Battery cell and battery

Abstract

The present application relates to the technical field of batteries. Disclosed are a battery cell and a battery. The battery cell has a width direction and a thickness direction; the battery cell comprises a main body, an outer seal, an adhesive tape, and a bonding member. The outer seal comprises an accommodating area and a sealing edge area. The main body is arranged in the accommodating area. Two opposite sides of the accommodating area in the thickness direction are provided with a first outer surface and a second outer surface respectively, and at least one side of the accommodating area in the width direction is further provided with a connecting side surface. The sealing edge area is connected to one side of the accommodating area in the width direction and is bent towards the side of the first outer surface to abut against the connecting side surface, and the sealing edge area comprises two overlapping sealing edges. The adhesive tape wraps around and is bonded to the top ends of the two sealing edges. The bonding member is at least partially bonded between the adhesive tape and the connecting side surface. The sealing edge area and the adhesive tape are both located between the first outer surface and the second outer surface. In the thickness direction, the distance between the first outer surface and the end of the adhesive tape facing the first outer surface is greater than or equal to 0 and less than or equal to 2 mm, thereby improving the corner drop performance of the battery cell.

Description

Battery cells and batteries

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202423167160.3, filed on December 20, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, specifically to a battery cell and a battery. Background Technology

[0004] As the industry develops, the requirements for batteries are becoming increasingly stringent. Corner drop performance of battery cells is an important indicator for evaluating the durability and safety of battery cells when they are subjected to accidental impacts (especially corner impacts) during transportation, carrying, or use.

[0005] Currently, the corner drop performance of battery cells is insufficient to meet user needs. Summary of the Invention

[0006] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a battery cell that can improve the corner drop performance of the battery cell.

[0007] This application also proposes a battery having the above-mentioned cells.

[0008] According to a first aspect embodiment of the present application, the battery cell has a width direction and a thickness direction. The battery cell includes a body, an outer seal, an adhesive tape, and an adhesive member. The outer seal includes a receiving area and a sealing edge area, and the body is disposed within the receiving area. The receiving area has a first outer surface and a second outer surface on opposite sides along the thickness direction, and at least one side along the width direction also has a connecting side. The sealing edge area is connected to one side of the receiving area along the width direction and bends toward one side of the first outer surface to approach the connecting side. The sealing edge area includes two overlapping sealing edges. The adhesive tape covers and is bonded to the top ends of the two sealing edges. The adhesive member is at least partially bonded between the adhesive tape and the connecting side. The sealing edge area and the adhesive tape are both located between the first outer surface and the second outer surface. Along the thickness direction, the distance between the end of the adhesive tape facing the first outer surface and the first outer surface is ≥0 and ≤2mm.

[0009] The battery cell according to the embodiments of this application has at least the following beneficial effects: by covering and bonding the top ends of the two sealing edges with tape, UV glue can be eliminated, simplifying the processing steps, reducing the impact on the width of the battery cell, and improving the utilization rate of the internal space of the outer casing, thereby increasing the energy density of the battery cell. In addition, setting the distance between the end of the tape facing the first outer surface and the first outer surface to ≥0 and ≤2mm helps to improve the corner drop performance of the battery cell, and improves the durability and safety of the battery cell in the face of drops, impacts and other situations.

[0010] According to some embodiments of this application, the distance between the end of the tape facing the first outer surface and the first outer surface is ≥0 and ≤1mm.

[0011] According to some embodiments of this application, the connecting side is an arc surface and has a vertex position along the width direction.

[0012] According to some embodiments of this application, the projection of the adhesive along the width direction is located between the first outer surface and the vertex position, and avoids the vertex position.

[0013] According to some embodiments of this application, the tape includes a first end, a second end, and a third end. The first end and the third end are respectively located at both ends of the tape facing the second outer surface. The first end is located between the sealing area and the connecting side, and the third end is located on the side of the sealing area away from the connecting side. The second end is located between the first end and the third end, and is located at one end of the tape facing the first outer surface. Along the width direction, the projections of the first end and the second end are both located between the vertex position and the first outer surface, and the projection of the third end is located between the first outer surface and the second outer surface.

