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 and a collector plate. The top cover comprises a first side and a second side which are opposite to each other in a first direction, and is provided with a first through hole. The first through hole penetrates through the first side and the second side of the top cover, at least three convex ribs are arranged on the inner circumferential wall of the first through hole, and the at least three convex ribs protrude and extend from the inner circumferential wall of the first through hole to the center direction of the first through hole. The flow collecting disc comprises a body part and a protruding part. The body portion includes a first side and a second side opposite to each other in the first direction, the first side of the body portion being closer to the second side of the top cover than the second side of the body portion. The protruding part protrudes from the first side of the body part to the top cover, at least part of the protruding part is contained in the first through hole, and the at least three protruding ribs are configured to make contact with the peripheral wall of the protruding part.

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, electrolyte is injected into the internal battery cell through an injection hole, which is then sealed with a sealing component.

[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, with some areas having larger gaps and others smaller gaps. 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 larger gap can reach a maximum of 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, allowing electrolyte to leak out 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 and a collector plate. 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 through the first side and the second side of the top cover, and the inner peripheral wall of the first through hole is provided with at least three ribs, the at least three ribs extending protruding from the inner peripheral wall of the first through hole toward the center of the first through hole. The collector plate includes a body portion and a protruding portion, the body portion including a first side and a second side opposite to each other in the first direction, the first side of the body portion being closer to the second side of the top cover than the second side of the body portion. The protruding portion protrudes from the first side of the body portion toward the top cover, the protruding portion being at least partially received within the first through hole. The at least three ribs are configured to contact the outer peripheral wall of the protruding portion.

[0006] The top cover assembly of the above technical solution utilizes ribs that contact the outer peripheral wall of the protrusion. These ribs effectively limit the position of the protrusion when it passes through the first through hole of the top cover, preventing a one-sided gap between the collector and the top cover. By incorporating ribs into the top cover assembly, the problem of enlarged injection holes caused by welding to cover one-sided gaps is avoided. Furthermore, the protrusion's insertion into the first through hole is prevented from becoming stuck and worn, ensuring a high yield rate for the top cover assembly.

[0007] As an optional technical solution of this application, the protrusion is coaxial with the first through hole. The gap between the inner peripheral wall of the first through hole and the outer peripheral wall of the protrusion is the same, which better ensures the yield of the top cover assembly.

[0008] As an optional technical solution of this application, the protrusion includes a first sub-part, a second sub-part, and a third sub-part connected sequentially. The third sub-part extends from a first side of the body portion, and the first sub-part at least partially extends into the first through hole and contacts the rib. In the first direction, the contact dimension between the rib and the first sub-part is at least 1 / 3 of the dimension of the first sub-part.

[0009] In the above technical solution, the first sub-part, the second sub-part, and the third sub-part connected sequentially by the protrusions are used to enable the top cover to mate with the collector plate through the protrusions. In the first direction, the contact dimension between the rib and the first sub-part is at least 1 / 3 of the dimension of the first sub-part. On the one hand, the rib can effectively limit the first sub-part, preventing the collector plate where the protrusion is located from being misaligned during assembly, thereby ensuring the yield of the top cover assembly. On the other hand, the rib will not affect the assembly with the first sub-part, avoiding the risk of jamming during the assembly of the collector plate and the top cover.

[0010] As an optional technical solution of this application, the rib includes a limiting surface that faces away from the inner peripheral wall of the first through hole and towards the center of the first through hole, and the outer peripheral wall of the protrusion includes a first outer surface. The first outer surface is configured as a plane, and the limiting surface is configured as a plane, so that the limiting surface contacts the first outer surface. The contact between the first outer surface and the limiting surface increases the degree of contact between the rib and the protrusion, and the rib can effectively limit the protrusion, preventing the protrusion from being skewed during assembly, thereby further ensuring the yield of the top cover assembly.

