Preparation method and application of anode of aluminum-air battery

Abstract

The application relates to a preparation method and application of an aluminum-air battery anode, which comprises the following steps: mixing aluminum alloy metal powder and nano-reinforced phase powder; ball milling the mixed powder; drying the mixed powder; designing a porous structure aluminum-air battery anode; preparing the porous structure aluminum-air battery anode; post-treating the porous structure aluminum-air battery anode; and heat-treating the porous structure aluminum-air battery anode. The mixed powder is prepared by adopting the nano-phase reinforced aluminum alloy metal powder and combining the ball milling process and the drying treatment, so that the self-corrosion rate of the anode is reduced and the corrosion uniformity of the anode is improved; the problem of small contact area between the anode and electrolyte is solved by designing the porous structure aluminum anode, the reaction area of the anode is improved, and the utilization rate of the anode is improved.

Description

Technical Field

[0001] This invention relates to the fields of aluminum-air batteries and 3D printing technology, and particularly to a method for preparing an aluminum-air battery anode and its application. Background Technology

[0002] Aluminum-air batteries, with their significant advantages such as high theoretical specific energy, abundant raw materials, and environmental friendliness, have become an ideal power source for various devices. However, aluminum-air battery anodes prepared using traditional processes generally suffer from problems such as surface passivation and discharge product adhesion, directly leading to decreased anode utilization and lag in discharge voltage, severely hindering their commercialization. Currently, the core pathways to improve the discharge performance of aluminum anodes mainly fall into two categories: optimizing anode materials and improving anode structures. Among these, research on the activation and modification of traditional aluminum anodes largely focuses on adding alloying elements to prepare novel anodes. This method not only suffers from drawbacks such as long preparation time, low efficiency, and immature processes, but also pays insufficient attention to aluminum alloy materials whose production processes are already mature.

[0003] Chinese patent CN 114614168A discloses a method for preparing an aluminum-air battery anode composite slurry and its application, which effectively improves the overall performance of aluminum-air batteries. However, subsequent tests revealed that this method still suffers from problems such as uneven metal powder dispersion and incomplete evaporation of organic solvents, limiting the potential for improving the discharge performance of the aluminum anode. By optimizing the anode material and modifying the anode structure—specifically, preparing a porous aluminum anode—the porosity and specific surface area of ​​the anode can be further increased, thereby increasing the contact area between the anode and the electrolyte and significantly improving discharge performance.

[0004] Currently, porous aluminum anodes are mainly prepared using foaming processes. However, porous aluminum foam prepared by this process suffers from defects such as uneven pore size and uncontrollable structure, which can easily lead to uneven anode corrosion and discharge voltage fluctuations during discharge. Selective laser melting (SLM) technology has the unique advantage of freely forming complex structures and shows great application potential in the field of porous aluminum anode preparation. However, the aluminum anode structures prepared using SLM technology are relatively simple, failing to fully utilize its processing advantages, resulting in limited improvement in anode discharge capacity. Tri-period minimal surface (TPMS) structures and Voronoi structures have the characteristics of smooth surface, high connectivity, compact structure, and controllable porosity, which can effectively make up for the shortcomings of traditional porous anodes and simple SLM-prepared anodes, providing a new approach to the structural design of porous aluminum anodes. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing an aluminum-aluminum battery anode with high discharge voltage and low self-corrosion rate, as well as its application.

[0006] A method for preparing an aluminum-air battery anode includes the following steps: Step (1) Preparation of aluminum alloy metal powder / nano-reinforcing phase powder mixture; Step (2) Ball milling of the mixed powder; Step (3) Drying of the mixed powder; Step (4) Design of the anode for a porous aluminum-air battery; Step (5) Preparation of the porous aluminum-air battery anode; Step (6) Post-processing of the porous aluminum-air battery anode; Step (7) Heat treatment of the porous aluminum-air battery anode.

[0007] Preferably, in step (1) of the present invention, the aluminum alloy metal powder is grade 6061 or 7075, and the particle size distribution is 15~53 μm; the nano-reinforcing phase material is TiB2 or CeO2 powder; the mixed powder, by mass percentage, includes 0.2~1.0 wt.% TiB2 powder, 0.5~1.5 wt.% CeO2 powder, and the balance being 6061 or 7075 aluminum alloy powder.

