Apparatus and method for ultrafast laser processing pole pieces

Abstract

The application relates to an apparatus and a method for processing pole pieces by using ultrafast lasers, wherein an ultrafast laser, a light box, a mirror one, a one-dimensional motion unit and an X-axis motion unit are arranged on a rack, a multi-focus diffractive optical element is arranged on the one-dimensional motion unit, a bottom plate is connected to the X-axis motion unit, a mirror two and a Z-axis motion module are arranged on the bottom plate, a mirror three and a galvanometer field mirror unit are arranged on the Z-axis motion module, the output light path of the ultrafast laser sequentially comprises the light box, the mirror one, the multi-focus diffractive optical element, the mirror two, the mirror three and the galvanometer field mirror unit, a Y-axis motion unit is arranged below the galvanometer field mirror unit, and an adsorption platform for adsorbing and loading pole pieces is arranged on the Y-axis motion unit. Holes are drilled in the pole pieces or the pole pieces are cut, a transmission light path passes through a one-dimensional beam-splitting diffractive optical element to obtain multiple focuses, and the drilling of the holes in the pole pieces improves the speed of lithium ion in and out; when the pole pieces are cut, the one-dimensional beam-splitting diffractive optical element is switched out of the transmission light path, and the light beam after the field mirror is single-focus.

Description

Technical Field

[0001] This invention relates to an apparatus and method for ultrafast laser processing of electrodes, belonging to the field of laser processing technology. Background Technology

[0002] The published paper (Paving the way for industrial ultrafast laser structuring of lithium-ion battery electrodes by increasing the scanning accuracy) discloses a method for drilling holes in graphite negative electrodes using a high-speed rotating mirror. The mirror speed reaches up to 2 km / s, and the control accuracy is improved from 10 ns to 0.5 ps, while the repeatability is improved from 20 μm to 1 nm. The rotating mirror is suitable for machining straight lines in one direction, but its speed differs greatly from that of the galvanometer, making it difficult to coordinate with it to cut curved patterns.

[0003] Patent publication number CN 114603253 A discloses a multi-mirror laser fabrication method and system for positive electrode sheets, employing a high-precision 20-bit resolution galvanometer and a 250W-1000W high-power laser; however, the cost is high. The laser used in this method is 2MHz-10MHz, with a high frequency and a point spacing of 35 micrometers at a maximum speed of 70000mm / s, which cannot meet the aperture spacing requirements of over 100 micrometers. Furthermore, the single-pulse energy of a 250W-1000W laser at 2MHz is less than 0.5mJ, making it difficult to meet beam splitting requirements.

[0004] It is difficult to flexibly adjust the width, diameter, depth, and spacing of the processing area, and it is difficult to ensure the uniformity of spacing, diameter, depth, and channel structure. It is difficult to be compatible with the production line. Too many pulses may accumulate at the processing start point, end point, and corners, breaking down the current collector, forming burrs, piercing the diaphragm, and causing battery short circuits. The large difference in speed between the rotating mirror and the galvanometer makes it difficult to coordinate them to cut curved patterns. High-precision resolution galvanometers are expensive, and the laser's single pulse energy does not exceed 0.5mJ, which is difficult to meet the beam splitting requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an apparatus and method for ultrafast laser processing of electrode sheets, which drills or cuts holes in the electrode sheets to achieve high-speed, large-format, roll-to-roll or roll-to-sheet processing of electrode sheets.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] The device for ultrafast laser processing of electrodes is characterized by the following: an ultrafast laser, an optical box, a first reflector, a one-dimensional motion unit, and an X-axis motion unit are mounted on a frame. A multifocal diffraction optical element is mounted on the one-dimensional motion unit. A base plate is connected to the X-axis motion unit. A second reflector and a Z-axis motion module are mounted on the base plate. A third reflector and a galvanometer / field mirror unit are mounted on the Z-axis motion module. The output optical path of the ultrafast laser consists of the optical box, the first reflector, the multifocal diffraction optical element, the second reflector, the third reflector, and the galvanometer / field mirror unit. A Y-axis motion unit is arranged below the galvanometer / field mirror unit. The Y-axis motion unit is equipped with an adsorption platform for adsorbing and loading electrodes.