[0011] As an optional technical solution of this application, the rib includes a limiting surface that faces away from the inner peripheral wall of the first through hole and towards the center of the first through hole, and the outer peripheral wall of the protrusion includes a first outer surface. At least one of the first outer surface and the limiting surface is configured as a curved surface, and the limiting surface contacts the line of the first outer surface. The contact between the limiting surface and the line of the first outer surface satisfies the contact degree between the rib and the protrusion, and also reduces the friction between the rib and the protrusion when the protrusion is assembled into the first through hole of the top cover, avoiding excessive friction and scratches on the appearance of the outer surface of the protrusion.

[0012] As an optional technical solution of this application, the opening of the first through hole near the second side of the top cover is provided with a chamfer, and the chamfer is provided with a chamfered surface connecting the inner peripheral wall of the first through hole and the second side of the top cover; the outer peripheral wall of the protrusion includes a first outer side, a second outer side, and a third outer side connected in sequence, the first outer side contacts the outer peripheral wall of the protruding rib, the third outer side is connected to the first side of the body, the second outer side is connected between the first outer side and the third outer side, and is inclined relative to both the first outer side and the third outer side, and the second outer side cooperates with the chamfered surface.

[0013] In the above technical solution, the chamfered inner peripheral wall corresponds to the protrusion extending into the first through hole, and the chamfered surface cooperates with the second outer surface of the protrusion. It can also play a guiding role when the protrusion is assembled into the first through hole of the top cover. At the same time, it reduces stress concentration when the top cover and the protrusion are assembled, and avoids scratching of the outer surface of the protrusion due to the presence of burrs in the contact part.

[0014] As an optional technical solution of this application, the free end of the rib near the second side of the top cover includes a guide surface. In the direction from the second side of the top cover to the first side of the top cover, the distance between the guide surface and the inner peripheral wall of the rib gradually increases in a second direction, and the second direction is perpendicular to the first direction.

[0015] In the above technical solution, the free end of the rib is chamfered and forms a guide surface, which guides the welding ring when it is assembled into the mounting groove. Simultaneously, when the welding protrusion reaches the first through hole of the top cover, the chamfer prevents the rib from melting due to welding and being squeezed out from the first side of the top cover near the first through hole, thus avoiding obvious defects in the appearance of the top cover assembly.

[0016] As an optional technical solution of this application, a first guide member is provided on the first side of the main body, and a second guide member is provided on the second side of the top cover. One of the first guide member and the second guide member is a protrusion, and the other is a groove. The protrusion includes a first guide surface, and the groove includes a second guide surface. The first guide surface and the second guide surface are both inclined relative to the first direction, and the inclination angles are the same. The protrusion is engaged in the groove, and the first guide surface and the second guide surface cooperate.

[0017] In the above technical solution, the first guide and the second guide further strengthen the fit between the first side of the main body and the second side of the top cover. One of the first guide and the second guide is a protrusion, and the other is a groove that fits with the protrusion. The fit between the structure of the protrusion and the groove has a guiding effect, so that the assembled manifold is coaxial with the center hole of the top cover, avoiding serious one-sided deviation.

[0018] As an optional technical solution of this application, the protrusion is provided with a second through hole extending through the thickness direction. The second through hole includes a first sub-cavity and a second sub-cavity that communicate with each other. In a projection plane perpendicular to the first direction, the size of the first sub-cavity is larger than the size of the second sub-cavity, and the first sub-cavity is closer to the first side of the top cover than the second sub-cavity. The top cover assembly also includes a plastic nail and a sealing element. The plastic nail is installed in the second sub-cavity, and the sealing element is installed in the first sub-cavity and welded to the top cover.

