Magnesium alloy anode material with gradient structure and preparation method thereof

Abstract

The invention discloses a magnesium alloy anode material with a gradient structure and a preparation method of the magnesium alloy anode material. The preparation method comprises the following steps: (1) selecting a magnesium alloy welding wire and a magnesium substrate, and polishing, deoiling, cleaning and drying the magnesium alloy welding wire and the magnesium substrate; (2) a magnesium substrate is preheated, and magnesium alloy wires are sequentially deposited on the surface of the magnesium substrate through an electric arc deposition additive method, so that deposition layers with different alloy components are formed; and (3) cutting the deposition layer to obtain the magnesium alloy anode material with the component gradient structure. The magnesium alloy anode material is of a gradient structure formed by sequentially depositing an Mg-Ca layer, an Mg-xCa-yIn layer and an Mg-In layer. The preparation method disclosed by the invention is simple in process and high in safety, gradient structure design and preparation of different components and thicknesses of the magnesium alloy anode material can be realized, and the obtained magnesium alloy anode material with the gradient structure has excellent discharge stability.

Description

Technical Field

[0001] This invention pertains to alloy materials and their preparation methods, specifically a gradient structure magnesium alloy anode material and its preparation method. Background Technology

[0002] Magnesium alloys, as anode materials for air batteries, have a series of significant advantages, including high energy density, negative electrode potential, low density, abundant resources, environmental friendliness, high safety, and good biocompatibility. They are one of the key materials for next-generation high-energy-density energy storage systems.

[0003] Despite this, the widespread application of magnesium alloy anodes is still constrained by several challenges: severe anodic polarization during discharge hinders sustained active discharge; and significant discharge efficiency loss is caused by hydrogen evolution corrosion exacerbated by the negative difference effect and the shedding of metal particles from the matrix ("bulk effect"). Alloying, heat treatment, and plastic deformation are currently the main methods for improving the performance of magnesium alloy anodes, all playing important roles in the activity or high-efficiency discharge of magnesium alloy anodes. However, none of these methods fundamentally solve the core problem of the gradual attenuation of discharge activity from the surface to the interior due to the continuous thickening and difficulty in peeling off the discharge product film during discharge. Based on current research, single-component magnesium alloy anodes cannot truly eliminate the obstacle of anodic polarization to active discharge. Therefore, we designed a composition-gradient magnesium alloy anode with intrinsically enhanced discharge activity from the outside to the inside, in order to achieve sustained and stable activity and high-efficiency discharge of magnesium alloy anodes.

[0004] Currently, surface treatment techniques are commonly used to prepare gradient structures. While these methods can improve mechanical properties, they often introduce high-density crystal defects and large surface roughness, which can actually reduce corrosion resistance. Additive manufacturing is an effective method for producing functional materials with gradient composition. CN201911181757.4 discloses a method for preparing biodegradable magnesium alloy materials, which involves stacking powders of different compositions layer by layer and using laser melting printing to prepare multi-component magnesium alloy materials. However, this method is difficult to use to prepare compositionally gradient magnesium alloys, and the use of magnesium powder as a raw material poses significant safety risks.

[0005] In summary, for magnesium alloy anodes with a single composition, existing technologies cannot truly eliminate the obstruction of anodic polarization to active discharge. Therefore, there is an urgent need for an effective, economical, safe, stable, and composition-gradient magnesium alloy anode preparation technology to regulate the composition gradient of the magnesium alloy anode and achieve a substantial improvement in its discharge performance. Summary of the Invention

[0006] Purpose of the invention: In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a safe and simple method for preparing gradient structure magnesium alloy anode materials. Another purpose of this invention is to provide a gradient structure magnesium alloy anode material with continuous and stable discharge.

[0007] Technical solution: The present invention provides a method for preparing a gradient structure magnesium alloy anode material, comprising the following steps:

[0008] Step 1: Polish, degrease, clean, and dry the substrate, then preheat it;

[0009] Step 2: Under an argon protective atmosphere, Mg-0.05Ca wire is deposited on the surface of the material obtained in Step 1 by a dual-wire arc deposition additive manufacturing method to form a deposition layer 1.

