Battery cell and battery

Abstract

The utility model provides a battery cell and a battery, the battery cell comprises a battery cell main body, a tab, a packaging film and a second adhesive layer, and the tab is connected with the battery cell main body; the packaging film comprises a base body layer and a first adhesive layer which are arranged in a stacked mode, and the first adhesive layer adheres to and covers the base body layer. The second adhesive layer is located on the side, away from the base body layer, of the first adhesive layer, and the second adhesive layer adheres to and covers a partial area of the first adhesive layer; the packaging film defines a containing cavity and an edge sealing structure, the battery cell body is located in the containing cavity, the edge sealing structure surrounds the outer periphery of the containing cavity and comprises a top sealing part, the electrode lugs extend outwards from the side where the top sealing part is located and are partially exposed out of the packaging film, and the second adhesive layer extends inwards into the containing cavity from the side where the top sealing part is located and is partially exposed out of the packaging film. And the second adhesive layer is adhered to and covers one part of the tab and is adhered to and covers one part of the battery cell main body. The battery comprises the battery cell. According to the battery cell and the battery, control of production parameters is facilitated, and the yield of the battery cell is improved.

Description

Technical Field

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

[0002] In the field of battery technology, the main body of the battery cell is located within a cavity defined by an aluminum-plastic film. Affected by vibration and external impact, the main body of the cell is prone to shifting, which in turn causes the tabs to move. The edges of the tabs are sharp, and during movement, they can easily cut through the aluminum-plastic film, contacting the aluminum foil layer and causing a short circuit. Furthermore, the gap between the tabs and the aluminum-plastic film can easily lead to electrolyte leakage. Therefore, protective adhesive is generally applied to the tabs and the main body of the cell. This protective adhesive not only stabilizes the main body of the cell and restricts its shifting, but also separates the tabs from the aluminum-plastic film and seals the gap between them, ensuring the cell's performance. However, during cell production, parameters such as the size and placement of the protective adhesive need to be controlled. The interrelationships between these parameters make control difficult, making it challenging to guarantee the yield rate of the cells. Utility Model Content

[0003] 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 facilitates the control of production parameters and is beneficial to improving the yield rate of the battery cell.

[0004] This application also proposes a battery having the above-mentioned cells.

[0005] The battery cell according to an embodiment of this application includes a battery cell body, tabs, an encapsulation film, and a second adhesive layer;

[0006] The electrode tabs are connected to the main body of the battery cell;

[0007] The encapsulation film includes a substrate layer and a first adhesive layer stacked together, wherein the first adhesive layer adheres to and covers the substrate layer;

[0008] The second adhesive layer is located on the side of the first adhesive layer that is away from the substrate layer, and the second adhesive layer covers a portion of the first adhesive layer.

[0009] The encapsulation film defines a receiving cavity and a sealing structure. The battery cell body is located inside the receiving cavity. The sealing structure surrounds the outer periphery of the receiving cavity. The sealing structure includes a top seal. The electrode extends outward from the side where the top seal is located and is partially exposed outside the encapsulation film. The second adhesive layer extends inward from the side where the top seal is located into the receiving cavity. The second adhesive layer adheres to and covers a portion of the electrode and a portion of the battery cell body.

[0010] The battery cell according to the embodiments of this application has at least the following beneficial effects: the second adhesive layer can replace the protective adhesive, and simultaneously bond and cover a portion of the electrode tab and a portion of the battery cell body. On the one hand, the second adhesive layer effectively restricts the movement of the battery cell body within the receiving cavity, improves the battery cell's drop resistance, and effectively prevents the electrode tab from moving due to the displacement of the battery cell body. On the other hand, the second adhesive layer blocks the contact between the electrode tab and the encapsulation film and seals the gap between the electrode tab and the encapsulation film, thereby avoiding short circuits and leakage of the battery cell, which is beneficial to improving the safety and sealing of the battery cell. Thus, the second adhesive layer can achieve the function of the protective adhesive, eliminating the parameter control process of the protective adhesive in the battery production process, reducing the complexity of the battery cell production process, and helping to improve the yield of the battery cell.

