End cover assembly, battery monomer, battery and electric device

Abstract

The invention discloses an end cover assembly, a battery monomer, a battery and a power utilization device, the end cover assembly comprises a cover plate, a pressure release valve and a fixing structure, the cover plate is provided with a pressure release hole, and the pressure release valve seals and covers the pressure release hole. The fixing structure is arranged on the cover plate and used for fixing the pressure relief valve, the fixing structure is located on the peripheral side of the pressure relief hole and protrudes out of the outer surface of the cover plate, and the fixing structure and the cover plate are integrally formed. According to the end cover assembly, the fixing structure used for fixing the pressure release valve protrudes out of the outer surface of the cover plate, so that the external space of the cover plate can be fully utilized, the thickness of the cover plate can be reduced, the cost of the cover plate can be reduced, the energy density of the single battery can be improved, and the service life of the battery can be prolonged. And the fixing structure and the cover plate are integrally formed, so that the damage to the pressure release valve caused by heat generated in the welding process can be avoided, the problems of sealing failure and the like caused by the damage can be avoided, and the yield of the end cover assembly is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an end cover assembly, a battery cell, a battery and an electrical device. Background Art

[0002] In the related art, a pressure relief valve is provided on the end cover assembly of the battery cell for safety protection. The pressure relief valve is fixed to the cover plate of the end cover assembly, and the pressure relief valve is usually fixed to the cover plate by welding. Usually, a groove is processed on the cover plate by removing material. The groove is used to accommodate the pressure relief valve and the fixing structure for fixing the pressure relief valve. In order to ensure the sealing strength between the pressure relief valve and the cover plate, the remaining thickness of the portion of the cover plate where the groove is formed needs to be set larger, so as to meet the sealing strength requirements between the pressure relief valve and the cover plate. This makes the overall thickness of the cover plate larger, which will make the cost of the cover plate higher. In addition, the thicker cover plate will occupy a larger space, resulting in a lower energy density of the battery cell.

[0003] In addition, the fixing structure and the cover plate are fixedly connected by welding to fix the pressure relief valve. The heat generated during the welding process may cause damage to the pressure relief valve, such as causing erosion of the pressure relief valve, which may cause problems such as sealing failure, thereby causing the end cover assembly to be scrapped and reducing the yield rate of the end cover assembly. Summary of the Invention

[0004] In view of the above problems, the present invention provides an end cover assembly, a battery cell, a battery and an electrical device. The pressure relief valve and the fixing structure of the end cover assembly can make full use of the space outside the cover plate of the end cover assembly, which is beneficial to reducing the thickness of the cover plate, thereby helping to reduce the cost of the cover plate and improve the energy density of the battery cell. The integral molding of the fixing structure and the cover plate can also avoid damage to the pressure relief valve caused by the heat generated during the welding process and avoid problems such as sealing failure caused thereby, thereby improving the yield rate of the end cover assembly.

[0005] In a first aspect, an embodiment of the present invention provides an end cover assembly, comprising: a cover plate provided with a pressure relief hole; a pressure relief valve, covering the pressure relief hole; a fixing structure, provided on the cover plate and used to fix the pressure relief valve, the fixing structure being located on the outer peripheral side of the pressure relief hole and protruding from the outer surface of the cover plate, and the fixing structure being integrally formed with the cover plate.

[0006] In the above technical solution, by arranging the fixing structure for fixing the pressure relief valve to protrude from the outer surface of the cover plate, the pressure relief valve and the fixing structure of the end cover assembly can make full use of the space outside the cover plate of the end cover assembly, reducing the space occupied by the pressure relief valve inside the cover plate or the pressure relief valve no longer occupies the space inside the cover plate, which is beneficial to reducing the thickness of the cover plate and reducing the cost of the cover plate. Reducing the thickness of the cover plate is also beneficial to improving the energy density of the battery cell; in addition, the fixing structure and the cover plate are integrally formed, and there is no need to fix the pressure relief valve to the cover plate by welding the fixing structure to the cover plate. This can avoid damage to the pressure relief valve caused by the heat generated during the welding process and avoid problems such as sealing failure caused by this, thereby improving the yield rate of the end cover assembly.

[0007] In some embodiments, a limiting groove is defined between the fixing structure and the cover plate, and an edge portion of the pressure relief valve is accommodated in the limiting groove.

[0008] In the above technical solution, by defining a limiting groove between the fixing structure and the cover plate and accommodating the edge of the pressure relief valve in the limiting groove, the limiting groove forms a limiting effect on the edge of the pressure relief valve, so that the pressure relief valve can be stably fixed on the cover plate.

[0009] In some embodiments, the cover plate has a thickness ranging from 1.0 mm to 2.5 mm.

[0010] In the above technical solution, if the thickness of the cover plate is less than 1.0 mm, the strength of the cover plate is low, which may lead to a weak bearing capacity of the end cover assembly, and deformation, cracking, etc. may occur due to the high pressure during operation, and it will also lead to a low sealing strength between the pressure relief valve and the cover plate; if the thickness of the cover plate is greater than 2.5 mm, the weight of the cover plate will be large and the cost will be high; by making the thickness range of the cover plate 1.0 mm to 2.5 mm, within this range, the thickness and weight of the cover plate are more appropriate, and it has higher strength, so that the cover plate is not easy to deform and can ensure the sealing strength requirements, and the cost is low.

[0011] In some embodiments, a protruding height of the fixing structure from the cover plate is greater than or equal to 1.7 mm.

[0012] In the above technical solution, by making the protruding height of the fixing structure from the cover plate greater than or equal to 1.7 mm, the height range of the fixing structure protruding from the cover plate is sufficient to accommodate the fixed pressure relief valve, and the pressure relief valve does not need to be sunken compared to the cover plate. The groove structure for fixing the pressure relief valve can be omitted on the cover plate, which is conducive to reducing the thickness of the cover plate. When the thickness of the cover plate is small, the sealing strength requirements between the pressure relief valve and the cover plate can also be met.

[0013] In some embodiments, the fixing structure includes a first fixing portion and a second fixing portion, the first fixing portion is connected to the outer surface of the cover plate and protrudes from the outer surface of the cover plate, the second fixing portion is connected to an end of the first fixing portion away from the cover plate, the second fixing portion is located on a side of the first fixing portion close to the central axis of the pressure relief hole and is spaced apart from the cover plate, and the first fixing portion, the second fixing portion and the cover plate jointly define the limiting groove.

