A kneading roller structure

Abstract

This utility model relates to the field of flattening roller technology, and proposes a flattening roller structure, including a fixing part and a flattening part. The flattening part is coaxially fixed to the fixing part and is used to flatten the electrode tab. The flattening part has a conical structure, and the outer diameter of the end of the flattening part near the fixing part is larger than the outer diameter of the end away from the fixing part. It also includes a blocking part, which is coaxially fixed to the end of the flattening part away from the fixing part, and the periphery of the blocking part extends outward from the periphery of the flattening part. This utility model, by providing a blocking part at the end of the flattening part and allowing the periphery of the blocking part to extend outward from the periphery of the flattening part, allows the blocking part to guide the electrode tab when the flattening part flattens it, preventing the electrode tab from blocking the center hole of the winding core. This eliminates the need for other components to block the center hole of the winding core in the flattening mechanism, reducing the structural complexity of the flattening mechanism and improving its overall performance and cost-effectiveness.

Description

Technical Field

[0001] This utility model relates to the field of flattening roller technology, and in particular to a flattening roller structure for a cylindrical lithium battery with multiple tabs. Background Technology

[0002] The all-tab battery is an innovative battery design. Its core feature lies in its structural innovation, directly utilizing the entire tail of the current collector as the tab. By increasing the conductive area of ​​the tab and the connection area at its junction, and shortening the conductive distance of the tab, the battery's internal resistance can be significantly reduced, improving its rate performance and cycle life. In the manufacturing process of all-tab batteries, the treatment of the tabs is crucial. Due to the large tab area of ​​all-tab batteries, a flattening process is required to ensure good contact between the tab and the current collector. The flattening process not only improves the flatness of the tab but also enhances the bonding strength between the tab and the current collector, thereby reducing contact resistance and improving battery performance.

[0003] The leveling process is typically achieved through a dedicated leveling mechanism. For example, the invention patent CN116116495B discloses a leveling head and a cylindrical battery cell leveling device. Its leveling wheel has a pressing section and a leveling section. The leveling section is used to level the tabs. Since the core has a central hole, a center pin is also included to prevent the leveled tabs from blocking the central hole. However, the center pin, as an additional component, not only increases the assembly complexity of the leveling mechanism but also increases its maintenance difficulty and operating costs, hindering the improvement of the overall performance and cost-effectiveness of the leveling mechanism. Utility Model Content

[0004] In view of this, the present invention proposes a kneading wheel structure, which reduces the structural complexity of the kneading mechanism and improves the overall performance and cost-effectiveness of the kneading mechanism by setting a blocking part on the kneading wheel.

[0005] The technical solution of this utility model is implemented as follows: This utility model provides a flattening wheel structure, including a fixing part and a flattening part. The flattening part is coaxially fixed on the fixing part and is used to flatten the electrode tab. The flattening part has a conical structure, and the outer diameter of the flattening part near the fixing part is larger than the outer diameter of the end away from the fixing part.

[0006] It also includes a blocking part, which is coaxially fixed to one end of the flattening part away from the fixing part. The periphery of the blocking part extends out of the periphery of the flattening part to prevent the flattening tab from extending into the center hole of the core.

[0007] Based on the above technical solutions, preferably, the thickness of the tab after flattening is H, wherein 0.3mm≤H≤0.6mm.

[0008] More preferably, the length by which the obstruction extends beyond the periphery of the flattening portion is L, where L < H.

[0009] Based on the above technical solutions, preferably, the blocking part includes a first end and a second end, wherein,

[0010] The first end is fixedly disposed on the kneading part, and the periphery of the first end is conical, with its outer diameter gradually increasing in the direction away from the kneading part;

[0011] The second end is fixedly disposed at the end of the first end that is away from the kneading part.

[0012] More preferably, the angle between the periphery of the first end and the periphery of the flattening portion is A, wherein 90°≤A≤120°.

[0013] Based on the above technical solutions, preferably, the connection between the blocking part and the kneading part is provided with a rounded corner.

[0014] More preferably, the radius of the rounded corner is R, where 0.5mm≤R≤1.5mm.

[0015] More preferably, the periphery of the second end is conical, and its outer diameter gradually decreases in the direction away from the flattened portion, and a weight-reducing groove is provided at the end of the second end away from the first end.

[0016] Based on the above technical solutions, preferably, it also includes an extrusion part, which is coaxially fixed on the fixing part. The extrusion part is located at the end of the kneading part away from the blocking part, and its periphery extends out of the periphery of the kneading part.

[0017] Based on the above technical solutions, preferably, an assembly hole is provided at the end of the fixing part away from the kneading part, and a limiting groove is provided on the periphery of the end of the fixing part away from the kneading part.

