Integrated rolling forming device for lithium cobalt oxide positive plate
By designing two sets of rolling mechanisms—support rollers and extrusion rollers with unequal diameters—and adjusting the rolling direction and stress concentration area, the problem of uneven internal stress distribution during the rolling process of lithium cobalt oxide cathode sheets was solved, achieving a high-quality rolling effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 合山市华美新能源科技有限公司
- Filing Date
- 2025-07-11
- Publication Date
- 2026-05-12
AI Technical Summary
In the existing technology, lithium cobalt oxide cathode sheets have the problem of uneven internal stress distribution during the rolling process, and conventional rolling devices cannot effectively reduce internal rolling stress.
An integrated roll forming device for lithium cobalt oxide cathode sheets was designed. It employs two sets of roll forming mechanisms, in which the diameters of the support roller and the extrusion roller are not equal. By adjusting the roll forming direction and stress concentration area, the roll forming time is increased using the two sets of roll forming mechanisms, thereby eliminating internal stress in the reverse direction.
有效保证了极片的辊压密实，降低了内部辊压应力，提高了极片的辊压质量，缓解了应力集中问题。
Smart Images
Figure CN224222322U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery processing technology, specifically to an integrated roll forming device for lithium cobalt oxide cathode sheets. Background Technology
[0002] During the forming process, battery electrodes need to be rolled. After rolling, the battery material and substrate are bonded and compacted. The compaction density of the positive or negative electrode material directly determines the energy density of the battery. During the rolling process, the compaction density can be ensured by increasing the contact area between the battery electrode and the roller and extending the compaction time.
[0003] Currently, the industry mainly adopts two methods to solve the above problems: one is to increase the diameter of the roller, which is the most direct approach, but is limited by production costs and equipment size. The other method is to achieve progressive compaction through multiple rolling processes. This increases both the rolling and compaction time, and the multiple rolling processes ensure that the force direction on the electrode sheet varies each time, which alleviates the problem of uneven stress distribution caused by the previous rolling process to some extent. However, this method also has certain problems. Since conventional rollers are mostly parallel and of equal diameter, the two sides of the electrode sheet have the same contact area during the rolling process, resulting in the same magnitude and direction of force each time. The internal stress generated in the electrode sheet during the subsequent rolling process still exists. Therefore, a rolling forming device that can ensure the dense compaction of the electrode sheet while reducing its internal rolling stress is needed to solve this problem. Utility Model Content
[0004] In order to overcome one of the shortcomings of the prior art, the purpose of this utility model is to provide an integrated roll forming device for lithium cobalt oxide positive electrode sheets. This integrated roll forming device for lithium cobalt oxide positive electrode sheets can not only ensure that the electrode sheets are rolled densely, but also reduce their internal rolling stress.
[0005] To solve the above problems, the technical solution adopted by this utility model is as follows:
[0006] An integrated roll forming apparatus for lithium cobalt oxide cathode sheets includes an unwinding mechanism, a roll forming mechanism, and a winding mechanism arranged in sequence. The cathode sheet unwound by the unwinding mechanism is rolled by the roll forming mechanism and then wound up by the winding mechanism. The roll forming mechanism is provided in two sets and arranged in sequence along the conveying direction of the cathode sheet. Each roll forming mechanism includes a support roller and a pressing roller that cooperate with each other. The diameter of the support roller and the diameter of the pressing roller are not equal. The pressing rollers in the two sets of roll forming mechanisms press the two sides of the cathode sheet respectively.
[0007] Furthermore, the ratio of the diameter of the support roller to the diameter of the extrusion roller is 1:3-5.
[0008] Furthermore, the gap between the support roller and the extrusion roller in the first set of roller pressing mechanisms is larger than the gap between the support roller and the extrusion roller in the second set of roller pressing mechanisms, and the gap between the support roller and the extrusion roller in the first set of roller pressing mechanisms and the gap between the support roller and the extrusion roller in the second set of roller pressing mechanisms are not set on the same horizontal plane.
[0009] Furthermore, the distance between the two sets of roller pressing mechanisms is less than 1m.
