As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)inser...As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)insertion,resulting in inferior cycling and rate performance.To address these challenges,a yolk-shell structured Sb_(2)S_(3)confined in N,S co-doped hollow carbon nanorod(YS-Sb_(2)S_(3)@NSC)working as a viable anode for PIBs is proposed.As directly verified by in situ transmission electron microscopy(TEM),the buffer space between the Sb_(2)S_(3)core and thin carbon shell can effectively accommodate the large expansion stress of Sb_(2)S_(3)without cracking the shell and the carbon shell can accelerate electron transport and K^(+)diffusion,which plays a significant role in reinforcing the structural stability and facilitating charge transfer.As a result,the YS-Sb_(2)S_(3)@NSC electrode delivers a high reversible K^(+)storage capacity of 594.58 m A h g^(-1)at 0.1 A g^(-1)and a long cycle life with a slight capacity degradation(0.01%per cycle)for 2000 cycles at 1 A g^(-1)while maintaining outstanding rate capability.Importantly,utilizing in in situ/ex situ microscopic and spectroscopic characterizations,the origins of performance enhancement and K^(+)storage mechanism of Sb_(2)S_(3)were clearly elucidated.This work provides valuable insights into the rational design of high-performance and durable transition metal sulfides-based anodes for PIBs.展开更多
Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume ch...Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.展开更多
Ni-rich layered oxides are considered promising cathodes for advanced lithium-ion batteries(LIBs)in the future,owing to their high capacity and low cost.However,the issues on structural and interfacial stability of Ni...Ni-rich layered oxides are considered promising cathodes for advanced lithium-ion batteries(LIBs)in the future,owing to their high capacity and low cost.However,the issues on structural and interfacial stability of Ni-rich cathodes still pose substantial obstacles in the practical application of advanced LIBs.Here,we employ a one-step method to synthesize a B-doped and La_(4)NiLiO_(8)-coated LiNi_(0.82)5Co_(0.115)Mn_(0.06)O_(2)(BL-1)cathode with reliable structure and interface,for the first time.The La_(4)NiLiO_(8)coating layer can prevent cathodes from electrolyte assault and facilitate Li+diffusion kinetics.Moreover,B-doping can effectively restrain the pernicious H_(2)-H_(3) phase transition and adjust the orientation of primary particles to a radial alignment,which is obstructive to the arise of microcracks induced by the change of anisotropic volume.Specifically,when tested in pouch cells,the BL-1 cathode exhibits outstanding capacity retention of 93.49%after 500 cycles at 1 C.This dual-modification strategy dramatically enhances the stability of the structure and interface for Ni-rich cathode materials,consequently accelerating the commercialization process of high-energy–density LIBs.展开更多
A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m lo...A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.展开更多
Metal-based core-shell nanostructures have garnered enduring interest due to their unique properties and functionalities.However,their growth and transformation mechanisms in liquid media remain largely unknown becaus...Metal-based core-shell nanostructures have garnered enduring interest due to their unique properties and functionalities.However,their growth and transformation mechanisms in liquid media remain largely unknown because they lack direct observation of the dynamic growth process with high spatial and temporal resolution.Developing the in situ liquid cell transmission electron microscopy(TEM)technique offers unprecedented real-time imaging and spectroscopy capabilities to directly track the evolution of structural and chemical transformation of metal-based core–shell nanostructures in liquid media under their working condition.Here,this review highlights recent progress in utilizing in situ liquid cell TEM characterization technique in investigating the dynamic evolution of material structure and morphology of metal-based core–shell nanostructures at the nano/atomic scale in real-time.A brief introduction of the development of liquid cells for in situ TEM is first given.Subsequently,recent advances in in situ liquid cell TEM for the fundamental study of growth mechanisms of metal based core–shell nanostructures are discussed.Finally,the challenge and future developments of metalbased core–shell nanostructures for in situ liquid cell TEM are proposed.Our review is anticipated to inspire ongoing interest in revealing unseen growth dynamics of core–shell nanostructures by in situ liquid cell TEM technique.展开更多
