An electrode sheet, a lamination cell, and a soft package battery

Abstract

The application relates to a pole piece, a lamination core and a soft package battery. The pole piece body comprises a coating area and a hollow foil area at one end corner of the pole piece body. The other end corner of the pole piece body is provided with a notch area, and the notch area is formed by beveling the end corner of the pole piece body. The hollow foil area comprises two right-angle edges in the long side direction and the short side direction of the pole piece body. The intersection line of the hollow foil area and the coating area is a first intersection line. The angle between the right-angle edge of the hollow foil area in the short side direction of the pole piece body and the first intersection line ranges from 30 DEG to 60 DEG. The notch area comprises two right-angle edges in the long side direction and the short side direction of the pole piece body. The intersection line of the notch area and the coating area is a second intersection line. The angle between the right-angle edge of the notch area in the short side direction of the pole piece body and the second intersection line ranges from 30 DEG to 60 DEG. The pole piece is beneficial to the punching of the packaging film of the soft package battery, improves the battery energy density of the soft package battery, and realizes the packaging and edge folding operation of the left and right sides and the top of the soft package battery.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery technology, and in particular to an electrode, a stacked cell, and a pouch cell. Background Technology

[0002] Compared to metal-cased batteries, soft-pack lithium-ion batteries with aluminum-plastic film casings are increasingly used in power batteries, portable devices, and other fields due to their unique safety features and flexible design.

[0003] Laminated cells are the most common cell type for pouch batteries, such as... Figure 1 As shown, for pouch batteries, traditional outer packaging only seals and folds the aluminum-plastic film on the left and right sides. To ensure a good seal while maintaining the original structure, the top sealing edge is set to be relatively long (e.g., ...). Figure 1 (at point a in the text), but due to the presence of sealant, the top of the battery cannot be folded, resulting in a large overall loss of energy density (ED);

[0004] In order to achieve the top encapsulation and folding operation, such as Figure 2 As shown, other pouch cells often use irregularly shaped electrode structures, with complex-shaped electrode notches (such as...). Figure 2 , Figure 3 (at point b) During the process of punching the packaging film, the material is repeatedly stretched, and the angle of the punched edge is too small, which easily causes wrinkles to form at the edge of the punch, or even damage to the punch, affecting the sealing effect.

[0005] Therefore, the two existing methods mentioned above cannot be simultaneously compatible in achieving the folding of the aluminum-plastic film on the top of the battery without affecting the energy density and encapsulation effect. Summary of the Invention

[0006] Based on this, an electrode sheet, a stacked cell, and a pouch cell are provided, which facilitates the perforation of the packaging film of the pouch cell, improves the energy density gain of the pouch cell, and enables the encapsulation and folding operations on the left and right sides and top of the pouch cell.

[0007] On one hand, an electrode sheet is provided, comprising: a plurality of electrode sheet bodies; each electrode sheet body includes a coating area and an empty foil area located at one end corner of the electrode sheet body, and the empty foil area forms an electrode tab of the electrode sheet body; a notch area is provided at the other end corner of the plurality of electrode sheet bodies, the notch area being used to avoid the empty foil areas of adjacent electrode sheet bodies among the plurality of electrode sheet bodies; the notch area is formed by oblique cutting at the end corner of the electrode sheet body; the empty foil area includes two right-angled sides in the long side direction and the short side direction of the electrode sheet body, the boundary line between the empty foil area and the coating area is a first boundary line, and the angle between the right-angled side of the empty foil area in the short side direction of the electrode sheet body and the first boundary line is in the range of 30°-60°; the notch area includes two right-angled sides in the long side direction and the short side direction of the electrode sheet body, the boundary line between the notch area and the coating area is a second boundary line, and the angle between the right-angled side of the notch area in the short side direction of the electrode sheet body and the second boundary line is in the range of 30°-60°.

[0008] Furthermore, a preferred embodiment is that the angle between the right-angled side of the empty foil area in the short side direction of the electrode body and the first boundary line is in the range of 45°-60°; and the angle between the right-angled side of the notched area in the long side direction of the electrode body and the second boundary line is in the range of 45°-60°.

[0009] Furthermore, a preferred embodiment is that the electrode body has multiple end corners; the empty foil area is located on the first end corner of the electrode body; and the notch area is located on the second end corner symmetrically arranged with respect to the first end corner.

[0010] Further, a preferred embodiment is that the electrode body has a first side and a second side that are parallel to each other, a third side that is perpendicular to the first side, and a fourth side that is perpendicular to the second side; wherein, the notch area is located at the second corner formed by the first side and the third side; and the empty foil area is located at the first corner formed by the second side and the third side.

[0011] Furthermore, a preferred embodiment is that both the empty foil area and the notch area are set as right-angled triangles.

