Battery tab welding area structure

Abstract

A battery tab welding area structure belongs to the technical field of battery structures, and adopts the specific scheme that the battery tab welding area structure comprises a coating layer, two nickel sheets and a plurality of tab welding pole pieces which are sequentially stacked, the two nickel sheets are respectively arranged on the upper surfaces and the lower surfaces of the plurality of tab welding sheets which are sequentially stacked to form a first structure unit, and the coating layer tightly coats the outer side of the first structure unit to form a second structure unit; and the laser irradiates the second structural unit from top to bottom to weld the second structural unit on the cover plate adapter plate. By using the tab welding area structure disclosed by the utility model, the energy density of a battery is improved, the conductivity of the tab is improved, the problem of insufficient welding is solved, the safety is good, and the overall weight and the cost are reduced.

Description

Technical Field

[0001] This utility model belongs to the field of battery structure technology, specifically relating to a battery tab welding area structure. Background Technology

[0002] With the development of battery technology, the energy density requirements for lithium-ion / sodium-ion energy storage batteries are becoming increasingly higher, the capacity of single cells is increasing, and safety requirements are becoming more stringent. To meet market demands, the industry is increasingly researching the welding of the stacked thickness of positive and negative electrode sheets in single cells. Positive and negative electrode sheets are the substrates of lithium / sodium batteries, primarily serving to facilitate ion insertion / extraction, electron migration, and support battery materials. The more positive and negative electrode sheets are stacked, the larger the single cell capacity, but this also leads to a greater amount of foil used for the current collectors. These foils are typically made of pure metals, with aluminum and copper foil being the most common. Due to the high metal density of aluminum and copper foil, the more layers are stacked, the more difficult it becomes to weld the tabs. Currently, the maximum ultrasonic welding power in the industry is 6KW, and the maximum number of layers for welding 12µm aluminum foil is no more than 100, while the maximum number of layers for welding 4-6µm copper foil is no more than 80. Currently, the industry often welds multiple small cells, which is costly, involves complex welding processes, increases welding difficulty, and raises safety risks. Utility Model Content

[0003] In view of the technical problems of difficult welding, complex process, high cost and poor safety performance of the current collector tab welding area of ​​existing positive and negative electrode plates, this utility model provides a battery tab welding area structure.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A battery tab welding area structure includes a cladding layer, two nickel sheets, and a plurality of tab welding plates stacked sequentially. The two nickel sheets are respectively disposed on the upper and lower surfaces of the plurality of tab welding plates stacked sequentially to form a first structural unit. The cladding layer tightly covers the outside of the first structural unit to form a second structural unit. A laser irradiates the second structural unit from top to bottom and welds the second structural unit onto the cover plate adapter piece.

[0006] Furthermore, the electrode tab welding piece is a positive electrode tab welding piece or a negative electrode tab welding piece.

[0007] Furthermore, the thickness of the nickel sheet is 0.1-2 mm.

[0008] Furthermore, the coating layer is a metal foil layer. The metal foil layer is an aluminum foil layer or a copper foil layer. The thickness of the coating layer is 0.1-3 mm.

[0009] Furthermore, the length of the covering layer is greater than the perimeter of the first structural unit.

[0010] Furthermore, the cover plate adapter is a metal sheet.

[0011] Furthermore, the plurality of electrode tabs (3) stacked sequentially are stacked sequentially from bottom to top.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] (1) The battery tab welding area structure proposed in this utility model is simple in structure. The middle layer is a reserved area for positive and negative current collectors. Multiple layers can be stacked according to the size of the battery cell. After stacking, nickel sheets are placed on the upper and lower reserved areas for current collectors, and then coated and laser welded. Due to the high energy of the laser and the relatively concentrated beam, the nickel can increase the uniformity and stability of the alloy composition, and at the same time improve the corrosion resistance and heat resistance of the alloy. The laser energy can make nickel ions migrate and fill the uncompacted areas of the reserved areas for positive and negative current collectors, preventing the bursting, molten pool and cracking caused by the concentrated energy of laser welding, ensuring the quality and performance of the weld, and is suitable for welding ultra-thick multi-layer current collectors. Therefore, the structure of this utility model can effectively solve the limitation of total foil thickness on ultrasonic welding, eliminate the ultrasonic pre-welding process, speed up the production process, reduce production costs, and explore a new welding process that can weld more than 100 layers of current collector tab welding area, improve battery energy density, increase single cell energy, and solve the problems of difficult and incomplete ultrasonic welding of ultra-thick multilayer materials by using a laser with high energy and ultra-concentrated beam, ensuring the conductivity of the foil and improving battery safety.

