Battery cell, terminal device and battery cell packaging method

Abstract

A battery cell, a terminal device, and a packaging method for the battery cell are disclosed. The battery cell includes an electrode assembly and a packaging bag. The packaging bag includes a main body and a packaging part. The electrode assembly is disposed within the main body. The main body includes a folded portion and a first wall connected to one end of the folded portion in a second direction. The packaging part includes a first packaging edge connected to the first wall in a second direction. The first packaging edge includes a first end connected to the folded portion, and the first end has a first recessed portion in a third direction. The first direction is the thickness direction of the battery cell, and the first direction, the second direction, and the third direction are perpendicular to each other. The packaging bag is formed by folding and sealing a packaging film along the folded portion. The aforementioned battery cell can improve energy density.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a battery cell, a terminal device, and a method for packaging the battery cell. Background Technology

[0002] Existing battery cell packaging bags are typically made of flexible film. This flexible film is formed by punching, folding, and cutting to create a cavity that houses the electrode assembly. The folds in the flexible film create outward protrusions, which occupy space along the length of the battery cell, resulting in a decrease in the cell's energy density. Summary of the Invention

[0003] In view of the above, this application provides a battery cell that can improve energy density.

[0004] This application provides a battery cell, which includes an electrode assembly and a packaging bag. The packaging bag includes a main body and a sealing portion. The electrode assembly is disposed within the main body, which includes a folded portion and a first wall connected to one end of the folded portion in a second direction. The sealing portion includes a first sealing edge, which is connected to the first wall in the second direction. The first sealing edge includes a first end portion connected to the folded portion, and the first end portion has a first recessed portion in a third direction. The first direction is the thickness direction of the battery cell, and the first direction, the second direction, and the third direction are perpendicular to each other. The packaging bag is formed by sealing a sealing film after folding it along the folded portion.

[0005] In the aforementioned battery cell, the packaging bag is formed by folding and sealing the encapsulation film along the fold portion. The fold portion, as the folding area, provides a suitable folding allowance, resulting in a surface without encapsulation edges. The first recess provides a recess distance that matches the fold portion, reducing the risk of the first end protruding from the fold portion in the third direction. This helps reduce the space occupied by the battery cell in the third direction, thereby increasing the energy density of the battery cell.

[0006] In some embodiments of this application, along the second direction, the projection of the first end is located within the projection of the first wall, so as to eliminate the portion of the first end protruding and folded portion along the third direction through the first recess, which helps to reduce the space occupied by the cell in the third direction and thus improve the energy density of the cell.

[0007] In some embodiments of this application, the main body further includes a second wall connected to the folded portion, the second wall being disposed opposite to the first wall along a second direction. The encapsulation portion further includes a second encapsulation edge, which is connected to the second wall along the second direction. The second encapsulation edge includes a second end connected to the folded portion, the second end having a second recess recessed along a third direction. The second recess provides a recess distance adapted to the folded portion, reducing the risk of the second end protruding from the folded portion along the third direction, which helps to reduce the space occupied by the battery cell in the third direction, thereby improving the energy density of the battery cell.

[0008] In some embodiments of this application, the projection of the second end along the second direction is located within the projection of the second wall, so as to eliminate the portion of the second end protruding and folded portion along the third direction through the second recess, which helps to reduce the space occupied by the cell in the third direction and thus improve the energy density of the cell.

[0009] In some embodiments of this application, viewed along a second direction, the first end portion includes a first bend, a second bend, and a first connecting portion. The first bend and the second bend are arranged along a first direction, and the first connecting portion connects the first bend and the second bend. The first bend includes a first surface, a second connecting portion, and a second surface, which are connected by the second connecting portion. The second bend includes a third surface, a third connecting portion, and a fourth surface, which are connected by the third connecting portion. Along a third direction, the second connecting portion and the third connecting portion are connected to a folded portion, and the first connecting portion is located away from the folded portion. A first recess is formed between the second surface, the third surface, and the first connecting portion.

[0010] In some embodiments of this application, the length of the second and third surfaces with the larger length in the third direction is D1, 0.5mm≤D1≤1mm, in order to reduce the risk of the first end protruding into the folded portion in the third direction and to reduce the risk of interference between the first recess and the main body.

[0011] In some embodiments of this application, the length of the first recess in the second direction is L, where 2mm≤L≤7.5mm, in order to reduce the risk of the first end protruding into the folded portion in the third direction and to reduce the risk of interference between the first recess and the main body.

[0012] In some embodiments of this application, the first encapsulation edge includes a first side extending in the third direction, one end of the first recess is located on the first side, and the other end of the first recess extends to the first wall, so as to eliminate the portion of the first end protruding and folded portion in the third direction through the first recess, which is beneficial to reduce the space occupied by the cell in the third direction and thereby improve the energy density of the cell.

[0013] In some embodiments of this application, viewed along a second direction, the first wall includes a first planar region and a first arcuate region arranged along a third direction, with the first arcuate region connecting the folded portion and the first planar region. The centerline of the first arcuate region in the second direction is defined as the first centerline. The first encapsulation edge includes a first side extending along a third direction, one end of the first recess is located on the first side, and the other end of the first recess is located between the first planar region and the first centerline, thereby reducing the risk of the first end protruding from the folded portion along the third direction and reducing the risk of interference between the first recess and the main body.

[0014] In some embodiments of this application, the battery cell further includes a first adhesive member connected between the second and third surfaces to reduce the risk of the first and second bent portions opening due to springback, thereby improving the structural stability of the first end.

[0015] In some embodiments of this application, the battery cell further includes a second adhesive member connected to the side of the first connecting portion away from the first recess, so as to improve the sealing performance inside the first encapsulation edge.

