Connecting structure of tab and battery cell
Through the sewing process, the electrode ears and battery cells are connected, which solves the abnormal quality caused by abnormal parameters during ultrasonic welding, and achieves higher quality and reliability connection.
Patent Information
- Application Number
- CN202420820246.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-19
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-04-19
AI Technical Summary
In the prior art, when ultrasonic welding of the electrode head and battery cell, abnormal parameters lead to abnormal quality phenomena such as false welding, insufficient welding tension, insufficient residual, etc., and it is difficult to ensure welding quality and battery cell quality.
The sewing process is used to connect the connecting part between the connecting body drawn from the battery cell and the package of the electrode, and the metal threads are interlaced and interwoven through the principle of the sewing machine to form a firm connection.
Connect the electrode ears and battery cells through the sewing process, avoiding problems such as false welding, insufficient tension, and insufficient residue, and improving the connection quality and product quality and reliability.
Smart Images
Figure CN222637587U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of connection structures, and in particular relates to a connection structure between a pole ear and a battery core. Background Art
[0002] Since its introduction, lithium-ion batteries have been widely used in various industries due to their superior performance, safety and environmental protection. With the continuous development of research and commercial applications, lithium-ion batteries tend to be lighter, thinner and smaller. According to its structural characteristics, soft-pack lithium-ion batteries are made of aluminum-plastic film wrapped with gel polymer electrolyte, which has the characteristics of high energy density, good safety performance, light weight and ultra-thinness, and can be made into batteries of various shapes and capacities.
[0003] Soft-pack lithium-ion batteries are mainly composed of positive and negative electrodes, electrolytes, diaphragms and shells. The protruding parts at both ends of the battery are the battery tabs. The tabs are usually connected to the pole pieces in the battery cell by ultrasonic welding, spot welding, pull welding, laser welding and other methods. Ultrasonic welding is currently widely used in the industry. The ultrasonic energy generated by high-frequency vibration causes the welding part to vibrate locally, and melts and forms a connection under the action of friction. However, various parameters such as welding temperature, time, and pressure need to be strictly controlled during the welding process. When a certain parameter varies during the process, it will cause quality abnormalities such as cold welding, insufficient welding tension, and insufficient residue, making it difficult to ensure the welding quality, thereby ensuring the quality of the battery cell. Utility Model Content
[0004] The purpose of the utility model is to provide a connection structure between a tab and a battery cell to solve the quality abnormalities such as cold welding, insufficient welding tension, insufficient residue, etc. caused by abnormal parameters during the current ultrasonic welding, thereby improving the welding quality and product quality and reliability.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A connection structure between a tab and a battery cell comprises a battery cell, a tab, a connector electrically connected to the battery cell, and a packaging body electrically connected to the tab, wherein the connector and the packaging body are connected by a sewing process.
[0007] Preferably, the connector and the packaging body have the same structure, and are sewn together after being overlapped to form a connecting portion, wherein the connecting portion is located at the center of the overlapping area of the connector and the packaging body structure.
[0008] Preferably, the connection portion is configured as a point, line or surface structure.
[0009] Preferably, the pole lug is a multi-layer stacked pole lug, the battery cell includes a pole piece overlapped with the pole lug, the connector is a hollow foil protruding from the pole piece, the packaging body is the lower end of the pole lug, the pole lug and the hollow foil are overlapped with each other to form a connecting part, the connecting part is provided with a plurality of through holes, and metal wires are cross-pierced in the through holes.
[0010] Preferably, the distance a between the bottom edge of the through hole and the top of the pole piece is 6-9 mm.
[0011] Preferably, the diameter of the through hole is 0.025-0.5 mm, the width of the tab is 2-150 mm, and the spacing between the through holes is 0.2-2 mm.
[0012] Preferably, the diameter of the metal wire is 0.01-0.2 mm, and the metal wire comprises a surface wire and a bottom wire, and the surface wire and the bottom wire are interlaced with each other in the through hole.
