A laser-etched three-dimensional alloy zinc negative electrode material and a preparation method and application thereof

Abstract

The application discloses a kind of three-dimensional alloy zinc negative electrode materials of laser etching and preparation method and application thereof, belong to battery negative technical field.Foam copper is placed below foam nickel and is pressed to obtain precursor, and the plasma effect of laser is used to irradiate precursor, and rich grain boundary foam copper nickel alloy material is obtained;Rich grain boundary foam copper nickel alloy material is immersed in three-electrode system in Zn 2+ Solution, electrochemical deposition is carried out, and rich grain boundary foam copper nickel alloy zinc negative electrode of zinc-loaded is obtained.The negative electrode material is three-dimensional through body alloy framework, and the inside is full of dense grain boundary, promotes Zn 2+ Prior deposition on grain boundary, so as to improve Zn homogeneous phase deposition on alloy matrix.The negative electrode material of the application effectively reduces the growth of zinc dendrite by providing more nucleation sites and improving current distribution;Three-dimensional structure can provide larger specific surface area, which helps uniform zinc ion deposition, thereby reducing the occurrence of side reaction and improving the performance of battery.

Description

Technical Field

[0001] This invention relates to the field of battery anode technology, specifically to a laser-etched three-dimensional alloy zinc anode material, its preparation method, and its application. Background Technology

[0002] With rapid global economic development and continuous population growth, energy demand is soaring, and the energy crisis has become a severe challenge facing the world. Traditional fossil fuel reserves are limited and non-renewable, while large-scale storage and stable supply of renewable energy sources such as wind, solar, and tidal power still face technological bottlenecks. Against this backdrop, lithium-ion batteries (LIBs), as the mainstream electrochemical energy storage system, have dominated the chemical energy storage application market for decades. Although lithium-ion batteries are widely used in daily life, their shortcomings in areas such as safety, lithium resource scarcity, production costs, sustainability, and economics limit their large-scale application in certain sectors.

[0003] To overcome the development bottlenecks of lithium-ion batteries (LIBs), novel battery systems such as sodium-ion batteries (SIBs), potassium-ion batteries (PIBs), sulfur-based batteries, and aqueous zinc-ion batteries (AZIBs) have been extensively researched and developed in recent years. Among these, AZIBs possess significant advantages such as low cost, environmental friendliness, and high safety: zinc metal has stable chemical properties, and the battery system uses a non-flammable aqueous electrolyte, resulting in high intrinsic safety; simultaneously, zinc metal, as a negative electrode material, is abundant, inexpensive, and has a high theoretical capacity (820 mAh g⁻¹). -1 Or volume capacity 5855 mAh cm -3 The zinc metal anode has several advantages, including a relatively low electrochemical potential (0.762 V relative to the standard hydrogen electrode). However, the zinc metal anode faces significant challenges in AZIB applications: it is prone to dendrite growth, hydrogen evolution, corrosion, and byproduct formation during charge and discharge. In particular, the formation of zinc dendrites can penetrate the separator, causing direct contact between the positive and negative electrodes, leading to an internal short circuit and ultimately battery failure, severely hindering the industrialization of AZIBs.

[0004] In contrast, using a highly conductive metallic material as a substrate, such as copper foam, allows the three-dimensional structure to accelerate electron transfer and promote uniform zinc deposition. Studies have shown that using metallic materials with excellent conductivity and low lattice mismatch with Zn, such as copper foam, as a substrate, the three-dimensional structure can accelerate electron transfer and promote uniform zinc deposition. Compared to traditional planar zinc anodes, three-dimensional alloy zinc anodes provide more nucleation sites and optimize current distribution, thus modulating the deposition of zinc. 2+Its adsorption behavior effectively inhibits zinc dendrite growth; its larger specific surface area helps zinc ions to be deposited uniformly, reducing side reactions; at the same time, the three-dimensional structure can alleviate electrode volume changes, further improve battery stability, and accelerate zinc ion migration efficiency. For example, patent application CN112864399A discloses a current collector and its preparation method, a zinc anode and its preparation method and application. In this current collector, which has a copper foam layer, a nickel foam layer, and a nickel oxide layer, zinc metal is deposited as the zinc anode. Zinc preferentially deposits onto the copper foam, followed by the nickel foam, and lastly the nickel oxide, resulting in a gradient-ordered zinc layer on the current collector. Furthermore, patent application CN113972351A discloses a preparation method and application of a zinc alloy anode, and patent application CN114497563A discloses a zinc-ion battery anode material constructed based on a hot-melt method and its preparation and application. Although both are based on alloying strategies, copper-based deposition carriers are ideal zinc anode carriers due to their excellent zinc affinity, conductivity, chemical stability, low zinc lattice mismatch, and tunable microstructure. However, they still face challenges such as insufficient structural anti-expansion properties, poor electrolyte compatibility, and difficulties in low-cost large-scale preparation. Therefore, there is a need to prepare three-dimensional alloy zinc anode materials with better performance. Summary of the Invention

