On-line smoothing device for folding deformation of battery cell tab

Abstract

The utility model discloses an on-line flattening device for folding deformation of a battery cell tab. The on-line flattening device comprises a tab folding and flattening assembly, a tab guide assembly and a tab flattening assembly which are sequentially arranged along the transmission direction of a material belt transmission line, the tab folding and smoothing assembly comprises a negative pressure suction nozzle; the tab guide assembly can guide the tab, so that the tab and the material belt are positioned on the same plane; the tab leveling station comprises two leveling rollers, and a heating assembly is arranged in each leveling roller; the two leveling rollers can synchronously and reversely rotate, and the rotating speed is equal to the conveying speed of the material belt conveying line; a floating gap with adjustable thickness is formed between the two leveling rollers; and the distance between the end surfaces of the necking ends of the two guide sheets and the center of the floating gap is smaller than the width of one tab along the transmission direction. According to the device, tabs on the outer side of a battery cell material belt during transmission can be automatically turned over, deformed and smoothed one by one on line, the automation degree is high, manual participation is not needed in the whole smoothing process, and the turnover frequency is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery cell manufacturing, and in particular to an online flattening device for bending and deforming battery cell tabs. Background Technology

[0002] As the energy density requirements of battery cells increase, both aluminum foil and copper foil battery cells are trending towards thinner designs. For example, the thickness of copper foil battery cells has decreased from 6μm to 4.5μm. With increasingly thinner foil materials, the outer corners of the electrode tabs in laser-cut cells are prone to folding or deformation due to several factors, specifically:

[0003] 1. Gravity-induced sagging: The increasingly thinner battery cell tabs become increasingly soft and prone to sagging due to gravity.

[0004] 2. Collision with Rollers: During the forward transmission of the battery cell strip, it may pass through heated pressure rollers or stress rollers. Due to sagging and other reasons, the limp electrode tabs 11 are prone to colliding with the rollers during this process, forming collisions such as... Figure 4 The problem is shown in section 111 after the fold.

[0005] 3. Damage during transport: During transport, the battery cell strip is easily folded and deformed due to bumps and knocks on the tabs.

[0006] Currently, there is no good solution to the increasingly serious problem of electrode deformation and folding. The main approach is to use CCD detection to remove defective electrodes from the production line. After leaving the production line, the electrodes are then manually inspected and smoothed out. This method has low automation and efficiency, and it is an offline operation that increases the number of turnovers and the probability of folding and deformation. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide an online flattening device for folding and deforming battery cell tabs, which can automatically fold, deform and flatten the tabs on the outside of the battery cell strip during transmission one by one online. It has a high degree of automation, and the entire flattening process does not require manual intervention, thus reducing the number of turnovers.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0009] An online flattening device for folding and deforming battery cell tabs includes a tab folding and flattening component, a tab guiding component, and a tab leveling component arranged sequentially along the conveying direction of the conveyor belt.

[0010] The conveyor belt is equipped with a tab folding and smoothing station, a tab guiding station, and a tab leveling station arranged sequentially along the conveying direction.

[0011] The material conveyor line enables the tabs to be leveled online without offline operation, resulting in a high degree of automation.

[0012] The tab folding and smoothing assembly includes a negative pressure suction nozzle, which is located on the outside of the tab in the tab folding and smoothing station and can simultaneously perform negative pressure adsorption on the upper and lower surfaces of the tab in the tab folding and smoothing station.

[0013] The negative pressure suction nozzle in the aforementioned tab folding and smoothing assembly allows for simultaneous negative pressure adsorption of the same gas flow rate on both the upper and lower surfaces of the tab. The outer side of the folded corner in the tab will have adsorption pressure, while the inner side will not. Under the pressure difference between the inner and outer sides, the folded corner will flip outward, achieving smoothing. Simultaneously, it can also adsorb and remove dust from the surface of the tab, such as metal particles.

[0014] The electrode guide assembly can guide the electrode to keep it on the same plane as the material strip, preventing sagging and other deformations.

[0015] The tab leveling station includes two leveling rollers, each equipped with a heating element. This heating element heats the tab, eliminating internal stress and metal fatigue. After the hot-pressing rollers reshape the tab, its strength is restored, preventing it from becoming soft and limp.

