With the rapid development of twodimensional MXene materials,numerous preparation strategies have been proposed to enhance synthesis efficiency,mitigate environmental impact,and enable scalability for large-scale prod...With the rapid development of twodimensional MXene materials,numerous preparation strategies have been proposed to enhance synthesis efficiency,mitigate environmental impact,and enable scalability for large-scale production.The compound etching approach,which relies on cationic oxidation of the A element of MAX phase precursors while anions typically adsorb onto MXene surfaces as functional groups,remains the main prevalent strategy.By contrast,synthesis methodologies utilizing elemental etching agents have been rarely reported.Here,we report a new elemental tellurium(Te)-based etching strategy for the preparation of MXene materials with tunable surface chemistry.By selectively removing the A-site element in MAX phases using Te,our approach avoids the use of toxic fluoride reagents and achieves tellurium-terminated surface groups that significantly enhance sodium storage performance.Experimental results show that Te-etched MXene delivers substantially higher capacities(exceeding 50%improvement over conventionally etched MXene)with superior rate capability,retaining high capacity at large current densities and demonstrating over 90%capacity retention after 1000 cycles.This innovative synthetic strategy provides new insight into controllable MXene preparation and performance optimization,while the as-obtained materials hold promises for high-performance sodium-ion batteries and other energy storage systems.展开更多
金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环...金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环稳定性和安全性都较差,限制了其应用推广。我们前期通过构建金属锂-碳纳米管(Li-CNT)复合结构,极大的提高了金属锂的比表面积,降低了电极电流密度,从而有效地抑制了锂枝晶的生长,提高了金属锂电极的循环稳定性和安全性能。本工作在前期工作基础上,采用简单的液相反应,利用4-氟苯乙烯(FPS)对Li-CNT进行表面修饰并进行原位聚合,得到了表面富含氟化锂(Li F)保护层的Li-CNT(FPS-Li-CNT)。该表面修饰层能够有效抑制电解液和空气对Li-CNT的侵蚀,显著的提高了LiCNT电极的界面稳定性。FPS-Li-CNT与磷酸铁锂正极(LFP)组成的LFP||FPS-Li-CNT全电池,在正负极容量配比为1:6条件下,能够稳定循环280圈,库伦效率达到97.7%。展开更多
Modal analysis,which provides modal parameters including frequencies,damping ratios,and mode shapes,is essential for assessing structural safety in structural health monitoring.Automated operational modal analysis(AOM...Modal analysis,which provides modal parameters including frequencies,damping ratios,and mode shapes,is essential for assessing structural safety in structural health monitoring.Automated operational modal analysis(AOMA)offers a promising alternative to traditional methods that depend heavily on human intervention and engineering judgment.However,estimating structural dynamic properties and managing spurious modes remain challenging due to uncertainties in practical application conditions.To address this issue,we propose an automated modal identification approach comprising three key aspects:(1)identification of modal parameters using covariance-driven stochastic subspace identification;(2)automated interpretation of the stabilization diagram;(3)an improved self-adaptive algorithm for grouping physical modes based on ordering points to identify the clustering structure(OPTICS)combined with k-nearest neighbors(KNN).The proposed approach can play a crucial role in enabling real-time structural health monitoring without human intervention.A simulated 10-story shear frame was used to verify the methodology.Identification results from a cable-stayed bridge demonstrate the practicality of the proposed method for conducting AOMA in engineering practice.The proposed approach can automatically identify modal parameters with high accuracy,making it suitable for a real-time structural health monitoring framework.展开更多
Integrating high-nickel layered oxide cathodes with aqueous slurry electrode preparation routes holds the potential to simultaneously meet the demands for high energy density and low-cost production of lithium-ion bat...Integrating high-nickel layered oxide cathodes with aqueous slurry electrode preparation routes holds the potential to simultaneously meet the demands for high energy density and low-cost production of lithium-ion batteries.However,the influence of dual exposure to air and liquid water as well as the heating treatment during aqueous slurry electrode processing on the high-nickel layered oxide electrode is yet to be understood.In this study,we systematically investigate the structural evolution and electro-chemical behaviors when LiNi_(0.83)Mn_(0.05)Co_(0.12)O_(2)(NMC83)is subjected to aqueous slurry processing.It was observed that the crystal structure near the surface of NMC83 is partially reconstructed to contain a mixture of rock-salt and layered phases when exposed to water,leading to the deteriorated rate capability of the NMC83 electrodes.This partial surface reconstruction layer completely converts into a pure rock-salt phase upon cycling,accompanied by the release of O_(2),Ni leaching,catalyzed decomposition of the electrolyte,and the formation of a thick cathode electrolyte interphase layer.The byproducts of the electrolyte and dissolved Ni could shuttle to the Li metal side,causing a crosstalk effect that results in a thick and unstable solid electrolyte interphase layer on the Li surface.These in combination severely undermined the cycling stability of the NMC83 electrodes obtained from the aqueous slurry.A mitigation strategy using molecular self-assembly technique was demonstrated to enhance the surface stability of water-treated NMC83.Our findings offer new insights for tailoring ambient environment stability and aqueous slurry processability for ultra-high nickel layered oxide and other water-sensitive cathode materials.展开更多
