Anodized Magnesium Alloy Research Articles

Revolutionizing Battery Longevity by Optimising Magnesium Alloy Anodes Performance

This research explores the enhancement of electrochemical performance in magnesium batteries by optimising magnesium alloy anodes, explicitly focusing on Mg-Al and Mg-Ag alloys. The study’s objective was to determine the impact of alloy composition on anode voltage stability and overall battery efficiency, particularly under extended cycling conditions. The research assessed the anodes’ voltage behaviour and internal resistance across magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) electrolyte formulations using a systematic setup involving cyclic voltammetry on the anode and electrochemical impedance spectroscopy. The Mg-Al alloy demonstrated superior performance, with minimal voltage drop and lower resistance increase than the Mg-Ag alloy. The results showed that the Mg-Al alloy maintained over 85% energy efficiency after 100 cycles, significantly outperforming the Mg-Ag alloy, which exhibited increased degradation and efficiency reduction to approximately 80%. These findings confirm that incorporating aluminium into magnesium anodes stabilises the anode voltage and enhances the overall battery efficiency by mitigating degradation mechanisms. Consequently, the Mg-Al alloy is identified as an up-and-coming candidate for use in advanced battery technologies, offering energy density and cycle life improvements. This study lays the groundwork for future research to refine magnesium alloy compositions further to boost battery performance.

Fabrication and characterization of hydroxyapatite coatings on anodized magnesium alloys by electrochemical and chemical methods intended for biodegradable implants

The fabrication of hydroxyapatite (HAP)/MgO composite coatings on Mg alloy is crucial for enhancing the corrosion resistance and biocompatibility of biomedical implants. In this study, we aimed to investigate the effects of two different surface modification methods, i.e., electrochemical (electrodeposition, ED) and chemical (solution treatment, ST), on the phase structure, degradation properties, and biocompatibility of the composite coatings in comparison to the anodized coating. The surface morphologies and crystalline structures of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Subsequently, the degradation rate of the coatings in simulated body fluid were comprehensively evaluated by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electrochemical microscopy (SECM) tests. Additionally, in-vitro cell proliferation assays were employed to quantitatively assess the biocompatibilities of the coatings. The results showed that both ED and ST methods were effective in depositing HAP on anodized Mg alloy, resulting in different surface morphologies with hydroxyapatite layer thicknesses of 2.71 μm and 3.56 μm, respectively. In this way, the HAP-deposited coatings exhibited improved corrosion resistances and biocompatibilities compared with those of the anodized coating. Specifically, the ST-deposited composite film displayed superior degradability and biocompatibility which was attributed to its filiform surface morphology and thicker HAP layer. Overall, the present study demonstrates the potential of HAP/MgO composite coatings for biomedical applications, with implications for the development of advanced implant materials with improved performance and biocompatibility.

Exploring the inhibition effect of tri-sodium phosphate concentrations on corrosion in Mg-sn-ca-mn anode for magnesium batteries

ABSTRACT The corrosion of magnesium (Mg) alloy anodes poses a significant challenge in the development of magnesium-based batteries. In this study, the inhibition effect of different concentrations of TSP in sodium chloride (NaCl) solution on the corrosion behaviour of Mg alloy anodes in magnesium batteries was investigated. The immersion periods were varied to assess the long-term efficacy of TSP as a corrosion inhibitor. Tafel polarisation analysis revealed a shift in corrosion potential towards more noble values with increasing TSP concentration, indicating enhanced corrosion resistance. EIS measurements provided insights into the changes in charge transfer resistance and double-layer capacitance, corroborating the protective effect of TSP against corrosion. Furthermore, CV and LSV analyses elucidated the dynamic corrosion processes and confirmed the efficacy of TSP as a corrosion inhibitor. This study comprehensively investigates the inhibition mechanism of TSP on the corrosion behaviour of Mg alloy anodes in magnesium batteries.

