Soft package battery cell and battery pack

Abstract

The utility model provides a soft package battery cell and a battery pack, and relates to the technical field of soft package battery cells. The soft package battery cell comprises a battery cell body, a plurality of layers of tabs, an adapter plate and a protection plate, the multiple layers of tabs protrude out of the battery cell body, and the multiple layers of tabs are subjected to ultrasonic welding to form a first connecting part; the adapter plate is welded with one surface of the multi-layer tab to form a second connecting part; the protection sheet is connected to the other surface of the multi-layer tab, and one side, far away from the battery cell body, of the protection sheet exceeds the edge of the tab. The protection sheet can prevent the surface layer from being strained and generating cracks when the multiple layers of tabs are welded with the adapter sheet, so that the multiple layers of tabs are protected. The protective sheet covers the edges of the multiple layers of tabs, so that the burrs are covered and are prevented from being in direct contact with the soft package film, the situation that the burrs pierce the surface layer of the soft package film is avoided, and the safety of the soft package battery cell is improved.

Description

Technical Field

[0001] This utility model relates to the field of soft-pack battery technology, specifically to a soft-pack battery cell and battery pack. Background Technology

[0002] Lithium-ion batteries have gradually become the mainstream product in the era of electrification due to their advantages such as high energy density, safety, and environmental friendliness. Based on different packaging methods, lithium-ion batteries can be divided into three main categories: pouch batteries, prismatic batteries, and cylindrical batteries. Among them, pouch batteries have attracted much attention due to their relatively simple structure and manufacturing process. Pouch batteries use an aluminum-plastic film instead of a traditional metal casing. This aluminum-plastic film is composed of a nylon layer, an aluminum foil layer, and a heat-sealing layer. During the heat-sealing process, the aluminum-plastic film needs to be in contact with the tabs to ensure that the tabs extend beyond the aluminum-plastic film.

[0003] When multi-layer tabs are stacked on the side away from the battery body, they may become uneven. Therefore, the tabs usually need to be cut. After cutting, burrs are likely to appear on the side of the tabs away from the battery body. These burrs can easily pierce the heat-sealing layer of the aluminum-plastic film and short-circuit with the aluminum foil layer, causing corrosion in mild cases and battery failure in severe cases. Utility Model Content

[0004] In view of the problems existing in the prior art, the present invention provides a soft-pack battery cell and battery pack to improve the problem that burrs are easy to appear after the existing tabs are cut, and the burrs are easy to puncture the inner layer of the aluminum-plastic film after contacting it.

[0005] To achieve the above and other related objectives, the first aspect of this utility model provides a pouch cell, comprising a cell body, multi-layer tabs, an adapter plate, and a protective plate. The multi-layer tabs protrude from the cell body and are ultrasonically welded to form a first connection portion; the adapter plate is welded to one surface of the multi-layer tabs to form a second connection portion; the protective plate is connected to the other surface of the multi-layer tabs, with the side of the protective plate away from the cell body extending beyond the edge of the tabs.

[0006] In an exemplary embodiment of the present invention, the end of the multilayer tab away from the cell body is a cut end, and the cut end intersects at least partially with the first connecting portion.

[0007] In an exemplary embodiment of the present invention, the first connecting portion is formed on the multilayer tab, and the distance between the two sides of the multilayer tab protruding from the battery cell body and the edge of the first connecting portion is 1 to 3 mm.

[0008] In an exemplary embodiment of the present invention, the second connecting portion connects the adapter plate, the multilayer tab, and the protective plate, one end of the second connecting portion is formed on the protective plate, and the second connecting portion is located in the middle of the protective plate.

[0009] In an exemplary embodiment of the present invention, the length of the protective sheet protruding from the cell body along the multi-layer tab is 0-2 mm longer than the length of the second connecting portion protruding from the cell body along the multi-layer tab.

[0010] The length of the protective sheet protruding from the cell body in a direction perpendicular to the multi-layer tabs is 0-2 mm longer than the length of the second connecting portion protruding from the cell body in a direction perpendicular to the multi-layer tabs.

[0011] In an exemplary embodiment of the present invention, the distance between the edge of the protective sheet and the edge of the second connecting portion is less than or equal to 1 mm.