[0014] According to some embodiments of this application, a reference surface perpendicular to the first outer surface is defined, and the central axis of the arc surface along the length direction of the cell is located on the reference surface; the angle between the line connecting the central axis and the end of the adhesive facing the second outer surface and the projection of the reference surface in the length direction is defined as α, and the angle between the line connecting the first end and the central axis and the projection of the reference surface in the length direction is defined as γ, where 20°≤α-γ≤50°.

[0015] According to some embodiments of this application, the distance between the first outer surface and the second outer surface along the thickness direction is defined as T, and the distance between the second outer surface and the second end is defined as E, where E≤T.

[0016] According to some embodiments of this application, T / 2 < E ≤ (T - 0.4 mm).

[0017] According to some embodiments of this application, the distance between the second end and the third end along the thickness direction is defined as D, and the extension distance of the sealing area along the thickness direction is defined as E, where D≤E.

[0018] According to some embodiments of this application, 0.8mm ≤ D ≤ E.

[0019] According to some embodiments of this application, along the thickness direction, the distance between one end of the adhesive member facing the second outer surface and the second end is defined as B, the distance between the first outer surface and the second outer surface is defined as T, and the distance between the first end and the second end is defined as F, wherein F < B and / or B < T / 2.

[0020] According to some embodiments of this application, between the sealing area and the connecting side, the adhesive is wrapped around one end of the tape facing the second outer surface and partially bonded between the sealing area and the connecting side; and / or, along the thickness direction, the distance from the vertex position to the first outer surface is equal to the distance from the vertex position to the second outer surface; and / or, in the unbent state of the sealing area, along the width direction, the sealing area extends outward from the receiving area along the width direction; the sealing area includes a bent section and a sealing section, the bent section connecting the receiving area and the sealing section, and the sealing section being used to connect the connecting side; along the width direction, the extension length of the bent section is ≥0.2mm, and / or the extension length of the sealing section is ≥1mm.

[0021] The battery according to the second aspect of this application includes the cell in any of the above embodiments.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 shows a schematic diagram of the structure of the battery cell provided in an embodiment of this application;

[0025] Figure 2 shows a partial structural schematic diagram of the battery cell in Figure 1;

[0026] Figure 3 shows a schematic diagram of the structure of the battery cell provided in the embodiment of this application when the sealing area is in an unbent state.

[0027] Reference numerals: Cell 100; Body 110; Corner 111; Outer seal 130; Receiving area 131; First outer surface 1311; Second outer surface 1313; Connecting side 1315; Vertex position 1317; Edge sealing area 133; First edge sealing 1331; Second edge sealing 1333; Bending section 1335; Sealing section 1337; Adhesive tape 150; First end 151; Second end 153; Third end 155; Adhesive component 170; Reference surface 190; Width direction X; Thickness direction Z. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0029] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0031] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0032] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] Please refer to Figures 1 and 2. An embodiment of this application provides a battery, which includes a cell 100 and a casing. The cell 100 can be housed in the casing, and the casing can be used to protect the cell 100.

[0034] Batteries can be used to provide power for devices such as new energy vehicles, mobile phones, tablets, and laptops.

[0035] In some embodiments, the battery cell 100 may be a wound battery cell.

[0036] In some embodiments, the cell 100 has a width direction X and a thickness direction Z.

[0037] As an example, the battery cell 100 may include a positive electrode, a separator, and a negative electrode, which are sequentially stacked and wound to form the battery cell body. The electrode (positive or negative) may include alternating straight sections and bent sections along the winding direction. After the electrode is wound, multiple straight sections are stacked, and the stacking direction of these straight sections can be the thickness direction Z of the battery cell 100. The battery cell body is generally square in structure, including a first side, a second side, a third side, and a fourth side that are sequentially connected and arranged around each other. The first and third sides are opposite each other, and the second and fourth sides are opposite each other.