Microstructure of Pure Magnesium and AZ31 Magnesium Alloy Anodes after Discharge/Charge Cycles for Rechargeable Magnesium Batteries

This study investigated the microstructure of pure magnesium (Mg) and AZ31 (Al—3 wt%; Zn—1 wt%) Mg alloy anodes after different discharge/charge cycles in an all phenyl complex (APC) electrolyte for rechargeable Mg batteries. When discharging the as-immersed Mg metal electrodes, the stripping morphologies of pure Mg and AZ31 Mg alloy electrodes are inhomogeneous with numerous discharge holes. In the subsequent charge stage, the plated Mg preferentially deposits along the circumferences of the discharge holes, which could be related to the distribution of Mg and Cl complex ions near the electrode surface after discharge. Later discharge/charge cycles on pure Mg show that both the plated Mg and the pure Mg substrate are stripped during discharge, resulting in an incomplete stripping of the plated Mg and a non-uniform electrode surface morphology after cycles. In contrast, AZ31 Mg alloy shows a higher stripping resistance than pure Mg, so the plated Mg is preferentially stripped during discharge. Near complete stripping of the plated Mg on AZ31 Mg alloy electrode results in a more uniform electrode surface morphology after cycles and a mitigated increase in the difference between the discharge and charge potentials.

Effect of Y content on performance of AZ31 magnesium alloy anode in air battery

Effect of Y content on performance of AZ31 magnesium alloy anode in air battery

Comparison of electrochemical discharge and corrosion performance of ATLa and ATCe magnesium alloy anodes

Comparison of electrochemical discharge and corrosion performance of ATLa and ATCe magnesium alloy anodes

Superhydrophobic Ca/Ce Coating on Anodized Magnesium Alloy by Electrodeposition and Its Corrosion Inhibition

Superhydrophobic Ca/Ce Coating on Anodized Magnesium Alloy by Electrodeposition and Its Corrosion Inhibition

Corrosion Behavior of AZ31B Magnesium Alloy Anode by Sulfate-Reducing Prokaryotes in the Tidal Flat Mud with Different Water Contents

At present, there are few studies on microbial corrosion of magnesium anode materials that provide protection for oil pipelines in tidal flat environment. In view of an abnormal failure of magnesium anodes in oil pipelines in a tidal flat mud environment, the influence of the change in water content in the beach mud on the corrosion of AZ31B magnesium anode by sulfate-reducing prokaryote (SRP) was investigated by electrochemical methods, weight loss and surface analysis techniques. SRP can grow well in a tidal flat mud environment and cause microbial corrosion of magnesium alloy. The results show that with the increase in water content, the number of SRP cells in the mud increased, that the corrosivity of tidal flat muds was enhanced and that the corrosion rate of AZ31B magnesium anode was accelerated: compared with the corrosion rate of 0.554 mm/y in 40% water content, the corrosion rate of magnesium alloy samples in 60% water content is as high as 1.38 mm/y.

Protein conformation and electric attraction adsorption mechanisms on anodized magnesium alloy by molecular dynamics simulations

Protein adsorption preferentially occurs and significantly affects the physicochemical reactions once the biodegradable magnesium alloys as bone replacements have been implanted. To date, interactions mechanisms between Mg implants and proteins remain unclear at a molecular level. Thereby, a combination of molecular dynamic (MD) simulations and experimental exploration is used to investigate the adsorption behavior and conformational change of bovine serum albumin (BSA), a representative protein of blood plasma, upon the surface of micro-arc oxidation (MAO) coated Mg alloy AZ31. The influences of absorbed proteins on the cytocompatibility of MAO coating are evaluated by virtue of cytotoxicity assay. Results indicate that the negatively charged O atoms (BSA) exhibit strong interaction with Mg 2+ ions of Mg(OH) 2 , revealing that BSA molecules are ionically adsorbed on the AZ31 surface. Interestingly, MD simulation reveals that MAO coating demonstrates superior ability to capture BSA molecules during the process of adsorption owing to strong electric attraction between the negatively charged O atoms in BSA molecules with Mg atoms of MgO in MAO coating. Moreover, the α -helix part of absorbed BSA molecules on AZ31 substrate and MAO coating markedly decreases with an increase in β -sheet, β -turn and unordered contents, which is attributed to the reduction in the number of hydrogen bonds in BSA molecules. Furthermore, the adsorbed BSA molecules improve the cytocompatibility of MAO coating since the positively charged -NH 3 + group and β -sheet content of absorbed BSA molecules mediate the cell adhesion by interacting with the negatively charged cell membrane.

