Laser-induced 3D self-supporting high-orientation twin grain boundary-rich zinc-copper alloy thin film electrode material and application thereof

Abstract

The application discloses a kind of laser-induced 3D self-supporting high orientation twin grain boundary rich zinc copper alloy thin film electrode material and its application, belong to battery material technical field.Zinc copper alloy thin film electrode material is obtained by using laser pulse processing copper powder and zinc powder mixture;Zinc copper alloy thin film electrode material is Cu5Zn8, Cu5Zn8 has nanometer ball structure and high orientation twin structure of fluff.The zinc powder and copper powder are mixed and tabletting to obtain zinc copper mixture tablet, then it is etched using pulse laser;Alloy thin film is formed on the surface of zinc copper mixture tablet, i.e.laser-induced 3D self-supporting high orientation twin grain boundary rich zinc copper alloy thin film electrode material.In zinc ion reversible stripping / deposition process, the high orientation characteristics and twin grain boundary structure of alloy thin film can induce zinc uniform nucleation, and drive zinc preferential orientation directional deposition, so that the growth of zinc dendrite is significantly inhibited;Meanwhile, the introduction of alloy can effectively improve the corrosion resistance of zinc negative electrode.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery materials, in particular to a laser-induced 3D self-supporting high-orientation twin grain boundary-rich zinc-copper alloy thin film electrode material and application thereof. BACKGROUND

[0002] With the growing demand for clean energy worldwide, efficient, safe and sustainable energy storage technology has become crucial. Aqueous zinc-ion batteries have shown great application potential in large-scale energy storage due to their low cost, high theoretical specific capacity, good safety and environmental friendliness, and have become one of the research hotspots in recent years. In the aqueous zinc-ion battery system, the reversible deposition / dissolution of the negative electrode material plays a decisive role in the stability of the battery. The traditional zinc metal negative electrode faces many challenges during the charging and discharging process. On the one hand, zinc is prone to form dendrites during deposition. The continuous growth of dendrites will cause internal short circuit of the battery, seriously affecting the safety and cycle life of the battery. On the other hand, the zinc electrode is prone to corrosion in the electrolyte, producing hydrogen gas, causing loss of active material, and reducing the coulombic efficiency and cycle stability of the battery.

[0003] In recent years, many researchers have proposed various solutions from the negative electrode side, including building an interface protection layer, improving the current collector, designing a three-dimensional structure, and alloying strategy. Among them, introducing foreign elements into the Zn matrix to construct a zinc-based alloy structure can fundamentally reshape the performance of the zinc negative electrode, which is an effective way to achieve a high-efficiency zinc stripping / deposition carrier. Alloying can change the crystal structure of zinc, provide a large number of uniform nucleation points for zinc ion deposition, effectively inhibit dendrite growth, and significantly enhance the corrosion resistance of the electrode. At the same time, the orientation of the Zn deposition substrate is an important condition for inducing homogeneous growth during the reversible stripping / deposition of zinc in the process of constructing alloy materials. In addition, the alloying strategy can optimize the ion transport path, reduce the reaction activation energy, and greatly improve the charging and discharging efficiency, providing a solid guarantee for the efficient and stable operation of zinc-ion batteries.

[0004] Although the above alloying strategy has shown significant advantages in improving the performance of the zinc negative electrode, there are still key problems such as random deposition and grain boundary corrosion in the existing technology, which leads to the stability and reversibility of the zinc negative electrode under high current density and long cycle life conditions not meeting the requirements of practical applications. At the same time, the existing alloying modification process has defects such as complex process, high cost and difficulty in large-scale production, which limits its popularization and application in the industrialization process of aqueous zinc-ion batteries. Therefore, developing a zinc-based alloy material with preferential deposition and grain boundary corrosion resistance, driving zinc to deposit along the preferential orientation, and effectively improving the corrosion resistance of the zinc negative electrode, is of great significance for promoting the commercialization of aqueous zinc-ion batteries. SUMMARY

[0005] To address the aforementioned limitations of existing technologies, the present invention aims to provide a laser-induced 3D self-supporting, highly oriented, twin-boundary-rich zinc-copper alloy thin-film electrode material and its applications. This invention utilizes laser technology to construct a highly oriented, twin-boundary-rich 3D self-supporting zinc-copper alloy electrode, which can be directly used as the anode in aqueous zinc-ion batteries. During the reversible stripping / deposition of zinc ions, the high orientation characteristics and twin-boundary-rich structure of the alloy film can induce uniform zinc nucleation and drive the preferred orientation and directional deposition of zinc, thereby significantly inhibiting zinc dendrite growth. Simultaneously, the introduction of the alloy effectively improves the corrosion resistance of the zinc anode. This electrode material can simultaneously solve key problems such as dendrite growth and hydrogen evolution corrosion faced by traditional zinc metal anodes, significantly improving the cycle stability of aqueous zinc-ion batteries.