[0038] The battery cell 100 may also include a conductive element (TAB), which can be electrically connected between one side of the first side of the battery cell body and the battery terminal. The direction from the first side to the third side can be the length direction of the battery cell 100, and the direction from the second side to the fourth side can be the width direction X of the battery cell 100. Understandably, the battery cell body forms two corners 111 on one side of the second and fourth sides.

[0039] In some embodiments, the battery cell 100 includes a body 110, an outer casing 130, an adhesive tape 150, and an adhesive 170.

[0040] The main body 110 can be the battery cell body in the above embodiments.

[0041] The outer enclosure 130 includes a receiving area 131 and a sealing area 133 connected to one side of the receiving area 131 along the width direction X. The main body 110 is disposed within the receiving area 131 to encapsulate the main body 110 within the outer enclosure 130. The sealing area 133 can be folded to fold against the side of the receiving area 131.

[0042] The accommodating area 131 has a first outer surface 1311 and a second outer surface 1313 on opposite sides along the thickness direction Z. The accommodating area 131 also has a connecting side 1315 on at least one side along the width direction X. The sealing area 133 is bent toward one side of the first outer surface 1311 to approach the connecting side 1315. Specifically, after the sealing area 133 is bent toward one side of the first outer surface 1311, it can be located on the side of the connecting side 1315 away from the main body 110 along the width direction X.

[0043] As an example, the first outer surface 1311 and the second outer surface 1313 can be approximately parallel.

[0044] It should be noted that the accommodating area 131 can be connected to a sealing area 133 on each of its opposite sides along the width direction X. The folding method and size of the two sealing areas 133 are roughly the same. Correspondingly, the accommodating area 131 has two connecting sides 1315 on each of its opposite sides along the width direction X. For ease of description, this application embodiment uses one of the sealing areas 133 as an example for explanation.

[0045] The edge sealing area 133 includes two overlapping edges that can be overlapped along the width direction X, and the ends of the two edges facing the first surface have top ends.

[0046] As an example, the accommodating area 131 may have an accommodating space, and the main body 110 may be located within the accommodating space. The two sealing edges are named the first sealing edge 1331 and the second sealing edge 1333, respectively. The accommodating area 131 is generally cuboid in shape, and has a connecting sidewall on one side along the width direction X; that is, the connecting sidewall can serve as a sidewall enclosing the accommodating space. The outer surface of the connecting sidewall along the width direction X can be the connecting side surface 1315.

[0047] The first sealing edge 1331 is connected to one end of the connecting sidewall facing the second outer surface 1313, and bends from the second outer surface 1313 toward one side of the first outer surface 1311 to approach the connecting side 1315.

[0048] The second edge seal 1333 can be connected to the second outer surface 1313 and can be stacked on the first edge seal 1331. The second edge seal 1333 can be bent together with the first edge seal 1331 from the second outer surface 1313 to one side of the first outer surface 1311, that is, the connecting side wall is away from the main body 110 along the width direction X. The connecting side 1315, the first edge seal 1331 and the second edge seal 1333 are distributed in sequence.

[0049] The tape 150 is wrapped around and bonded to the top of the two sealing edges, thereby fixing the two sealing edges and sealing the gap between them. This helps to prevent the liquid (electrolyte) in the containment space from leaking out from the gap between the two sealing edges. In addition, the tape 150 is thin and easy to apply, which reduces the impact of the thickness of the tape 150 on the width of the battery cell 100 and improves the utilization rate of the internal space (i.e., containment space) of the outer casing 130, thereby increasing the energy density of the battery cell. Furthermore, the tape 150 only needs to be bonded to the top of the sealing edges, eliminating the need for complex processes such as dispensing and curing, simplifying the processing steps and increasing production speed.

[0050] Specifically, in related technologies, UV adhesive is usually used to bond the two sealing edges together, and the UV adhesive is cured by light. However, the thickness of the cured UV adhesive is relatively thick, which can easily affect the width of the battery cell and the space utilization of the inner space of the outer casing. Moreover, the dispensing and curing process is relatively complex and the processing cycle is long. In this embodiment, tape 150 is used to cover the top of the two sealing edges. The thickness of tape 150 is thinner than that of the cured UV adhesive, which helps to reduce the thickness of the two sealing edges after stacking. It has less impact on the width of the battery cell 100. Furthermore, tape 150 only needs to be bonded to the top of the sealing edges to fix and seal the two sealing edges, without the need for complicated processes such as dispensing and curing. This simplifies the processing of the battery cell 100 and improves the processing speed.

