Battery cell, battery, and terminal device
By adopting a top-seal folded structure and sealing area design in the battery cell, the problems of large space occupation and interference of the top seal are solved, thereby improving the energy density and packaging stability of the battery cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN NVT TECH
- Filing Date
- 2025-04-30
- Publication Date
- 2026-06-09
AI Technical Summary
The large space occupied by the bend in the top seal of the battery cell leads to a decrease in energy density and may interfere with the circuit board assembly.
The top-sealed folded structure is adopted, with the top-sealed body connected to the top wall and bent. The top-sealed folded part is connected to both ends of the top-sealed body along the second direction and is divided into the first and second folded parts through the first crease. The first folded part is warped to reduce space waste. The design of the sealing area and the inner unsealed area is combined to improve the sealing strength and stability.
It effectively reduces space waste, increases the energy density of the battery cell, reduces the risk of interference between the top seal fold and the circuit board assembly, and enhances packaging stability.
Smart Images
Figure CN224342357U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to a battery cell, battery and terminal device. Background Technology
[0002] In a top-sealed battery cell, the top seal of the cell bends towards one of the cell's top walls, creating two angles at the corners of the cell with the side seal. These two angles occupy a significant amount of space, leading to a reduction in the cell's energy density. Utility Model Content
[0003] In view of the above, this application provides a battery cell that is beneficial to improving energy density.
[0004] An embodiment of this application provides a battery cell, which includes an electrode assembly, two tabs, and a packaging bag. The two tabs are connected to the electrode assembly. The packaging bag includes a main body and a packaging part, with the electrode assembly disposed within the main body. The main body includes a top wall. The packaging part includes a top sealing part. The top sealing part includes a top sealing body and two top sealing folds. Viewed along a first direction, the top sealing body is connected to the top wall and bent toward the top wall, and the two top sealing folds are connected to both ends of the top sealing body along a second direction, with at least a portion of each top sealing fold overlapping the top sealing body. The tabs extend from the top sealing body, and the two tabs are spaced apart along the second direction. At least a portion of each top sealing fold is located between the top sealing body and the top wall. The top sealing fold has a first crease, which divides the top sealing fold into a first fold and a second fold. The first fold is disposed between the second fold and the top sealing body, and the second fold is disposed between the first fold and the top wall. Viewed along the second direction, the first fold warps outward relative to the second fold along a third direction. The first direction is the thickness direction of the battery cell, and the first, second, and third directions are perpendicular to each other.
[0005] In the aforementioned battery cell, viewed along a first direction, the top sealing body is connected to and bent toward the top wall, and two top sealing folds are connected to both ends of the top sealing body along a second direction, with at least a portion of each top sealing fold overlapping the top sealing body. Compared to existing methods of setting corners at the corners of the battery cell, the top sealing folds reduce space waste, thereby improving the energy density of the battery cell. The first fold is disposed between the second fold and the top sealing body, and the second fold is disposed between the first fold and the top wall, further reducing the space occupied by the top sealing folds on the top wall, thereby reducing space waste and lowering the risk of interference with circuit board assemblies disposed on the top wall. Viewed along the second direction, the first fold warps outward relative to the second fold along a third direction to alleviate stress concentration in the top sealing folds.
[0006] In some embodiments of this application, along the extending direction of the top seal, the top seal includes a first sealing area and a first inner unsealed area located on the side of the first sealing area near the electrode assembly. The first inner unsealed area can reduce the tensile stress on the portion of the top seal fold near the electrode assembly in the folded state, thereby reducing the risk of the portion of the top seal fold near the electrode assembly extending outward or breaking. The first sealing area includes a first region and a second region connected to both sides of the first region along a second direction. The second region extends from the first region into the corresponding top seal fold. The first sealing area is used to improve the sealing strength of the top seal body, and the second region is used to improve the sealing strength of the top seal fold.
[0007] In some embodiments of this application, the first sealing area is the area of the top seal that has been heat-sealed, and the first unsealed inner area is the area of the top seal that has not been heat-sealed.
[0008] In some embodiments of this application, along the extension direction of the top seal, the width of the first region is W1, and the width of the second region is W2. A clearance area is provided on the side of the second region closest to the first unsealed inner region. The width of the clearance area is W1-W2, 0.1mm≤W1-W2≤0.5mm, to reduce the tensile stress on the portion of the top seal fold near the electrode assembly in the folded state, and to mitigate the risk of reduced encapsulation strength in the second region due to an excessively wide clearance area. When the encapsulation is in the folded state, along the second direction, the width of the cell is L1, and along the direction perpendicular to the extension direction of the top seal, the length of the clearance area is L2, 1mm≤L2<0.5L1, to allow the clearance area to extend into the corresponding top seal fold, and to mitigate the risk of reduced encapsulation strength in the first region due to an excessively long clearance area.
[0009] In some embodiments of this application, along the extending direction of the top seal, the width of the first region is W1, the width of the second region is W2, and W1=W2, so as to make the sealing strength of the top seal consistent and improve the sealing stability of the top seal.