Metal sulphide electrocatalyst is considered as one of the most promising low-cost candidates for oxygen evolution reaction(OER).In this work,we report a novel free-standing Cu2S branch array via a facile TiO2-induced...Metal sulphide electrocatalyst is considered as one of the most promising low-cost candidates for oxygen evolution reaction(OER).In this work,we report a novel free-standing Cu2S branch array via a facile TiO2-induced electrodeposition-sulfurization method.Interestingly,cross-linked Cu2S nanoflake branch is strongly anchored on the TiO2 backbone forming high-quality Cu2S/TiO2/Cu2S core-branch arrays.The branch formation mechanism is also proposed.As compared to the pure Cu2S nanowire arrays,the asprepared Cu2S/TiO2/Cu2S core-branch arrays show much better alkaline OER performance with lower overpotential(284 mV at 10 mA cm^-2)and smaller Tafel slope(72 dec-1)as well as enhanced longterm durability mainly due to larger exposed area and more active electrocatalytic sites.Our work provides a new way for construction of advanced metal sulphide electrocatalysts for electrochemical energy conversion.展开更多
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
Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid el...Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid electrolytes.Therefore,continuous efforts have been put into improving the cycling Coulombic efficiency(CE)to extend the lifespan of the lithium metal negative electrode.Herein,we report that using dual-salt additives of LiPF_(6) and LiNO_(3) in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon(Li-CNT)composite.As a result,an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm^(-2) and an negative electrode to positive electrode capacity(N/P)ratio of 2.The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether.The former component mainly originates from the decomposition of the LiNO_(3) additive,while the latter comes from the LiPF_(6)-induced ring-opening polymerization of the ether solvent.This novel surface chemistry significantly improves the CE of Li negative electrode,revealing its importance for the practical application of lithium metal batteries.展开更多
P2-type sodium layered oxide cathode (Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)P2-NNMO) has attracted great attention as a promising cathode material for sodium ion batteries because of its high specific capacity. However, this m...P2-type sodium layered oxide cathode (Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)P2-NNMO) has attracted great attention as a promising cathode material for sodium ion batteries because of its high specific capacity. However, this material suffers from a rapid capacity fade during high-voltage cycling. Several mechanisms have been proposed to explain the capacity fade, including intragranular fracture caused by the P2-O2 phase transion, surface structural change, and irreversible lattice oxygen release. Here we systematically investigated the morphological, structural, and chemical changes of P2-NNMO during high-voltage cycling using a variety of characterization techniques. It was found that the lattice distortion and crystal-plane buckling induced by the P2-O2 phase transition slowed down the Na-ion transport in the bulk and hindered the extraction of the Na ions. The sluggish kinetics was the main reason in reducing the accessible capacity while other interfacial degradation mechanisms played minor roles. Our results not only enabled a more complete understanding of the capacity-fading mechanism of P2-NNMO but also revealed the underlying correlations between lattice doping and the moderately improved cycle performance.展开更多
High-perfo rmance anodes of sodium ion batteries(SIBs)largely depends on rational architecture design and binder-free smart hybridization.Herein,we report TiC/C core/shell nanowires arrays prepared by a one-step chemi...High-perfo rmance anodes of sodium ion batteries(SIBs)largely depends on rational architecture design and binder-free smart hybridization.Herein,we report TiC/C core/shell nanowires arrays prepared by a one-step chemical vapor deposition(CVD)method and apply it as the anode of SIBs for the first time.The conductive TiC core is intimately decorated with carbon shell.The as-obtained TiC/C nanowires are homogeneously grown on the substrate and show core/shell heterostructure and porous architecture with high electronic conductivity and reinforced stability.Owing to these merits,the TiC/C electrode displays good rate performance and outstanding cycling performance with a capacity of 135.3 mAh/g at 0.1 A/g and superior capacity retention of 90.14%after 1000 cycles at 2 A/g.The reported strategy would provide a promising way to construct binder-free arrays electrodes for sodium ion storage.展开更多
Contrary to conventional design methods that assume uniform and slow temperature changes tied to atmospheric conditions,single-layer spherical reticulated shells undergo significant non-uniform and time-variant temper...Contrary to conventional design methods that assume uniform and slow temperature changes tied to atmospheric conditions,single-layer spherical reticulated shells undergo significant non-uniform and time-variant temperature variations due to dynamic environmental coupling.These differences can affect structural performance and pose safety risks.Here,a systematic numerical method was developed and applied to simulate long-term temperature variations in such a structure under real environmental conditions,revealing its non-uniform distribution characteristics and time-variant regularity.A simplified design method for non-uniform thermal loads,accounting for time-variant environmental factors,was theoretically derived and validated through experiments and simulations.The maximum deviation and mean error rate between calculated and tested results were 6.1℃ and 3.7%,respectively.Calculated temperature fields aligned with simulated ones,with deviations under 6.0℃.Using the design method,non-uniform thermal effects of the structure are analyzed.Maximum member stress and nodal displacement under non-uniform thermal loads reached 119.3 MPa and 19.7 mm,representing increases of 167.5%and 169.9%,respectively,compared to uniform thermal loads.The impacts of healing construction time on non-uniform thermal effects were evaluated,resulting in construction recommendations.The methodologies and conclusions presented here can serve as valuable references for the thermal design,construction,and control of single-layer spherical reticulated shells or similar structures.展开更多
