Battery cell and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery, the battery cell comprises a battery cell main body, a packaging film and gummed paper, the packaging film comprises a coating part and an edge folding part, the coating part is coated outside the battery cell main body, and the edge folding part extends outside the coating part; the bent edge folding part is adhered to the outer surface, back to the battery cell main body, of the coating part through the gummed paper; wherein the gummed paper comprises a base material layer, a gelatinous layer and a hot melting layer, the gelatinous layer and the hot melting layer are respectively positioned on two opposite sides of the base material layer, the gelatinous layer is adhered to the edge folding part, and the hot melting layer is adhered to the outer surface of the coating part, so that the energy density of the battery can be improved.

Description

Technical Field

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

[0002] As the industry develops, the requirements for battery energy density are becoming increasingly stringent. As a crucial component of the battery, the battery cell needs to be encapsulated within an aluminum-plastic film. During the encapsulation process, the sides of the aluminum-plastic film are typically folded and glued to seal the bare battery cell within the film.

[0003] Currently, the common adhesive method is to use hot melt adhesive to fix the folded edges. However, it is difficult to accurately control the position and amount of hot melt adhesive during the application process, which can easily affect the size of the cell and the energy density of the battery. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery cell that can improve the energy density of batteries.

[0005] This utility model also proposes a battery having the above-mentioned battery cell.

[0006] According to a first aspect of the present invention, a battery cell includes a battery cell body, an encapsulation film, and adhesive tape. The encapsulation film includes a covering portion and a folded edge portion. The covering portion covers the outside of the battery cell body, and the folded edge portion extends outside the covering portion. The adhesive tape adheres the folded edge portion to the outer surface of the covering portion facing away from the battery cell body. The adhesive tape includes a substrate layer, an adhesive layer, and a hot-melt layer. The adhesive layer and the hot-melt layer are located on opposite sides of the substrate layer. The adhesive layer is adhered to the folded edge portion, and the hot-melt layer is adhered to the outer surface of the covering portion.

[0007] The battery cell and battery according to the embodiments of this utility model have at least the following beneficial effects: the encapsulation film covers the outside of the battery cell body, the folded edge of the encapsulation film extends outside the encapsulation film, and the adhesive tape adheres the folded edge to the outer surface of the encapsulation film facing away from the battery cell body, thereby fixing the folded edge to the encapsulation film. The adhesive tape includes a substrate layer, an adhesive layer, and a hot-melt layer. The adhesive layer and the hot-melt layer are located on opposite sides of the substrate layer. The adhesive layer is adhered to the folded edge, and the hot-melt layer is adhered to the outer surface of the encapsulation film. Compared with the method of fixing the folded edge and the encapsulation film by applying hot-melt adhesive in related technologies, the adhesive tape in the embodiments of this application integrates the hot-melt layer, which can better control the position and amount of the hot-melt layer, reduce the impact of the hot-melt layer on the size of the battery cell, and improve the energy density of the battery under the same battery cell size. Furthermore, the embodiments of this application can conveniently adhere and fix the folded edge to the encapsulation film by pasting adhesive tape, which helps to simplify the adhesive steps and improve production efficiency.

[0008] According to some embodiments of the present invention, along the extension direction of the folded edge, the length of the hot melt layer is less than the length of the substrate layer, and / or the ratio of the length of the adhesive layer to the length of the substrate layer is ≥0.8 and ≤1.

[0009] According to some embodiments of the present invention, the folded edge portion bonded to the covering portion includes a first surface, a second surface, and a free end face. The second surface is located between the first surface and the covering portion, and the free end face is located between the first surface and the second surface. The substrate layer and the adhesive layer both extend from the first surface through the free end face to the second surface. The hot melt layer is located between the second surface and the covering portion.