The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In t...The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In this paper,we focus on the abnormal subsequence detection.The original definition of discord subsequences is defective for some kind of time series,in this paper we give a more robust definition which is based on the k nearest neighbors.We also donate a novel method for time series representation,it has better performance than traditional methods(like PAA/SAX)to represent the characteristic of some special time series.To speed up the process of abnormal subsequence detection,we used the clustering method to optimize the outer loop ordering and early abandon subsequence which is impossible to be abnormal.The experiment results validate that the algorithm is correct and has a high efficiency.展开更多
Silicon(Si)-based solid-state batteries(Si-SSBs)are attracting tremendous attention because of their high energy density and unprecedented safety,making them become promising candidates for next-generation energy stor...Silicon(Si)-based solid-state batteries(Si-SSBs)are attracting tremendous attention because of their high energy density and unprecedented safety,making them become promising candidates for next-generation energy storage systems.Nevertheless,the commercialization of Si-SSBs is significantly impeded by enormous challenges including large volume variation,severe interfacial problems,elusive fundamental mechanisms,and unsatisfied electrochemical performance.Besides,some unknown electrochemical processes in Si-based anode,solid-state electrolytes(SSEs),and Si-based anode/SSE interfaces are still needed to be explored,while an in-depth understanding of solid–solid interfacial chemistry is insufficient in Si-SSBs.This review aims to summarize the current scientific and technological advances and insights into tackling challenges to promote the deployment of Si-SSBs.First,the differences between various conventional liquid electrolyte-dominated Si-based lithium-ion batteries(LIBs)with Si-SSBs are discussed.Subsequently,the interfacial mechanical contact model,chemical reaction properties,and charge transfer kinetics(mechanical–chemical kinetics)between Si-based anode and three different SSEs(inorganic(oxides)SSEs,organic–inorganic composite SSEs,and inorganic(sulfides)SSEs)are systemically reviewed,respectively.Moreover,the progress for promising inorganic(sulfides)SSE-based Si-SSBs on the aspects of electrode constitution,three-dimensional structured electrodes,and external stack pressure is highlighted,respectively.Finally,future research directions and prospects in the development of Si-SSBs are proposed.展开更多
Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the explo...Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.展开更多
Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for ...Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for the lithium difluorophosphate(LiPO_(2)F_(2))solution as an effective film-forming additive via direct adding the Li_(2)CO_(3) into LiPF6 solution at 45℃.Benefiting from the significantly reduced interface resistance(RSEI)and charge transfer impedance(Rct)of both the cathode and anode by adding the prepared LiPO_(2)F_(2)solution into a baseline electrolyte,the cycling performance of the graphite||LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2) pouch cell is remarkably improved under all-climate condition.展开更多
Background:Antimicrobial resistance(AMR)is one of the top ten global public health challenges.However,given the lack of a comprehensive assessment of worldwide AMR status,our objective is to develop a One Health-based...Background:Antimicrobial resistance(AMR)is one of the top ten global public health challenges.However,given the lack of a comprehensive assessment of worldwide AMR status,our objective is to develop a One Health-based system-wide evaluation tool on global AMR.Methods:We have further developed the three-hierarchical Global One Health Index(GOHI)-AMR indicator scheme,which consists of five key indicators,17 indicators,and 49 sub-indicators,by incorporating 146 countries'data from diverse authoritative databases,including WHO's Global Antimicrobial Resistance and Use Surveillance System(GLASS)and the European CDC.We investigated the overall-or sub-rankings of GOHI-AMR at the international/regional/national levels for data preprocessing and score calculation utilizing the existing GOHI methodology.Additionally,a correlation analysis was conducted between the GOHI-AMR and other socioeconomic factors.Results:The average GOHI-AMR score for 146 countries is 38.45.As expected,high-income countries(HICs)outperform the other three income groups on overall rankings and all five key indicators of GOHI-AMR,whereas lowincome countries unexpectedly outperform upper-middle-income countries and lower-middle-income countries on the antibiotics-resistant key indicator(ARR)and ARR-subordinate indicators,including carbapenem-,β-lactam-,and quinolone resistance,and even HICs on aminoglycoside resistance.There were no significant differences among the four groups on the environmental-monitoring indicator(P>0.05).GOHI-AMR was positively correlated with gross domestic product,life expectancy,and AMR-related publications,but negatively with natural growth rate and chronic