[0010] Step 3: Under an argon protective atmosphere, adjust the feed rates of Mg-0.05Ca wire and Mg-0.1In wire to deposit the two wires together on the surface of deposition layer 1 or a certain deposition layer at different volume ratios. The volume percentage of Mg-0.05Ca wire is 9-91%.

[0011] Step four: Under an argon protective atmosphere, only Mg-0.1In wire is fed in and deposited on the surface of the product obtained in step three;

[0012] Step 5: Remove the substrate from the material obtained in Step 4, grind and polish it, and then perform hot rolling to obtain a gradient structure magnesium alloy anode material.

[0013] Furthermore, step three includes the following steps:

[0014] (1) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca wire and Mg-0.1In wire, and deposit the two wires together on the surface of the first deposition layer at a volume ratio of 4 to 10:1 to form the second deposition layer. Since the volume ratio can be controlled by adjusting the feeding speed, it is convenient to adjust the composition. Generally, the volume ratio is used to limit it.

[0015] (2) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca wire and Mg-0.1In wire, and deposit the two wires together on the surface of the second deposition layer at a volume ratio of 3 to 9:2 to form the third deposition layer;

[0016] (3) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca wire and Mg-0.1In wire, and deposit the two wires together on the surface of the deposition layer three at a volume ratio of 2~8:3 to form the deposition layer four.

[0017] (4) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca wire and Mg-0.1In wire, and deposit the two wires together on the surface of the fourth deposition layer at a volume ratio of 1~7:4 to form the fifth deposition layer.

[0018] Furthermore, step three also includes the following steps:

[0019] (5) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fifth deposition layer at a volume ratio of 2~6:5 to form the sixth deposition layer;

[0020] (6) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the sixth deposition layer at a volume ratio of 1~5:6 to form the seventh deposition layer.

[0021] Furthermore, step three also includes the following steps:

[0022] (7) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer seven in a volume ratio of 4:7 to form the deposition layer eight.

[0023] (8) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer eight at a volume ratio of 3~5:8 to form the deposition layer nine.

[0024] (9) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer nine at a volume ratio of 2~4:9 to form the deposition layer ten.

[0025] (10) Under the protective atmosphere of argon, adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer 10 at a volume ratio of 1~3:10 to form the deposition layer 11.

[0026] Furthermore, the substrate is pure magnesium or magnesium alloy, and the diameters of the Mg-0.05Ca wire and the Mg-0.1In wire are 0.8~1.6mm.

[0027] Furthermore, in step one, the temperature is preheated to 45~55℃.

[0028] Furthermore, in step two, the current of the dual-wire arc deposition additive manufacturing method is 75~130A, the AC frequency is 400~450Hz, and the pulse frequency is 10~15Hz.

[0029] Furthermore, in step three, the thickness of each deposition layer is 2-4 mm.

[0030] Furthermore, in step five, the single reduction in hot rolling is 3-5%, and the thickness after hot rolling is 15-20 mm.

[0031] The gradient structure magnesium alloy anode material obtained by the above preparation method includes, in sequence, a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer, with the Mg-Ca layer being the outer layer, the Mg-Ca-In layer being the middle layer, and the Mg-In layer being the inner layer; the composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, wherein 0 < x < 0.05 and 0 < y < 0.1.

[0032] Preparation principle: By constructing a gradient structure of Mg-Ca and Mg-In, the synergistic effect of Ca and In elements is fully utilized. That is, the outer Mg-Ca activates the anode while maintaining good corrosion resistance and preventing premature self-corrosion; the inner Mg-In enhances discharge activity through the "dissolution-redeposition" mechanism; the composition of the middle layer is continuously transitioned, forming a gradient distribution in which the corrosion potential decreases from the outside to the inside and the discharge activity increases layer by layer. This composition gradient avoids the excessive accumulation of discharge products on the surface, which hinders the activity, and achieves continuous and stable high-activity discharge as a whole.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0034] 1. A dual-wire arc additive manufacturing process is adopted to achieve safe and simple preparation of magnesium alloy composition gradient structures. By controlling the wire feed speed of the two wires, the alloy composition of each deposition layer can be adjusted to achieve continuous and stable discharge of the anode material.