[0010] According to some embodiments of the present invention, the folded edge includes a first folded edge and a second folded edge stacked together. The second folded edge is located between the first folded edge and the covering part. The surface of the first folded edge facing away from the second folded edge forms a first surface, and the surface of the second folded edge facing away from the first folded edge forms a second surface. The free ends of the first folded edge and the free ends of the second folded edge are stacked together to form a free end face. The substrate layer includes a first substrate segment, a second substrate segment, and a third substrate segment connected in sequence. The adhesive layer includes a first adhesive segment stacked on the first substrate segment, a second adhesive segment stacked on the second substrate segment, and a third adhesive segment stacked on the third substrate segment. The hot melt layer is stacked on at least a portion of the third substrate segment on the side facing away from the third adhesive segment. The first adhesive segment is bonded to at least a portion of the first surface, the second adhesive segment is bonded to the free end face, and the third adhesive segment is bonded to at least a portion of the second surface.

[0011] According to some embodiments of the present invention, the thickness of the first fold and / or the second fold is defined as T, and the length of the hot melt layer along the extension direction of the fold is defined as A, where A = k * T, and 10 ≤ k ≤ 12.

[0012] According to some embodiments of the present invention, the battery cell body includes a first side, a second side, and a third side. The first side and the second side are spaced apart and opposite to each other, and the third side is connected between the first side and the second side. The covering part includes a first sub-covering part covering the first side, a second sub-covering part covering the second side, and a third sub-covering part covering the third side. The folded edge extends from the first sub-covering part and is bonded to the third sub-covering part with adhesive tape. The third sub-covering part has a middle part, and the distance from the middle part to the first sub-covering part is equal to the distance to the second sub-covering part. The hot-melt layer is located between the middle part and the second sub-covering part.

[0013] According to some embodiments of this utility model, the third side and the third sub-covering part are both arranged in an outwardly convex arc shape, and the middle part is the part with the largest distance from the center of the battery cell body on the third sub-covering part.

[0014] According to some embodiments of the present invention, the hot-melt layer and the second sub-covering portion are spaced apart; and / or, the hot-melt layer and the intermediate portion are spaced apart.

[0015] According to some embodiments of the present invention, the folded edge is located between the first sub-covering portion and the second sub-covering portion; and / or, the substrate layer and the adhesive layer are both located between the middle portion and the second sub-covering portion.

[0016] The battery according to a second aspect of the present invention includes the battery cell of any of the above embodiments.

[0017] Additional aspects and advantages of this invention 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 the invention. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 A schematic diagram of the battery cell provided in an embodiment of this utility model is shown;

[0020] Figure 2 This invention provides a schematic diagram of the battery cell structure without adhesive tape according to an embodiment of the present invention.

[0021] Figure 3 It shows Figure 1 A partial structural diagram of the battery cell in the diagram;

[0022] Figure 4 It shows Figure 1 A magnified structural diagram of point III in the diagram.

[0023] Figure label:

[0024] 100 cells;

[0025] Battery cell body 110; First side 111; Second side 113; Third side 115;

[0026] Encapsulation film 130; Covering portion 131; First sub-covering portion 1313; Second sub-covering portion 1315; Third sub-covering portion 1317; Intermediate portion 1319;

[0027] Folded edge 133; First folded edge 1331; First surface 1333; Second folded edge 1335; Second surface 1337; Free end face 1339; Unsealed section 1341; Sealed section 1343;

[0028] Adhesive tape 150; Substrate layer 151; First substrate segment 1511; Second substrate segment 1513; Third substrate segment 1515;

[0029] Gel layer 153; First gelatinous segment 1531; Second gelatinous segment 1533; Third gelatinous segment 1535;

[0030] Hot melt layer 155; width direction X; thickness direction Z. Detailed Implementation

[0031] The embodiments of this utility model 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 utility model, and should not be construed as limiting this utility model.

[0032] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0033] In the description of this utility model, "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.

[0034] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "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 utility model in conjunction with the specific content of the technical solution.

[0035] In the description of this utility model, 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 utility model. 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.

[0036] Please see Figure 1 This application provides a battery that can be used to provide power to electrical devices such as new energy vehicles, mobile phones, tablets, and laptops.

[0037] The battery 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.

[0038] Please see Figures 1 to 3 In some embodiments, the battery cell 100 includes a battery cell body 110, an encapsulation film 130, and an adhesive tape 150.

