Novel cylindrical aluminum shell battery cell and battery structure

Abstract

The utility model belongs to the technical field of lithium battery preparation, in particular to a novel cylindrical aluminum shell battery cell and battery structure, which comprises a positive plate, a negative plate, an aluminum shell and a diaphragm, the positive plate and the negative plate are wound through the diaphragm to form the cylindrical aluminum shell battery cell, and the positive plate and the negative plate have the same structure. A positive pole lug and a negative pole lug are respectively arranged on the positive pole piece and the negative pole piece, the positive pole lug consists of an aluminum strip piece and a positive pole foil blank area, and the negative pole lug consists of a copper-nickel strip piece or a nickel strip piece and a negative pole foil blank area; the positive plate is composed of a positive foil blank area and a positive slurry area, the upper surface of the positive foil blank area is coated with positive slurry to form the positive slurry area, the current collecting plate welding position structure is optimized, the welding quality is improved, and therefore the product percent of pass is improved; by optimizing the integral structure of the liquid holes and the current collecting plate, the rapid infiltration of the battery during liquid injection is realized, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery manufacturing technology, and in particular to a novel cylindrical aluminum-cased battery cell and battery structure. Background Technology

[0002] Currently, there are two main types of electrode structures: one is a full-tab or multi-tab structure where the edges of foil are cut and shaped to form the electrodes; the other is a single-tab structure where a single aluminum strip and nickel strip are welded together as the positive and negative electrodes. Cells using a single-tab structure have higher internal resistance, lower current carrying capacity, and poor heat transfer, resulting in lower cell performance. While full-tab or multi-tab structures can simplify the process and effectively reduce the battery's internal resistance, increasing energy density, the method of flattening and welding the current collector with full-tabs increases the thickness of the wound cell ends due to the stacked electrodes. This leads to significant metal shavings during flattening, which can puncture the separator and cause micro-short circuits, affecting the cell's long-term cycle performance. The method of flattening multi-tabs involves bending the vertical electrodes to make them contact each other for better current collection. However, the flattened ends are too tightly packed, directly blocking the ends of the cell's coating area, making it difficult to dry internal moisture and increasing the difficulty of electrolyte penetration. Meanwhile, regardless of whether it is a full-tab or multi-tab battery, the burrs on the electrode foil are relatively large during punching or cutting, which can easily cause short circuits in the battery. To address this issue, we propose a new cylindrical aluminum-cased cell and battery structure. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies, such as the method of flattening and welding current collectors with all tabs. The stacking of tabs increases the thickness of the wound cell ends, leading to significant metal shavings during flattening, which can puncture the separator and cause micro-short circuits, affecting the long-term cycle performance of the cell. While the method of flattening multiple tabs involves bending vertical tabs to allow them to contact each other for better current collection, the resulting tightness directly blocks the ends of the cell's coating area, making it difficult to dry internal moisture and increasing the difficulty of electrolyte penetration. Furthermore, both all-tab and multi-tab methods suffer from large burrs during the punching or cutting of the electrode foil, which can easily cause short circuits. Therefore, this invention proposes a novel cylindrical aluminum-cased cell and battery structure.

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

[0005] A novel cylindrical aluminum-cased battery cell and battery structure includes a positive electrode sheet, a negative electrode sheet, an aluminum shell, and a separator. The positive and negative electrode sheets are wound together by the separator to form a cylindrical aluminum-cased battery cell. The positive and negative electrode sheets have the same structure, each having a positive electrode tab and a negative electrode tab respectively. The positive electrode tab is composed of an aluminum strip and a blank area of ​​positive foil. The negative electrode tab is composed of a copper-nickel strip or a nickel strip and a blank area of ​​negative foil.

[0006] The positive electrode sheet is composed of a positive electrode foil blank area and a positive electrode slurry area. The upper surface of the positive electrode foil blank area is coated with positive electrode slurry to form a positive electrode slurry area. The foil surface has several foil blank areas of equal width, namely the positive electrode foil blank areas. The positive electrode tab is formed by ultrasonic welding to the aluminum strip on the positive electrode foil blank areas.