[0014] In the above technical solution, the fixing structure includes a first fixing part and a second fixing part, and the second fixing part is connected to an end of the first fixing part away from the cover plate and spaced apart from the cover plate, and the second fixing part is located on a side of the central axis of the first fixing part close to the pressure relief hole. This arrangement facilitates the first fixing part, the second fixing part and the cover plate to jointly define a limiting groove. The limiting groove has a simple structure and is easy to form. The second fixing part forms a limiting and fixing effect on the pressure relief valve located in the limiting groove, which can prevent the pressure relief valve from falling out of the limiting groove.

[0015] In some embodiments, at least one of the first fixing portion and the second fixing portion is in a ring shape extending along the circumference of the pressure relief valve.

[0016] In the above technical solution, by making at least one of the first fixing portion and the second fixing portion into a ring extending along the circumference of the pressure relief valve, the fixing structure forms a limiting and fixing effect on the pressure relief valve in the circumferential direction, so that the pressure relief valve is stably fixed on the cover plate along the circumferential direction.

[0017] In some embodiments, the protruding height of the first fixing portion relative to the cover plate is H1, the extending width of the second fixing portion relative to the first fixing portion toward the central axis of the pressure relief hole is H2, and the sum of H1 and H2 ranges from 0.9 mm to 3.106 mm.

[0018] In the above technical solution, if the sum of H1 and H2 is less than 0.9 mm, the area of ​​the limiting groove formed by the first fixing portion, the second fixing portion, and the cover plate is limited, making the limiting and fixing effect of the fixing structure on the pressure relief valve unstable. If the sum of H1 and H2 is greater than 3.106 mm, the protrusion height of the first fixing portion may be too high, and a large gap may exist between the pressure relief valve and the second fixing portion. This may cause the pressure relief valve to wobble relative to the fixing structure, thereby making the fixing effect of the fixing structure on the pressure relief valve unstable and the sealing effect of the pressure relief valve on the pressure relief hole poor. It may also cause the extension width of the second fixing portion to be too large, making the second fixing portion easily interfere with the pressure relief valve, thereby affecting the installation effect of the pressure relief valve. By setting the sum of H1 and H2 to a value in the range of 0.9 mm to 3.106 mm, the height of the first fixing portion, the width of the second fixing portion, and the area of ​​the formed limiting groove are all relatively appropriate, so that the second fixing portion and the pressure relief valve are in close contact and are not prone to interference, so that the second fixing portion can form a stable limiting effect on the pressure relief valve. All of these are conducive to the fixing structure forming a stable fixing effect on the pressure relief valve.

[0019] In some embodiments, the pressure relief valve includes a valve plate and a pressing plate, the valve plate covers the pressure relief hole, the pressing plate is arranged on the side of the valve plate away from the cover plate, the melting point of the pressing plate is lower than the melting point of the valve plate, and the second fixing portion is located on the side of the pressing plate away from the valve plate, so as to fix the valve plate to the cover plate through the pressing plate.

[0020] In the above technical solution, the pressure relief valve includes a valve plate for sealing the pressure relief hole and a pressing plate provided on the side of the valve plate away from the cover plate, and the melting point of the pressing plate is lower than the melting point of the valve plate. When high temperature occurs in the use environment of the end cover assembly and the melting point of the pressing plate is reached, for example, when the battery cell including the end cover assembly is thermally instable, the pressing plate will melt before the valve plate, and the fixing constraint force of the pressing plate on the valve plate will be greatly reduced, so that the valve plate can be detached from the cover plate to release the seal on the pressure relief hole, so that the pressure can be quickly relieved through the pressure relief hole, thereby avoiding the formation of a large amount of energy accumulation inside the end cover assembly and causing a high-pressure explosion.

[0021] In some embodiments, the thickness of the pressing sheet is greater than the thickness of the valve sheet.

[0022] In the above technical solution, by making the thickness of the pressing sheet greater than the thickness of the valve sheet, the thickness of the valve sheet is smaller, so that the weight of the valve sheet is smaller. After the pressing sheet is melted, the valve sheet can easily detach from the cover plate to contact the cover of the pressure relief hole. For example, the valve sheet can be easily blown away from the pressure relief hole by the gas in the end cover assembly; and by setting the thickness of the pressing sheet to be larger, the limiting and fixing effect of the pressing sheet on the valve sheet can be ensured.

[0023] In some embodiments, the pressing plate is a plastic part, and the valve plate is a metal part.

[0024] In the above technical solution, by making the pressing sheet a plastic part and the valve sheet a metal part, the melting point of the plastic part is relatively low. When the valve sheet is exposed to high temperatures in the use environment of the end cover assembly, the plastic part is easily melted, thereby greatly reducing the restraining force of the pressing sheet on the valve sheet formed as a metal part, and the valve sheet can easily detach from the cover plate to contact the cover of the pressure relief hole.

[0025] In some embodiments, a fitting notch is formed on an edge portion of the pressure relief valve, and at least a portion of the second fixing portion is accommodated in the fitting notch.

[0026] In the above technical solution, a matching notch is formed on the edge of the pressure relief valve, and at least a portion of the second fixing portion is accommodated in the matching notch. The matching notch is used to avoid the second fixing portion, thereby avoiding mutual interference between the pressure relief valve and the second fixing portion. In addition, at least a portion of the second fixing portion is accommodated in the matching notch, so that the second fixing portion fixes the pressure relief valve, which is beneficial for the pressure relief valve to be stably fixed to the cover plate.

[0027] In some embodiments, the pressure relief valve includes a valve plate and a pressing plate, the valve plate covers the pressure relief hole, the pressing plate is provided on a side of the valve plate away from the cover plate, and the second fixing portion is located on a side of the pressing plate away from the valve plate, so as to fix the valve plate to the cover plate through the pressing plate;

[0028] The edge of the valve plate is the first edge, the edge of the pressing plate is the second edge, the first edge and the second edge together constitute the edge of the pressure relief valve, and the second edge is formed with the matching notch.

[0029] In the above technical solution, the pressure relief valve includes a valve plate that covers the pressure relief hole and a pressing plate arranged on the side of the valve plate away from the cover plate, the second fixing portion is located on the side of the pressing plate away from the valve plate, and a matching notch is formed on the second edge portion of the pressing plate, so that the second fixing portion fixes the pressing plate at the second edge portion, and then the second edge portion of the pressing plate fixes the first edge portion of the valve plate, so that the valve plate and the pressing plate are stably fixed to the cover plate by the second fixing portion.

[0030] In some embodiments, the end cover assembly includes: an inner insulating plate, which is arranged on the inner side of the cover plate, and a portion of the inner insulating plate is recessed inward to form an exhaust groove, the exhaust groove is opposite to the pressure relief valve and is connected to the pressure relief hole, and a ventilation structure connected to the exhaust groove is formed on the inner insulating plate.

