Top cover assembly, energy storage device and electric equipment

Abstract

The utility model provides a top cover assembly of an energy storage device, the energy storage device and electric equipment. The top cover assembly comprises a top cover, a flow collecting disc, a rivet head of a pulling rivet and a sealing piece. The top cover is provided with a first through hole, the first through hole comprises a first cavity and a second cavity which are communicated, and the size of the first cavity is larger than that of the second cavity to form a step part. The first side of the collector plate is closer to the top cover. The flow collecting disc comprises a body part and a protruding part. The protruding part protrudes from the first side of the body part to the direction of the top cover, and the protruding part is partially contained in the second cavity and provided with a second through hole penetrating through the protruding part. The nail head comprises an insertion part, a first blocking part and a second blocking part. The insertion part penetrates through the second through hole. The first blocking part and the second blocking part are located at the two opposite ends of the insertion part and located outside the second through hole. The first blocking part abuts against the second side of the protruding part. The second blocking part abuts against the first side of the protruding part and the step part. The sealing piece is located in the first cavity and clamped between the second blocking part and the bottom of the second cavity.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, specifically to a top cover assembly, an energy storage device, and an electrical appliance. Background Technology

[0002] Energy storage devices, such as battery cells, are widely used as the main power source for electrical equipment due to their recyclability. Current battery cell top cover assemblies typically include a top cover and a current collector. The current collector and top cover are fitted together and then laser-welded. After laser welding, liquid is injected into the internal electrode assembly through an injection hole, which is then sealed with a sealing element.

[0003] Currently, in the top cover assembly, the manifold and top cover are not coaxial after being fitted together, and the circumferential gap between them is inconsistent; that is, the gap is large in some areas and small in others. Looking at the longitudinal section, there is a one-sided gap problem, meaning one side has a larger gap than the other. Dimensional chain calculations show that the largest gap on the larger side can reach 0.275mm. To address this one-sided gap problem, the weld width and depth are increased during laser welding of the manifold and top cover, resulting in excessive welding heat. After laser welding, the surrounding welded areas experience tensile stress due to cooling. This stress pulls on the injection hole in the center of the manifold, causing it to enlarge. Because of the enlarged injection hole, the interference fit between the seal, which originally had a good fit, and the enlarged injection hole is insufficient, causing electrolyte leakage and affecting the sealing performance of the top cover assembly. Utility Model Content

[0004] In view of the above problems, this application provides a top cover assembly, an energy storage device, and an electrical device.

[0005] In a first aspect, this application provides a top cover assembly. The top cover assembly includes a top cover, a manifold, a rivet head, and a seal. The top cover includes a first side and a second side facing away from each other in a first direction, and has a first through hole. The first through hole penetrates both the first side and the second side of the top cover. The first through hole includes a communicating first cavity and a second cavity. The first cavity is closer to the first side of the top cover than the second cavity, and in a projection plane perpendicular to the first direction, the size of the first cavity is larger than the size of the second cavity, forming a stepped portion. The manifold includes a first side and a second side facing away from each other in the first direction, with the first side of the manifold closer to the second side of the top cover than the second side of the manifold. The manifold also includes a body portion and a protrusion. The protrusion protrudes from the first side of the body portion toward the top cover and includes both the first side and the second side facing away from each other in the first direction. The protrusion is at least partially accommodated within the second cavity, and the protrusion has a second through hole penetrating both the first side and the second side of the protrusion. The rivet head includes an insertion portion, a first blocking portion, and a second blocking portion. The insertion portion passes through the second through hole. The first blocking portion and the second blocking portion are located at opposite ends of the insertion portion and are both located outside the second through hole. The first blocking portion abuts against the second side of the protrusion. The second blocking portion abuts against the first side of the protrusion and the stepped portion. The sealing member is located inside the first cavity and is sandwiched between the second blocking portion and the bottom of the second cavity.

[0006] In the above technical solution, the top cover assembly uses rivets to rivet the top cover, manifold, and seals together, thus achieving a secure connection without welding. Because the assembly process of the top cover assembly does not involve welding of the top cover and manifold, there is no tensile stress generated at the weld joint during cooling. The second through-hole, serving as the injection port, will not be stretched and will maintain its original size. Furthermore, the insertion part can seal against the second through-hole. Simultaneously, the second blocking part and the seal further enhance the sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly.

[0007] As an optional technical solution of this application, the second blocking part includes a first surface and a second surface facing away from each other. The first surface abuts against the first side of the step part and the protrusion part, and the second surface is provided with a groove, the bottom of which is higher than the first side of the protrusion part.

[0008] In the above technical solution, the first surface of the second blocking part restricts the degree of freedom of the top cover and the collector plate in the first direction L by abutting against the stepped part and the protrusion. The groove provided on the second surface of the second blocking part is a spatial structure formed by the breakage of the rivet after riveting. The bottom of the groove is higher than the first side of the protrusion, so that more insertion parts are filled into the second through hole. On the one hand, it can ensure the riveting force between the top cover and the collector plate; on the other hand, it can play a good sealing role in the second through hole to prevent electrolyte leakage.

[0009] As an optional technical solution of this application, the stepped portion is provided with a receiving groove, and the sealing element is at least partially received in the receiving groove.

[0010] In the above technical solution, the receiving groove provided on the step provides space for the installation of the seal, so that the seal can be kept in the fixed position of the top cover, avoiding displacement of the seal during assembly, riveting and other operations, and maintaining good sealing between the nail head and the top cover, thereby effectively preventing the leakage of electrolyte inside the energy storage device, and also preventing external moisture and impurities from entering the energy storage device.

[0011] As an optional technical solution of this application, a solder mark is provided between the second blocking part and the top cover.

[0012] In the above technical solution, the second blocking part is the component that directly contacts the nail head and the top cover. A weld mark is provided between the second blocking part and the top cover to achieve welding between the nail head and the top cover. When the energy storage device is working, the path of current transmission outward is sequentially the current collector, the nail head, and the top cover; the path of current transmission inward is sequentially the top cover, the nail head, and the current collector. If there is a problem of insufficient overcurrent, a weld can be added between the second blocking part, which directly contacts the nail head and the top cover, and the top cover to enhance the current overcurrent.

[0013] As an optional technical solution of this application, the second cavity is provided with a first chamfer at the opening on the second side of the top cover, and the top of the protrusion is provided with a second chamfer. The first chamfer is configured to cooperate with the second chamfer.

[0014] In the above technical solution, the second cavity and the protrusion are the components that directly contact the top cover and the collector plate when they mate along the first direction L. The first chamfer provided at the opening of the second cavity on the second side of the top cover and the second chamfer provided at the top of the protrusion can remove sharp edges and play a certain guiding role, increasing the smoothness of the process of the protrusion extending into the second cavity, avoiding scratches when the second cavity or the protrusion is in contact, and helping to improve the appearance yield of the top cover assembly.