[0018] The kneading wheel structure of this utility model has the following advantages over the prior art:

[0019] (1) By setting a blocking part at the end of the flattening part and allowing the periphery of the blocking part to extend out of the periphery of the flattening part, when the flattening part flattens the electrode tab, the blocking part can guide the electrode tab and prevent the electrode tab from blocking the center hole of the core. There is no need to use other components to block the center hole of the core in the flattening mechanism, which reduces the structural complexity of the flattening mechanism and improves the overall performance and cost-effectiveness of the flattening mechanism.

[0020] (2) By setting blocking and squeezing parts at both ends of the flattening part, the electrode ear can be constrained between the blocking and squeezing parts during the flattening process of the electrode ear, making the electrode ear more compact, increasing the density and thickness of the flattened layer of the electrode ear, and improving the weldability of the flattened layer.

[0021] (3) By limiting the specifications of the blocking part, not only can the guiding performance of the blocking part on the tab be improved, and the flattening effect of the tab be further improved, but the damage caused by the blocking part to the tab can also be reduced, thereby improving the processing safety of the battery. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a cross-sectional view of a kneading wheel structure according to the present invention.

[0024] Figure 2 This is a cross-sectional view of the blocking part in a kneading wheel structure according to the present invention.

[0025] Figure 3 This is a perspective view of a kneading wheel structure of the present invention located on one side of the blocking part.

[0026] Figure 4 This is a perspective view of a kneading wheel structure of the present invention located on one side of the fixed part.

[0027] Figure 5 This is a cross-sectional view of the flattening electrode tab of a flattening wheel structure according to this utility model.

[0028] Figure 6 This is a cross-sectional view of the flattening wheel structure of this utility model after flattening the electrode tabs.

[0029] Among them: 1. Fixing part; 101. Assembly hole; 102. Limiting groove; 2. Flattening part; 3. Blocking part; 31. First end; 32. Second end; 301. Rounded corner part; 302. Weight reduction groove; 4. Extrusion part; 5. Electrode; 6. Core; 601. Center hole. Detailed Implementation

[0030] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] Core 6 and tab 5 are important core components of a full-tab battery, such as Figure 5 As shown, the core 6 is formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. A central hole 601 is provided in the center of the core 6, serving as a channel for electrolyte injection. Injecting electrolyte through the central hole 601 allows it to penetrate more quickly and evenly into all parts of the core 6, improving the wetting effect, reducing internal battery resistance, and enhancing charge / discharge performance. One end of the tab 5 extends into the electrode material within the core 6, while the other end extends out of the core 6 for connection to the current collector.

[0032] In the production process of all-tab cylindrical batteries, flattening tab 5 is an indispensable step. Flattened tab 5 forms a dense solid, effectively increasing the contact area, making welding more stable, improving welding quality, and thus enhancing battery safety and rate performance.

[0033] The present invention provides a kneading wheel structure, comprising a fixing part 1, a kneading part 2, a blocking part 3, and a squeezing part 4, which are used to be installed on a kneading device and to knead the electrode ear 5 in conjunction with the rotation of the kneading device.

[0034] The kneading device includes a rotating shaft and a bearing seat fixed on the rotating shaft. The bearing seat is eccentrically arranged with respect to the rotating shaft. The fixing part 1 is fixed inside the bearing seat, and the kneading part 2 is coaxially fixed to one end of the fixing part 1. When the rotating shaft of the kneading device rotates, the fixing part 1 can rotate not only around the axis of the rotating shaft, but also around the axis of the bearing seat, so that the periphery of the kneading part 2 can roll and knead the tab 5.

[0035] An assembly hole 101 is provided at the end of the fixing part 1 away from the flattening part 2, so that the fixing part 1 can be fixedly installed in the bearing housing. In order to prevent the fixing part 1 from rotating relative to the inner ring of the bearing housing, a limiting groove 102 is also provided on the periphery of the end of the fixing part 1 away from the flattening part 2. A shaft pin is installed in this limiting groove 102 to prevent the fixing part 1 from rotating relative to the inner ring of the bearing housing.

[0036] The flattening part 2 has a conical structure, and the outer diameter of the flattening part 2 near the fixing part 1 is larger than the outer diameter of the flattening part 2 away from the fixing part 1. The blocking part 3 is coaxially fixed to the end of the flattening part 2 away from the fixing part 1, and the periphery of the blocking part 3 extends out of the periphery of the flattening part 2.

[0037] like Figure 5 As shown, the blocking part 3 is located above the center hole 601, and its position corresponds to the inner wall of the center hole 601. During the smoothing process, the blocking part 3 and the smoothing part 2 rotate together around the axis of the center hole 601. The rotation of the smoothing part 2 causes the tab 5 to wrinkle. The wrinkled tab 5 is guided by the blocking part 3 and will not extend into the center hole 601, thus ensuring the unobstructed flow of the center hole 601 and not affecting the liquid injection and air venting operation of the core 6.