[0016] In some embodiments of this application, the material of the second adhesive is selected from at least one of polypropylene, polyethylene, and polyethylene terephthalate.

[0017] In some embodiments of this application, the second adhesive member further extends between the first and second surfaces to reduce the risk of the first bent portion opening due to springback, thereby improving the structural stability of the first end. And / or, the second adhesive member further extends between the third and fourth surfaces to reduce the risk of the second bent portion opening due to springback, thereby improving the structural stability of the first end.

[0018] In some embodiments of this application, the encapsulation film includes a first encapsulation region and a second encapsulation region located on both sides of the first connection portion, and the first encapsulation region and / or the second encapsulation region are provided with a receiving portion, which is configured to receive an electrode assembly.

[0019] In some embodiments of this application, the main body further includes a top wall, the top wall and the folded portion being disposed opposite each other along a third direction, and a first wall connecting the top wall and the folded portion. The encapsulation portion further includes a top sealing edge, which is connected to the top wall and connected to the first encapsulation edge. The battery cell further includes a tab, which is connected to an electrode assembly and extends from the top sealing edge.

[0020] In some embodiments of this application, the battery cell further includes a tab that connects to an electrode assembly and extends from the first encapsulation edge.

[0021] Embodiments of this application also provide a terminal device, which includes the battery cell described in the above embodiments.

[0022] In the aforementioned battery cell and terminal device, the packaging bag is formed by folding and sealing the encapsulation film along the folded portion and the first recess. The folded portion, as the folding part, provides a suitable folding allowance, allowing the folded portion to form a surface without encapsulation edges. The first recess provides a recess distance adapted to the folded portion, reducing the risk of the first end protruding from the folded portion in the third direction, which helps to reduce the space occupied by the battery cell in the third direction, thereby increasing the energy density of the battery cell.

[0023] Embodiments of this application also provide a method for packaging a battery cell, wherein the battery cell is the same as the one described in the above embodiments. The method for packaging the battery cell includes the following steps:

[0024] The portion of the encapsulation film in the unfolded state corresponding to the first end is punched with a groove;

[0025] The encapsulation film in the unfolded state is folded along the folded portion and the punched groove to form the first encapsulation edge;

[0026] Two opposing hot press blocks are provided. Moving the two hot press blocks toward each other applies pressure to the first encapsulation edge to complete the encapsulation.

[0027] In some embodiments of this application, the first encapsulation edge includes a first segment and a second segment arranged along a third direction, the groove is located at the end of the first segment away from the second segment, and the thickness of the first segment is greater than the thickness of the second segment along the first direction. Each hot-pressing block has a hot-pressing surface on one side, the hot-pressing surface including a first region and a second region recessed relative to the first region.

[0028] The second segment is placed between the two first segments, and the first segment is placed between the two second segments;

[0029] Two hot-pressing blocks are moved toward each other to apply pressure to the first and second sections, so that the compression ratio of the first section is equal to that of the second section. After hot pressing, the first section forms the first end, and the groove position forms the first recess.

[0030] In the aforementioned battery cell packaging method, by setting a first region on the hot-pressing surface and a second region recessed relative to the first region, the first and second segments can be hot-pressed simultaneously, thereby improving packaging efficiency. By making the compression ratio of the first segment equal to that of the second segment, the risk of the first segment breaking due to excessive force or excessive bending can be reduced.

[0031] In some embodiments of this application, along a third direction, the length of the junction of the first region and the second region from the side of the groove position away from the first recess is D2, 1mm≤D2≤3mm, so as to form a transition structure on one side of the first end, improve the structural stability of the first end, and facilitate the setting of the second adhesive.

[0032] In some embodiments of this application, the first encapsulation edge includes a first segment and a second segment arranged along a third direction, the groove is located at the end of the first segment away from the second segment, and the thickness of the first segment is greater than the thickness of the second segment along the first direction. Each hot-pressing block has a hot-pressing surface on one side.

[0033] The first segment is placed between two hot pressing surfaces. The two hot pressing blocks move towards each other and apply pressure to the first segment. After hot pressing, the first segment forms the first end, and the groove position forms the first recess.

[0034] The second section is placed between the two hot pressing surfaces. The two hot pressing blocks move towards each other and apply pressure to the second section, so that the compression ratio of the first section is equal to that of the second section.

[0035] In the above-mentioned battery cell packaging method, by hot-pressing the first segment and the second segment in sequence with the hot-pressing surface, and making the compression ratio of the first segment equal to that of the second segment, the risk of the first segment being damaged due to excessive force or excessive bending can be reduced.

[0036] In some embodiments of this application, the maximum dimension of the first recess in the first direction is W, 0.3 mm.

[0037] The diameter is ≤W≤0.5mm to reduce the risk of the first end protruding into the folded portion in the third direction, and to reduce the risk of interference between the first recess and the main body.

[0038] In some embodiments of this application, the battery cell packaging method further includes the following steps: providing a second adhesive on the side of the punched groove location away from the first recess, so that the second adhesive is connected to the side of the first connecting portion away from the first recess, thereby improving the sealing performance inside the first packaging edge. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the first packaging edge of the battery cell in one embodiment of this application.

[0040] Figure 2 yes Figure 1 A magnified view of section II.

[0041] Figure 3 This is a schematic diagram of the structure of the battery cell after the encapsulation film is unfolded and viewed along the first direction in one embodiment of this application.

[0042] Figure 4 yes Figure 3 A sectional view along section line AA.

[0043] Figure 5 This is a schematic diagram of the structure of the second encapsulation side of the battery cell in one embodiment of this application.