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

[0007] In a first aspect, the present invention provides a laser-induced 3D self-supporting, highly oriented, twin-boundary-rich zinc-copper alloy thin-film electrode material, wherein the zinc-copper alloy thin-film electrode material is obtained by laser pulse treatment of a mixture of copper powder and zinc powder; the zinc-copper alloy thin-film electrode material is Cu5Zn8, which has a villous nanosphere structure and a highly oriented, twin-boundary-rich structure.

[0008] Preferably, the copper content in the zinc-copper alloy thin-film electrode material is 5-15%.

[0009] Preferably, the Cu5Zn8 is oriented with the (330) crystal plane.

[0010] Preferably, the zinc-copper alloy thin-film electrode material is prepared by the following method:

[0011] Zinc powder and copper powder are mixed and pressed into tablets to obtain zinc-copper mixture tablets, which are then etched using pulsed lasers. An alloy thin film is formed on the surface of the zinc-copper mixture tablets, which is the laser-induced 3D self-supporting highly oriented zinc-copper alloy thin film electrode material with rich twin boundaries.

[0012] Preferably, the mass ratio of zinc powder to copper powder is 9:1.

[0013] Preferably, the parameters of the pulsed laser are: laser wavelength of 1064 nm, laser power of 10~15W, etching speed of 200~2000 mm / s, line spacing of 0.001~0.05 mm, and focusing.

[0014] A second aspect of the present invention provides the application of zinc-copper alloy thin-film electrode materials in improving the performance of aqueous zinc-ion batteries.

[0015] Preferably, the zinc-copper alloy thin-film electrode material inhibits the formation of zinc dendrites by regulating the nucleation sites and growth direction of zinc deposition, thereby improving the performance of aqueous zinc-ion batteries.

[0016] Preferably, the zinc-copper alloy thin-film electrode material improves the performance of aqueous zinc-ion batteries by reconstructing the electronic structure of the electrode surface and reducing the corrosive activity of zinc.

[0017] The beneficial effects of this invention are:

[0018] (1) The 3D self-supporting zinc-copper alloy electrode with high orientation and rich twin grain boundary structure constructed by laser technology has high orientation crystallographic characteristics and rich twin grain boundary structure. By controlling the nucleation sites and growth direction of zinc deposition, the uniform nucleation of zinc can be achieved, and zinc can be driven to be deposited along the preferred orientation, thereby inhibiting the nucleation and growth of zinc dendrites from the thermodynamic and kinetic perspectives.

[0019] (2) The zinc-copper alloy electrode material with high orientation and rich twin boundaries constructed in this invention can reconstruct the electronic structure of the electrode surface by introducing copper element to form a zinc-copper alloy phase (Cu5Zn8), thereby reducing the corrosion activity of zinc and effectively improving the corrosion resistance of zinc anode.

[0020] (3) This invention proposes a method for one-step synthesis of zinc-copper alloy electrode materials by laser etching. This material preparation method has the advantages of being fast, scalable, environmentally friendly, low-cost and in-situ processing. It is easy to achieve mass production, greatly reduces production costs, and has good industrial application prospects. Attached Figure Description

[0021] Figure 1 : Figure 1 X-ray diffraction (XRD) patterns of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1, the pure zinc electrode prepared in Comparative Example 1, and the pure copper electrode prepared in Comparative Example 2.

[0022] Figure 2 X-ray diffraction (XRD) patterns of electrode materials prepared in Example 1 (Zn:Cu=9:1), Comparative Example 3 (Zn:Cu=5:1), and Comparative Example 4 (Zn:Cu=1:1);

[0023] Figure 3 X-ray diffraction (XRD) patterns of electrode materials prepared in Example 1 (10W), Comparative Example 5 (5W), and Comparative Example 6 (20W);

[0024] Figure 4 Scanning electron microscope (SEM) image of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode material prepared in Example 1;

[0025] Figure 5Electron backscatter diffraction (EBSD) images and statistical histograms of Cu5Zn8 grain size of the 3D self-supporting zinc-copper alloy electrode with a highly oriented twin-rich structure prepared in Example 1 and the pure zinc electrode prepared in Comparative Example 1 are shown, where (a) is the EBSD image of Cu5Zn8; (b) is the EBSD image of pure zinc; (c) is the statistical histogram of Cu5Zn8 grain size; and (d) is the statistical histogram of pure zinc grain size.

