Pouch battery cell and electric device

Abstract

The present disclosure provides a soft package battery cell and an electric device, wherein the soft package battery cell comprises a packaging shell, an electrode assembly, a plurality of conductive sheets and sealing glue. The packaging shell is internally formed with an accommodating cavity, and a top sealing edge is formed on one side edge of the packaging shell. The accommodating cavity is provided with electrolyte. The electrode assembly is located in the accommodating cavity. In a first direction, one end of the conductive sheet is electrically connected to the electrode assembly, and the other end extends to the outside of the packaging shell through a sealing area of the top sealing edge. The sealing glue is partially located in the sealing area and partially located in the accommodating cavity. In a second direction, the sealing glue comprises a first part and a second part, the first part covers part of any conductive sheet, and the second part extends towards another adjacent conductive sheet. The distance between the two adjacent conductive sheets is L1, the length of the second part is D1, and D1>0.5L1. The first direction is perpendicular to the second direction. Through the above technical solution, the risk of the top sealing edge being broken and the battery cell leaking is reduced, and the service life of the battery cell is prolonged.

Description

Technical Field

[0001] This disclosure relates to the technical field of battery products, specifically to a pouch cell and its electrical equipment. Background Technology

[0002] The pouch cell includes a package and an electrode assembly disposed inside the package. The package is filled with an electrolyte, the electrode assembly is immersed in the electrolyte, and the tabs of the electrode assembly protrude from the top edge of the package.

[0003] When a pouch cell is subjected to external impacts such as collisions or drops, the electrolyte moves within the packaging shell, impacting the inner wall of the shell, especially the sealing area at the top edge. This can easily cause the sealing area to be broken, leading to leakage of the cell. Summary of the Invention

[0004] In view of this, the present disclosure aims to provide a pouch cell and an electrical device to solve the problem that the top seal of a pouch cell is easily broken, leading to leakage.

[0005] In a first aspect, this disclosure provides a pouch cell, including a package shell, an electrode assembly, a plurality of conductive sheets, and a sealant. A receiving cavity is formed inside the package shell, and a top sealing edge is formed along one edge of the package shell. An electrolyte is disposed within the receiving cavity. The electrode assembly is located within the receiving cavity. Along a first direction, one end of each conductive sheet is electrically connected to the electrode assembly, and the other end extends from the top sealing edge to the outside of the package shell. The sealant is partially located within the sealing area and partially located within the receiving cavity. Along a second direction, the sealant includes a first part and a second part. The first part covers a portion of any conductive sheet, and the second part extends toward another adjacent conductive sheet. The distance between the two adjacent conductive sheets is L1, and the length of the second part is D1, where D1 > 0.5L1. The first direction is perpendicular to the second direction.

[0006] In the above technical solution, by setting the size D1 of the second part of the sealant to be greater than the distance between the two conductive sheets, it is ensured that the sealant can reinforce the area of ​​the sealing zone that is easily broken, reducing the risk of the sealing zone being broken. Furthermore, the sealant is partially located within the sealing zone and partially within the receiving cavity. Thus, when the electrolyte impacts the top sealing edge and the sealing zone, it first contacts the sealant. The electrolyte droplets collide with the sealant and disperse, while the kinetic energy of the droplets is consumed, reducing the direct impact of droplets on the sealing zone and decreasing the impact force of the electrolyte on the sealing zone, further reducing the risk of the sealing zone being broken. In other words, the sealant provided by this embodiment provides good protection for the sealing zone, especially the part of the sealing zone between the two conductive sheets, reducing the risk of the sealing zone being broken due to electrolyte impact, causing leakage of the soft-pack battery cell, and improving the service life of the soft-pack battery cell.

[0007] In one specific implementation scheme, the size of the sealing area along the first direction is H1; The conditions of D1, H1, and 1L are satisfied as follows: .

[0008] In one specific implementation, the encapsulation shell includes a first shell and a second shell. The first shell has a first perforation, and the second shell has a second perforation. The first shell and the second shell together enclose the first perforation and the second perforation to form the receiving cavity. Along a third direction, the size of the first perforation is H2, and the size of the second perforation is H3. H2 and H3 satisfy: 0.167≤H2 / H3≤1. The condition D1, H1, and 1L satisfy: D1 ≥ 0.5L1 + E1, 0.008 ≤ E1 × X1 ≤ 1.5; The first direction, the second direction, and the third direction are perpendicular to each other.

[0009] In one specific implementation, the package includes a top wall connected to the top sealing edge, the top wall having an inner reference surface facing the receiving cavity, and the top wall being located on one side of the electrode assembly along the first direction; The sealant includes a free end facing into the receiving cavity, the free end being located between the electrode assembly and the inner reference surface; In the first direction, the distance between the free end and the inner reference surface is L5, where 0.15mm≤L5≤2mm, preferably 0.3mm≤L5≤1.4mm; In the first direction, the distance between the free end and the electrode assembly is L6, where 0.15mm≤L6≤2.3mm, preferably 0.3mm≤L6≤1.2mm; In the first direction, the distance between the inner reference plane and the electrode assembly is L7, 0.045≤L5 / L7≤0.9, and / or 0.045≤L6 / L7≤0.9, preferably 0.09≤L5 / L7≤0.7, and / or 0.09≤L6 / L7≤0.7; The encapsulation shell includes a first shell and a second shell. The first shell has a first perforation, and the second shell has a second perforation. The first shell and the second shell together enclose the first perforation and the second perforation to form the receiving cavity. In the third direction, the smaller dimension of the first perforation and the second perforation is W1. W1 and L5 satisfy: 0.15≤W1×L5≤12.

[0010] In one specific implementation, along the first direction, the sealant includes a sealing section and an extension section, the sealing section being located in the sealing area, the extension section being located on the side of the sealing area facing the receiving cavity, a portion of the sealing section and the extension section being located in the first part, and a portion of the sealing section and the extension section being located in the second part.

[0011] In one specific implementation, the extension portion is located within the sealing area. In the first direction, the dimension of the extension portion within the sealing area is d1, and the dimension of the extension portion outside the sealing area is d2. The d1 and d2 satisfy: 2 ≤ d2 / d1 ≤ 5; and / or, The sealing segment and the extension segment are integrally formed; and / or, Along the first direction, the sealing segment and the extension segment are arranged at intervals, and the Shore A hardness of the extension segment is greater than that of the sealing segment; and / or, Along the second direction, the size of the extension segment is larger than the size of the sealing segment, preferably, the size of the extension segment on the second part is larger than the size of the sealing segment on the second part.

[0012] In one specific implementation, two conductive sheets are provided, and the sealant is provided on both conductive sheets. The two sealants are a first sealant and a second sealant, and a second part is provided on both the first sealant and the second sealant. In the third direction, the extension of the second adhesive is spaced apart from the extension of the first adhesive; and / or, in the first direction, the extension of the second adhesive is spaced apart from the extension of the first adhesive. The first direction, the second direction, and the third direction are perpendicular to each other.