[0012] On the other hand, a stacked cell is also provided, comprising a plurality of the aforementioned electrodes and a plurality of separators, wherein the electrodes are configured as anode electrodes and cathode electrodes, the anode electrodes and the cathode electrodes are stacked alternately in sequence, and the separators are sandwiched between adjacent anode electrodes and cathode electrodes.

[0013] Further, a preferred embodiment is as follows: the empty foil area of ​​the anode electrode is located at a first position, and the notch area of ​​the cathode electrode avoids the empty foil area; the empty foil area of ​​the cathode electrode is located at a second position, and the notch area of ​​the anode electrode avoids the empty foil area; multiple empty foil areas located at the same first position are bundled together to form an anode tab group of the stacked battery cell; multiple empty foil areas located at the same second position are bundled together to form a cathode tab group of the stacked battery cell.

[0014] Furthermore, a soft-pack battery is also provided, comprising the aforementioned stacked battery cells, a packaging film, and at least two tab adapters, wherein: the stacked battery cells are housed within the packaging film; one of the tab adapters is electrically connected to the anode tab group of the stacked battery cells, with one end of the tab adapter electrically connected to the anode tab group and the other end extending to the outside of the packaging film to form a power transmission channel; and one of the tab adapters is electrically connected to the cathode tab group of the stacked battery cells, with one end of the tab adapter electrically connected to the cathode tab group and the other end extending to the outside of the packaging film to form a power transmission channel.

[0015] Furthermore, a preferred embodiment is that the packaging film includes a recess, a top sealing edge integrally formed in the recess, and two side sealing edges; the stacked battery cell is housed in the recess; the top sealing edge is connected to the stacked battery cell and bent at the top of the stacked battery cell; the two side sealing edges are respectively connected to the stacked battery cell and bent on the corresponding side surfaces.

[0016] Furthermore, a preferred embodiment is that the tab adapter is configured as a straight adapter or an irregularly shaped adapter; the straight adapter extends from the end corner of the packaging film along the oblique side perpendicular to the empty foil area; the irregularly shaped adapter includes a first segment and a second segment, the first segment extends from the end corner of the packaging film along the oblique side perpendicular to the empty foil area, and the second segment is integrally connected to the free end of the first segment and extends along the long side of the stacked battery cell.

[0017] Beneficial effects:

[0018] The aforementioned electrode, stacked cell, and pouch battery, through the design of the electrode shape, feature an empty foil area at one end corner and a notch area at the other end corner of the electrode body. Compared to the electrodes of traditional stacked cells, this application uses an empty foil area instead of the tab structure of traditional electrodes, which can reduce the gap between the packaging film and the electrode during packaging. Furthermore, the notch area is formed by oblique cutting at one end corner of the electrode body, such that the angle between the right-angled side of the notch area in the short side direction of the electrode body and the second boundary line is in the range of 30°-60°, and the angle between the right-angled side of the empty foil area in the short side direction of the electrode body and the second boundary line is also within the range of 30°-60°. The angle range of the first boundary line is also 30°-60°. Compared with the irregular electrode structure, this application adopts a bevel cutting method, which makes the electrode die-cutting notch simpler and the die-cutting edge smoother. Moreover, the edge angle of the packaging film is large, and it is not easy to form wrinkles when punching the packaging film, resulting in a good sealing effect. Compared with traditional stacked cells, this application can set the sealing and folding edges on both sides. Due to the special electrode structure design, the top can also be set with sealing and folding edges, and the top seal length is reduced, eliminating the traditional top seal, thereby improving the battery energy density of the soft pack battery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating that the top sealing plate of a traditional pouch cell cannot be folded.

[0020] Figure 2 A schematic diagram showing a traditional pouch cell configured with irregularly shaped electrode sheets.

[0021] Figure 3 for Figure 2 A partially enlarged schematic diagram of the irregularly shaped electrode structure;

[0022] Figure 4 This is a schematic diagram of the electrode structure in this embodiment;

[0023] Figure 5 This is a schematic diagram showing that the angle between the empty foil area and the notched area of ​​the anode electrode sheet in this embodiment is set to 45 degrees;

[0024] Figure 6 This is a schematic diagram showing that the angle between the empty foil area and the notched area of ​​the cathode electrode in this embodiment is set to 45 degrees;

[0025] Figure 7 This is a schematic diagram showing that the angle between the empty foil area and the notched area of ​​the anode electrode sheet in this embodiment is set to 30 degrees;

[0026] Figure 8 This is a schematic diagram showing that the angle between the empty foil area and the notched area of ​​the cathode electrode is set to 30 degrees in this embodiment;

[0027] Figure 9 This is a front view of the stacked battery cell in this embodiment;

[0028] Figure 10 This is a schematic diagram of the structure in this embodiment where the empty foil areas of the stacked battery cells are bundled together to form an anode tab group and a cathode tab group;

[0029] Figure 11 This is a front view of the pouch battery in this embodiment. Figure 1 ;

[0030] Figure 12 This is a partial schematic diagram of the connection between the irregularly shaped adapter plate and the anode tab group in this embodiment;

[0031] Figure 13 This is a front view of the pouch battery in this embodiment. Figure 2 ;

[0032] Figure 14 This is a partial schematic diagram of the connection between the straight adapter piece and the anode tab group in this embodiment;

[0033] Figure 15 This is a three-dimensional schematic diagram of the pouch battery in this embodiment;

[0034] Figure 16 This is a magnified view of a portion of the perforated area on the packaging film in this embodiment.