[0010] In some embodiments of this application, the side of the top seal body near the top wall is the root portion along the extending direction of the top seal portion. The body portion includes a first wall and a second wall connected to both sides of the top wall along a first direction. The top wall includes a first surface and a second surface. Along the first direction, the first surface is located between the first wall and the root portion, and the second surface is located between the second wall and the root portion. The width of the first surface is greater than the width of the second surface. A first reference line is defined to extend along the second direction and lie on the first surface. Along the first direction, the distance between the first reference line and the root portion is D1, 0.4mm≤D1≤1mm. Along the extending direction of the top seal portion, the distance between the side of the first region near the first inner unsealed region and the first reference line is D2, 0.5mm≤D2≤2mm, so that the first sealing region is moved upward as a whole, reducing the risk that the part of the top seal folding portion near the electrode assembly will be subjected to large tensile stress in the folded state due to insufficient width of the first inner unsealed region, and also helping to reduce the risk that the sealing strength of the top seal portion will be reduced due to excessive upward movement of the first sealing region.
[0011] In some embodiments of this application, the maximum distance between the overlapping portion of the top seal body and the first folding portion and the first reference line along the third direction is D3, 0.3mm≤D3≤2mm, so as to alleviate stress concentration in the top seal folding portion and reduce space waste caused by the large space occupied by the top seal folding portion along the third direction.
[0012] In some embodiments of this application, the main body includes two sidewalls connected to both sides of the top wall along a second direction. The encapsulation portion includes two side seals, one side seal connected to a sidewall and bent toward the sidewall, and the other side seal connected to a top seal fold. Along the extending direction of the side seal, the side seal includes a second sealing area and a second unsealed area located on the side of the second sealing area near the electrode assembly. The top seal also includes two third sealing areas, one third sealing area located in a top seal fold, and the third sealing area disposed between the first sealing area and the second sealing area to improve the encapsulation stability at the corner of the cell.
[0013] In some embodiments of this application, the battery cell includes an adhesive member connected between the top seal body and the top wall to improve the positional stability of the top seal body on the top wall. Along a third direction, the projection of the top seal fold does not overlap with the projection of the adhesive member, thereby reducing space waste caused by the large space occupied by the top seal fold along the third direction.
[0014] In some embodiments of this application, the surface of the top seal body portion away from the top wall along a third direction includes a first reference surface, which is located between the two tabs along a second direction. A first reference line passes through the highest point of the first fold portion along a third direction and the end of the adhesive member adjacent to the corresponding top seal fold portion along the second direction. The upturn angle of the first fold portion is θ, which is the acute angle formed by the intersection of the first reference line and the plane containing the first reference surface. The side seal portion includes a side seal body portion and a protruding portion. The side seal body portion is disposed opposite to the side wall along the second direction, and the protruding portion connects the side seal body portion and the second fold portion, protruding outward relative to the side seal body portion along the second direction. The surface of the side seal body portion away from the side wall along the second direction is the second reference surface. Along the second direction, the distance between the end of the adhesive and the corresponding second reference surface is D5. 3mm≤D5≤4mm, and 5°≤θ≤45°; or 4mm≤D5≤5mm, and 3°≤θ≤35°, so as to reduce stress concentration at the top seal fold and reduce the increase in the size of the cell in the first and second directions.
[0015] In some embodiments of this application, along the second direction, the distance between the highest point of the convex portion and the corresponding second reference surface is D6, 0mm < D6 ≤ 1mm, so as to reduce stress concentration in the top sealing fold and reduce the risk of the electrode sheet located at the corner of the main body being squeezed and damaged.
[0016] In some embodiments of this application, the top cover body includes a first sub-part and two second sub-parts. The two second sub-parts are connected to both sides of the first sub-part along a second direction, and a tab extends from one of the second sub-parts. Viewed along a first direction, the first sub-part is recessed relative to the second sub-parts toward the top wall and abuts against the top wall, thereby expanding the space available for accommodating the circuit board assembly on the side of the top cover body away from the top wall. The height difference between the first sub-part and the second sub-part is D4, where 0mm < D4 ≤ 2mm, to reduce the risk of interference between the excessively recessed first sub-part and the top wall.
[0017] An embodiment of this application provides a battery cell, which includes an electrode assembly, two tabs, and a packaging bag. The two tabs are connected to the electrode assembly. The packaging bag includes a main body and a packaging part, and the electrode assembly is disposed within the main body. The main body includes a top wall. The packaging part includes a top sealing part. The top sealing part includes a top sealing body and two top sealing folds. Viewed along a first direction, the top sealing body is connected to the top wall and bent toward the top wall, and the two top sealing folds are connected to both ends of the top sealing body along a second direction, and at least a portion of each top sealing fold overlaps with the top sealing body. The tabs extend from the top sealing body, and the two tabs are spaced apart along the second direction. The first direction is the thickness direction of the battery cell and is perpendicular to the second direction. The top sealing folds include a fitting part, a third fold, and a fourth fold. The fitting part is fitted to the corner of the top wall and the side wall, the third fold is bent toward the corner, and at least a portion of the third fold overlaps with the fitting part, and the fourth fold is bent toward the corner, and at least a portion of the fourth fold overlaps with the fitting part.
[0018] The embodiments of this application also provide a battery, which includes a circuit board assembly and a battery cell as described in the above embodiments. The circuit board assembly is disposed on the side of the top sealing body away from the top wall, and the circuit board assembly is electrically connected to the electrode tab.
[0019] Embodiments of this application also provide a terminal device, which includes a battery as described in the above embodiments.
