Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two crit...Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.展开更多
Since the as-cast microstructure benefits dynamic recrystallization(DRX)nucleation,the present research is focused on the microstructure evolution associated with the dendrites and precipitates during the thermal defo...Since the as-cast microstructure benefits dynamic recrystallization(DRX)nucleation,the present research is focused on the microstructure evolution associated with the dendrites and precipitates during the thermal deformation of an ingot without homogenization treatment aiming at exploring a new efficient strategy of ingot cogging for superalloys.The as-cast samples were deformed at the sub-solvus temperature,and the DRX evolution from dendritic arms(DAs)to inter-dendritic regions(IDRs)was discussed based on the observation of the fishnet-like DRX microstructures and the gradient of DRX grain size at IDRs.The difference in the precipitates at DAs and IDRs played an essential role during the deformation and DRX process,which finally resulted in very different microstructures in the two areas.A selective straininduced grain boundary bulging(SIGBB)mechanism was found to function well and dominate the DRX nucleation at DAs.The grain boundary was able to migrate and bulge to nucleate on the condition that the boundary was located at DAs and had a great difference in dislocation density between its opposite sides at the same time.As for DRX nucleation at IDRs,the particle-stimulated nucleation(PSN)mechanism played a leading role,and the progressive subgrain rotation(PSR)and geometric DRX were two important supplementary mechanisms.The dislocation accumulation around the coarse precipitates at IDR resulted in progressive orientation rotation,which would generate DRX nuclei once the maximum misorientation there was sufficient to form a high-angle boundary with the matrix.The PSR or geometric DRX functioned at the severely elongated IDRs at the later stage of deformation,depending on the thickness of the elongated IDRs.The uniform microstructure was obtained by the deformation without homogenization and the subsequent annealing treatment.The smaller strain,the lower annealing temperature,and the much shorter soaking time requested in the above process lead to a smaller risk of cracking and a lower consumption of energy during the ingot-cogging process.展开更多
The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of den...The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.展开更多
Lithium metal has emerged as a highly promising anode material for enhancing the energy density of secondary batteries,attributed to its high theoretical specific capacity and low electrochemical potential.However,saf...Lithium metal has emerged as a highly promising anode material for enhancing the energy density of secondary batteries,attributed to its high theoretical specific capacity and low electrochemical potential.However,safety concerns related to lithium dendrite-induced short circuits and suboptimal electrochemical performance have impeded the commercial viability of lithium metal batteries.Current research efforts primarily focus on altering the solvated structure of Li+by modifying the current collector or introducing electrolyte additives to lower the nucleation barrier,expedite the desolvation process,and suppress the growth of lithium dendrites.Nevertheless,an integrated approach that combines the advantages of these two strategies remains elusive.In this study,we successfully employed metal-organic salt additives with lithophilic properties to accelerate the desolvation process,reduce the nucleation barrier of Li+,and modulate its solvated structure.This approach enhanced the inorganic compound content in the solid electrolyte interphase(SEI)on lithium foil surfaces,leading to stable Li+deposition and stripping.Specifically,Li||Cu cells demonstrated excellent cycle life and Coulombic efficiency(97.28%and 98.59%,respectively)at 0.5 m A/cm^(2)@0.5 m Ah/cm^(2)and 1 m A/cm^(2)@1 m Ah/cm^(2)for 410 and 240 cycles,respectively.Li||Li symmetrical cells showed no short circuit at 1 m A/cm^(2)@1 m Ah/cm^(2)for 1150 h,and Li||LFP full cells retained 68.9%of their capacity(104.6 m Ah/g)after 250 cycles at N/P(1.1:1.0)with a current density of 1C.展开更多