[0005] To address the aforementioned limitations of existing technologies, the present invention aims to provide a laser-etched three-dimensional alloy zinc anode material, its preparation method, and its applications. This invention utilizes laser sputtering plasma to obtain a foamed copper-nickel alloy by controlling the laser sputtering power and sweep rate, followed by electrochemical deposition to obtain a three-dimensional alloy zinc anode. This anode material is characterized by densely packed grain boundaries, promoting Zn deposition. 2+ Preferential deposition at grain boundaries enhances homogeneous Zn deposition on the alloy matrix; this anode material effectively reduces zinc dendrite growth by providing more nucleation sites and improving current distribution; the three-dimensional structure provides a larger specific surface area, which facilitates uniform zinc ion deposition, thereby reducing side reactions and improving battery performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a three-dimensional alloy zinc anode material by laser etching, comprising the following steps:

[0008] (1) Place copper foam under nickel foam and press it to obtain a precursor. The thickness of the copper foam is 1 mm and the thickness of the nickel foam is 0.5 mm. Irradiate the precursor with the plasma effect of laser to obtain a grain boundary-rich copper-nickel foam alloy material.

[0009] (2) Immerse the rich-grain-bound foam copper-nickel alloy material in a Zn-containing solution. 2+Electrochemical deposition was performed using a three-electrode system in solution to obtain a zinc-loaded grain boundary-rich foam copper-nickel alloy zinc anode.

[0010] Preferably, in step (1), the thickness of the precursor is 400 micrometers.

[0011] Preferably, in step (1), the wavelength of the laser is 1064nm, the scanning speed is 200nm / s, the power is 15~25%, the line spacing is 0.002mm, and the frequency is 30KHz.

[0012] Preferably, in step (2), the Zn-containing... 2+ The solution is a zinc sulfate solution; the concentration of the zinc sulfate solution is 2M.

[0013] Preferably, in step (2), the reference electrode in the three-electrode system is a saturated calomel electrode and the counter electrode is a platinum sheet.

[0014] Preferably, in step (2), the current for electrochemical deposition is 5 mA / cm. 2 The time is 900s.

[0015] In a second aspect, the present invention provides a three-dimensional alloy zinc anode material obtained by the above preparation method, wherein the three-dimensional alloy zinc anode material is a three-dimensional solid alloy framework, the interior of the three-dimensional solid alloy framework is filled with dense grain boundaries, and elemental Zn is deposited on the grain boundaries.

[0016] Preferably, the three-dimensional solid alloy framework is a foamed copper-nickel alloy nanocluster with a size of 1~5μm; the atomic percentage of copper and nickel in the foamed copper-nickel alloy nanocluster is 0.81:0.19.

[0017] A third aspect of the present invention provides the application of a three-dimensional alloy zinc anode material in improving the energy storage performance of aqueous zinc-ion batteries and suppressing the growth of zinc dendrites.

[0018] The beneficial effects of this invention are:

[0019] (1) This invention is the first to propose a method for preparing alloys on foamed copper-nickel substrates using laser plasma. It is simple to operate and has the characteristics of being fast, scalable, environmentally friendly, low-cost and in-situ processed. It is easy to achieve mass production and significantly reduces production costs. It opens up new ideas for the preparation of anode materials for aqueous zinc-ion batteries and has good prospects for industrial application.

[0020] (2) The laser sputtered three-dimensional alloy zinc anode material prepared by the present invention has abundant zinc ion storage active sites, which is conducive to rapid ion diffusion; its three-dimensional structure has a low activation energy barrier in the battery charge and discharge reaction, which can greatly improve the electrochemical performance of aqueous zinc ion batteries.

