests in recent years with the increasing demand of energy storage owing to their dependence on more abundant Na than Li. The exploration of the industrialization of NIBs is also on the march, where some challenges are still limiting its step. For instance, the relatively low initial Coulombic efficiency(ICE) of anode can cause undesired energy density loss in the full cell. In addition to the strategies from the sight of materials design that to improve the capacity and ICE of electrodes, presodiation technique is another important method to efficiently offset the irreversible capacity and enhance the energy density. Meanwhile, the slow release of the extra Na during the cycling is able to improve the cycling stability.In this review, we would like to provide a general insight of presodiation technique for high-performance NIBs.The recent research progress including the principles and strategies of presodiation will be introduced, and some remaining challenges as well as our perspectives will be discussed. This review aims to exhibit the basic knowledge of presodiation to inspire the researchers for future studies.展开更多
The editor of Chinese Physics B decided to organize a special topic on lithium batteries. We are sure the decision is very correct because one of the important tasks of physics is to serve the needs of society. Energy...The editor of Chinese Physics B decided to organize a special topic on lithium batteries. We are sure the decision is very correct because one of the important tasks of physics is to serve the needs of society. Energy and environment are two related major problems facing mankind today. Physics has been dedicating itself to semiconductors for several decades. Now is the right time for physicists to study the problems related to new energy sources and related tools. Currently, it is most urgent to develop electric vehicles （EVs） and to develop renewable energies. The rechargeable battery is essential for both. Scientists and engineers have been racing to design smaller, cheaper and more efficient reclaargeable batteries to meet society＇s power storage needs.展开更多
文摘The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an initial Coulombic efficiency(ICE)of 87%as well as excellent cycling performance.More attention is paid to exploration of the relationships between the sodium status on various storage sites at different sodiation states and the ICE by solidstate^(23)Na nuclear magnetic resonance spectroscopy.The adsorbed Na ions contribute the most to the irreversible capacity.The de-solvated Na ions entering the closed pores are reduced to Na atoms and aggregated to Na clusters.Also,this process contributes the most to the reversible capacity and is characteristic of a long plateau in the voltage profile.Intercalation is partially reversible;it is the main source of capacity for slope-type HCs but plays a minor role in the reversible capacity of plateau-type HCs.Therefore,increasing the content of the closed pores can improve the reversible plateau capacity and reducing the open mesopores of HC increases the ICE.These findings provide insights into the structural design and cost-efficient preparation of high-performance HC anode materials for advanced sodium-ion batteries.
基金supported by the National Natural Science Foundation of China(U22B2026)the ZTE Industry-Academia-Research Project(HC-CN-20221029003,IA20230628015)。
文摘With the introduction of 5G,users and devices can access the industrial network from anywhere in the world.Therefore,traditional perimeter-based security technologies for industrial networks can no longer work well.To solve this problem,a new security model called Zero Trust(ZT)is desired,which believes in“never trust and always verify”.Every time the asset in the industrial network is accessed,the subject is authenticated and its trustworthiness is assessed.In this way,the asset in industrial network can be well protected,whether the subject is in the internal network or the external network.However,in order to construct the zero trust model in the 5G Industrial Internet collaboration system,there are still many problems to be solved.In this paper,we first introduce the security issues in the 5G Industrial Internet collaboration system,and illustrate the zero trust architecture.Then,we analyze the gap between existing security techniques and the zero trust architecture.Finally,we discuss several potential security techniques that can be used to implement the zero trust model.The purpose of this paper is to point out the further direction for the realization of the Zero Trust Architecture(ZTA)in the 5G Industrial Internet collaboration system.
文摘Material is the basis for manufacturing.Materials innovation has always been the core of disruptive technical revolution.However,it takes 15–20 years or more to place a material on the market after its initial discovery.Therefore,the traditional scientific methods of intuition and trial and error cannot keep
基金supported by the National Natural Science Foundation of China(NSFC No.52172257 and 22005334)the Natural Science Foundation of Beijing(Grant No.Z200013)the National Key Research and Development Program of China(Grant No.2022YFB2502200).