[0016] Two leveling rollers are symmetrically arranged on the upper and lower sides of the electrode in the electrode leveling station. They can rotate synchronously in opposite directions, and their rotation speed is equal to the transmission speed of the conveyor belt. The advantage of this arrangement is that the electrode and the conveyor belt are driven synchronously, preventing the electrode, which is in a floating and compressed state, from tearing due to the difference in transmission speed with the conveyor belt.

[0017] There is a floating gap between the two leveling rollers with adjustable thickness. On the one hand, it allows the tabs to enter freely and maintain contact and tightness, and facilitates the elimination of creases and stress. On the other hand, it can also adapt to the automatic tightness of tabs of different thicknesses.

[0018] The distance between the outlet end face of the tab guide assembly and the center of the floating gap is less than the width of one tab along the conveying direction. The advantage of this setting is that when the tab enters the floating gap, the tail of the tab is still inside the constricted end of the guide plate, preventing the tab from sagging and folding due to impact with the leveling roller.

[0019] Furthermore, the tab folding and flattening assembly also includes a vacuum pump connected to the negative pressure nozzle, and the negative pressure suction force of the vacuum pump can be adjusted.

[0020] Furthermore, the opening width of the negative pressure nozzle along the transmission direction is greater than the width of one tab, but smaller than the distance between two adjacent tabs.

[0021] Furthermore, the vertical opening depth of the negative pressure nozzle is greater than the thickness of the tab.

[0022] Furthermore, each leveling roller includes an integrally formed large cylindrical roller and a small cylindrical roller; wherein the diameter of the large cylindrical roller is larger than the diameter of the small cylindrical roller.

[0023] Furthermore, both large cylindrical rollers have built-in heating components and are symmetrically arranged on the upper and lower sides of the electrode tab in the electrode tab leveling station. There is a floating gap between the two large cylindrical rollers with adjustable thickness.

[0024] Furthermore, two small cylindrical rollers are symmetrically arranged on the upper and lower sides of the material belt, and there is a transmission gap between them and the material belt.

[0025] Furthermore, the other ends of the two small cylindrical rollers are mounted on a bracket, which is located on the outside of the electrode leveling station away from the electrode tab; one or two small cylindrical rollers are floatingly connected to the bracket.

[0026] Furthermore, the two small cylindrical rollers are an upper small cylindrical roller and a lower small cylindrical roller, wherein the upper small cylindrical roller is floatingly connected to the support, and the lower small cylindrical roller is connected to the lower rotation drive device in the support.

[0027] Furthermore, the bracket is equipped with a sliding window, inside which is a slider whose height can be freely raised and lowered. An upper rotation drive device is installed on the slider, and the upper rotation drive device is connected to an upper small cylindrical roller. A floating spring is installed in the sliding window below the slider. A pressure rod that can drive the slider to descend in height is installed in the sliding window above the slider.

[0028] Furthermore, the pressure rod is connected to the clamping cylinder, and a pressure sensor capable of detecting the clamping force of the pressure rod is installed inside the clamping cylinder.

[0029] Furthermore, the electrode guide assembly includes two guide plates; the two guide plates are symmetrically arranged in a figure-eight shape on the upper and lower sides of the electrode in the electrode guide position.

[0030] This utility model has the following beneficial effects:

[0031] 1. This invention can automatically fold, deform and flatten the tabs on the outside of the battery cell strip during transmission one by one. It has a high degree of automation and the entire flattening process does not require manual intervention, reducing the number of turnovers.

[0032] 2. This invention can automatically fold, deform and flatten tabs of varying thicknesses. After flattening, the tabs have high strength and are less prone to problems such as softness and deformation. Attached Figure Description

[0033] Figure 1 The diagram shows the structure of an online flattening device for bending and deforming battery cell tabs according to this application.

[0034] Figure 2This image shows a partially enlarged schematic diagram of an online flattening device for bending and deforming battery cell tabs, as described in this application.

[0035] Figure 3 This diagram shows the installation structure of the leveling roller and the support in this application.

[0036] Figure 4 The diagram shows the structure with a folded angle after the tab is folded.

[0037] Among them are:

[0038] 10. Material strip;

[0039] 11. Electrode tab; 111. Folding angle; 12. Electrode tab to be folded and smoothed; 13. Electrode tab to be guided; 14. Electrode tab to be leveled;

[0040] 20. Negative pressure suction nozzle;

[0041] 30. Guide plate;

[0042] 40. Leveling roller; 41. Large cylindrical roller; 411. Heating wire; 42. Small cylindrical roller; 43. Chamfer;

[0043] 50. Bracket; 51. Sliding window; 52. Slider; 53. Floating spring; 54. Pressure rod; 541. Pressing cylinder; 55. Upper rotary motor; 56. Lower rotary motor. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0045] In the description of this utility model, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the protection scope of this utility model.