[0020] In the aforementioned battery cell, battery, and terminal device, viewed along the first direction, the top sealing body is connected to the top wall and bent towards the top wall. Two top sealing folds are connected to both ends of the top sealing body along the second direction, and at least a portion of each top sealing fold overlaps with the top sealing body. Compared to existing methods of setting corners at the corners of the battery cell, the top sealing folds can reduce space waste, thereby improving the energy density of the battery cell. At least a portion of the second fold is stacked on the top wall, and at least a portion of the first fold is stacked between the second fold and the top sealing body, further reducing the space occupied by the top sealing folds on the top wall, thereby reducing space waste and lowering the risk of interference with circuit board assemblies disposed on the top wall. Viewed along the second direction, the first fold warps outward relative to the second fold along a third direction to alleviate stress concentration in the top sealing folds. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the battery cell structure in one embodiment of this application.
[0022] Figure 2 This is a schematic diagram of the top seal of the battery cell in one embodiment of this application.
[0023] Figure 3 This is a schematic diagram of the structure of the first sealing area of the battery cell in one embodiment of this application.
[0024] Figure 4 This is a schematic diagram of the structure of the first sealing area of the battery cell in another embodiment of this application.
[0025] Figure 5 yes Figure 1 A sectional view along section line AA.
[0026] Figure 6 This is a schematic diagram of the structure of the first fold of the battery cell in one embodiment of this application.
[0027] Figure 7 This is a schematic diagram of the adhesive component for the battery cell in one embodiment of this application.
[0028] Figure 8 This is a schematic diagram of the top sealing body of the battery cell in one embodiment of this application.
[0029] Figure 9 This is a schematic diagram of the top seal and side seal of the battery cell in one embodiment of this application.
[0030] Figure 10 This is a schematic diagram of the battery cell structure in another embodiment of this application.
[0031] Figure 11 This is a schematic diagram of the battery structure in one embodiment of this application.
[0032] Figure 12 This is a schematic diagram of the dual-cell structure of a battery in one embodiment of this application.
[0033] Figure 13 This is a schematic diagram of the terminal device in one embodiment of this application.
[0034] Explanation of main component symbols
[0035] Battery cells 100A, 100B
[0036] Battery 200
[0037] Terminal device 300
[0038] Electrode assembly 10
[0039] JE15
[0040] Packaging bag 20
[0041] Main body 30
[0042] Top Wall 31
[0043] Page 311
[0044] Second page 312
[0045] First Wall 32
[0046] Second Wall 33
[0047] Side wall 34
[0048] Packaging section 40
[0049] Top sealing part 41
[0050] Top seal body part 411
[0051] Root 411A
[0052] First Subsection 4111
[0053] Second subsection 4112
[0054] First Reference Plane 411B
[0055] Top sealing folding part 412
[0056] First crease 412A
[0057] First fold section 412B
[0058] Second fold section 412C
[0059] Adhesion part 412D
[0060] Third fold section 412E
[0061] Fourth fold section 412F
[0062] First Sealed Area 41A
[0063] Zone 1, 41A1
[0064] Second Zone 41A2
[0065] Safe Zone 41A3
[0066] First Unsealed Zone 41B
[0067] Third Sealed Area 41C
[0068] Side sealing part 42
[0069] Second Sealed Area 42A
[0070] Second Unsealed Zone 42B
[0071] Side sealing part body part 421
[0072] Second Reference Plane 421A
[0073] convex hull 422
[0074] Adhesive parts 50
[0075] Circuit board assembly 60
[0076] Connector 61
[0077] First baseline S1
[0078] First Reference Line S2
[0079] First direction X
[0080] Second direction Y
[0081] Third direction Z
[0082] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation
[0083] 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.
[0084] 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 there may be components positioned in between. When a component is considered to be "set" on another component, it can be directly set on the other component or there may be components positioned in between. It should be understood that, considering the factors of actual machining tolerances, in the technical solution of this application, when two components are set parallel / perpendicularly, they are set in the same direction, and there may be a certain angle between the two components. The angle between the two components is allowed to have a tolerance of 0-±10%.
[0085] When one value is considered "equal" to another, it means that they are equal within a set deviation range, which is within 10%. 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 10%. 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.
[0086] 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 or coincidence of the projected portions of two components when viewed in a certain direction.
[0087] One embodiment of this application provides a battery cell, which includes an electrode assembly, two tabs, and a packaging bag. The two tabs are connected to the electrode assembly. The packaging bag includes a main body and a packaging part, with the electrode assembly disposed within the main body. The main body includes a top wall. The packaging part includes a top sealing part. The top sealing part includes a top sealing body and two top sealing folds. Viewed along a first direction, the top sealing body is connected to the top wall and bent toward the top wall, and the two top sealing folds are connected to both ends of the top sealing body along a second direction, with at least a portion of each top sealing fold overlapping the top sealing body. The tabs extend from the top sealing body, and the two tabs are spaced apart along the second direction. At least a portion of each top sealing fold is located between the top sealing body and the top wall. The top sealing fold has a first crease, which divides the top sealing fold into a first fold and a second fold. The first fold is disposed between the second fold and the top sealing body, and the second fold is disposed between the first fold and the top wall. Viewed along the second direction, the first fold is warped outward relative to the second fold along a third direction. The first direction is the thickness direction of the battery cell, and the first, second, and third directions are perpendicular to each other.
[0088] In the aforementioned battery cell, viewed along a first direction, the top sealing body is connected to and bent toward the top wall. Two top sealing folds are connected to both ends of the top sealing body along a second direction, and at least a portion of each top sealing fold overlaps with the top sealing body. Compared to existing methods of setting corners at the corners of the battery cell, the top sealing folds reduce space waste, thereby improving the battery's energy density. At least a portion of the second fold is stacked on the top wall, and at least a portion of the first fold is stacked between the second fold and the top sealing body, further reducing the space occupied by the top sealing folds on the top wall, thereby reducing space waste and lowering the risk of interference with circuit board assemblies mounted on the top wall. Viewed along the second direction, the first fold warps outward relative to the second fold along a third direction to alleviate stress concentration in the top sealing folds.
