Plating Voltage Research Articles

Investigating Anode Potential Errors of Real-Time Capable DFN Type Models Induced by Inhomogeneity for Fast Charging of Cylindrical Lithium-Ion Batteries

The occurrence of lithium plating during fast charging poses a safety risk and can reduce the battery lifespan. To prevent plating during the application of model-based charging protocols, a safety margin is added to the lithium plating voltage criterion to compensate for unaccounted in-plane heterogeneities. This article investigates the value of this safety buffer when using real-time capable 1D-DFNs coupled with a 0D thermal model. Through comparison with a multi-scale model, the 1D-DFN error to the local minimum in the anode potential can be characterized. An adjusted cooling coefficient enables 0D temperature modeling with an average error of less than 1 ◦C, despite the inability to consider temperature gradients. For a high-energy NMC811/SiC parameterization of a 4680 format cell with tabless current collectors, the 1D-DFN error in the anode potential deviates by a maximum of 10 mV during charging up to 3C at 50 W m−2 K−1 convective mantle cooling. The anode potential error is influenced by the charging rate, cooling strategy, cell format, and current collector design.

Unveiling voltage evolution during Li plating-relaxation-Li stripping cycling of lithium-ion batteries

The unwanted Li plating on graphite anode surface in lithium-ion batteries causes poor cycling performance along with raised safety risk once Li dendrites penetrate separator. Voltage characteristics during relaxation and discharging have been recognized as the most direct and convenient indictor for Li plating detection, where unveiling voltage evolution during plating-relaxation-stripping cycling needs to be emphasized to facilitate Li plating detection. This study fabricates Li|graphite cells to implement Li plating-relaxation-stripping protocols through over-lithiation before internal short circuit, and the Li nucleation-growth process is linked to voltage evolution assisting with the post-mortem approaches. The Li plating voltage initially displays continuous decline indicated as Li nucleation, until the formation of Li plating plateau indicated as Li growth. The plating-relaxation-stripping voltage patterns show highly correlation that the occurrence of Li plating plateau exactly corresponds to the appearance of a mixed relaxation plateau attributed to the equilibrium of Li stripping and Li re-intercalation into graphite, while the disappearance of the mixed relaxation plateau just corresponds to the advent of Li stripping plateau. Three stages are finally divided associated with characteristic Li plating -relaxation-stripping voltage patterns, where Stage I indicates the occurrence of Li plating plateau behaving as predominant LixC6; Stage II is characterized as the occurrence of mixed relaxation plateau manifested as Li coexisting with LixC6; Stage III is distinguished by the appearance of Li stripping plateau indicated as predominant Li and dead Li. This work proposes underlying evolution mechanism of Li plating-relaxation-stripping cycling, which contributes to sufficient evidence for reliable Li plating detection.

Targeting the low-temperature performance degradation of lithium-ion batteries: A non-destructive bidirectional pulse current heating framework

The poor low-temperature performance of lithium-ion batteries (LIBs) significantly impedes the widespread adoption of electric vehicles (EVs) and energy storage systems (ESSs) in cold regions. In this paper, a non-destructive bidirectional pulse current (BPC) heating framework considering different BPC parameters is proposed. To determine the lithium plating boundary of graphite anode, a three-electrode battery is first fabricated. Then, an electro-thermal coupled model is established and the model parameters consider not only the effects of temperature and heating frequency but also the effect of current amplitude. Subsequently, a novel lithium plating criterion is derived based on the thermodynamic theory and the graphite anode model. Finally, leveraging the electro-thermal coupled model and considering the constraints of lithium plating and terminal voltage, the effects of different BPC heating parameters on battery heat generation are discussed and a novel BPC heating strategy is designed. The results show that the heat generation power is highest when the ratio of discharge time to charge time is 0.55. Additionally, the BPC heating strategy proposed in this paper is 45 s faster than the traditional BPC heating strategy when the battery is heated from -15 °C to 10 °C at 100 Hz. The heating rate of the new BPC strategy is 3.51 °C/min and there is no observed capacity degradation after 100 heating cycles. The BPC heating framework proposed in this paper effectively improves the low-temperature performance of the battery and contributes positively to the promotion of EVs and ESSs in cold regions.

