Method and device for constructing a dual-structure to synergistically inhibit lithium electrode dendrites

Abstract

This invention provides a method and apparatus for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites. The method specifically includes the following steps: Step 1, cleaning and drying a copper foil current collector to obtain a pretreated copper foil current collector, which is then mounted on a three-dimensional moving work platform and adjusted to obtain a sample-loaded worktable. The pretreated copper foil current collector on the sample-loaded worktable is designated as the copper foil current collector sample. Step 2, a laser generator generates a pulsed laser. After emission, the pulsed laser sequentially passes through a first reflecting mirror group, a λ / 4 waveplate, a beam expander, an aperture stop, and a second reflecting mirror group, reaching a two-dimensional scanning galvanometer. The two-dimensional scanning galvanometer is equipped with a telecentric field mirror capable of focusing. The two-dimensional scanning galvanometer also controls the scanning trajectory of the laser focus on the upper surface of the copper foil current collector sample, obtaining a processed copper foil current collector sample. This method achieves an organic combination of physical confinement and chemical induction through a one-step single-pulse laser processing method, suppressing the growth of lithium electrode dendrites.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery technology and relates to suppressing lithium electrode dendrites, specifically to a method and apparatus for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites. Background Technology

[0002] As the physical substrate and current carrier for lithium metal deposition, the physical morphology and chemical properties of the current collector have a decisive influence on the nucleation and growth behavior of lithium. Traditional two-dimensional planar copper foil current collectors have two inherent defects: first, their low specific surface area leads to high local current density, which easily induces preferential deposition of lithium at its tips; second, their intrinsic lithium-phobicity results in a high lithium nucleation barrier and a random and uneven distribution of nucleation sites. These two factors work together to easily trigger a vicious cycle of lithium deposition: "protrusion-tip concentration-dendritic growth".

[0003] To address these challenges, existing technologies primarily modify current collectors from two independent dimensions: physical structure modification, including mechanical imprinting, chemical etching, and template methods. However, these methods are often complex, suffer from poor structural consistency, and struggle to precisely control the size and distribution of the structure. Chemical surface modification, including electrodeposition, chemical vapor deposition, atomic layer deposition, or coating, introduces inactive substances that reduce the battery's energy density, and the coating's adhesion to the substrate is weak, making it prone to detachment or failure during long-term cycling. More critically, most existing technologies treat "physical structure construction" and "surface chemical modification" as two separate process steps, making it difficult to achieve simultaneous, precise, and integrated control of both. This step-by-step process not only increases complexity and cost but may also lead to problems such as weak interfacial bonding and uneven distribution of modified layers, failing to create a synergistic effect from both physical confinement and chemical induction dimensions, and thus failing to fundamentally guide uniform lithium deposition.

[0004] Laser processing technology, especially ultrafast laser processing, offers new possibilities for the efficient and high-quality modification of current collectors due to its high precision, non-contact nature, and strong controllability. However, traditional research and applications have largely focused on using the ablation capability of lasers for simple microstructure processing or utilizing their thermal effects for surface alloying. How to simultaneously achieve "high-precision construction of three-dimensional geometric microstructures" and "in-situ generation and crystal plane optimization of the surface lithiophilic chemical layer" in a single laser processing step—that is, to achieve a one-step synergistic construction of a "dual-effect structure"—remains a gap in current technology.

[0005] Therefore, there is an urgent need to develop a new method and dedicated device that can achieve synergistic modification of geometric structure and chemical properties on the surface of copper foil current collectors in one step, simultaneously and precisely, so as to fundamentally solve the problems of uneven lithium deposition and dendrite growth caused by poor current collector interface characteristics. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method and apparatus for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, thereby solving the technical problem that in the existing copper foil current collector processing method, the construction of the physical structure and surface chemical modification are difficult to be carried out in one step when suppressing lithium electrode dendrite growth.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0008] A method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, the method specifically includes the following steps.

[0009] Step 1: Sample pretreatment.

