L-type tab welding device for laminated batteries

Abstract

The present invention discloses a laminated battery L-shaped pole ear welding device, comprising a base fixed on a bottom plate, a battery pressing plate assembly, and a positioning frame for positioning the battery, a welding seat is arranged on the base, and a battery pole ear limiting groove for positioning the L-shaped pole ear of the battery is formed on the welding seat, the battery pressing plate assembly comprises a pressing plate for pressing the battery positioned by the positioning frame when welding the battery, the pressing plate and the welding seat are arranged relative to each other, and a battery positioning space is formed therebetween, the positioning frame is located outside the battery positioning space, and the pressing plate can press the battery on the welding seat by horizontally moving toward the welding seat; a pole ear pressing assembly is arranged on the pressing plate, and the pole ear pressing assembly comprises a pole ear pressing claw, which is used for pressing and fixing the L-shaped pole ear and the foil pole ear of the battery after the L-shaped pole ear is inserted into the battery pole ear positioning groove for positioning, and then welding by a welding head above the welding seat. The present invention solves the problem of welding and positioning of soft-pack laminated batteries in a narrow space.

Description

Technical Field

[0001] The invention relates to the technical field of tab bending and assembly, and in particular to an L-shaped tab welding device for a laminated battery. Background Art

[0002] With the rapid development of soft-pack lithium-ion batteries, the energy density of lithium-ion batteries has become an important indicator for evaluating their performance. At present, soft-pack laminated structure batteries have the following problems: the foil tabs that extend beyond the diaphragm are generally 4 to 10 mm. Based on welding efficiency and production cost considerations, flat welding is generally used, that is, the transfer tabs are laid flat on the foil tabs for welding. However, this welding method requires a larger welding space, resulting in space waste at the welding position, which reduces the volume energy density of the battery.

[0003] Invention CN112599935A introduces a welding method for L-shaped tabs, that is, the foil tabs are pre-welded sideways first, and then the pre-bent transfer tabs and foil tabs are finally welded. However, this method has complicated operation steps, low welding efficiency, and poor consistency. At the same time, the battery cell undergoes two turnovers and welding, which is prone to problems such as pole piece powder shedding and tab welding cracks, resulting in a high battery self-discharge rate and a low yield rate.

[0004] CN111799429 discloses a soft-pack battery and an assembly method of a soft-pack battery, wherein the tab is pre-bent so that the bent portion is welded to the foil. After the tab is welded to the foil, the foil is bent. The foil tab is easily lifted up and there is no flattening measure, making welding difficult. The foil tab is tightly attached to the welding head, which can easily cause the foil tab to be cracked.

[0005] CN112599935A provides a method for manufacturing a lithium-ion power soft-pack battery tab and a battery, which adopts a pre-welding and final welding method. The addition of pre-welding solves the problem of fixing the foil tab, but the foil tab undergoes two weldings, the stress strength increases, and the tab is easy to break in the later stage. In addition, the welding process is cumbersome, and the excess foil needs to be cut after pre-welding, which can easily cause pollution to the battery body and cause self-discharge.

[0006] CN104577025A discloses a method for welding the tabs of a soft-package battery. The method adopts the method of pre-welding + final welding. The addition of pre-welding solves the problem of fixing the foil tabs. However, the foil tabs undergo two welding processes, which increases the stress strength and makes the tabs easy to break in the later stage. In addition, the welding process is cumbersome, and the excess foil and tabs must be cut at the same time, which can easily tear the tabs, causing stress on the front end of the battery cell and powder loss of the pole piece. Summary of the invention

[0007] The purpose of the present invention is to provide an L-type tab welding device for a laminated battery in response to the technical defects existing in the prior art, aiming to solve the welding problem in a narrow space; optimize the welding process, realize the integration of pre-welding and final welding, reduce the turnover frequency of battery cells, and reduce the risk of tab welding cracks; solve the positioning problem of battery cells and transfer tabs in vertical welding.