[0031] In the above technical solution, an exhaust groove and a ventilation structure are formed on the inner insulating plate of the end cover assembly, and the exhaust groove is opposite to the pressure relief valve and connected to the pressure relief hole, and the ventilation structure is connected to the exhaust groove, so that after the pressure relief valve is separated from the pressure relief hole, the gas inside the end cover assembly can be smoothly discharged through the ventilation structure, the exhaust groove and the pressure relief hole in sequence to achieve the purpose of pressure relief, thereby avoiding a large amount of energy accumulation in the end cover assembly and even a high-pressure explosion.

[0032] In some embodiments, the exhaust groove includes a main exhaust groove and an auxiliary exhaust groove, the main exhaust groove is opposite to and connected to the pressure relief hole, the auxiliary exhaust groove surrounds the outer peripheral side of the main exhaust groove and is connected to the main exhaust groove, and the depth of the main exhaust groove is greater than the depth of the auxiliary exhaust groove.

[0033] In the above technical solution, the exhaust groove includes a main exhaust groove and an auxiliary exhaust groove surrounding the outer peripheral side of the main exhaust groove, and the main exhaust groove is connected to the auxiliary exhaust groove, so that more gas can flow toward the pressure relief hole through the exhaust groove; by making the depth of the main exhaust groove greater than the depth of the auxiliary exhaust groove, the space between the main exhaust groove and the pressure relief hole is larger, and before the pressure relief valve is separated from the pressure relief hole and the cover of the pressure relief hole is released, more gas can be stored between the main exhaust groove and the pressure relief hole, which is beneficial to reducing the gas pressure on the inner side of the end cover assembly, thereby delaying the explosion caused by excessive gas accumulation pressure.

[0034] In a second aspect, an embodiment of the present invention provides a battery cell, comprising: a shell having an opening; an electrode assembly disposed in the shell; and an end cap assembly according to an embodiment of the first aspect of the present invention, covering the opening.

[0035] In the above technical solution, the battery cell is provided with the above-mentioned end cover assembly, and the fixing structure of the end cover assembly protrudes from the outer surface of the cover plate, which is conducive to reducing the thickness of the end cover assembly, thereby reducing the cost of the cover plate and the space occupied by the cover plate in the battery cell, which is conducive to reducing the cost of the battery cell and improving the energy density of the battery cell; the fixing structure of the end cover assembly is integrally formed with the cover plate, which can avoid damage to the pressure relief valve during the process of fixing the pressure relief valve to the cover plate, thereby avoiding the problem of failure of the end cover assembly to seal the battery cell, so that the battery cell has good sealing performance, reduces the scrapping of the end cover assembly, improves the yield rate in the production process, and reduces production costs.

[0036] In a third aspect, an embodiment of the present invention provides a battery, comprising: a battery cell according to an embodiment of the second aspect of the present invention.

[0037] In the above technical solution, by making the battery include the above battery monomer, it is beneficial to reduce production costs.

[0038] In a fourth aspect, an embodiment of the present invention provides an electrical device, comprising: a battery according to the third aspect of the present invention.

[0039] In the above technical solution, the use of an electrical device including the above-mentioned battery is beneficial to reducing production costs.

[0040] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0042] Figure 1 is an exploded schematic diagram of an end cap assembly according to some embodiments of the present invention;

[0043] Figure 2 yes Figure 1 a cross-sectional view of the end cap assembly in FIG.

[0044] Figure 3 yes Figure 1 Schematic diagram of the three-dimensional structure of the tablet;

[0045] Figure 4 is a schematic diagram of a battery according to some embodiments of the present invention;

[0046] Figure 5 is a schematic diagram of an electrical device according to some embodiments of the present invention.

[0047] Reference numerals:

[0048] 100. End cover assembly;

[0049] 1. Cover plate; 11. Pressure relief hole;

[0050] 2. Pressure relief valve; 21. Edge; 22. Valve plate; 221. First edge; 23. Pressing plate; 231. Second edge; 2311. Matching notch;

[0051] 3. Fixing structure; 31. First fixing portion; 32. Second fixing portion;

[0052] 4. Limiting slot;

[0053] 5. Inner insulation plate; 51. Exhaust groove; 511. Main exhaust groove; 512. Auxiliary exhaust groove; 52. Ventilation structure;

[0054] 61. Positive pole; 62. Negative pole;

[0055] 7. Sealing ring;

[0056] 200, battery;

[0057] 1000. Electrical equipment. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0059] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification and application of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having," as well as any variations thereof, in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," etc., in the specification and claims of the present invention and the accompanying drawings are used to distinguish between different objects, rather than to describe a specific order or a primary-secondary relationship.

[0060] Reference to an "embodiment" in the present invention means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0061] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0062] The term "and / or" in this disclosure simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this disclosure generally indicates that the related objects are in an "or" relationship.

[0063] In the embodiments of the present invention, identical reference numerals denote identical components, and for the sake of brevity, detailed descriptions of identical components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present invention, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings, are merely illustrative and do not constitute any limitation on the present invention.

[0064] The term "plurality" used in the present invention refers to two or more (including two).

[0065] In this disclosure, a battery refers to a single physical module that includes one or more battery cells to provide a higher voltage and capacity. For example, the battery referred to in this disclosure may include a battery module or battery pack. Some batteries may include a casing that encloses one or more battery cells or multiple battery modules. This casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0066] In the present invention, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of the present invention do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of the present invention do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of the present invention do not limit this.

[0067] Currently, market developments indicate that batteries are becoming increasingly widely used. Batteries are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0068] In the related art, a pressure relief valve is provided on the end cap assembly of a battery cell to seal the pressure relief hole and provide safety protection. The pressure relief valve is fixed to the cover plate of the end cap assembly and is usually fixed to the cover plate by welding. However, due to the unreasonable spatial layout of the relevant structures on the cover plate, in order to ensure that the installation of the pressure relief valve does not affect the strength requirements of the cover plate, the thickness of the cover plate needs to be increased. This will increase the cost of the cover plate and the cover plate will also occupy a large space in the battery cell, resulting in a lower energy density of the battery cell. In addition, the pressure relief valve and the cover plate are fixedly connected by welding. The welding process may cause damage to the pressure relief valve, such as burning of the pressure relief valve, which may cause problems such as sealing failure of the pressure relief valve.

[0069] Based on this, the applicant proposed an end cover assembly, which includes a cover plate provided with a pressure relief hole and a pressure relief valve covering the pressure relief hole. The end cover assembly also includes a fixing structure, and the fixing structure is provided on the cover plate for fixing the pressure relief valve. The fixing structure is located on the outer peripheral side of the pressure relief hole and protrudes from the outer surface of the cover plate, and the fixing structure is integrally formed with the cover plate.

