Electrode sheet slitting and winding method and device

Abstract

An electrode sheet slitting and winding method, comprising the following steps: by means of a cutting member, cutting a foil region (82) in the middle of an initial electrode sheet to form two identical first slit electrode sheets, and separately winding the two first slit electrode sheets; and transporting each of the wound first slit electrode sheets to a laser cutting station to process tabs on the foil regions (82) on two sides of the first slit electrode sheet, and upon completion of tab processing, further slitting the electrode sheet provided with the tabs to form two identical second slit electrode sheets, and synchronously winding the two second slit electrode sheets to form a battery cell. Further provided is a slitting and winding device for implementing the method.

Description

A pole piece slitting and winding method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on September 15, 2023, with application number 202311198387.1 and application name “A method and device for slitting and winding pole pieces”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present invention relates to the technical field of battery core processing, and in particular to a pole piece slitting and winding method and equipment. Background Art

[0004] In the battery cell manufacturing process, electrode slitting is a key step, ensuring that the size and shape of the electrode meet the design requirements to meet the performance and safety requirements of the battery. The slitting process can be achieved through different methods such as mechanical cutting, laser cutting, and press cutting.

[0005] The purpose of cell electrode slitting is to cut large electrode sheets into appropriate sizes and shapes based on battery design requirements. This allows for an effective electrochemical reaction zone between the positive and negative electrodes of the cell, providing good current conduction and ion diffusion channels. Furthermore, electrode slitting ensures cell consistency and reliability, ensuring stable and controllable battery performance.

[0006] At present, the commonly used method of cutting the electrode is to cut the electrode at the same time through three synchronous cutting devices, and then the cut electrode sheets are rolled up separately to enter the next process. Since the three cutting devices are cutting at the same time, four rolls of electrode sheets will be produced. The four rolls of electrode sheets are transported through the transfer device, and then the electrode ears are processed in turn, which greatly prolongs the processing time of the battery cell and reduces production efficiency.

[0007] Therefore, how to shorten the processing time of battery cells and improve the production efficiency of battery cells has become a technical problem that needs to be solved urgently.

[0008] Summary of the Invention

[0009] The main purpose of the present invention is to provide a method and equipment for slitting and winding pole pieces, aiming to shorten the processing time of battery cells and improve the production efficiency of battery cells.

[0010] In order to achieve the above object, the present invention proposes a pole piece slitting and winding method, comprising the following steps:

[0011] Cutting the foil area in the middle of the initial electrode piece by a cutting member to generate two identical first split electrode pieces, and respectively rolling up the two first split electrode pieces;

[0012] The first split electrode sheet that has been wound is transported to the laser cutting station to process the pole ears on the foil area on both sides of the first split electrode sheet. After the pole ear processing is completed, the pole sheet with the pole ear is split again to generate two identical second split electrode sheets, and the two second split electrode sheets are synchronously wound to generate battery cells.

[0013] In one embodiment of the present application, before re-slicing the pole piece with the pole tab, the method further includes: correcting the pole piece with the pole tab by a correction component and / or correcting the re-cut pole piece after the re-slicing is completed.

[0014] In one embodiment of the present application, processing the tab includes the following steps:

[0015] A laser cutting unit is used to cut annular through holes in the foil area on both sides of the first split electrode. The width of the through hole is the length of the electrode tab, and the outer side of the through hole is used to prevent the electrode tab from bending during transportation.

[0016] Before the pole piece with the pole lug is cut again, the waste edge is cut off by a cutting piece.

[0017] The present application also discloses a pole piece cutting device, which is characterized by comprising:

[0018] A tab cutting device is used to cut an annular through hole in the foil area at the edge of the first split electrode piece, wherein the width of the annular through hole is equal to the length of the tab;

[0019] a slitting device for cutting off the edge outside the annular through hole to form a pole ear, and dividing the first slitting pole piece into two identical second slitting pole pieces along the middle position of the length direction of the first slitting pole piece; and

[0020] The winding device is used to wind the two second split electrode sheets to synchronously generate two battery cells.