[0015] As an optional technical solution of this application, the collector plate and the top cover are connected together by ultrasonic welding on the second side of the collector plate.

[0016] In the above technical solution, ultrasonic torque welding can weld a larger area than conventional welding, so the flow capacity of the protrusion and the top cover is better after welding. In addition, ultrasonic torque welding does not require the use of additional welding materials or flux, which can reduce the production cost of the top cover assembly.

[0017] As an optional technical solution of this application, the protrusion includes a first sub-part and a second sub-part. The first sub-part protrudes from a first side of the main body and includes a first side and a second side opposite to each other in the first direction. The second sub-part is connected to the first sub-part and extends into the second cavity. In the projection plane perpendicular to the first direction, the size of the second sub-part is smaller than the size of the first sub-part. A recess is provided on the second side of the first sub-part. The first blocking part is located in the recess and abuts against the bottom surface of the recess. The bottom surface of the recess is provided with a weld mark for ultrasonic welding of the top cover and the collector plate. The weld mark corresponds to the step part in the first direction.

[0018] In the above technical solution, a recess is provided on the second side of the first sub-part, and the first blocking part is located in the recess and abuts against the bottom surface of the recess. This allows the first blocking part to be accommodated in the recess rather than exposed to the outside. The recess serves to hide the first blocking part, thereby improving the energy density of the battery cell. In addition, the bottom surface of the recess is provided with solder marks for ultrasonic welding of the top cover and the current collector. The solder marks correspond to the stepped part in the first direction, that is, there can also be a welded connection between the current collector and the top cover, further strengthening the connection between the two and the current transmission capacity.

[0019] As an optional technical solution of this application, the body portion includes a plurality of first regions and a plurality of second regions, which are arranged alternately around the center of the protrusion. A third through hole is provided in the first region, which penetrates the first side and the second side of the body portion. The first side of the second region is recessed into the second side of the second region to form a receiving groove. The recess is connected to at least one of the third through holes in each first region through a connecting groove.

[0020] In the above technical solution, the multiple third through holes in the first zone serve to provide exhaust channels for pressure relief. The multiple first zones are alternately arranged around the center of the protrusion, ensuring a uniform distribution of exhaust channels across the collector plate. This results in uniform airflow during the pressure relief process, improving the operational safety of the energy storage device. The bottom of the receiving groove protrudes relative to the portion of the second zone other than the receiving groove itself, maintaining a certain gap between the second side of the collector plate and the internal structure of the energy storage device. This addresses the issue of increased internal pressure due to faults, further enhancing the operational safety of the energy storage device.

[0021] Secondly, this application provides an energy storage device. The energy storage device includes the top cover assembly described in any of the above embodiments.

[0022] In the energy storage device described above, the top cover assembly utilizes rivets to rivet the top cover, collector plate, and seals together, thus achieving a secure connection without welding. Because the assembly process of the top cover assembly does not involve welding of the top cover and collector plate, there is no tensile stress generated at the weld joint due to cooling. The second through-hole, serving as the injection port, will not be stretched and will maintain its original size. Furthermore, the insertion part can seal against the second through-hole. Simultaneously, the second blocking part and the seals further enhance the sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly.

[0023] Thirdly, this application provides an electrical appliance. The electrical appliance includes the energy storage device described in any of the above embodiments.

[0024] In the electrical equipment described above, the top cover assembly utilizes rivets to rivet the top cover, manifold, and seals together, thus achieving a secure connection without welding. Because the assembly process of the top cover assembly does not involve welding of the top cover and manifold, there is no tensile stress generated at the weld joint during cooling. The second through-hole, serving as the injection port, will not be stretched and will maintain its original size. Furthermore, the insertion part can seal against the second through-hole. Simultaneously, the second blocking part and the seal further enhance the sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 This is a three-dimensional assembly diagram of the top cover assembly according to some embodiments of this application;

[0028] Figure 2 for Figure 1An exploded perspective view of the top cover assembly shown;

[0029] Figure 3 for Figure 1 The diagram shows a cross-sectional view of the top cover assembly taken by line III-III;

[0030] Figure 4 for Figure 3 An enlarged schematic diagram of point IV in the top cover assembly shown;

[0031] Figure 5 for Figure 1 A bottom view of the manifold in the top cover assembly shown;

[0032] Figure 6 for Figure 1 The diagram shows a three-dimensional assembly of the top cover assembly before riveting.

[0033] Figure 7 for Figure 6 An exploded three-dimensional view of the top cover assembly before riveting is shown.

[0034] Figure 8 for Figure 6 The diagram shows a cross-sectional view of the top cover assembly before riveting, taken by line VIII-VIII.

[0035] Figure 9 for Figure 8 An enlarged schematic diagram of point IX in the top cover assembly before riveting;

[0036] Figure 10 This is a three-dimensional structural diagram of a battery cell according to some embodiments of this application;

[0037] Figure 11 This is a three-dimensional structural diagram of a battery pack according to some embodiments of this application;

[0038] Figure 12 This is a schematic diagram of the planar structure of an electrical device according to some embodiments of this application.

[0039] The reference numerals in the detailed embodiments are as follows:

[0040] 10,000 electrical devices; 1,000 battery packs; 100 individual battery cells; 2,000 and 3,000 loads; 4,000 conversion devices;

[0041] Top cover assembly 10;

[0042] Top cover 11; First side of top cover 1101; Second side of top cover 1102; First through hole 111; First cavity 1111; Second cavity 1113; Bottom of second cavity 11131; Step portion 1115; Receiving groove 11151; First surface 11153; Second surface 11155; First chamfer 11157; Explosion-proof hole 113;

[0043] Explosion-proof valve 12;

[0044] Collector plate 13; First side of collector plate 1301; Second side of collector plate 1302; Protrusion 131; Second through hole 1311; First sub-part 1313; Recess 13131; Second chamfer 13133; Second sub-part 1315; Body part 133; First zone 1331; Third through hole 13311; Positioning groove 13313; Positioning notch 13315; Connecting groove 13317; Second zone 1333; Receiving groove 13331;

[0045] Rivet 15; rivet head 151; insertion part 1511; first blocking part 1513; second blocking part 1515; groove 15151; rivet core 153;

[0046] Seal 17;

[0047] Casing 30; Battery box 300; Box body 310; Box cover 330;

[0048] First direction L. Detailed Implementation

[0049] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0052] In this document, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that the implementations described herein can be combined with other implementations.

[0053] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, the simultaneous existence of mounting protrusions and mounting holes, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0054] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0055] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "level", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0056] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components.