[0008] A dust collection device is installed next to the adsorption platform, and an aperture is installed between the dust collection device and the electrode. The adsorption platform and the dust collection device are connected to the vacuum system.

[0009] Furthermore, in the aforementioned ultrafast laser processing device for electrode sheets, the frame is a marble frame, fixed on a marble base.

[0010] Furthermore, in the aforementioned ultrafast laser processing device for electrodes, the optical box includes a reflector and a beam expander arranged sequentially along the optical path.

[0011] Furthermore, in the aforementioned apparatus for ultrafast laser processing of electrodes, the ultrafast laser is an ultrafast laser with a pulse width of 290 fs to 15 ps, a power of 100 W to 600 W, and a frequency of 50 kHz to 40 MHz.

[0012] Furthermore, in the aforementioned ultrafast laser processing electrode apparatus, the multifocal diffraction optical element is a multifocal diffraction optical element with a multifocal separation angle ≤0.230° and a number of focal points not exceeding 300, and the multifocal diffraction optical element is mounted on a one-dimensional motion unit.

[0013] Furthermore, in the aforementioned ultrafast laser processing device for electrodes, an aperture is installed between the galvanometer field mirror unit and the electrode, with two apertures arranged along the feeding direction of the roll material.

[0014] Furthermore, in the aforementioned ultrafast laser processing electrode apparatus, a camera module for focusing is mounted on the base plate.

[0015] The present invention discloses a method for ultrafast laser processing of electrodes. An ultrafast laser emits an ultrafast pulsed laser beam that passes through an optical box, then through a first reflector, through a multifocal diffraction optical element, and then through a second and third reflector before entering a galvanometer field lens unit, where it is focused onto the electrode on an adsorption platform. A Z-axis motion module moves the third reflector and the galvanometer field lens unit up and down, adjusting the laser focus on the electrode surface. A camera module is used to find the focus for electrodes of different thicknesses. An X-axis motion unit moves the second and third reflectors and the galvanometer field lens unit upwards, adjusting the processing center of the electrode along the X-axis.

[0016] Furthermore, in the above-mentioned method for ultrafast laser processing of electrodes, the electrodes are supported on an adsorption platform. The Y-axis motion unit drives the adsorption platform to move. After reaching the processing position, the adsorption platform remains stationary during processing. The galvanometer and field mirror unit moves along processing trajectory one or processing trajectory two. At the processing start point, the ultrafast laser is switched on and off, and at the processing end point, the ultrafast laser is switched off. After processing a region, the Y-axis motion unit pulls the electrodes, and the moving distance is the length of the processing region plus the pattern spacing.

[0017] The electrode moves along the Y-direction. The processing trajectories 1 and 2 of the two scanning areas are combined to form the slurry processing area. The electrode consists of an aluminum foil area, a ceramic area, and a slurry area. Drilling processing trajectories 1 and 2 are formed by a closed bow-shaped pattern, with only one start and end point along the arrow, reducing the delay at the start and end points in the middle area. An aperture prevents laser damage to the aluminum foil, and the aperture is located at both ends of the Y-direction of processing trajectories 1 and 2. For square holes, the line spacing in processing trajectory 1 is equal to the hole spacing; for rhomboid holes, the line spacing in processing trajectory 2 is equal to the hole spacing multiplied by [missing information]. The drilling trajectory one and the drilling trajectory two are multi-segment lines, but when the galvanometer field mirror unit moves at high speed along the Y direction, the laser pulse irradiates discrete position points, forming equally spaced holes rather than line segments.

[0018] Furthermore, in the above-mentioned method for ultrafast laser processing of electrode sheets, the electrode sheet includes a positive electrode sheet or a negative electrode sheet; an aperture installed between the dust collection device and the electrode sheet is used to avoid perforation of the aluminum foil and reduction of the hole spacing; the dust collection device covers the processing area, the airflow of the dust collection device is laminar, and it unidirectionally adsorbs the dust generated by drilling or cutting, with a flow velocity greater than or equal to 23 m / s.

