Pole piece slitting device

Abstract

The invention discloses a pole piece slitting device, and relates to the technical field of lithium ion battery pole piece processing equipment, the pole piece slitting device comprises a knife rest assembly, the knife rest assembly comprises a first knife rest and a second knife rest, the first knife rest is arranged at the upper end of the second knife rest, a first cutter is arranged on the first knife rest, and a second cutter is arranged on the second knife rest; wherein the first cutter and the second cutter are oppositely arranged in a longitudinally overlapped and transversely separated state, the transverse distance between the first cutter and the second cutter can be dynamically adjusted according to the thickness and the compaction density of the pole piece, and the transverse distance is in positive correlation with the thickness parameter of the pole piece and is in negative correlation with the compaction density parameter of the pole piece; and the heating module is arranged on the first cutter rest, and the heating module covers the shearing area of the first cutter.

Description

Technical Field

[0001] This application relates to the technical field of lithium-ion battery electrode processing equipment, and in particular to an electrode slitting device. Background Technology

[0002] In the production of lithium-ion batteries, electrode slitting is a critical step that determines the performance and safety of the cell. The slitting quality directly affects the flatness of the electrode end face, the size of the burrs, and the subsequent assembly efficiency and safety of the cell.

[0003] In the existing slitting process, after the unwinding device of the slitting machine releases the lithium-ion battery electrode sheet, the upper and lower slitting blades, which overlap longitudinally and fit seamlessly laterally, operate synchronously under the drive of the drive device. The blade edge at the fitting point applies shearing force to the electrode sheet conveyed to the slitting area, dividing it into strips of the required width. However, since the upper and lower blades are in rigid contact and have no buffer structure, the impact force of the blade edge on the electrode sheet at the moment of cutting cannot be released, causing the electrode sheet edge to break and lose material due to severe impact. At the same time, the blade edge is prone to additional friction with the electrode sheet under rigid collision, ultimately resulting in significant material loss at the shearing end face and excessive metal burrs.

[0004] In view of this, we provide an electrode slitting device to solve the above problems. Summary of the Invention

[0005] The purpose of this application is to solve the technical problem of significant material loss and excessive metal burrs on the shearing end face during slitting. In order to solve the above technical problem, an electrode slitting device is provided that makes material loss on the shearing end face minimal and the metal burrs meet the standard.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solution: an electrode slitting device, comprising: a blade holder assembly, the blade holder assembly including a first blade holder and a second blade holder, the first blade holder being disposed on the upper end of the second blade holder, a first cutting blade being disposed on the first blade holder, and a second cutting blade being disposed on the second blade holder; wherein, the first cutting blade and the second cutting blade are arranged opposite each other in a longitudinally overlapping and laterally separated state, the lateral spacing between the first cutting blade and the second cutting blade can be dynamically adjusted according to the compaction density and material properties of the electrode, the lateral spacing is positively correlated with the thickness parameter of the electrode and negatively correlated with the compaction density parameter of the electrode; a heating module, the heating module being disposed on the first blade holder, the heating module covering the shearing area of ​​the first cutting blade, the heating module being used to preheat the first cutting blade to reduce the shearing strength of the electrode.

[0007] Furthermore, according to an embodiment of this application, a first transmission shaft is provided at one end of the tool holder assembly, and an unwinding shaft is provided at the other end of the first transmission shaft. The transmission shaft is used to transmit the electrode sheet to the tool holder assembly.

[0008] Furthermore, according to an embodiment of this application, the heating module is designed with an arc-shaped structure, and the arc-shaped heating surface of the heating module is adapted to the profile of the cutting edge of the first cutter to form a fan-shaped coverage area.

[0009] Furthermore, according to an embodiment of this application, a sealing cover is provided on the blade holder assembly, the sealing cover being used to block external environmental interference to the first and second cutters.

[0010] Furthermore, according to an embodiment of this application, an upper transmission shaft and a lower transmission shaft are provided on the other side of the tool holder assembly, and both the upper and lower transmission shafts are provided with dust removal devices.