Tin Modified Carbon Nanofibers as an Effective Catalytic Electrode for Bromine Redox Reactions in Static Zinc‐bromine Batteries

AbstractZinc‐bromine batteries (ZBBs) have emerged as a compelling solution for large‐scale energy storage, yet they confront significant technical challenges impeding widespread commercialization. The electrochemical processes within ZBBs rely on a stoichiometric mechanism, where the bromine reaction at the cathode drives the zinc plating reaction on the anode. However, the sluggish electrochemical kinetics of Br2/Br− redox reactions lead to substantial electrochemical polarization, resulting in interruptions in zinc plating and significant voltage losses in ZBBs. This study introduces a new solution to address these challenges by leveraging carbon nanofiber decorated with tin nanoparticles as an efficient catalyst. The catalyst serves to enhance the Br2/Br– redox reaction, effectively reducing voltage losses in ZBBs. When implemented in static ZBB configurations, the Sn/CNF catalysts demonstrate exceptional long‐term stability, achieving an impressive 3000 cycles with minimal voltage loss. In contrast, ZBBs utilizing SnO2 based catalysts experience a substantially higher voltage loss of 736 mV, along with limited and unstable cycling performance. These findings signify a promising approach for the development of catalytic electrodes, paving the way for high‐performance ZBBs with improved efficiency and cycling durability.

Evaluation of the mechanical properties and corrosion behavior of hBN-Zn composite coatings on the weathering steel

Mechanical tests were conducted and analyzed to investigate the efficacy of Zinc-based coating methods enhanced with hexagonal Boron Nitride (h-BN) nanoparticles. Various methods are employed to deposit these coatings, including Zinc electroplating, Zinc hot-dip, and Zinc-rich coat (ZRC). Different parameters, such as plating time, temperature, voltage, pH, and concentrations of additives, are carefully selected during the process. The introduction of h-BN nanoparticles at varying concentrations into a Zinc- based coating significantly enhanced mechanical properties and performance measures. This improvement was achieved through the diffusion and dispersion of the nanoparticles within the coating. Furthermore, the incorporation of h-BN nanoparticles has exhibited notable enhancements in corrosion resistance when subjected to a 3.5% (NaCl) solution. The best microhardness and adhesion strength values can be achieved by increasing the h-BN concentration (1.5 to 2.5) wt.% in the plating baths. For instance, electroplating with h-BN at a concentration of 15.75 g/l yields a microhardness of 606.7 HV and an adhesion strength of 14.48 MPa. Similarly, hot dip galvanizing with h-BN at a concentration of 2.0% results in a microhardness of 542.1 HV and an adhesion strength of 10.28 MPa. Lastly, when using h-BN at a concentration of 2.5% in ZRC, the microhardness and adhesion strength values obtained are 557.8 HV and 8.5 MPa, respectively. The incorporation of h-BN nanoparticles resulted in a significant improvement and augmentation of the thickness of the coating exhibited the least amount of porosity and the most uniform dispersion when compared to other Zinc composite coatings, namely Zinc electroplating (with a thickness of 97 µm of h-BN at a concentration of 21 g/l), Zinc hot dip (with a thickness of 144 µm of h-BN at a concentration of 2.5%), and ZRC (with a thickness of 123 µm of h-BN at a concentration of 2.5%). Moreover, the utilization of Tafel extrapolation curves and corrosion analysis has demonstrated that Zinc- based coating techniques, when reinforced with the incorporation of h-BN, exhibit significantly improved corrosion current densities (icorr) and corrosion rates (CR). Zinc electroplating technique with h-BN at a concentration of 15.75 g/l yields current density and corrosion rate values of 0.72 µA/cm2 and 0.00659 mpy, respectively. Similarly, Zinc hot dip with a 2.0% h-BN concentration results in current density and corrosion rate values of 3.5 µA/cm2 and 0.032 mpy, while ZRC with a 2.5% h-BN concentration exhibits values of 5.2 µA/cm2 and 0.04758 mpy. OM, SEM, XRD, and EDS mapping analysis were used to characterize the Zinc composite coating's grain structure, grain size, nanoparticle distribution, and chemical composition. The coating matrix contained Zinc and h-BN nanoparticles without impurities. h- BN in the composite coating does not affect grain size. As nucleation sites, h-BN nanoparticles can reduce porosity and refine grains after integration. SubjectsMaterials Chemistry; Corrosion-Materials Science; Surface Engineering-Materials Science.