[0035] 2. By constructing a gradient structure of Mg-Ca and Mg-In, the excessive accumulation of discharge products on the surface is avoided, which hinders the activity and achieves continuous and stable high-activity discharge as a whole.

[0036] 3. By hot rolling the gradient magnesium alloy produced by arc additive manufacturing, coarse columnar crystals can be refined, pores can be closed, and the second phase can be broken and dispersed, which can effectively improve the anode density and microstructure uniformity of magnesium alloy, promote the uniform active dissolution of magnesium alloy anode, and thus achieve more continuous and stable discharge.

[0037] 4. The design adopts a low alloy composition, which can reduce the cost of raw materials and at the same time avoid excessive precipitation of second phase due to high alloy elements, which weakens the discharge performance. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a dual-wire electric arc additive manufacturing equipment;

[0039] Figure 2 This is a schematic diagram of the compositional gradient structure of the magnesium alloy anode material in Example 1;

[0040] Figure 3 This is a comparison chart of the discharge performance of Example 1 and Comparative Example 1;

[0041] Figure 4 This is a comparison chart of the discharge performance of Example 2 and Comparative Example 2;

[0042] Figure 5 This is a comparison chart of the discharge performance of Example 3 and Comparative Example 3. Detailed Implementation

[0043] In the following examples, all materials and reagents used, unless otherwise specified, are commercially available. Experimental methods not specifically described in the examples are generally performed under standard conditions or as recommended by the manufacturer. Mg-0.05Ca indicates that the mass of Ca is 0.05% of the mass of Mg, and Mg-0.1In indicates that the mass of In is 0.1% of the mass of Mg. Figure 1 As shown, the dual-wire arc deposition additive manufacturing equipment includes a power supply 1, a worktable 2, a heating blanket 3, a TIG welding torch 4, a wire feeder 5, a shielding gas 6, and an argon gas cylinder 7. A substrate 8 is placed on the heating blanket 3 on the surface of the worktable 2. The wire feeder 5 controls the feed speed of the Mg-0.05Ca and Mg-0.1In wires. The TIG welding torch 4 is used for deposition additive manufacturing. The shielding gas 6 output from the argon gas cylinder 7 is transported to the welding end of the TIG welding torch 4.

[0044] Example 1

[0045] A method for preparing a gradient structure magnesium alloy anode material includes the following steps:

[0046] (1) Select pure magnesium as substrate 8, grind, degrease, wash, dry, and preheat to 50°C.

[0047] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 1.2 mm.

[0048] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the surface of a pure magnesium substrate 8 to form a deposition layer 9.

[0049] (4) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of deposition layer 9 at a volume ratio of 4:1 to form deposition layer 10.

[0050] (5) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the second deposition layer 10 at a volume ratio of 3:2 to form the third deposition layer 11.

[0051] (6) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the third deposition layer 11 at a volume ratio of 2:3 to form the fourth deposition layer 12.

[0052] (7) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fourth deposition layer 12 at a volume ratio of 1:4 to form the fifth deposition layer 13.

[0053] (8) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, so that only Mg-0.1In wires are fed and deposited on the surface of the deposition layer 13 to form Mg-0.1In deposition layer 14.

[0054] (9) All deposited layers are cut from the pure magnesium substrate 8 as a whole, and then ground and polished. They are then hot-rolled until the thickness reaches 15 mm. The single reduction in hot rolling is 5%, resulting in a magnesium alloy anode material with a compositional gradient structure, such as... Figure 2 As shown.

[0055] In the process, steps (3) to (8) of the dual-wire arc deposition additive manufacturing method were all completed under an argon protective atmosphere. The parameters were: current 120A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 4mm, and total thickness 24mm.

[0056] The magnesium alloy anode material with a compositional gradient structure obtained in this embodiment includes a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer. The Mg-Ca layer is the outer layer, the Mg-Ca-In layer is the middle layer, and the Mg-In layer is the inner layer. The composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, where 0 < x < 0.05 and 0 < y < 0.1.

[0057] Example 2

[0058] A method for preparing a gradient structure magnesium alloy anode material includes the following steps:

[0059] (1) Select AZ31 magnesium alloy as substrate 8, grind, degrease, clean, dry, and preheat to 50°C.

[0060] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 0.8 mm.

[0061] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the surface of substrate 8 to form deposition layer 9.