[0007] The width W1 of the plurality of positive electrode tabs is less than the width W of the blank area of ​​the positive electrode foil, and W ranges from 5 to 10 mm. The distance d between the welding position of the positive electrode tab and the end of the positive electrode sheet is 10 to 15 mm.

[0008] The positive and negative electrode tabs are rectangular in shape, and each has a liquid hole at one end. The liquid hole is divided into a positive electrode tab liquid hole and a negative electrode tab liquid hole, and its diameter D is 3-12mm.

[0009] The aluminum shell has a positive end cap assembly and a negative end cap assembly at its two ends, respectively. The positive end cap assembly and the negative end cap assembly have the same structure. The positive electrode tab is connected to the positive end cap assembly to form a conductive connection, and the negative electrode tab is connected to the negative end cap assembly to form a conductive connection.

[0010] As a preferred embodiment of this utility model, the positive electrode tab and the negative electrode tab are located at both ends of the cylindrical aluminum shell battery cell, and each positive electrode tab forms a certain angle with the positive end face of the cylindrical aluminum shell battery cell, with the angle between each pair of positive electrode tabs being 120°.

[0011] As a preferred embodiment of this utility model, the cylindrical aluminum shell battery cell is provided with a central hole, and the positive electrode tab liquid hole and the negative electrode tab liquid hole are respectively aligned with the central hole.

[0012] As a preferred embodiment of this utility model, the positive electrode cap assembly includes a positive electrode current collector plate welded to the positive electrode tab and a positive electrode cap plate integrally formed at the end of the aluminum shell; one end of the positive electrode current collector plate adopts a circular structure.

[0013] As a preferred embodiment of this utility model, the positive electrode current collector is provided with a positive electrode welding position, a positive electrode current collector liquid hole and a positive electrode current collector center hole, and the other end of the positive electrode current collector is a positive electrode connecting piece with a semi-circular structure.

[0014] In a preferred embodiment of this utility model, the outer diameter of the positive current collector is smaller than the outer diameter of the cylindrical aluminum shell battery cell. The positive current collector is welded to the positive terminal face of the cylindrical aluminum shell battery cell, and the positive welding position is tightly fitted to the positive electrode tab of the cylindrical aluminum shell battery cell.

[0015] As a preferred embodiment of this utility model, the positive electrode welding position and the positive electrode manifold liquid hole are provided in three sets, and the three sets of positive electrode welding positions and positive electrode manifold liquid holes are arranged alternately.

[0016] As a preferred embodiment of this utility model, the shape of the positive electrode welding position is consistent with the shape of the positive electrode tab, and its width is smaller than the width W of the blank area of ​​the positive electrode foil. The holes of the positive electrode current collector are arranged in groups of three circular holes, and the surface of the positive electrode current collector is arranged radially around the central hole of the positive electrode current collector. Beneficial effects

[0017] 1. This utility model provides uncoated foil areas in the middle of both the negative and positive electrode sheets. Multiple aluminum and nickel strips are welded into the uncoated foil areas and wound into a battery cell to form negative and positive electrode tabs. This makes the battery's conductive path no longer dependent on a single tab. The current is transmitted along three or more tabs simultaneously instead of along a single tab, thereby shortening the current transmission distance, effectively reducing the battery's internal resistance, improving the battery's charging and discharging efficiency, increasing the current transmission area, reducing losses, and improving the battery's heat dissipation.

[0018] 2. The positive and negative electrode tabs of the cylindrical aluminum shell battery cell of this utility model are respectively welded to the blank area of ​​the foil with three or more aluminum strips or nickel strips. This avoids the safety hazards caused by excessive burrs caused by cutting the edges of the full tabs or multiple tabs and the inability to effectively remove the metal powder generated during the rolling process, which may cause short circuits inside the battery cell. It also avoids the problem of slow liquid injection and wetting efficiency caused by flattening and welding the current collector with multiple tabs. This improves the yield rate of battery processing and the production efficiency of the production line.