[0070] In the above-mentioned end cover assembly, by arranging the fixing structure for fixing the pressure relief valve to protrude from the outer surface of the cover plate, the pressure relief valve and the fixing structure of the end cover assembly can make full use of the space outside the cover plate of the end cover assembly, reducing the space occupied by the pressure relief valve inside the cover plate or the pressure relief valve no longer occupies the space inside the cover plate, which is conducive to reducing the thickness of the cover plate and reducing the cost of the cover plate. Reducing the thickness of the cover plate is also conducive to improving the energy density of the battery cell.

[0071] By integrally forming the fixing structure with the cover plate, the pressure relief valve is fixed to the cover plate through the fixing structure, and there is no need to fix the pressure relief valve to the cover plate by welding the fixing structure to the cover plate. This can avoid damage to the pressure relief valve caused by the heat generated during the welding process and avoid problems such as sealing failure caused by this.

[0072] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and the spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0073] Reference below Figure 1-Figure 3 An end cap assembly 100 according to an embodiment of the present invention is described.

[0074] refer to Figure 1 In a first aspect, an embodiment of the present invention provides an end cap assembly 100 comprising a cover plate 1, a pressure relief valve 2, and a fixing structure 3. The cover plate 1 is provided with a pressure relief hole 11, and the pressure relief valve 2 covers the pressure relief hole 11. The fixing structure 3 is provided on the cover plate 1 and is used to fix the pressure relief valve 2. The fixing structure 3 is located on the outer periphery of the pressure relief hole 11 and protrudes from the outer surface of the cover plate 1. The fixing structure 3 and the cover plate 1 are integrally formed.

[0075] Optionally, the cover plate 1 of the end cover assembly 100 is a metal part, and the fixing structure 3 of the end cover assembly 100 is a metal structure.

[0076] For example, when the end cap assembly 100 is used for a battery cell, during the operation of the battery cell, a large amount of gas is generated inside the end cap assembly 100 of the battery cell, causing energy accumulation. At this time, the pressure relief valve 2 can open the pressure relief hole 11, so that the gas in the battery cell can be discharged through the pressure relief hole 11, thereby achieving the purpose of pressure relief.

[0077] When the end cap assembly 100 is used for a battery cell, the outer surface of the cap plate 1 refers to the surface of the cap plate 1 facing the outside of the battery cell.

[0078] For example, a method of manufacturing the end cap assembly 100 may include the following steps:

[0079] First, a cover plate blank is provided. The cover plate blank is processed to form a cover plate 1 having a pressure relief hole 11 and a fixing structure 3 blank connected to the cover plate 1. The fixing structure 3 blank is located on the outer periphery of the pressure relief hole 11 and defines a mounting groove between the fixing structure 3 and the cover plate 1.

[0080] Next, install the pressure relief valve 2 into the installation groove;

[0081] Finally, the fixing structure 3 blank is bent toward the central axis close to the pressure relief hole 11 to form the fixing structure 3 , and a portion of the fixing structure 3 is pressed against the side of the pressure relief valve 2 away from the cover plate 1 to fix the pressure relief valve 2 to the cover plate 1 .

[0082] In the above technical solution, by arranging the fixing structure 3 for fixing the pressure relief valve 2 to protrude from the outer surface of the cover plate 1, the pressure relief valve 2 and the fixing structure 3 of the end cover assembly 100 can make full use of the space outside the cover plate 1 of the end cover assembly 100, reducing the space occupied by the pressure relief valve 2 inside the cover plate 1 or the pressure relief valve 2 no longer occupies the space inside the cover plate 1, which is beneficial to reducing the thickness of the cover plate 1 and reducing the cost of the cover plate 1. Reducing the thickness of the cover plate 1 is also beneficial to improving the energy density of the battery cell; in addition, the fixing structure 3 and the cover plate 1 are integrally formed, and there is no need to fix the pressure relief valve 2 to the cover plate 1 by welding the fixing structure 3 to the cover plate 1. This can avoid damage to the pressure relief valve 2 caused by the heat generated during welding and avoid problems such as sealing failure, thereby improving the yield rate of the end cover assembly 100.

[0083] refer to Figure 2 In some embodiments, a limiting groove 4 is defined between the fixing structure 3 and the cover plate 1 , and the edge portion 21 of the pressure relief valve 2 is accommodated in the limiting groove 4 .

[0084] In the above technical solution, by defining a limiting groove 4 between the fixing structure 3 and the cover plate 1 and accommodating the edge portion 21 of the pressure relief valve 2 in the limiting groove 4, the limiting groove 4 forms a limiting effect on the edge portion 21 of the pressure relief valve 2, so that the pressure relief valve 2 can be stably fixed on the cover plate 1.

[0085] refer to Figure 2In some embodiments, the thickness of the cover plate 1 is e, and the thickness e of the cover plate 1 ranges from 1.0 mm to 2.5 mm. Optionally, the thickness e of the cover plate 1 can be 1.0 mm, 1.2 mm, 1.5 mm, 2.0 mm, 2.3 mm, 2.5 mm, etc.

[0086] In the above technical solution, if the thickness e of the cover plate 1 is less than 1.0 mm, the strength of the cover plate 1 is low, which may lead to a weak bearing capacity of the end cover assembly 100, and deformation, cracking, etc. may occur due to the large pressure during operation; if the thickness e of the cover plate 1 is greater than 2.5 mm, the weight of the cover plate 1 will be large and the cost will be high; by making the thickness e of the cover plate 1 range from 1.0 mm to 2.5 mm, within this range, the thickness and weight of the cover plate 1 are more appropriate, and it has higher strength, so that the cover plate 1 is not easy to deform and can ensure the sealing strength requirements, and the cost is low.

[0087] refer to Figure 2 In some embodiments, the protrusion height d1 of the fixing structure 3 from the cover plate 1 is greater than or equal to 1.7 mm. Alternatively, the protrusion height d1 of the fixing structure 3 from the cover plate 1 can be 1.7 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.7 mm, 3.0 mm, etc.

[0088] In the above technical solution, by making the protruding height of the fixing structure 3 from the cover plate 1 greater than or equal to 1.7 mm, the height range of the fixing structure 3 protruding from the cover plate 1 is sufficient to accommodate the fixed pressure relief valve 2, and the pressure relief valve 2 does not need to be sunken compared to the cover plate 1. The groove structure for fixing the pressure relief valve 2 can be omitted on the cover plate 1, which is conducive to reducing the thickness of the cover plate 1. When the thickness of the cover plate 1 is small, the sealing strength requirements between the pressure relief valve 2 and the cover plate 1 can also be met.