[0044] Figure 6 This is a schematic diagram of the structure of the first adhesive component and the second adhesive component of the battery cell in one embodiment of this application.

[0045] Figure 7 This is a schematic diagram of a structure in one embodiment of the present application, showing a receiving portion provided in the encapsulation film of the battery cell.

[0046] Figure 8 This is a schematic diagram of the structure of the first encapsulation edge of the battery cell in another embodiment of this application.

[0047] Figure 9 This is a schematic diagram of the structure of the battery cell after the encapsulation film is unfolded and viewed along the first direction in one embodiment of this application.

[0048] Figure 10 This is a schematic diagram of the structure of the first encapsulation edge of the battery cell in another embodiment of this application.

[0049] Figure 11 This is a schematic diagram of the structure of the first encapsulation edge of the battery cell in another embodiment of this application.

[0050] Figure 12 This is a flowchart of a battery cell packaging method in one embodiment of this application.

[0051] Figure 13 This is a schematic diagram of the structure of the hot press block in one embodiment of this application.

[0052] Figure 14 This is a schematic diagram of the terminal device in one embodiment of this application.

[0053] Explanation of main component symbols

[0054] Battery cells 100A, 100B, 100C, 100D

[0055] Terminal device 200

[0056] Electrode assembly 10

[0057] Packaging bag 20

[0058] Encapsulation film 20A

[0059] First Packaging Area 201

[0060] Second packaging area 202

[0061] Reception Section 203

[0062] Main body 30

[0063] Folding section 31

[0064] First Wall 32

[0065] First Plane Area 321

[0066] First arc area 322

[0067] First centerline O

[0068] Second Wall 33

[0069] Top wall 34

[0070] Packaging section 40

[0071] First encapsulation edge 41

[0072] Section 1, 41A

[0073] Second paragraph 41B

[0074] First end 411

[0075] First recess 411A

[0076] First bend 411B

[0077] First page 4111

[0078] Second connecting part 4112

[0079] Second page 4113

[0080] First connecting part 411C

[0081] Second bend 411D

[0082] Third page 4114

[0083] Third connecting part 4115

[0084] Page 4116

[0085] First side 412

[0086] Second encapsulation edge 42

[0087] Second end 421

[0088] Second recess 421A

[0089] Top edge sealing 43

[0090] First adhesive component 50

[0091] Second adhesive component 60

[0092] JE70

[0093] Hot press block 90

[0094] Hot-pressed surface 91

[0095] Area 1, 91A

[0096] Area 2, 91B

[0097] First direction X

[0098] Second direction Y

[0099] Third direction Z

[0100] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0101] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0102] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have a component that is centrally located. When a component is considered to be "set" on another component, it can be directly set on the other component or may also have a component that is centrally located.

[0103] When one value is considered "equal" to another, it means that they are equal within a set deviation range, which is within 5%. In other words, if at least one of the two values ​​fluctuates within the set deviation range, they are considered approximately equal even if their values ​​are not equal. Similarly, when one value is considered to have a "1:1" ratio with another, it means that they are equal within a set deviation range, which is within 5%. Again, if at least one of the two values ​​fluctuates within the set deviation range, they are considered equal in ratio even if their values ​​are not equal.

[0104] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. The term "overlap" as used herein refers to the overlapping of the projected portions of two components or the coincidence of the projected portions of two components.

[0105] This application provides a battery cell, which includes an electrode assembly and a packaging bag. The packaging bag includes a main body and a sealing portion. The electrode assembly is disposed within the main body, which includes a folded portion and a first wall connected to one end of the folded portion in a second direction. The sealing portion includes a first sealing edge, which is connected to the first wall in the second direction. The first sealing edge includes a first end portion connected to the folded portion, and the first end portion has a first recessed portion in a third direction. The first direction is the thickness direction of the battery cell, and the first direction, the second direction, and the third direction are perpendicular to each other. The packaging bag is formed by sealing a sealing film after folding it along the folded portion.

[0106] In the aforementioned battery cell, the packaging bag is formed by folding and sealing the encapsulation film along the folded portion and the first recess. The folded portion, as the folding part, provides a suitable folding allowance, allowing the folded portion to form a surface without encapsulation edges. The first recess provides a recess distance that matches the folded portion, reducing the risk of the first end protruding from the folded portion in the third direction. This helps to reduce the space occupied by the battery cell in the third direction, thereby increasing the energy density of the battery cell.

[0107] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0108] Example 1

[0109] Please see Figure 1 One embodiment of this application provides a battery cell 100A, which is used in a secondary battery. A secondary battery is a battery that can be used again after being discharged by recharging to activate the active materials.

[0110] The battery cell 100A includes an electrode assembly 10 and a packaging bag 20. The electrode assembly 10 is used to convert chemical energy into electrical energy. The electrode assembly 10 is formed by winding or stacking a positive electrode, a separator, and a negative electrode in sequence. The packaging bag 20 includes a main body 30 and a sealing part 40. The electrode assembly 10 is disposed within the main body 30, and the sealing part 40 is used to seal the main body 30.

[0111] Viewed along the first direction X, the main body 30 includes a folded portion 31 and a first wall 32 connected to one end of the folded portion 31 along the second direction Y. The first direction X is the thickness direction of the battery cell 100A. The encapsulation portion 40 includes a first encapsulation edge 41, which is connected to the first wall 32 along the second direction Y.

