Deposition Behavior Research Articles

Tailoring Lithium Horizontal Deposition for Long-Lasting High-Loading NCA (≥5 mA h cm-2)||Lithium-Metal Full Cells in Carbonate Electrolytes.

We report a design for a synergistic lithium (Li) metal hosting layer for high-loading Li(Ni,Co,Al)O2 (NCA) (≥5 mA h cm-2)||Li-metal full cells in carbonate electrolytes. Based on density functional theory calculations, the hosting layer was designed as a three-dimensional silver/carbon composite nanofiber (Ag/CNF) network with high Li affinity and a platinum (Pt)-coated polypropylene separator with low Li affinity. This design enabled the tailoring of horizontal Li deposition on the Ag/CNF hosting layer. The Li deposition behavior modulated by the hosting layer was thoroughly examined based on the initial Li deposition and cycling behaviors of the Li||Li symmetric cell configuration. Cryogenic focused-ion beam cross-sectional images of the cycled Li anodes clearly demonstrated that dense lithium deposition was enabled by the synergistic hosting layer high-loading NCA (≥5 mA h cm-2)||Li-metal full cells. When the hosting layer was used, the average cycling performance improved by 78.27% under various cycling conditions. Our work demonstrates that the synergistic hosting layer design is a fruitful pathway to accelerate the commercialization of high-energy-density Li-metal batteries in carbonate electrolytes.

Toward the Rechargeable Aqueous Zinc Ion Batteries with Improved Overall Performance: Electrolyte with Surface Adsorptive Additive.

Aqueous zinc-ion batteries (AZIBs) with slightly acidic electrolytes process advantages such as high safety, competitive cost, and satisfactory electrochemical performance. However, the failure behaviors of both electrodes, regarding zinc dendrite growth, interfacial parasitic reactions, and the collapse of cathode materials hinder the practical application of ZIBs. To alleviate the issues of both anode and cathode at the same time, D-xylose (DX) is introduced to the electrolyte as a multifunctional additive. As a result, the side reaction of the anode is suppressed and the metallic deposition behavior is regulated due to the hydrogen bonding network reconstruction and preferential surface adsorption of DX; for the MnO2 cathode, the DX adsorption can help the interfacial charge transfer and increase the reactive sites. Benefiting from these merits, DX-optimized Zn//Zn battery displays reveal a prolonged lifespan of 6912h and an ultra-high cumulative capacity of 17.28Ahcm-2 at 5mAcm-2. With the function of water reactivity suppression, the Coulombic efficiency reaches 99.91% at 2mAcm-2; the Zn||MnO2 full batteries exhibit excellent cyclability over 2000 cycles at 5C with an increased capacity of 118.9mAhg-1, indicating the dual functions to both of the electrodes for AZIBs.

Effect of particle materials on deposition behavior and microstructural features of films prepared via vacuum kinetic spraying

Vacuum kinetic spraying (VKS) is a particle deposition process by which various materials can be deposited as films, even at room temperature. In this study, Al2O3 (ceramic, completely brittle), Fe-based bulk metallic glass (BMG, brittle with some plastic deformability), and Ag (metal, completely ductile) were used as powder materials, and the effects of the particle materials on the deposition behavior and microstructural features of the film were investigated. Deposition tests were performed under identical experimental conditions, and the microstructural features were comprehensively analyzed. The deposition behavior and film microstructure of the three materials were completely different. The Al2O3 film formed at the lowest deposition rate was extremely dense and comprised nanocrystals with a relatively low surface roughness, indicating fragmentation-dominant deposition. The deposition rate of Ag was between those of the other two materials, and the film consisted of relatively dense large grains with nanopores and a smooth surface, resulting from plasticity-dominant deposition. The deposition rate of BMG was considerably high, and the resulting film consisted of a porous structure with relatively large fragments and an extremely rough film surface. These features of BMG were attributed to the insufficient fragmentation or plastic deformation of the particles. Consequently, even under identical deposition conditions, the deposition rate and behavior and the resulting film microstructure vary depending on the particle materials. Therefore, the microstructural features of the film must be examined before selecting powder materials and fabricating films through process optimization for each material.