[0019] In the above technical solution, the second through hole serves as the electrolyte injection hole for a single battery cell. A plastic stud fills the second cavity, initially sealing the second through hole, and the sealing element is welded to the top cover to further seal it. The plastic stud and the sealing element together provide a good seal between the top cover and the current collector, preventing electrolyte leakage from the battery cell and preventing external moisture and impurities from entering the battery cell. Simultaneously, the plastic stud has good insulation properties, preventing internal short circuits within the battery cell and improving the safety of the battery cell in use.

[0020] Secondly, this application provides an energy storage device. The energy storage device includes the top cover assembly described in any of the above embodiments.

[0021] In the energy storage device described above, the top cover assembly utilizes ribs to contact the outer peripheral wall of the protrusion. These ribs effectively position the protrusion when it passes through the first through-hole of the top cover, preventing a one-sided gap between the collector and the top cover. By incorporating ribs into the top cover assembly, the problem of enlarged injection holes caused by welding to cover one-sided gaps is avoided. Furthermore, the protrusion's insertion through the first through-hole is prevented from becoming stuck and worn, ensuring a high-quality appearance for the top cover assembly.

[0022] Thirdly, this application provides an electrical appliance. The electrical appliance includes the energy storage device described in any of the above embodiments.

[0023] In the electrical equipment described above, the top cover assembly utilizes ribs to contact the outer peripheral wall of the protruding portion. These ribs effectively limit the position of the protruding portion of the collector plate when it passes through the first through hole of the top cover, preventing a one-sided gap between the collector plate and the top cover. By incorporating ribs into the top cover assembly, the problem of enlarged injection holes caused by welding to cover one-sided gaps can be avoided. Furthermore, it prevents jamming and wear when the protruding portion passes through the first through hole, ensuring a high-quality appearance for the top cover assembly.

[0024] 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

[0025] 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:

[0026] Figure 1 This is a three-dimensional assembly diagram of the top cover assembly according to some embodiments of this application;

[0027] Figure 2 for Figure 1 An exploded perspective view of the top cover assembly shown.

[0028] Figure 3 for Figure 1 The diagram shows a cross-sectional view of the top cover assembly taken by line III-III;

[0029] Figure 4 for Figure 3 An enlarged schematic diagram of point IV in the top cover assembly shown;

[0030] Figure 5 for Figure 3 An enlarged schematic diagram of point V in the top cover assembly shown;

[0031] Figure 6 for Figure 2 A bottom view of the top cover in the top cover assembly shown;

[0032] Figure 7 for Figure 6 An enlarged schematic diagram of point VII in the top cover is shown;

[0033] Figure 8 This is a three-dimensional structural diagram of a battery cell according to some embodiments of this application;

[0034] Figure 9 This is a three-dimensional structural diagram of a battery pack according to some embodiments of this application;

[0035] Figure 10 This is a schematic diagram of the planar structure of an electrical device according to some embodiments of this application.

[0036] The reference numerals in the detailed embodiments are as follows:

[0037] 10,000 electrical devices; 1,000 battery packs; 100 individual battery cells; 2,000 and 3,000 loads; 4,000 conversion devices; 10 top cover assemblies;

[0038] Top cover 11; First side of top cover 1101; Second side of top cover 1102; First through hole 111; Rib 1111; Limiting surface 11111; Guide surface 11113; Chamfer 1113; Chamfered surface 11131; Second guide 113; Second guide surface 1133; Explosion-proof hole 115; Explosion-proof valve 117;

[0039] Collector plate 13; First side of collector plate 1301; Second side of collector plate 1302; Body part 131; First guide member 1311; First guide surface 13111; Protrusion 133; First sub-part 1331; Second sub-part 1333; Third sub-part 1335; First outer surface 1337; Second outer surface 1339; Third outer surface 1341; Second through hole 1343; First sub-cavity 13431; Second sub-cavity 13433;

[0040] 15 plastic nails; 17 seals;

[0041] Casing 30; Battery box 300; Box body 310; Cover 330; First direction L; Positive direction of the first direction L1; Negative direction of the first direction L2; Second direction W. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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).

[0048] 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.