[0046] An online flattening device for folding and deforming battery cell tabs includes a tab folding and flattening component, a tab guiding component, and a tab leveling component arranged sequentially along the transmission direction of the conveyor belt 10.

[0047] The material conveyor line (not shown in the figure) is arranged along the conveying direction with a tab folding and smoothing station, a tab guiding station, and a tab leveling station. The material conveyor line is an existing conveyor line used in cell manufacturing, and the forward transmission of the conveyor line is also existing technology, such as traction transmission via tension rollers.

[0048] Currently, there are three processes for stacking battery cells: winding, Z-stacking, and thermal bonding.

[0049] When using a winding process, the leveling device of this application can be designed on the material conveyor line before the winding step of the needle winding process.

[0050] When using the Z-stack process, the electrode sheet is cut, which cuts the strip 10 of the electrode roll. Therefore, the leveling device of this application is usually designed on the strip transport line before the electrode sheet is cut.

[0051] When using a thermal bonding process, the leveling device of this application can be installed on the material conveyor line before the stacking step of thermal bonding.

[0052] For ease of expression, in this application, as follows Figure 1 and Figure 2 As shown, the electrode 11 in the electrode folding and smoothing station is called the electrode 12 to be folded and smoothed, the electrode 11 in the electrode guiding station is called the electrode 13 to be guided, and the electrode 11 in the electrode leveling station is called the electrode 14 to be leveled.

[0053] The tab folding and flattening assembly includes a vacuum pump and a negative pressure suction nozzle 20 connected to the vacuum pump.

[0054] The vacuum pump and its connection to the negative pressure nozzle 20 are existing technologies and are therefore not shown in the figure. The negative pressure suction of the vacuum pump is adjustable, preferably with a wind speed >25m / s. This allows the negative pressure suction in the negative pressure nozzle 20 to be adjusted according to the thickness or strength of the tab 11, preventing excessive suction from damaging the tab 11 again and insufficient suction from making it difficult to straighten the bend 111.

[0055] The negative pressure nozzle 20 is positioned on the outside of the tab 12 to be folded and flattened, without contacting it. The negative pressure nozzle 20 allows for simultaneous negative pressure adsorption of the same gas flow rate on both the upper and lower surfaces of the tab 11. When the tab 11 is folded, the outer side of the fold 111 experiences adsorption pressure, but the gas flow rate and atmospheric pressure decrease. Because the tab 11 blocks the low gas flow rate (i.e., no adsorption pressure), the fold 111 will flip outwards under the pressure difference between its inner and outer sides, opening the tab 11 until it is completely straightened. The airflow direction is parallel to the tab 11, and the tab 11 is no longer under pressure, achieving flattening. Simultaneously, the adsorption airflow in the negative pressure nozzle 20 can also adsorb and remove dust from the surface of the tab 11, such as metal particles.

[0056] Furthermore, in this application, the cross-section of the negative pressure nozzle 20 is preferably rectangular, and its opening width along the transmission direction is greater than the width of one tab 11, but smaller than the distance between two adjacent tabs 11. This configuration ensures that the negative pressure nozzle 20 can only flatten one tab 12 to be folded and flattened at a time.

[0057] Furthermore, the vertical opening depth of the negative pressure nozzle 20 is greater than the thickness of the tab 11, and the tab 12 to be folded and flattened is located on the central axis of its thickness. This arrangement ensures that there is airflow on both the upper and lower surfaces of the tab 12 to be folded and flattened, and that the gas flow rate is equal.

[0058] The tab guide assembly guides the tab 11, ensuring it is on the same plane as the conveyor belt 10 and preventing sagging or other deformation. In this embodiment, it includes two guide plates 30. These two guide plates 30 are symmetrically arranged in a V-shape on the upper and lower sides of the tab 11 in the tab guiding position. The bottom surface of the end of each guide plate 30 is preferably tangent to the contact surface of the tab 13 to be guided, with a distance of 2-5 mm. Because the guide plates 30 are V-shaped, the flared end facilitates the guidance of the tab 11 without impact; the constricted end limits the position of the tab 11, preventing sagging or other deformation. The method of fixing the guide plates 30 is existing technology, such as mounting them on the conveyor belt or ground via a mounting bracket, and will not be elaborated here.

