Composite laser processing method for solid-state battery electrode sheet and applications thereof

Abstract

The application provides a composite laser processing method for solid-state battery pole pieces and application thereof, and relates to the technical field of solid-state batteries, and comprises the following steps: laser cleaning is performed on solid-state electrolyte pole pieces and / or negative pole pieces, electrolyte-negative composite pole pieces are formed by compounding, laser tab processing is performed on the composite pole pieces, laser densification processing is performed on the surface and / or interlayer interface region of the composite pole pieces; laser cleaning is performed on positive pole pieces, laser tab processing is performed on the pole pieces, laser densification processing is performed on the surface and / or interlayer interface region of the pole pieces; the composite pole pieces and the positive pole pieces are arranged in a laminated mode to obtain multilayer composite pole pieces. By using the method, the solid-state battery pole pieces are significantly improved in terms of interface cleaning, interface densification, microstructure construction and laminated composite consistency, and problems such as high interface impedance, unstable interface combination and insufficient material layer density in the prior art are effectively overcome.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, and in particular to a composite laser processing method for solid-state battery electrodes and its application. Background Technology

[0002] Solid-state batteries are considered a crucial development direction for next-generation power batteries due to their high safety and high energy density. However, their fabrication is constrained by key technological bottlenecks. The core issues lie in insufficient interfacial contact between the solid electrolyte and electrode materials, high interfacial impedance, poor interfacial stability, and uneven overall density after multilayer material stacking. Currently, roll forming, isostatic pressing, hot pressing, material coating, and interface modification technologies are commonly used, with roll forming and isostatic pressing being the most typical mechanical densification methods. In the fabrication stage, the roll forming process applies external force to create high density in the active material, electrolyte material, and bonding system of the electrode sheet, thereby reducing porosity and increasing contact area. In the assembly stage, the isostatic pressing process applies isotropic pressure uniformly to the cell, increasing the density of the solid electrolyte layer and the positive and negative electrode layers. However, for brittle and unevenly distributed porous structures like solid electrolytes and electrode materials, excessive mechanical force can easily lead to the generation of microcracks within the material, which in turn exacerbates interfacial delamination during subsequent cycles; conversely, insufficient pressure cannot achieve the desired densification effect. In addition, roll pressing and isostatic pressing processes are poorly adaptable to electrodes with different coating thicknesses, binder contents and particle distributions, and often result in problems such as uneven density and local morphological collapse, which affect the consistency of interfacial impedance.

[0003] Furthermore, as solid-state batteries develop towards thinner profiles, multi-layered composite structures, and high-area-density electrodes, relying solely on the aforementioned mechanical densification methods is no longer sufficient to meet the requirements for precise interface control, nor can it simultaneously meet the demands for lightweight, continuous mass production, and precision manufacturing. Summary of the Invention

[0004] One of the objectives of this invention is to provide a composite laser processing method for solid-state battery electrodes, so as to at least solve one of the technical problems existing in the prior art.

[0005] The second objective of this invention is to provide a composite laser processing method for solid-state battery electrodes and its application in the fabrication of solid-state batteries.

[0006] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a composite laser processing method for solid-state battery electrodes, comprising: (a) Laser cleaning of solid electrolyte electrode sheet and / or negative electrode sheet, then coating the solid electrolyte electrode sheet onto at least one side surface of the negative electrode sheet to form an electrolyte-negative electrode composite sheet, then laser cutting of the electrode tabs on the electrolyte-negative electrode composite sheet, and then laser densification treatment on the surface and / or interlayer interface area of ​​the electrolyte-negative electrode composite sheet. (b) The positive electrode sheet is laser-cleaned, then the positive electrode sheet is laser-cut with tabs, and then the surface and / or interlayer interface area of ​​the positive electrode sheet is laser-densified. (c) The electrolyte-negative electrode composite sheet obtained after steps (a) and (b) is stacked with the positive electrode sheet to obtain a multilayer composite electrode sheet.

[0007] Furthermore, when performing laser cleaning on the solid electrolyte electrode, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm and an energy density of 0.02 J / cm² is used. 2 Up to 1 J / cm 2 ; Preferably, when performing laser cleaning on the negative electrode sheet, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm and an energy density of 0.02 J / cm² is used. 2 Up to 0.5 J / cm 2 ; Preferably, when performing laser cleaning on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 0.3 J / cm 2 .

[0008] Furthermore, when performing laser tab cutting on the electrolyte-negative electrode composite sheet, a laser with a wavelength of 532 nm or 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 5 J / cm 2 ; Preferably, when performing laser tab cutting on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 1 J / cm² is used. 2 Up to 5 J / cm 2 .

[0009] Furthermore, when performing laser densification on the electrolyte-negative electrode composite sheet, a laser with a wavelength of 808 nm, 1030 nm, 1064 nm, or 1550 nm is used, with an energy density of 0.05 J / cm². 2 Up to 1 J / cm 2 ; Preferably, when performing laser densification on the positive electrode sheet, a laser with a wavelength of 355 nm or 532 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

[0010] Furthermore, the laser pulse width used in steps (a) and (b) for laser cleaning, laser tab cutting, and laser densification is 100 fs to 200 ns, and the scanning speed is 50 mm / s to 1000 mm / s.

[0011] Furthermore, after laser cleaning and before coating, the solid electrolyte electrode and / or negative electrode are pre-densified by applying a pressure of 0.5 MPa-20 MPa using a pressure roller.

[0012] Furthermore, after laser cleaning and before laser tab cutting, the positive electrode sheet is pre-densified by applying a pressure of 0.5 MPa-20 MPa through a pressure roller.

[0013] Furthermore, the composite laser processing method for solid-state battery electrodes also includes: after obtaining multilayer composite electrodes, stacking the multilayer composite electrodes to form a solid-state battery cell stacked structure. Preferably, before the lamination, the surface and / or interlayer interface region of the multilayer composite electrode is subjected to laser densification treatment.