[0049] 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.

[0050] Please refer to this as well. Figure 1 and Figure 2 This application provides a top cover assembly 10. The top cover assembly 10 includes a top cover 11 and a collector plate 13. 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 inner peripheral wall of the first through hole 111 is provided with at least three ribs 1111, which protrude from the inner peripheral wall of the first through hole 111 and extend toward the center of the first through hole 111. The collector plate 13 includes a body portion 131 and a protrusion portion 133. The collector plate 13 includes a first side 1301 and a second side 1302 opposite to each other in the 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 first side 1301 of the collector plate is also the first side 1301 of the body portion 131, and the second side 1302 of the collector plate is also the second side 1302 of the body portion 131. A protrusion 133 protrudes from the first side 1301 of the body portion 131 toward the top cover 11, and the protrusion 133 is at least partially accommodated within the first through hole 111. At least three ribs 1111 are configured to contact the outer peripheral wall of the protrusion 133.

[0051] Please combine Figure 8 and Figure 9 The top cover assembly 10 is a component that covers the top opening of the housing 30 of the battery cell 100 and provides a sealed space for the electrode assembly and electrolyte (not shown) located inside the housing 30, while the electrical energy of the electrode assembly can be led out to the outside through the top cover assembly 10.

[0052] Please refer to the following: Figure 1 and Figure 8The top cover 11 refers to a component that closes onto the opening of the housing 30 to isolate the internal environment of the battery cell 100 from the external environment. Indiscriminately, the shape of the top cover 11 can be adapted to the shape of the opening of the housing 30 to fit the housing 30. Specifically, the shape of the cross-section of the top cover 11 (defined as the thickness direction of the top cover assembly 10 as the first direction L, and the plane intercepted by a plane perpendicular to the first direction L as the cross-section; the cross-section referred to below uses this definition) can be determined according to the shape of the opening of the housing 30; that is, the cross-sectional shape of the top cover 11 can be, but is not limited to, a circle, a square, or other polygonal shapes. For example, if the opening is circular, the corresponding cross-sectional shape of the top cover 11 can be circular; if the opening is rectangular, the corresponding cross-sectional shape of the top cover 11 can be rectangular. In this application, the cross-sectional shape of the top cover 11 is described as circular. Optionally, the top cover 11 can be made of a material with certain hardness and strength (such as aluminum alloy). This makes the top cover 11 less prone to deformation under pressure and impact, allowing the battery cell 100 to have higher structural strength and better safety performance. The first side 1101 of the top cover faces the outside of the housing 30, and the second side 1102 of the top cover faces the inside of the housing 30. The thickness direction of the top cover 11, defined in this application as the first direction L, refers to either the direction from the first side 1101 to the second side 1102, or vice versa. The first direction L is also the height direction of the battery cell 100. The top cover 11 has a first through hole 111 extending along the first direction L through the first side 1101 and the second side 1102 of the top cover.

[0053] Please refer to further information. Figure 6 and Figure 7 The inner peripheral wall of the first through hole 111 is provided with at least three ribs 1111, which are protruding structures extending from the inner peripheral wall of the first through hole 111 towards the center of the first through hole 111. As mentioned above, since the protrusion 133 of the collector plate 13 and the inner peripheral wall of the first through hole 111 of the top cover 11 are spaced apart, if the gap between the two is inconsistent in the circumferential direction, that is, there is a one-sided gap problem. When the protrusion 133 of the collector plate 13 passes through the first through hole 111 of the top cover 11 and the top cover 11 and the collector plate 13 are welded, it is necessary to cover the one-sided gap problem by increasing the weld width and depth. Moreover, the welding heat will cause the collector plate 13 to deform, resulting in poor appearance and reduced sealing of the top cover assembly 10. In this embodiment, a rib 1111 is provided on the inner peripheral wall of the first through hole 111 of the top cover 11. The rib 1111 can limit the position of the protrusion 133 of the collector plate 13 when it passes through the first through hole 111 of the top cover 11, thereby avoiding or reducing the problem of single-sided gap.