[0035] Reference numerals: 1. Electrode body; 11. Empty foil area; 12. Notch area; 13. Coated area; 14. First boundary line; 15. Second boundary line; 16. First side; 17. Second side; 18. Third side; 19. Fourth side; 2. Stacked cell; 21. Anode tab group; 22. Cathode tab group; 3. Packaging film; 31. Recess; 32. Top seal edge; 33. Side seal edge; 4. Tab adapter piece. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0037] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0038] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0039] The orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "middle," "longitudinal," "lateral," "horizontal," "inner," "outer," "radial," and "circumferential" used in this specification are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the purpose of simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] This application provides an electrode sheet, a stacked cell, and a pouch cell. By designing the shape of the electrode sheet, it is beneficial to punch holes in the packaging film of the pouch cell, thereby improving the energy density (ED) gain of the pouch cell and enabling the encapsulation and folding operations on the left and right sides and top of the pouch cell.

[0041] The electrode sheet provided in this embodiment will be described in detail below. Please refer to [link / reference]. Figure 4 As shown, it includes: multiple electrode bodies 1; each electrode body 1 includes a coating area 13 and an empty foil area 11 located at one corner of the electrode body 1, and the empty foil area 11 forms the electrode tab of the electrode body 1; a notch area 12 is provided at the other corner of the multiple electrode bodies 1, the notch area 12 is used to avoid the empty foil areas 11 of adjacent electrode bodies 1 in the multiple electrode bodies 1, so that two adjacent empty foil areas 11 of the same polarity can contact each other, wherein the notch area 12 is formed by oblique cutting at the corner of the electrode body 1; the empty foil area 11 includes two right-angled sides in the long side direction and the short side direction of the electrode body 1, the boundary line between the empty foil area 11 and the coating area 13 is the first boundary line 14, and the angle between the right-angled side of the empty foil area 11 in the short side direction of the electrode body 1 and the first boundary line 14 is in the range of 30°-60°. The notch area 12 includes two right-angled sides in the long and short sides of the electrode body 1. The boundary line between the notch area 12 and the coating area 13 is the second boundary line 15. The angle between the right-angled side of the notch area 12 in the short side direction of the electrode body 1 and the second boundary line 15 ranges from 30° to 60°. In this embodiment, the end corner of the electrode body 1 is the corner with an included angle formed at its end position. In this embodiment, the oblique cut is a method of obliquely cutting the end corner of the electrode body 1 at a certain angle.

[0042] In this embodiment, the empty foil area 11 at one corner of the electrode body 1 is used instead, changing the traditional way of the electrode extending from the head to the tab. This reduces the gap between the packaging film and the electrode during packaging. Simultaneously, the notch area 12 is formed by a bevel cut at one corner of the electrode body 1. Compared to the traditional irregular electrode structure (which has a rectangular structure cut at the corner, resulting in a vertical corner, a small angle at the punched edge, and easy wrinkling or even damage to the punched area, and is also difficult to close), this embodiment uses a bevel cut, making the electrode body 1... The die-cutting is simpler and the edges are smoother. The angle between the right-angled side of the notch area 12 in the short side direction of the electrode body 1 and the second boundary line 15 is in the range of 30°-60°. The angle between the right-angled side of the empty foil area 11 in the short side direction of the electrode body 1 and the first boundary line 14 is also in the range of 30°-60°. As a result, when the packaging film is punched in the subsequent packaging process, the punching edge angle is large, which makes it less likely to form wrinkles. The later sealing effect is good. Furthermore, the stacked cells formed by the electrode with this structure design can achieve sealing and folding operations on the left and right sides and the top.

[0043] Please continue to refer to Figure 4 As shown in this embodiment, it should be noted that the electrode body 1 is configured as a sheet structure with multiple end corners. The empty foil area 11 and the notch area 12 are respectively located at different end corner positions. Specifically, the empty foil area 11 is located on the first end corner of the electrode body 1, and the notch area 12 is located on the second end corner. The first end corner and the second end corner are symmetrically arranged with the center line of the electrode body 1 as a reference. In this embodiment, the electrode body 1 is set as a rectangle for detailed explanation. The rectangular electrode body 1 has a first side 16 and a second side 17 that are parallel to each other, and a third side 18 that is perpendicular to the first side 16 and a fourth side 19 that is perpendicular to the second side 17. The first side 16, the second side 17, the third side 18 and the fourth side 19 together form a closed rectangular structure. The rectangular electrode body 1 has four corners. The first corner is formed by the connection of the second side 17 and the third side 18, and the second corner is formed by the connection of the first side 16 and the third side 18. It can be understood that the first corner and the second corner are symmetrically arranged on the sheet-like surface of the electrode body 1 with reference to the center line perpendicular to the third side 18 and the fourth side 19. Therefore, in this embodiment, the empty foil area 11 is disposed on the first end corner formed by the second side 17 and the third side 18, and the notch area 12 is disposed on the second end corner formed by the first side 16 and the third side 18. That is, the notch area 12 and the empty foil area 11 are located at the two end corners of the same end of the electrode body 1.