[0010] Furthermore, a stable clamping mechanism is provided between the two sets of roller pressing mechanisms.
[0011] Furthermore, the stabilizing clamping mechanism includes a frame and a pair of stabilizing clamping rollers. Both ends of the pair of stabilizing clamping rollers are slidably mounted on the frame via sliding blocks. The electrode passes through the gap between the pair of stabilizing clamping rollers. The frame is provided with adjusting bolts for adjusting the sliding position of each sliding block.
[0012] Furthermore, the unwinding mechanism includes a frame and a plurality of unwinding shafts rotatably mounted on the frame. A converging roller is provided on the side of the frame near the rolling mechanism. All the sheets unwound from the unwinding shafts pass around the converging roller in the same direction and enter the rolling mechanism.
[0013] Furthermore, the frame is provided with a plurality of tension rollers that are adapted to each of the unwinding shafts.
[0014] Furthermore, a pair of cooperating traction and feeding rollers are provided between the winding mechanism and the subsequent set of rolling mechanisms.
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] This invention relates to an integrated roll forming device for lithium cobalt oxide cathode sheets. Based on existing roll forming equipment, the device improves the roll forming mechanism by designing two sets of roll forming mechanisms. These two sets increase the roll forming and compaction time, ensuring the quality of the cathode sheet roll forming. Simultaneously, the diameters of the support rollers and extrusion rollers within each set of roll forming mechanisms are not equal. This artificially alters the force direction and stress concentration area during the roll forming process, causing the stress to concentrate more on the side with the smaller diameter between the support roller and the extrusion roller. The extrusion rollers in the two sets of roll forming mechanisms extrude the electrode sheets from both sides respectively. This ensures that the latter set of roll forming mechanisms rolls the electrode sheet in the opposite direction of stress, effectively eliminating stress concentration within the electrode sheet and significantly mitigating the stress concentration problem remaining during unidirectional roll forming.
[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description
[0018] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;
[0019] Figure 2 This is a diagram showing the working state of the roller pressing mechanism in an embodiment of this utility model;
[0020] Figure 3 This is a partial structural schematic diagram of another embodiment of the present invention;
[0021] Figure 4 This is a schematic diagram of the structure of the stable clamping mechanism in an embodiment of this utility model.
[0022] Explanation of icon numbers:
[0023] Unwinding mechanism 10, frame 11, unwinding shaft 12, converging roller 13, tensioning roller 14, rolling mechanism 20, support roller 21, extrusion roller 22, winding mechanism 30, stabilizing clamping mechanism 40, frame 41, stabilizing clamping roller 42, sliding block 43, adjusting bolt 44, traction clamping roller 50. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.
[0025] Reference Figures 1 to 4 An integrated roll forming apparatus for lithium cobalt oxide cathode sheets is shown, comprising an unwinding mechanism 10, a roll forming mechanism 20, and a winding mechanism 30 arranged sequentially. The cathode sheet unwound by the unwinding mechanism 10 is rolled by the roll forming mechanism 20 and then wound by the winding mechanism 30. The roll forming mechanism 20 is provided in two sets and arranged sequentially along the conveying direction of the cathode sheet. Each roll forming mechanism 20 includes a support roller 21 and a pressing roller 22 that cooperate with each other. The diameter of the support roller 21 is not equal to the diameter of the pressing roller 22. The pressing rollers 22 in the two sets of roll forming mechanisms 20 respectively press the two sides of the cathode sheet.
[0026] The unwinding mechanism 10 and the winding mechanism 30 are both structures used in conventional roll material processing, and their specific structures are not detailed here. In this application, the unwinding mechanism 10, the rolling mechanism 20, and the winding mechanism 30 are arranged in a straight line. In this application, the two sets of rolling mechanisms 20 are either horizontally or vertically arranged, depending on the actual usage requirements. In this application, a horizontal arrangement is preferred, as it facilitates the later arrangement of other structures. See also... Figure 2Furthermore, in this application, the support roller 21 and the extrusion roller 22 have different diameters. This causes the electrode sheet to naturally bend towards the side with the smaller diameter when it is being rolled. As a result, there is a difference in deformation on both sides of the entire electrode sheet, and the internal stress is mainly directed towards the side with the smaller diameter, leading to a certain bending tendency in the electrode sheet. See also... Figure 3 When the electrode is subjected to reverse rolling force by the next set of rolling mechanisms 20, the electrode bends in the opposite direction, thereby eliminating the internal stress generated by the first rolling.
