Battery cell assembly and battery pack

Abstract

The utility model discloses a battery cell assembly and a battery pack, the battery cell assembly comprises a battery cell, the battery cell comprises a shell and an anti-explosion valve, and the anti-explosion valve is arranged on the shell; the insulating film covers the outer wall surface of the shell, the insulating film is provided with a windowing area and a first avoiding hole opposite to the anti-explosion valve, the windowing area is located on at least one side, in the length direction of the battery cell, of the first avoiding hole, and the shell opposite to the windowing area is suitable for being connected with the shell in an adhesive mode. According to the battery cell assembly disclosed by the utility model, the shell opposite to the windowing area is connected with the outer shell in a bonding manner, so that the battery cell assembly is fixed in the battery pack, the reliability of connection between the battery cell assembly and the outer shell is ensured, and the risk that the battery cell assembly is loosened under the action of dynamic loads such as vibration, impact and the like of the battery pack is effectively reduced; and the reliability and the safety of the battery pack are improved.

Description

Technical Field

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

[0002] As the core component of a battery pack, the performance stability and safety of the battery cell are crucial. To ensure the insulation effect of the cell under complex operating conditions, an insulating film is usually wrapped around the outer wall of the cell. This insulating film can effectively isolate the cell from the external environment and improve the overall safety performance of the battery pack. However, the presence of the insulating film can affect the bonding strength between the cell and the battery pack casing, leading to a decrease in the stability of the connection between the cell and the casing. Under dynamic loads such as vibration and impact, there is a risk of loosening, affecting the reliability of the battery pack. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery cell assembly that ensures the reliability of the connection between the battery cell assembly and the casing, effectively reducing the risk of the battery cell assembly loosening under dynamic loads such as vibration and impact, and improving the reliability and safety of the battery pack.

[0004] This utility model also proposes a battery pack, which includes the above-mentioned cell assembly.

[0005] According to an embodiment of the present invention, a battery cell assembly is used in a battery pack. The battery pack has a housing and includes: a battery cell, the battery cell including a housing and an explosion-proof valve, the explosion-proof valve being disposed on the housing; an insulating film, the insulating film covering the outer wall surface of the housing, the insulating film having a window area and a first clearance hole disposed opposite to the explosion-proof valve, the window area being located on at least one side of the first clearance hole along the length direction of the battery cell, and the housing disposed opposite to the window area being adapted to be bonded to the housing.

[0006] According to an embodiment of the present invention, the battery cell assembly includes a housing and an explosion-proof valve. The explosion-proof valve is disposed on the housing. An insulating film covers the outer wall of the housing. The insulating film has a window area and a first clearance hole disposed opposite to the explosion-proof valve. The window area is located on at least one side of the first clearance hole along the length direction of the battery cell. The battery cell assembly is fixed in the battery pack by bonding the housing and the outer shell disposed opposite to the window area, and the reliability of the connection between the battery cell assembly and the outer shell is ensured. This effectively reduces the risk of the battery cell assembly loosening under dynamic loads such as vibration and impact, and improves the reliability and safety of the battery pack.

[0007] In some embodiments of this utility model, it further includes: a first foam, which is disposed on the insulating film and extends along the width direction of the battery cell, and the first foam is located between the window area and the first clearance hole; and a second foam, which is disposed on the insulating film and extends along the width direction of the battery cell, and the second foam is located on the side of the window area away from the first clearance hole.

[0008] In some embodiments of this utility model, the size of the first foam is 5mm-10mm along the length direction of the battery cell; and / or, the size of the second foam is 5mm-10mm.

[0009] In some embodiments of this utility model, along the length direction of the battery cell, the dimension from the first foam to the first clearance hole is n, where n≥10mm; and / or, the dimension from the second foam to the nearest end face of the battery cell along its length direction is m, where m≥10mm.

[0010] In some embodiments of this utility model, the distance of the battery cell along the width direction of the battery cell is y, the distance of the first foam and the second foam along the length direction of the battery cell is w, and the shell disposed opposite to the window area is bonded to the outer shell by structural adhesive. The surface area of ​​the structural adhesive is greater than the surface area of ​​the window area and is S, wherein 1 / 2*(y*w)<S<4 / 5*(y*w).

[0011] In some embodiments of this utility model, along the length direction of the battery cell, the size of the battery cell is h, and the size of the windowed area is k, wherein 1 / 3≤k / h≤1 / 4.