[0044] Please continue to refer to Figure 4As shown, in one example, the empty foil area 11 and the notch area 12 are set to the same size and shape, and in this embodiment, the empty foil area 11 and the notch area 12 are symmetrically arranged on the sheet-like surface of the electrode body 1 with reference to the center line perpendicular to the third side 18 and the fourth side 19. Preferably, in this embodiment, the shape of both the empty foil area 11 and the notch area 12 is set as a right-angled triangle. In this embodiment, a right-angled triangle is obliquely cut off at the second end corner formed by the first side 16 and the third side 18 of the electrode body 1, thereby forming the notch area 12; an empty foil area 11 with the same shape and size as the cut right-angled triangle is set at the first end corner formed by the second side 17 and the third side 18 of the electrode body 1.

[0045] Please refer to Figures 4-8 As shown, in this embodiment, a right-angled triangle is obliquely cut off at the second end corner of the electrode body 1. Depending on different requirements, the cut-off right-angled triangle can have different shapes, such as an isosceles right-angled triangle, etc. In addition, while ensuring that the area of ​​the right-angled triangle is constant, the angle between the right-angled side of the right-angled triangle on the long side of the electrode body 1, that is, the acute angle between the hypotenuse and the third side 18 of the right-angled triangle, is defined as the first angle ∠1. The obtuse angle between the hypotenuse and the first side 16 of the right-angled triangle is defined as the second angle ∠2. The obtuse angle between the hypotenuse and the third side 18 of the right-angled triangle is defined as the second angle ∠3. In this embodiment, the size of the second angle ∠2 and the second angle ∠3 are adjusted by adjusting the size of the first angle ∠1.

[0046] It should be noted that the size of the first angle ∠1 affects the size of the area that can be accommodated for welding. A larger area that can accommodate welding essentially corresponds to a larger first angle ∠1, and a smaller area that can accommodate welding essentially corresponds to a smaller first angle ∠1. Furthermore, the size of the first angle ∠1 also affects the proportion of dent damage. For example, if the first angle ∠1 is set too small, the area that can be accommodated for welding will be too small. According to the principle of the sum of straight angles, the second angle ∠2 will also be too small. In this case, the corner at position a will be sharper and more prone to damage. Conversely, if the first angle ∠1 is set too large, the area that can be accommodated for welding will be too large. According to the principle of the sum of straight angles, the third angle ∠3 will be too small. In this case, the corner at position b will be sharper and more prone to damage.

[0047] In this embodiment, both excessively large and excessively small first angle ∠1 will lead to insufficient space for subsequent welding and cratering damage. Furthermore, if the area of ​​the right triangle is too large, it will also cause the electrode coating area to become smaller, resulting in energy density loss. Therefore, it is necessary to reasonably set the size of the first angle ∠1 between the hypotenuse and the third side 18 of the right triangle in the empty foil area 11 and the notch area 12. In this embodiment, the first angle ∠1 is set to 30°-60°. In other words, the range of the first angle ∠1 between the hypotenuse of the empty foil area 11, i.e., the first boundary line 14 and the third side 18, is set to 30°-60°, and the range of the first angle ∠1 between the hypotenuse of the notch area 12, i.e., the second boundary line 15 and the third side 18, is set to 30°-60°. More preferably, the first angle ∠1 is uniformly set to 45°-60°.

[0048] To better illustrate the effects of setting the first angle ∠1 to 30°-60° and 45°-60° in this embodiment, several cases with the first angle ∠1 set at 20°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, and 70° are compared and listed in Table 1 below:

[0049] Table 1

[0050] First angle ED Area that can accommodate welding Crater breakage ratio Example 1 30 102.13％(+2.13％) 68.71％(-31.29％) 0.2％ Example 2 35 101.51％(+1.51％) 79.50％(-20.50％) 0.2％ Example 3 40 100.81％(+0.81％) 89.97％(-10.03％) 0.1％ Example 4 45 100% (base) 100% (base) 0％ Example 5 50 99.03％(-0.97％) 109.64％(+0.64％) 0％ Example 6 55 97.84％(-2.16％) 118.65％(+18.65％) 0％ Example 7 60 96.31％(-3.69％) 127.08％(+27.08％) 0％ Comparative Example 1 20 103.21％(+3.21％) 46.36％(-53.64％) 0.5％ Comparative Example 2 70 91.19％(-8.81％) 141.70％(+41.70％) 0.5％

