Method for efficiently treating magnesium negative electrode metal surface and application
By immersing the magnesium anode surface in an acidic organic solution to form an organic film, the problems of cumbersome processes and oxidation associated with existing methods are solved, resulting in a simplified process and improved performance.
Patent Information
- Application Number
- CN202511347526.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2026-01-23
AI Technical Summary
Existing methods for treating magnesium anode surfaces are cumbersome, requiring large amounts of water and acid, which leads to oxidation reactions and makes it difficult to effectively remove the stress concentration layer, thus affecting electrochemical performance.
The magnesium matrix is immersed in an acidic organic solution in a vacuum environment, and then washed until neutral to form an organic film. This reduces the use of acid, avoids oxidation, and improves the uniformity of the microstructure.
Simplify the processing technology, reduce acid usage, avoid oxidation, improve the electrochemical performance of magnesium anode batteries, and enhance interfacial compatibility and battery life.
Smart Images
Figure CN121380969A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electrode materials, in particular to a method for efficiently treating the surface of a magnesium negative electrode and application thereof. BACKGROUND
[0002] Magnesium and its alloys face serious plastic deformation and oxidation processes during plastic deformation, forming a stress concentration layer and an oxidation layer on the surface. Existing treatment methods mainly include polishing, acid treatment and preparation of an artificial interface layer. The problems of the above methods are: (1) the process is complicated, a large amount of water, alkali and acid are needed; (2) the whole process will contact water, which will inevitably cause oxidation reaction, thereby affecting the performance of the negative electrode; (3) the stress concentration layer generated during the deformation process cannot be well removed. This time-consuming and laborious treatment process restricts the development of rechargeable magnesium batteries to some extent.
[0003] Therefore, on the basis of ensuring and improving the electrochemical performance of the magnesium negative electrode, it is necessary to study a high-efficiency, simple-to-operate magnesium negative electrode cleaning method to simplify the time-consuming and labor-consuming problem of magnesium negative electrode treatment in the laboratory and industrial production.
[0004] In view of this, the present application is proposed. SUMMARY
[0005] The purpose of the present application is to provide a method for efficiently treating the surface of a magnesium negative electrode and application thereof, to solve the above technical problems.
[0006] The present application is implemented as follows: In a first aspect, the embodiments of the present application provide a method for efficiently treating the surface of a magnesium negative electrode, comprising the following steps: immersing the pretreated magnesium matrix in an acid organic solution, then washing the system to neutral, removing the organic solvent, and preparing a modified magnesium matrix; The pH of the acid organic solution is 0.1-6.
[0007] In a second aspect, the embodiments of the present application provide a magnesium negative electrode material, which is prepared by the method described above.
[0008] In a third aspect, the embodiments of the present application provide the use of the method described above in the preparation of a rechargeable magnesium battery.
[0009] The present application has the following advantages: The method for efficiently treating the surface of a magnesium negative electrode metal provided by the embodiment of the present application can remove the micro stress layer on the surface of the magnesium negative electrode, improve the uniformity of the microstructure, and form an organic film on the surface of the magnesium matrix to slow down the oxidation of the magnesium matrix. The treatment process is simple, and the raw materials are easy to obtain. The modified magnesium matrix can be prepared by only one step of pickling, which greatly reduces the amount of acid used. The whole process is free of water and oxygen, which avoids the oxidation of the magnesium matrix during production / transferring, and provides technical support for improving the high-efficiency and stable electrical performance of the magnesium matrix used in rechargeable magnesium batteries. The method is beneficial to simplify the time- and labor-consuming problems of magnesium negative electrode treatment in the laboratory and industrial production, and is worthy of popularization and application. BRIEF DESCRIPTION OF DRAWINGS