[0012] In some embodiments of this utility model, a mica plate is also included, which is located between the electrode group of the battery cell and the explosion-proof valve and within the first clearance hole. The mica plate has a second clearance hole disposed opposite to the explosion-proof valve.

[0013] In some embodiments of this utility model, there is one explosion-proof valve, one first clearance hole, and two window areas located on both sides of the first clearance hole along the length of the battery cell, with the two window areas symmetrically arranged along the central axis of the first clearance hole.

[0014] In some embodiments of this utility model, the dimension of the windowed area along the length direction of the battery cell is a, and the dimension of the windowed area along the width direction of the battery cell is b, wherein 40mm≤a≤53mm, 15mm≤b≤25mm.

[0015] A battery pack according to an embodiment of the present invention includes: a housing; the aforementioned battery cell assembly, wherein the housing has a through hole disposed opposite to the explosion-proof valve, and the housing is bonded to the shell disposed opposite to the window area.

[0016] According to the battery pack of this utility model embodiment, a cell assembly is provided. The cell includes a shell and an explosion-proof valve. The explosion-proof valve is disposed on the shell. An insulating film covers the outer wall surface of the shell. The insulating film has a window area and a first clearance hole disposed opposite to the explosion-proof valve. The window area is located on at least one side of the first clearance hole along the length direction of the cell. The cell assembly is fixed in the battery pack by bonding the shell to the shell disposed opposite to the window area. This ensures the reliability of the connection between the cell assembly and the shell, effectively reduces the risk of cell assembly loosening under dynamic loads such as vibration and impact, and improves the reliability and safety of the battery pack.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a structural diagram of a battery cell assembly according to an embodiment of the present utility model;

[0020] Figure 2 This is a front view of the battery cell assembly and the first and second foam according to an embodiment of the present utility model;

[0021] Figure 3 This is a structural diagram of the battery pack according to an embodiment of the present utility model;

[0022] Figure 4 It is along Figure 3 Sectional view of line AA in the middle;

[0023] Figure 5 yes Figure 4 Enlarged view of section B in the middle.

[0024] Figure label:

[0025] 100. Battery pack;

[0026] 1. Battery cell assembly; 11. Housing; 12. Explosion-proof valve; 13. Insulating film; 131. First clearance hole; 132. Window area; 14. First foam; 15. Second foam;

[0027] 2. Outer shell;

[0028] 3. Structural adhesive. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] The following description, with reference to the accompanying drawings, describes a battery cell assembly 1 according to an embodiment of the present invention.

[0033] like Figures 1-5 As shown, according to an embodiment of the present invention, a cell assembly 1 is used in a battery pack 100. The battery pack 100 has a shell 2, and the cell assembly 1 includes a cell and an insulating film 13. The cell includes a shell 11 and an explosion-proof valve 12. The explosion-proof valve 12 is disposed on the shell 11. The insulating film 13 covers the outer wall of the shell 11. The insulating film 13 has a window area 132 and a first clearance hole 131 disposed opposite to the explosion-proof valve 12. The window area 132 is located on at least one side of the first clearance hole 131 along the length direction of the cell. The shell 11 disposed opposite to the window area 132 is adapted to be bonded to the shell 2.

[0034] Understandably, when thermal runaway occurs in the battery cell assembly 1, the gas inside the casing 11 can escape through the explosion-proof valve 12 and flow out through the first clearance hole 131, achieving pressure relief and releasing the internal pressure of the battery cell. The first clearance hole 131 can prevent the insulating film 13 from obstructing the gas inside the casing 11, thus preventing the gas inside the casing 11 from being difficult to escape through the explosion-proof valve 12, ensuring the safety of the battery cell assembly 1 in use. At the same time, by protecting the outer wall surface of the casing 11 with the insulating film 13, the insulating film 13 can achieve insulation protection for the outer wall surface of the casing 11, avoiding short circuit problems, which is conducive to improving the safety and reliability of the battery cell assembly 1, ensuring personnel safety, and preventing wear and scratches on the casing 11, which is conducive to extending the service life of the battery cell assembly 1. In addition, when the battery cell assembly 1 is located inside the battery pack 100, the outer shell 2 of the battery pack 100 has a through hole that is opposite to the explosion-proof valve 12. The gas inside the shell 11 can be rushed out through the explosion-proof valve 12, pass through the first clearance hole 131, and then flow out of the outer shell 2 through the through hole, thereby effectively reducing the internal pressure of the battery pack 100 and preventing the occurrence of an explosion accident.