[0019] Compared with the prior art, the present invention has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0020] This invention utilizes ultrafast lasers to drill or cut electrodes. The transmission optical path passes through a one-dimensional beam-splitting diffraction optical element to obtain multiple focal points. Drilling holes in the electrodes increases the lithium-ion entry and exit speed, improving battery capacity during rapid charging and discharging. The post-drilling process involves cutting and stacking, also functioning as electrode cutting. During electrode cutting, the one-dimensional beam-splitting diffraction optical element switches to outside the transmission optical path, resulting in a single focal point beam behind the field lens. Using a roll-mounted feeding system and a multi-head galvanometer, intermittent processing is employed to cut aluminum foil, ceramic, and electrode areas according to the processing drawings, or to drill holes in designated areas of the electrodes. After processing, the material is unloaded from the roll or the sheet is unloaded from the platform shaft. This achieves high-speed, large-format, roll-to-roll or roll-to-sheet electrode processing, offering advantages such as high versatility, fast processing efficiency, no need for leveling, and wide applicability to various electrode types.

[0021] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing specific embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 : Front view schematic diagram of the device of the present invention;

[0024] Figure 2 : A side view of the device of the present invention;

[0025] Figure 3 : Schematic diagram of splicing and processing electrode sheets. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, directional and ordinal terms are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] like Figures 1-3 As shown, the device for ultrafast laser processing of electrodes includes an ultrafast laser 10, an optical box 1, a reflector 20, a one-dimensional motion unit, and an X-axis motion unit 16 mounted on a frame 2. The frame 2 is a marble frame fixed on a marble base 15. The optical box 1 includes a reflector 4 and a beam expander arranged sequentially along the optical path. A multifocal diffraction optical element 5 is mounted on the one-dimensional motion unit. A base plate 19 is connected to the X-axis motion unit 16. A reflector 21 and a Z-axis motion module 3 are mounted on the base plate 19. A reflector 3 4 and a galvanometer field lens unit 12 are mounted on the Z-axis motion module 3. The output optical path of the ultrafast laser 10 consists of the optical box 1, the reflector 20, the multifocal diffraction optical element 5, the reflector 21, the reflector 3 4, and the galvanometer field lens unit 12. A Y-axis motion unit 7 is arranged below the galvanometer field lens unit 12. The Y-axis motion unit 7 is equipped with an adsorption platform 14 for adsorbing and loading electrodes. A camera module 6 for focusing is mounted on the base plate 19, which is used for focusing on electrodes of different thicknesses.

[0029] A dust collection device 13 is installed next to the adsorption platform 14. An aperture 22 is installed between the dust collection device 13 and the electrode. The adsorption platform 14 and the dust collection device 13 are connected to the vacuum system through a pipe tee 11. The airflow of the dust collection device is laminar rather than turbulent. Laminar flow has a high velocity, while turbulent flow is difficult to adsorb dust generated by drilling or cutting in one direction. The airflow velocity in the dust collection device pipe is greater than 1 m / s, and preferably greater than or equal to 23 m / s during cutting. The dust collection device 13 covers the processing area.

[0030] The equipment is used for feeding with a roller and for unloading with a roller or for sheet cutting with a platform.

[0031] Holes are drilled in the electrode sheet, and an aperture is installed between the galvanometer field lens unit 12 and the electrode sheet to prevent the current collector from being punctured at the starting point, ending point or corner of the drilling area and generating burrs. The two apertures are arranged along the feeding direction of the coil and do not obstruct the vertical direction of the feeding direction during cutting.

[0032] The ultrafast laser 10 has a pulse width of 290 fs to 15 ps, a power of 100 W to 600 W, and a frequency of 50 kHz to 40 MHz. Preferably, the power is 200 W to 500 W. The slab amplifier has a high single-pass gain, and 500 W can be achieved through single-pass or multi-pass amplifiers, with multiple sub-pulse capabilities. The disk amplifier, due to its low single-pass gain coefficient, can achieve 780 W through multiple amplifications via a regeneration cavity, with a single pulse energy of 2.6 mJ, but without multiple sub-pulses. Preferably, the frequency is 100 kHz to 10 MHz. The maximum single pulse energy of the ultrafast laser reaches the mJ level, preferably 3 mJ. Drilling requires a small crater, maintaining or approaching the flatness before drilling to avoid sharp peaks piercing the diaphragm. For ultrashort pulse laser ablation processing, the small crater eliminates the need for leveling operations.