[0062] (4) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of deposition layer 9 at a volume ratio of 6:1 to form deposition layer 10.

[0063] (5) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the second deposition layer 10 at a volume ratio of 5:2 to form the third deposition layer 11.

[0064] (6) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the third deposition layer 11 at a volume ratio of 4:3 to form the fourth deposition layer 12.

[0065] (7) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fourth deposition layer 12 at a volume ratio of 3:4 to form the fifth deposition layer 13.

[0066] (8) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer 513 at a volume ratio of 2:5 to form the deposition layer 6.

[0067] (9) Adjust the feed rate of Mg-0.05Ca and Mg-0.1In wires and deposit the two wires together on the surface of the sixth deposition layer at a volume ratio of 1:6 to form the seventh deposition layer.

[0068] (10) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, so that only Mg-0.1In wires are fed and deposited on the surface of the deposition layer 7 to form Mg-0.1In deposition layer 14.

[0069] (11) All deposited layers are cut off from the substrate 8 as a whole, and then ground and polished. Then hot rolling is carried out until the thickness is 15mm. The single reduction of hot rolling is 5%, and magnesium alloy anode material with composition gradient structure is obtained.

[0070] In the process, steps (3) to (10) of the dual-wire arc deposition additive manufacturing method are all completed under an argon protective atmosphere. The parameters are: current 100A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 3mm, and total thickness 24mm.

[0071] The magnesium alloy anode material with a compositional gradient structure obtained in this embodiment includes a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer. The Mg-Ca layer is the outer layer, the Mg-Ca-In layer is the middle layer, and the Mg-In layer is the inner layer. The composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, where 0 < x < 0.05 and 0 < y < 0.1.

[0072] Example 3

[0073] A method for preparing a gradient structure magnesium alloy anode material includes the following steps:

[0074] (1) Select Mg-Ca alloy as substrate 8, grind, degrease, wash, dry, and preheat to 50℃.

[0075] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 1.6 mm.

[0076] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the surface of substrate 8 to form deposition layer 9.

[0077] (4) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of deposition layer 9 at a volume ratio of 10:1 to form deposition layer 10.

[0078] (5) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the second deposition layer 10 at a volume ratio of 9:2 to form the third deposition layer 11.

[0079] (6) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the third deposition layer 11 at a volume ratio of 8:3 to form the fourth deposition layer 12.

[0080] (7) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fourth deposition layer 12 at a volume ratio of 7:4 to form the fifth deposition layer 13.

[0081] (8) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer 513 at a volume ratio of 6:5 to form the deposition layer 6.

[0082] (9) Adjust the feed rate of Mg-0.05Ca and Mg-0.1In wires and deposit the two wires together on the surface of the sixth deposition layer at a volume ratio of 5:6 to form the seventh deposition layer.

[0083] (10) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer seven in a volume ratio of 4:7 to form the deposition layer eight.

[0084] (11) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer eight at a volume ratio of 3:8 to form the deposition layer nine.

[0085] (12) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer nine at a volume ratio of 2:9 to form the deposition layer ten.

[0086] (13) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the deposition layer 10 at a volume ratio of 1:10 to form the deposition layer 11.

[0087] (14) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, so that only Mg-0.1In wires are fed and deposited on the surface of the deposition layer eleven to form Mg-0.1In deposition layer 14.

[0088] (15) All deposited layers are cut off from the substrate 8 as a whole, and then ground and polished. Then hot rolling is performed until the thickness is 15mm. The single reduction of hot rolling is 5%, and magnesium alloy anode material with composition gradient structure is obtained.

[0089] In the process, steps (3) to (14) of the dual-wire arc deposition additive manufacturing method are all completed under an argon protective atmosphere. The parameters are: current 75A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 2mm, and total thickness 24mm.

[0090] The magnesium alloy anode material with a compositional gradient structure obtained in this embodiment includes a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer. The Mg-Ca layer is the outer layer, the Mg-Ca-In layer is the middle layer, and the Mg-In layer is the inner layer. The composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, where 0 < x < 0.05 and 0 < y < 0.1.

[0091] Example 4

[0092] A method for preparing a gradient structure magnesium alloy anode material includes the following steps:

[0093] (1) Select pure magnesium as substrate 8, grind, degrease, wash, dry, and preheat to 45°C.

