Zinc Powder Research Articles

Wear-Resistant Low-friction Atmospheric Pressure Plasma Spray Coatings for Sustainable (Bio-based Recyclable) Materials

Coatings from polyetheretherketone (PEEK), polyamide 12 (PA12), molybdenumdisulfide (MoS2), zinc (Zn), and graphite (C) powder mixtures were deposited on PA6, PA12, and PEEK substrates by an atmospheric pressure plasma (APP) spray jet system. Several tenth of µm thick coatings on PA6 and PA12 substrates result in an almost halved surface roughness Ra ~8 µm, Rq ~10 µm and Rz ~60 µm, whereas a significant increase of all surface roughness parameters is observed for PEEK substrates (Ra < 1 µm → 4 µm, Rq < 1 µm → 5 µm, Rz < 5 µm → 20 µm). The surface roughness, powder composition, and selected APP process parameter strongly influence the coefficient of friction (COF) and specific wear rate ki of the APP coatings in rotational ball-on-disc tribological testing. The COF of PA12/MoS2/C coatings on PA6 substrates manufactured by selective laser sintering (SLS) is ~0.2 after 628 m sliding distance, resulting in a very low calculated ki of 6.3 × 10−7 mm3/Nm. A similarly low COF and ki was observed for PEEK coatings deposited at a current of 75 A and 60 mm jet–substrate distance on SLS PA12 substrate. Although the COF of Zn/C/MoS2 coatings on PEEK drops down below 0.1 after 1884 m sliding distance under nitrogen atmosphere the corresponding ki of 5.6 × 10−5 mm3/Nm is higher. Still all calculated specific wear rates are significantly lower than the reported values of polyamide-polytetrafluorethylene (PTFE)-polyethylene composites (1.9–8.0 × 10−2 mm3/Nm) and partly even outperform PEEK-PTFE composites (1.0 × 10−7–2.5 × 10−6), currently applied in demanding wear regimes.

Ultrasonically enhanced zinc powder replacement method for cobalt removal: Electrochemical behavior, numerical simulation

The zinc powder replacement method for Co removal is characterized by several challenges, such as poor mass transfer and agglomeration. To solve this problem, the ultrasonically enhanced zinc powder replacement method was developed and used to remove Co from the sulfate solution, and a 95.02% removal rate of Co was achieved under the optimized condition. Compared with conventional conditions, the removal rate increased by 24.5%. The behavior and mechanism of zinc powder replacing Co were comprehensively analyzed through electrochemistry and COMSOL Multiphysics. Chronoamperometry curves showed that after the introduction of ultrasound, the reaction current increased by approximately two times compared with the conventional condition. The cyclic voltammetry (CV) curves showed that the reduction potential of Co positively shifted, accompanied by an increase in peak current. The electrochemical impedance spectroscopy (EIS) tests showed that the nuclear transmission resistance decreased by approximately 1.6 times compared with conventional conditions. In addition, the COMSOL simulation revealed that, after the system was subjected to ultrasonic conditions, the temperature, flow rate, and sound pressure physical field increased, which accelerated the heat and mass transfer process in the solution. The removal behavior of the system was studied using scanning electron microscopy and X-ray diffraction. Ultrasonic waves decomposed the insoluble substances on the surface of zinc powder, refined the particles, and improved the removal rate of Co. This provides new insights into the ultrasound-enhanced reaction.