[0026] Figure 6 (a) Transmission electron microscope image of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1; (b) Elemental distribution diagram of Cu5Zn8.

[0027] Figure 7 Transmission electron microscope image of the pure copper electrode prepared in Comparative Example 2;

[0028] Figure 8 Transmission electron microscope image of the electrode prepared in Comparative Example 5;

[0029] Figure 9 Transmission electron microscope image of the electrode prepared in Comparative Example 6;

[0030] Figure 10 Young's modulus diagram of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1;

[0031] Figure 11 (a) Schematic diagram of the contact angle of the pure zinc film of Comparative Example 1 in 2 M ZnSO4 electrolyte; (b) Schematic diagram of the contact angle of the zinc-copper alloy electrode of Example 1 in 2 M ZnSO4 electrolyte;

[0032] Figure 12 Tafel curves of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1 and the pure zinc thin film electrode prepared in Comparative Example 1 were tested in a three-electrode system to characterize the corrosion rate of the zinc anode (electrolyte: 2 M ZnSO4).

[0033] Figure 13 The hydrogen evolution polarization curves of the 3D self-supporting zinc-copper alloy electrode with a highly oriented twin-rich structure prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode prepared in Comparative Example 1 were tested in a three-electrode system to characterize the hydrogen evolution corrosion resistance (electrolyte: 1 M Na2SO4).

[0034] Figure 14 In-situ differential mass spectra and corresponding galvanostatic time curves of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode prepared in Comparative Example 1.

[0035] Figure 15 The highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode material prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode material prepared in Comparative Example 1 were compared at 5 mA cm⁻¹. -2 / 1 mAh cm -2 In-situ optical microscope images;

[0036] Figure 16 The 2D-GIXRD pattern and (101) pole figure of the 3D self-supporting zinc-copper alloy electrode material with high orientation and rich twin structure prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode material prepared in Comparative Example 1 after 50 cycles are shown in the following figures: (a) 2D-GIXRD pattern of pure zinc; (b) (101) pole figure of pure zinc; (c) 2D-GIXRD pattern of 3D self-supporting zinc-copper alloy electrode with high orientation and rich twin structure; (d) (101) pole figure of 3D self-supporting zinc-copper alloy electrode with high orientation and rich twin structure.

[0037] Figure 17 The highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode material prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode material prepared in Comparative Example 1 were respectively assembled into symmetrical cells, and the cells were tested at a current density of 1 mAcm⁻¹. -2 The cutoff capacity is 1 mAh cm⁻¹ -2 Constant current charge-discharge test under the conditions;

[0038] Figure 18 Desolvation activation energy curves of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode material prepared in Comparative Example 1;

[0039] Figure 19 Cyclic voltammetry (CV) curves (scan rate 1 mV / s) of zinc-copper half-cells were obtained by assembling the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode prepared in Comparative Example 1. -1 (Voltage range -0.2~0.4 V).

[0040] Figure 20 The long cycle life of the 3D self-supporting zinc-copper alloy electrode material with a highly oriented twin-rich structure prepared in Example 1 and the 3D self-supporting pure zinc thin film electrode material prepared in Comparative Example 1, respectively, assembled with MnO2 into full cells at a current density of 1.5 A / g.

[0041] Figure 21Actual power supply diagram of the 3D self-supporting zinc-copper alloy electrode material with high orientation and rich twin boundaries prepared in Example 1 after being assembled with MnO2 into a soft-pack battery device. Detailed Implementation

[0042] 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.

[0043] As introduced in the background section, zinc powder has disadvantages such as easy corrosion, poor mechanical properties, and many side reactions. Furthermore, during electrochemical cycling, the dissolution of zinc leads to uncontrollable volume shrinkage, which consumes the electrical contact between zinc powder particles. Repeated deposition / stripping can easily lead to the formation of dead zinc and dendrite growth. These problems can have a significant impact on the cycle life and stability of the battery.

[0044] Based on this, the purpose of this invention is to provide a laser-induced 3D self-supporting highly oriented, twin-boundary-rich zinc-copper alloy thin-film electrode material and its application. This invention innovatively proposes a laser-induced one-step plasma etching method for synthesizing a highly oriented, twin-boundary-rich 3D self-supporting zinc-copper alloy electrode material. Zinc powder and copper powder are mixed, and the mixture is then plasma-etched using a pulsed laser to obtain a Cu5Zn8 zinc-copper alloy. This alloy mainly displays the (330) crystal plane, proving its high orientation. Further structural analysis reveals that this Cu5Zn8 highly oriented alloy thin film has a high abundance of nanoscale twins.

