Reverse stretching mechanism and slitting and folding machine for pole piece

Abstract

The application relates to the technical field of pole piece processing, in particular to a reverse stretching mechanism and a cutting and stacking machine for pole pieces. The reverse stretching mechanism comprises at least two adjusting roller assemblies, the at least two adjusting roller assemblies are arranged at intervals, the horizontal spacing and / or height difference between two adjacent adjusting roller assemblies are adjustable, the pole piece sequentially passes through the at least two adjusting roller assemblies, and in any two adjacent adjusting roller assemblies, one adjusting roller assembly is in contact with the upper surface of the pole piece, and the other adjusting roller assembly is in contact with the lower surface of the pole piece. At least the first adjusting roller assembly through which the pole piece passes is configured to provide a stretching force to stretch the pole piece in the direction opposite to the warping direction of the pole piece. The problems of cutting and stacking difficulty, pole piece collision and defective pole piece flowing into the battery cell caused by the warping of the pole piece are avoided, the quality risk is effectively reduced, and the stability of the lithium battery pole piece production process and the reliability of the product quality are improved.

Description

Technical Field

[0001] This application relates to the field of electrode processing technology, and in particular to a reverse stretching mechanism and a cutting and stacking machine for electrodes. Background Technology

[0002] In the current lithium battery electrode manufacturing process, the electrodes are stored and transported in a roll-up manner after rolling. During the winding process, the electrodes undergo curling changes. The closer the electrode is to the center of the roll, the higher the curling curvature, meaning the more severe the bending. As the roll diameter increases (typically 850mm), the curling curvature decreases further away from the center of the roll, resulting in less bending. In addition, the wound electrode rolls are stored in a buffer warehouse, with process requirements allowing for a storage time between 72-120 hours. During this resting period, the electrode rolls are affected by gravity, causing the curling degree of the electrode core inside the roll to increase with the storage time. When these electrodes are unwound and sliced ​​during the cutting or die-cutting process, they are in a warped state, affecting the cutting and stacking process and causing collisions at the transfer belt. This results in incomplete electrodes flowing into subsequent cell production, further increasing the quality risk. Summary of the Invention

[0003] To address the technical problem of electrode curling affecting the cutting and stacking effect, this application provides a reverse stretching mechanism and a cutting and stacking machine for electrodes.

[0004] The first aspect of this application provides a reverse stretching mechanism for an electrode, comprising at least two adjusting roller assemblies, the at least two adjusting roller assemblies being arranged at a distance in a horizontal direction, the horizontal distance and / or height difference between two adjacent adjusting roller assemblies being adjustable, the electrode sequentially passing around the at least two adjusting roller assemblies, and in any two adjacent adjusting roller assemblies, one adjusting roller assembly contacts the upper surface of the electrode, the other adjusting roller assembly contacts the lower surface of the electrode, and the first adjusting roller assembly around which the electrode passes is configured to provide a stretching force to stretch the electrode in the direction opposite to its warping direction.

[0005] In some embodiments, the adjusting roller assembly includes a roller body and a support, the support having a plurality of locking portions disposed at different heights of the support, and the roller body engaging with the locking portions at different heights to achieve height adjustment of the roller body.

[0006] In some embodiments, the reverse tensioning mechanism further includes a fixing frame, on which a plurality of first fixing parts are spaced apart along the horizontal direction, and a second fixing part is provided at the lower end of the bracket, wherein the second fixing part cooperates with the first fixing part to achieve the fixing of the two parts.

[0007] In some embodiments, the snap-fit ​​portion is a snap-fit ​​groove provided on one side of the bracket, and the two ends of the roller are provided with snap-fit ​​sections, which are snapped into the snap-fit ​​groove.

[0008] In some embodiments, the bracket is further provided with a quick-release locking member, which is detachably disposed at the opening of the snap-fit ​​groove for locking the snap-fit ​​section in the snap-fit ​​groove.

[0009] In some embodiments, the upper and lower sides of the slot of the snap-fit ​​groove are provided with first mounting holes, the quick-release locking component includes a locking block and a fastener, the locking block is provided with a second mounting hole, and the fastener passes through the second mounting hole and the first mounting hole in sequence to fix the locking block on the bracket.

[0010] In some embodiments, the roller body is provided with a sealed heating channel, and a heating element is provided within the heating channel.

[0011] In some embodiments, the roller body is provided with an insulating layer and a wear-resistant layer, the wear-resistant layer being disposed between the roller body and the insulating layer, such that the insulating layer protrudes from the outer circumferential surface of the roller body.

[0012] A second aspect of this application provides an electrode sheet cutting and stacking machine, including a conveying mechanism, a die-cutting mechanism, and a reverse stretching mechanism as described in any of the preceding claims, wherein the reverse stretching mechanism is disposed between the conveying mechanism and the die-cutting mechanism.

[0013] In some embodiments, the conveying mechanism includes a conveying roller, and the adjusting roller assembly includes a roller body, the diameter of which is smaller than the diameter of the conveying roller.