[0008] The technical solution adopted to achieve the purpose of the present invention is:

[0009] A laminated battery L-shaped tab welding device comprises a base fixed on a bottom plate, a battery pressing plate assembly, and a positioning frame for positioning the battery, a welding seat is arranged on the base, and a battery tab limiting groove for positioning the L-shaped tab of the battery is formed on the welding seat, the battery pressing plate assembly comprises a pressing plate for pressing the battery positioned by the positioning frame when welding the battery, the pressing plate and the welding seat are arranged opposite to each other, a battery positioning space is formed therebetween, the positioning frame is located on the outside of the battery positioning space, and the pressing plate can press the battery onto the welding seat by horizontally moving toward the welding seat; a tab pressing assembly is arranged on the pressing plate, and the tab pressing assembly comprises a tab pressing claw, which is used for pressing and fixing the L-shaped tab and the foil tab of the battery after the L-shaped tab is inserted into the battery tab positioning groove for positioning, and then welding by a welding head above the welding seat.

[0010] The present invention adopts an L-shaped tab vertical welding method, which solves the welding and positioning problems of soft-pack laminated batteries in a narrow space, improves the space utilization rate of the soft-pack laminated batteries, and improves the volume energy density of the soft-pack laminated batteries.

[0011] The present invention eliminates the pre-welding step of the foil pole ear, integrates the pre-welding and final welding, reduces the turnover frequency of the battery cell, reduces the risk of the pole ear welding crack, greatly reduces the battery self-discharge rate, and improves the welding yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the appearance of an L-shaped tab welding device for a laminated battery according to an embodiment of the present invention.

[0013] Figure 2 This is a partial enlarged view of the tab pressing assembly of the L-shaped tab welding device for laminated batteries according to an embodiment of the present invention.

[0014] Figure 3 It is a partial schematic diagram of the battery pressing plate assembly of the L-shaped tab welding device for laminated batteries according to an embodiment of the present invention.

[0015] Figure 4 It is a rear view of the partial structure of the L-shaped tab welding device for laminated batteries according to an embodiment of the present invention.

[0016] Figure 5It is a schematic diagram of the positioning frame of the L-shaped tab welding device for a laminated battery according to an embodiment of the present invention.

[0017] Figure 6 Schematic diagram of a base of an L-shaped tab welding device for a laminated battery according to an embodiment of the present invention.

[0018] Figure 7 Schematic diagram of the battery after the tab welding is completed.

[0019] In the figure:

[0020] 1. Bottom plate; 2. Base; 3. Welding seat; 3-1. Battery tab positioning groove; 3-2. Top of tab support boss; 3-3. Tab support boss; 4. Welding head; 5. L-shaped tab; 5-1. Tab glue; 6. Battery; 6-1. Foil tab; 7. Tab pressing assembly; 7-1. Linear guide rail 1; 7-2. Fixing plate; 7-3. Bolt 1; 7-4. Spring 1; 7-5. Bolt 2; 7-6. Tab pressing claw; 8. Positioning frame; 9. Battery pressure plate assembly; 9-1. Knob plunger; 9-2. Plunger mounting plate; 9-3. Linear guide rail 2; 9-4. Positioning bottom plate; 9-5. Guide column mounting plate; 9-6. Guide column; 9-7. Locking nut; 9-8. Spring 2; 9-9. Handle; 9-10. Pressure plate. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] like Figure 1 As shown, the L-shaped tab welding device for laminated batteries according to the embodiment of the present invention comprises a bottom plate 1, a base 2 fixed on the bottom plate, a welding seat 3 arranged on the base 2, a battery pressing plate assembly 9 arranged on the bottom plate 1, and a positioning frame 8 for positioning the battery. The welding seat 3 is formed with a battery tab positioning groove 3-1 for positioning the L-shaped tab 5 of the battery. The battery pressing plate assembly 9 comprises pressing plates 9-10 for pressing the battery 6 positioned by the positioning frame 8 when welding the battery. The pressing plates are arranged opposite to the welding seat, and a space for placing the battery 6 is formed between them. The battery positioning space of the battery 6, the positioning frame 8 is located on the outside of the battery positioning space, and the pressing plate 9-10 can press the battery onto the welding seat 3 by moving horizontally toward the base 2; a pressing ear assembly 7 is provided on the pressing plate 9-10, and the pressing ear assembly 7 includes an ear pressing claw 7-6, which is used to press and fix the L-shaped ear 5 and the foil ear 6-1 of the battery after the L-shaped ear 5 is inserted into the battery ear positioning groove 3-1 and positioned, and the welding head 4 for welding the ear is installed and fixed on the welding equipment and is located above the welding seat 3.

