Design of multifunctional polymeric binders in silicon anodes for lithium‐ion batteries

Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface layers.As a result,the cycling stability of Si anodes is insufficient for commercialization in LIBs.Polymeric binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the electrodes.This review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si anodes.In particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of binders.Furthermore,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.

Enhancing Li-S battery performance via functional polymer binders for polysulfide inhibition

The commercialization of lithium-sulfur(Li-S)batteries faces several challenges,including poor conductivity,unexpected volume expansion,and continuous sulfur loss from the cathode due to redox shuttling.In this study,we introduce a novel polymer via a simple cross-linking between poly(ether-thioureas)(PETU)and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)as a bifunctio nal binder for Li-S batteries(devotes as"PPTU").Compared to polyvinylidene fluoride(PVDF),as-prepared PPTU exhibits significantly higher electrical conductivity,facilitating electrochemical reactions.Additionally,PPTU demonstrates effective adsorption of lithium polysulfides,leading to improved cycling stability by suppressing the shuttling effect.We investigate this behavior by monitoring morphological changes at the cell interface using synchrotron X-ray tomography.Cells with PPTU binders exhibit remarkable rate performance,desired reversibility,and excellent cycling stability even under stringent bending and twisting conditions.Our work represents promising progress in functional polymer binder development for Li-S batteries.

Alkali Metal Ion Substituted Carboxymethyl Cellulose as Anode Polymeric Binders for Rapidly Chargeable Lithium-Ion Batteries

The increasing demand for short charging time on electric vehicles has motivated realization of fast chargeable lithium-ion batteries(LIBs).However,shortening the charging time of LIBs is limited by Li^(+)intercalation process consisting of liquid-phase diffusion,de-solvation,SEI crossing,and solid-phase diffusion.Herein,we propose a new strategy to accelerate the de-solvation step through a control of interaction between polymeric binder and solvent-Li^(+)complexes.For this purpose,three alkali metal ions(Li^(+),Na^(+),and K^(+))substituted carboxymethyl cellulose(Li-,Na-,and K-CMC)are prepared to examine the effects of metal ions on their performances.The lowest activation energy of de-solvation and the highest chemical diffusion coefficient were observed for Li-CMC.Specifically,Li-CMC cell with a capacity of 3 mAh cm^(-2)could be charged to>95%in 10 min,while a value above>85%was observed after 150 cycles.Thus,the presented approach holds great promise for the realization of fast charging.

Silk fibroin-based biopolymer composite binders with gradient binding energy and strong adhesion force for high-performance micro-sized silicon anodes

Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.

Designandconstructionof athree-dimensionalelectrodewith biomass-derived carbon current collector andwater-soluble binder for high-sulfur-loading lithium-sulfur batteries

Lithium-sulfur batteries attract lots of attention due to their high specific capacity,low cost,and environmental friendliness.However,the low sulfur utilization and short cycle life extremely hinder their application.Herein,we design and fabricate a three-dimensional electrode by a simple filtration method to achieve a high-sulfur loading.Biomass porous carbon is employed as a current collector,which not only enhances the electronic transport but also effectively limits the volume expansion of the active material.Meanwhile,an optimized carboxymethyl cellulose binder is chosen.The chemical bonding restricts the shuttle effect,leading to improved electrochemical performance.Under the ultrahigh sulfur load of 28mg/cm2,the high capacity of 18mAh/cm2 is still maintained,and stable cycling performance is obtained.This study demonstrates a viable strategy to develop promising lithium-sulfur batteries with a three-dimensional electrode,which promotes sulfur loading and electrochemical performance.