[0089] The embodiments of this application will be further described below with reference to the accompanying drawings.
[0090] Example 1
[0091] Please refer to the following: Figure 1 , Figure 2 and Figure 3 One embodiment of this application provides a battery cell 100A. The battery cell 100A can be used in secondary batteries, which are batteries that can be recharged after discharge to activate the active materials and continue to be used.
[0092] The battery cell 100A includes an electrode assembly 10, two tabs 15, and a packaging bag 20. The electrode assembly 10 is formed by winding or stacking a positive electrode, a separator, and a negative electrode in sequence. The two tabs 15 are connected to the electrode assembly 10, and the two tabs 15 have opposite polarities. Viewed along a first direction X, the two tabs 15 are spaced apart along a second direction Y. The packaging bag 20 is a sealing film made by punching, folding, and heat sealing.
[0093] Optionally, the packaging film is an aluminum-plastic film, which includes a fused layer, an aluminum layer, and a nylon layer stacked sequentially from the inside out. The fused layer is made of polypropylene, which melts at a preset temperature and has adhesive properties. The aluminum layer improves the structural strength of the packaging bag 20, and after oxidation, it forms a dense oxide film to isolate moisture. The nylon layer is used to resist external physical impacts.
[0094] Wherein, the first direction X is the thickness direction of the 100A battery cell, and the first direction X is perpendicular to the second direction Y.
[0095] Please refer to the following: Figure 1 and Figure 2 The packaging bag 20 includes a main body 30 and a packaging part 40. The main body 30 is the portion of the packaging film with perforations, and the packaging part 40 is the portion where the packaging films overlap and join. The electrode assembly 10 is disposed within the main body 30. The main body 30 includes a top wall 31, and the packaging part 40 includes a top sealing part 41. The top sealing part 41 includes a top sealing body 411 and two top sealing folds 412. Viewed along a first direction X, the top sealing body 411 is connected to the top wall 31 and bent toward the top wall 31. The two top sealing folds 412 are connected to both ends of the top sealing body 411 along a second direction Y, and at least a portion of each top sealing fold 412 overlaps with the top sealing body 411. Compared to the existing method of setting corners at the corners of the battery cell, the top sealing folds 412 can reduce space waste, thereby helping to improve the energy density of the battery cell 100A. The tab 15 extends from the top sealing body 411 to facilitate connection with the circuit board assembly disposed on the top wall 31. The top fold 412 can also reduce the risk of interference with the circuit board assembly located on the top wall 31.
[0096] In the battery 100 described above, viewed along the first direction X, the top sealing body 411 is connected to the top wall 31 and bent toward the top wall 31. Two top sealing folds 412 are connected to both ends of the top sealing body 411 along the second direction Y, and at least a portion of each top sealing fold 412 overlaps with the top sealing body 411. Compared to the existing method of setting corners at the corners of the battery cell, the top sealing folds 412 reduce space waste, thereby helping to improve the energy density of the battery cell 100A.
[0097] Please refer to the following: Figure 1 and Figure 2 In some embodiments, at least a portion of each top-sealing fold 412 is located between the top-sealing body portion 411 and the top wall 31. The top-sealing fold 412 has a first crease 412A that divides the top-sealing fold 412 into a first fold 412B and a second fold 412C. The first fold 412B is disposed between the second fold 412C and the top-sealing body portion 411, and the second fold 412C is disposed between the first fold 412B and the top wall 31. At least a portion of the second fold 412C overlaps with the top wall 31, and at least a portion of the first fold 412B overlaps with the second fold 412C and the top-sealing body portion 411, further reducing the space occupied by the top-sealing fold 412 on the top wall 31, thereby reducing space waste and lowering the risk of interference with circuit board assemblies disposed on the top wall 31.
[0098] Please refer to the following: Figure 1 and Figure 2 In some embodiments, along the extending direction of the top sealing portion 41, the side of the top sealing body portion 411 near the top wall 31 is the root portion 411A. The main body portion 30 includes a first wall 32 and a second wall 33 connected to both sides of the top wall 31 along a first direction X. The top wall 31 includes a first surface 311 and a second surface 312. Along the first direction X, the first surface 311 is located between the first wall 32 and the root portion 411A, and the second surface 312 is located between the second wall 33 and the root portion 411A. The width of the first surface 311 is greater than the width of the second surface 312. The top sealing body portion 411 is bent toward the first surface 311 so that after bending, the top sealing body portion 411 does not exceed the first wall 32 in the first direction X, which is beneficial to improving the energy density of the battery 100.
[0099] It should be noted that the extension direction of the top sealing part 41 specifically refers to the direction of the top sealing part 41 from the end connected to the main body part 30 to the end away from the main body part 30.
[0100] Please see Figure 3Along the extending direction of the top seal portion 41, the top seal portion 41 includes a first sealing area 41A and a first inner unsealed area 41B located on the side of the first sealing area 41A near the electrode assembly 10. The first sealing area 41A is the area of the top seal portion 41 that has been heat-sealed, and the encapsulation film is fused to the portion corresponding to the first sealing area 41A. The first inner unsealed area 41B is the area of the top seal portion 41 that has not been heat-sealed, and the encapsulation film is not fused to the portion corresponding to the first inner unsealed area 41B. The first inner unsealed area 41B extends into the top seal fold portion 412 to reduce the tensile stress on the portion of the top seal fold portion 412 near the electrode assembly 10 in the folded state, thereby reducing the risk of the portion of the top seal fold portion 412 near the electrode assembly 10 extending outward or breaking.