[0011] Furthermore, according to an embodiment of this application, a take-up shaft assembly is provided on the other side of the dust removal device, the take-up shaft assembly including a first take-up shaft and a second take-up shaft.

[0012] Furthermore, according to an embodiment of this application, the first take-up shaft is disposed at the upper end of the second take-up shaft.

[0013] Furthermore, according to an embodiment of this application, the first take-up shaft corresponds to the upper transmission shaft, and the second take-up shaft corresponds to the lower transmission shaft.

[0014] Furthermore, according to the embodiments of this application, there are several first cutters and several second cutters, and the number of each is corresponding. The several first cutters are evenly distributed along the axial direction of the first cutter holder, and the several second cutters are evenly distributed along the axial direction of the second cutter holder.

[0015] Furthermore, according to an embodiment of this application, the width of the first cutter is smaller than the width of the second cutter.

[0016] Compared with the prior art, this application has the following beneficial effects: The first and second cutters of this application adopt a structure of longitudinal overlap and lateral separation, which avoids direct contact between the cutting edges from a physical perspective, reduces wear to maintain the sharpness of the cutting edges, and eliminates tearing burrs caused by the dulling of the cutting edges. At the same time, the lateral distance between the first and second cutters can be dynamically adjusted according to the thickness of the electrode sheet, accurately adapting to the material characteristics. With the heating module preheating the first cutter, the shear resistance of the electrode sheet is weakened, making the cutting process more stable and neat. This solves the technical problem of significant material loss and excessive metal burrs on the shearing end face caused by slitting, and achieves the technical effect of minimal material loss and compliant metal burrs on the shearing end face during slitting. Attached Figure Description

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of an electrode slitting device according to an embodiment of this application.

[0019] Figure 2This is a schematic diagram of the heating module of an electrode slitting device according to an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the structure of a blade holder assembly of an electrode slitting device according to an embodiment of this application.

[0021] Figure 4 This is a partially enlarged structural diagram showing the positions of the first and second cutters of an electrode slitting device according to an embodiment of this application.

[0022] Figure 5 This is a schematic diagram of the permanent magnet position structure of an electrode slitting device according to an embodiment of this application.

[0023] In the attached diagram: 1. Tool holder assembly; 11. First cutter; 12. Second cutter; 13. Heating module; 14. First tool holder; 15. Second tool holder; 16. Permanent magnet; 2. Unwinding shaft; 3. First transmission shaft; 4. Dust removal device; 5. Upper transmission shaft; 6. Lower transmission shaft; 7. First winding shaft; 8. Second winding shaft. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit 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.

[0025] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "a," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] For purposes of simplicity and illustration, the principles of the embodiments are described primarily by way of example. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that these embodiments may not be limited to these specific details in practice. In some instances, well-known methods and structures have not been described in detail to avoid unnecessarily obscuring these embodiments. Furthermore, all embodiments can be used in combination with each other. Example

[0028] like Figure 1 , 2 As shown, this embodiment provides an electrode slitting device, including: a blade holder assembly 1, which includes a first blade holder 14 and a second blade holder 15. The first blade holder 14 is disposed on the upper end of the second blade holder 15, and a first cutter 11 is disposed on the first blade holder 14. A second cutter 12 is disposed on the second blade holder 15. The first cutter 11 and the second cutter 12 are longitudinally overlapped and laterally separated. The lateral spacing between the first cutter 11 and the second cutter 12 can be dynamically adjusted according to the compaction density and material properties of the electrode. The lateral spacing is positively correlated with the thickness parameter of the electrode and negatively correlated with the compaction density parameter of the electrode. A heating module 13 is disposed on the first blade holder 14 and covers the shearing area of ​​the first cutter 11. The heating module 13 is used to preheat the first cutter 11 to reduce the shearing strength of the electrode. The distance between the first cutter 11 and the second cutter 12 is adjusted. At the same time, the heating module 13 preheats the cutting area of ​​the first cutter 11 to reduce the shearing intensity of the electrode. During cutting, the first cutter 11 and the second cutter 12, which are longitudinally overlapping and laterally separated, cut the electrode to avoid direct contact between the first cutter 11 and the second cutter 12 to reduce wear and ensure normal subsequent cutting.