[0035] The window area 132 is located on at least one side of the first clearance hole 131 along the length of the battery cell. It is understood that the housing 11 opposite to the window area 132 is not covered by the insulating film 13, allowing the housing 11 opposite to the window area 132 to be directly bonded to the outer casing 2. This secures the battery cell assembly 1 within the battery pack 100 and ensures the reliability of the connection between the battery cell assembly 1 and the outer casing 2. This effectively reduces the risk of the battery cell assembly 1 loosening under dynamic loads such as vibration and impact, improving the reliability and safety of the battery pack 100. Furthermore, compared to the existing technology where the insulating film 13 is connected to the outer casing 2, this application allows the housing 11 opposite to the window area 132 to be directly bonded to the outer casing 2, avoiding the risk of connection failure due to aging, damage, or poor connection of the insulating film 13.

[0036] Optionally, the housing 11, which is disposed opposite to the window area 132, is bonded to the outer shell 2 by structural adhesive 3.

[0037] In some embodiments, the battery cell assembly 1 can be a lithium-ion battery. Lithium-ion batteries have advantages such as large capacity, high operating voltage, strong charge retention capability, and long cycle life. They can be widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry, etc., to meet the required usage needs.

[0038] According to the embodiment of the present invention, the battery cell assembly 1 includes a housing 11 and an explosion-proof valve 12. The explosion-proof valve 12 is disposed on the housing 11. An insulating film 13 covers the outer wall surface of the housing 11. The insulating film 13 has a window area 132 and a first clearance hole 131 disposed opposite to the explosion-proof valve 12. The window area 132 is located on at least one side of the first clearance hole 131 along the length direction of the battery cell. The battery cell assembly 1 is fixed in the battery pack 100 by bonding the housing 11 disposed opposite to the window area 132 to the outer shell 2, and the reliability of the connection between the battery cell assembly 1 and the outer shell 2 is ensured. This effectively reduces the risk of the battery cell assembly 1 loosening under dynamic loads such as vibration and impact, and improves the reliability and safety of the battery pack 100.

[0039] In some embodiments of this utility model, such as Figure 2 and Figure 5 As shown, the battery cell assembly 1 also includes a first foam 14 and a second foam 15. The first foam 14 is disposed on the insulating film 13 and extends along the width direction of the battery cell, and is located between the window area 132 and the first clearance hole 131. The second foam 15 is disposed on the insulating film 13 and extends along the width direction of the battery cell, and is located on the side of the window area 132 away from the first clearance hole 131.

[0040] It is understandable that, since the housing 11, which is positioned opposite to the window area 132, is directly bonded to the outer shell 2, and the first foam 14 is located between the window area 132 and the first clearance hole 131, the first foam 14 can effectively block the glue from flowing to the first clearance hole 131 during the glue application process in the window area 132. This avoids the glue application near the explosion-proof valve 12 from blocking the opening channel of the explosion-proof valve 12 or causing the explosion-proof valve 12 to fail to open normally under vibration, thereby improving the reliability and safety of the cell assembly 1 and the battery pack 100.

[0041] Meanwhile, since the second foam 15 is located on the side of the window area 132 away from the first clearance hole 131, the second foam 15 can effectively block the glue from flowing to one end face of the battery cell in the length direction during the glue application process in the window area 132. This avoids the battery cell end face in the length direction from being subjected to additional constraints or stress under vibration environment due to glue application, which may cause the battery cell weld to be subjected to excessive stress and crack or break, thereby improving the reliability and safety of the battery cell assembly 1.

[0042] In some embodiments of this utility model, such as Figure 2As shown, the size of the first foam 14 is 5mm-10mm along the length of the battery cell. It is understandable that if the size of the first foam 14 is too small along the width of the battery cell, its structural strength will be weak and it will easily detach. Conversely, if the size of the first foam 14 is too large, it will waste space and increase costs. Therefore, by limiting the size of the first foam 14 to 5mm-10mm along the width of the battery cell, it is possible to ensure that the first foam 14 prevents adhesive from flowing to the first clearance hole 131 while reducing costs.

[0043] Optionally, the size of the first foam 14 is 5mm, 6mm, 7mm, 8mm, 9 or 10mm.