[0021] In one embodiment of the present application, the slitting device includes:

[0022] frame;

[0023] a first cutter, rotatably connected to the frame, for dividing the first cut electrode piece into two identical second cut electrode pieces along the middle position of the length direction of the first cut electrode piece;

[0024] a second cutter connected to the frame and located in front of the process of the first cutter, for cutting an annular through hole in the foil area at the edge of the first cut electrode; and

[0025] A first driving member is connected to the frame and is used for driving the first cutter and the second cutter to rotate.

[0026] In one embodiment of the present application, the slitting device further comprises:

[0027] The feeding guide roller is connected to the frame and is used to guide the pole piece entering the second cutting station.

[0028] In one embodiment of the present application, the slitting device further comprises:

[0029] The discharge guide roller is connected to the frame and is used for guiding the output of the second cut electrode piece.

[0030] In one embodiment of the present application, the slitting device further comprises:

[0031] The second driving member is connected to the frame, and the driving part of the second driving member is connected to the feeding guide roller and the discharging guide roller through a transmission belt.

[0032] By adopting the above technical solution, the initial electrode sheet is cut for the first time by the cutting piece, so that the initial electrode sheet is divided into two parts, which reduces the number of windings, thereby reducing the number of handling times during the subsequent tab processing, and improving the efficiency of battery cell processing. After the tab processing of the first split electrode sheet, the tab is cut on the first split electrode sheet so that the first split electrode sheet obtains the tab structure, and at the same time, the electrode sheet with the tab is split again to generate the second split electrode sheet, so that two electrode sheets can be produced at a time, thereby improving production efficiency and the yield rate in the production process. The process is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0034] FIG1 is a schematic diagram of the process structure of the first embodiment of the present invention;

[0035] FIG2 is a schematic diagram of the three-dimensional structure of the slitting device of the present invention;

[0036] Figure 3 is a schematic diagram of the structure of the initial pole piece;

[0037] 10. First cutter; 20. Second cutter; 30. Infeed guide roller; 40. Outfeed guide roller; 50. Machine frame; 60. Second driving member. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation of the present invention.

[0039] As shown in FIG1 and FIG3, in order to achieve the above-mentioned purpose, the present invention proposes a pole piece slitting and winding method, comprising the following steps:

[0040] The foil area 82 in the middle of the initial electrode sheet is cut by a cutting member to generate two identical first split electrode sheets, and the two first split electrode sheets are respectively rolled up;

[0041] The first split electrode sheet that has been wound is transported to the laser cutting station to process the electrode tabs on the foil area 82 on both sides of the first split electrode sheet. After the electrode tab processing is completed, the electrode sheet with the electrode tabs is split again to generate two identical second split electrode sheets, and the two second split electrode sheets are synchronously wound to generate battery cells.

[0042] Specifically, the initial large-sized electrode sheet is cut by a cutting piece to obtain two identical first-cut electrode sheets. Each first-cut electrode sheet is rolled up and wound into a compact roll form for subsequent processing. According to the process requirements, the first-cut electrode sheets that have been rolled up are transported one by one to the laser cutting station. At this station, the two ends of the first-cut electrode sheet are processed to form a pole ear structure for subsequent battery assembly. After the pole ear processing is completed, the pole sheet with the pole ear is cut again. Through appropriate cutting technology and equipment, the pole sheet is cut into two identical second-cut pole sheets.

[0043] The initial electrode sheet, along its width, consists of a first foil area, a first coating area, a second foil area, a second coating area, and a third foil area. The first coating area and the second coating area are equal in area and symmetrical about the center of the second coating area. The width of the second foil area is twice that of the first foil area, and the width of the first foil area is equal to that of the second foil area. The first slitting is performed along the length of the electrode sheet at the middle of the second foil area, thereby forming two identical first-slit electrode sheets.

[0044] Since the initial electrode is only cut once, only the two first-cut electrode sheets need to be rolled up, which reduces the number of rolls, thereby reducing the number of subsequent handling times and improving work efficiency.

[0045] By adopting the above technical solution, the initial electrode sheet is cut for the first time by the cutting piece, so that the initial electrode sheet is divided into two parts, which reduces the number of windings, thereby reducing the number of handling times during the subsequent tab processing, and improving the efficiency of battery cell processing. After the tab processing of the first split electrode sheet, the tab is cut on the first split electrode sheet so that the first split electrode sheet obtains the tab structure, and at the same time, the electrode sheet with the tab is split again to generate the second split electrode sheet, so that two electrode sheets can be produced at a time, thereby improving production efficiency and the yield rate in the production process. The process is simple and easy to implement.