[0014] The technical solution provided in this application has the following advantages compared with the prior art:

[0015] The reverse stretching mechanism for electrodes provided in this application embodiment is configured to provide a stretching force through the first adjusting roller assembly around which the electrode passes, causing the electrode to bend in the opposite direction to its warping direction. This reverse stretching method can directly act on the warped portion of the electrode, gradually flattening the warped electrode by applying an appropriate stretching force, restoring the flatness of the electrode, thereby ensuring that the electrode can be used smoothly in subsequent processes and improving the overall quality of the product. Since the horizontal spacing and height difference between adjacent adjusting roller assemblies are adjustable, this mechanism can adapt to the processing needs of electrode sheets with different curvature directions and curvature degrees, improving the versatility and flexibility of the equipment, eliminating the need to replace a large number of special equipment or make complex adjustments for different electrode sheets. It avoids problems such as difficulties in cutting and stacking, electrode collisions, and defective electrode sheets flowing into the battery cell caused by electrode warping, effectively reducing quality risks and improving the stability of the lithium battery electrode production process and the reliability of product quality. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the reverse stretching of the electrode sheet as described in the embodiments of this application;

[0019] Figure 2 This is a schematic diagram of the reverse stretching mechanism of the electrode sheet described in the embodiments of this application;

[0020] Figure 3 This is a schematic diagram of the structure of the cutting and stacking machine described in the embodiments of this application.

[0021] Among them, 1 is the fixing frame; 11 is the first fixing part;

[0022] 2. Adjusting roller assembly; 21. Bracket; 22. Roller body; 23. Quick-release locking element; 211. Snap-fit ​​groove;

[0023] 3. Electrode;

[0024] 10. Conveying mechanism; 20. Reverse stretching mechanism; 30. Die-cutting mechanism. Detailed Implementation

[0025] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0027] In related technologies, solving the problem of electrode warping mainly relies on process adjustments in the rolling section. Specifically, increasing the stretching effect of the rolling section and appropriately shortening the electrode storage time can alleviate the warping problem to some extent. However, when encountering electrode rolls incompatible with existing processes, the current approach is rework, which involves rewinding the electrode rolls to adjust their curling state. This rework is a double-edged sword; while it improves the electrode condition, it severely impacts production efficiency and easily causes secondary damage to the electrodes during rewinding, posing a potential threat to product quality. Furthermore, at the equipment level, neither the slitting machine nor the die-cutting machine is equipped with a stretching mechanism, which limits further optimization and control of the electrode condition.

[0028] To address the issues of electrode curling affecting the slitting and stacking effect and secondary damage to the electrode caused by secondary rewinding in related technologies, this application provides a reverse stretching mechanism for the electrode, which can improve the curling state of the electrode.

[0029] like Figure 1 and Figure 2 As shown in the embodiment of this application, a reverse stretching mechanism for an electrode sheet includes at least two adjusting roller assemblies 2. These at least two adjusting roller assemblies 2 are spaced apart horizontally. The adjusting roller assemblies 2 can be directly fixed to the ground or fixed to a cutting and stacking machine. The horizontal distance and / or height difference between two adjacent adjusting roller assemblies 2 are adjustable. By adjusting the horizontal distance or height difference between the two adjusting roller assemblies 2, the wrap angle between the electrode sheet 3 and the adjusting roller assembly 2 can be adjusted. The wrap angle can be understood as the angle between the electrode sheet 3 and the vertical direction. The smaller the wrap angle, the greater the tensile force on the electrode sheet 3; conversely, the larger the wrap angle, the smaller the tensile force on the electrode sheet 3. Figure 1 The angle 'a' shown is the wrap angle between the electrode 3 and the adjusting roller assembly 2. The electrode 3 passes over at least two adjusting roller assemblies 2 in sequence, and in any two adjacent adjusting roller assemblies 2, one adjusting roller assembly 2 contacts the upper surface of the electrode 3, and the other adjusting roller assembly 2 contacts the lower surface of the electrode 3. At least the first adjusting roller assembly 2 that the electrode 3 passes over is configured to provide a tensile force to cause the electrode 3 to bend in the direction opposite to its warping direction.

[0030] For example, such as Figure 1As shown, when the electrode 3 bends upward, the first adjusting roller assembly 2 around which the electrode 3 passes contacts the lower surface of the electrode. That is, the electrode 3 is wound around the upper surface of the first adjusting roller assembly 2, and then around the lower surface of the second adjusting roller assembly 2 around which it passes, and so on, alternatingly around the downstream adjusting roller assembly 2. Taking three adjusting roller assemblies 2 as an example, the electrode 3 passes over the upper surface of the first adjusting roller assembly 2, the lower surface of the second adjusting roller assembly 2, and the upper surface of the third adjusting roller assembly 2. This causes the electrode 3 to be positioned to the left of the first adjusting roller assembly 2 when passing through the first and third adjusting roller assemblies 2. Under the action of the second adjusting roller assembly 2, the electrode 3 extends downward, forming an upward arch on the first adjusting roller assembly 2, providing a downward tensile force, thus causing the electrode 3 to bend in the opposite direction at the first adjusting roller assembly 2. Similarly, it also bends in the opposite direction when passing through the third adjusting roller assembly 2.

[0031] It is understandable that when the electrode 3 warps downward, the first adjusting roller assembly 2 around which the electrode 3 passes contacts the upper surface of the electrode 3. That is, the electrode 3 is wound around the lower surface of the first adjusting roller assembly 2, and then around the upper surface of the second adjusting roller assembly 2 around which it passes, and so on, alternatingly around the downstream adjusting roller assembly 2. Taking three adjusting roller assemblies 2 as an example, the electrode 3 passes over the lower surface of the first adjusting roller assembly 2, the upper surface of the second adjusting roller assembly 2, and the lower surface of the third adjusting roller assembly 2. This causes the electrode 3, located behind the first adjusting roller assembly 2, to extend upward under the action of the second adjusting roller assembly 2 when passing through either the first or third adjusting roller assembly 2. The electrode 3 forms a downward arch on the first adjusting roller assembly 2, providing an upward tensile force, thus causing the electrode 3 to bend in the opposite direction at the first adjusting roller assembly 2. Similarly, it also bends in the opposite direction when passing through the third adjusting roller assembly 2.

