Binder system is critical to the success of metal injection molding(MIM). A novel PEG based binder for MIM was developed, which was made of high density polyethylene (HDPE), polyethylene glycol (PEG), polymer W, stear...Binder system is critical to the success of metal injection molding(MIM). A novel PEG based binder for MIM was developed, which was made of high density polyethylene (HDPE), polyethylene glycol (PEG), polymer W, stearic acid(SA) and dioctyl phthalate (DOP). The components of binder have interactions with each other, so the binder have good compatibility. The thermal decomposition process of binder exhibits three stages during debinding. The binder could be debound by pyrolysis or solvent, and could easily be removed in a short time in ethanol without defects and evironmental concern. A lot of interconnected pores formed after solvent debinding, which is helpful to the escape of pyrolysis gases during subsequent thermal debinding or presintering. [展开更多
The thermal debinding dynamics of newly developed binders for cemented carbides extrusion molding was studied. It is shown that the thermal debinding processes can be divided into two stages: low temperature region, i...The thermal debinding dynamics of newly developed binders for cemented carbides extrusion molding was studied. It is shown that the thermal debinding processes can be divided into two stages: low temperature region, in which the low molecular mass components (LMMCs) are removed; and high temperature region, in which the polymer components are removed. The rate of thermal debinding is controlled by diffusion mechanism. The thermal debinding activation energies were solved out by differential method and integral method. The results show that the addition of other components acted as a catalyzer can effectively decrease the activation energy of thermal debinding processes.展开更多
Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further ex...Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further extend the life span of LIBs,it is essential to intensify investments in battery design,manufacturing processes,and the advancement of ancillary materials.The pursuit of long durability introduces new challenges for battery energy density.The advent of electrode material offers effective support in enhancing the battery’s long-duration performance.Often underestimated as part of the cathode composition,the binder plays a pivotal role in the longevity and electrochemical performance of the electrode.Maintaining the mechanical integrity of the electrode through judicious binder design is a fundamental requirement for achieving consistent long-life cycles and high energy density.This paper primarily concentrates on the commonly employed cathode systems in lithium-ion batteries,elucidates the significance of binders for both,discusses the application status,strengths,and weaknesses of novel binders,and ultimately puts forth corresponding optimization strategies.It underscores the critical function of binders in enhancing battery performance and advancing the sustainable development of lithium-ion batteries,aiming to offer fresh insights and perspectives for the design of high-performance LIBs.展开更多
Cubic boron nitride(cBN)with high hardness,thermal conductivity,wear resistance,and chemical inertness has become the most promising abrasive and machining material.Due to the difficulty of fabricating pure cBN body,g...Cubic boron nitride(cBN)with high hardness,thermal conductivity,wear resistance,and chemical inertness has become the most promising abrasive and machining material.Due to the difficulty of fabricating pure cBN body,generally,some binders are incorporated among cBN particles to prepare polycrystalline cubic boron nitride(PcBN).Hence,the binders play a critical factor to the performances of PcBN composites.In this study,the PcBN composites with three binder systems containing ceramic and metal phases were fabricated by spark plasma sintering(SPS)from 1400 to 1700℃.The sintering behaviors and mechanical properties of the composites were investigated.Results show that the effect of binder formulas on mechanical properties mainly related to the compactness,mechanical performances,and thermal expansion coefficient of binder phases,which affect the carrying capacity of the composites and the bonding strength between binder phases and cBN particles.The PcBN composite with SiAlON phase as binder presented optimal flexural strength(465±29 MPa)and fracture toughness(5.62±0.37 MPa·m^(1/2)),attributing to the synergistic effect similar to transgranular and intergranular fractures.Meanwhile,the excellent mechanical properties can be maintained a comparable level when the temperature even rises to 800℃.Due to the weak bonding strength and high porosity,the PcBN composites with Al_(2)O_(3)–ZrO_(2)(3Y)and Al–Ti binder systems exhibited inferior mechanical properties.The possible mechanisms to explain these results were also analyzed.展开更多
In this work,various backbone binders were used in wax-based binder system to formulate zirconia parts by ceramic injection molding (CIM).The effect of different backbone binders on the molding,debinding,and sintering...In this work,various backbone binders were used in wax-based binder system to formulate zirconia parts by ceramic injection molding (CIM).The effect of different backbone binders on the molding,debinding,and sintering behaviors was investigated.After blending process,the feedstock using multi-polymer components exhibited more homogeneous structure compared with that using the mono-polymer ones due to the synergistic effect of multi-polymers.During solvent debinding,some defects such as 'slumping' and 'peeling' appeared in the parts containing ethylene-vinyl acetate copolymer (EVA),but they were not found in the parts with other thermal polymers.Also,as for the parts after sintering,the one using low density polyethylene (LDPE) and high density polyethylene (HDPE) as backbone binders presented a more uniform microstructure with finer zirconia grains among all the investigated compositions,and thus obtained the highest flexural strength (～949 MPa) and relative density (～98.9％).展开更多
Thermal spraying of cermet coatings is widely used for protection of machining parts against wear and corrosion. These coatings consist of WC particles in metal binders such as Co, Cr and Ni. Three kinds of WC powders...Thermal spraying of cermet coatings is widely used for protection of machining parts against wear and corrosion. These coatings consist of WC particles in metal binders such as Co, Cr and Ni. Three kinds of WC powders with different metal binders (Co, NiCr and CoCr) were sprayed by low power plasma spray system on Al-Si-Cu alloy substrate. Fundamental aspects of sprayed cermet coatings, including (i) the effects of binder type on the coating structure, (ii) the hardness and (iii) the microstructure, were investigated. All cermet coatings have the same phase structure such as WC and W2 C. However, the intensities of these phases are different in each coating, mainly due to the difference in solidification rate in each case. Moreover, the hardness measurements are found to be different in each coating. The results show that, binder type has a significant effect on the physical and mechanical properties of the sprayed coatings.展开更多