[0008] Preferably, in step (2) of the present invention, the ball milling process parameters for the mixed powder are: ball milling speed 80~120 rpm, ball milling time 0.5~1.5 h, forward and reverse rotation 10~20 minutes, grinding balls are agate balls with a diameter of 3~7 mm, and ball-to-material ratio 4:1~8:1.

[0009] Preferably, in step (3) of the present invention, the drying parameters of the mixed powder are: drying temperature 80~150 ℃, drying time 1~1.5 h.

[0010] Preferably, in step (4) of the present invention, the designed aluminum-air battery anode structure is a three-period minimal surface (TPMS) structure, a Voronoi polygon structure, or a combination of both; the porous aluminum-air battery anode includes a uniform structure and a gradient structure; the porosity of the porous aluminum-air battery anode is 50%~70%.

[0011] Preferably, in step (5) of the present invention, the preparation process of the porous aluminum-air battery anode is selective laser melting (SLM); the process parameters for preparing the porous aluminum-air battery anode by SLM are: laser power 200~400 W, scanning speed 600~1400 mm / s, scanning spacing 0.08~0.16 mm, and powder thickness 0.025~0.045 mm.

[0012] Preferably, in step (6) of the present invention, the post-treatment method of the porous aluminum-air battery anode is high-pressure air blowing and vibration cleaning for 0.2~1.0 h.

[0013] Preferably, in step (7) of the present invention, the heat treatment method of the porous aluminum-air battery anode is a stress-relief annealing process, in which the anode is heated to 200~400℃, held for 1~2 h and then slowly cooled with the furnace.

[0014] This invention also provides the application of an aluminum-air battery anode in the preparation of air batteries.

[0015] Compared with the prior art, the technical solution of this invention has the following advantages: The preparation processes for 1.6061 and 7075 aluminum alloys are relatively mature, avoiding problems such as large tooling investment, high manufacturing costs, low production efficiency, and long development cycles caused by optimizing anode materials.

[0016] 2. By adding nano-reinforcing phases with different compositions, the self-corrosion rate of the anode can be reduced and the corrosion uniformity of the anode can be improved.

[0017] 3. By preparing porous aluminum anodes, the contact area between the anode and the electrolyte can be increased, thereby increasing the reaction area of ​​the anode and thus improving the anode utilization rate.

[0018] 4. By preparing porous composite aluminum anodes, the adhesion of corrosion products on the anode surface can be reduced, the passivation of the anode can be slowed down, and the discharge voltage of the anode can be increased. Attached Figure Description

[0019] Figure 1 This is a comparison chart of the anode utilization rates of Examples 1-6 and Comparative Examples 1-2; Figure 2 This is a comparison chart of the average discharge voltage of Examples 1-6 and Comparative Examples 1-2; Figure 3 Comparison graphs of real-time discharge curves for Examples 1-6 and Comparative Examples 1-2; Figure 4 This is a schematic diagram of the surface morphology after discharge in Example 1; Figure 5 This is a schematic diagram of the surface morphology after discharge in Example 2; Figure 6 This is a schematic diagram of the surface morphology after discharge in Example 3; Figure 7 This is a schematic diagram of the surface morphology after discharge in Example 4; Figure 8 This is a schematic diagram of the surface morphology after discharge in Example 5; Figure 9 This is a schematic diagram of the surface morphology after discharge in Example 6; Figure 10 This is a schematic diagram of the surface morphology after discharge in Comparative Example 1. Figure 11 This is a schematic diagram of the surface morphology after discharge in Comparative Example 2. Detailed Implementation

[0020] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments: A method for preparing an aluminum-air battery anode includes the following steps: Step (1) Preparation of aluminum alloy metal powder / nano-reinforcing phase powder mixture. The aluminum alloy metal powder is grade 6061 or 7075 with a particle size distribution of 15~53 μm; the nano-reinforcing phase material is TiB2 or CeO2 powder; the mixed powder, by mass percentage, includes 0.2~1.0 wt.% TiB2 powder, 0.5~1.5 wt.% CeO2 powder, and the balance being 6061 or 7075 aluminum alloy powder.