[0013] Preferably, the metal wire is a copper wire, a copper alloy wire, an aluminum wire or an aluminum alloy wire.
[0014] Preferably, the penetration speed of the metal wire is 50-200 stitches / min, and the metal wire is cut and sutured by back stitch, and the number of back stitches is 1-10 stitches.
[0015] Preferably, the number of stacked layers of the pole tab is 10-40, the thickness of a single layer of the pole tab is 6-15 μm, and the total stacked thickness of the pole tab is 0.06-0.3 mm.
[0016] Compared with the prior art, the beneficial effect of the utility model is that: the utility model provides a connection method between the pole ear and the battery cell, and the connection part between the connector led out of the battery cell and the packaging body of the pole ear is connected by a sewing process. Specifically, the principle of a sewing machine is used to interweave and stagger the connection part with the upper and lower layers of surface threads and bottom threads, so that the multi-layer stacked pole ears and battery cells are firmly attached together, the connection effect is better, and the stability is stronger. Compared with the usual pole ear welding method, it can effectively avoid the occurrence of cold welding, insufficient tension, insufficient residue and the like, thereby improving the connection quality and product quality and reliability. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of the first embodiment of the utility model.
[0018] Figure 2 yes Figure 1 Enlarged view of point A in the middle.
[0019] Figure 3 It is a structural schematic diagram of another angle of embodiment 1 of the present utility model.
[0020] Figure 4 It is a structural schematic diagram of embodiment 4 of the present utility model.
[0021] Figure 5 It is a schematic diagram of the metal wire suturing process in the utility model.
[0022] Reference numerals:
[0023] 1. Battery cell, 11. Pole piece, 12. Empty foil, 13. Connector,
[0024] 2. Tab, 21. Package;
[0025] 3. connecting portion, 31. through hole;
[0026] 4. Metal thread, 41. Upper thread, 42. Lower thread;
[0027] a. The distance between the bottom edge of the through hole and the top of the pole piece. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0029] refer to Figure 1-3 A connection structure between a tab and a cell includes a cell 1 and a tab 2. The cell 1 is provided with a connector 13, and the tab 2 has a package 21. The connector 13 and the package 21 are connected by sewing. The connector 13 and the package 21 are sewn together to achieve a tight fit, and the cell 1 and the tab 2 electrically connected thereto have good electrochemical properties.
[0030] In some embodiments, the connector 13 and the packaging body 21 have the same structure, and they are sewn together to form a connecting portion 3, which is located in the center or around the connecting area of the connector 13 and the packaging body 21. Sewing the connecting portion 3 can achieve a stable connection effect and have good mechanical properties.
[0031] In some embodiments, the connection portion 3 is configured as a point, line or surface structure. The point structure is a point structure with a regular continuous arrangement, the line structure is a regular line structure composed of straight lines and / or curves, and the surface structure is a regular surface structure composed of triangles, ellipses or squares. Figure 1As shown, the connection part 3 is a continuous linear sewing connection. Similarly, a plurality of suture lines can be added to the upper and lower sides of the existing connection part 3 to form a planar connection part 3. Similarly, the existing connection part 3 can also be divided into short linear sewing connection points, which can be fixedly connected by setting a plurality of sewing connection points.
[0032] In some embodiments, the pole lug 2 is a multi-layer stacked pole lug, the battery cell 1 includes a pole piece 11 overlapped with the pole lug 2, the connector 13 is a hollow foil 12 protruding from the pole piece 11, the packaging body 21 is the lower end of the pole lug 2, the pole lug 2 and the hollow foil 12 overlap with each other to form a connecting part 3, a plurality of through holes 31 are provided on the connecting part 3, and metal wires 4 are cross-pierced in the through holes 31.
