Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites wer...Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites were investigated by X-ray diffraction(XRD) and transmission electron microscopy (TEM). The nanocrystallites obtained experimentally are mixture of anatase and rutile, the uniform diameters of particles are about 30 nm. The phase transformation from anatase to rutile was accelerated by AlCl3, and rutile content is increased from 26.7 wt pct to 53.6 wt pct with increasing of addition of AlCl3 from 0.0 wt pct to 5.0 wt pct. The particle size is reduced and the size distribution becomes very narrow. The crystal lattice constants have the trend to decrease, and celi volumes appear as shrinkable.展开更多
Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors....Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors.Their fabrication requires exceptional precision in structural integrity,material control,and functional integration.Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional(3D)architectures and integrating multiple materials.While additive manufacturing(AM)provides flexibility,challenges remain in material alignment control,microstructural organization,and multifunctional integration.To overcome these limitations,field-assisted additive manufacturing(FAM)has emerged as a promising approach that combines magnetic,acoustic,or electric fields to regulate material alignment,microstructural organization,and spatial alignment.This capability improves fabrication precision,enhances material anisotropy and facilitates functional integration.This review systematically explores the mechanisms,fabrication process,and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based,while further exploring their applications in microrobotics,biomedical devices,and electronic sensors.Moreover,this review provides a comparative overview of different FAM approaches,highlighting their respective characteristics,typical applications,and unique advantages.In addition,the major challenges facing FAM research are comprehensively assessed and future directions are explored,including advances in spatial precision control capability,intelligent control for process integration,and multi-field coupling optimization.This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication.展开更多
Support structure,a critical component in the design for additive manufacturing(DfAM),has been largely overlooked by additive manufacturing(AM)communities.The support structure stabilises overhanging sections,aids in ...Support structure,a critical component in the design for additive manufacturing(DfAM),has been largely overlooked by additive manufacturing(AM)communities.The support structure stabilises overhanging sections,aids in heat dissipation,and reduces the risk of thermal warping,residual stress,and distortion,particularly in the fabrication of complex geometries that challenge traditional manufacturing methods.Despite the importance of support structures in AM,a systematic review covering all aspects of the design,optimisation,and removal of support structures remains lacking.This review provides an overview of various support structure types—contact and non-contact,as well as identical and dissimilar material configurations—and outlines optimisation methods,including geometric,topology,simulation-driven,data-driven,and multi-objective approaches.Additionally,the mechanisms of support removal,such as mechanical milling and chemical dissolution,and innovations like dissolvable supports and sensitised interfaces,are discussed.Future research directions are outlined,emphasising artificial intelligence(AI)-driven intelligent design,multi-material supports,sustainable support materials,support-free AM techniques,and innovative support removal methods,all of which are essential for advancing AM technology.Overall,this review aims to serve as a foundational reference for the design and optimisation of the support structure in AM.展开更多
Aqueous zinc-ion batteries(AZIBs)have emerged as a promising next-generation energy storage solution due to their high energy density,abundant resources,low cost,and high safety.However,unstable zinc anode caused by s...Aqueous zinc-ion batteries(AZIBs)have emerged as a promising next-generation energy storage solution due to their high energy density,abundant resources,low cost,and high safety.However,unstable zinc anode caused by side reactions and dendritic growth always severely worsens the long-term operation of AZIBs.Herein,a novel 3-cyclobutene sulfone(CS)additive was employed in the aqueous electrolyte to achieve a highly reversible Zn anode.The CS additive can offer strong electronegativity and high binding energy for the coordination with Zn^(2+),which enables its entry into the solvent sheath structure of Zn^(2+)and eliminates the free H_(2)O molecules from the solvated{Zn^(2+)-SO_(4)^(2-)-(H_(2)O)_(5)}.Thus,the occurrence of side reactions and dendritic growth can be effectively inhibited.Accordingly,the Zn anode achieves long cycle-life(1400 h at 1 m A cm^(-2),1 m Ah cm^(-2),and 400 h at 5 m A cm^(-2),5 m Ah cm^(-2))and high average coulombic efficiency(99.5% over 500 cycles at 10 m A cm^(-2),1 m Ah cm^(-2)).Besides,the assembled Zn||NH_(4)V_(4)O_(10)full cell suggests enhanced cycling reversibility(123.8 m Ah g^(-1)over 500 cycles at 2 A g^(-1),84.9 m Ah g^(-1)over 800 cycles at 5 A g^(-1))and improved rate capability(139.1 m Ah g^(-1)at 5 A g^(-1)).This work may exhibit the creative design and deep understanding of sulfone-based electrolyte additives for the achievement of high-performance AZIBs.展开更多
Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-...Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-free printing,which has specific applications in fields such as life sciences and optics.However,traditional VAM processes require numerous projections and extensive computational preparation,limiting practical applications due to low projection efficiency and prolonged calculation times.In this study,we developed sparse-view irradiation processing VAM(SVIP-VAM),employing an optimized odd-even(OE) irradiation strategy inspired by sparse-view computed tomography.Theoretically,we demonstrated structural contour reconstruction feasibility with as few as 8 projections.Using this sparse-view approach,we achieved high-quality fabrication with only 15 projections,enhancing each projection efficiency by over 60 times and reducing projection set computational time by nearly 10-fold.Ultimately,this efficient sparse-view method significantly expands VAM applications into fields requiring rapid manufacturing,such as tissue engineering,medical implants,and aerospace manufacturing.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising technique for producing large-scale metal components,favoured by high deposition rates,flexibility and low cost.Despite its potential,the complexity of W...Wire arc additive manufacturing(WAAM)has emerged as a promising technique for producing large-scale metal components,favoured by high deposition rates,flexibility and low cost.Despite its potential,the complexity of WAAM processes,which involves intricate thermal dynamics,phase transitions,and metallurgical,mechanical,and chemical interactions,presents considerable challenges in final product qualities.Simulation technologies in WAAM have proven invaluable,providing accurate predictions in key areas such as material properties,defect identification,deposit morphology,and residual stress.These predictions play a critical role in optimising manufacturing strategies for the final product.This paper provides a comprehensive review of the simulation techniques applied in WAAM,tracing developments from 2013 to 2023.Initially,it analyses the current challenges faced by simulation methods in three main areas.Subsequently,the review explores the current modelling approaches and the applications of these simulations.Following this,the paper discusses the present state of WAAM simulation,identifying specific issues inherent to WAAM simulation itself.Finally,through a thorough review of existing literature and related analysis,the paper offers future perspectives on potential advancements in WAAM simulation strategies.展开更多
Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio o...Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio of Li/Si and the sintering temperatures on properties were discussed in terms of electrical properties and microstructures of materials.The results showed thatSrTiO 3 based varistor ceramics,with 0.6 mol% Li 2CO 3 SiO 2(Li/Si=3/2) and sintered at 1 380 ℃ in graphite and N 2 reducing atomosphere,had excellent current volatage sensing and dielectric characteristics.展开更多
Electromagnetic(EM)metamaterial absorbers(MMAs)with broadband absorption are of growing interest for applications such as stealth and EM interference mitigation.In this work,we present a novel 3D-printed MMA based on ...Electromagnetic(EM)metamaterial absorbers(MMAs)with broadband absorption are of growing interest for applications such as stealth and EM interference mitigation.In this work,we present a novel 3D-printed MMA based on a fused annular microfluidic metaatom(FAMMA)architecture,designed for W-band absorption.The FAMMA structure features three kinds of orthogonally fused annual meta-atoms,forming a complex 3D microfluidic meta-atom with intricate architecture.Fabricated via high-precision micro 3D printing technology,the FAMMA-based MMA exploits the synergistic solid-liquid coupling effect of the unique three-dimensional orthogonal structure to achieve strong broadband absorption.Three representative FAMMAs with different geometric dimensions have achieved ultra-low reflection loss(RL of-42.1 dB),ultra-broadband effective absorption bandwidth(EAB of 31.3 GHz),and dual-band absorption(in 76.0-85.3 and 99.1-105.6 GHz),respectively.The underlying absorption mechanisms are elucidated by impedance matching theory and electromagnetic field distribution analyses.Application demonstrations show that the FAMMA-based MMA significantly suppresses radar echo power and renders metallic targets undetectable to both radar detector and radar imaging systems,highlighting its potential in stealth technology.Overall,this work establishes a new design concept for high-performance broadband millimeter wave MMAs,opening new avenue for future applications such as high-speed communication,through-wall sensing,and drone detection.展开更多