[0027] See Figure 1 In this application, the electrode sheet is formed by pressing together multiple battery materials and substrates. To adapt to this production process, the unwinding mechanism 10 includes a frame 11 and multiple unwinding shafts 12 rotatably mounted on the frame 11. A converging roller 13 is provided on the side of the frame 11 near the rolling mechanism 20. The sheets unwound from all the unwinding shafts 12 pass around the converging roller 13 in the same direction and enter the rolling mechanism 20. Furthermore, in this embodiment, the frame 11 is provided with several tension rollers 14 that are adapted to each of the unwinding shafts 12. These designs are actually conventional and will not be described in detail here. Similarly, the winding mechanism 30 can be provided with winding rollers and tension rollers 14; these are essentially similar designs and will not be described in detail here.
[0028] This integrated roll forming device for lithium cobalt oxide cathode sheets improves upon existing roll forming equipment by incorporating two sets of roll forming mechanisms 20. These two sets increase the rolling and compaction time, ensuring the quality of the electrode sheet. Simultaneously, the diameters of the support rollers 21 and extrusion rollers 22 within each set of roll forming mechanisms are unequal. This artificially alters the force direction and stress concentration area during the roll forming process, concentrating stress on the side with the smaller diameter between the support roller 21 and extrusion roller 22. The extrusion rollers 22 in the two sets of roll forming mechanisms extrude stress on both sides of the electrode sheet, ensuring that the latter set of roll forming mechanisms rolls the electrode sheet in the opposite direction of stress, thus eliminating stress concentration within the electrode sheet and significantly mitigating the residual stress concentration problem that occurs during unidirectional roll forming.
[0029] In one set of embodiments of this application, in order to better perform rolling and take into account overall production, design and other issues, and at the same time control the stress inside the electrode sheet, the ratio of the diameter of the support roller 21 to the diameter of the extrusion roller 22 is 1:3-5.
[0030] See Figure 2In the above embodiments, to match the normal rolling process, the gap between the support roller 21 and the extrusion roller 22 in the first rolling mechanism 20 is larger than the gap between the support roller 21 and the extrusion roller 22 in the second rolling mechanism 20. The gaps between the support roller 21 and the extrusion roller 22 in the first and second rolling mechanisms 20 are not co-horizontal. It should be noted that the second rolling mechanism 20 is located on one side of the support roller 21 in the first rolling mechanism 20, thus conforming to the bending trend of the entire electrode sheet and preventing the electrode sheet from breaking during the rolling process. It should be noted that after the first rolling mechanism 20 passes through the electrode sheet, the electrode sheet tends to bend. However, in actual production, since the electrode sheet is under tension between both rolling mechanisms 20, both rolling mechanisms 20 pre-tension the electrode sheet, applying prestress. For ease of explanation, in... Figure 2 In the diagram, the direction indicated by the dashed arrow inside the electrode sheet represents the bending tendency caused by stress within the electrode sheet. The bending tendency indicates the presence of internal stress forcing the electrode sheet to bend. In reality, because the electrode sheet is relatively taut during the rolling process and is also subjected to pre-tension stress, it normally does not bend directly during rolling. During the subsequent secondary rolling, the extrusion roller 22 applies a reverse bending tendency towards the support roller 21. This tendency counteracts the bending tendency applied by the previous extrusion roller 22 towards the support roller 21, thereby altering the stress distribution within the electrode sheet and partially eliminating stress.
[0031] In the above embodiment, in order to better achieve the rolling state of the fitting electrode, the distance between the two sets of rolling mechanisms 20 is less than 1m.