[0038] The extrusion section 4 is coaxially fixed to the fixing section 1. The extrusion section 4 is located at the end of the flattening section 2 away from the blocking section 3, and the periphery of the extrusion section 4 also extends out of the periphery of the flattening section 2. During the flattening process, the extrusion section 4 is located on the periphery of the core 6, thereby restricting the tab 5 between the blocking section 3 and the extrusion section 4, causing the flattened tab 5 to converge inward, increasing the density and thickness at the edge of the flattened layer, and improving the welding performance of the tab 5.

[0039] By setting the blocking part 3, the kneading device no longer needs to be equipped with an intermediate pin to seal the center hole 601, thereby reducing the structural complexity of the kneading device and improving its overall performance and cost-effectiveness.

[0040] To improve the processing efficiency of the flattening roller, it is preferable to process the fixing part 1, flattening part 2, blocking part 3, and extrusion part 4 using an integral molding method. The flattening roller can be made of non-metallic materials such as polyetheretherketone, ceramic, or Teflon, which have strong electrical insulation, high temperature resistance, and wear resistance.

[0041] The surface roughness of the blocking part 3 and the flattening part 2 is no greater than Ra0.3. During the flattening process, the friction between the flattening roller and the tab 5 can be reduced, thereby reducing the generation of metal chips and reducing the safety risks generated during battery processing.

[0042] like Figure 6 As shown, the thickness of the flattened tab 5 is H, as follows. Figure 2 As shown, the length of the obstruction part 3 extending from the flattening part 2 is L.

[0043] Preferably, L < H, meaning the length of the blocking portion 3 extending beyond the flattening portion 2 is less than the thickness of the tab 5 after flattening. For example... Figure 6 As shown, during the kneading process, the blocking part 3 will not come into contact with the diaphragm in the core 6, thus providing a good protective effect.

[0044] In some embodiments, 0.3mm ≤ H ≤ 0.6mm, meaning the thickness of the flattened tab 5 is 0.3mm, 0.45mm, or 0.6mm, etc. If H < 0.3mm, the flattened tab 5 layer is too thin, failing to effectively collect and conduct current evenly to the external circuit, resulting in uneven current density distribution on the electrode surface, with excessive current density in some areas, accelerating the aging and damage of the electrode material in those areas, affecting the battery's consistency and overall performance. If H > 0.6mm, the flattened tab 5 layer is too thick, hindering rapid electron transport. During high-rate charging and discharging, the internal polarization of the battery intensifies, and the battery cannot respond promptly to changes in large current, causing a decrease in the battery's rate performance.

[0045] The blocking part 3 includes a first end portion 31 and a second end portion 32. The first end portion 31 is fixedly disposed on the kneading part 2, and the second end portion 32 is fixedly disposed at the end of the first end portion 31 away from the kneading part 2; for example Figure 2 As shown, the periphery of the first end 31 is conical, and the outer diameter of the first end 31 gradually increases in the direction away from the flattening part 2. By using this conical structure, the angle between the periphery of the first end 31 and the periphery of the flattening part 2 can be increased, thereby improving the guiding ability of the first end 31 to the tab 5, so that the tab 5 is drawn towards the middle position of the flattening part 2, and the gap of the flattening layer of the tab 5 above the central hole 601 is larger, so as to ensure the unobstructed flow of the central hole 601.

[0046] like Figure 1 As shown, the angle between the periphery of the first end 31 and the periphery of the flattened part 2 is A.

[0047] In some embodiments, 90°≤A≤120°, that is, the angle between the periphery of the first end 31 and the periphery of the flattening part 2 is 90°, 105° or 120°, etc. Since the flattening part 2 and the end of the tab 5 abut against each other, if A<90°, the angle between the periphery of the first end 31 and the periphery of the flattening part 2 is an acute angle, which causes the flattened tab 5 to get stuck between the periphery of the first end 31 and the periphery of the flattening part 2, making it difficult for the flattening wheel to separate from the flattened tab 5, affecting the flattening quality and efficiency of the tab 5; if A>120°, the angle between the periphery of the first end 31 and the periphery of the flattening part 2 is too large, the guiding effect of the second end 31 on the tab 5 is poor, and it cannot guide the tab 5 well, which also affects the flattening quality and efficiency of the tab 5.

[0048] like Figure 2 As shown, the connection between the blocking part 3 and the kneading part 2 is provided with a rounded corner 301, that is, the connection between the blocking part 3 and the kneading part 2 is arc-shaped. This not only improves the guiding performance of the kneading wheel on the electrode ear 5, but also effectively avoids friction damage to the electrode ear 5 at the connection between the blocking part 3 and the kneading part 2, thereby improving the kneading quality of the electrode ear 5.