[0021] (3) This invention utilizes laser sputtering to prepare grain boundary-rich foamed copper-nickel alloy anode materials based on an alloying strategy. The influence of the quality of deposited zinc on the electrochemical performance of the anode material was investigated. It was found that laser etching of the three-dimensional zinc anode improved ion migration rate, alleviated the zinc dendrite problem in zinc-ion batteries, provided more active sites, and enhanced long-cycle performance. This better meets the development needs of the battery industry and has great application prospects. Attached Figure Description

[0022] Figure 1 The images shown are scanning electron microscope (SEM) images of the grain boundary-rich foam copper-nickel alloy prepared in Example 1, where (a) is a scanning image with an overall surface magnification of 50µm, (b) is a scanning image with a local surface magnification of 10µm, and (c) is a scanning image with an overall cross-sectional magnification of 50µm.

[0023] Figure 2 X-ray diffraction (XRD) patterns of grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial alloy electrode materials for Example 1, Comparative Example 1, and Comparative Example 2.

[0024] Figure 3 The images shown are transmission electron microscope (TEM) images of the foamed copper-nickel alloy prepared in Example 1, where (a) is a TEM image with an overall magnification of 100 nm, (b) is a TEM image with a local magnification of 5 nm, and (c) is a TEM image with a clear lattice marked.

[0025] Figure 4 High-magnification transmission electron microscopy (HRTEM) image of the grain boundary-rich foam copper-nickel alloy prepared in Example 1.

[0026] Figure 5 XPS spectra of copper in the grain boundary-rich foam copper-nickel alloy of Example 1;

[0027] Figure 6 XPS spectra of nickel in the grain boundary-rich foam copper-nickel alloy of Example 1;

[0028] Figure 7 This is a synchrotron radiation near-edge structure diagram (XANES) of copper element in the grain boundary-rich foam copper-nickel alloy in Example 1;

[0029] Figure 8 The image shows the synchrotron radiation wavelet transform (EXAFS) of copper in the grain boundary-rich foam copper-nickel alloy in Example 1.

[0030] Figure 9 This is a synchrotron radiation near-edge structure diagram (XANES) of nickel in the grain boundary-rich foam copper-nickel alloy of Example 1;

[0031] Figure 10 The image shows the synchrotron radiation wavelet transform (EXAFS) of nickel in the grain boundary-rich foam copper-nickel alloy in Example 1.

[0032] Figure 11 This is a schematic diagram illustrating the application of this material in secondary ion batteries;

[0033] Figure 12 The grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Examples 1, 2, and 3 were compared at 1 mA cm⁻¹. -2 / 1mAh cm -2 A comparison of the long-cycle performance of symmetrical batteries under different current densities and capacities;

[0034] Figure 13 The grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 were subjected to a 5 mA cm⁻¹ test. -2 / 1mAh cm -2 A comparison of the long-cycle performance of symmetrical batteries under different current densities and capacities;

[0035] Figure 14 Comparison of rate performance of symmetrical cells with grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials at different current densities in Example 1, Comparative Example 2, and Comparative Example 3.

[0036] Figure 15 The grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1 were used at 5 mA cm⁻¹. -2 / 1mAh cm -2 Cyclic stability of a half-cell after more than 3000 cycles at a given current density;

[0037] Figure 16 The grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1 were tested at 10 mA cm⁻¹. -2 / 1mAh cm -2 Cyclic stability of a half-cell after nearly 4000 cycles at a current density;

[0038] Figure 17 This is a comparison chart showing the rate performance of half-cells with grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 at different current densities.

[0039] Figure 18 The rate performance curves of the full cells of grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 at different current densities are shown.

[0040] Figure 19 The charge-discharge curves of full cells with grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 are shown at different current densities.

[0041] Figure 20 The CV curves of full cells with grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 at different current densities are shown.

[0042] Figure 21 The long-cycle performance curves of the grain boundary-rich foamed copper-nickel alloy, foamed copper, and commercial copper-nickel alloy electrode materials in Example 1, Comparative Examples 2 and 3 are shown for the full cells at a capacity of 5 A / g.

[0043] Figure 22 The images are scanning electron microscope (SEM) images of the copper-nickel alloy prepared in Comparative Example 4, where (a) is the SEM at a scale of 50 μm and (b) is the SEM at a scale of 400 μm. Detailed Implementation

[0044] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0045] As introduced in the background section, although there have been reports on the preparation of zinc anode materials by loading zinc ions onto copper foam and nickel foam, these materials all involve zinc being loaded onto a foam skeleton. Not only is the copper-nickel alloy preparation uneven, but problems such as zinc dendrites and corrosion still occur, which seriously affect the performance of aqueous zinc-ion batteries.

