Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stre...Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT), showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the展开更多
An environmental friendly anodizing treatment (Anomag) from a phosphate-based so lution without heavy metals on AZ91D magnesium alloy was studied. The characteri stics of the coatings, such as structure, composition a...An environmental friendly anodizing treatment (Anomag) from a phosphate-based so lution without heavy metals on AZ91D magnesium alloy was studied. The characteri stics of the coatings, such as structure, composition and corrosion resistance w ere investigated. The effects of this anodizing treatment on the mechanical prop erties were examined. X-ray diffraction (XRD) analysis revealed that the structu re of the coatings is amorphous or glassy. In salt spray tests coatings with an average thickness of 10μm had an anticorrosive performance of over 1000 hours. Fatigue tests revealed that anodizing onto AZ91D magnesium alloy does not affect the fatigue strength. These results demonstrate the utility of this anodizing t reatment on magnesium alloy for application as a structural material, such as in the automotive field.展开更多
The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversi...The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversion treatment and anodizing can increase the bonding strength. The anodizing treatment gives higher bonding strength and better corrosion resistance than chemical conversion treatment. The increase of bonding strength by the treatmetlts may be attributed to the uneven surface structures with micro-pores, resulting in increased bonding areas and the embedding effect.展开更多
An anodizing process, based on environmental friendly electrolyte solutions has been studied on AZ 91 magnesium alloys by using three types of electrolytes: the first is based on sodium silicate, the second on sodium ...An anodizing process, based on environmental friendly electrolyte solutions has been studied on AZ 91 magnesium alloys by using three types of electrolytes: the first is based on sodium silicate, the second on sodium hydroxide-boric acid-borax and the third on sodium silicate- potassium hydroxide-sodium carbonate-sodium tetra borate. A pretreatment including fluoride activation was applied before the anodizing process. It was found that the anodic film thickness increases as current density or anodizing voltage increases. It is also increased with deposition time until the deposition stops due to the formation of a thick anodic film. Optimization of the anodizing conditions - current density and deposition time- was made for each electrolyte. Characterization of anodizing layer was achieved by determination of surface morphology, microstructure, phase analysis, coat thickness, adhesion and corrosion resistance. In all cases, excellent adhesion and corrosion resistance was obtained. A corrosion efficiency ranging from 94% to 97% was reached;the highest value corresponding to the third electrolyte.展开更多
2024 T3 is one of aluminium alloys which are widely used in the aircraft structures. Anodizing of alluminium alloy in tartaric-sulphuric acid (TSA) electrolyte is developed to obtain more environmentally-friendly proc...2024 T3 is one of aluminium alloys which are widely used in the aircraft structures. Anodizing of alluminium alloy in tartaric-sulphuric acid (TSA) electrolyte is developed to obtain more environmentally-friendly process and to produce anodize layer with better corrosion resistance. In this research work, the influences of anodizing parameters of Al 2024 T3 in TSA on the thickness, weight and corrosion resistance of the anodize layer are studied. Corrosion resistance test was carried out by conducting salt spray test for 336 hours and anodic polarization measurements using potentiostat. Results of three-factor analysis of variance (ANOVA) demonstrated that the most influencing factor that determines the thickness and weight of the anodize layer is temperature, followed by applied voltage, duration of anodizing, voltage-temperature interaction, interaction of temperature-duration of anodizing, interaction of voltage-temperature-duration of anodizing, and interaction of voltage and duration of anodizing. The pit density and corrosion current density (icorr) were found to be dependent on the coating thickness. The anodize layer with a thickness of higher than 3 μm was not experienced to pitting corrosion during 336 hours of salt spray test.展开更多
Magnesium alloy, a kind of environment-friendly material with promising and excellent properties, is a good choice for a number of applications. The research and development of anodizing on magnesium alloys and its ap...Magnesium alloy, a kind of environment-friendly material with promising and excellent properties, is a good choice for a number of applications. The research and development of anodizing on magnesium alloys and its application situation are reviewed, and the anodizing development trend on magnesium alloys is summarized.展开更多
The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The ano...The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.展开更多