Constructing low-cost stable zinc-ion batteries with sodium-rich monoclinic manganese hexacyanoferrate cathode

Manganese-based Prussian blue analogues are ideal candidate cathode materials for constructing high-voltage zinc-ion batteries. However, challenges have persisted in realizing envisioned highly stable electrochemical cycling systems due to manganese dissolution under aqueous conditions and self-corrosion of zinc metal anodes. Considering practical application demands and cost-effectiveness, non-aqueous organic zinc-ion batteries have shown significant development potential by avoiding interference from active hydrogen and offering a stable wide voltage window. Herein, a sodium-rich monoclinic structured manganese hexacyanoferrate (m-MnHCF) was synthesized via a simple coprecipitation method, achieving a stable high-voltage zinc-ion battery energy storage system in a diluted 0.2 M Zn(CF3SO3)2 electrolyte in acetonitrile, a non-protonic polar solvent. The battery exhibited a discharge specific capacity of 77 mAh g−1 at the current density of 1 A g−1 after 620 cycles. Furthermore, by circumventing interference from active hydrogen, a cost-advantaged zinc powder anode (Zn-P) was successfully introduced into the energy storage system. Assembled Zn-P||m-MnHCF cells exhibited stable cycling for 100 cycles at a current density of 0.5 A g−1 with close to 100 % coulombic efficiency, showcasing limitless possibilities for the future, as demonstrated by illuminated LED arrays.

The Burgeoning Zinc Powder Anode for Aqueous Zinc Metal Batteries: from Electrode Preparation to Performance Enhancement

AbstractAqueous zinc metal batteries (AZMBs) have emerged as a focal point of interest in academic research and industrial strategic planning. Zinc powder (ZP) is poised to assume a prominent position in both future research and practical applications due to its high Zn utilization rate and processability. However, critical challenges need to be addressed before realizing substantial progress. Notably, severe voltage polarization and gas production of ZP electrodes stand out as the primary causes of battery failure, differing with zinc foil where short circuits caused by zinc dendrites contribute to battery failure. While numerous comprehensive reviews have offered effective strategies for zinc foil, a systematic summary of ZP electrodes is still lacking. For ZP, electrode preparation dictates the performance. This review summarizes the criteria for optimal ZP electrodes, covering electrode components, preparation methods, and technique parameters. It emphatically introduces the underlying causes and strategies of water‐related side reactions and briefly analyzes the stripping/plating behaviors of ZP electrodes. The status quo of ZP‐based batteries is then discussed in categories of ZP, current collector, conductive scaffold, binder, and electrolytes. Finally, potential avenues for future research are proposed from three aspects to enhance the focus on ZP electrodes and facilitate the practical application of AZMBs.

Dinitrogen-bridged ruthenium(II) complexes featuring dithiocarbamate ligands

In quest of low molecular weight metal-thiolate complexes as model complexes for nitrogenase, four binuclear ruthenium(II) dinitrogen-bridged complexes featuring dithiocarbamate ligands, [{(Me3tacn)Ru(κ2-S2CNR2)}2(µ-N2)][PF6]2 (Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane; 1, R = Me; 2, R = Et; 3, R = nPr; 4, R = iPr), were synthesized by reduction of [(Me3tacn)RuIII(κ2-S2CNR2)Cl]PF6 with zinc powder in a nitrogen atmosphere. A 16-electron mononuclear ruthenium(II) species [(Me3tacn)Ru(κ2-S2CNnPr2)]PF6 (3′) was isolated during preparation of 3, which may help elucidate the formation of complexes 1-4. Molecular structures of complexes 1, 2, 4 and 3′ were established by single crystal X-ray diffraction analysis. Moreover, complexes 1-4 were characterized by infrared, 1H NMR, UV–vis, fluorescence, Raman (solid state and solution state) spectroscopies and mass spectrometry, and their electrochemical properties were also investigated. Density functional theory (DFT) calculation was performed on complex 2 to study its Lewis structure and explain the UV–vis absorption spectra. Structural and DFT analyses demonstrate that N2 activation is accompanied by electron redistribution of the dithiocarbamate ligands.

