Battery tab pre-welding device and current collector tab pre-welding method

Abstract

The present invention relates to the technical field of batteries and discloses a battery tab pre-welding device and a current collector tab pre-welding method, comprising a main body; a tab insertion portion, arranged on a first side of the main body, for inserting or removing the tab; a fixing portion, arranged on a second side of the main body opposite to the first side; and spacing portions, arranged between the tab insertion portion and the fixing portion, with each group of spacing portions being equidistantly arranged in parallel for clamping the tab. In the present invention, since the tabs at both ends are fitted and then bent along the sidewalls of the main body, the length of the tabs can be left with a margin for welding, thereby solving the problem that the current collector tabs are in a compressed state during pre-welding, and the bent portion of the current collector tabs is the junction of the dressing and the current collector. The current collector tabs farther away from the compressed position are subjected to excessive tension, which makes the current collector tabs prone to breakage and powdering, increases the internal resistance of the battery, and increases self-discharge.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery tab pre-welding device and a current collector tab pre-welding method. Background Art

[0002] With the continuous development of battery technology, laminated batteries have gradually demonstrated their advantages due to their excellent high energy density, high capacity density, low internal resistance, and flexible design. They are widely used in the 3C digital field, new energy vehicle power energy and energy storage fields, etc. Patent document (CN110871332A) discloses a power battery tab pre-welding device, which includes a battery cell body, copper tabs, aluminum tabs, a tab folding robot, pre-welding points, and a fracture point. The battery cell body is provided with a copper tab at one end, and aluminum tabs are respectively provided on both sides of the copper tab for welding to form the pre-welding points. The tab folding robot is provided on both sides of the pre-welding points. That is, when the tabs are welded in the patent document, the tabs are pressed together, and the tab pressing position is pre-welded. Because the current collector tabs are in a compressed state during pre-welding, and the bend of the current collector tabs is the junction of the dressing and the current collector, the current collector tabs farther away from the compression position are subjected to greater tension and have a larger bending angle. During the use of the battery, the current collector tabs are prone to breakage and powdering, leading to a series of problems such as increased internal resistance and self-discharge of the battery, and even causing accidents such as fire and explosion. Therefore, the existing technology has defects and needs to be improved. Summary of the Invention

[0003] In order to solve one or more of the above-mentioned technical problems, the present invention provides a battery tab pre-welding device and a current collector tab pre-welding method.

[0004] The technical solution of the present invention is as follows: A battery tab pre-welding device, comprising:

[0005] main body;

[0006] A tab insertion portion is provided on the first side of the main body and is used for implanting or removing the tab;

[0007] a fixing portion, provided on a second side of the main body opposite to the first side;

[0008] The spacing portion is provided between the tab insertion portion and the fixing portion, and each group of the spacing portions is equidistantly and parallelly arranged and perpendicular to the fixing portion, and is used to clamp the tab;

[0009] The first area of ​​the tab enters the spacing portion from the tab insertion portion, so that the second area of ​​the tab is attached to the main body for bending. When the tab is bent, the tab is removed from the tab insertion portion.

[0010] Using the above technical solution, the battery tab pre-welding device also includes a fitting portion, and the second area of ​​the tab is tightly attached to the fitting portion when bent. The fitting portion is arranged on a side close to the fixed portion, and the thickness of the fitting portion gradually increases from the middle toward the two ends, and the fitting portion has a V-shaped structure.

[0011] By adopting the above-mentioned technical solutions, the battery tab pre-welding device further includes a supporting portion, which is arranged on both sides of the spacing portion and is perpendicular to the fixing portion. The spacing portion is used to support the tab when it is bent.

[0012] By adopting the above-mentioned technical solutions, in the battery tab pre-welding device, the distance between the tab insertion portion and the fixing portion is 2mm-5mm, and the thickness of the bonding portion is greater than the thickness of the laminated battery.

[0013] By adopting the above-mentioned technical solutions, in the battery tab pre-welding device, the height of the spacing portion is greater than the thickness of the tab, and the number of the spacing portions corresponds to the number of the tabs.

[0014] A method for pre-welding a current collector tab, comprising the battery tab pre-welding device, is characterized in that the method comprises:

[0015] Pressurize and fix the battery core;

[0016] Selecting a target number of layers of the spacing portion according to the number of tab layers of the battery core;

[0017] Place the tab from the tab placement portion into the spacing portion and fix it at the spacing portion, and press and bend the tab along the fitting portion;

[0018] The pressing points of the pressed and bent tabs are pre-welded.