[0051] The sealing area 133 and the tape 150 are both located between the first outer surface 1311 and the second outer surface 1313, thereby avoiding the sealing area 133 and the tape 150 from affecting the thickness of the battery cell.

[0052] The adhesive 170 is bonded between the tape 150 and the connecting side 1315 to fix the edge sealing to the connecting side 1315, completing the edge folding process. For example, the adhesive 170 can be made of hot melt adhesive, which helps to reduce the curing time of the adhesive 170, or other adhesives can be used for the adhesive 170.

[0053] Along the thickness direction Z, the distance between the end of the tape 150 facing the first outer surface 1311 and the first outer surface 1311 is ≥0 and ≤2mm, i.e., 0≤A≤2mm. Thus, controlling the size of A within a suitable range helps improve the corner drop performance of the battery cell 100, enhancing its durability and safety in the face of drops, impacts, and other situations. Furthermore, it ensures that the adhesive 170 has a sufficiently large bonding area between the tape 150 and the connecting side 1315, guaranteeing the connection strength between the sealing area 133 and the connecting side 1315.

[0054] The corner drop performance of cell 100 under different value ranges is shown in the table below:

[0055] As can be seen from the test results in the table above, when A < 0, although the corner drop performance of the battery cell 100 is good, the tape 150 and the sealing area 133 extend beyond or cover the first outer surface 1311 along the thickness direction Z, affecting the thickness dimension of the battery cell 100. Therefore, it is not recommended to adopt this method.

[0056] When 0≤A≤2mm, such as when A is 0.5mm, 0.8mm and 2mm respectively, cell 100 can have good corner drop performance without affecting the thickness of cell 100. Therefore, it is recommended to adopt this method.

[0057] Preferably, when 1mm≤A≤2mm, the corner drop performance of the battery cell 100 is better, and the end of the tape 150 facing the first outer surface 1311 and the space between the tape 150 and the first outer surface 1311 can also provide space for the adhesive to overflow, which helps to prevent the adhesive to overflow onto the first outer surface 1311 and affect the thickness of the battery cell 100.

[0058] When A > 2mm, such as when A = 2.2mm, the corner drop performance of cell 100 is poor, so it is not recommended to adopt it.

[0059] In some embodiments, the connecting side 1315 is an arc surface and has a vertex position 1317 along the width direction X.

[0060] Specifically, the corner 111 of the main body 110 is roughly in the shape of a cylindrical arc, so the connecting side wall is also roughly in the shape of a cylindrical arc. Therefore, the connecting side 1315 is roughly a cylindrical arc surface. Thus, the connecting side 1315 will have a widest point along the width direction X, which is the vertex position 1317. It can be understood that since the connecting side 1315 is a cylindrical arc surface extending along the length direction, the vertex position 1317 is roughly a line extending along the length direction.

[0061] In some embodiments, the projection of the adhesive 170 along the width direction X is located between the first outer surface 1311 and the vertex position 1317, and avoids the vertex position 1317. This helps to prevent the adhesive 170 from overlapping with the vertex position 1317 along the width direction X, thereby preventing the adhesive 170 from affecting the width dimension of the cell 100. Under the same cell 100 size, this helps to increase the volume of the internal space of the outer casing 130, improve space utilization, and increase the energy density of the cell.

[0062] In some embodiments, the outer cover 130 may be made of aluminum-plastic film.

[0063] In some embodiments, the tape 150 may include an attached plastic film layer and an adhesive layer, the adhesive layer being used for bonding.

[0064] There are several options available for tape 150.

[0065] As an example, tape 150 can be made of high-flammability tape, such as yellow high-flammability tape or other high-flammability tape.