[0033] An ultrafast laser and a galvanometer are used to drill or cut holes in the electrode sheet. The transmitted optical path passes through a one-dimensional beam-splitting multifocal diffraction optical element 5 to obtain multiple focal points. The galvanometer control uses a 16-bit or higher number of bits. Cutting the electrode sheet uses a single focal point. The one-dimensional beam-splitting multifocal diffraction optical element 5 is switched via a one-dimensional motion unit and can be switched either within the transmitted optical path or externally. The multifocal diffraction optical element 5 has a multifocal separation angle ≤0.230° and a focal number not exceeding 300. The number of focal points should be greater than or equal to 1, preferably exceeding 10 but not exceeding 80.

[0034] The entire device is supported by a foot adjustment mechanism 8, which is used to adjust the height and level.

[0035] The electrode 28 includes a positive electrode or a negative electrode. The positive electrode includes ternary lithium or lithium iron phosphate, and the negative electrode includes natural graphite, as well as a mixture of natural graphite and mesophase carbon microspheres, modified artificial graphite, and silicon-carbon composite negative electrode materials.

[0036] The ultrafast laser 10 emits an ultrafast pulsed laser beam that passes through the optical box 1, then through the first reflector 20, through the multifocal diffraction optical element 5, and then through the second reflector 21 and the third reflector 4 before entering the galvanometer field lens unit 12 and focusing onto the electrode on the adsorption platform 14. The Z-axis motion module 3 can drive the third reflector 4 and the galvanometer field lens unit 12 to move up and down, and the up and down movement of the galvanometer field lens unit 12 adjusts the laser focus to the surface of the electrode. The camera module 6 is used to find the focus for electrodes of different thicknesses. The X-axis motion unit 16 drives the second reflector 21, the third reflector 4 and the galvanometer field lens unit 12 to move upwards, adjusting the processing center of the electrode along the X-axis.

[0037] The electrode is supported on the adsorption platform 14. The Y-axis motion unit 7 drives the adsorption platform 14 to move. After reaching the processing position, the adsorption platform 14 is stationary during processing. The galvanometer field lens unit 12 moves along the processing trajectory 1 26 or the processing trajectory 29. At the processing start point, the ultrafast laser 10 is switched on and off, and at the processing end point, the ultrafast laser 10 is switched off. After processing an area, the Y-axis motion unit 7 pulls the electrode, and the moving distance is the length of the processing area plus the pattern spacing. The roll-to-roll or roll-to-sheet loading and unloading device uses a PLC to adjust tension, correction, rotation, speed, etc., and interacts with the host. The host is operated by the display 18, which controls the loading, ultrafast laser 10, galvanometer field lens unit 12, Z-axis motion module 3, X-axis motion unit 16, Y-axis motion unit 7, etc.

[0038] Electrode 28 moves along the Y direction. The processing trajectories 26 and 29 of the two scanning areas are spliced ​​together to form the processing area of ​​slurry area 25. Electrode 28 consists of aluminum foil area, ceramic area 24, and slurry area 25. Drilling processing trajectory 26 and processing trajectory 29 are formed by a bow-shaped closed pattern. There is only one start and end point along arrow 23, which reduces the delay at the start and end points in the middle area. At the corner 27, due to the long dwell time of deceleration and acceleration, it is easy to penetrate the aluminum foil and the hole spacing becomes smaller. The aperture 22 blocks laser damage to the aluminum foil. The aperture 22 is located at both ends of the Y direction of processing trajectory 26 and processing trajectory 29. For square hole 31, the line spacing in processing trajectory 26 is equal to the hole spacing. For rhomboid hole 32, the line spacing in processing trajectory 29 is equal to the hole spacing multiplied by 1. The drilling trajectory 126 and the drilling trajectory 29 are multi-segment lines. However, when the galvanometer field mirror unit 12 moves at high speed along the Y direction, the laser pulse irradiates discrete position points, forming equally spaced holes instead of line segments. The spacing between holes 30, square holes 31, and rhomboid holes 32 is 200μm, and the depth is 41μm. The processing methods for multiple splicing areas of 4, 6, and 8 are similar, and the slurry area is spliced ​​along the Y direction.