[0112] Please refer to the following: Figure 1 and Figure 2 The folded portion 31 has a surface without a sealing edge. The first sealing edge 41 includes a first end portion 411 connected to the folded portion 31. Specifically, the first end portion 411 is adjacent to the folded portion 31 in the second direction Y. The first end portion 411 is provided with a first recess 411A recessed along the third direction Z to reduce the risk of the first end portion 411 protruding from the folded portion 31 along the third direction Z, which helps to reduce the space occupied by the packaging bag 20 in the third direction Z. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0113] Optionally, the second direction Y is the width direction of the battery cell 100A, and the third direction Z is the length direction of the battery cell 100A.

[0114] It is understandable that the position of the first end 411 can also be defined by the thickness of the first encapsulation edge 41. Specifically, the thickness of the first end 411 is greater than the thickness of other areas of the first encapsulation edge 41.

[0115] Please refer to the following: Figure 3 and Figure 4The packaging bag 20 is formed by folding and sealing the encapsulation film 20A along the folding portion 31. The main body 30 is the portion of the encapsulation film 20A with perforations, and the encapsulation portion 40 is the overlapping and joining portion of the encapsulation film 20A after folding. The folding portion 31, as the folding portion, provides a suitable folding allowance, allowing the folding portion 31 to form a surface without encapsulation edges. The first recess 411A provides a recess distance adapted to the folding portion 31, reducing the risk of the first end 411 protruding from the folding portion 31 along the third direction Z, which helps reduce the space occupied by the battery cell 100A in the third direction Z, thereby increasing the energy density of the battery cell 100A. Furthermore, it also helps reduce the risk of wear caused by the first end 411 contacting external structural components, which could expose the metal layer inside the encapsulation film 20A, thereby improving the durability of the packaging bag 20.

[0116] Optionally, the encapsulation film 20A is an aluminum-plastic film.

[0117] Please continue reading. Figure 1 and Figure 2 In some embodiments, along the second direction Y, the projection of the first end 411 is located within the projection of the first wall 32, so that the portion of the first end 411 protruding from the folded portion 31 along the third direction Z can be eliminated by the first recess 411A, which helps to reduce the space occupied by the cell 100A in the third direction Z, thereby improving the energy density of the cell 100A.

[0118] Please refer to the following: Figure 1 and Figure 5 In some embodiments, the main body 30 further includes a second wall 33 connected to the folding portion 31, the second wall 33 being disposed opposite to the first wall 32 along the second direction Y. The encapsulation portion 40 further includes a second encapsulation edge 42. The second encapsulation edge 42 is connected to the second wall 33 along the second direction Y.

[0119] The second encapsulation edge 42 includes a second end portion 421 connected to the folded portion 31. Specifically, the second end portion 421 is adjacent to the folded portion 31 in the second direction Y. The second end portion 421 is provided with a second recess 421A recessed along the third direction Z. The second recess 421A can provide a recess distance adapted to the folded portion 31 to reduce the risk of the second end portion 421 protruding from the folded portion 31 in the third direction Z, which helps to reduce the space occupied by the cell 100A in the third direction Z, thereby improving the energy density of the cell 100A.

[0120] In some embodiments, along the second direction Y, the projection of the second end portion 421 lies within the projection of the second wall 33. This facilitates the elimination of the portion of the second end portion 421 that protrudes from the folded portion 31 along the third direction Z by the second recess 421A, thereby reducing the space occupied by the battery cell 100A in the third direction Z and thus increasing the energy density of the battery cell 100A. Furthermore, it also helps reduce the risk of wear caused by contact between the second end portion 421 and external structural components, which could expose the metal layer inside the encapsulation film 20A, thereby improving the durability of the packaging bag 20.

[0121] In some embodiments, along the second direction Y, the projection of the second wall 33 coincides with the projection of the first wall 32.

[0122] Please refer to it again. Figure 2 In some embodiments, viewed along the second direction Y, the first end portion 411 includes a first bend 411B, a second bend 411D, and a first connecting portion 411C. The first bend 411B and the second bend 411D are arranged along the first direction X, and the first connecting portion 411C connects the first bend 411B and the second bend 411D. The first bend 411B, the second bend 411D, and the first connecting portion 411C form an "M"-shaped structure.

[0123] The first bending portion 411B includes a first surface 4111, a second connecting portion 4112, and a second surface 4113, which are connected by the second connecting portion 4112. The second bending portion 411D includes a third surface 4114, a third connecting portion 4115, and a fourth surface 4116, which are connected by the third connecting portion 4115. Along the third direction Z, the second connecting portion 4112 and the third connecting portion 4115 are connected to the folded portion 31, the first connecting portion 411C is away from the folded portion 31, and a first recess 411A is formed between the second surface 4113, the third surface 4114, and the first connecting portion 411C.

[0124] Optionally, along the third direction Z, the length of the second face 4113 and the length of the third face 4114 are equal, or the length of the second face 4113 and the length of the third face 4114 are not equal.

[0125] In some embodiments, the first bending portion 411B, the second bending portion 411D, and the first connecting portion 411C are respectively provided with arc-shaped bends to reduce the risk of damage to the first end portion 411 due to excessive bending.

[0126] Please continue reading. Figure 2In some embodiments, the maximum dimension of the first recess 411A in the first direction X is W, where 0.3mm ≤ W ≤ 0.5mm. When W is small (less than 0.3mm), the recess distance provided by the first recess 411A is small, making it easy for the first end 411 to bulge out the folded portion 31 in the third direction Z. When W is large (greater than 0.5mm), it is easy for the first recess 411A to interfere with the main body 30, thereby causing deformation of the main body 30 and interference with the electrode assembly 10. By limiting W to 0.3mm ≤ W ≤ 0.5mm, the risk of the first end 411 bulging out the folded portion 31 in the third direction Z can be reduced, as can the risk of interference between the first recess 411A and the main body 30.