Additive Manufacturing,also known as 3D printing,has transformed conventional manufacturing by building objects layer by layer,with material extrusion or fused deposition modeling standing out as particularly popular....Additive Manufacturing,also known as 3D printing,has transformed conventional manufacturing by building objects layer by layer,with material extrusion or fused deposition modeling standing out as particularly popular.However,due to its manufacturing process and thermal nature,internal voids and pores are formed within the thermoplastic materials being fabricated,potentially leading to a decrease in mechanical properties.This paper discussed the effect of printing parameters on the porosity and the mechanical properties of the 3D printed polylactic acid(PLA)through micro-computed tomography(microCT),computational image analysis,and Charpy impact testing.The results for both tests were correlated to investigate the relationship between porosity and Charpy impact strength.PLA samples of 1 cm^(3)×1 cm^(3)×1 cm^(3) were 3D printed at printing temperatures of 180℃,200℃,220℃,and 240℃,and at printing speeds of 50,80,and 110 mm/s,while porosity was measured frommicroCT-reconstructed data.Additionally,impact strength was assessed using a notched Charpy impact tester following ASTMD6610-18.In general,results show that higher printing temperatures and lower printing speeds reduced pore size by improving material flow and fusion,while also increasing impact strength due to better thermal bonding and interlayer adhesion.A maximum 36.8% reduction in mean pore size and a 114% improvement in impact strength were observed at 110 mm/s and 220℃.Conversely,increasing printing speed led to lowerCharpy impact strength.Optimal impact behavior andminimal voids were observed at a printing temperature of 220℃ and a printing speed of 50 mm/s.展开更多
The electrolyte additive,lithium nitrate(LiNO_(3)),is widely recognized for suppressing dendritic lithium growth in anode-free lithium metal batteries,yet its stabilizing effect is transient,and the mechanistic origin...The electrolyte additive,lithium nitrate(LiNO_(3)),is widely recognized for suppressing dendritic lithium growth in anode-free lithium metal batteries,yet its stabilizing effect is transient,and the mechanistic origin of this limitation has remained unresolved.Here,we uncover the origin of this behavior through a comprehensive analysis driven by artifact/damage-free direct cryogenic transmission electron microscopy,which enabled one of the most chemically specific and morphologically intuitive visualizations to date of intact solid-electrolyte interphases(SEIs)and lithium growth.Contrary to conventional interpretations centered on nitrogen-rich or single-component SEIs,we reveal that LiNO_(3) rapidly generates lithium hydroxide(LiOH)and lithium oxide(Li_(2)O)rich interphases,whose complementary functions—ionic transport through LiOH and mechanical robustness from Li_(2)O—synergistically suppress whisker nucleation and favor compact,particle-like growth.Over the extended plating,however,depletion of these species in combination with crystallographically favored orientations drives the particle-towhisker transition,explaining why the effectiveness of LiNO_(3) is inherently limited.This direct mechanistic visualization resolves a long-standing ambiguity regarding the transient efficacy of LiNO_(3) and reframes its function from a nitrogen-driven mechanism to a synergistic dual oxygen-interphase framework.Beyond mechanistic clarification,these findings establish that continuous regeneration of LiOH and Li_(2)O is essential for stable lithium deposition,offering a design principle for the development of durable electrolytes in high-performance anode-free lithium metal batteries.展开更多
Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio o...Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio of Li/Si and the sintering temperatures on properties were discussed in terms of electrical properties and microstructures of materials.The results showed thatSrTiO 3 based varistor ceramics,with 0.6 mol% Li 2CO 3 SiO 2(Li/Si=3/2) and sintered at 1 380 ℃ in graphite and N 2 reducing atomosphere,had excellent current volatage sensing and dielectric characteristics.展开更多
文摘Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites were investigated by X-ray diffraction(XRD) and transmission electron microscopy (TEM). The nanocrystallites obtained experimentally are mixture of anatase and rutile, the uniform diameters of particles are about 30 nm. The phase transformation from anatase to rutile was accelerated by AlCl3, and rutile content is increased from 26.7 wt pct to 53.6 wt pct with increasing of addition of AlCl3 from 0.0 wt pct to 5.0 wt pct. The particle size is reduced and the size distribution becomes very narrow. The crystal lattice constants have the trend to decrease, and celi volumes appear as shrinkable.