[0039] The encapsulation film 130 includes a covering portion 131 and a folded edge portion 133. The covering portion 131 covers the outside of the battery cell body 110, and the folded edge portion 133 extends outside the covering portion 131.

[0040] As an example, the encapsulation film 130 can be made of aluminum-plastic film. During encapsulation, a groove can be formed by punching in the aluminum-plastic film, and the battery cell body 110 can be placed in the groove. The battery cell body 110 may include a main body portion formed by stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet, as well as a positive electrode tab connected to the positive electrode sheet and a negative electrode tab connected to the negative electrode sheet. The positive electrode tab and the negative electrode tab are both located on one side of the main body portion along the length direction, and the direction from the positive electrode tab to the negative electrode tab is approximately the width direction X of the battery cell body 110. The aluminum-plastic film can be bent along the length direction to cover the battery cell body 110. The portion covering the battery cell body 110 can be called the covering portion 131, and the aluminum-plastic film located on both sides of the covering portion 131 along the width direction X can be called two folded edges 133.

[0041] For ease of description, the following explanation will take the folded edge 133 on the X side of the covering part 131 along the width direction as an example.

[0042] The adhesive tape 150 is used to attach the bent edge 133 to the outer surface of the covering part 131 facing away from the main body 110 of the battery cell, so as to fix the bent edge 133 to the covering part 131.

[0043] As an example, the adhesive tape 150 can bond the folded edge 133 to the side of the covering portion 131 along the width direction X.

[0044] Specifically, the adhesive tape 150 includes a substrate layer 151, an adhesive layer 153, and a hot-melt layer 155. The adhesive layer 153 and the hot-melt layer 155 are located on opposite sides of the substrate layer 151. The adhesive layer 153 is bonded to the folded edge portion 133, and the hot-melt layer 155 is bonded to the outer surface of the covering portion 131. Compared with the method of fixing the folded edge portion and the covering portion by applying hot-melt adhesive in related technologies, the adhesive tape 150 in this embodiment integrates the hot-melt layer 155, which can better control the position and amount of the hot-melt layer 155, reduce the impact of the hot-melt layer 155 on the size of the cell 100, and improve the energy density of the battery under the same cell 100 size. Furthermore, the method of pasting the adhesive tape 150 in this embodiment can conveniently bond and fix the folded edge portion 133 to the covering portion 131, which helps to simplify the adhesive steps and improve production efficiency.

[0045] The substrate layer 151 can be made of plastic materials such as polyethylene (PE) and polyethylene terephthalate (PET), while the adhesive paper 150 provides overall structural strength and sealing performance. The adhesive layer 153 can be made of materials that are viscous at room temperature, such as acrylic resin, and the hot-melt layer 155 can be made of hot-melt materials that are viscous when heated, such as polyethylene, polyamide, and polyester.

[0046] Both the adhesive layer 153 and the hot melt layer 155 can be connected to the substrate layer 151 by coating or rolling.

[0047] In some embodiments, the hot melt layer 155 may be bonded to the covering portion 131 after being heated and pressed.

[0048] As an example, the hot melt layer 155 can become viscous at temperatures ≥140°C and ≤190°C.

[0049] In some embodiments, there can be multiple ways to apply the adhesive tape 150.

[0050] As an example, before applying the adhesive tape 150, the heat-melt layer 155 can be heated first, and then the adhesive layer 153 of the adhesive tape 150 can be adhered to the folded edge 133. The heated heat-melt layer 155 can then be adhered to the outer surface of the covering part 131, and the folded edge 133 can be pressed to increase the bonding strength between the heat-melt layer 155 and the outer surface of the covering part 131. The pressing of the folded edge 133 can be done manually or by machine.

[0051] As another example, when applying the adhesive tape 150, the adhesive layer 153 of the adhesive tape 150 can be first applied to the folded edge 133, then the heat-melt layer 155 can be heated, and then the folded edge 133 can be bent and pressed to bond the heat-melt layer 155 to the outer surface of the covering part 131. The pressing of the folded edge 133 can be done manually or by machine.