[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. Other related drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0011] Figure 1 SEM images of Example 1, Example 2, Comparative Example 1, and Comparative Example 2; Figure 2 TEM image of Example 1; Figure 3 Crystal orientation distribution map of EBSD of Example 1 and Comparative Example 2: the left side is Comparative Example 2, and the right side is Example 1; Figure 4 Energy spectrum of Example 1 and Comparative Example 2; Figure 5 NRM image of Example 1; Figure 6 EIS image of Example 1 and Comparative Example 2; Figure 7 Nucleation overpotential curve of Example 1 and Comparative Example 2; Figure 8 Cycle test results of symmetric batteries composed of Example 1, Example 2, Comparative Example 1, and Comparative Example 2; Figure 9 Long cycle test results of Example 1 and Comparative Example 2; Figure 10 Morphology of SEI formed by Example 1 and Comparative Example 2 in 0.4M APC electrolyte; Figure 11 Morphology of SEI after cycling of Example 1 and Comparative Example 2 in 0.3M Mg[B(hfip)4]2 / DME electrolyte; Figure 12The composition of the SEI after cycling in 0.4M APC electrolyte for Example 1 and Comparative Example 2; Figure 13 The composition of the SEI after cycling in 0.3M Mg[B(hfip)4]2 / DME electrolyte is shown in Example 1 and Comparative Example 2. Detailed Implementation
[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0013] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0014] In a first aspect, embodiments of the present invention provide a method for efficiently treating the surface of a magnesium anode metal, comprising the following steps: The pretreated magnesium matrix was immersed in an acidic organic solution, and then the system was washed until neutral to remove the organic solvent, thus obtaining the modified magnesium matrix. The pH of the acidic organic solution is 0.1-6.
[0015] It should be noted that this method features a simple processing technique and readily available raw materials. Only one acid washing step is required to obtain the modified magnesium matrix, significantly reducing the amount of acid used. The process ensures a completely anhydrous and oxygen-free environment, preventing oxidation of the magnesium matrix during production / transfer and providing technical support for improving the efficient and stable electrical performance of this magnesium matrix in rechargeable magnesium batteries. It can remove the micro-stress layer on the surface of the magnesium anode, improving the uniformity of the microstructure, while simultaneously forming an organic film on the surface of the magnesium matrix, slowing down its oxidation.
[0016] In an optional implementation, the pH of the acidic organic solution is 0.4-5; if the acidity is too strong (pH<0.4), the excess acid will quickly corrode the magnesium matrix, increasing unnecessary losses; if the acidity is too weak (pH>5), the soaking treatment time will be too long, increasing time costs.
[0017] Furthermore, the pH of the acidic organic solution is 0.5-1, and exemplarily, the pH of the acidic organic solution can be selected from any one of 0.5, 0.6, 0.7, 0.8, 0.9 and 1.
[0018] In an optional embodiment, the acidic organic solution includes an acid solution and an organic solvent, wherein the acid solution is selected from hydrochloric acid, sulfuric acid, nitric acid, and at least one organic acid containing carboxylic acid, sulfonic acid, sulfinic acid, and thiocarboxylic acid.
[0019] It should be noted that the use of the acidic solution is conducive to gently removing the magnesium oxide layer on the surface of the magnesium matrix, so that the inner layer of the metal magnesium is exposed to the acidic organic solution system as much as possible to form an organic film on the surface of the magnesium matrix to slow down the oxidation of the magnesium matrix while improving the uniformity of the microstructure. The soaking treatment is carried out in a vacuum environment, which is water-free and oxygen-free, avoids the oxidation of the magnesium matrix during production / transferring, and provides technical support for improving the high-efficiency and stable electrical performance of the magnesium matrix for rechargeable magnesium batteries.
[0020] In an optional embodiment, the organic solvent is selected from at least one of monohydric alcohol compounds, polyhydric alcohol compounds, acetone, dimethyl sulfoxide or dimethyl formamide.
[0021] In an optional embodiment, the monohydric alcohol compounds are selected from at least one or several of ethanol, difluoroethanol, trifluoroethanol, isopropanol, trifluoropropanol, trifluoroisopropanol, hexafluoroisopropanol, perfluoro-tert-butyl alcohol, 2-trifluoromethyl-2-propanol, 3-perfluorobutylpropanol, 2,2-bis(trifluoromethyl)propanol, tetrahydropyran-4-ol and tetrahydrofurfuryl alcohol. Preferably, the polyhydric alcohol compounds are selected from at least one of ethylene glycol, 2,3-butanediol, 2,3-diphenyl-2,3-butanediol, 2,3-dimethyl-2,3-butanediol, 1,2,4-butanetriol and hexafluoro-2,3-bis(trifluoromethyl)-2,3-butanediol.