B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)t...B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)to facilitate the rapid Li+migration.Nevertheless,its wide-temperature application has been limited by the instability of B-derived CEI layer at high temperature.Herein,dual electrolyte additives,consisting of lithium tetraborate(Li_(2)TB)and 2,4-difluorobiphenyl(FBP),are proposed to boost the widetemperature performances of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM)cathode.Theoretical calculation and electrochemical performances analyses indicate that Li_(2)TB and FBP undergo successive decomposition to form a unique dual-layer CEI.FBP acts as a synergistic filming additive to Li_(2)TB,enhancing the hightemperature performance of NCM cathode while preserving the excellent low-temperature cycle stability and the superior rate capability conferred by Li_(2)TB additive.Therefore,the capacity retention of NCM‖Li cells using optimal FBP-Li_(2)TB dual electrolyte additives increases to 100%after 200 cycles at-10℃,99%after 200 cycles at 25℃,and 83%after 100 cycles at 55℃,respectively,much superior to that of base electrolyte(63%/69%/45%).More surprisingly,galvanostatic c ha rge/discharge experiments at different temperatures reveal that NCM‖Li cells using FBP-Li_(2)TB additives can operate at temperatures ranging from-40℃to 60℃.This synergistic interphase modification utilizing dual electrolyte additives to construct a unique dual-layer CEI adaptive to a wide temperature range,provides valuable insights to the practical applications of NCM cathodes for all-climate batteries.展开更多
Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Bu...Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Butyrolactone(GBL)has emerged as a promising solvent;however,its incompatibility with graphite anode has hindered its application.This limitation necessitates a comprehensive investigation into the underlying mechanisms and potential solutions.In this study,we achieve a molecular-level understanding of the perplexing interphase formation process by employing in-situ spectroelectrochemical techniques and density function calculations.Our findings reveal that,even at high salt concentrations,GBL consistently occupies the primary Li^(+)solvation sheath,leading to extensive GBL decomposition and the formation of a high-impedance and inorganic-poor solid-electrolyte interphase(SEI)layer.Contrary to manipulating solvation structures,our research demonstrates that the utilization of filmforming additives with higher reduction potential facilitates the pre-establishment of a robust SEI film on the graphite anode.This approach effectively inhibits GBL decomposition and significantly enhances the battery's lifespan.This study provides the first reported intrinsic understanding of the unique GBLgraphite incompatibility and offers valuable insights for the development of wide-temperature and high-safety LIBs.展开更多
The authors regret that the Fig.S3 in supporting information of this published article needs to be revised.And the BET values are correct and unaffected.All the conclusions in the manuscript are unaffected by this uni...The authors regret that the Fig.S3 in supporting information of this published article needs to be revised.And the BET values are correct and unaffected.All the conclusions in the manuscript are unaffected by this unintentional error.展开更多
Ni-rich layered oxide cathode materials,such as LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM811),exhibit high specific capacity and low cost,and become cathode material preference of high-energy-density Li-ion batteries.How...Ni-rich layered oxide cathode materials,such as LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM811),exhibit high specific capacity and low cost,and become cathode material preference of high-energy-density Li-ion batteries.However,these cathode materials are not stable and will form Li-poor reconstructed layers and alkaline compounds(Li_(2)CO_(3),LiOH)on the surface during the storage and processing in humid air,resulting in serious deterioration of electrochemical properties.During the past two decades,the consensus on the surface instability mechanism during humid air storage has not been reached.The main controversy focuses on the unstable octahedron mechanism and the Li/H exchange mechanism.Herein,we investigate the instability mechanism in the humid air by conducting scanning electronic microscopy,scanning transmission electron microscopy,and x-ray photoelectron spectroscopy analysis on NCM811 samples stored in designed atmospheres,etc.,and realize that the surface instability of the NCM811 during storage should be mainly originated from Li/H exchange when it contacts with moisture.展开更多
