Welding system and welding process

Abstract

The application provides a welding system and a welding process, and relates to the technical field of battery manufacturing, so as to solve the problem that two welding machines are needed to perform two times of welding of large-capacity point overlapping tabs with different parameters, resulting in poor welding effect, unstable welding quality and high welding cost. The welding system provided by the application comprises welding of a current collector and a tab of a battery cell, and comprises a welding head, a welding seat and a limiting assembly. The limiting assembly is arranged between the welding head and the welding seat, and forms a limiting space. The current collector and the tab of the battery cell are located in the limiting space, and the welding head and the welding seat can pass through the limiting assembly to enter the limiting space to weld the current collector and the tab.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a welding system and welding process. Background Technology

[0002] In the production process of lithium batteries, the welding of the tabs is a crucial step. As the channel connecting the current collector of the battery cell to the external environment, the tabs require excellent welding quality and must meet tensile strength requirements. During this process, for some high-capacity batteries, the current collector needs to be enlarged, which correspondingly increases the size of the tabs, significantly increasing the welding difficulty.

[0003] Due to current equipment and technological limitations, welding large-capacity overlapping tabs requires two different welding machines with different welding parameters, performed in two separate welding operations to ensure consistent weld quality in both passes. If the parameters for both welds are identical, either the first pass will crack, or the second pass will result in a weak weld, leading to unstable welding results and compromised weld quality.

[0004] Therefore, there is an urgent need to provide a welding system and welding process to address the problems existing in the prior art to a certain extent. Summary of the Invention

[0005] The purpose of this invention is to provide a welding system and welding process to solve, to some extent, the problems of poor welding effect, unstable welding quality and high welding cost caused by the need for two welding machines with different parameters to perform two welding operations on large-capacity overlapping tabs.

[0006] The present invention provides a welding system for welding the current collector and the electrode tab of a battery cell, comprising a welding head, a welding base, and a limiting component; the limiting component is disposed between the welding head and the welding base, and the limiting component forms a limiting space, the current collector and the electrode tab of the battery cell are located within the limiting space, and the welding head and the welding base can pass through the limiting component to enter the limiting space to weld the current collector and the electrode tab together.

[0007] The limiting component includes a first limiting member and a second limiting member. The first limiting member is provided corresponding to the welding head, and the second limiting member is provided corresponding to the welding seat. The welding head can pass through the first limiting member to enter the limiting space. The second limiting member has a first through hole and a second through hole. The welding seat enters the first through hole and the second through hole in sequence to cooperate with the welding head to perform two welding operations on the current collector and the electrode tab.

[0008] Specifically, the first limiting member is cylindrical, the electrode is located inside the first limiting member, and when the welding head passes through the first limiting member, it can press the electrode out of the first limiting member and enter the limiting space to weld with the current collector.

[0009] The first limiting component includes a limiting body, a first movable member, and a second movable member. The limiting body is cylindrical, and the first movable member and the second movable member are disposed opposite to each other at both ends inside the limiting body. Both the first movable member and the second movable member have positioning grooves, so that the two ends of the tab can be located in the positioning grooves of the first movable member and the second movable member, respectively.

[0010] Specifically, both the first movable member and the second movable member include a positioning section, a transition section, and a connecting section. The positioning groove is formed on the positioning section, the transition section is located between the positioning section and the connecting section, and both the first movable member and the second movable member are rotatably connected to the limiting body through the connecting section.

[0011] Furthermore, the transition section is inclined, so that a rotational space is formed between the transition section and the inner end face of the limiting body.

[0012] Furthermore, a mounting hole is formed on the inner end face of the transition section facing the limiting body, and a reset member is provided in the mounting hole. The end of the reset member away from the mounting hole abuts against the inner end face of the limiting body.

[0013] Compared with existing technologies, the welding system provided by this invention has the following advantages:

[0014] The welding system provided by the present invention is used for welding the current collector and the electrode tab of a battery cell, including a welding head, a welding seat, and a limiting component; the limiting component is disposed between the welding head and the welding seat, and the limiting component forms a limiting space, the current collector and the electrode tab of the battery cell are located in the limiting space, and the welding head and the welding seat can pass through the limiting component to enter the limiting space to weld the current collector and the electrode tab together.

[0015] Analysis shows that by setting a limiting component between the welding head and the welding base, and making the limiting component form a limiting space, the current collector of the battery cell can be gathered through the limiting space. The gathered current collector can ensure the consistency of each position during welding. Therefore, even if the same parameters are used for two welding operations, the welding effect can be guaranteed to be good, and the problem of weld cracking or incomplete welding can be reduced to a certain extent.

[0016] In addition, the present invention also provides a welding process using the above-mentioned welding system, comprising the following steps: Step 1, preparation before welding; Step 2, performing positive electrode welding and negative electrode welding in sequence; Step 3, flattening, testing and encapsulation.