[0012] In an exemplary embodiment of the present invention, the protective sheet does not extend beyond the two sides adjacent to the multilayer tabs and the battery cell body.

[0013] In an exemplary embodiment of the present invention, the soft-pack battery cell includes a sealant and a soft-pack film. The sealant is disposed on the adapter piece and does not contact the tab or the protective sheet. The soft-pack film covers the battery cell body and the adapter piece protrudes from the soft-pack film.

[0014] In an exemplary embodiment of the present invention, the battery cell body includes a positive electrode and a negative electrode, which are stacked alternately, or the positive electrode and the negative electrode are stacked and then wound together.

[0015] A second aspect of this utility model provides a battery pack comprising the pouch cells described in any one of the above-mentioned methods.

[0016] In combination with existing technologies, the beneficial effects of this utility model are as follows:

[0017] The soft-pack battery cell of this application includes a cell body, multi-layer tabs, an adapter plate, and a protective plate. The multi-layer tabs are ultrasonically welded to form a first connecting part, which connects the multi-layer tabs into one unit. The adapter plate abuts against one surface of the multi-layer tab, and the protective plate is connected to the other surface of the multi-layer tab. Then, the adapter plate and the multi-layer tab are welded together. The protective plate can prevent surface scratches and cracks from occurring during the welding of the multi-layer tab and the adapter plate, thus protecting the multi-layer tab.

[0018] Stacked multi-layer tabs often exhibit irregularities on the side facing away from the cell body, necessitating tab trimming. After trimming, burrs easily appear on the side of the tabs facing away from the cell body, which can easily puncture the soft-pack cell's protective film. The protective sheet in this application extends beyond the edge of the multi-layer tabs on the side furthest from the cell body, thus covering the edge of the multi-layer tabs and concealing the burrs. This prevents direct contact between the burrs and the soft-pack film, avoiding punctures and improving the safety of the soft-pack cell. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of an exemplary soft-pack battery cell of the present invention;

[0021] Figure 2 This utility model Figure 1 Enlarged view of region A in the middle;

[0022] Figure 3 This utility model Figure 2 Enlarged view of region B in the middle.

[0023] Component designation explanation:

[0024] 100. Battery cell body; 200. Multilayer tabs; 300. Adapter plate; 400. Protective plate; 500. Sealant; 600. Second connection part. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0026] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, equipment, and materials similar to or equivalent to those in the embodiments of this invention.

[0027] It should be noted that the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0028] Please see Figures 1 to 3 The first aspect of this utility model provides a soft-pack battery cell, including a cell body 100, multi-layer tabs 200, an adapter piece 300, and a protective piece 400. The multi-layer tabs 200 protrude from the cell body 100 and are ultrasonically welded to form a first connecting portion, which penetrates the multi-layer tabs 200, thus connecting the multi-layer tabs 200 into a single unit. The adapter piece 300 abuts against one surface of the multi-layer tabs 200, and the abutting surface of the adapter piece 300 and the multi-layer tabs 200 are welded to form a second connecting portion 600, thereby fixing the adapter piece 300 to the multi-layer tabs 200. The protective piece 400 is connected to the other surface of the multi-layer tabs 200, with the side of the protective piece 400 away from the cell body 100 extending beyond the edge of the tabs.

[0029] The adapter piece 300 abuts against one surface of the multilayer tab 200, and the protective piece 400 is connected to the other surface of the multilayer tab 200. Then, the adapter piece 300 and the multilayer tab 200 are welded together. Since the multilayer tab 200 has the adapter piece 300 and the protective piece 400 on both sides, the multilayer tab 200 is not the outermost layer for welding. This avoids surface scratches and cracks during welding of the multilayer tab 200 and the adapter piece 300, protecting the multilayer tab 200 and ensuring weld strength.

[0030] The stacked multilayer tabs 200 may appear uneven at the end facing away from the cell body 100, thus requiring tab trimming to ensure a neater finish at this end, facilitating subsequent processes. However, the trimmed multilayer tabs 200 are prone to developing burrs at the end facing away from the cell body 100, which can easily puncture the soft-pack cell's protective film. The protective sheet 400 of this application extends beyond the edge of the multilayer tabs 200 on the side furthest from the cell body 100, thus covering the edge of the multilayer tabs 200 and preventing direct contact between the burrs and the soft-pack film. This avoids burrs puncturing the surface of the soft-pack film and improves the safety of the soft-pack cell.