[0049] like Figure 2 As shown, the radius of the rounded corner 301 is R.

[0050] In some embodiments, 0.5mm≤R≤1.5mm, that is, the radius of the rounded corner 301 is 0.5mm, 1mm, or 1.5mm, etc. This results in a better guiding effect at the connection between the blocking part 3 and the flattening part 2, making the flattening layer of the tab 5 smoother.

[0051] During the kneading process, the kneading device can be equipped with one or more kneading wheels, and these kneading wheels can be arranged in a circular array around the rotation axis of the kneading device to improve the kneading efficiency and quality of the tab 5.

[0052] The length of the blocking part 3 along its axial direction is closely related to the inner diameter of the center hole 601 and the number of smoothing rollers used in the smoothing device. When one smoothing roller is used in the smoothing device, the length of the blocking part 3 along its axial direction should be less than the inner diameter of the center hole 601. When two smoothing rollers are used in the smoothing device, the length of the blocking part 3 along its axial direction should be less than half the inner diameter of the center hole 601, so as to ensure the guiding effect of the blocking part 3.

[0053] like Figure 2 As shown, the periphery of the second end 32 is conical, and the outer diameter of the second end 32 gradually decreases in the direction away from the flattening part 2, thereby reducing the volume of the second end 32 and reducing the space occupied by the blocking part 3.

[0054] Preferably, a weight-reducing groove 302 is provided at the end of the second end 32 that is away from the first end 31, thereby reducing the weight of the kneading wheel and improving its rotational capacity.

[0055] The method of using the kneading wheel structure of this utility model is as follows:

[0056] First, the fixing part 1 is installed in the bearing seat of the leveling device, and the fixing part 1 and the bearing seat are reinforced through the assembly hole 101 and the limiting groove 102. Then, the core 6 is moved to one side of the leveling device, so that the end of the tab 5 extending out of the core 6 is located on the periphery of the leveling part 2. Next, the rotating shaft of the leveling device is rotated, and the core 6 is brought closer to the leveling wheel. The leveling part 2 is used to level the tab 5, so that the tab 5 is formed as shown in the figure. Figure 6 The flattened layer shown.

[0057] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A flattening wheel structure, comprising a fixing part (1) and a flattening part (2), wherein the flattening part (2) is coaxially fixed on the fixing part (1) for flattening the tab (5), wherein the flattening part (2) has a conical structure, and the outer diameter of the end of the flattening part (2) near the fixing part (1) is larger than the outer diameter of the end away from the fixing part (1); Its features are: It also includes a blocking part (3), which is coaxially fixed to one end of the flattening part (2) away from the fixing part (1). The periphery of the blocking part (3) extends out of the periphery of the flattening part (2), and the tab (5) used to block the flattening extends into the center hole (601) of the core (6).

2. The kneading roller structure as described in claim 1, characterized in that: The thickness of the tab (5) after being flattened is H, where 0.3mm≤H≤0.6mm.

3. The kneading roller structure as described in claim 2, characterized in that: The length of the obstruction part (3) extending from the periphery of the flattening part (2) is L, where L < H.

4. The kneading roller structure as described in claim 1, characterized in that: The blocking part (3) includes a first end (31) and a second end (32), wherein, The first end (31) is fixedly disposed on the kneading part (2), and the periphery of the first end (31) is conical, with its outer diameter gradually increasing in the direction away from the kneading part (2); The second end (32) is fixedly disposed at the end of the first end (31) away from the kneading part (2).

5. The kneading roller structure as described in claim 4, characterized in that: The angle between the periphery of the first end (31) and the periphery of the flattened part (2) is A, wherein 90°≤A≤120°.

6. The kneading roller structure as described in claim 1, characterized in that: The connection between the blocking part (3) and the flattening part (2) is provided with a rounded corner (301).

7. The kneading roller structure as described in claim 6, characterized in that: The radius of the rounded corner (301) is R, where 0.5mm≤R≤1.5mm.

8. The kneading roller structure as described in claim 4, characterized in that: The periphery of the second end (32) is conical, and its outer diameter gradually decreases in the direction away from the flattening part (2). The end of the second end (32) away from the first end (31) is provided with a weight reduction groove (302).

9. A kneading roller structure as described in any one of claims 1-8, characterized in that: It also includes a squeezing part (4), which is coaxially fixed on the fixing part (1). The squeezing part (4) is located at the end of the kneading part (2) away from the blocking part (3), and its periphery extends out of the periphery of the kneading part (2).

10. A kneading roller structure as described in any one of claims 1-8, characterized in that: The fixing part (1) has an assembly hole (101) at one end away from the flattening part (2), and a limiting groove (102) is provided on the periphery of the fixing part (1) away from the flattening part (2).

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