[0054] Furthermore, the top cover assembly 10 also includes a current collector 13. The current collector 13 is a functional component, such as an electrode assembly, used to electrically connect to functional components inside the battery cell 100, to conduct current from the functional components inside the battery cell 100 to the outside of the battery cell 100 or to introduce external current into the battery cell 100. Typically, the current collector 13 is made of a conductive material to conduct current. The current collector 13 can be made of metals such as aluminum and copper, or other conductive materials such as aluminum alloys and copper alloys. The current collector 13 includes a positive current collector 13 and a negative current collector 13. The positive current collector 13 is disposed at the positive terminal of the battery cell 100 and used to electrically connect to the functional components inside the battery cell 100, while the negative current collector 13 is disposed at the negative terminal of the battery cell 100 and used to electrically connect to the functional components inside the battery cell 100. Additionally, the current collector 13 in this application can be a bent current collector or a non-bent current collector. The bent collector plate includes at least one bend, and its extension direction lies in multiple planes. For example, an S-shaped collector plate has three extension planes. The non-bent collector plate does not contain a bend, and its extension direction lies in one plane, such as a disc-shaped collector plate. The illustrations in this application only show a non-bent collector plate 13 as an example.

[0055] The current is transmitted from the inside of the battery cell 100 to the outside in the following order: the functional components inside the battery cell 100 transmit the current to the current collector 13, and then the current collector 13 further transmits the current to the top cover 11, and then the top cover 11 transmits the current to the external circuit to realize the discharge of the battery cell 100. The current is transmitted from the outside of the battery cell 100 to the inside in the following order: the current from the external circuit is transmitted to the current collector 13 through the top cover 11, and then the current collector 13 transmits the current to the functional components inside the battery cell 100 to realize the charging of the battery cell 100.

[0056] Please refer to further information. Figure 2The collector plate 13 includes a body portion 131 and a protrusion 133, and is located on the second side 1102 of the top cover. The body portion 131 includes a first side and a second side opposite to each other in a first direction L. The first side 1301 of the body portion 131 is the side closer to the second side 1102 of the top cover, and the first side 1302 of the body portion 131 is the side farther away from the second side 1102 of the top cover. The protrusion 133 is connected to the body portion 131, and the protrusion 133 protrudes from the first side 1301 of the body portion 131 along the positive direction L1 of the first direction L (the direction from the collector plate 13 to the top cover 11 in the first direction L is defined as the positive direction L1 of the first direction L, and the direction from the top cover 11 to the collector plate 13 in the first direction L is defined as the negative direction L2 of the first direction L). The body portion 131 and the protrusion 133 can be integrally formed or separately formed. When the body portion 131 and the protrusion 133 are separately formed, the body portion 131 and the protrusion 133 can be detachably connected or non-detachably connected. When the body portion 131 and the protrusion 133 are detachably connected, the connection method can be, but is not limited to, one or more combinations of detachable connection methods such as threaded connection and snap-fit. When the body portion 131 and the protrusion 133 are non-detachably connected, the connection method can be, but is not limited to, one or more combinations of non-detachable connection methods such as adhesive bonding and welding. The protrusion 133 is at least partially accommodated within the first through hole 111, and the shape and size of the protrusion 133 match the shape and size of the first through hole 111. The surface of the protrusion 133 facing the first direction L1 can protrude from or not protrude from the first side 1101 of the top cover. The outer peripheral wall of the protrusion 133 and the inner peripheral wall of the first through hole 111 are circumferentially opposite and spaced apart.