[0011] According to some embodiments of this application, the second adhesive layer includes a top sealing adhesive segment, the tab includes a top sealing segment, the top sealing segment extends from one side edge of the top sealing portion to the opposite side edge along the extension direction of the tab, and the top sealing adhesive segment surrounds and covers the top sealing segment, and the top sealing portion covers the top sealing adhesive segment.

[0012] According to some embodiments of this application, the second adhesive layer covers the side of the battery cell body facing the top seal.

[0013] According to some embodiments of this application, along the thickness direction of the battery cell, the battery cell body includes opposing first and second sides, and a second adhesive layer covers the first and / or second sides.

[0014] According to some embodiments of this application, the outer periphery of the first adhesive layer extends beyond the outer periphery of the second adhesive layer.

[0015] According to some embodiments of this application, the thickness of the second adhesive layer is T1, where 19 μm ≤ T1 ≤ 61 μm.

[0016] According to some embodiments of this application, the second adhesive layer includes an inner adhesive section located within the receiving cavity. The width of the inner adhesive section is W1, and the thickness of the battery cell body is T2, where T2 / 2+4mm≤W1≤T2 / 2+20mm.

[0017] According to some embodiments of this application, the second adhesive layer includes an inner adhesive section located within the receiving cavity. The width of the inner adhesive section is W1, the width of the second adhesive layer is W2, and the width of the top seal is W3, where W1+W3+10mm≤W2≤W1+W3+250mm.

[0018] According to some embodiments of this application, the length of the second adhesive layer is L, the width of the main body of the battery cell is W4, and the sealing structure also includes a side sealing part, which is connected to the top sealing part. The width of the side sealing part is W5, and 2W4+W5+14mm≤L≤2W4+W5+100mm.

[0019] The battery according to the embodiments of this application includes the battery cell in any of the above embodiments.

[0020] The battery according to the embodiments of this application has at least the following beneficial effects: When using the above-described battery cells to assemble the battery, the interference of the protective adhesive on the assembly process can be effectively avoided, reducing assembly problems caused by improper control of protective adhesive parameters or deviations in attachment position, and significantly improving the battery yield. In addition, the battery cells have good sealing and drop resistance, which helps ensure the stability of battery performance.

[0021] 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

[0022] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 This is a partial cross-sectional view of the battery cell according to an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of the encapsulation film and the second adhesive layer in an embodiment of this application;

[0025] Figure 3 This is a top view of the battery cell according to an embodiment of this application;

[0026] Figure 4 This is a schematic diagram showing the coating range of the second adhesive layer in an embodiment of this application;

[0027] Figure 5 This is a cross-sectional view of the top sealing portion according to an embodiment of this application;

[0028] Figure 6 for Figure 3 Sectional view at point AA;

[0029] Figure 7 This is a schematic diagram of the coating range of the second adhesive layer in another embodiment of this application.

[0030] Reference numerals: Cell body 100, first side 110, second side 120;

[0031] Electrode 200, top sealing section 210;

[0032] Encapsulation film 300, substrate layer 310, nylon layer 311, aluminum foil layer 312, first adhesive layer 320, receiving cavity 330, edge sealing structure 340, top sealing part 341, side sealing part 342, bottom sealing part 343;

[0033] Second adhesive layer 400, top sealing adhesive section 410, inner covering adhesive section 420. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The embodiments of this application are described below with reference to the accompanying drawings:

[0040] refer to Figures 1 to 3According to an embodiment of this application, a battery cell includes a battery cell body 100, a tab 200, an encapsulation film 300, and a second adhesive layer 400. The tab 200 is connected to the battery cell body 100. Along the thickness direction of the encapsulation film 300, the encapsulation film 300 includes a substrate layer 310 and a first adhesive layer 320 stacked together, with the first adhesive layer 320 adhesively covering the substrate layer 310. The second adhesive layer 400 is located on the side of the first adhesive layer 320 opposite to the substrate layer 310, and the second adhesive layer 400 adhesively covers a portion of the first adhesive layer 320. The encapsulation film 300 defines a receiving cavity 330 and a sealing structure 340. The battery cell body 100 is located inside the receiving cavity 330. The sealing structure 340 surrounds the outer periphery of the receiving cavity 330. The sealing structure 340 includes a top seal portion 341. The tab 200 extends outward from the side where the top seal portion 341 is located and is partially exposed outside the encapsulation film 300. The second adhesive layer 400 extends inward from the side where the top seal portion 341 is located into the receiving cavity 330. The second adhesive layer 400 adheres to and covers a portion of the tab 200 and a portion of the battery cell body 100.