Solid-state batteries(SSBs)are considered as the next-generation battery technology,poised to deliver both high energy and enhanced safety.Nonetheless,their transition from laboratory to market is impeded by several c...Solid-state batteries(SSBs)are considered as the next-generation battery technology,poised to deliver both high energy and enhanced safety.Nonetheless,their transition from laboratory to market is impeded by several critical challenges.Among these,the solid–solid interfaces within SSBs represent a bottleneck,characterized by issues such as poor physical contact,side reactions,temporal separation,and sluggish charge carrier transfer.Developing key materials to construct the efficient solid–solid interface is critical for building high-performance SSBs.Organic mixed ionic–electronic conductors(OMIECs)have emerged as a promising alternative to conventional conductors in addressing the abovementioned issues owing to their intrinsic properties,including the capability of conducting both ions and electrons,mechanical flexibility,and structural designability.This review will first elucidate the necessity of the integration of OMIECs in SSBs.Next,a comprehensive exploration of the composition,preparation methods,key advantages,and basic characterizations of OMIECs is presented.This review then delves into recent research progress on OMIECs in SSBs,with a special focus on their application in cathode coating layers,the creation of a 3D mixed conductive framework for Li hosting,and their integration as inner layers in Li anodes.Conclusively,potential future applications and innovative designs of OMIECs are discussed.展开更多
Owing to their advantages such as high energy density and excellent cycle performance,lithium-ion batteries have occupied a dominant position for many years in the fields of consumer electronics,energy storage,and new...Owing to their advantages such as high energy density and excellent cycle performance,lithium-ion batteries have occupied a dominant position for many years in the fields of consumer electronics,energy storage,and new energy vehicles.Graphite is the most widely commercialized anode material because of its stable layered structure,excellent electrical conductivity,and cost-effectiveness.However,its inherent limitations,notably its relatively low theoretical specific capacity(372 mAh/g)and sluggish intrinsic ion diffusion kinetics,pose significant challenges to the development of high-energy and power density battery systems.This article briefly introduces the intercalation and failure mechanisms of graphite anode materials,reviews the research progress in the bulk and surface regulation of these materials,and discusses their future development prospects.展开更多
Organic-based electrode materials for lithium-ion batteries (LIBs) are promising due to their high theoretical capacity,structure versatility and environmental benignity.However,the poor intrinsic electric conductivit...Organic-based electrode materials for lithium-ion batteries (LIBs) are promising due to their high theoretical capacity,structure versatility and environmental benignity.However,the poor intrinsic electric conductivity of most polymers results in slow reaction kinetics and hinders their application as electrode materials for LIBs.A binder-free self-supporting organic electrode with excellent redox kinetics is herein demonstrated via in situ polymerization of a uniform thin polyimide (PI) layer on a porous and highly conductive carbonized nanofiber (CNF) framework.The PI active material in the porous PI@CNF film has large physical contact area with both the CNF and the electrolyte thus obtains superior electronic and ionic conduction.As a result,the PI@CNF cathode exhibits a discharge capacity of 170 mAh·g^-1 at 1 C (175 mA·g^-1),remarkable rate-performance (70.5% of 0.5 C capacity can be obtained at a 100 C discharge rate),and superior cycling stability with 81.3% capacity retention after 1,000 cycles at 1 C.Last but not least,a four-electron transfer redox process of the PI polymer was realized for the first time thanks to the excellent redox kinetics of the PI@CNF electrode,showing a discharge capacity exceeding 300 mAh·g^-1 at a current of 175 mA·g^-1.展开更多
基金supported by the National Natural Science Foundation of China(52472228,22309202)Natural Science Foundation of Sichuan Province(2023NSFSC1942)the Gusu Leading Talents Program(ZXL2023190)。
文摘With the rapid development of twodimensional MXene materials,numerous preparation strategies have been proposed to enhance synthesis efficiency,mitigate environmental impact,and enable scalability for large-scale production.The compound etching approach,which relies on cationic oxidation of the A element of MAX phase precursors while anions typically adsorb onto MXene surfaces as functional groups,remains the main prevalent strategy.By contrast,synthesis methodologies utilizing elemental etching agents have been rarely reported.Here,we report a new elemental tellurium(Te)-based etching strategy for the preparation of MXene materials with tunable surface chemistry.By selectively removing the A-site element in MAX phases using Te,our approach avoids the use of toxic fluoride reagents and achieves tellurium-terminated surface groups that significantly enhance sodium storage performance.Experimental results show that Te-etched MXene delivers substantially higher capacities(exceeding 50%improvement over conventionally etched MXene)with superior rate capability,retaining high capacity at large current densities and demonstrating over 90%capacity retention after 1000 cycles.This innovative synthetic strategy provides new insight into controllable MXene preparation and performance optimization,while the as-obtained materials hold promises for high-performance sodium-ion batteries and other energy storage systems.