[0101] In some embodiments, the first sealing region 41A includes a first region 41A1 and a second region 41A2 connected to both sides of the first region 41A1 along a second direction Y. The second region 41A2 extends from the first region 41A1 into the corresponding top sealing fold 412. The first sealing region 41A is used to improve the sealing strength of the top sealing body 411, and the second region 41A2 is used to improve the sealing strength of the top sealing fold 412.
[0102] In some embodiments, two tabs 15 extend from the first region 41A1.
[0103] In some embodiments, along the extending direction of the top seal portion 41, the width of the first region 41A1 is W1, and the width of the second region 41A2 is W2. A clearance region 41A3 is provided on the side of the second region 41A2 near the first unsealed inner region 41B. The width of the clearance region 41A3 is W1-W2, where 0.1mm≤W1-W2≤0.5mm. The clearance region 41A3 is the area of the top seal portion 41 that has not been heat-sealed, and the portion of the encapsulation film corresponding to the clearance region 41A3 is not fused together. The clearance region 41A3 and the first unsealed inner region 41B are disposed in the top seal fold portion 412 to further reduce the tensile stress experienced by the portion of the top seal fold portion 412 near the electrode assembly 10 in the folded state, thereby further reducing the risk of the portion of the top seal fold portion 412 near the electrode assembly 10 extending outwards or breaking. By limiting the size to 0.1mm≤W1-W2≤0.5mm, the tensile stress on the part of the top seal fold 412 near the electrode assembly 10 in the folded state is reduced, and the risk of the encapsulation strength of the second region 41A2 being reduced due to the excessive width of the clearance area 41A3 is also reduced.
[0104] It should be noted that W1 and W2 are measured in the following manner: The encapsulation part 40 is unfolded so that its thickness direction is parallel to the first direction X. At this time, the extension direction of the top seal part 41 is the third direction Z, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. Along the second direction Y, three measurement points are selected on the first region 41A1, and the width of each measurement point along the third direction Z is measured. The average of the three spacing values is calculated, and the average value is W1. Along the second direction Y, three measurement points are selected on the second region 41A2, and the width of each measurement point along the third direction Z is measured. The average of the three spacing values is calculated, and the average value is W2.
[0105] Optionally, W1-W2 can be any value within the range of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, and any other value within the range of 0.1mm≤W1-W2≤0.5mm.
[0106] In some embodiments, the width of the cell 100A along the second direction Y is L1. The length of the clearance area 41A3 along the direction perpendicular to the extension direction of the top seal 41 is L2, where 1mm ≤ L2 < 0.5L1, so that the clearance area 41A3 can extend into the corresponding top seal fold 412, and it helps to reduce the risk of the first region 41A1 being reduced due to the clearance area 41A3 being too long.
[0107] It should be noted that L2 is measured in the following way: the encapsulation part 40 is unfolded so that the thickness direction of the encapsulation part 40 is parallel to the first direction X. At this time, the length direction of the clearance area 41A3 is the second direction Y. Along the third direction Z, three measurement points are selected on the clearance area 41A3, and the length of each measurement point along the second direction Y is measured. The average value of the three spacing values is calculated, and the average value is L2.
[0108] Optionally, L1 can be any value within the range of 1mm, 1.5mm, 2mm, and 1mm≤L2<0.5L1.
[0109] Please see Figure 4 In some embodiments, along the extending direction of the top seal 41, the width of the first region 41A1 is W1 and the width of the second region 41A2 is W2, W1=W2, so that the sealing strength of the top seal 41 is consistent and the sealing stability of the top seal 41 is improved.
[0110] Please refer to the following: Figure 1 , Figure 3 and Figure 4In some embodiments, the main body 30 includes two sidewalls 34 connected to both sides of the top wall 31 along a second direction Y. The encapsulation portion 40 includes two side sealing portions 42, one side sealing portion 42 connected to a sidewall 34 and bent toward the sidewall 34, and the other side sealing portion 42 connected to a top sealing fold 412. Along the extending direction of the side sealing portion 42, the side sealing portion 42 includes a second sealing area 42A and a second unsealed area 42B located on the side of the second sealing area 42A near the electrode assembly 10. The top sealing portion 41 also includes two third sealing areas 41C. The third sealing area 41C is the area of the top sealing portion 41 that has been heat-sealed, and the encapsulation film is fused to the portion corresponding to the third sealing area 41C. One third sealing area 41C is located in a top sealing fold 412, and the third sealing area 41C is disposed between the second area 41A2 and the second sealing area 42A to improve the encapsulation stability at the corner of the cell 100A.
[0111] It should be noted that the extension direction of the side sealing part 42 specifically refers to the direction of the side sealing part 42 from the end connected to the main body part 30 to the end away from the main body part 30.
[0112] In some embodiments, the width of the third sealing area 41C is smaller than the width of the second sealing area 42A along the extending direction of the side sealing portion 42, so as to reduce the tensile stress on the portion of the top sealing fold 412 near the electrode assembly 10 in the folded state.