[0029] The electrode sheet released by the unwinding shaft 2 is conveyed to the blade holder assembly 1 via the first transmission shaft 3. The heating module 13 preheats the cutting edge of the first cutter 11 to reduce the shear strength of the electrode sheet. During cutting, the first cutter 11 and the second cutter 12, which are longitudinally overlapping and laterally separated, cut the electrode sheet. The distance between the first cutter 11 and the second cutter 12 is adjusted by calculating G=k×t×ρ^(-β), where k is the material property coefficient, t is the electrode sheet thickness, ρ is the electrode sheet compaction density, and β is the density correction index. For example, when cutting a graphite negative electrode with a thickness of 120μm and a compaction density of 1.8g / cm³, k=0.15 and β=0.15 are taken, and the calculated cutter distance is approximately 18μm. In implementation, the initial distance is first set according to the calculated value, and then... Fine-tuning within ±2μm is performed based on the actual cutting effect. If burrs appear, the spacing is appropriately reduced; if cracks occur, the spacing is moderately increased. At the same time, the spacing between the cutters must be ensured to be no less than 5μm. This ensures that the first cutter 11 and the second cutter 12 adapt to the characteristics of the electrode sheet during the cutting process, avoiding problems such as uneven force on the electrode sheet caused by improper spacing, which can lead to material loss at the cutting end. The sealing cover blocks external interference. The slit electrode sheet is transported via the upper transmission shaft 5 and the lower transmission shaft 6. The dust removal device 4 removes impurities, and finally, the corresponding first winding shaft 7 and second winding shaft 8 complete the winding. This solves the technical problem of significant material loss at the cutting end and excessive metal burrs caused by slitting, achieving the technical effect of minimal material loss at the cutting end and compliant metal burrs during slitting.

[0030] like Figure 5 As shown, a pair of permanent magnets 16 are symmetrically arranged on both sides of the vertical pole plane of the first cutter 11 to form a vertical magnetic field; a pair of permanent magnets 16 are symmetrically arranged on both sides of the second cutter 12 along the parallel pole plane to form a parallel magnetic field.

[0031] The first cutting blade 11 processes the positive electrode aluminum foil. On both sides of the blade edge, perpendicular to the electrode transport direction, a rectangular permanent magnet 16 is vertically mounted. The left permanent magnet 16 has its N pole facing the electrode plane and its S pole facing outward, while the right permanent magnet 16 has its S pole facing the electrode plane and its N pole facing outward, forming a magnetic field perpendicular to the electrode plane. During cutting, the Lorentz force constrains the lateral migration of aluminum atoms, thereby suppressing burr generation. The second cutting blade 12 processes the negative electrode copper foil. On both sides of the blade edge, parallel to the electrode transport direction, a rectangular permanent magnet 16 is horizontally mounted at the electrode input and output ends. Both permanent magnets 16 are set with their N poles facing left and their S poles facing right, forming a magnetic field parallel to the electrode plane. Through the magnetostrictive effect, the local rigidity of the copper foil shearing zone is enhanced, causing it to fracture neatly and brittlely, thus reducing material loss. A simple bracket with a long slot is installed at the corresponding position of the tool holder assembly 1. The permanent magnet 16 is directly inserted into the bracket slot. A knob screw is screwed on the side of the bracket to hold the permanent magnet 16 in place. When it needs to be moved, loosen the screw, push the permanent magnet 16 to the target position, and then tighten it again. When it needs to be disassembled, the permanent magnet 16 can be removed from the slot by completely loosening the screw. Physical interventions targeting the different material properties of positive and negative electrodes are employed. Positive electrode aluminum foil is soft and ductile, making it prone to tearing and burr formation during cutting. A perpendicular magnetic field can effectively constrain the lateral migration of aluminum atoms during shearing by means of the Lorentz force, thereby suppressing burr formation. In contrast, negative electrode copper foil is hard and brittle, making it prone to microscopic fractures due to stress concentration during cutting, resulting in material loss. A parallel magnetic field can instantly enhance the local rigidity of the copper foil shearing zone through the magnetostrictive effect, making it more prone to neat brittle fracture rather than irregular fracture, thereby significantly reducing material loss. Example