[0039] The dust collection device 13 covers the processing area. The airflow of the dust collection device is laminar and unidirectionally adsorbs the dust generated by drilling or cutting. The flow velocity is greater than or equal to 23m / s. The aperture 22 installed between the dust collection device 13 and the electrode is used to avoid perforation of the aluminum foil and reduce the hole spacing.

[0040] To balance speed, area, and aperture spacing, field lenses with focal lengths of 100mm or more are used, with an aperture spacing of 200 micrometers. Considering the spacing during processing, the multifocal separation angle is ≤0.230°. To ensure sufficient processing power for each beam, the number of focal points does not exceed 300, with an optimal number not exceeding 80. To fully utilize the laser power, the number of focal points is greater than or equal to 1, with an optimal number exceeding 10. High-efficiency diffractive optical elements are used.

[0041] Example 1

[0042] An ultrafast laser is used to drill holes in lithium cobalt oxide electrodes. A 500W laser is used to transmit the galvanometer, with a pulse width of 10 ps. The square holes are spaced 200 μm apart. A high-efficiency one-dimensional beam-splitting diffraction optical element standard is used, with a beam splitting angle of 0.028° and a field lens focal length of 409 mm. The beam is split into 15 beams after the galvanometer. The processing frequency is 200 kHz, and the speed is 40 m / s. The galvanometer processing area is 25 mm, and the galvanometer control caliper has 16 positions. The processing depth is 30 μm. If only a 25 mm area is processed, the corresponding roll-up speed is 5 m / min. If a 120 mm wide electrode is processed, a certain gap is left between the processing areas to avoid overlapping and drilling through the current collector. Four sets of lasers are used in conjunction with the galvanometer to process a 25 × 4 = 100 mm area, with a corresponding roll-up speed of 5 m / min.

[0043] Example 2

[0044] Drilling holes in graphite electrodes using an ultrashort pulse laser was performed using a single laser with two galvanometers. The laser power was 300W, and the pulse width was 800 fs. The diamond-shaped holes were spaced 173 micrometers apart. A high-efficiency one-dimensional beam-splitting diffraction optical element standard was used, with a beam splitting angle of 0.060°. Both field lenses had a focal length of 330mm, and the beam was split into 13 beams after the galvanometers. The processing frequency was 100kHz, the processing speed was 20m / s, the electrode width was 120mm, the processing area of ​​a single galvanometer was 50mm, the drilling depth was 40μm, and the corresponding roll-up speed was 10m / min.

[0045] Example 3

[0046] A 300W ultrafast laser was used to cut lithium iron phosphate electrodes with a pulse width of 300 fs and a frequency of 4 MHz. Laser processing was performed on electrodes with a thickness of 180 micrometers, including a ceramic thickness of 120 μm, achieving an equivalent processing speed of 1000 mm / s. For a 300 mm long electrode, the laser cutting time plus the material feeding time was approximately 0.43 s, with an electrode width of 120 mm and a processing efficiency of 16.7 m / min. For a 600 mm long electrode, a dual-laser approach was used to achieve a processing efficiency of 16.7 m / min.

[0047] Example 4

[0048] A 200W ultrafast laser is used to cut lithium iron phosphate electrodes with a pulse width of 14ps and a frequency of 5MHz. Laser processing of electrodes with a thickness of 180 micrometers (60 micrometers of ceramic) achieves an equivalent processing speed of 1500mm / s. For a 300mm long electrode, the laser cutting time plus the material feeding time is approximately 0.32s, with an electrode width of 120mm and a processing efficiency of 22.5m / min. For a 600mm long electrode, a dual-laser approach achieves a processing efficiency of 22.5m / min.