Effect of Potassium Carbonate Additives on the Properties of Copper Foils Electroplated at High Current Density

The amount and kind of additives in electrolytes play a very important role on the electroplating of Cu foil, which is used as a cathode materials for secondary batteries. As the use of Cu foil increased, various studies on the electroplated Cu foil are urgently needed. We studied surface characteristics and changes in structural properties due to the addition of inhibitors under electroplating conditions with high current density. The surface layer was observed, to analyze the effect of the amount of potassium carbonate as an inhibitor. When the potassium carbonate was added at 5~25 ppm without any other additives, the initial plating voltage was observed to decrease. To uniformly distribute crystals without agglomeration at the initial stage of electroplating, it is reasonable to add potassium carbonate within the range of 20~25 ppm. There was no significant difference in surface roughness and specific resistance due to the amount of potassium carbonate, when the additives were added complexly. There was an increase in the relative strength of the preferred growth orientation of (220) in a group with 20 ppm potassium carbonate, compared to the group with 10 ppm potassium carbonate. The grain size decreased with the amount of potassium carbonate added with other additives. However, there was no significant difference in tensile strength and elongation (p-value: 0.000). To ensure uniform properties with a combination of 4 kinds of additives it is reasonable to add potassium carbonate in the range of 10~20 ppm.

Engineering interface upgrade of LiNi0.8Co0.1Mn0.1O2 cells from PYR1(4CN)(2O2)TFSI with cyano and ether groups as dual functional pyrrolidine electrolyte

It is a concern that cells with lithium (Li) metal anodes and LiNi0.8Co0.1Mn0.1O2 (NCM 811) cathodes exhibit high energy density. However, the chemical and electrochemical properties of an original solid electrolyte interphase (SEI) film formed by the Li metal reaction are unstable, resulting in uneven plating and rapid growth of Li dendrites. Due to the high nickel content of NCM 811, Ni4+ dissolved at the electrode interface leads to side reactions and irreversible rock salt structure, forming an unstable cathodic electrolyte interphase (CEI) film. Ion liquid (IL) electrolytes provide a strategy for forming stable SEI/CEI and keeping NCM 811 structural stability, but their high viscosity has limited their electrochemical performance. Functionalize pyrrolidine with ether and cyano groups is introduced, the high flexibility of the ether group can reduce the viscosity of the IL-based electrolyte, and the oxygen atom can provide Li+ coordination sites to accelerate Li+ transport. The strong electron absorption ability of the cyano group shows the strong coordination ability with transition metal ions to inhibit the erosion of CEI by side reactions. Under the dual function of cyano and ether groups, more TFSI− participate in the formation of the SEI film, which leads to the increase in beneficial components with high ionic conductivity, further inhibiting dendrite growth and promoting uniform plating. Thus, LiǁLi cells, with 0.5 wt. % 1-cyanopropyl-1-diethyl ether pyrrolidine bisfluoromethanesulfonimide salt [PYR1(4CN)(2O2)TFSI], revealed excellent plating voltage stability for more than 450 h. After 200 cycles, the discharge specific capacity of LiǁNCM 811 cells was 123 mAh g−1 and an excellent capacity retention of 62.1% at 1 C. This work shows a strategy of improving SEI/CEI from the electrolyte with cyano and ether groups and provides a feasible horizon in the long-term cycle performance of lithium metal batteries.

Interplay of Lithium Plating Quantification on Thermal Safety Characteristics of Lithium-Ion Batteries

Adverse lithium plating is a significant side reaction during the fast charging of lithium-ion (Li-ion) batteries when the Li-ion flux exceeds the intercalation or diffusion limits of graphite electrodes. Accurate quantification of lithium plating has always been a tough challenge given the severe defects of online detection methods such as coulombic efficiency and voltage relaxation plateau, making the mathematical correlation between cell-level thermal safety hazards and quantitative lithium plating events still a bottleneck problem. In this study, we apply a three-electrode (3E) Li-ion cell configuration and the accelerating rate calorimeter (ARC) to comprehensively investigate the interplay of unfavorable lithium plating on thermal runaway characteristics of Li-ion batteries. Lithium plating is introduced by cycling 3E Li-ion cells at low temperatures and quantified by analyzing potential-based plating energy, coulombic inefficiency, internal resistance, and voltage relaxation plateau. Surface microscopic characterization is carried out on graphite electrodes to reveal the morphologies and chemical states of lithium deposition. ARC experiments are implemented at full-cell and partial-cell scales to fundamentally understand the effects and contributions of thermally unstable lithium plating to the overall safety performance of Li-ion cell chemistries.