产前超声诊断Binder综合征

Binder综合征是罕见的先天性面中部发育畸形[1],发病率约1/18000[2]。三维超声具有立体成像、动态可视化等优点,能实时、动态观察胎儿颜面部结构,已广泛应用于临床。本研究观察产前超声诊断Binder综合征的价值。1资料与方法1.1研究对象收集2019年10月—2022年10月于甘肃省妇幼保健院经产前超声诊断为Binder综合征的7胎胎儿,均为单胎,孕周22~24周、平均(22.9±0.7)周;孕妇年龄26~36岁、平均(30.0±3.3)岁,其中1名孕期有环境毒害物(甲醛)接触史,1名有孕早期服药史(布洛芬),1名孕期从事美甲工作并频繁接触甲醇、乙醛等化学溶剂。本研究经院伦理委员会批准[(2021)GSFY伦审[47]号];孕妇及其家属均知情同意。

Rational Design of Robust and Universal Aqueous Binders to Enable Highly Stable Cyclability of High-Capacity Conversion and Alloy-Type Anodes

The development of high-performance binders is a simple but effective approach to address the rapid capacity decay of high-capacity anodes caused by large volume change upon lithiation/delithiation.Herein,we demonstrate a unique organic/inorganic hybrid binder system that enables an efficient in situ crosslinking of aqueous binders(e.g.,sodium alginate(SA)and carboxymethyl cellulose(CMC))by reacting with an inorganic crosslinker(sodium metaborate hydrate(SMH))upon vacuum drying.The resultant 3D interconnected networks endow the binders with strong adhesion and outstanding self-healing capability,which effectively improve the electrode integrity by preventing fracturing and exfoliation during cycling and facilitate Li^(+)ion transfer.SiO anodes fabricated from the commercial microsized powders with the SA/0.2SMH binder maintain 1470 mAh g^(-1)of specific capacity at 100 mA g^(-1)after 200 cycles,which is 5 times higher than that fabricated with SA binder alone(293 mAh g^(-1)).Nearly,no capacity loss was observed over 500 cycles when limiting discharge capacity at 1500 mAh g^(-1).The new binders also dramatically improved the performance of Fe_(2)O_(3),Fe_(3)O_(4),NiO,and Si electrodes,indicating the excellent applicability.This finding represents a novel strategy in developing high-performance aqueous binders and improves the prospect of using high-capacity anode materials in Li-ion batteries.

Optimization of Animal-Glue Binders for Casting Applications

In typical metal foundry applications,sand casting is still the most used technology.The related binder plays a very important role as its performances can directly influence the quality of castings.Among many binders,glues of animal origin have attracted much attention in recent years due to their reduced environmental impact.How-ever,they display some drawbacks such as the tendency to coagulate easily at room temperature and a relatively low strength.In this study,a novel gas-hardening casting binder was prepared using an animal glue and anhy-drous potassium carbonate as a hydrolyzing agent to avoid undesired agglomeration.Moreover,sodium pyropho-sphate and furfuryl alcohol were exploited as modifiers to obtain a binder with a high compressive strength.The best modification conditions,determined by means of an orthogonal design matrix approach,were 4 g of Na2CO3,sodium pyrophosphate,furfuryl alcohol and animal glue with a ratio of 4:12:100,at 85°C and with a duration of 115 min,respectively.The viscosity of the mixture obtained under these optimized conditions was 1250 mPa⋅s.The compressive strength of the binder,hardened by CO_(2) gas,was 4.00 MPa.Its gas evolution at 850°C was 15 ml⋅g-1,and its residual strength after 10 min calculation at 800°C was 0.01 MPa,which is high enough to meet the requirement of core-making in foundry.Moreover,after hydrolysis and further modification,animal glue and modifiers displayed a grafting reaction and an esterification reaction,respectively,which made the adhesive network denser and improved its thermal stability.

Recycling arsenic-containing bio-leaching residue after thermal treatment in cemented paste backfill:Structure modification,binder properties and environmental assessment

The substantial arsenic(As)content present in arsenic-containing bio-leaching residue(ABR)presents noteworthy environ-mental challenges attributable to its inherent instability and susceptibility to leaching.Given its elevated calcium sulfate content,ABR exhibits considerable promise for industrial applications.This study delved into the feasibility of utilizing ABR as a source of sulfates for producing super sulfated cement(SSC),offering an innovative binder for cemented paste backfill(CPB).Thermal treatment at varying temperatures of 150,350,600,and 800℃ was employed to modify ABR’s performance.The investigation encompassed the examination of phase transformations and alterations in the chemical composition of As within ABR.Subsequently,the hydration characteristics of SSC utilizing ABR,with or without thermal treatment,were studied,encompassing reaction kinetics,setting time,strength development,and microstructure.The findings revealed that thermal treatment changed the calcium sulfate structure in ABR,consequently impacting the resultant sample performance.Notably,calcination at 600℃ demonstrated optimal modification effects on both early and long-term strength attributes.This enhanced performance can be attributed to the augmented formation of reaction products and a densified micro-structure.Furthermore,the thermal treatment elicited modifications in the chemical As fractions within ABR,with limited impact on the As immobilization capacity of the prepared binders.