[0033] The pole piece 11 of the battery cell 1 includes a positive pole piece and a negative pole piece, and a diaphragm between the two pole pieces. The battery cell is made by winding or laminating the pole piece 11 and the diaphragm. The positive pole piece and the negative pole piece are provided with a hollow foil 12 for connecting with the pole ear 2, and the corresponding pole ear 2 also includes a positive pole ear and a negative pole ear. The position where the pole ear 2 and the hollow foil 12 overlap each other forms a connecting portion 3, and the connecting portion 3 is provided with a through hole 31 that penetrates all the pole ears 2 and the hollow foil 12 so as to fit them tightly together. The connection method used in the utility model is to use the principle of a sewing machine, replace the cotton thread with a metal wire 4, insert the metal wire 4 into the through hole 31 through a machine needle, and then sew it with another metal wire 4 in the bottom coil in an interlaced manner, that is, a "double-thread chain stitch", and this sew connection method is more solid and has strong stability. Compared with welding, this connection method will not cause cold welding, insufficient pulling force, insufficient residue and other phenomena, thereby improving the connection quality of the tabs and the quality and reliability of the product.
[0034] In some embodiments, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 6-9 mm. Preferably, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 6 mm, 7 mm, 8 mm, or 9 mm. When in use, it needs to be set according to the size of the battery cell 1.
[0035] In some embodiments, the diameter of the through hole 31 is 0.025-0.5 mm. Because the metal wire 4 needs to be staggered through the through hole 31, the diameter of the through hole 31 is set according to the diameter of the metal wire 4, for example, 0.025 mm, 0.05 mm, 0.1 mm, 0.25 mm, etc. The width of the pole lug 2 is 2-150 mm, and the spacing of the through holes 31 is 0.2-2 mm. A number of equidistant through holes 31 can be set on the pole lug 2 according to the width of the pole lug 2. The spacing of the through holes 31 here is the distance between the closest outer edges of two adjacent through holes 31. Preferably, the width of the pole lug 2 is 3 mm, 4 mm, 5 mm, 6 mm; preferably, the spacing of the through holes 31 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm. The corresponding spacing of the through holes 31 can be selected according to the width of the pole lug 2 and the diameter of the through holes 31 to set the number of through holes 31 thereon and the stitching density.
[0036] In some embodiments, the diameter of the metal wire 4 is 0.01-0.2 mm, and the metal wire 4 includes an upper wire 41 and a lower wire 42, and the upper wire 41 and the lower wire 42 are interlaced in the through hole 31. After interlaced winding, two sections of the upper wire 41 and two sections of the lower wire 42 are simultaneously stored in the through hole 31. Preferably, the diameter of the metal wire 4 can be selected from 0.01 mm, 0.02 mm, 0.04 mm, 0.1 mm, etc. Figure 5 As shown, the utility model adopts the principle of a sewing machine, in which the upper thread 41 is threaded by the needle, and the lower thread 42 is wound in the bobbin, and a winder is provided outside the bobbin. When the needle drives the upper thread 41 to pass through the through hole 31 of the connecting part 3, the winder grabs the upper thread 41 on the needle and makes it pass around the bobbin, and the upper thread 41 and the lower thread 42 are intertwined and interlaced, and then the needle drives the upper thread 41 to withdraw, and the lower thread 42 is hooked up and enters the through hole 31 at the same time, forming a chain stitching line, and the cycle is repeated.
[0037] In some embodiments, the metal wire 4 is a copper wire, a copper alloy wire, an aluminum wire or an aluminum alloy wire. The metal wire 4 made of the above materials has higher tensile strength and rigidity, uniform mechanical properties, good chemical stability, and excellent electrical properties and thermal conductivity.
[0038] In some embodiments, the penetration speed of the metal wire 4 is 50-200 needles / min. Preferably, the penetration speed of the metal wire 4 is 50 needles / min, 100 needles / min, 150 needles / min, 200 needles / min, and the penetration speed of the metal wire 4 can be determined by the number of uniformly arranged through holes 31 provided on the corresponding tab 2 according to conditions such as the width of the tab 2 and the spacing of the through holes 31, so as to achieve a quick connection between the tab 2 and the battery cell 1.