[0052] As another example, when applying the adhesive tape 150, the adhesive layer 153 of the adhesive tape 150 can be first applied to the folded edge 133, and then the folded edge 133 can be pressed onto the outer surface of the covering part 131 by a hot press machine. The hot press machine heats the folded edge 133 simultaneously, and the hot melt layer 155 is bonded to the outer surface of the covering part 131 after being heated and pressed.

[0053] In some embodiments, the folded edge 133 bonded to the covering portion 131 may include a first surface 1333, a second surface 1337, and a free end face 1339.

[0054] The second surface 1337 may be located between the first surface 1333 and the covering portion 131, and the free end face 1339 may be located between the first surface 1333 and the second surface 1337.

[0055] As an example, the free end face 1339 can refer to the end face of the folded edge 133 that is away from the covering portion 131 in the extending direction. The free end face 1339 can be connected between the first surface 1333 and the second surface 1337. The extending direction can refer to the direction in which the folded edge 133 extends along the outer surface of the covering portion 131 after bending, or it can roughly refer to the thickness direction Z.

[0056] Both the substrate layer 151 and the adhesive layer 153 can be bent from the first surface 1333 through the free end face 1339 to the second surface 1337. The hot melt layer 155 can be located between the second surface 1337 and the covering portion 131. In this way, the adhesive layer 153 can be bonded to the two opposite surfaces of the folded edge portion 133 to cover the end of the folded edge portion 133, which helps to improve the bonding strength between the adhesive tape 150 and the folded edge portion 133. As a result, the hot melt layer 155 can be bonded to the covering portion 131 more stably, thus improving the problem of the adhesive tape 150 opening and failing.

[0057] In some embodiments, the length of the hot melt layer 155 along the extending direction of the folded edge 133 may be less than the length of the substrate layer 151, which helps to ensure that the adhesive tape 150 can bond the folded edge 133 to the covering portion 131 while controlling the position and amount of the hot melt layer 155.

[0058] As an example, the length of the hot melt layer 155 along the extension direction of the folded portion 133 may be less than the length of the substrate layer 151 on the first surface 1333 along the extension direction of the folded portion 133.

[0059] As another example, the length of the hot melt layer 155 along the extension direction of the folded portion 133 may be less than the length of the substrate layer 151 along the extension direction of the first surface 1333 and the second surface 1337 along the extension direction of the folded portion 133.

[0060] As another example, the length of the hot melt layer 155 along the extension direction of the folded portion 133 may be less than the length of the substrate layer 151 along the extension direction of the first surface 1333, the second surface 1337 and the third surface.

[0061] In some embodiments, along the extending direction of the folded edge 133, the ratio of the length of the adhesive layer 153 to the length of the substrate layer 151 can be ≥0.8 and ≤1, that is, 0.8≤length of adhesive layer 153 / length of substrate layer 151≤1, thereby helping to better bond the adhesive tape 150 to the folded edge 133.

[0062] In some embodiments, the folded edge 133 may include a first folded edge 1331 and a second folded edge 1335 that are stacked together.

[0063] The first fold 1331 and the second fold 1335 can both extend outward from the covering part 131, and the second fold 1335 can be located between the first fold 1331 and the covering part 131.

[0064] The surface of the first folded edge 1331 facing away from the second folded edge 1335 can form a first surface 1333, and the surface of the second folded edge 1335 facing away from the first folded edge 1331 can form a second surface 1337.

[0065] The free end of the first folded edge 1331 and the free end of the second folded edge 1335 can be stacked to form a free end face 1339. That is, the free end face 1339 may include the end face of the first folded edge 1331 on the side away from the covering portion 131 in the extension direction and the end face of the second folded edge 1335 on the side away from the covering portion 131 in the extension direction.

[0066] The adhesive layer 153 can be bonded to the first surface 1333 of the first fold 1331 and bend through the free end face 1339 to the second surface 1337 of the second fold 1335. Thus, the adhesive tape 150 can bond and fix the first fold 1331 and the second fold 1335 and seal the gap between the first fold 1331 and the second fold 1335, which helps to reduce the problem of leakage between the first fold 1331 and the second fold 1335.