[0051] According to Table 1 above, taking the first angle ∠1 in Example 4 as 45 degrees as a baseline, when the first angle ∠1 is set to 20 degrees in Comparative Example 1, the energy density (ED) is 103.21%, which is 3.21% higher than in Example 4. However, the area of ​​the weldable region is 46.36%, which is 53.64% lower than in Example 2, and the crater breakage rate is as high as 0.5%. When the first angle ∠1 is set to 70 degrees in Comparative Example 2, the energy density (ED) is 91.19%, which is 8.81% lower than in Example 2. However, the area of ​​the weldable region is 141.70%, which is higher than in Example 2. The improvement was 41.70%, while the crater breakage rate was only 0.5%. This shows that if the first angle ∠1 is set too large, although the area that can be accommodated for welding is increased, the third angle ∠3 will be too small. The corner where the third angle ∠3 is located is sharper, and therefore more prone to breakage, resulting in a moderate crater breakage rate. Similarly, if the first angle ∠1 is set too small, the second angle ∠2 will be too small. The corner where the second angle ∠2 is located is sharper, and therefore more prone to breakage, resulting in a moderate crater breakage rate and a reduced area that can be accommodated for welding. Therefore, setting the first angle ∠1 too large or too small may lead to insufficient space for subsequent welding or a high crater breakage rate.

[0052] When the first angle ∠1 is set to 30 degrees in this embodiment 1, the energy density (ED) is 102.13%, which is 2.13% higher than that in embodiment 4. However, the area that can accommodate the welding area is 68.71%, which is 31.29% lower than that in embodiment 4. The crater breakage rate is as low as 0.2%.

[0053] When the first angle ∠1 is set to 35 degrees in this embodiment 2, the energy density (ED) is 101.51%, which is 1.51% higher than that in embodiment 4. However, the area that can accommodate the welding area is 79.50%, which is 20.50% lower than that in embodiment 4. The crater breakage rate is as low as 0.2%.

[0054] When the first angle ∠1 is set to 40 degrees in this embodiment 3, the energy density (ED) is 100.81%, which is 0.81% higher than that in embodiment 4. However, the area that can accommodate the welding area is 89.97%, which is 10.03% lower than that in embodiment 4. The crater breakage rate is as low as 0.1%.

[0055] When the first angle ∠1 is set to 50 degrees in this embodiment 5, the energy density (ED) is 99.03%, which is 0.97% lower than that in embodiment 4, but the area that can accommodate the welding area is 109.64%, which is 0.64% higher than that in embodiment 4, and the crater breakage rate is 0%.

[0056] When the first angle ∠1 is set to 55 degrees in this embodiment 6, the energy density (ED) is 97.84%, which is 2.16% lower than that in embodiment 4, but the area that can accommodate the welding area is 118.65%, which is 18.65% higher than that in embodiment 4, and the crater breakage rate is 0%.

[0057] When the first angle ∠1 is set to 60 degrees in this embodiment 7, the energy density (ED) is 96.31%, which is 3.69% lower than that in embodiment 4, but the area that can accommodate the welding area is 127.08%, which is 27.08% higher than that in embodiment 4, and the crater breakage rate is 0%.

[0058] Taking into account the three factors mentioned above—energy density (ED), area of ​​the weldable area, and crater breakage rate—in this embodiment, setting the first angle ∠1 to 30°-60° results in a reduction in the area of ​​the weldable area, but a low crater breakage rate. More preferably, setting the first angle ∠1 to 45°-60° increases the area of ​​the weldable area and results in a crater breakage rate of 0%.

[0059] In this embodiment, a stacked battery is also provided, including a plurality of the above-mentioned electrodes and a plurality of separators, wherein the electrodes are configured as anode electrodes and cathode electrodes, the anode electrodes and cathode electrodes are stacked alternately in sequence, and a separator is sandwiched between adjacent anode electrodes and cathode electrodes.

[0060] In one feasible method, multiple anode plates, cathode plates, and separators can be stacked in the following manner: anode plate, separator, cathode plate, separator, stacked cyclically in this order; or cathode plate, separator, anode plate, separator, stacked cyclically in this order; or the top and bottom surfaces of the anode plate are first hot-pressed together with the separator, then sequentially combined with the cathode plate, then combined with the anode plate, and so on, stacked cyclically in this order; or the top and bottom surfaces of the cathode plate are first hot-pressed together with the separator, then the anode plate and cathode plate are stacked cyclically in this order. The specific stacking of the anode plates, cathode plates, and separators is not specifically limited in this embodiment.