[0014] Furthermore, when performing laser densification on the surface and / or interlayer interface region of the multilayer composite electrode, a laser with a wavelength of 1064 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

[0015] Secondly, the present invention provides an application of a composite laser processing method for solid-state battery electrodes in the preparation of solid-state batteries.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a composite laser processing method for solid-state battery electrodes, which integrates laser cleaning, laser tab cutting, and laser densification processes to achieve precise control over the solid-solid interface state. Laser cleaning removes contaminants, microparticles, and localized oxide layers from the electrode surface, ensuring a highly clean interface between the solid electrolyte and electrode materials before lamination, avoiding the introduction of moisture or secondary contamination by traditional cleaning methods. Laser tab cutting achieves high-precision, heat-free edge shaping, ensuring geometric alignment consistency and conductivity reliability during subsequent stacking. Laser densification, through localized thermal effects and material micro-melting mechanisms, increases local density without damaging the main structure, increases the effective contact area of ​​the solid-solid interface, and promotes a tighter mechanical locking structure between the electrolyte and electrode materials, thereby significantly improving the continuity of ion transport and the interfacial bonding strength. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 The laser processing composite process flow diagram provided by the present invention; Figure 2 This is a schematic diagram of the laser process; Figure 3 This describes the process flow for electrode laser densification. Figure 4 This is a schematic diagram of a stacked wafer with laser densification technology.

[0019] icon: 101 - First electrolyte feeding roller; 103 - Second electrolyte feeding roller; 102 - Negative electrode feeding roller; 104 - First rubber roller; 105 - Second rubber roller; 106 - Third rubber roller; 110 - Fourth rubber roller; 111 - Fifth rubber roller; 112 - Sixth rubber roller; 120 - Seventh rubber roller; 121 - Eighth rubber roller; 124 - Ninth rubber roller; 125 - Tenth rubber roller; 130 - Eleventh rubber roller; 131 - Twelfth rubber roller; 137 - Thirteenth rubber roller; 138 - Fourteenth rubber roller; 140 - Fifteenth rubber roller; 107 - First laser cleaning device; 108 - Second laser cleaning device; 109 - Third laser cleaning device; 117 - Fourth laser cleaning device; 129 - Fifth laser cleaning device; 132 - Sixth laser cleaning device; 113 - First pressure roller; 114 - Second pressure roller; 115 - Third pressure roller; 116 - Fourth pressure roller; 118 - Fifth pressure roller; 119 - Sixth pressure roller; 133 - Seventh pressure roller; 134 - Eighth pressure roller; 122-First transfer roller; 123-Second transfer roller; 126-Double-layer coated positive electrode feeding roller; 127-First electrolyte transfer film receiving roller; 128-Second electrolyte transfer film receiving roller; 135-First laser tab cutting device; 136-Second laser tab cutting device; 139-First laser densification device; 141-Second laser densification device; 142-First composite roller; 143-Second composite roller; 144-First die-cutting blade; 145-Second die-cutting blade; 146-Third laser densification device; 147 - Fourth laser densification device; 148-Layer stacking process; 149-Bare cell after stacking; 150-First electrolyte electrode laser sealing device; 152-Second electrolyte electrode laser sealing device; 151-Negative electrode laser processing and sealing device; 153-Double-coated positive electrode laser processing and sealing device; 154-Electrolyte-negative electrode composite electrode laser cutting tab sealing device; 155-First electrode laser densification and sealing device; 156-Second electrode laser densification and sealing device; 157-Workshop environment; 201-Laser device; 202-Laser; 203-Material layer; 301-Positive electrode material layer; 302-Electrolyte material layer; 303-Negative electrode material layer; 306-Aluminum foil; 307-Copper foil; 308-Bare cell electrode sheet; 401-First bare cell electrode sheet; 402-Second bare cell electrode sheet. Detailed Implementation

[0020] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The first aspect of the present invention provides a composite laser processing method for solid-state battery electrodes, comprising: (a) laser cleaning a solid electrolyte electrode and / or a negative electrode, then depositing the solid electrolyte electrode on at least one side surface of the negative electrode to form an electrolyte-negative electrode composite electrode, subsequently performing laser tab cutting on the electrolyte-negative electrode composite electrode, and then performing laser densification on the surface and / or interlayer interface region of the electrolyte-negative electrode composite electrode; (b) laser cleaning a positive electrode, then performing laser tab cutting on the positive electrode, and then performing laser densification on the surface and / or interlayer interface region of the positive electrode; (c) stacking the electrolyte-negative electrode composite electrode obtained after steps (a) and (b) with a positive electrode to obtain a multilayer composite electrode.

[0023] It is understandable that steps (a) and (b) can be performed simultaneously; or steps (a) can be performed first, followed by steps (b); or steps (b) can be performed first, followed by steps (a).

[0024] This invention addresses key bottlenecks in the interface cleaning, interface densification, microstructure control, and multilayer composite processing of solid-state battery electrodes by proposing a composite laser processing method capable of covering the entire process. This method uses laser cleaning, laser cutting, and laser densification as core unit operations, deeply coupling them with traditional mechanical processing techniques such as rolling, transfer printing, die-cutting, and stacking. This forms a complete equipment chain that can operate continuously in a low dew point, sealed, inert environment, significantly improving the interfacial bonding quality between the solid electrolyte and the positive and negative electrodes. The process flow of this invention uses double-coated positive and negative electrode sheets as initial raw materials and stacked solid-state battery cell electrodes as the final product. The entire processing encompasses surface purification, interface structure control, material stacking and composite, and final densification.

[0025] In this invention, the laser cleaning process utilizes a high-energy-density, short-pulse mechanism to selectively remove contaminants, microparticles, and localized oxide layers from the electrode surface under non-contact conditions, ensuring a highly clean interface between the solid electrolyte and electrode materials before bonding. Compared to traditional plasma or solvent cleaning methods, laser cleaning exhibits higher selectivity and environmental adaptability in a sealed inert gas environment, avoiding the introduction of water vapor or secondary contamination into sensitive sulfide electrolytes, thus significantly reducing the risk of subsequent interface reactions. The laser densification process, through localized thermal effects and material micro-melting mechanisms, forms a uniform and controllable microstructure on the material layer surface, while simultaneously increasing local density without damaging the main structure. This treatment not only increases the effective contact area of ​​the solid-solid interface but also creates a tighter mechanical locking structure between the electrolyte and electrode materials, further improving the continuity of ion transport. Compared to mechanical densification methods that rely solely on rolling, laser densification offers advantages such as strong fine-tuning capabilities, designable action areas, and minimal impact on internal material stress, enabling the electrode to achieve higher interfacial bonding quality while maintaining overall flatness. Each laser process is completed continuously in a sealed cavity with a low dew point and an inert atmosphere, which effectively suppresses problems such as moisture absorption and decomposition of solid electrolytes, interface debonding and electrochemical performance degradation, resulting in a more uniform microstructure of the electrode, significantly reduced interface impedance, improved mechanical strength and enhanced interface stability.