respiratory disease.In contrast to Cyprus,the remarkably lower prevalence of"ESKAPE pathogens"in high-scoring Sweden and Denmark highlights Europe's huge gaps.China and Russia outperformed the other three BRICS countries on all key indicators,particularly India's ARR and Brazil's AMR laboratory network and coordination capacity.Furthermore,significant internal disparities in carbapenem-resistant Klebsiella pneumoniae(CRKP)and methicillin-resistant Staphylococcus aureus(MRSA)prevalence were observed between China and the USA,with MRSA prevalence both gradually declining,whereas CRKP prevalence has been declining in the USA but increasing in China,consistent with higher carbapenems-related indicator'performance in USA.Conclusions:GOHI-AMR is the most comprehensive tool currently available for the assessment of AMR status worldwide.We discovered unique features impacting AMR in each country and offered precise recommendations to improve the capacity to tackle AMR in low-ranking countries.展开更多
The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a signific...The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a significant challenge.Here,we report using in situ liquid cell transmission electron microscopy(TEM)to directly capture the dynamic nucleation process and track the real-time growth pathway of hcp Ni nanocrystals at the atomic scale.It is demonstrated that the growth of amorphous-phase-mediated hcp Ni nanocrystals is from the metal-rich liquid phases.In addition,the reshaped preatomic facet development of a single nanocrystal is also imaged.Theoretical calculations further identify the non-classical features of hcp Ni crystallization.These discoveries could enrich the nucleation and growth model theory and provide useful information for the rational design of synthesis pathways of hcp nanocrystals.展开更多
The modern aircraft Thermal Management System(TMS)faces significant challenges due to increasing thermal loads and limited heat dissipation pathways.To optimize TMS during the conceptual design stage,the development o...The modern aircraft Thermal Management System(TMS)faces significant challenges due to increasing thermal loads and limited heat dissipation pathways.To optimize TMS during the conceptual design stage,the development of a modeling and simulation tool is crucial.In this study,a TMS simulation model library was created using MATLAB/SIMULINK.To simplify the complexity of the Vapor Cycle System(VCS)model,a Response Surface Model(RSM)was constructed using the Monte Carlo method and validated through simulation experiments.Taking the F-22 fighter TMS as an example,a thermal dynamic simulation model was constructed to analyze the variation of thermal response parameters in key subsystems and elucidate their coupling relationships.Furthermore,the impact of total fuel flow and ram air flow on the TMS was investigated.The findings demonstrate the existence of an optimal total fuel flow that achieves a balance between maximizing fuel heat sink utilization and minimizing bleed air demand.The adaptive distribution of fuel and ram air flow was found to enhance aircraft thermal management performance.This study contributes to improving modeling efficiency and enhancing the understanding of the thermal dynamic characteristics of TMS,thereby facilitating further optimization in aircraft TMS design.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.52072323 and 52122211)the"Double-First Class"Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen Universitythe State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Grant No.LAPS22005)。
文摘As promising anode candidates for potassium-ion batteries(PIBs),antimony sulfide(Sb_(2)S_(3))possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K^(+)insertion,resulting in inferior cycling and rate performance.To address these challenges,a yolk-shell structured Sb_(2)S_(3)confined in N,S co-doped hollow carbon nanorod(YS-Sb_(2)S_(3)@NSC)working as a viable anode for PIBs is proposed.As directly verified by in situ transmission electron microscopy(TEM),the buffer space between the Sb_(2)S_(3)core and thin carbon shell can effectively accommodate the large expansion stress of Sb_(2)S_(3)without cracking the shell and the carbon shell can accelerate electron transport and K^(+)diffusion,which plays a significant role in reinforcing the structural stability and facilitating charge transfer.As a result,the YS-Sb_(2)S_(3)@NSC electrode delivers a high reversible K^(+)storage capacity of 594.58 m A h g^(-1)at 0.1 A g^(-1)and a long cycle life with a slight capacity degradation(0.01%per cycle)for 2000 cycles at 1 A g^(-1)while maintaining outstanding rate capability.Importantly,utilizing in in situ/ex situ microscopic and spectroscopic characterizations,the origins of performance enhancement and K^(+)storage mechanism of Sb_(2)S_(3)were clearly elucidated.This work provides valuable insights into the rational design of high-performance and durable transition metal sulfides-based anodes for PIBs.