In vitro characterization of anodized magnesium alloy as a potential biodegradable material for biomedical applications

Pure metals and their alloys are used to partially or completely restore bone fractures. Biodegradable metals emerged as promising candidates for fracture fixation devices since they are able to self-degrade in the body environment. The main challenge of the devices is to reach an adequate degradation rate relative to the bone healing and also to present safe degradation by-products. Magnesium alloys are very much studied because of their promising properties, but the main limitation for their application in biomedical devices is the hydrogen evolution that results from their corrosion in aqueous media. This work assesses the effects of low potential anodizing process of AZ91 alloys in basic media on surface topography, electrochemical response, hydrogen evolution and cell attachment compared with the non-treated alloys. A comparative approach to determine the electrochemical parameters for assessing the degradation rate is also discussed. Results show that the electrochemical treatment of anodizing at low voltage in 5 mol/L KOH solution generates magnesium oxide/hydroxide on the surface which could act as a barrier to prevent fast degradation, and consequently to reduce hydrogen release. In turn, this treatment improved the adhesion of bovine embryonic fibroblasts (BEFs) and MCT3T3 pre-osteoblastic cells to the surface, showing that it could be a good candidate to be used in temporary implants.

Application of Pulsed Potential Waveform in Electrochemical Phosphate Recovery As Struvite from Wastewater

Phosphate production is apprehended to peak as early as 2030, and post-peak, phosphate production, and thus food supply, will be limited by dwindling resources, strained economics, and reduced rock quality, with remaining resources expected to last 50-300 years. The limited supply of phosphate demands P conservation by changing the food production system, from fertilization to wastewater treatment. Stuvite (MgNH4PO4.6H2O) has been recognized as a high-value, slow-release, effective fertilizer that can be obtained from both solid (e.g., food, animal, and human waste) and liquid wastes (e.g., wastewater from industrial, municipal, and agricultural operations). The goal of our research is to recover struvite from wastewater using an alkaline electrochemical reactor with a magnesium alloy anode and a cathode constructed of standard catalysts for reducing water to hydrogen gas and hydroxide. Over time with successive reactor batches, the magnesium electrode used to generate magnesium cations in solution and precipitate struvite becomes severely fouled, which in turn increases energy demand and decrease struvite fertilizer recovery. A dynamic, pulsed voltage waveform, as opposed to a constant voltage, causes a stress-strain-like effect at the magnesium electrode surface, thereby preventing or reducing the amount of struvite precipitate that would attach to the electrode. In an aqueous solution of ammonium dihydrogen phosphate (NH4H2PO4, 10 mM) at neutral pH, a significant 50% increase in magnesium release is observed compared to constant voltage applications, resulting in a 30% increase in phosphate recovery. Studies of the recovered precipitate using X-ray diffraction and scanning electron microscopy (SEM) indicate the presence of struvite.

Effect of Solution-treated on Electrochemical Properties of AZ91 Magnesium Alloy Anode

The effect of solution-treated on the self-corrosion performance and discharge performance of AZ91 magnesium alloy as anode material was analyzed by microscopic characterization, immersion tests, electrochemical measurements, and discharge performance tests. The study shows that the β-phase in the AZ91 magnesium alloy gradually dissolved in the matrix with the increase of the solution temperature, and the electrochemical activity of the magnesium alloy anode was significantly improved. Through the comparison of three different solution-treated processes, it is found that the AZ91 magnesium alloy has the most vigorous activity and better discharge performance after solution-treated of 415°C+12 h. In addition, the proportion and distribution of β-phase AZ91 magnesium alloy have a direct impact on its discharge performance as an anode material.