[0022] It should be noted that the use of the organic solvent is conducive to weakening the oxidation of the magnesium matrix in a water-oxygen environment; secondly, the organic solvent can react with the metal magnesium to form an organic film, thereby weakening the oxidation process of the metal magnesium.
[0023] In an optional embodiment, the pretreatment includes cutting the magnesium matrix to a desired size, treating the surface thereof, and storing it in the organic solvent for standby.
[0024] It should be noted that the cutting size in the embodiments of the present application is not particularly limited and can be reasonably adjusted according to actual needs. The surface of the magnesium matrix is changed from an “inert / polluted state” to an “active / clean state”, which provides high interfacial compatibility for subsequent processes (such as electroplating, coating, battery cycling), directly determines the adhesion strength, uniformity or functional efficiency of the subsequent layer. The metal magnesium matrix after surface treatment is stored in the solvent to isolate oxygen and water vapor, dissolve the residual contaminants on the surface, keep the surface clean and maintain the surface activity, which is conducive to avoiding the surface of the metal magnesium foil from being oxidized or contaminated again, preventing passivation and inhibiting corrosion reaction. In addition, the soaking treatment system is in a vacuum environment, which ensures a water-free and oxygen-free environment throughout the process.
[0025] Preferably, the magnesium matrix is selected from a metal magnesium foil or a metal magnesium negative electrode.
[0026] Preferably, the surface treatment is selected from any one of mechanical polishing, chemical cleaning and electrochemical activation treatment. The surface treatment is used to remove the oxide film and surface contaminants of the magnesium substrate, and to expose the inner layer of the metal surface. The treatment method can be reasonably adjusted according to actual needs. In the embodiment of the present application, mechanical polishing is used, and 3000# sandpaper is used for polishing.
[0027] In an optional embodiment, the soaking process further includes stirring treatment, and the stirring treatment has a rotation speed of 200 rpm / min-320 rpm / min, which can be reasonably adjusted according to the size of the magnesium substrate to be treated.
[0028] Preferably, the soaking treatment time is 1 min-5 min. It should be noted that the soaking treatment time is reasonably adjusted according to the concentration of the acid in the reagent acid organic solution.
[0029] Preferably, the soaking treatment is completed in a vacuum environment. It should be noted that the present application does not particularly limit the equipment or container for providing a vacuum environment, which can be reasonably adjusted according to actual needs. In the embodiment of the present application, a vacuum reaction kettle is used.
[0030] In an optional embodiment, the neutral cleaning system is the same as the organic solvent used in the soaking treatment, which can quickly remove the acid remaining on the surface of the magnesium substrate and ensure that the generated organic film is stable and single. Preferably, the organic solvent is removed by vacuum distillation and drying treatment.
[0031] The magnesium substrate (especially elemental magnesium or high-activity magnesium alloy) is prone to oxidation, hydrolysis or reaction with other substances at normal pressure and high temperature. Vacuum distillation can realize accurate separation of solvents or low-boiling-point impurities at low temperature (such as 20-80℃), reduce the residual organic solvent, improve the purity of the magnesium substrate, and avoid irreversible damage to the magnesium substrate caused by high temperature.
[0032] In a second aspect, the embodiments of the present application provide a metal magnesium negative electrode material prepared by the method described above.
[0033] In a third aspect, the embodiments of the present application provide a use of the method described above in the preparation of a rechargeable magnesium battery.
[0034] Example 1 The present embodiment provides a method for efficiently treating the surface of a magnesium negative electrode metal, which comprises the following steps: (1) Cut the metal magnesium foil into a circular sheet with a diameter of 14 mm; add 150 mL of anhydrous ethanol into a vacuum reaction kettle, and reserve.