[0031] The soft-pack cell soft-pack film covers the outside of the cell body 100, and the adapter piece 300 protrudes from the soft-pack film.

[0032] Flexible packaging films include, but are not limited to, composite films. For example, a flexible packaging film may be an aluminum-plastic film, with an outer nylon layer, a middle aluminum foil layer, and an inner heat-sealing layer. The nylon layer ensures the shape of the aluminum-plastic film and prevents deformation before it is manufactured into a battery. The aluminum foil layer is mainly used to prevent water and air penetration, maintaining the environment inside the battery cell 100. The heat-sealing layer is mainly used for heat-pressing the flexible packaging film onto the battery cell 100. The heat-sealing layer can be a polypropylene layer to provide good heat-sealing performance.

[0033] Please see Figure 2 In one embodiment, the soft-pack battery cell includes a sealant 500, which is disposed on the adapter piece 300. The sealant 500 is bonded to the inner layer of the soft-pack film to seal the soft-pack film at the adapter piece 300, thereby ensuring that the soft-pack film covers and seals the battery cell body and protects the internal environment of the battery cell body.

[0034] The sealant 500 does not come into contact with the multilayer tabs 200, thereby preventing the tabs from affecting the sealing of the soft casing, ensuring the sealing performance of the soft casing, and ensuring the stability of the internal environment of the battery cell.

[0035] The protective sheet 400 and the sealant 500 do not contact each other. The protective sheet 400 extends beyond the multilayer tab 200 and is located on the side opposite to the main body of the cell. The projection of the protective sheet 400 along the axial direction of the multilayer tab 200 does not coincide with the projection of the sealant 500 along the axial direction of the multilayer tab 200. The sealant 500 contacts the inner layer of the pouch film. If the protective sheet 400 and the sealant 500 overlap, on the one hand, the pouch film and the sealant 500 will not adhere tightly, affecting the sealing effect of the pouch film; on the other hand, the distance between the sealing part of the pouch film and the edge of the protective sheet 400 will be too close, causing the edge of the protective sheet 400 to abut against the pouch film, which can easily lead to the protective sheet 400 piercing the inner layer of the pouch film and short-circuiting with the aluminum foil layer, causing quality problems such as poor resistance and corrosion. By ensuring that the protective sheet 400 does not contact the sealant 500, the situation of the protective sheet 400 easily piercing the inner layer of the pouch film can be effectively improved, ensuring the quality of the pouch cell.

[0036] In one embodiment, the first connecting portion is formed on the multilayer tab 200. The distance between the two sides of the multilayer tab 200 protruding from the cell body 100 and the edge of the first connecting portion is 1-3 mm. The direction of the multilayer tab 200 protruding from the cell body 100 is a first direction. The two edges of the multilayer tab 200 in the same direction as the first direction are the two sides of the multilayer tab 200 protruding from the cell body 100. In other words, the distance between the two sides of the multilayer tab 200 adjacent to the cell body 100 and the edge of the first connecting portion is 1-3 mm. The distance can be any value between 1-3 mm, such as 1 mm, 2 mm, 3 mm, etc. The larger the area occupied by the first connecting part on the multilayer tab 200, the more stable the connection between the multilayer tabs 200. The appropriate distance between the edge of the first connecting part and the edge of the multilayer tab 200 can ensure that the first connecting part occupies a large area on the multilayer tab 200, while avoiding the situation where the edge of the multilayer tab 200 is not neat due to the first connecting part being too close to the edge of the multilayer tab 200 after welding.

[0037] Please see Figure 2 In one embodiment, the second connecting portion 600 connects the adapter plate 300, the multilayer tab 200, and the protective plate 400, thereby fixing the adapter plate 300, the multilayer tab 200, and the protective plate 400 together. One end of the second connecting portion 600 is formed on the protective plate 400, and the other end of the second connecting portion 600 is formed on the adapter plate 300.