[0094] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 0.8 mm.

[0095] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the surface of a pure magnesium substrate 8 to form a deposition layer 9.

[0096] (4) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of deposition layer 9 at a volume ratio of 4:1 to form deposition layer 10.

[0097] (5) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the second deposition layer 10 at a volume ratio of 3:2 to form the third deposition layer 11.

[0098] (6) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the third deposition layer 11 at a volume ratio of 2:3 to form the fourth deposition layer 12.

[0099] (7) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fourth deposition layer 12 at a volume ratio of 1:4 to form the fifth deposition layer 13.

[0100] (8) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, so that only Mg-0.1In wires are fed and deposited on the surface of the deposition layer 13 to form Mg-0.1In deposition layer 14.

[0101] (9) All deposited layers are cut off from the pure magnesium substrate 8 as a whole, and then ground and polished. Then hot rolling is carried out until the thickness is 18mm. The single reduction of hot rolling is 4%, and magnesium alloy anode material with composition gradient structure is obtained.

[0102] In the process, steps (3) to (8) of the dual-wire arc deposition additive manufacturing method were all completed under an argon protective atmosphere. The parameters were: current 75A, AC frequency 450Hz, pulse frequency 15Hz, thickness of each deposition layer 4mm, and total thickness 24mm.

[0103] The magnesium alloy anode material with a compositional gradient structure obtained in this embodiment includes a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer. The Mg-Ca layer is the outer layer, the Mg-Ca-In layer is the middle layer, and the Mg-In layer is the inner layer. The composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, where 0 < x < 0.05 and 0 < y < 0.1.

[0104] Example 5

[0105] A method for preparing a gradient structure magnesium alloy anode material includes the following steps:

[0106] (1) Select pure magnesium as substrate 8, grind, degrease, wash, dry, and preheat to 55°C.

[0107] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 1.6 mm.

[0108] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the surface of a pure magnesium substrate 8 to form a deposition layer 9.

[0109] (4) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of deposition layer 9 at a volume ratio of 4:1 to form deposition layer 10.

[0110] (5) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the second deposition layer 10 at a volume ratio of 3:2 to form the third deposition layer 11.

[0111] (6) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the third deposition layer 11 at a volume ratio of 2:3 to form the fourth deposition layer 12.

[0112] (7) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, and deposit the two wires together on the surface of the fourth deposition layer 12 at a volume ratio of 1:4 to form the fifth deposition layer 13.

[0113] (8) Adjust the feeding speed of Mg-0.05Ca and Mg-0.1In wires, so that only Mg-0.1In wires are fed and deposited on the surface of the deposition layer 13 to form Mg-0.1In deposition layer 14.

[0114] (9) All deposited layers are cut off from the pure magnesium substrate 8 as a whole, and then ground and polished. Then hot rolling is carried out until the thickness is 20mm. The single reduction of hot rolling is 3%, and magnesium alloy anode material with composition gradient structure is obtained.

[0115] In the process, steps (3) to (8) of the dual-wire arc deposition additive manufacturing method were all completed under an argon protective atmosphere. The parameters were: current 130A, AC frequency 430Hz, pulse frequency 13Hz, thickness of each deposition layer 4mm, and total thickness 24mm.

[0116] The magnesium alloy anode material with a compositional gradient structure obtained in this embodiment includes a Mg-Ca layer, a Mg-Ca-In layer, and a Mg-In layer. The Mg-Ca layer is the outer layer, the Mg-Ca-In layer is the middle layer, and the Mg-In layer is the inner layer. The composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, where 0 < x < 0.05 and 0 < y < 0.1.

[0117] Comparative Example 1

[0118] A method for preparing a magnesium alloy anode material includes the following steps:

[0119] (1) Select pure magnesium as the substrate, grind, degrease, wash, dry, and preheat to 50°C.

[0120] (2) Select Mg-0.05Ca alloy wire with a diameter of 1.2 mm.

[0121] (3) Using a dual-wire arc deposition additive manufacturing equipment, Mg-0.05Ca wire is deposited onto the substrate surface to form a deposition layer.