[0057] At least three ribs 1111 are configured to contact and abut against the outer peripheral wall of the protrusion 133. Specifically, the inner peripheral wall of the first through hole 111 with ribs 1111 contacts the outer peripheral wall of the protrusion 133 through the ribs 1111, while the inner peripheral wall of the first through hole 111 without ribs 1111 has a gap with the outer peripheral wall of the protrusion 133. The dimensions of the ribs 1111 need to match the outer contour dimensions of the protrusion 133 and the inner contour dimensions of the first through hole 111. The number and layout of the ribs 1111 need to be evenly distributed along the inner peripheral wall of the first through hole 111 to ensure a force balance between the protrusion 133 and the first through hole 111 during installation. When the number of ribs 1111 is odd, any two ribs 1111 have the same shape and size; when the number of ribs 1111 is even, any two ribs 1111 have the same shape and size or any two ribs 1111 symmetrical about the central axis of the first through hole 111 have the same shape and size, which can achieve a more flexible fit between the ribs 1111 and the protrusion 133.

[0058] In the above-described technical solution, the top cover assembly 10 utilizes a rib 1111 to contact the outer peripheral wall of the protrusion 133. The rib 1111 can positionally limit the protrusion 133 when it passes through the first through hole 111 of the top cover 11, thus avoiding a one-sided gap between the collector 13 and the top cover 11. By providing the rib 1111 in the top cover assembly 10, the problem of enlarged injection holes caused by welding to cover one-sided gaps can be avoided. Furthermore, the protrusion 133 can be prevented from getting stuck and worn when passing through the first through hole 111, ensuring a high yield rate for the top cover assembly 10.

[0059] More specifically, the rib 1111 ensures that the gap between the inner peripheral wall of the first through hole 111 and the outer peripheral wall of the protrusion 133 is within an appropriate range. The gap between the inner peripheral wall of the first through hole 111 with the rib 1111 and the outer peripheral wall of the protrusion 133 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm, that is, the gap value ranges from greater than or equal to 0.1 mm to less than or equal to 0.2 mm. Specifically, the gap can be any value between any two of 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, and 0.2 mm. If the gap is less than 0.1mm, the gap is too small, and there is a risk of jamming and wear when the protrusion 133 passes through the first through hole 111; if the gap is greater than 2mm, the gap is too large, and it is difficult to avoid the problem of using welding to cover the gap on one side, which will cause the second through hole 1343 to become larger and thus cause leakage.

[0060] Please see Figure 2 , Figure 3 and Figure 4 As an optional technical solution of this application, the protrusion 133 is coaxial with the first through hole 111.

[0061] As mentioned above, the protrusion 133 is a component that allows the collector plate 13 to extend into the first through hole 111 of the top cover 11 to achieve a mating between the collector plate 13 and the top cover 11. The matching of the shape and size of the protrusion 133 with the shape and size of the first through hole 111 ensures that the collector plate 13 and the top cover 11 can be installed accordingly. When the protrusion 133 and the first through hole 111 are coaxial, that is, when the central axis of the protrusion 133 coincides with the central axis of the first through hole 111, and the projection planes of the protrusion 133 and the first through hole 111 in a projection plane perpendicular to the first direction L are concentric, the collector plate 13 and the top cover 11 are aligned and installed. At this time, the gap between the inner peripheral wall of the first through hole 111 and the outer peripheral wall of the protrusion 133 is the same everywhere in the circumferential direction of the protrusion 133 or in the circumferential direction of the first through hole 111, which can better ensure the yield of the top cover assembly 10.

[0062] Please see Figure 2 and Figure 4 As an optional technical solution of this application, the protrusion 133 includes a first sub-part 1331, a second sub-part 1333, and a third sub-part 1335 connected sequentially. The third sub-part 1335 extends from the first side 1301 of the body part 131, and the first sub-part 1331 at least partially extends into the first through hole 111 and contacts the rib 1111. In the first direction L, the contact dimension between the rib 1111 and the first sub-part 1331 is at least 1 / 3 of the dimension of the first sub-part 1331.