基金financial support from the National Natural Science Foundation of China(Nos.52205590,52575652,52322502,52175009)State Key Laboratory of Robotics and Systems(HIT)(No.SKLRS-2024-KF11)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20220834)the Taihu Lake Innovation Fund for the School of Future Technology of Southeast University,the Start-up Research Fund of Southeast University(No.RF1028623098)the National Heilongjiang Providence Nature Science Foundation of China(YQ2022E022)the European Research Council(ERC)under the European Union’s Horizon Europe research and innovation programme(I-BOT Project,Grant Agreement No.101162939)。
文摘Micro/nano devices(MNDs)are characterized by miniaturization,high precision,and multifunctional integration,making them highly suitable for use in areas such as microrobotics,biomedical devices and electronic sensors.Their fabrication requires exceptional precision in structural integrity,material control,and functional integration.Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional(3D)architectures and integrating multiple materials.While additive manufacturing(AM)provides flexibility,challenges remain in material alignment control,microstructural organization,and multifunctional integration.To overcome these limitations,field-assisted additive manufacturing(FAM)has emerged as a promising approach that combines magnetic,acoustic,or electric fields to regulate material alignment,microstructural organization,and spatial alignment.This capability improves fabrication precision,enhances material anisotropy and facilitates functional integration.This review systematically explores the mechanisms,fabrication process,and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based,while further exploring their applications in microrobotics,biomedical devices,and electronic sensors.Moreover,this review provides a comparative overview of different FAM approaches,highlighting their respective characteristics,typical applications,and unique advantages.In addition,the major challenges facing FAM research are comprehensively assessed and future directions are explored,including advances in spatial precision control capability,intelligent control for process integration,and multi-field coupling optimization.This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication.
基金supported by the Advanced Research and Technology Innovation Centre (ARTIC)the National University of Singapore under Grant (Project Number:ADTRP1)the sponsorship of the China Scholarship Council (No. 202306130143).
文摘Support structure,a critical component in the design for additive manufacturing(DfAM),has been largely overlooked by additive manufacturing(AM)communities.The support structure stabilises overhanging sections,aids in heat dissipation,and reduces the risk of thermal warping,residual stress,and distortion,particularly in the fabrication of complex geometries that challenge traditional manufacturing methods.Despite the importance of support structures in AM,a systematic review covering all aspects of the design,optimisation,and removal of support structures remains lacking.This review provides an overview of various support structure types—contact and non-contact,as well as identical and dissimilar material configurations—and outlines optimisation methods,including geometric,topology,simulation-driven,data-driven,and multi-objective approaches.Additionally,the mechanisms of support removal,such as mechanical milling and chemical dissolution,and innovations like dissolvable supports and sensitised interfaces,are discussed.Future research directions are outlined,emphasising artificial intelligence(AI)-driven intelligent design,multi-material supports,sustainable support materials,support-free AM techniques,and innovative support removal methods,all of which are essential for advancing AM technology.Overall,this review aims to serve as a foundational reference for the design and optimisation of the support structure in AM.
基金the financial support from the Foshan Talents Special Foundation(BKBS202003)。
文摘Aqueous zinc-ion batteries(AZIBs)have emerged as a promising next-generation energy storage solution due to their high energy density,abundant resources,low cost,and high safety.However,unstable zinc anode caused by side reactions and dendritic growth always severely worsens the long-term operation of AZIBs.Herein,a novel 3-cyclobutene sulfone(CS)additive was employed in the aqueous electrolyte to achieve a highly reversible Zn anode.The CS additive can offer strong electronegativity and high binding energy for the coordination with Zn^(2+),which enables its entry into the solvent sheath structure of Zn^(2+)and eliminates the free H_(2)O molecules from the solvated{Zn^(2+)-SO_(4)^(2-)-(H_(2)O)_(5)}.Thus,the occurrence of side reactions and dendritic growth can be effectively inhibited.Accordingly,the Zn anode achieves long cycle-life(1400 h at 1 m A cm^(-2),1 m Ah cm^(-2),and 400 h at 5 m A cm^(-2),5 m Ah cm^(-2))and high average coulombic efficiency(99.5% over 500 cycles at 10 m A cm^(-2),1 m Ah cm^(-2)).Besides,the assembled Zn||NH_(4)V_(4)O_(10)full cell suggests enhanced cycling reversibility(123.8 m Ah g^(-1)over 500 cycles at 2 A g^(-1),84.9 m Ah g^(-1)over 800 cycles at 5 A g^(-1))and improved rate capability(139.1 m Ah g^(-1)at 5 A g^(-1)).This work may exhibit the creative design and deep understanding of sulfone-based electrolyte additives for the achievement of high-performance AZIBs.
