A lithium electrode tab calendering mechanism

Abstract

This invention discloses a lithium electrode tab rolling mechanism, relating to the field of lithium battery manufacturing technology. It aims to solve the problem of wrinkling and breakage of electrode sheets during current roll forming production. The key technical points are: a lithium electrode tab rolling mechanism, comprising a pre-rolling assembly and a roll forming assembly. The pre-rolling assembly includes a pre-rolling section that contacts the tab's rolling area and a first straightening section. The pre-rolling section includes several rolling rollers that contact and press the tab's rolling area, and several second straightening elements disposed on the non-working side of the rolling rollers. The second straightening elements contact and position the rolling rollers. The first straightening section includes several straightening power sources with opposite power output directions. When the rolling rollers contact the tab's rolling area and begin rolling, the straightening power sources apply force to the rolling rollers from multiple directions to position the working trajectory of the rolling rollers. The beneficial effect of this invention is that it improves the pre-rolling effect through multi-directional positioning and straightening force, thereby reducing the occurrence of wrinkling and breakage.

Description

Technical Field

[0001] This invention relates to the field of lithium battery manufacturing technology, and more specifically, to a lithium electrode tab rolling mechanism. Background Technology

[0002] In the production of lithium-ion batteries, the rolling process is a very critical process. The rolling process mainly targets the electrodes and tabs on the battery. The performance of the rolling process depends on the electrode characteristics output from previous manufacturing steps such as slurry preparation, coating, and drying. It also further affects subsequent steps and the final electrochemical performance of the battery cells.

[0003] Current battery rolling processes employ either an integral or step-by-step method. Integral rolling simultaneously rolls the thicker electrode coating area and the thinner tab area. However, due to the high tension during rolling, there is a significant difference in the elongation between the electrode and the tab, resulting in wrinkles and breakage at the connection between the electrode and the tab.

[0004] Chinese Patent Publication No. CN115138683A discloses an electrode rolling equipment, the key technical points of which are: the rolling mechanism and the calendering mechanism are respectively arranged on the conveyor path of the electrode; the rolling mechanism includes a first roll and a second roll, the first roll and the second roll are spaced apart, and the first roll and the second roll work together to roll the coating area of ​​the electrode; the calendering mechanism includes a calendering wheel, the calendering wheel is spaced apart from the first roll, and the calendering wheel and the first roll work together to calender the tab area of ​​the electrode.

[0005] The above solution decomposes the rolling process into rolling the tab area to be rolled and rolling the electrode coating area, which to some extent solves the problems of wrinkles and strip breakage caused by the large difference in elongation between the electrode and the tab. However, because the rolling roller can only be controlled to move closer to or further away from the tab area, the following situations and problems will occur when rolling the tab:

[0006] When the width of the calendering wheel is less than the width of the tab area to be calendered, the tab is not calendered sufficiently, which weakens the effect of calendering. When the width of the calendering wheel is equal to or greater than the width of the tab area to be calendered, the calendering wheel applies uneven force due to the contact between the two sides of the calendering wheel and the electrode coating area, which also prevents the calendering effect from meeting expectations.

[0007] Therefore, a new solution is needed to address this problem. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a lithium electrode tab rolling mechanism.

[0009] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a lithium electrode tab rolling mechanism, comprising a pre-rolling assembly and a rolling assembly arranged sequentially, wherein the pre-rolling assembly includes a pre-rolling section that contacts the tab to be rolled area and a first straightening section, wherein the pre-rolling section includes a plurality of rolling rollers that contact and press the tab to be rolled area and a plurality of second straightening members disposed on the non-working side of the rolling rollers, wherein the second straightening members contact the non-working side of the rolling rollers and position the contact between the rolling rollers and the tab to be rolled area, wherein the first straightening section includes a plurality of straightening power sources with different power output directions, wherein the straightening power source includes at least one first power source with a power output direction that brings the pre-rolling section closer to the tab to be rolled area, wherein when the rolling rollers contact the tab to be rolled area and start rolling operation, the straightening power sources apply force to the rolling rollers from multiple directions to position the working trajectory of the rolling rollers.