[0032] The reverse stretching mechanism for the electrode sheet provided in this application provides a stretching force to the electrode sheet 3 at the first adjusting roller assembly 2 around which the electrode sheet 3 passes, as well as at other adjusting roller assemblies 2, causing the electrode sheet 3 to bend in the opposite direction to its warping direction. This reverse stretching method can directly act on the warped portion of the electrode sheet 3. By applying an appropriate stretching force, the warped electrode sheet 3 is gradually flattened, restoring its flatness and ensuring that the electrode sheet 3 can be used smoothly in subsequent processes, thus improving the overall quality of the product. Furthermore, since the horizontal spacing and height difference between adjacent adjusting roller assemblies 2 are adjustable, this mechanism can adapt to the processing needs of electrode sheets 3 with different curvature directions and degrees of curvature, improving the versatility and flexibility of the equipment. It eliminates the need to replace a large number of specialized equipment or make complex adjustments for different electrode sheets 3. This avoids problems such as difficult cutting and processing, electrode collisions, and defective electrode sheets 3 flowing into the battery cell caused by electrode sheet warping, effectively reducing quality risks and improving the stability of the lithium battery electrode sheet 3 production process and the reliability of product quality.

[0033] Each adjusting roller assembly 2 includes a roller body 22 and a support 21. In some embodiments, each adjusting roller assembly 2 includes a U-shaped support or a V-shaped support with the connecting arm of the U-shaped support or V-shaped support facing upward. Multiple snap-fit ​​parts are provided on the connecting arm of the U-shaped support or V-shaped support. The height of the roller body 22 is adjusted by cooperating with the snap-fit ​​parts of different heights.

[0034] In other embodiments of this application, each adjusting roller assembly 2 includes a roller body 11 and two supports 21. The two supports 21 are arranged vertically, and multiple locking parts are spaced apart along the vertical direction on the supports 21. The two ends of the roller body 22 are respectively connected to two locking parts of equal height on the two supports 21. That is, after the roller body 22 is connected to the two supports 21, the roller body 22 is set in a horizontal state. The two ends of the roller body 22 cooperate with the locking parts of different heights, so the height of the roller body 22 is different after installation. By fixing the two adjusting roller assemblies 2 to different positions of the fixing frame 1, the horizontal distance between the two roller bodies 22 can be adjusted. By cooperating with the locking parts of different heights, the vertical distance between the two roller bodies 22 can be adjusted, thereby adjusting the wrap angle of the electrode 3 wrapped between the two roller bodies 22, and thus adjusting the reverse tensile force on the electrode 3.

[0035] In existing tensioning mechanisms, the installation and adjustment of the roller 22 are usually quite complex, requiring a significant amount of time and manpower, and the adjustment accuracy is difficult to guarantee. In the adjusting roller assembly 2 of this mechanism, the bracket 21 has multiple locking parts spaced apart along the vertical direction, and the two ends of the roller 22 are respectively connected to the locking parts of equal height on two brackets 21. This design allows the vertical installation position of the roller 22 to be quickly and accurately adjusted according to actual needs, without the need for complex tools and cumbersome operating procedures, greatly improving the convenience of roller 22 installation and adjustment, and solving the problem of inconvenient roller 22 installation and adjustment in traditional mechanisms.

[0036] Furthermore, such as Figure 2 As shown, in some embodiments of this application, the reverse tensioning mechanism further includes a fixing frame 1, which is arranged in a horizontal direction. There are two fixing frames 1, which are arranged in parallel. Two supports 21 are respectively arranged corresponding to the two fixing frames 1.

[0037] This mechanism features two parallel fixed frames 1, with each of the two brackets 21 mounted on one fixed frame 1, providing dual support and guidance for the adjusting roller assembly 2. This allows the adjusting roller assembly 2 to move smoothly along the parallel fixed frames 1 during movement and operation, effectively preventing swaying and offset, and solving the problem of insufficient operational stability of the adjusting roller assembly 2. The design of two parallel fixed frames 1 provides more precise guidance for the movement of the adjusting roller assembly 2, allowing operators to more accurately control the position of the adjusting roller assembly 2 on the fixed frames 1, thereby ensuring the adjustment accuracy of the spacing between adjacent adjusting roller assemblies 2 and solving the problem of difficulty in guaranteeing adjustment accuracy.

[0038] Understandably, the two parallel fixed frames 1 provide a clear path and stable support for the movement of the adjusting roller assembly 2, allowing operators to adjust the horizontal spacing of adjacent adjusting roller assemblies 2 more easily and accurately. This eliminates the need to spend significant time and effort ensuring the stability and precise positioning of the adjusting roller assembly 2, greatly improving the ease of operation and reducing operational difficulty and labor intensity.

[0039] In some embodiments of this application, a plurality of first fixing parts 11 are arranged at intervals along the horizontal direction on the fixing frame 1, and a second fixing part that cooperates with the first fixing parts 11 is provided at the lower end of the bracket 21. The second fixing part cooperates with the first fixing parts 11 at different positions, so that the bracket 21 can be fixed to different positions of the fixing frame 1.

[0040] For example, such as Figure 1As shown, in some embodiments of this application, the reverse stretching mechanism includes five adjusting roller assemblies 2, with the roller bodies 22 of the five adjusting roller assemblies 2 arranged alternately one above the other. From right to left, the first roller body 22, the third roller body 22, and the fifth roller body 22 form the first row, and the second roller body 22 and the fourth roller body 22 form the second row. The first row is located above the second row.