In-Depth Understanding of Interfacial Na+ Behaviors in Sodium Metal Anode: Migration, Desolvation, and Deposition.

Interfacial Na+ behaviors of sodium (Na) anode severely threaten the stability of sodium-metal batteries (SMBs). This review systematically and in-depth discusses the current fundamental understanding of interfacial Na+ behaviors in SMBs including Na+ migration, desolvation, diffusion, nucleation, and deposition. The key influencing factors and optimization strategies of these behaviors are further summarized and discussed. More importantly, the high-energy-density anode-free sodium metal batteries (AFSMBs) are highlighted by addressing key issues in the areas of limited Na sources and irreversible Na loss. Simultaneously, recent advanced characterization techniques for deeper insights into interfacial Na+ deposition behavior and composition information of SEI film are spotlighted to provide guidance for the advancement of SMBs and AFSMBs. Finally, the prominent perspectives are presented to guide and promote the development of SMBs and AFSMBs.

Calibration of the UBC3D-PLM soil model from Dilatometer Marchetti Test (DMT) for the liquefaction behaviour and cyclic resistance ratio (CRR) of sandy soils

Seismic liquefaction is one of the most devastating natural hazards that can cause significant damage to structures and infrastructure. The liquefaction behaviour is simulated in the finite element code PLAXIS by the UBC3D-PLM constitutive model that is 3-D generalized formulation of the 2-D UBCSAND model developed at the University of British Colombia. The UBC3D-PLM model used in this work was successfully employed in many recent studies, e.g. to evaluate the liquefaction effects on the seismic soil–structure interaction, to assess the dynamic behaviour of earthen embankments built on liquefiable soil and to investigate the seismic performance of offshore foundations. Moreover, UBC3D-PLM model involves many input parameters to model the onset of the liquefaction phenomenon. Therefore, their determination becomes a crucial concern. Previous studies elaborated a specific formulation that requires the corrected Standard Penetration Test (SPT) blow counts as input. However, the Dilatometer Marchetti Test (DMT), compared to the SPT, is more sensitive to several factors that affect the liquefaction resistance such as aging, stress history, overconsolidation and horizontal earth pressure. For this reason, a new parameter selection procedure, which uses the horizontal stress index derived from DMT, was developed in this study.The new relationships were applied for determining the initial parameters of the UBC3D-PLM model to describe the behavior of several liquefiable deposits located in eastern Sicily (Italy) that experienced destructive earthquakes in the past. For each site, the model was calibrated to the DMT-based liquefaction triggering curve, developed by combining DMT correlations with the current method based on SPT test, by the simulation of cyclic direct simple shear tests (CDSS). Finally, CDSS tests were performed by means of the CDSS device at the Soil Dynamics and Geotechnical Engineering Laboratory of the University “Kore” of Enna (Italy). This allowed to validate the applicability of the proposed procedure in simulating the liquefaction behavior of sandy soils.

Deposition behaviour of FeCrMnNiCo coatings deposited using mechanically alloyed powder: Comparing Cold Spray, HVOF, HVAF, and Laser Cladding processes

This study examined the characteristics of mechanically alloyed (MA) Cantor alloy powder and the coatings produced from it using various deposition techniques, including cold spray (CS), high-velocity oxy-fuel, high-velocity air-fuel, and laser cladding (LC). Microstructure analysis of the MA powder revealed an irregular morphology and incomplete elemental mixing. The microstructure of the CS coating displayed an FCC crystal structure, with some XRD peaks corresponding to BCC phases due to the presence of unmixed elements. In contrast, all other coatings also exhibited oxides alongside FCC and BCC phases, with the LC coating containing a higher concentration of oxides. These coatings demonstrated high density and diverse microstructures, with CS coatings demonstrating effective transfer of powder microstructure. The CS coating had the highest hardness (679 ± 17 HV0.1) due to the retention of deformed microstructure from the powder, whilst the LC coating had the lowest hardness (215 ± 10 HV0.1). CALPHAD calculations using Thermo-Calc suggest that the presence of oxides in the coatings could be thermodynamically feasible, depending on the conditions. Deposition efficiency varied significantly among the methods, with LC achieving the highest efficiency (63 ± 6 %) and CS the lowest (14 ± 1 %).