Regulating the crystal texture of zinc deposition is a promising approach to suppress dendrite formation and improve the reversibility of zinc anodes in aqueous zinc-ion batteries.While previous research has mainly fo...Regulating the crystal texture of zinc deposition is a promising approach to suppress dendrite formation and improve the reversibility of zinc anodes in aqueous zinc-ion batteries.While previous research has mainly focused on developing the Zn(002)texture,investigations into other crystal planes remain scarce.However,exploring alternative crystal planes is crucial for advancing zinc anode performance,as different planes may offer unique advantages in terms of stability and reversibility.Herein,we introduce N-acetylcysteamine(NAC)as an electrolyte additive.It revealed that NAC induces an unexpected exfoliation of the electrodeposited zinc layer,which exhibits preferred orientations along the(102)and(103)planes.Inspired by this anomalous deposition phenomenon,we achieved unconventional Zn(102)and Zn(103)oriented deposition.We demonstrate that NAC molecules adsorb on the Zn surface via thiol groups,modulating the surface energy of different planes to promote the exposure of the two textures.Further characterization,including electrochemical quartz crystal microbalance,electric double-layer capacitance,and contact angle tests,confirms that NAC forms a hydrophobic selfassembled layer,effectively suppressing side reactions.Benefiting from this multifunctional additive,the zinc anode exhibited a long lifespan of 1150 and 780 h under 1 mA cm^(-2)/1 mAh cm^(-2)and 5 mA cm^(-2)/5 mAh cm^(-2),respectively.Moreover,the assembled Zn||V_(2)O_(5)H_(2)O full cells demonstrated prominent electrochemical reversibility.This work not only achieves unconventional Zn(102)and Zn(103)oriented deposition but also provides a novel strategy for designing high-performance zinc-ion batteries.展开更多
Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effe...Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effect of polysulfides and the growth of lithium dendrites greatly hinder their further development and commercial application.In this paper,cobalt-molybdenum bimetallic carbides heterostructure(Co_(6)Mo_(6)C_(2)@Co@NC)was successfully prepared through chemical etching procedure of ZIF-67 precursor with sodium molybdate and the subsequent high temperature annealing process.The obtained dodecahedral Co_(6)Mo_(6)C_(2)@Co@NC with hollow and porous structure provides large specific surface area and plentiful active sites,which speeds up the chemisorption and catalytic conversion of polysulfides,thus mitigating the shuttle effect of polysulfides and the generation of lithium dendrites.When applied as the LSBs separator modifier layer,the cell with modified separator present excellent rate capability and durable cycling stability.In particular,the cell with Co_(6)Mo_(6)C_(2)@Co@NC/PP separator can maintain the high capacity of 738 mAh/g at the current density of 2 C and the specific capacity of 782.6 mAh/g after 300 cycles at 0.5 C,with the coulombic efficiency(CE)near to 100%.Moreover,the Co_(6)Mo_(6)C_(2)@Co@NC/PP battery exhibits the impressive capacity of 431 mAh/g in high sulfur loading(4.096 mg/cm^(2))at 0.5 C after 200 cycles.This work paves the way for the development of bimetallic carbides heterostructure multifunctional catalysts for durable Li-S battery applications and reveals the synergistic regulation of polysulfides and lithium dendrites through the optimization of the structure and composition.展开更多
Effect of direct current electric field （DCEF） on corrosion behaviour of copper printed circuit board （PCB-Cu）, Cl-ion migration behaviour, dendrites growth under thin electrolyte layer was investigated using pote...Effect of direct current electric field （DCEF） on corrosion behaviour of copper printed circuit board （PCB-Cu）, Cl-ion migration behaviour, dendrites growth under thin electrolyte layer was investigated using potentiodynamic polarization and scanning electron microscopy （SEM） with energy dispersive spectrometer （EDS）. Results indicate that DCEF decreases the corrosion of PCB-Cu;Cl-ions directionally migrate from the negative pole to the positive pole, and enrich on the surface of the positive pole, which causes serious localized corrosion; dendrites grow on the surface of the negative pole, and the rate and scale of dendrite growth become faster and greater with the increase of external voltage and exposure time, respectively.展开更多