[0010] The present invention is further configured such that: the pre-calendering section includes a stepped roller, and baffles are provided at both ends of the stepped roller.

[0011] By adopting the above technical solution, the baffle provides positioning and control in the length extension direction of the stepped roller.

[0012] The present invention is further configured such that: the stepped roller includes several adjacent large-diameter sections and small-diameter sections, the second straightening member is configured as a small-diameter section, and the calendering roller is configured as a large-diameter section.

[0013] By adopting the above technical solution, the calendering roll and the second straightening component are divided according to the diameter change of the stepped roll, and the calendering roll and the second straightening component are integrated.

[0014] The present invention is further configured such that the projection of the small diameter section of the stepped roller toward the electrode sheet falls within the electrode sheet coating area, and the projection of the large diameter section of the stepped roller toward the electrode sheet covers the electrode tab to be rolled area.

[0015] By adopting the above technical solution, the dimensional accuracy requirements of the stepped roller are reduced while ensuring the calendering effect of the stepped roller under excessive tightness.

[0016] The present invention is further configured such that the projection of the small diameter section of the stepped roller toward the electrode sheet coincides with the electrode sheet coating area, and the projection of the large diameter section of the stepped roller toward the electrode sheet coincides with the electrode tab to be rolled area.

[0017] By adopting the above technical solution, when the stepped roller size is optimal, the impact of friction between the side of the large-diameter section of the stepped roller and the electrode coating area on the calendering effect is reduced.

[0018] The present invention is further configured such that: the number of small-diameter sections of the stepped roller is the same as the number of electrode coating areas, and the number of large-diameter sections of the stepped roller is the same as the number of electrode tab areas to be rolled.

[0019] By adopting the above technical solutions and using better stepped rollers, the range of calendering can be changed according to the actual production needs.

[0020] The present invention is further configured such that the corrective power source also includes a set of symmetrically arranged second power sources.

[0021] By adopting the above technical solution, the output force at the calendering roll is adjusted to stabilize the force in the tab-to-calendering area.

[0022] The present invention is further configured such that the output direction of the second power source is in the same plane as the output direction of the first power source and intersects with it.

[0023] By adopting the above technical solution, it is convenient for operators to control and adjust the force on the electrode tab rolling area through the output of the second power source.

[0024] The present invention is further configured such that: the pre-calendering section further includes a third straightening member, the third straightening member being in contact with the side of the calendering roll away from the tab to be calendered area.

[0025] By adopting the above technical solution, the third straightening component provides auxiliary support for the calender roll, thereby reducing the slight deformation of the calender roll during the calendering process.

[0026] The present invention is further configured such that: the third straightening element is an auxiliary roller, and the auxiliary roller is arranged parallel to the calendering roller.

[0027] By adopting the above technical solution, the auxiliary support provided by the third straightening component to the calendering roll is made more uniform.

[0028] In summary, the present invention has the following beneficial effects:

[0029] The lithium electrode tab rolling mechanism of the present invention replaces a single rolling-related workpiece with a stepped roller. Through multi-directional power and positioning control, it not only reduces the dimensional accuracy requirements of the rolling-related workpiece, but also better accommodates overly tight rolling-related workpieces. At the same time, it suppresses the skew and uneven force phenomenon generated by the stepped roller during rolling, thereby reducing the occurrence of wrinkles and strip breakage, and thus improving the pre-rolling effect. Attached Figure Description

[0030] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein:

[0031] Figure 1 This is a schematic diagram of the cross-sectional structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the present invention;

[0033] Figure 3 This is a schematic diagram of the pre-calendering assembly in this invention;

[0034] Figure 4 This is a schematic diagram of the stepped roller structure in this invention.