[0021] Step (2) Ball milling of the mixed powder. The ball milling process parameters for the mixed powder are: ball milling speed 80~120rpm, ball milling time 0.5~1.5h, forward and reverse rotation 10~20 minutes each, grinding balls are agate balls with a diameter of 3~7 mm, and ball-to-powder ratio 4:1~8:1.

[0022] Step (3) Drying of the mixed powder. The drying parameters for the mixed powder are: drying temperature 80~150 ℃, drying time 1~1.5 h.

[0023] Step (4) Design of the porous aluminum-air battery anode. The designed aluminum-air battery anode structure is a three-period minimal surface (TPMS) structure, a Voronoi polygon structure, or a combination of both; the porous aluminum-air battery anode includes uniform structures and gradient structures; the porosity of the porous aluminum-air battery anode is 50%~70%.

[0024] Step (5) Preparation of porous aluminum-air battery anode. The preparation process of porous aluminum-air battery anode is selective laser melting (SLM); the process parameters for preparing porous aluminum-air battery anode by SLM are: laser power 200~400W, scanning speed 600~1400 mm / s, scanning spacing 0.08~0.16 mm, and powder thickness 0.025~0.045 mm.

[0025] Step (6) Post-treatment of porous aluminum-air battery anode. The post-treatment method for porous aluminum-air battery anode is high-pressure air blowing and vibration cleaning for 0.2~1.0 h.

[0026] Step (7) Heat treatment of porous aluminum-air battery anode. The heat treatment method for porous aluminum-air battery anode is stress-relief annealing process, in which the anode is heated to 200~400℃, held for 1~2 h and then slowly cooled in the furnace.

[0027] As a preferred embodiment of the present invention, a method for preparing an aluminum-air battery anode includes the following steps: Step (1) Preparation of aluminum alloy metal powder / nano-reinforcing phase powder: the aluminum alloy metal powder is 6061, the particle size distribution is 15-53 μm, and the average particle size is 35 μm; the mass fractions of TiB2 and CeO2 powder are 0.6 wt.% and 1.0 wt.%, respectively.

[0028] Step (2) Ball milling of mixed powder: the ball milling speed is 100 rpm, the ball milling time is 1 h, the forward and reverse rotation is 15 min, the grinding ball is an agate ball with a diameter of 3 mm, and the ball-to-powder ratio is 6:1.

[0029] Step (3) Drying treatment of mixed powder: The drying temperature of aluminum alloy metal mixed powder is 150 ℃ and the drying time is 1 h.

[0030] Step (4) Design of porous aluminum-air battery anode: The designed aluminum-air battery anode structure is a three-period minimal surface (TPMS) structure and a Voronoi composite structure; the porosity of the composite structure is 60%.

[0031] Step (5) Preparation of porous aluminum-air battery anode: aluminum alloy metal powder is placed in SLM equipment for printing by powder spreading. The SLM process parameters are: laser power 300 W, scanning speed 1000 mm / s, scanning spacing 0.12 mm, and powder spreading thickness 0.03 mm.

[0032] Step (6) Post-treatment of porous aluminum-air battery anode: high-pressure air blowing and vibration cleaning for 0.7 h; Step (7) Heat treatment of porous aluminum-air battery anode: stress relief annealing process to heat the anode to 300℃, hold for 1.5 h and then slowly cool with the furnace.

[0033] 1. This invention uses nano-phase reinforced aluminum alloy metal powder and combines ball milling and drying processes to prepare mixed powder, thereby reducing the anodic self-corrosion rate and improving the uniformity of anodic corrosion.

[0034] 2. This invention solves the problem of small contact area between the anode and the electrolyte by designing a porous aluminum anode, thereby increasing the reaction area of ​​the anode and thus improving the anode utilization rate.

[0035] 3. This invention solves the problems of corrosion product adhesion and anode passivation on the anode surface by preparing a porous composite structure aluminum anode, thereby improving the discharge voltage of the anode.

[0036] 4. This invention uses SLM technology to prepare porous aluminum anodes, which can realize the integrated forming of anode materials, structure and process, and solve the problems of large tooling investment, high manufacturing cost, low production efficiency and long development cycle in anode material optimization.