[0017] In step one, the pre-welding preparation includes stacking, weighing, initial short-circuit testing, positioning, pre-welding, and cutting.

[0018] Specifically, in step two, the positive electrode welding includes placing the current collector and tab of the positive electrode into the limiting space, gathering the current collector of the positive electrode through the limiting component, and then welding it through the welding head and welding base; the negative electrode welding includes placing the current collector and tab of the negative electrode into the limiting space, gathering the current collector of the negative electrode through the limiting component, and then welding it through the welding head and welding base.

[0019] The welding process using the welding system provided in this application can integrate and gather the current collector before welding, so that two welding operations can be performed with the same parameters during welding. This allows the welding process of the positive electrode to be completed with only one welding machine, and the welding process of the negative electrode to be completed with only one welding machine. Compared with the current stage of using two welding machines for welding the positive and negative electrodes respectively, the number of equipment is reduced by half, which not only reduces material loss and reduces the difficulty of on-site management, but also improves the welding effect. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the external structure of the limiting component in the welding system provided in an embodiment of the present invention;

[0022] Figure 2 This is a perspective view of the internal structure of a limiting component in a welding system provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the first moving part in the welding system provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the welding process of the welding system provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the welding process provided in an embodiment of the present invention.

[0026] In the diagram: 1-Battery cell; 101-Current collector; 2-Electrode tab; 3-Welding head; 4-Welding base; 5-First limiting component; 501-Limiting body; 5011-Rotation space; 502-First movable component; 5021-Positioning section; 5022-Transition section; 5023-Connecting section; 5024-Positioning groove; 5025-Mounting hole; 5026-Connecting hole; 503-Second movable component; 504-Reset component; 6-Second limiting component; 601-First through hole; 602-Second through hole; 7-Limiting space. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0032] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” may be used herein to describe the relationship between one element and another as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also the different orientations of the device during use or operation.

[0033] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0034] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0035] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have various constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis that they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0036] like Figures 1-3As shown, the present invention provides a welding system for welding the current collector 101 and the tab 2 of a battery cell 1, including a welding head 3, a welding base 4, and a limiting component; the limiting component is disposed between the welding head 3 and the welding base 4, and the limiting component forms a limiting space 7, the current collector 101 and the tab 2 of the battery cell 1 are located in the limiting space 7, and the welding head 3 and the welding base 4 can pass through the limiting component to enter the limiting space 7 to weld the current collector 101 and the tab 2 together.

[0037] Compared with existing technologies, the welding system provided by this invention has the following advantages:

[0038] The welding system provided by the present invention, by setting a limiting component between the welding head 3 and the welding seat 4, and making the limiting component form a limiting space 7, can gather the current collector 101 of the battery cell 1 through the limiting space 7. The gathered current collector 101 can ensure the consistency of each position during welding. Therefore, even if the same parameters are used for two welding operations, the welding effect can be guaranteed to be good, and the problem of weld cracking or incomplete welding can be reduced to a certain extent.

[0039] Optionally, such as Figures 1-3 As shown, the limiting component in this application includes a first limiting member 5 and a second limiting member 6. The first limiting member 5 is provided corresponding to the welding head 3, and the second limiting member is provided corresponding to the welding seat 4. The welding head 3 can pass through the first limiting member 5 to enter the limiting space 7. The second limiting member 6 has a first through hole 601 and a second through hole 602. The welding seat 4 enters the first through hole 601 and the second through hole 602 in sequence to cooperate with the welding head 3 to perform two welding operations on the current collector 101 and the electrode 2.

[0040] Currently, welding large-capacity overlapping tabs 2 requires two welding operations to ensure structural strength and welding quality. Therefore, this application utilizes a first through hole 601 and a second through hole 602 formed on the second limiting member 6. During welding, the welding seat 4 passes through the first through hole 601 and the second through hole 602 sequentially, thereby cooperating with the welding head 3 to achieve welding of the current collector 101 and the tab 2 within the limiting space 7. It is understood that during the first welding operation, the welding head 3 is positioned corresponding to the first through hole 601, allowing the welding seat 4 to accurately align with the welding head 3 after passing through the first through hole 601, achieving a single welding operation. After completing the first welding operation, the welding head 3 moves to the position corresponding to the second through hole 602, allowing the welding seat 4 to accurately align with the welding head 3 after passing through the second through hole 602, achieving a second welding operation.

[0041] Since the second limiting member 6 has a first through hole 601 and a second through hole 602, two weld marks corresponding to the positions of the first through hole 601 and the second through hole 602 can be formed after welding to ensure welding quality.

