Gluing method for preventing tab tearing after ultrasonic welding

Abstract

The invention relates to the technical field of lithium battery production, and particularly discloses a rubberizing method for preventing a tab from being torn after ultrasonic welding, which comprises the following steps: preparing an L-shaped adhesive tape or a U-shaped adhesive tape according to the rubberizing position size of a roll core, cleaning the roll core, and then laminating the L-shaped adhesive tape or the U-shaped adhesive tape on the roll core in an L-shaped or U-shaped laminating path, the method comprises the following steps: attaching an L-shaped adhesive tape to an end face of a battery, compacting the attached adhesive tape by using a compacting tool to firmly adhere the L-shaped adhesive tape to the end face of the battery, finally connecting two adjacent roll cores through a connecting piece to form a battery cell, and gluing the roll cores by using an L-shaped gluing mode or a U-shaped gluing mode, so that the tab can be completely wrapped, the short circuit condition can be isolated, and the battery cell can be prevented from being damaged. Meanwhile, the adhesive tape is not adhered to the roll core, so that tab tearing caused by the fact that the roll core is pressed downwards by the adhesive tape adhering mechanism during adhesive tape adhering and rebounds is avoided, and the condition that the battery end is high in charging and low in discharging can be avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium battery production, and particularly relates to a gluing method for preventing tabs from tearing after ultrasonic welding. Background Art

[0002] In the lithium battery manufacturing process, the practice of tearing the tabs after ultrasonic welding is to ensure the quality and safety of the battery. Ultrasonic welding is used to connect the positive and negative electrodes of the battery to the external lead wires (i.e., the tabs) to ensure welding quality and battery safety.

[0003] After ultrasonic welding, the core is usually in a fluffy state. In order to ensure the structural stability and performance of the battery, an effective bonding method is required. However, the current diaphragms are basically base film or ceramic diaphragms, and then Z-type bonding is used, such as Figure 5 As shown, starting from one end of the battery roll, the tape is evenly applied in a "Z"-shaped path. This method of applying the tape ensures that all parts of the battery roll are well covered, thereby providing sufficient fixation and protection.

[0004] However, when using the Z-type gluing method, the tape will stick to the core during gluing. During the operation, the core needs to be pressed down, which will pull the tabs during the rebound of the core, increasing the chance of the tabs tearing. The tab tearing will cause the battery to be overcharged and undercharged at the user end, thereby affecting the service life of the battery. Therefore, we need to propose a gluing method that prevents the tabs from tearing after ultrasonic welding to solve the above-mentioned problems, so that it can effectively avoid pressing down on the core, greatly reducing the chance of the tabs tearing, thereby avoiding the battery end being overcharged and undercharged. Summary of the Invention

[0005] The purpose of the present invention is to provide a gluing method for preventing the tabs from tearing after ultrasonic welding, which can effectively avoid the downward pressure on the winding core, greatly reduce the probability of the tabs tearing, and thus avoid the high-charge and low-discharge situation at the battery end, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preventing tab tearing after ultrasonic welding, comprising the following steps:

[0008] S1. Prepare L-shaped tape according to the size of the adhesive tape position on the roll core;

[0009] S2. Clean the glue-sticking area of ​​the core and remove the oil and dust on the surface of the core package glue-sticking area;

[0010] S3. Start applying the tape at one end of the core, then move along the thickness direction of the core, and then apply the other end of the tape to the connecting piece to form an L-shaped bonding path so that the tape completely covers the tab;

[0011] S4. Use a compacting tool to bring the L-shaped tape into contact with the end surface of the battery to ensure that the L-shaped tape and the end surface of the battery are firmly bonded;

[0012] S5. Then, two adjacent winding cores are connected through a connecting piece to form a battery cell.

[0013] Preferably, the L-shaped tape is configured as a base film or a ceramic film, the base film includes polyethylene or polypropylene, and the ceramic film is configured as polypropylene with a surface that is not coated or coated with one of zirconium oxide and silicon carbide.

[0014] Preferably, the preparation process of the L-shaped tape is as follows:

[0015] A1. Measure and mark the dimensions that require adhesive tape according to the battery cell design drawing.

[0016] A2. Use cutting equipment to cut out L-shaped tape of corresponding size according to the measured size, so that the width of the L-shaped tape can completely cover the edge of the tab and the core;

[0017] A3. Cut two parallel indentations in the middle of the L-shaped tape's bonding surface. The distance between the two indentations is equal to the sum of the lengths of the two sides of the bend angle, and the depth of the indentations is one-quarter of the tape's thickness.