文摘Fast-charging lithium-ion batteries are highly required,especially in reducing the mileage anxiety of the widespread electric vehicles.One of the biggest bottlenecks lies in the sluggish kinetics of the Li^(+)intercalation into the graphite anode;slow intercalation will lead to lithium metal plating,severe side reactions,and safety concerns.The premise to solve these problems is to fully understand the reaction pathways and rate-determining steps of graphite during fast Li^(+)intercalation.Herein,we compare the Li^(+)diffusion through the graphite particle,interface,and electrode,uncover the structure of the lithiated graphite at high current densities,and correlate them with the reaction kinetics and electrochemical performances.It is found that the rate-determining steps are highly dependent on the particle size,interphase property,and electrode configuration.Insufficient Li^(+)diffusion leads to high polarization,incomplete intercalation,and the coexistence of several staging structures.Interfacial Li^(+)diffusion and electrode transportation are the main rate-determining steps if the particle size is less than 10μm.The former is highly dependent on the electrolyte chemistry and can be enhanced by constructing a fluorinated interphase.Our findings enrich the understanding of the graphite structural evolution during rapid Li^(+)intercalation,decipher the bottleneck for the sluggish reaction kinetics,and provide strategic guidelines to boost the fast-charging performance of graphite anode.
基金supported by the National Key Technologies R&D Program,China (2016YFB0901500)the National Natural Science Foundation of China (51672275,51421002)
文摘Na metal anode, benefiting from its high theoretical capacity and lowest electrochemical potential, ~sone of the most favorable candidates for future Na-based batteries with high energy density. Dendritegrowth, volume change and high reactivity are the formidable challenges in terms of good cycling perfor-mance and high Coulombic efficiency as well as an expected safety guarantee of Na metal anode for thepractical application. Solid electrolyte interphase （SEI） layer as an indispensable component of a battery,its formation and stability play the critical role in the feasibility of Na metal anode. In this review, wefirst discuss the current consideration and challenges of Na metal anode, and then summarize severalstrategies to suppress dendrite growth and improve electrochemical performance, including interface en-gineering, electrolyte composition, electrode construction, and so on. Finally, the conclusion and futureperspective of potential development on Na metal anode are proposed.
基金Project supported by the National Key Technologies R&D Program,China(Grant No.2016YFB0901500)the National Natural Science Foundation(NSFC)of China(Grant Nos.51725206 and 51421002)+3 种基金NSFCUKRI EPSRC(Grant No.51861165201)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA21070500)Beijing Municipal Science and Technology Commission,China(Grant No.Z181100004718008)Beijing Natural Science Fund–Haidian Original Innovation Joint Fund,China(Grant No.L182056)。
文摘Safety requirements stimulate Na-based batteries to evolve from high-temperature Na–S batteries to room-temperature Na-ion batteries(NIBs).Even so,NIBs may still cause thermal runaway due to the external unexpected accidents and internal high activity of electrodes or electrolytes,which has not been comprehensively summarized yet.In this review,we summarize the significant advances about the failure mechanisms and related strategies to build safer NIBs from the selection of electrodes,electrolytes and the construction of electrode/electrolyte interfaces.Considering the safety risk,the thermal behaviors are emphasized which will deepen the understanding of thermal stability of different NIBs and accelerate the exploitation of safe NIBs.
基金supported by the Outstanding Youth Fund Project by the Department of Science and Technology of Jiangsu Province(Grant No.BK20220045)the Key R&D Project funded by the Department of Science and Technology of Jiangsu Province(Grant No.BE2020003)+6 种基金Key Program-Automobile Joint Fund of National Natural Science Foundation of China(Grant No.U1964205)General Program of National Natural Science Foundation of China(Grant No.51972334)General Program of National Natural Science Foundation of Beijing(Grant No.2202058)Cultivation project of leading innovative experts in Changzhou City(CQ20210003)National Overseas High-level Expert recruitment Program(Grant No.E1JF021E11)Talent Program of Chinese Academy of Sciences,“Scientist Studio Program Funding”from Yangtze River Delta Physics Research Center,and Tianmu Lake Institute of Advanced Energy Storage Technologies(Grant No.TIESSS0001)Science and Technology Research Institute of China Three Gorges Corporation(Grant No.202103402)
文摘All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.
基金the National Key Technologies Research and Development Program,China(2016YFB0901500)the Opening Project of the Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(JDGD-201703)+2 种基金the National Natural Science Foundation of China(51725206 and 51421002)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21070500)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2020006).