[0039] In some embodiments, the metal wire 4 is cut and sewn with a back stitch, and the number of back stitches is 1-10. Preferably, the number of back stitches is 1 stitch, 2 stitches, 3 stitches, or 5 stitches, and the number of back stitches can be determined according to the width of the tab 2 and the number of evenly arranged through holes 31 on the tab 2 to achieve the best sewing and locking effect.
[0040] In some embodiments, the number of stacked layers of the pole lug 2 is 10-40 layers. Preferably, the number of stacked layers of the pole lug 2 is 10 layers, 20 layers, 30 layers, and 40 layers. The number of stacked layers of the corresponding pole lug 2 can be set according to the number of layers of winding or lamination of the battery cell 1. Moreover, the single-layer thickness of the pole lug 2 is 6-15 μm, and the total stacked thickness of the pole lug 2 is 0.06-0.3 mm. Preferably, the single-layer thickness of the pole lug 2 is 6 μm, 8 μm, 10 μm, and 12 μm. According to the different number of stacked layers of the pole lug 2, pole lugs 2 of different thicknesses are used to achieve a more ideal total thickness of the pole lug.
[0041] Embodiment 1:
[0042] like Figure 1-3 , a connection structure between a tab and a cell, comprising a cell 1 and a multi-layered tab 2, wherein the cell 1 comprises a stacked pole piece 11 and a hollow foil 12 protruding from the pole piece 11, the tab 2 and the hollow foil 12 are stacked to form a connection portion 3, the connection portion 3 is provided with a plurality of through holes 31, and metal wires 4 are cross-pierced in the through holes 31. The pole piece 11 of the cell 1 comprises a positive pole piece and a negative pole piece, and a diaphragm between the two pole pieces 11, the cell 1 is made by winding or laminating the pole piece 11 and the diaphragm, the positive pole piece and the negative pole piece are both provided with a hollow foil 12 for connecting with the tab 2, and the corresponding tab 2 also comprises a positive pole piece and a negative pole piece.
[0043] In this embodiment, the positive electrode tab and the negative electrode tab are arranged on the same side, the number of stacked layers of the tab 2 is 10, and the thickness of the single-layer tab 2 is selected to be 10 μm, that is, the total thickness of the tab 2 is 0.1 mm. At the same time, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 6 mm, and the metal wire 4 has good mechanical and electrical properties after being sutured and connected.
[0044] Furthermore, the width of the pole ear 2 selected here is 3mm, the diameter of the through hole 31 is 0.025mm, and the spacing between the two through holes 31 is 0.2mm. Therefore, a total of 13 through holes 31 are required on the single pole ear 2. According to the diameter of the through hole 31, 0.01mm pure copper wire is selected, and the surface wire 41 and the bottom wire 42 are intersected and hooked in pairs and placed in the through hole 31. The corresponding needle penetration speed is 100 needles / min, and the number of back stitches is 2 needles on each side edge. Through the above settings, the pole ear 2 and the empty foil 12 of the pole piece 11 can be tightly connected, with good mechanical properties, and stable conductive properties can also be obtained by sewing with pure copper wire.
[0045] Embodiment 2:
[0046] like Figure 1-3 , a connection structure between a tab and a cell, comprising a cell 1 and a multi-layered tab 2, wherein the cell 1 comprises a stacked pole piece 11 and a hollow foil 12 protruding from the pole piece 11, the tab 2 and the hollow foil 12 are stacked to form a connection portion 3, the connection portion 3 is provided with a plurality of through holes 31, and metal wires 4 are cross-pierced in the through holes 31. The pole piece 11 of the cell 1 comprises a positive pole piece and a negative pole piece, and a diaphragm between the two pole pieces 11, the cell 1 is made by winding or laminating the pole piece 11 and the diaphragm, the positive pole piece and the negative pole piece are both provided with a hollow foil 12 for connecting with the tab 2, and the corresponding tab 2 also comprises a positive pole piece and a negative pole piece.