Highly Stable Sodium Metal Batteries Enabled by Manipulating the Fluorinated Organic Components of Solid‐Electrolyte‐Interphase

AbstractNa metal batteries (NMBs) stand at the forefront of advancing energy storage technologies, but are severely hampered by Na dendrite issues, especially when using carbonate electrolytes. Suppressing the growth of Na dendrites through constructing NaF‐rich solid‐electrolyte‐interphase (SEI) is a commonly‐used strategy to prolong the lifespan of NMBs. In contrast, fluorinated organic SEI components are often underutilized. Inspired by unveiling the adsorption configuration of fluorinated organic compounds on the surface of Na metal, an optimized SEI architecture for stabilizing NMBs is proposed by investigating the C4H9SO2F‐/C4F9SO2F‐treated Na metal anodes. It is revealed that the SEI built on a fluorinated inorganic/organic hybrid layer exhibit favorable Na passivation capability, significantly improving Na deposition behavior. As a result, the NMB with a high‐loading cathode (15 mg cm−2) and a negative/positive capacity ratio (N/P) ratio of 4 shows a long‐term life span over 1000 cycles with 92.8% capacity retention at 2 C. This work opens a new pathway for developing robust and high‐energy‐density NMBs.

Effect of Al precursor’s properties on interactions with self-assembled monolayers for area selective deposition

Area selective deposition (ASD) is a high-precision atomic-level manufacturing technology that enables the development of bottom-up manufacturing methods in the future semiconductor field. The area selective deposition behavior of Al precursors on 1-octadecylthiol (ODT) passivated Cu/SiO2 surfaces was studied through experimental and theoretical analysis. The relationship between precursor steric hindrance, symmetry, penetration depth in ODT, and adsorption energy was elucidated. The loss of selectivity caused by different penetration depths of the precursor in ODT can be post-treated with acids or H2 plasma to remove the physisorption of precursor molecules between ODT chains, thereby improving the selectivity. Reliable ASD technology has been successfully applied to Cu/SiO2 patterns. Dimethylaluminum isopropoxide can selectively deposit about 10 nm of Al2O3 on SiO2 without detectable defects on the Cu area. This provides important insights into the choice of precursors in the ASD process and can extend its application to a wider range of device manufacturing schemes.

Synergistic Gradient Anodes for Long-Term Stability in Aqueous Zinc-Ion Batteries.

The stability of aqueous zinc metal anodes is still constrained by their severe dendrite growth. Optimizing electric field distribution and crystallography to modulate the diffusion and deposition behavior of zinc ions can effectively suppress dendrite growth. However, the fabrication strategy to directly endow specific textured zinc anodes with gradient electric field distribution is still lacking. Herein, a strategy combining crystal reconstruction of commercial zinc foil with graphene oxide (GO) protective layer is proposed to construct an in situ gradient electric field-enhanced strong (002) textured GO@ZnO/Zn(002) anode. Based on the experimental and theoretical results, the GO protective layer can regulate a wide-range homogeneous Zn2+ ions flow, while the dense and uniform ZnO/Zn(002) nanoneedles /nanoparticles can enhance localized polarized electric field to accelerate rapid localized transfer of Zn2+ ions and guide them toward directional deposition along (002) plane. Therefore, the hierarchical GO@ZnO/Zn(002) anode enables the symmetric cell to operate continuously and stably for 5700 and 4200h at 2 and 4mA cm-2, respectively, which is comparable to or better than most high-end Zn anodes. This work presents new insights into the zinc foil reconstruction and gradient electric field fabrication strategy, offering a scalable approach for the development of long-term stable metal anodes.