[0013] In one specific implementation, in the three directions, the extension segment is bent relative to the sealing segment to form a deflection angle α1 with the sealing segment, wherein α satisfies: 30°≤α1≤80°; The first direction, the second direction, and the third direction are perpendicular to each other.

[0014] In one specific possible implementation, the extension near the side edge of the receiving cavity is at least partially wavy or W-shaped; and / or, The surface of the extension section is provided with multiple through holes, the radius of which is R1, and R1 satisfies: 0.2mm ≤ R1 ≤ 1mm; and / or, The surface of the extension section is provided with multiple through holes, the sum of the areas of the multiple through holes is S1, the area of ​​the part of the extension section located outside the sealing area is S2, and S1 and S2 satisfy: 0.2≤S1 / S2≤0.6.

[0015] Secondly, this disclosure provides an electrical device including a pouch cell as described in any of the preceding claims. Attached Figure Description

[0016] Figure 1 The diagram shown is a cross-sectional view of the overall structure of a pouch cell provided in an embodiment of this disclosure.

[0017] Figure 2 As shown Figure 1 The diagram shows a cross-sectional view of the pouch cell provided in the image from another perspective.

[0018] Figure 3 As shown Figure 2 A partial schematic diagram of one side of the top sealing edge of the soft-pack battery cell.

[0019] Figure 4 for Figure 1 A schematic diagram of the conductive sheet and sealant in the image.

[0020] Figure 5 To distinguish from Figure 4 A schematic diagram of the structure of the sealant in another embodiment.

[0021] Figure 6 To distinguish from Figure 4 as well as Figure 5 A schematic diagram of the structure of a sealant according to another embodiment.

[0022] Figure 7 for Figure 1 A cross-sectional schematic diagram of the pouch cell in another embodiment.

[0023] Figure 8 To distinguish from Figure 7 A cross-sectional schematic diagram of another embodiment of the pouch cell.

[0024] The attached figures are labeled as follows: 10. Encapsulation shell; 11. Receiving cavity; 12. Top sealing edge; 121. Sealing area; 13. Side sealing edge; 14. First shell; 15. Second shell; 16. Punch pit; 101. Top wall; 102. Bottom wall; 103. Inner reference surface; 20. Electrode assembly; 30. Conductive sheet; 31. First conductive sheet; 32. Second conductive sheet; 40. Sealant; 41. First part; 42. Second part; 43. Sealing section; 44. Extension section; 441. Through hole; 401. Free end. Detailed Implementation

[0025] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure are within the scope of protection of this disclosure.

[0026] To facilitate understanding of the pouch cell and electrical device provided in the embodiments of this disclosure, a brief description of the relevant content is provided first. The pouch cell includes a package shell and an electrode assembly disposed inside the package shell. The package shell is filled with an electrolyte, and the electrode assembly is immersed in the electrolyte. The electrode assembly includes at least two tabs. Unless otherwise specified in the following embodiments, two tabs are used as examples, which are positive and negative tabs, respectively. The two tabs extend from the top sealing edge of the package shell to form the tabs of the pouch cell.

[0027] To ensure the sealing of the top seal at the point where the tabs protrude, tab adhesive is provided on the tabs. In the width direction of the pouch cell, the width of the tab adhesive is greater than the width of the tab. In addition, in the length direction of the battery, the size of the tab adhesive is larger than the sealing area of ​​the top seal, and both ends of the tab adhesive extend to the outside of the sealing area.

[0028] When a pouch cell is subjected to external impacts such as collisions or drops, the electrolyte flows within the packaging shell, impacting the inner wall of the shell. A gap exists between the top seal and the electrode assembly; if the electrolyte flows into this gap, it impacts the sealing area of ​​the top seal, potentially causing the seal to break and leading to leakage. Furthermore, in most pouch cell structures, the two tabs are located on one side of the top seal near the ends to mitigate heat concentration. This makes the sealing area of ​​the top seal, situated between the two tabs, less able to withstand external impact loads, making it more susceptible to cracking and leakage under the impact of the electrolyte.

[0029] It should be understood that for pouch cell structures, a relatively large gap is left between the top seal and the electrode assembly to prevent the top seal from compressing the electrode sheets and tabs. However, the main body, side seals, and electrode assembly of the pouch cell can remain in close contact. This is because the electrode assembly consists of multiple layers of positive and negative electrodes and a separator structure, formed by winding, and has tabs connected to one end of the top seal. If the package and electrode assembly were in close contact, it would compress the electrode structure. The reduced gap between the main body, side seals, and electrode assembly also reduces the likelihood of compression of the electrode assembly structure, thus preventing damage to its quality. Furthermore, the package shell, corresponding to the bottom side of the pouch cell, is a single-piece structure, capable of withstanding greater impact without cracking. Therefore, the area between the two tabs on the top seal side of the package shell is susceptible to being ruptured by the internal electrolyte, leading to leakage.

[0030] To overcome the above problems, this disclosure provides a pouch cell that improves the sealant structure between the tab and the top seal, reinforcing the connection of the sealing area of ​​the top seal. This allows it to withstand greater load impacts and reduces the risk of cracking and leakage at the top seal of the pouch cell. The following detailed description, in conjunction with specific drawings and embodiments, further illustrates this improvement.

[0031] refer to Figure 1 The main structure of the pouch cell provided in this embodiment is shown. The pouch cell includes a package shell 10, an electrode assembly 20, a plurality of conductive sheets 30, and a sealant 40. The package shell 10 has a receiving cavity 11 inside, the electrode assembly 20 is located in the receiving cavity 11, and the receiving cavity 11 is also filled with an electrolyte, so that the electrode assembly 20 is immersed in the electrolyte.

[0032] A top sealing edge 12 is formed on one side edge of the package housing 10, and side sealing edges 13 are formed on the other two opposite edges of the package housing 10. The two side sealing edges 13 are located on opposite sides of the package housing 10, and the top sealing edge 12 is located on the edge between the two side sealing edges 13.

[0033] refer to Figure 1 and Figure 2 For ease of description, in this embodiment, a first direction, a second direction, and a third direction that are perpendicular to each other are defined. In the accompanying drawings, the opposite sides of the first direction can be indicated by arrows X+ and X-, respectively; the opposite sides of the second direction can be indicated by arrows Y+ and Y-, respectively; and the opposite sides of the third direction can be indicated by arrows Z+ and Z-, respectively.

[0034] For example, the first direction can be the length direction of the pouch cell, the second direction can be the width direction of the pouch cell, and the third direction can be the thickness direction of the pouch cell.

[0035] refer to Figure 1 Taking two conductive sheets 30 as an example, one end of the conductive sheet 30 is electrically connected to the electrode assembly 20, and the other end extends to the outside of the package shell 10 through the sealing area 121 of the top sealing edge 12. In this way, the two conductive sheets 30 form a channel for electrical connection between the electrode assembly 20 and the outside, forming the positive and negative tabs of the soft-pack battery cell.