[0044] In some embodiments of this utility model, such as Figure 2 As shown, the size of the second foam 15 is 5mm-10mm along the length of the battery cell. It is understandable that if the size of the second foam 15 is too small along the width of the battery cell, its structural strength will be weak, making it prone to detachment. Conversely, if the size of the second foam 15 is too large, it will result in wasted space and increased cost. Therefore, by limiting the size of the second foam 15 to 5mm-10mm along the width of the battery cell, it is possible to ensure that the second foam 15 prevents adhesive from flowing to one end face along the length of the battery cell while reducing cost.

[0045] Optionally, the second foam 15 may have a size of 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm.

[0046] In some embodiments of this utility model, such as Figure 2 As shown, along the length of the battery cell, the dimension from the first foam 14 to the first clearance hole 131 is n, where n ≥ 10 mm. This limitation further prevents adhesive from flowing to the first clearance hole 131, thus avoiding the blockage of the opening channel of the explosion-proof valve 12 due to adhesive application near the valve or the inability of the explosion-proof valve 12 to open properly under vibration, thereby improving the reliability and safety of the battery cell assembly 1 and the battery pack 100.

[0047] In some embodiments of this utility model, such as Figure 2 As shown, along the length of the battery cell, the dimension from the second foam 15 to the nearest end face of the battery cell along its length is m, where m ≥ 10 mm. This limitation further prevents adhesive from flowing to the end face of the battery cell along its length, thus avoiding the application of adhesive that could cause additional constraints or stress on the battery cell under vibration, leading to excessive stress on the battery cell welds and resulting in cracking or breakage. This improves the reliability and safety of the battery cell assembly 1.

[0048] In some embodiments of this utility model, such as Figure 2As shown, the distance of the battery cell along the width direction is y. The shell 11, which is disposed opposite to the window area 132, is bonded to the outer shell 2 by structural adhesive 3. The surface area of ​​the structural adhesive 3 is larger than the surface area of ​​the window area 132 and is S, where 1 / 2*(y*w)<S<4 / 5*(y*w).

[0049] Understandably, having a larger surface area of ​​structural adhesive 3 than the window area 132 ensures that structural adhesive 3 completely covers the shell 11 opposite to the window area 132, guaranteeing the reliability of the connection between the cell assembly 1 and the shell 2. Furthermore, complete coverage of the shell 11 by structural adhesive 3 prevents the shell 11 from being exposed, thus avoiding insulation failure and cell corrosion caused by condensation, and improving the safety of the battery pack 100. However, if the surface area of ​​structural adhesive 3 is too small, the bonding strength may be insufficient to withstand vibration, leading to delamination. Conversely, if the surface area of ​​structural adhesive 3 is too large, vibration stress concentration may cause cracking or breakage. Therefore, limiting 1 / 2*(y*w) < S < 4 / 5*(y*w) ensures the reliability of the connection between the cell assembly 1 and the shell 2.

[0050] In some embodiments of this utility model, the battery cell assembly 1 further includes a mica plate. The mica plate is located between the electrode group of the battery cell and the explosion-proof valve 12, and has a second clearance hole disposed opposite to the first clearance hole 131. Thus, gas inside the housing 11 can be released through the explosion-proof valve 12 and flow out through the second clearance hole and the first clearance hole 131, achieving pressure relief and releasing the internal pressure of the battery cell. Simultaneously, the mica plate provides insulation protection for the explosion-proof valve 12, improving the electrical safety of the battery pack 100.

[0051] In some embodiments of this utility model, such as Figures 1-5 As shown, there is one explosion-proof valve 12, one first clearance hole 131, and two window areas 132 located on either side of the first clearance hole 131 along the length of the battery cell. The two window areas 132 are symmetrically arranged along the central axis of the first clearance hole 131. Thus, by connecting the housing 11 to the outer shell 2 opposite to the two window areas 132, the connection strength between the battery cell assembly 1 and the outer shell 2 is effectively improved, ensuring the stability of the battery cell assembly 1 within the battery pack 100. Simultaneously, the symmetrical arrangement of the two window areas 132 along the central axis of the first clearance hole 131 reduces the processing difficulty of the battery cell assembly 1 and improves efficiency.