[0035] (2) Put the cut magnesium foil in step (1) and the magnetic sub into the vacuum reaction kettle system of step (1), and stir at a speed of 300 rpm / min.
[0036] (3) Gradually add concentrated hydrochloric acid (9.0 mol / L) to the vacuum reaction kettle system of step (2) to make the pH of the solution reach 0.5, stir for 3 min, stir at a speed of 300 rpm / min, and the reaction temperature is 25℃.
[0037] (4) Add 200 mL of anhydrous ethanol to the vacuum reaction kettle system of step (3) and wash until the solution system is neutral.
[0038] (5) Remove the anhydrous ethanol in the vacuum reaction kettle system of step (4) by vacuum distillation drying to obtain a modified magnesium foil, i.e. magnesium negative electrode.
[0039] Example 2 This example provides a method for efficiently treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that: (1) Add 150 mL of isopropyl alcohol to the vacuum reaction kettle, and reserve.
[0040] (4) Add 200 mL of isopropyl alcohol to the vacuum reaction kettle system of step (3) and wash until the solution system is neutral.
[0041] (5) Remove the isopropyl alcohol in the vacuum reaction kettle system of step (4) by vacuum distillation drying to obtain a modified magnesium foil.
[0042] Example 3 This example provides a method for efficiently treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that: (3) Gradually add concentrated sulfuric acid (6.0 mol / L) to the vacuum reaction kettle system of step (2) to make the pH of the solution reach 1, stir for 3 min, stir at a speed of 300 rpm / min, and the reaction temperature is 25℃.
[0043] Example 4 This example provides a method for efficiently treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that: (3) Add citric acid to the vacuum reaction kettle system of step (2) to make the pH of the solution reach 2.5, stir for 30 min, stir at a speed of 300 rpm / min, and the reaction temperature is 25℃.
[0044] Example 5 This example provides a method for efficiently treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that: Add concentrated nitric acid to the ethanol solution to make the pH of the solution reach 0.7.
[0045] Example 6 This example provides a method for efficiently treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that:
[0046] Comparative Example 1 This comparative example provides a method for treating the surface of a magnesium negative electrode metal, and the steps are the same as in Example 1, except that: (3) Add a hydrochloric acid aqueous solution with a pH of 1 to the vacuum reactor system of step (2) and stir for 2 min.
[0047] Comparative Example 2 This comparative example provides a method for treating the surface of a magnesium negative electrode metal, and the steps are as follows: Polish the magnesium foil with 400#, 1000#, and 3000# sandpaper in sequence until it is shiny.
[0048] Test Example 1 This test example analyzes the surface of the modified magnesium metal foils (i.e., magnesium negative electrodes) prepared in Example 1, Example 4, Comparative Example 1, and Comparative Example 2 as follows: SEM (scanning electron microscope) is used to test the surface morphology of Example 1, Example 4, Comparative Example 1, and Comparative Example 2; TEM (transmission electron microscope) is used to test the high-resolution structure of Example 1; and the SEM test results are shown in Figure 1 ; and the TEM test results are shown in Figure 2 .
[0049] As can be seen from the SEM images of Figure 1 , the magnesium negative electrodes in Example 1 and Example 4 exhibit a relatively flat morphology, with a large number of crystal grains clearly visible; there are a large number of white particles on the surface of the magnesium negative electrode substrate in Comparative Example 1, and there are a large number of scratches on the surface of the magnesium negative electrode obtained by mechanical polishing in Comparative Example 2. As can be seen from the TEM images of Figure 2 , a clear interface layer is formed on the surface of the magnesium negative electrode in Example 1, with a thickness of about 8.5 nm, a smooth surface, and a complete structure.
[0050] Test Example 2 This test example analyzes the crystal structure and orientation distribution of the surface of the modified magnesium metal foils prepared in Example 1 and Comparative Example 2, using EBSD (electron backscatter diffraction) testing, and the test results are shown in Figure 3 .
[0051] In the microstructure characterization, there is a stress concentration layer of about 30 microns in thickness in the comparative example 2, and the microstructure is not uniform; in the example 1, the magnesium negative electrode exhibits a uniform microstructure, and no stress concentration occurs.