文摘The low ionic conductivity of solid-state electrolytes(SSEs)and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium batteries(SSSBs).Herein,sodium(Na)super ionic conductor(NASICON)-type SSEs with a nominal composition of Na_(3+2x)Zr_(2-x)MgxSi_(2)PO_(12) were synthesized using a facile two-step solid-state method,among which Na_(3.3)Zr_(1.85)Mg_(0.15)Si_(2)PO_(12)(x=0.15,NZSP-Mg_(0.15))showed the highest ionic conductivity of 3.54mS∙cm^(-1) at 25℃.By means of a thorough investigation,it was verified that the composition of the grain boundary plays a crucial role in determining the total ionic conductivity of NASICON.Furthermore,due to a lack of examination in the literature regarding whether NASICON can provide enough anodic electrochemical stability to enable high-voltage SSSBs,we first adopted a high-voltage Na_(3)(VOPO_(4))2F(NVOPF)cathode to verify its compatibility with the optimized NZSP-Mg_(0.15) SSE.By comparing the electrochemical performance of cells with different configurations(low-voltage cathode vs high-voltage cathode,liquid electrolytes vs SSEs),along with an X-ray photoelectron spectroscopy evaluation of the after-cycled NZSP-Mg_(0.15),it was demonstrated that the NASICON SSEs are not stable enough under high voltage,suggesting the importance of investigating the interface between the NASICON SSEs and high-voltage cathodes.Furthermore,by coating NZSP-Mg_(0.15) NASICON powder onto a polyethylene(PE)separator(PE@NASICON),a 2.42 A∙h non-aqueous Na-ion cell of carbon|PE@NASICON|NaNi_(2/9)Cu_(1/9)Fe_(1/3)Mn_(1/3)O_(2) was found to deliver an excellent cycling performance with an 88%capacity retention after 2000 cycles,thereby demonstrating the high reliability of SSEs with NASICON-coated separator.
基金financially supported by the National Natural Science Foundation of China(No.21773301)。
文摘With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretical capacity and low redox potential.However,the commercial application of LMAs is impeded by the uncontrolled growth of lithium dendrites.Such dendrite growth may result in internal short circuits,detrimental side reactions,and the formation of dead lithium.Therefore,the growth of lithium metal must be controlled.This article summarizes our recent efforts in inhibiting such dendrite growth,decreasing the detrimental side reactions,and elongating the LMA lifespan by optimizing the electrolyte structure and by designing appropriate current collectors.After identifying that the unstable solid electrolyte inter-face(SEI)film is responsible for the potential dropping in carbonate electrolytes,we developed LiPF_(6)-LiNO_(3) dual-salt electrolyte and lithium bis(fluorosulfonyl)imide(LiFSI)-carbonate electrolyte to stabilize the SEI film of LMAs.In addition,we achieved controlled lithium depos-ition by designing the structure and material of the current collectors,including selective lithium deposition in porous current collectors,lithio-philic metal guided lithium deposition,and iron carbide induced underpotential lithium deposition in nano-cavities.The limitations of the cur-rent strategies and prospects for future research are also presented.
基金Supported by the National Key Technology R&D Program of China(Grant No.2016YFB0901500)the National Natural Science Foundation of China(Grant No.51725206)+2 种基金NSFCUKRI_EPSRC(Grant No.51861165201)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA21070500)Beijing Natural Science Fund-Haidian Original Innovation Joint Fund(Grant No.L182056).
文摘As a new electrochemical power system,safety(especially thermal safety)of Na-ion batteries(NIBs)is the key towards large-scale industrialization and market application.Thus,research on the thermal stability of NIBs is helpful to evaluate the safety properties and to provide effective strategies to prevent the occurrence of battery safety failure.Thermal stability of the high-power 26650 cylindrical NIBs using Cu-based layered oxide cathode and hard carbon anode is studied.The high power NIBs can achieve fast charge and discharge at 5–10 C rate and maintain 80%capacity after 4729 cycles at 2 C/2 C rate,where the unit C denotes a measure of the rate at which a battery is charge-discharged relative to its maximum capacity.The results of accelerating rate calorimeter and differential scanning calorimetry(ARC-DSC)test results show that NIBs have a higher initial decomposition temperature(≥110℃)and a lower maximum thermal runaway temperature(≤350℃)than those of Li-ion batteries(LIBs),exhibiting a favorable thermal stability.It should be noted that the heat generation of cathode accounts for a large proportion of the total heat generation while the thermal stability of the anode determines the initial thermal runaway temperature,which is similar to LIBs.Finally,the whole temperature characteristics of the NIBs in the range of−60℃–1000℃are summarized,which provide guidance for the safety design and applications of NIBs.