[0037] The instruments used in this invention are as follows: the ball mill used in this invention is manufactured by Nanjing Nanda Instrument Co., Ltd., model QM-3SP2; the drying oven used in this invention is manufactured by Shanghai Precision Instruments Co., Ltd., model DZF-6020; the SLM equipment used in this invention is manufactured by Suzhou Xidimo 3D Printing Technology Co., Ltd., model XDM F60; the constant current discharge testing instrument used in this invention is manufactured by Wuhan Landian Electronics Co., Ltd., model CT3001A; and the 4 mol / L NaOH solution used in this invention is from Sinopharm Chemical Reagent Co., Ltd.

[0038] Example 1: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 99.3g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.2g of TiB2 powder and 0.5g of CeO2 powder and place them in a ball mill.

[0039] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 100 rpm for 1 hour, with 10 minutes of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0040] Step (3) Place the ball-milled mixed powder in a drying oven at 100 ℃ and dry it for 1 h.

[0041] The aluminum-air battery anode structure designed in step (4) is a three-period minimal surface (TPMS) structure with a porosity of 50%.

[0042] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 200 W, scanning speed 600 mm / s, scanning spacing 0.08 mm, and powder thickness 0.03 mm.

[0043] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0044] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 250 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0045] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 4 A schematic diagram of the surface morphology after discharge in Example 1 is shown.

[0046] Example 2: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 99.1g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.4g of TiB2 powder and 0.5g of CeO2 powder and place them in a ball mill.

[0047] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 100 rpm for 1 hour, with 15 minutes of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0048] Step (3) Place the ball-milled mixed powder in a drying oven at 100 ℃ and dry it for 1.5 h.

[0049] The aluminum-air battery anode structure designed in step (4) is a Voronoi polygonal structure with a porosity of 50%.

[0050] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 250 W, scanning speed 800 mm / s, scanning spacing 0.08 mm, and powder thickness 0.03 mm.

[0051] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0052] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 250 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0053] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 5 A schematic diagram of the surface morphology after discharge in Example 2 is shown.

[0054] Example 3: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 98.6g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.4g of TiB2 powder and 1.0g of CeO2 powder and place them in a ball mill.

[0055] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 150 rpm for 1 hour, with 15 minutes of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0056] Step (3) Place the ball-milled mixed powder in a drying oven at 100 ℃ and dry it for 1.5 h.

[0057] The aluminum-air battery anode structure designed in step (4) is a composite structure of three-period minimal surface (TPMS) and Voronoi polygon with a porosity of 50%.

[0058] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 300 W, scanning speed 800 mm / s, scanning spacing 0.10 mm, and powder thickness 0.03 mm.

[0059] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0060] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 300 ℃, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0061] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 6 A schematic diagram of the surface morphology after discharge in Example 3 is shown.

[0062] Example 4: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 98.1g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.4g of TiB2 powder and 1.5g of CeO2 powder and place them in a ball mill.

[0063] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 200 rpm for 1.5 h, with 20 min of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0064] Step (3) Place the ball-milled mixed powder in a drying oven at 150 ℃ and dry it for 1.5 h.

[0065] The aluminum-air battery anode structure designed in step (4) is a composite structure of three-period minimal surface (TPMS) and Voronoi polygon with a porosity of 60%.

[0066] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 300 W, scanning speed 900 mm / s, scanning spacing 0.10 mm, and powder thickness 0.03 mm.

[0067] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0068] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 350 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0069] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 7 A schematic diagram of the surface morphology after discharge in Example 4 is shown.

[0070] Example 5: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 99.1g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.6g of TiB2 powder and 0.5g of CeO2 powder and place them in a ball mill.

[0071] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 150 rpm for 1.5 h, with 15 min of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0072] Step (3) Place the ball-milled mixed powder in a drying oven at 150 ℃ and dry it for 1.5 h.

[0073] The aluminum-air battery anode structure designed in step (4) is a composite structure of three-period minimal surface (TPMS) and Voronoi polygon with a porosity of 70%.

[0074] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 350 W, scanning speed 1000 mm / s, scanning spacing 0.12 mm, and powder thickness 0.04 mm.

[0075] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.5 h.

[0076] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 350 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0077] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 8 A schematic diagram of the surface morphology after discharge in Example 5 is shown.