[0047] In this embodiment, the positive electrode tab and the negative electrode tab are arranged on the same side, the number of stacked layers of the tab 2 is 20, and the thickness of the single-layer tab 2 is selected to be 8 μm, that is, the total thickness of the tab 2 is 0.16 mm. At the same time, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 7 mm, and the metal wire 4 has good mechanical and electrical properties after being sutured and connected.
[0048] Furthermore, the width of the pole ear 2 selected here is 4mm, the diameter of the through hole 31 is 0.05mm, and the spacing between the two through holes 31 is 0.3mm. Therefore, a total of 11 through holes 31 are required on the single pole ear 2. According to the diameter of the through hole 31, a 0.02mm copper alloy wire is selected, and the surface wire 41 and the bottom wire 42 are intersected and hooked in pairs and placed in the through hole 31. The corresponding needle penetration speed is 100 needles / min, and the number of back stitches is 2 needles on each side edge. Through the above settings, the pole ear 2 and the empty foil 12 of the pole piece 11 can be tightly connected, with good mechanical properties, and stable conductive properties can also be obtained by suturing with copper alloy wire.
[0049] Embodiment 3:
[0050] like Figure 1-3 , a connection structure between a tab and a cell, comprising a cell 1 and a multi-layered tab 2, wherein the cell 1 comprises a stacked pole piece 11 and a hollow foil 12 protruding from the pole piece 11, the tab 2 and the hollow foil 12 are stacked to form a connection portion 3, the connection portion 3 is provided with a plurality of through holes 31, and metal wires 4 are cross-pierced in the through holes 31. The pole piece 11 of the cell 1 comprises a positive pole piece and a negative pole piece, and a diaphragm between the two pole pieces 11, the cell 1 is made by winding or laminating the pole piece 11 and the diaphragm, the positive pole piece and the negative pole piece are both provided with a hollow foil 12 for connecting with the tab 2, and the corresponding tab 2 also comprises a positive pole piece and a negative pole piece.
[0051] In this embodiment, the positive electrode tab and the negative electrode tab are arranged on the same side, the number of stacked layers of the tab 2 is 30, and the thickness of the single-layer tab 2 is selected to be 6 μm, that is, the total thickness of the tab 2 is 0.18 mm. At the same time, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 8 mm, and the metal wire 4 has good mechanical and electrical properties after being sutured and connected.
[0052] Furthermore, the width of the pole ear 2 selected here is 5mm, the diameter of the through hole 31 is 0.1mm, and the spacing between the two through holes 31 is 0.4mm. Therefore, a total of 10 through holes 31 are required on a single pole ear 2. According to the diameter of the through hole 31, 0.04mm pure aluminum wire is selected, and the surface wire 41 and the bottom wire 42 are intersected and hooked in pairs and placed in the through hole 31. The corresponding needle penetration speed is 50 needles / min, and the number of return needles is 1 needle on each edge of both sides. Through the above settings, the pole ear 2 and the empty foil 12 of the pole piece 11 can be tightly connected, with good mechanical properties, and stable conductive properties can also be obtained by sewing with pure aluminum wire.
[0053] Embodiment 4:
[0054] like Figure 4 , a connection structure between a tab and a cell, comprising a cell 1 and a multi-layered tab 2, wherein the cell 1 comprises a stacked pole piece 11 and a hollow foil 12 protruding from the pole piece 11, the tab 2 and the hollow foil 12 are stacked to form a connection portion 3, the connection portion 3 is provided with a plurality of through holes 31, and metal wires 4 are cross-pierced in the through holes 31. The pole piece 11 of the cell 1 comprises a positive pole piece and a negative pole piece, and a diaphragm between the two pole pieces 11, the cell 1 is made by winding or laminating the pole piece 11 and the diaphragm, the positive pole piece and the negative pole piece are both provided with a hollow foil 12 for connecting with the tab 2, and the corresponding tab 2 also comprises a positive pole piece and a negative pole piece.