Nucleation of dendritic primaryα（Al） phase with addition of element Ce and Sr in hypoeutectic Al-7%Si-Mg cast alloy was investigated by using differential scanning calorimetry （DSC） and scanning electron microsco...Nucleation of dendritic primaryα（Al） phase with addition of element Ce and Sr in hypoeutectic Al-7%Si-Mg cast alloy was investigated by using differential scanning calorimetry （DSC） and scanning electron microscopy. DSC results were used to calculate the activation energy and nucleation work of primaryα（Al） phase. The results show that the values of activation energy and nucleation work are decreased and the nucleation frequency is increased with the additions of Ce and Sr to the alloys. Moreover, the grain size of dendriticα（Al） phase is well refined, and the nucleation temperatures of primaryα（Al） dendrites are decreased with the additions of Ce and Sr. The effects of elements Ce and Sr additions on kinetic nucleation of primary α（Al） phases were also discussed in hypoeutectic Al-7%Si-Mg cast alloy.展开更多
The large and small sized Cu（solid）/Al（liquid） couples were prepared to investigate the directional growth behavior of primary a（Al） phase during a concentration-gradient-controlled solidification process under ...The large and small sized Cu（solid）/Al（liquid） couples were prepared to investigate the directional growth behavior of primary a（Al） phase during a concentration-gradient-controlled solidification process under various static magnetic fields（SMFs）.The results show that in the large couples,the α（Al） dendrites reveal a directional growth character whether without or with the SMF.However,the 12 T magnetic field induces regular growth,consistent deflection and the decrease of secondary arm spacing of the dendrites.In the small couples,the α（Al） dendrites still reveal a directional growth character to some extent with a SMF of ≤5 T.However,an 8.8 T SMF destroys the directional growth and induces severe random deflections of the dendrites.When the SMF increases to 12 T,the a（Al） dendrites become quite regular despite of the consistent deflection.The directional growth arises from the continuous long-range concentration gradient field built in the melt.The morphological modification is mainly related to the suppression of natural convections and the induction of thermoelectric magnetic convection by the SMF.展开更多
The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the cent...The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the central determinant of the functional properties of neurons and neural circuits.The topological and structural morphology of axons and dendrites defines and determines how synapses are conformed.The morphological diversity of axon and dendrite arborization governs the neuron’s inputs,synaptic integration,neuronal computation,signal transmission,and network circuitry,hence defining the particular connectivity and function of the different brain areas.展开更多
Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread applica...Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.展开更多
Sliver defects are a group of low-to-medium angle misoriented grains in Ni-based single crystal superalloys that have received more attention in recent years.Occurrence of these defects can negatively affect the mecha...Sliver defects are a group of low-to-medium angle misoriented grains in Ni-based single crystal superalloys that have received more attention in recent years.Occurrence of these defects can negatively affect the mechanical properties of single crystal components.Therefore,studying the mechanisms of sliver formation and its effects on the final properties of alloys is of great importance.In this article,recent studies on the sliver defects were reviewed.Accordingly,the mechanisms of sliver formation as well as factors contributing to sliver initiation were studied.Additionally,effects of slivers on the mechanical properties of single crystal superalloys were discussed.Dendrite deformation and dendrite fracture are the main mechanisms for the sliver formation.This is a consequence of local stress concentration on dendrites during solidification.Therefore,locations such as