[0127] Optionally, W can be any value within the range of 0.3mm, 0.4mm, 0.5mm, and any other value within the range of 0.3mm≤W≤0.5mm.

[0128] Please continue reading. Figure 2 In some embodiments, the length of the larger of the second surface 4113 and the third surface 4114 in the third direction Z is D1, where 0.5mm ≤ D1 ≤ 1mm. When D1 is small (less than 0.5mm), the recessed distance provided by the first recess 411A is small, making it easy for the first end 411 to protrude the folded portion 31 along the third direction Z. When D1 is large (greater than 1mm), it is easy for the first recess 411A to interfere with the main body 30, thereby causing the main body 30 to deform and interfere with the electrode assembly 10. By limiting 0.5mm ≤ D1 ≤ 1mm, the risk of the first end 411 protruding the folded portion 31 along the third direction Z can be reduced, as can the risk of interference between the first recess 411A and the main body 30.

[0129] Optionally, D1 can be any value within the range of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, and any other value within the range of 0.5mm≤D1≤1mm.

[0130] Please continue reading. Figure 2 In some embodiments, the length of the first recess 411A in the second direction Y is L, where 2mm ≤ L ≤ 7.5mm. When L is small (less than 2mm), the recess distance provided by the first recess 411A is small, making it easy for the first end 411 to bulge out the folded portion 31 in the third direction Z. When L is large (greater than 7.5mm), it is easy for the first recess 411A to interfere with the main body 30, thereby causing deformation of the main body 30 and interference with the electrode assembly 10. By limiting 2mm ≤ L ≤ 7.5mm, the risk of the first end 411 bulging out the folded portion 31 in the third direction Z can be reduced, and the risk of interference between the first recess 411A and the main body 30 can also be reduced.

[0131] Optionally, L can be any value within the range of 2mm, 3.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, and any other value within the range of 2mm≤L≤7.5mm.

[0132] Please refer to the following: Figure 1 and Figure 2 In some embodiments, the first encapsulation edge 41 includes a first side edge 412 extending along a third direction Z. Specifically, the first side edge 412 is the edge of the first encapsulation edge 41 extending along a third direction Z, and when viewed along the third direction Z, the first side edge 412 is away from the first wall 32 in the extension direction of the first encapsulation edge 41. One end of the first recess 411a is located at the first side edge 412, and the other end of the first recess 411a extends to the first wall 32, so as to eliminate the portion of the first end 411 protruding from the folded portion 31 along the third direction Z by the first recess 411a, which helps to reduce the space occupied by the cell 100A in the third direction Z, thereby improving the energy density of the cell 100A.

[0133] Please see Figure 6 In some embodiments, the battery cell 100A further includes a first adhesive 50, which is connected between the second surface 4113 and the third surface 4114. That is, the first adhesive 50 fills the first recess 411A to reduce the risk of the first bent portion 411B and the second bent portion 411D opening due to springback, which is beneficial to improving the structural stability of the first end 411.

[0134] Specifically, the outer side of the encapsulation film 20A is a nylon layer, which is used to improve the structural strength of the encapsulation film 20A. The first adhesive 50 is bonded to the nylon layer corresponding to the first bending portion 411B.

[0135] Please continue reading. Figure 6 In some embodiments, the battery cell 100A further includes a second adhesive member 60, which is connected to the side of the first connecting portion 411C opposite to the first recess 411A, to improve the sealing performance inside the first encapsulation edge 41. Specifically, the inner side of the encapsulation film 20A is a molten layer, which is used to be melted by heat to form a sealing structure, and the second adhesive member 60 is connected to the molten layer adjacent to the first recess 411A to form a sealing structure.

[0136] In some embodiments, the second adhesive 60 extends between the first surface 4111 and the second surface 4113, that is, the second adhesive 60 fills the inside of the first bend 411B to reduce the risk of the first bend 411B opening due to springback, which is beneficial to improving the structural stability of the first end 411.

[0137] In some embodiments, the second adhesive 60 also extends between the third surface 4114 and the fourth surface 4116, that is, the second adhesive 60 fills the inside of the second bend 411D to reduce the risk of the second bend 411D opening due to springback, which is beneficial to improving the structural stability of the first end 411.

[0138] Optionally, the material of the second adhesive 60 is selected from at least one of polypropylene, polyethylene and polyethylene terephthalate to facilitate fusion with the molten layer and to provide excellent sealing performance.

[0139] Please refer to it again. Figure 4 In some embodiments, the encapsulation film 20A includes a first encapsulation region 201 and a second encapsulation region 202 located on both sides of the first connecting portion 411C. At least one of the first encapsulation region 201 and the second encapsulation region 202 is provided with a receiving portion 203, which is configured to receive the electrode assembly 10. Specifically, the receiving portion 203 is formed by punching a pit in the encapsulation film 20A. Optionally, both the first encapsulation region 201 and the second encapsulation region 202 are provided with receiving portions 203.

[0140] Please see Figure 7 In some embodiments, the first packaging area 201 does not have a receiving portion 203, while the second packaging area 202 has a receiving portion 203.

[0141] It is understood that in some embodiments, the first packaging region 201 is provided with a receiving portion 203, while the second packaging region 202 is not provided with a receiving portion 203.

[0142] Please refer to it again. Figure 1 In some embodiments, the main body 30 further includes a top wall 34, which and the folded portion 31 are disposed opposite each other along a third direction Z, and a first wall 32 is connected between the top wall 34 and the folded portion 31. The encapsulation portion 40 further includes a top sealing edge 43, which is connected to the top wall 34 and connected to the first encapsulation edge 41. The battery cell 100 further includes a tab 70, which is connected to the electrode assembly 10 and extends from the top sealing edge 43.