[0089] refer to Figure 1Optionally, the end cap assembly 100 further includes two electrode structures, namely a positive electrode 61 and a negative electrode 62. The positive electrode 61 and the negative electrode 62 are spaced apart and can be located on either side of the pressure relief hole 11. The height d2 of the positive electrode 61 and the negative electrode 62 protruding from the cover plate 1 is the same as the height d2 of the fixed structure 3 protruding from the cover plate 1. The height d1 of the fixed structure 3 protruding from the cover plate 1 can be less than or equal to d2. By ensuring that d1 is less than or equal to d2, the fixed structure 3 and the pressure relief valve 2 can fully utilize the space between the cover plate 1 and the highest point of the electrode, making the end cap assembly 100 structurally rational and compact. However, the fixed structure 3 does not occupy space outside the highest point of the electrode due to its protrusion exceeding the electrode. The highest point of the electrode is the point farthest from the cover plate 1. For example, when the end cap assembly 100 is used for a battery cell and multiple battery cells are arranged and assembled to form a module, the fixed structure 3 and the pressure relief valve 2 do not occupy space at the module interface.

[0090] refer to Figure 2 In some embodiments, the fixing structure 3 includes a first fixing portion 31 and a second fixing portion 32. The first fixing portion 31 is connected to the outer surface of the cover plate 1 and protrudes from the outer surface of the cover plate 1. The second fixing portion 32 is connected to the end of the first fixing portion 31 away from the cover plate 1. The second fixing portion 32 is located on the side of the first fixing portion 31 close to the central axis of the pressure relief hole 11 and is spaced apart from the cover plate 1. The first fixing portion 31, the second fixing portion 32 and the cover plate 1 jointly define a limiting groove 4.

[0091] In the above technical solution, the fixing structure 3 includes a first fixing portion 31 and a second fixing portion 32, and the second fixing portion 32 is connected to the end of the first fixing portion 31 away from the cover plate 1 and spaced apart from the cover plate 1, and the second fixing portion 32 is located on the side of the first fixing portion 31 close to the central axis of the pressure relief hole 11. This arrangement facilitates the first fixing portion 31, the second fixing portion 32 and the cover plate 1 to jointly define a limiting groove 4. The limiting groove 4 has a simple structure and is easy to form. The second fixing portion 32 forms a limiting and fixing effect on the pressure relief valve 2 located in the limiting groove 4, which can prevent the pressure relief valve 2 from falling out of the limiting groove 4.

[0092] refer to Figure 1-Figure 2 In some embodiments, at least one of the first fixing portion 31 and the second fixing portion 32 is in a ring shape extending along the circumference of the pressure relief valve 2 .

[0093] Among them, at least one of the first fixing portion 31 and the second fixing portion 32 is in a ring shape extending along the circumference of the pressure relief valve 2, including the following situations: for example, the first fixing portion 31 is in a ring shape extending along the circumference of the pressure relief valve 2; for another example, the second fixing portion 32 is in a ring shape extending along the circumference of the pressure relief valve 2; for another example, both the first fixing portion 31 and the second fixing portion 32 are in a ring shape extending along the circumference of the pressure relief valve 2.

[0094] Optionally, the outer contour of the pressure relief valve 2 may be in the shape of a circle, a polygon, etc. When the outer contour of the pressure relief valve 2 is circular, the first fixing portion 31 and the second fixing portion 32 may be in the shape of a circular ring; when the outer contour of the pressure relief valve 2 is polygonal, the first fixing portion 31 and the second fixing portion 32 may be in the shape of a polygonal ring.

[0095] In the above technical solution, by making at least one of the first fixing portion 31 and the second fixing portion 32 into a ring extending along the circumference of the pressure relief valve 2, the fixing structure 3 forms a limiting and fixing effect on the pressure relief valve 2 in the circumferential direction, so that the pressure relief valve 2 is stably fixed to the cover plate 1 along the circumferential direction.

[0096] refer to Figure 2 In some embodiments, the protruding height of the first fixing portion 31 relative to the cover plate 1 is H1, and the extending width of the second fixing portion 32 relative to the first fixing portion 31 in the direction close to the central axis of the pressure relief hole 11 is H2. The sum of H1 and H2 ranges from 0.9 mm to 3.106 mm. Alternatively, the sum of H1 and H2 can be 0.9 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 2.7 mm, 3.0 mm, 3.106 mm, etc.

[0097] In the above technical solution, if the sum of H1 and H2 is less than 0.9 mm, the area of ​​the limiting groove 4 formed by the first fixing portion 31, the second fixing portion 32, and the cover plate 1 is limited, making the limiting and fixing effect of the fixing structure 3 on the pressure relief valve 2 unstable. If the sum of H1 and H2 is greater than 3.106 mm, the protrusion height of the first fixing portion 31 may be too high, and a large gap may exist between the pressure relief valve 2 and the second fixing portion 32. This may cause the pressure relief valve 2 to rock relative to the fixing structure 3, thereby making the fixing effect of the fixing structure 3 on the pressure relief valve 2 unstable and the sealing effect of the pressure relief valve 2 on the pressure relief hole 11 poor. It may also cause the extension width of the second fixing portion 32 to be too large, making it easy for the second fixing portion 32 to interfere with the pressure relief valve 2, thereby affecting the installation effect of the pressure relief valve 2. By setting the sum of H1 and H2 to a value in the range of 0.9 mm to 3.106 mm, the height of the first fixing portion 31, the width of the second fixing portion 32, and the area of ​​the formed limiting groove 4 are all relatively suitable, so that the second fixing portion 32 and the pressure relief valve 2 are in close contact and are not prone to interference, so that the second fixing portion 32 can form a stable limiting effect on the pressure relief valve 2. These are all conducive to the fixing structure 3 forming a stable fixing effect on the pressure relief valve 2, and are also conducive to the pressure relief valve 2 forming a good seal on the pressure relief hole 11.

[0098] refer to Figure 1-Figure 2In some embodiments, the pressure relief valve 2 includes a valve plate 22 and a pressing plate 23. The valve plate 22 covers the pressure relief hole 11. The pressing plate 23 is arranged on the side of the valve plate 22 away from the cover plate 1. The melting point of the pressing plate 23 is lower than the melting point of the valve plate 22. The second fixing portion 32 is located on the side of the pressing plate 23 away from the valve plate 22 to fix the valve plate 22 on the cover plate 1 through the pressing plate 23.