[0010] The copper foil current collector is cleaned and dried to obtain a pretreated copper foil current collector. The pretreated copper foil current collector is then mounted flat on a three-dimensional moving work platform. The upper surface of the pretreated copper foil current collector is adjusted to be parallel to the laser focal plane formed by the pulsed laser after being focused by the telecentric lens, and the laser focus formed by the pulsed laser after being focused by the telecentric lens is positioned on the upper surface of the pretreated copper foil current collector. After the adjustment is completed, a sample loading worktable is obtained. The pretreated copper foil current collector on the sample loading worktable is recorded as the copper foil current collector sample.

[0011] Step 2: Laser construction of a dual-effect synergistic structure.

[0012] A laser generator is used to generate pulsed laser with set parameters. After the pulsed laser is emitted, it passes through the first reflecting mirror group, λ / 4 waveplate, beam expander, aperture stop and the second reflecting mirror group in sequence, and then reaches the two-dimensional scanning galvanometer.

[0013] The bottom of the light output port of the scanning head of the two-dimensional scanning galvanometer is also equipped with the aforementioned telecentric field mirror. The telecentric field mirror focuses the pulsed laser and forms a laser focus. The two-dimensional scanning galvanometer also controls the scanning trajectory of the laser focus on the upper surface of the copper foil current collector sample obtained in step one, so that the upper surface of the copper foil current collector sample forms a three-dimensional microstructure array and a lithium-loving oxide layer through laser induction, and finally obtains the processed copper foil current collector sample.

[0014] The present invention also has the following technical features.

[0015] Specifically, in step two, the microstructures in the three-dimensional microstructure array include groove-type microstructures and blind-hole-type microstructures.

[0016] Specifically, in step two, the parameters of the pulsed laser in the set parameters include: the average power of the pulsed laser is 1 to 3 W, and the repetition frequency of the pulsed laser is 50 to 200 kHz.

[0017] Specifically, in step two, when the microstructure in the three-dimensional microstructure array is a groove-shaped microstructure, the scanning process requirements for the two-dimensional scanning galvanometer to scan the surface of the copper foil current collector sample include: the scanning method is line scanning, and the scanning speed is set to 2-10 mm / s.

[0018] In step two, when the microstructure in the three-dimensional microstructure array is a blind hole type microstructure, the scanning process requirements for the two-dimensional scanning galvanometer to scan the surface of the copper foil current collector sample specifically include: the scanning method is single-point impact scanning, and the scanning time is 1 to 5 ms.

[0019] The present invention also protects a device for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites. The device includes a laser generator, a λ / 4 waveplate is arranged in the output optical path of the laser generator, a beam expander is arranged in the output optical path of the λ / 4 waveplate, an aperture stop is arranged in the output optical path of the beam expander, a two-dimensional scanning galvanometer is arranged in the output optical path of the aperture stop, a telecentric field mirror is installed at the bottom of the output port of the scanning head of the two-dimensional scanning galvanometer, and a three-dimensional moving working platform is arranged in the output optical path of the telecentric field mirror.

[0020] Specifically, the device also includes a first reflector group, which includes a first reflector disposed in the output light path of the laser generator. The output light path of the first reflector is also provided with the second reflector, and the output light path of the second reflector is also provided with the λ / 4 waveplate.

[0021] Specifically, both the first and second reflectors are offset at 45° to reflect the light beam perpendicularly for propagation.

[0022] Specifically, the device also includes a second mirror group, which includes a third mirror, and the third mirror is disposed in the outgoing light path of the aperture stop.

[0023] Specifically, the third reflecting mirror is offset at 45°, thereby perpendicularly reflecting the light beam for optical path propagation.

[0024] Compared with the prior art, the present invention has the following technical effects.

[0025] (I) The method in this invention abandons the traditional step-by-step process and completes the construction of three-dimensional microstructure and the in-situ generation of surface lithiophilic chemical layer in one step through single-pulse laser processing. The one-step method realizes the organic combination of physical confinement and chemical induction, fundamentally and synergistically guiding the uniform deposition of lithium and inhibiting the growth of lithium electrode dendrites.

[0026] (II) The method in this invention relies on the processing characteristics and device of pulsed laser to achieve synchronous and precise control of microstructure morphology and surface chemical state. The batch consistency and structural repeatability are far superior to chemical etching or physical imprinting methods.