[0046] In one embodiment of the present application, before re-slicing the pole piece with the pole tab, the method further includes: correcting the pole piece with the pole tab by a correction component and / or correcting the re-cut pole piece after the re-slicing is completed.

[0047] Specifically, before the electrode with the tab is cut again, the electrode is fed into a deflection correction assembly, which can adjust and correct the electrode by adjusting a conveyor belt, rollers or other devices to correct its offset or deflection angle.

[0048] The correction component corrects the pole piece according to the set parameters and control system. The correction device can be adjusted automatically or manually to meet the specific needs of the pole piece. Through real-time monitoring and feedback control, the pole piece is ensured to achieve the desired position and attitude during the correction process.

[0049] The corrected pole piece is inspected to ensure that the correction operation achieved the desired results. Sensors, vision systems, or other inspection tools can be used to assess the degree and quality of the pole piece correction and make necessary adjustments and corrections. After the correction operation is completed, the corrected pole piece is re-slit. After the re-slit is completed, the re-cut pole piece is corrected. This can be performed using steps similar to the pre-correction treatment to further improve the flatness and dimensional consistency of the pole piece.

[0050] By adopting the above technical solution, the deviation of the pole piece with the pole ear is corrected by the deviation correction component, and the offset and deflection of the pole piece can be corrected, thereby improving the dimensional consistency of the pole piece. This helps to ensure that the pole piece has the same width and length after being cut again. The deviation correction operation can eliminate the distortion and warping of the pole piece and make it flatter. This helps to improve the surface quality of the pole piece and provide better processing performance in subsequent processes. By using the deviation correction component, the deviation correction operation can be precisely controlled and adjusted. This allows the deviation correction parameters to be optimized as needed during the production process and achieve consistent deviation correction effects. The deviation correction operation can reduce production problems caused by deviation or distortion of the pole piece, such as equipment blockage, inaccurate processing, etc. By ensuring the flatness and dimensional consistency of the pole piece, failures and downtime in production can be reduced, and production efficiency and output can be improved.

[0051] In one embodiment of the present application, processing the tab includes the following steps:

[0052] A laser cutting unit is used to cut annular through holes in the foil area on both sides of the first split electrode. The width of the through hole is the length of the electrode tab, and the outer side of the through hole is used to prevent the electrode tab from bending during transportation.

[0053] Before the pole piece with the pole lug is cut again, the waste edge is cut off by a cutting piece.

[0054] Specifically, during the electrode preparation process, a cutting tool is used to cut the foil area at the edge of the electrode, forming multiple annular through holes on both sides of the length direction of the first cut electrode. The width of the cut annular through hole is the length of the electrode ear. Since the annular through hole is a closed structure, the electrode ear is connected through the waste edge outside the annular through hole, which improves the stability of the electrode ear during transmission and avoids wrinkles on the electrode ear during movement.

[0055] By adopting the above technical solution, the foil area at the edge of the electrode piece is cut to form the pole ear contour, while the outer sides of any adjacent pole ear contours are retained and connected by waste edges, thereby reducing the possibility of the pole ear wrinkling during transportation.

[0056] The present application also discloses a pole piece cutting device, which is characterized by comprising:

[0057] A tab cutting device is used to cut an annular through hole in the foil area at the edge of the first split electrode piece, wherein the width of the annular through hole is equal to the length of the tab;

[0058] a slitting device for cutting off the edge outside the annular through hole to form a pole ear, and dividing the first slitting pole piece into two identical second slitting pole pieces along the middle position of the length direction of the first slitting pole piece; and

[0059] The winding device is used to wind the two second split electrode sheets to synchronously generate two battery cells.

[0060] Specifically, the tab cutting device is used to cut an annular through hole in the foil area 82 at the edge of the first split electrode sheet. The width of the annular through hole is equal to the length of the tab. The basic outline of the tab is cut by the tab cutting device.

[0061] The slitting device is used to remove the edge outside the annular through-hole to form the tab. The tab is the portion of the foil region 82 that protrudes outward. After completing the removal of the waste edge, the slitting device separates the first-cut electrode sheet into two identical second-cut electrode sheets along the middle of its length. The slitting device typically includes components such as cutting tools, a conveyor system, and a control system to ensure the accuracy and stability of the waste edge removal and re-slitting processes. Finally, the tab is wound by a winding device to produce two battery cells.