[0067] Please see Figures 2 to 4 In some embodiments, the substrate layer 151 may include a first substrate segment 1511, a second substrate segment 1513 and a third substrate segment 1515 connected in sequence.

[0068] The adhesive layer 153 includes a first adhesive segment 1531 stacked on the first substrate segment 1511, a second adhesive segment 1533 stacked on the second substrate segment 1513, and a third adhesive segment 1535 stacked on the third substrate segment 1515, wherein the first adhesive segment 1531, the second adhesive segment 1533, and the third adhesive segment 1535 may also be connected sequentially.

[0069] In this embodiment, the first adhesive segment 1531 can be bonded to at least a portion of the first surface 1333, the second adhesive segment 1533 can be bonded to the free end face 1339, and the third adhesive segment 1535 can be bonded to at least a portion of the second surface 1337. Thus, the adhesive tape 150 can bond and seal the first folded edge 1331 and the second folded edge 1335. Compared with the method of sealing the first folded edge and the second folded edge with UV glue in related technologies, the present application embodiment uses the adhesive layer 153 of the adhesive tape 150 to bond and seal the first folded edge 1331 and the second folded edge 1335. The thickness of the adhesive layer 153 and the substrate layer 151 is smaller than the thickness of the cured UV glue, which helps to reduce the impact on the width dimension of the cell 100. Under the same cell 100 size, it helps to improve the utilization rate of the internal space of the covering part 131 and improve the energy density of the battery.

[0070] The hot-melt layer 155 is stacked on at least a portion of the third substrate segment 1515 on the side opposite to the third adhesive segment 1535. This allows the hot-melt layer 155 to be provided only on the third substrate segment 1515, helping to ensure that the adhesive tape 150 can bond the folded edge 133 to the covering portion 131 while reducing the exposure of the hot-melt layer 155. It also reduces the amount of hot-melt layer 155 used, lowering costs and minimizing the impact on the size of the battery cell 100. Furthermore, compared to the method of applying hot-melt adhesive by dotting in related technologies to fix the folded edge and covering portion, this embodiment integrates the hot-melt layer 155 onto the adhesive tape 150, which not only improves processing efficiency but also allows for better control over the position and amount of the hot-melt layer 155, reducing its impact on the size of the battery cell 100.

[0071] In some embodiments, the thickness of the first fold 1331 and / or the second fold 1335 is defined as T, and the length of the hot melt layer 155 along the extension direction of the fold portion 133 is defined as A, where A = k * T, and 10 ≤ k ≤ 12. Thus, the length of the hot melt layer 155 can be controlled according to the thickness of the first fold 1331 and / or the second fold 1335. The thicker the first fold 1331 and / or the second fold 1335, the longer the length of the hot melt layer 155, which helps to ensure that there is a sufficiently large bonding area between the hot melt layer 155 and the covering portion 131, thereby reducing the problem of the fold portion 133 opening.

[0072] The length of the hot melt layer 155 along the extension direction of the folded edge 133 can be approximately the length of the hot melt layer 155 along the thickness direction Z.

[0073] As an example, when the thickness of the first fold 1331 is < 60 μm, the length of the hot melt layer 155 in the extension direction can be 600 μm; when the thickness of the first fold 1331 is > 60 μm and ≤ 80 μm, the length of the hot melt layer 155 in the extension direction can be 700 μm; when the thickness of the first fold 1331 is > 80 μm and ≤ 100 μm, the length of the hot melt layer 155 in the extension direction can be 900 μm; when the thickness of the first fold 1331 is > 100 μm and ≤ 120 μm, the length of the hot melt layer 155 in the extension direction can be 1200 μm; when the thickness of the first fold 1331 is > 120 μm, the length of the hot melt layer 155 in the extension direction can be 1400 μm.

[0074] It should be noted that the thickness of the first fold 1331 and the thickness of the second fold 1335 are approximately equal. The thickness of the first fold 1331 and the thickness of the second fold 1335 can both be the thickness of the encapsulation film 130 when the battery cell body 110 is not encapsulated.