[0026] By employing the composite laser processing technology proposed in this invention, solid-state battery electrodes achieve significant improvements in interface cleaning, interface densification, microstructure construction, and consistency of stacked composites. This effectively overcomes the problems of high interface impedance, unstable interface bonding, insufficient material layer density, and difficulty in meeting the characteristics of solid electrolytes in the existing technology.

[0027] In some preferred embodiments, the composite laser processing method for solid-state battery electrodes further includes: after obtaining multilayer composite electrodes, stacking the multilayer composite electrodes to form a solid-state cell stacked structure; preferably, before stacking, laser densification treatment is performed on the surface and / or interlayer interface region of the multilayer composite electrodes.

[0028] Optionally, the laser densification device of the present invention can employ a pulse width adjustable laser (nanosecond, picosecond, or femtosecond lasers are all acceptable; femtosecond lasers are preferred for sulfide solid electrolytes, depending on the material selection), and a scanning strategy can be set based on the thermal diffusion characteristics of the electrode and / or composite electrode. The scanning path can be parallel line scanning, grid scanning, or concentric circle scanning, wherein grid scanning can achieve more uniform energy coverage when the two scanning directions are perpendicular.

[0029] Optionally, such as Figure 2As shown, the laser 202 emitted by the laser device 201 acts on the material layer 203, and the direction of movement of the laser generator can be freely selected. Figure 2 The movement direction shown in the demonstration is from right to left.

[0030] Optionally, such as Figure 3 As shown, the positive electrode material layer 301 (with aluminum foil 306) is densified by the second laser densification device 141, and the composite electrode sheet (with copper foil 307) of the electrolyte material layer 302 and the negative electrode material layer 303 is densified by the first laser densification device 139, and then the composite is formed into a bare battery cell electrode sheet 308.

[0031] Optionally, such as Figure 4 As shown, the first bare cell electrode 401 and the second bare cell electrode 402 are densified by the third laser densification device 146 and the fourth laser densification device 147, respectively, and then composited to form the stacked bare cell 149.

[0032] In some preferred embodiments, the method provided by the present invention can be adapted to various solid electrolyte systems and electrode systems, including but not limited to sulfide electrolytes (such as Li6PS5Cl, Li...). 10 GeP2S 12 ), oxide electrolytes (LLZO, LATP), high-nickel oxide cathode materials (NCM, NCA), lithium iron phosphate cathode materials, graphite anodes and silicon-based anode materials, etc.

[0033] In some preferred embodiments, when laser cleaning the solid electrolyte electrode, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm and an energy density of 0.02 J / cm² is used. 2 Up to 1 J / cm 2 ; Preferably, when performing laser cleaning on the negative electrode sheet, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm and an energy density of 0.02 J / cm² is used. 2 Up to 0.5 J / cm 2 ; Preferably, when performing laser cleaning on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 0.3 J / cm 2 .

[0034] In some preferred embodiments, when performing laser tab cutting on the electrolyte-negative electrode composite sheet, a laser with a wavelength of 532 nm or 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 5 J / cm 2 ; Preferably, when performing laser tab cutting on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 1 J / cm² is used. 2 Up to 5 J / cm 2 .

[0035] In some preferred embodiments, when performing laser densification on the electrolyte-negative electrode composite sheet, a laser with a wavelength of 808 nm, 1030 nm, 1064 nm, or 1550 nm is used, and the energy density is 0.05 J / cm². 2 Up to 1 J / cm 2 ; Preferably, when performing laser densification on the positive electrode sheet, a laser with a wavelength of 355 nm or 532 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

[0036] In some preferred embodiments, the laser pulse width used in steps (a) and (b) for laser cleaning, laser tab cutting, and laser densification is 100 fs to 200 ns, and the scanning speed is 50 mm / s to 1000 mm / s.

[0037] In some preferred embodiments, after laser cleaning and before coating, the solid electrolyte electrode and / or negative electrode are pre-densified by applying a pressure of 0.5 MPa-20 MPa using pressure rollers.

[0038] In some preferred embodiments, after laser cleaning and before laser tab cutting, the positive electrode sheet is pre-densified by applying a pressure of 0.5 MPa-20 MPa through a pressure roller.

[0039] In some preferred embodiments, when performing laser densification on the surface and / or interlayer interface regions of the multilayer composite electrode, a laser with a wavelength of 1064 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

[0040] Optionally, the laser settings in this invention can be appropriately adjusted according to the material thickness, structure, and light absorption characteristics. Different lasers can be switched and used through the same laser platform, thereby achieving continuous process operation and equipment integration.

[0041] In the optional embodiments of the present invention, the composite laser processing method for solid-state battery electrodes is more preferred: First, the solid electrolyte electrode and the double-sided coated negative electrode are laser-cleaned. The negative electrode is preferably a graphite-solid electrolyte composite structure or a pure graphite system. Short-pulse or ultrashort-pulse lasers are used to selectively remove surface contaminants, weakly bound particles, or localized oxide layers, ensuring the cleanliness of the subsequent composite interface. The mechanism of laser cleaning is as follows: high-energy-density pulsed lasers are used to instantaneously evaporate or peel off weakly bound particles, oxide impurities, or extremely thin contaminant layers on the electrode surface. The energy density is controlled to ensure that the main structure of the solid electrolyte is not damaged. After this step, the surface cleanliness of the solid electrolyte is significantly improved, providing a high-quality interface for subsequent composite processes.

[0042] It should be noted that the laser energy density for laser cleaning of the negative electrode sheet can be appropriately reduced according to the absorption rate of the negative electrode material to avoid local ablation or excessive volatilization of the binder.

[0043] After laser cleaning, the electrode sheet is pre-rolled using pressure rollers to achieve a higher initial density in the material layer and provide a more stable morphological substrate for subsequent laser densification. Simultaneously, the pre-rolled negative electrode sheet exhibits a more uniform surface flatness and density, creating conditions for the uniform adhesion of the electrolyte layer. The pressure rollers are made of hard metal and have an adjustable gap. The purpose of pre-rolling is to eliminate some of the porosity within the solid electrolyte electrode sheet, achieving initial flatness of the material and improving the mechanical strength of the electrode sheet, facilitating stable subsequent transfer steps.