[0036] The sealing area 121 is part of the top sealing edge 12, which is the overall sealing area of ​​the top of the package shell 10. The sealing area 121 is the core sealing area formed inside the top sealing edge 12 by heat sealing. In the first direction, the top sealing edge 12 sequentially includes an outer unsealed area 122, a sealing area 121, and an inner unsealed area 123. The outer unsealed area 122 is located on the side of the sealing area 121 facing the outside of the package shell 10, and the inner unsealed area 123 is located on the side of the sealing area 121 facing the receiving cavity 11.

[0037] refer to Figure 1 and Figure 2 The sealant 40 is partially located within the sealing area 121 and partially located within the receiving cavity 11. Along the second direction, the sealant 40 includes a first portion 41 and a second portion 42, wherein the first portion 41 covers a portion of any conductive sheet 30, and the second portion 42 extends toward another adjacent conductive sheet 30.

[0038] Taking two conductive sheets 30 as an example, the two conductive sheets 30 are a first conductive sheet 31 and a second conductive sheet 32. A first part 41 covers the first conductive sheet 31, and a second part 42 extends from the first conductive sheet 31 towards the second conductive sheet 32 ​​along a second direction. When there are three or more conductive sheets 30, the second part 42 is located on the side of the conductive sheet 30 containing the sealant 40 facing the adjacent conductive sheet 30. For example, if there are three conductive sheets 30, the sealant 40 is located on the middle conductive sheet 30, the first part 41 covers the middle conductive sheet 30, and there are two second parts 42, located on the side of the two conductive sheets 30 facing the first part 41. Of course, the second part 42 can also be provided on only one side as needed.

[0039] In this embodiment, only two conductive sheets 30 are used as an example. Along the second direction, the distance between two adjacent conductive sheets 30 is L1, and the length of the second part 42 is D1. L1 and D1 satisfy: D1 > 0.5L1.

[0040] It should be further explained that the dividing line between the second part 42 and the first part 41 is the edge of the conductive sheet 30, that is, the length D1 of the second part 42 mentioned above refers to the length extending from the conductive sheet 30 to the adjacent conductive sheet 30.

[0041] For the soft-pack battery cell structure, when the soft-pack battery cell is subjected to external load due to collisions, drops, or other situations, the internal electrolyte impacts the sealing area 121 of the top sealing edge 12. The impact is most severe in the area between the two conductive sheets 30, meaning that the sealing area 121 between the two conductive sheets 30 is at higher risk of being broken.

[0042] In this embodiment, by setting the size D1 of the second part 42 of the sealant 40 to be greater than 1 / 2 of the distance between the two conductive sheets 30, the sealant 40 is able to reinforce the area of ​​the seal area 121 that is easily broken, thereby reducing the risk of the seal area 121 being broken.

[0043] Furthermore, the sealant 40 is partially located within the sealing area 121 and partially within the receiving cavity 11. Thus, when the electrolyte impacts the top sealing edge 12 and the sealing area 121, it first contacts the sealant 40. The electrolyte droplets collide with and disperse in the sealant 40, simultaneously consuming the droplets' kinetic energy. This reduces the direct impact of droplets on the sealing area 121, decreasing the impact force of the electrolyte on the sealing area 121 and lowering the risk of the sealing area 121 being breached. In other words, the sealant 40 provided in this embodiment provides good protection for the sealing area 121, especially the portion of the sealing area 121 located between the two conductive sheets 30, reducing the risk of the sealing area 121 being breached due to electrolyte impact and causing leakage of the soft-pack battery cell, thereby extending the service life of the soft-pack battery cell.

[0044] The electrolyte impacts the sealing area 121 between the two conductive sheets 30. The closer to the center of the two conductive sheets 30, the more pronounced the impact on the sealing area 121. For ease of understanding, the impact frequency of the electrolyte on the sealing area 121 is used to represent the impact effect. Specifically, the impact frequency is highest at the center of the sealing area 121 between the two conductive sheets 30, and gradually decreases from the center towards the point closer to the two conductive sheets 30. Thus, the impact frequency of the electrolyte on the sealing area 121 between the two conductive sheets 30 exhibits a near-normal distribution trend.

[0045] In order to more accurately determine the different impact effects on the sealing area 121 in different regions, and to assist in improving the structure of the sealant 40, so as to better achieve the reinforcement effect on the sealing area 121 of the top sealing edge 12, a fitted normal distribution curve is established for the impact received by the sealing area 121 between the two conductive sheets 30.

[0046] refer to Figure 1The sealing area 121 has a dimension of H1 in the first direction. A normal distribution curve is fitted to three points A, B, and C. The coordinates of point A are (0, 0.01), point B is (L1, 0.01), and point C is (0.5L1, H1). Specifically, point A is the intersection of the edge of the first conductive sheet 31 facing the second conductive sheet 32 ​​and the edge of the sealing area 121 facing the receiving cavity 11; point B is the intersection of the edge of the second conductive sheet 32 ​​facing the first conductive sheet 31 and the edge of the sealing area 121 facing the receiving cavity 11; and point C is the intersection of the centerline between the first and second conductive sheets 31 and the edge of the sealing area 121 away from the receiving cavity 11. The distance between the centerline and the first conductive sheet 31 is equal to the distance between the centerline and the second conductive sheet 32.

[0047] A near-normal distribution curve was obtained through fitting, with a mean of 0.5L1 and a standard deviation of [missing value]. The average value is 0.5L1, indicating that the fitted near-normal distribution curve is symmetrical about the midline between the first conductive sheet 31 and the second conductive sheet 32. Along the second direction, within one standard deviation to the left and right of the aforementioned midline, the curve height can be understood to some extent as the curve height near the midline, or it can be understood as the electrolyte's impact on the sealing area 121 being more pronounced within one standard deviation to the left and right of the aforementioned midline, resulting in a higher risk of the sealing area 121 being breached.

[0048] Based on this, D1, H1, and L1 satisfy: .

[0049] With the above limitations, the sealant 40 can extend to cover a width of one standard deviation on both sides of the center line of the two conductive sheets 30. Thus, the sealant 40 not only provides good protection for the sealing area 121 in the middle of the two conductive sheets 30, but also provides good protection for the surrounding area in the middle position, further reducing the risk of the sealing area 121 being broken and causing leakage of the soft-pack battery cell, and improving the quality of the soft-pack battery cell.

[0050] Additionally, refer to Figure 2 and Figure 3 The encapsulation shell 10 includes a first shell 14 and a second shell 15. The first shell 14 has a first perforation 141, and the second shell 15 has a second perforation 151. The first shell 14 and the second shell 15 are assembled, and together they enclose the first perforation 141 and the second perforation 151, so that the first perforation 141 and the second perforation 151 form a receiving cavity 11. In some embodiments, the first perforation 141 may be provided only on the first shell 14 or the second perforation 151 may be provided only on the second shell 15. In this embodiment, the simultaneous provision of the first perforation 141 and the second perforation 151 is used as an example for explanation.