[0057] Please see Figure 1 and Figure 2This application provides a top cover assembly 10. The top cover assembly 10 includes a top cover 11, a manifold 13, a rivet head 151 of a rivet 15, and a seal 17. The top cover 11 includes a first side 1101 and a second side 1102 opposite to each other in a first direction L, and is provided with a first through hole 111. The first through hole 111 penetrates the first side 1101 and the second side 1102 of the top cover. The first through hole 111 includes a first cavity 1111 and a second cavity 1113 that communicate with each other. The first cavity 1111 is closer to the first side 1101 of the top cover than the second cavity 1113. In the projection plane perpendicular to the first direction L, the size of the first cavity 1111 is larger than the size of the second cavity 1113 to form a stepped portion 1115. The collector plate 13 includes a first side 1301 and a second side 1302 opposite to each other in a first direction L. The first side 1301 of the collector plate is closer to the second side 1102 of the top cover than the second side 1302 of the collector plate. The collector plate 13 also includes a body portion 133 and a protrusion 131. The protrusion 131 protrudes from the first side 1301 of the body portion 133 toward the top cover 11 and includes the first side 1301 and the second side 1302 opposite to each other in the first direction L. The protrusion 131 is at least partially accommodated in the second cavity 1113. The protrusion 131 is provided with a second through hole 1311, which penetrates the first side 1301 and the second side 1302 of the protrusion 131. Please refer to... Figure 3 and Figure 4 The nail head 151 includes an insertion portion 1511, a first blocking portion 1513, and a second blocking portion 1515. The insertion portion 1511 passes through the second through hole 1311. The first blocking portion 1513 and the second blocking portion 1515 are located at opposite ends of the insertion portion 1511 and are both located outside the second through hole 1311. The first blocking portion 1513 abuts against the second side 1302 of the protrusion 131, and the second blocking portion 1515 abuts against the first side 1301 and the stepped portion 1115 of the protrusion 131. The sealing member 17 is located in the first cavity 1111 and is sandwiched between the second blocking portion 1515 and the bottom 11131 of the second cavity.

[0058] Specifically, please combine Figure 10The top cover assembly 10 is used to seal the opening of the housing 30 of the battery cell 100 and provide necessary electrical connections and mechanical protection. The shape of the cross-section of the top cover assembly 10 (defined as the thickness direction in this application as the first direction L, and the plane intercepted by a plane perpendicular to the first direction L is the cross-section, and this definition is used for all subsequent cross-sections) can be determined according to the shape of the opening of the housing 30. Specifically, the cross-sectional shape of the top cover assembly 10 can be circular, square, polygonal, or other shapes. For example, if the opening is circular, the corresponding cross-sectional shape of the top cover assembly 10 can be circular; if the opening is rectangular, the corresponding cross-sectional shape of the top cover assembly 10 can be rectangular. In this application, a top cover assembly 10 with a circular cross-sectional shape is described, and the diameter direction of the top cover assembly 10 is radial R. The central axis of the first cavity 1111 coincides with the central axis of the second cavity 1113. The cavity shape of the first cavity 1111 can be a cylinder, a hexahedron, or a frustum, etc., and the shape of the second cavity 1113 can also be a cylinder, a hexahedron, or a frustum, etc. The shapes of the first cavity 1111 and the second cavity 1113 can be the same or different. Taking a plane perpendicular to the first direction L as the projection plane, the area of ​​the projection of the first cavity 1111 in the projection plane is greater than the area of ​​the projection of the second cavity 1113 in the projection plane.

[0059] The first side 1301 of the collector plate is closer to the second side 1102 of the top cover than the second side 1302 of the collector plate, that is, the first side 1301 of the collector plate and the second side 1102 of the top cover are arranged opposite each other. The collector plate 13 includes a body portion 133 and a protrusion 131, which protrudes from the center portion of the body portion 133. The protrusion 131 is a protruding structure formed by extending from the first side 1301 of the collector plate in a direction away from the second side 1302 of the collector plate. The protrusion 131 includes a first side 1301 and a second side 1302 that are opposite to each other in the first direction L. That is, the first side 1301 of the protrusion 131 is the first side 1301 of the collector plate; the second side 1302 of the protrusion 131 is the first side 1302 of the collector plate. The protrusion 131 and the body portion 133 can be integrally formed or separately formed. It is understood that both the body portion 133 and the protrusion portion 131 are made of conductive materials. The conductive materials include, but are not limited to, single metal materials such as copper, aluminum, and nickel, or alloy materials containing copper, aluminum, and nickel. The body portion 133 and the protrusion portion 131 may be made of the same material or different materials.

[0060] At least a portion of the protrusion 131 is accommodated within the second cavity 1113. The outer contour shape of the portion of the protrusion 131 accommodated within the second cavity 1113 can be circular, elliptical, triangular, quadrilateral, or other polygonal, as long as it matches the inner contour shape of the second cavity 1113 to achieve a fit and ensure the sealing of the top cover assembly 10. The protrusion 131 has a second through hole 1311 penetrating the first side 1301 and the second side 1302 of the protrusion 131. With a plane perpendicular to the first direction L as the projection plane, the area of ​​the projection of the second through hole 1311 in the projection plane is smaller than the area of ​​the projection of the second cavity 1113 in the projection plane.

[0061] Please combine further Figure 4 The sealing element 17 can be a sealing structure with a fixed shape, such as a rubber ring. The sealing element 17 can also be a sealing structure with a non-fixed shape, such as sealant. The sealing element 17 is sandwiched between the second blocking portion 1515 and the bottom 11131 of the second cavity. The surface of the stepped portion 1115 corresponding to the side of the second blocking portion 1515 can be flat or have a mating structure that mates with the sealing element 17, i.e., a receiving groove 11151 (described below). When the surface of the stepped portion 1115 corresponding to the side of the second blocking portion 1515 is flat, the sealing element 17 is disposed between the side of the second blocking portion 1515 corresponding to the stepped portion 1115 and the side of the stepped portion 1115 corresponding to the second blocking portion 1515. When the surface of the step portion 1115 corresponding to the second blocking portion 1515 has a receiving groove 11151 that mates with the seal 17, the surface of the seal 17 corresponding to the second blocking portion 1515 can be flush with the surface of the step portion 1115 corresponding to the second blocking portion 1515, or it can protrude from the surface of the step portion 1115 corresponding to the second blocking portion 1515. Furthermore, since the seal 17 has a certain thickness in the first direction L, the seal 17 is at least partially embedded in the step portion 1115 and mates with the receiving groove 11151. In this case, the surface of the seal 17 corresponding to the step portion 1115 does not exceed the bottom 11131 of the second cavity, meaning the seal 17 does not penetrate the step portion 1115 and protrude from the second side 1102 of the top cover.

[0062] Please refer to the following: Figure 1 and Figure 6 The rivet head 151 is a structure formed by using rivets 15 to join the top cover 11, the manifold 13 and the seal 17 together using a riveting process.