文摘金属锂负极由于比容量高(3860 mAh·g^(-1))及氧化还原电位极低(-3.04 V vs.标准氢气电极(SHE)),被认为是实现高能量密度锂电池的理想负极。然而,金属锂电极与电解液反应剧烈,且锂离子在电极表面沉积不均匀容易产生枝晶,导致其循环稳定性和安全性都较差,限制了其应用推广。我们前期通过构建金属锂-碳纳米管(Li-CNT)复合结构,极大的提高了金属锂的比表面积,降低了电极电流密度,从而有效地抑制了锂枝晶的生长,提高了金属锂电极的循环稳定性和安全性能。本工作在前期工作基础上,采用简单的液相反应,利用4-氟苯乙烯(FPS)对Li-CNT进行表面修饰并进行原位聚合,得到了表面富含氟化锂(Li F)保护层的Li-CNT(FPS-Li-CNT)。该表面修饰层能够有效抑制电解液和空气对Li-CNT的侵蚀,显著的提高了LiCNT电极的界面稳定性。FPS-Li-CNT与磷酸铁锂正极(LFP)组成的LFP||FPS-Li-CNT全电池,在正负极容量配比为1:6条件下,能够稳定循环280圈,库伦效率达到97.7%。
基金supported by the National Natural Science Foundation of China(No.52408200)the Natural Science Foundation of Jiangsu Province(No.BK20240996)+1 种基金China,the Suzhou Science and Technology Plan(Basic Research)Project(No.SJC2023002)China,and the Natural Science Research Projects of Colleges and Universities in Jiangsu Province(No.24KJB560022),China.
文摘Modal analysis,which provides modal parameters including frequencies,damping ratios,and mode shapes,is essential for assessing structural safety in structural health monitoring.Automated operational modal analysis(AOMA)offers a promising alternative to traditional methods that depend heavily on human intervention and engineering judgment.However,estimating structural dynamic properties and managing spurious modes remain challenging due to uncertainties in practical application conditions.To address this issue,we propose an automated modal identification approach comprising three key aspects:(1)identification of modal parameters using covariance-driven stochastic subspace identification;(2)automated interpretation of the stabilization diagram;(3)an improved self-adaptive algorithm for grouping physical modes based on ordering points to identify the clustering structure(OPTICS)combined with k-nearest neighbors(KNN).The proposed approach can play a crucial role in enabling real-time structural health monitoring without human intervention.A simulated 10-story shear frame was used to verify the methodology.Identification results from a cable-stayed bridge demonstrate the practicality of the proposed method for conducting AOMA in engineering practice.The proposed approach can automatically identify modal parameters with high accuracy,making it suitable for a real-time structural health monitoring framework.
基金financially supported by the National Key R&D Program of China(2021YFB3800300)the National Natural Science Foundation of China(22179143 and 22309202)+1 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talentthe Gusu Leading Talents Program(ZXL2023190)。
文摘Integrating high-nickel layered oxide cathodes with aqueous slurry electrode preparation routes holds the potential to simultaneously meet the demands for high energy density and low-cost production of lithium-ion batteries.However,the influence of dual exposure to air and liquid water as well as the heating treatment during aqueous slurry electrode processing on the high-nickel layered oxide electrode is yet to be understood.In this study,we systematically investigate the structural evolution and electro-chemical behaviors when LiNi_(0.83)Mn_(0.05)Co_(0.12)O_(2)(NMC83)is subjected to aqueous slurry processing.It was observed that the crystal structure near the surface of NMC83 is partially reconstructed to contain a mixture of rock-salt and layered phases when exposed to water,leading to the deteriorated rate capability of the NMC83 electrodes.This partial surface reconstruction layer completely converts into a pure rock-salt phase upon cycling,accompanied by the release of O_(2),Ni leaching,catalyzed decomposition of the electrolyte,and the formation of a thick cathode electrolyte interphase layer.The byproducts of the electrolyte and dissolved Ni could shuttle to the Li metal side,causing a crosstalk effect that results in a thick and unstable solid electrolyte interphase layer on the Li surface.These in combination severely undermined the cycling stability of the NMC83 electrodes obtained from the aqueous slurry.A mitigation strategy using molecular self-assembly technique was demonstrated to enhance the surface stability of water-treated NMC83.Our findings offer new insights for tailoring ambient environment stability and aqueous slurry processability for ultra-high nickel layered oxide and other water-sensitive cathode materials.