Engineering zinc slurry anodes for high-performance primary alkaline batteries

The anode in Zn alkaline batteries is complex, comprised of zinc powder, gelled electrolyte, and additives, including surfactants. Optimizing the performance of these anodes means improving material utilization and suppressing corrosion of the electroactive zinc, which translates in real cells to higher energy density and longer shelf life. A challenge with optimizing these anodes has been in isolating the performance of the zinc slurry from the rest of the cell components in traditional, high-throughput cell-build studies. In this work, we use a combination of ex-situ and in-situ platforms to understand the effects of Zn content, KOH weight percent in the electrolyte, surfactant type and surfactant level on anode behavior. This is done by using electrochemical techniques including electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), potentiodynamic polarization (PDP), and constant current (galvanostatic) discharge (CCD). The results of these experiments were combined with a systematic design of experiments (DoE) matrix, allowing for optimized slurries to be realized and tested in-situ in commercially representative cells. This work can aid in intelligently designing zinc slurries for deployment in commercial products.

A Macroscopic Interpretation of the Correlation between Electrical Percolation and Mechanical Properties of Poly-(Ethylene Vinyl Acetate)/Zn Composites.

Elastic composites were prepared using a procedure involving hot plates and zinc powder that was directly dispersed into an EVA matrix. The correlation between the zinc content and the conductive properties of the material was studied via impedance spectroscopy, the thermal properties of the material were studied via differential calorimetry and the mechanical properties of the composites were studied via tensile strength curves, representing an important advancement in the characterization of this type of composite material. The composites' tensile strength and elongation at break decrease with the addition of filler since zinc particles act as stress-concentrating centres, while the composites' hardness and Young's modulus increase because of an increase in the stiffness of the material. The AC perturbation across the EVA/Zn composites was characterized using an RC parallel equivalent circuit that allowed us to easily measure their resistivity (ρp) and permittivity (εp). The dependence of these electrical magnitudes on the zinc content is correlated with their mechanical properties across the characteristic time constant τp = ρp·εp of this equivalent circuit. The dependence of the mechanical and electrical magnitudes on the zinc content is consistent with the formation of percolation clusters. The addition of graphite particles increases their potential performance. Three possible mechanisms for the electrical transport of the ac-perturbation across the EVA/Zn composites have been identified. Chemical corrosion in acid media causes the loss of zinc surface particles, but their bulk physical properties practically remain constant.

A comprehensive setting method for the optimal setpoint of controlled variables in the zinc smelting solution purification process under multi-variation inlet status

The zinc smelting solution purification process regulates the oxidation-reduction reactions (characterized by the oxidation-reduction potential (ORP)) by controlling the amount of zinc powder added to remove the impurity ions. In order to ensure the optimal operation of the process, the target key technical indicators should be converted into the optimal setpoint of controlled variables (that is, ORP). Based on the mechanism knowledge, fuzzy rules, and preference-guided predictive optimization, a comprehensive setting method for the optimal setpoint of controlled variables under multi-variation inlet status is proposed. It includes a hybrid trend detection method for inlet status, a mechanism model under multiple operating modes, and a fuzzy correction method and a preference-guided predictive optimization method to deal with slight and violent fluctuations in the inlet status, respectively. The experimental results show that the proposed method can obtain the optimal setpoint of controlled variables and reduce zinc powder consumption by approximately 3.6%.

Monitoring the Geopolymerization Reaction of Geopolymer Foams Using 29Si and 27Al MAS NMR

This study aims to investigate the geopolymerization reaction of geopolymer foams produced with three different foaming agents: aluminum powder, zinc powder, and hydrogen peroxide. The geopolymerization reaction of geopolymer foam was monitored using the 27Al and 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy technique. 27Al MAS-NMR was used to monitor the reaction at an early stage, while 29Si and 27Al MAS-NMR analyses were employed at specific time intervals of 3, 6, 10, 15, and 28 days to examine the changes that occurred in the formed gel over time. We discussed in detail how the type of foaming agent used and the duration of the reaction both influence the quantity of gel formed and the amount of remnant fly ash. Our findings indicate that the type of foaming agent used affects the formation and structure of the gel, with aluminum powder leading to the highest gel formation. Additionally, the duration of the reaction plays a significant role in determining the quantity of remnant fly ash, with longer reaction times resulting in decreased fly ash content. This study sheds light on the relevance of understanding the role of foaming agents in the geopolymerization reactions of geopolymer foams and the influence of reaction time on the formed gel properties.