[0055] In this embodiment, the difference from the above-mentioned other embodiments is that the positive electrode tab and the negative electrode tab are arranged on opposite sides of the battery cell 1, the number of stacked layers of the tab 2 is 10, and the thickness of the single-layer tab 2 is selected to be 10 μm, that is, the total thickness of the tab 2 is 0.1 mm. At the same time, the distance a between the bottom edge of the through hole 31 and the top of the pole piece 11 is 6 mm, and the metal wire 4 has good mechanical and electrical properties after being sutured and connected.
[0056] Furthermore, the width of the pole ear 2 selected here is 6mm, the diameter of the through hole 31 is 0.25mm, and the spacing between the two through holes 31 is 0.5mm. Therefore, a total of 8 through holes 31 are required on a single pole ear 2. According to the diameter of the through hole 31, 0.1mm pure copper wire is selected, and the surface wire 41 and the bottom wire 42 are intersected and hooked in pairs and placed in the through hole 31. The corresponding needle penetration speed adopts 50 needles / min, and the number of back stitches is 1 needle on each edge of both sides. Through the above settings, the pole ear 2 and the empty foil 12 of the pole piece 11 can be tightly connected, with good mechanical properties, and stable conductive properties can also be obtained by sewing with pure copper wire.
[0057] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.
Claims
1. A connection structure between a tab and a battery cell, characterized in that: The invention comprises a battery cell and a pole ear, wherein the battery cell is led out with a connector, the pole ear has a packaging body, and the connector and the packaging body are connected by a sewing process.
2. The connection structure between the tab and the battery cell according to claim 1, characterized in that: The connector and the packaging body have the same structure, and they are sewn together to form a connecting portion, which is located at the center or around the connecting area of the connector and the packaging body structure.
3. The connection structure between the tab and the battery cell according to claim 2, characterized in that: The connecting portion is configured as a point, line or surface structure, wherein the point structure is a point structure with a regular continuous arrangement, the line structure is a regular line structure composed of straight lines and / or curves, and the surface structure is a regular surface structure composed of triangles, ellipses or squares.
4. The connection structure between the tab and the battery cell according to claim 3, characterized in that: The pole lug is a multi-layer stacked pole lug, the battery cell includes a pole piece corresponding to the pole lug, the connector is a hollow foil protruding from the pole piece, the packaging body is a partial structure of the pole lug, the connecting part is provided with a plurality of through holes, and metal wires are cross-pierced in the through holes.
5. The connection structure between the tab and the battery cell according to claim 4, characterized in that: The distance a between the bottom edge of the through hole and the top of the pole piece is 6-9 mm.
6. The connection structure between the tab and the battery cell according to claim 5, characterized in that: The diameter of the through hole is 0.025-0.5 mm, the width of the tab is 2-150 mm, and the spacing between the through holes is 0.2-2 mm.
7. The connection structure between the tab and the battery cell according to claim 4, characterized in that: The diameter of the metal wire is 0.01-0.2 mm. The metal wire comprises a surface wire and a bottom wire. The surface wire and the bottom wire are interlaced with each other in the through hole.
8. The connection structure between the tab and the battery cell according to claim 7, characterized in that: The metal wire is a copper wire, a copper alloy wire, an aluminum wire or an aluminum alloy wire.
9. The connection structure between the tab and the battery cell according to claim 8, characterized in that: The penetration speed of the metal wire is 50-200 stitches / min, and the metal wire is cut and sutured by back stitch, and the number of back stitches is 1-10 stitches.
10. The connection structure between the tab and the battery cell according to claim 1, characterized in that: The number of stacked layers of the pole tab is 10-40, the thickness of a single layer of the pole tab is 6-15 μm, and the total stacked thickness of the pole tab is 0.06-0.3 mm.