[0066] As another example, tape 150 can be a standard adhesive tape, such as green standard adhesive tape, blue standard adhesive tape, or other standard adhesive tapes.

[0067] As another example, tape 150 can be made of transparent tape.

[0068] In some embodiments, between the sealing area 133 and the connecting side 1315, the adhesive 170 covers one end of the tape 150 facing the second outer surface 1313 and is partially bonded between the sealing area 133 and the connecting side 1315, thereby improving the problem of the tape 150 opening between the sealing area 133 and the connecting side 1315, and also helping to improve the bonding strength between the sealing area 133 and the connecting side.

[0069] As an example, the adhesive 170 covers one end of the tape 150 facing the second outer surface 1313 and is bonded to the first sealing edge 1331. That is, the adhesive 170 can be partially bonded between the tape 150 and the connecting side 1315, and the other part is bonded between the first sealing edge 1331 and the connecting side 1315.

[0070] In some embodiments, the tape 150 includes a first end 151, a second end 153, and a third end 155. The first end 151 and the third end 155 are located at opposite ends of the tape 150 facing the second outer surface 1313. The first end 151 is located between the sealing area 133 and the connecting side 1315, and the third end 155 is located on the side of the sealing area 133 away from the connecting side 1315. The second end 153 is located between the first end 151 and the third end 155, and is located at one end of the tape 150 facing the first outer surface 1311.

[0071] As an example, tape 150 may include a first segment, a second segment, and a third segment connected in sequence. The first segment may be adhered to the first sealing edge 1331 and located between the first sealing edge 1331 and the connecting side 1315; the second segment may be adhered to the top surfaces of the first sealing edge 1331 and the second sealing edge 1333 facing the first outer surface 1311 to seal the gap between the first sealing edge 1331 and the second sealing edge 1333; the third segment may be adhered to the outer surface of the second sealing edge 1333 facing away from the first sealing edge 1331. The cooperation of the first, second, and third segments allows for a tighter fit between the first sealing edge 1331 and the second sealing edge 1333. The top of the first segment facing the second outer surface 1313 can be the first end 151, the end of the third segment facing the second outer surface 1313 can be the third end 155, and the end of the second segment facing the first outer surface 1311 can be the second end 153, or the second segment itself can be the second end 153.

[0072] Along the width direction X, the projections of the first end 151 and the second end 153 are both located between the vertex position 1317 and the first outer surface 1311, thereby confining the first segment and the second segment between the first outer surface 1311 and the vertex position 1317, which helps to reduce the influence of the first segment and the second segment on the thickness dimension of the cell 100.

[0073] As an example, the first end 151 can avoid the vertex position 1317, and the second end 153 can face the vertex on the side of the first outer surface 1311. The vertex can be located on the plane where the first outer surface 1311 is located, or the projection along the width direction X can be located between the first outer surface 1311 and the vertex position 1317.

[0074] The projection of the third end 155 is located between the first outer surface 1311 and the second outer surface 1313, thereby avoiding the third end 155 being located on the second outer surface 1313 along the thickness direction Z, which helps to avoid the tape 150 affecting the thickness dimension of the cell 100.

[0075] The vertex of the third end 155 facing the second outer surface 1313 can be located in the plane of the second outer surface 1313, or the projection along the width direction X can be located between the vertex position 1317 and the second outer surface 1313.

[0076] In some embodiments, a reference surface 190 is defined that is perpendicular to the first outer surface 1311, and the central axis of the connecting side 1315 along the length direction of the cell 100 is located on the reference surface 190.

[0077] As an example, the connecting sidewall where the connecting side 1315 is located is roughly a semi-cylindrical shape extending along the length direction, and the central axis can be the axis of the semi-cylindrical shape.