基金supported financially by the Beijing Municipal Natural Science Foundation (L232109)National Natural Science Foundation of China (22073003)Fundamental Research Funds for the Central Universities (YWF-22-K-101)。
文摘Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-free printing,which has specific applications in fields such as life sciences and optics.However,traditional VAM processes require numerous projections and extensive computational preparation,limiting practical applications due to low projection efficiency and prolonged calculation times.In this study,we developed sparse-view irradiation processing VAM(SVIP-VAM),employing an optimized odd-even(OE) irradiation strategy inspired by sparse-view computed tomography.Theoretically,we demonstrated structural contour reconstruction feasibility with as few as 8 projections.Using this sparse-view approach,we achieved high-quality fabrication with only 15 projections,enhancing each projection efficiency by over 60 times and reducing projection set computational time by nearly 10-fold.Ultimately,this efficient sparse-view method significantly expands VAM applications into fields requiring rapid manufacturing,such as tissue engineering,medical implants,and aerospace manufacturing.
基金supported in part by China Scholarship Council under Grant 202208200010。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising technique for producing large-scale metal components,favoured by high deposition rates,flexibility and low cost.Despite its potential,the complexity of WAAM processes,which involves intricate thermal dynamics,phase transitions,and metallurgical,mechanical,and chemical interactions,presents considerable challenges in final product qualities.Simulation technologies in WAAM have proven invaluable,providing accurate predictions in key areas such as material properties,defect identification,deposit morphology,and residual stress.These predictions play a critical role in optimising manufacturing strategies for the final product.This paper provides a comprehensive review of the simulation techniques applied in WAAM,tracing developments from 2013 to 2023.Initially,it analyses the current challenges faced by simulation methods in three main areas.Subsequently,the review explores the current modelling approaches and the applications of these simulations.Following this,the paper discusses the present state of WAAM simulation,identifying specific issues inherent to WAAM simulation itself.Finally,through a thorough review of existing literature and related analysis,the paper offers future perspectives on potential advancements in WAAM simulation strategies.
文摘Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio of Li/Si and the sintering temperatures on properties were discussed in terms of electrical properties and microstructures of materials.The results showed thatSrTiO 3 based varistor ceramics,with 0.6 mol% Li 2CO 3 SiO 2(Li/Si=3/2) and sintered at 1 380 ℃ in graphite and N 2 reducing atomosphere,had excellent current volatage sensing and dielectric characteristics.
基金support by the National Key Research and Development Program of China(Xiaosheng Zhang:No.2022YFB3206100)the National Natural Science Foundation of China(Yi Zhang:No.62271107,Qiye Wen:No.62235004,62311530115,Shaomeng Wang:T2241002)+2 种基金the Natural Science Foundation of Sichuan Province(Yi Zhang:No.2025ZNSFSC0464)the Key R&D Program of Mianyang(Xiaosheng Zhang:No.2023ZYDF019)the Fundamental Research Funds for the Central Universities(Yi Zhang:No.ZYGX2022YGRH007).
文摘Electromagnetic(EM)metamaterial absorbers(MMAs)with broadband absorption are of growing interest for applications such as stealth and EM interference mitigation.In this work,we present a novel 3D-printed MMA based on a fused annular microfluidic metaatom(FAMMA)architecture,designed for W-band absorption.The FAMMA structure features three kinds of orthogonally fused annual meta-atoms,forming a complex 3D microfluidic meta-atom with intricate architecture.Fabricated via high-precision micro 3D printing technology,the FAMMA-based MMA exploits the synergistic solid-liquid coupling effect of the unique three-dimensional orthogonal structure to achieve strong broadband absorption.Three representative FAMMAs with different geometric dimensions have achieved ultra-low reflection loss(RL of-42.1 dB),ultra-broadband effective absorption bandwidth(EAB of 31.3 GHz),and dual-band absorption(in 76.0-85.3 and 99.1-105.6 GHz),respectively.The underlying absorption mechanisms are elucidated by impedance matching theory and electromagnetic field distribution analyses.Application demonstrations show that the FAMMA-based MMA significantly suppresses radar echo power and renders metallic targets undetectable to both radar detector and radar imaging systems,highlighting its potential in stealth technology.Overall,this work establishes a new design concept for high-performance broadband millimeter wave MMAs,opening new avenue for future applications such as high-speed communication,through-wall sensing,and drone detection.