Pigment printing was carried out on lab scale by simple screen-printing techniques. By the application of acrylate and butadiene based binder, the crocking fastness, formaldehyde release and PVC migration of fabric pr...Pigment printing was carried out on lab scale by simple screen-printing techniques. By the application of acrylate and butadiene based binder, the crocking fastness, formaldehyde release and PVC migration of fabric printed with Imparon red KB pigment was evaluated. The effect of curing time on K/S values was also investigated. It has been found that butadiene based binder shows good performance in terms of crocking fastness, formaldehyde release and PVC migra-tion. It has also been observed that by increasing the binder concentration, the release of formaldehyde decreased and by increasing the curing time, the K/S values of printed fabric were decreased.展开更多
By the analysis of vulnerabilities of Android native system services,we find that some vulnerabilities are caused by inconsistent data transmission and inconsistent data processing logic between client and server.The ...By the analysis of vulnerabilities of Android native system services,we find that some vulnerabilities are caused by inconsistent data transmission and inconsistent data processing logic between client and server.The existing research cannot find the above two types of vulnerabilities and the test cases of them face the problem of low coverage.In this paper,we propose an extraction method of test cases based on the native system services of the client and design a case construction method that supports multi-parameter mutation based on genetic algorithm and priority strategy.Based on the above method,we implement a detection tool-BArcherFuzzer to detect vulnerabilities of Android native system services.The experiment results show that BArcherFuzzer found four vulnerabilities of hundreds of exception messages,all of them were confirmed by Google and one was assigned a Common Vulnerabilities and Exposures(CVE)number(CVE-2020-0363).展开更多
1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7]...1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.展开更多
An energetic binder based on hydroxyl-terminated polybutadiene(HTPB),doped with different ratios of nitrocellulose(NC)(10%,20%,30%,and 50%),was developed to study the effect of NC doping on the thermal decomposition b...An energetic binder based on hydroxyl-terminated polybutadiene(HTPB),doped with different ratios of nitrocellulose(NC)(10%,20%,30%,and 50%),was developed to study the effect of NC doping on the thermal decomposition behavior of a composite propellant(CP)comprising ammonium nitrate(AN)as an oxidizer and magnesium(Mg)as a fuel.Optimization of the propellant formulation was conducted using Chemical Equilibrium with Applications-National Aeronautics and Space Administration(CEA-NASA)software,which demonstrated an increase in specific impulse by 12.09 s when the binder contained 50%NC.Fourier-transform infrared spectroscopy(FTIR)analysis confirmed the excellent compatibility between the components,and density measurements revealed an increase of 6.4%with a higher NC content.Morphological analysis using optical microscopy showed that NC doping improved the uniformity and compactness of the surface,reduced cavities,and achieved a more homogeneous particle distribution.Differential scanning calorimetry(DSC)analysis indicated a decrease in the decomposition temperature of the propellant as the NC content increased,while kinetic studies revealed a 48.68%reduction in the activation energy when 50%NC was incorporated into the binder.These findings suggest that the addition of NC enhances combustion efficiency and improves overall propellant performance.This study highlights the potential of the new HTPB-NC energetic binder as a promising approach for advancing solid propellant technology.展开更多
Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by ...Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.展开更多
Introduction The widespread use of cement in concrete leads to increased carbon emissions,so the demand for supplementary cementitious materials increases significantly.Limestone powder and steel slag powder are widel...Introduction The widespread use of cement in concrete leads to increased carbon emissions,so the demand for supplementary cementitious materials increases significantly.Limestone powder and steel slag powder are widely used as supplementary cementitious materials in modern concrete.However,for UHPC and self-compacting concrete,an extremely low water/binder(W/B)ratio is on one hand a key factor in achieving ultra-high strength and ultra-low porosity of the materials,on the other hand,also leads to the deterioration of the rheological properties of the fresh paste.Meanwhile,the existing researches focus on the influence of single limestone powder or steel slag powder on the mechanical properties or microstructure of cement-based materials.Little work on the influence of steel slag powder or limestone powder on the rheological properties of composite paste at an extremely low water/binder ratio has been investigated quantitatively.The mechanism of the effect of steel slag powder or limestone powder on the rheological properties of composite paste at extremely low water/binder ratios is still unclear.In this work,the effects of steel slag powder and limestone powder on the rheological properties of composite paste at different low water/binder ratios were analyzed via determining the flow diameter,setting time,marsh cone flow time,rheological parameters,and total organic carbon content.Methods A composite paste was prepared with P.I 42.5 ordinary Portland cement,steel slag powder,limestone powder,blast furnace slag and silica fume as raw materials in a certain proportion.To achieve the preparation of composite paste with extremely low water/binder ratios,a polycarboxylate superplasticizer with a water/reducing rate of 40%(Jiangsu Subot New Materials Co.,Ltd.,China)was used.The dosage of polycarboxylate superplasticizer for the composite paste with different water/binder ratios of 0.16 and 0.21 was 2%and 0.8%,respectively.Composite pastes with different proportions of steel slag powder or limestone powder at water/binder ratios of 0.16 and 0.21 were prepared.The