基金supported by the National Natural Science Foundation of China(Grants No.21703185)the leading Project Foundation of Science Department of Fujian Province(Grants No.2018H0034)+1 种基金Fundamental Research Funds for the Central Universities(Xiamen University:20720170042)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University。
文摘Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.
基金financially supported by the National Natural Science Foundation of China(51774051,52072323,52122211)the Science and Technology Planning Project of Hunan Province(2019RS2034)+1 种基金the Hunan High-tech Industry Science and Technology Innovation Leading Plan(2020GK2072)the Changsha City Fund for Distinguished and Innovative Young Scholars(KQ1707014)。
文摘Ni-rich layered oxides are considered promising cathodes for advanced lithium-ion batteries(LIBs)in the future,owing to their high capacity and low cost.However,the issues on structural and interfacial stability of Ni-rich cathodes still pose substantial obstacles in the practical application of advanced LIBs.Here,we employ a one-step method to synthesize a B-doped and La_(4)NiLiO_(8)-coated LiNi_(0.82)5Co_(0.115)Mn_(0.06)O_(2)(BL-1)cathode with reliable structure and interface,for the first time.The La_(4)NiLiO_(8)coating layer can prevent cathodes from electrolyte assault and facilitate Li+diffusion kinetics.Moreover,B-doping can effectively restrain the pernicious H_(2)-H_(3) phase transition and adjust the orientation of primary particles to a radial alignment,which is obstructive to the arise of microcracks induced by the change of anisotropic volume.Specifically,when tested in pouch cells,the BL-1 cathode exhibits outstanding capacity retention of 93.49%after 500 cycles at 1 C.This dual-modification strategy dramatically enhances the stability of the structure and interface for Ni-rich cathode materials,consequently accelerating the commercialization process of high-energy–density LIBs.
基金supported by Comprehensive Research Facility for Fusion Technology Program of China (No. 2018000052-73-01001228)the Youth Innovation Promotion Association CAS (No. 2018484)
文摘A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.
基金financially supported by the National Natural Science Foundation of China(22001083,52072323,52122211)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University。
文摘Metal-based core-shell nanostructures have garnered enduring interest due to their unique properties and functionalities.However,their growth and transformation mechanisms in liquid media remain largely unknown because they lack direct observation of the dynamic growth process with high spatial and temporal resolution.Developing the in situ liquid cell transmission electron microscopy(TEM)technique offers unprecedented real-time imaging and spectroscopy capabilities to directly track the evolution of structural and chemical transformation of metal-based core–shell nanostructures in liquid media under their working condition.Here,this review highlights recent progress in utilizing in situ liquid cell TEM characterization technique in investigating the dynamic evolution of material structure and morphology of metal-based core–shell nanostructures at the nano/atomic scale in real-time.A brief introduction of the development of liquid cells for in situ TEM is first given.Subsequently,recent advances in in situ liquid cell TEM for the fundamental study of growth mechanisms of metal based core–shell nanostructures are discussed.Finally,the challenge and future developments of metalbased core–shell nanostructures for in situ liquid cell TEM are proposed.Our review is anticipated to inspire ongoing interest in revealing unseen growth dynamics of core–shell nanostructures by in situ liquid cell TEM technique.