[0041] The second adhesive layer 400 replaces the protective adhesive, bonding and covering a portion of the tab 200 and a portion of the cell body 100. On one hand, the second adhesive layer 400 effectively restricts the movement of the cell body 100 within the receiving cavity 330, improving the cell's drop resistance and preventing the tab 200 from moving due to displacement of the cell body 100. On the other hand, the second adhesive layer 400 blocks contact between the tab 200 and the encapsulation film 300 and seals the gap between them, preventing short circuits and leakage, thus improving the cell's safety and sealing. Therefore, the second adhesive layer 400 achieves the function of a protective adhesive, eliminating the need for parameter control of the protective adhesive during battery production, reducing the complexity of the cell manufacturing process, and improving the cell's yield.

[0042] refer to Figures 1 to 3Specifically, the substrate layer 310 includes a nylon layer 311 and an aluminum foil layer 312. Along the thickness direction of the encapsulation film 300, the aluminum foil layer 312 is located between the nylon layer 311 and the first adhesive layer 320. The nylon layer 311 possesses good mechanical strength and flexibility, ensuring the overall impact and wear resistance of the encapsulation film 300. It effectively protects the internal structure of the encapsulation film 300 from damage during transportation and installation, preventing collisions and friction. The aluminum foil layer 312 isolates the battery cell body 100 from the external humid and oxygen-rich environment, preventing performance degradation due to moisture or oxidation, thereby extending the battery cell's lifespan. The first adhesive layer 320 is made of PP (Polypropylene). When exposed to high temperatures, the PP first adhesive layer 320 melts, achieving heat sealing of the battery cell body 100 and forming a sealing structure 340. At the same time, the first adhesive layer 320 can also provide a certain degree of insulation protection to prevent the battery cell from malfunctioning due to leakage during operation.

[0043] The second adhesive layer 400 is located on the side of the first adhesive layer 320 away from the aluminum foil layer 312, and adheres to and covers a portion of the first adhesive layer 320. The material of the second adhesive layer 400 includes, but is not limited to, modified polyimide adhesive, polyimide adhesive and tetrafluoroethylene adhesive, which have corrosion resistance, high viscosity and insulation properties. The modified polyimide is an adhesive that has been irradiated with ultraviolet light from 10 nm to 380 nm. After ultraviolet light irradiation, the molecular structure of the polyimide adhesive changes, thereby improving the high-temperature bonding performance of the polyimide adhesive.

[0044] refer to Figures 1 to 3 The second adhesive layer 400 is disposed on the side of the first adhesive layer 320 opposite to the aluminum foil layer 312, and adhesively covers a portion of the first adhesive layer 320. The material of the second adhesive layer 400 includes, but is not limited to, modified polyimide adhesive, polyimide adhesive, and at least one adhesive possessing corrosion resistance, high viscosity, and insulating properties such as tetrafluoroethylene adhesive. The aforementioned modified polyimide adhesive is an adhesive obtained by irradiating polyimide with ultraviolet light ranging from 10 nm to 380 nm. Upon ultraviolet irradiation, the molecular structure of the polyimide adhesive changes, altering its original molecular arrangement and chemical bond characteristics, thereby improving its high-temperature bonding performance. This allows it to better exert its bonding effect in high-temperature environments, ensuring the stability of the battery structure.

[0045] The second adhesive layer 400 adheres to the first adhesive layer 320 and can melt at high temperature to bond the tab 200 and the cell body 100. It is used to replace the protective adhesive, which can not only ensure the barrier of the tab 200 and effectively prevent the tab 200 from contacting the aluminum foil layer 312 and short circuit, but also fix the cell body 100 to prevent the cell body 100 from moving in the receiving cavity 330, thereby enhancing the drop resistance of the cell.