[0041] When the electrode 3 warps upward, as it passes through the reverse stretching mechanism from right to left, it first goes around the upper surface of the first roller 22. Due to the height difference and horizontal distance between the first and second rollers 22, the electrode 3 extends downward on both sides of the first roller 22, forming an upward arch on the first roller 22. This provides a downward stretching force to restore the electrode 3 to a straight state. The electrode 3 passes through the first, third, and fifth rollers 22, which is equivalent to undergoing three reverse bending operations. Therefore, the number of rollers 22 in the first row can be set according to the degree of warping of the electrode 3. If the warping of the electrode 3 is more severe, more rollers 22 can be set in the first row. If the warping of the electrode 3 is weak, fewer rollers 22 can be set in the first row.

[0042] When the electrode 3 bends downward, the first row of rollers 22 is located below the second row of rollers 22. That is, when the electrode 3 passes through the reverse stretching mechanism, the electrode 3 passes over the lower surface of the first roller 22. Due to the height difference and horizontal distance between the first roller 22 and the second roller 22, the electrode 3 is located behind the first roller 22 and extends upward under the action of the second roller 22. The electrode 3 forms a downward arched state on the first roller 22, providing an upward stretching force for the electrode 3, thereby causing the electrode 3 to bend in the reverse direction at the first roller 22.

[0043] The wrap angle of the electrode 3 on the first roller 22 can be adjusted by regulating the horizontal distance or height difference between the first roller 22 and the second roller 22, thereby adjusting the tensile force exerted by the first roller 22 on the electrode 3. When the electrode 3 warps upwards severely, the horizontal distance between the first roller 22 and the second roller 22 can be reduced or the height difference between them can be increased, thus reducing the wrap angle of the electrode 3 on the first roller 22 and increasing the tensile force exerted by the first roller 22 on the electrode 3. Conversely, when the electrode 3 warps upwards only slightly, the horizontal distance between the first roller 22 and the second roller 22 can be increased or the height difference between them can be decreased, thus increasing the wrap angle of the electrode 3 on the first roller 22 and decreasing the tensile force exerted by the first roller 22 on the electrode 3.

[0044] like Figure 1As shown, the three rollers 22 in the first row are at the same height, and the two rollers 22 in the second row are also at the same height. It can be understood that the heights of the three rollers 22 in the first row can be the same or different, and the heights of the two rollers 22 in the second row can also be the same or different. However, when the electrode 3 is being stretched in the reverse direction, the rollers 22 in the first row and the rollers 22 in the second row need to be set to different heights. When the electrode 3 does not need to be bent in the reverse direction, the heights of the rollers 22 in the first row and the rollers 22 in the second row can be adjusted to be the same. When the electrode 3 passes over each roller 22, it is not subjected to tensile force, and each roller 22 only serves to pass through.

[0045] For example, in some embodiments of this application, the first fixing part 11 is a first fixing hole, the second fixing part is a second fixing hole, and the lower end of each bracket 21 is provided with at least two second fixing holes. The at least two second fixing holes are spaced apart in the horizontal direction, and the distance between two adjacent second fixing holes is equal to the distance between two adjacent first fixing holes. After the fastening bolt or bolt passes around the first fixing hole and the corresponding second fixing hole in sequence, the lower end of the bracket 21 is fixed on the fixing frame 1, thereby realizing the adjustment of the position of the bracket 21.

[0046] Because the position of the adjusting roller assembly 2 can be firmly and precisely fixed on the fixing frame 1 through the cooperation of the first fixing part 11 and the second fixing part, the adjusting roller assembly 2 will not be displaced during the electrode 3 stretching process. It can always stretch the electrode 3 according to the preset position and spacing, thereby ensuring the stretching accuracy of the electrode 3, making the size and shape of the electrode 3 more in line with the design requirements, and improving the quality stability of the product. The multiple first fixing parts 11 provide the adjusting roller assembly 2 with multiple position options, enabling the reverse stretching mechanism 20 to adapt to the production of electrode 3 with different specifications and different stretching requirements.

[0047] For example, the fixing frame 1 is made of a high-strength, wear-resistant metal material, such as stainless steel, to ensure that it is not easily deformed or worn during long-term use. The two fixing frames 1 are placed parallel and horizontally, and their length is determined according to actual production needs and site space. The surface is finely processed to be smooth and flat, reducing the friction when the adjusting roller assembly 2 moves.

[0048] The bracket 21 is made of aluminum alloy, which is lightweight and high-strength. Each bracket 21 is vertically arranged in a long strip shape, and the second fixing part at the lower end of the bracket 21 cooperates with the first fixing part 11 on the fixing frame 1. Specifically, the lower end of the bracket 21 is provided with two through holes as the second fixing part. The diameter of the through holes matches the diameter of the threaded holes on the fixing frame 1, and the position of the through holes corresponds to the position of the threaded holes on the upper part of the fixing frame 1, so as to fix the bracket 21 to the fixing frame 1 with bolts.

[0049] When installing the adjusting roller assembly 2, first fix the two fixing brackets 1 parallel to each other on the work platform. Then, determine the approximate position of the adjusting roller assembly 2 according to the initial specifications of the electrode sheet 3 (including the curling direction and degree of curling, etc.) and the production process requirements. Place the bracket 21 of the adjusting roller assembly 2 on the fixing bracket 1, aligning the through hole at the lower end of the bracket 21 with the appropriate threaded hole on the fixing bracket 1. Then, use bolts to bypass the through hole and screw them into the threaded hole to firmly fix the bracket 21 on the fixing bracket 1. Next, engage the two ends of the roller body 22 with the corresponding snap-fit ​​parts on the two brackets 21 to ensure that the roller body 22 can rotate freely.