[0032] See Figure 3 and Figure 4 In one embodiment of this application, a stabilizing clamping mechanism 40 is provided between the two sets of rolling mechanisms 20. The stabilizing clamping mechanism 40 is mainly used to apply a prestress to the electrode sheet, so that it can temporarily counteract the bending tendency of the previous rolling mechanism 20 after rolling the electrode sheet.
[0033] See Figure 3 and Figure 4In the above-described improved embodiment, to better adjust the levelness of different sides of the electrode and achieve differential stretching, the stabilizing clamping mechanism 40 includes a frame 41 and a pair of stabilizing clamping rollers 42. Both ends of the pair of stabilizing clamping rollers 42 are slidably mounted on the frame 41 via sliding blocks 43. The electrode passes through the gap between the pair of stabilizing clamping rollers 42. The frame 41 is provided with adjusting bolts 44 for adjusting the sliding position of each sliding block 43. In this embodiment, the operator can make minor adjustments to each adjusting bolt 44, thereby adjusting the height of each sliding block 43 and the corresponding end of each stabilizing clamping roller 42, suitable for actual production needs.
[0034] See you again Figure 1 In one embodiment of this application, a pair of cooperating traction and pinching rollers 50 are provided between the winding mechanism 30 and the subsequent set of rolling mechanisms 20. The main purpose of designing the traction and pinching rollers 50 is to pull the rolled electrode sheet to maintain a certain pretension, which is beneficial for the electrode sheet to be wound by the winding mechanism 30. At the same time, it can maintain a certain tension difference on both the feeding and discharging sides of the electrode sheet, which is suitable for neutralizing some of the residual prestress in the electrode sheet.
[0035] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.
Claims
1. An integrated roll forming apparatus for lithium cobalt oxide cathode sheets, comprising an unwinding mechanism, a roll forming mechanism, and a winding mechanism arranged sequentially, wherein the cathode sheet unwound by the unwinding mechanism is roll-formed by the roll forming mechanism and then wound up by the winding mechanism, characterized in that, The roller pressing mechanism is provided in two sets and arranged sequentially along the conveying direction of the electrode sheet. Each roller pressing mechanism includes a support roller and a pressing roller that cooperate with each other. The diameter of the support roller and the diameter of the pressing roller are not equal. The pressing rollers in the two sets of roller pressing mechanisms press the two sides of the electrode sheet respectively.
2. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 1, characterized in that: The ratio of the diameter of the support roller to the diameter of the extrusion roller is 1:3-5.
3. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 1, characterized in that: In the first set of roller pressing mechanisms, the gap between the support roller and the extrusion roller is larger than that between the support roller and the extrusion roller in the second set of roller pressing mechanisms. The gap between the support roller and the extrusion roller in the first set of roller pressing mechanisms and the gap between the support roller and the extrusion roller in the second set of roller pressing mechanisms are not set on the same horizontal plane.
4. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 1, characterized in that: The distance between the two sets of roller pressing mechanisms is less than 1m.
5. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 1, characterized in that: A stable clamping mechanism is provided between the two sets of roller pressing mechanisms.
6. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 5, characterized in that: The stabilizing clamping mechanism includes a frame and a pair of stabilizing clamping rollers. Both ends of the pair of stabilizing clamping rollers are slidably mounted on the frame via sliding blocks. The electrode passes through the gap between the pair of stabilizing clamping rollers. The frame is provided with adjusting bolts for adjusting the sliding position of each sliding block.
7. An integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to any one of claims 1-6, characterized in that: The unwinding mechanism includes a frame and a plurality of unwinding shafts that are rotatably mounted on the frame. A converging roller is provided on the side of the frame near the rolling mechanism. All the sheets unwound from the unwinding shafts pass around the converging roller in the same direction and enter the rolling mechanism.
8. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 7, characterized in that: The frame is equipped with several tension rollers that are adapted to each of the unwinding shafts.
9. The integrated roll forming apparatus for lithium cobalt oxide cathode sheets according to claim 1, characterized in that: A pair of cooperating traction and feeding rollers are provided between the winding mechanism and the subsequent set of rolling mechanisms.