基金supported by the National Natural Science Foundation of China(21625304,21733012,and 21772190)the Ministry of Science and Technology of China(2016YFB0100102)。
基金supported by the National Natural Science Foundation of China(Grant Nos.51728204 and 51772272)Fundamental Research Funds for the Central Universities(Grant No.2018QNA4011)+1 种基金Qianjiang Talents Plan D(QJD1602029)Startup Foundation for Hundred-Talent Program of Zhejiang University
文摘Metal sulphide electrocatalyst is considered as one of the most promising low-cost candidates for oxygen evolution reaction(OER).In this work,we report a novel free-standing Cu2S branch array via a facile TiO2-induced electrodeposition-sulfurization method.Interestingly,cross-linked Cu2S nanoflake branch is strongly anchored on the TiO2 backbone forming high-quality Cu2S/TiO2/Cu2S core-branch arrays.The branch formation mechanism is also proposed.As compared to the pure Cu2S nanowire arrays,the asprepared Cu2S/TiO2/Cu2S core-branch arrays show much better alkaline OER performance with lower overpotential(284 mV at 10 mA cm^-2)and smaller Tafel slope(72 dec-1)as well as enhanced longterm durability mainly due to larger exposed area and more active electrocatalytic sites.Our work provides a new way for construction of advanced metal sulphide electrocatalysts for electrochemical energy conversion.
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the National Natural Science Foundation of China(Grant nos.21625304 and 21733012)the Ministry of Science and Technology(Grant No.2016YFA0200703).
文摘Lithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density.However,it suffers from poor cycling stability because of its high reactivity with liquid electrolytes.Therefore,continuous efforts have been put into improving the cycling Coulombic efficiency(CE)to extend the lifespan of the lithium metal negative electrode.Herein,we report that using dual-salt additives of LiPF_(6) and LiNO_(3) in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon(Li-CNT)composite.As a result,an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm^(-2) and an negative electrode to positive electrode capacity(N/P)ratio of 2.The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether.The former component mainly originates from the decomposition of the LiNO_(3) additive,while the latter comes from the LiPF_(6)-induced ring-opening polymerization of the ether solvent.This novel surface chemistry significantly improves the CE of Li negative electrode,revealing its importance for the practical application of lithium metal batteries.
基金financial support from the National Natural Science Foundation of China (21938005, 21573147, 22005190, 22008154, 21872163)the Science & Technology Commission of Shanghai Municipality, the Natural Science Foundation of Shanghai (19DZ1205500, 19ZR1424600, 19ZR1475100)the Sichuan Science and Technology Program (2021JDRC0015 to L.S.L)。
文摘P2-type sodium layered oxide cathode (Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)P2-NNMO) has attracted great attention as a promising cathode material for sodium ion batteries because of its high specific capacity. However, this material suffers from a rapid capacity fade during high-voltage cycling. Several mechanisms have been proposed to explain the capacity fade, including intragranular fracture caused by the P2-O2 phase transion, surface structural change, and irreversible lattice oxygen release. Here we systematically investigated the morphological, structural, and chemical changes of P2-NNMO during high-voltage cycling using a variety of characterization techniques. It was found that the lattice distortion and crystal-plane buckling induced by the P2-O2 phase transition slowed down the Na-ion transport in the bulk and hindered the extraction of the Na ions. The sluggish kinetics was the main reason in reducing the accessible capacity while other interfacial degradation mechanisms played minor roles. Our results not only enabled a more complete understanding of the capacity-fading mechanism of P2-NNMO but also revealed the underlying correlations between lattice doping and the moderately improved cycle performance.
基金supported by the National Natural Science Foundation of China(Nos.51772272,51728204)Fundamental Research Funds for the Central Universities(No.2018QNA4011)+4 种基金Qianjiang Talents Plan D(No.QJD1602029)Startup Foundation for Hundred-Talent Program of Zhejiang UniversityAnalysis Testing and Commonweal Project of Zhejiang Province(No.GC19E020005)the TEM support from Qiaohong He and Xiaokun DingSEM support from Fang Chen from Department of Chemistry,Zhejiang University。
文摘High-perfo rmance anodes of sodium ion batteries(SIBs)largely depends on rational architecture design and binder-free smart hybridization.Herein,we report TiC/C core/shell nanowires arrays prepared by a one-step chemical vapor deposition(CVD)method and apply it as the anode of SIBs for the first time.The conductive TiC core is intimately decorated with carbon shell.The as-obtained TiC/C nanowires are homogeneously grown on the substrate and show core/shell heterostructure and porous architecture with high electronic conductivity and reinforced stability.Owing to these merits,the TiC/C electrode displays good rate performance and outstanding cycling performance with a capacity of 135.3 mAh/g at 0.1 A/g and superior capacity retention of 90.14%after 1000 cycles at 2 A/g.The reported strategy would provide a promising way to construct binder-free arrays electrodes for sodium ion storage.