[0050] When it is necessary to adjust the position of the adjusting roller assembly 2 to accommodate different specifications of electrode sheets 3 or to change the stretching parameters, simply loosen the bolts of the fixing bracket 21, move the bracket 21 along the fixing frame 1 to the new target position, align the through hole at the lower end of the bracket 21 with the new threaded hole on the fixing frame 1, and then retighten the bolts to complete the adjustment of the position of the adjusting roller assembly 2. The entire adjustment process is simple and quick, requiring no complicated tools or extensive disassembly work.

[0051] During production, the electrode 3 enters from one end of the reverse stretching mechanism 20 and sequentially passes around each set of adjusting roller assemblies 2. By adjusting the spacing between adjacent adjusting roller assemblies 2 and the position of the adjusting roller assemblies 2 on the fixed frame 1, the stretching path and degree of stretching of the electrode 3 are changed. When the electrode 3 passes around the adjusting roller assemblies 2, the adjusting roller assemblies 2 apply a stretching force to the electrode 3 in the opposite direction of warping, ensuring that the electrode 3 is subjected to uniform force during stretching and effectively avoiding quality problems such as wrinkles and deformation of the electrode 3. At the same time, due to the cooperation of the first fixing part 11 on the fixed frame 1 and the second fixing part on the bracket 21, the position of the adjusting roller assembly 2 can be stably maintained, ensuring the stretching accuracy and stability of the electrode 3. After reverse stretching, the electrode 3 is output from the other end of the mechanism and enters the subsequent production process.

[0052] To achieve vertical adjustment of the roller 22, in some embodiments of this application, the locking part is configured as a locking groove 211 on one side of the bracket 21, and the roller 22 has locking sections at both ends, which are locked into the locking groove 211. The locking groove 211 is a rectangular groove, the width of which is slightly larger than the diameter of the locking section of the roller 22, and the groove depth is designed according to the specifications of the roller 22 and the stress conditions to ensure the firmness of the locking.

[0053] The sidewall of the snap-fit ​​groove 211 has a certain inclination angle to match the snap-fit ​​section. When the snap-fit ​​section is snapped into the snap-fit ​​groove 211, the inclination sidewall provides a certain self-locking force, further enhancing the snap-fit's firmness. Simultaneously, positioning protrusions and positioning grooves are provided at the bottom of the snap-fit ​​groove 211 and the end of the snap-fit ​​section. When the snap-fit ​​section is fully snapped into the snap-fit ​​groove 211, the positioning protrusions embed into the positioning grooves, providing precise positioning and preventing axial movement of the roller body 22 within the snap-fit ​​groove 211. When installing the roller body 22, align the snap-fit ​​section of the roller body 22 with the snap-fit ​​groove 211 on the bracket 21, and slowly push the snap-fit ​​section into the snap-fit ​​groove 211 until the positioning protrusion is embedded in the positioning groove. A "click" sound indicates that the roller body 22 has been installed correctly. If it is necessary to replace the roller body 22 or adjust the height of the roller body 22 (by selecting a different height of the snap-fit ​​slot 211), simply pull the snap-fit ​​section out of the snap-fit ​​slot 211 and then snap it into the new snap-fit ​​slot 211.

[0054] To facilitate the rapid installation and disassembly of the roller body 22 and the bracket 21, and to adjust the height of the roller assembly 22, in some embodiments of this application, the bracket 21 is provided with a quick-release locking member 23. The quick-release locking member 23 is detachably disposed at the opening of the snap-fit ​​groove 211, and is used to lock the snap-fit ​​section within the snap-fit ​​groove 211. When the snap-fit ​​section is engaged within the snap-fit ​​groove 211, the quick-release locking member 23 is positioned at the corresponding opening of the snap-fit ​​groove 211 to block the opening and prevent the snap-fit ​​section from coming out of the snap-fit ​​groove 211. When it is necessary to disassemble the roller body 22, the quick-release locking member 23 is removed from the bracket 21, exposing the opening of the snap-fit ​​groove 211, thereby allowing the snap-fit ​​section to disengage from the snap-fit ​​groove 211.

[0055] In some embodiments of this application, the upper and lower sides of the slot of the snap-fit ​​groove 211 are provided with first mounting holes. The quick-release locking member 23 includes a locking block and a fastener. The locking block is provided with a second mounting hole. The fastener passes through the second mounting hole and the first mounting hole in sequence to fix the locking block on the bracket, thereby locking the snap-fit ​​section in the snap-fit ​​groove 211.

[0056] When relying solely on the snap-fit ​​between the snap-fit ​​groove 211 and the snap-fit ​​section, the snap-fit ​​section may experience slight loosening or wobbling within the snap-fit ​​groove 211 due to the significant dynamic tension and vibration generated during the stretching of the electrode 3. This loosening not only affects the uniformity of the stretching of the electrode 3, leading to localized overstretching or understretching, but may also cause the snap-fit ​​section to gradually detach from the snap-fit ​​groove 211 over time, resulting in equipment malfunction and production interruption. The quick-release locking element 23, located at the opening of the snap-fit ​​groove 211, applies additional locking force to the snap-fit ​​section from the outside, effectively enhancing the stability of the snap-fit ​​and preventing the snap-fit ​​section from loosening or detaching.