[0023] Among them, the bottom plate plays a supporting and connecting role and is placed on a horizontal plane; the base is installed and fixed on the bottom plate and serves as a mounting platform for the welding seat; the welding seat is installed and fixed on the base and is used for welding the L-shaped pole ear 5 of the battery.

[0024] Among them, a battery tab positioning groove 3-1 is opened in the vertical direction on the bottom surface of the groove near the groove wall at the upper end of the welding seat 3, which is used to position the L-shaped tab; the welding seat has a tab support boss 3-3 that is tightly matched with the tab pressing claw. After the vertical part of the L-shaped tab of the battery is vertically inserted into the battery tab positioning groove 3-1, its horizontal part is just located on the top 3-2 of the tab support boss, and the vertical part contacts the side surface of the tab support boss. Among them, the slot width of the battery tab positioning groove of the welding seat is smaller than the tab glue width of the L-shaped tab, which can achieve insertion limitation.

[0025] When in use, one end of the L-shaped tab 5 is inserted into the positioning notch, and the tab glue 5 - 1 of the L-shaped tab 5 is just stuck in the notch of the battery tab positioning groove 3 - 1 of the welding seat to complete the positioning of the L-shaped tab 5 .

[0026] As a preferred embodiment, the tab pressing claw 7-6 is an overall L-shaped structure, and the part of its gold front end used to press the tab forms a U-shaped opening groove structure or a concave structure, which is used to press and fix the foil tab and the edge of the L-shaped tab of the battery to improve the welding effect. After the tab is pressed at the edge, the welding head is used to perform welding at the U-shaped opening position.

[0027] Among them, the welding head is a T-shaped structure, and its welding tooth width is smaller than the opening width of the tab pressure claw 7-6 to facilitate welding. The welding equipment is an ultrasonic welding equipment, which melts the tab glue through ultrasound to achieve welding.

[0028] As a preferred embodiment, there are two positioning frames, which are symmetrically installed and fixed on the bottom plate, and are used for left and right positioning when welding the battery. When in use, the battery to be welded is placed between the welding seat and the pressure plate of the battery pressure plate assembly, and then positioned with the positioning frame, and finally pressed by the pressure plate to achieve compression or clamping of the battery. When the battery is positioned on the left side of the positioning frame, positive electrode welding can be performed, and when it is positioned on the right side, negative electrode welding can be performed.

[0029] As a preferred embodiment, the pressure plate 9-10 is L-shaped and is fixed on the linear slide rail 2 9-3 through its horizontal part; the linear slide rail 2 9-3 is installed on the positioning base plate 9-4, and the positioning base plate 9-4 is installed on the base plate 1, which plays a supporting connection and battery bottom positioning role, and together with the positioning frame 8, positions the battery.

[0030] There are two linear guide rails 9-3, which are symmetrically installed and fixed on the positioning base plate 9-4, and their axial directions are consistent with the clamping direction of the pressure plate.

[0031] Furthermore, a knob plunger 9-1 is arranged at one end of the positioning base plate 9-4 and is mounted on a plunger mounting plate 9-2. The plunger mounting plate 9-2 is fixed to the base plate 1. A matching plunger hole (not shown) is opened on the side of the horizontal portion of the pressing plate. The knob plunger is connected to the plunger hole. The pressing plate 9-10 can be fixed in the waiting position by using the knob plunger 9-1. After the pressing plate is pulled back, the knob plunger 9-1 is inserted into the plunger hole for positioning, thereby fixing the pressing plate in a certain position. When the pressing plate needs to be moved forward, the knob plunger 9-1 can be pulled out.