[0113] It should be noted that the width of the third sealing area 41C and the width of the second sealing area 42A are measured in the following manner: The packaging part 40 is unfolded so that the thickness direction of the packaging part 40 is parallel to the first direction X. At this time, the extension direction of the top sealing part 41 is the third direction Z, and the extension direction of the side sealing part 42 is the second direction Y. Along the third direction Z, three measurement points are selected on the third sealing area 41C, and the width of each measurement point along the second direction Y is measured. The average value of the three spacing values is calculated, and the average value is the width of the third sealing area 41C. Along the third direction Z, three measurement points are selected on the second sealing area 42A, and the width of each measurement point along the second direction Y is measured. The average value of the three spacing values is calculated, and the average value is the width of the second sealing area 42A.
[0114] Please see Figure 5 In some embodiments, a first reference line S1 is defined to extend along the second direction Y and lie on the first surface 311. Along the first direction X, the distance between the first reference line S1 and the root 411A is D1, where 0.4mm ≤ D1 ≤ 1mm. When viewed along the second direction Y, the first surface 311 typically has a slope. Setting the first reference line S1 helps improve the accuracy of the measurement.
[0115] Please refer to the following: Figure 3 and Figure 5Along the extending direction of the top seal portion 41, the distance between the side of the first region 41A1 near the first inner unsealed region 41B and the first reference line S1 is D2, 0.5mm≤D2≤2mm, so that the first sealing region 41A moves upward as a whole, reducing the risk that the part of the top seal fold portion 412 near the electrode assembly 10 will be subjected to greater tensile stress in the folded state due to insufficient width of the first inner unsealed region 41B, and also helping to reduce the risk that the sealing strength of the top seal portion 41 will be reduced due to excessive upward movement of the first sealing region 41A.
[0116] It should be noted that D2 is measured in the following manner: the encapsulation part 40 is unfolded so that the thickness direction of the encapsulation part 40 is parallel to the first direction X. At this time, the extension direction of the top seal part 41 is the third direction Z. Along the second direction Y, three measurement points are selected on the side of the first region 41A1 near the first inner unsealed region 41B. The distance between each measurement point and the first reference line S1 is measured, and the average value of the three distance values is calculated. The average value is D2.
[0117] Optionally, D2 can be any value within the range of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or any other value within the range of 0.5mm≤D2≤2mm.
[0118] Please refer to the following: Figure 6 and Figure 7 In some embodiments, when viewed along the second direction Y, the first fold 412B warps outward relative to the second fold 412C along the third direction Z. Along the third direction Z, the maximum distance between the overlapping portion of the top sealing body 411 and the first fold 412B and the first reference line S1 is D3, where 0.3mm ≤ D3 ≤ 2mm. This helps alleviate stress concentration in the top sealing fold 412 and reduces space waste caused by the large space occupied by the top sealing fold 412 along the third direction Z.
[0119] Optionally, D3 can be any value within the range of 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or any other value within the range of 0.3mm≤D3≤2mm.
[0120] In some embodiments, the warping amplitude of the first fold 412B gradually increases outward from the first crease 412A, so that the highest point of the first fold 412B is located on both sides of the top wall 31 in the second direction Y, which helps to reduce the risk of interference between the first fold 412B and the circuit board assembly disposed on the top wall 31.
[0121] Please see Figure 7 In some embodiments, the battery cell 100A includes an adhesive 50 connected between the top sealing body 411 and the top wall 31 to improve the positional stability of the top sealing body 411 on the top wall 31. Along the third direction Z, the projection of the top sealing fold 412 does not overlap with the projection of the adhesive 50, thereby reducing space waste caused by the large space occupied by the top sealing fold 412 along the third direction Z.
[0122] Please see Figure 8 In some embodiments, the top cover body 411 includes a first sub-part 4111 and two second sub-parts 4112, which are connected to both sides of the first sub-part 4111 along a second direction Y. A tab 15 extends from one of the second sub-parts 4112. Viewed along a first direction X, the first sub-part 4111 is recessed relative to the second sub-parts 4112 toward and abuts against the top wall 31, thereby expanding the space available for accommodating the circuit board assembly on the side of the top cover body 411 away from the top wall 31.
[0123] In some embodiments, the height difference between the first sub-part 4111 and the second sub-part 4112 is D4, where 0 mm < D4 ≤ 2 mm, to reduce the risk of excessive recess in the first sub-part 4111 interfering with the top wall 31.
[0124] Optionally, D4 can be any value within the range of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, and any other value within the range of 0mm < D4 ≤ 2mm.
[0125] Please see Figure 9 In some embodiments, the surface of the top seal body 411 away from the top wall 31 along the third direction Z includes a first reference surface 411B, which is located between the two tabs 15 along the second direction Y. Viewed along the first direction X, the first reference line S2 passes through the highest point of the first fold 412B along the third direction Z and the end of the adhesive 50 adjacent to the corresponding top seal fold 412 along the second direction Y. The tilt angle of the first fold 412B is θ, where θ is the acute angle formed by the intersection of the first reference line S2 and the plane containing the first reference surface 411B.
[0126] The side sealing portion 42 includes a side sealing portion body portion 421 and a protruding portion 422. The side sealing portion body portion 421 is disposed opposite to the side wall 34 along the second direction Y. The protruding portion 422 connects the side sealing portion body portion 421 and the second folded portion 412C, and the protruding portion 422 protrudes outward relative to the side sealing portion body portion 421 along the second direction Y. The surface of the side sealing portion body portion 421 away from the side wall 34 along the second direction X is the second reference surface 421A. Along the second direction Y, the distance between the end of the adhesive member 50 and the corresponding second reference surface 421A is D5.
[0127] D5 and θ are negatively correlated; that is, the larger D5 is, the smaller θ is, and the smaller D5 is, the larger θ is.