flow diameter(i.e.,the larger the flow diameter,the better the fluidity),setting time(i.e.,the time when the fluidity is lost)and marsh cone flow time(i.e.,the shorter the flow time,the better the fluidity)were determined to analyze the fluidity of the composite pastes.the rheological properties of composite paste at a water/binder ratio of 0.16 for rheological properties tests were determined,and the rheological parameters were obtained by the H-B model.The adsorption performance of the polycarboxylate superplasticizer was analyzed by testing the TOC content.Results and discussion When the ratio of water/binder is 0.16,both limestone powder and steel slag powder initially increase the flow diameter of the composite paste.However,the fluidity of the composite paste decreases over time,and the reduction is more pronounced with steel slag powder.This is because the nucleation and hydration promotion effect of limestone powder can reduce the loss rate of flow diameter,while the rough particles of steel slag powder increase the internal friction force,resulting in a decrease in the flow diameter of composite paste.Adding limestone powder and steel slag powder both shortens the setting time and marsh cone flow time of the composite paste.However,the steel slag powder addition of 30%delays the final setting time due to its delaying effect.Also,limestone powder can enhance the thixotropy and reduce the yield stress and plastic viscosity,thereby improving the rheological properties.In contrast,steel slag powder can increase the yield stress and plastic viscosity,thereby weakening the rheological properties and thixotropy.Steel slag powder and limestone powder both can enhance the adsorption effect of polycarboxylate superplasticizer.Steel slag powder has a stronger adsorption effect.The composite paste containing limestone powder has a higher free water content.This is because the rough and porous surface of steel slag itself and the uneven particle shape lead to the physical adsorption of polycarboxylate superplasticizer molecules on the surface of steel slag particles,thereby reducing the effective content of the water reducer dispersion.Increasing the water/binder ratio to 0.21 results in a decrease in the flow diameter of the composite paste.Furthermore,the setting time and marsh cone flow time can prolong due to the reduction in the dosage of polycarboxylate superplasticizer.Conclusions The results showed that the fluidity loss rate of composite paste with limestone powder could be lower than that of composite paste with steel slag powder.Compared to steel slag powder,the addition of limestone powder reduced the setting time and marsh cone flow time of the composite paste.The addition of limestone powder could shorten the yield stress and plastic viscosity of the composite paste.Therefore,the composite paste with limestone powder had better rheological properties and stronger thixotropy rather than that with steel slag powder.The addition of limestone powder could improve the rheological properties of the composite paste.Compared to composite paste with limestone powder,a better adsorption effect of polycarboxylate superplasticizer on the surface of the composite binder with steel slag powder could be obtained.The free water content of the composite paste with limestone powder was still higher than that of the composite paste with steel slag powder.The fluidity and rheological properties of the composite paste with limestone powder could be better.The comprehensive analysis indicated that a positive effect of limestone powder on rheological properties of composite paste at an extremely low water/binder ratio could be more dominant than that of steel slag powder.展开更多
Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)...Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.展开更多
The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Repl...The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Replace“a composition of ethylene glycol monobutyl ether and ethylene glycol”by“50% binder saturation”.展开更多
Anode binders undergo decomposition during thermal runaway,generating highly flammable and explosive hydrogen,which poses a significant threat to the safety of lithium-ion batteries.However,the binder due to its relat...Anode binders undergo decomposition during thermal runaway,generating highly flammable and explosive hydrogen,which poses a significant threat to the safety of lithium-ion batteries.However,the binder due to its relatively small proportion is often overlooked in terms of its importance.This study elucidates the universal mechanism of hydrogen generation from the decomposition of binders and identifies the hydrogen-containing chemical bonds within the molecular structure of binders as the fundamental sources of hydrogen.The Fourier transform infrared spectroscopy of six commonly used binders reveals that five of them possess hydrogen-containing chemical bonds,indicating a potential for hydrogen generation,whereas the polytetrafluoroethylene binder lacks such bonds and cannot generate hydrogen.Differential scanning calorimetry is employed to compare the decomposition of these binders and their reaction with lithiated graphite.The results demonstrate that cyclic molecular structures not only enhance thermal stability but also increase the difficulty of hydrogen generation.Moreover,binders devoid of hydrogen atoms exhibit superior thermal stability and completely eliminate the risk of hydrogen generation.These findings provide critical insights into the molecular design of binders,offering promising strategies to mitigate or prevent hydrogen generation from binder decomposition and thereby substantially improve the safety of lithium-ion batteries.展开更多
High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode material...High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode materials is crucial to enhance the electrochemical performance of LIBs.However,the traditional fluoropolymer binder,poly(vinylidene difluoride)(PVDF),can potentially leach components or break down into poly(fluoroalkyl substances)(PFAS)chemicals,thereby contributing to PFAS contamination.A novel fluorine-free polymer,polysulfone-polyamide-polyimide(SPIO),was designed and synthesized as a binder for NCM811 cathodes.The SPIO binder exhibits exceptional mechanical properties and superior electrochemical characteristics.The cathode film fabricated with SPIO demonstrated a remarkable delamination force of 8 N(390 N·m^(-1)),indicating robust adhesion.The Li‖NCM811 cell incorporating the SPIO binder retained 80%of its initial capacity after 300 cycles at a current density of 0.2 C.In comparison,the control cells assem bled with the PVDF binder retained only 52%of their capacities under the same cycling conditions.Furthermore,the SPIO binder exhibited improved compatibility with the electrolyte.Transmission electron microscopy analysis of the cathode films after 100 cycles revealed the formation of a unifo rm,dense,and continuous chemical-electrochemical interface(CEI)by the SPIO binder on the surface of the NCM811 particles,which significantly contributed to the enhancement of the electrochemical performance.These results highlight the potential of SPIO as an advanced binder material for high-perfo rmance lithium-ion batteries.展开更多
Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fi...Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.展开更多
The rheological properties of an innovative coal-based colloidal composite binder(3Co-Binder)prepared via alkaline–oxygen excitation and mechanochemical synthesis are revealed.Derived from low-rank coal,3Co–Binder i...The rheological properties of an innovative coal-based colloidal composite binder(3Co-Binder)prepared via alkaline–oxygen excitation and mechanochemical synthesis are revealed.Derived from low-rank coal,3Co–Binder is applied in iron ore pelletization as a replacement for traditional bentonite,with the aim of improving the iron grades of the pellets.Cryoscanning electron microscopy revealed that 3Co-Binder exhibits a densely populated,porous network structure.It was determined to be a pseudo-plastic fluid with yield stress and shear-thinning characteristics.The stability of 3Co-Binder was influenced by the humic acid extraction rate,temperature,and static placing time.An extraction rate of humic acids above 96%was found to prevent sedimentation of 3Co-Binder,while lower temperatures and prolonged static placing time increased its apparent viscosity.A storage duration of less than 2 weeks and a temperature range of 25–35℃ were found to be optimal for maintaining the stability of 3Co-Binder.The viscous flow activation energy of 3Co-Binder remained stable at approximately 60 kJ mol^(-1) as the shear rate increased from 0.5 to 5 s^(-1).However,at higher shear rates,up to 100 s^(-1),the viscous flow activation energy decreased to 46.48 kJ mol^(–1).To ensure stability and dispersibility during storage,the rheological parameters of 3Co-Binder must meet the following criteria:yield stress below 10 Pa,consistency coefficient below 1.5 Pa s,non-Newtonian index below 1,and apparent viscosity below 10,000 mPa s at a shear rate of 1 s^(–1).展开更多
With the increasing prevalence of lithium-ion batteries(LIBs)applications,the demand for high-capacity next-generation materials has also increased.SiO_(x)is currently considered a promising anode material due to its ...With the increasing prevalence of lithium-ion batteries(LIBs)applications,the demand for high-capacity next-generation materials has also increased.SiO_(x)is currently considered a promising anode material due to its exceptionally high capacity for LIBs.However,the significant volumetric changes of SiO_(x)during cycling and its initial Coulombic efficiency(ICE)complicate its use,whether alone or in combination with graphite materials.In this study,a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiO_(x)blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker.In addition,a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiO_(x).The combination of these two strategies increased the CE of SiO_(x)from 74%to87%and effectively mitigated its volume expansion in the graphite/SiO_(x)blended electrode,resulting in an efficient electron-conductive binder network.This led to a remarkable capacity retention of 94%after30 cycles,even under challenging conditions,with a high capacity of 550 mA h g^(-1)and a current density of 4 mA cm^(-2).Furthermore,to validate the feasibility of utilizing prelithiated SiO_(x)anode materials and the conductive binder network in LIBs,a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used.This cell demonstrated a~27.3%increase in discharge capacity of the first cycle(~185.7 mA h g^(-1))and exhibited a cycling stability of 300 cycles.Thus,this study reports a simple,feasible,and insightful method for designing high-performance LIB electrodes.展开更多
Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial ...Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial volume expansion during cycling,which leads to material pulverization and an unstable solid electrolyte interphase(SEI)layer.Inspired by the natural root fixation in soil,we designed a root-like topological structure binder,cassava starch-citric acid(CS-CA),based on the synergistic action of covalent and hydrogen bonds.The abundant-OH and-COOH groups in CS-CA molecules effectively form hydrogen bonds with the-OH groups on the SiO surface,significantly enhancing the interfacial interaction between CS-CA and SiO.The root-like topological structure of CS-CA with a high tolerance alleviates the mechanical stress generated by the volume changes of SiO.More encouragingly,the hydrogen bond action among CS-CA molecules produces a self-healing effect,which is advantageous for repairing damaged electrodes and preserving their structural integrity.As such,the CS-CA/SiO electrode exhibits exceptional cycling performance(963.1 mA h g^(-1)after 400 cycles at 2 A g^(-1))and rate capability(558.9 mA h g^(-1)at 5 A g^(-1)).This innovative,topologically interconnected,root-inspired binder will greatly advance the practical application of long-lasting micron-sized SiO anodes.展开更多
文摘Binder system is critical to the success of metal injection molding(MIM). A novel PEG based binder for MIM was developed, which was made of high density polyethylene (HDPE), polyethylene glycol (PEG), polymer W, stearic acid(SA) and dioctyl phthalate (DOP). The components of binder have interactions with each other, so the binder have good compatibility. The thermal decomposition process of binder exhibits three stages during debinding. The binder could be debound by pyrolysis or solvent, and could easily be removed in a short time in ethanol without defects and evironmental concern. A lot of interconnected pores formed after solvent debinding, which is helpful to the escape of pyrolysis gases during subsequent thermal debinding or presintering. [
文摘The thermal debinding dynamics of newly developed binders for cemented carbides extrusion molding was studied. It is shown that the thermal debinding processes can be divided into two stages: low temperature region, in which the low molecular mass components (LMMCs) are removed; and high temperature region, in which the polymer components are removed. The rate of thermal debinding is controlled by diffusion mechanism. The thermal debinding activation energies were solved out by differential method and integral method. The results show that the addition of other components acted as a catalyzer can effectively decrease the activation energy of thermal debinding processes.