[0078] Example 6: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 98.4g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm, 0.6g of TiB2 powder and 1.0g of CeO2 powder and place them in a ball mill.

[0079] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 100 rpm for 1.5 h, with 15 min of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0080] Step (3) Place the ball-milled mixed powder in a drying oven at 150 ℃ and dry it for 1.0 h.

[0081] The aluminum-air battery anode structure designed in step (4) is a composite structure of three-period minimal surface (TPMS) and Voronoi polygon with a porosity of 60%.

[0082] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 300 W, scanning speed 1000 mm / s, scanning spacing 0.12 mm, and powder thickness 0.03 mm.

[0083] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.7 h.

[0084] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 300 ℃, held for 1.5 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0085] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 9 A schematic diagram of the surface morphology after discharge in Example 6 is shown.

[0086] Comparative Example 1: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 99.0g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm and 1.0g of TiB2 powder and place them in a ball mill.

[0087] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 100 rpm for 1 hour, with 10 minutes of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0088] Step (3) Place the ball-milled mixed powder in a drying oven at 100 ℃ and dry it for 1 h.

[0089] The aluminum-air battery anode structure designed in step (4) is a three-period minimal surface (TPMS) structure with a porosity of 50%.

[0090] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 200 W, scanning speed 600 mm / s, scanning spacing 0.08 mm, and powder thickness 0.03 mm.

[0091] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0092] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 250 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0093] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 10 A schematic diagram of the surface morphology after discharge is shown for Comparative Example 1.

[0094] Comparative Example 2: A method for preparing an anode for an aluminum-air battery, comprising the following steps: Step (1) Take 99.5g of 6061 aluminum alloy powder with a particle size distribution of 15-53 μm and 0.5g of CeO2 powder and place them in a ball mill.

[0095] Step (2) The mixed powder is ball-milled in a ball mill at a speed of 100 rpm for 1 hour, with 10 minutes of forward and reverse rotation. The grinding balls are agate balls with a diameter of 6 mm and a ball-to-material ratio of 6:1.

[0096] Step (3) Place the ball-milled mixed powder in a drying oven at 100 ℃ and dry it for 1 h.

[0097] The aluminum-air battery anode structure designed in step (4) is a Voronoi polygonal structure with a porosity of 50%.

[0098] Step (5) Place the dried mixed metal powder into an SLM device for printing. The process parameters are: laser power 200 W, scanning speed 600 mm / s, scanning spacing 0.08 mm, and powder thickness 0.03 mm.

[0099] Step (6) Post-process the printed sample by high-pressure air blowing and vibration cleaning for 0.2 h.

[0100] Step (7) The post-processed sample is subjected to stress-relief annealing, the anode is heated to 250 °C, held for 1 h and then slowly cooled in the furnace to obtain the aluminum-air battery anode.

[0101] The prepared samples were subjected to constant current discharge testing. The test solution used was 300 ml of 4 mol / L NaOH solution, and the discharge rate during the constant current discharge test was 10 mA / cm². 2 . Figure 11 A schematic diagram of the surface morphology after discharge is shown for Comparative Example 2.

[0102] Figures 1-3 The battery performance differences of 6 sets of examples and 2 sets of comparative examples were compared from three dimensions: anode utilization rate, average discharge voltage, and average discharge voltage. Together, they verified the significant improvement effect of the example scheme on battery performance. Figure 1 The bar chart of anode utilization rate shows that the utilization rate of the six sets of embodiments shows a step-by-step increasing trend, with 30% in embodiment 1 and nearly 50% in embodiment 6; while the two comparative proportions are only 21% and 27%, which are significantly lower than all embodiments, proving that the embodiment schemes greatly improve the utilization efficiency of anode active materials, and the degree of optimization gradually improves with the iteration of the schemes. Figure 2 The discharge voltage histogram is highly consistent with the utilization trend: the voltage of Example 1 is about 1.48V, Example 6 is increased to about 1.70V, and the comparative examples are only 1.36V and 1.45V. The discharge voltage advantage of the examples is obvious, indicating that the example scheme effectively reduces electrode polarization and improves reaction potential and energy output level. Figure 3 The real-time discharge curves further verified the performance stability: the voltage plateau of all embodiments was significantly higher than that of the comparative examples. The plateau voltage of embodiment 6 was stable above 1.67V with minimal fluctuations throughout the process; while the plateau voltages of comparative examples 1 and 2 were only 1.37V and 1.45V, respectively, and the voltage drop in the early stage was more obvious, reflecting that the battery discharge process under the embodiment scheme was more stable and the polarization was smaller. Figures 4-11The discharge morphology of this embodiment is shown, which further verifies the above results: the discharge morphology of the 6 sets of embodiments gradually improves and the corrosion degree gradually becomes uniform corrosion, while the discharge morphology of the two comparative sets of embodiments shows obvious non-uniform corrosion, and the degree of corrosion non-uniformity is significantly higher than that of all embodiments, proving that the embodiment scheme greatly improves the corrosion uniformity of the anode.