[0122] (4) Repeat the above steps 5 times to form a total of 6 sedimentary layers.

[0123] (5) All deposited layers are cut from the pure magnesium substrate as a whole, and then ground and polished. Then hot rolling is performed until the thickness is 15mm to obtain Mg-0.05Ca alloy anode material.

[0124] The dual-wire arc deposition additive manufacturing method was completed under an argon protective atmosphere, with the following parameters: current 120A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 4mm, and total thickness 24mm.

[0125] The gradient structure magnesium alloy anode material prepared in Example 1 and the Mg-0.05Ca magnesium alloy anode material obtained in Comparative Example 1 were tested at 40 mA cm⁻¹. -2 Discharge performance results at current density are as follows Figure 3 As shown, it can be seen that the Mg-0.05Ca magnesium alloy anode operates at 40 mA cm⁻¹. -2 The discharge curves at the current density were sawtooth-shaped, exhibiting significant fluctuations, and the discharge voltage generally showed a clear decreasing trend. In contrast, the gradient structure magnesium alloy anode prepared in Example 1 showed no significant fluctuations in its discharge curve throughout the entire discharge process, demonstrating good discharge stability and strong discharge activity.

[0126] Comparative Example 2

[0127] A method for preparing an alloy anode material includes the following steps:

[0128] (1) Select AZ31 magnesium alloy as the substrate, grind, degrease, clean, dry, and preheat to 50°C.

[0129] (2) Select Mg-0.1In alloy wire with a diameter of 0.8 mm.

[0130] (3) The Mg-0.1In wire is deposited onto the substrate surface using a dual-wire arc deposition additive manufacturing equipment to form a deposition layer.

[0131] (4) Repeat the above steps 7 times to form a total of 8 sedimentary layers.

[0132] (5) Cut all the deposited layers from the substrate as a whole, grind and polish them, and then hot roll them until the thickness is 15mm to obtain Mg-0.1In alloy anode material.

[0133] The dual-wire arc deposition additive manufacturing method was completed under an argon protective atmosphere, with the following parameters: current 100A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 3mm, and total thickness 24mm.

[0134] The Mg-0.1In alloy anode material prepared in Comparative Example 2 and the gradient structure magnesium alloy anode material prepared in Example 2 were tested at 40 mA cm⁻¹. -2 Discharge performance results at current density are as follows Figure 4 As shown. Figure 4As shown, it can be seen that the Mg-0.1In magnesium alloy anode operates at 40 mA cm⁻¹. -2 The discharge curves at different current densities exhibit significant fluctuations, with the discharge voltage gradually decreasing overall. In contrast, the gradient-structured magnesium alloy anode prepared in Example 2 shows an approximately horizontal straight line discharge curve throughout the entire discharge process, demonstrating good discharge stability.

[0135] Comparative Example 3

[0136] A method for preparing an alloy anode material includes the following steps:

[0137] (1) Select Mg-Ca alloy as substrate, grind, degrease, wash, dry, and preheat to 50℃.

[0138] (2) Select magnesium alloy wires with two compositions, Mg-0.05Ca and Mg-0.1In, with a diameter of 1.6 mm.

[0139] (3) Using a dual-wire arc deposition additive manufacturing equipment, the Mg-0.05Ca and Mg-0.1In wires are deposited on the substrate surface in a 1:1 volume ratio to form a deposition layer.

[0140] (4) Repeat the above steps 11 times to form a total of 12 sedimentary layers.

[0141] All deposited layers are cut from the substrate as a whole, and then ground and polished. They are then hot rolled until the thickness is 15mm to obtain Mg-Ca-In alloy anode material.

[0142] The dual-wire arc deposition additive manufacturing method was completed under an argon protective atmosphere, with the following parameters: current 75A, AC frequency 400Hz, pulse frequency 10Hz, thickness of each deposition layer 2mm, and total thickness 24mm.

[0143] The gradient structure magnesium alloy anode material prepared in Example 3 and the Mg-Ca-In alloy anode material prepared in Comparative Example 3 were tested at 40 mA cm⁻¹. -2 Discharge performance results at current density are as follows Figure 5 As shown, it can be seen that the Mg-Ca-In magnesium alloy anode operates at 40 mA cm⁻¹. -2 The discharge curves at current density exhibit abrupt voltage changes, showing significant fluctuations, and the discharge voltage generally decreases. In contrast, the gradient-structured magnesium alloy anode prepared in Example 3 shows an approximately horizontal straight line discharge curve throughout the entire discharge process, demonstrating good discharge stability.