基金We would like to show gratitude to the Yunnan Province Basic Research Major Project(202501BC070006(Y.Wang))Key Industry Science and Technology Projects for University Services in Yunnan Province(FWCY ZNT2024002(Y.Wang))+3 种基金National Natural Science Foundation of China(22279070(L.Wang))and(U21A20170(X.He))the Ministry of Science and Technology of China(2019YFA0705703(L.Wang))Beijing Natural Science Foundation(L242005(X.He))Key Industry Science and Technology Projects for University Services in Yunnan Province(FWCY BSPY2024011(T.Lai)).
文摘Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further extend the life span of LIBs,it is essential to intensify investments in battery design,manufacturing processes,and the advancement of ancillary materials.The pursuit of long durability introduces new challenges for battery energy density.The advent of electrode material offers effective support in enhancing the battery’s long-duration performance.Often underestimated as part of the cathode composition,the binder plays a pivotal role in the longevity and electrochemical performance of the electrode.Maintaining the mechanical integrity of the electrode through judicious binder design is a fundamental requirement for achieving consistent long-life cycles and high energy density.This paper primarily concentrates on the commonly employed cathode systems in lithium-ion batteries,elucidates the significance of binders for both,discusses the application status,strengths,and weaknesses of novel binders,and ultimately puts forth corresponding optimization strategies.It underscores the critical function of binders in enhancing battery performance and advancing the sustainable development of lithium-ion batteries,aiming to offer fresh insights and perspectives for the design of high-performance LIBs.
基金This work was supported by the National Natural Science Foundation of China(No.51775534)the West Light Foundation of the Chinese Academy of Sciences(2019)the LICP Cooperation Foundation for Young Scholars(No.HZJJ21-07).
文摘Cubic boron nitride(cBN)with high hardness,thermal conductivity,wear resistance,and chemical inertness has become the most promising abrasive and machining material.Due to the difficulty of fabricating pure cBN body,generally,some binders are incorporated among cBN particles to prepare polycrystalline cubic boron nitride(PcBN).Hence,the binders play a critical factor to the performances of PcBN composites.In this study,the PcBN composites with three binder systems containing ceramic and metal phases were fabricated by spark plasma sintering(SPS)from 1400 to 1700℃.The sintering behaviors and mechanical properties of the composites were investigated.Results show that the effect of binder formulas on mechanical properties mainly related to the compactness,mechanical performances,and thermal expansion coefficient of binder phases,which affect the carrying capacity of the composites and the bonding strength between binder phases and cBN particles.The PcBN composite with SiAlON phase as binder presented optimal flexural strength(465±29 MPa)and fracture toughness(5.62±0.37 MPa·m^(1/2)),attributing to the synergistic effect similar to transgranular and intergranular fractures.Meanwhile,the excellent mechanical properties can be maintained a comparable level when the temperature even rises to 800℃.Due to the weak bonding strength and high porosity,the PcBN composites with Al_(2)O_(3)–ZrO_(2)(3Y)and Al–Ti binder systems exhibited inferior mechanical properties.The possible mechanisms to explain these results were also analyzed.
基金This work was financially supported by National Natural Science Foundation of China
文摘In this work,various backbone binders were used in wax-based binder system to formulate zirconia parts by ceramic injection molding (CIM).The effect of different backbone binders on the molding,debinding,and sintering behaviors was investigated.After blending process,the feedstock using multi-polymer components exhibited more homogeneous structure compared with that using the mono-polymer ones due to the synergistic effect of multi-polymers.During solvent debinding,some defects such as 'slumping' and 'peeling' appeared in the parts containing ethylene-vinyl acetate copolymer (EVA),but they were not found in the parts with other thermal polymers.Also,as for the parts after sintering,the one using low density polyethylene (LDPE) and high density polyethylene (HDPE) as backbone binders presented a more uniform microstructure with finer zirconia grains among all the investigated compositions,and thus obtained the highest flexural strength (～949 MPa) and relative density (～98.9％).
基金Project (50075011) supported by the National Natural Science Foundation of China
文摘Thermal spraying of cermet coatings is widely used for protection of machining parts against wear and corrosion. These coatings consist of WC particles in metal binders such as Co, Cr and Ni. Three kinds of WC powders with different metal binders (Co, NiCr and CoCr) were sprayed by low power plasma spray system on Al-Si-Cu alloy substrate. Fundamental aspects of sprayed cermet coatings, including (i) the effects of binder type on the coating structure, (ii) the hardness and (iii) the microstructure, were investigated. All cermet coatings have the same phase structure such as WC and W2 C. However, the intensities of these phases are different in each coating, mainly due to the difference in solidification rate in each case. Moreover, the hardness measurements are found to be different in each coating. The results show that, binder type has a significant effect on the physical and mechanical properties of the sprayed coatings.