inclusions,pores,geometrically complex areas,mould walls,freckle channels,etc.can be considered as the potential factors that promote the sliver initiation.Sliver formation significantly degrades the creep life of single-crystal superalloys.Studies have shown that when crystallographic misorientation exceeds approximately15°,creep life can be reduced by up to 47%.Despite the absence of a standardized criterion for predicting or preventing sliver initiation and propagation,their occurrence can be minimized through optimization of solidification parameters,careful grain selection,proper casting geometry design,and rigorous control of material purity and equipment conditions.展开更多
Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that pla...Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that plays an important role in a broad range of cellular activities from calcium regulation to protein synthesis and trafficking.In neurons,the ER extends from the soma through the axon to presynaptic terminals,and throughout the dendritic arbor into as many as half of all postsynaptic dendritic spines at any given time(Falahati et al.,2022).展开更多
Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for sign...Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.展开更多
Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from...Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.展开更多
锂金属负极由于其高比容量(3860 mAh/g)和低还原电位(-3.04 V vs.标准氢电极电位),被认为是电池负极材料的“圣杯”。然而,锂金属电极表面不可控的枝晶生长会导致电池库仑效率降低和循环性能下降,严重时造成电池短路,甚至发生爆炸。基...锂金属负极由于其高比容量(3860 mAh/g)和低还原电位(-3.04 V vs.标准氢电极电位),被认为是电池负极材料的“圣杯”。然而,锂金属电极表面不可控的枝晶生长会导致电池库仑效率降低和循环性能下降,严重时造成电池短路,甚至发生爆炸。基于以上挑战及聚合物策略的应用,从固态电解质、隔膜修饰层、粘结剂、人工固态电解质相界面(SEI)层、复合负极等方面综述了含氟聚合物在锂金属电池中的重要作用,并对含氟聚合物在金属锂电池领域中未来的研究方向和发展趋势进行了展望。展开更多
Aqueous zinc-ion batteries(AZIBs)are considered promising for safe,low-cost,and sustainable energy storage.However,their practical deployment is critically hindered by dendrite formation and parasitic reactions at the...Aqueous zinc-ion batteries(AZIBs)are considered promising for safe,low-cost,and sustainable energy storage.However,their practical deployment is critically hindered by dendrite formation and parasitic reactions at the Zn anode-electrolyte interface.To address this challenge,we present a self-assembly strategy to construct vertically aligned organic-inorganic hybrid nanosheet arrays composed of polyethyleneimine-zinc hydroxide sulfate(PEI-ZHS)via a simple coating-immersion method.The protonation of polyethyleneimine in ZnSO_(4) electrolyte provides localized alkaline conditions for controlled nucleation and growth of ZHS nanosheets at the anode interfa ce.This vertically aligned na noarchitectu re allows for fast Zn^(2+)transport and even nucleation by providing abundant oriented ion-conductive microchannels and accelerating desolvation.Benefiting from these characteristics,the PEI-ZHS layer effectively mitigates side reactions and dendrite growth.As a result,the modified zinc anodes achieve excellent cycling lifespans of 5200 and 1200 h at 1 mA cm^(-2)/1 mAh cm^(-2) and 5 mA cm^(-2)/5 mAh cm^(-2),respectively,in symmetric cells.The Zn‖I_(2) full cell also shows great reversibility,retaining 93.02%of initial capacity after 4000 cycles at 1 A g^(-1).This work introduces a thermodynamically guided and scalable interfacial engineering approach that advances the stability and performance of Zn metal anodes in AZIBs.展开更多
基金the financial support from the Natural Science Foundation of Jiangsu Province(BK20231292)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(24)3091)+6 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25_1429)the National Key R&D Program of China(2024YFE0109200)the Fundamental Research Funds for the Central Universities(No.2024300440)Guangdong Basic and Applied Basic Research Foundation(2025A1515011098)the National Natural Science Foundation of China(12464032)the Natural Science Foundation of Jiangxi Province(20232BAB201032)Ji'an Science and Technology Plan Project(2024H-100301)。
文摘Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.
基金supported by the Natural Science Foundation of Shaanxi Province of China(No.2023-JC-QN-0466)the National Natural Science Foundation of China(Nos.52305421 and 52175363)+1 种基金the General Research Fund of Hong Kong(No.15223520)the project No.1-ZE1W from the Hong Kong Polytechnic University.