[0061] Please refer to Figure 9 , Figure 10 As shown in this embodiment, it should also be noted that the notch area 12 and the empty foil area 11 on the anode and cathode electrodes are arranged in opposite directions. In other words, the empty foil area 11 of the anode electrode is located in the first position, and the notch area 12 of the cathode electrode avoids the empty foil area 11 of the anode electrode; the empty foil area 11 of the cathode electrode is located in the second position, and the notch area 12 of the anode electrode avoids the empty foil area 11 of the cathode electrode. In this way, during stacking, multiple empty foil areas 11 located in the same first position are bundled together by welding or other composite methods to form an anode tab group 21 of a stacked battery 2, and in the anode tab group 21, at least a portion of the area between any two adjacent empty foil areas 11 is in contact with each other to form an electrical connection; multiple empty foil areas 11 located in the same second position are bundled together by welding or other composite methods to form a cathode tab group 22 of a stacked battery 2, and in the cathode tab group 22, at least a portion of the area between any two adjacent empty foil areas 11 is in contact with each other to form an electrical connection. The contact surfaces between the empty foil areas 11 of adjacent anode tab groups 21 and between the empty foil areas 11 of adjacent cathode tab groups 22 are fixedly connected by welding. Ultrasonic welding is preferred for the fixed connection, which can ensure the sealing and connection stability between the formed anode tab groups 21 and cathode tab groups 22.

[0062] It should also be noted that the shapes of the anode tab group 21 and the cathode tab group 22 formed above are both right-angled triangles.

[0063] Please refer to Figures 11-16As shown, in this embodiment, a soft-pack battery is also provided, including the aforementioned stacked battery cell 2, packaging film 3, and at least two tab adapter pieces 4. The stacked battery cell 2 is housed within the packaging film 3, and one of the tab adapter pieces 4 is electrically connected to the anode tab group 21 of the stacked battery cell 2, that is, one end of the tab adapter piece 4 is electrically connected to the anode tab group 21, and the other end extends to the outside of the packaging film 3 to form an energy transmission channel; one of the tab adapter pieces 4 is electrically connected to the cathode tab group 22 of the stacked battery cell 2, that is, one end of the tab adapter piece 4 is electrically connected to the cathode tab group 22, and the other end extends to the outside of the packaging film 3 to form an energy transmission channel.

[0064] The stacked battery cell 2 is encapsulated in the packaging film 3. One end of the tab adapter 4 is located inside the packaging film 3 and is electrically connected to the anode tab group 21 or the cathode tab group 22. The tab adapter 4 is electrically connected to the anode tab group 21 or the cathode tab group 22 by laser welding or ultrasonic welding. The position of the electrical connection can be at the center of the anode tab group 21 or the cathode tab group 22, or on both sides of the anode tab group 21 or the cathode tab group 22. No specific limitation is made in this embodiment.

[0065] In one example, due to the special design of the electrode, the electrode adapter 4 can be made of either a conventional straight adapter or an irregularly shaped adapter. The following explanation uses the connection of the electrode adapter 4 to the anode electrode group 21 as an example. (Refer to...) Figure 11 , Figure 12 As shown, when the tab adapter 4 is set as an irregularly shaped adapter, the irregularly shaped adapter includes a first section and a second section. The fixed end of the first section extends from the end corner of the packaging film 3 along the oblique side perpendicular to the empty foil area 11, i.e., the anode tab group 21. The second section is integrally connected to the free end of the first section and extends along the long side of the stacked cell 2. Since the first section of the irregularly shaped adapter extends from the end corner of the packaging film 3 along the oblique side perpendicular to the empty foil area 11, the overlapping area of ​​the end of the first section of the irregularly shaped adapter with the empty foil area 11, i.e., the contact welding area, is large, and the welding stability is high. At the same time, the second section of the irregularly shaped adapter extends along the long side of the stacked cell 2, so that it is on the same side as the long side of the stacked cell 2 and electrically connected to the external equipment. In this way, the overall width will not increase when the product battery is made, which can save space. However, the irregularly shaped adapter is not a standard part and has a high manufacturing cost.

[0066] Reference Figure 13 , Figure 14As shown, when the tab adapter 4 is set as a conventional straight adapter, the fixed end of the straight adapter extends from the end corner of the packaging film 3 along the inclined side perpendicular to the empty foil area 11, i.e., the anode tab group 21. When using a straight adapter, the fixed end of the straight adapter extends from the end corner of the packaging film 3 along the inclined side perpendicular to the empty foil area 11, i.e., the anode tab group 21. This ensures that the overlapping area between the straight adapter and the empty foil area 11, i.e., the contact welding area, is large, resulting in high welding stability. The straight adapter is a standard part, which is easy to manufacture and can save costs, but the width increases during subsequent packaging, which is not conducive to saving space. In this embodiment, there is no specific limitation on which type of tab adapter 4 is used, and it can be selected according to the actual situation.

[0067] In this embodiment, the end corner of the packaging film 3 is set to be exactly opposite to the end corner of the stacked battery cell 2 when the stacked battery cell 2 is stored; and the verticality described in this embodiment is not strictly vertical, and there may be an error of 5°.