[0044] Subsequently, a transfer roller is used to uniformly transfer the upper and lower layers of solid electrolyte material onto the surface of the negative electrode sheet, forming a complete electrolyte-negative electrode sheet. Optionally, the transfer roller is covered with a flexible material to reduce local stress concentration of the solid electrolyte during the contact process. At the same time, an inert gas sealing device is used to keep the entire processing path in a low dew point environment to prevent the solid electrolyte from absorbing moisture and decomposing.

[0045] In the positive electrode processing stage, the preferred positive electrode sheet is a double-layer coating structure containing high-nickel layered oxide (such as NCM811) and sulfide positive electrode material. The double-layer coated positive electrode sheet also undergoes laser cleaning and mechanical pre-rolling sequentially. During laser cleaning, the scanning path covers the entire electrode surface in a linear scanning manner, with a small overlap area (10%-20%) between each scanning line to ensure cleaning uniformity. After laser cleaning, residual coating solvent, weakly adhering particles, and thin metal oxide layers on the positive electrode surface are effectively removed, significantly improving the interface state of the positive electrode material. Simultaneously, pre-rolling helps eliminate voids between the double-layer structure, improving overall mechanical stability and compacting the positive electrode surface into a structure with higher flatness, providing a precise reference surface for subsequent laser tab cutting. After laser cleaning and mechanical pre-rolling, a clean and flat positive electrode material layer is obtained, and tab structures are formed at predetermined positions using a laser tab cutting device. The tab structure formed through this step has neat edges and no carbonized layer, improving the weldability and conductivity of subsequent lamination.

[0046] Furthermore, laser tab cutting is also performed simultaneously on the electrolyte-negative electrode composite sheet to ensure accurate and consistent correspondence between the positive and negative electrodes during the stacking process. Since the negative electrode material typically contains graphite, carbon materials, or a composite solid electrolyte layer, its laser absorption rate and thermal diffusion characteristics differ from those of the positive electrode. Therefore, the negative electrode laser cutting device can employ a nanosecond or picosecond laser, with the wavelength selected based on the material's absorption characteristics. Optionally, to avoid thermal damage to the negative electrode / electrolyte interface during cutting, a multiple low-energy pulse scanning method is used, i.e., at a lower energy density (e.g., 0.51 J / cm²). 2 Perform 2-5 repeated scans to peel off the material layer by layer rather than penetrating it all at once, thus effectively reducing the thickness of the heat-affected zone. The cutting area is equipped with a localized inert gas curtain to quickly remove smoke and debris, ensuring clean cutting edges. The resulting negative electrode tab is precisely positioned and strictly aligned with the positive electrode tab, providing a geometric reference for the lamination stage.

[0047] Next, the positive electrode sheet and the electrolyte-negative electrode composite sheet that has been transferred are fed into the laser densification device. The laser densification device uses an adjustable pulse width laser. By adjusting the energy density, scanning speed and focal position, the laser acts on the material surface and its near-surface area to achieve local microstructure rearrangement, pore collapse and interface reconstruction.

[0048] Optionally, to take into account the different thermal properties of the solid electrolyte and the positive and negative electrode materials, this invention employs a two-stage energy mode control: a low-energy primary scan (0.1 J / cm²) is performed on the material surface to remove particles and weak bonding interfaces, followed by a high-energy secondary scan (0.5 J / cm²) to promote local densification of the material layer. The laser focal spot diameter is 90-110 μm, preferably 100 μm, and repeated scanning covers the entire laminated interface to achieve uniform densification. The laser induces local ablation and cladding within the material layer, thereby improving the interfacial bonding strength and the continuity of electron-ion dual-channel transport in the material layer. The laser-densified electrode sheet, before cooling, is then laminated using a composite roller to obtain a structurally stable composite electrode sheet with good interfacial contact, and finally output via a winding device.

[0049] Optionally, the composite roller employs a flexible coating structure to ensure that the sensitive solid electrolyte is not damaged under the applied composite pressure. During composite processing, the upper and lower laser-densified electrodes are further bonded under pressure, resulting in an interface with high uniformity, high bonding strength, and low porosity. Finally, the composite electrodes are wound into rolls by a winding mechanism, awaiting further processing.

[0050] Furthermore, this invention employs a die-cutting machine to precisely die-cut the composite electrode sheets, obtaining composite electrode units with consistent dimensions. The purpose of the die-cutting process is to process continuous composite electrode sheets into single electrode structures with fixed dimensions, regular shapes, and preset tab positions, in order to meet the subsequent requirements of solid-state battery stacking. The edges of the die-cut electrode sheets should be flat and smooth, without burrs or chipping, and maintain high-precision consistency in the geometric position of the positive and negative tabs to ensure good mechanical positioning during subsequent stacking.

[0051] Optionally, the die-cutting blade is a high-precision cutter made of hard steel or powder metallurgy material, which achieves rapid forming of the electrode shape through mechanical punching. The cutting area is also in an inert protective environment and a low dew point environment to prevent the cut edges from being exposed to moisture and affecting the stability of the solid electrolyte-material interface.

[0052] In the final forming stage, the composite electrode undergoes another laser densification treatment to strengthen the contact between the upper and lower interfaces. Stacking and subsequent assembly are then carried out in a sealed, low-dew-point environment, resulting in a more stable and uniform structure after the electrode is stacked. Specifically, the micro-melting effect of the laser causes localized flow of the electrode surface material, leading to the collapse of micropores and thus higher local density. Simultaneously, the laser-induced thermal compression effect repairs residual weak bonding areas at the interface, further enhancing the bonding strength between the solid electrolyte and the positive and negative electrode interfaces. After this final densification treatment, the overall mechanical strength of the electrode is significantly improved, making it less prone to interlayer slippage or localized warping under stacking pressure.

[0053] The laser processing device in this invention can select laser sources with different wavelengths, powers and pulse parameters according to different processes, including but not limited to nanosecond, picosecond or femtosecond lasers, to adapt to the different absorption characteristics of solid electrolyte, positive electrode and negative electrode materials, and realize regional and path-based processing through a precision scanning system, so that the functional modules of cleaning, cutting and densification can be continuously integrated in the same production line.