[0051] Along the third direction, the size of the first crater 141 is H2, and the size of the second crater 151 is H3. H2 and H3 satisfy: 0.167≤H2 / H3≤1. For ease of expression, let X1 represent the ratio of H2 to H3, that is, 0.8≤X1≤1.2.

[0052] By limiting the ratio of H2 and H3 to the above range, the problem of excessive dimensional difference between the first crater 141 and the second crater 151 in the third direction is avoided, reducing the risk of cracks or even breakage of the sealant 40, and helping to ensure the stability of the protective effect of the sealant 40 on the sealing area 121.

[0053] In this case, D1, H1, and L1 satisfy: D1≥0.5L1+E1, where 0.008≤E1×X1≤1.5.

[0054] It should be understood that when the dimensions of the first crater 141 and the second crater 151 are different, the receiving cavity 11 will be asymmetrical about the plane of the top sealing edge 12. This will change the flow path and distribution area of ​​the electrolyte in the receiving cavity 11 when it impacts the top sealing edge 12. It will also cause the position where the electrolyte has the greatest impact on the sealing area 121 between the two conductive sheets 30 to be offset from the centerline position between the two conductive sheets 30. Therefore, in this embodiment, by introducing E1, the size of the sealant 40 is adapted to the different size ratios of the first crater 141 and the second crater 151, mainly adjusting the size of the second part 42. This allows the sealant 40 to be adjusted accordingly when the sizes of the two craters 16 change, protecting the sealing area 121 of the top sealing edge 12 and reducing the risk of leakage damage to the soft-pack battery cell caused by the sealing area 121 being punctured.

[0055] The first housing 14 and the second housing 15 are integrally formed structures. When they are assembled and sealed to form the receiving cavity 11, the first housing 14 and the second housing 15 form a bent connecting portion at their connection point, and then the other sides of the first housing 14 and the second housing 15 are heat-pressed together. It should be noted that the packaging shell 10 for the soft-pack battery cell is a structure well-known and conventionally used in the art, and its specific structure will not be described in detail in this embodiment.

[0056] refer to Figure 1 and Figure 3The encapsulation shell 10 has a top wall 101 and a bottom wall 102 disposed opposite to each other along a first direction. That is, in the first direction, the top wall 101 is located on one side of the electrode assembly 20, and the top sealing edge 12 is connected to the top wall 101. The top wall 101 has an inner reference surface 103 facing the receiving cavity 11. The inner reference surface 103 can also be understood as the side wall surface of the first perforation 141 and the second perforation 151 located on one side of the top sealing edge 121. The side wall surfaces of the first perforation 141 and the second perforation 151 located on the top sealing edge 121 are located in the same plane, which is the inner reference surface 103. The sealant 40 includes a free end 401 facing into the receiving cavity 11, and the free end 401 is located between the electrode assembly 20 and the inner reference surface 103.

[0057] By setting the free end 401 of the sealant 40 between the electrode assembly 20 and the inner reference surface 103, when the soft-pack battery cell is subjected to external impact due to collision, drop or other conditions, the electrolyte moves within the receiving cavity 11. When it moves towards the sealing area 121 of the top sealing edge 12, which mainly refers to the sealing area 121 between the two conductive sheets 30, it will first collide with the free end 401 of the sealant 40 before impacting the sealing area 121.

[0058] On the one hand, the aforementioned collisions absorb the kinetic energy of the electrolyte. Even if this portion of the electrolyte continues to travel to the sealing area 121 and impact it, the reduced kinetic energy makes it less likely to cause catastrophic damage. On the other hand, the electrolyte droplets impacting the free end 401 of the sealant 40 are dispersed into smaller volumes, weakening the impact on the sealing area 121 and providing better protection.

[0059] refer to Figure 3 In the first direction, the distance between the free end 401 and the inner reference surface 103 is L5, and L5 satisfies: 0.15mm≤L5≤2mm.

[0060] The distance between the free end 401 and the inner reference surface 103 is limited to the above-mentioned range to ensure that the sealant 40 provides good protection for the sealing area 121.

[0061] If the distance is too small, it means that the part of the sealant 40 extending into the receiving cavity 11 is too small. As a result, when the electrolyte moves within the receiving cavity 11 to impact the sealing area 121, the effective area of ​​the sealant 40 colliding with the electrolyte to protect the sealing area 121 is reduced, and the protective effect is weakened.

[0062] If the distance is too large, it means that the size of the part of the sealant 40 that extends into the receiving cavity 11 is too large, and the size of the part of the sealant 40 that is suspended is too large. Its stability is poor. When the soft-pack battery cell shakes, the sealant 40 is prone to colliding with the electrode plate of the electrode assembly 20 or the conductive sheet 30, which can easily increase the risk of soft-pack battery cell failure.

[0063] For example, in this embodiment of the disclosure, the value of L5 is 1mm. Of course, in other embodiments, the value of L5 can also be set to 0.15mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc.

[0064] Preferably, the value of L5 can be set to satisfy: 0.3mm≤L5≤1.4mm.

[0065] Furthermore, in the actual design, the first crater 141 and the second crater 151 have different dimensions in the first direction, forming a shallow crater and a deep crater respectively. The shallow crater has a dimension W1 in the first direction. It should be understood that the shallow crater could be either the first crater 141 or the second crater 151, meaning the value of W1 could be either H2 or H3. In this embodiment, we take the example where H2 is less than H3, meaning W1 is taken as the value of H2. W1 and L5 satisfy: 0.15 ≤ W1 × L5 ≤ 12.

[0066] By limiting the product of the distance L5 between the free end 401 and the inner reference surface and the smaller dent size W1 to a specific range, a proportional relationship is established between the two dimensions, allowing the extension length of the sealant 40 to adaptively match the space within the receiving cavity 11. This not only ensures that the sealant 40 has sufficient length within the limited space to effectively block the impact of the electrolyte, but also prevents the sealant 40 from extending too far and compressing the electrode assembly 20, or from becoming too large for its unconstrained portion to provide effective protection. Thus, without increasing the battery volume, the impact resistance of the sealant 40 is maximized, and space is utilized to the maximum extent.

[0067] Additionally, refer to Figure 3 In the first direction, the distance between the free end 401 and the electrode assembly 20 is L6, and L6 satisfies: 0.15mm≤L6≤2.3mm.

[0068] If the size between the free end 401 and the electrode assembly 20 is too small, the sealant 40 may collide with the electrode plate of the electrode assembly 20 or the conductive sheet 30 when the soft-pack battery cell shakes, which may increase the risk of soft-pack battery cell failure.

[0069] If the size between the free end 401 and the electrode assembly 20 is too large, it means that the size of the part of the sealant 40 extending into the receiving cavity 11 is too small. As a result, when the electrolyte moves within the receiving cavity 11 to impact the sealing area 121, the effective area of ​​the sealant 40 colliding with the electrolyte to protect the sealing area 121 is reduced, and the protective effect is weakened.