[0027] (III) The method in this invention can construct a dual-effect structure, which can effectively reduce local current density, provide abundant lithium-affinity sites, and buffer volume changes. After processing, the copper foil current collector sample exhibits a lower lithium nucleation overpotential, a more uniform lithium deposition morphology, significantly improved coulombic efficiency, and a greatly extended cycle life, which fundamentally improves the safety and stability of the battery.

[0028] (IV) The entire process of the method in this invention is a dry operation, which does not require chemical reagents, templates or subsequent heat treatment. The process is simple, environmentally friendly and fast. It has the potential to be directly connected to existing battery electrode production lines, and provides a practical and feasible core technology solution for the large-scale manufacturing of high-performance lithium metal batteries.

[0029] (V) The device in this invention not only prepares a groove-shaped or blind-hole-shaped microstructure array in a controllable and precise manner by performing one-step pulsed laser treatment on the surface of the copper foil current collector sample, but also generates a lithiophilic oxide layer rich in appropriate amount of CuO / Cu2O in situ at the edge of the microstructure and improves the proportion of Cu(100) crystal plane, realizing the dual-effect structure construction of micro-geometric structure and chemical phase structure, effectively solving the problem of uneven lithium deposition and dendrite growth caused by the low specific surface area and poor lithiophilicity of traditional current collectors. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the device in Embodiment 3 of the present invention.

[0031] Figure 2(a) is a SEM image of LSG@3 obtained in Example 1 of the present invention.

[0032] Figure 2(b) is a SEM image of LSP@15 obtained in Embodiment 2 of the present invention.

[0033] Figure 3(a) is the EDS energy spectrum of LSG@3 obtained in Example 1 of the present invention.

[0034] Figure 3(b) shows the EDS energy spectrum of LSP@15 obtained in Example 2 of the present invention.

[0035] Figure 4(a) is the XRD pattern of LSG@3 obtained in Example 1 of the present invention.

[0036] Figure 4(b) is the XRD pattern of LSP@15 obtained in Example 2 of the present invention.

[0037] Figure 5The coulombic efficiency comparison curves are obtained by using the LSG@3 obtained in Example 1 of this invention and the optical foil obtained in the comparative example as working electrodes, and then assembling them into a half-cell. The coulombic efficiency test conditions are a capacity-current density of 1 mAh cm⁻¹. -2 .

[0038] Figure 6 The LSP@15 obtained in Example 2 of this invention and the optical foil obtained in the comparative example are used as working electrodes, and the coulombic efficiency comparison curves are obtained after further assembling them into a half cell. The coulombic efficiency test conditions are a capacity-current density of 1 mAh cm⁻¹. -2 .

[0039] Figure 7(a) is a SEM image of lithium deposition on the optical foil obtained in the comparative example after cycling.

[0040] Figure 7(b) is a SEM image of lithium deposition on LSG@3 obtained in Example 1 of the present invention after cycling.

[0041] Figure 7(c) is a SEM image of lithium deposition on LSP@15 obtained in Example 2 of the present invention after cycling.

[0042] The meanings of the labels in the figure are as follows: 1-Laser generator, 2-λ / 4 waveplate, 3-Beam expander, 4-Aperture stop, 5-Two-dimensional scanning galvanometer, 6-Telecentric field mirror, 7-Three-dimensional moving work platform, 8-First reflecting mirror, 9-Second reflecting mirror, 10-Third reflecting mirror.

[0043] The specific content of the present invention will be further described in detail below with reference to the embodiments. Detailed Implementation

[0044] It should be noted that, unless otherwise specified, all components, materials, testing methods and equipment in this invention are commonly used in the art in the prior art. For example, the copper foil current collector is a known copper foil current collector, the first reflector is a known reflector, and the testing methods and equipment for the EDS spectrum are all known testing methods and equipment.

[0045] The method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites according to the present invention employs the apparatus of the present invention for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites.

[0046] Following the above technical solution, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of the present invention fall within the protection scope of the present invention.