[0054] This invention achieves precise control of interface state and improvement of overall processing quality: by employing a highly selective, high-energy-density laser processing method that can operate in a sealed, inert environment, it effectively cleans, regulates microstructure, and locally densifies the electrode surface during the preparation of solid electrolytes, electrode materials, and composite electrodes, thereby improving the interface contact area and interface bonding quality; without damaging the morphology of the electrode body or the structural integrity of the solid electrolyte, it achieves laser densification treatment that is universally applicable and suitable for double-sided coated electrodes; and it integrates multiple steps such as cleaning, cutting, transfer printing, rolling, and composite stacking. A continuous, stable, precisely aligned processing link with consistent environmental conditions was established to ensure the consistency of material state and interface quality between each process segment, avoiding contamination, oxidation, and microcrack formation. Multiple laser processes, such as laser cleaning, laser tab cutting, laser microstructuring, and laser densification, were integrated into the same production line, forming a sealed laser processing equipment that can operate in a low dew point and inert gas protection environment. This allows the laser process to work synergistically with the mechanical processing steps in solid-state battery electrode preparation, thereby effectively reducing interface impedance, improving ion transport continuity, enhancing rate performance, and improving cycle stability.

[0055] Furthermore, in the composite processing stage, by continuously integrating laser processing with rolling, transfer printing, die-cutting, and stacking processes, this invention achieves stable alignment, uniform pressure transmission, and consistent interface states between material layers. This chain-integrated process effectively reduces the risk of contamination and morphological damage caused by multiple transfers of the electrode between equipment, resulting in a significant improvement in the structural integrity and interlayer bonding strength of the final composite electrode. Continuously performing laser processing and machining in a sealed, low-dew-point environment also ensures that the solid electrolyte does not undergo hygroscopic decomposition, thus preventing problems such as hydrogen sulfide generation, interface debonding, and electrochemical performance degradation from the outset.

[0056] In summary, this invention forms a composite laser processing technology that integrates cleaning, cutting, densification, and lamination to solve the problem of difficult interface quality control during solid-state battery electrode preparation. It forms a more efficient, stable, and mass-producible processing path. This invention can achieve multi-step integration, continuous and controllable material state, and fine-tuning of interface structure, which significantly improves the interface cleanliness, interface density, interlayer bonding strength, and overall morphological consistency of solid-state battery electrodes, thereby meeting the requirements of stability, processing speed, and reliability for large-scale production of solid-state cells.

[0057] Furthermore, this invention makes the microstructure of solid-state battery electrodes more uniform, significantly reduces interfacial impedance, improves electrode mechanical strength, and significantly enhances the stability of the electrolyte-electrode interface. Simultaneously, under high-rate charge-discharge conditions, the ion transport paths between material layers are more continuous, thereby effectively improving the rate performance and cycle life of the solid-state battery cell. The composite laser processing method of this invention not only demonstrates significant effects on experimental samples but is also suitable for large-scale continuous processing of solid-state batteries, providing a reliable technological foundation and industrialization path for achieving high-consistency, high-energy-density, and high-safety solid-state power cells.

[0058] Optionally, the sealed cavity is continuously purified by inert gas (such as argon or nitrogen) through continuous circulation. An online dew point control module maintains the internal dew point between -50°C and -80°C, preferably below -60°C. The dew point monitoring system uses a laser absorption online dew point meter to monitor humidity changes in the cavity in real time and feeds the data back to the gas control module for closed-loop regulation. A dust collection area is provided inside the cavity, using low-pressure adsorption to draw particles generated during laser cleaning into a filter device, preventing them from re-falling onto the electrode surface.

[0059] The second aspect of this invention provides an application of a composite laser processing method for solid-state battery electrodes in the fabrication of solid-state batteries.

[0060] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0061] Example 1 This embodiment provides a composite laser processing method for solid-state battery electrodes. The main process flow is as follows: laser cleaning—rolling—transfer printing—laser cutting—laser densification—composite—die cutting—stacking, and eliminating the subsequent isostatic pressing process. The specific process is as follows: (1) Composite processing of solid electrolyte and negative electrode sheet like Figure 1As shown in the figure, 157 represents the overall workshop environment 157. The solid electrolyte electrode is first introduced into the processing area by the first electrolyte feeding roller 101 and the second electrolyte feeding roller 103. The solid electrolyte is a sulfide system material. The entire processing is carried out in the first electrolyte electrode laser sealing processing device 150 and the second electrolyte electrode laser sealing processing device 152. The sealing environment is filled with inert gas (argon), and the ambient dew point is controlled within the range of -60±5℃ through online dew point monitoring to avoid material decomposition or side reactions on the surface.

[0062] The solid electrolyte electrode sheets pass through the feeding rollers and then enter the first laser cleaning device 107 and the third laser cleaning device 109. This cleaning device uses a nanosecond laser source with a wavelength of 1064 nm and an energy density controlled at 0.5 ± 0.02 J / cm². 2 The laser pulse width is 100ns and the scanning speed is 50mm / s. The laser beam is rapidly scanned on the electrode surface through a scanning galvanometer.

[0063] Subsequently, the solid electrolyte electrode sheet enters the first pressure roller 113, the second pressure roller 114, the fifth pressure roller 118 and the sixth pressure roller 119, and the material is pre-densified by rolling. The pressure of the pressure roller is 10 MPa.

[0064] Meanwhile, the double-coated negative electrode sheet is introduced into the negative electrode sheet laser processing sealing device 151 by the negative electrode feeding roller 102. The negative electrode sheet has a graphite-solid electrolyte composite structure. The negative electrode sheet sequentially passes through the second laser cleaning device 108, the fourth laser cleaning device 117, and the third pressure roller 115 and the fourth pressure roller 116; wherein, the cleaning device uses a nanosecond laser source with a wavelength of 1064 nm and an energy density controlled at 0.3±0.02 J / cm². 2 The laser pulse width is 100ns, the scanning speed is 50mm / s, and the laser beam is rapidly scanned on the electrode surface through a scanning galvanometer; the pressure of the pressure roller is 10MPa.