[0038] The second connecting portion 600 is located in the middle of the protective sheet 400. The second connecting portion 600 being at the edge of the protective sheet 400 easily causes the other side of the protective sheet 400 to warp, potentially leading to a short circuit between the protective sheet 400 and the interlayer of the soft-pack film after damage to the inner layer. By positioning the second connecting portion 600 in the middle of the protective sheet 400, the warping of the protective sheet 400's edge can be effectively mitigated, thereby reducing the occurrence of short circuits between the protective sheet 400 and the interlayer of the soft-pack film, and improving the quality of the soft-pack battery cell.

[0039] Please see Figure 2 and Figure 3 In one embodiment, the length of the protective sheet 400 protruding from the cell body 100 along the multilayer tab 200 is 0-2 mm longer than the length of the second connecting portion 600 protruding from the cell body 100 along the multilayer tab 200. In other words, the length of the protective sheet 400 along the first direction is 0-2 mm longer than the length of the second connecting portion 600 along the first direction. The difference in length can be any value between 0 and 2 mm, such as 0 mm, 1 mm, or 2 mm. This ensures welding strength and effectively improves the situation of edge warping of the protective sheet 400, reduces the occurrence of short circuits between the protective sheet 400 and the interlayer of the soft-pack film, and ensures the quality of the soft-pack cell.

[0040] In one embodiment, the length of the protective sheet 400 protruding from the cell body 100 in a direction perpendicular to the multilayer tab 200 is 0-2 mm longer than the length of the second connecting portion 600 protruding from the cell body 100 in the same direction. The direction perpendicular to the multilayer tab 200 protruding from the cell body 100 is the second direction, which is perpendicular to the first direction. The length of the protective sheet 400 in the second direction is 0-2 mm longer than the length of the second connecting portion 600 in the same direction. The difference in length can be any value between 0 and 2 mm, such as 0 mm, 1 mm, or 2 mm. This ensures welding strength and effectively improves the situation of edge warping of the protective sheet 400, reduces the occurrence of short circuits between the protective sheet 400 and the interlayer of the soft-pack film, and ensures the quality of the soft-pack cell.

[0041] In one embodiment, the distance between the edge of the protective sheet 400 and the edge of the second connecting portion 600 is less than or equal to 1 mm, the distance between the edge of the protective sheet 400 along the first direction and the edge of the second connecting portion 600 along the first direction is less than or equal to 1 mm, and the distance between the edge of the protective sheet 400 along the second direction and the edge of the second connecting portion 600 along the second direction is also less than or equal to 1 mm. This effectively avoids the situation where the edge of the protective sheet 400 is raised too high, reduces the risk of the protective sheet 400 puncturing the inner layer of the soft packaging film, reduces the situation of short circuit between the protective film and the middle layer of the soft packaging film, reduces the defect rate of the soft packaging cell, and improves the quality of the soft packaging cell.

[0042] Please see Figure 2 In one embodiment, the protective sheet 400 does not extend beyond the two sides adjacent to the tab and the cell body 100. The two sides adjacent to the cell body 100 are parallel to the first direction. Since the protective sheet 400 does not extend beyond the multilayer tab 200, the edge of the protective sheet 400 does not contact the soft film or the edge of the protective sheet 400 exerts a small force on the soft film, thus avoiding damage to the soft film by the edge of the protective sheet 400, preventing short circuit between the protective sheet 400 and the intermediate layer of the soft film, improving the yield and quality of the soft-pack cell.

[0043] In one embodiment, the cell body 100 includes a positive electrode and a negative electrode, which are stacked alternately. The cell body 100 also includes a separator, and the positive electrode, negative electrode, and separator are stacked alternately in a certain order to form a cell structure.

[0044] In this application, the positive and negative electrode sheets can be conventional electrode types and shapes used in the battery cell industry. For example, the positive electrode sheet can be an aluminum sheet, and the negative electrode sheet can be a copper sheet with a rectangular cross-section. A separator is disposed between adjacent electrode sheets and covers the surface of the outer electrode sheet, providing insulation so that the positive and negative electrode sheets do not directly contact each other. The specific arrangement of the separator is not limited; for example, multiple separators can be used to isolate and / or cover the electrode sheets separately, or a single separator can be bent and coiled to isolate and / or cover the electrode sheets. The separator is side-sealed to simultaneously fix at least two adjacent electrode sheets; that is, when the separator is side-sealed, both the positive and negative electrode sheets are simultaneously fixed. The side-sealing of the separator fixes the electrode sheets within the area enclosed by the separator, preventing relative movement between the electrode sheets and the separator. The separator simultaneously fixes both the positive and negative electrode sheets, maintaining their relative positions during transport and use, thus improving yield and reducing production costs.