文摘Additive Manufacturing,also known as 3D printing,has transformed conventional manufacturing by building objects layer by layer,with material extrusion or fused deposition modeling standing out as particularly popular.However,due to its manufacturing process and thermal nature,internal voids and pores are formed within the thermoplastic materials being fabricated,potentially leading to a decrease in mechanical properties.This paper discussed the effect of printing parameters on the porosity and the mechanical properties of the 3D printed polylactic acid(PLA)through micro-computed tomography(microCT),computational image analysis,and Charpy impact testing.The results for both tests were correlated to investigate the relationship between porosity and Charpy impact strength.PLA samples of 1 cm^(3)×1 cm^(3)×1 cm^(3) were 3D printed at printing temperatures of 180℃,200℃,220℃,and 240℃,and at printing speeds of 50,80,and 110 mm/s,while porosity was measured frommicroCT-reconstructed data.Additionally,impact strength was assessed using a notched Charpy impact tester following ASTMD6610-18.In general,results show that higher printing temperatures and lower printing speeds reduced pore size by improving material flow and fusion,while also increasing impact strength due to better thermal bonding and interlayer adhesion.A maximum 36.8% reduction in mean pore size and a 114% improvement in impact strength were observed at 110 mm/s and 220℃.Conversely,increasing printing speed led to lowerCharpy impact strength.Optimal impact behavior andminimal voids were observed at a printing temperature of 220℃ and a printing speed of 50 mm/s.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2024-00406724(50%)RS-2023-00222411,RS-2025-24533073)+2 种基金the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Korea government(MOE)(RS-2024-00436346)the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea government(MOTIE)(RS-2024-00417730,HRD Program for Industrial Innovation)the research fund of Hanyang University(HY-202100000003295)。
文摘The electrolyte additive,lithium nitrate(LiNO_(3)),is widely recognized for suppressing dendritic lithium growth in anode-free lithium metal batteries,yet its stabilizing effect is transient,and the mechanistic origin of this limitation has remained unresolved.Here,we uncover the origin of this behavior through a comprehensive analysis driven by artifact/damage-free direct cryogenic transmission electron microscopy,which enabled one of the most chemically specific and morphologically intuitive visualizations to date of intact solid-electrolyte interphases(SEIs)and lithium growth.Contrary to conventional interpretations centered on nitrogen-rich or single-component SEIs,we reveal that LiNO_(3) rapidly generates lithium hydroxide(LiOH)and lithium oxide(Li_(2)O)rich interphases,whose complementary functions—ionic transport through LiOH and mechanical robustness from Li_(2)O—synergistically suppress whisker nucleation and favor compact,particle-like growth.Over the extended plating,however,depletion of these species in combination with crystallographically favored orientations drives the particle-towhisker transition,explaining why the effectiveness of LiNO_(3) is inherently limited.This direct mechanistic visualization resolves a long-standing ambiguity regarding the transient efficacy of LiNO_(3) and reframes its function from a nitrogen-driven mechanism to a synergistic dual oxygen-interphase framework.Beyond mechanistic clarification,these findings establish that continuous regeneration of LiOH and Li_(2)O is essential for stable lithium deposition,offering a design principle for the development of durable electrolytes in high-performance anode-free lithium metal batteries.
文摘Semiconducting SrTiO 3 based voltage sensing and dielectric ceramics were prepared by single step sintering with Li 2CO 3 SiO 2 as liquid phase additives.The effects of the content of liquid phase,the ratio of Li/Si and the sintering temperatures on properties were discussed in terms of electrical properties and microstructures of materials.The results showed thatSrTiO 3 based varistor ceramics,with 0.6 mol% Li 2CO 3 SiO 2(Li/Si=3/2) and sintered at 1 380 ℃ in graphite and N 2 reducing atomosphere,had excellent current volatage sensing and dielectric characteristics.