基金This work is supported by the National Natural Science Foundation of China(Nos.51578491 and 52238001).
文摘Contrary to conventional design methods that assume uniform and slow temperature changes tied to atmospheric conditions,single-layer spherical reticulated shells undergo significant non-uniform and time-variant temperature variations due to dynamic environmental coupling.These differences can affect structural performance and pose safety risks.Here,a systematic numerical method was developed and applied to simulate long-term temperature variations in such a structure under real environmental conditions,revealing its non-uniform distribution characteristics and time-variant regularity.A simplified design method for non-uniform thermal loads,accounting for time-variant environmental factors,was theoretically derived and validated through experiments and simulations.The maximum deviation and mean error rate between calculated and tested results were 6.1℃ and 3.7%,respectively.Calculated temperature fields aligned with simulated ones,with deviations under 6.0℃.Using the design method,non-uniform thermal effects of the structure are analyzed.Maximum member stress and nodal displacement under non-uniform thermal loads reached 119.3 MPa and 19.7 mm,representing increases of 167.5%and 169.9%,respectively,compared to uniform thermal loads.The impacts of healing construction time on non-uniform thermal effects were evaluated,resulting in construction recommendations.The methodologies and conclusions presented here can serve as valuable references for the thermal design,construction,and control of single-layer spherical reticulated shells or similar structures.
基金supported by the National Natural Science Foundation of China(No.21972049)。
文摘B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)to facilitate the rapid Li+migration.Nevertheless,its wide-temperature application has been limited by the instability of B-derived CEI layer at high temperature.Herein,dual electrolyte additives,consisting of lithium tetraborate(Li_(2)TB)and 2,4-difluorobiphenyl(FBP),are proposed to boost the widetemperature performances of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM)cathode.Theoretical calculation and electrochemical performances analyses indicate that Li_(2)TB and FBP undergo successive decomposition to form a unique dual-layer CEI.FBP acts as a synergistic filming additive to Li_(2)TB,enhancing the hightemperature performance of NCM cathode while preserving the excellent low-temperature cycle stability and the superior rate capability conferred by Li_(2)TB additive.Therefore,the capacity retention of NCM‖Li cells using optimal FBP-Li_(2)TB dual electrolyte additives increases to 100%after 200 cycles at-10℃,99%after 200 cycles at 25℃,and 83%after 100 cycles at 55℃,respectively,much superior to that of base electrolyte(63%/69%/45%).More surprisingly,galvanostatic c ha rge/discharge experiments at different temperatures reveal that NCM‖Li cells using FBP-Li_(2)TB additives can operate at temperatures ranging from-40℃to 60℃.This synergistic interphase modification utilizing dual electrolyte additives to construct a unique dual-layer CEI adaptive to a wide temperature range,provides valuable insights to the practical applications of NCM cathodes for all-climate batteries.
基金financially supported by the National Natural Science Foundation of China(21972049,22272175)the National Key R&D Program of China(2022YFA1504002)+3 种基金the“Scientist Studio Funding”from Tianmu Lake Institute of Advanced Energy Storage Technologies Co.,Ltd.Dalian Supports High-Level Talent Innovation and Entrepreneurship Projects(2021RD14)the Dalian Institute of Chemical Physics(DICP I202213)the 21C Innovation Laboratory,Contemporary Ampere Technology Ltd.by project No.21C-OP-202208。
文摘Developing wide-temperature and high-safety lithium-ion batteries(LIBs)presents significant challenges attributed to the absence of suitable solvents possessing broad liquid range and non-flammability properties.γ-Butyrolactone(GBL)has emerged as a promising solvent;however,its incompatibility with graphite anode has hindered its application.This limitation necessitates a comprehensive investigation into the underlying mechanisms and potential solutions.In this study,we achieve a molecular-level understanding of the perplexing interphase formation process by employing in-situ spectroelectrochemical techniques and density function calculations.Our findings reveal that,even at high salt concentrations,GBL consistently occupies the primary Li^(+)solvation sheath,leading to extensive GBL decomposition and the formation of a high-impedance and inorganic-poor solid-electrolyte interphase(SEI)layer.Contrary to manipulating solvation structures,our research demonstrates that the utilization of filmforming additives with higher reduction potential facilitates the pre-establishment of a robust SEI film on the graphite anode.This approach effectively inhibits GBL decomposition and significantly enhances the battery's lifespan.This study provides the first reported intrinsic understanding of the unique GBLgraphite incompatibility and offers valuable insights for the development of wide-temperature and high-safety LIBs.
文摘The authors regret that the Fig.S3 in supporting information of this published article needs to be revised.And the BET values are correct and unaffected.All the conclusions in the manuscript are unaffected by this unintentional error.