[0070] For example, in this embodiment of the disclosure, the value of L6 is 1 mm. Of course, in other embodiments, the value of L6 can also be set to 0.15 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, etc.

[0071] Preferably, the value of L6 can be set to satisfy: 0.3mm≤L6≤1.2mm.

[0072] Referring to the figure, in the first direction, the distance between the inner reference plane 103 and the electrode assembly 20 is L7, and L5 and L7 satisfy: 0.045≤L5 / L7≤0.9.

[0073] By limiting the proportion of the portion of the sealant 40 extending into the cavity 11 to the dimensions between the inner reference surface 103 and the electrode assembly 20 to the aforementioned range, it is possible to ensure that the sealant 40 provides good protection for the sealing area 121 of the top sealing plate 12, while reducing the shaking amplitude of the portion of the sealant 40 located in the cavity 11, thereby reducing the risk of the sealant 40 colliding with the electrode assembly 20.

[0074] For example, in this embodiment of the disclosure, the value of L5 / L7 can be set to 0.5. Of course, in other embodiments, the value of L5 / L7 can also be set to 0.045, 0.06, 0.09, 0.1, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, etc.

[0075] Preferably, L7 and L5 can be set to satisfy: 0.09≤L5 / L7≤0.7.

[0076] In addition, L6 and L7 satisfy: 0.045≤L5 / L7≤0.9.

[0077] By limiting L6 and L7 to meet the above-mentioned limits, the sealant 40 can protect the sealing area 121 of the top sealing edge 12 while reducing the risk of the sealant 40 colliding with the electrode assembly 20.

[0078] For example, in this embodiment of the disclosure, the value of L6 / L7 can be set to 0.5. Of course, in other embodiments, the value of L6 / L7 can also be set to 0.045, 0.06, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.55, 0.6, 0.7, 0.75, 0.8, 0.85, 0.9, etc.

[0079] Preferably, L7 and L6 can be set to satisfy: 0.09≤L6 / L7≤0.7.

[0080] refer to Figure 3 and Figure 4 Along the first direction, the sealant 40 includes a sealing section 43 and an extension section 44, wherein the sealing section 43 is located in the sealing area 121, and the extension section 44 is located on the side of the sealing area 121 facing into the receiving cavity 11. Parts of the sealing section 43 and the extension section 44 are located in the first part 41, and parts of the sealing section 43 and the extension section 44 are located in the second part 42.

[0081] It should be understood that the first part 41 and the second part 42 are structures that differentiate the sealant 40 in the second direction, while the sealing section 43 and the extension section 44 are structures that differentiate the sealant 40 in the first direction. The above structural division of the sealant 40 in different directions does not imply any conflict between the first part 41, the second part 42, the sealing section 43, and the extension section 44. Rather, it is for the purpose of facilitating the description of different functional divisions, and thus providing corresponding limiting descriptions of different parts of the sealant 40.

[0082] In the above technical solution, the sealing section 43 centrally realizes the encapsulation and sealing of the conductive sheet 30 at the protrusion position, and the extension section 44 is mainly used to form an impact-resistant barrier in the receiving cavity 11. The two parts are functionally separated, so they can be optimized separately without restricting each other, which not only ensures the sealing performance of the sealing area 121, but also obtains effective resistance to electrolyte impact.

[0083] Additionally, refer to Figure 4 and Figure 5 The extension segment 44 is located within the sealing area 121. In the first direction, the dimension of the extension segment 44 within the sealing area 121 is d1, and the dimension of the extension segment 44 outside the sealing area 121 is d2. d1 and d2 satisfy: 2≤d2 / d1≤5.

[0084] If the value of d2 / d1 is too small, it indicates that the size of the part of the extension section 44 extending outside the sealing area 121 is small, the area of ​​the barrier forming in the receiving cavity 11 to protect the sealing area 121 is reduced, and the protective effect is weakened.

[0085] If the value of d2 / d1 is too large, the extension section 44 will extend too far into the receiving cavity 11, which may interfere with the electrode assembly 20 and disrupt the stability of the soft-pack battery cell. Taking the sealing section 43 and the extension section 44 as relatively independent structures as an example, if the size of the extension section 44 within the sealing area 121 is too small, the stability of the connection between the extension section 44 and the packaging shell 10 will be reduced, and the protective effect on the sealing area 121 will be weakened.

[0086] By limiting the value of d2 / d1 to the above range, we can ensure that the sealing area 121 is well protected, reduce the risk of the sealing area 121 of the top sealing edge 12 being broken and causing leakage of the soft-pack battery cell, and at the same time reduce the problem of interference to the electrode assembly.

[0087] For example, in this embodiment of the disclosure, the value of d2 / d1 is 3. Of course, in other embodiments, the value of d2 / d1 can also be set to 2, 2.5, 3.5, 4, 4.5, 5, etc.

[0088] refer to Figure 5 Along the second direction, the dimension of the extension section 44 is larger than the dimension of the sealing section 43. The extension section 44 is the main part that plays a role in covering the sealing area 121. The extension section 44 is set to be larger in the second direction, that is, the dimension of the sealant 40 is set according to actual needs, so as to ensure that the sealing area 121 provides good protection while avoiding the problem of material waste.

[0089] Preferably, along the second direction, the dimension of the extension segment 44 on the second part 42 is greater than the dimension of the sealing segment 43 on the second part 42.

[0090] In another embodiment, the extension 44 is larger than the sealing section 43 in the third direction. By increasing the size of the extension 44 in the third direction, the contact and collision area between the sealant 40 and the electrolyte is increased, resulting in better protection for the sealing area 121.

[0091] In some embodiments, reference Figure 4 and Figure 5 The sealing section 43 and the extension section 44 can be set as an integral molded structure.

[0092] In some embodiments, reference Figure 6The sealing segment 43 and the extension segment 44 can be configured as independent separate structures, or as relatively independent and fixedly connected structures. For example, the sealing segment 43 and the extension segment 44 are spaced apart along the first direction, and the Shore A hardness of the extension segment 44 is greater than that of the sealing segment 43.

[0093] By making the extension section 44 harder, it can maintain its structural stability when impacted by the electrolyte, and is less likely to deform and collide with the electrode assembly 20 or the conductive sheet 30, thus improving the stability of the soft-pack battery cell structure. The sealing section 43 has lower hardness and a softer texture, and better ability to conform to deformation, resulting in a better sealing effect when placed in the sealing area 121.

[0094] For example, the sealing section 43 is a three-layer modified polypropylene composite adhesive, and the extension section 44 is a highly filled modified polypropylene.

[0095] refer to Figure 1 The sealant 40 structure described in the above technology mainly refers to the sealant 40 disposed on the first conductive sheet 31. On this basis, the second conductive sheet 32 ​​is also provided with sealant 40. The sealant 40 on the first conductive sheet 31 is the first adhesive, and the sealant 40 on the second conductive sheet 32 ​​is the second adhesive.