Anode-Free Sodium Ion Batteries: Effect of Pressure on Sodium Plating on Copper

Sodium ion anode-free battery technology puts extra emphasis on high plating and stripping efficiency of sodium metal at the anode surface, due to the lack of an excess of the transporting ion. Recent studies have shown the importance of strict control of water content in enabling efficient plating and stripping of sodium on copper in the 1M NaPF6 in diglyme electrolyte[1]. We have achieved promising results at coin cell level in this configuration: 99.9% coulombic efficiency over 400 cycles, low nucleation overpotential of 40mV and 10mV hysteresis at 0.2mA cm-2, without dendrite formation. To demonstrate the scalability of the anode-free concept, we attempted plating and stripping of sodium metal on copper foils with areas that are 10-fold higher (>10 cm2) than those previously achievable in coin cells (~1cm2) using a split pouch cell configuration. Furthermore, we investigate the effect of pressure at this scale by using two methods. The initial method involves increasing spacer thickness, which acts to compress a wave spring within the split pouch cell. These experiments demonstrate that the plating and stripping voltage hysteresis can be decreased from 125mV -> 40mV -> 10mV, with increasing spacer thickness on the order 3mm -> 3.5mm -> 4mm. The hysteresis observed in coin cells is then matched when 4mm of spacers is used in split pouch cells, indicating a similar pressure applied in these two cell formats. Voltage instabilities are also reduced by increasing the spacer thickness, indicating the formation an increasingly stable solid electrolyte interface (SEI). Secondly, the optimal pressure for the Na||Cu half-cell is investigated by using a pressure calibration unit to accurately measure the applied force within a compressive jig.

Condensation heat transfer deterioration on superhydrophobic surface with dense nanostructures

Superhydrophobic surface with dense nanostructures was fabricated on copper substrate by template-assisted electrochemical deposition. During deposition process, bubbles generated and stayed at some regions to prevent the fabrication of nanostructure, yielding heterogeneous surface. To prepare homogeneous surface, the electrolyte composition and plating voltage are optimized. Repeated experiments of condensation heat transfer on superhydrophobic surface were performed. The heat transfer performance is deteriorated during experiments. Compared with hydrophilic and smooth surface, heat transfer coefficient on fresh superhydrophobic surface was improved by 154.3%, maximally. However, the heat transfer coefficient of superhydrophobic surface after repeated tests behaves only maximum 67.2% improvement. To explore the mechanism of heat transfer deterioration, SEM images and EDS elemental analysis were used. There is no obvious change of nanostructure after repeated experiments. However, the polymer attached on nanostructure to provide hydrophobicity is destroyed. This paper warns that the robustness of both nanostructure and polymer need to be considered to fabricate superhydrophobic surface with excellent condensation heat transfer performance.

Influence of electric brush‐plating voltage on hydrophobic behaviour of a cauliflower‐like Ni coating surface

The effect of the plating voltage on the surface roughness, morphology, chemical composition and wettability of the Ni coatings was investigated by means of Laser scanning confocal microscopy, scanning electronic microscope, X-ray diffraction, energy-dispersive spectroscopy, and water contact angle measurements. The results indicate that the evolution of surface morphology on Ni coatings prepared by brush-plating depends strongly on the variation of plating voltage. The microstructure characterization shows that the typical hierarchical cauliflower-like structures was formed uniformly on the as-prepared Ni coatings. The combination of the porous morphology and hierarchical cauliflower-like structures plays a crucial role in improving the hydrophobic property. In absence of surface chemical modification, the Ni coatings exhibit an excellent hydrophobicity and have a high contact angle of 141 degree. Based on the Cassie-Baxier models, the relationship of two dimensionless geometrical parameters and the wetting property of the Ni coatings were investigated. It was demonstrated that to obtain the stable Cassie hydrophobic state, the aspect ratio and the water contact angle on the basal surface should be as large as possible and the spacing factor should be limited within a specific range for given aspect ratio and water contact angle on the basal surface.

Parametric Appraisal of Wear Behavior of Coated FDM Build parts using Firefly Algorithm

Among all Rapid Prototyping (RP) technologies, the Fused Deposition Modelling (FDM) is one of the advantageous technology due to its ease in handling of 3D complex jobs with less material waste and time. Now-a-days, metallization of FDM build parts are deeply necessary to meet challenges in the fabrication of complex electrical discharge machining (EDM) tools, preservation of artefacts, manufacturing of circuit boards etc. Therefore, experiments are conducted adopting design of experiment (DOE) technique to minimize experimental runs and to get maximum data for analysis purpose. Two FDM build parameters i.e. raster angle and air gap and two coating parameters i.e plating time and voltage are selected to investigate their effects on the surface texture of the copper metallized FDM build parts. Analysis of variance (ANOVA) has been performed to check the significance of each process parameters and their interactions. One regression equation is developed relating process parameters with the surface texture of the metallized FDM build parts. Using surface plots, effect of process parameters on the surface texture are studied and analyzed. One metaheuristic, nature inspired firefly algorithm is adopted to get an optimum parameter setting in order to improve the performance characteristic