[0032] like Figure 1 As shown, a first transmission shaft 3 is provided at one end of the tool holder assembly 1, and an unwinding shaft 2 is provided at the other end of the first transmission shaft 3. The transmission shaft is used to transmit the electrode sheet to the tool holder assembly 1.

[0033] The unwinding shaft 2 is responsible for releasing the electrode roll to be slit. Guided and pulled by the first transmission shaft 3, the electrode is smoothly and continuously transported to the cutting area of ​​the cutter assembly 1. This ensures that the electrode maintains stable tension before entering the cutting station, avoiding deviations in the cutting position caused by wrinkles or offsets during the transport process. This provides the prerequisite for accurate slitting by the subsequent cutter and realizes the automated continuous flow of the electrode from unwinding to cutting, ensuring the continuity and efficiency of the slitting process.

[0034] like Figure 1-4 As shown, the heating module 13 has an arc-shaped structure design. The arc-shaped heating surface of the heating module 13 is adapted to the edge contour of the first cutter 11 to form a fan-shaped coverage area. The width of the first cutter 11 is smaller than the width of the second cutter 12.

[0035] The heating module 13 adopts a quarter-circle arc-shaped structure design. Its arc-shaped heating surface forms a thermal coupling with the profile of the first cutter 11. The fan-shaped coverage area achieves directional heating of the cutting front end, ensuring that the first cutter 11 obtains a stable and suitable thermal state before contacting the electrode. The thick electrode is heated to reduce the deep shearing resistance, while the thin electrode is kept moderately heated to avoid excessive softening. With the stepped shearing of the first cutter 11, which is narrower than the width of the second cutter 12, the first cutter 11 contacts the electrode first to form an initial cut. Its narrow blade structure can concentrate the shearing force to ensure accurate cutting into the surface of electrode layers of different thicknesses. The wide second cutter 12 then provides support to the cutting area and disperses the shearing stress by utilizing its larger contact area, avoiding the problem of local excessive compression or incomplete cutting of the electrode due to thickness fluctuations. With the cooperation of the heating module 13, this achieves the technical effect of slitting with minimal material loss at the shearing end and meeting the metal burr standard.

[0036] like Figure 1 As shown, a sealing cover is provided on the blade holder assembly 1. The sealing cover is used to block the interference of the external environment on the first cutter 11 and the second cutter 12.

[0037] Before the electrode sheet enters the cutter assembly 1 via the first transmission shaft 3, a sealing cover forms an isolation barrier. The first cutter 11 and the second cutter 12 are located inside the sealing cover. During operation, the sealing cover physically blocks dust, debris, and other foreign objects from the external environment from entering the working area of ​​the first cutter 11 and the second cutter 12. This prevents foreign objects from adhering to the blades of the first cutter 11 and the second cutter 12 or the surface of the electrode sheet, which could cause slag inclusions or uneven force during shearing, thus reducing material loss and burrs. At the same time, it isolates the cutter from the influence of external airflow disturbances and equipment vibrations, ensuring that the first cutter 11 and the second cutter 12 always maintain a precise relative position and shear the electrode sheet according to a preset trajectory. This avoids problems such as slanted cuts and miscuts caused by the offset of the first cutter 11 and the second cutter 12. As a result, the first cutter 11 and the second cutter 12 work efficiently and accurately throughout the entire slitting process, ultimately achieving the technical effect of minimal material loss at the shearing end face and meeting the metal burr standard.