[0062] By adopting the above technical solution, the initial electrode sheet is cut once by the cutting piece, so that the initial electrode sheet is divided into two parts, which reduces the number of windings, thereby reducing the number of handling times during the subsequent tab processing and improving the efficiency of battery cell processing. After the tab processing of the first split electrode sheet, the tab is cut on the first split electrode sheet so that the first split electrode sheet obtains the tab structure. At the same time, the electrode sheet with the tab is split again to generate the second split electrode sheet, which improves production efficiency and the yield rate in the production process. The process is simple and easy to implement.

[0063] As shown in FIG2 , in one embodiment of the present application, the slitting device includes:

[0064] Rack 50;

[0065] A first cutter 10 is rotatably connected to the frame and is used to split the first cut electrode piece into two identical second cut electrode pieces along the middle position of the length direction of the first cut electrode piece;

[0066] A second cutter 20 is connected to the frame and is located in front of the process of the first cutter, and is used to cut an annular through hole in the foil area at the edge of the first split electrode; and

[0067] A first driving member is connected to the frame and is used for driving the first cutter and the second cutter to rotate.

[0068] Specifically, the frame 50 is the supporting structure of the entire processing system, which is used to provide a stable platform and support the installation of various components. It plays a fixing and supporting role in the entire processing process, ensuring the stability of the position and relative relationship of various components.

[0069] The first cutter 10 is connected to the frame 50 and is primarily used to further split the coating area 81 of the electrode after the waste edge has been removed, forming two identical second-cut electrode pieces. The first cutter 10 is typically a cutting tool that uses mechanical movement and cutting force to cut the electrode into the desired size. It is conceivable that the cutting tool can also be a laser, etc. The first cutter 10 cuts with upper and lower blades. The upper blade is a single-sided circular cutting blade with a blade angle of 30°; the lower blade is a flat blade with a blade angle of 90° and a flat blade tip of 3mm.

[0070] The second cutter 20 is connected to the frame 50 and is located in front of the process of the first cutter 10. Its main function is to cut off the waste edge of the pole piece after the tab cutting is completed. The second cutter 20 is usually also a cutting tool, which cuts off the waste edge of the pole piece through mechanical movement and cutting force. The number of blades of the second cutter 20 is two. The second cutter is a suspended single-sided circular ring cutter with an upper single blade angle of 30°.

[0071] The first driving member is connected to the frame 50 and is used to drive the movement of the first cutter 10 and the second cutter 20. The first driving member provides power and control signals so that the first cutter 10 and the second cutter 20 can perform cutting operations according to a predetermined path and speed.

[0072] Using this technical solution, the first and second cutters 10, 20, through mechanical motion and cutting force, can precisely separate the electrode sheets, ensuring dimensional consistency between the first and second cut pieces. The second cutter 20 is responsible for removing the waste edge of the electrode sheet after the tabs have been cut, reducing waste and resource consumption. The frame 50, as a supporting structure, provides a stable platform, ensuring the positional relationship and stability of various components, thereby achieving efficient electrode processing and production.

[0073] In one embodiment of the present application, the slitting device further comprises:

[0074] The feed guide roller 30 is connected to the frame 50 and is used to guide the pole piece entering the second cutter 20 station.

[0075] Specifically, the feed guide roller 30 is connected to the frame 50 and is located in the path of the electrode sheet entering the second cutter station 20. It is typically a roller-shaped device that guides and directs the incoming electrode sheet, ensuring that it maintains the correct position and orientation before entering the second cutter station 20. The feed guide roller 30 provides the necessary guidance and support to ensure that the electrode sheet maintains a stable position and orientation during the cutting process. This helps prevent the electrode sheet from shifting, shaking, or rotating, thereby ensuring accurate and consistent cutting.

[0076] In one embodiment of the present application, the slitting device further comprises:

[0077] The discharge guide roller 40 is connected to the frame 50 and is used to guide the discharge of the second cut electrode piece.