Occurrence and fate of atmospheric short/medium chain chlorinated paraffins: Size distribution and inhalation exposure

Chlorinated paraffins (CPs) are intricate industrial compounds synthesized through alkane chlorination. Researches on the size distribution of short-chain (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in atmospheric particulate matter (PM) are limited. Here, we conducted a thorough investigation on the size-dependent distribution characteristics, deposition behavior in respiratory tract, and health risks associated with CPs in atmospheric PM. The concentration of SCCPs in atmospheric particulate matter (PM10) was much higher than MCCPs, with concentration ranges of 2.53–31.8 and 1.07–4.62 ng m−3, respectively. Concentrations of CPs increase with decreasing PM size, peaking at aerodynamic diameters (Dp) < 0.49 μm. Physicochemical properties influence the distribution of CP homologs in PM. Those with lower vapor pressure, higher octanol-air and octanol-water partition coefficients tended to accumulate in PM with larger geometric mean diameters. Most of the inhaled CPs in PM deposited in the upper airways, with a small amount in the trachea and alveolar regions. The estimated daily intakes values were highest when Dp < 0.49 μm. Particle size is an essential determinant for the deposition of inhaled CPs in PM and should be considered in health risk assessments.

Numerical study for atmospheric transport of radioactive materials for hypothetical severe nuclear accident under different meteorological conditions

A study for atmospheric transport is essential for the consequence assessment of severe nuclear accidents since radionuclides could be released from the nuclear facility into the atmosphere and cause radioactive pollution in the environment. Atmospheric transport behaviors are strongly related with meteorological conditions, which can obviously influence the transport and diffusion characteristics of radioactive materials in the atmosphere; thus, it is meaningful to investigate the coupling effects between meteorological processes and transport behaviors of radioactive materials. To evaluate the influence of meteorological conditions on atmospheric transport, meteorological parameters for different seasons were first acquired by the weather research forecast model. Furthermore, atmospheric transport behaviors of radioactive materials were simulated by the meso-scale numerical model under different meteorological conditions, and numerical analyses were conducted toward transport and deposition behaviors of radioactive materials. In addition, the influence of FDDA (four-dimensional data assimilation) on meteorological parameters and atmospheric transport behaviors was researched. The present study is important for strengthening consequence assessment for severe nuclear accident and made it possible to apply the data assimilation technology in further research works.

Numerical simulation of hydrate flow in gas-dominated undulating pipes considering nucleation and deposition behaviors

The distribution and deposition of hydrates in deep-water gas transportation pipelines are crucial for safety. Current simulations of hydrate flow based on the population balance model have predominantly focused on water-dominant systems and neglect the nucleation and deposition of hydrates. By establishing a model for a hydrate flow in a gas-dominant system that considers the uneven distribution of the liquid film on the wall, hydrate nucleation, gas–liquid mass transfer, particle adhesion and aggregation, and dynamic deposition, we achieved simulation of the entire process of hydrate formation, aggregation, breakage, and deposition. Simulations in undulating pipelines were carried out to investigate the effects of gas velocity, liquid injection, pressure, and pipeline structure on distribution patterns. The results showed increasing the gas velocity enhanced the dispersion of particles and increasing the pressure increased the rate of aggregation. The formation of blocky aggregates posed significant risk in the rear section of the lower-bend pipe.

High-temperature deposition model for molten particle prediction based on droplet-surface interaction criteria

Particle deposition in gas turbine engines damages blade surfaces and diminishes engine performance. Deposition results from heat and momentum exchanges between fluid and particles, coupled with the interactions between particles and surfaces. The increasing turbine inlet temperatures cause particles to become molten, complicating their interaction with surfaces. Existing models fail to convincingly explain the deposition behaviors of molten particles. In the present study, considering particle fluidity and the nonlinear accumulation of deposits, the deposition criteria for viscous droplets and the maximum steady deposit layer model were incorporated to establish an unsteady high-temperature deposition model. The new model, validated against experiment results in the literatures, predicts molten particle deposition behavior with an average error of 3.89 % in capture efficiency at high-temperature conditions. It accurately predicts crown-like deposit morphology and nonlinear accumulation, matching experimental observations. Applied to nozzle guide vanes with film cooling, results show that deposits primarily occur on the leading edge and pressure side near the trailing edge. The particle capture efficiency initially rises before diminishing as particle size increases, whereas an inverse trend is noted with the escalation of the mass flow ratio. At a mass flow ratio of 0.15, the capture efficiency hits the minimum of about 13.2 %.