[0052] Furthermore, such as Figure 2 and Figure 5As shown, the battery cell assembly 1 also includes a first foam 14 and a second foam 15. The first foam 14 is disposed on the insulating film 13 and extends along the width direction of the battery cell. There are two first foams 14, each located between the two window areas 132 and the first clearance hole 131. The second foam 15 is disposed on the insulating film 13 and extends along the width direction of the battery cell. There are two second foams 15, each located on the side of the two window areas 132 away from the first clearance hole 131.

[0053] It is understandable that, since the housing 11, which is positioned opposite to the window area 132, is directly bonded to the outer shell 2, and the first foam 14 is located between the window area 132 and the first clearance hole 131, the first foam 14 can effectively block the glue from flowing to the first clearance hole 131 during the glue application process in the window area 132. This avoids the glue application near the explosion-proof valve 12 from blocking the opening channel of the explosion-proof valve 12 or causing the explosion-proof valve 12 to fail to open normally under vibration, thereby improving the reliability and safety of the cell assembly 1 and the battery pack 100.

[0054] Meanwhile, since the second foam 15 is located on the side of the window area 132 away from the first clearance hole 131, the second foam 15 can effectively block the glue from flowing to one end face of the battery cell in the length direction during the glue application process in the window area 132. This avoids the battery cell end face in the length direction from being subjected to additional constraints or stress under vibration environment due to glue application, which may cause the battery cell weld to be subjected to excessive stress and crack or break, thereby improving the reliability and safety of the battery cell assembly 1.

[0055] In some embodiments of this utility model, such as Figure 2 As shown, the dimension of the window area 132 along the length of the battery cell is 'a', and the dimension of the window area 132 along the width of the battery cell is 'b', where 40mm ≤ a ≤ 53mm and 15mm ≤ b ≤ 25mm. It can be understood that if the dimension of the window area 132 is too small, the area where the shell 11 and the outer shell 2 are bonded together opposite to the window area 132 will be too small, potentially leading to insufficient bonding strength to resist vibration and resulting in delamination. Conversely, if the dimension of the window area 132 is too large, the area where the shell 11 and the outer shell 2 are bonded together will be too large, potentially leading to stress concentration during vibration and cracking or breakage. Therefore, by limiting the dimension 'a' of the window area 132 along the length of the battery cell to 40mm ≤ a ≤ 53mm, and limiting the dimension 'b' of the window area 132 along the width of the battery cell to 15mm ≤ b ≤ 25mm, the reliability of the connection between the battery cell assembly 1 and the outer shell 2 is ensured.

[0056] Optionally, the dimensions of the window area 132 along the length of the battery cell are 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 51mm, 52mm or 53mm.

[0057] Optionally, the dimensions of the window area 132 along the width direction of the battery cell are 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm or 25mm.

[0058] In some embodiments of this utility model, such as Figure 2 As shown, along the length of the battery cell, the size of the battery cell is h, and the size of the window area 132 is k, where 1 / 3 ≤ k / h ≤ 1 / 4. This can be understood as follows: if the size of the window area 132 is too small along the length of the battery cell, the area where the shell 11 and the outer shell 2 are bonded together opposite to the window area 132 will be too small, potentially leading to insufficient bonding strength to resist vibration and resulting in delamination. Conversely, if the size of the window area 132 is too large, the area where the shell 11 and the outer shell 2 are bonded together will be too large, potentially leading to stress concentration during vibration and cracking or breakage. Therefore, limiting 1 / 3 ≤ k / h ≤ 1 / 4 ensures the reliability of the connection between the battery cell assembly 1 and the outer shell 2.

[0059] Furthermore, such as Figure 2 As shown, there is one explosion-proof valve 12, one first clearance hole 131, and two window areas 132 located on both sides of the first clearance hole 131 along the length of the battery cell. The two window areas 132 are symmetrically arranged along the central axis of the first clearance hole 131. k is the total length of the two window areas 132 along the length of the battery cell, which is k = 2a.

[0060] Optionally, the cell size is 300mm-1200mm along the length of the cell.

[0061] Optionally, the cell size is 53mm along the width direction of the cell.

[0062] The following describes a battery pack 100 according to an embodiment of the present invention.

[0063] like Figures 1-5 As shown, the battery pack 100 according to an embodiment of the present utility model includes a housing 2 and a cell assembly 1. The housing 2 has a through hole disposed opposite to the explosion-proof valve 12, and the housing 2 is bonded to the shell disposed opposite to the window area 132.