A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The fi...A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The films were then anodized in 0.3 M oxalic acid.Through appropriate chemical dissolution,the alumina film was removed and the underlying micro-porous 316 L with diameters ranging from 500 nm to 2.4m was obtained.The morphology of the porous 316 L surface was examined by scanning electron microscope.The results indicate that the thickness of aluminum films and the anodizing potential have a combined action on the formation of porous structure on 316 L surface.Then anodic current density could be affected evidently by the film thickness.The pores size increases obviously with the increasing of the anodizing potential,when the thickness of aluminum film was about 1.4m.展开更多
Independent microstructures made of Ni metal were fabricated by fivesequential processes: porous anodic oxide film formation, pore sealing, laser irradiation, Nielectroplating, and removal of the aluminum substrate an...Independent microstructures made of Ni metal were fabricated by fivesequential processes: porous anodic oxide film formation, pore sealing, laser irradiation, Nielectroplating, and removal of the aluminum substrate and anodic oxide films. Aluminum plates androds were anodized in an oxalic acid solution to form porous type anodic oxide films, and thenimmersed in boiling distilled water for pore sealing. The anodized and pore-sealed specimens wereirradiated with a pulsed neodymium-doped yttrium aluminum garnet (Nd-YAG) laser beam in a Ni platingsolution to remove anodic oxide film locally by rotating and moving up I down with anXYZ(theta)-stage. Nickel was deposited at the area where film had been removed by cathodicpolarization in the solution before removing the aluminum substrate and anodic oxide films in NaOHsolutions. Cylindrical or plain network structures were fabricated successfully.展开更多
With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes ...With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox kinetics.Therefore,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for KIBs.Through effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was enhanced.The potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).Furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain material.Ex-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the niobium.This work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.展开更多
Based on the attributes of nonflammability,environmental benignity,and cost-effectiveness of aqueous electrolytes,as well as the favorable compatibility of zinc metal with them,aqueous zinc ions batteries(AZIBs)become...Based on the attributes of nonflammability,environmental benignity,and cost-effectiveness of aqueous electrolytes,as well as the favorable compatibility of zinc metal with them,aqueous zinc ions batteries(AZIBs)become the leading energy storage candidate to meet the requirements of safety and low cost.Yet,aqueous electrolytes,acting as a double-edged sword,also play a negative role by directly or indirectly causing various parasitic reactions at the zinc anode side.These reactions include hydrogen evolution reaction,passivation,and dendrites,resulting in poor Coulombic efficiency and short lifespan of AZIBs.A comprehensive review of aqueous electrolytes chemistry,zinc chemistry,mechanism and chemistry of parasitic reactions,and their relationship is lacking.Moreover,the understanding of strategies for suppressing parasitic reactions from an electrochemical perspective is not profound enough.In this review,firstly,the chemistry of electrolytes,zinc anodes,and parasitic reactions and their relationship in AZIBs are deeply disclosed.Subsequently,the strategies for suppressing parasitic reactions from the perspective of enhancing the inherent thermodynamic stability of electrolytes and anodes,and lowering the dynamics of parasitic reactions at Zn/electrolyte interfaces are reviewed.Lastly,the perspectives on the future development direction of aqueous electrolytes,zinc anodes,and Zn/electrolyte interfaces are presented.展开更多
The Al-Ti composite oxide films with high dielectric constant were prepared by hydrolysis precipitation and anodizing. The growth, structure and electrical properties of the Al-Ti composite oxide films formed at diffe...The Al-Ti composite oxide films with high dielectric constant were prepared by hydrolysis precipitation and anodizing. The growth, structure and electrical properties of the Al-Ti composite oxide films formed at different anodizing temperatures from 25℃ to 85℃ have been studied by dissolution of anodic oxide films, Auger electron spectroscopy (AES), and electrical measurements. With the anodizing temperature increasing, the film growth rate increases, the structure of two layers in the Al-Ti composite oxide film converts into three layers, I-V characteristics change evidently, and the specific capacitance achieves a peak value at about 75℃. The local breakdown in the composite oxide films formed at 50℃ occurs obviously, which may be contributed to the lowest leakage current and the highest withstanding voltage.展开更多
Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy de...Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy density,low cost,and recyclability.However,the study on Mg-air battery(MAB)is still at the laboratory level currently,mainly owing to the low anodic efficiency caused by the poor corrosion resistance.In order to reduce corrosion losses and achieve optimal utilization efficiency of Mg anode,the design strategies are reviewed from microstructure perspectives.Firstly,the corrosion behaviors have been discussed,especially the negative difference effect derived by hydrogen evolution.Special attention is given to the effect of anode micro-structures on the MAB,which includes grain size,grain orientation,second phases,crystal structure,twins,and dislocations.For further improvement,the discharge performance,long period stacking ordered phase and its enhancing effect are considered.Meanwhile,given the current debates over Mg dendrites,the potential risk,the impact on discharge,and the elimination strategies are discussed.Microstructure control and single crystal would be promising ways for MAB anode.展开更多
Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile me...Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data encryption.However,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing times.In contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient conditions.By means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare memristors.Oxide film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and time.Thus memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield rate.This article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of memristors.Firstly,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.展开更多
Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reserv...Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reservoir.Here,alloying Li metal with low-content magnesium(Mg)is proposed to mitigate the reaction kinetics between Li metal anodes and electrolytes.Mg atoms enter the lattice of Li atoms,forming solid solution due to the low amount(5 wt%)of Mg.Mg atoms mainly concentrate near the surface of Mg-alloyed Li metal anodes.The reactivity of Mg-alloyed Li metal is mitigated kinetically,which results from the electron transfer from Li to Mg atoms due to the electronegativity difference.Based on quantitative experimental analysis,the consumption rate of active Li and electrolytes is decreased by using Mgalloyed Li metal anodes,which increases the cycle life of Li metal batteries under demanding conditions.Further,a pouch cell(1.25 Ah)with Mg-alloyed Li metal anodes delivers an energy density of 340 Wh kg^(-1)and a cycle life of 100 cycles.This work inspires the strategy of modifying Li metal anodes to kinetically mitigate the side reactions with electrolytes.展开更多
Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zin...Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zinc dendrites, passivation, corrosion, and hydrogen evolution reactions during the charging and discharging of batteries, becoming obstacles to the practical application of ZIBs. Appropriate zinc metal-free anodes provide a higher working potential than metallic zinc anodes, effectively solving the problems of zinc dendrites, hydrogen evolution, and side reactions during the operation of metallic zinc anodes. The improvement in the safety and cycle life of batteries creates conditions for further commercialization of ZIBs. Therefore, this work systematically introduces the research progress of zinc metal-free anodes in “rocking chair” ZIBs. Zinc metal-free anodes are mainly discussed in four categories: transition metal oxides,transition metal sulfides, MXene(two dimensional transition metal carbide) composites, and organic compounds, with discussions on their properties and zinc storage mechanisms. Finally, the outlook for the development of zinc metal-free anodes is proposed. This paper is expected to provide a reference for the further promotion of commercial rechargeable ZIBs.展开更多
The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recyc...The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recycling of LIBs at the end of their life.Herein,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—from spent LIBs and investigate its reuse in newly assembled LIBs.It has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities from the recycling process,the recycled graphite provides a remarkable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NMC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.展开更多
Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal ...Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.展开更多
Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material...Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.展开更多