[0019] 3. This utility model can, under completely existing process equipment, change the structure of the battery cell tabs and the current collector, so that the electrolyte can be distributed more quickly and evenly in all parts of the electrode, ensuring the wetting effect of the electrolyte injection and improving product quality.

[0020] 4. This utility model improves welding quality and thus increases product qualification rate by optimizing the welding position structure of the current collector plate; it also improves production efficiency by optimizing the overall structure of the liquid hole and current collector plate to achieve rapid immersion during battery liquid injection. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the coating between the positive electrode plates of the cylindrical aluminum shell battery cell of this utility model;

[0022] Figure 2 This is a schematic diagram of the coating between the negative electrode plates of the cylindrical aluminum shell battery cell of this utility model.

[0023] Figure 3 This is a schematic diagram of the cylindrical aluminum shell battery cell of this utility model;

[0024] Figure 4 This is a schematic diagram of the positive electrode tab of the cylindrical aluminum shell battery cell of this utility model after being folded over;

[0025] Figure 5 This is a top perspective view of the positive end of the cylindrical aluminum shell battery cell of this utility model;

[0026] Figure 6 This is a schematic diagram of the cylindrical aluminum shell battery structure assembly of this utility model;

[0027] Figure 7 This is an exploded view of the cylindrical aluminum-cased battery structure of this utility model;

[0028] Figure 8 This is a schematic diagram of the positive terminal structure of the cylindrical aluminum-cased battery of this utility model;

[0029] Figure 9 This is a schematic diagram of the negative terminal structure of the cylindrical aluminum-cased battery of this utility model;

[0030] Figure 10 This is a left and right isometric schematic diagram of the positive terminal structure of the cylindrical aluminum-cased battery of this utility model;

[0031] Figure 11 This is a left and right isometric schematic diagram of the negative terminal structure of the cylindrical aluminum-cased battery of this utility model.

[0032] In the diagram: 1. Cylindrical aluminum-cased battery cell; 2. Positive electrode sheet; 21. Blank area of ​​positive electrode foil; 22. Positive electrode slurry area; 23. Positive electrode tab; 231. Liquid hole of positive electrode tab; 3. Negative electrode sheet; 31. Blank area of ​​negative electrode foil; 32. Negative electrode slurry area; 33. Negative electrode tab; 331. Liquid hole of negative electrode tab; 4. Center hole of battery cell; 5. High-temperature protective adhesive; 6. Positive electrode cap assembly; 61. Positive electrode cap... 62. Positive electrode cover plate; 621. Positive electrode current collector plate liquid hole; 622. Positive electrode soldering position; 623. Positive electrode current collector plate center hole; 624. Positive electrode connecting piece; 7. Aluminum shell; 8. Negative electrode end cap assembly; 81. Negative electrode cover plate; 82. Negative electrode current collector plate; 821. Negative electrode current collector plate liquid hole; 822. Negative electrode soldering position; 823. Negative electrode current collector plate center hole; 824. Negative electrode connecting piece. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Example

[0034] Reference Figures 1-11 A novel cylindrical aluminum shell battery cell and battery structure, comprising a positive electrode 2, a negative electrode 3 and a separator, wherein the positive electrode 2 and the negative electrode 3 are wound together by the separator to form a cylindrical aluminum shell battery cell 1.

[0035] In this embodiment, positive electrode tabs 23 and negative electrode tabs 33 are respectively provided on the positive electrode plate 2 and the negative electrode plate 3; the positive electrode tab 23 is composed of an aluminum strip and a blank area 21 of the positive electrode foil; the negative electrode tab 33 is composed of a copper-nickel strip or a nickel strip and a blank foil 31 of the negative electrode; this structure avoids the problem of large burrs on the edge of the foil piercing the diaphragm caused by laser cutting or mold cutting of the foil.