[0099] For example, the end cover assembly 100 is used for a battery cell. When the battery cell reaches a high temperature, the temperature of the battery cell reaches the melting point of the pressing piece 23. The pressing piece 23 located on the side of the valve sheet 22 away from the cover plate 1 will melt after reaching the melting point. The restraining force of the valve sheet 22 by the pressing piece 23 is greatly reduced, and the gas inside the battery cell can bounce the valve sheet 22, thereby realizing the function of early exhaust.

[0100] In the above technical solution, the pressure relief valve 2 includes a valve plate 22 for sealing the pressure relief hole 11 and a pressing plate 23 provided on the side of the valve plate 22 away from the cover plate 1, and the melting point of the pressing plate 23 is lower than the melting point of the valve plate 22. When high temperature occurs in the use environment of the end cover assembly 100 and the melting point of the pressing plate 23 is reached, for example, when the battery cell including the end cover assembly 100 has thermal runaway, the pressing plate 23 will melt before the valve plate 22, and the fixing constraint force of the pressing plate 23 on the valve plate 22 will be greatly reduced, so that the valve plate 22 can be detached from the cover plate 1 to release the seal on the pressure relief hole 11, so that the pressure can be quickly relieved through the pressure relief hole 11, thereby avoiding the formation of a large amount of energy accumulation inside the end cover assembly 100 and causing a high-pressure explosion, etc., and is also conducive to reducing the damage caused by the explosion.

[0101] refer to Figure 1-Figure 2 In some embodiments, the thickness of the pressing sheet 23 is greater than the thickness of the valve sheet 22 .

[0102] In the above technical solution, by making the thickness of the pressing sheet 23 greater than the thickness of the valve sheet 22, the thickness of the valve sheet 22 is smaller, so that the weight of the valve sheet 22 is smaller. After the pressing sheet 23 melts, the valve sheet 22 can easily detach from the cover plate 1 to contact the cover of the pressure relief hole 11. For example, the valve sheet 22 can be easily blown away from the pressure relief hole 11 by the gas in the end cover assembly 100; and, by setting the thickness of the pressing sheet 23 to be larger, the limiting and fixing effect of the pressing sheet 23 on the valve sheet 22 can be ensured.

[0103] In some embodiments, the pressing plate 23 is a plastic part, and the valve plate 22 is a metal part. Optionally, the pressing plate 23 can be made of PP (polypropylene) material.

[0104] In the above technical solution, by making the pressing sheet 23 a plastic part and the valve sheet 22 a metal part, the melting point of the plastic part is relatively low. When the valve sheet 22 is exposed to high temperatures in the operating environment of the end cover assembly 100, the plastic part is easily melted, thereby greatly reducing the restraining force of the pressing sheet 23 on the valve sheet 22 formed as a metal part, and the valve sheet 22 is easily detached from the cover plate 1 to contact the cover of the pressure relief hole 11.

[0105] refer to Figure 1-Figure 2 In some embodiments, a matching notch 2311 is formed on the edge portion 21 of the pressure relief valve 2 , and at least a portion of the second fixing portion 32 is accommodated in the matching notch 2311 .

[0106] At least part of the second fixing portion 32 is accommodated in the matching notch 2311 , including the following situations: for example, part of the second fixing portion 32 is accommodated in the matching notch 2311 ; for example, the entire second fixing portion 32 is accommodated in the matching notch 2311 .

[0107] In the above technical solution, a matching notch 2311 is formed on the edge portion 21 of the pressure relief valve 2, and at least a portion of the second fixing portion 32 is accommodated in the matching notch 2311. The matching notch 2311 is used to avoid the second fixing portion 32, thereby avoiding mutual interference between the pressure relief valve 2 and the second fixing portion 32. In addition, at least a portion of the second fixing portion 32 is accommodated in the matching notch 2311, so that the second fixing portion 32 fixes the pressure relief valve 2, which is beneficial for the pressure relief valve 2 to be stably fixed to the cover plate 1.

[0108] refer to Figure 1-Figure 3 In some embodiments, the pressure relief valve 2 includes a valve disc 22 and a pressing disc 23. The valve disc 22 covers the pressure relief hole 11. The pressing disc 23 is disposed on the side of the valve disc 22 away from the cover plate 1. The second fixing portion 32 is located on the side of the pressing disc 23 away from the valve disc 22, so as to fix the valve disc 22 to the cover plate 1 via the pressing disc 23. The edge portion 21 of the valve disc 22 is a first edge portion 221, and the edge portion 21 of the pressing disc 23 is a second edge portion 231. The first edge portion 221 and the second edge portion 231 together constitute the edge portion 21 of the pressure relief valve 2. The second edge portion 231 is formed with a mating notch 2311.

[0109] In the above technical solution, the pressure relief valve 2 includes a valve plate 22 that covers the pressure relief hole 11 and a pressing plate 23 provided on the side of the valve plate 22 away from the cover plate 1, the second fixing portion 32 is located on the side of the pressing plate 23 away from the valve plate 22, and the second edge portion 231 of the pressing plate 23 is formed with a matching notch 2311, so that the second fixing portion 32 fixes the pressing plate 23 at the second edge portion 231, and then the second edge portion 231 of the pressing plate 23 fixes the first edge portion 221 of the valve plate 22, so that the valve plate 22 and the pressing plate 23 are stably fixed on the cover plate 1 by the second fixing portion 32.

[0110] Optionally, the outer surface of the second fixing portion 32 may be flush with the outer surface of the pressing sheet 23 , or the outer surface of the second fixing portion 32 may be higher than the outer surface of the pressing sheet 23 , or the outer surface of the second fixing portion 32 may be lower than the outer surface of the pressing sheet 23 .

[0111] refer to Figure 1-Figure 3 In some embodiments, the edge portion 21 of the valve plate 22 is a first edge portion 221, and the edge portion 21 of the pressing plate 23 is a second edge portion 231. The first edge portion 221 and the second edge portion 231 together constitute the edge portion 21 of the pressure relief valve 2. The second edge portion 231 is formed with a matching notch 2311, and the second fixing portion 32 is accommodated in the matching notch 2311. The protruding height of the first fixing portion 31 relative to the cover plate 1 is H1, and the portion of the second fixing portion 32 extending relative to the first fixing portion 31 toward the central axis of the pressure relief hole 11 is accommodated in the matching notch 2311. The extension width of the portion of the second fixing portion 32 accommodated in the matching notch 2311 is H2, and the sum of H1 and H2 ranges from 0.9 mm to 3.106 mm.

[0112] In some embodiments, the end cover assembly 100 further includes a plurality of sealing rings 7 , wherein one sealing ring 7 is disposed between the pressure relief hole 11 and the valve plate 22 of the pressure relief valve 2 , and the pressing plate 23 compresses the sealing ring 7 to achieve a sealing function.