[0038] like Figure 1 As shown, an upper transmission shaft 5 and a lower transmission shaft 6 are provided on the other side of the tool holder assembly 1, and both the upper transmission shaft 5 and the lower transmission shaft 6 are equipped with dust removal devices 4.

[0039] The slit electrodes enter the conveying paths of the upper conveyor shaft 5 and the lower conveyor shaft 6, respectively. As they pass through the dust removal device 4, the device uses brush cleaning and negative pressure adsorption to remove residual cutting debris, dust, and impurities from the electrode surface. This prevents the slit electrodes from carrying impurities into the winding shaft, thus preventing impurities from embedding in the electrodes or contaminating the winding shaft, ensuring electrode cleanliness. It also reduces the risk of impurities re-adhering to the first cutter 11 and the second cutter 12 during transport, indirectly maintaining the stability of the cutting environment. This reduces post-slit processing abnormalities caused by impurities and improves overall slit quality.

[0040] like Figure 1 As shown, a take-up shaft assembly is provided on the other side of the dust removal device 4. The take-up shaft assembly includes a first take-up shaft 7 and a second take-up shaft 8. The first take-up shaft 7 is located on the upper end of the second take-up shaft 8. The first take-up shaft 7 corresponds to the upper transmission shaft 5, and the second take-up shaft 8 corresponds to the lower transmission shaft 6.

[0041] After slitting, the electrode sheets are conveyed via the upper transmission shaft 5 to the corresponding first take-up shaft 7, and via the lower transmission shaft 6 to the corresponding second take-up shaft 8. During the transmission process, surface impurities are first removed by the dust removal device 4. Then, the take-up shafts operate synchronously with the transmission system, winding the electrode sheets into rolls. The independent upper and lower take-up paths prevent the slitting electrode sheets from contacting each other and causing friction, contamination, or abnormal stacking. This ensures that the take-up tension of different slitting strips is uniform. At the same time, the corresponding setting of the take-up shaft and the transmission shaft achieves path matching from slitting to cleaning to take-up, ensuring that the electrode sheets remain flat during continuous transmission and avoiding wrinkles and stretching deformation caused by misalignment during take-up, ultimately improving the winding quality of the slitting electrode sheets.

[0042] like Figure 1 , 3 As shown, there are several first cutters 11 and several second cutters 12, and the number of each is corresponding. The several first cutters 11 are evenly distributed along the axial direction of the first cutter holder 14, and the several second cutters 12 are evenly distributed along the axial direction of the second cutter holder 15.

[0043] Several first cutters 11 are evenly arranged along the axis of the first cutter holder 14, and a corresponding number of second cutters 12 are synchronously distributed along the axis of the second cutter holder 15, forming multiple sets of parallel shearing stations. When the electrode sheet is conveyed to the cutter holder assembly 1, multiple sets of first cutters 11 and second cutters 12 simultaneously slit the electrode sheet, completing the synchronous cutting of multiple electrode sheets at one time, greatly improving the slitting efficiency. By working in parallel at multiple stations, the slitting time of a single batch of electrode sheets is shortened, and the spacing of each slitting strip is ensured to be consistent. Because the first cutters 11 and second cutters 12 are evenly distributed, the equidistant spacing of adjacent shearing paths can be guaranteed. This technology is suitable for the slitting requirements of electrode sheets. Multiple sets of first cutters 11 and second cutters 12 distribute the shearing load, avoiding uneven wear caused by long-term high-intensity operation of a single set of first cutters 11 and second cutters 12. Furthermore, several first cutters 11 and second cutters 12 are evenly distributed along the first cutter holder 14 and the second cutter holder 15, ensuring that the force on each shearing part of the electrode sheet is consistent, avoiding irregular electrode sheet breakage caused by excessive or insufficient local force, reducing end face material loss, and thus effectively controlling the generation of metal burrs. Ultimately, it achieves the technical effect of slitting with minimal end face material loss and meeting the metal burr standard. The first cutter 11 and the second cutter 12 employ right-angled cutting edges. These right-angled edges, with their 90° vertical structure, achieve high sharpness and rapid contact with the electrode. Stress concentration at the cutting edge tip allows for instantaneous shearing. An annular rubber pad is also installed between the first cutter 11 and the first blade holder 14. When the electrode is transferred to the blade holder assembly 1, the first cutter 11 rotates around the first blade holder 14. The rubber pad at the end of the first blade holder 14 experiences slight compression due to the force exerted by the first cutter 11, converting the instantaneous impact force into elastic potential energy and preventing... The blades of the first cutter 11 and the second cutter 12 collide hard with the electrode sheet, and the high-frequency vibration of the first cutter 11 causes the blade to miscut the electrode sheet, thus reducing burr generation from the source. After cutting, the rubber pad rebounds and resets. The micro-deformation of the rubber pad allows the first cutter 11 to adapt to the slight undulations of the electrode sheet surface, ensuring that the shearing force is evenly applied to the material and preventing excessive local compression. This reduces cutting abnormalities such as burrs and curling, thereby achieving the technical effect of minimal material loss at the shearing end face and meeting the metal burr standard during cutting.