[0045] When a highly oriented, twin-boundary-rich zinc-copper alloy is used as the anode in an aqueous zinc-ion battery, its high orientation induces zinc to reversibly peel off / deposit along crystal planes with low lattice mismatch. Simultaneously, the twin-boundary-rich structure of this highly oriented alloy film facilitates the regulation of zinc ion adsorption energy and induces uniform nucleation sites, preventing zinc dendrite formation caused by heterogeneous zinc deposition. Therefore, this highly oriented, twin-boundary-rich Cu5Zn8 film, as a zinc anode deposition / stripping support, ensures the induction of homogeneous preferential zinc growth during reversible cycling. Thus, by controlling the nucleation sites and growth direction of zinc deposition, uniform zinc nucleation can be achieved, inhibiting zinc dendrite nucleation and growth from a thermodynamic and kinetic perspective. Furthermore, the zinc-copper alloy phase (Cu5Zn8) formed by the introduction of copper can reconstruct the electronic structure of the electrode surface, reducing the corrosive activity of zinc and effectively improving the corrosion resistance of the zinc anode. Based on the above synergistic effect, the electrode material of the present invention can simultaneously solve the two major technical problems of dendrite growth and hydrogen evolution corrosion commonly faced by traditional zinc metal anodes in aqueous electrolytes, and significantly improve the cycle stability and service safety of aqueous zinc-ion batteries.

[0046] 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.

[0047] 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.

[0048] Example 1: Preparation of zinc-copper alloy thin film electrode material

[0049] Zinc powder and copper powder were mixed uniformly at a mass ratio of 9:1 to obtain a zinc-copper mixture. 500 mg of the zinc-copper mixture was compressed into tablets using a tablet press. The tablets were then laser-etched using a pulsed laser under an argon protective atmosphere. The laser parameters were: laser wavelength of 1064 nm, laser power of 10 W, etching rate of 2000 mm / s, and line spacing of 0.005 mm. The pulsed laser was focused onto the tablet for etching. After etching, an alloy thin film was formed on the tablet surface, which could be peeled off to obtain a highly oriented, twin-boundary-rich 3D self-supporting zinc-copper alloy thin-film electrode material.

[0050] Comparative Example 1

[0051] The difference from Example 1 is that no copper powder is added; only zinc powder is used as the raw material. The final product is a pure zinc electrode material.

[0052] Comparative Example 2

[0053] The difference from Example 1 is that no zinc powder is added; only copper powder is used as the raw material. The final product is a pure copper electrode material.

[0054] Comparative Example 3

[0055] The difference from Example 1 is that the mass ratio of zinc powder to copper powder is 5:1. A zinc-copper alloy thin-film electrode material was finally prepared.

[0056] Comparative Example 4

[0057] The difference from Example 1 is that the mass ratio of zinc powder to copper powder is 1:1. A zinc-copper alloy thin-film electrode material was ultimately prepared.

[0058] Comparative Example 5

[0059] The difference from Example 1 is that the laser power is 5W.

[0060] Comparative Example 6

[0061] The difference from Example 1 is that the laser power is 20W.

[0062] Example 2: Characterization

[0063] The crystal phase structure of the electrode materials prepared in Example 1, Comparative Example 1, and Comparative Example 2 was analyzed using X-ray diffraction (XRD). Figure 1 As shown, the XRD characteristic peaks of the highly oriented, twin-rich 3D self-supporting zinc-copper alloy electrode material prepared in Example 1 perfectly match the standard PDF card of Cu5Zn8 alloy, confirming that the phase of the prepared electrode material is Cu5Zn8 alloy. More importantly, a strong and single diffraction peak appears at 2θ = 43.29°, indicating that the Cu5Zn8 alloy electrode material possesses significant high orientation characteristics. Furthermore, the pure zinc electrode of Comparative Example 1 and the pure copper electrode of Comparative Example 2 both correspond one-to-one with the corresponding standard PDF cards of elemental zinc and elemental copper, but exhibit characteristic diffraction peaks of polycrystalline planes. This indicates that while etching zinc or copper powder with pulsed lasers will produce crystals, it will not produce twins or high orientation; further highlighting the high purity and orientation advantages of the Cu5Zn8 alloy phase in Example 1. X-ray diffraction was performed on the electrode materials prepared in Example 1, Comparative Example 3, and Comparative Example 4, as shown... Figure 2 As shown, with the increase of copper powder content, a new CuZn5 alloy phase began to appear in the electrode materials of Comparative Examples 3 and 4. The intensity of the characteristic peak of this new phase gradually increased with the increase of copper powder content. This phenomenon indicates that the copper powder doping ratio is a key factor in controlling the high orientation of the zinc-copper alloy. The X-ray diffraction patterns of the electrode materials prepared by changing the laser power in Examples 1, 5, and 6 are shown below. Figure 3 As shown, the low-power prepared Comparative Example 5 sample contains a pure zinc phase, indicating that the high-purity alloy was not successfully synthesized. The high-power prepared Comparative Example 6 sample contains a new CuZn5 alloy phase and does not exhibit high orientation characteristics. Therefore, adjusting the laser power is an important parameter for high-orientation twin-rich alloys.