[0128] In some embodiments, 3mm≤D5≤4mm and 5°≤θ≤45° are used to reduce stress concentration in the top sealing fold 412 and reduce the dimensional increase of the cell 100A in the first direction X and the second direction Y.
[0129] Optionally, D5 can be any value within the range of 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, or any other value within the range of 3mm≤D5≤4mm. θ can be any value within the range of 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, or any other value within the range of 5°≤θ≤45°.
[0130] In some embodiments, 4mm≤D5≤5mm and 3°≤θ≤35° are used to reduce stress concentration in the top sealing fold 412 and reduce the dimensional increase of the cell 100A in the first direction X and the second direction Y.
[0131] Optionally, D5 can be any value within the range of 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, or any other value within the range of 4mm≤D5≤5mm. θ can be any value within the range of 3°, 4°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, or any other value within the range of 3°≤θ≤35°.
[0132] In some embodiments, along the second direction Y, the distance between the highest point of the convex portion 422 and the corresponding second reference surface 421A is D6, 0mm < D6 ≤ 1mm, so as to reduce stress concentration in the top sealing fold portion 412 and reduce the risk of the electrode sheet located at the corner of the main body portion 30 being squeezed and damaged.
[0133] Optionally, D6 can be any value within the range of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, and any other value within the range of 0mm < D6 ≤ 1mm.
[0134] Example 2
[0135] Please see Figure 10 An embodiment of this application also provides a battery cell 100B, which differs from battery cell 100A in that the folding method of the top sealing folding part 412 is different.
[0136] The top sealing folding portion 412 includes a fitting portion 412D, a third folding portion 412E, and a fourth folding portion 412F. The fitting portion 412D fits into the corner of the top wall 31 and the side wall 34. The third folding portion 412E is bent toward the corner, and at least a portion of the third folding portion 412E overlaps with the fitting portion 412D. The fourth folding portion 412F is bent toward the corner, and at least a portion of the fourth folding portion 412F overlaps with the fitting portion 412D.
[0137] 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.
[0138] Example 3
[0139] Please see Figure 11 An embodiment of this application also provides a battery 200, including a circuit board assembly 60 and the battery cells (100A, 100B) in any of the above embodiments. The circuit board assembly 60 is disposed on the side of the top seal 41 away from the top wall 31, and the circuit board assembly 60 is electrically connected to the tab 15.
[0140] In some embodiments, the circuit board assembly 60 is provided with a connector 61, which is connected to the tab 15. The connector 61 is a U-shaped nickel sheet, an L-shaped nickel sheet, or a nickel brick.
[0141] Please see Figure 12 In some embodiments, the battery 200 includes two cells 100A arranged along the second direction Y. The top sealing folds 412 at the adjacent corners of the two cells 100A do not significantly interfere with the arrangement of the circuit board assembly 60, so that the circuit board assembly 60 can be placed closer to the top wall 31, which is beneficial to improving the energy density of the battery 200.
[0142] Example 4
[0143] Please see Figure 13 An embodiment of this application also provides a terminal device 300, including the battery 200 in any of the above embodiments.
[0144] Optionally, the terminal device 300 may be a device with a rechargeable battery, such as a mobile phone, tablet computer, laptop computer, smart wearable product (e.g., smartwatch, smart bracelet), virtual reality (VR) terminal device, augmented reality (AR) terminal device, etc.
[0145] In summary, in the aforementioned battery cells (100A, 100B), battery 200, and terminal device 200A, viewed along the first direction X, the top sealing body 411 is connected to the top wall 31 and bent towards the top wall 31, and two top sealing folds 412 are connected to both ends of the top sealing body 411 along the second direction Y, with at least a portion of each top sealing fold 412 overlapping the top sealing body 411. Compared to the existing method of setting corners at the corners of the battery cell, the top sealing folds 412 can reduce space waste, thereby helping to improve the energy density of the battery cells (100A, 100B).
[0146] In addition, those skilled in the art may make other changes within the spirit of this application. Of course, all such changes made in accordance with the spirit of this application should be included within the scope disclosed in this application.
Claims
1. A battery cell, characterized in that, The battery cell includes: Electrode assembly; Two tabs are connected to the electrode assembly; A packaging bag, comprising a main body and a sealing part, wherein the electrode assembly is disposed within the main body, the main body includes a top wall, the sealing part includes a top sealing part, the top sealing part includes a top sealing body and two top sealing folds, and viewed along a first direction, the top sealing body is connected to the top wall and bent toward the top wall, the two top sealing folds are connected to both ends of the top sealing body along a second direction, and at least a portion of each top sealing fold overlaps with the top sealing body, the electrode tabs extend from the top sealing body, and the two electrode tabs are spaced apart along the second direction; At least a portion of each of the top sealing folds is located between the top sealing body and the top wall. The top sealing fold has a first crease that divides the top sealing fold into a first fold and a second fold. The first fold is located between the second fold and the top sealing body, and the second fold is located between the first fold and the top wall. Viewed along the second direction, the first folded portion warps outward relative to the second folded portion along a third direction, the first direction being the thickness direction of the battery cell, and the first direction, the second direction, and the third direction are perpendicular to each other.
2. The battery cell as described in claim 1, characterized in that, Along the extending direction of the top seal, the top seal includes a first sealing area and a first unsealed area located in the first sealing area on the side closer to the electrode assembly; The first sealing area includes a first area and a second area connected to both sides of the first area along the second direction, the second area extending from the first area into the corresponding top sealing fold.