[0063] Specifically, please refer to the following: Figures 7 to 9Before using the rivet 15 to rivet the top cover 11 and the manifold 13, the rivet 15 includes a rivet head 151 and a rivet core 153 that are joined together. At this time, the rivet head 151 includes an insertion part 1511 and a second blocking part 1515. The insertion part 1511 and the rivet core 153 are located on opposite sides of the second blocking part 1515, and both the insertion part 1511 and the rivet core 153 have a cylindrical structure. The insertion part 1511 can pass smoothly through the second through hole 1311, and the second blocking part 1515 can be supported on the stepped part 1115 and housed in the first cavity 1111. The specific process of using rivets 15 to rivet the top cover 11 and the collector plate 13 is as follows: First, the insertion part 1511 is passed through the second through hole 1311, and the second blocking part 1515 is supported on the stepped part 1115. At least a portion of the insertion part 1511 will protrude from the second through hole 1311 (this portion is referred to below as the protruding portion of the insertion part 1511); then, a clamping fixture is used to clamp the second blocking part 1515 to the stepped part 1115 (the second blocking part 1515 is subjected to a positive pressure L1 in the first direction), and at the same time, the rivet core 153 is pulled in the direction away from the collector plate 13 using the rivet fixture (the rivet core 153 is subjected to a reverse pulling force L2 in the first direction). Please refer to... Figure 3 and Figure 4 During the continuous pulling of the nail core 153, the protruding portion of the insertion part 1511 expands under pressure to form a first blocking part 1513. The size of the first blocking part 1513 is larger than the size of the second through hole 1311, and it abuts against the second side 1302 of the protruding part 131. When the second blocking part 1515 is subjected to a positive pressure L1 in the first direction, and the first blocking part 1513 is subjected to a reverse tension L2 in the first direction, the top cover 11 and the collector plate 13 sandwiched between the second blocking part 1515 and the first blocking part 1513 can be tightly connected together. At the same time, the seal 17 is also clamped between the second blocking part 1515 and the step part 1115. When the tension on the nail core 153 reaches a certain value, the nail core 153 will break and separate from the nail head 151. The nail head 151 is retained in the top cover 11 and the collector plate 13 and serves to rivet the top cover 11, the collector plate 13 and the seal 17. Groove 15151 is formed at the break point between the nail core 153 and the nail head 151.

[0064] Therefore, after the riveting process, the insertion part 1511 passes through the second through hole 1311, and the outer contour of the insertion part 1511 mates with the inner contour of the second through hole 1311. The first blocking part 1513 and the second blocking part 1515 are located at opposite ends of the insertion part 1511. In one example, the central axis of the insertion part 1511, the central axis of the first blocking part 1513, and the central axis of the second blocking part 1515 coincide with the central axis of the second through hole 1311 and the central axis of the second cavity 1113. Taking a plane perpendicular to the first direction L as the projection plane, the area of ​​the projection of the first blocking part 1513 in the projection plane can be greater than, less than, or equal to the area of ​​the projection of the second blocking part 1515 in the projection plane.

[0065] In the above technical solution, the top cover assembly 10 uses rivets 15 to rivet the top cover 11, the collector plate 13, and the seal 17 together, thereby achieving a firm connection between the top cover 11, the collector plate 13, and the seal 17 without the need for welding. Since the assembly process of the top cover assembly 10 does not employ welding for the top cover 11 and the collector plate 13, there will be no tensile stress generated due to cooling at the weld. The second through hole 1131, which serves as the injection hole, will not be stretched and will maintain its original size. Furthermore, the insertion part 1511 can seal with the second through hole 1131. At the same time, the second blocking part 1155 and the seal 17 can further provide a sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly 10.

[0066] Please see Figures 2 to 4 As an optional technical solution of this application, the second blocking part 1515 includes a first surface 11153 and a second surface 11155 facing away from each other. The first surface 11153 abuts against the first side 1301 of the step part 1115 and the protrusion 131. The second surface 11155 is provided with a groove 15151. The bottom of the groove 15151 is higher than the first side 1301 of the protrusion 131.

[0067] The first surface 11153 abuts against the first side 1301 of the protrusion 131 and the stepped portion 1115. The first surface 11153 is connected to the insertion portion 1511. Please refer to [link / reference]. Figure 1 and Figure 6 The groove 15151 on the second surface 11155 is a recessed structure formed by the breakage of the rivet core 153 after the rivet 15 is riveted, or it may be formed by further processing of the recessed structure. The projected size of the groove 15151 in the above-mentioned projection plane can be greater than, less than or equal to the projected size of the insertion part 1511 in the projection plane. The bottom of the groove 15151 can be a circle, square, polygon, or other shapes. The bottom of the groove 15151 is higher than the first side 1301 of the protrusion 131, that is, the bottom of the groove 15151 is higher than the first surface 11153 and the insertion part 1511.

[0068] In the above technical solution, the first surface 11153 of the second blocking part 1515 restricts the degree of freedom of the top cover 11 and the collector plate 13 in the first direction L by abutting against the stepped part 1115 and the protrusion 131. The groove 15151 provided on the second surface 11155 of the second blocking part 1515 is a spatial structure formed by the breakage of the rivet 15 after riveting. The bottom of the groove 15151 is higher than the first side 1301 of the protrusion 131, so that more insertion parts 1511 are filled into the second through hole 1311. On the one hand, it can ensure the riveting force between the top cover 11 and the collector plate 13; on the other hand, it can play a good sealing role for the second through hole 1311 and prevent electrolyte leakage.

[0069] Please see Figure 2 and Figure 4 As an optional technical solution of this application, the step portion 1115 is provided with a receiving groove 11151, and the sealing member 17 is at least partially received in the receiving groove 11151.

[0070] Specifically, the receiving groove 11151 is a spatial structure opened on the side of the stepped portion 1115 facing the second blocking portion 1515, and this spatial structure is used to receive the sealing member 17. The receiving groove 11151 can be a continuous annular groove or multiple discontinuous annular grooves. The shape of the cross-section of the receiving groove 11151 (the cross-section obtained by a plane perpendicular to the first direction L) can be a complete annular shape or a partial annular shape. When the cross-section of the receiving groove 11151 is a complete annular shape, the longitudinal section of the receiving groove 11151 (the plane obtained by a plane parallel to the first direction L) includes, but is not limited to, a rectangle, a V-shape, or a trapezoid. The shape and size of the receiving groove 11151 only need to be adapted to the shape and size of the sealing member 17. At least a portion of the seal 17 is accommodated in the receiving groove 11151, meaning that the seal 17 can be completely accommodated in the receiving groove 11151, and the upper surface of the seal 17 can be flush with the top surface of the receiving groove 11151 (the upper surface of the stepped portion 1115); or, a portion of the seal 17 is accommodated in the receiving groove 11151, and another portion protrudes from the receiving groove 11151, that is, the upper surface of the seal 17 extends beyond the top surface of the receiving groove 11151 (the upper surface of the stepped portion 1115).