[0035] In the diagram: 1. Calendering assembly; 11. Pre-calendering section; 111. Calendering roll; 112. Second straightening component; 113. Stepped roll; 114. Third straightening component; 12. First straightening section; 121. Straightening power source; 1211. First power source; 1212. Second power source; 13. Baffle; 2. Roll pressing assembly; 21. Upper roll; 22. Lower roll; 3. Frame; 31. Slide rail one; 32. Slide rail two. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0037] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0038] Example,

[0039] The above-mentioned technical objective of the present invention is achieved through the following technical solutions, such as... Figures 1 to 4As shown, a lithium electrode tab rolling mechanism includes a pre-rolling assembly 1 and a rolling assembly 2 arranged sequentially. The pre-rolling assembly 1 includes a pre-rolling section 11 that contacts the tab to be rolled area and a first straightening section 12. The pre-rolling section 11 includes several rolling rollers 111 that contact and press the tab to be rolled area and four second straightening members 112 disposed on the non-working side of the rolling rollers 111. The second straightening members 112 contact the non-working side of the rolling rollers 111 and position the rolling rollers 111 to contact the tab to be rolled area. The first straightening section 12 includes several straightening power sources 121 with different power output directions. At least one straightening power source 121 includes a first power source 1211 whose power output direction brings the pre-rolling section 11 closer to the tab to be rolled area. In this embodiment, the straightening... The positive power source 121 includes a set of first power sources 1211 with two power output directions that bring the pre-calendering section 11 close to the tab-to-calendering area, so that the inner walls of the two frames 3 are symmetrical. The first power sources 1211 are parallel and symmetrical to each other. The correcting power source 121 also includes a set of symmetrically arranged second power sources 1212. The symmetrical plane of the second power sources 1212 is also the aforementioned plane that makes the inner walls of the two frames 3 symmetrical. The output direction of the second power sources 1212 is in the same plane as the output direction of the first power sources 1211 and intersects with it. When the calendering roll 111 contacts the tab-to-calendering area and starts the calendering operation, the correcting power source 121 applies force to the calendering roll 111 from multiple directions to position the working trajectory of the calendering roll 111.

[0040] Preferably, the roll forming assembly 2 includes an upper roll 21 and a lower roll 22, which are close to each other for roll forming, and the calendering roll 111 is close to the upper roll 21 for pre-calendering.

[0041] Preferably, the first power source 1211 is a hydraulic cylinder, and the second power source 1212 is a pneumatic cylinder, with the output of the first power source 1211 being greater than that of the second power source 1212.

[0042] like Figure 1 and Figure 4 As shown, the pre-calendering section 11 includes a stepped roller 113. A set of baffles 13 are provided at both ends of the stepped roller 113. The stepped roller 113 is rotatably connected to the surfaces of the baffles 13 that are close to each other. A frame 3 is provided on the surfaces of the baffles 13 that are far apart from each other. The frame 3 is U-shaped. The rotating shafts of the upper roller 21 and the lower roller 22 pass through the frame 3 and are connected to an external power source. The relevant external power source is hidden in the figure. The baffles 13 are slidably connected to the surfaces of the frame 3 that are close to each other.

[0043] The pre-calendering section 11 also includes a third straightening member 114. The third straightening member 114 contacts the side of the curved surface of the calendering roll 111 away from the tab to be calendered. The third straightening member 114 is an auxiliary roll, which is arranged parallel to the calendering roll 111. In this embodiment, there are two auxiliary rolls. The auxiliary rolls do not contact each other. The diameter and length of the auxiliary rolls are both greater than those of the stepped roll 113. The auxiliary rolls are symmetrical to each other. The symmetrical surface of the auxiliary rolls is the surface where the axis of the calendering roll 111 is located.