文摘Since the as-cast microstructure benefits dynamic recrystallization(DRX)nucleation,the present research is focused on the microstructure evolution associated with the dendrites and precipitates during the thermal deformation of an ingot without homogenization treatment aiming at exploring a new efficient strategy of ingot cogging for superalloys.The as-cast samples were deformed at the sub-solvus temperature,and the DRX evolution from dendritic arms(DAs)to inter-dendritic regions(IDRs)was discussed based on the observation of the fishnet-like DRX microstructures and the gradient of DRX grain size at IDRs.The difference in the precipitates at DAs and IDRs played an essential role during the deformation and DRX process,which finally resulted in very different microstructures in the two areas.A selective straininduced grain boundary bulging(SIGBB)mechanism was found to function well and dominate the DRX nucleation at DAs.The grain boundary was able to migrate and bulge to nucleate on the condition that the boundary was located at DAs and had a great difference in dislocation density between its opposite sides at the same time.As for DRX nucleation at IDRs,the particle-stimulated nucleation(PSN)mechanism played a leading role,and the progressive subgrain rotation(PSR)and geometric DRX were two important supplementary mechanisms.The dislocation accumulation around the coarse precipitates at IDR resulted in progressive orientation rotation,which would generate DRX nuclei once the maximum misorientation there was sufficient to form a high-angle boundary with the matrix.The PSR or geometric DRX functioned at the severely elongated IDRs at the later stage of deformation,depending on the thickness of the elongated IDRs.The uniform microstructure was obtained by the deformation without homogenization and the subsequent annealing treatment.The smaller strain,the lower annealing temperature,and the much shorter soaking time requested in the above process lead to a smaller risk of cracking and a lower consumption of energy during the ingot-cogging process.
基金supported by Open Foundation of the State Key Laboratory of Refractories and Metallurgy(No.G201711)the National Natural Science Foundation of China(Nos.52104317 and 51874001).
文摘The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.
基金supported by Yunnan Natural Science Foundation Project(No.202202AG050003)Yunnan Fundamental Research Projects(Nos.202101BE070001-018 and 202201AT070070)+1 种基金the National Youth Talent Support Program of Yunnan Province China(No.YNQR-QNRC-2020-011)Yunnan Engineering Research Center Innovation Ability Construction and Enhancement Projects(No.2023-XMDJ-00617107)。
文摘Lithium metal has emerged as a highly promising anode material for enhancing the energy density of secondary batteries,attributed to its high theoretical specific capacity and low electrochemical potential.However,safety concerns related to lithium dendrite-induced short circuits and suboptimal electrochemical performance have impeded the commercial viability of lithium metal batteries.Current research efforts primarily focus on altering the solvated structure of Li+by modifying the current collector or introducing electrolyte additives to lower the nucleation barrier,expedite the desolvation process,and suppress the growth of lithium dendrites.Nevertheless,an integrated approach that combines the advantages of these two strategies remains elusive.In this study,we successfully employed metal-organic salt additives with lithophilic properties to accelerate the desolvation process,reduce the nucleation barrier of Li+,and modulate its solvated structure.This approach enhanced the inorganic compound content in the solid electrolyte interphase(SEI)on lithium foil surfaces,leading to stable Li+deposition and stripping.Specifically,Li||Cu cells demonstrated excellent cycle life and Coulombic efficiency(97.28%and 98.59%,respectively)at 0.5 m A/cm^(2)@0.5 m Ah/cm^(2)and 1 m A/cm^(2)@1 m Ah/cm^(2)for 410 and 240 cycles,respectively.Li||Li symmetrical cells showed no short circuit at 1 m A/cm^(2)@1 m Ah/cm^(2)for 1150 h,and Li||LFP full cells retained 68.9%of their capacity(104.6 m Ah/g)after 250 cycles at N/P(1.1:1.0)with a current density of 1C.