[0078] Define the angle α between the line connecting the central axis and the end of the adhesive 170 facing the second outer surface 1313 and the projection of the reference surface 190 in the length direction. Define the angle γ between the line connecting the first end 151 and the central axis and the projection of the reference surface 190 in the length direction. 20°≤α-γ≤50°. This helps to control the position of the adhesive 170 so that the adhesive 170 can cover the first end 151 and be bonded to the corresponding sealing edge (first sealing edge 1331). This helps to improve the problem of the tape 150 opening at the first end 151. In addition, limiting the difference angle between α and γ can also control the length of the first segment within a suitable range, which helps to ensure the bonding area between the first segment and the first sealing edge 1331, further improving the problem of the tape 150 opening at the first end 151.

[0079] As an example, the difference between α and γ can be 20°, 25°, 30°, 50°, or other values ​​within the interval [20°, 50°].

[0080] The following table shows the failure test results of the 133-layer edge sealing area under different value ranges of α-γ:

[0081] The test results in the table above show that when α-γ < 20°, tape 150 and / or adhesive 170 are at risk of failure, and the sealing area 133 is at risk of opening. Therefore, it is not recommended to adopt these methods.

[0082] When 20°≤α-γ≤50°, the pass rate is 100%, and there is no risk of opening in the sealing area 133 or the risk of opening is very low. Therefore, it is recommended to adopt this method.

[0083] When α-γ > 50°, although the pass rate is also 100%, and there is no risk of opening in the sealing area 133 or the risk of opening is very low, the distance between the first end 151 and the end of the adhesive 170 facing the second outer surface 1313 is large, the amount of adhesive 170 used is increased, which can easily affect the width dimension of the cell 100. Therefore, it is not recommended to adopt this method.

[0084] In some embodiments, along the thickness direction Z, the distance from the vertex position 1317 to the first outer surface 1311 is equal to the distance from the vertex position 1317 to the second outer surface 1313. In this way, the battery cell 100 is more symmetrical along the thickness direction Z, which helps to ensure that the battery cell 100 has a better appearance. It also helps to ensure that the connecting side 1315 has a sufficiently large area between the vertex position 1317 and the first outer surface 1311 to connect the sealing area 133. This helps to ensure the bonding area of ​​the tape 150 and the adhesive 170 and improve the bonding strength of the tape 150 and the adhesive 170.

[0085] Specifically, along the thickness direction Z, the straight-line distance from vertex position 1317 to the first outer surface 1311 is equal to the straight-line distance from vertex position 1317 to the second outer surface 1313.

[0086] Please refer to Figures 1 and 2. In some embodiments, the distance between the first outer surface 1311 and the second outer surface 1313 along the thickness direction Z is defined as T, and the distance between the second outer surface 1313 and the second end 153 is defined as E, where E≤T. This allows the sealing area 133 to control the side of the cell 100 along the width direction X, helping to prevent the sealing area 133 from extending beyond the first outer surface 1311 and affecting the thickness dimension of the cell 100.

[0087] It should be noted that the distance between the second outer surface 1313 and the second end 153 can refer to the straight-line distance between the second outer surface 1313 and the second end 153 along the thickness direction Z.

[0088] Preferably, T / 2 < E ≤ (T - 0.4 mm). This helps to leave a certain space between the top of the sealing area 133 and the first outer surface 1311, providing space for the adhesive 170 to overflow. This helps to reduce the situation where the adhesive 170 overflows onto the first outer surface 1311 and affects the thickness of the battery cell 100, thus reducing the impact on the energy density of the battery cell. In addition, it can increase the coverage area of ​​the sealing area 133 on the connecting side 1315, which helps to provide a larger bonding area for the tape 150 and the adhesive 170, and also helps to improve the safety performance of the battery cell 100 when it is dropped.

[0089] Understandably, TE = A.

[0090] In some embodiments, the distance between the third end 155 and the second end 153 along the thickness direction Z is D, where D≤E, thereby limiting the maximum size of D and helping to prevent the sealing area 133 from extending beyond the first outer surface 1311 and affecting the thickness of the cell 100.

[0091] The distance between the second end 153 and the third end 155 can be the straight-line distance between the second end 153 and the third end 155 along the thickness direction Z.