Constructing high-toughness polyimide binder with robust polarity and ion-conductive mechanisms ensuring long-term operational stability of silicon-based anodes

Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion anode.Herein,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high toughness.The plentiful polar carboxyl(-COOH) groups establish robust bonding strength.Rapid ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles electrode.Meanwhile,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 cycles.The perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.

Research,application and development of inorganic binder for casting process

Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the future.However,compared to organic binders(such as resin binders),inorganic binders exhibit lower bonding strength and are more sensitive to environmental humidity.This sensitivity poses challenges,particularly in the reclamation of used sand,thus limiting their broader application.In this paper,the research and application status of inorganic binders(mainly silicate inorganic binders)and their curing methods are summarized.In addition,the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are introduced.Meanwhile,a detailed comparative analysis is conducted on the challenging issue of“reclamation for used sand”in the application of inorganic binders.Finally,the development direction of inorganic binders is clarified.

A Web-like Three-dimensional Binder for Silicon Anode in Lithium-ion Batteries

Si anode is of paramount importance for advanced energy-dense lithium-ion batteries(LIBs).However,the large volume change as well as stress generates during its lithiation-delithiation process poses a great challenge to the long-term cycling and hindering its application.Herein this work,a composite binder is prepared with a soft component,guar gum(GG),and a rigid linear polymer,anionic polyacrylamide(APAM).Rich hydroxy,carboxyl,and amide groups on the polymer chains not only enable intermolecular crosslinking to form a web-like binder,A2G1,but also realize strong chemical binding as well as physical encapsulating to Si particles.The resultant electrode shows limited thickness change of merely 9%on lithiation and almost recovers its original thickness on delithiation.It demonstrates high reversible capacity of 2104.3 mAh g^(-1)after 100 cycles at a current density of 1800 mA g^(-1),and in constant capacity(1000 mAh g^(-1))test,it also shows a long life of 392 cycles.Therefore,this soft-hard combining web-like binder illustrates its great potential in the future applications.

Mechanical and corrosion properties of full liquid phase sintered WE43 magnesium alloy specimens fabricated via binder jetting additive manufacturing

This study investigates full liquid phase sintering as a process of fabrication parts from WE43(Mg-4wt.%Y-3wt.%RE-0.7wt.%Zr)alloy using binder jetting additive manufacturing(BJAM).This fabrication process is being developed for use in producing structural or biomedical devices.Specifically,this study focused on achieving a near-dense microstructure with WE43 Mg alloy while substantially reducing the duration of sintering post-processing after BJAM part rendering.The optimal process resulted in microstructure with 2.5%porosity and significantly reduced sintering time.The improved sintering can be explained by the presence of Y_(2)O_(3)and Nd_(2)O_(3)oxide layers,which form spontaneously on the surface of WE43 powder used in BJAM.These layers appear to be crucial in preventing shape distortion of the resulting samples and in enabling the development of sintering necks,particularly under sintering conditions exceeding the liquidus temperature of WE43 alloy.Sintered WE43 specimens rendered by BJAM achieved significant improvement in both corrosion resistance and mechanical properties through reduced porosity levels related to the sintering time.

Ten-Minute Synthesis of a New Redox-Active Aqueous Binder for Flame-Retardant Li-S Batteries