[0143] It is understood that the structure of the second encapsulation edge 42 is the same as the structure of the first encapsulation edge 41, the structure of the second end 421 is the same as the structure of the first end 411, and the structure of the second recess 421A is the same as the structure of the first recess 411A. Correspondingly, the above-mentioned dimensional parameters of the first recess 411A also apply to the second recess 421A.

[0144] It should be noted that, for ease of measurement, the dimensional parameters involved in this application are measured when the first encapsulation edge 41 is in the unfolded state, that is, when viewed along the third direction Z, the first encapsulation edge 41 extends from the first wall 32 along the second direction Y and continues to extend along the second direction Y.

[0145] Example 2

[0146] Please refer to the following: Figure 8 and Figure 9 An embodiment of this application also provides a battery cell 100B. The difference between battery cell 100B and battery cell 100A lies in the structure of the first wall 32.

[0147] In some embodiments, when viewed along the second direction Y, the first wall 32 includes a first planar region 321 and a first arcuate region 322 arranged along the third direction Z, with the first arcuate region 322 connecting the folded portion 31 and the first planar region 321. The centerline of the first arcuate region 322 in the second direction Y is defined as the first centerline O.

[0148] It should be noted that the method for measuring the first center line O is as follows: a cross-sectional view of the cell 100B is obtained along the first direction X using CT (computed tomography). After obtaining the outline of the receiving part 203, the position of the first center line O can be obtained by measuring the center line of the first arc surface area 322 in the second direction Y.

[0149] The first encapsulation edge 41 includes a first side edge 412 extending along the third direction Z. One end of the first recess 411A is located on the first side edge 412, and the other end of the first recess 411A is located between the first planar region 321 and the first center line O, so as to reduce the risk of the first end 411 protruding the folded portion 31 along the third direction Z, and reduce the risk of interference between the first recess 411A and the main body portion 30.

[0150] When viewed along the first direction X, the first arc surface area 322 is located at one of the corners of the main body 30 and forms a rounded corner.

[0151] In some embodiments, the other corners of the main body 30 are rounded.

[0152] Apart from the differences mentioned above, the parameters of cell 100B and cell 100A are roughly the same, and you can refer to the description of cell 100A above.

[0153] Example 3

[0154] Please see Figure 10 An embodiment of this application also provides a battery cell 100C. The difference between battery cell 100C and battery cell 100A lies in the position of the protruding tab 70.

[0155] In some embodiments, the battery cell 100C further includes a tab 70, which is connected to the electrode assembly 10 and extends from the first encapsulation edge 41. Specifically, the tab 70 is also spaced apart from the first end 411 to reduce the risk of interference between the tab 70 and the first recess 411A, which could lead to poor sealing of the tab 70.

[0156] Apart from the differences mentioned above, the parameters of cell 100C and cell 100A are roughly the same. Please refer to the description of cell 100A above.

[0157] Example 4

[0158] Please see Figure 11 An embodiment of this application also provides a battery cell 100D. The difference between battery cell 100D and battery cell 100A lies in the different states of the first packaging edge 41 and the second packaging edge 42.

[0159] In some embodiments, the first encapsulation edge 41 is in a folded state. Specifically, viewed along the third direction Z, the first encapsulation edge 41 extends from the first wall 32 along the second direction Y and then folds towards the first wall 32 to reduce the space occupied by the packaging bag 20 in the second direction Y, thereby increasing the energy density of the battery cell 100D.

[0160] In some embodiments, the second encapsulation edge 42 is in a folded state. Specifically, viewed along the third direction Z, the second encapsulation edge 42 extends from the first wall 32 and folds towards the second wall 33 along the second direction Y, so as to reduce the space occupied by the packaging bag 20 in the second direction Y, thereby increasing the energy density of the battery cell 100D.

[0161] It is understandable that the first encapsulation edge 41 and the second encapsulation edge 42 can be bent multiple times.

[0162] Apart from the differences mentioned above, the parameters of cell 100D and cell 100A are roughly the same. Please refer to the description of cell 100A above.

[0163] Please refer to the following: Figure 12 and Figure 13 An embodiment of this application also provides a method for packaging a battery cell, wherein the battery cell is one of the battery cells (100A, 100B, 100C, 100D) in any of the above embodiments, and the method for packaging the battery cell includes the following steps:

[0164] The portion of the encapsulation film 20A in the unfolded state corresponding to the first end 411 is punched with a groove;

[0165] The encapsulation film 20A in the unfolded state is folded along the grooved position of the folded portion 31 and the first end 411 to form the first encapsulation edge 41;

[0166] Two opposing hot press blocks 90 are provided, and the two hot press blocks 90 are moved toward each other to apply pressure to the first encapsulation edge 41 to complete the encapsulation.

[0167] Please continue reading. Figure 13In some embodiments, the first encapsulation edge 41 includes a first segment 41A and a second segment 41B arranged along a third direction Z. The groove is located at the end of the first segment 41A away from the second segment 41B. Along the first direction X, the thickness of the first segment 41A is greater than the thickness of the second segment 41B. Each hot-pressing block 90 has a hot-pressing surface 91 on one side, which includes a first region 91A and a second region 91B recessed relative to the first region 91A.

[0168] The specific steps for applying pressure to the first encapsulation edge 41 to complete the encapsulation are as follows:

[0169] The second segment 41B is positioned between the two first regions 91A, and the first segment 41A is positioned between the two second regions 91B;

[0170] Two hot-pressing blocks 90 are moved toward each other to apply pressure to the first segment 41A and the second segment 41B, so that the compression ratio of the first segment 41A is equal to that of the second segment 41B. After hot pressing, the first segment 41A forms the first end 411, and the grooved position forms the first recess 411A.