[0052] Test Example 3 In this test example, the surface of the modified metal magnesium foil prepared in the example 1 and the comparative example 2 is analyzed for element composition, EDS (energy spectrometer) test is used, and the test results are shown in Figure 4 .
[0053] From the EDS spectrum results of Figure 4 , it can be seen that the content of O element in the example 1 is obviously lower than that in the comparative example 2, indicating that after polishing, the oxide layer on the surface of the magnesium negative electrode substrate cannot be well removed, while the example 1 can effectively remove the surface magnesium oxide and generate a new interface layer.
[0054] Test Example 4 In this test example, the surface of the modified metal magnesium foil prepared in the example 1 is analyzed for molecular structure and kinetic analysis, NRM (nuclear magnetic resonance) test is used, and the test results are shown in Figure 5 .
[0055] From Figure 5 , it can be seen that in 1 H NMR spectrum, the characteristic proton signals corresponding to -CH2 and -CH3 groups are observed. In 13 CNMR spectrum, consistent signals also appear, about 18.38 ppm and 28.34 ppm. The signals of (C2H5O)2Mg in these signals show excellent consistency, indicating that a (C2H5O)2Mg interface layer is generated.
[0056] Test Example 5 In this test example, the surface of the modified metal magnesium foil prepared in the example 1 and the comparative example 2 is analyzed as follows: impedance characteristic analysis of electrochemical system uses EIS (electrochemical impedance spectrum) test; kinetic and thermodynamic performance analysis uses nucleation overpotential test, wherein the EIS test results are shown in Figure 6 , and the nucleation overpotential curve is shown in Figure 7 .
[0057] From the results of EIS of Figure 6 , it can be seen that the interface impedance of the example 1 is obviously lower than that of the comparative example 2, indicating that the interface kinetics is improved. Figure 7 The nucleation overpotential of indicates that the first circle nucleation overpotential of the example 1 is obviously lower than that of the comparative example 2, indicating that the surface of the example 1 has abundant nucleation sites, reducing the desolvation energy barrier of magnesium ions.
[0058] Test Example 6 The surface of the modified magnesium metal foils prepared from Example 1, Example 4, Comparative Example 1 and Comparative Example 2 was subjected to cycle performance analysis, and the electrolyte components were 0.4M APC electrolyte and 0.3M Mg[B(hfip)4]2 / DME electrolyte. The morphology and composition of the SEI (solid electrolyte interface film) formed in the electrolyte were tested and analyzed. The test method was as follows: the magnesium metal anodes obtained from Example 1, Example 4, Comparative Example 1 and Comparative Example 2 were assembled into symmetrical batteries, and constant temperature testing was carried out at 30°C. After a certain period of cycling, the symmetrical batteries were disassembled, and then the morphology of the SEI formed on the magnesium anode was characterized by transmission electron microscopy.
[0059] The cycle test results of the symmetrical batteries are shown in Figure 8 and the long cycle test results are shown in 9; the morphology test of the SEI formed in the 0.4M APC electrolyte is shown in Figure 10 ; and the morphology test of the SEI formed in the 0.3M Mg[B(hfip)4]2 / DME electrolyte is shown in Figure 11 .
[0060] In the cycle test of the symmetrical batteries, both Example 1 and Example 4 exhibited lower cycle overpotential. In the long cycle test, Example 1 exhibited a longer service life compared to Comparative Example 2. In the TEM images, the SEI formed in Example 1 exhibited a thinner and denser morphology, which helped to accelerate the transport of magnesium ions and weaken the interface side reactions.
[0061] Test Example 7 In this test example, the surface of the modified magnesium metal foils prepared from Example 1 and Comparative Example 2 was subjected to interface component analysis, and the electrolyte components were 0.4M APC electrolyte and 0.3M Mg[B(hfip)4]2 / DME electrolyte. The XPS results of the test are shown in Figure 12 and 13 The test method was as follows: the magnesium metal anodes obtained by different treatment methods were assembled into symmetrical batteries, and constant temperature testing was carried out at 30°C. After a certain period of cycling, the symmetrical batteries were disassembled, and then the magnesium anodes were subjected to XPS characterization.