[0018] A4. Use a bending device to bend the L-shaped tape into an L-shape toward the non-dented side. After bending, one end of the tape can be attached to the end face of the roll core, and the other end of the tape can be attached to the connecting piece.

[0019] Preferably, when cleaning the gluing position of the core, first use a dust-free cloth to gently wipe the surface of the core to remove surface dust, then dip the dust-free cloth in degreaser and wipe the position of the core to be glued for a second time, and then use an air gun to blow dry the surface of the position of the core to be glued.

[0020] Preferably, when the L-shaped tape is applied to the core, the L-shaped tape is applied starting from one end of the core, and then moves smoothly along the length of the core until it reaches one of the indentations, the other indentation is located on the connecting piece, and the L-shaped tape is set at a right angle, and the edge of the L-shaped tape after application is aligned with the edge of the connecting piece.

[0021] Preferably, the connecting piece is used as a skeleton for connecting two adjacent winding cores, a boss is provided on the connecting piece, the other end of the L-shaped tape is located on the boss, and a through hole is provided on one side of the connecting piece located on the boss.

[0022] Preferably, the compacting tool is configured as a scraper, which is placed on the L-shaped tape at an inclination angle of 30-45 degrees, and moved from one end of the L-shaped tape to the other end of the L-shaped tape, and the moving direction is the width direction of the L-shaped tape.

[0023] Preferably, a U-shaped tape made of polyethylene or polypropylene is further included, and using the U-shaped tape instead of the L-shaped tape comprises the following steps:

[0024] S1. Prepare U-shaped tape according to the size of the tape core;

[0025] S2. Clean the glue-sticking area of ​​the core and remove the oil and dust on the surface of the core package glue-sticking area;

[0026] S3. Start applying the tape at one end of the core, then move along the thickness direction of the core, and then apply the other end of the tape to the connecting piece to form a U-shaped bonding path so that the tape completely covers the tab;

[0027] S4. Use a compacting tool to bring the U-shaped tape into contact with the battery end surface to ensure that the U-shaped tape and the battery end surface are firmly bonded;

[0028] S5. Then, two adjacent winding cores are connected through a connecting piece to form a battery cell.

[0029] Preferably, the preparation process of the U-shaped tape is as follows:

[0030] B1. Measure the required U-shaped tape size according to the battery cell design size, and use cutting equipment to cut the tape to the corresponding size so that the width of the tape can completely cover the edge of the tab and the core;

[0031] B2. Cut four parallel indentations in the middle of the tape's bonding surface, symmetrically spaced two by two on either side of the lower corner of the U-shaped tape. The vertical distance between the indentations and the corners should be 2-3 mm. The width of the lower end of the U-shaped tape should be the width of the connecting piece, and the depth of the indentations should be one-quarter of the tape's thickness.

[0032] B3. Use a bending device to bend the tape into a U-shape toward the non-dented side. After bending, one end of the tape can be attached to the end face of the core, and the other end of the tape can be attached to the end face of the adjacent battery cell.

[0033] Preferably, when the U-shaped tape is being laminated, the U-shaped tape is laminated starting at one end of the roll core, and then is smoothly moved along the length of the roll core until it reaches the indentation at one end, and the other end of the U-shaped tape is smoothly moved along the length of an adjacent roll core until it reaches the indentation at the other end and stops, and the bottom end of the U-shaped tape contacts the surface of the connecting piece, and the edge of the U-shaped tape after lamination is aligned with the edge of the connecting piece.

[0034] The present invention proposes a method for preventing tab tearing after ultrasonic welding, which has the following advantages over the prior art:

[0035] 1. The present invention uses an L-shaped gluing method to glue the core, which not only completely covers the tabs and isolates the short circuit, but also because the tape is not attached to the core, the tabs will not be torn due to the rebound of the core caused by the gluing mechanism pressing down the core during gluing. This can avoid the occurrence of high-charge and low-charge situations at the battery end.

[0036] 2. The present invention uses a U-shaped tape to glue the core, which can completely cover the tabs. During the gluing process, the gluing mechanism will not press down the core, so that the tabs will not be affected by the tape, reducing the chance of the tabs being torn during later use, thereby increasing the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flowchart of Example 1 of the present invention;

[0038] Figure 2 Schematic diagram of the L-shaped tape laminating structure in Example 1 of the present invention;

[0039] Figure 3 This is a flowchart of Example 2 of the present invention;

[0040] Figure 4 Schematic diagram of the U-shaped tape laminating structure in Example 2 of the present invention;

[0041] Figure 5 Schematic diagram of the Z-type tape bonding structure in the prior art.

