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
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
Zinc(Zn)-air batteries are widely used in secondary battery research owing to their high theoretical energy density,good electrochemical reversibility,stable discharge performance,and low cost of the anode active mate...Zinc(Zn)-air batteries are widely used in secondary battery research owing to their high theoretical energy density,good electrochemical reversibility,stable discharge performance,and low cost of the anode active material Zn.However,the Zn anode also leads to many challenges,including dendrite growth,deformation,and hydrogen precipitation self-corrosion.In this context,Zn dendrite growth has a greater impact on the cycle lives.In this dissertation,a dendrite growth model for a Zn-air battery was established based on electrochemical phase field theory,and the effects of the charging time,anisotropy strength,and electrolyte temperature on the morphology and growth height of Zn dendrites were studied.A series of experiments was designed with different gradient influencing factors in subsequent experiments to verify the theoretical simulations,including elevated electrolyte temperatures,flowing electrolytes,and pulsed charging.The simulation results show that the growth of Zn dendrites is controlled mainly by diffusion and mass transfer processes,whereas the electrolyte temperature,flow rate,and interfacial energy anisotropy intensity are the main factors.The experimental results show that an optimal electrolyte temperature of 343.15 K,an optimal electrolyte flow rate of 40 ml·min^(-1),and an effective pulse charging mode.展开更多
Metallic zinc is an excellent anode material for Zn-ion batteries,but the growth of Zn dendrite severely hinders its practical application.Herein,an efficient and economical cationic additive,poly dimethyl diallyl amm...Metallic zinc is an excellent anode material for Zn-ion batteries,but the growth of Zn dendrite severely hinders its practical application.Herein,an efficient and economical cationic additive,poly dimethyl diallyl ammonium(PDDA) was reported,used in aqueous Zn-ion batteries electrolyte for stabilizing Zn anode.The growth of zinc dendrites can be significantly restrained by benefiting from the pronounced electrostatic shielding effect from PDDA on the Zn metal surface.Moreover,the PDDA is preferentially absorbed on Zn(002) plane,thus preventing unwanted side reactions on Zn anode.Owing to the introduction of a certain amount of PDDA additive into the common ZnSO_(4)-based electrolyte,the cycle life of assembled Zn‖Zn cells(1 mA·cm^(-2) and 1 mAh·cm^(-2)) is prolonged to more than 1100 h.In response to the perforation issue of Zn electrodes caused by PDDA additives,the problem can be solved by combining foamy copper with zinc foil.For real application,Zn-ion hybrid supercapacitors and MnO_(2)‖Zn cells were assembled,which exhibited excellent cycling stability with PDDA additives.This work provides a new solution and perspective to cope with the dendrite growth problem of Zn anode.展开更多
目的:制备急性海马脑片,探讨睾酮(T)、双氢睾酮(DHT)、睾酮-牛血清白蛋白(T-BSA)对海马脑片神经元树突棘密度和突触蛋白[突触素(SYN)、突触后致密物质95(PSD95)]的非基因组效应。方法:选用3月龄SD雄性大鼠,麻醉后取脑,在人工脑脊液中剥...目的:制备急性海马脑片,探讨睾酮(T)、双氢睾酮(DHT)、睾酮-牛血清白蛋白(T-BSA)对海马脑片神经元树突棘密度和突触蛋白[突触素(SYN)、突触后致密物质95(PSD95)]的非基因组效应。方法:选用3月龄SD雄性大鼠,麻醉后取脑,在人工脑脊液中剥离海马组织,制备300μm的冠状海马脑片。随机在0、15、30、60、120 min 5个时间点使用细胞核染料DAPI和PI染色,评估神经元活性。将急性海马脑片随机分为对照组、睾酮组、DHT组和T-BSA组。睾酮和DHT的药物作用浓度为10 nmol/L,T-BSA为0.36 nmol/L。给药1 h后,通过Golgi-Cox染色、免疫荧光组织化学染色和免疫印迹观察各组神经元树突棘密度以及SYN和PSD95的变化。结果:DAPI和PI同时染色显示,急性海马脑片神经元在0、15、30、60、120 min 5个时间点上活细胞百分比差异无统计学意义。Golgi-Cox染色实验显示,与对照组相比,睾酮组、DHT组和T-BSA组的树突棘密度明显增加;睾酮组、DHT组和T-BSA组之间树突棘密度差异无统计学意义。免疫荧光组织化学染色和免疫印迹实验显示,与对照组相比,睾酮组、DHT组和T-BSA组的SYN和PSD95蛋白表达明显增加;睾酮组、DHT组和T-BSA组之间SYN和PSD95蛋白表达差异无统计学意义。结论:制备的急性海马脑片神经元在2 h内细胞活性良好。雄激素通过非基因组效应增加了急性海马脑片神经元树突棘密度以及SYN和PSD95的表达。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
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 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financially supported by the National Natural Science Foundation of China(22168019 and 52074141)the Major Science and Technology Projects in Yunnan Province(202202AB080014)+1 种基金The authors are grateful to the National Natural Science Foundation of Chinathe Major Science and Technology Projects in Yunnan Province for their support.