[0047] Example 1:

[0048] This embodiment provides a method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, which specifically includes the following steps.

[0049] Step 1: Sample pretreatment.

[0050] A circular copper foil current collector with a thickness of 9 micrometers and a diameter of 16 micrometers is cleaned and dried to obtain a pretreated copper foil current collector. The pretreated copper foil current collector is then mounted flat on a three-dimensional moving work platform 7. The upper surface of the pretreated copper foil current collector is adjusted to be parallel to the laser focal plane formed by the pulsed laser after being focused by the telecentric field lens 6, and the laser focus formed by the pulsed laser after being focused by the telecentric field lens 6 is positioned on the upper surface of the pretreated copper foil current collector. After the adjustment is completed, a sample loading worktable is obtained, and the pretreated copper foil current collector on the sample loading worktable is recorded as the copper foil current collector sample.

[0051] Step 2: Laser construction of a dual-effect synergistic structure.

[0052] A laser generator 1 generates a pulsed laser with an average power of 1.59W and a repetition frequency of 100kHz. After the pulsed laser is emitted, it passes sequentially through the first reflecting mirror group, the λ / 4 waveplate 2, the beam expander 3, the aperture stop 4, and the second reflecting mirror group, and then reaches the two-dimensional scanning galvanometer 5.

[0053] The bottom of the light output port of the scanning head of the two-dimensional scanning galvanometer 5 is also equipped with a telecentric field mirror 6. The telecentric field mirror 6 focuses the pulsed laser and forms a laser focus. The two-dimensional scanning galvanometer 5 also controls the scanning trajectory of the upper surface of the copper foil current collector sample obtained in step one. The scanning mode of the two-dimensional scanning galvanometer 5 is line scanning and the scanning speed is 7 mm / s. This allows the upper surface of the copper foil current collector sample to form a groove-shaped microstructure array and a lithium-loving oxide layer through pulsed laser induction, and finally obtains the processed copper foil current collector sample.

[0054] In this embodiment, the grooved microstructure array includes multiple grooved microstructures, that is, multiple grooves, which are arranged in parallel. The width of each groove is 3 micrometers. The processed copper foil current collector sample obtained in step two of this embodiment is denoted as LSG@3.

[0055] In this embodiment, the specific method for cleaning and drying the copper foil current collector is as follows: first, ultrasonically clean it in acetone and anhydrous ethanol for 10 minutes each to thoroughly remove surface grease, oxides, and organic contaminants, and then dry it with high-purity nitrogen gas for later use. The acetone used is acetone commonly known in the art, the anhydrous ethanol used is anhydrous ethanol commonly known in the art, and the high-purity nitrogen gas used is high-purity nitrogen gas commonly known in the art.

[0056] In this embodiment, the three-dimensional microstructure array serves to: increase the specific surface area of ​​the copper foil current collector sample, reduce the local current density at the interface, and provide a space for lithium metal deposition, thereby alleviating the volume expansion stress during cycling.

[0057] The LSG@3 obtained in step two of this embodiment was characterized by SEM morphology, and the results are shown in Figure 2(a). As can be seen from Figure 2(a), a groove-shaped microstructure array is formed on the surface of LSG@3. The grooves of each groove-shaped microstructure are clearly defined, and the inner wall has micro-nano roughness features, which significantly increases the specific surface area, provides a space for lithium deposition, and helps to reduce the local current density.

[0058] In the trench edges and sidewall regions of each groove-shaped microstructure, the pulsed laser-induced thermo-chemical effect generates a lithophile oxide layer rich in CuO / Cu2O in situ, and increases the proportion of Cu(100) crystal planes.

[0059] The LSG@3 obtained in step two of this embodiment was characterized by EDS energy dispersive spectroscopy, and the results are shown in Figure 3(a). As can be seen from Figure 3(a), pulsed laser processing of the copper foil current collector sample will increase the O element content on its surface; as the depth increases, the O element content increases, and the grid-like distribution becomes more obvious, which is consistent with the processing range and shape of the pulsed laser. This can be attributed to the oxide growth induced by the thermal effect during the pulsed laser processing.