[0144] Of the above embodiments, the preferred embodiment is Embodiment 3.

Claims

1. A method for preparing a gradient-structured magnesium alloy anode material, characterized in that, The method comprises the following steps: Step 1, after polishing, degreasing, cleaning and drying the substrate, preheating; Step 2, under the protection of argon atmosphere, Mg-0.05Ca wire is deposited on the surface of the product obtained in step 1 by double-wire arc deposition to form a deposition layer 1; Step 3, under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 1 or a certain deposition layer at different volume ratios, and the volume ratio of Mg-0.05Ca wire is 9-91%; Step 4, under the protection of argon atmosphere, only Mg-0.1In wire is fed to deposit on the surface of the product obtained in step 3; Step 5, the substrate of the product obtained in step 4 is removed, polished and polished, and then hot-rolled to obtain a gradient structure magnesium alloy anode material.

2. The method of claim 1, wherein the method comprises the steps of: The step 3 comprises the following steps: ​ (1) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 1 at a volume ratio of 4-10:1 to form a deposition layer 2; (2) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 2 at a volume ratio of 3-9:2 to form a deposition layer 3; (3) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 3 at a volume ratio of 2-8:3 to form a deposition layer 4; (4) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 4 at a volume ratio of 1-7:4 to form a deposition layer 5.

3. The method of claim 2, wherein the method further comprises: The step 3 further comprises the following steps: ​ (5) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 5 at a volume ratio of 2-6:5 to form a deposition layer 6; (6) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 6 at a volume ratio of 1-5:6 to form a deposition layer 7.

4. The method of claim 3, wherein the method further comprises: The step 3 further comprises the following steps: ​ (7) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 7 at a volume ratio of 4:7 to form a deposition layer 8; (8) under the protection of argon atmosphere, the wire feeding speed of Mg-0.05Ca wire and Mg-0.1In wire is adjusted, and the two kinds of wires are deposited on the surface of the deposition layer 8 at a volume ratio of 3-5:8 to form a deposition layer 9; (9) Under the atmosphere of argon, the wire feed speed of Mg-0.05Ca and Mg-0.1In wires is adjusted, and the two kinds of wires are deposited together on the surface of the deposition layer nine at a volume ratio of 2-4:9 to form a deposition layer ten; (10) Under the atmosphere of argon, the wire feed speed of Mg-0.05Ca and Mg-0.1In wires is adjusted, and the two kinds of wires are deposited together on the surface of the deposition layer ten at a volume ratio of 1-3:10 to form a deposition layer eleven.

5. The method of claim 1, wherein the method further comprises: The substrate is pure magnesium or magnesium alloy, and the diameter of the Mg-0.05Ca wire and the Mg-0.1In wire is 0.8-1.6 mm. ​ 6. The method of claim 1, wherein the method further comprises: In the step one, the preheating temperature is 45-55℃. ​ 7. The method of claim 1, wherein the method further comprises: In the step two, the current of the double-wire arc deposition additive method is 75-130 A, the alternating frequency is 400-450 Hz, and the pulse frequency is 10-15 Hz. ​ 8. The method of claim 1, wherein the method further comprises: In the step three, the thickness of each layer of the deposition layer is 2-4 mm. ​ 9. The method of claim 1, wherein the method comprises: In the step five, the single reduction of the hot rolling is 3-5%, and the thickness after the hot rolling is 15-20 mm. ​ 10. The gradient structure magnesium alloy anode material prepared according to the method of any one of claims 1-9, characterized in that: The Mg-Ca layer, the Mg-Ca-In layer and the Mg-In layer are sequentially arranged, the Mg-Ca layer is an outer layer, the Mg-Ca-In layer is an intermediate layer, and the Mg-In layer is an inner layer; the composition of the Mg-Ca layer is Mg-0.05Ca, the composition of the Mg-In layer is Mg-0.1In, and the composition of the Mg-Ca-In layer is Mg-xCa-yIn, wherein 0

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