Highly oriented (002) crystals zinc powder from recovery of zinc smelting slag

As an important secondary resource, the recovery of zinc smelting slag into high value-added substances has been regarded as a meaningful mission. Response surface methodology was used to assess the effect of various factors on the leaching of zinc smelting slag and model the zinc leaching process. The interactions between the influencing factors were explored to reveal the critical factors on the leaching efficiency. Importantly, the prediction model for the leaching of zinc smelting slag was established, and the predicted leaching rates were in general agreement with the actual values. The ionic form of zinc in the leaching solution is Zn(NH3)42+, which could be directly recognized as electrolyte in electrowinning after purification. Next, the electrolyte is formulated using the leaching solution. The highly oriented Zn (002) crystals zinc powder was prepared from the electrolyte using electrodeposition and the physical phase of the zinc powder was observed. The nucleation and cathodic kinetics in the electrolyte were explored using an electrochemical workstation. Finally, zinc powder with highly oriented (002) crystals was coated to form the electrode for Zn||Zn symmetric cell. A series of electrochemical tests were performed on the zinc powder anode and the symmetric cell to verify the excellent performances of the zinc powder anode with highly oriented (002) crystals.

Investigation of corrosion resistance and interfacial bonding properties of silver/silicone zinc-rich coating/substrate system in marine environment

This paper aims to study the corrosion resistance and interfacial bonding properties of the silver zinc-rich coating/substrate system and silicone zinc-rich coating/substrate system. The actual working state of the system in marine environment was simulated by the coupled effects of corrosion and pre-stretching. Scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDS) was used in corrosion test to analyze the surface morphology and corrosion products. Meanwhile, the degradation degree of the corrosion resistance was investigated based on the electrochemical impedance spectroscopy (EIS) and water absorption rate. Three-point bending test and tensile test combined with digital image correlation (DIC) were performed to evaluate the interfacial bonding properties of these two systems based on the elastic modulus and critical cracking strain. Results show that the dense accumulation of aluminum and zinc powders makes the silver zinc-rich coating have higher corrosion resistance compared to the silicone zinc-rich coating. The combined effects of corrosion and pre-stretching on the fracture toughness of silicone zinc-rich coating are larger than that of the silver zinc-rich coating. The interfacial bonding properties of the coating/substrate systems gradually degrade as the pre-stretching load approaches the critical cracking load of the coating.

Algorithm for the numerical investigation of cathode processes of zinc electroextraction

Subject of research: the paper presents a numerical algorithm for detecting the rate constants of heterogeneous processes for their further investigation. Purpose of research: Digital prototyping of electrodeposition of zinc coating by leaching depleted zinc ore. Methods of research: the algorithm is presented on the example of predicting the dezincification during parallel hydrogen release reaction in electrolysis of a sodium hydroxide solution, which contains sodium tetrahydroxozincate, and verified using full-scale experiments. So, in this article, there are detected the constants of cathode stepwise electrochemical reactions for zinc powder obtaining using direct search method. The kinetic equation system itself, which describes cathode stepwise reactions, is solved using classical Runge-Kutta method. Main results of research: the modeling makes allowance for the presence of parallel process of hydrogen release and occurs in the approximation of porous film during the settling-out. The numerical algorithm, developed by the authors, make it also possible to predict the current yield of substance.