[0065] After pretreatment, the solid electrolyte electrode and the negative electrode simultaneously enter the first transfer roller 122 and the second transfer roller 123. During the transfer process, the upper and lower layers of the solid electrolyte are precisely adhered to the upper and lower sides of the negative electrode, forming a symmetrical electrolyte-negative electrode composite structure. After the transfer is completed, the two protective films from the electrolyte are wound up by the first electrolyte transfer film take-up roller 127 and the second electrolyte transfer film take-up roller 128, respectively, to avoid interfering with subsequent processes.

[0066] After the above steps are completed, the entire electrolyte-negative electrode composite sheet enters the electrolyte-negative electrode composite sheet laser cutting tab sealing device 154 to provide a clean and stable environment for subsequent laser cutting tab processing.

[0067] (2) Laser-cut electrode tab treatment of electrolyte-negative electrode composite sheet After the electrode composite is completed, the electrolyte-negative electrode is introduced into the electrolyte-negative electrode composite laser-cut tab sealing device 154, and then the negative electrode tab is processed by the first laser-cut tab device 135. This embodiment employs a multiple low-energy pulse scanning method, i.e., at a relatively low energy density (0.51 J / cm²). 2 The laser was scanned three times, with a wavelength of 1064 nm, a pulse width of 100 ns, and a scanning speed of 50 mm / s.

[0068] (3) Processing of double-coated positive electrode sheets and laser cutting of electrode tabs At the same time, such as Figure 1 As shown, the double-coated positive electrode sheet (sulfide positive electrode material) is conveyed by the double-coated positive electrode feeding roller 126 to the double-coated positive electrode sheet laser processing sealing device 153.

[0069] The positive electrode sheet enters the fifth laser cleaning device 129 and the sixth laser cleaning device 132. To avoid oxidation, phase transition, or crystal structure damage to the high-nickel positive electrode material under the action of high-energy beams, this embodiment uses a picosecond laser source with more controllable energy, employing a laser with a wavelength of 1064nm, a pulse width of 25 ps, and an energy density controlled at 0.2 J / cm². 2 The scanning speed is 50 mm / s. During laser cleaning, the scanning path covers the entire electrode surface in a linear scanning manner, with a small overlapping area (15% overlap) between each scanning line.

[0070] Subsequently, the positive electrode sheet enters the seventh pressure roller 133 and the eighth pressure roller 134 for pre-rolling treatment, with the pre-rolling pressure controlled at 10 MPa.

[0071] After pre-rolling, the positive electrode sheet enters the second laser tab cutting device 136. This device uses a high-precision fiber laser (1064 nm), coupled with a high-speed galvanometer and a cooling protection module, to cut tabs of a specified shape on the edge of the electrode sheet. The energy density of the laser cutting is controlled at 2.5 J / cm². 2 The cutting speed is 150 mm / s, and the cutting line width is kept stable at 50 μm to avoid burning the material edges or excessive heat-affected zone. During the cutting process, the double-layer coated positive electrode laser processing sealing device 153 continuously maintains a low dew point inert environment to prevent the high-nickel positive electrode material from oxidizing and deactivating due to local exposure to air at high temperatures.

[0072] (4) Laser densification and composite process of positive electrode and electrolyte-negative electrode composite sheet like Figure 1As shown, within the first electrode laser densification sealing device 155, after the positive electrode and the electrolyte-negative electrode composite electrode have undergone laser cleaning, pre-rolling, and tab cutting processes respectively, they are simultaneously fed into the first laser densification device 139 and the second laser densification device 141 via guide rollers. The laser densification device employs an adjustable pulse width laser.

[0073] This embodiment employs a two-stage energy mode control, namely, performing a low-energy primary scan (0.1 J / cm²) on the material surface. 2 To remove particles and weakly bound interfaces, a high-energy secondary scan (0.5 J / cm²) is then performed. 2 This promotes localized densification of the material layer. The laser focal spot diameter is 100 μm.

[0074] The densified positive electrode, negative electrode, and electrolyte materials will then be laminated together using the first composite roller 142 and the second composite roller 143. The lamination pressure of the composite rollers is 10 MPa.

[0075] (5) Die-cutting of composite electrodes After the positive electrode and electrolyte-negative electrode are combined, the electrode sheets are collected in rolls and then fed into a die-cutting device via guide rollers. The first die-cutting blade 144 and the second die-cutting blade 145 are high-precision cutters made of hard steel. After die-cutting, the resulting monomer composite electrode sheets are transferred to the next processing stage via a vacuum adsorption structure.

[0076] (6) Final laser densification treatment of composite electrodes like Figure 1 As shown, the die-cut composite electrode sheet enters the third laser densification device 146 and the fourth laser densification device 147 within the second electrode sheet laser densification sealing device 156. The purpose of this step is to perform final densification treatment on the upper and lower surfaces of the electrode sheet and their interface areas, thereby further improving the surface flatness, interface bonding, and structural stability of the electrode sheet before stacking. The laser densification device uses a grid scanning method with a laser wavelength of 1064 nm. The final densification laser energy density is controlled at 0.3 J / cm², the laser pulse width is 100 ns, and the scanning speed is 400 mm / s.

[0077] (7) Lamination process and solid cell structure forming like Figure 1 As shown in the stacking process 148, the composite electrode sheet that has undergone final laser densification will enter the stacking unit device. The stacking process is to stack the positive electrode-electrolyte-negative electrode structure in a predetermined order to form a solid cell stacked structure (i.e., the bare cell 149 after stacking) under the premise of ensuring the dimensional accuracy, positional alignment and electrode tab matching consistency of the electrode sheet.

[0078] After the stacking is completed, as follows Figure 4 As shown, a preliminary solid-state battery cell structure is obtained. Because the present invention performs laser densification treatment on each interface before stacking, the stacking pressure can further compact the material layers and form a stable interface, fundamentally reducing the interfacial impedance of the solid-solid interface. Therefore, the isostatic pressing process is eliminated in subsequent processes. The target product produced in this embodiment is a 10Ah pouch battery.

[0079] It should be noted that the overall process involves several rubber rollers, such as... Figure 1 As shown, it includes: first rubber roller 104, second rubber roller 105, third rubber roller 106, fourth rubber roller 110, fifth rubber roller 111, sixth rubber roller 112, seventh rubber roller 120, eighth rubber roller 121, ninth rubber roller 124, tenth rubber roller 125, eleventh rubber roller 130, twelfth rubber roller 131, thirteenth rubber roller 137, fourteenth rubber roller 138, and fifteenth rubber roller 140.