[0042] In the picture: 1. Reel core; 2. Coding glue; 3. Z-shaped glue; 4. Connecting piece; 5. L-shaped tape; 6. U-shaped tape. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] The present invention provides Figure 1-2 A method for preventing tab tearing after ultrasonic welding is shown, comprising the following steps:

[0046] S1, prepare L-shaped tape 5 according to the gluing position and size of the core 1;

[0047] The L-shaped tape 5 is configured as a base film or a ceramic film. The base film includes polyethylene or polypropylene. The ceramic film is configured as polypropylene with a surface that is not coated or coated with one of zirconium oxide and silicon carbide.

[0048] The preparation process of the L-shaped tape 5 is as follows:

[0049] A1. Measure and mark the dimensions that require adhesive tape according to the battery cell design drawing.

[0050] A2. Use a cutting device to cut out L-shaped tape 5 of corresponding size according to the measured size, so that the width of the L-shaped tape 5 can completely cover the edge of the tab and the core 1;

[0051] A3. Cut two parallel indentations in the middle of the bonding surface of the L-shaped tape 5. The distance between the two indentations is equal to the sum of the lengths of the two sides of the bending angle. This ensures a precise bending angle, a more secure bond, and effectively prevents rebound. The depth of the indentations is one-quarter of the tape thickness, allowing the L-shaped tape 5 to maintain strength during bending without excessive deformation, thus preventing rebound.

[0052] A4. Use a bending device to bend the L-shaped tape 5 into an L-shape toward the non-dented surface. After bending, one end of the tape can be attached to the end surface of the winding core 1, and the other end of the tape can be attached to the connecting piece 4.

[0053] By cutting two parallel indentations on the L-shaped tape 5, stress concentration can be reduced, making the tape smoother when bending and avoiding rebound caused by excessive stress. This not only improves the manufacturing quality of the lithium battery, but also enhances the stability and safety of the battery during use.

[0054] S2. Clean the glue-attaching position of the core 1 to remove the oil and dust on the surface of the glue-attaching position of the core package;

[0055] When cleaning the gluing position of the core 1, first use a dust-free cloth to gently wipe the surface of the core 1 to remove surface dust, then dip the dust-free cloth in degreasing agent and wipe the position of the core 1 to be bonded for the second time, and then use an air gun to blow dry the surface of the position of the core 1 to be bonded. The combined use of the dust-free cloth and degreasing agent can completely remove conductive impurities such as oil and dust, thereby reducing the risk of micro-short circuits inside the battery. Using an air gun to blow dry can ensure that there are no water stains or other residues after cleaning. If there are residual water stains or other residues, it may affect the performance and reliability of the battery.

[0056] S3. Start applying the tape at one end of the core 1, then move along the thickness direction of the core 1, and then apply the other end of the tape to the connecting piece 4 to form an L-shaped bonding path so that the tape completely covers the tab;

[0057] When the L-shaped tape 5 is attached to the core 1, the L-shaped tape 5 is attached starting from one end of the core 1 and then moves smoothly along the length of the core 1 until it reaches one of the indentations. The other indentation is located on the connecting piece 4, and the L-shaped tape 5 is arranged at a right angle. The edge of the L-shaped tape 5 after attachment is aligned with the edge of the connecting piece 4, which increases the contact area between the L-shaped tape 5 and the connecting piece 4, improves the bonding stability, reduces the gap or overlap caused by inaccurate alignment, and thus improves the stability of the battery structure.

[0058] The connecting piece 4 is used as a skeleton for connecting two adjacent winding cores 1. A boss is provided on the connecting piece 4. The other end of the L-shaped tape 5 is located on the boss. A through hole is provided on one side of the connecting piece 4 located on the boss. The boss provides a solid support base for the other end of the L-shaped tape 5, which helps to maintain the position of the tape stable and prevent poor connection caused by tape displacement or rolling up. In addition, the boss design helps to disperse stress, avoid material fatigue or damage caused by stress concentration, and improve the durability and reliability of the battery.

[0059] S4. Use a compacting tool to bring the L-shaped tape 5 into contact with the end surface of the battery so that the L-shaped tape 5 and the end surface of the battery are firmly bonded;

[0060] The compacting tool is set as a scraper, which is placed on the L-shaped tape 5 at an inclination angle of 30-45 degrees, and moved from one end of the L-shaped tape 5 to the other end of the L-shaped tape 5, and the direction of movement is the width direction of the L-shaped tape 5. The scraper is tilted and compacted at a certain angle, which can better adapt to the surface shape of the L-shaped tape 5, ensure that the pressure is evenly distributed on the entire tape, and effectively avoid the formation of air bubbles and wrinkles.