[0019] According to the above technical solutions, the pre-welding method for the current collector tab, wherein the tab is placed from the tab placement portion into the spacing portion, comprises:

[0020] The tab is placed into the spacing portion along the axial direction of the tab placement portion.

[0021] According to the above technical solutions, the pre-welding method for the current collector tab further comprises the following steps after the step of pre-welding the pressing points of the pressed and bent tabs:

[0022] The pre-welding device is pulled out along the axial direction of the tab insertion portion.

[0023] The above-mentioned technical solutions are used in the pre-welding method of the current collector tab, wherein the tab is compressed and bent along the bonding portion, and the tab is bent, and the method includes:

[0024] a bending portion connected to the battery coil core;

[0025] a movable portion connected to the bending portion;

[0026] a pre-welding portion connected to the movable portion;

[0027] The unwelded area is connected to the pre-welded portion, and the tab is formed into a Z-shaped structure as a whole after being bent.

[0028] Using the above technical solutions, the pre-welding method of the current collector tab, wherein the pressing points of the compressed and bent tabs are pre-welded, comprises:

[0029] After the multiple groups of tabs are compressed, a starting compression point and a compression area are formed, and the compression area is used for welding with the metal tabs.

[0030] The beneficial effects brought by the present invention are as follows: in the battery tab pre-welding device of the present invention, one end of the tab is installed into the spacing portion along the tab insertion portion for fixation, and then the other end of the tab is bent and pre-welded. Since the spacing portion is equidistantly and parallelly arranged, the tabs at both ends of the spacing portion will be bent to fit the side wall of the main body, so that the tabs on both sides and the tab in the middle are merged into the pre-welding point in the middle. Since the tabs at both ends are fitted and then bent along the side wall of the main body, the length of the tab can be made to have a margin for welding, thereby solving the problem that the current collector tab is in a tightly compressed state during pre-welding of the existing tabs, and the bent part of the current collector tab is the junction of the dressing and the current collector. The current collector tab that is farther away from the compressed position is subjected to excessive tension, the current collector tab is prone to breakage and powdering, the internal resistance of the battery increases, and the self-discharge increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 It is a structural schematic diagram of the fixing part of the present invention;

[0033] Figure 3 Schematic diagram of the spacing portion and the tab insertion portion structure of the present invention;

[0034] Figure 4 Schematic diagram of the tab structure of the present invention;

[0035] Figure 5 Schematic diagram of the process of pre-welding the current collector tab of the present invention;

[0036] Among them, 1. Main body; 2. Tab insertion part; 3. Fixing part; 4. Spacing part; 5. Fitting part; 6. Support part; 70. Bending part; 71. Movable part; 72. Pre-welding part; 73. Unwelded area; 74. Starting pressing point; 75. Pressing area.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0038] It should be understood that the embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0040] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections, direct connections, or indirect connections through an intermediate medium; they may refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0042] like Figure 1 and Figure 2 As shown, the embodiment of the present application provides a pre-welding device, comprising

[0043] Subject 1;

[0044] The tab insertion portion 2 is provided on the first side of the main body 1 and is used for implanting or removing the tab;

[0045] a fixing portion 3 , provided on a second side of the main body 1 opposite to the first side;

[0046] The spacing portion 4 is provided between the tab placement portion 2 and the fixing portion 3. Each group of the spacing portions 4 is equidistantly arranged in parallel and perpendicular to the fixing portion 3, and is used to clamp the tab.