[0071] In the above technical solution, the receiving groove 11151 provided on the step portion 1115 provides space for the installation of the seal 17, so that the seal 17 can be kept in the fixed position of the top cover 11, avoiding the displacement of the seal 17 during assembly, riveting and other operations, and maintaining good sealing between the nail head 151 and the top cover 11, thereby effectively preventing the leakage of electrolyte in the energy storage device, and also preventing external moisture and impurities from entering the interior of the energy storage device.

[0072] Please see Figure 2 and Figure 4 As an optional technical solution of this application, a solder mark is provided between the second blocking part 1515 and the top cover 11.

[0073] Specifically, the second blocking part 1515 is the portion where the nail head 151 directly contacts the top cover 11. A weld mark is provided between the second blocking part 1515 and the top cover 11. That is, after the riveting process, to strengthen the connection between the nail head 151 and the top cover 11, a welding process can be further used to reinforce the connection between the second blocking part 1515 and the top cover 11. The weld mark can be continuous or discontinuous. The welding method for forming the weld mark can be arc welding, laser welding, ultrasonic torque welding, or plasma welding, etc. The welding position can be directly opposite the second blocking part 1515 and the stepped part 1115, or between the peripheral wall of the second blocking part 1515 and the inner wall of the first cavity 1111, or a combination of both. It should be noted that the welding process here is performed after the riveting process. Since there is no problem of excessive gap on one side, the weld width and depth of the weld mark formed by the welding process here do not need to be large. Therefore, after the welding cools down, it will not generate tensile stress sufficient to deform the second through hole 1311.

[0074] In the above technical solution, the second blocking part 1515 is the component that directly contacts the nail head 151 and the top cover 11. A weld mark is provided between the second blocking part 1515 and the top cover 11 to achieve welding between the nail head 151 and the top cover 11. When the energy storage device is working, the path of current transmission outward is sequentially through the current collector 13, the nail head 151, and the top cover 11; the path of current transmission inward is sequentially through the top cover 11, the nail head 151, and the current collector 13. If there is a problem of insufficient overcurrent, a weld can be added between the second blocking part 1515, which directly contacts the nail head 151 and the top cover 11, to enhance the current overcurrent.

[0075] Please see Figure 2 and Figure 4 As an optional technical solution of this application, the second cavity 1113 is provided with a first chamfer 11157 at the opening of the second side 1102 of the top cover, and the top of the protrusion 131 is provided with a second chamfer 13133. The first chamfer 11157 is configured to cooperate with the second chamfer 13133.

[0076] Specifically, the type of the first chamfer 11157 can be, but is not limited to, a straight chamfer, a rounded chamfer, or an irregular chamfer, etc., and the machining method of the first chamfer 11157 can be, but is not limited to, turning, milling, drilling, grinding, or laser processing, etc. The type of the second chamfer 13133 can be, but is not limited to, a straight chamfer, a rounded chamfer, or an irregular chamfer, etc., and the machining method of the second chamfer 13133 can be, but is not limited to, turning, milling, drilling, grinding, laser processing, etc. The type and dimensions of the first chamfer 11157 and the second chamfer 13133 need to match. The first chamfer 11157 and the second chamfer 13133 can be the same type or different types, and the first chamfer 11157 and the second chamfer 13133 can be processed using the same method or different methods.

[0077] In the above technical solution, the second cavity 1113 and the protrusion 131 are the components that directly contact the top cover 11 and the collector plate 13 when they are fitted together along the first direction L. The first chamfer 11157 provided at the opening of the second side 1102 of the top cover in the second cavity 1113 and the second chamfer 13133 provided at the top of the protrusion 131 can remove sharp edges and play a certain guiding role, increasing the smoothness of the process of the protrusion 131 extending into the second cavity 1113, avoiding scratches between the second cavity 1113 and the protrusion 131 during assembly, and helping to improve the appearance yield of the top cover assembly 10.

[0078] Please combine Figure 1 and Figure 2 As an optional technical solution of this application, the collector plate 13 and the top cover 11 are connected together by ultrasonic welding on the second side 1302 of the collector plate.

[0079] Specifically, the welding needle of the ultrasonic torque welding can pass through the core hole in the middle of the core inside the battery cell 100 and perform ultrasonic torque welding on the second side 1302 of the protrusion 131. This is a bottom-up welding, that is, welding from the second side 1302 of the protrusion 131 to the first side 1101 of the top cover.

[0080] In the above technical solution, ultrasonic torque welding can weld a larger area than conventional welding, so the flow capacity of the protrusion 131 and the top cover 11 after welding is better. In addition, ultrasonic torque welding does not require the use of additional welding materials or flux, which can reduce the production cost of the top cover assembly 10.

[0081] Please see Figure 2 and Figure 4As an optional technical solution of this application, the protrusion 131 includes a first sub-part 1313 and a second sub-part 1315. The first sub-part 1313 protrudes from the first side 1301 of the body part 133 and includes a first side 1301 and a second side 1302 opposite to each other in the first direction L. The second sub-part 1315 is connected to the first sub-part 1313 and extends into the second cavity 1113. In the projection plane perpendicular to the first direction L, the size of the second sub-part 1315 is smaller than the size of the first sub-part 1313. The second side 1302 of the first sub-part 1313 is provided with a recess 13131, and a first blocking part 1513 is located in the recess 13131 and abuts against the bottom surface of the recess 13131. The bottom surface of the recess 13131 is provided with a welding mark for ultrasonic welding of the top cover 11 and the collector plate 13, and the welding mark corresponds to the stepped part 1115 in the first direction L.

[0082] Specifically, in the direction from the collector plate 13 to the top cover 11, the first sub-part 1313 and the second sub-part 1315 are connected sequentially, with the second sub-part 1315 extending into the second cavity 1113. In one example, the central axis of the first sub-part 1313 and the central axis of the second sub-part 1315 coincide, as do the central axis of the nail head 151 and the central axis of the top cover 11, to ensure uniform force distribution on the top cover assembly 10. Taking a plane perpendicular to the first direction L as the projection plane, the area of ​​the projection of the second sub-part 1315 in the projection plane is smaller than the area of ​​the projection of the first sub-part 1313 in the projection plane. The protrusion 131, through the two structures of the first sub-part 1313 and the second sub-part 1315, enables at least a portion of the collector plate 13 to be connected to the top cover 11, and at least another portion of the collector plate 13 to be sandwiched between the top cover 11 and the nail head 151, thus achieving the function of tightly connecting the collector plate 13 and the top cover 11 through the protrusion 131.