[0049] Laser drilling is used for electrode materials such as graphite and lithium cobalt oxide. Lithium cobalt oxide has structures including monoclinic, hexagonal, layered, or spinel structures, where lithium ions can move rapidly between layers or within large channels. Lithium iron phosphate has an orthorhombic olivine structure, with lithium ion diffusion channels being one-dimensional pores. Graphite has a layered structure, allowing lithium ions to move rapidly between layers. After laser processing, the structure or composition of the active material deposited in the heat-affected zone changes, affecting the entry of lithium ions into the electrode from the front side; therefore, a smaller heat-affected zone is better. During charging, lithium ions move from lithium cobalt oxide or lithium iron phosphate into graphite, and then embed into rings formed by carbon atoms via the electrolyte.

[0050] The laser drilling process avoids shock waves and compacts the area around the processing zone, reducing interatomic spacing and hindering lithium ion entry. Laser drilling should penetrate as deeply as possible into the graphite layer, avoiding damage to the aluminum foil current collector to prevent lithium ions from accumulating on the foil and depositing lithium. The holes should be as close together as possible to improve lithium ion migration efficiency. This is because lithium ions diffuse rapidly in the electrolyte, while their diffusion coefficient in graphite is only 10⁻⁶. -13 -10 -6 cm 2 Between / s, the diffusion coefficient of lithium nickel manganese oxide is 10. -8 cm 2 / s. The reference (Increasing the Discharge Rate Capability of Lithium-Ion Cells with Laser-Structured Graphite Anodes: Modeling and Simulation) summarizes the diffusion parameters in the positive and negative electrodes and the electrolyte. The diffusion coefficient of the graphite aluminum foil negative electrode is 10. -14 cm 2 / s, positive electrode diffusion coefficient 1.8×10 -13 cm 2 / s, the diffusion coefficient of the 3 mmol electrolyte at room temperature is 5.8 × 10⁻⁶. -11 cm 2 The diffusion rate is approximately 5800 times that of graphite. The radius of a lithium ion is only 0.068 nm, therefore the micron-sized pores are sufficient for lithium ions to pass through the electrolyte. Diffusion time is inversely proportional to the diffusion coefficient; during lithium-ion charging, most of the lithium ion movement time occurs within the graphite.

[0051] In summary, this invention utilizes ultrafast lasers to drill or cut electrodes. The transmission optical path obtains multiple focal points through a one-dimensional beam-splitting diffraction optical element. Drilling holes in the electrodes increases the lithium-ion entry and exit speed, thereby improving battery capacity during rapid charging and discharging. The post-drilling process involves cutting and stacking, also functioning as electrode cutting. When cutting the electrodes, the one-dimensional beam-splitting diffraction optical element switches to the outside of the transmission optical path, resulting in a single focal point beam behind the field lens. Using a roll-mounted feeding system and a multi-head galvanometer, intermittent processing is employed to cut aluminum foil, ceramic, and electrode areas according to the processing drawings, or to drill holes in designated areas of the electrodes. After processing, the material is unloaded from the roll or the sheet is unloaded from the platform shaft. This achieves high-speed, large-format, roll-to-roll or roll-to-sheet electrode processing, offering advantages such as strong versatility, high processing efficiency, no need for leveling, and wide applicability to various electrode types.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0053] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. An apparatus for ultrafast laser processing of electrodes, characterized in that: An ultrafast laser (10), an optical box (1), a first reflector (20), a one-dimensional motion unit and an X-axis motion unit (16) are installed on the rack (2). A multi-focus diffraction optical element (5) is installed on the one-dimensional motion unit. The multi-focus diffraction optical element (5) can be switched in the transmission optical path or externally through the one-dimensional motion unit. A base plate (19) is connected to the X-axis motion unit (16). A second reflector (21) and a Z-axis motion module (3) are installed on the base plate (19). A third reflector (4) and a galvanometer field lens unit (12) are installed on the Z-axis motion module (3). The output optical path of the ultrafast laser (10) consists of an optical box (1), a first reflector (20), a multi-focus diffraction optical element (5), a second reflector (21), a third reflector (4) and a galvanometer field lens unit (12). A Y-axis motion unit (7) is arranged below the galvanometer field lens unit (12). An adsorption platform (14) for adsorbing loaded electrodes is provided on the Y-axis motion unit (7). A dust collection device (13) is provided next to the adsorption platform (14). An aperture (22) is installed between the dust collection device (13) and the electrode. The adsorption platform (14) and the dust collection device (13) are connected to the vacuum system.

2. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: The frame (2) is a marble frame, which is fixed on a marble base (15).

3. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: The optical box (1) includes four reflectors and a beam expander arranged sequentially along the optical path.

4. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: The ultrafast laser (10) is an ultrafast laser with a pulse width of 290 fs to 15 ps, a power of 100 W to 600 W, and a frequency of 50 kHz to 40 MHz.

5. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: The multifocal diffractive optical element (5) is a multifocal diffractive optical element with a multifocal separation angle ≤0.230° and a number of focal points not exceeding 300.

6. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: An aperture (22) is installed between the galvanometer field lens unit (12) and the electrode sheet, and the two apertures are arranged along the feeding direction of the roll material.

7. The apparatus for ultrafast laser processing of electrodes according to claim 1, characterized in that: A camera module (6) for focusing is mounted on the base plate (19).

8. A method for ultrafast laser processing of electrode sheets using the apparatus of claim 7, characterized in that: The ultrafast laser (10) emits an ultrafast pulsed laser that passes through the optical box (1), then through the first reflector (20), through the multifocal diffraction optical element (5), and then through the second reflector (21) and the third reflector (4) into the galvanometer field lens unit (12), and is focused onto the electrode on the adsorption platform (14); the Z-axis motion module (3) can drive the third reflector (4) and the galvanometer field lens unit (12) to move up and down, and the galvanometer field lens unit (12) moves up and down to adjust the laser focus to the surface of the electrode; the camera module (6) is used to find the focus for electrodes of different thicknesses; the X-axis motion unit (16) drives the second reflector (21), the third reflector (4) and the galvanometer field lens unit (12) to move, and adjusts the processing center of the electrode along the X-axis.

9. The method for ultrafast laser processing of electrode sheets according to claim 8, characterized in that: The electrode is supported on the adsorption platform (14). The Y-axis motion unit (7) drives the adsorption platform (14) to move. After reaching the processing position, the adsorption platform (14) is stationary during processing. The galvanometer field lens unit (12) moves along the processing trajectory one (26) or the processing trajectory two (29). At the processing start point, the ultrafast laser (10) is turned on and at the processing end point, the ultrafast laser (10) is turned off. After processing a region, the Y-axis motion unit (7) pulls the electrode. The moving distance is the length of the processing region plus the pattern spacing. The electrode (28) moves along the Y direction, and the processing trajectory one (26) or processing trajectory two (29) of the two scanning areas are spliced ​​to form the processing area of ​​the slurry area (25). The electrode (28) is composed of the aluminum foil area, the ceramic area (24), and the slurry area (25). The drilling processing trajectory one (26) and processing trajectory two (29) are composed of a bow-shaped closed pattern with only one start and end point, reducing the delay of the start and end points in the middle area. The aperture (22) blocks the laser from damaging the aluminum foil. The aperture (22) is located at both ends of the Y direction of processing trajectory one (26) and processing trajectory two (29). For square holes (31), the line spacing in processing trajectory one (26) is equal to the hole spacing. For rhomboid holes (32), the line spacing in processing trajectory two (29) is equal to the hole spacing multiplied by 1. / 2; Drilling trajectory one (26) and machining trajectory two (29) are multi-segment lines, but when the galvanometer field mirror unit (12) moves at high speed along the Y direction, the laser pulse irradiates discrete position points, forming equally spaced holes rather than line segments.

10. The method for ultrafast laser processing of electrode sheets according to claim 8, characterized in that: The electrode includes a positive electrode or a negative electrode; the aperture (22) installed between the dust collection device (13) and the electrode is used to avoid perforation of the aluminum foil and the hole spacing becoming smaller; the dust collection device covers the processing area, the airflow of the dust collection device is laminar, and it adsorbs the dust generated by drilling or cutting in one direction, with a flow rate greater than or equal to 23 m / s.

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