基金supported by the National Natural Science Foundation of China(52432007 and 52422212)。
文摘Regulating the crystal texture of zinc deposition is a promising approach to suppress dendrite formation and improve the reversibility of zinc anodes in aqueous zinc-ion batteries.While previous research has mainly focused on developing the Zn(002)texture,investigations into other crystal planes remain scarce.However,exploring alternative crystal planes is crucial for advancing zinc anode performance,as different planes may offer unique advantages in terms of stability and reversibility.Herein,we introduce N-acetylcysteamine(NAC)as an electrolyte additive.It revealed that NAC induces an unexpected exfoliation of the electrodeposited zinc layer,which exhibits preferred orientations along the(102)and(103)planes.Inspired by this anomalous deposition phenomenon,we achieved unconventional Zn(102)and Zn(103)oriented deposition.We demonstrate that NAC molecules adsorb on the Zn surface via thiol groups,modulating the surface energy of different planes to promote the exposure of the two textures.Further characterization,including electrochemical quartz crystal microbalance,electric double-layer capacitance,and contact angle tests,confirms that NAC forms a hydrophobic selfassembled layer,effectively suppressing side reactions.Benefiting from this multifunctional additive,the zinc anode exhibited a long lifespan of 1150 and 780 h under 1 mA cm^(-2)/1 mAh cm^(-2)and 5 mA cm^(-2)/5 mAh cm^(-2),respectively.Moreover,the assembled Zn||V_(2)O_(5)H_(2)O full cells demonstrated prominent electrochemical reversibility.This work not only achieves unconventional Zn(102)and Zn(103)oriented deposition but also provides a novel strategy for designing high-performance zinc-ion batteries.
基金supported by National Natural Science Foundation of China(Nos.52472194,52101243)Natural Science Foundation of Guangdong Province,China(No.2023A1515012619)the Science and Technology Planning Project of Guangzhou(No.202201010565).
文摘Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effect of polysulfides and the growth of lithium dendrites greatly hinder their further development and commercial application.In this paper,cobalt-molybdenum bimetallic carbides heterostructure(Co_(6)Mo_(6)C_(2)@Co@NC)was successfully prepared through chemical etching procedure of ZIF-67 precursor with sodium molybdate and the subsequent high temperature annealing process.The obtained dodecahedral Co_(6)Mo_(6)C_(2)@Co@NC with hollow and porous structure provides large specific surface area and plentiful active sites,which speeds up the chemisorption and catalytic conversion of polysulfides,thus mitigating the shuttle effect of polysulfides and the generation of lithium dendrites.When applied as the LSBs separator modifier layer,the cell with modified separator present excellent rate capability and durable cycling stability.In particular,the cell with Co_(6)Mo_(6)C_(2)@Co@NC/PP separator can maintain the high capacity of 738 mAh/g at the current density of 2 C and the specific capacity of 782.6 mAh/g after 300 cycles at 0.5 C,with the coulombic efficiency(CE)near to 100%.Moreover,the Co_(6)Mo_(6)C_(2)@Co@NC/PP battery exhibits the impressive capacity of 431 mAh/g in high sulfur loading(4.096 mg/cm^(2))at 0.5 C after 200 cycles.This work paves the way for the development of bimetallic carbides heterostructure multifunctional catalysts for durable Li-S battery applications and reveals the synergistic regulation of polysulfides and lithium dendrites through the optimization of the structure and composition.
基金Project(50871044)supported by the National Natural Science Foundation of ChinaProject(2012M511207)supported by the Postdoctoral Science Foundation of ChinaProject(10122011)supported by the Science Research Foundation of Wuhan Institute Technology,China
文摘Effect of direct current electric field （DCEF） on corrosion behaviour of copper printed circuit board （PCB-Cu）, Cl-ion migration behaviour, dendrites growth under thin electrolyte layer was investigated using potentiodynamic polarization and scanning electron microscopy （SEM） with energy dispersive spectrometer （EDS）. Results indicate that DCEF decreases the corrosion of PCB-Cu;Cl-ions directionally migrate from the negative pole to the positive pole, and enrich on the surface of the positive pole, which causes serious localized corrosion; dendrites grow on the surface of the negative pole, and the rate and scale of dendrite growth become faster and greater with the increase of external voltage and exposure time, respectively.