[0083] Meanwhile, the first sub-part 1313 and the second sub-part 1315 enable the manifold 13 to achieve a tight connection with the top cover 11 without bending. On the one hand, since the assembly equipment does not need to perform a bending process, the structure of the assembly equipment is simplified, and the assembly stability can be guaranteed. Correspondingly, the stability of mass production of the top cover assembly 10 can also be guaranteed. On the other hand, the reduction of the bending process of the manifold 13 is conducive to the high-speed production of the top cover assembly 10 and improves the production efficiency of the top cover assembly 10. Furthermore, since the manifold 13 does not need to be bent, compared with the manifold that requires bending, the material of the manifold 13 of this application is more economical, thereby saving the production cost of the top cover assembly 10.

[0084] The first sub-part 1313 includes a first side 1301 and a second side 1302 that are opposite to each other in the first direction L. Specifically, the first side 1301 of the first sub-part 1313 is the first side 1301 of the collector plate; the second side 1302 of the first sub-part 1313 is the first side 1302 of the collector plate. The second side 1302 of the first sub-part 1313 has a recess 13131, with a plane perpendicular to the first direction L as its projection plane. The area of ​​the recess 13131 projected onto the projection plane is smaller than the area of ​​the first sub-part 1313 projected onto the projection plane. The longitudinal section of the recess 13131 is symmetrical about the central axis of the nail head 151, so that when the first blocking part 1513 abuts against the bottom surface of the recess 13131, the force between the first blocking part 1513 and the bottom surface of the recess 13131 is uniform. The cross-sectional shape of the recess 13131 can be square or circular, etc. The bottom surface of the recess 13131 has weld marks for ultrasonic welding of the top cover 11 and the current collector 13. The welding needle of the ultrasonic torque welding can pass through the core hole in the middle of the core inside the battery cell 100. Ultrasonic torque welding is performed at the corresponding position of the bottom surface of the recess 13131 and the step portion 1115 in the first direction L. It is a bottom-to-top welding, that is, welding from the opening of the recess 13131 towards the step portion 1115. The weld marks can be used to strengthen the connection between the protrusion 131 and the top cover 11. The weld marks can be continuous or discontinuous.

[0085] In the above technical solution, direct contact and current flow between the current collector 13 and the top cover 11 are ensured. On the other hand, the recess 13131 abuts against the first blocking portion 1513 of the nail head 151, causing the nail head 151 to press against the top cover assembly 10 from the second side 1302 of the current collector 10, ensuring the current flow from the current collector 13 to the rivet and then to the top cover 11. Simultaneously, the second sub-part 1315 extends into the second cavity 1113 and connects to both the insertion portion 1511 of the nail head 151 and the second cavity 1113 of the top cover 11, ensuring the current flow from the current collector 13 to the rivet and the top cover 11. The structure of the protruding portion 131 ensures that the current transmission direction includes both direct flow from the current collector 13 to the top cover 11 and flow from the current collector 13 to the nail head 151 and then to the top cover 11, increasing the current flow capacity of the top cover assembly 10.

[0086] A recess 13131 is provided on the second side 1302 of the first sub-part 1313. A first blocking part 1513 is located in the recess 13131 and abuts against the bottom surface of the recess 13131. This allows the first blocking part 1513 to be accommodated in the recess 13131 instead of being exposed to the outside. The recess 13131 serves to hide the first blocking part 1513, thereby increasing the energy density of the battery cell 100. In addition, the bottom surface of the recess 13131 is provided with weld marks for ultrasonic welding of the top cover 11 and the current collector 13. The weld marks correspond to the step part 1115 in the first direction L. That is, there can also be a welded connection between the current collector 13 and the top cover 11, which further strengthens the connection between the two and the current transmission capacity. It should also be noted that the welding process here is performed after the riveting process. Since there is no problem of excessive gap on one side, the weld width and depth of the weld mark formed by the welding process here do not need to be large. Therefore, after the welding cools down, there will be no tensile stress sufficient to deform the second through hole 1311.

[0087] Please see Figure 2 and Figure 5 As an optional technical solution of this application, the body portion 133 includes a plurality of first regions 1331 and a plurality of second regions 1333. The plurality of first regions 1331 and the plurality of second regions 1333 are arranged alternately around the center of the protrusion 131. A third through hole 13311 is provided in the first region 1331, which penetrates the first side 1301 and the second side 1302 of the body portion 133. The first side 1301 of the second region 1333 is recessed toward the second side 1302 of the second region 1333 to form a receiving groove 13331. The recess 13131 communicates with at least one third through hole 13311 in each first region 1331 through a connecting groove 13317.

[0088] Specifically, the number of first zones 1331 and second zones 1333 is the same, both being multiple, such as 2, 3, 4, 5, or more. The area ratio of the first zone 1331 within the body portion 133 can be greater than, less than, or equal to the area ratio of the second zone 1333 within the body portion 133. Multiple first zones 1331 and multiple second zones 1333 are arranged alternately around the center of the protrusion 131, that is, the adjacent sides of any first zone 1331 are second zones 1333, and the adjacent sides of any second zone 1333 are first zones 1331.

[0089] The second region 1333 is provided with a receiving groove 13331, the cross-sectional shape of which can be rectangular, circular, racetrack-shaped, or elliptical, etc. The receiving groove 13331 extends from the periphery of the body portion 133 towards the center of the body portion 133, thereby allowing the battery cell 100 ( Figure 10The tabs of the battery cell (as shown) inside can be bent to the first side 1301 of the body portion 133 and welded into the receiving groove 13331 to achieve electrical connection between the battery cell and the current collector 13. The bottom of the receiving groove 13331 is relative to the portion of the second region 1333 other than the receiving groove 13331 towards the battery cell 100 (as shown). Figure 10 The protruding cells inside (as shown) serve two purposes. First, they maintain a certain gap between the second side 1302 of the first region 1331 and the cells within the battery cell 100 in the first direction L. When the internal pressure of the battery cell 100 increases due to a fault, this gap provides additional space to store more gas, preventing the battery cell 100 from rapidly expanding and exploding. Furthermore, the gap also serves as a pressure relief path for high-pressure gas. Second, the bottom of the receiving groove 13331 protrudes relative to the portion of the second region 1333 excluding the receiving groove 13331, guiding gas to converge at the third through-hole 13311, allowing high-pressure gas to enter the exhaust space through the third through-hole 13311.