[0046] Therefore, the purpose of this invention is to provide a laser-sputtered, grain-bound, three-dimensional alloy zinc anode material, its preparation method, and its applications. This invention utilizes existing laser technology, through laser-induced thermal and plasma effects, and leverages the ultrafast high-temperature cooling characteristics of plasma to prepare metastable phases, solid solutions, and high-density grain boundaries that are difficult to achieve using conventional methods, providing possibilities for deep electronic manipulation. Furthermore, the optical path scanning method facilitates the uniform preparation of meter-scale materials and possesses good scalability. Therefore, constructing a three-dimensional alloy zinc anode based on laser technology is of great significance for improving the overall performance and practicality of zinc-ion batteries.

[0047] First, the copper-nickel foam roll is fed into a BMR-100A electric roller mill. The scale is adjusted to control the thickness of the roll from both mechanical rollers to a uniform standard, obtaining a precursor. Then, an HTF50M laser marking machine is used to adjust the etching process parameters and etch the sample. When a continuous fiber laser acts on the precursor surface, the laser energy is absorbed by the copper and nickel skeleton surface in an extremely short time (nanoseconds to microseconds), instantly raising the local temperature above the melting point of copper and nickel, and even exceeding their boiling point. This triggers the vaporization and ionization of the metal on the substrate surface, forming a laser-induced plasma composed of copper and nickel ions, electrons, and neutral particles. The plasma has extremely high energy density and kinetic energy, and sputtering occurs under its influence. Due to the three-dimensional porous structure of the foam preform, sputtered particles deposit and collide on adjacent copper and nickel skeleton surfaces. In this process, the high-energy characteristics of laser plasma break the original lattice constraints of copper and nickel atoms: on the one hand, sputtered copper atoms penetrate into the surface lattice of the nickel framework, and nickel atoms diffuse in the opposite direction to the surface of the copper framework, forming a copper-nickel solid solution transition layer. The disordered arrangement of copper and nickel atoms in this transition layer provides the "atomic basis" for the formation of the initial grain boundary; on the other hand, the instantaneous high temperature and rapid cooling of the plasma inhibit the growth of copper and nickel grains, causing a large number of fine subgrains to form in the transition layer. The interface between these subgrains is the initial grain boundary core, laying the groundwork for the subsequent construction of a grain boundary-rich structure. As the laser action continues, plasma sputtering and interfacial diffusion intensify, and the mutual penetration of the copper and nickel skeletons extends from the surface to the interior: copper atoms in the copper skeleton gradually fill the lattice gaps or defect sites of the nickel skeleton through grain boundary diffusion, vacancy diffusion, and other means, while nickel atoms also diffuse into the interior of the copper skeleton. The diffusion processes of both occur simultaneously in the three-dimensional porous skeleton of the foam substrate, ultimately forming a continuous alloy network of "you in me, me in you", that is, a three-dimensional through alloy skeleton. In this alloying process, the "multiplication effect" of grain boundaries is particularly crucial: First, copper and nickel have different atomic radii. Although the numerical values ​​are similar, their electron cloud distribution and lattice constants differ. Copper's lattice constant is 3.615 Å, while nickel's is 3.524 Å. When they form a solid solution, the lattice undergoes a slight distortion, which induces the formation of numerous dislocations. The accumulation and intersection of dislocations further form new grain boundaries. Second, the pulsed characteristics of the laser cause the substrate to undergo a "heating-cooling" cycle. Each cooling generates new nucleation points within the already formed alloy layer. The newly nucleated grains squeeze against the existing grains, forming even more grain boundaries. Ultimately, the entire three-dimensional alloy framework is filled with dense grain boundaries, forming a grain boundary-rich structure. In aqueous zinc-ion battery systems, when grain boundary-rich foamed copper-nickel alloys are used as negative electrode current collectors or substrates, their dense grain boundary structure can regulate zinc deposition behavior throughout the entire "nucleation-diffusion-growth" process, effectively suppressing dendrite formation and achieving uniform deposition. In summary, grain boundaries have appropriate zinc affinity for the entire alloy carrier, thereby achieving uniform deposition.