Due to concerns regarding the future availability,cost,and safety of lithium in Li-ion batteries(LIBs),researchers are exploring alternative chemistries such as Na-ion,Li-S,Li-air,and multivalent ion technologies.Mult...Due to concerns regarding the future availability,cost,and safety of lithium in Li-ion batteries(LIBs),researchers are exploring alternative chemistries such as Na-ion,Li-S,Li-air,and multivalent ion technologies.Multivalent ion technologies,which utilize divalent or trivalent ions,like Mg^(2+),Ca^(2+),and Al^(3+),show promise in achieving greater energy densities than LIBs due to their ability to deposit uniformly on anodes and intercalate into cathodes.While magnesium-ion batteries(MIBs) have been the primary area of research for multivalent ion batteries,the cost-effectiveness and abundance of calcium have sparked a growing interest in calcium-ion batteries(CIBs) in recent years.Compared to LIBs,CIBs have the potential to provide longer cycle life,enhanced safety,and increased energy densities.However,the development of CIBs comes with several challenges,such as finding suitable electrode and electrolyte materials that ensure the stability and safety of the battery.The primary hurdle in CIBs lies in the plating/stripping process.There is a significant hindrance preventing the occurrence of plating/stripping in CIBs,which lies in the formation of a passive layer resulting from the decomposition of the electrolyte.The objective of this article is to examine the advancements made in CIBs.Additionally,it aims to comprehensively assess the mechanisms and materials employed in various battery components,as well as the obstacles encountered in CIBs.This includes recent advancements in electrode materials,electrolytes,cell configurations,and the challenges and opportunities for enhancing the performance and commercial viability of CIBs.展开更多
基金The authors are grateful to the National Nature Science Foundation of China (Grant No. 50635030) and the development project on industrialization of bionic non-adhesive cooker (Grant No. 2006D90304010) for the support of this work.
文摘Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT), showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the
文摘An environmental friendly anodizing treatment (Anomag) from a phosphate-based so lution without heavy metals on AZ91D magnesium alloy was studied. The characteri stics of the coatings, such as structure, composition and corrosion resistance w ere investigated. The effects of this anodizing treatment on the mechanical prop erties were examined. X-ray diffraction (XRD) analysis revealed that the structu re of the coatings is amorphous or glassy. In salt spray tests coatings with an average thickness of 10μm had an anticorrosive performance of over 1000 hours. Fatigue tests revealed that anodizing onto AZ91D magnesium alloy does not affect the fatigue strength. These results demonstrate the utility of this anodizing t reatment on magnesium alloy for application as a structural material, such as in the automotive field.
基金Funded by the Key Project of Science and Technology of Ministry of Education of China(No.108129)
文摘The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversion treatment and anodizing can increase the bonding strength. The anodizing treatment gives higher bonding strength and better corrosion resistance than chemical conversion treatment. The increase of bonding strength by the treatmetlts may be attributed to the uneven surface structures with micro-pores, resulting in increased bonding areas and the embedding effect.
文摘An anodizing process, based on environmental friendly electrolyte solutions has been studied on AZ 91 magnesium alloys by using three types of electrolytes: the first is based on sodium silicate, the second on sodium hydroxide-boric acid-borax and the third on sodium silicate- potassium hydroxide-sodium carbonate-sodium tetra borate. A pretreatment including fluoride activation was applied before the anodizing process. It was found that the anodic film thickness increases as current density or anodizing voltage increases. It is also increased with deposition time until the deposition stops due to the formation of a thick anodic film. Optimization of the anodizing conditions - current density and deposition time- was made for each electrolyte. Characterization of anodizing layer was achieved by determination of surface morphology, microstructure, phase analysis, coat thickness, adhesion and corrosion resistance. In all cases, excellent adhesion and corrosion resistance was obtained. A corrosion efficiency ranging from 94% to 97% was reached;the highest value corresponding to the third electrolyte.
文摘2024 T3 is one of aluminium alloys which are widely used in the aircraft structures. Anodizing of alluminium alloy in tartaric-sulphuric acid (TSA) electrolyte is developed to obtain more environmentally-friendly process and to produce anodize layer with better corrosion resistance. In this research work, the influences of anodizing parameters of Al 2024 T3 in TSA on the thickness, weight and corrosion resistance of the anodize layer are studied. Corrosion resistance test was carried out by conducting salt spray test for 336 hours and anodic polarization measurements using potentiostat. Results of three-factor analysis of variance (ANOVA) demonstrated that the most influencing factor that determines the thickness and weight of the anodize layer is temperature, followed by applied voltage, duration of anodizing, voltage-temperature interaction, interaction of temperature-duration of anodizing, interaction of voltage-temperature-duration of anodizing, and interaction of voltage and duration of anodizing. The pit density and corrosion current density (icorr) were found to be dependent on the coating thickness. The anodize layer with a thickness of higher than 3 μm was not experienced to pitting corrosion during 336 hours of salt spray test.