[0090] The third through hole 13311 may include one, two, three, four, or more, without limitation. The cross-sectional shape of the third through hole 13311 may be, but is not limited to, circular, polygonal, or other regular or irregular shapes. Among multiple third through holes 13311, the cross-sectional shapes of the third through holes 13311 may be exactly the same or not exactly the same. The third through hole 13311 is used to allow high-pressure gas to flow out when the internal gas pressure of the battery cell 100 reaches a critical threshold, thereby achieving the purpose of depressurization. Especially when the internal gas pressure of the battery cell 100 increases due to a fault, it can prevent the battery cell 100 from rapidly expanding and exploding, thus improving the safety of the battery cell 100. The recess 13131 is connected to at least one third through hole 13311 in each first region 1331 through a connecting groove 13317. The cross-sectional and longitudinal shapes of the connecting groove 13317 are not limited and can be arbitrarily set.

[0091] Furthermore, the top cover 11 is also provided with an explosion-proof hole 113, and an explosion-proof valve 12 is disposed in the explosion-proof hole 113 to seal the explosion-proof hole 113. When the battery cell 100 is in a normal state (internal air pressure has not reached the critical pressure), the explosion-proof valve 12 will keep the explosion-proof hole 113 sealed. When the internal air pressure of the battery cell 100 is relatively high, the recess 13131 can store a large amount of high-pressure gas. When the air pressure increases further, the high-pressure gas will flow along the connecting groove 13317 to the third through hole 13311 (forming an exhaust channel). When the internal air pressure reaches the critical pressure, the high-pressure gas flowing from the third through hole 13311 to the explosion-proof hole 113 will break through the explosion-proof valve 12 to achieve pressure relief, thereby preventing the battery cell 100 from exploding and causing injury.

[0092] In addition, the collector plate 13 is provided with a positioning groove 13313 and a positioning notch 13315 in the first zone 1331. There can be one or more positioning notches 13315 and positioning grooves 13313. The positioning notches 13315 and positioning grooves 13313 have specific shapes relative to the outer periphery of the collector plate 13, which helps to achieve precise alignment of the collector plate 13 during installation, ensuring that the collector plate 13 is correctly positioned in the top cover assembly 10. During the assembly of the top cover assembly 10, the positioning notches 13315 and positioning grooves 13313 provide clear positioning points for the collector plate 13, facilitating its installation and improving the assembly speed of the top cover assembly 10.

[0093] In the above technical solution, the multiple third through holes 13311 provided in the first zone 1331 serve to provide exhaust channels for pressure relief. The multiple first zones 1331 are alternately arranged around the center of the protrusion 131, ensuring a uniform distribution of exhaust channels in the collector plate 13. This allows for uniform airflow during the pressure relief process, improving the safety of the battery cell 100. The bottom of the receiving groove 13331 protrudes relative to the portion of the second zone 1333 excluding the receiving groove 13331, allowing a certain gap to be maintained between the second side 1302 of the collector plate and the internal structure of the battery cell 100. This addresses the issue of increased internal pressure due to malfunctions within the battery cell 100, further enhancing the safety of the battery cell 100.

[0094] Please see Figure 10 and Figure 11 This application also provides an energy storage device. The energy storage device includes the top cover assembly 10 described in any of the above embodiments.

[0095] Specifically, the energy storage device can be a single battery cell 100 or a battery pack 1000 composed of one or more battery cells 100. The functions of the energy storage device include, but are not limited to, energy storage, energy dispatch, and energy storage power stations. Specifically, in some applications, the energy storage device can convert electrical energy into chemical energy for storage to meet electricity demand during peak periods, thus fulfilling the function of energy storage. In other applications, the energy storage device can flexibly adjust the supply and demand of electrical energy to achieve energy balance and dispatch, improving energy utilization efficiency, thus fulfilling the function of energy dispatch. In still other applications, energy storage devices can form energy storage power stations to store and dispatch energy on a large scale, providing a reliable energy supply, thus fulfilling the function of energy storage power stations.

[0096] Please refer to the following: Figure 10 and Figure 11When the energy storage device is a battery pack 1000 composed of multiple battery cells 100, the battery pack 1000 includes battery cells 100 and a battery box 300. A battery cell 100 is the smallest unit for storing and releasing electrical energy. The battery pack 1000 can store and release energy by connecting and controlling the battery cells 100. Multiple battery cells 100 can be connected in series, parallel, or in a hybrid configuration; a hybrid configuration means that multiple battery cells 100 are connected in both series and parallel. Multiple battery cells 100 can be directly connected in series, parallel, or in a hybrid configuration, and then the entire assembly of the multiple battery cells 100 is housed within a carrier (e.g., the battery box 300). The battery pack 1000 may also include other structures; for example, the battery pack 1000 may also include a busbar (not shown) for electrical connection between multiple battery cells 100. It is understood that the number of battery cells 100 in the battery pack 1000 can be adaptively adjusted according to the application scenario and capacity.

[0097] The battery cell 100 includes a top cover assembly 10, a housing 30, and a battery cell (not shown). The housing 30 has an opening, and the top cover assembly 10 is installed in the housing 30 and closes the opening. The battery cell is housed within the housing 30. The housing 30 is a structure for mounting the battery cell. The cross-section of the housing 30 may be, but is not limited to, circular, elliptical, square, or other polygonal shapes. The material of the housing 30 includes, but is not limited to, metals or non-metals, wherein metals include aluminum, iron, steel, aluminum alloys, or iron alloys, and non-metals include, but are not limited to, plastics. The battery cell is the core structure in the battery cell 100 that converts electrical energy into chemical energy through a chemical reaction for charging and discharging. The battery cell is generally made by winding an electrode assembly onto a core rod. The electrode assembly mainly includes a negative electrode, a positive electrode, and a separator. In one possible design, the negative electrode, separator, and positive electrode are sequentially stacked, bonded to the core rod by adhesive or hot-melt methods, and then wound to form the battery cell. After the battery cell is formed, it has gaps through which the electrolyte can enter the cell. The electrolyte is used to wet the cell, ensuring that ions can move freely during charging and discharging. The electrolyte includes, but is not limited to, lithium salts, organic solvents, and additives. The negative electrode includes a negative current collector (e.g., copper foil) and a layer of negative active material (e.g., carbon or silicon) coated on the surface of the negative current collector. The positive electrode includes a positive current collector (e.g., aluminum foil) and a layer of positive active material (e.g., ternary materials, lithium iron phosphate, or lithium cobalt oxide) coated on the surface of the positive current collector. A separator is located between adjacent negative and positive electrodes to separate them.