[0046] The second adhesive layer 400 adheres to the first adhesive layer 320 and can melt at high temperatures. This characteristic allows it to bond the tab 200 and the cell body 100, thus replacing the protective adhesive. The second adhesive layer 400 acts as a barrier between the tab 200 and the first adhesive layer 320, effectively preventing the tab 200 from cutting through the first adhesive layer 320 and contacting the aluminum foil layer 312, thus avoiding short circuits caused by contact between the tab 200 and the aluminum foil layer 312 and ensuring safe battery operation. Simultaneously, the second adhesive layer 400 bonds and fixes the cell body 100, effectively restricting its movement and displacement within the receiving cavity 330 when the battery is subjected to external impacts such as vibration or drops, enhancing the cell's drop resistance.

[0047] refer to Figure 1 In other embodiments, based on current battery cells with protective adhesive, to compensate for parameters such as the dimensional error of the encapsulation film 300 and the positioning error of the tab 200, and to ensure the sealing of the tab 200, the edge of the protective adhesive generally extends beyond the edge of the encapsulation film 300. However, during the battery cell assembly process, the protective adhesive extending beyond the edge of the encapsulation film 300 can easily interfere with the welding of structures such as the thermal element to the tab 200. To solve this problem, in this application, the edge of the second adhesive layer 400 is flush with the edge of the first adhesive layer 320, and since the second adhesive layer 400 is connected to the first adhesive layer 320, their relative positions are fixed. During the encapsulation of the battery cell body 100, the second adhesive layer 400 can not only simultaneously complete the bonding and coverage of the tab 200 and the battery cell body 100, but also, compared with the method of attaching protective adhesive, the position of the second adhesive layer 400 relative to the encapsulation film 300 is more certain, eliminating the need for control over the protective adhesive parameters during the battery cell encapsulation process, which is beneficial to improving battery cell production efficiency and yield.

[0048] refer to Figures 3 to 5 In some embodiments, the second adhesive layer 400 includes a top sealing adhesive segment 410, and the tab 200 includes a top sealing segment 210. Along the extending direction of the tab 200, the top sealing segment 210 extends from one side edge of the top sealing portion 341 to the opposite side edge. With the extending direction of the tab 200 as the axis, the top sealing adhesive segment 410 surrounds and covers the top sealing segment 210, and the top sealing portion 341 adhesively covers the top sealing adhesive segment 410. The top sealing adhesive segment 410 has two functions: first, it is used to block the tab 200, preventing the edge of the tab 200 from scratching the first adhesive layer 320 and contacting the aluminum foil layer 312, which helps to avoid short circuits; second, it is used to seal the gap between the first adhesive layer 320 and the tab 200, which helps to increase the sealing performance of the battery cell and helps to avoid battery cell leakage.

[0049] refer to Figures 3 to 5In other embodiments, during the cell packaging process, the encapsulation film 300 is composed of a first part and a second part connected together. During packaging, the encapsulation film 300 is folded at the connection point, bringing the corresponding edges of the first part and the second part closer together. Then, heat sealing is used to seal the corresponding edges of the two parts together, forming a top seal 341. Along the thickness direction of the cell, the top seal 341 includes two substrate layers 310 and two first adhesive layers 320. The two first adhesive layers 320 are located between the two substrate layers 310, and a top seal adhesive segment 410 is located between the two first adhesive layers 320. Furthermore, the outer periphery of the top seal adhesive segment 410 is flush with the outer periphery of the top seal 341 to increase the sealing area of ​​the top seal adhesive segment 410, thereby further improving the sealing performance of the top seal 341 and helping to prevent electrolyte leakage.

[0050] refer to Figures 1 to 3 In other embodiments, the tab 200 includes a bent section located within the receiving cavity 330. During actual use of the battery cell, the tab 200 may be stretched due to external pulling, vibration, or other factors. In this case, the bent section can produce a deformation that tends to straighten, effectively mitigating the impact on the tab 200 when stretched, preventing the tensile force from being directly transmitted to the connection between the tab 200 and the battery cell body 100, and helping to ensure the stability of the connection between the tab 200 and the battery cell body 100.

[0051] refer to Figures 1 to 3 In other embodiments, to effectively avoid the risk of short circuit in the battery cell, the second adhesive layer 400 covers the bent section. When the bent section deforms due to vibration during battery cell operation or external force pulling on the tab 200, the second adhesive layer 400 can prevent the edge of the bent section from cutting through the first adhesive layer 320, thereby preventing the bent section from contacting the aluminum foil layer 312, avoiding short circuit in the battery cell, and helping to ensure the safe and stable operation of the battery cell.