[0064] Figure 4 Scanning electron microscope (SEM) images show that the surface of the laser-treated Cu5Zn8 alloy electrode is uniformly loaded with a large number of particles, forming a typical villous nanosphere structure. This microstructure can provide abundant nucleation sites and unobstructed ion transport channels. Figure 5 (a) and Figure 5 The electron backscatter diffraction (EBSD) image in (c) further confirms that the Cu5Zn8 alloy electrode exhibits a fine and uniform microstructure with a uniform grain size of approximately 200 μm; while Figure 5 (b) and Figure 5 As shown in Figure (d), the pure zinc electrode material prepared in Comparative Example 1 exhibits a wide grain size distribution and poor uniformity. The grain refinement characteristic of the Cu5Zn8 alloy electrode essentially stems from the alloying effect inducing grain boundary formation, which significantly increases the grain boundary density, laying a structural foundation for subsequent electrochemical performance optimization. Furthermore, Figure 6Transmission electron microscopy (STEM) analysis in (a) shows clear lattice fringes with a spacing of 0.208 nm in the electrode material, corresponding to the (330) crystal plane of the Cu5Zn8 alloy; simultaneously, the STEM image clearly reveals a highly oriented twinned structure with the (330) orientation in the Cu5Zn8 alloy. Combined with the above EBSD characterization results, the high abundance of nanoscale twins in the Cu5Zn8 alloy electrode is fully confirmed. Furthermore, Figure 6 In (b), elemental mappings and energy-dispersive X-ray spectroscopy (EDX) analysis confirmed that zinc and copper elements were uniformly distributed in the Cu5Zn8 alloy electrode, effectively avoiding performance degradation caused by elemental segregation. Figure 7 The pure copper electrode material prepared in Comparative Example 2 has multiple phases (111) and (200), and does not have high orientation and rich twin characteristics. This shows that laser etching of copper powder or zinc powder alone cannot obtain nanotwins, let alone high orientation. Only by forming Cu5Zn8 alloy can high abundance of nanotwins be obtained at the same time, thus having rich grain boundaries and high orientation. This shows the importance of alloying for the control of high orientation and rich twin structure. Figure 8 The low-power synthesis of Comparative Example 5 showed that the sample contained pure zinc (002) phase, further indicating that the high-purity alloy was not successfully synthesized. Figure 9 The high-power synthesis of Comparative Example 6 showed that the sample contained a new CuZn5 alloy phase, and further indicated the absence of high orientation and twin-boundary rich features. Therefore, the laser power synthesis parameters are crucial for the preparation of highly oriented, twin-boundary rich Cu5Zn8 alloys.

[0065] Example 3: Investigation of Zinc Deposition

[0066] (1) such as Figure 10 As shown, the mechanical properties of the Cu5Zn8 alloy electrode prepared in Example 1 were quantitatively characterized using atomic force microscopy (AFM). The results showed that its Young's modulus was 10.1 GPa, indicating that the electrode possesses excellent mechanical flexibility. This enhanced mechanical compliance can effectively adapt to the significant volume changes of the electrode during electrochemical cycling, alleviating interfacial stress concentration. Furthermore, the optimized stress distribution characteristics not only inhibit the initiation and propagation of electrode cracks but also maintain the long-term structural stability of the electrode, providing a key guarantee for improving battery cycle performance.

[0067] (2) Interfacial wettability tests were conducted using a contact angle tester for different electrode materials. For example... Figure 11 As shown, in a 2 M ZnSO4 electrolyte, the contact angle of the Cu5Zn8 alloy electrode was 18.66°, significantly smaller than the 36.99° of the pure zinc electrode prepared in Comparative Example 1, confirming a substantial improvement in the compatibility between the Cu5Zn8 alloy electrode and the electrolyte. Excellent wettability can significantly promote the contact of Zn at the electrode-electrolyte interface.2+ Uniform diffusion, while reducing Zn 2+ To Zn 0 The energy barrier of the transformation provides thermodynamic and kinetic advantages for efficient zinc ion deposition / stripping.