[0042] It should be noted that, since the welding surfaces of the welding head 3 and the welding seat 4 are both rectangular, the cross-sections of the first limiting member 5 and the second limiting member 6 in this application are both rectangular, and the cross-sections of the first through hole 601 and the second through hole 602 are both rectangular.

[0043] Further explanation is needed here: during welding, the portion of the welding head 3 that passes through the first limiting member 5 and enters the limiting space 7 is the same as the portion of the welding seat 4 that passes through the second limiting member 6 and enters the limiting space 7, so that the welding process is carried out in the middle position of the limiting space 7, making the welding more uniform.

[0044] Optionally, such as Figures 1-3 As shown, the first limiting member 5 in this application is cylindrical, the electrode 2 is located inside the first limiting member 5, and when the welding head 3 passes through the first limiting member 5, it can press the electrode 2 out of the first limiting member 5 and enter the limiting space 7 to weld with the current collector 101.

[0045] Since the welding head 3 needs to pass through the first limiting member 5 during welding, by making the first limiting member 5 cylindrical, the welding head 3 can smoothly enter the limiting space 7.

[0046] The cylindrical first limiting member 5 can also support the tab 2, so that the limiting space 7 can only integrate and gather the current collector 101, avoiding interference from the tab 2.

[0047] Preferably, such as Figures 1-3 As shown, the first limiting member 5 in this application includes a limiting body 501, a first movable member 502, and a second movable member 503. The limiting body 501 is cylindrical, and the first movable member 502 and the second movable member 503 are disposed opposite to each other at both ends inside the limiting body 501. The first movable member 502 and the second movable member 503 are each formed with a positioning groove 5024 so that the two ends of the tab 2 can be located in the positioning groove 5024 of the first movable member 502 and the positioning groove 5024 of the second movable member 503, respectively.

[0048] It is understood that the first limiting member 5 mentioned above in this application is cylindrical, which means that the limiting body 501 is cylindrical, so that the welding head 3 can pass through and the first movable member 502 and the second movable member 503 can be stably accommodated.

[0049] By providing a first movable member 502 and a second movable member 503 at both ends within the limiting body 501, and by forming positioning grooves 5024 on both the first movable member 502 and the second movable member 503, the electrode tab 2 can be stably supported. When the welding head 3 moves down through the limiting body 501, it can press the electrode tab 2 into the limiting space 7, thereby achieving welding with the current collector 101.

[0050] More preferably, such as Figures 1-3 As shown, the first movable member 502 and the second movable member 503 in this application both include a positioning section 5021, a transition section 5022 and a connecting section 5023. The positioning groove 5024 is formed on the positioning section 5021, the transition section 5022 is located between the positioning section 5021 and the connecting section 5023, and the first movable member 502 and the second movable member 503 are rotatably connected to the limiting body 501 through the connecting section 5023.

[0051] like Figure 3 As shown, the first movable member 502 and the second movable member 503 in this application both have an approximately Z-shaped structure. They are rotatably connected to the limiting body 501 through the connecting section 5023. Specifically, the side wall of the connecting section 5023 has a connecting hole 5026, and the limiting body 501 has an alignment hole at the position corresponding to the connecting hole 5026. A connecting shaft is provided in the alignment hole and the connecting hole 5026, thereby enabling the connecting section 5023 to rotate relative to the limiting body 501, and thus enabling the first movable member 502 and the second movable member 503 to rotate relative to the limiting body 501.

[0052] And such Figure 3 As shown, the transition section 5022 in this application is inclined, so that a rotation space 5011 can be formed between the transition section 5022 and the inner end face of the limiting body 501. Thus, when the welding head 3 presses down to drive the electrode 2, a certain degree of rotation can be generated to ensure the smooth release of the electrode 2.

[0053] Optionally, such as Figure 3 As shown, in this application, a mounting hole 5025 is formed on the inner end face of the transition section 5022 facing the limiting body 501. A reset member 504 is provided in the mounting hole 5025. The end of the reset member 504 away from the mounting hole 5025 abuts against the inner end face of the limiting body 501.

[0054] The reset component 504 in this application is a pressure spring. By setting the pressure spring in the mounting hole 5025, the first movable component 502 and the second movable component 503 can be automatically reset. When the welding head 3 presses down and drives the electrode tab 2 to move into the limiting space 7, the first movable component 502 and the second movable component 503 will rotate relative to the limiting body 501, thereby releasing the electrode tab 2. During the rotation, the pressure spring will be compressed. After the two ends of the electrode tab 2 are completely separated from the positioning grooves 5024 of the first movable component 502 and the second movable component 503, the pressure spring can return to its natural extension state, thereby driving the first movable component 502 and the second movable component 503 back to their original positions.

[0055] In addition, such as Figure 4 Combination Figure 5As shown, the present invention also provides a welding process using the above-mentioned welding system, comprising the following steps: Step 1, preparation before welding; Step 2, performing positive electrode welding and negative electrode welding in sequence; Step 3, flattening, testing and encapsulation.