[0080] Example 2 This embodiment provides a composite laser processing method for solid-state battery electrodes. The difference from Embodiment 1 lies in adjusting parameters such as energy density and wavelength of each laser process. The specific parameters are as follows: Laser cleaning of solid electrolyte electrodes: wavelength 808 nm, energy density 0.02 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Laser cleaning of negative electrode: wavelength 808 nm, energy density 0.02 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Laser cleaning of positive electrode: wavelength 1064 nm, energy density 0.1 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Electrolyte-anode composite electrode laser cutting tab: wavelength 532 nm, energy density 0.1 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Laser cutting of positive electrode tabs: wavelength 1064 nm, energy density 1 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Electrolyte-anode composite electrode laser densification: wavelength 808 nm, energy density 0.05 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Laser densification of the positive electrode: wavelength 355 nm, energy density 0.05 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; Laser densification of multilayer composite electrodes: wavelength 1064 nm, energy density 0.05 J / cm² 2 Pulse width 100 fs, scan speed 50 mm / s; The remaining process steps are the same as in Example 1.

[0081] Example 3 This embodiment provides a composite laser processing method for solid-state battery electrodes. The difference from Embodiment 1 lies in adjusting parameters such as energy density and wavelength of each laser process. The specific parameters are as follows: Laser cleaning of solid electrolyte electrodes: wavelength 1064 nm, energy density 1.0 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; Laser cleaning of negative electrode: wavelength 1064 nm, energy density 0.5 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; Laser cleaning of positive electrode: wavelength 1064 nm, energy density 0.3 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; Electrolyte-anode composite electrode laser cutting tab: wavelength 1064 nm, energy density 5.0 J / cm² 2 Pulse width 200ns, scan speed 1000 mm / s; Laser cutting of positive electrode tabs: wavelength 1064 nm, energy density 5.0 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; Electrolyte-anode composite electrode laser densification: wavelength 1550 nm, energy density 1.0 J / cm² 2 Pulse width 200ns, scan speed 1000 mm / s; Laser densification of the positive electrode: wavelength 532 nm, energy density 1.0 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; Laser densification of multilayer composite electrodes: wavelength 1064 nm, energy density 1.0 J / cm² 2 Pulse width 200 ns, scan speed 1000 mm / s; The remaining process steps are the same as in Example 1.

[0082] Example 4 This embodiment provides a composite laser processing method for solid-state battery electrodes. The difference from Embodiment 1 lies in adjusting the laser energy density. The specific parameters are as follows: Laser cleaning of solid electrolyte electrodes: energy density 0.01 J / cm² 2 ; Laser cleaning of negative electrode sheet: energy density 0.01 J / cm² 2 ; Laser cleaning of positive electrode: energy density 0.05 J / cm² 2 ; Electrolyte-negative electrode composite sheet laser-cut electrode tabs: energy density 0.05 J / cm² 2 ; Laser cutting of tabs on positive electrode: energy density 0.5 J / cm² 2 ; Laser densification of electrolyte-anode composite electrode: energy density 0.03 J / cm² 2 ; Laser densification of positive electrode: energy density 0.03 J / cm² 2 ; Laser densification of multilayer composite electrodes: energy density 0.03 J / cm² 2 ; The remaining process steps are the same as in Example 1.

[0083] Example 5 This embodiment provides a composite laser processing method for solid-state battery electrodes. The difference from Embodiment 1 lies in adjusting the laser energy density. The specific parameters are as follows: Laser cleaning of solid electrolyte electrodes: energy density 1.5 J / cm² 2 ; Laser cleaning of negative electrode sheet: energy density 0.8 J / cm² 2 ; Laser cleaning of positive electrode: energy density 0.5 J / cm² 2 ; Electrolyte-negative electrode composite sheet laser-cut electrode tabs: energy density 6.0 J / cm² 2 ; Laser cutting of tabs on positive electrode: energy density 6.0 J / cm² 2 ; Electrolyte-anode composite electrode laser densification: energy density 1.5 J / cm² 2 ; Laser densification of positive electrode: energy density 1.5 J / cm² 2 ; Laser densification of multilayer composite electrodes: energy density 1.5 J / cm² 2 ; The remaining process steps are the same as in Example 1.

[0084] Example 6 This embodiment provides a composite laser processing method for solid-state battery electrodes. The process flow of this embodiment is as follows: laser cleaning—rolling—transfer printing—laser cutting—laser densification—composite—die cutting—stacked and subsequent isostatic pressing. The difference from Embodiment 1 is that the isostatic pressing process is still used in the subsequent processes.

[0085] Example 7 This embodiment provides a composite laser processing method for solid-state battery electrodes. The process flow of this embodiment is as follows: laser cleaning—transfer printing—laser cutting—laser densification—composite—die cutting—stacked, and the subsequent isostatic pressing process is eliminated. The difference from Embodiment 1 is that the rolling process is eliminated after laser cleaning.

[0086] Example 8 This embodiment provides a composite laser processing method for solid-state battery electrodes, which differs from Embodiment 1 in that the laser cleaning step for the solid electrolyte electrode is omitted.

[0087] Example 9 This embodiment provides a composite laser processing method for solid-state battery electrodes, which differs from Embodiment 1 in that the laser cleaning step for the negative electrode is omitted.

[0088] Example 10 This embodiment provides a composite laser processing method for solid-state battery electrodes. The difference from Embodiment 1 is that the processing steps of the solid electrolyte / negative electrode sheet (including laser cleaning, cutting the tabs, and laser densification) and the processing steps of the positive electrode sheet (including laser cleaning, cutting the tabs, and laser densification) are not performed simultaneously. The processing steps of the solid electrolyte / negative electrode sheet are performed first, and then the processing steps of the positive electrode sheet are performed.

[0089] Comparative Example 1 This comparative example provides a processing method for solid-state battery electrodes. The process flow is as follows: rolling, transfer printing, die cutting, stacking, and subsequent isostatic pressing. The difference from Example 1 is that the laser processing step in the entire process is eliminated.

[0090] Test case Test method: The battery was packaged in a flexible packaging form. After packaging, the battery was subjected to hot-pressing formation treatment at 60°C (pressure 0.5 MPa, time 2 hours), followed by electrochemical performance testing.