[0092] Preferably, 0.8mm≤D≤E, which limits the maximum and minimum size of D, helps to prevent the sealing area 133 from extending beyond the first outer surface 1311, and also helps to ensure that the tape 150 has a sufficiently large bonding area on the second sealing edge 1333, which helps to prevent the tape 150 from opening on the second sealing edge 1333.

[0093] In some embodiments, along the thickness direction Z, the distance between one end of the adhesive 170 facing the second outer surface 1313 and the second end 153 is defined as B, and the distance between the first end 151 and the second end 153 is defined as F, where F < B, so that the adhesive 170 can cover the second end 153 to bond to the second end 153 and the first sealing edge 1331, which helps to improve the problem of the second end 153 opening.

[0094] The distance between one end of the adhesive 170 facing the second outer surface 1313 and the second end 153 can refer to the straight-line distance between one end of the adhesive 170 facing the second outer surface 1313 and the second end 153 along the thickness direction Z.

[0095] In some embodiments, B < T / 2 helps to prevent the adhesive 170 from extending along the width direction X to the vertex position 1317, thereby preventing the adhesive 170 from affecting the width dimension of the cell 100.

[0096] Please refer to Figures 1 and 3. In some embodiments, with the edge sealing area 133 in an unbent state (as shown in Figure 3), the edge sealing area 133 extends outward from the receiving area 131 along the width direction X. The edge sealing area 133 includes a bent section 1335 and a sealing section 1337. The bent section 1335 connects the receiving area 131 and the sealing section 1337, and the sealing section 1337 is used to connect the connecting side 1315.

[0097] As an example, the first edge seal 1331 and the second edge seal 1333 need to be stacked along the thickness direction Z and then bent towards one side of the first outer surface 1311. When the first edge seal 1331 and the second edge seal 1333 are stacked, there will be an unattached area between the first edge seal 1331 and the second edge seal 1333 at the position where the edge seal area 133 and the receiving area 131 are connected (i.e., the first edge seal 1331 and the second edge seal 1333 are separated in this area). The edge seal area 133 where this area is located can be the bent section 1335 of the edge seal area 133, and the side of the edge seal area 133 away from the bent section 1335 along the width direction X can be the sealing section 1337. In the sealing section 1337, the first edge seal 1331 and the second edge seal 1333 are stacked and attached along the thickness direction Z.

[0098] In some embodiments, the extension length of the bending segment 1335 along the width direction X is ≥0.2mm (as shown in dimension F in FIG3). Thus, controlling the minimum size of the bending segment 1335 helps to ensure that the bending shape has a sufficiently large size so that the bending segment 1335 can effectively release stress when the battery cell 100 is transported or subjected to impact, thereby improving the stability of the connection between the sealing segment 1337 and the connecting side 1315, and reducing the difficulty of folding the edge of the sealing area 133.

[0099] As an example, the extension length of the bend 1335 can be 0.2mm, 0.3mm, 0.5mm or other dimensions.

[0100] Understandably, the maximum extension dimension of the bending segment 1335 can be affected by the thickness dimension of the battery cell 100. The thicker the battery cell 100, the greater the extension length of the bending segment 1335.

[0101] In some embodiments, the extension length of the sealing segment 1337 is ≥1mm (as shown in dimension H in FIG3). Thus, controlling the minimum size of the sealing segment 1337 helps the tape 150 to have a sufficiently large bonding area on the sealing segment 1337, and helps the adhesive 170 to have a sufficiently large bonding area between the connecting side and the tape 150, thereby improving the connection strength between the sealing segment 1337 and the connecting side.

[0102] As an example, the extension length of the sealing segment 1337 can be 1mm, 2mm, 4mm or other sizes. Understandably, the maximum length of the sealing segment 1337 can be affected by the thickness of the battery cell 100. The thicker the battery cell 100, the larger the length of the sealing segment 1337.

[0103] In the battery cell 100 and battery provided in this application embodiment, the top ends of the two sealing edges are covered and bonded by tape 150, thereby eliminating the need for UV adhesive, simplifying the processing steps, reducing the impact on the width dimension of the battery cell 100, and improving the utilization rate of the internal space of the outer casing 130, thereby increasing the energy density of the battery cell. In addition, setting the distance between the end of the tape 150 facing the first outer surface 1311 and the first outer surface 1311 to ≥0 and ≤2mm helps to improve the corner drop performance of the battery cell 100, and improves the durability and safety of the battery cell 100 in the face of drops, impacts and other situations.