[0063] Please refer to details. Figure 4 The protrusion 133 extends sequentially from the body portion 131 in the first direction L1, forming a third sub-part 1335, a second sub-part 1333 connected to the third sub-part 1335, and a first sub-part 1331 connected to the second sub-part 1333. The first sub-part 1331 and the second sub-part 1333, or the second sub-part 1333 and the third sub-part 1335, can be integrally formed or separately formed. When the first sub-part 1331 and the second sub-part 1333, or the second sub-part 1333 and the third sub-part 1335, are separately formed, the first sub-part 1331 and the second sub-part 1333, or the second sub-part 1333 and the third sub-part 1335, can be detachably connected or non-detachably connected. When the first sub-part 1331 and the second sub-part 1333, or the second sub-part 1333 and the third sub-part 1335, are detachably connected, the connection method of the first sub-part 1331 and the second sub-part 1333, or the connection method of the second sub-part 1333 and the third sub-part 1335, may be, but is not limited to, one or more combinations of detachable connection methods such as threaded connection and snap-fit. When the first sub-part 1331 and the second sub-part 1333, or the second sub-part 1333 and the third sub-part 1335, are non-detachably connected, the connection method of the first sub-part 1331 and the second sub-part 1333, or the connection method of the second sub-part 1333 and the third sub-part 1335, may be, but is not limited to, one or more combinations of non-detachable connection methods such as adhesive bonding and welding.

[0064] The third sub-part 1335 is connected to the main body 131. The third sub-part 1335 and the main body 131 can be integrally formed or separately formed. When the third sub-part 1335 and the main body 131 are separately formed, they can be detachably connected or non-detachably connected. When the third sub-part 1335 and the main body 131 are detachably connected, the connection method can be, but is not limited to, one or more combinations of detachable connection methods such as threaded connection and snap-fit. When the third sub-part 1335 and the main body 131 are non-detachably connected, the connection method can be, but is not limited to, one or more combinations of non-detachable connection methods such as adhesive bonding and welding. The first sub-part 1331 extends at least partially into the first through hole 111. The shape and size of the first sub-part 1331 match the shape and size of the first through hole 111. The surface of the first sub-part 1331 facing the first direction L1 may or may not protrude from the first side 1101 of the top cover. The outer peripheral wall of the first sub-part 1331 is circumferentially opposite to and spaced apart from the inner peripheral wall of the first through hole 111.

[0065] For further information, please refer to [link / reference]. Figure 6 and Figure 7 The rib 1111 is a protruding structure that extends from the inner peripheral wall of the first through hole 111 toward the center of the first through hole 111. As mentioned above, since the outer peripheral wall of the first sub-part 1331 is opposite to and spaced from the inner peripheral wall of the first through hole 111, if the gap between them is too large, it is necessary to increase the weld width and depth to cover the single-sided gap problem when welding the top cover 11 and the current collector 13. The welding heat will cause the second through hole 1343 of the current collector 13 to deform and affect the sealing performance of the battery cell 100, reducing the yield of the battery cell 100. In this embodiment, the inner peripheral wall of the first through hole 111 is provided with a rib 1111 to limit the position of the first sub-part 1331 of the protruding part 133 in the first through hole 111 of the top cover 11. Moreover, the rib 1111 is in contact with the first sub-part 1331, so the degree of contact between the two plays a crucial role in the limiting effect. If, in the first direction L, the contact dimension between the rib 1111 and the first sub-part 1331 is less than 1 / 3 of the dimension of the first sub-part 1331, then the degree of contact between the two is too low, and the rib 1111 cannot restrain the first sub-part 1331, thus failing to ensure that the collector plate 13 where the protrusion 133 is located will not be misaligned during assembly. At the same time, the contact dimension between the rib 1111 and the first sub-part 1331 cannot be too large. If it is too large, for example, if the total dimension of the surface of all the ribs 1111 facing the central axis of the first through hole 111 is close to the dimension of the first sub-part 1331 facing the inner peripheral wall of the first through hole 111, there will be a risk of jamming during the assembly of the rib 1111 and the first sub-part 1331.