[0064] Therefore, when thermal runaway occurs in the battery cell assembly 1, the gas inside the casing 11 can be rushed out through the explosion-proof valve 12, pass through the first clearance hole 131, and then flow out of the outer casing 2 through the through hole, thereby effectively reducing the internal pressure of the battery pack 100 and preventing the occurrence of an explosion accident.

[0065] Meanwhile, the housing 11 opposite to the window area 132 is not covered by the insulating film 13, so that the housing 11 opposite to the window area 132 can be directly bonded to the outer shell 2, thereby fixing the cell assembly 1 in the battery pack 100 and ensuring the reliability of the connection between the cell assembly 1 and the outer shell 2. This effectively reduces the risk of the cell assembly 1 loosening under dynamic loads such as vibration and impact, and improves the reliability and safety of the battery pack 100.

[0066] According to the battery pack 100 of this utility model embodiment, a cell assembly 1 is provided. The cell includes a housing 11 and an explosion-proof valve 12. The explosion-proof valve 12 is disposed on the housing 11. An insulating film 13 covers the outer wall surface of the housing 11. The insulating film 13 has a window area 132 and a first clearance hole 131 disposed opposite to the explosion-proof valve 12. The window area 132 is located on at least one side of the first clearance hole 131 along the length direction of the cell. The cell assembly 1 is fixed in the battery pack 100 by adhesive connection between the outer shell 2 and the housing 11 disposed opposite to the window area 132, and the reliability of the connection between the cell assembly 1 and the outer shell 2 is ensured. This effectively reduces the risk of the cell assembly 1 loosening under dynamic loads such as vibration and impact, and improves the reliability and safety of the battery pack 100.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. 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.

[0068] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A cell assembly for a battery pack, the battery pack having a housing, characterized in that, include: A battery cell, the battery cell comprising a housing and an explosion-proof valve, the explosion-proof valve being disposed on the housing; An insulating film covers the outer wall of the housing. The insulating film has a window area and a first clearance hole disposed opposite to the explosion-proof valve. The window area is located on at least one side of the first clearance hole along the length direction of the battery cell. The housing disposed opposite to the window area is adapted to be bonded to the outer shell.

2. The battery cell assembly according to claim 1, characterized in that, Also includes: The first foam is disposed on the insulating film and extends along the width direction of the battery cell, and the first foam is located between the window area and the first clearance hole. The second foam is disposed on the insulating film and extends along the width direction of the battery cell. The second foam is located on the side of the window area away from the first clearance hole.

3. The cell assembly according to claim 2, characterized in that, Along the length of the battery cell, the size of the first foam is 5mm-10mm; And / or, the size of the second foam is 5mm-10mm.

4. The cell assembly according to claim 2, characterized in that, Along the length of the battery cell, the dimension from the first foam to the first clearance hole is n, where n≥10mm; And / or, the dimension of the second foam to the end face of the nearest end of the battery cell along its length is m, where m ≥ 10 mm.

5. The cell assembly according to claim 2, characterized in that, The distance between the battery cell along its width is y, and the distance between the first foam and the second foam along the length of the battery cell is w. The housing opposite to the window area is bonded to the outer shell by structural adhesive. The surface area of ​​the structural adhesive is greater than the surface area of ​​the window area and is S, where 1 / 2*(y*w) < S < 4 / 5*(y*w).

6. The cell assembly according to claim 1, characterized in that, Along the length of the battery cell, the size of the battery cell is h, and the size of the windowed area is k, where 1 / 3 ≤ k / h ≤ 1 / 4.

7. The cell assembly according to claim 1, characterized in that, Also includes: A mica plate is located between the electrode group of the battery cell and the explosion-proof valve and within the first clearance hole. The mica plate has a second clearance hole that is disposed opposite to the explosion-proof valve.

8. The cell assembly according to claim 1, characterized in that, The explosion-proof valve is one, the first clearance hole is one, and the window area is two, which are respectively located on both sides of the first clearance hole along the length of the battery cell. The two window areas are symmetrically arranged along the central axis of the first clearance hole.

9. The cell assembly according to claim 8, characterized in that, The dimension of the windowed area along the length of the battery cell is 'a', and the dimension of the windowed area along the width of the battery cell is 'b', wherein 40mm≤a≤53mm and 15mm≤b≤25mm.

10. A battery pack, characterized in that, include: shell; According to any one of claims 1-9, the outer casing has a through hole disposed opposite to the explosion-proof valve, and the outer casing is bonded to the housing disposed opposite to the window area.

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