[0096] The second adhesive can be configured to include only the first part 41 and a portion of the second part 42. The second part 42 of the sealant 40 on the second conductive sheet 32 ​​is smaller in size, so as to avoid the second part 42 of the sealant 40 on the first conductive sheet 31.

[0097] In another embodiment, reference Figure 7 and Figure 8 Furthermore, the size of the second part 42 of the second adhesive can be set to be the same as the size of the second part 42 of the first adhesive.

[0098] In a first direction, the extensions 44 of the first adhesive and the second adhesive are arranged at intervals. And / or, in a third direction, the extensions 44 of the first adhesive and the second adhesive are arranged at intervals.

[0099] By arranging the two extension segments 44 at intervals, physical interference between them is avoided, allowing each extension segment 44 to independently and undisturbed block the electrolyte impact. At the same time, the space in the thickness and length directions of the cavity 11 is used in a reasonable manner, avoiding the problem of reduced energy density caused by increased size of the pouch cell.

[0100] refer to Figure 3 In the third direction, the extension segment 44 bends relative to the sealing segment 43 to form a deflection angle α1 with the sealing segment 43, where α1 satisfies: 30°≤α1≤80°.

[0101] When the dimensions of the dents 16 on the first housing 14 and the second housing 15 are different, deep dents and shallow dents are formed respectively. The conductive sheet 30 is led out from the electrode assembly 20. In some cases, the conductive sheet 30 is located on the side of the shallow dent, and in other cases, the conductive sheet 30 is located on the side of the deep dent. When the position of the conductive sheet 30 is different, the conductive sheet 30 will also have different bending angles.

[0102] The extension section 44 is set to form a deflection angle relative to the sealing section 43, which can adapt to the arrangement angle of the conductive sheet 30 under different conditions. In addition, compared with the case where the extension section 44 is parallel to the large surface of the soft-pack battery, the extension section 44 has a certain deflection angle, which can increase the contact area with the electrolyte in the cavity 11, and provide better protection for the sealing area 121.

[0103] Alternatively, the extension section 44 can be configured such that at least part of its side edge near the receiving cavity 11 is wavy or W-shaped. This also increases the contact area with the electrolyte, improving the protective effect on the sealing area 121.

[0104] Additionally, refer to Figure 4 and Figure 5 Multiple through holes 441 are provided on the surface of the extension section 44. These through holes 441 allow some electrolyte to pass through the extension section 44 when it collides with the electrolyte, preventing all the electrolyte from impacting the surface of the extension section 44 and causing excessive impact pressure. This effectively disperses the impact pressure, preventing irreversible deformation of the extension section due to excessive pressure. The extension section 44 has better impact resistance and provides better protection for the sealing section 43.

[0105] It should be understood that the multiple through holes 441 on the extension section 44 refers to the through holes 441 being opened on the portion of the extension section 44 located outside the sealing area 121.

[0106] For example, the radius of the through hole 441 is R1, and R1 satisfies: 0.2mm≤R1≤1mm.

[0107] If the size of the through hole 441 is too large, the electrolyte droplets will directly pass through the through hole 441 and impact the sealing area 121, weakening the protective effect of the extension section 44 on the sealing area 121. If the size of the through hole 441 is too small, the electrolyte will have difficulty passing through the through hole 441, and the through hole 441 will be unable to effectively disperse the impact of the electrolyte on the extension section 44.

[0108] Therefore, in this embodiment of the present disclosure, by limiting the radius of the through hole 441 to the above-mentioned range, it is possible to disperse the impact force of the electrolyte on the extension section 44 while ensuring a good protective effect on the sealing area 121, reducing the risk of the sealing area 121 being broken and thus causing problems such as leakage of the soft-pack battery cell.

[0109] For example, in this embodiment of the present disclosure, the radius R1 of the through hole 441 can be set to 0.5 mm. Of course, in other embodiments, the value of R1 can also be set to 0.2 mm, 0.3 mm, 0.4 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0110] In addition, the opening ratio of the through holes 441 on the part of the extension section 44 located outside the sealing area is 20%. Specifically, the sum of the areas of the multiple through holes 441 is S1, and the area of ​​the part of the extension section 44 located outside the sealing area 121 is S2. S1 and S2 satisfy: 0.2≤S1 / S2≤0.6.

[0111] If the opening ratio is too low, the through-hole 441 can only weaken the impact of a very small amount of electrolyte, and its protective effect on the sealing area 121 is not significant. On the other hand, if the opening ratio is too high, it will reduce the deformation resistance of the extension section 44 itself. When the electrolyte impacts the extension section 44, it will be difficult to effectively block the droplets formed by the electrolyte, which means that the protective effect on the sealing area 121 will also change.

[0112] By limiting the opening ratio within the above range, it is ensured that by opening the through hole 441, the weakening effect of the extension section 44 on the electrolyte impact can be significantly improved, and the protection of the sealing area 121 can be better strengthened.

[0113] This disclosure also provides an electrical device that may include the aforementioned pouch cell.

[0114] By way of example only, the electrical equipment in the embodiments of this disclosure can be, but is not limited to, vehicles, ships, aircraft, household appliances, or industrial equipment. Vehicles referred to herein can be, but are not limited to, passenger cars, trucks, and construction vehicles. Furthermore, the electrical equipment in the embodiments of this disclosure can also be an energy storage system for storing, converting, and releasing recyclable electrical energy.

[0115] The present disclosure is described in detail below with reference to specific embodiments, which are intended to understand rather than limit the present disclosure.

[0116] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Unless otherwise specified, the processing procedures and techniques involved are conventional technical methods.

[0117] Example 1 I. Electrode pulping, coating, and roller pressing / slitting Lithium cobalt oxide (LCO), polyvinylidene fluoride (PVDF), and conductive carbon (Super P) were dissolved in N-methylpyrrolidone (NMP) at a mass ratio of 98:1:1 and stirred evenly to prepare a positive electrode slurry. The positive electrode slurry was then coated onto an aluminum foil current collector. Graphite, conductive carbon black, polyacrylic acid, sodium carboxymethyl cellulose, and styrene-butadiene rubber were mixed at a mass ratio of 96.9:0.5:1.3:0.4:0.9, added to deionized water, and stirred evenly to prepare a negative electrode slurry. The negative electrode slurry was then coated onto an aluminum foil current collector.

[0118] After coating, the electrode sheets are dried in an oven and then rolled to a compaction density of 3.45 g / cm³ for the positive electrode and 1.65 g / cm³ for the negative electrode. After rolling, the electrode sheets are cut into standard widths using a slitting machine. Burrs are removed from the sides of the electrode sheets to ensure that there are no metal debris at the cut edges.