[0078] Specifically, the discharge guide roller 40 is connected to the frame 50 and is located in the discharge path of the first cutter 10. It is typically a roller-shaped device that guides and directs the discharge direction of the second-slit electrode sheet, ensuring its smooth exit from the processing system. By providing the necessary guidance and support, the discharge guide roller 40 ensures that the second-slit electrode sheet maintains the correct position and orientation when leaving the processing system, preventing accumulation, entanglement, and other discharge problems.

[0079] In one embodiment of the present application, the slitting device further comprises:

[0080] The second driving member 60 is connected to the frame 50 , and the driving portion of the second driving member 60 is connected to the feed guide roller 30 and the discharge guide roller 40 via a transmission belt.

[0081] Specifically, the second drive member 60 is connected to the frame 50 and is connected to the feed guide roller 30 and the discharge guide roller 40 via a transmission belt. The second drive member 60 typically includes a drive motor for transmitting power and motion to the feed guide roller 30 and the discharge guide roller 40. The primary function of the second drive member 60 is to provide driving force and motion for the feed guide roller 30 and the discharge guide roller 40. Through the operation of the drive unit, the second drive member 60 transmits power from the frame 50 to the transmission belt, thereby driving the feed guide roller 30 and the discharge guide roller 40 to rotate or move, ensuring proper guidance and output. The drive unit of the second drive member 60 enables the feed guide roller 30 and the discharge guide roller 40 to achieve synchronized movement. This enables them to work in coordination, maintain correct position and orientation, and avoid deviation or misalignment, thereby improving the efficiency and accuracy of the entire processing system.

[0082] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the contents of the present description and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A pole piece slitting and winding method, characterized in that: The following steps are involved: Cutting the foil area in the middle of the initial pole piece by a cutting piece to generate two identical first split pole pieces, and rolling up the two first split pole pieces respectively; The first cut electrode sheet that has been rolled up is transported to the laser cutting station to process the pole ears on the foil area on both sides of the first cut electrode sheet. After the pole ear processing is completed, the pole sheet with the pole ear is cut again to generate two identical second cut electrode sheets, and the two second cut electrode sheets are synchronously wound to generate battery cells.

2. The pole piece slitting and winding method according to claim 1, characterized in that: Before the pole piece with the pole ear is re-cut, the method further includes: correcting the pole piece with the pole ear by a correction component and / or correcting the re-cut pole piece after the re-cutting is completed.

3. The pole piece slitting and winding method according to claim 1, characterized in that: The processing of the tab comprises the following steps: A circular through hole is cut in the foil area on both sides of the first split electrode piece by a laser cutting member. The width of the through hole is the length of the electrode ear. The outer side of the through hole is to prevent the waste edge of the electrode ear from bending during the transmission process. Before the pole piece with the pole lug is cut again, the waste edge is cut off by a cutting piece.

4. A pole piece cutting device, characterized in that: include: A pole ear cutting device, used for cutting an annular through hole in the foil area at the edge of the first cut pole piece, wherein the width of the annular through hole is equal to the length of the pole ear; A slitting device, used for cutting off the edge outside the annular through hole to form a pole ear, and dividing the first slitting pole piece into two identical second slitting pole pieces along the middle position of the length direction of the first slitting pole piece; as well as The winding device is used to wind the two second split pole pieces to synchronously generate two battery cells.

5. The pole piece cutting device according to claim 4, characterized in that: The slitting device comprises: frame; A first cutter, rotatably connected to the frame, for dividing the first cut electrode piece into two identical second cut electrode pieces along a middle position in the length direction of the first cut electrode piece; A second cutter, connected to the frame and located at the process front side of the first cutter, is used to cut an annular through hole in the foil area at the edge of the first cut electrode piece; and A first driving member is connected to the frame and is used for driving the first cutter and the second cutter to rotate.

6. The pole piece cutting device according to claim 5, characterized in that: The slitting device also includes: The feeding guide roller is connected to the frame and is used to guide the pole piece entering the second cutting station.

7. The pole piece cutting device according to claim 6, characterized in that: The slitting device also includes: The material discharging guide roller is connected to the frame and is used for guiding the output of the second cut pole piece.

8. The pole piece cutting device according to claim 7, characterized in that: The slitting device also includes: The second driving member is connected to the frame, and the driving part of the second driving member is connected to the feeding guide roller and the discharging guide roller through a transmission belt.

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