[0068] (3) Study on the hydrogen evolution corrosion resistance of the prepared electrode materials using the Shanghai Chenhua electrochemical workstation (Chenhua CHI660E). The test conditions were as follows: in a three-electrode system, the electrodes were connected to the workstation circuit, the green clamp was connected to the electrode materials prepared in Example 1 and Comparative Example 1 respectively, the red clamp was connected to the Pt sheet and the white clamp was connected to the saturated silver chloride electrode. The Tafel test was conducted in a 2 mol / L zinc sulfate solution, the test voltage range was -0.9 to -1.1 V, and the scan rate was 5 mV·s. -1 Linear voltammetry (LSV) was performed in a 1 mol / L sodium sulfate solution, with a test voltage range of -1.0 to -1.8 V and a scan rate of 5 mV·s. -1 . Figure 12 According to Tafel testing results, the corrosion potential of the Cu5Zn8 alloy electrode prepared in Example 1 is -0.981 V, which is significantly higher than that of the pure zinc electrode prepared in Comparative Example 1, and its corrosion current density is as low as 3.333 mA·cm. -2 The above results indicate that the Cu5Zn8 alloy electrode can effectively suppress the hydrogen evolution reaction (HER) and significantly improve corrosion resistance.

[0069] Using the three-electrode system described above, with an electrolyte of 1 M Na₂SO₄, linear voltammetry (LSV) was performed. Figure 13 The display shows that at 10 mA·cm -2 At current density, the HER overpotential of the Cu5Zn8 alloy electrode is significantly lower than that of the pure zinc electrode in Comparative Example 1.

[0070] (4) To quantitatively verify the HER inhibition effect, in-situ differential electrochemical mass spectrometry (DEMS) was used at 1 mA·cm⁻¹. -2 Symmetrical cell cycling tests were conducted at current density using 1825-150 glass fiber as the separator and 2 mol / L zinc sulfate aqueous solution as the electrolyte. Electrodes were prepared using Cu5Zn8 alloy (Example 1), pure zinc (Comparative Example 1), and pure copper (Comparative Example 2) (using the same positive and negative electrode materials), respectively, and symmetrical cells were assembled. In-situ differential mass spectrometry (CIS-DEMS, serial number: SH241022) was used to quantitatively verify the HER suppression effect by real-time monitoring of H2 gas release during zinc deposition / stripping. The Cu5Zn8 alloy electrode system showed no significant H2 gas product release during the test, while the H2 signal of the pure zinc anode rapidly increased, indicating a severe hydrogen evolution side reaction (H2). Figure 14The above results fully demonstrate that the Cu5Zn8 alloy electrode possesses excellent HER suppression capability.

[0071] (5) The dynamic process of zinc deposition on the electrodes prepared in Example 1 and Comparative Examples 1-2 was observed in real time using an in-situ optical microscope in a 2M ZnSO4 electrolyte. Figure 15 As shown, in the Cu5Zn8 alloy electrode prepared in Example 1, zinc was deposited in a uniform and dense morphology throughout the entire electrodeposition process, without dendrite formation. In stark contrast, the pure zinc electrode prepared in Comparative Example 1 showed random nucleation of large zinc particles on its surface during the initial deposition stage, followed by uneven growth, eventually forming obvious zinc dendrites; the pure copper electrode prepared in Comparative Example 2 showed uniform nucleation on its surface during the initial deposition stage, but with further uneven deposition, obvious zinc dendrites were eventually formed.

[0072] (6) Figure 16 In (a) and (c) of 16, two-dimensional grazing incident X-ray diffraction (2D-GIXRD) was used to conduct an in-depth analysis of the zinc deposition orientation on the electrodes prepared in Example 1 and Comparative Example 1: The 2D-GIXRD pattern of the pure zinc electrode in Comparative Example 1 showed diffuse Debye-Scherler rings, indicating that it has a polycrystalline orientation and the characteristic diffraction rings of Zn4SO4(OH)6·4H2O corrosion byproducts were present; while in the Cu5Zn8 alloy electrode of Example 1, the Zn deposition was mainly along the (101) crystal plane of Zn. The diffraction intensity was significantly enhanced, indicating that since the lattice mismatch between the (330) plane of Cu5Zn8 alloy and the (101) plane of Zn is low, at 1.7%, it can induce zinc to preferentially deposit along its (101) crystal plane. This shows that the high orientation of Cu5Zn8 alloy and the (330) plane are conducive to Zn deposition, thereby reducing dendrite growth. Figure 16 (b) and Figure 16 The pole figure analysis results in (d) show that after long-term cycling, the intensity distribution of the zinc deposition layer on the surface of the Cu5Zn8 alloy electrode at the (101) pole of Zn becomes increasingly concentrated, while the pole distribution of the pure zinc electrode is diffuse. The above multi-scale structural characterization results confirm that the Cu5Zn8 alloy electrode can optimize the zinc deposition morphology by precisely controlling the crystal orientation, thereby suppressing zinc dendrite growth from the root and providing core technical support for the electrode design of stable zinc-based energy storage systems.