基金Project (42-QP-009) support by Research Fund of the State Key Laboratory of Solidification Processing,ChinaProject (B08040) supported by the Program of Introducing Talents of Discipline to Universities ("111"Project),China
文摘Nucleation of dendritic primaryα（Al） phase with addition of element Ce and Sr in hypoeutectic Al-7%Si-Mg cast alloy was investigated by using differential scanning calorimetry （DSC） and scanning electron microscopy. DSC results were used to calculate the activation energy and nucleation work of primaryα（Al） phase. The results show that the values of activation energy and nucleation work are decreased and the nucleation frequency is increased with the additions of Ce and Sr to the alloys. Moreover, the grain size of dendriticα（Al） phase is well refined, and the nucleation temperatures of primaryα（Al） dendrites are decreased with the additions of Ce and Sr. The effects of elements Ce and Sr additions on kinetic nucleation of primary α（Al） phases were also discussed in hypoeutectic Al-7%Si-Mg cast alloy.
基金Projects(51201029,51071042,51374067)supported by the National Natural Science Foundation of ChinaProjects(N130409002,N130209001)supported by the Research Funds for the Central UniversitiesProject(2012M520637)supported by the China Postdoctoral Science Foundation
文摘The large and small sized Cu（solid）/Al（liquid） couples were prepared to investigate the directional growth behavior of primary a（Al） phase during a concentration-gradient-controlled solidification process under various static magnetic fields（SMFs）.The results show that in the large couples,the α（Al） dendrites reveal a directional growth character whether without or with the SMF.However,the 12 T magnetic field induces regular growth,consistent deflection and the decrease of secondary arm spacing of the dendrites.In the small couples,the α（Al） dendrites still reveal a directional growth character to some extent with a SMF of ≤5 T.However,an 8.8 T SMF destroys the directional growth and induces severe random deflections of the dendrites.When the SMF increases to 12 T,the a（Al） dendrites become quite regular despite of the consistent deflection.The directional growth arises from the continuous long-range concentration gradient field built in the melt.The morphological modification is mainly related to the suppression of natural convections and the induction of thermoelectric magnetic convection by the SMF.
基金supported by the Wellcome Trust(grant No.103852).
文摘The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the central determinant of the functional properties of neurons and neural circuits.The topological and structural morphology of axons and dendrites defines and determines how synapses are conformed.The morphological diversity of axon and dendrite arborization governs the neuron’s inputs,synaptic integration,neuronal computation,signal transmission,and network circuitry,hence defining the particular connectivity and function of the different brain areas.
基金financially supported by the National Natural Science Foundation of China (No.52372188)Natural Science Foundation of Henan (Nos.242300421625,252300421333)+4 种基金CAS Henan Industrial Technology Innovation & Incubation Center (No.2024121)Key Scientific Research Project of Education Department of Henan Province (Nos.22A150042,23A150038,and 24A150019)2023 Introduction of studying abroad talent programthe China Postdoctoral Science Foundation (No.2019 M652546)Key Project of Science and Technology of Henan Province (No.252102240007)。
文摘Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.