文摘Zinc(Zn)-air batteries are widely used in secondary battery research owing to their high theoretical energy density,good electrochemical reversibility,stable discharge performance,and low cost of the anode active material Zn.However,the Zn anode also leads to many challenges,including dendrite growth,deformation,and hydrogen precipitation self-corrosion.In this context,Zn dendrite growth has a greater impact on the cycle lives.In this dissertation,a dendrite growth model for a Zn-air battery was established based on electrochemical phase field theory,and the effects of the charging time,anisotropy strength,and electrolyte temperature on the morphology and growth height of Zn dendrites were studied.A series of experiments was designed with different gradient influencing factors in subsequent experiments to verify the theoretical simulations,including elevated electrolyte temperatures,flowing electrolytes,and pulsed charging.The simulation results show that the growth of Zn dendrites is controlled mainly by diffusion and mass transfer processes,whereas the electrolyte temperature,flow rate,and interfacial energy anisotropy intensity are the main factors.The experimental results show that an optimal electrolyte temperature of 343.15 K,an optimal electrolyte flow rate of 40 ml·min^(-1),and an effective pulse charging mode.
基金financially supported by Fuzhou science and technology project (Nos.2021-ZD-213 and 2020-Z-6)Fujian Provincial Department of Science and Technology(Nos.2021T3036,2020T3004,2020T3030 and 2020H0040)+2 种基金STS Science And Technology Project of the Chinese Academy of Sciences(No.KFJ-STS-QYZD-2021-09-001)Quanzhou Science and Technology Project (No.2020G17)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy (No.2021009)。
文摘Metallic zinc is an excellent anode material for Zn-ion batteries,but the growth of Zn dendrite severely hinders its practical application.Herein,an efficient and economical cationic additive,poly dimethyl diallyl ammonium(PDDA) was reported,used in aqueous Zn-ion batteries electrolyte for stabilizing Zn anode.The growth of zinc dendrites can be significantly restrained by benefiting from the pronounced electrostatic shielding effect from PDDA on the Zn metal surface.Moreover,the PDDA is preferentially absorbed on Zn(002) plane,thus preventing unwanted side reactions on Zn anode.Owing to the introduction of a certain amount of PDDA additive into the common ZnSO_(4)-based electrolyte,the cycle life of assembled Zn‖Zn cells(1 mA·cm^(-2) and 1 mAh·cm^(-2)) is prolonged to more than 1100 h.In response to the perforation issue of Zn electrodes caused by PDDA additives,the problem can be solved by combining foamy copper with zinc foil.For real application,Zn-ion hybrid supercapacitors and MnO_(2)‖Zn cells were assembled,which exhibited excellent cycling stability with PDDA additives.This work provides a new solution and perspective to cope with the dendrite growth problem of Zn anode.
文摘目的:制备急性海马脑片,探讨睾酮(T)、双氢睾酮(DHT)、睾酮-牛血清白蛋白(T-BSA)对海马脑片神经元树突棘密度和突触蛋白[突触素(SYN)、突触后致密物质95(PSD95)]的非基因组效应。方法:选用3月龄SD雄性大鼠,麻醉后取脑,在人工脑脊液中剥离海马组织,制备300μm的冠状海马脑片。随机在0、15、30、60、120 min 5个时间点使用细胞核染料DAPI和PI染色,评估神经元活性。将急性海马脑片随机分为对照组、睾酮组、DHT组和T-BSA组。睾酮和DHT的药物作用浓度为10 nmol/L,T-BSA为0.36 nmol/L。给药1 h后,通过Golgi-Cox染色、免疫荧光组织化学染色和免疫印迹观察各组神经元树突棘密度以及SYN和PSD95的变化。结果:DAPI和PI同时染色显示,急性海马脑片神经元在0、15、30、60、120 min 5个时间点上活细胞百分比差异无统计学意义。Golgi-Cox染色实验显示,与对照组相比,睾酮组、DHT组和T-BSA组的树突棘密度明显增加;睾酮组、DHT组和T-BSA组之间树突棘密度差异无统计学意义。免疫荧光组织化学染色和免疫印迹实验显示,与对照组相比,睾酮组、DHT组和T-BSA组的SYN和PSD95蛋白表达明显增加;睾酮组、DHT组和T-BSA组之间SYN和PSD95蛋白表达差异无统计学意义。结论:制备的急性海马脑片神经元在2 h内细胞活性良好。雄激素通过非基因组效应增加了急性海马脑片神经元树突棘密度以及SYN和PSD95的表达。
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.