[0113] refer to Figure 1-Figure 2 In some embodiments, the end cover assembly 100 includes an inner insulating plate 5, which is arranged on the inner side of the cover plate 1. Part of the inner insulating plate 5 is recessed inward to form an exhaust groove 51. The exhaust groove 51 is opposite to the pressure relief valve 2 and is connected to the pressure relief hole 11. A ventilation structure 52 connected to the exhaust groove 51 is formed on the inner insulating plate 5.

[0114] In the above technical solution, an exhaust groove 51 and a ventilation structure 52 are formed on the inner insulating plate 5 of the end cover assembly 100, and the exhaust groove 51 is opposite to the pressure relief valve 2 and connected to the pressure relief hole 11, and the ventilation structure 52 is connected to the exhaust groove 51, so that after the pressure relief valve 2 is separated from the pressure relief hole 11, the gas inside the end cover assembly 100 can be smoothly discharged through the ventilation structure 52, the exhaust groove 51 and the pressure relief hole 11 in sequence to achieve the purpose of pressure relief, thereby avoiding a large amount of energy accumulation in the end cover assembly 100 or even a high-pressure explosion.

[0115] refer to Figure 1 In some embodiments, the exhaust groove 51 includes a main exhaust groove 511 and an auxiliary exhaust groove 512. The main exhaust groove 511 is opposite to and connected to the pressure relief hole 11, and the auxiliary exhaust groove 512 surrounds the outer peripheral side of the main exhaust groove 511 and is connected to the main exhaust groove 511. The depth of the main exhaust groove 511 is greater than the depth of the auxiliary exhaust groove 512.

[0116] In the above technical solution, by making the exhaust groove 51 include a main exhaust groove 511 and an auxiliary exhaust groove 512 surrounding the outer peripheral side of the main exhaust groove 511, and making the main exhaust groove 511 and the auxiliary exhaust groove 512 connected, more gas can flow toward the pressure relief hole 11 through the exhaust groove 51, and this arrangement also facilitates rapid pressure relief through the pressure relief hole 11; by making the depth of the main exhaust groove 511 greater than the depth of the auxiliary exhaust groove 512, the space between the main exhaust groove 511 and the pressure relief hole 11 is larger, and when the pressure relief valve 2 has not yet separated from the pressure relief hole 11 and released the cover of the pressure relief hole 11, more gas can be stored between the main exhaust groove 511 and the pressure relief hole 11, which is beneficial to reducing the gas pressure on the inner side of the end cover assembly 100, thereby helping to delay the explosion caused by excessive gas accumulation pressure.

[0117] In a second aspect, an embodiment of the present invention provides a battery cell, comprising: a shell, an electrode assembly, and the above-mentioned end cap assembly 100 . The shell has an opening, the electrode assembly is disposed in the shell, and the end cap assembly 100 covers the opening.

[0118] In the above technical solution, the battery cell is provided with the above-mentioned end cover assembly 100, and the fixing structure 3 of the end cover assembly 100 protrudes from the outer surface of the cover plate 1, which is beneficial to reducing the thickness of the end cover assembly 100, thereby reducing the cost of the cover plate 1 and the space occupied by the cover plate 1 in the battery cell, which is beneficial to reducing the cost of the battery cell and improving the energy density of the battery cell; the fixing structure 3 of the end cover assembly 100 is integrally formed with the cover plate 1, which can avoid damage to the pressure relief valve 2 during the process of fixing the pressure relief valve 2 to the cover plate 1, thereby avoiding the problem of sealing failure of the end cover assembly 100 on the battery cell caused by this, so that the battery cell has good sealing performance, reduces the scrapping of the end cover assembly 100, improves the yield rate in the production process, and reduces production costs.

[0119] refer to Figure 4 In a third aspect, an embodiment of the present invention provides a battery 200 comprising the above-mentioned battery cell.

[0120] In the above technical solution, by making the battery 200 include the above battery cells, it is beneficial to reduce the production cost of the battery 200.

[0121] refer to Figure 5 In a fourth aspect, an embodiment of the present invention provides an electrical device 1000 , comprising the above-mentioned battery 200 .

[0122] In the above technical solution, the electric device 1000 includes the above-mentioned battery 200 , which is beneficial to reducing the production cost of the electric device 1000 .

[0123] Next, we will refer to Figure 1-Figure 3 An end cap assembly 100 according to some embodiments of the present invention is described.

[0124] refer to Figure 1-Figure 3 In this embodiment, the end cap assembly 100 includes a cover plate 1, a pressure relief valve 2, a fixing structure 3, a positive electrode column 61, a negative electrode column 62, and an inner insulating plate 5. The cover plate 1 is provided with a pressure relief hole 11. The pressure relief valve 2 is used to cover the pressure relief hole 11. The fixing structure 3 is provided on the cover plate 1 and is integrally formed with the cover plate 1. The inner insulating plate 5 is provided on the inner side of the cover plate 1. The fixing structure 3 is located on the outer peripheral side of the pressure relief hole 11, and the fixing structure 3 protrudes from the outer surface of the cover plate 1. The fixing structure 3 is used to fix the pressure relief valve 2 to the cover plate 1. The positive electrode column 61 and the negative electrode column 62 also protrude from the outer surface of the cover plate 1, and the pressure relief hole 11, the pressure relief valve 2, and the fixing structure 3 are located between the positive electrode column 61 and the negative electrode column 62. The height of the fixing structure 3 protruding from the cover plate 1 is less than or equal to the height of the positive electrode column 61 and the negative electrode column 62 protruding from the cover plate 1.

[0125] The fixing structure 3 includes a first fixing portion 31 and a second fixing portion 32. The first fixing portion 31 is connected to the outer surface of the cover plate 1 and protrudes from the outer surface of the cover plate 1. The second fixing portion 32 is connected to the end of the first fixing portion 31 away from the cover plate 1. The second fixing portion 32 is located on the side of the first fixing portion 31 close to the central axis of the pressure relief hole 11 and is spaced apart from the cover plate 1. The first fixing portion 31 and the second fixing portion 32 are in a circular ring shape extending along the circumference of the pressure relief valve 2. The first fixing portion 31, the second fixing portion 32 and the cover plate 1 jointly define a limiting groove 4.

[0126] The pressure relief valve 2 includes a valve plate 22 and a pressing plate 23. The valve plate 22 covers the pressure relief hole 11. The pressing plate 23 is arranged on the side of the valve plate 22 away from the cover plate 1. The thickness of the pressing plate 23 is greater than the thickness of the valve plate 22. The pressing plate 23 is a PP plastic part, and the valve plate 22 is a metal part. The melting point of the pressing plate 23 is lower than the melting point of the valve plate 22.