[0056] The welding process using the welding system provided in this application can integrate and gather the current collector 101 before welding, so that two welding operations can be performed with the same parameters during welding. This allows the welding process of the positive electrode to be completed with only one welding machine, and the welding process of the negative electrode to be completed with only one welding machine. Compared with the current stage of using two welding machines for welding the positive and negative electrodes respectively, the number of equipment is reduced by half, which not only reduces material loss and reduces the difficulty of on-site management, but also improves the welding effect.

[0057] In step one, the pre-welding preparation includes stacking, weighing, initial short-circuit testing, positioning, pre-welding, and cutting.

[0058] In step two, positive electrode welding includes placing the current collector 101 and the tab 2 of the positive electrode into the limiting space 7, gathering the current collector 101 of the positive electrode through the limiting component, and then welding it through the welding head 3 and the welding base 4; negative electrode welding includes placing the current collector 101 and the tab 2 of the negative electrode into the limiting space 7, gathering the current collector 101 of the negative electrode through the limiting component, and then welding it through the welding head 3 and the welding base 4.

[0059] It is understood that the welding processes for the positive and negative electrodes are performed separately in this application; that is, one device is used for welding the positive electrode and another device is used for welding the negative electrode. Therefore, the limiting component in this application corresponds to the corresponding welding equipment. The aforementioned welding with the same parameters refers to welding the positive electrode and welding the negative electrode with the same parameters. However, the parameters for welding the positive electrode and welding the negative electrode may be the same or different depending on the actual operational requirements, product parameters, and circumstances.

[0060] It should be further explained here that, in this application, before performing positive and negative electrode welding, inserting the current collector 101 into the limiting space 7 for positioning means compacting all positions of the current collector 101 except for the welding positions corresponding to the welding head 3 and the welding seat 4, thereby achieving the above-mentioned improved welding effect and welding of positive and negative electrodes with the same parameters.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding system for welding current collectors and tabs of a battery cell, characterized in that, Includes welding head, welding base, and limiting components; The limiting component is disposed between the welding head and the welding base, and the limiting component forms a limiting space. The current collector and the electrode of the battery cell are located in the limiting space. The welding head and the welding base can pass through the limiting component and enter the limiting space to weld the current collector and the electrode together. The limiting component includes a first limiting member and a second limiting member, wherein the first limiting member is provided corresponding to the welding head and the second limiting member is provided corresponding to the welding base; The first limiting component includes a limiting body, a first movable component, and a second movable component; The limiting body is cylindrical, and the first movable member and the second movable member are disposed opposite to each other at both ends inside the limiting body. Both the first movable member and the second movable member have positioning grooves, so that the two ends of the electrode can be located in the positioning grooves of the first movable member and the second movable member, respectively. Both the first movable member and the second movable member include a positioning section, a transition section, and a connecting section. The positioning groove is formed on the positioning section, the transition section is located between the positioning section and the connecting section, and both the first movable member and the second movable member are rotatably connected to the limiting body through the connecting section.

2. The welding system according to claim 1, characterized in that, The welding head can pass through the first limiting member and enter the limiting space. The second limiting member has a first through hole and a second through hole. The welding seat enters the first through hole and the second through hole in sequence to cooperate with the welding head to perform two welding operations on the current collector and the electrode tab.

3. The welding system according to claim 2, characterized in that, The first limiting member is cylindrical, the electrode is located inside the first limiting member, and when the welding head passes through the first limiting member, it can press the electrode out of the first limiting member and enter the limiting space to weld with the current collector.

4. The welding system according to claim 1, characterized in that, The transition section is inclined, so that a rotation space is formed between the transition section and the inner end face of the limiting body.

5. The welding system according to claim 4, characterized in that, A mounting hole is formed on the inner end face of the transition section facing the limiting body. A reset member is provided in the mounting hole, and the end of the reset member away from the mounting hole abuts against the inner end face of the limiting body.

6. A welding process using the welding system according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Preparations before welding; Step 2: Perform positive electrode welding and negative electrode welding in sequence; Step 3: Flattening, testing, and packaging.

7. The welding process according to claim 6, characterized in that, In step one, the pre-welding preparation includes stacking, weighing, initial short-circuit testing, positioning, pre-welding, and cutting.

8. The welding process according to claim 6, characterized in that, In step two, the positive electrode welding includes placing the current collector and the tab of the positive electrode into the limiting space, gathering the current collector of the positive electrode by the limiting component, and then welding it by the welding head and the welding seat. The negative electrode welding process involves placing the current collector and tab of the negative electrode into a limiting space, concentrating the current collector of the negative electrode through a limiting component, and then welding it through a welding head and a welding base.

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