[0014] (2) By changing the number of layers of the electrode current collector foil layer stacked in sequence, the number of cells in the battery can be reduced better without affecting the conductivity of the current collector foil layer. This simplifies the process, reduces production costs, optimizes the welding structure of the cells in the battery, and improves the energy density and capacity of the battery.

[0015] (3) Due to the above-mentioned electrode tab welding area structure, the positive and negative electrode sheets can not only effectively increase the number of electrode stacking layers of a single cell, reduce the number of single cells inside the battery, reduce the cover plate adapter piece welded to the single cell, but also simplify the internal structure of the battery, reduce the number of internal structural components, reduce the overall weight of the battery, reduce production costs, improve battery energy density and capacity, and improve battery safety.

[0016] (4) The battery using the electrode welding area structure described in this utility model has high energy density, good safety, and reduces overall weight and cost. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the electrode welding area structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the welding structure of the electrode lug welding area and the welding structure of the cover plate adapter piece of this utility model;

[0019] Figure 3 This is a schematic diagram of a battery cell structure using the electrode welding area structure described in this utility model;

[0020] In the diagram: 1. Coating layer, 2. Nickel sheet, 3. Electrode tab welding plate, 4. Cover plate adapter plate, 5. Battery cell, 6. Laser, 11. Excess part, 31. Positive electrode tab welding plate, 32. Negative electrode tab welding plate. Detailed Implementation

[0021] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0022] Example 1:

[0023] A battery tab welding area structure includes a covering layer 1, two nickel sheets 2, and a plurality of tab welding electrodes 3 stacked sequentially. The two nickel sheets 2 are respectively disposed on the upper and lower surfaces of the plurality of stacked tab welding electrodes 3 to form a first structural unit. The covering layer 1 tightly covers the outside of the first structural unit to form a second structural unit. A laser irradiates the second structural unit from top to bottom and welds the second structural unit to a cover plate adapter piece 4. Figure 1-3 As shown.

[0024] Furthermore, the electrode tab welding piece 3 is either a positive electrode tab welding piece 31 or a negative electrode tab welding piece 32.

[0025] Furthermore, the thickness of the nickel sheet 2 is 0.1-2 mm.

[0026] Furthermore, the covering layer 1 is a metal foil layer. Preferably, the metal foil layer is an aluminum foil layer or a copper foil layer.

[0027] Furthermore, the thickness of the covering layer 1 is 0.1-3 mm.

[0028] Furthermore, the length of the covering layer 1 is greater than the perimeter of the first structural unit, such as... Figure 1As shown, the purpose is to prevent the laser 6 from directly welding to the positive electrode tab welding plate 31 or the negative electrode tab welding plate 32. There are micro-gaps in the internal connection and contact surfaces of the positive electrode tab welding plate 31 or the negative electrode tab welding plate 32 under the covering layer 1. To prevent technical risks such as weld pools, cracking, and bursting points, nickel sheets 2 are respectively placed on the upper and lower surfaces of the electrode tab welding plate 3, forming a first structural unit. The covering layer 1 tightly covers the outside of the first structural unit, forming a second structural unit. After the second structural unit is fully welded to the cover plate adapter plate 4 by the laser 6, the excess part 11 of the covering layer 1 is manually trimmed, such as... Figure 2 As shown.

[0029] Furthermore, the cover plate adapter piece 4 is a metal sheet.

[0030] Furthermore, the plurality of electrode tabs 3 stacked sequentially are stacked from bottom to top.