[0047] The first region of the tab is passed from the tab insertion portion 2 into the spacing portion 4, and the second region of the tab is bent against the main body 1. When the tab bending is completed, the tab is removed from the tab insertion portion 2. In this embodiment, since the laminated battery comprises a plurality of current collectors, and each current collector is provided with tabs, it is necessary to press-bend the multiple tabs to a single welding point for pre-welding. In order to prevent the multiple tabs from breaking and chipping due to excessive tension at the intersection during the pressing and pre-welding, By providing a pre-welding device, the force point of the tab during welding can be changed. By providing a tab insertion portion 2, the tab can be inserted into the device along the tab insertion portion 2 when installed in the device. When the tab is bent and pre-welded, the tab is removed from the tab insertion portion 2 to prevent the tab from being damaged during removal and insertion. By providing a fixing portion 3, it can be used to fix each group of spacing portions 4 and protect the end of the tab from damage. Specifically, a buffer can be provided between the fixing portion 3 and the spacing portion 4. The spacing portion 4 is provided to clamp the tab, and the number of spacing portions 4 can be set according to the number of tabs, so that each group of tabs can be stored on each group of spacing portions 4 for clamping. Specifically, one area of ​​the pole ear is installed along the pole ear insertion portion 2 into the spacing portion 4 for fixation, and then the other area of ​​the pole ear is bent and pre-welded. Since the spacing portion 4 is arranged in parallel with equal distances, the pole ears at both ends of the spacing portion 4 will be bent to fit the side wall of the main body 1, so that the pole ears on both sides and the pole ear in the middle converge at the pre-welding point in the middle. Since the pole ears at both ends are fitted and then bent along the side wall of the main body 1, the length of the pole ear can be made to have a margin for welding, thereby solving the problem that the collector pole ear is in a tightly compressed state during pre-welding, and the bent part of the collector pole ear is the junction of the dressing and the collector. The collector pole ear that is farther away from the compressed position is subjected to excessive tension, and the collector pole ear is prone to breakage and powdering, which increases the internal resistance of the battery and the self-discharge.

[0048] like Figure 2As shown, further, when the second region of the tab is bent, it is in close contact with the bonding portion 5. The bonding portion 5 is provided on the side close to the fixing portion 3. The thickness of the bonding portion 5 gradually increases from the middle toward the two ends, and the bonding portion 5 has a V-shaped structure. In this embodiment, the provision of the bonding portion 5 allows the second region of the tab to be bonded during bending and pre-welding. Since the bending point of the current collector ear is the junction of the dressing and the current collector, the current collector ear that is farther away from the pressing position will be subject to greater tension. Therefore, the ears on both sides will have length margins when they are bent along the fitting portion 5. Moreover, the overall structure of the fitting portion 5 is a V-shaped structure, which can clearly indicate that the fitting at both ends is the longer end, and the fitting portion 5 from the two ends to the middle position will gradually become shorter, so that the ears that are farther away from the pressing position at both ends can have more appropriate length margins when they are bent along the fitting portion 5, preventing the current collector ear that is farther away from the pressing position from being subject to excessive tension, which may cause the current collector ear to break and lose powder easily, and even cause accidents such as battery fire and explosion.

[0049] like Figure 3 As shown, further, the pre-welding device also includes a support portion 6, which is arranged on both sides of the spacing portion 4 and is perpendicular to the fixing portion 3. The spacing portion 4 is used to support the tab when it is bent. In this embodiment, the setting of the support portion 6 can be used to control the distance between two adjacent groups of spacing portions 4 to avoid the distance between the two adjacent groups of spacing portions 4 being too far or too close, so that the two adjacent groups of spacing portions 4 are kept at a suitable distance, so that the tab has a more suitable length margin when it is bent, and prevents the current collector tab that is farther away from the clamping position from being subjected to excessive tension, which causes the current collector tab to easily break and lose powder, and the support portion 6 can support the tab, making the tab more stable when it is bent.

[0050] like Figure 1 As shown, the distance between the tab insertion portion 2 and the fixing portion 3 is 2mm-5mm, and the thickness of the fitting portion 5 is greater than the thickness of the laminated battery. In this embodiment, the distance between the tab insertion portion 2 and the fixing portion 3 is set to 3mm, and the width of the main body 1 can be set to be greater than the width of the tab; the height of the main body 1 is set to be greater than the thickness of the laminated battery, so that the tabs of the laminated battery can be placed within the main body 1 for pre-welding.

[0051] like Figure 3As shown, further, the height of the spacing portion 4 is greater than the thickness of the tab, and the number of the spacing portions 4 corresponds to the number of the tabs. In this embodiment, the height of the spacing portion 4 is greater than the thickness of the tab, which can prevent the height of the spacing portion 4 from being too narrow and wearing onto the surface of the tab. It is worth mentioning that the material of the pre-welding device as a whole can be set to be a flexible material. When the main body 1 is pressurized, the whole can be compressed and deformed, thereby fixing the tab in the spacing portion 4 to facilitate the bending of the tab. The number of spacing portions 4 is set to correspond to the number of tabs, so that each group of tabs can be placed in the spacing portion 4 for clamping and fixing.