[0060] XRD characterization was performed on the LSG@3 obtained in step two of this embodiment and the optical foil obtained in the comparative example. The results are shown in Figure 4(a). As can be seen from Figure 4(a), the characteristic diffraction peaks of both LSG@3 and the optical foil at positions of 43°, 50°, and 74°, respectively, coincide with the peak positions of the standard XRD pattern (PDF:#04-0836), corresponding to the three crystal planes of Cu(111), Cu(200), and Cu(220), respectively. Meanwhile, compared to the optical foil, the diffraction intensity of the three crystal planes of Cu(111), Cu(200), and Cu(220) is weakened in LSG@3. Furthermore, no obvious new phase appeared, indicating that the chemical composition of the unprocessed optical foil and the pulsed laser-processed LSG@3 is consistent and has not changed significantly.

[0061] EDS and XRD results confirmed the presence of lithophile oxides and crystal plane optimization.

[0062] The LSG@3 obtained in this embodiment and the optical foil obtained in the comparative example were used as working electrodes to assemble a CR2032 type lithium metal half-cell for testing. At 1 mA cm⁻¹ -2 At a current density of 1 mAh cm -2 Lithium deposition / stripping cycle.

[0063] like Figure 5 As shown, the coulombic efficiency of LSG@3 is significantly higher than that of the photofoil, and it remains stable during long-term cycling, demonstrating the synergistic advantage of the dual-effect structure in promoting reversible lithium deposition.

[0064] The deposition morphology after LSG@3 cycling was measured by SEM, and the results are shown in Figure 7(b). As can be seen from Figure 7(b), lithium metal is preferentially and uniformly deposited inside the trench, forming a dense and flat deposition layer; while a large number of dendrites and "dead lithium" appear on the surface of the foil, as shown in Figure 7(a).

[0065] The method used in this embodiment to assemble the working electrode into a CR2032 lithium metal half-cell is a commonly known method in the art. The CR2032 lithium metal half-cell is a commonly known CR2032 lithium metal half-cell in the art. 1mAh cm -2 The testing method for lithium deposition / stripping cycles is a commonly used method known in the art.

[0066] Example 2: This embodiment provides a method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites. The method in this embodiment is basically the same as the method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites in Embodiment 1, with the only difference being: in step two, the pulsed laser is a pulsed laser with an average power of 2.39W and a repetition frequency of 100kHz; in step two, the scanning mode of the two-dimensional scanning galvanometer 5 is a single-point impact scanning and the scanning time is 2ms; in step two, the microstructure in the three-dimensional microstructure array is a blind hole type microstructure.

[0067] The blind hole depth in the processed copper foil current collector sample with blind hole microstructure array obtained in step two of this embodiment is 15 micrometers, and the processed copper foil current collector sample obtained in step two of this embodiment is denoted as LSP@15.

[0068] The LSP@15 obtained in step two of this embodiment was characterized by SEM, and the results are shown in Figure 2(b). As can be seen from Figure 2(b), a blind hole microstructure array was formed on the surface of the processed copper foil current collector sample. The walls of the blind holes exhibit a micro-nano rough structure, which significantly improves the surface area and porosity, providing abundant three-dimensional space for lithium deposition.

[0069] The LSP@15 obtained in step two of this embodiment was characterized by EDS energy dispersive spectroscopy, and the results are shown in Figure 3(b). As can be seen from Figure 3(b), pulsed laser processing of the copper foil current collector sample will cause an increase in the O element content on its surface; as the depth increases, the O element content increases, and the circular distribution becomes more obvious, which is consistent with the laser processing range and shape.

[0070] The LSP@15 obtained in step two of this embodiment was characterized by XRD, and the results are shown in Figure 4(b). As can be seen from Figure 4(b), no new phase was introduced into LSP@15 due to pulsed laser processing, which is the same as the XRD test results of LSG@3 in Example 1. Compared with the unprocessed foil, the diffraction intensity of the Cu(111) and Cu(200) crystal planes of LSP@15 is weaker. Thermal stress and crystal defects generated during pulsed laser processing can disrupt the periodic structure of the crystal, leading to a decrease in the diffraction intensity of some crystal planes. On the surface of LSP@15 with the same blind-hole microstructure array, the diffraction intensity of the Cu(111) and Cu(200) crystal planes further weakens with increasing average power of the pulsed laser.