[0052] refer to Figures 3 to 6 In some embodiments, the second adhesive layer 400 adheres to and covers the side of the cell body 100 facing the top seal 341. Specifically, a portion of the second adhesive layer 400 fills the space between the cell body 100 and the top seal 341. One side of the second adhesive layer 400 is adhered to the first adhesive layer 320, and the other side is adhered to and covers the side of the cell body 100 facing the top seal 341. When the electrolyte flows towards the side where the top seal 341 is located, it is hindered by the second adhesive layer 400, thereby effectively preventing electrolyte leakage on the side where the top seal 341 is located, which helps to further improve the sealing performance of the cell. In addition, the second adhesive layer 400 can melt at high temperature to adhere to the cell body 100, restricting the movement of the cell body 100 within the receiving cavity 330, resulting in better drop resistance of the cell.

[0053] It should be noted that there are two ways in which the second adhesive layer 400 adheres to the side of the battery cell body 100 facing the top seal 341: it can be a partial cover or a complete cover. In both ways, the second adhesive layer 400 seals the path from the receiving cavity 330 to the gap of the top seal 341, thereby improving the sealing performance of the battery cell.

[0054] refer to Figure 6 In some embodiments, along the thickness direction of the battery cell, the battery cell body 100 includes a first side 110 and a second side 120 opposite to each other. A second adhesive layer 400 is bonded to and covers the first side 110 and / or the second side 120, that is, the second adhesive layer 400 is bonded to and covers at least one of the first side 110 and the second side 120. By bonding and covering the first side 110 and / or the second side 120, the second adhesive layer 400 can bond to the battery cell body 100, thereby fixing the battery cell body 100 in the thickness direction. For example, at the moment of a battery cell drop, the second adhesive layer 400 can buffer part of the impact force, preventing the battery cell body 100 from being damaged due to displacement along the thickness direction within the receiving cavity 330, thereby further improving the drop resistance performance of the battery cell.

[0055] It should be noted that the coverage in this embodiment can be complete coverage or partial coverage.

[0056] refer to Figure 6 In other embodiments, the second adhesive layer 400 covers one end of the cell body 100 facing the top seal portion 341. Specifically, the coverage area of ​​the second adhesive layer 400 includes the side of the cell body 100 facing the top seal portion 341, the first side 110 and the second side 120 opposite to the cell body 100, and reduces the occupation of the internal space of the receiving cavity 330, which helps to improve the volumetric energy density of the cell.

[0057] refer to Figure 7 In some embodiments, the outer periphery of the first adhesive layer 320 extends beyond the outer periphery of the second adhesive layer 400, creating a gap between the outer periphery of the second adhesive layer 400 and the outer periphery of the first adhesive layer 320. Specifically, the outer periphery of the first adhesive layer 320 extends further outward than the outer periphery of the second adhesive layer 400, thus forming a gap between them. During the cell heat-sealing stage, the application of heat causes the second adhesive layer 400 to melt, resulting in flow. This gap serves to limit the flow area of ​​the second adhesive layer 400, preventing it from crossing the boundary of the first adhesive layer 320, thereby preventing overflowing second adhesive layer 400 from blocking the injection port and helping to ensure the yield rate of the cell.

[0058] It should be noted that the first adhesive layer 320 completely adheres to and covers the substrate layer 310, so the outer periphery of the first adhesive layer 320 is equivalent to the outer periphery of the encapsulation film 300.

[0059] refer to Figures 1 to 3 In some embodiments, the thickness of the second adhesive layer 400 is T1, where 19μm ≤ T1 ≤ 61μm. For example, T1 can be any value among 19μm, 19.6μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 60.6μm, and 70μm, or a range of values ​​using any two of the above values ​​as endpoints. To achieve the sealing and insulation function of the battery cell, this application sets a lower limit on the thickness of the second adhesive layer 400 to ensure the adhesion and insulation performance of the second adhesive layer 400. Simultaneously, to prevent adhesive overflow in the second adhesive layer 400 during heat sealing and other processes, this application sets an upper limit on the thickness of the second adhesive layer 400. It should be noted that in this application, the second adhesive layer 400 only adheres to a portion of the first adhesive layer 320. By reasonably controlling the thickness of the second adhesive layer 400, the overall surface of the battery cell can be made smoother, avoiding unevenness in the shape of the battery cell due to uneven adhesive layer thickness.