文摘Pigment printing was carried out on lab scale by simple screen-printing techniques. By the application of acrylate and butadiene based binder, the crocking fastness, formaldehyde release and PVC migration of fabric printed with Imparon red KB pigment was evaluated. The effect of curing time on K/S values was also investigated. It has been found that butadiene based binder shows good performance in terms of crocking fastness, formaldehyde release and PVC migra-tion. It has also been observed that by increasing the binder concentration, the release of formaldehyde decreased and by increasing the curing time, the K/S values of printed fabric were decreased.
基金This work was supported by the National Key R&D Program of China(2023YFB3106800)the National Natural Science Foundation of China(Grant No.62072051).We are overwhelmed in all humbleness and gratefulness to acknowledge my depth to all those who have helped me to put these ideas.
文摘By the analysis of vulnerabilities of Android native system services,we find that some vulnerabilities are caused by inconsistent data transmission and inconsistent data processing logic between client and server.The existing research cannot find the above two types of vulnerabilities and the test cases of them face the problem of low coverage.In this paper,we propose an extraction method of test cases based on the native system services of the client and design a case construction method that supports multi-parameter mutation based on genetic algorithm and priority strategy.Based on the above method,we implement a detection tool-BArcherFuzzer to detect vulnerabilities of Android native system services.The experiment results show that BArcherFuzzer found four vulnerabilities of hundreds of exception messages,all of them were confirmed by Google and one was assigned a Common Vulnerabilities and Exposures(CVE)number(CVE-2020-0363).
基金supported by the National Key R&D Pro-gram of China(No.2022YFB3805701)National Natural Science Foundation of China(NSFC)(No.52371182,51701052,52192592,52192593)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001)the Heilongjiang Touyan Innovation Team Program.
文摘1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.
文摘An energetic binder based on hydroxyl-terminated polybutadiene(HTPB),doped with different ratios of nitrocellulose(NC)(10%,20%,30%,and 50%),was developed to study the effect of NC doping on the thermal decomposition behavior of a composite propellant(CP)comprising ammonium nitrate(AN)as an oxidizer and magnesium(Mg)as a fuel.Optimization of the propellant formulation was conducted using Chemical Equilibrium with Applications-National Aeronautics and Space Administration(CEA-NASA)software,which demonstrated an increase in specific impulse by 12.09 s when the binder contained 50%NC.Fourier-transform infrared spectroscopy(FTIR)analysis confirmed the excellent compatibility between the components,and density measurements revealed an increase of 6.4%with a higher NC content.Morphological analysis using optical microscopy showed that NC doping improved the uniformity and compactness of the surface,reduced cavities,and achieved a more homogeneous particle distribution.Differential scanning calorimetry(DSC)analysis indicated a decrease in the decomposition temperature of the propellant as the NC content increased,while kinetic studies revealed a 48.68%reduction in the activation energy when 50%NC was incorporated into the binder.These findings suggest that the addition of NC enhances combustion efficiency and improves overall propellant performance.This study highlights the potential of the new HTPB-NC energetic binder as a promising approach for advancing solid propellant technology.
文摘Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.
文摘Introduction The widespread use of cement in concrete leads to increased carbon emissions,so the demand for supplementary cementitious materials increases significantly.Limestone powder and steel slag powder are widely used as supplementary cementitious materials in modern concrete.However,for UHPC and self-compacting concrete,an extremely low water/binder(W/B)ratio is on one hand a key factor in achieving ultra-high strength and ultra-low porosity of the materials,on the other hand,also leads to the deterioration of the rheological properties of the fresh paste.Meanwhile,the existing researches focus on the influence of single limestone powder or steel slag powder on the mechanical properties or microstructure of cement-based materials.Little work on the influence of steel slag powder or limestone powder on the rheological properties of composite paste at an extremely low water/binder ratio has been investigated quantitatively.The mechanism of the effect of steel slag powder or limestone powder on the rheological properties of composite paste at extremely low water/binder ratios is still unclear.In this work,the effects of steel slag powder and limestone powder on the rheological properties of composite paste at different low water/binder ratios were analyzed via determining the flow diameter,setting time,marsh cone flow time,rheological parameters,and total organic carbon content.Methods A composite paste was prepared with P.I 42.5 ordinary Portland cement,steel slag powder,limestone powder,blast furnace slag and silica fume as raw materials in a certain proportion.To achieve the preparation of composite paste with extremely low water/binder ratios,a polycarboxylate superplasticizer with a water/reducing rate of 40%(Jiangsu Subot New Materials Co.,Ltd.,China)was used.The dosage of polycarboxylate superplasticizer for the composite paste with different water/binder ratios of 0.16 and 0.21 was 2%and 0.8%,respectively.Composite pastes with different proportions of steel slag powder or limestone powder at water/binder ratios of 0.16 and 0.21 were prepared.The flow diameter(i.e.,the larger the flow diameter,the better the fluidity),setting time(i.e.,the time when the fluidity is lost)and marsh cone flow time(i.e.,the shorter the flow time,the better the fluidity)were determined to analyze the fluidity of the composite pastes.the rheological properties of composite paste at a water/binder ratio of 0.16 for rheological properties tests were determined,and the rheological parameters were obtained by the H-B model.The adsorption performance of the polycarboxylate superplasticizer was analyzed by testing the TOC content.Results and discussion When the ratio of water/binder is 0.16,both limestone powder and steel slag powder initially increase the flow diameter of the composite paste.However,the fluidity of the composite paste decreases over time,and the reduction is more pronounced with steel slag powder.This