[0036] In this embodiment, taking the positive electrode sheet 2 as an example: the positive electrode sheet 2 is composed of a positive electrode foil blank area 21 and a positive electrode slurry area 22. The positive electrode slurry is coated on the entire positive electrode foil blank area 21 to form the positive electrode slurry area 22. The foil surface has several foil blank areas of equal width, namely the positive electrode foil blank areas 21. The positive electrode tab 23 is formed by ultrasonic welding with the aluminum strip on the positive electrode foil blank area 21. This ensures the reliability of the connection between the positive electrode foil blank area 21 and the positive electrode tab 23.

[0037] In this embodiment, the width W1 of the plurality of positive electrode tabs 23 is smaller than the width W of the blank area 21 of the positive electrode foil; the range of W is 5-10mm, and the distance d between the welding position of the positive electrode tab 23 and the end of the positive electrode sheet 2 is 10-15mm.

[0038] In this embodiment, after the positive electrode tab 23 is welded to the blank area 21 of the positive electrode foil, a layer of high-temperature protective adhesive 5 is covered on the surface to protect the welding area. The width W3 of the high-temperature protective adhesive 5 is greater than the width W of the blank area 21 of the positive electrode foil. In this way, multiple positive electrode tabs 23 are led out, which shortens the current transmission distance, effectively reduces the internal resistance of the battery, improves the charging and discharging efficiency of the battery, and effectively increases the current transmission area, reduces losses, and improves the heat dissipation of the battery.

[0039] In this embodiment, the positive electrode tab 23 (aluminum strip) and the negative electrode tab 33 (copper-nickel strip or nickel strip) are rectangular in shape, and one end is provided with a liquid hole; the liquid hole is divided into positive electrode tab liquid hole 231 and negative electrode tab liquid hole 331, and its diameter D is 3-12mm (which can be set according to the diameter of the cylindrical cell winding needle); it can quickly conduct the heat inside the cylindrical aluminum shell cell 1 to the outside, avoid heat accumulation inside the battery, and improve the safety of use.

[0040] In this embodiment, a cylindrical aluminum shell battery cell 1 is formed by winding the above positive electrode 2 and negative electrode 3. The positive electrode tab 23 and the negative electrode tab 33 are respectively located at both ends of the cylindrical aluminum shell battery cell 1. Each positive electrode tab 23 forms a certain angle with the positive end face of the cylindrical aluminum shell battery cell 1, and the angle between each pair of positive electrode tabs 23 is set at 120°. Similarly, the negative electrode tab 33 is set in the same way.

[0041] In this embodiment, after the positive electrode tab 23 and the negative electrode tab 33 are folded and attached to the two ends of the cylindrical aluminum shell battery cell 1, the liquid holes 231 of the positive electrode tab and the liquid holes 331 of the negative electrode tab are aligned with the center holes 4 of the battery cell at both ends of the cylindrical aluminum shell battery cell 1. Gas and electrolyte can flow through these liquid holes, which can effectively reduce the difficulty of baking moisture and the difficulty of electrolyte penetration.

[0042] In this embodiment, the negative electrode 3 (negative electrode foil blank area 31, negative electrode slurry area 32, negative electrode tab 33 and negative electrode tab liquid hole 331) has the same structure as the positive electrode 2 (positive electrode foil blank area 21, positive electrode slurry area 22, positive electrode tab 23 and positive electrode tab liquid hole 231), and will not be described in detail here.

[0043] In this embodiment, there are aluminum shells 7, cylindrical aluminum shell battery cells 1, and positive terminal cover 6 and negative terminal cover 8 respectively disposed at both ends of the aluminum shells 7; wherein the positive terminal tab 23 is connected to the positive terminal cover 6 to form conductivity, and the negative terminal tab 33 is connected to the negative terminal cover 8 to form conductivity.