3. The battery cell as described in claim 2, characterized in that, The first sealing area is the area of the top seal that has been heat-sealed, and the first unsealed inner area is the area of the top seal that has not been heat-sealed.
4. The battery cell as described in claim 3, characterized in that, Along the extending direction of the top seal, the width of the first area is W1, the width of the second area is W2, and the second area has a clearance area on the side of the first unsealed inner area. The width of the clearance area is W1-W2, 0.1mm≤W1-W2≤0.5mm. Along the second direction, the width of the battery cell is L1, and along the direction perpendicular to the extension direction of the top seal, the length of the clearance area is L2, where 1mm ≤ L2 < 0.5L1.
5. The battery cell as described in claim 3, characterized in that, Along the extending direction of the top seal, the width of the first region is W1, and the width of the second region is W2, where W1 = W2.
6. The battery cell as described in claim 4 or 5, characterized in that, Along the extending direction of the top sealing portion, the side of the top sealing body portion near the top wall is the root portion. The body portion includes a first wall and a second wall connected to both sides of the top wall along the first direction. The top wall includes a first surface and a second surface. Along the first direction, the first surface is located between the first wall and the root portion, and the second surface is located between the second wall and the root portion. The width of the first surface is greater than the width of the second surface. A first baseline is defined to extend along the second direction and lie on the first surface. Along the first direction, the distance between the first baseline and the root is D1, where 0.4mm≤D1≤1mm. Along the extending direction of the top seal, the distance between the side of the first area near the first unsealed inner area and the first baseline is D2, where 0.5mm≤D2≤2mm.
7. The battery cell as described in claim 6, characterized in that, Along the third direction, the maximum distance between the overlapping portion of the top sealing body and the first folding portion and the first baseline is D3, where 0.3mm≤D3≤2mm.
8. The battery cell as described in claim 7, characterized in that, The main body includes two sidewalls connected to both sides of the top wall along the second direction. The encapsulation part includes two side sealing parts, one of which is connected to one of the sidewalls and bent toward the sidewall, and the other of which is connected to one of the top sealing folding parts. Along the extending direction of the side sealing part, the side sealing part includes a second sealing area and a second unsealed area located on the side of the second sealing area near the electrode assembly. The top seal also includes two third sealing areas, one of which is located in one of the top seal folds, and the third sealing area is disposed between the second area and the second sealing area.
9. The battery cell as described in claim 8, characterized in that, The battery cell includes an adhesive component that connects the top seal body and the top wall. Along the third direction, the projection of the top seal fold does not overlap with the projection of the adhesive component.
10. The battery cell as described in claim 9, characterized in that, The surface of the top seal body away from the top wall along the third direction includes a first reference surface. The first reference surface is located between the two tabs along the second direction. The first reference line passes through the highest point of the first fold along the third direction and the end of the adhesive member adjacent to the corresponding top seal fold along the second direction. The tilt angle of the first fold is θ, where θ is the acute angle formed by the intersection of the first reference line and the plane containing the first reference surface. The side sealing portion includes a side sealing portion body and a protruding portion. The side sealing portion body is disposed opposite to the side wall along the second direction. The protruding portion is connected between the side sealing portion body and the second folded portion. The protruding portion protrudes outward relative to the side sealing portion body along the second direction. The surface of the side sealing portion body away from the side wall along the second direction is a second reference surface. Along the second direction, the distance between the end of the adhesive and the corresponding second reference surface is D5. 3mm≤D5≤4mm, and 5°≤θ≤45°; or 4mm≤D5≤5mm, and 3°≤θ≤35°.
11. The battery cell as described in claim 10, characterized in that, Along the second direction, the distance between the highest point of the convex bulge and the corresponding second reference surface is D6, where 0mm < D6 ≤ 1mm.
12. The battery cell as described in claim 1, characterized in that, The top sealing body includes a first sub-part and two second sub-parts. The two second sub-parts are connected to both sides of the first sub-part along a second direction. A tab extends from one of the second sub-parts. When viewed along the first direction, the first sub-part is recessed relative to the second sub-parts and abuts against the top wall. The height difference between the first sub-part and the second sub-part is D4, where 0mm < D4 ≤ 2mm.
13. A battery cell, characterized in that, The battery cell includes: Electrode assembly; Two tabs are connected to the 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 top wall and a side wall. The sealing part includes a top sealing part, which includes a top sealing body and two top sealing folds. Viewed along a first direction, the top sealing body is connected to the top wall and bent toward the top wall. The two top sealing folds are connected to both ends of the top sealing body along a second direction, and at least a portion of each top sealing fold overlaps with the top sealing body. The electrode tabs extend from the top sealing body, and the two electrode tabs are spaced apart along the second direction. The first direction is the thickness direction of the battery cell, and the first direction is perpendicular to the second direction. The top sealing fold includes a fitting part, a third fold, and a fourth fold. The fitting part fits into the corner of the top wall and the side wall. The third fold is bent toward the corner, and at least a portion of the third fold overlaps with the fitting part. The fourth fold is bent toward the corner, and at least a portion of the fourth fold overlaps with the fitting part.
14. A battery, characterized in that, The battery includes a circuit board assembly and a cell as described in any one of claims 1 to 13, wherein the circuit board assembly is disposed on the side of the top sealing body away from the top wall, and the circuit board assembly is electrically connected to the tab.
15. A terminal device, characterized in that, The terminal device includes a battery cell as described in any one of claims 1 to 13 or a battery as described in claim 14.