基金support from the National Natural Science Foundation of China(NSFC nos.52172257,22005334,21773301 and 52022106)the Natural Science Foundation of Beijing(grant no.Z200013).
文摘Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalation compounds with intriguing staging structures,which however are still unclear,especially in their nanostructure and dynamic transition mechanism.Herein,the nature of the staging structure and evolution of the lithium(Li)‐intercalated graphite was revealed by cryogenic‐transmission electron microscopy and other methods at the nanoscale.The intercalated Li‐ions distribute unevenly,generating local stress and dislocations in the graphitic structure.Each staging compound is found macroscopically ordered but microscopically inhomogeneous,exhibiting a localized‐domains structural model.Our findings uncover the correlation between the long‐range ordered structure and short‐range domains,refresh the insights on the staging structure and transition of Li‐intercalated/deintercalated graphite,and provide effective ways to enhance the reaction kinetic in rechargeable batteries by defect engineering.
基金supported in part by the European Commission Marie Curie IRSES project "AdvIOT"the National Natural Science Foundation of China (NSFC) under grant No.61372103
文摘In network-connected UAV(NCUAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anonymous attestation(DAA) is an attractive cryptographic scheme that provides an elegant balance between platform authentication and anonymity. However, because of the low-level computing capability and limited transmission bandwidth in UAV, the existing DAA schemes are not suitable for NC-UAV communication systems. In this paper, we propose an enhanced DAA scheme with mutual authentication(MA-DAA scheme), which meets the security requirements of NC-UAV communication systems. The proposed MA-DAA scheme, which is based on asymmetric pairings, bundles the identities of trusted platform module(TPM) and Host to solve the malicious module changing attacks. Credential randomization, batch proof and verification, and mutual authentication are realized in the MA-DAA scheme. The computational workload in TPM and Host is reduced in order to meet the low computation and resource requirements in TPM and Host.The entire scheme and protocols are presented,and the security and efficiency of the proposed MA-DAA scheme are proved and analyzed.Our experiment results also confirm the high efficiency of the proposed scheme.
基金supported by the funding from"863"Project(2011AA11A235)"973"Projects(2010CB833102 and 2012CB932900)+1 种基金NSFC(No.51222210 and 11234013)the 100 Talent Project of the Chinese Academy of Sciences
文摘Nano-sized caiboxylales Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries.Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs.Li＋/Li.potentially improving the safety of the batteries.In addition,good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.
基金supported by National Key R&D Program of China(2017YFB0903504)
文摘In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configuration and optimization. Based on the most promising battery energy storage technology, this paper introduces the current status of the grid technology, the application of large-scale energy storage technology and the supporting role of battery energy storage for GEI. Based on several key technologies of large-scale battery energy storage system, preliminary analysis of the standard system construction of energy storage system is made, and the future prospect is put forward.
基金supported by funding from the National Key Technologies R&D Program (2016YFB0901500)the NSFC (11234013 and 51421002)the One Hundred Talent Project of the Chinese Academy of Sciences
文摘Organic materials, especially the carbonyl compounds, are promising anode materials for room temperature sodium-ion batteries owing to their high reversible capacity, structural diversity as well as eco-friendly synthesis from bio-mass. Herein, we report a novel anthraquinone derivative, C_(14)H_6 O_4 Na_2 composited with carbon nanotube(C_(14)H_6 O_4 Na_2-CNT), used as an anode material for sodium-ion batteries in etherbased electrolyte. The C_(14)H_6 O_4 Na_2-CNT electrode delivers a reversible capacity of 173 mAh g^(-1) and an ultra-high initial Coulombic efficiency of 98% at the rate of 0.1 C. The capacity retention is 82% after 50 cycles at 0.2 C and a good rate capability is displayed at 2 C.Furthermore, the average Na insertion voltage of 1.27 V vs. Na^+/Na makes it a unique and safety battery material, which would avoid Na plating and formation of solid electrolyte interface. Our contribution provides new insights for designing developed organic anode materials with high initial Coulombic efficiency and improved safety capability for sodium-ion batteries.