[0032] As a preferred embodiment, a handle 9-9 is installed on the horizontal part of the pressure plate 9-10, and the handle 9-9 facilitates the pushing and pulling of the pressure plate to move linearly along the linear guide rail 2 9-3.

[0033] As a preferred embodiment, a guide column mounting plate 9-5 is vertically mounted on the positioning base plate, and a horizontally arranged guide column 9-6 is mounted on the guide column mounting plate, one end of the guide column 9-6 passes through the guide column mounting plate 9-5, and the other end passes through a circular guide hole (not shown) formed on the side end surface of the horizontal portion of the pressure plate 9-10; a spring 9-8 is mounted on the guide column, and the spring 9-8 is located between the guide column mounting plate and the horizontal portion of the pressure plate, and is always in a compressed state, which can provide a force for the pressure plate 9-10 to tightly fix the battery, and the outer end of the guide column 9-6 is fixed by a locking nut 9-7.

[0034] Among them, one end of the guide column can be configured with a stepped thread and cooperate with the locking nut 9-7 to facilitate installation and fixation on the guide column mounting plate 9-5.

[0035] As a preferred embodiment, the tab pressing claw 7-6 is in an L-shaped structure as a whole, and its vertical portion is connected to a linear slide rail 7-1, and moves up and down along the linear slide rail 7-1, and the linear slide rail is installed and fixed on the pressure plate 9-10.

[0036] Among them, a bolt 2 7-5 is provided on the vertical part of the tab pressing claw 7-6, and a Z-shaped fixing plate 7-2 is provided below the tab pressing claw 7-6, and the fixing plate 7-2 is installed and fixed on the pressure plate 9-10; a bolt 1 7-3 is installed and fixed on the fixing plate 7-2 through a threaded connection; a spring 1 7-4 is arranged between the bolt 1 and the bolt 2, and the spring 1 7-4 is a tension spring, and its two ends are respectively hung on the bolt 1 and the bolt 2; the spring 1 is always in a tension state, and through the transmission of the force of the bolt 1 and the bolt 2, it provides a force for the tab pressing claw to press and fix the battery foil tab and the L-shaped tab.

[0037] When using the device of the present invention to weld the tabs of a soft-pack laminated battery, the following steps may be referred to:

[0038] (1) Cut the foil tab 6-1 on the battery to a suitable size, which is less than or equal to the thickness of the battery;

[0039] (2) Place the cut battery upright between the pressing plate and the welding seat, and after positioning it with the positioning frame, use the pressing plate to press and fix the battery;

[0040] (3) Insert one end of the L-shaped tab 5 into the battery tab positioning groove 3-1 of the welding base, and the tab glue 5-1 of the L-shaped tab is stuck in the notch of the battery tab positioning groove 3-1 of the welding base to complete the positioning of the L-shaped tab 5;

[0041] (4) Lift the tab pressing claw to press and fix the upper end of the L-shaped tab and the foil tab 6-1 on the battery;

[0042] (5) Trigger the ultrasonic welding equipment and use the welding head to weld the L-shaped tab 5 and the foil tab 6-1 to complete the soft-pack battery tab welding.

[0043] The structure of the battery after the tabs are welded is shown below: Figure 7 shown.

[0044] The embodiment of the present invention eliminates the pre-welding step of the foil tabs through the structural design of the device and the optimization of the process, integrates the pre-welding and final welding, reduces the turnover frequency of the battery cells, reduces the risk of tab welding cracks, greatly reduces the battery self-discharge rate, and improves the welding yield rate.

[0045] The L-shaped tab welding device for a laminated battery disclosed in an embodiment of the present invention has a compact structure and is easy to operate. It adopts a vertical welding method of the L-shaped tab, which solves the welding and positioning problems of soft-pack laminated batteries in a narrow space, improves the space utilization rate of the soft-pack laminated battery, and improves the volume energy density of the soft-pack laminated battery.