[0060] refer to Figures 3 to 6 In some embodiments, the second adhesive layer 400 includes an inner adhesive section 420 located within the receiving cavity 330. The width of the inner adhesive section 420 is W1, and the thickness of the cell body 100 is T2. T2 / 2 + 4 mm ≤ W1 ≤ T2 / 2 + 20 mm defines the width range of the inner adhesive section 420, ensuring that the inner adhesive section 420 can effectively adhere to and cover the side of the cell body 100 facing the top seal 341. Simultaneously, based on this width range, the inner adhesive section 420 can also partially adhere to and cover the opposite first side 110 and second side 120 of the cell body 100. During actual operation of the cell, multi-directional coverage of the cell body 100 helps improve the cell's sealing performance and prevents internal electrolyte leakage.

[0061] Specifically, the encapsulation film 300 includes a bottom wall and a side wall. The side wall is connected to the outer periphery of the bottom wall, and the bottom wall and the side wall are connected to define a receiving cavity 330. The sealing structure 340 is connected to the side wall and distributed around the receiving cavity 330. The bottom wall of the receiving cavity 330 corresponds to the first side 110 and the second side 120 of the battery cell body 100. The encapsulation film 300 forms a receiving cavity 330 by folding. Therefore, the width of the inner adhesive section 420 only needs to be set to half the thickness of the battery cell to achieve adhesive coverage of the side wall connected to the top seal 341. This achieves adhesive coverage of the side of the battery cell body 100 facing the top seal 341. On this basis, by increasing the size, it is possible to ensure complete wrapping of the end of the battery cell body 100 facing the top seal 341, and also to achieve partial adhesive coverage of the first side 110 and the second side 120. While achieving the sealing and fixing functions of the battery cell, it can reduce the use of the second adhesive layer 400, which is beneficial to reduce costs and the encroachment on the space inside the receiving cavity 330. The battery cell has a higher energy density.

[0062] refer to Figures 3 to 6 The encapsulation film 300 includes a first part and a second part that are interconnected. The first part includes a bottom wall and a side wall, and the second part is folded to fit with the first part, together defining a receiving cavity 330. The sealing structure 340 includes a portion connected to the side wall of the first part and is distributed around the receiving cavity 330. The bottom wall of the receiving cavity 330 corresponds to the first side 110 or the second side 120 of the cell body 100. Therefore, the width of the inner adhesive section 420 is set to half the thickness of the cell, which enables adhesive coverage of the side wall connected to the top seal 341, thereby adhesively covering the side of the cell body 100 facing the top seal 341.

[0063] Based on this, appropriately increasing the additional dimensions not only ensures that the end of the battery cell body 100 facing the top seal 341 is completely wrapped, but also allows for partial adhesive coverage of the first side 110 and / or the second side 120. Thus, while achieving the functions of sealing and fixing the battery cell, it reduces the amount of material used in the second adhesive layer 400, which helps reduce raw material costs. Furthermore, it reduces the encroachment on the space within the receiving cavity 330, allowing the battery cell to hold more active material within the limited receiving cavity 330, which helps improve the energy density of the battery cell.

[0064] refer to Figures 3 to 6In some embodiments, the second adhesive layer 400 includes an inner adhesive section 420 located within the receiving cavity 330. The width of the inner adhesive section 420 is W1, the width of the second adhesive layer 400 is W2, and the width of the top sealing portion 341 is W3. W1+W3+10mm≤W2≤W1+W3+250mm. By further limiting the total width of the second adhesive layer 400, the sealing performance of the side where the top sealing portion 341 of the battery cell is located can be guaranteed to prevent electrolyte leakage from the top sealing side. At the same time, the second adhesive layer 400 can be partially bonded to cover the first side 110 and the second side 120 of the battery cell body 100, thereby achieving stable fixation of the battery cell body 100 and reducing costs and minimizing encroachment on the space of the receiving cavity 330.