[0048] Next, the prepared grain boundary-rich foamed copper-nickel alloy material was electrochemically deposited in a 2M zinc sulfate solution using a three-electrode method. After drying, the foamed copper-nickel alloy zinc anode material was obtained. Grain boundaries provide high-density active nucleation sites, preventing localized zinc atom aggregation and deposition. If nucleation sites are scarce, zinc atoms tend to accumulate continuously at a few active sites, forming dendrites. The grain boundary-rich structure precisely solves this problem: as a "defect region" in the crystal structure, grain boundaries have a high degree of atomic disorder and contain a large number of unsaturated bonds and lattice distortion sites. The surface energy of these sites is significantly higher than that of the grain interior, which is beneficial for Zn. 2+ It possesses stronger adsorption capacity and can serve as a "preferred nucleation site" for zinc deposition. In grain boundary-rich foamed copper-nickel alloys, the high grain boundary density means that there may be millions of active nucleation sites per unit area, and these sites are uniformly distributed along the three-dimensional alloy framework. When Zn... 2+ When migrating to the substrate surface, it is rapidly captured by dense grain boundary sites, preventing Zn from being trapped. 2+ Excessive enrichment in localized areas enables "multi-point synchronous nucleation" from the source, laying the foundation for subsequent uniform deposition. Furthermore, grain boundaries optimize the local electric field distribution, eliminating deposition unevenness caused by the "tip effect." The presence of grain boundaries disrupts the continuous lattice structure of a single grain, creating an alternating "grain-grain boundary" microstructure on the substrate surface. This morphology disperses locally concentrated electric fields, preventing excessive field enhancement in any particular area. On the other hand, atomic defects at grain boundaries form tiny "electric field buffer zones," allowing Zn to... 2+ During migration under the influence of an electric field, grain boundaries can guide Zn. 2+ Diffusion to multiple nucleation sites results in a more uniform electric field distribution across the entire substrate surface, leading to a more consistent zinc deposition rate. Grain boundaries accelerate zinc atom diffusion kinetics, promoting densification of the deposition layer and resulting in a dense, flat microstructure that reduces space for dendrite growth. Grain boundaries also inhibit the growth and penetration of zinc dendrites, enhancing deposition stability. Even if tiny zinc dendrite buds appear in the early stages of deposition, the grain-bound structure can disrupt the dendrite growth direction through the different orientations of grains, making it difficult for them to form continuous long dendrites.

[0049] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0050] The test materials used in the embodiments of this invention are all conventional test materials in the art and can be purchased through commercial channels.

[0051] Example 1: Preparation of three-dimensional alloy zinc anode material rich in grain boundaries

[0052] (1) Preparation: Add 7.5g ZnSO4•7H2O, 7.5g NaSO4, 1.25g boric acid, and 50ml deionized water to a 100ml beaker. Add a magnetic stir bar and place the beaker on a stirring table to stir until completely dissolved to obtain a Zn-containing solution. 2+ Solution, for later use.

[0053] Take 1mm thick copper foam and 0.5mm thick nickel foam, clean the surface impurities with ethanol, and dry them in a 60°C electric thermostatic drying oven. Using a BMR-100A electric roller press, place the nickel foam on top of the copper foam and stack them, then place them in the electric roller press. Adjust the pressure to 80Pa, control the thickness of the rolled material to 400μm, and ensure that both are of equal length and width. After pressing, the precursor is obtained.

[0054] (2) Laser pretreatment: The precursor prepared in step (1) is scanned by a laser marking machine (using a pulsed laser with a wavelength of 1064nm as the laser source, setting the laser power to 25%, the scanning speed to 200mm / s, the scanning area to be a rectangle with a diameter of 20cm, the scanning method to be line scanning, the line spacing to be 0.002mm, the number of scanning circles to be 1, and focusing). The etching area is 20×20mm. The black area sputtered after the scanning is the desired grain boundary-rich foam copper-nickel alloy material.

[0055] (3) Preparation of Zn-supported copper-nickel foam material: Electrochemical deposition using a three-electrode system was performed on a Chenhua electrochemical workstation (CHI 660E). The reference electrode was saturated calomel, the counter electrode was a platinum sheet, and the working electrode was a grain boundary-rich copper-nickel foam material. The electrolyte was a 2M zinc sulfate solution. The deposition current was adjusted to 5 mA / cm². 2 The deposition time was 900 s. After electrodeposition, the material was dried in a DHG-9035AD thermostatic drying oven at 60℃ to obtain a grain boundary-rich three-dimensional alloy zinc anode material.