[0045] In another embodiment, the cell body 100 includes a positive electrode, a negative electrode, and a separator, wherein the positive electrode, the negative electrode, and the separator are stacked and wound to form a cell structure.

[0046] A second aspect of this utility model provides a battery pack comprising the pouch cell described in any of the above descriptions. The battery pack also includes a protection circuit and a housing. By utilizing a protective sheet 400 extending beyond the end of the multi-layer tab 200 away from the cell body, the battery pack effectively protects the multi-layer tab 200 and covers burrs at the cut ends of the multi-layer tab 200, preventing burrs from piercing the inner layer of the pouch film and short-circuiting with the middle layer of the pouch film, thus effectively improving the quality of the battery pack.

[0047] The soft-pack battery cells and battery packs of this application are applicable to batteries and electrical devices that use batteries. Electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electrical devices.

[0048] The soft-pack battery cell and battery pack of this application have adapter plates 300 and protective plates 400 on both sides of the multi-layer tabs 200. The multi-layer tabs 200 are not the outermost layer for welding, thus avoiding surface scratches and cracks during welding of the multi-layer tabs 200 and adapter plates 300, protecting the multi-layer tabs 200 and ensuring welding strength. The protective plate 400 extends beyond the edge of the multi-layer tabs 200 on the side furthest from the cell body 100, thus covering the edge of the multi-layer tabs 200 and concealing burrs. This prevents burrs from directly contacting the soft-pack film and thus avoids burrs piercing the surface of the soft-pack film, improving the safety of the soft-pack battery cell. Therefore, this utility model effectively overcomes some practical problems in the prior art and has high utilization value and significance.

[0049] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A pouch cell, characterized in that, include: Battery cell body; Multi-layer tabs protrude from the cell body, and the multi-layer tabs are ultrasonically welded to form a first connection part; The adapter piece is welded to one surface of the multilayer electrode tab to form a second connection part; A protective sheet is attached to the other surface of the multilayer tab, with the side of the protective sheet away from the cell body extending beyond the edge of the multilayer tab.

2. The soft-pack battery cell according to claim 1, characterized in that, The end of the multi-layer electrode away from the cell body is a cut end, and the cut end intersects at least partially with the first connecting portion.

3. The soft-pack battery cell according to claim 1, characterized in that, The first connection portion is formed on the multilayer tab, and the distance between the two sides of the multilayer tab protruding from the cell body and the edge of the first connection portion is 1 to 3 mm.

4. The soft-pack battery cell according to claim 1, characterized in that, The second connecting part connects the adapter plate, the multilayer tab and the protective plate. One end of the second connecting part is formed on the protective plate, and the second connecting part is located in the middle of the protective plate.

5. The soft-pack battery cell according to claim 4, characterized in that, The length of the protective sheet protruding from the cell body along the multi-layer tab is 0-2 mm longer than the length of the second connecting portion protruding from the cell body along the multi-layer tab. The length of the protective sheet protruding from the cell body in a direction perpendicular to the multi-layer tabs is 0-2 mm longer than the length of the second connecting portion protruding from the cell body in a direction perpendicular to the multi-layer tabs.

6. The pouch cell according to claim 4 or 5, characterized in that, The distance between the edge of the protective sheet and the edge of the second connecting part is less than or equal to 1 mm.

7. The soft-pack battery cell according to claim 1, characterized in that, The protective sheet does not extend beyond the two sides adjacent to the multilayer tabs and the battery cell body.

8. The soft-pack battery cell according to claim 1, characterized in that, include: A sealant is applied to the adapter plate, and the sealant does not contact the electrode tab or the protective plate. A soft film covers the outside of the battery cell body, and the adapter plate protrudes from the soft film.

9. The soft-pack battery cell according to claim 1, characterized in that, The battery cell body includes a positive electrode and a negative electrode, which are stacked alternately, or the positive electrode and the negative electrode are stacked and then wound together.

10. A battery pack, characterized in that, Includes the pouch cell as described in any one of claims 1 to 9.

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