[0075] In some embodiments, the folded edge 133 may include an unsealed section 1341 and a sealed section 1343, wherein the unsealed section 1341 may be connected between the covering section 131 and the sealed section 1343.

[0076] The unsealed section 1341 can refer to the area where the first folded edge 1331 and the second folded edge 1335 are not completely adhered after being stacked. The sealed section 1343 can refer to the area where the first folded edge 1331 and the second folded edge 1335 are completely adhered after being stacked. The extension length of the sealed section 1343 can be greater than the extension length of the unsealed section 1341. The adhesive layer 153 of the adhesive tape 150 can be bonded to the sealed section 1343 to increase the bonding area.

[0077] In some embodiments, the cell body 110 may include a first side 111, a second side 113, and a third side 115.

[0078] The first side 111 and the second side 113 are arranged opposite each other at intervals, and the third side 115 is connected between the first side 111 and the second side 113.

[0079] As an example, the first side 111 and the second side 113 can be two outer surfaces of the cell body 110 that are opposite to each other along the thickness direction Z, and the third side 115 can be a side of the cell body 110 along the width direction X. Understandably, the cell body 110 has two sides along the width direction X, meaning the cell body 110 can also include a fourth side. The fourth side connects between the first side 111 and the second side 113, and is located on both sides of the cell body 110 along the width direction X, along with the third side 115.

[0080] The covering portion 131 may include a first sub-covering portion 1313 covering the first side 111, a second sub-covering portion 1315 covering the second side 113, and a third sub-covering portion 1317 covering the third side 115.

[0081] As an example, the first sub-covering portion 1313 and the second sub-covering portion 1315 are two film layers on both sides of the covering portion 131 along the thickness direction Z, respectively. The third sub-covering portion 1317 can be a film layer on one side of the covering portion 131 along the width direction X. The third sub-covering portion 1317 can be connected to the second sub-covering portion 1315. The first sub-covering portion 1313 can be attached to the first side surface 111, the second sub-covering portion 1315 is attached to the second side surface 113, and the third sub-covering portion 1317 can be attached to the third side surface 115.

[0082] The folded edge 133 can be bent and extended from the first sub-covering part 1313 and bonded to the third sub-covering part 1317 through the adhesive tape 150.

[0083] As an example, the first fold 1331 of the folded edge 133 can be connected to the first sub-covering portion 1313, and the second fold 1335 of the folded edge 133 can be connected to the side of the third sub-covering portion 1317 away from the second sub-covering. After the first fold 1331 and the second fold 1335 are stacked, they can be bent at the connection between the first sub-covering portion 1313 and the first fold 1331 to stack the second fold 1335 and the first fold 1331 sequentially on the outer surface of the third sub-covering portion 1317. The adhesive tape 150 layer of the adhesive tape 150 is bonded to the first fold 1331 and the second fold 1335, and the hot melt layer 155 is bonded to the outer surface of the third sub-covering portion 1317 to bond the folded edge 133 to the third sub-covering portion 1317.

[0084] The third sub-covering portion 1317 may have a middle portion 1319. The distance from the middle portion 1319 to the first sub-covering portion 1313 may be equal to the distance from the middle portion 1319 to the second sub-covering portion 1315. The hot melt layer 155 is located between the middle portion 1319 and the second sub-covering portion 1315, thereby controlling the position of the hot melt layer 155. This helps to prevent the hot melt layer 155 from overflowing onto the outer surface of the second sub-covering portion 1315 and affecting the thickness of the cell 100. It also helps to prevent the hot melt layer 155 from overflowing toward the bend between the second fold 1335 and the third sub-covering portion 1317 and affecting the width of the cell 100.

[0085] It should be noted that the hot melt layer 155 is located between the middle part 1319 and the second sub-covering part 1315, which can refer to the hot melt layer 155 after hot pressing and overflowing glue being located between the middle part 1319 and the second sub-covering part 1315.

[0086] In some embodiments, the third side 115 and the third sub-covering portion 1317 can both be arranged in an outwardly convex arc shape. The middle portion 1319 is the part on the third sub-covering portion 1317 with the largest distance from the center of the cell body 110. In this way, the hot melt layer 155 is located between the middle portion 1319 and the second sub-covering portion 1315, which can also avoid the hot melt layer 155 and the middle portion 1319 from overlapping and affecting the width dimension of the cell 100. This helps to improve the utilization rate of the internal space of the covering portion 131 and improve the energy density of the battery.