[0046] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0047] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A laminated battery L-shaped tab welding device, characterized in that: It includes a base fixed on the bottom plate, a battery pressing plate assembly, and a positioning frame for positioning the battery. A welding seat is arranged on the base, and a battery pole ear limiting groove for positioning the L-shaped pole ear of the battery is formed on the welding seat. The battery pressing plate assembly includes a pressing plate for pressing the battery positioned by the positioning frame when welding the battery. The pressing plate and the welding seat are arranged opposite to each other to form a battery positioning space therebetween. When welding, the battery is placed upright between the pressing plate and the welding seat; one end of the L-shaped pole ear is inserted into the battery pole ear positioning groove, and the pole ear glue of the L-shaped pole ear is stuck in the notch of the battery pole ear positioning groove to complete the positioning of the L-shaped pole ear. The positioning frame is located outside the battery positioning space, and the pressing plate can press the battery onto the welding seat by horizontally moving toward the welding seat; a tab pressing assembly is provided on the pressing plate, and the tab pressing assembly includes a tab pressing claw, which is used to press and fix the L-shaped tab and the foil tab of the battery after the L-shaped tab is inserted into the battery tab positioning groove for positioning, and then welded by the welding head above the welding seat; the tab pressing claw is L-shaped as a whole, and the front end of the horizontal part forms a U-shaped opening groove structure, which is used to press and fix the foil tab of the battery and the edge of the L-shaped tab, and then welded by the welding head at the position of the U-shaped opening; The vertical part of the tab pressing claw is connected to the linear slide rail 1, and moves linearly along the linear slide rail 1, and the linear slide rail 1 is installed and fixed on the pressure plate; a bolt 2 is arranged on the vertical part of the tab pressing claw, and a fixing plate is arranged below the tab pressing claw, and the fixing plate is installed and fixed on the pressure plate; the bolt 1 is installed and fixed on the fixing plate; the two ends of the spring 1 are respectively hung on the bolt 1 and the bolt 2; the spring 1 is a tension spring, which is always in a tension state, and provides a force for the tab pressing claw to press and fix the foil tab and the L-shaped tab of the battery through the transmission of the force of the bolt 1 and the bolt 2; the welding seat has a tab support boss that is pressed and matched with the tab pressing claw, and after the vertical part of the L-shaped tab of the battery is vertically inserted into the battery tab limiting groove, its horizontal part is just located at the top of the tab support boss and the vertical part is in contact with the side surface of the tab support boss; the slot width of the battery tab positioning groove on the welding seat is smaller than the width of the tab glue on the L-shaped tab.

2. The L-shaped tab welding device for laminated batteries according to claim 1, characterized in that: There are two positioning frames, which are symmetrically installed and fixed on the bottom plate and are used for left and right positioning when welding the battery.

3. The L-shaped tab welding device for laminated batteries according to claim 1, characterized in that: The pressure plate is L-shaped and is fixed on the second linear slide rail through its horizontal portion; the second linear slide rail is installed on the positioning base plate, and the positioning base plate is installed on the base plate to play a supporting connection and battery bottom positioning role.

4. The L-shaped tab welding device for laminated batteries according to claim 1, characterized in that: A knob plunger is arranged at one end of the positioning base plate and mounted on a plunger mounting plate. The plunger mounting plate is fixed to the base plate. A matching plunger hole is opened on the side of the horizontal part of the pressure plate. The knob plunger is connected to the plunger hole. The pressure plate can be fixed in the waiting position by the knob plunger.

5. The L-shaped tab welding device for laminated batteries according to claim 1, characterized in that: A guide column mounting plate is vertically mounted on the positioning base plate, and a horizontally arranged guide column is mounted on the guide column mounting plate. One end of the guide column passes through the guide column mounting plate, and the other end passes through a circular guide hole formed on the side end surface of the horizontal portion of the pressure plate. A second spring is mounted on the guide column, and the second spring is located between the guide column mounting plate and the horizontal portion of the pressure plate. The spring is always in a compressed state to provide a force for the pressure plate to tightly fix the battery.

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