[0071] The LSP@15 obtained in this embodiment was used as the working electrode, and the coulombic efficiency was tested using the same test conditions and methods as the comparative example. The results are as follows: Figure 6 As shown. By Figure 6 The results show that LSP@15 exhibits high and stable coulombic efficiency, which is better than that of optical foil, proving that blind hole microstructures can also guide uniform lithium deposition through dual-effect synergy.

[0072] The deposition morphology after LSP@15 cycling was measured by SEM, and the results are shown in Figure 7(c). As can be seen from Figure 7(c), lithium metal fully fills the micropores and forms a flat interface at the pore opening, achieving uniform "bottom-up" deposition and effectively suppressing the initiation of lithium electrode dendrites.

[0073] In Examples 1 and 2 of this invention, a three-dimensional microstructure array with groove-shaped or blind-hole-shaped microstructures is constructed on the surface of a copper foil current collector sample to increase the specific surface area, optimize the current distribution, provide lithium deposition space, and alleviate volume expansion. By utilizing the controllable thermo-chemical effect during pulsed laser processing in the edge region of the groove-shaped or blind-hole-shaped microstructures, a lithophile oxide layer rich in CuO / Cu2O is generated in situ, and the proportion of Cu(100) crystal planes is increased to reduce the lithium nucleation overpotential and induce uniform deposition. Through the synergistic effect of geometric morphology and chemical phase change, lithium metal is guided to achieve uniform and dense deposition on the surface of the copper foil current collector sample, thereby inhibiting the growth of lithium electrode dendrites and improving the electrochemical stability of the electrode.

[0074] Comparative example: This comparative example provides a planar optical foil current collector that has not undergone pulsed laser processing. The planar optical foil current collector in this comparative example is referred to as optical foil. The planar optical foil current collector is obtained by cleaning and drying a circular copper foil current collector with a thickness of 9 micrometers and a diameter of 16 micrometers.

[0075] The circular copper foil current collector in this comparative example is the same as the circular copper foil current collector in Example 1, and both use circular copper foil current collectors commonly known in the art; the cleaning and drying methods in this comparative example are also the same as those in Example 1.

[0076] As a baseline control, the foil was cycled and tested under the same conditions as LSG@3 in Example 1, and the results are as follows: Figure 5 and Figure 6 As shown, by Figure 5 and Figure 6 It is known that the coulombic efficiency of the foil decays rapidly and its cycle life is short.

[0077] The recycled foil was subjected to SEM testing, and the results are shown in Figure 7(a). As can be seen from Figure 7(a), the deposited lithium exhibits typical moss-like and dendritic morphology, which fully exposes the inherent defects of traditional planar foil current collectors.

[0078] Example 3: This embodiment provides a device for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, such as... Figure 1 As shown, the device includes a laser generator 1, a λ / 4 waveplate 2 is arranged in the output light path of the laser generator 1, a beam expander 3 is also arranged in the output light path of the λ / 4 waveplate 2, an aperture stop 4 is also arranged in the output light path of the beam expander 3, a two-dimensional scanning galvanometer 5 is also arranged in the output light path of the aperture stop 4, a telecentric field mirror 6 is also installed at the bottom of the light output port of the scanning head of the two-dimensional scanning galvanometer 5, and a three-dimensional moving work platform 7 is also arranged in the output light path of the telecentric field mirror 6.

[0079] As a preferred embodiment, the device further includes a first reflector group, which includes a first reflector 8. The first reflector 8 is disposed in the output light path of the laser generator 1. A second reflector 9 is also disposed in the output light path of the first reflector 8, and a λ / 4 waveplate 2 is also disposed in the output light path of the second reflector 9.

[0080] As a preferred embodiment, both the first reflector 8 and the second reflector 9 are offset at 45°, thereby perpendicularly reflecting the light beam for optical path propagation.

[0081] As a preferred embodiment, the device further includes a second reflector group, which includes a third reflector 10, which is disposed in the outgoing light path of the aperture stop 4.