Adsorption of single and mixed surfactants consisting of cocoamidopropyl betaine (CAPB) and sodium dodecyl benzene sulfonate (SDBS) onto zinc surface

Abstract Aqueous solutions of surfactants exhibit remarkable differences in their adsorption properties on metal surfaces. This study evaluates the adsorption of surfactant mixtures on zinc metal surfaces. The adsorption of single surfactants cocamidopropyl betaine (CAPB) and sodium dodecyl benzenesulfonate (SDBS) and their mixtures from aqueous solution at mole fractions of 0.00, 0.25, 0.50, 0.75 and 1.00 on zinc powder at 25 °C was studied. The surface tension of the single and CAPB/SDBS surfactant mixtures was measured in the presence and absence of 2 % zinc powder to determine the adsorption isotherms. The depletion method was employed to carry out the adsorption investigation. The amount of the surfactant adsorbed was also calculated from the shaded area between the surface tension versus concentration curves of these surfactants in the presence and absence of 2 % zinc powder. The highest adsorbed amounts were found to increase with the SDBS content. Furthermore, scanning electron microscope (SEM) images of zinc sheets in solutions containing single or mixed CAPB/SDBS surfactants were taken in the presence and absence of 0.05 M HCl. The micrographs indicated that the CAPB-SDBS surfactant layers formed by precipitation can protect zinc metal from acid corrosion.

Unfolded graphene riveted on layered double hydroxide as a highly efficient enhancer for the corrosion protective performance of zinc-rich epoxy coatings

The performance enhancement of zinc-rich epoxy coating brought by embedding conventional graphene nanosheets (GNs) is severely restricted due to the inevitable crumpling and folding nature of two-dimensional GNs. Herein, unfolded GNs are riveted on both sides of MgAl-layered double hydroxides (LDHs) via chemical graft method, achieving a novel LDHs/GNs nanocomposites (LGs). Experimental results reveal that, compared with pristine zinc-rich epoxy coatings (ZREs), the cathodic protection duration of LG/ZREs is roughly tripled under an ultra-low loading of net GNs (0.007 wt%), and this performance is even better than 0.2 wt% GNs-embedded ZRE. Compared with conventional GNs with crumpling and folding morphology, unfolded GNs riveted on LDHs perform better in “bridging” the available zinc powders into integrated conductive pathway and twisting the diffusion path of diffusing species in coating matrix.

Study on Optimization of Deep Purification Process Design of Zinc Oxygen Pressure Acid Leaching Solution

According to the characteristics of high impurity content and complex composition of oxygen pressure leaching (OPL) solution of zinc sulfide concentrate, combined with the quality requirements of large plate electrowinning and automatic plate stripping, the advanced purification process of solution was designed. Through the deep purification process consisting of neutralization indium precipitation and low iron purification, high temperature antimony salt nickel and cobalt removal, copper slag chlorine removal, low temperature zinc powder replacement copper and cadmium removal, fine purification, calcium and magnesium removal, the contents of harmful impurities such as iron, indium, copper, cadmium, nickel, cobalt, fluorine and chlorine in the solution are strictly controlled to ensure that the quality of the deeply purified zinc sulfate solution is qualified and can meet the needs of continuous and stable production. The energy-saving effect of advanced purification process is obvious, and the average DC power consumption per ton of electric zinc is 2880kWh, reaching the advanced level of the same industry in China. The good effect of advanced purification process ensures the successful application of OPL and large plate zinc electrowinning, and improves the technology and equipment level of zinc smelting industry, which has important popularization and application value.

Synthesis of nanocrystalline zinc powder: Investigating the influence of crystallite size and lattice strain on Debye-Waller factors

In this investigation, nano-sized zinc particles were synthesized through a ball milling process. The Zn metal powder, milled for durations ranging from 0 to 150 h, underwent analysis using X-ray diffraction (XRD). The study focused on determining PS (particle size) and assessing the influence of LS (lattice strain) on the DWFs (Debye–Waller factors), employing XRD principles. LSs were induced in zinc through varying milling durations, and X-ray diffractograms were captured at different stages of the milling process. The results revealed a reduction in PS and an increase in LS with prolonged milling, reaching a predominantly amorphous state at 150 h. By establishing the correlation between strain and effective DWF, the study estimated DWFs for zero strain in zinc.