[0057] During the reverse stretching process of electrode 3, the physical properties of electrode 3 are significantly affected by temperature. If electrode 3 is in a low-temperature environment during stretching, its elastic modulus is large and its plastic deformation capacity is poor, making it prone to defects such as fracture and cracks during stretching, resulting in a decrease in the quality of electrode 3. Traditional reverse stretching mechanisms 20 lack effective means of controlling the temperature of the roller 22, and cannot heat the electrode 3 according to its characteristics and stretching process requirements. This embodiment of the application heats the roller 22 by setting a closed heating channel within the roller 22 and a heating element within the heating channel, thereby increasing the temperature of the electrode 3 in contact with the roller 22, improving the plastic deformation capacity of the electrode 3, reducing defects generated during stretching, and improving the stretching quality and yield of the electrode 3.

[0058] For example, the roller body 22 is made of stainless steel, specifically chrome-plated steel, which has good corrosion resistance and mechanical strength. The length of the roller body 22 is designed according to the width of the electrode 3. A spiral heating channel is formed inside the roller body 22. This spiral structure increases the length of the heating channel, making the contact area between the heating element and the roller body 22 larger and improving heating efficiency. Sealing plugs are provided at both ends of the heating channel to prevent leakage of the liquid heating element.

[0059] The heating section uses electric heating tubes, the length of which is customized according to the length of the heating channel. The surface of the electric heating tube is covered with an insulating ceramic layer, which serves to insulate and prevent short circuits between the heating tube and the roller 22, while also reducing heat loss to the outside. Both ends of the electric heating tube are connected to an external power control system via wires. The power control system can automatically adjust the heating power of the electric heating tube according to the set temperature parameters.

[0060] The heating section can also be filled with heat-conducting oil in the heating channel and equipped with a heat-conducting oil circulation heating system to heat the roller body 22 to meet the temperature requirements during the stretching process of the electrode sheet 3.

[0061] In some embodiments of this application, an insulating layer and a wear-resistant layer are provided on the outer surface of the roller body 22, with the wear-resistant layer disposed between the roller body 22 and the insulating layer, so that the insulating layer protrudes from the outer circumferential surface of the roller body 22.

[0062] The insulation layer is made of ceramic adhesive, and the wear-resistant layer is made of Teflon. Using ceramic adhesive as the insulation material offers excellent insulation properties; its extremely high resistivity effectively prevents current conduction. During the reverse stretching process of electrode 3, if there is a risk of leakage between the roller 22 and other conductive components, the ceramic adhesive insulation layer prevents current from being transmitted through the roller 22 to electrode 3. This prevents localized overheating, ablation, or even short circuits in electrode 3 due to current, ensuring the safety of the production process.

[0063] By applying a certain thickness of Teflon tape, a step is formed in the ceramic adhesive area. When the reverse roller rotates one revolution, the linear velocity of the area with Teflon tape is different from that of other areas without Teflon tape, thus creating a differential stretching effect. This allows the ceramic adhesive area of ​​the roller body 22 to be further extended and achieve a better stretching effect.

[0064] By applying a certain thickness of Teflon tape to create steps, the geometry of the roller body 22 surface is altered. When the reverse roller rotates, areas at different heights (areas with Teflon tape and areas without tape) will have different linear velocities at the same angular velocity due to their different rotation radii. According to the linear velocity formula v = ωr (where v is the linear velocity, ω is the angular velocity, and r is the rotation radius), the linear velocity of the area with Teflon tape will differ from that of the area without tape, thus creating a differential stretching effect. This differential stretching allows for more precise control of the stretching degree of different parts of the electrode 3, meeting the needs of complex electrode 3 stretching processes. For example, in areas requiring focused stretching, by adjusting the application position and thickness of the Teflon tape, the ceramic adhesive in that area can be subjected to greater tensile force, thereby achieving more precise localized stretching.

[0065] like Figure 3 As shown, embodiments of this application also provide an electrode sheet slicing and stacking machine, including a conveying mechanism 10, a die-cutting mechanism 30, and a reverse stretching mechanism 20 as described in any of the above embodiments, wherein the reverse stretching mechanism 20 is disposed between the conveying mechanism 10 and the die-cutting mechanism 30. Before the electrode sheet 3 is conveyed to the die-cutting mechanism 30 for slicing, the reverse stretching mechanism 20 improves its curling state, making the electrode sheet 3 tend to be flat after unwinding and slicing, reducing warping.

[0066] The conveying mechanism 10 adopts a combination of multi-roller synchronous transmission and vacuum adsorption to ensure the flatness and stability of the electrode 3 during the conveying process; the die-cutting mechanism 30 is equipped with a high-precision laser cutting system, which can achieve high-precision die-cutting of the electrode 3, and the cutting edge is smooth and burr-free.

[0067] In the process of cutting and stacking electrode 3 using the electrode cutting and stacking machine of this application embodiment, the electrode 3 needs to pass through the conveying mechanism 10, the reverse stretching mechanism 20 and the die-cutting mechanism 30 in sequence.

[0068] Working process of conveying mechanism 10: The electrode 3 is drawn out from the raw material roll, passes through the multi-roller synchronous transmission part, and is conveyed forward under the drive of the conveying roller. At the same time, the vacuum adsorption device is activated to firmly adsorb the electrode 3 onto the surface of the conveying roller, ensuring the flatness and stability of the electrode 3 during the conveying process.