[0082] As a preferred embodiment, the third reflector 10 is offset at 45°, thereby perpendicularly reflecting the light beam for optical path propagation.

[0083] In this embodiment, the laser generator 1 is used to generate pulsed lasers, and more preferably, a femtosecond laser source with a pulse width of less than 1 ps is used to meet the requirements of "cold processing" and strong nonlinear interaction; the laser generator 1 adopts a laser generator commonly known in the art.

[0084] In this embodiment, the λ / 4 waveplate 2 is used to convert linearly polarized light into circularly polarized light to eliminate the non-uniformity of peeling that may be caused by the anisotropic absorption of the material during the scanning process of the two-dimensional scanning galvanometer 5; the λ / 4 waveplate 2 is a commonly used λ / 4 waveplate known in the art.

[0085] In this embodiment, the beam expander 3 is used for beam expansion and shaping; the beam expander 3 adopts a beam expander commonly known in the art.

[0086] In this embodiment, the aperture stop 4 is used as a homogenizing element to optimize energy distribution; the aperture stop 4 adopts the aperture stop commonly known in the art.

[0087] In this embodiment, the telecentric field lens 6 is used to focus and further form a laser focus or focused spot; the telecentric field lens 6 adopts a commonly used telecentric field lens known in the art.

[0088] In this embodiment, the laser focal plane is an imaginary plane passing through the laser focus and perpendicular to the main axis of the laser beam. The laser focal plane adopts a commonly used laser focal plane known in the art.

[0089] In this embodiment, the two-dimensional scanning galvanometer 5 is used to control the laser focal point formed after the telecentric field mirror 6 is focused to scan within the processing plane; the two-dimensional scanning galvanometer 5 adopts a commonly known two-dimensional scanning galvanometer in the art, and the installation method of the telecentric field mirror 6 at the bottom of the scanning head output port of the two-dimensional scanning galvanometer 5 adopts a commonly known installation method in the art.

[0090] In this embodiment, the three-dimensional moving work platform 7 is used to support and position the copper foil current collector sample, so that the copper foil current collector sample is vacuum adsorbed and fixed on the horizontal plane; the vertical lead screw of the three-dimensional moving work platform 7 is arranged perpendicular to the horizontal plane, and the three-dimensional moving work platform 7 adopts a three-dimensional moving work platform commonly known in the art.

[0091] In this embodiment, the functions of the first reflector 8, the second reflector 9, and the third reflector 10 are to change the propagation of the light path, to bend the light path and guide the light path, and to transmit the pulsed laser beam to the two-dimensional scanning galvanometer 5 under the condition of reducing the lateral distance between the laser generator 1 and the two-dimensional scanning galvanometer 5, thereby effectively saving lateral space.

[0092] The device in this embodiment can convert pulsed laser into a focused spot with uniform energy distribution. The focused spot is a Gaussian spot commonly known in the art. Then, combined with the high-speed vector scanning of the two-dimensional scanning galvanometer 5, it ensures that the pulsed laser energy can be accurately and controllably deposited locally on the surface of the copper foil current collector sample, providing the necessary optical field conditions for the simultaneous realization of three-dimensional microstructure ablation and controllable thermo-chemical surface modification. While completing the geometric morphology construction of the three-dimensional microstructure, the controllable thermal accumulation unique to pulsed laser is used to induce the in-situ generation of a lithophile oxide layer in the edge region of the three-dimensional microstructure and optimize the surface crystal plane, realizing a one-step and synergistic modification of physical structure and chemical properties.