[0119] II. Electrode cutting and sealant coating Continuous metal strips were cut into 45mm long independent tab units. A double-layer PP modified tab adhesive (hot-melt electrolyte-resistant insulating adhesive) was used to bond and cover the middle section of the tab using a hot-pressing device at 165℃, 0.4MPa, and a holding time of 2s. After coating, CCD visual inspection was performed to remove defective tabs with misaligned adhesive layers, insufficient adhesive, air bubbles, or out-of-tolerance dimensions.

[0120] The sealant has a portion reserved for sealing within the sealing area and a portion of the sealing area facing the electrode assembly. Through holes are formed on the portion of the sealing area facing the electrode assembly, with multiple through holes formed at an opening rate of 40% and a radius of 0.5 mm.

[0121] III. Ultrasonic Welding of Electrode and Electrode Sheet The positive and negative tabs with sealant are respectively positioned to correspond to the positive current collector and negative current collector of the stacked electrode assembly, leaving blank metal areas. An ultrasonic metal welding machine is used to fix the tabs to the electrode foil.

[0122] IV. Stacking / winding to form electrode assemblies The electrode assembly is formed using a fully automated winding machine. The positive electrode sheet, separator, and negative electrode sheet are continuously wound in a stacked sequence. During winding, the welded tab sections are uniformly aligned to the same end of the cell, ensuring all positive and negative tabs are concentrated and aligned. After winding, insulating tape is used to secure the winding end to prevent the electrode assembly from loosening, ultimately forming a square wound electrode assembly. After winding, the wound electrode assembly undergoes room temperature leveling and pressing. A flat jig is used to apply slight pressure for shaping, ensuring uniform pressing pressure adapted to the specifications of the wound electrode assembly. The resulting electrode assembly has a width dimension L1 for both the positive and negative tabs.

[0123] V. Aluminum-plastic film stamping and pre-sealing of electrode assembly housing An aluminum-plastic composite film (nylon / aluminum layer / PP layer) is selected, and a punching mold is used to form a punched structure, forming the first punch and the second punch respectively. The first punch and the second punch have the same depth, 6mm, and three-sided sealing areas and liquid injection ports are reserved.

[0124] The electrode assembly is placed inside the punched structure. The distance L7 between the electrode assembly and the inner wall of the first and second punches on the top sealing edge side is 2mm. The sections with sealant on the positive and negative electrodes are aligned with the aluminum-plastic film sealing area. The conductive section of the metal electrode extends outward from the aluminum-plastic film shell. The sealant is completely located between the upper and lower sealing areas of the aluminum-plastic film.

[0125] A heat-sealing machine is used to heat-seal the top and both sides of the aluminum-plastic film at a temperature of 170℃ and a sealing width of 5mm. The heat-sealing pressure causes the inner PP layer of the aluminum-plastic film to fuse with the tab adhesive, achieving insulation and sealing at the tab lead-out position and preventing electrolyte leakage.

[0126] The two tabs are a first tab and a second tab with opposite polarities. The sealant on the first tab extends in the width direction to both opposite sides of the tab, with a length D1 extending towards the second tab, and the value of D1 / L1 is 0.7. In the length direction of the pouch cell, the sealant on the first tab includes a sealing section and an extension section. Part of the extension section is sealed within the sealing area, and the other part is deflected along the thickness direction of the pouch cell by an angle α1, where α1 is 60°. The sealing area extends towards the electrode assembly. In the length direction of the pouch cell, the dimension of the extension section within the sealing area is d1, and the dimension outside the sealing area is d2, satisfying a value of d2 / d1 of 3.

[0127] In addition, the distance between the free end of the sealant facing the electrode assembly and the inner wall of the encapsulation shell on the top sealing edge side is L5, and the distance between the free end and the electrode assembly is L6. The value of L5 is 1mm, and the value of L6 is also 1mm.

[0128] In addition, each embodiment and comparative example is set up to distinguish it from the above embodiment 1. The specific differences between the embodiments and comparative examples are shown in Table 1.

[0129] Table 1 Performance testing I. Top edge seal damage detection Fifty pouch cells were selected as test samples and subjected to drop tests. After the drop tests, the cell samples were batch-screened to observe whether there were any failure phenomena such as electrolyte wetting, leakage, or overflow. Cells identified as having electrolyte leakage were placed under a high-magnification metallographic microscope, focusing on the top sealing area. The microscope observed whether the sealing line formed by the heat-fused adhesive between the tabs and the aluminum-plastic film showed structural damage such as cracking, opening, peeling, or local breakage. Simultaneously, the adhesive printing position of the top sealing area was observed to determine whether there were any abnormal defects in the aluminum-plastic film sealing layer, such as local bulging, delamination, or interface separation, thus determining whether the top sealing structure had suffered mechanical failure. The number of pouch cells whose top sealing area was punctured was recorded to obtain the probability of top sealing puncture.

[0130] II. Change rate of top edge sealing adhesive line Take 50 pouch cells that have not undergone drop testing, and measure the width of the sealing area on the top edge of each cell using a microscope. The width refers to the dimension of the sealing area along the length of the pouch cell, and the average value is recorded as the width of the sealing area.

[0131] Drop tests were conducted on the aforementioned 50 pouch cells, and the width of the sealing area on the top edge of each cell was measured as described above. Because the top edge of each individual pouch cell was impacted by the electrolyte, the width of the sealing area varied at different locations. Therefore, when measuring the width of the sealing area on the top edge of an individual pouch cell, the minimum remaining width of the top edge was taken as the remaining width of the sealing area for that pouch cell.

[0132] The ratio of the remaining width of the sealing area after the drop test to the width of the sealing area before the drop test is taken as the rate of change of the sealing glue line.

[0133] III. Sealant Failure Rate Take 50 soft-pack battery cells that have not undergone drop testing, and after conducting drop tests, disassemble all the dropped soft-pack battery cells. Use a microscope to observe whether there are obvious breaks, cracks, gaps, scratches, etc. between the sealant and the layers of the cells that have not been dropped.

[0134] IV. Energy Density The pouch cells prepared in the comparative and example cases were subjected to 0.5C / 0.5C charge-discharge cycles for capacity calibration and weighing. The cell thickness, width, and height were also measured. The cell volume V = height × thickness × width was calculated, and the volumetric energy density was calculated. The volumetric energy density ED = (V1 × C) / V, where V1: nominal voltage of the cell (unit: V), C: nominal capacity of the cell (unit: Ah), and V: cell volume (unit: cm³). 3 ).

[0135] The test results are shown in Table 2.

[0136] Table 2 The data above shows that when the value of D1 / L1 is below the lower limit, i.e., less than 0.5, the probability of the top seal 12 of the pouch cell being punctured and the rate of change of the sealing line of the sealing area 121 both increase significantly. In other words, under these conditions, the impact of the electrolyte on the sealing area 121 of the top seal 12 increases significantly, leading to a higher risk of leakage from the pouch cell. This disclosure, by limiting the value of D1 / L1 to a specific range, provides better protection for the sealing area 121, reducing the probability of the sealing area 121 of the top seal 12 of the pouch cell being punctured.