[0073] Experimental Example 1: Performance Testing of Symmetrical Cells

[0074] To evaluate the cycling stability of the Cu5Zn8 alloy electrode, a symmetrical cell was assembled using 1825-150 glass fiber as the separator and 2 mol / L zinc sulfate aqueous solution as the electrolyte. Electrodes were prepared from the Cu5Zn8 alloy of Example 1, pure zinc of Comparative Example 1, and pure copper of Comparative Example 2 (the positive and negative electrode materials were the same). Long-cycle performance tests were conducted on the symmetrical cell using a Blue Battery Testing System (CT3002A). The AC impedance of the symmetrical cell was tested using a Shanghai Chenhua electrochemical workstation (Chenhua CHI660E). The test conditions were as follows: the assembled symmetrical cell was clamped by electrode clips, the electrodes were connected to the workstation circuitry, the green clip was connected to the working electrode, and the red and white clips were connected to the counter electrode. The electrochemical workstation and CHI660E software were opened, the impedance test program was selected, and the frequency range was set to 0.01~100000 Hz with an amplitude of 0.005 V. Figure 17 To assess the long-cycle performance of symmetrical cells with different electrode materials at a current density of 1 mA·cm⁻¹ -2 / 1 mAh·cm -2 Under the test conditions, the Cu5Zn8 symmetric cell of Example 1 exhibited a voltage hysteresis as low as 40 mV and a cycle life of up to 2550 hours; while the pure copper symmetric cell of Comparative Example 2 exhibited a high overpotential (100 mV) and a short cycle life of only 150 hours; the pure zinc symmetric cell of Comparative Example 1 showed problems such as an overpotential rising to 100 mV and voltage oscillation instability after 170 hours of cycling. Figure 16 This indicates that, compared to pure zinc electrodes, pure copper electrodes have a larger overpotential and poorer electrochemical properties when used in batteries. Furthermore, due to the significant material differences between copper and zinc, the lattice mismatch between copper and zinc electrodes is greater, making pure copper electrodes less suitable for use than pure zinc electrodes.

[0075] Figure 18 The activation energy is the reaction activation energy of Cu5Zn8 in Example 1 and pure zinc electrode materials in Comparative Example 1. The zinc desolvation process is a key step determining the charge transfer rate of zinc deposition. Based on the Arrhenius equation, the activation energy (E0) was calculated using temperature-dependent electrochemical impedance spectroscopy (EIS) data. a This is used to characterize the electrochemical reaction kinetics of the electrode surface. For example... Figure 18 As shown, the activation energy of the desolvation reaction of the Cu5Zn8 alloy electrode prepared in Example 1 (31.676 kJ / mol) is significantly lower than that of the pure zinc electrode prepared in Comparative Example 1 (32.576 kJ / mol), indicating that the alloy electrode can effectively reduce the energy barrier of the zinc dissolution reaction, accelerate the interfacial charge transfer, and optimize the reaction kinetics.

[0076] Experimental Example 2: Half-cell performance test

[0077] A half-cell was assembled using 1825-150 glass fiber as the separator, 2 mol / L zinc sulfate aqueous solution as the electrolyte, and electrode materials prepared in Example 1 and Comparative Example 1 as the negative electrode, with a 13 mm diameter Cu sheet as the positive electrode. The nucleation overpotential of the Zn||Cu half-cell was tested using a Shanghai Chenhua electrochemical workstation (Chenhua CHI660E). The test conditions were as follows: the assembled half-cell was clamped by electrode clips, the electrodes were connected to the workstation circuitry, the green clip was connected to the working electrode, and the red and white clips were connected to the counter electrode. The electrochemical workstation and CHI660E software were opened, and the cyclic voltammetry (CV) test program was selected. The voltage test range was -0.2 to 0.3 V, and the scan rate was 1 mV·s. -1 .

[0078] Figure 19 This study investigated the zinc deposition / growth behavior of different prepared electrode materials. The nucleation overpotential of zinc on the Cu5Zn8 alloy electrode surface prepared in Example 1 was significantly reduced (Δt) compared to the pure zinc prepared in Comparative Example 1. E = 7.62 mV), this phenomenon is mainly attributed to the high zinc affinity of Cu5Zn8 alloy, which can effectively control zinc nucleation sites and nucleation modes.