Claims

1. A method for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, characterized in that, The method specifically includes the following steps: Step 1, Sample Pretreatment: The copper foil current collector is cleaned and dried to obtain a pretreated copper foil current collector. The pretreated copper foil current collector is flatly installed on the three-dimensional moving work platform (7). The upper surface of the pretreated copper foil current collector is adjusted to be parallel to the laser focal plane formed after the pulse laser is focused by the telecentric field lens (6). The laser focus formed after the pulse laser is focused by the telecentric field lens (6) is positioned on the upper surface of the pretreated copper foil current collector. After the adjustment is completed, the sample loading worktable is obtained. The pretreated copper foil current collector on the sample loading worktable is recorded as the copper foil current collector sample. Step 2: Laser construction of a dual-effect synergistic structure: A laser generator (1) is used to generate a pulsed laser with set parameters. After the pulsed laser is emitted, it passes through the first reflecting mirror group, the λ / 4 wave plate (2), the beam expander (3), the aperture stop (4), and the second reflecting mirror group in sequence, and then reaches the two-dimensional scanning galvanometer (5). The bottom of the light output port of the scanning head of the two-dimensional scanning galvanometer (5) is also equipped with the aforementioned telecentric field mirror (6). The telecentric field mirror (6) focuses the pulsed laser and forms a laser focus. The two-dimensional scanning galvanometer (5) also controls the scanning trajectory of the upper surface of the copper foil current collector sample obtained in step one, so that the upper surface of the copper foil current collector sample forms a three-dimensional microstructure array and a lithium-loving oxide layer through laser induction, and finally obtains the processed copper foil current collector sample.

2. The method for constructing a dual-effect structure to synergistically inhibit lithium electrode dendrite according to claim 1, wherein, In step two, the microstructures in the three-dimensional microstructure array include groove-type microstructures and blind-hole-type microstructures.

3. The method for constructing a dual-effect structure to synergistically inhibit lithium electrode dendrite according to claim 2, wherein, In step two, the parameters of the pulsed laser in the set parameters specifically include: the average power of the pulsed laser is 1 to 3 W, and the repetition frequency of the pulsed laser is 50 to 200 kHz.

4. The method for constructing a dual-effect structure to synergistically inhibit lithium electrode dendrite according to claim 2, wherein, In step two, when the microstructure in the three-dimensional microstructure array is a groove-shaped microstructure, the scanning process requirements of the two-dimensional scanning galvanometer (5) when scanning the surface of the copper foil current collector sample specifically include: the scanning method is line scanning, and the scanning speed is set to 2-10 mm / s; In step two, when the microstructure in the three-dimensional microstructure array is a blind hole type microstructure, the scanning process requirements of the two-dimensional scanning galvanometer (5) when scanning the surface of the copper foil current collector sample specifically include: the scanning method is single-point impact scanning, and the scanning time is 1 to 5 ms.

5. A device for constructing a dual-effect structure to synergistically suppress lithium electrode dendrites, the device comprising a laser generator (1), characterized in that, The laser generator (1) is provided with a λ / 4 waveplate (2) on its output optical path. A beam expander (3) is also provided on the output optical path of the λ / 4 waveplate (2). An aperture stop (4) is also provided on the output optical path of the beam expander (3). A two-dimensional scanning galvanometer (5) is also provided on the output optical path of the aperture stop (4). A telecentric field mirror (6) is also installed at the bottom of the light output port of the scanning head of the two-dimensional scanning galvanometer (5). A three-dimensional moving work platform (7) is also provided on the output optical path of the telecentric field mirror (6).

6. The apparatus for constructing a dual-effect structure synergistically inhibiting lithium electrode dendrite according to claim 5, wherein, The device also includes a first reflector group, which includes a first reflector (8). The first reflector (8) is disposed in the output light path of the laser generator (1). The output light path of the first reflector (8) is also provided with the second reflector (9). The output light path of the second reflector (9) is also provided with the λ / 4 waveplate (2).

7. The apparatus for constructing a dual-effect structure synergistically inhibiting lithium electrode dendrite according to claim 6, wherein, The first reflector (8) and the second reflector (9) are both offset at 45°, thereby reflecting the light beam vertically for optical path propagation.

8. The apparatus for constructing a dual-effect structure synergistically inhibiting lithium electrode dendrite according to claim 5, wherein, The device also includes a second mirror group, which includes a third mirror (10) disposed on the outgoing light path of the aperture stop (4).

9. The apparatus for constructing a dual-effect structure synergistically inhibiting lithium electrode dendrite according to claim 8, wherein, The third reflector (10) is set at a 45° offset to reflect the light beam vertically for optical path propagation.

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