[0044] Preferably, a set of slide rail 1 31 and a set of slide rail 2 32 are fixedly connected to the adjacent sides of the frame 3. The planes on which slide rail 1 31 and slide rail 2 32 are located are parallel to the inner wall of the frame 3. Slide rail 1 31 is set perpendicular to the ground, and slide rail 2 32 is inclined to the ground at an angle between zero and ninety degrees. This angle is adjusted according to actual production needs. The side of slide rail 2 32 closer to the electrode waiting area is horizontally higher than the side farther from the electrode waiting area. The output end of the first power source 1211 is fixedly connected to a roller slider and a slider. The output end of the first power source 1211 is connected to the slider and the slide rail 1. The first power source 1211 moves along the direction of the slide rail 31. The output end of the first power source 1211 drives the roller slider to contact the bottom side of the baffle 13 to push the baffle 13. A U-shaped slider is fixedly connected to the baffle 13. The baffle 13 is slidably connected to the frame 3 through the cooperation of the slider and the slide rail 32. When the roller slider presses the baffle 13, the baffle 13 moves along the extension direction of the slide rail 32 and drives the stepped roller 113 and the auxiliary roller to approach the electrode tab to be calendered. The output end of the second power source 1212 is fixedly connected to the baffle 13. The output direction of the second power source 1212 is adjusted according to the actual production needs.

[0045] The stepped roller 113 includes several adjacent large-diameter sections and small-diameter sections. In this embodiment, the stepped roller 113 includes three large-diameter sections and four small-diameter sections. The second straightening member 112 is set as a small-diameter section, and the calendering roller 111 is set as a large-diameter section. The difference in radius between the large-diameter section and the small-diameter section is greater than or equal to the difference in thickness between the electrode coating area and the electrode tab calendering area. The length of each large-diameter section on the stepped roller 113 is less than that of each small-diameter section.

[0046] The projections of the four small diameter segments of the stepped roller 113 toward the electrode sheet fall within the electrode sheet coating area, and the projections of the three large diameter segments of the stepped roller 113 toward the electrode sheet cover the tab area to be rolled. The number of small diameter segments of the stepped roller 113 is the same as the number of electrode sheet coating areas, and the number of large diameter segments of the stepped roller 113 is the same as the number of tab areas to be rolled.

[0047] Preferably, the projection of the small diameter section of the stepped roller 113 toward the electrode sheet coincides with the electrode sheet coating area, and the projection of the large diameter section of the stepped roller 113 toward the electrode sheet coincides with the electrode tab calendering area.