Application of magnesium alloy sacrificial anode for restraining chloride ingress into mortar

This study aims to restrain the chloride ingress into mortar by magnesium alloy sacrificial anode system. Cube reinforced mortar specimens with embedded magnesium alloy anode meshes were prepared. The output electrochemical parameters of magnesium alloy mesh, the chloride profiles and corrosion electrochemical performance of steel in mortars immersed in chloride-contaminated solutions were detected. Besides, the visual inspection of steel surface after immersion was performed. The results indicate that the magnesium alloy mesh can restrain effectively chloride ingress into mortar. With increasing water-cement ratio and chloride content, the galvanic potential and current density between the steel and magnesium alloy mesh increase. The chloride diffusion coefficient of mortar decreases after the application of magnesium alloy sacrificial anode and the decreased magnitude rises with increasing water-cement ratio, chloride concentration and decreasing steel cover thickness. The mitigation of steel corrosion and morphology of the steel surface after immersion further demonstrate the good effect of magnesium alloy sacrificial anode on reducing chloride ingress into mortar.

Achieving high-energy-density magnesium/sulfur battery via a passivation-free Mg-Li alloy anode

Magnesium/sulfur batteries have emerged as one of the considerable choices for next-generation batteries. However, its low voltage platform caused by the passivation of magnesium anode limits its actual energy density. Herein, a magnesium-lithium alloy is screened out as a passivation-free anode, which hinders the passivation reaction on the anode through the substitution reaction between lithium in the alloy and the magnesium ions in the electrolyte. The alloy anode exhibits an improved interfacial reaction kinetics, and the impedance is reduced by 5 orders of magnitude compared to that of magnesium anode. With passivation-free Mg-Li alloy anode, the magnesium/sulfur battery achieves an enhanced discharge voltage platform of 1.5 V and an energy density of 1829 Wh kg−1. This study provides a novel design of passivation-free magnesium alloy anode for high-energy-density magnesium/sulfur batteries.

Effects of Inorganic Metabolites of Sulphate-Reducing Bacteria on the Corrosion of AZ31B and AZ63B Magnesium Alloy in 3.5 wt.% NaCl Solution.

This study seeks prevent and alleviate the failure of magnesium alloy anodes in pipelines, which we suspect is a problem related to SRB. The electrochemical corrosion behaviour of two kinds of magnesium alloys, AZ31B and AZ63B, in 3.5 wt.% NaCl solution with sulphide or phosphide—the two main inorganic metabolites of sulphate-reducing bacteria—were studied by electrochemical tests combined with other characterisation methods such as scanning electron microscopy and X-ray diffraction. The results show that the corrosion film formed by inorganic metabolites of SRB’s initial stage of corrosion (1–3 d) can lead to the corrosion of magnesium alloys. However, the loose and porous corrosion product film cannot protect the substrate effectively. The inorganic metabolites in the solution can accelerate the corrosion of the surface of magnesium alloy after the corrosion products have fallen off. This study provides a theoretical basis for alleviating the premature failure of magnesium alloy anodes and for corrosion protection in the future.