[0031] In this invention, a single cell 5 is formed by alternately stacking several positive and negative electrode sheets. The more layers of positive and negative electrode sheets there are, the thicker the stack of the positive electrode tab welding sheet 31 and the negative electrode tab welding sheet 32 ​​becomes. Due to the high energy and concentrated beam of the laser 6, and the nickel sheets 2 placed on the upper and lower surfaces of the stacked electrode tab welding sheet 3, the number of single cells 5 and cover plate adapter pieces 4 in the ultra-thick multilayer current collector welding process is reduced, the structure of the cover plate adapter piece 4 is simplified, the overall weight of the single battery is reduced, the production cost is lowered, and the energy density, capacity, and safety performance of the battery are improved. Under the action of the laser, the addition of nickel sheets 2 can increase the uniformity and stability of the alloy composition, and also improve the corrosion resistance and heat resistance of the alloy. At the same time, nickel ions can migrate and fill the uncompacted areas of the electrode tab welding sheet, preventing bursting, molten pool, and cracking caused by concentrated laser welding energy, ensuring the quality and performance of the weld, and making it suitable for ultra-thick multilayer current collector welding processes. Currently, the maximum power of ultrasonic welding used in the industry is 6KW, and the maximum number of layers for welding 12um aluminum foil is no more than 100, while the maximum number of layers for welding 4-6um copper foil is no more than 80. Furthermore, the electrode tab welding area needs to be pre-welded before ultrasonic welding. Therefore, the structure of this utility model can effectively solve the limitation of ultrasonic welding on the total foil thickness, eliminate the ultrasonic pre-welding process, speed up the production process, reduce production costs, and explore a new welding process that can weld more than 100 layers of current collector electrode tab welding area, improve battery energy density, increase single cell energy, and solve the problems of difficult and incomplete ultrasonic welding of ultra-thick multilayer materials by lasers, ensuring the conductivity of the foil and improving battery safety.

[0032] To ensure weld strength, the thickness of the nickel sheet 2 can be adjusted according to the number of layers of the positive and negative electrode sheets before preparation. The thickness of the nickel sheet is typically 0.1-2mm. The width of the nickel sheet extends outward by 0-5mm compared to the sequentially stacked electrode tabs 3, depending on the battery product requirements.

[0033] In practical applications, compared to traditional ultrasonic welding, the laser welding process for the battery tab welding area structure described in this invention is simpler. The general steps are as follows: positive and negative electrode sheets are stacked using a stacking machine; nickel sheets 2 are placed on the upper and lower surfaces of the stacked cell; a coating layer 1 is applied; a cover plate adapter 4 is placed; and laser welding is performed. Placing the nickel sheets 2 is the core production step, followed by the coating. The entire battery tab welding area structure is primarily manufactured using laser welding. The battery cell 5 produced using this process is then supplied to downstream customers. Downstream customers can directly insert the cell 5 into the casing without needing to consider technical challenges such as tab welding. This not only effectively enhances battery safety, increases battery energy density and capacity, but also reduces overall weight and lowers raw material costs.

[0034] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A battery tab welding area structure, characterized in that: The structure includes a cladding layer (1), two nickel sheets (2), and several electrode tabs (3) stacked sequentially. The two nickel sheets (2) are respectively disposed on the upper and lower surfaces of the several electrode tabs (3) stacked sequentially to form a first structural unit. The cladding layer (1) tightly covers the outside of the first structural unit to form a second structural unit. The laser irradiates the second structural unit from top to bottom and welds the second structural unit onto the cover plate adapter piece (4).

2. The battery tab welding area structure according to claim 1, characterized in that: The electrode tab welding piece (3) is either a positive electrode tab welding piece (31) or a negative electrode tab welding piece (32).

3. The battery tab welding area structure according to claim 1, characterized in that: The thickness of the nickel sheet (2) is 0.1-2 mm.

4. The battery tab welding area structure according to claim 1, characterized in that: The covering layer (1) is a metal foil layer.

5. The battery tab welding area structure according to claim 4, characterized in that: The metal foil layer is an aluminum foil layer or a copper foil layer.

6. A battery tab welding area structure according to claim 1 or 4, characterized in that: The thickness of the coating layer (1) is 0.1-3 mm.

7. The battery tab welding area structure according to claim 1, characterized in that: The length of the covering layer (1) is greater than the perimeter of the first structural unit.

8. The battery tab welding area structure according to claim 1, characterized in that: The cover plate adapter piece (4) is a metal sheet.

9. The battery tab welding area structure according to claim 1, characterized in that: The plurality of electrode tabs (3) stacked sequentially are arranged from bottom to top.

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