Fabrication of Superhydrophobic Surfaces on Stainless Steel Mesh Substrates via Electro-brush Flow Plating Technology

Recently, superhydrophobic surface has attracted increasing attention because of its possible application prospect on self-cleaning, anti-icing, drag-reduction and corrosion-resistance. Although the main route to fabricate superhydrophobic surfaces is first constructing the micro-structures and then lowering the surface energy, the lack of effective method to large-area fabricate suitable micro-structures limits its application. Here, we developed an electro-brush flow plating method to high-effectively fabricate micro-structures and superhydrophobic surfaces on stainless steel mesh substrate. The processing parameters including the plating voltage, plating time and brush speed which have significant influences on the superhydrophobicity of substrate were discussed. Under the proper parameters, the water contact angle on the prepared surface reaches to 158° and the water sliding angle is less than 10°. The SEM and XRD results demonstrate that the wires of superhydrophobic mesh were coated with micro/nano hierarchical Ni structures which trapped enough air to support water droplet and provide high mechanical robustness because of the high hardness of the coating.

Intercalating Ti2Nb14O39 Anode Materials for Fast‐Charging, High‐Capacity and Safe Lithium–Ion Batteries

Ti-Nb-O binary oxide materials represent a family of promising intercalating anode materials for lithium-ion batteries. In additional to their excellent capacities (388-402 mAh g-1 ), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti-Nb-O family, Ti2 Nb14 O39 , as an advanced anode material. Ti2 Nb14 O39 porous spheres (Ti2 Nb14 O39 -S) exhibit a defective shear ReO3 crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li+ -ion transport length and fast Li+ -ion diffusivity. Consequently, the Ti2 Nb14 O39 -S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g-1 at 0.1 C), high first-cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li+ ), outstanding rate capability (223 mAh g-1 at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti2 Nb14 O39 -S can be a promising anode material for fast-charging, high capacity, safe and stable lithium-ion batteries.

Fabricated composite structure with hydrophobicity and anti-corrosion by sandblasting and electro-brush plating

The micro-nano composite structure on carbon steel substrate can be fabricated, and the composite structure not only has the property of hydrophobicity, but also has the property of corrosion resistance, which can be fabricated by combining a sandblasting technology and electro-brush plating method. The micro-nano composite structure fabricated by combining methods have been studied by the different preparation technology parameters, and then the different surface morphologies were obtained, at the same time, the different micro surface structures were formed. The parameters of the brush plating voltage plays an important part in this preparation process, so we can select the best parameters by changing the parameters of the brush plating voltage during the preparation process, and after the preparation process, hydrophobic surface has a bigger static contact angle than before, which is up to 149.3°±2.5° without any modification. In this paper, the qualitative and quantitative ananlysis of various properties of the fabricated surface with the composite structure were studied by advanced techniques. The hydrophobic surface morphologies were investigated by means of scanning electron microscope (SEM), and the wettability of the surface were investigated by water contact angle measurements (WCA), the corrosion resistance of the fabricated surface on carbon steel substrate was investigated by potentiodynamic measurements. Through the above analysis, we can get a lot of corresponding results, and the results what we get showed that the micro-nano composite structure that constructed on the surface of carbon steel not only has the property of hydrophobic on the surface, and the hydrophobic surface also has the property of corrosion resistance by combining the technology of sand blasting and electro-brush plating. Moreover, based on potentiodynamic polarization measurement in 3.5 wt% NaCl solution, the average corrosion current density of the sample surface that was fabricated by combining methods on carbon steel substrate is decreased by 1–2 orders of magnitude, and which is also less 1–2 orders of magnitude than the bare carbon steel, and because of that, the corrosion rate is also decreased, and the corrosion electric potential has an ascending tendency because of the average corrosion current density decreased. So its corrosion resistance is improved after this preparation process. It is seen that, through the method that design of combining sandblasting technology and electro-brush plating method constructed on the surface of carbon steel, the micro-nano composite structure was obtained excellent properties which included hydrophobic and corrosion resistance.