[0098] The battery box 300 is a structure for placing battery cells 100. The cross-section of the battery box 300 may be, but is not limited to, circular, elliptical, square, or other polygonal shapes. The material of the battery box 300 includes, but is not limited to, metal or non-metal, wherein metals include aluminum, iron, steel, aluminum alloys, or iron alloys, and non-metals include, but are not limited to, plastics. The battery box 300 includes a box body 310 and a box cover 330. The box body 310 and the box cover 330 are combined to form a receiving cavity, in which the battery cells 100 are housed. The box body 310 is the component in the battery box 300 that loads and supports the battery cells 100; one end of the box body 310 is closed, and the other end has an opening for the battery cells 100 to be inserted into the receiving cavity. The box cover 330 is the component in the battery box 300 that covers the opening. The connection between the box body 310 and the box cover 330 can be detachable or non-detachable. Detachable connections include, but are not limited to, screw connections, snap-fit ​​connections, or a combination of screw connections and snap-fit ​​connections. Non-removable connections include, but are not limited to, glued connections, welded connections, or a combination of glued connections and welded connections. Furthermore, when the battery box 300 includes a body 310 and a cover 330, the battery box 300 may not be made of a single material. For example, the body 310 and the cover 330 may be made of the same material, aluminum alloy. The battery box 300 may also have different components made of different materials. For example, the body 310 may be made of metal, while the cover 330 may be made of plastic. Of course, the materials of the body 310 and the cover 330 can also be combined in other ways, which will not be listed here.

[0099] In the energy storage device described above, the top cover assembly 10 uses rivets 15 to rivet the top cover 11, the collector plate 13, and the seal 17 together, thus achieving a secure connection without welding. Since the assembly process of the top cover assembly 10 does not involve welding of the top cover 11 and the collector plate 13, there is no tensile stress generated at the weld joint due to cooling. The second through hole 1131, serving as the injection port, will not be stretched and will maintain its original size. Furthermore, the insertion part 1511 can seal with the second through hole 1131. Simultaneously, the second blocking part 1155 and the seal 17 further enhance the sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly 10.

[0100] Please see Figure 12 This application also provides an electrical appliance 10000. The electrical appliance 10000 includes any kind of energy storage device.

[0101] Furthermore, this application also provides an electrical appliance 10000 that uses an energy storage device as its power source. The electrical appliance 10000 may include, but is not limited to, power tools, mobile phones, ships, spacecraft, or residential energy storage systems. Spacecraft may include drones, rockets, space shuttles, etc. This application only uses a residential energy storage system as an example for illustration.

[0102] The residential energy storage system includes an energy storage device (taking a battery pack 1000 as an example), a conversion device 4000 (photovoltaic panel), one type of user load 2000 (streetlight), and another type of user load 3000 (household appliances). The energy storage device can be wall-mounted on an outdoor wall. Specifically, the conversion device 4000 can be a photovoltaic conversion device installed on the roof to convert solar energy into electrical energy. The energy storage device is used to store this electrical energy and supply it to streetlights and household appliances during peak electricity prices, or to supply power during grid outages, or to supply power to the grid after grid connection. It should be noted that the energy storage device in this application is not limited to residential energy storage scenarios.

[0103] In the electrical equipment 10000 described above, the top cover assembly 10 uses rivets 15 to rivet the top cover 11, the collector plate 13, and the seal 17 together, thereby achieving a secure connection without welding. Since the assembly process of the top cover assembly 10 does not employ welding for the top cover 11 and the collector plate 13, tensile stress is avoided due to cooling at the weld joint. The second through hole 1131, serving as the injection port, will not be stretched and will maintain its original size. Furthermore, the insertion part 1511 can seal with the second through hole 1131. Simultaneously, the second blocking part 1155 and the seal 17 further enhance the sealing effect, preventing electrolyte leakage and ensuring the sealing performance of the top cover assembly 10.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A top cover assembly, characterized in that, include: The top cover includes a first side and a second side opposite to each other in a first direction, and is provided with a first through hole. The first through hole penetrates the first side and the second side of the top cover. The first through hole includes a first cavity and a second cavity that communicate with each other. The first cavity is closer to the first side of the top cover than the second cavity. In a projection plane perpendicular to the first direction, the size of the first cavity is larger than the size of the second cavity to form a stepped portion. The collector plate includes a first side and a second side opposite to each other in the first direction. The first side of the collector plate is closer to the second side of the top cover than the second side of the collector plate. The collector plate also includes a body portion and a protrusion portion. The protrusion portion protrudes from the first side of the body portion toward the top cover and includes a first side and a second side opposite to each other in the first direction. The protrusion portion is at least partially accommodated in the second cavity. The protrusion portion is provided with a second through hole, which penetrates the first side and the second side of the protrusion portion. The head of a rivet includes an insertion portion, a first blocking portion, and a second blocking portion. The insertion portion passes through a second through hole. The first blocking portion and the second blocking portion are located at opposite ends of the insertion portion and are both outside the second through hole. The first blocking portion abuts against a second side of a protrusion, and the second blocking portion abuts against a first side of the protrusion and the stepped portion. A sealing element is located within the first cavity and sandwiched between the second blocking portion and the bottom of the second cavity.

2. The top cover assembly according to claim 1, characterized in that, The second blocking portion includes a first surface and a second surface facing away from each other. The first surface abuts against the first side of the stepped portion and the protrusion. The second surface is provided with a groove, the bottom of which is higher than the first side of the protrusion.

3. The top cover assembly according to claim 1, characterized in that, The stepped portion is provided with a receiving groove, and the sealing element is at least partially received in the receiving groove.

4. The top cover assembly according to claim 1, characterized in that, A solder mark is provided between the second blocking part and the top cover.

5. The top cover assembly according to claim 1, characterized in that, The second cavity has a first chamfer at the opening on the second side of the top cover, and the top of the protrusion has a second chamfer. The first chamfer is configured to cooperate with the second chamfer.

6. The top cover assembly according to claim 1, characterized in that, The collector plate and the top cover are connected together on the second side of the collector plate by ultrasonic welding.

7. The top cover assembly according to claim 6, characterized in that, The protrusion includes a first sub-part and a second sub-part. The first sub-part protrudes from a first side of the main body and includes a first side and a second side opposite to each other in the first direction. The second sub-part is connected to the first sub-part and extends into the second cavity. In the projection plane perpendicular to the first direction, the size of the second sub-part is smaller than the size of the first sub-part. A recess is provided on the second side of the first sub-part. The first blocking part is located in the recess and abuts against the bottom surface of the recess. The bottom surface of the recess is provided with a weld mark for ultrasonic welding of the top cover and the collector plate. The weld mark corresponds to the step portion in the first direction.

8. The top cover assembly according to claim 7, characterized in that, The body portion includes a plurality of first regions and a plurality of second regions, which are arranged alternately around the center of the protrusion. A third through hole is provided in the first region, which penetrates the first side and the second side of the body portion. The first side of the second region is recessed into the second side of the second region to form a receiving groove. The recess is connected to at least one of the third through holes in each of the first regions through a connecting groove.

9. An energy storage device, characterized in that, The energy storage device includes the top cover assembly as described in any one of claims 1-8.

10. An electrical appliance, characterized in that, The electrical equipment includes the energy storage device as described in claim 9.

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