[0127] The second fixing portion 32 is located on the side of the pressing disc 23 away from the valve disc 22, thereby securing the valve disc 22 to the cover plate 1 via the pressing disc 23. The edge 21 of the valve disc 22 is a first edge 221, and the edge 21 of the pressing disc 23 is a second edge 231. The first and second edge 221, 231 together constitute the edge 21 of the pressure relief valve 2. The second edge 231 is formed with a mating notch 2311. The edge 21 of the pressure relief valve 2 is accommodated in the retaining groove 4, and the second fixing portion 32 is accommodated in the mating notch 2311.

[0128] The thickness e of the cover plate 1 ranges from 1.0 mm to 2.5 mm, the protruding height of the first fixing portion 31 relative to the cover plate 1 is H1, the extending width of the second fixing portion 32 relative to the first fixing portion 31 toward the central axis close to the pressure relief hole 11 is H2, and the sum of H1 and H2 ranges from 0.9 mm to 3.106 mm.

[0129] A portion of the inner insulating plate 5 is recessed inward to form a vent groove 51. The vent groove 51 opposes the pressure relief valve 2 and communicates with the pressure relief hole 11. A vent structure 52 is formed on the inner insulating plate 5 and communicates with the vent groove 51. The vent groove 51 includes a primary vent groove 511 and a secondary vent groove 512. The primary vent groove 511 opposes and communicates with the pressure relief hole 11. The secondary vent groove 512 surrounds the primary vent groove 511 and communicates with the primary vent groove 511. The primary vent groove 511 is deeper than the secondary vent groove 512.

[0130] For example, the end cover assembly 100 can be used for a battery cell. When the battery cell reaches a high temperature, a large amount of gas is generated and accumulated on the inner side of the end cover assembly 100 of the battery cell, and the problem of the battery cell reaches the melting point of the pressing plate 23. The pressing plate 23 located on the side of the valve plate 22 away from the cover plate 1 will melt after reaching the melting point. The restraining force of the valve plate 22 by the pressing plate 23 is greatly reduced. The gas inside the battery cell can bounce the valve plate 22 to contact the pressure relief valve 2 to cover the pressure relief hole 11, so that the gas in the battery cell can be discharged successively through the ventilation structure 52, the exhaust groove 51 and the pressure relief hole 11, thereby realizing the function of early exhaust to achieve the purpose of decompression of the battery cell.

[0131] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses 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 any one or more embodiments or examples.

[0132] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An end cap assembly, characterized in that: include: The cover plate is provided with a pressure relief hole; a pressure relief valve, sealing the pressure relief hole; A fixing structure is provided on the cover plate and is used to fix the pressure relief valve. The fixing structure is located on the outer peripheral side of the pressure relief hole and protrudes from the outer surface of the cover plate. The fixing structure is integrally formed with the cover plate.

2. The end cap assembly according to claim 1, wherein: A limiting groove is defined between the fixing structure and the cover plate, and an edge portion of the pressure relief valve is accommodated in the limiting groove.

3. The end cap assembly according to claim 2, wherein: The thickness of the cover plate is in the range of 1.0 mm to 2.5 mm; and / or the protruding height of the fixing structure from the cover plate is greater than or equal to 1.7 mm.

4. The end cap assembly according to claim 2, wherein: The fixing structure includes a first fixing portion and a second fixing portion, the first fixing portion is connected to the outer surface of the cover plate and protrudes from the outer surface of the cover plate, the second fixing portion is connected to an end of the first fixing portion away from the cover plate, the second fixing portion is located on a side of the first fixing portion close to the central axis of the pressure relief hole and is spaced apart from the cover plate, and the first fixing portion, the second fixing portion and the cover plate jointly define the limiting groove.

5. The end cap assembly according to claim 4, wherein: At least one of the first fixing portion and the second fixing portion has a ring shape extending along a circumferential direction of the pressure relief valve.

6. The end cap assembly according to claim 4, wherein: The protruding height of the first fixing portion relative to the cover plate is H1, the extending width of the second fixing portion relative to the first fixing portion toward the central axis of the pressure relief hole is H2, and the sum of H1 and H2 ranges from 0.9 mm to 3.106 mm.

7. The end cap assembly according to claim 4, wherein: The pressure relief valve includes a valve plate and a pressing plate, the valve plate covers the pressure relief hole, the pressing plate is arranged on the side of the valve plate away from the cover plate, the melting point of the pressing plate is lower than the melting point of the valve plate, and the second fixing portion is located on the side of the pressing plate away from the valve plate, so that the valve plate is fixed to the cover plate through the pressing plate.

8. The end cap assembly according to claim 7, wherein: The thickness of the pressing sheet is greater than the thickness of the valve sheet; and / or the pressing sheet is a plastic part, and the valve sheet is a metal part.

9. The end cap assembly according to claim 4, wherein: A matching notch is formed on the edge of the pressure relief valve, and at least a portion of the second fixing portion is accommodated in the matching notch.

10. The end cap assembly according to claim 9, wherein: The pressure relief valve includes a valve plate and a pressing plate, the valve plate covers the pressure relief hole, the pressing plate is provided on a side of the valve plate away from the cover plate, and the second fixing portion is located on a side of the pressing plate away from the valve plate, so as to fix the valve plate to the cover plate through the pressing plate; The edge of the valve plate is the first edge, the edge of the pressing plate is the second edge, the first edge and the second edge together constitute the edge of the pressure relief valve, and the second edge is formed with the matching notch.

11. The end cap assembly according to any one of claims 1 to 10, characterized in that: include: An inner insulating plate is arranged on the inner side of the cover plate, and a portion of the inner insulating plate is recessed inward to form an exhaust groove, the exhaust groove is opposite to the pressure relief valve and is connected to the pressure relief hole, and a ventilation structure connected to the exhaust groove is formed on the inner insulating plate.

12. The end cap assembly according to claim 11, wherein: The exhaust groove includes a main exhaust groove and an auxiliary exhaust groove. The main exhaust groove is opposite to and connected to the pressure relief hole. The auxiliary exhaust groove surrounds the outer peripheral side of the main exhaust groove and is connected to the main exhaust groove. The depth of the main exhaust groove is greater than the depth of the auxiliary exhaust groove.

13. A battery cell, characterized in that: include: a housing having an opening; an electrode assembly, disposed in the housing; The end cover assembly according to any one of claims 1 to 12, wherein the cover is provided on the opening.

14. A battery, characterized in that: include: The battery cell according to claim 13.

15. An electrical device, characterized in that: include: The battery according to claim 14.

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