基金Project supported by Scientific Research Foundation of Chinese Education Committee and Chinese Aeronautics Science Foundation Committee
文摘Magnesium alloy, a kind of environment-friendly material with promising and excellent properties, is a good choice for a number of applications. The research and development of anodizing on magnesium alloys and its application situation are reviewed, and the anodizing development trend on magnesium alloys is summarized.
基金financially supported by the National Nature Science Foundation of China (No. 21371019)the Aero Science Foundation of China (No. 2011ZE51057)
文摘The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.
文摘A novel process for fabricating an in-situ micro-porous on 316 L stainless steel was described.Aluminum films about 0.7-1.4 m in thickness were deposited on 316 L stainless steel surface by magnetron sputtering.The films were then anodized in 0.3 M oxalic acid.Through appropriate chemical dissolution,the alumina film was removed and the underlying micro-porous 316 L with diameters ranging from 500 nm to 2.4m was obtained.The morphology of the porous 316 L surface was examined by scanning electron microscope.The results indicate that the thickness of aluminum films and the anodizing potential have a combined action on the formation of porous structure on 316 L surface.Then anodic current density could be affected evidently by the film thickness.The pores size increases obviously with the increasing of the anodizing potential,when the thickness of aluminum film was about 1.4m.
文摘Independent microstructures made of Ni metal were fabricated by fivesequential processes: porous anodic oxide film formation, pore sealing, laser irradiation, Nielectroplating, and removal of the aluminum substrate and anodic oxide films. Aluminum plates androds were anodized in an oxalic acid solution to form porous type anodic oxide films, and thenimmersed in boiling distilled water for pore sealing. The anodized and pore-sealed specimens wereirradiated with a pulsed neodymium-doped yttrium aluminum garnet (Nd-YAG) laser beam in a Ni platingsolution to remove anodic oxide film locally by rotating and moving up I down with anXYZ(theta)-stage. Nickel was deposited at the area where film had been removed by cathodicpolarization in the solution before removing the aluminum substrate and anodic oxide films in NaOHsolutions. Cylindrical or plain network structures were fabricated successfully.
基金Y.X.acknowledges the financial support of the Engineering and Physical Sciences Research Council(EP/X000087/1,EP/V000152/1)Leverhulme Trust(RPG-2021-138)Royal Society(IEC\NSFC\223016).
文摘With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox kinetics.Therefore,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for KIBs.Through effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was enhanced.The potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).Furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain material.Ex-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the niobium.This work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.
基金supported by the Academic Excellence Foundation of BUAA for PhD Studentsthe National Natural Science Foundation of China (Grant Number: 52001016)
文摘Based on the attributes of nonflammability,environmental benignity,and cost-effectiveness of aqueous electrolytes,as well as the favorable compatibility of zinc metal with them,aqueous zinc ions batteries(AZIBs)become the leading energy storage candidate to meet the requirements of safety and low cost.Yet,aqueous electrolytes,acting as a double-edged sword,also play a negative role by directly or indirectly causing various parasitic reactions at the zinc anode side.These reactions include hydrogen evolution reaction,passivation,and dendrites,resulting in poor Coulombic efficiency and short lifespan of AZIBs.A comprehensive review of aqueous electrolytes chemistry,zinc chemistry,mechanism and chemistry of parasitic reactions,and their relationship is lacking.Moreover,the understanding of strategies for suppressing parasitic reactions from an electrochemical perspective is not profound enough.In this review,firstly,the chemistry of electrolytes,zinc anodes,and parasitic reactions and their relationship in AZIBs are deeply disclosed.Subsequently,the strategies for suppressing parasitic reactions from the perspective of enhancing the inherent thermodynamic stability of electrolytes and anodes,and lowering the dynamics of parasitic reactions at Zn/electrolyte interfaces are reviewed.Lastly,the perspectives on the future development direction of aqueous electrolytes,zinc anodes,and Zn/electrolyte interfaces are presented.