[0103] In summary, the embodiments not only significantly improved anode utilization and discharge voltage, but also optimized the stability of the discharge process. Furthermore, the performance continuously improved with each iteration of the scheme, significantly outperforming the unmodified comparative examples, providing reliable experimental support for improving battery performance. The discharge performance data from Examples 1-6 and Comparative Examples 1 and 2 can be obtained (e.g.) Figure 3 Compared to the comparative example, the aluminum-air battery anode sample prepared in the examples has superior discharge performance. The technical solution of preparing porous aluminum-air battery anodes using SLM technology provided by the present invention has a significant effect on improving discharge performance. The parameters for preparing the aluminum-air battery anode sample in Example 6 are the preferred preparation parameters of the present invention.

[0104] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing an anode for an aluminum-air battery, characterized in that, Includes the following steps: Step (1) Preparation of aluminum alloy metal powder / nano-reinforcing phase powder mixture; Step (2) Ball milling of the mixed powder; Step (3) Drying of the mixed powder; Step (4) Design of the anode for a porous aluminum-air battery; Step (5) Preparation of the porous aluminum-air battery anode; Step (6) Post-processing of the porous aluminum-air battery anode; Step (7) Heat treatment of the porous aluminum-air battery anode.

2. The preparation method according to claim 1, characterized in that, In step (1), the aluminum alloy metal powder is grade 6061 or 7075, with a particle size distribution of 15~53 μm; the nano-reinforcing phase material is TiB2 or CeO2 powder; the mixed powder, by mass percentage, includes 0.2~1.0 wt.% TiB2 powder, 0.5~1.5 wt.% CeO2 powder, and the balance being 6061 or 7075 aluminum alloy powder.

3. The preparation method according to claim 1, characterized in that, In step (2), the ball milling process parameters for the mixed powder are: ball milling speed 80~120 rpm, ball milling time 0.5~1.5 h, forward and reverse rotation 10~20 minutes, grinding balls are agate balls with a diameter of 3~7 mm, and ball-to-material ratio 4:1~8:

1.

4. The preparation method according to claim 1, characterized in that, In step (3), the drying parameters for the mixed powder are: drying temperature 80~150 ℃, drying time 1~1.5 h.

5. The preparation method according to claim 1, characterized in that, In step (4), the designed aluminum-air battery anode structure is a three-period minimal curved surface structure, a Thiessen polygon structure, or a composite structure of the two; the porous aluminum-air battery anode includes a uniform structure and a gradient structure; the porosity of the porous aluminum-air battery anode is 50%~70%.

6. The preparation method according to claim 1, characterized in that, In step (5), the preparation process of the porous aluminum-air battery anode is selective laser melting; the process parameters for preparing the porous aluminum-air battery anode by selective laser melting are: laser power 200~400 W, scanning speed 600~1400 mm / s, scanning spacing 0.08~0.16 mm, and powder thickness 0.025~0.045 mm.

7. The preparation method according to claim 1, characterized in that, In step (6), the post-treatment method for the porous aluminum-air battery anode is high-pressure air blowing and vibration cleaning for 0.2~1.0 h.

8. The preparation method according to claim 1, characterized in that, In step (7), the heat treatment method for the porous aluminum-air battery anode is stress-relief annealing process, in which the anode is heated to 200~400℃, held for 1~2 h, and then slowly cooled with the furnace.

9. The application of an aluminum-air battery anode obtained by the preparation method according to any one of claims 1-8 in the preparation of an air battery.

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