[0137] Furthermore, when the value of L5 is below the lower limit or above the upper limit, the risk of the sealing area 121 being breached increases. Additionally, an excessively high value of L5 can also lead to a decrease in the energy density of the pouch cell. By setting the value of L5 within the corresponding range, the sealing area 121 can be better protected, reducing the risk of the top sealing plate 12 being breached while also minimizing the reduction in the energy density of the pouch cell.

[0138] With the extension segment 44 partially located within and partially located outside the sealing area 121, if the portion within the sealing area 121 is too small, the stability of the extension segment 44 will be poor, making it difficult to effectively weaken the impact of the electrolyte. Conversely, if the portion within the sealing area 121 is too large, the portion extending outside the sealing area 121 will be too small, reducing the portion that can collide with the electrolyte to dissipate its kinetic energy, thus weakening its impact-weakening effect. Therefore, by setting the values ​​of d2 / d1 within an appropriate range, the robustness of the extension segment 44 and its protective effect on the sealing area 121 can be ensured.

[0139] By setting the deflection angle of the extension section 44 relative to the sealing section 43 within a suitable range, the contact area between the extension section 44 and the electrolyte can be maximized, thereby better mitigating the impact force of the electrolyte. If the deflection angle is too small, the area in contact with and colliding with the electrolyte will be small, weakening the protective effect on the sealing area 121. If the deflection angle is too large, the impact force on the extension section 44 will be too great and cannot be effectively released, easily leading to irreversible deformation of the extension section 44 and weakening the mitigation effect on the electrolyte impact.

[0140] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A pouch cell, characterized in that, include: The encapsulation shell has an internal cavity, and a top sealing edge is formed on one side edge of the encapsulation shell. The cavity contains an electrolyte. The electrode assembly is located within the receiving cavity; Multiple conductive sheets are arranged along a first direction, with one end of each conductive sheet electrically connected to an electrode assembly and the other end extending through the sealing area of ​​the top sealing edge to the outside of the encapsulation shell. The sealant is partially located within the sealing area and partially located within the receiving cavity. Along the second direction, the sealant includes a first part and a second part. The first part covers a portion of any of the conductive sheets, and the second part extends toward another adjacent conductive sheet. The distance between the two adjacent conductive sheets is L1, and the length of the second part is D1, where D1 > 0.5L1. The first direction is perpendicular to the second direction.

2. The soft-pack battery cell according to claim 1, characterized in that, Along the first direction, the size of the sealing area is H1; The conditions of D1, H1, and L1 are: .

3. The soft-pack battery cell according to claim 1, characterized in that, The encapsulation shell includes a first shell and a second shell. The first shell has a first perforation, and the second shell has a second perforation. The first shell and the second shell together enclose the first perforation and the second perforation to form the receiving cavity. Along a third direction, the size of the first perforation is H2, and the size of the second perforation is H3. The size of H2 and the size of H3 satisfy: 0.167≤H2 / H3≤1. The condition D1, H1, and L1 satisfy: D1≥0.5L1+E1, 0.008≤E1×H2 / H3≤1.5; The first direction, the second direction, and the third direction are perpendicular to each other.

4. The soft-pack battery cell according to claim 1, characterized in that, The encapsulation housing includes a top wall connected to the top sealing edge, the top wall having an inner reference surface facing the receiving cavity, and the top wall being located on one side of the electrode assembly along the first direction; The sealant includes a free end facing into the receiving cavity, the free end being located between the electrode assembly and the inner reference surface; In the first direction, the distance between the free end and the inner reference surface is L5, where 0.15mm≤L5≤2mm, preferably 0.3mm≤L5≤1.4mm; In the first direction, the distance between the free end and the electrode assembly is L6, where 0.15mm≤L6≤2.3mm, preferably 0.3mm≤L6≤1.2mm; In the first direction, the distance between the inner reference plane and the electrode assembly is L7, 0.045≤L5 / L7≤0.9, and / or 0.045≤L6 / L7≤0.9, preferably 0.09≤L5 / L7≤0.7, and / or 0.09≤L6 / L7≤0.7; The encapsulation shell includes a first shell and a second shell. The first shell has a first perforation, and the second shell has a second perforation. The first shell and the second shell together enclose the first perforation and the second perforation to form the receiving cavity. In the third direction, the smaller dimension of the first perforation and the second perforation is W1. W1 and L5 satisfy: 0.15≤W1×L5≤12.

5. The soft-pack battery cell according to claim 1, characterized in that, Along the first direction, the sealant includes a sealing section and an extension section, the sealing section being located in the sealing area, the extension section being located on the side of the sealing area facing the receiving cavity, a portion of the sealing section and the extension section being located in the first part, and a portion of the sealing section and the extension section being located in the second part.

6. The soft-pack battery cell according to claim 5, characterized in that, The extension portion is located within the sealing area. In the first direction, the dimension of the extension portion within the sealing area is d1, and the dimension of the extension portion outside the sealing area is d2. d1 and d2 satisfy: 2 ≤ d2 / d1 ≤ 5; and / or, The sealing segment and the extension segment are integrally formed; and / or, Along the first direction, the sealing segment and the extension segment are arranged at intervals, and the Shore A hardness of the extension segment is greater than that of the sealing segment; and / or, Along the second direction, the size of the extension segment is larger than the size of the sealing segment, preferably, the size of the extension segment on the second part is larger than the size of the sealing segment on the second part.

7. The soft-pack battery cell according to claim 5, characterized in that, The conductive sheet is provided in two parts, and the sealant is provided on both conductive sheets. The two sealants are a first sealant and a second sealant, and a second part is provided on both the first sealant and the second sealant. In the third direction, the extension of the second adhesive is arranged at a distance from the extension of the first adhesive; And / or, in the first direction, the extension of the second adhesive is arranged at a distance from the extension of the first adhesive; The first direction, the second direction, and the third direction are perpendicular to each other.

8. The soft-pack battery cell according to claim 5, characterized in that, In the third direction, the extension segment bends relative to the sealing segment to form a deflection angle α1 between them, wherein α1 satisfies: 30°≤α1≤80°; The first direction, the second direction, and the third direction are perpendicular to each other.

9. The soft-pack battery cell according to claim 8, characterized in that, The extension section is at least partially wavy or W-shaped near the side edge of the receiving cavity; and / or, The surface of the extension section is provided with multiple through holes, the radius of which is R1, and R1 satisfies: 0.2mm ≤ R1 ≤ 1mm; and / or, The surface of the extension section is provided with multiple through holes, the sum of the areas of the multiple through holes is S1, the area of ​​the part of the extension section located outside the sealing area is S2, and S1 and S2 satisfy: 0.2≤S1 / S2≤0.

6.

10. An electrical appliance, characterized in that, Includes pouch cells as described in any one of claims 1-9.

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