[0056] Comparative Example 1

[0057] The difference from Example 1 is that foamed nickel (with the same size as in Example 1) is used instead of grain boundary-rich foamed copper-nickel alloy material to finally prepare foamed nickel-zinc anode material.

[0058] Because the pure nickel foam used in Comparative Example 1 has high activity and good hydrogen evolution properties, it will cause the battery to bulge. Therefore, Comparative Example 1 is not suitable for preparing zinc-ion batteries.

[0059] Comparative Example 2

[0060] The difference from Example 1 is that foamed copper (with the same size as in Example 1) is used instead of the grain boundary-rich foamed copper-nickel alloy material to finally prepare foamed copper-zinc anode material.

[0061] Comparative Example 3

[0062] The difference from Example 1 is that a commercially available copper-nickel alloy (purchased from Kunshan Longshengbao Electronic Materials Co., Ltd., 400μm electrode material) was used instead of the grain boundary-rich foam copper-nickel alloy material to finally prepare the alloy zinc anode material.

[0063] Comparative Example 4

[0064] (1) Using copper foil (0.1 mm) and nickel foil (0.01 mm) as precursors, laser processing was performed (laser parameters were the same as in Example 1) to obtain copper-nickel alloy sheets.

[0065] (2) The method for preparing Zn-loaded copper-nickel alloy material using the copper-nickel alloy sheet obtained in step (1) is the same as step (3) in Example 1.

[0066] according to Figure 22 As shown, copper foil and nickel foil, and nickel foil and copper foam cannot achieve uniform etching after laser treatment. After zinc deposition, there is a tendency for dendrites to form on the surface, which causes zinc dendrite growth and greatly reduces the energy storage performance of zinc-ion batteries, making them unsuitable for the preparation of zinc-ion batteries.

[0067] Example 2: Characterization

[0068] (1) The microstructure of the grain boundary-rich three-dimensional alloy zinc anode material prepared in Example 1 was obtained by scanning electron microscopy (SEM). Figure 1 The data shows that the three-dimensional alloy zinc anode material with rich grain boundaries is composed of uniformly distributed nanoclusters, and the Cu and Ni elements are evenly distributed.

[0069] like Figure 2 As shown, X-ray diffraction tests were performed on the grain boundary-rich copper-nickel foam alloy material, copper foam, and nickel foam prepared in Example 1. The analysis further confirmed that the phase diffraction peaks of the grain boundary-rich copper-nickel foam alloy material were shifted relative to those of copper foam and nickel foam, and the diffraction peak intensities were higher, indicating that it has good crystallinity. MDI jade6 analysis showed that the alloy phase was Cu. 0.81 Ni 0.19 The formation of the alloy was confirmed, consistent with the design expectations. These results demonstrate that laser-plasma effects can effectively prepare three-dimensional porous CuNi alloy current collectors with uniform composition and controllable structure.

[0070] To verify the above effects, transmission electron microscopy (TEM) tests were performed on the grain boundary-rich foam copper-nickel alloy material, such as... Figure 3The image shows the microcrystalline structure of the alloy, revealing clear lattice fringes corresponding to CuNi(111) and CuNi(200), further confirming the phase composition of the alloy and demonstrating its good crystallinity as a current collector. (Spherical aberration image) Figure 4 It allows for clearer and more precise observation of the microstructure of materials, especially fine structures such as grain boundaries.

[0071] The above results demonstrate that three-dimensional porous CuNi alloy current collectors with uniform composition and controllable structure can be effectively prepared through laser plasma effect.

[0072] (2) In order to investigate the regulatory effect of Ni on the electronic structure of Cu, the electronic structure of the grain boundary-rich foam copper-nickel alloy material was characterized. Figure 5 and Figure 6 XPS results showed that there was significant electron transfer between Cu and Ni. This electronic interaction is beneficial to the charge / mass transport kinetics when the alloy acts as a carrier. XPS analysis revealed that the binding energy of Cu and Ni in the grain boundary-rich foamed copper-nickel alloy shifted, further confirming that the introduction of Ni changed the electronic density of states of Cu. Cu and Ni formed a stable alloy phase, and the electron cloud was redistributed, laying the electronic basis for enhanced zinc affinity.