A Study of the Effect of Gold Thickness Distribution in the Jet Plating Process to Optimize Gold Usage and Plating Voltage Using Design of Experiments

A gold plating process in the electronics industry can be classified as (i) all surface plating or (ii) selective plating. Selective plating is more widely used than all surface plating because it can save more gold used in the plating process and takes less plating time. In this research, the selective plating process called jet plating was studied. Factors that possibly affected the gold usage and plating voltage were also studied to reduce the production cost. These factors included (a) plating temperature, (b) crystal (inhibitor) amount, (c) distance between workpiece and anode, (d) plating current and (e) plating speed. A two-level Full Factorial design with center points was first performed to screen the factors. A Central Composite Design (CCD) was then employed to optimize the factors in jet plating. The amount of gold usage should be reduced to 0.366 g / 10,000 pieces, the plating speed should be increased to 4 m/min and the plating voltage should not exceed 8.0 V. According to the analysis, the optimal settings should be as follows: the plating temperature at 55.5 deg C, the crystal amount at 90%, the distance at 0.5 mm, the plating current at 2.8 A, and the plating speed at 4.5 m/min. This optimal setting led to gold usage of 0.350 g / 10,000 pieces and a plating voltage of 7.16 V. Confirmation runs of 30 experiments at the optimal conditions were then performed. It was found that the gold usage and the plating voltage of the confirmation runs were not different from the optimized gold usage and plating voltage. The optimal condition was then applied in production, which could reduce the gold usage by 4.5% and increase the plating speed by 12.5% while the plating voltage did not exceed the limit.

Electrochemical plating of I125 on silver matrix for microsources

A technique for plating of I125 on silver matrices by electrochemical plating at alkaline pH was developed and approved. The direct covering of I125 showed to be impossible and to take place only after pre-treatment of matrices by reagents with reductive and chelating properties. According to results of set of experiments the hydrazine hydrate was chosen as activating agent. The developed method includes preparatory activation of surface of silver matrices by processing with 0,01 mM hydrazine solution and then plating of I125 from NaI125 solution in 0,05 M alkaline solution with I125 volumetric activity of 50 mCi/ml (plating voltage of 950 mV). Radioactivity of samples made by developed method with time of coating for 30 or 60 min accounted for 1,12±0,12 mCi and 1.43±0.14 mCi, respectively. Thus, the developed method is efficient technique for plating of I125 on silver matrices, has replicable results and may be used for manufacturing of microsources.

Influences of brush plating solutions composition and technological parameters on the quality of rolled copper foil surface coatings

Abstract

Fabrication of superhydrophobic surfaces on copper substrates via flow plating technology

The preparation of superhydrophobic surfaces on hydrophilic metal substrates depends on both surface microstructures and low surface energy. Composite electro-brush flow plating technology was developed to prepare appropriate microstructures leading to superhydrophilicity on copper surfaces. The effects of plating voltage and plating time on the coating surface structures and hydrophobicity were discussed. The surface morphology and chemical composition were characterised by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results demonstrate that the prepared surfaces have the appearance of micro–nano hierarchical structures composed of submicron papilla-like Ni structures and nanoscale Al2O3 particles. After fluoridation, the coating surfaces prepared by proper parameters show superhydrophobicity with a water contact angle of 162° and a sliding angle of less than 10°. Tests of micro hardness, wear resistance and persistence show that the obtained superhydrophobic n-Al2O3/Ni coating surfaces have outstanding mechanical properties and stability. This sample preparation technique has prospective application in the large-scale and continuous production of superhydrophobic engineering materials.

Fabrication of Superhydrophobic Surfaces on Copper Substrates via Brush Plating Technique

Superhydrophobic surfaces on metal substrates are often prepared via roughing the surfaces and lowering their surface energy. Composite brush plating technique is developed to prepare superhydrophobic n-SiO2/Ni brush plating composite coating on copper surfaces. Under the better process parameters, the water contact angle of the obtained superhydrophobic surface is approximately 160°, and the water sliding angle is less than 10°. The influences of plating voltage and plating time on the coating surface structure and hydrophobicity were discussed. The surface morphology and chemical composition were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).The results show that the prepared surfaces have the appearance of the uniform micron papilla-like structures, which are composed of submicron globular Ni particles covered with n-SiO2nanoscale villiform structures. These hierarchical micro/nanostructures are similar to the lotus leaf and play an important role in gaining superhydrophobicity. It is expected that this sample technique will be widely used for large-scale production of superhydrophobic engineering materials.