Targeting inerratic deposition behaviour via interface regulation toward dendrite-free zinc metal anodes

Aqueous zinc ion batteries are of interest due to their inherent safety, low cost and high energy density. Nevertheless, critical issues such as uncontrollable dendrite growth, hydrogen evolution reaction and corrosion have dramatically impeded the widespread utilization. To tackle above issues, the versatile artificial protective layer strategy consisting of Zn-friendly, porous and conductive carbon shells is presented for yolk-shell SiO2@void@C (SVC) nanospheres for guiding rapid and homogeneous Zn plating/stripping. On the one hand, the highly zincophilic SiO2 and pore structure interacted significantly with low nucleation overpotential and uniform Zn2+ flux, which favored homogeneous zinc deposition and ionic migration, thereby dramatically aiding in inhibition of Zn dendrites and interruption of interfacial side reactions. On the other hand, SVC nanospheres confer excellent electrical conductivity and mechanical properties, which play an important role in accelerating ion diffusion and boosting structural stability. Consequently, the SVC@Zn electrode exhibits high reversibility and electrochemical stability with a long cycling stability of 1800 h at 5 mA cm−2/1.25 mAh cm−2 and average CE of 99 %. The good properties associated with composition simplicity and abundant yield affords a feasible scheme for high-performance AZIBs.

Leveraging Ion Pairing and Transport in Localized High-Concentration Electrolytes for Reversible Lithium Metal Anodes at Low Temperatures.

Coulombic efficiency of over 99 % is rarely achieved for Li metal anode below -40 °C, hindering the practical application of high-energy-density Li metal batteries under extreme conditions. Herein, limiting factors for Li metal reversibility are investigated utilizing ether-based localized high-concentration electrolytes of different solvent-diluent combinations. We find that along with the desolvation barrier, bulk ion transport properties including ionic conductivity, transference number, and diffusivity are also crucial factors for low-temperature Li deposition behavior. Superior Li metal reversibility was observed within the combination of the solvent with moderately weak solvating power and the diluent with minimal viscosity, highlighting the role of ion transport and the necessity for a trade-off with desolvation. The optimized electrolyte composed of lithium bis(fluorosulfonyl)imide, methyl n-propyl ether, and 1,1,2,2-tetrafluoroethyl methyl ether delivers exceptional Coulombic efficiency of 99.34 % at -40 °C and 98.96 % at -60 °C under a current density of 0.5 mA cm-2. Furthermore, Li||LiCoO2 (2.7 mAh cm-2) cells demonstrate impressive reversible capacity and cycling stability at these temperatures. This work sheds light on the less-recognized relevance of bulk ion transport to low-temperature performance and provides guidelines for the electrolyte design of Li metal batteries operating in cold environments.

Numerical model of asphaltene deposition in vertical wellbores: Considerations of particle shape and drag force

Asphaltene deposition and plugging are common phenomena during crude oil production, significantly reducing production efficiency. Understanding the deposition behavior of asphaltene particles in vertical wellbores, particularly in relation to drag force interactions and settlement velocity, is imperative to mitigate these issues. Existing empirical models often fail due to their inherent inaccuracies and neglect of asphaltene particles' irregular shapes. This work established a quantitative method to describe irregular geometries of asphaltene particles. Shape coefficient, ∅, and shape coefficient influence factor, θ, are used to assess the impact of particle shape on the drag force coefficient and settling velocity. Experimental results from sedimentation experiments reveal particles with smaller shape coefficients encounter greater flow resistance and higher drag force coefficients. Moreover, the impact of shape coefficient on the drag coefficient gradually decreases as the Reynolds number increases. Based on these experimental findings, distinct models for the drag force coefficient and settling velocity of asphaltene particles are established, achieving a reduction in average error ranging between 2 % ∼ 25 % compared to existing models.

Unraveling the Deposition and Dissolution Behavior of the Ag-Modified Li Surface Based on Electrochemical Atomic Force Microscopy.