As a critical role in battery systems,polymer binders have been shown to efficiently suppress the lithium polysulfide shuttling and accommodate volume changes in recent years.However,preparation processes and safety,as the key criterions for Li-S batteries'practical applications,still attract less attention.Herein,an aqueous multifunction binder(named PEI-TIC)is prepared via an easy and fast epoxy-amine ring-opening reaction(10 min),which can not only give the sulfur cathode a stable mechanical property,a strong chemical adsorption and catalytic conversion ability,but also a fire safety improvement.The Li-S batteries based on the PEI-TIC binder display a high discharge capacity(1297.8 mAh g^(-1)),superior rate performance(823.0 mAh g^(-1)at 2 C),and an ultralow capacity decay rate of 0.035%over more than 800 cycles.Even under 7.1 mg cm^(-2)S-loaded,the PEI-TIC electrode can also achieve a high areal capacity of 7.2 mA h g^(-1)and excellent cycling stability,confirming its application potential.Moreover,it is also noted that TG-FTIR test is performed for the first time to explore the flame-retardant mechanism of polymer binders.This work provides an economically and environmentally friendly binder for the practical application and inspires the exploration of the flame-retardant mechanism of all electrode components.

Quantitative lithium substitution of carboxyl hydrogens in polyacrylic acid binder enables robust SiO electrodes with durable lithium storage stability

The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.

High energy density in ultra-thick and flexible electrodes enabled by designed conductive agent/binder composite

Thick electrodes can increase incorporation of active electrode materials by diminishing the proportion of inactive constituents,improving the overall energy density of batteries.However,thick electrodes fabricated using the conventional slurry casting approach frequently exhibit an exacerbated accumulation of carbon additives and binders on their surfaces,invariably leading to compromised electrochemical properties.In this study,we introduce a designed conductive agent/binder composite synthesized from carbon nanotube and polytetrafluoroethylene.This agent/binder composite facilitates production of dry-process-prepared ultra-thick electrodes endowed with a three-dimensional and uniformly distributed percolative architecture,ensuring superior electronic conductivity and remarkable mechanical resilience.Using this approach,ultra-thick LiCoO_(2)(LCO) electrodes demonstrated superior cycling performance and rate capabilities,registering an impressive loading capacity of up to 101.4 mg/cm^(2),signifying a 242% increase in battery energy density.In another analytical endeavor,time-of-flight secondary ion mass spectroscopy was used to clarify the distribution of cathode electrolyte interphase(CEI) in cycled LCO electrodes.The results provide unprecedented evidence explaining the intricate correlation between CEI generation and carbon distribution,highlighting the intrinsic advantages of the proposed dry-process approach in fine-tu ning the CEI,with excellent cycling performance in batteries equipped with ultra-thick electrodes.

BArcherFuzzer:An Android System Services Fuzzier via Transaction Dependencies of BpBinder

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).

Dry Mix Slag—High-Calcium Fly Ash Binder. Part Two: Durability

This work investigates durability of cement-free mortars with a binder comprised of ground granulated blast furnace slag (GGBFS) activated by high-calcium fly ash (HCFA) and sodium carbonate (Na2CO3): the soundness, sulfate resistance, alkali-silica reactivity and efflorescence factors are considered. Results of tests show that such mortars are resistant to alkali-silica expansion. Mortars are also sulfate-resistant when the amount of HCFA in the complex binder is within a limit of 10 wt%. The fineness of fly ash determines its’ ability to activate GGBFS hydration, and influence soundness of the binder, early strength development, sulfate resistance and efflorescence behavior. The present article is a continuation of authors’ work, previously published in MSA, Vol. 14, 240-254.

Release Model of Water-soluble Chitosan Nanoparticles for Protein Delivery

[Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinetics model, Gompertz model, Weibull model, Higuchi model and Logistic model were used to fit the BSA release profile from WSC carriers. [Result] Except Higuchi model and Logistic model, other models could fit BSA release profile better. [Conclusion] Gompertz two-order kinetics model could fit the release of WSC nano-particles better and model parameters had practical physical meaning.

A study of the properties of hydrophobically associating water-soluble polymers used in drilling fluids

Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution by radical polymerization. New polymer drilling fluids are made up of HPAP, which is used as viscosifiers and encapsulation agents. Properties of this system are reported in this paper. Results indicate that this system has a high value of yield point to plastic viscosity (YP/PV≥0.7), high viscosity at a low-shear rate (LSRV≥30000mPa·s), excellent shear thinning behavior, good solid-carrying behavior, resistance to shear, good thermal stability (as high as 140℃) and salt resistance. The system has excellent behavior in high-density solution of NaCl and in calcium and magnesium rich saline solutions. Hence, HPAP also can be used in saltwater polymer drilling fluids.