文摘The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In this paper,we focus on the abnormal subsequence detection.The original definition of discord subsequences is defective for some kind of time series,in this paper we give a more robust definition which is based on the k nearest neighbors.We also donate a novel method for time series representation,it has better performance than traditional methods(like PAA/SAX)to represent the characteristic of some special time series.To speed up the process of abnormal subsequence detection,we used the clustering method to optimize the outer loop ordering and early abandon subsequence which is impossible to be abnormal.The experiment results validate that the algorithm is correct and has a high efficiency.
基金supported by the National Natural Science Foundation of China(Grants Nos.52072323,52122211 and 21875155)the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Grant No.LAPS22005)+3 种基金the Frontier Exploration Projects of Longmen Laboratory(Grant No.LMQYTSKT008)the Shenzhen Technical Plan Project(No.JCYJ20220818101003008)the support of High-Tech Industrialization Project of Tan Kah Kee Innovation Laboratory(Grant No.RD2021010101)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University.L.Zhang and Q.Zhang acknowledge the support of the Nanqiang Young Top-notch Talent Fellowship at Xiamen University.
文摘Silicon(Si)-based solid-state batteries(Si-SSBs)are attracting tremendous attention because of their high energy density and unprecedented safety,making them become promising candidates for next-generation energy storage systems.Nevertheless,the commercialization of Si-SSBs is significantly impeded by enormous challenges including large volume variation,severe interfacial problems,elusive fundamental mechanisms,and unsatisfied electrochemical performance.Besides,some unknown electrochemical processes in Si-based anode,solid-state electrolytes(SSEs),and Si-based anode/SSE interfaces are still needed to be explored,while an in-depth understanding of solid–solid interfacial chemistry is insufficient in Si-SSBs.This review aims to summarize the current scientific and technological advances and insights into tackling challenges to promote the deployment of Si-SSBs.First,the differences between various conventional liquid electrolyte-dominated Si-based lithium-ion batteries(LIBs)with Si-SSBs are discussed.Subsequently,the interfacial mechanical contact model,chemical reaction properties,and charge transfer kinetics(mechanical–chemical kinetics)between Si-based anode and three different SSEs(inorganic(oxides)SSEs,organic–inorganic composite SSEs,and inorganic(sulfides)SSEs)are systemically reviewed,respectively.Moreover,the progress for promising inorganic(sulfides)SSE-based Si-SSBs on the aspects of electrode constitution,three-dimensional structured electrodes,and external stack pressure is highlighted,respectively.Finally,future research directions and prospects in the development of Si-SSBs are proposed.
基金This work was supported by the National Key R&D Program of China(Grant No.2018YFB1304902)the National Natural Science Foundation of China(Grant Nos.12004034,U1813211,22005247,11904372,51502007,52072323,52122211,12174019,and 51972058)+1 种基金the Gen-eral Research Fund of Hong Kong(Project No.11217221)China Postdoctoral Science Foundation Funded Project(Grant No.2021M690386).
文摘Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.
基金National Natural Science Foundation of China(Nos.21935009,21761132030 and 21621091)National Key Research and Development Program of China(No.2018YFB0905400)the Doctoral Research Foundation of Binzhou University(No.2016Y06)。
文摘Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for the lithium difluorophosphate(LiPO_(2)F_(2))solution as an effective film-forming additive via direct adding the Li_(2)CO_(3) into LiPF6 solution at 45℃.Benefiting from the significantly reduced interface resistance(RSEI)and charge transfer impedance(Rct)of both the cathode and anode by adding the prepared LiPO_(2)F_(2)solution into a baseline electrolyte,the cycling performance of the graphite||LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2) pouch cell is remarkably improved under all-climate condition.