基金support of National High Technology Research and Development Program of China ("863" Program) (2015AA034201)the National Natural Science Foundation of China (11234013 and 11264014)+1 种基金Natural Science Foundation of Jiangxi Province (20133ACB21010, 20142BAB212002,20132BAB212005)Foundation of Jiangxi Education Committee (GJJ14254 and KJLD14024)
文摘The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and E The strong and localized Coulomb attraction between Li and F atoms breaks the C-F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.
基金supported by funding from the Science and Technology Project of the State Grid Corporation of China ("research on key technology of low-strain layered oxides for long-life sodium-ion batteries", DG71-16-027)
文摘Recently,sodium-ion batteries(SIBs),regarded as promising supplements for lithium-ion batteries(LIBs),especially in the large-scale energy storage field,are attracting more and more attention.However,the limited suitable cathode materials hinder the wide commercialization of SIBs.Given this aspect,in this work,a new layered oxide with 4d metal Tin was synthesized and investigated as cathode material for SIBs.Two optimized sodium-deficient O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2and O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2were selected for comprehensive investigation,both of which exhibited high operating voltage of around 3.45 V with smooth charge/discharge curves.In comparison,O3-Na_(0.9)Ni_(0.4)Mn_(0.1)Sn_(0.5)O_2shows a higher reversible capacity(65 m A h/g,0.1 C),better rate capability and cycling stability than that of O3-Na_(0.9)Ni_(0.45)Sn_(0.55)O_2(50 mA h/g,0.1 C),indicating that a small amount of Mn-substitution can improve the electrochemical performance.This work presents a new possibility of discovering potential cathode candidates by exploring the Tin-based layered oxides.
基金supported by National key research and development program of China, Joint research of IoT security system and key technologies based on quantum key (2020YFE0200600)
文摘The one-time pad(OTP)is an applicationlayer encryption technique to achieve the informationtheoretic security,and the physical-layer secret key generation(SKG)technique is a promising candidate to provide the random keys for OTP.In this paper,we propose a joint SKG and OTP encryption scheme with the aid of a reconfigurable intelligent surface(RIS)to boost secret key rate.To maximize the efficiency of secure communication,we divide the process of secure transmission into two stages:SKG and then encrypted packet transmission.Meanwhile,we design an optimal algorithm for allocating time slots for SKG to maximize SKG efficiency without security risk.Furthermore,we design a key updating protocol based on our SKG scheme for OTP encryption.Simulation results verify that our scheme can generate keys securely and efficiently,and significantly improve the secure communication performance in an intelligent IoT system.
基金Supported by the National Natural Science Foundation of China (NSFC)(Grant Nos. 51725206 and 52072403)the NSFCUK-RI EPSRC (Grant No. 51861165201)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA21070500)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No. 2020006)the Beijing Municipal Natural Science Foundation (Grant No. 2212022)the Youth Innovation Promotion Association,Chinese Academy of Sciences (Grant No. 2020006)China Postdoctoral Science Foundation founded Project (Grant No. 2021M693367)。
文摘Na-ion batteries(NIBs) have been attracting growing interests in recent years with the increasing demand of energy storage owing to their dependence on more abundant Na than Li. The exploration of the industrialization of NIBs is also on the march, where some challenges are still limiting its step. For instance, the relatively low initial Coulombic efficiency(ICE) of anode can cause undesired energy density loss in the full cell. In addition to the strategies from the sight of materials design that to improve the capacity and ICE of electrodes, presodiation technique is another important method to efficiently offset the irreversible capacity and enhance the energy density. Meanwhile, the slow release of the extra Na during the cycling is able to improve the cycling stability.In this review, we would like to provide a general insight of presodiation technique for high-performance NIBs.The recent research progress including the principles and strategies of presodiation will be introduced, and some remaining challenges as well as our perspectives will be discussed. This review aims to exhibit the basic knowledge of presodiation to inspire the researchers for future studies.
文摘The editor of Chinese Physics B decided to organize a special topic on lithium batteries. We are sure the decision is very correct because one of the important tasks of physics is to serve the needs of society. Energy and environment are two related major problems facing mankind today. Physics has been dedicating itself to semiconductors for several decades. Now is the right time for physicists to study the problems related to new energy sources and related tools. Currently, it is most urgent to develop electric vehicles （EVs） and to develop renewable energies. The rechargeable battery is essential for both. Scientists and engineers have been racing to design smaller, cheaper and more efficient reclaargeable batteries to meet society＇s power storage needs.