[0044] In this embodiment, taking the positive end cap assembly 6 as an example: the positive end cap assembly 6 includes a positive current collector 62 welded to the positive current collector tab 23 and a positive current cover plate 61 integrally formed on the end of the aluminum shell 7; wherein one end of the positive current collector 62 adopts a circular structure, and the positive current collector 62 is provided with a positive current welding position 622, a positive current collector liquid hole 621 and a positive current collector center hole 623; the other end of the positive current collector 62 is a positive current connecting piece 624 with a semi-circular structure, and the positive current connecting piece 624 forms a 120° angle with one end of the positive current collector 62, and the positive current connecting piece 624 is connected to the positive current cover plate 61 by welding;

[0045] In this embodiment, when the positive current collector 62 is welded to the positive terminal of the cylindrical aluminum shell cell 1, it is positioned by the cell center hole 4, which can ensure the positioning and concentricity of the positive current collector 62. At the same time, the positive current collector center hole 623 of the positive current collector 62 can also simultaneously satisfy the positioning and concentricity of the positive cover plate 61.

[0046] In this embodiment, as Figure 6As shown, the outer diameter of the positive current collector 62 is smaller than the outer diameter of the cylindrical aluminum shell cell 1. The positive current collector 62 is welded to the positive end face of the cylindrical aluminum shell cell 1. The positive welding position 622 and the positive electrode tab 23 of the cylindrical aluminum shell cell 1 are positioned by the positive current collector center hole 623, the positive electrode tab liquid hole 231, the cylindrical aluminum shell cell 1 and the cell center hole 4, so that the two are in close contact and are connected by laser welding. This ensures the contact area between the positive electrode tab 23 and the positive current collector 62, improves the current carrying capacity, and at the same time, the positive electrode tab 23 does not cover the entire end face of the cylindrical aluminum shell cell 1 after welding with the positive current collector 62, which is conducive to the rapid penetration of electrolyte into the interior of the cylindrical aluminum shell cell 1 during liquid injection, and greatly shortens the liquid injection time.

[0047] In this embodiment, three sets of positive electrode soldering positions 622 and positive electrode current collector liquid holes 621 are provided respectively, and the three sets of positive electrode soldering positions 622 and positive electrode current collector liquid holes 621 are staggered. The shape of the positive electrode soldering position 622 is consistent with the shape of the positive electrode tab 23, and its width is smaller than the width W of the positive electrode foil blank area 21. The holes of the positive electrode current collector liquid holes 621 are three circular holes in a group, arranged radially around the central hole 623 of the positive electrode current collector on the surface of the positive electrode current collector 62. The rectangular design can increase the contact length between the positive electrode soldering position 622 and the positive electrode tab 23 at the end of the cylindrical aluminum shell cell 1, thereby increasing stability. The wavy solder mark is welded to the end face of the tab of the cylindrical aluminum shell cell 1, thereby extending the welding line length and making the welding between the positive electrode current collector 62 and the end face of the cylindrical aluminum shell cell 1 more stable, and less prone to short circuits caused by poor soldering.

[0048] In this embodiment, the negative end cap assembly 8 (negative end cap plate 81, negative end manifold 82, negative end manifold liquid hole 821, negative end soldering position 822, negative end manifold center hole 823 and negative end connecting piece 824) has the same structure as the positive end cap assembly 6 (positive end cap plate 61, positive end manifold 62, positive end manifold liquid hole 621, positive end soldering position 622, positive end manifold center hole 623 and positive end connecting piece 624), and will not be described in detail here.