[0091] (1) Cyclic stability test (capacity retention rate after 500 cycles): Test temperature: 25±1℃; Charge / discharge rate: 0.5C charging / 0.5C discharging; Voltage range: 2.8V-4.2V (adjusted according to the cathode material system); Cycle count: 500 times.

[0092] First, three activation cycles were performed at a 0.2C rate, and the discharge capacity of the third cycle was used as the initial capacity. Then, 500 charge-discharge cycles at 0.5C / 0.5C were performed. The discharge capacity was recorded after every 50 cycles.

[0093] (2) Rate performance test (1C capacity retention) Test temperature: 25±1℃; charging rate: constant at 0.2C; discharging rate: tested at 0.2C, 0.5C, 1C, and 2C respectively (this invention mainly focuses on 1C performance); voltage range: 2.8V-4.2V.

[0094] First, cycle the system three times under 0.2C charging / 0.2C discharging conditions, and take the capacity of the last discharge as the baseline capacity. Then, under 0.2C charging conditions, conduct discharge tests at different rates, with each rate cycled three times. Record the average discharge capacity at a 1C discharge rate.

[0095] The test results are shown in Table 1.

[0096] Table 1

[0097] As can be seen from the data in Table 1, Comparative Example 1 completely abandons all laser processes and relies solely on the traditional rolling-die-cutting-stacking-isostatic pressing path. Compared with Example 1, the performance of Comparative Example 1 is significantly inferior, which directly confirms the irreplaceable role of composite laser treatment in improving interface cleanliness, controlling local densification, and strengthening solid-solid contact.

[0098] In Examples 2-3, most parameters were within the boundary range. Although the performance was slightly lower than that of Example 1, the cycle retention rate remained stable at 86%-87%, and the 1C performance was 90%-91% (1C performance). However, some parameters in Examples 4-5 exceeded the preferred range defined by this invention, and their performance decreased significantly. Specifically, in Example 4, due to insufficient laser energy density, the interface could not be effectively cleaned and sufficient densification could not be achieved, resulting in increased interface impedance, a 500-cycle capacity retention rate of 76%, and an 1C performance of 80%. In Example 5, due to excessively high energy density, localized thermal damage was caused to the material, resulting in microcracks, and the performance also decreased significantly.

[0099] Examples 8-9 show that laser cleaning of the electrolyte or negative electrode was omitted, resulting in a significant decrease in performance, demonstrating the crucial role of laser cleaning in interface cleanliness.

[0100] Example 7 shows that the performance of Example 1 is weaker after the pre-rolling process is removed, indicating that mechanical pre-densification provides a necessary basis for laser densification and the two are functionally complementary. Example 6 retains the isostatic pressing process and the performance is similar to that of Example 1, indicating that the present invention can replace the traditional isostatic pressing process. Example 10 verifies that the step-by-step execution of the positive and negative electrode processes does not significantly affect the final effect.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite laser processing method for solid-state battery electrodes, characterized in that, include: (a) Laser cleaning of solid electrolyte electrode sheet and / or negative electrode sheet, then coating the solid electrolyte electrode sheet onto at least one side surface of the negative electrode sheet to form an electrolyte-negative electrode composite sheet, then laser cutting of the electrode tabs on the electrolyte-negative electrode composite sheet, and then laser densification treatment on the surface and / or interlayer interface area of ​​the electrolyte-negative electrode composite sheet. (b) The positive electrode sheet is laser-cleaned, then the positive electrode sheet is laser-cut with tabs, and then the surface and / or interlayer interface area of ​​the positive electrode sheet is laser-densified. (c) The electrolyte-negative electrode composite sheet obtained after steps (a) and (b) is stacked with the positive electrode sheet to obtain a multilayer composite electrode sheet.

2. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, When performing laser cleaning on the solid electrolyte electrode, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm is used, and the energy density is 0.02 J / cm². 2 Up to 1 J / cm 2 ; Preferably, when performing laser cleaning on the negative electrode sheet, a laser with a wavelength of 808 nm, 1030 nm, or 1064 nm and an energy density of 0.02 J / cm² is used. 2 Up to 0.5 J / cm 2 ; Preferably, when performing laser cleaning on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 0.3 J / cm 2 .

3. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, When performing laser tab cutting on the electrolyte-negative electrode composite sheet, a laser with a wavelength of 532 nm or 1064 nm and an energy density of 0.1 J / cm² is used. 2 Up to 5 J / cm 2 ; Preferably, when performing laser tab cutting on the positive electrode sheet, a laser with a wavelength of 1064 nm and an energy density of 1 J / cm² is used. 2 Up to 5 J / cm 2 .

4. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, When performing laser densification on the electrolyte-negative electrode composite sheet, lasers with wavelengths of 808 nm, 1030 nm, 1064 nm, or 1550 nm are used, with an energy density of 0.05 J / cm². 2 Up to 1 J / cm 2 ; Preferably, when performing laser densification on the positive electrode sheet, a laser with a wavelength of 355 nm or 532 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

5. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, The laser pulse width used in steps (a) and (b) for laser cleaning, laser tab cutting and laser densification is 100 fs to 200 ns, and the scanning speed is 50 mm / s to 1000 mm / s.

6. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, After laser cleaning and before coating, the solid electrolyte electrode and / or negative electrode are pre-densified by applying a pressure of 0.5 MPa-20 MPa through a pressure roller.

7. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, After laser cleaning and before laser tab cutting, the positive electrode sheet is pre-densified by applying a pressure of 0.5 MPa-20 MPa through a pressure roller.

8. The composite laser processing method for solid-state battery electrodes according to claim 1, characterized in that, The composite laser processing method for solid-state battery electrodes further includes: after obtaining multi-layer composite electrodes, stacking the multi-layer composite electrodes to form a solid-state battery cell stacked structure. Preferably, before the lamination, the surface and / or interlayer interface region of the multilayer composite electrode is subjected to laser densification treatment.

9. The composite laser processing method for solid-state battery electrodes according to claim 8, characterized in that, When performing laser densification on the surface and / or interlayer interface region of the multilayer composite electrode, a laser with a wavelength of 1064 nm and an energy density of 0.05 J / cm² is used. 2 Up to 1 J / cm 2 .

10. The application of the composite laser processing method for solid-state battery electrodes as described in any one of claims 1-9 in the preparation of solid-state batteries.

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