[0068] In one feasible approach, to enhance sealing, sealant 5 is applied and fixedly connected between the surface of the packaging film 3 and the anode tab group 21, and between the surface of the packaging film 3 and the cathode tab group 22. The sealant 5 improves the sealing reliability of the top seal formed by the connection between the anode tab group 21 and the packaging film 3, and the top seal formed by the connection between the cathode tab group 22 and the packaging film 3, ensuring that the electrolyte in the laminated cell 2 is sealed inside the pouch battery, thereby improving the safety of the pouch battery. Preferably, the sealant 5 is a solid sealant that meets the requirements of the pouch battery's operating environment. The solid sealant's characteristic of not easily flowing around facilitates control of its placement, thus ensuring the sealing of the connection between the laminated cell 2 and the packaging film 3.

[0069] Reference Figure 15 , Figure 16 As shown in this embodiment, it should be noted that the packaging film 3 is pre-stamped with a recess 31, a top sealing edge 32 integrally formed in the recess 31, and two side sealing edges 33. The recess 31 is stamped according to the shape of the stacked battery cell 2, and the edge of the end of the recess can be adapted to the die-cut notch of the electrode body 1. The stacked battery cell 2 is placed in the stamped recess 31. Since the die-cut notch of the electrode body 1 forming the stacked battery cell 2 is simpler and the die-cut edge is smooth, when the packaging film 3 punches the recess during the packaging process, the edge angle of the recess is large, and wrinkles are not easily formed at the edge of the recess, resulting in a good sealing effect. The top sealing edge 32 of the packaging film 3 is connected to the stacked battery cell 2 and bent on the top surface, and the two side sealing edges 33 are respectively connected to the stacked battery cell 2 and bent on the corresponding side surfaces.

[0070] This embodiment also describes the specific operation process of packaging the laminated battery cells, which mainly includes the following steps:

[0071] Step S201: Forming the anode and cathode plates;

[0072] A right-angled triangle is cut off at the second end corner of the anode electrode to form a notch area 12. The first end corner is set as an empty foil area 11 with the same shape and size as the cut right-angled triangle. This empty foil area 11 is used to replace the electrode tab. The cathode electrode is the opposite of the anode electrode, and will not be described in detail here.

[0073] Step S202: Stacking the wafers to form a laminated battery cell:

[0074] Along the stacking direction of the anode plates, the contact surfaces between the empty foil areas 11 of adjacent anode plates are fixedly connected, and the notch area 12 of the cathode plate avoids the empty foil area 11 of the anode plate; along the stacking direction of the cathode plates, the contact surfaces between the empty foil areas 11 of adjacent cathode plates are fixedly connected, and the notch area 12 of the anode plate avoids the empty foil area 11 of the cathode plate, thereby forming a stacked cell 2.

[0075] Step S203, Adapter Welding:

[0076] The transition welding of the laminated cell 2 first involves gathering the empty foil areas 11 of the multilayer anode electrode sheets together to form the anode tab group 21 of the laminated cell 2 through welding or other composite methods, and gathering the empty foil areas 11 of the multilayer cathode electrode sheets together to form the cathode tab group 22 of the laminated cell 2. Then, the anode tab group 21 and the cathode tab group 22 are connected by tab transition pieces 4 respectively.

[0077] Step S204: Install sealant;

[0078] The sealant 5 is pre-adheded to the surface of both the anode tab group 21 and the cathode tab group 22, specifically at the solder marks of the anode tab group 21 and the cathode tab group 22, thereby improving the sealing between the solder marks of the anode tab group 21 and the packaging film 3, and between the solder marks of the cathode tab group 22 and the packaging film 3.

[0079] Step S205: Fix the sealant and stacked battery cells;

[0080] The anode tab group 21 and the cathode tab group 22 are heated by the tab heating head, and the anode tab group 21 and the sealant 5 are respectively connected and fixed.

[0081] Step S206: Package the stacked battery cells;

[0082] First, the pre-adhesive stacked battery cell 2 is placed in the recess 31 of the stamped packaging film 3. Then, the two sides are sealed and folded by two side sealing edges 33, and the top is sealed and folded by top sealing edge 32. Finally, the packaging film 3 is heated by the battery sealing head. The heated packaging film 3 forms a seal and fixes with the stacked battery cell 2, the anode tab group 21, the cathode tab group 22 and the sealant 5, respectively, thus completing the packaging of the stacked battery cell 2.