[0087] The center of the battery cell body 110 can refer to the geometric center of the battery cell body 110.

[0088] The middle part 1319 is roughly the widest position of the covering part 131 along the width direction X.

[0089] As an example, the cell body 110 can be a wound cell body 110. After the cell body 110 is wound and formed, two outwardly convex arc corners are formed on both sides in the width direction X. The third side surface 115 can be the arc surface outside the arc corners. When the third sub-covering portion 1317 covers the third side surface 115, the third sub-covering portion 1317 can be approximately fitted to the third side surface 115 to form an outwardly convex arc-shaped curved structure with the same shape as the third side surface 115. Understandably, at this time, the third sub-covering portion 1317 can have the widest part in the width direction X, which can be the middle part 1319.

[0090] Understandably, the middle portion 1319 can be a line extending along the length direction of the cell 100, and the hot melt layer 155 can be located between the middle portion 1319 and the second sub-covering portion 1315, and can avoid the middle portion 1319, which helps to prevent the hot melt layer 155 and the middle portion 1319 from overlapping and affecting the width dimension of the cell 100.

[0091] In some embodiments, the hot melt layer 155 and the second sub-covering portion 1315 may be spaced apart, thereby leaving a gap for excess adhesive between the hot melt layer 155 and the second sub-covering portion 1315, which helps to prevent the hot melt layer 155 from overflowing adhesive onto the outer surface of the second sub-covering portion 1315 and affecting the thickness of the cell 100.

[0092] In some embodiments, the hot melt layer 155 and the intermediate portion 1319 may be spaced apart, thereby leaving a gap for excess adhesive between the hot melt layer 155 and the intermediate portion 1319, which helps to prevent the hot melt layer 155 from overflowing and overlapping with the intermediate layer, thus affecting the width dimension of the cell 100.

[0093] In some embodiments, the folded edge 133 may be located between the first sub-covering portion 1313 and the second sub-covering portion 1315, which helps to prevent the folded edge 133 from extending beyond the outer surface of the first sub-covering portion 1313 and / or the outer surface of the second sub-covering portion 1315 and thus affecting the thickness dimension of the cell 100.

[0094] In some embodiments, the substrate layer 151 and the adhesive layer 153 can both be located between the intermediate portion 1319 and the second sub-covering portion 1315. This helps to prevent the substrate layer 151 and the adhesive layer 153 from extending beyond the outer surface of the second sub-covering portion 1315 and affecting the thickness of the cell 100. It also helps to prevent the substrate layer 151, the adhesive layer 153 and the intermediate portion 1319 from being stacked, thus affecting the width of the cell 100.

[0095] Specifically, along the thickness direction Z of the cell 100, both the substrate layer 151 and the adhesive layer 153 can be located between the middle portion 1319 and the second sub-covering portion 1315.

[0096] In the battery cell 100 and battery provided in this application embodiment, the covering portion 131 of the encapsulation film 130 covers the outside of the battery cell body 110, the folded edge portion 133 of the encapsulation film 130 extends outside the covering portion 131, and the adhesive tape 150 adheres the bent folded edge portion 133 to the outer surface of the covering portion 131 facing away from the battery cell body 110, so as to fix the folded edge portion 133 to the covering portion 131. The adhesive tape 150 includes a substrate layer 151, an adhesive layer 153, and a hot-melt layer 155. The adhesive layer 153 and the hot-melt layer 155 are located on opposite sides of the substrate layer 151. The adhesive layer 153 is bonded to the folded edge portion 133, and the hot-melt layer 155 is bonded to the outer surface of the covering portion 131. Compared with the method of fixing the folded edge portion and the covering portion by applying hot-melt adhesive in related technologies, the adhesive tape 150 in this embodiment integrates the hot-melt layer 155, which can better control the position and amount of the hot-melt layer 155, reduce the impact of the hot-melt layer 155 on the size of the cell 100, and improve the energy density of the battery under the same cell 100 size. Furthermore, the method of pasting the adhesive tape 150 in this embodiment can conveniently bond and fix the folded edge portion 133 to the covering portion 131, which helps to simplify the adhesive steps and improve production efficiency.