文摘Background:Antimicrobial resistance(AMR)is one of the top ten global public health challenges.However,given the lack of a comprehensive assessment of worldwide AMR status,our objective is to develop a One Health-based system-wide evaluation tool on global AMR.Methods:We have further developed the three-hierarchical Global One Health Index(GOHI)-AMR indicator scheme,which consists of five key indicators,17 indicators,and 49 sub-indicators,by incorporating 146 countries'data from diverse authoritative databases,including WHO's Global Antimicrobial Resistance and Use Surveillance System(GLASS)and the European CDC.We investigated the overall-or sub-rankings of GOHI-AMR at the international/regional/national levels for data preprocessing and score calculation utilizing the existing GOHI methodology.Additionally,a correlation analysis was conducted between the GOHI-AMR and other socioeconomic factors.Results:The average GOHI-AMR score for 146 countries is 38.45.As expected,high-income countries(HICs)outperform the other three income groups on overall rankings and all five key indicators of GOHI-AMR,whereas lowincome countries unexpectedly outperform upper-middle-income countries and lower-middle-income countries on the antibiotics-resistant key indicator(ARR)and ARR-subordinate indicators,including carbapenem-,β-lactam-,and quinolone resistance,and even HICs on aminoglycoside resistance.There were no significant differences among the four groups on the environmental-monitoring indicator(P>0.05).GOHI-AMR was positively correlated with gross domestic product,life expectancy,and AMR-related publications,but negatively with natural growth rate and chronic respiratory disease.In contrast to Cyprus,the remarkably lower prevalence of"ESKAPE pathogens"in high-scoring Sweden and Denmark highlights Europe's huge gaps.China and Russia outperformed the other three BRICS countries on all key indicators,particularly India's ARR and Brazil's AMR laboratory network and coordination capacity.Furthermore,significant internal disparities in carbapenem-resistant Klebsiella pneumoniae(CRKP)and methicillin-resistant Staphylococcus aureus(MRSA)prevalence were observed between China and the USA,with MRSA prevalence both gradually declining,whereas CRKP prevalence has been declining in the USA but increasing in China,consistent with higher carbapenems-related indicator'performance in USA.Conclusions:GOHI-AMR is the most comprehensive tool currently available for the assessment of AMR status worldwide.We discovered unique features impacting AMR in each country and offered precise recommendations to improve the capacity to tackle AMR in low-ranking countries.
基金supported by the National Natural Science Foundation of China(Nos.22001083,52072323,and 52122211)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University.J.Y.L.thanks the Research Startup Fund from Harbin Institute of Technology(Shenzhen)with the project number University(No.20210028)the Shenzhen Steady Support Plan(No.GXWD20201230155427003-20200824103000001).
文摘The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a significant challenge.Here,we report using in situ liquid cell transmission electron microscopy(TEM)to directly capture the dynamic nucleation process and track the real-time growth pathway of hcp Ni nanocrystals at the atomic scale.It is demonstrated that the growth of amorphous-phase-mediated hcp Ni nanocrystals is from the metal-rich liquid phases.In addition,the reshaped preatomic facet development of a single nanocrystal is also imaged.Theoretical calculations further identify the non-classical features of hcp Ni crystallization.These discoveries could enrich the nucleation and growth model theory and provide useful information for the rational design of synthesis pathways of hcp nanocrystals.
文摘The modern aircraft Thermal Management System(TMS)faces significant challenges due to increasing thermal loads and limited heat dissipation pathways.To optimize TMS during the conceptual design stage,the development of a modeling and simulation tool is crucial.In this study,a TMS simulation model library was created using MATLAB/SIMULINK.To simplify the complexity of the Vapor Cycle System(VCS)model,a Response Surface Model(RSM)was constructed using the Monte Carlo method and validated through simulation experiments.Taking the F-22 fighter TMS as an example,a thermal dynamic simulation model was constructed to analyze the variation of thermal response parameters in key subsystems and elucidate their coupling relationships.Furthermore,the impact of total fuel flow and ram air flow on the TMS was investigated.The findings demonstrate the existence of an optimal total fuel flow that achieves a balance between maximizing fuel heat sink utilization and minimizing bleed air demand.The adaptive distribution of fuel and ram air flow was found to enhance aircraft thermal management performance.This study contributes to improving modeling efficiency and enhancing the understanding of the thermal dynamic characteristics of TMS,thereby facilitating further optimization in aircraft TMS design.