[0069] The reverse stretching mechanism 20 operates as follows: When the electrode 3 is conveyed to the reverse stretching mechanism 20, it comes into contact with the roller 22. Because the Teflon tape adhered to the roller 22 forms a stepped structure, there is a difference in linear velocity between the areas with and without the Teflon tape, resulting in a differential stretching force on the electrode 3. Simultaneously, the ceramic adhesive insulation layer covering the Teflon tape area extends under the stretching force, further optimizing the stretching effect of the electrode 3 and ensuring uniform and suitable tension. Before reverse stretching, the number of adjusting roller assemblies 2, the spacing between adjacent adjusting roller assemblies 2, and the height of each roller 22 are rationally set according to the degree and direction of curling of the electrode 3, thereby adjusting the reverse stretching force exerted on the electrode 3 by the reverse stretching mechanism 20.

[0070] The working process of the die-cutting mechanism 30: After reverse stretching, the electrode sheet 3 is conveyed to the cutting platform of the die-cutting mechanism 30, and the vacuum adsorption device fixes the electrode sheet 3 on the platform. The laser cutting system controls the laser cutting head to move on the three-dimensional moving platform according to a preset program, performing high-precision die-cutting on the electrode sheet 3. After cutting, the cut electrode sheet 3 is collected in a designated container, completing the entire cutting and stacking process.

[0071] Furthermore, in some embodiments of this application, the conveying mechanism 10 includes a conveying roller, the diameter of which is smaller than the diameter of the conveying roller body 22.

[0072] The conveyor roller smoothly transports the electrode sheet 3 to the reverse stretching mechanism 20. Due to the large diameter of the conveyor roller, its linear velocity is relatively stable, ensuring that the electrode sheet 3 enters the reverse stretching mechanism 20 at a uniform speed. Meanwhile, the smaller diameter roller 22 in the reverse stretching mechanism 20, upon contacting the electrode sheet 3, generates a different linear velocity due to the diameter difference between itself and the conveyor roller, thus applying a reverse stretching force to the electrode sheet 3. This close integration of conveying and stretching allows the electrode sheet 3 to successfully complete its stretching deformation during conveying, providing a high-quality electrode sheet 3 for subsequent die-cutting processes.

[0073] Considering that if the diameters of the conveying roller and the roller body 22 in the reverse stretching mechanism 20 are the same, the electrode 3 may not be able to form an effective tension difference during the conveying process, resulting in poor stretching effect; while if the diameter difference is too large, the electrode 3 may suffer from tearing or wrinkling during the stretching process. By precisely controlling the diameter difference, it is possible to ensure effective stretching of the electrode 3 while avoiding excessive stress concentration on the electrode 3 during the conveying and stretching process, thereby minimizing damage to the electrode 3 and improving the product qualification rate.

[0074] After the equipment is started, the electrode sheet 3 is drawn out from the raw material roll and smoothly conveyed by the conveyor rollers into the reverse stretching mechanism 20. In the reverse stretching mechanism 20, due to the difference in diameter between the conveyor rollers and the roller body 22, the electrode sheet 3 is subjected to a reverse stretching force, resulting in uniform bending deformation. The stretched electrode sheet 3 is then conveyed to the die-cutting mechanism 30 for cutting.

[0075] During production, the stretching and quality of the electrode sheet 3 are monitored in real time using online inspection equipment. Inspection indicators include the stretching rate, flatness, presence of wrinkles and tears, etc. If the stretching rate of the electrode sheet 3 does not meet requirements or quality issues arise, optimization can be achieved by adjusting the diameter difference between the conveyor rollers and the rollers 22 in the reverse stretching mechanism 20. Actual production verification has shown that the cutting and stacking machine with a reasonable diameter difference design can produce electrode sheets 3 of stable quality that meet requirements, significantly improving the product qualification rate.

[0076] In some embodiments of this application, the electrode cutting and stacking machine further includes an unwinding mechanism and a stacking mechanism, wherein the unwinding mechanism is disposed before the conveying mechanism 10 and the stacking mechanism is disposed after the die-cutting mechanism 30.

[0077] The unwinding mechanism is used to hold the raw material roll of electrode sheet 3. It consists of an unwinding shaft, a braking device, and a tension control device. The unwinding shaft is made of high-strength alloy steel and can withstand the weight of the raw material roll of electrode sheet 3. The braking device uses an electromagnetic brake, which can quickly stop the rotation of the unwinding shaft when the equipment stops running, preventing the electrode sheet 3 from continuing to unwind due to inertia. The tension control device monitors the tension of the electrode sheet 3 in real time through sensors and maintains the stability of the tension of the electrode sheet 3 by adjusting the speed of the unwinding motor. For example, when the sensor detects that the tension of the electrode sheet 3 is too high, the control system will reduce the speed of the unwinding motor, slowing down the unwinding speed of the electrode sheet 3 and thus reducing the tension; conversely, when the tension is too low, the speed of the unwinding motor will be increased.

[0078] The stacking mechanism is located downstream of the die-cutting mechanism 30 and mainly consists of a stacking platform, a suction cup device, and a robotic arm. The stacking platform is made of high-precision marble with a surface flatness error of no more than 0.01mm, ensuring the accuracy of the electrode stacking. The suction cup device consists of multiple vacuum suction cups, which generate negative pressure through a vacuum generator to pick up the die-cut electrode 3.

[0079] The robotic arm employs a six-axis design, possessing high flexibility and precise motion control capabilities. Once the electrode 3 is attracted by the suction cup device, the robotic arm moves it to a stacking platform according to a pre-programmed sequence. During stacking, positioning devices and sensors on the platform monitor the position and stacking status of the electrode 3 in real time, ensuring neat and accurate stacking. For example, the sensors can detect the edge position of the electrode 3; when a positional shift is detected, the control system promptly adjusts the robotic arm's trajectory to return the electrode 3 to its correct position.