[0061] S5. Connect two adjacent winding cores 1 through the connecting piece 4 to form a battery cell.

[0062] By using L-shaped gluing method instead of Z-shaped gluing method to glue the core 1, not only can the tabs be completely covered to isolate the short circuit, but also because the tape is not attached to the core 1, the tabs will not be torn due to the gluing mechanism pressing down the core 1 and the core 1 rebounding during gluing. This can avoid the battery end from being overcharged and undercharged.

[0063] Example 2

[0064] The similarities are not repeated here, but the difference from Example 1 is that Figure 3-4As shown, a U-shaped tape 6 made of polyethylene or polypropylene is also included. Using the U-shaped tape 6 to replace the L-shaped tape 5 includes the following steps:

[0065] S1, prepare U-shaped tape 6 according to the gluing position and size of the core 1;

[0066] The preparation process of the U-shaped tape 6 is as follows:

[0067] B1. Measure the required size of the U-shaped tape 6 according to the design size of the battery cell, and use a cutting device to cut the tape to the corresponding size so that the width of the tape can completely cover the edge of the tab and the core 1;

[0068] B2. Cut four parallel indentations in the middle of the tape's bonding surface, symmetrically spaced two by two on either side of the lower corner of the U-shaped tape 6. The vertical distance between the indentations and the corners should be 2-3 mm. The width of the lower end of the U-shaped tape 6 should be the width of the connecting piece 4, and the depth of the indentations should be one-quarter of the tape's thickness.

[0069] B3. Use a bending device to bend the tape into a U shape toward the non-dented surface. After bending, one end of the tape can be attached to the end face of the winding core 1, and the other end of the tape can be attached to the end face of the adjacent battery cell.

[0070] By cutting four parallel indentations on the U-shaped tape 6, the distribution of the indentations at each corner of the U-shaped tape 6 is the same as the distribution of the indentations at the corners of the L-shaped tape 5. The indentations can reduce stress concentration, making the tape smoother when bending, and avoiding rebound caused by excessive stress. This not only improves the manufacturing quality of the lithium battery, but also enhances the stability and safety of the battery during use.

[0071] S2. Clean the glue-attaching position of the core 1 to remove the oil and dust on the surface of the glue-attaching position of the core package;

[0072] S3. Start applying the tape at one end of the core 1, then move along the thickness direction of the core 1, and then apply the other end of the tape to the connecting piece 4 to form a U-shaped bonding path so that the tape completely covers the tab;

[0073] When the U-shaped tape 6 is being laminated, it is started at one end of the core 1, and then smoothly moved along the length of the core 1 until it reaches the indentation at one end. The other end of the U-shaped tape 6 is smoothly moved along the length of an adjacent core 1 until it reaches the indentation at the other end and stops. The bottom end of the U-shaped tape 6 contacts the surface of the connecting piece 4, and the edge of the U-shaped tape 6 after lamination is aligned with the edge of the connecting piece 4.

[0074] S4. Use a compacting tool to bring the U-shaped tape 6 into contact with the end surface of the battery so that the U-shaped tape 6 is firmly bonded to the end surface of the battery;

[0075] S5. Connect two adjacent winding cores 1 through the connecting piece 4 to form a battery cell.

[0076] By replacing the Z-shaped tape 3 laminating method with the U-shaped tape 6 laminating method to glue the core 1, the pole ear can be completely wrapped, and the gluing mechanism will not press down the core 1 during gluing, so that the pole ear will not be pulled by the tape, reducing the chance of the pole ear being torn during later use, thereby increasing the service life of the battery.

[0077] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preventing the tab from tearing after ultrasonic welding, characterized in that: The steps include: S1. Prepare L-shaped tape according to the size of the adhesive tape position on the roll core; S2. Clean the glue sticking position of the core and remove the oil and dust on the surface of the glue sticking position of the core package; S3, start to attach the tape at one end of the core, then move along the thickness direction of the core, and attach the other end of the tape to the connecting piece to form an L-shaped attachment path, so that the tape completely wraps the tab; S4. Use a compaction tool to bring the L-shaped tape into contact with the end surface of the battery so that the L-shaped tape and the end surface of the battery are firmly bonded; S5. Connect two adjacent winding cores through a connecting piece to form a battery cell.

2. A method for preventing the tab from tearing after ultrasonic welding according to claim 1, characterized in that: The L-shaped tape is configured as a base film or a ceramic film, the base film includes polyethylene or polypropylene, and the ceramic film is configured as polypropylene whose surface is not coated or coated with one of zirconium oxide and silicon carbide.