[0079] Test Example 3: Full Battery Performance Test

[0080] (1) MnO2, carbon powder, and binder (polyvinylidene fluoride) were mixed in a mass ratio of 7:2:1. N-methylpyrrolidone was added, and the mixture was ground evenly to obtain a viscous electrode slurry. The viscous electrode slurry was then evenly coated onto a titanium foil substrate (0.02 mm), and the loading was controlled at 1 mg·cm⁻¹. -2 The manganese dioxide electrode sheets were dried in a vacuum drying oven and cut into circular pieces with a radius of 6 mm using a cutting machine. These manganese dioxide electrode sheets were used as the positive electrode, and the Cu5Zn8 alloy prepared in Example 1 and the pure zinc electrode material prepared in Comparative Example 1 were used as the negative electrodes, respectively. The separator was 1825-150 glass fiber, and the electrolyte was a 2 mol / L ZnSO4 + 0.1 mol / L MnSO4 solution. Cu5Zn8@Cu||MnO2 and Zn||MnO2 all-electric button batteries were assembled. The long-cycle rate performance of the all-electric button batteries was tested using a Blue Battery Testing System (CT3002A) and an electrochemical workstation (Chenhua CHI660E). The long-cycle test conditions were: current density test (2 A·g) -1 The constant current discharge voltage range is less than or equal to 0.8V; the constant current charging voltage range is greater than or equal to 1.8V; and the MnO2 loading is 1.32 mg·cm³. -2 Record the specific capacity and coulomb efficiency for each revolution.

[0081] The results show that ( Figure 20), at 1.5 A·g -1 At high current density, the full cell containing Cu5Zn8 alloy still retains a capacity of up to 90.5% after 4000 cycles; while the full cell using pure zinc anode in Comparative Example 1 fails rapidly after only 230 cycles.

[0082] (2) To verify the practical application feasibility of this electrode material, a Cu5Zn8||MnO2 soft-pack battery was prepared. This soft-pack battery can stably power commercial LED lighting systems. Figure 21 This confirms its potential for practical industrial application.

[0083] In summary, the 3D self-supporting zinc-copper alloy with a highly oriented, twinned structure prepared by this invention can be used as a zinc anode in aqueous zinc-ion batteries. It can simultaneously solve the two major technical problems of dendrite growth and hydrogen evolution corrosion commonly faced by traditional zinc metal anodes in aqueous electrolytes, and significantly improve the cycle stability and service safety of aqueous zinc-ion batteries.

[0084] 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 laser-induced 3D self-supporting, highly oriented, twin-boundary-rich zinc-copper alloy thin-film electrode material, characterized in that, The zinc-copper alloy thin film electrode material is obtained by laser pulse treatment of a mixture of copper powder and zinc powder; the zinc-copper alloy thin film electrode material is Cu5Zn8, which has a villous nanosphere structure and a highly oriented twin boundary rich structure; the Cu5Zn8 is oriented with the 330 crystal plane.

2. The zinc-copper alloy thin-film electrode material according to claim 1, characterized in that, The zinc-copper alloy thin-film electrode material is prepared by the following method: Zinc powder and copper powder are mixed and pressed into tablets to obtain zinc-copper mixture tablets, which are then etched using pulsed lasers. An alloy thin film is formed on the surface of the zinc-copper mixture tablets, which is the laser-induced 3D self-supporting highly oriented zinc-copper alloy thin film electrode material with rich twin boundaries.

3. The zinc-copper alloy thin-film electrode material according to claim 2, characterized in that, The mass ratio of zinc powder to copper powder is 9:

1.

4. The zinc-copper alloy thin-film electrode material according to claim 2, characterized in that, The parameters of the pulsed laser are as follows: laser wavelength of 1064 nm, laser power of 10~15W, etching speed of 200~2000 mm / s, line spacing of 0.001~0.05 mm, and focusing.

5. The application of the zinc-copper alloy thin-film electrode material according to any one of claims 1 to 4 in improving the performance of aqueous zinc-ion batteries.

6. The application according to claim 5, characterized in that, The zinc-copper alloy thin-film electrode material improves the performance of aqueous zinc-ion batteries by controlling the nucleation sites and growth direction of zinc deposition to suppress zinc dendrite formation.

7. The application according to claim 5, characterized in that, The zinc-copper alloy thin-film electrode material improves the performance of aqueous zinc-ion batteries by reconstructing the electronic structure of the electrode surface and reducing the corrosive activity of zinc.

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