[0080] The electrode cutting and stacking machine also includes an electrical control system, which is the core control component of the machine. It uses a programmable logic controller (PLC) as the main controller, in conjunction with a human-machine interface (HMI) to achieve automated control and operation of the equipment. The PLC features high reliability, strong anti-interference capabilities, and rich programming functions, enabling precise control of the actions of each mechanism according to preset programs. The HMI uses a touchscreen design, allowing operators to easily set equipment operating parameters such as the conveying speed of electrode 3, the die-cutting size, and the number of stacked layers. Simultaneously, the HMI can display the equipment's operating status and fault information in real time, facilitating monitoring and troubleshooting by operators.

[0081] The electrical control system collects real-time operating data of the equipment, such as the tension, position, and speed of electrode 3, through sensors and encoders, and feeds this data back to the PLC. The PLC compares and analyzes the feedback data with preset parameters, and adjusts the actions of each mechanism in a timely manner to ensure stable and efficient operation of the equipment. For example, when the sensor detects an abnormal change in the tension of electrode 3, the PLC will immediately adjust the speed of the unwinding motor or the conveyor motor to restore the tension to the normal range.

[0082] For example, when processing the electrode 3, it is necessary to detect the humidity of the processing environment. The PLC adjusts the heating temperature of the roller 22 according to the detected humidity of the processing environment.

[0083] In summary, the reverse stretching mechanism 20 and the electrode cutting and stacking machine provided in this application embodiment can reverse stretch the electrode 3 before slicing, thereby improving the curling state of the electrode 3 and making it flatter during slicing. Consequently, the sliced ​​electrode 3 is less prone to warping, and during quality inspection of the sliced ​​electrode 3, it is less likely to misjudge a good quality electrode 3 as a defective product. At the same time, the sliced ​​electrode 3 does not warp and is less prone to collision, effectively reducing quality risks and improving the stability of the lithium battery electrode 3 production process and the reliability of product quality.

[0084] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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.

[0085] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reverse stretching mechanism for an electrode sheet, characterized in that, It includes at least two adjusting roller assemblies (2), which are spaced apart in the horizontal direction, and the horizontal spacing and / or height difference between two adjacent adjusting roller assemblies (2) is adjustable; the electrode (3) passes around at least two adjusting roller assemblies in sequence, and in any two adjacent adjusting roller assemblies (2), one adjusting roller assembly (2) contacts the upper surface of the electrode (3), and the other adjusting roller assembly (2) contacts the lower surface of the electrode (3), and the first adjusting roller assembly (2) that the electrode (3) passes around is configured to provide a tensile force to cause the electrode (3) to bend in the opposite direction to its warping direction.

2. The reverse stretching mechanism for the electrode sheet according to claim 1, characterized in that, Each of the adjusting roller assemblies (2) includes a roller body (22) and a support (21). The support (21) has multiple locking parts, which are disposed at different heights of the support (21). The roller body (22) cooperates with the locking parts at different heights to achieve height adjustment of the roller body.

3. The reverse stretching mechanism for the electrode sheet according to claim 2, characterized in that, The reverse stretching mechanism also includes a fixing frame (1), on which a plurality of first fixing parts (11) are arranged at intervals along the horizontal direction. The lower end of the bracket (21) is provided with a second fixing part. The second fixing part cooperates with the first fixing part (11) to fix the bracket (21) and the fixing frame (1).

4. The reverse stretching mechanism for the electrode sheet according to claim 2, characterized in that, The snap-fit ​​part is a snap-fit ​​groove (211) provided on one side of the bracket (21), and the two ends of the roller body (22) are provided with snap-fit ​​sections, which are snapped into the snap-fit ​​groove (211).

5. The reverse stretching mechanism for the electrode sheet according to claim 4, characterized in that, The bracket (21) is also provided with a quick-release locking member (23), which is detachably disposed at the opening of the snap-fit ​​groove (211) to lock the snap-fit ​​section in the snap-fit ​​groove (211).

6. The reverse stretching mechanism for the electrode sheet according to claim 5, characterized in that, The upper and lower sides of the slot of the snap-fit ​​groove (211) are provided with first mounting holes. The quick-release locking component (23) includes a locking block and a fastener. The locking block is provided with a second mounting hole. The fastener passes through the second mounting hole and the first mounting hole in sequence to fix the locking block on the bracket (21).

7. The reverse stretching mechanism for the electrode sheet according to claim 2, characterized in that, The roller body (22) is provided with a sealed heating channel, and a heating element is provided in the heating channel.

8. The reverse stretching mechanism for the electrode sheet according to claim 2, characterized in that, The roller body (22) is provided with an insulating layer and a wear-resistant layer. The wear-resistant layer is disposed between the roller body (22) and the insulating layer, so that the insulating layer protrudes from the outer circumferential surface of the roller body (22).

9. An electrode cutting and stacking machine, characterized in that, It includes a conveying mechanism (10), a die-cutting mechanism (30), and a reverse stretching mechanism (20) as described in any one of claims 1-8, wherein the reverse stretching mechanism (20) is disposed between the conveying mechanism (10) and the die-cutting mechanism (30).

10. The cutting and stacking machine according to claim 9, characterized in that, The conveying mechanism includes a conveying roller, and the adjusting roller assembly (2) includes a roller body (22), the diameter of which is smaller than the diameter of the conveying roller.

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