[0059] The tab leveling station includes two leveling rollers 40, each equipped with a heating component. In this embodiment, the heating component is preferably a heating wire 411, and the heating temperature is adjustable. The heating component allows for hot pressing of the tab 11, eliminating internal stress and metal fatigue caused by deformation and creases. After the hot pressing roller reshapes the tab 11, its shape and strength are restored, and it no longer becomes soft.

[0060] Two leveling rollers 40 are symmetrically arranged on the upper and lower sides of the tab 11 in the tab leveling station. They can rotate synchronously in opposite directions, and the rotation speed is equal to the transmission speed of the material belt conveyor. The advantage of this arrangement is that the tab 11 and the material belt 10 are driven synchronously, preventing the tab 11, which is in a floating and compressed state, from tearing or other phenomena due to the difference in transmission speed with the material belt.

[0061] There is a floating gap between the two leveling rollers 40 with adjustable thickness. On the one hand, it can facilitate the free entry of the tabs 11 and maintain contact and pressing, and facilitate the elimination of creases and stress. On the other hand, it can also adapt to the automatic pressing of tabs 11 of different thicknesses.

[0062] Furthermore, the distance between the constricted end faces of the two guide plates 30 and the center of the floating gap is less than the width of one tab 11 along the conveying direction. The advantage of this arrangement is that when the tab 11 enters the floating gap, the tail of the tab 11 is still within the constricted end of the guide plate 30, preventing the tab 11 from sagging or colliding with the leveling roller 40 and folding over.

[0063] In this embodiment, as Figure 3 As shown, each leveling roller 40 includes an integrally formed large cylindrical roller 41 and a small cylindrical roller 42; wherein, the diameter of the large cylindrical roller 41 is larger than the diameter of the small cylindrical roller 42, and their connection is preferably transitioned by a chamfer 43.

[0064] Both large cylindrical rollers 41 have the aforementioned heating components built in, and are symmetrically arranged on the upper and lower sides of the tab 11 in the tab leveling station. There is a floating gap between the two large cylindrical rollers 41 with adjustable thickness.

[0065] Two small cylindrical rollers 42 are symmetrically arranged on the upper and lower sides of the material belt 10, and there is a transmission gap between them and the material belt 10.

[0066] The other ends of the two small cylindrical rollers 42 are mounted on the bracket 50, which is located on the outside of the electrode leveling station away from the electrode tab 11; one or two small cylindrical rollers 42 are floatingly connected to the bracket 50.

[0067] The two small cylindrical rollers 42 are designated as the upper small cylindrical roller and the lower small cylindrical roller, respectively. In this embodiment, the upper small cylindrical roller is floatingly connected to the support 50, and the lower small cylindrical roller is connected to the lower rotation drive device in the support 50. Preferably, the lower rotation drive device is a lower rotation motor 56. Alternatively, both the upper and lower small cylindrical rollers can be floatingly connected to the support 50, or only the lower small cylindrical roller can be floatingly connected to the support 50.

[0068] A sliding window 51 is provided on the bracket 50, and a slider 52 with a height that can be freely raised and lowered is provided inside the sliding window 51. An upper rotation drive device is installed on the slider 52, and the upper rotation drive device is connected to the upper small cylindrical roller 42. In this embodiment, the upper rotation drive device is preferably an upper rotation motor 55, but it can also be a cylinder or the like.

[0069] Furthermore, a floating spring 53 is provided in the sliding window 51 below the slider 52, and a pressure rod 54 is provided in the sliding window 51 above the slider 52 to drive the slider 52 to descend in height. The pressure rod 54 is preferably connected to a clamping cylinder 541. A pressure sensor (not shown in the figure) is provided in the clamping cylinder 541 to detect the clamping force of the pressure rod 54. The clamping force of the clamping cylinder 541 is adjustable, and the size of the floating gap is controlled by the pressure detected by the pressure sensor.

[0070] In this embodiment, the preferred design of the leveling roller 40 is: diameter ≥100mm, surface hardness ≥60HRC, cylindricity ≤3um, runout after assembly ≤10um, alloy steel material, and the center lines of the two leveling rollers 40 are located in the same vertical plane ≤0.05mm.