[0065] It should be noted that the second adhesive layer 400 includes a top sealing adhesive section 410 and an inner covering adhesive section 420, and the sum of the widths of the top sealing adhesive section 410 and the inner covering adhesive section 420 is the width of the second adhesive layer 400.

[0066] refer to Figures 3 to 6 In some embodiments, the length of the second adhesive layer 400 is L, the width of the cell body 100 is W4, and the sealing structure 340 further includes a side sealing portion 342, which is connected to the top sealing portion 341. The width of the side sealing portion 342 is W5, and 2W4+W5+14mm≤L≤2W4+W5+100mm, to ensure the sealing of the top sealing portion 341.

[0067] It should be noted that the sealing structure 340 includes a top sealing portion 341, a bottom sealing portion 343, and two side sealing portions 342. Along the width direction of the second adhesive layer 400, the top sealing portion 341 and the bottom sealing portion 343 are spaced apart. One end of each of the two side sealing portions 342 is connected to the top sealing portion 341, and the other end is connected to the bottom sealing portion 343. Along the length direction of the second adhesive layer 400, the two side sealing portions 342 are spaced apart. The width of each side sealing portion 342 should be understood as the width of any one of the side sealing portions 342.

[0068] refer to Figures 1 to 7 The battery according to the embodiments of this application includes the battery cell in any of the above embodiments. By using the battery cell, the control of the protective adhesive parameters is eliminated, and the sealing and drop resistance of the battery are guaranteed. The battery may include multiple battery cells, and the thermistor and other safety components are welded on the tab 200 to monitor the temperature and ensure safety.

[0069] 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, characterized in that, include: Battery cell body; The electrode tab is connected to the main body of the battery cell; An encapsulation film includes a substrate layer and a first adhesive layer stacked together, wherein the first adhesive layer adheres to and covers the substrate layer; The second adhesive layer is located on the side of the first adhesive layer that is away from the substrate layer, and the second adhesive layer adheres to and covers a portion of the first adhesive layer. The encapsulation film defines a receiving cavity and a sealing structure. The battery cell body is located within the receiving cavity. The sealing structure surrounds the outer periphery of the receiving cavity and includes a top seal. The electrode extends outward from the side where the top seal is located and is partially exposed outside the encapsulation film. The second adhesive layer extends inward from the side where the top seal is located into the receiving cavity. The second adhesive layer adheres to and covers a portion of the electrode and a portion of the battery cell body.

2. The battery cell according to claim 1, characterized in that, The second adhesive layer includes a top sealing section, and the tab includes a top sealing section. Along the extension direction of the tab, the top sealing section extends from one side edge of the top sealing portion to the opposite side edge, and the top sealing section surrounds and covers the top sealing section. The top sealing portion adhesively covers the top sealing section.

3. The battery cell according to claim 1, characterized in that, The second adhesive layer is bonded to and covers the side of the battery cell body facing the top seal.

4. The battery cell according to claim 1, characterized in that, Along the thickness direction of the battery cell, the battery cell body includes a first side and a second side opposite to each other, and the second adhesive layer is bonded to cover the first side and / or the second side.

5. The battery cell according to claim 1, characterized in that, The outer periphery of the first adhesive layer extends beyond the outer periphery of the second adhesive layer.

6. The battery cell according to claim 1, characterized in that, The thickness of the second adhesive layer is T1, where 19μm≤T1≤61μm.

7. The battery cell according to claim 1, characterized in that, The second adhesive layer includes an inner adhesive section located within the receiving cavity. The width of the inner adhesive section is W1, and the thickness of the cell body is T2, where T2 / 2+4mm≤W1≤T2 / 2+20mm.

8. The battery cell according to claim 1, characterized in that, The second adhesive layer includes an inner adhesive section located within the receiving cavity. The width of the inner adhesive section is W1, the width of the second adhesive layer is W2, and the width of the top seal is W3. W1+W3+10mm≤W2≤W1+W3+250mm.

9. The battery cell according to claim 1, characterized in that, The length of the second adhesive layer is L, the width of the main body of the battery cell is W4, the sealing structure also includes a side sealing part, the side sealing part is connected to the top sealing part, the width of the side sealing part is W5, 2W4+W5+14mm≤L≤2W4+W5+100mm.

10. A battery, characterized in that, The battery cell includes any one of claims 1 to 9.

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