[0049] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A novel cylindrical aluminum-cased battery cell and battery structure, characterized in that, The battery includes a positive electrode (2), a negative electrode (3), an aluminum shell (7), and a separator. The positive electrode (2) and the negative electrode (3) are wound together by the separator to form a cylindrical aluminum shell battery cell (1). The positive electrode (2) and the negative electrode (3) have the same structure and are provided with positive electrode tabs (23) and negative electrode tabs (33) respectively. The positive electrode tab (23) is composed of an aluminum strip and a blank area (21) of the positive electrode foil. The negative electrode tab (33) is composed of a copper-nickel strip or a nickel strip and a blank area (31) of the negative electrode foil. The positive electrode sheet (2) is composed of a positive electrode foil blank area (21) and a positive electrode slurry area (22). The positive electrode foil blank area (21) is coated with positive electrode slurry to form a positive electrode slurry area (22). The foil surface has several foil blank areas of equal width, namely the positive electrode foil blank areas (21). The positive electrode foil blank areas (21) are formed by ultrasonic welding with aluminum strip to form a positive electrode tab (23). The width W1 of the multiple positive electrode tabs (23) is less than the width W of the blank area (21) of the positive electrode foil, and the range of W is generally 5-10 mm. The welding position of the positive electrode tab (23) is d from the end of the positive electrode sheet (2), and the range of d is generally 10-15 mm. The positive electrode tab (23) and the negative electrode tab (33) are rectangular in shape and have liquid holes at one end. The liquid holes are divided into positive electrode tab liquid holes (231) and negative electrode tab liquid holes (331), and their diameter D is 3-12 mm. The aluminum shell (7) is provided with a positive end cap assembly (6) and a negative end cap assembly (8) at its two ends respectively. The positive end cap assembly (6) and the negative end cap assembly (8) have the same structure. The positive electrode tab (23) is connected to the positive end cap assembly (6) to form a conductive connection, and the negative electrode tab (33) is connected to the negative end cap assembly (8) to form a conductive connection.

2. The novel cylindrical aluminum shell battery cell and battery structure according to claim 1, characterized in that, The positive electrode tab (23) and negative electrode tab (33) are located at both ends of the cylindrical aluminum shell cell (1). Each positive electrode tab (23) forms a certain angle with the positive end face of the cylindrical aluminum shell cell (1), and the angle between each pair of positive electrode tabs (23) is set at 120°.

3. The novel cylindrical aluminum-cased battery cell and battery structure according to claim 1, characterized in that, The cylindrical aluminum shell battery cell (1) is provided with a central hole (4), and the positive electrode tab liquid hole (231) and the negative electrode tab liquid hole (331) are respectively aligned with the central hole (4).

4. The novel cylindrical aluminum shell battery cell and battery structure according to claim 1, characterized in that, The positive electrode cap assembly (6) includes a positive electrode current collector (62) welded to the positive electrode tab (23) and a positive electrode cap plate (61) integrally formed on the end of the aluminum shell (7); one end of the positive electrode current collector (62) adopts a circular structure.

5. The novel cylindrical aluminum-cased battery cell and battery structure according to claim 4, characterized in that, The positive electrode collector plate (62) is provided with a positive electrode soldering position (622), a positive electrode collector plate liquid hole (621) and a positive electrode collector plate center hole (623), and the other end of the positive electrode collector plate (622) is a positive electrode connecting piece (624) with a semi-circular structure.

6. The novel cylindrical aluminum-cased battery cell and battery structure according to claim 4, characterized in that, The outer diameter of the positive current collector (62) is smaller than the outer diameter of the cylindrical aluminum shell cell (1). The positive current collector (62) is welded to the positive end face of the cylindrical aluminum shell cell (1), and the positive welding position (622) is closely attached to the positive electrode tab (23) of the cylindrical aluminum shell cell (1).

7. The novel cylindrical aluminum-cased battery cell and battery structure according to claim 5, characterized in that, The positive electrode welding position (622) and the positive electrode manifold liquid hole (621) are respectively provided in three sets, and the three sets of positive electrode welding positions (622) and positive electrode manifold liquid holes (621) are arranged alternately.

8. The novel cylindrical aluminum-cased battery cell and battery structure according to claim 5, characterized in that, The shape of the positive electrode welding position (622) is consistent with the shape of the positive electrode tab (23), and its width is smaller than the width W of the blank area (21) of the positive electrode foil. The holes of the positive electrode collector plate liquid hole (621) are three circular holes arranged in a group, and the surface of the positive electrode collector plate (62) is arranged radially around the central hole (623) of the positive electrode collector plate.

Images