[0052] like Figure 5 As shown, a pre-welding method for a current collector tab comprises:

[0053] S1. Pressurize and fix the battery core;

[0054] S2. Selecting a target number of layers of the spacing portion 4 according to the number of tab layers of the battery core;

[0055] S3, placing the tab from the tab placement portion 2 into the spacing portion 4, fixing it in the spacing portion 4, and pressing and bending the tab along the fitting portion 5;

[0056] S4. Pre-weld the pressing points of the pressed and bent tabs.

[0057] As described above, when the tabs are processed and bent, the battery core is pressurized and fixed, wherein the pressurization can be achieved by using a clamping tool to clamp and fix the two ends of the battery core to facilitate the processing and bending of the tabs. The specific number of layers of the spacing portion 4 is selected according to the number of tabs in the battery core. The specific number of layers must be the same as the number of tabs or more than the number of tabs. An area of ​​the tab is fixed in the spacing portion 4, wherein the fixing method can be the same as the method of clamping and fixing the battery core. By pressurizing and fixing the two ends of the spacing portion 4, the tab is prevented from moving in the spacing portion 4 and affecting the bending accuracy of the tab. The tab is pressed and bent along the fitting portion 5 to reduce the internal resistance. By pre-welding the compression points on all the tabs, the length of the tab can have a margin for welding, thereby avoiding the current collector tab being in a compressed state during pre-welding, thereby reducing the internal resistance of the tab after pre-welding.

[0058] like Figure 4 As shown, further, when the tab is bent, the tab includes:

[0059] A bending portion 70 connected to the battery coil;

[0060] a movable portion 71 connected to the bending portion 70;

[0061] a pre-welding portion 72 connected to the movable portion 71;

[0062] The unwelded area 73 is connected to the pre-welded portion 72, and the tab is bent into a Z-shaped structure. In this embodiment, after the tab is bent, the tab is formed with a bent portion 70, a movable portion 71, a pre-welded portion 72, and an unwelded area 73. The tab is formed into a Z-shaped structure after bending, so that the battery end face after the tab is folded can remain straight in the vertical plane and will not tilt outward. The movable portion 71 can reserve a certain length margin for the tab for welding, thereby reducing the difficulty of welding and preventing the tab from tearing due to insufficient length.

[0063] like Figure 4 As shown, further, after the tabs are bent and pre-welded, multiple groups of the tabs are compressed to form a starting compression point 74 and a compression area 75, which is used for welding with the metal tabs. In this embodiment, after all the tabs are compressed and pre-welded along the fitting portion 5, a starting compression point 74 and a compression area 75 are formed between the tabs. By using the compression area 75 for welding with the external metal tabs, a certain length margin is reserved for the tabs for welding, thereby improving the stability of the welding between the compression area 75 of the tabs and the external metal tabs, and preventing the current collector tabs from being in a compressed state during the pre-welding of the tabs.

[0064] Furthermore, before the step of fixing the tabs in the spacing portion 4, the steps include: pressurizing and fixing the battery roll core; selecting a target number of layers of the spacing portion 4 according to the number of tab layers of the battery roll core; and placing the tabs into the spacing portion 4 along the axial direction of the tab insertion portion 2.

[0065] As described above, when the tab is installed in the spacing portion 4, it enters the spacing portion 4 along the tab insertion portion 2. When the tab enters the spacing portion 4, the spacing portion 4 is pressurized to prevent the tab from moving and slipping in the spacing portion 4, thereby reducing the processing error of the tab bending.

[0066] Furthermore, after the step of pre-welding the pressing points of the compressed and bent tabs, the step further includes: withdrawing the pre-welding device from the axial direction of the tab insertion portion 2. As described above, by providing the tab insertion portion 2, the tabs can be inserted into the device along the tab insertion portion 2 when being installed in the device. After the tab bending and pre-welding are completed, the tabs can be removed from the tab insertion portion 2, thereby preventing the tabs from being damaged during removal and insertion.