Zinc Powder Anodes for Rechargeable Aqueous Zinc-Based Batteries.

Aqueous rechargeable zinc-based batteries hold great promise for energy storage applications, with most research utilizing zinc foils as the anode. Conversely, the high tunability of zinc powder (Zn-P) makes it an ideal choice for zinc-based batteries, seamlessly integrating with current battery production technologies. However, challenges such as contact loss, dendrite formation, and a high tendency for corrosion significantly hamper the performance enhancement of Zn-P anodes. This review provides an overview of strategies adopted from various perspectives, including zinc powder optimization, electrode engineering, and electrolyte modification, to address these issues. Additionally, it explores the limitations of existing research and offers valuable insights into potential future directions for further advancements in Zn-P anodes.

Production of high purity MoO3 from spent catalyst of formaldehyde synthesis process via a novel two-step leaching-cementation method

This study presents a two-step methodology for producing high-purity MoO3 from spent FORMOX process catalysts. In the first step, a leaching process with a Na2CO3 solution is used to get molybdenum out of formaldehyde synthesis catalyst. The second step involves molybdenum-ion cementation in the presence of metallic zinc powder and plates. The leaching process is thoroughly explored using the design of experiments (DOE) to analyze critical parameters such as temperature, leaching time, Na2CO3/Mo stoichiometric ratio, and catalyst average particle size. A robust quadratic model with an R2 value exceeding 97 % is developed, serving as a predictive tool for molybdenum extraction. Through rigorous numerical optimization, the optimal conditions for 100 % extraction were found to be 74.5 °C, 92.3 min, a stoichiometric ratio of 2.52, and a particle size of 183 μm. However, the use of zinc powder in the cementation stage introduces impurities due to increased solution pH and reduced zinc dissolution. The strategic adoption of zinc plates mitigates these challenges, resulting in a notable enhancement of the final product's purity. Over 91 % of MoO4-2 ions with a purity surpassing 99.8 % are successfully obtained as hexagonal MoO3 powder at 85 °C with an initial solution pH of 1.0 after 15 min of the cementation process.

Production of Sm2Fe17N3 Bulk Magnets

Sm2Fe17N3 powder exhibits excellent magnetic properties but is unstable and decomposes into α-Fe and SmN phases at high temperatures. Therefore, the key to producing Sm2Fe17N3 bulk magnets is to reduce the deterioration of Sm2Fe17N3 powder during sintering. Herein, Sm2Fe17N3 bulk magnets were made using the spark plasma sintering (SPS) method with the addition of zinc stearate powder and zinc powder. Adding small amounts of zinc stearate powder and zinc powder improved the magnetic anisotropy and the coercivity of the magnets, respectively. The magnets produced by the SPS method using zinc stearate powder and zinc powder exhibited enhanced magnetic properties almost comparable to those of Sm2Fe17N3 powder.

High areal energy zinc-ion micro-batteries enabled by 3D printing

Rechargeable zinc-ion micro-batteries (ZIMBs) are promising candidates for powering various microelectronic devices, although they typically exhibit low areal energy of ∼0.1 mWh cm−2. In this study, we reported the design and assembly of zinc micro-batteries through an ink extrusion-based printing approach. In the process, a three-axis printer was adopted, allowing for the fabrication of microelectrodes with large areal loading and diverse morphologies. Vanadium oxide anchored with carbon nanotubes was employed as the cathode material, zinc powder was used as the anode material, and a polyacrylamide gel containing ethylene glycol was selected as the electrolyte. The printed micro-batteries demonstrate an areal capacity of 0.51 mAh cm−2 and an energy density of 0.37 mWh cm−2 at a charge-discharge current of 0.2 mA, outperforming state-of-the-art zinc counterparts. This work provides a simple yet efficient solution to the development of high-energy micro-batteries.