Lithium is a promising anode material for advanced batteries because of its high capacity and low redox potential. However, its practical use is hindered by nonuniform Li deposition and dendrite formation, leading to safety concerns in Li metal batteries. Our study shows that Ag-based materials enhance the uniformity of Li deposition on Ag-modified Li (AgLi) surfaces, thereby addressing these key challenges. This improvement is due to the strong affinity of Ag for Li, which promotes uniform deposition and dissolution. Additionally, the AgLi surface demonstrated an improved cycling stability, which is crucial for long-term battery reliability. Emphasizing our analytical approach, we utilized comprehensive techniques such as Kelvin probe force microscopy (KPFM) and electrochemical atomic force microscopy (EC-AFM) to locally analyze the electrical properties and unravel the Li deposition/dissolution mechanisms. KPFM analysis provided crucial insights into surface potential variations, while EC-AFM highlighted topographical changes during the Li deposition and dissolution processes, contributing significantly to the development of safer and more efficient Li metal batteries.

Fluorine-Rich Electrolyte Additive for Achieving Dendrite-Free Lithium Anodes at Low Temperatures.

The practical application of lithium metal anodes is significantly impeded by poor interfacial stability and uncontrolled dendrite growth. Herein, we introduce methyl trifluoroacetate (MTFA), a low-melting-point small molecule, as an electrolyte additive in an ether-based electrolyte. This additive facilitates the formation of an in situ composite solid electrolyte interphase (SEI) layer that is rich in LiF and features an ester-based flexible matrix. The resulting composite layer exhibits high ionic conductivity and mechanical stability, effectively regulating the lithium deposition behavior over a broad temperature range and inhibiting dendrite formation. Based on MTFA, the Li||Li symmetrical cell achieves a lifespan exceeding 5000 h at room temperature and 800 h at -20 °C, both with ultralow overpotential and exceptional cycling stability. In Li||LiFePO4 full cells with a high-area loading (10.52 mg cm-2) and an N/P ratio of 1.68, an average capacity decay of merely 0.096% per cycle is observed over 200 cycles. Even at -20 °C, the Li||LiFePO4 cell shows a CE of over 99% and maintains stable cycling performance. This work provides an innovative approach for optimizing lithium metal anode interfaces and enhancing low-temperature operation capabilities through the use of electrolyte additives.

Interfacial Zn2+-solvation regulator towards reversible and stable Zn anode

Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface, predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution. Particularly, the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn2+-solvation and deposition behavior demand comprehensive investigation. Organic molecules endowed with special functional groups (such as hydroxyl, carboxyl, etc.) have the potential to significantly optimize the solvation structure of Zn2+ and regulate the interfacial electric double layer (EDL). By increasing nucleation overpotential and decreasing interfacial free energy, these functional groups facilitate a lower critical nucleation radius, thereby forming an asymptotic nucleation model to promote uniform Zn deposition. Herein, this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure. The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques, indicating that the H-Zn anode exhibits dendrite-free growth, no by-products, and weak hydrogen evolution, in sharp contrast to the bare Zn. Consequently, the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h. Moreover, the H-Zn//NH4V4O10 (NVO) full battery showcases exceptional cycle stability, retaining 95.04% capacity retention after 400 cycles at a large current density of 5 A g−1. This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.

Influence of the inner roughness of powder channels on the powder propagation behavior in laser metal deposition

The powder propagation behavior of powder nozzles for the laser metal deposition process has a significant influence on powder utilization rate and track geometry. A well-focused powder stream will lead to a higher process efficiency and lower material loss. Powder channels with different roughness and a constant diameter of 1.5 mm were placed by wire electrical discharge machining into a copper alloy printed by powder bed fusion. Nickel base powder with a size of −106 to +45 μm was delivered through the powder channels with varied carrier gas flow rates and varied powder mass flow rates. High-speed imaging was used to analyze the powder flow. From these recordings, the dispersion angle of the powder stream from single channels could be measured as well as the velocity of particles. Moreover, the relationship between individual particle velocity and individual particle flight angle was investigated. It was found that the inner roughness of powder channels has a major impact on powder propagation behavior. It could be shown that with a decrease in Ra from 2.16 to 0.27 μm the divergence angle decreased by around 61% while the particle velocity was increased by at least 28% for all varied parameters. Particles with a high velocity tend to have a lower particle flight angle.