[0104] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A battery cell having a width direction and a thickness direction, the battery cell comprising: main body; The outer seal includes a receiving area and a sealing edge area, and the main body is disposed within the receiving area; the receiving area has a first outer surface and a second outer surface on opposite sides along the thickness direction, and at least one side along the width direction also has a connecting side; the sealing edge area is connected to one side of the receiving area along the width direction and bends toward one side of the first outer surface to approach the connecting side, and the sealing edge area includes two overlapping sealing edges; Adhesive tape, which covers and adheres to the tops of the two sealing edges; as well as An adhesive element, which is at least partially bonded between the tape and the connecting side; The sealing area and the tape are both located between the first outer surface and the second outer surface; Along the thickness direction, the distance between the end of the tape facing the first outer surface and the first outer surface is ≥0 and ≤2mm.

2. The battery cell according to claim 1, wherein, The distance between the end of the tape facing the first outer surface and the first outer surface is ≥0 and ≤1mm.

3. The battery cell according to any one of claims 1 to 2, wherein, The connecting side is an arc surface and has a vertex position along the width direction.

4. The battery cell according to claim 3, wherein, The projection of the adhesive along the width direction is located between the first outer surface and the vertex position, and avoids the vertex position.

5. The battery cell according to claim 3, wherein, The tape includes a first end, a second end, and a third end. The first end and the third end are respectively located at the two ends of the tape facing the second outer surface. The first end is located between the sealing area and the connecting side, and the third end is located on the side of the sealing area away from the connecting side. The second end is located between the first end and the third end, and is located at the end of the tape facing the first outer surface. Along the width direction, the projections of the first end and the second end are both located between the vertex position and the first outer surface, and the projection of the third end is located between the first outer surface and the second outer surface.

6. The battery cell according to claim 5, wherein, Define a reference surface perpendicular to the first outer surface, and the central axis of the arc surface along the length direction of the cell is located on the reference surface; Define the angle α between the line connecting the central axis and the end of the adhesive member facing the second outer surface and the projection of the reference surface in the length direction, and define the angle γ between the line connecting the first end and the central axis and the projection of the reference surface in the length direction, where 20°≤α-γ≤50°.

7. The battery cell according to claim 5, wherein, Along the thickness direction, the distance between the first outer surface and the second outer surface is defined as T, and the distance between the second outer surface and the second end is defined as E, where E≤T.

8. The battery cell according to claim 7, wherein, T / 2<E≤(T-0.4mm).

9. The battery cell according to claim 5, wherein, Define D as the distance between the second end and the third end along the thickness direction, and E as the extension distance of the sealing area along the thickness direction, where D≤E.

10. The battery cell according to claim 9, wherein, 0.8mm≤D≤E.

11. The battery cell according to claim 5, wherein, Define B as the distance between the end of the adhesive member facing the second outer surface and the second end along the thickness direction, T as the distance between the first outer surface and the second outer surface, and F as the distance between the first end and the second end, where F < B and / or B < T / 2.

12. The battery cell according to claim 3, wherein, Between the edge sealing area and the connecting side, the adhesive covers one end of the tape facing the second outer surface and is partially bonded between the edge sealing area and the connecting side; And / or, along the thickness direction, the distance from the vertex position to the first outer surface is equal to the distance from the vertex position to the second outer surface; And / or, in the unbent state of the edge sealing area, the edge sealing area extends outward from the receiving area along the width direction; the edge sealing area includes a bent section and a sealing section, the bent section connecting the receiving area and the sealing section, the sealing section being used to connect the connecting side; along the width direction, the extension length of the bent section is ≥0.2mm, and / or the extension length of the sealing section is ≥1mm.

13. A battery comprising a cell according to any one of claims 1 to 12.

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