[0083] The implementation principle of this embodiment is as follows: A right-angled triangle is obliquely cut off at the second corner of the head of the electrode body 1 to form a notch area 12. The oblique cutting method makes electrode die-cutting simpler and the edges smoother. When the packaging film 3 punches a hole during the packaging process, the edge angle of the hole is large, and wrinkles are not easily formed at the edge of the hole, resulting in a good sealing effect. An empty foil area 11 with the same shape and size as the notch area 12 is set at the first corner of the head of the electrode body 1. This empty foil area 11 replaces the traditional electrode tab structure, reducing the electrode tabs that traditionally protrude from the electrode. During packaging, the gap between the packaging film 3 and the electrode can be reduced. The stacked cell 2 formed by stacking the electrode bodies 1 as described above, in addition to the encapsulation and folding edges on both sides, can also be encapsulated and folded at the top because right-angled triangles are formed at the two corners of the top. The traditional top seal is eliminated, and the length of the top seal is also reduced. This reduces the overall length of the encapsulation structure of the stacked cell 2 in the length direction, effectively improving space utilization and energy density, thereby improving the energy density benefits of the soft-pack battery.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electrode sheet, characterized in that, include: Multiple electrode bodies; Each electrode body includes a coated area and an empty foil area located at one corner of the electrode body, and the empty foil area forms the tab of the electrode body; A notch area is provided at the other corner of the plurality of electrode bodies, and the notch area is used to avoid the empty foil area of ​​adjacent electrode bodies among the plurality of electrode bodies; The notch area is formed by oblique cutting at the end corner of the electrode body; The empty foil area includes two right-angled sides in the long side direction and the short side direction of the electrode body. The boundary line between the empty foil area and the coating area is the first boundary line. The angle between the right-angled side of the empty foil area in the short side direction of the electrode body and the first boundary line is in the range of 30°-60°. The notch area includes two right-angled sides in the long and short sides of the electrode body. The boundary line between the notch area and the coating area is the second boundary line. The angle between the right-angled side of the notch area in the short side of the electrode body and the second boundary line is in the range of 30°-60°.

2. The electrode sheet according to claim 1, characterized in that, The angle between the right-angled side of the empty foil area in the short side direction of the electrode body and the first boundary line is in the range of 45°-60°. The angle between the right-angled side of the notched area in the short side direction of the electrode body and the second boundary line is in the range of 45°-60°.

3. The electrode sheet according to claim 1 or 2, characterized in that, The electrode body has multiple end corners; The empty foil area is located at the first end corner of the electrode body; The notch area is located on the second corner, which is symmetrically arranged with respect to the first corner.

4. The electrode sheet according to claim 3, characterized in that, The electrode body has a first side and a second side that are parallel to each other, a third side that is perpendicular to the first side, and a fourth side that is perpendicular to the second side. The notch area is located at the second corner formed by the first side and the third side; the empty foil area is located at the first corner formed by the second side and the third side.

5. The electrode sheet according to claim 4, characterized in that, Both the empty foil area and the notched area are set as right-angled triangles.

6. A laminated battery cell, characterized in that, It includes a plurality of electrodes as described in any one of claims 1-5 and a plurality of separators, wherein the electrodes are configured as anode electrodes and cathode electrodes, the anode electrodes and the cathode electrodes are stacked alternately in sequence, and the separators are sandwiched between adjacent anode electrodes and cathode electrodes.

7. The laminated cell according to claim 6, characterized in that, The empty foil area of ​​the anode electrode is located in the first position, and the notch area of ​​the cathode electrode avoids the empty foil area; The empty foil area of ​​the cathode electrode is located in the second position, and the notch area of ​​the anode electrode avoids the empty foil area; Multiple empty foil regions located at the same first position are bundled together to form an anode tab group of the stacked battery cell; Multiple empty foil regions located at the same second position are bundled together to form a cathode tab group of the stacked battery cell.

8. A pouch battery, characterized in that, Includes the stacked battery cell, packaging film, and at least two tab adapters as described in claim 6 or 7, wherein; The stacked battery cells are housed within the packaging film; One of the electrode adapter pieces is electrically connected to the anode electrode group of the stacked battery cell. One end of the electrode adapter piece is electrically connected to the anode electrode group, and the other end extends to the outside of the packaging film to form an electrical energy transmission channel. One of the electrode adapter pieces is electrically connected to the cathode electrode group of the stacked battery cell. One end of the electrode adapter piece is electrically connected to the cathode electrode group, and the other end extends to the outside of the packaging film to form an electrical energy transmission channel.

9. The soft-pack battery according to claim 8, characterized in that, The packaging film includes a recess, a top seal integrally formed in the recess, and two side seals; The laminated battery cells are housed within the recess; The top sealing edge is connected to the laminated cell and bent at the top of the laminated cell; The two side seals are respectively connected to the laminated battery cell and bent on the corresponding side surfaces.

10. The soft-pack battery according to claim 8, characterized in that, The electrode adapter piece is configured as a straight adapter piece or an irregularly shaped adapter piece; The straight adapter plate extends from the end corner of the packaging film along the oblique side perpendicular to the empty foil area; The irregularly shaped adapter includes a first segment and a second segment. The first segment extends from the end corner of the packaging film along the oblique side perpendicular to the empty foil area. The second segment is integrally connected to the free end of the first segment and extends along the long side of the stacked battery cell.

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