[0071] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A device for online smoothing and straightening of battery cell tabs after folding and deformation, characterized in that: It includes an electrode tab folding and smoothing assembly, an electrode tab guiding assembly, and an electrode tab leveling assembly arranged sequentially along the conveying direction of the material conveyor line; The conveyor belt is equipped with a tab folding and smoothing station, a tab guiding station, and a tab leveling station arranged sequentially along the conveying direction; The tab folding and smoothing assembly includes a negative pressure suction nozzle (20), which is located on the outside of the tab (11) in the tab folding and smoothing station, and can simultaneously perform negative pressure adsorption on the upper and lower surfaces of the tab (11) in the tab folding and smoothing station. The electrode guide assembly can guide the electrode (11) so that the electrode (11) and the material strip (10) are on the same plane; The tab leveling station includes two leveling rollers (40), and each leveling roller (40) is equipped with a heating component. Two leveling rollers (40) are symmetrically arranged on the upper and lower sides of the electrode (11) in the electrode leveling station. They can rotate synchronously in opposite directions, and the rotation speed is equal to the transmission speed of the material belt transmission line. There is a floating gap between the two leveling rollers (40) with adjustable thickness; The distance between the outlet end face of the tab guide assembly and the center of the floating gap is less than the width of a tab (11) along the transmission direction.

2. The online smoothing device for cell tab folding and deformation according to claim 1, characterized in that: The tab folding and flattening assembly also includes a vacuum pump connected to the negative pressure nozzle (20), the magnitude of the negative pressure suction of the vacuum pump can be adjusted.

3. The online smoothing device for cell tab folding and deformation according to claim 1, characterized in that: The opening width of the negative pressure nozzle (20) along the transmission direction is greater than the width of one tab (11), but less than the distance between two adjacent tabs (11).

4. The online smoothing device for cell tab folding and deformation according to claim 1, characterized in that: The opening depth of the negative pressure nozzle (20) in the vertical direction is greater than the thickness of the tab (11).

5. The online smoothing device for cell tab folding and deformation according to claim 1, characterized in that: Each leveling roller (40) includes an integrally formed large cylindrical roller (41) and a small cylindrical roller (42); wherein the diameter of the large cylindrical roller (41) is larger than the diameter of the small cylindrical roller (42); Both large cylindrical rollers (41) are equipped with heating components and are symmetrically arranged on the upper and lower sides of the electrode (11) in the electrode leveling station. There is a floating gap between the two large cylindrical rollers (41) with adjustable thickness. Two small cylindrical rollers (42) are symmetrically arranged on the upper and lower sides of the material belt (10) and have a transmission gap with the material belt (10).

6. The online smoothing device for cell tab folding and deformation according to claim 5, characterized in that: The other ends of the two small cylindrical rollers (42) are mounted on the bracket (50), which is located on the outside of the electrode leveling station away from the electrode tab (11); one or two small cylindrical rollers (42) are floatingly connected to the bracket (50).

7. The online smoothing device for cell tab folding and deformation according to claim 6, characterized in that: The two small cylindrical rollers (42) are an upper small cylindrical roller and a lower small cylindrical roller, respectively. The upper small cylindrical roller is floatingly connected to the bracket (50), and the lower small cylindrical roller is connected to the lower rotation drive device in the bracket (50).

8. The online smoothing device for cell tab folding and deformation according to claim 7, characterized in that: A sliding window (51) is provided on the bracket (50), and a slider (52) with a height that can be freely raised and lowered is provided inside the sliding window (51). An upper rotation drive device is installed on the slider (52), and the upper rotation drive device is connected to the upper small cylindrical roller. A floating spring (53) is provided inside the sliding window (51) below the slider (52). A pressure rod (54) that can drive the slider (52) to descend in height is provided inside the sliding window (51) above the slider (52).

9. The online smoothing device for cell tab folding and deformation according to claim 8, characterized in that: The pressure rod (54) is connected to the clamping cylinder (541), and a pressure sensor that can detect the clamping force of the pressure rod (54) is installed inside the clamping cylinder (541).

10. The online smoothing device for cell tab folding and deformation according to claim 1, characterized in that: The electrode guide assembly includes two guide plates (30); the two guide plates (30) are symmetrically arranged in a figure-eight shape on the upper and lower sides of the electrode (11) in the electrode guide position.

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