[0044] Although the illustrative specific embodiments of this application have been described above to enable those skilled in the art to understand this application, this application is not limited to the scope of the specific embodiments. For those skilled in the art, all applications utilizing the concept of this application are protected as long as various variations are within the spirit and scope of this application as defined and determined by the appended claims.

Claims

1. An electrode slitting device, comprising: A tool holder assembly, comprising a first tool holder and a second tool holder, wherein the first tool holder is disposed on the upper end of the second tool holder, a first cutting blade is disposed on the first tool holder, and a second cutting blade is disposed on the second tool holder; The first cutter and the second cutter are arranged opposite each other in a longitudinally overlapping and laterally separated state. The lateral distance between the first cutter and the second cutter can be dynamically adjusted according to the thickness and compaction density of the electrode. The lateral distance is positively correlated with the thickness parameter of the electrode and negatively correlated with the compaction density parameter of the electrode. A heating module is disposed on the first blade holder and covers the shearing area of ​​the first cutter. The heating module is used to preheat the first cutter to reduce the shearing intensity of the electrode sheet.

2. The electrode slitting device according to claim 1, characterized in that, The tool holder assembly has a first transmission shaft at one end and an unwinding shaft at the other end. The transmission shaft is used to transmit the electrode sheet to the tool holder assembly.

3. The electrode slitting device according to claim 1, characterized in that, The heating module has an arc-shaped structure design, and the arc-shaped heating surface of the heating module is adapted to the edge contour of the first cutter to form a fan-shaped coverage area.

4. The electrode slitting device according to claim 1, characterized in that, The blade holder assembly is equipped with a sealing cover, which is used to block external environmental interference to the first cutter and the second cutter.

5. The electrode slitting device according to claim 1, characterized in that, The tool holder assembly is provided with an upper transmission shaft and a lower transmission shaft on the other side, and both the upper transmission shaft and the lower transmission shaft are equipped with dust removal devices.

6. The electrode slitting device according to claim 5, characterized in that, A take-up shaft assembly is provided on the other side of the dust removal device, the take-up shaft assembly including a first take-up shaft and a second take-up shaft.

7. The electrode slitting device according to claim 6, characterized in that, The first take-up shaft is disposed on the upper end of the second take-up shaft.

8. The electrode slitting device according to claim 6, characterized in that, The first take-up shaft corresponds to the upper transmission shaft, and the second take-up shaft corresponds to the lower transmission shaft.

9. The electrode slitting device according to claim 1, characterized in that, The first cutter and the second cutter are provided in a plurality of corresponding numbers. The plurality of first cutters are evenly distributed along the axial direction of the first cutter holder, and the plurality of second cutters are evenly distributed along the axial direction of the second cutter holder.

10. The electrode slitting device according to claim 1, characterized in that, The width of the first cutter is smaller than the width of the second cutter.

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