[0048] In actual production, this embodiment works as follows: First, the operator places the electrode sheet between the upper roller 21 and the stepped roller 113. The electrode sheet moves with the upper roller 21, passing sequentially through the stepped roller 113 and the lower roller 22. During this process, pre-calendering and rolling are completed respectively. In the pre-calendering process, the first power source 1211 outputs force and presses the baffle 13. The baffle 13 drives the stepped roller 113 closer to the electrode sheet. The larger diameter section of the stepped roller 113, i.e., the calendering roller 111, approaches and contacts the electrode tab of the electrode sheet in the calendering area, generating pressure. The smaller diameter section of the stepped roller 113 is the second straightening element. 112 is close to the electrode coating area but does not compress the electrode coating area. During the pre-calendering process, since the electrode tab is made of metal, the electrode resists the calendering of the calendering roll 111. This resistance can be decomposed into two forces perpendicular to each other. The component force along the length of the stepped roll 113 is transmitted through the calendering roll 111 to the area of ​​the second straightener 112. The second straightener 112 is connected to the baffle 13 and resists this component force in the opposite direction. The other component force is along the stepped roll 113 away from the electrode tab to be calendered area. This component force is transmitted through the stepped roll... 113 is passed to the third straightening element 114 and resisted by it. The second straightening element 112 and the third straightening element 114 play the role of positioning the calendering roll 111 when the skewness of the calendering roll 111 is small. Then, the pre-calendered electrode sheet enters between the upper roll 21 and the lower roll 22 for rolling. Due to the pre-calendering of the electrode tabs, the required tension of the electrode sheet between the upper roll 21 and the lower roll 22 is reduced, and the wrinkles and strip breakage phenomena are also reduced. During the pre-calendering process, the operator adopts different work procedures according to different situations. When the rolled electrode sheet does not produce obvious wrinkles or incomplete rolling in the connection area with the electrode tab, the operator does not change the output of the first power source 1211. When the electrode tab produces obvious partial incomplete rolling, the calendering roll 111 is significantly skewed. The operator then activates the second power source 1212 to apply an inclined load to the stepped roll 113, thereby pushing the calendering roll 111 back to the correct position. This restores the calendering force on the area to be calendered, thereby reducing wrinkles and strip breakage, and improving the pre-calendering effect.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium electrode tab rolling mechanism, characterized in that: The assembly includes a pre-calendering component (1) and a roll forming component (2) arranged sequentially. The pre-calendering component (1) includes a pre-calendering section (11) for the contact tabs to be calendered and a first straightening section (12). The pre-calendering section (11) includes several calendering rolls (111) for the contact tabs to be calendered and several second straightening members (112) disposed on the non-working side of the calendering rolls (111). The second straightening members (112) squeeze the non-working side of the calendering rolls (111) and position the calendering rolls (111). The first straightening section (12) includes several straightening power sources (121) with different power output directions. The straightening power source (121) includes at least one first power source (1211) with a power output direction that brings the pre-calendering section (11) closer to the electrode rolling area. When the calendering roll (111) contacts the electrode rolling area and starts the calendering operation, the straightening power source (121) applies force to the calendering roll (111) from multiple directions to position the calendering. The working trajectory of the roller (111); the pre-calendering section (11) includes a stepped roller (113), and baffles (13) are provided at both ends of the stepped roller; the stepped roller (113) includes several adjacent large-diameter sections and small-diameter sections, the second straightening member (112) is set as the small-diameter section, and the calendering roller (111) is set as the large-diameter section; the straightening power source (121) also includes a set of symmetrically arranged second power sources (1212); the output of the second power source (1212) is... The direction is in the same plane and intersects with the output direction of the first power source (1211); during the pre-calendering process, the first power source (1211) outputs force and squeezes the baffle (13), and the baffle (13) drives the stepped roller (113) to approach the electrode sheet. When the calendering roller (111) is significantly skewed, the second power source (1212) is activated to apply an inclined load to the stepped roller (113), thereby pushing the calendering roller (111) back to the correct position, so that the calendering force on the area to be calendered is balanced again.

2. The lithium electrode tab rolling mechanism according to claim 1, characterized in that: The projection of the small diameter section of the stepped roller (113) toward the electrode sheet falls within the electrode sheet coating area, and the projection of the large diameter section of the stepped roller (113) toward the electrode sheet covers the electrode tab to be rolled area.

3. The lithium electrode tab rolling mechanism according to claim 1, characterized in that: The projection of the small diameter section of the stepped roller (113) toward the electrode sheet coincides with the electrode sheet coating area, and the projection of the large diameter section of the stepped roller (113) toward the electrode sheet coincides with the electrode tab calendering area.

4. The lithium electrode tab rolling mechanism according to claim 1, characterized in that: The number of small-diameter sections of the stepped roller (113) is the same as the number of electrode coating areas, and the number of large-diameter sections of the stepped roller (113) is the same as the number of electrode tab calendering areas.

5. The lithium electrode tab rolling mechanism according to claim 1, characterized in that: The pre-calendering section (11) also includes a third straightening member (114), which contacts the side of the curved surface of the calendering roll (111) away from the tab to be calendered.

6. The lithium electrode tab rolling mechanism according to claim 1, characterized in that: The third straightening element (114) is an auxiliary roller, which is arranged parallel to the calendering roller (111).

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