[0067] By adopting the above-mentioned technical solutions, a pre-welding device is provided to change the force point of the tab during welding. By providing a tab insertion portion 2, the tab can be inserted into the device along the tab insertion portion 2 when installed in the device. When the tab is bent and pre-welded, the tab is removed from the tab insertion portion 2 to prevent the tab from being damaged during removal and insertion. By providing a fixing portion 3, it can be used to fix each group of spacing portions 4 and protect the end of the tab from damage. Specifically, a buffer can be provided between the fixing portion 3 and the spacing portion 4. The spacing portion 4 is provided to clamp the tab, and the number of spacing portions 4 can be set according to the number of tabs, so that each group of tabs can be stored on each group of spacing portions 4 for clamping. Specifically, one end of the pole ear is installed into the spacing portion 4 along the pole ear insertion portion 2 for fixation, and the other end of the pole ear is bent and pre-welded. Since the spacing portion 4 is arranged in parallel with equal distances, the pole ears at both ends of the spacing portion 4 will be bent to fit the side wall of the main body 1, so that the pole ears on both sides and the pole ear in the middle converge at the pre-welding point in the middle. Since the pole ears at both ends are fitted along the side wall of the main body 1 and then bent, the length of the pole ear can be made to have a margin for welding, thereby solving the problem that the collector pole ear is in a tightly compressed state during pre-welding, and the bent part of the collector pole ear is the junction of the dressing and the collector. The collector pole ear that is farther away from the compressed position is subjected to excessive tension, and the collector pole ear is prone to breakage and powdering, which increases the internal resistance of the battery and the self-discharge.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A battery tab pre-welding device, characterized in that: include: main body; A tab insertion portion is provided on the first side of the main body and is used for implanting or removing the tab; a fixing portion, provided on a second side of the main body opposite to the first side; The spacing portion is provided between the tab insertion portion and the fixing portion, and each group of the spacing portions is equidistantly and parallelly arranged and perpendicular to the fixing portion, and is used to clamp the tab; The first area of ​​the tab enters the spacing portion from the tab insertion portion, so that the second area of ​​the tab is attached to the main body for bending, and the tab is removed from the tab insertion portion after the tab bending is completed; The battery tab pre-welding device also includes a fitting portion, and the second area of ​​the tab is tightly fitted to the fitting portion when bent. The fitting portion is arranged on a side close to the fixing portion, and the thickness of the fitting portion gradually increases from the middle toward the two ends, and the fitting portion has a V-shaped structure.

2. The battery tab pre-welding device according to claim 1, characterized in that: It also includes a supporting portion, which is arranged on both sides of the spacing portion and is perpendicular to the fixing portion. The spacing portion is used to support the tab when it is bent.

3. The battery tab pre-welding device according to claim 1, characterized in that: The distance between the tab insertion portion and the fixing portion is 2 mm to 5 mm, and the thickness of the bonding portion is greater than the thickness of the laminated battery.

4. The battery tab pre-welding device according to claim 1, characterized in that: The height of the spacing portion is greater than the thickness of the tab, and the number of the spacing portions corresponds to the number of the tabs.

5. A method for pre-welding a current collector tab, comprising the battery tab pre-welding device according to any one of claims 1 to 4, characterized in that: The method comprises: Pressurize and fix the battery core; Selecting a target number of layers of the spacing portion according to the number of tab layers of the battery core; Place the tab from the tab placement portion into the spacing portion and fix it at the spacing portion, and press and bend the tab along the fitting portion; The pressing points of the pressed and bent tabs are pre-welded.

6. The pre-welding method for the current collector tab according to claim 5, characterized in that: The step of placing the tab from the tab placement portion into the spacing portion includes: The tab is placed into the spacing portion along the axial direction of the tab placement portion.

7. The pre-welding method for the current collector tab according to claim 5, characterized in that: After the step of pre-welding the pressing points of the compressed and bent tabs, the method further includes: The pre-welding device is pulled out along the axial direction of the tab insertion portion.

8. The method for pre-welding a current collector tab according to claim 5, wherein: The tab is compressed and bent along the fitting portion, and the tab bending comprises: a bending portion connected to the battery coil core; a movable portion connected to the bending portion; a pre-welding portion connected to the movable portion; The unwelded area is connected to the pre-welded portion, and the tab is formed into a Z-shaped structure as a whole after being bent.

9. The pre-welding method for the current collector tab according to claim 8, characterized in that: The pressing points of the pressed and bent tabs are pre-welded, and after the tab pre-welding is completed, the steps include: After the multiple groups of tabs are compressed, a starting compression point and a compression area are formed, and the compression area is used for welding with the metal tabs.

Images