[0171] Specifically, the thickness of the first segment 41A before hot pressing is S1, the thickness of the first segment 41A after hot pressing is S2, and the compression ratio of the first segment 41A is (S1-S2) / S1. The thickness of the second segment 41B before hot pressing is S3, the thickness of the second segment 41B after hot pressing is S4, and the compression ratio of the second segment 41B is (S3-S4) / S3.

[0172] In the above-described battery cell packaging method, by providing a first region 91A and a second region 91B recessed relative to the first region 91A on the hot-pressing surface 91, the first segment 41A and the second segment 41B can be hot-pressed simultaneously, thereby improving packaging efficiency. By making the compression ratio of the first segment 41A equal to that of the second segment 41B, the risk of the first segment 41A being damaged due to excessive force or excessive bending can be reduced.

[0173] In some embodiments, along the third direction Z, the length of the distance from the junction of the first region 91A and the second region 91B away from the groove position on the side away from the first recess 411A (i.e., the side of the first connecting part 411C away from the first recess 411A) is D2, 1mm≤D2≤3mm, so as to form a transition structure on one side of the first end 411, improve the structural stability of the first end 411, and facilitate the setting of the second adhesive 60.

[0174] Optionally, D2 can be any value within the range of 1mm, 1.5mm, 2mm, 2.5mm, 3mm, and 1mm≤D2≤3mm.

[0175] In some embodiments, each hot press block 90 has a hot press surface 91 on one side, and the hot press surface 91 is a plane.

[0176] The specific steps for applying pressure to the first encapsulation edge 41 to complete the encapsulation are as follows:

[0177] The first segment 41A is placed between two hot pressing surfaces 91, and the two hot pressing blocks 90 move toward each other and apply pressure to the first segment 41A. After hot pressing, the first segment 41A forms the first end 411, and the grooved position forms the first recess 411A.

[0178] The second segment 41B is positioned between the two hot pressing surfaces 91. The two hot pressing blocks 90 move toward each other and apply pressure to the second segment 41B, so that the compression ratio of the first segment 41A is equal to the compression ratio of the second segment 41B.

[0179] In the above-mentioned battery cell packaging method, by hot-pressing the first segment 41A and the second segment 41B sequentially with the hot-pressing surface 91, and making the compression ratio of the first segment 41A equal to that of the second segment 41B, the risk of the first segment 41A being damaged due to excessive force or excessive bending can be reduced.

[0180] Understandably, in some embodiments, the second segment 41B can be placed between the two hot pressing surfaces 91, and the two hot pressing blocks 90 can move toward each other and apply pressure to the second segment 41B. Then, the first segment 41A can be placed between the two hot pressing surfaces 91, and the two hot pressing blocks 90 can move toward each other and apply pressure to the first segment 41A, so that the compression ratio of the first segment 41A is equal to the compression ratio of the second segment 41B.

[0181] In some embodiments, the battery cell packaging method further includes the following steps:

[0182] A second adhesive member 60 is provided on the side of the groove location away from the first recess 411A, so that the second adhesive member 60 is connected to the side of the first connecting part 411C away from the first recess 411A, thereby improving the sealing performance inside the first encapsulation edge 41.

[0183] Please continue reading. Figure 14 An embodiment of this application also provides a terminal device 200, which includes the battery cells (100A, 100B, 100C, 100D) in any of the above embodiments.

[0184] Optionally, the terminal device 200 may be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc.

[0185] In the aforementioned battery cells (100A, 100B, 100C, 100D) and terminal device 200, the packaging bag 20 is formed by folding and sealing the encapsulation film 20A along the folding portion 31 and the first recess 411A. The folding portion 31, as the folding part, provides a suitable folding allowance, allowing the folding portion 31 to form a surface without encapsulation edges. The first recess 411A provides a recess distance adapted to the folding portion 31, reducing the risk of the first end 411 protruding from the folding portion 31 along the third direction Z. This helps to reduce the space occupied by the battery cells (100A, 100B, 100C, 100D) in the third direction Z, thereby increasing the energy density of the battery cells (100A, 100B, 100C, 100D).

[0186] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of this application.

Claims

1. A battery cell, characterized in that, The battery cell includes: Electrode assembly; The packaging bag includes a main body and a sealing part. The electrode assembly is disposed within the main body. The main body includes a folding part and a first wall connected to one end of the folding part in a second direction. The sealing part includes a first sealing edge, which is connected to the first wall in the second direction. The first sealing edge includes a first end connected to the folding part. The first end has a first recessed part recessed in a third direction. The first direction is the thickness direction of the battery cell, the second direction is the width direction of the battery cell, and the third direction is the length direction of the battery cell. The first direction, the second direction, and the third direction are perpendicular to each other. The packaging bag is formed by sealing a sealing film after folding it along the folding part.

2. The battery cell as described in claim 1, characterized in that, Along the second direction, the projection of the first end is located within the projection of the first wall.

3. The battery cell as described in claim 1 or 2, characterized in that, The main body also includes a second wall connected to the folding portion, the second wall being disposed opposite to the first wall along the second direction; The encapsulation part further includes a second encapsulation edge, which is connected to the second wall along the second direction. The second encapsulation edge includes a second end connected to the folded part, and the second end is provided with a second recessed part along the third direction.

4. The battery cell as described in claim 3, characterized in that, Along the second direction, the projection of the second end is located within the projection of the second wall.