文摘Ni-rich layered oxide cathode materials,such as LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM811),exhibit high specific capacity and low cost,and become cathode material preference of high-energy-density Li-ion batteries.However,these cathode materials are not stable and will form Li-poor reconstructed layers and alkaline compounds(Li_(2)CO_(3),LiOH)on the surface during the storage and processing in humid air,resulting in serious deterioration of electrochemical properties.During the past two decades,the consensus on the surface instability mechanism during humid air storage has not been reached.The main controversy focuses on the unstable octahedron mechanism and the Li/H exchange mechanism.Herein,we investigate the instability mechanism in the humid air by conducting scanning electronic microscopy,scanning transmission electron microscopy,and x-ray photoelectron spectroscopy analysis on NCM811 samples stored in designed atmospheres,etc.,and realize that the surface instability of the NCM811 during storage should be mainly originated from Li/H exchange when it contacts with moisture.
基金supported by the National Key R&D Program of China(grant no.2021YFB3800300)the National Natural Science Foundation of China(grant nos.22179143,22309201,and 22309202)the Jiangsu Funding Program for Excellent Postdoctoral Talent,and the Gusu Leading Talents Program(grant no.ZXL2023190).
文摘Solid-state batteries(SSBs)are considered as the next-generation battery technology,poised to deliver both high energy and enhanced safety.Nonetheless,their transition from laboratory to market is impeded by several critical challenges.Among these,the solid–solid interfaces within SSBs represent a bottleneck,characterized by issues such as poor physical contact,side reactions,temporal separation,and sluggish charge carrier transfer.Developing key materials to construct the efficient solid–solid interface is critical for building high-performance SSBs.Organic mixed ionic–electronic conductors(OMIECs)have emerged as a promising alternative to conventional conductors in addressing the abovementioned issues owing to their intrinsic properties,including the capability of conducting both ions and electrons,mechanical flexibility,and structural designability.This review will first elucidate the necessity of the integration of OMIECs in SSBs.Next,a comprehensive exploration of the composition,preparation methods,key advantages,and basic characterizations of OMIECs is presented.This review then delves into recent research progress on OMIECs in SSBs,with a special focus on their application in cathode coating layers,the creation of a 3D mixed conductive framework for Li hosting,and their integration as inner layers in Li anodes.Conclusively,potential future applications and innovative designs of OMIECs are discussed.
基金the funding from the National Natural Science Foundation of China(52071225)the European Union’s Horizon Europe research and innovation programme under the grant agreement No.101087143(Electron Beam Emergent Additive Manufacturing(EBEAM))+2 种基金REFRESH-Research Excellence For Region Sustainability and High-tech Industries project No.CZ.10.03.01/00/22_003/0000048 via the Operational Programme Just TransitionNorway Grants project No.2019/34/H/ST8/00547 through the National Science Centrethe Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘Owing to their advantages such as high energy density and excellent cycle performance,lithium-ion batteries have occupied a dominant position for many years in the fields of consumer electronics,energy storage,and new energy vehicles.Graphite is the most widely commercialized anode material because of its stable layered structure,excellent electrical conductivity,and cost-effectiveness.However,its inherent limitations,notably its relatively low theoretical specific capacity(372 mAh/g)and sluggish intrinsic ion diffusion kinetics,pose significant challenges to the development of high-energy and power density battery systems.This article briefly introduces the intercalation and failure mechanisms of graphite anode materials,reviews the research progress in the bulk and surface regulation of these materials,and discusses their future development prospects.
基金the "Strategic Priority Research Program:of the CAS (No.XDA09010600)the National Natural Science Foundation of China (Nos.21473242,21625304 and 21733012).
文摘Organic-based electrode materials for lithium-ion batteries (LIBs) are promising due to their high theoretical capacity,structure versatility and environmental benignity.However,the poor intrinsic electric conductivity of most polymers results in slow reaction kinetics and hinders their application as electrode materials for LIBs.A binder-free self-supporting organic electrode with excellent redox kinetics is herein demonstrated via in situ polymerization of a uniform thin polyimide (PI) layer on a porous and highly conductive carbonized nanofiber (CNF) framework.The PI active material in the porous PI@CNF film has large physical contact area with both the CNF and the electrolyte thus obtains superior electronic and ionic conduction.As a result,the PI@CNF cathode exhibits a discharge capacity of 170 mAh·g^-1 at 1 C (175 mA·g^-1),remarkable rate-performance (70.5% of 0.5 C capacity can be obtained at a 100 C discharge rate),and superior cycling stability with 81.3% capacity retention after 1,000 cycles at 1 C.Last but not least,a four-electron transfer redox process of the PI polymer was realized for the first time thanks to the excellent redox kinetics of the PI@CNF electrode,showing a discharge capacity exceeding 300 mAh·g^-1 at a current of 175 mA·g^-1.