Improving the Corrosion Resistance of Magnesium Alloy AZ31 by a Duplex Anodized and Sol-Gel Coating

Abstract Magnesium and its alloys have found application in several areas viz., aerospace, electronics industry, and automobile, owing to their specific strength-to-weight ratio, thermal conductivity, electromagnetic shielding, etc. However, poor corrosion resistance limits their applicability for widespread use. Anodization and micro arc oxidation (MAO) are commonly used to enhance the corrosion protection of magnesium alloys. The anodized or MAO layers are porous, and hence, organic sealants are conventionally used for sealing the pores. There are not many reports on the use of organic-inorganic hybrid coatings as sealants on anodized layers of magnesium alloys. In this study, the hybrid sol-gel silica-based coatings were investigated as sealants on anodized magnesium alloy AZ31 substrates. A thick (∼20 µm) and porous oxide layer was deposited by anodization using sodium silicate as electrolyte. Ambient curable hybrid silica coatings with and without corrosion inhibitors like cerium oxide and 8-hydroxyquinoline were deposited by dip coating method. The anodized layer and the duplex coating were analyzed using X-ray diffraction and field emission scanning electron microscopy with energy-dispersive X-ray analysis (EDAX) attachment. Electrochemical impedance spectroscopy and potentiodynamic polarization studies were used to assess the corrosion protection performance of these coatings in 0.61M NaCl solution. The porous anodized magnesium oxide layer improved the binding strength of the adjacent sol-gel layer; the sol-gel layer physically sealed the porous anodized coating and offered higher corrosion protection. The duplex coating prevented the diffusion of aggressive ions onto the magnesium alloy AZ31 and enhanced the corrosion resistance significantly.

Effect of Multi-Pass Rolling on the Performance of AZ31 Magnesium Alloy Anode in Mg-Air Battery

In this work, the influence of rolling passes on microstructure, corrosion behavior, electrochemical performance, and battery performance of AZ31 magnesium alloy was studied. The experimental results show that the grain size decreases first and then increases with rolling passes. Among them, the grain size of three passes rolled sample is the smallest, while the grain size of the four passes rolled sample is obviously refined and evenly distributed, accompanied by a small number of twins. Therefore, it exhibits more muscular discharge activity. In addition, the corrosion products of the four passes rolled samples are distributed loosely and evenly on the surface during immersion, which is easy to fall off, thus reducing the polarization. The surface of the discharged four passes rolled sample is flat, indicating that the dissolution is uniform, conducive to promoting the self-peeling of discharge products. The results show that the samples with four passes of rolling have high electrochemical activity and anode efficiency. The average cell voltage and anodic efficiency of the four passes rolled anode for Mg-air battery within 5 h at 10 mA cm-2 were 1.065 V and 56.4%, respectively. Therefore, the electrochemical performance of the four passes rolled sample is the best, and the process is more suitable for preparing magnesium alloy anode plate.

Effect of Y Content on Performance of Az31 Magnesium Alloy Anode in Air Battery

Effect of Y Content on Performance of Az31 Magnesium Alloy Anode in Air Battery

Effect of Solution-Treated on Electrochemical Properties of Az91 Magnesium Alloy Anode

Effect of Solution-Treated on Electrochemical Properties of Az91 Magnesium Alloy Anode

Effect of Ce content on performance of AZ31 magnesium alloy anode in air battery

In this work, five AZ31-xCe magnesium alloy anode materials were prepared, and their microstructure, electrochemical properties and discharge properties were studied to reveal the effect of Ce content on the casting anode of magnesium air battery. The introduction of the Ce element can refine the grain and purify the α-Mg matrix. AZ31–1Ce magnesium alloy has the best corrosion resistance, and the activity of magnesium alloy enhances with the increase of Ce content. Compared with AZ31 magnesium alloy, AZ31-xCe magnesium alloy has higher discharge activity, which is due to the introduction of Ce element to purify the magnesium alloy, and the Al4Ce phase can promote the uniform dissolution of Mg matrix. When the discharge current density is 10 mA cm−2 the AZ31–4Ce anode shows the highest energy density of 1552.370 mWh g−1 and the best specific capacity of 1282.051 mAh g−1 which are 46.05% and 29.901% higher than the AZ31 anode. Compared with AZ31 magnesium alloy, the anode of AZ31–4Ce magnesium alloy has a smoother discharge surface morphology, which is beneficial to the desquamation of the discharge products.