[0097] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention 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 the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A battery cell, characterized in that, include: Battery cell body; An encapsulation film, the encapsulation film including a covering portion and a folded edge portion, the covering portion covering the outside of the battery cell body, and the folded edge portion extending outside the covering portion; as well as Adhesive tape, which adheres the bent edge to the outer surface of the covering portion facing away from the main body of the battery cell; The adhesive tape includes a substrate layer, an adhesive layer, and a hot-melt layer. The adhesive layer and the hot-melt layer are located on opposite sides of the substrate layer. The adhesive layer is bonded to the folded edge, and the hot-melt layer is bonded to the outer surface of the covering part.

2. The battery cell according to claim 1, characterized in that, Along the extending direction of the folded edge, the length of the hot melt layer is less than the length of the substrate layer, and / or the ratio of the length of the adhesive layer to the length of the substrate layer is ≥0.8 and ≤1.

3. The battery cell according to claim 1, characterized in that, The folded edge portion bonded to the covering portion includes a first surface, a second surface, and a free end face. The second surface is located between the first surface and the covering portion, and the free end face is located between the first surface and the second surface. Both the substrate layer and the adhesive layer extend from the first surface through the free end face to the second surface; The hot-melt layer is located between the second surface and the covering portion.

4. The battery cell according to claim 3, characterized in that, The folded edge includes a first folded edge and a second folded edge stacked together. The second folded edge is located between the first folded edge and the covering part. The surface of the first folded edge facing away from the second folded edge forms the first surface, and the surface of the second folded edge facing away from the first folded edge forms the second surface. The free end of the first folded edge and the free end of the second folded edge are stacked to form the free end surface. The substrate layer includes a first substrate segment, a second substrate segment, and a third substrate segment connected in sequence. The adhesive layer includes a first adhesive segment stacked on the first substrate segment, a second adhesive segment stacked on the second substrate segment, and a third adhesive segment stacked on the third substrate segment. The hot melt layer is stacked on at least a portion of the third substrate segment on the side opposite to the third adhesive segment. The first adhesive segment is bonded to at least a portion of the first surface, the second adhesive segment is bonded to the free end face, and the third adhesive segment is bonded to at least a portion of the second surface.

5. The battery cell according to claim 4, characterized in that, The thickness of the first fold and / or the second fold is defined as T, and the length of the hot melt layer along the extension direction of the fold is defined as A, where A = k * T, and 10 ≤ k ≤ 12.

6. The battery cell according to claim 1, characterized in that, The battery cell body includes a first side, a second side, and a third side, wherein the first side and the second side are disposed opposite to each other at a distance, and the third side is connected between the first side and the second side; The covering portion includes a first sub-covering portion covering the first side, a second sub-covering portion covering the second side, and a third sub-covering portion covering the third side; The folded edge extends from the first sub-covering portion and is bonded to the third sub-covering portion by the adhesive tape; The third sub-covering portion has a middle portion, and the distance from the middle portion to the first sub-covering portion is equal to the distance to the second sub-covering portion; The hot-melt layer is located between the middle part and the second sub-covering part.

7. The battery cell according to claim 6, characterized in that, Both the third side and the third sub-covering portion are convex arc-shaped bends, and the middle portion is the part on the third sub-covering portion that is the furthest from the center of the battery cell body.

8. The battery cell according to claim 7, characterized in that, The hot-melt layer and the second sub-covering portion are spaced apart; and / or, the hot-melt layer and the intermediate portion are spaced apart.

9. The battery cell according to claim 6, characterized in that, The folded edge is located between the first sub-covering portion and the second sub-covering portion; and / or, the substrate layer and the adhesive layer are both located between the middle portion and the second sub-covering portion.

10. A battery, characterized in that, Includes the battery cell according to any one of claims 1 to 9.

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