5. The battery cell as described in claim 1, characterized in that, Viewed along the second direction, the first end portion includes a first bend, a second bend, and a first connecting portion. The first bend and the second bend are arranged along the first direction, and the first connecting portion connects the first bend and the second bend. The first bending portion includes a first surface, a second connecting portion, and a second surface. The first surface and the second surface are connected by the second connecting portion. The second bending portion includes a third surface, a third connecting portion, and a fourth surface. The third surface and the fourth surface are connected by the third connecting portion. Along the third direction, the second connecting portion and the third connecting portion are connected to the folded portion. The first connecting portion is away from the folded portion. The first recess is formed between the second surface, the third surface, and the first connecting portion.

6. The battery cell as described in claim 5, characterized in that, The length of the second surface and the third surface that has the larger length in the third direction is D1, where 0.5mm≤D1≤1mm.

7. The battery cell as described in claim 5, characterized in that, The length of the first recess in the second direction is L, where 2mm ≤ L ≤ 7.5mm.

8. The battery cell as described in claim 1, characterized in that, The first encapsulation edge includes a first side extending along the third direction, one end of the first recess is located on the first side, and the other end of the first recess extends to the first wall.

9. The battery cell as described in claim 1, characterized in that, Viewed along the second direction, the first wall includes a first planar area and a first arcuate area arranged along the third direction. The first arcuate area connects the folded portion and the first planar area. The centerline of the first arcuate area in the second direction is defined as the first centerline. The first encapsulation edge includes a first side extending along the third direction, one end of the first recess is located on the first side, and the other end of the first recess is located between the first planar area and the first centerline.

10. The battery cell as described in claim 5, characterized in that, The battery cell also includes a first adhesive component, which is connected between the second surface and the third surface.

11. The battery cell as described in claim 5 or 10, characterized in that, The battery cell also includes a second adhesive component, which is connected to the side of the first connecting portion opposite to the first recess.

12. The battery cell as described in claim 11, characterized in that, The material of the second adhesive is selected from at least one of polypropylene, polyethylene and polyethylene terephthalate.

13. The battery cell as described in claim 11 or 12, characterized in that, The second adhesive also extends between the first surface and the second surface, and / or the second adhesive also extends between the third surface and the fourth surface.

14. The battery cell as described in claim 5, characterized in that, The encapsulation film includes a first encapsulation area and a second encapsulation area located on both sides of the first connection portion. The first encapsulation area and / or the second encapsulation area are provided with a receiving portion, which is configured to receive the electrode assembly.

15. The battery cell as described in claim 1, characterized in that, The main body also includes a top wall, the top wall and the folding part are disposed opposite to each other along the third direction, the first wall is connected between the top wall and the folding part, and the encapsulation part also includes a top sealing edge, the top sealing edge is connected to the top wall and connected to the first encapsulation edge; The battery cell also includes tabs that are connected to the electrode assembly and extend from the top seal edge.

16. The battery cell as described in claim 1, characterized in that, The battery cell also includes tabs that are connected to the electrode assembly and extend from the first package edge.

17. A terminal device, characterized in that, The terminal device includes a battery cell as described in any one of claims 1 to 16.

18. A method for packaging a battery cell, characterized in that, The battery cell is the battery cell according to claim 1, and the packaging method of the battery cell includes the following steps: The portion of the encapsulation film in its unfolded state corresponding to the first end is punched with a groove; The encapsulation film, which is in the unfolded state, is folded along the folded portion and the punched groove to form the first encapsulation edge; Two opposing hot press blocks are provided, and the two hot press blocks are moved toward each other to apply pressure to the first encapsulation edge to complete the encapsulation.

19. The battery cell packaging method as described in claim 18, characterized in that, The first encapsulation edge includes a first segment and a second segment arranged along the third direction, the punched groove is located at the end of the first segment away from the second segment, and along the first direction, the thickness of the first segment is greater than the thickness of the second segment; Each of the hot-pressing blocks has a hot-pressing surface on one side, the hot-pressing surface including a first region and a second region recessed relative to the first region; The second segment is positioned between the two first regions, and the first segment is positioned between the two second regions; The two hot-pressing blocks are moved toward each other to apply pressure to the first segment and the second segment, so that the compression ratio of the first segment is equal to that of the second segment. After hot pressing, the first segment forms the first end, and the grooved position forms the first recess.

20. The battery cell packaging method as described in claim 19, characterized in that, Along the third direction, the length of the junction of the first region and the second region from the side of the groove location away from the first recess is D2, where 1mm≤D2≤3mm.

21. The battery cell packaging method as described in claim 18, characterized in that, The first encapsulation edge includes a first segment and a second segment arranged along the third direction, the punched groove is located at the end of the first segment away from the second segment, and along the first direction, the thickness of the first segment is greater than the thickness of the second segment; Each of the hot-pressed blocks has a hot-pressing surface on one side; The first segment is placed between the two hot pressing surfaces, the two hot pressing blocks move towards each other and apply pressure to the first segment, the first segment forms the first end after hot pressing, and the groove position forms the first recess. The second segment is placed between the two hot pressing surfaces, and the two hot pressing blocks move toward each other and apply pressure to the second segment, so that the compression ratio of the first segment is equal to the compression ratio of the second segment.

22. The battery cell packaging method as described in claim 19 or 21, characterized in that, The maximum dimension of the first recess in the first direction is W, where 0.3mm ≤ W ≤ 0.5mm.

23. The battery cell packaging method as described in claim 18, characterized in that, The battery cell packaging method further includes the following step: setting a second adhesive on the side of the punched groove that is away from the first recess.

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