基金This work was supported by the Science and Technology Foundation of UESTC of Young Scholars(Grant No.L0801301JX04018).
文摘The Al-Ti composite oxide films with high dielectric constant were prepared by hydrolysis precipitation and anodizing. The growth, structure and electrical properties of the Al-Ti composite oxide films formed at different anodizing temperatures from 25℃ to 85℃ have been studied by dissolution of anodic oxide films, Auger electron spectroscopy (AES), and electrical measurements. With the anodizing temperature increasing, the film growth rate increases, the structure of two layers in the Al-Ti composite oxide film converts into three layers, I-V characteristics change evidently, and the specific capacitance achieves a peak value at about 75℃. The local breakdown in the composite oxide films formed at 50℃ occurs obviously, which may be contributed to the lowest leakage current and the highest withstanding voltage.
基金supported by National Natural Science Foundation of China(52371095)Innovation Research Group of Universities in Chongqing(CXQT21030)+2 种基金Chongqing Talents:Exceptional Young Talents Project(CQYC201905100)Chongqing Youth Expert Studio,Chongqing Overseas Chinese Entrepreneurship and Innovation Support Program(cx2023117)Chongqing Natural Science Foundation Innovation and Development Joint Fund(CSTB 2022NS CQLZX0054)。
文摘Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy density,low cost,and recyclability.However,the study on Mg-air battery(MAB)is still at the laboratory level currently,mainly owing to the low anodic efficiency caused by the poor corrosion resistance.In order to reduce corrosion losses and achieve optimal utilization efficiency of Mg anode,the design strategies are reviewed from microstructure perspectives.Firstly,the corrosion behaviors have been discussed,especially the negative difference effect derived by hydrogen evolution.Special attention is given to the effect of anode micro-structures on the MAB,which includes grain size,grain orientation,second phases,crystal structure,twins,and dislocations.For further improvement,the discharge performance,long period stacking ordered phase and its enhancing effect are considered.Meanwhile,given the current debates over Mg dendrites,the potential risk,the impact on discharge,and the elimination strategies are discussed.Microstructure control and single crystal would be promising ways for MAB anode.
基金supported by the National Key Research and Development Program of China (Grant No.2018YFE0203802)Natural Science Foundation of Hubei Province, China (Grant No.2022CFA031)Dongguan Innovative Research Team Program (2020607101007)。
文摘Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data encryption.However,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing times.In contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient conditions.By means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare memristors.Oxide film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and time.Thus memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield rate.This article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of memristors.Firstly,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.
基金supported by the National Key Research and Development Program(2021YFB2400300)National Natural Science Foundation of China(22379013 and 22209010)the Beijing Institute of Technology“Xiaomi Young Scholars”program。
文摘Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reservoir.Here,alloying Li metal with low-content magnesium(Mg)is proposed to mitigate the reaction kinetics between Li metal anodes and electrolytes.Mg atoms enter the lattice of Li atoms,forming solid solution due to the low amount(5 wt%)of Mg.Mg atoms mainly concentrate near the surface of Mg-alloyed Li metal anodes.The reactivity of Mg-alloyed Li metal is mitigated kinetically,which results from the electron transfer from Li to Mg atoms due to the electronegativity difference.Based on quantitative experimental analysis,the consumption rate of active Li and electrolytes is decreased by using Mgalloyed Li metal anodes,which increases the cycle life of Li metal batteries under demanding conditions.Further,a pouch cell(1.25 Ah)with Mg-alloyed Li metal anodes delivers an energy density of 340 Wh kg^(-1)and a cycle life of 100 cycles.This work inspires the strategy of modifying Li metal anodes to kinetically mitigate the side reactions with electrolytes.