is because the nucleation and hydration promotion effect of limestone powder can reduce the loss rate of flow diameter,while the rough particles of steel slag powder increase the internal friction force,resulting in a decrease in the flow diameter of composite paste.Adding limestone powder and steel slag powder both shortens the setting time and marsh cone flow time of the composite paste.However,the steel slag powder addition of 30%delays the final setting time due to its delaying effect.Also,limestone powder can enhance the thixotropy and reduce the yield stress and plastic viscosity,thereby improving the rheological properties.In contrast,steel slag powder can increase the yield stress and plastic viscosity,thereby weakening the rheological properties and thixotropy.Steel slag powder and limestone powder both can enhance the adsorption effect of polycarboxylate superplasticizer.Steel slag powder has a stronger adsorption effect.The composite paste containing limestone powder has a higher free water content.This is because the rough and porous surface of steel slag itself and the uneven particle shape lead to the physical adsorption of polycarboxylate superplasticizer molecules on the surface of steel slag particles,thereby reducing the effective content of the water reducer dispersion.Increasing the water/binder ratio to 0.21 results in a decrease in the flow diameter of the composite paste.Furthermore,the setting time and marsh cone flow time can prolong due to the reduction in the dosage of polycarboxylate superplasticizer.Conclusions The results showed that the fluidity loss rate of composite paste with limestone powder could be lower than that of composite paste with steel slag powder.Compared to steel slag powder,the addition of limestone powder reduced the setting time and marsh cone flow time of the composite paste.The addition of limestone powder could shorten the yield stress and plastic viscosity of the composite paste.Therefore,the composite paste with limestone powder had better rheological properties and stronger thixotropy rather than that with steel slag powder.The addition of limestone powder could improve the rheological properties of the composite paste.Compared to composite paste with limestone powder,a better adsorption effect of polycarboxylate superplasticizer on the surface of the composite binder with steel slag powder could be obtained.The free water content of the composite paste with limestone powder was still higher than that of the composite paste with steel slag powder.The fluidity and rheological properties of the composite paste with limestone powder could be better.The comprehensive analysis indicated that a positive effect of limestone powder on rheological properties of composite paste at an extremely low water/binder ratio could be more dominant than that of steel slag powder.
文摘Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.
文摘The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Replace“a composition of ethylene glycol monobutyl ether and ethylene glycol”by“50% binder saturation”.
基金supported by the National Natural Science Foundation of China(Grant No.92372111 and 22179070)the Fundame ntal Research Funds for the Central Universities(Grant No.RF1028623157)the SEU Innovation Capability Enhancement Plan for Doctoral Students(CXJH_SEU 24063)。
文摘Anode binders undergo decomposition during thermal runaway,generating highly flammable and explosive hydrogen,which poses a significant threat to the safety of lithium-ion batteries.However,the binder due to its relatively small proportion is often overlooked in terms of its importance.This study elucidates the universal mechanism of hydrogen generation from the decomposition of binders and identifies the hydrogen-containing chemical bonds within the molecular structure of binders as the fundamental sources of hydrogen.The Fourier transform infrared spectroscopy of six commonly used binders reveals that five of them possess hydrogen-containing chemical bonds,indicating a potential for hydrogen generation,whereas the polytetrafluoroethylene binder lacks such bonds and cannot generate hydrogen.Differential scanning calorimetry is employed to compare the decomposition of these binders and their reaction with lithiated graphite.The results demonstrate that cyclic molecular structures not only enhance thermal stability but also increase the difficulty of hydrogen generation.Moreover,binders devoid of hydrogen atoms exhibit superior thermal stability and completely eliminate the risk of hydrogen generation.These findings provide critical insights into the molecular design of binders,offering promising strategies to mitigate or prevent hydrogen generation from binder decomposition and thereby substantially improve the safety of lithium-ion batteries.
基金supported by the Shenzhen Science and Technology Program(No.JCYJ20220818100407016)the National Natural Science Foundation of China(No.22275059)+1 种基金Guangdong Special Support Program(No.2021TX06L775)high-level special funds(No.G03050K002)。
文摘High-voltage LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathodes are critical for enhancing the energy density of lithium-ion batteries(LIBs).The development of binders compatible with high-voltage NCM811 cathode materials is crucial to enhance the electrochemical performance of LIBs.However,the traditional fluoropolymer binder,poly(vinylidene difluoride)(PVDF),can potentially leach components or break down into poly(fluoroalkyl substances)(PFAS)chemicals,thereby contributing to PFAS contamination.A novel fluorine-free polymer,polysulfone-polyamide-polyimide(SPIO),was designed and synthesized as a binder for NCM811 cathodes.The SPIO binder exhibits exceptional mechanical properties and superior electrochemical characteristics.The cathode film fabricated with SPIO demonstrated a remarkable delamination force of 8 N(390 N·m^(-1)),indicating robust adhesion.The Li‖NCM811 cell incorporating the SPIO binder retained 80%of its initial capacity after 300 cycles at a current density of 0.2 C.In comparison,the control cells assem bled with the PVDF binder retained only 52%of their capacities under the same cycling conditions.Furthermore,the SPIO binder exhibited improved compatibility with the electrolyte.Transmission electron microscopy analysis of the cathode films after 100 cycles revealed the formation of a unifo rm,dense,and continuous chemical-electrochemical interface(CEI)by the SPIO binder on the surface of the NCM811 particles,which significantly contributed to the enhancement of the electrochemical performance.These results highlight the potential of SPIO as an advanced binder material for high-perfo rmance lithium-ion batteries.