文摘Sliver defects are a group of low-to-medium angle misoriented grains in Ni-based single crystal superalloys that have received more attention in recent years.Occurrence of these defects can negatively affect the mechanical properties of single crystal components.Therefore,studying the mechanisms of sliver formation and its effects on the final properties of alloys is of great importance.In this article,recent studies on the sliver defects were reviewed.Accordingly,the mechanisms of sliver formation as well as factors contributing to sliver initiation were studied.Additionally,effects of slivers on the mechanical properties of single crystal superalloys were discussed.Dendrite deformation and dendrite fracture are the main mechanisms for the sliver formation.This is a consequence of local stress concentration on dendrites during solidification.Therefore,locations such as inclusions,pores,geometrically complex areas,mould walls,freckle channels,etc.can be considered as the potential factors that promote the sliver initiation.Sliver formation significantly degrades the creep life of single-crystal superalloys.Studies have shown that when crystallographic misorientation exceeds approximately15°,creep life can be reduced by up to 47%.Despite the absence of a standardized criterion for predicting or preventing sliver initiation and propagation,their occurrence can be minimized through optimization of solidification parameters,careful grain selection,proper casting geometry design,and rigorous control of material purity and equipment conditions.
基金supported by AHA Career Development Award 938683 (to PJD)NIH grant R01MH123700 (to MLD)
文摘Since the first electron micrograph of“lace-like structures”over 75 years ago,the endoplasmic reticulum(ER)is now viewed as a highly dynamic,constantly remodeling,continuous network of tubules and cisternae that plays an important role in a broad range of cellular activities from calcium regulation to protein synthesis and trafficking.In neurons,the ER extends from the soma through the axon to presynaptic terminals,and throughout the dendritic arbor into as many as half of all postsynaptic dendritic spines at any given time(Falahati et al.,2022).
基金supported by the National Natural Science Foundation of China(NSFC/RGC/JRF N_HKU735/21)Research Grant Council of Hong Kong,China(17102120,17108821,17103922,C1024-22GF,C7074-21G)+1 种基金Health and Medical Research Fund(HMRF 09200966)(to CSWL)FRQS Postdoctoral Fellowship(to AHKF).
文摘Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.
基金supported by the financial support from the National Research Foundation,Singapore,under its Singapore-China Joint Flagship Project(Clean Energy).
文摘Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.
文摘锂金属负极由于其高比容量(3860 mAh/g)和低还原电位(-3.04 V vs.标准氢电极电位),被认为是电池负极材料的“圣杯”。然而,锂金属电极表面不可控的枝晶生长会导致电池库仑效率降低和循环性能下降,严重时造成电池短路,甚至发生爆炸。基于以上挑战及聚合物策略的应用,从固态电解质、隔膜修饰层、粘结剂、人工固态电解质相界面(SEI)层、复合负极等方面综述了含氟聚合物在锂金属电池中的重要作用,并对含氟聚合物在金属锂电池领域中未来的研究方向和发展趋势进行了展望。
基金supported by the National Natural Science Foundation of China(No.22179093 and 21905202)。
文摘Aqueous zinc-ion batteries(AZIBs)are considered promising for safe,low-cost,and sustainable energy storage.However,their practical deployment is critically hindered by dendrite formation and parasitic reactions at the Zn anode-electrolyte interface.To address this challenge,we present a self-assembly strategy to construct vertically aligned organic-inorganic hybrid nanosheet arrays composed of polyethyleneimine-zinc hydroxide sulfate(PEI-ZHS)via a simple coating-immersion method.The protonation of polyethyleneimine in ZnSO_(4) electrolyte provides localized alkaline conditions for controlled nucleation and growth of ZHS nanosheets at the anode interfa ce.This vertically aligned na noarchitectu re allows for fast Zn^(2+)transport and even nucleation by providing abundant oriented ion-conductive microchannels and accelerating desolvation.Benefiting from these characteristics,the PEI-ZHS layer effectively mitigates side reactions and dendrite growth.As a result,the modified zinc anodes achieve excellent cycling lifespans of 5200 and 1200 h at 1 mA cm^(-2)/1 mAh cm^(-2) and 5 mA cm^(-2)/5 mAh cm^(-2),respectively,in symmetric cells.The Zn‖I_(2) full cell also shows great reversibility,retaining 93.02%of initial capacity after 4000 cycles at 1 A g^(-1).This work introduces a thermodynamically guided and scalable interfacial engineering approach that advances the stability and performance of Zn metal anodes in AZIBs.