[0073] In the grain boundary-rich foamed copper-nickel alloy material prepared in step 2 of Example 1, analysis will be performed... Figures 7-8 The X-ray absorption near-edge structure (XANES) spectra reveal the phase composition, valence state, and structural information of copper in the grain boundary-rich foam copper-nickel alloy (using standard samples Cu₂O, Cu foil, and CuO for reference). Comparison with the standard samples shows that the copper in the alloy is close to zero and has a slightly negative valence state. Differences in the XANES spectra reflect differences in the electronic state and local structure of Cu in the samples. The differences between the grain boundary-rich foam copper-nickel alloy and other Cu-containing samples in specific energy regions further indicate that the electronic environment of Cu in the grain boundary-rich foam copper-nickel alloy is altered by its interaction with Ni. The presence and intensity variations of coordination peaks such as Cu-Cu, Cu-O, and Cu-Ni reflect the atomic structure of Cu in different samples. In the grain boundary-rich foam copper-nickel alloy material prepared in step 2 of Example 1, the appearance of Cu-Ni coordination peaks indicates a direct interaction between Cu and Ni. This interaction is related to electron transfer and helps to understand the kinetics of charge / mass transport in the alloy. Using Ni foil and NiO as standard samples, the coordination environment of Ni in the grain boundary foam copper-nickel alloy material prepared in step 2 of Example 1 was analyzed, such as... Figures 9-10As shown, by analyzing coordination peaks such as Ni-Ni, Ni-O, and Ni-Cu, we can more comprehensively study the atomic structure of Ni in the alloy. Combined with the EXAFS results of Cu, we can further elucidate the interaction between Cu and Ni and its influence on charge / mass transport dynamics.

[0074] Experimental Example 1

[0075] The three-dimensional alloy zinc anode material with rich grain boundaries prepared in Example 1, the foamed copper-zinc anode material prepared in Comparative Example 2, and the alloy zinc anode material prepared in Comparative Example 3 were respectively assembled into zinc-ion batteries, and are referred to as Example 1, Comparative Example 2, and Comparative Example 3. Figure 11 As shown, 1 is the negative electrode shell of the CR2025 battery, 2 is a CR2025 spring sheet with a thickness of 1.2 mm, 3 is a CR2025 gasket with a thickness of 0.5 mm, 4 is a mineral-rich foamed copper-nickel alloy zinc negative electrode material, 5 is a GF / F glass fiber separator of Whatman brand, 6 is a modified manganese dioxide positive electrode material, and 7 is the positive electrode shell of the CR2025 battery. Aqueous zinc-ion batteries assembled based on the above materials were tested. The batteries assembled in Example 1, Comparative Example 2, and Comparative Example 3 were tested using a Chenhua CH660E electrochemical workstation and a LanDian CT2001A battery testing system at 5 mV s. -1 At a scanning rate, the kinetic reversibility of redox is observed. The cycle stability and coulombic efficiency of symmetric cells and half-cells are tested at different current densities. The charge-discharge curves of the full cell are tested at different current densities to determine its capacity.

[0076] like Figures 12-13 As shown, compared with Comparative Examples 2-3, the battery assembled with the grain-bound three-dimensional alloy zinc anode material prepared in Example 1 has lower voltage hysteresis and longer cycle life (up to 12000h). Compared with the foamed copper in Comparative Example 2 and the commercial copper-nickel alloy in Comparative Example 3, the grain-bound foamed copper-nickel alloy prepared in Example 1 has stronger voltage stability during long-term cycling, indicating that it can effectively suppress dendrite growth and side reactions, and significantly improve the cycle stability of the battery.

[0077] Figure 14 This demonstrates the rate performance of the grain boundary-rich foamed copper-nickel alloy from Example 1 as the current collector. The curves show that the voltage is relatively stable during cycling, especially after long-term cycling, with minimal voltage fluctuations. This indicates that Example 1 effectively maintains the electrochemical stability of the battery, reduces the adverse effects of side reactions on voltage, and helps improve the cycle performance of aqueous zinc-ion batteries.

[0078] Experimental Example 2

[0079] Using the three-dimensional alloy zinc anode material rich in grain boundaries prepared in Example 1, the foamed copper-zinc anode material prepared in Comparative Example 2, and the alloy zinc anode material prepared in Comparative Example 3 as anodes, and a 0.1 mm zinc foil as anode, a Whatman GF / F glass fiber separator, and 300 µL of 2M ZnSO4 electrolyte, the half-cells were assembled in the following order: anode shell-anode-separator-electrolyte-anode-gasket-spring sheet. The assembly was carried out using an MSK-110 battery packaging machine with a pressure of 50 Pa. The zinc storage performance of the materials was further verified by testing on the Blue Electric CT2001A battery testing system.