基金supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade,Industry and Energy of Korean government under grant No 23-CM-AI-08.
文摘Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.
基金supported by National Natural Science Foundation of China(No.52204302)Young Elite Scientist Sponsorship Program by CAST(No.YESS20220533)+1 种基金China Postdoctoral Science Foundation(No.2022M713519)Graduate Research Innovation Project of Central South University(No.1053320210230).
文摘The rheological properties of an innovative coal-based colloidal composite binder(3Co-Binder)prepared via alkaline–oxygen excitation and mechanochemical synthesis are revealed.Derived from low-rank coal,3Co–Binder is applied in iron ore pelletization as a replacement for traditional bentonite,with the aim of improving the iron grades of the pellets.Cryoscanning electron microscopy revealed that 3Co-Binder exhibits a densely populated,porous network structure.It was determined to be a pseudo-plastic fluid with yield stress and shear-thinning characteristics.The stability of 3Co-Binder was influenced by the humic acid extraction rate,temperature,and static placing time.An extraction rate of humic acids above 96%was found to prevent sedimentation of 3Co-Binder,while lower temperatures and prolonged static placing time increased its apparent viscosity.A storage duration of less than 2 weeks and a temperature range of 25–35℃ were found to be optimal for maintaining the stability of 3Co-Binder.The viscous flow activation energy of 3Co-Binder remained stable at approximately 60 kJ mol^(-1) as the shear rate increased from 0.5 to 5 s^(-1).However,at higher shear rates,up to 100 s^(-1),the viscous flow activation energy decreased to 46.48 kJ mol^(–1).To ensure stability and dispersibility during storage,the rheological parameters of 3Co-Binder must meet the following criteria:yield stress below 10 Pa,consistency coefficient below 1.5 Pa s,non-Newtonian index below 1,and apparent viscosity below 10,000 mPa s at a shear rate of 1 s^(–1).
基金supported by the National Research Foundation(NRF)of Korea grant funded by the Korean government(MSIT)(No.NRF-2021 M3 H4A1A02045962).
文摘With the increasing prevalence of lithium-ion batteries(LIBs)applications,the demand for high-capacity next-generation materials has also increased.SiO_(x)is currently considered a promising anode material due to its exceptionally high capacity for LIBs.However,the significant volumetric changes of SiO_(x)during cycling and its initial Coulombic efficiency(ICE)complicate its use,whether alone or in combination with graphite materials.In this study,a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiO_(x)blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker.In addition,a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiO_(x).The combination of these two strategies increased the CE of SiO_(x)from 74%to87%and effectively mitigated its volume expansion in the graphite/SiO_(x)blended electrode,resulting in an efficient electron-conductive binder network.This led to a remarkable capacity retention of 94%after30 cycles,even under challenging conditions,with a high capacity of 550 mA h g^(-1)and a current density of 4 mA cm^(-2).Furthermore,to validate the feasibility of utilizing prelithiated SiO_(x)anode materials and the conductive binder network in LIBs,a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used.This cell demonstrated a~27.3%increase in discharge capacity of the first cycle(~185.7 mA h g^(-1))and exhibited a cycling stability of 300 cycles.Thus,this study reports a simple,feasible,and insightful method for designing high-performance LIB electrodes.
基金supported by the National Natural Science Foundation of China(Grant Nos.22378342,92372101,52162036,and 21875155)the Fundamental Research Funds for the Central Universities(20720220010)+3 种基金the National Key Research and Development Program of China(2021YFA1201502)the Natural Science Foundation of Sichuan Province(Grant No.2024NSFSC1160)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20230608)support of Nanqiang Young Top-notch Talent Fellowship in Xiamen University。
文摘Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial volume expansion during cycling,which leads to material pulverization and an unstable solid electrolyte interphase(SEI)layer.Inspired by the natural root fixation in soil,we designed a root-like topological structure binder,cassava starch-citric acid(CS-CA),based on the synergistic action of covalent and hydrogen bonds.The abundant-OH and-COOH groups in CS-CA molecules effectively form hydrogen bonds with the-OH groups on the SiO surface,significantly enhancing the interfacial interaction between CS-CA and SiO.The root-like topological structure of CS-CA with a high tolerance alleviates the mechanical stress generated by the volume changes of SiO.More encouragingly,the hydrogen bond action among CS-CA molecules produces a self-healing effect,which is advantageous for repairing damaged electrodes and preserving their structural integrity.As such,the CS-CA/SiO electrode exhibits exceptional cycling performance(963.1 mA h g^(-1)after 400 cycles at 2 A g^(-1))and rate capability(558.9 mA h g^(-1)at 5 A g^(-1)).This innovative,topologically interconnected,root-inspired binder will greatly advance the practical application of long-lasting micron-sized SiO anodes.