3. A method for preventing the tab from tearing after ultrasonic welding according to claim 2, characterized in that: The preparation process of the L-shaped tape is as follows: A1. Measure and mark the dimensions that need to be glued according to the battery design drawing; A2. Use cutting equipment to cut out L-shaped tape of corresponding size according to the measured size, so that the width of the L-shaped tape can completely cover the edge of the tab and the core; A3. Cut two parallel indentations in the middle of the L-shaped tape's bonding surface. The distance between the two indentations is the sum of the lengths of the two sides of the bending angle, and the depth of the indentation is one-fourth of the tape's thickness. A4. Use a bending device to bend the L-shaped tape into an L-shape in the direction of the non-dented surface. After bending, one end of the tape can be attached to the end surface of the roll core, and the other end of the tape can be attached to the connecting piece.

4. A method for preventing the tab from tearing after ultrasonic welding according to claim 3, characterized in that: When cleaning the glue-sticking position of the roll core, first use a dust-free cloth to gently wipe the surface of the roll core to remove surface dust, then dip the dust-free cloth in a degreasing agent and wipe the roll core to be glued for a second time, and then use an air gun to blow dry the surface of the roll core to be glued.

5. A method for preventing the tab from tearing after ultrasonic welding according to claim 4, characterized in that: When the L-shaped tape is applied to the core, the L-shaped tape is applied starting from one end of the core and then smoothly moved along the length of the core until it reaches one of the indentations, the other indentation being located on the connecting piece, and the L-shaped tape being arranged at a right angle, and the edge of the L-shaped tape after application being aligned with the edge of the connecting piece.

6. A method for preventing the tab from tearing after ultrasonic welding according to claim 5, characterized in that: The connecting piece is used as a framework for connecting two adjacent winding cores. A boss is arranged on the connecting piece. The other end of the L-shaped tape is located on the boss. A through hole is opened on one side of the connecting piece located on the boss.

7. A method for preventing the tab from tearing after ultrasonic welding according to claim 6, characterized in that: The compacting tool is configured as a scraper, which is placed on the L-shaped tape at an inclination angle of 30-45 degrees, and is moved from one end of the L-shaped tape to the other end of the L-shaped tape, and the moving direction is the width direction of the L-shaped tape.

8. The method for preventing the tab from tearing after ultrasonic welding according to claim 1, characterized in that: Also included is a U-shaped tape made of polyethylene or polypropylene, and using the U-shaped tape to replace the L-shaped tape comprises the following steps: S1. Prepare U-shaped tape according to the size of the adhesive tape position on the roll core; S2. Clean the glue sticking position of the core and remove the oil and dust on the surface of the glue sticking position of the core package; S3, start to stick the tape at one end of the core, then move along the thickness direction of the core, and stick the other end of the tape to the connecting piece to form a U-shaped sticking path, so that the tape completely wraps the tab; S4. Use a compaction tool to bring the U-shaped tape into contact with the end surface of the battery so that the U-shaped tape and the end surface of the battery are firmly bonded; S5. Connect two adjacent winding cores through a connecting piece to form a battery cell.

9. A method for preventing the tab from tearing after ultrasonic welding according to claim 8, characterized in that: The preparation process of the U-shaped tape is as follows: B1. Measure the required U-shaped tape size according to the design size of the battery cell, and use the cutting equipment to cut the tape of the corresponding size so that the width of the tape can completely cover the edge of the tab and the core; B2. Cut four parallel indentations in the middle of the tape bonding surface, so that the four indentations are symmetrically distributed on both sides of the corner of the lower end of the U-shaped tape, and the vertical distance between the indentation and the corner is 2-3mm. The width of the lower end of the U-shaped tape is the width of the connecting piece, and the depth of the indentation is one-fourth of the thickness of the tape; B3. Use a bending device to bend the tape into a U-shape toward the non-dented surface. After bending, one end of the tape can be attached to the end face of the winding core, and the other end of the tape can be attached to the end face of the adjacent battery cell.

10. A method for preventing the tab from tearing after ultrasonic welding according to claim 9, characterized in that: When the U-shaped tape is attached, the U-shaped tape is attached at one end of the core, and then smoothly moved along the length of the core until it reaches the indentation at one end, and then the other end of the U-shaped tape is smoothly moved along the length of an adjacent core until it reaches the indentation at the other end and stops, the bottom end of the U-shaped tape contacts the surface of the connecting piece, and the edge of the U-shaped tape after attachment is aligned with the edge of the connecting piece.

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