[0062] From the XPS results of Figure 12 and 13 , it can be seen that the Mg-O component in Example 1 was significantly lower than that in Comparative Example 1, indicating that the MgO component on the surface of the SEI generated in Example 1 was lower.
[0063] In summary, the method for efficiently processing the surface of a magnesium negative electrode metal provided by the embodiment of the present application can remove the micro stress layer on the surface of the magnesium negative electrode, improve the uniformity of the microstructure, and form an organic film on the surface of the magnesium matrix to slow down the oxidation of the magnesium matrix. The processing technology is simple, the raw materials are easy to obtain, and the modified magnesium matrix can be prepared only by one step of acid pickling, which greatly reduces the amount of acid used. The process of drying by reduced pressure distillation ensures that there is no water and oxygen throughout the process, avoiding the oxidation of the magnesium matrix during production / transferring, and providing technical support for improving the high-efficiency and stable electrical performance of the magnesium matrix used in rechargeable magnesium batteries. It is conducive to simplifying the time and labor consumption of magnesium negative electrode processing in the laboratory and industrial production, and is worthy of popularization and application.
[0064] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for efficiently treating the surface of a magnesium negative metal electrode characterized by, comprising the steps of: immersing the pretreated magnesium matrix in an acidic organic solution, then washing the system to neutral, removing the organic solvent, and obtaining a modified magnesium matrix; wherein the pH of the acidic organic solution is 0.1-6.
2. The method of claim 1, wherein, The pH of the acidic organic solution is 0.4-5; preferably 0.5-1.
3. The method of claim 1, wherein, The acidic organic solution comprises an acid solution and an organic solvent, and the acid solution is selected from at least one of hydrochloric acid, sulfuric acid, nitric acid, and organic acids containing carboxylic acid, sulfonic acid, sulfinic acid, and thio-carboxylic acid.
4. The method of claim 3, wherein, The organic solvent is selected from at least one of monohydric alcohol compounds, polyhydric alcohol compounds, acetone, dimethyl sulfoxide, or dimethyl formamide.
5. The method of claim 4, wherein, The monohydric alcohol compounds include at least one of ethanol, difluoroethanol, trifluoroethanol, isopropyl alcohol, trifluoropropyl alcohol, trifluoroisopropyl alcohol, hexafluoroisopropyl alcohol, perfluoro-tert-butyl alcohol, 2-trifluoromethyl-2-propanol, 3-perfluorobutylpropanol, 2,2-bis(trifluoromethyl)propanol, tetrahydropyran-4-ol, and tetrahydrofurfuryl alcohol. Preferably, the polyhydric alcohol compounds are selected from at least one of ethylene glycol, 2,3-butanediol, 2,3-diphenyl-2,3-butanediol, 2,3-dimethyl-2,3-butanediol, 1,2,4-butanetriol, and hexafluoro-2,3-bis(trifluoromethyl)-2,3-butanediol.
6. The method of claim 1, wherein, The pretreatment comprises cutting the magnesium matrix to the required size, treating the surface, and storing in an organic solvent for use; Preferably, the magnesium matrix is selected from magnesium metal foil or magnesium metal negative electrode; Preferably, the surface treatment is selected from any one of mechanical polishing, chemical cleaning, and electrochemical activation treatment.
7. The method of claim 1, wherein, The stirring treatment has a rotation speed of 200 rpm / min-320 rpm / min; Preferably, the immersion treatment time is 1 min-5 min; Preferably, the immersion treatment is completed in a vacuum environment.
8. The method of claim 1, wherein, The solution used to wash the system to neutral is the same as the organic solvent used in the immersion treatment; Preferably, the organic solvent is removed by vacuum distillation and drying treatment.
9. A metallic magnesium negative electrode material, characterized by, The method is prepared by any one of claims 1-8.
10. Use of the method of any one of claims 1-8 in the preparation of rechargeable magnesium batteries.