[0080] like Figures 15-17 At 5mA cm -2 / 1mAh cm -2 Under the specified conditions, the half-cell assembled with the grain-bound foam copper-nickel alloy zinc anode material prepared in Example 1 maintained an average coulombic efficiency of 96.73% after 3000 cycles; at 10 mA·cm -2 / 1mAh·cm -2 Under high-rate conditions, the average coulombic efficiency reached 93.41% after 6000 cycles, demonstrating excellent rate performance and cycle stability.

[0081] Experimental Example 3

[0082] Using the three-dimensional alloy zinc anode material rich in grain boundaries prepared in Example 1, the foamed copper-zinc anode material prepared in Comparative Example 2, and the alloy zinc anode material prepared in Comparative Example 3 as anodes, and modified manganese dioxide as anode, and Whatman's GF / F glass fiber separator as a separator, 300µL of 2M ZnSO4+0.1M MnSO4 electrolyte was injected. The cells were assembled in the following order: anode shell-anode-separator-electrolyte-anode-gasket-spring sheet-anode shell. The pressure was set to 50Pa using an MSK-110 battery packaging machine, and the full cells were tested on the Blue Electric CT2001A battery testing system.

[0083] like Figure 18 The rate performance tests shown indicate that, at different current densities, the specific capacity of the full cell based on Example 1 is higher than that of the full cells assembled in Comparative Examples 2 and 3. Furthermore... Figure 19 The results show that the GCD curve of the full cell based on Example 1 exhibits a clear plateau, indicating that the capacity decay rate of the battery is slow at different current densities, which indirectly verifies the good rate performance and highlights the rapid reaction kinetics.

[0084] like Figure 20 As shown, in cyclic voltammetry testing, the full cell based on Example 1 exhibits a lower voltage gap and a higher peak current density, reflecting its superior electrochemical activity and lower voltage polarization. Figure 21 In 5 A g-1 After 7000 cycles at high current density, the full cell based on Example 1 still retains approximately 81.37% of its capacity and maintains stable coulombic efficiency. These results indicate that the grain boundary-rich foamed copper-nickel alloy prepared based on Example 1 can significantly improve the overall performance of the full cell and has practical application potential.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a three-dimensional alloy zinc anode material by laser etching, characterized in that, Includes the following steps: (1) Place copper foam under nickel foam and press it together to obtain a precursor. The thickness of the copper foam is 1 mm and the thickness of the nickel foam is 0.5 mm. Irradiate the precursor with the plasma effect of a laser to obtain a grain boundary-rich copper-nickel foam alloy material. The wavelength of the laser is 1064 nm, the scanning speed is 200 nm / s, the power is 15~25%, the line spacing is 0.002 mm, and the frequency is 30 kHz. (2) Immerse the rich-grain-bound foam copper-nickel alloy material in a Zn-containing solution. 2+ Electrochemical deposition was performed using a three-electrode system in solution to obtain a zinc-loaded grain boundary-rich foam copper-nickel alloy zinc anode.

2. The preparation method according to claim 1, characterized in that, In step (1), the thickness of the precursor is 400 micrometers.

3. The preparation method according to claim 1, characterized in that, In step (2), the Zn-containing 2+ The solution is a zinc sulfate solution; the concentration of the zinc sulfate solution is 2M.

4. The preparation method according to claim 1, characterized in that, In step (2), the reference electrode in the three-electrode system is a saturated calomel electrode and the counter electrode is a platinum sheet.

5. The preparation method according to claim 1, characterized in that, In step (2), the current for electrochemical deposition is 5 mA / cm. 2 The time is 900s.

6. The grain boundary-rich three-dimensional alloy zinc anode material obtained by the preparation method according to any one of claims 1 to 5, characterized in that, The three-dimensional alloy zinc anode material is a three-dimensional solid alloy framework, the interior of which is filled with dense grain boundaries; elemental zinc is deposited on the grain boundaries.

7. The grain boundary-rich three-dimensional alloy zinc anode material according to claim 6, characterized in that, The three-dimensional solid alloy framework is a foamed copper-nickel alloy nanocluster with a size of 1~5μm; the atomic percentage of copper and nickel in the foamed copper-nickel alloy nanocluster is 0.81:0.

19.

8. The application of the three-dimensional alloy zinc anode material according to claim 6 or 7 in improving the energy storage performance of aqueous zinc-ion batteries and inhibiting the growth of zinc dendrites.

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