基金financially supported by the National Natural Science Foundation of China (Nos.51872090 and51772097)the Hebei Natural Science Fund for Distinguished Young Scholar,China (No.E2019209433)+2 种基金the Youth Talent Program of Hebei Provincial Education Department,China (No.BJ2018020)the Natural Science Foundation of Hebei Province,China (No.E2020209151)the Science and Technology Project of Hebei Education Department,China (No.SLRC2019028)。
文摘Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zinc dendrites, passivation, corrosion, and hydrogen evolution reactions during the charging and discharging of batteries, becoming obstacles to the practical application of ZIBs. Appropriate zinc metal-free anodes provide a higher working potential than metallic zinc anodes, effectively solving the problems of zinc dendrites, hydrogen evolution, and side reactions during the operation of metallic zinc anodes. The improvement in the safety and cycle life of batteries creates conditions for further commercialization of ZIBs. Therefore, this work systematically introduces the research progress of zinc metal-free anodes in “rocking chair” ZIBs. Zinc metal-free anodes are mainly discussed in four categories: transition metal oxides,transition metal sulfides, MXene(two dimensional transition metal carbide) composites, and organic compounds, with discussions on their properties and zinc storage mechanisms. Finally, the outlook for the development of zinc metal-free anodes is proposed. This paper is expected to provide a reference for the further promotion of commercial rechargeable ZIBs.
基金Bundesministerium für Bildung und Forschung,Grant/Award Numbers:03XP0138C,03XP0306C。
文摘The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the future.This great success,however,urgently calls for the efficient recycling of LIBs at the end of their life.Herein,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—from spent LIBs and investigate its reuse in newly assembled LIBs.It has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities from the recycling process,the recycled graphite provides a remarkable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NMC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.
基金sponsored by the National Natural Science Foundation of China(21905221,21805221)the Suzhou Technological innovation of key industries-research and development of key technologies(SGC2021118)。
文摘Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.
基金financially supported by the Jiangsu Distinguished Professors Project(No.1711510024)the funding for Scientific Research Startup of Jiangsu University(Nos.4111510015,19JDG044)+3 种基金the Jiangsu Provincial Program for High-Level Innovative and Entrepreneurial Talents Introductionthe National Natural Science Foundation of China(No.22008091)Natural Science Foundation of Guangdong Province(2023A1515010894)the Open Project of Luzhou Key Laboratory of Fine Chemical Application Technology(HYJH-2302-A).
文摘Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.
文摘Due to concerns regarding the future availability,cost,and safety of lithium in Li-ion batteries(LIBs),researchers are exploring alternative chemistries such as Na-ion,Li-S,Li-air,and multivalent ion technologies.Multivalent ion technologies,which utilize divalent or trivalent ions,like Mg^(2+),Ca^(2+),and Al^(3+),show promise in achieving greater energy densities than LIBs due to their ability to deposit uniformly on anodes and intercalate into cathodes.While magnesium-ion batteries(MIBs) have been the primary area of research for multivalent ion batteries,the cost-effectiveness and abundance of calcium have sparked a growing interest in calcium-ion batteries(CIBs) in recent years.Compared to LIBs,CIBs have the potential to provide longer cycle life,enhanced safety,and increased energy densities.However,the development of CIBs comes with several challenges,such as finding suitable electrode and electrolyte materials that ensure the stability and safety of the battery.The primary hurdle in CIBs lies in the plating/stripping process.There is a significant hindrance preventing the occurrence of plating/stripping in CIBs,which lies in the formation of a passive layer resulting from the decomposition of the electrolyte.The objective of this article is to examine the advancements made in CIBs.Additionally,it aims to comprehensively assess the mechanisms and materials employed in various battery components,as well as the obstacles encountered in CIBs.This includes recent advancements in electrode materials,electrolytes,cell configurations,and the challenges and opportunities for enhancing the performance and commercial viability of CIBs.