[0066] In the above technical solution, the first sub-part 1331, the second sub-part 1333, and the third sub-part 1335, which are sequentially connected by the protrusion 133, are used to enable the top cover 11 to cooperate with the collector plate 13 through the protrusion 133. In the first direction L, the contact dimension between the rib 1111 and the first sub-part 1331 is at least 1 / 3 of the dimension of the first sub-part 1331. On the one hand, the rib 1111 can effectively limit the first sub-part 1331, which can prevent the collector plate 13 where the protrusion 133 is located from being misaligned during assembly, thereby ensuring the yield of the top cover assembly 10. On the other hand, the rib 1111 will not affect the assembly with the first sub-part 1331, avoiding the risk of jamming during the assembly of the collector plate 13 and the top cover 11.

[0067] Please see Figure 3 , Figure 4 and Figure 7 As an optional technical solution of this application, the rib 1111 includes a limiting surface 11111 that is away from the inner peripheral wall of the first through hole 111 and faces the center of the first through hole 111, and the outer peripheral wall of the protrusion 133 includes a first outer surface 1337.

[0068] In some embodiments, the limiting surface 11111 is in contact with the first outer surface 1337. The limiting surface 11111 is configured as a plane, and the first outer surface 1337 is configured as a plane. For example, if the rib 1111 is a cuboid structure and the protrusion 133 is a square ring structure, then the limiting surface 11111 is a rectangular or rectangular plane, and the first outer surface 1337 is a rectangular or rectangular plane.

[0069] The first outer surface 1337 of the protrusion 133 contacts the limiting surface 11111 of the rib 1111, which can increase the contact degree between the rib 1111 and the protrusion 133. The rib 1111 can effectively limit the protrusion 133, and can prevent the collector plate 13 where the protrusion 133 is located from being misaligned when assembled with the top cover 11, thereby further ensuring the yield of the top cover assembly 10.

[0070] In other embodiments, the limiting surface 11111 is in line contact with the first outer surface 1337. For example, the limiting surface 11111 is a curved surface, and the first outer surface 1337 can be a plane or a curved surface. Specifically, for example, the rib 1111 is a cylindrical structure, and the limiting surface 11111 is the circumferential surface of the cylinder. The protrusion 133 is a ring structure, a square ring structure, or other irregular ring structure. In another example, the first outer surface 1337 is a curved surface, and the limiting surface 11111 can be a plane or a curved surface. Specifically, for example, the protrusion 133 is a ring structure, the first outer surface 1337 is the circumferential surface of the ring structure, and the limiting surface 11111 is a rectangular plane, a triangular plane, or other polygonal plane.

[0071] The limiting surface 11111 makes line contact with the first outer surface 1337. While satisfying the contact degree between the rib 1111 and the protrusion 133, it can also reduce the friction between the rib 1111 and the protrusion 133 when the protrusion 133 is assembled into the first through hole 111, and avoid excessive friction causing scratches on the outer surface of the protrusion 133.

[0072] Please see Figure 3 and Figure 4 As an optional technical solution of this application, the opening of the first through hole 111 near the second side 1102 of the top cover is provided with a chamfer 1113, and the chamfer 1113 is provided with a chamfered surface 11131 connecting the inner peripheral wall of the first through hole 111 and the second side 1102 of the top cover. The outer peripheral wall of the protrusion 133 includes a first outer surface 1337, a second outer surface 1339, and a third outer surface 1341 connected in sequence. The first outer surface 1337 contacts the outer peripheral wall of the protruding rib 1111, the third outer surface 1341 is connected to the first side 1301 of the body part 131, the second outer surface 1339 is connected between the first outer surface 1337 and the third outer surface 1341, and is inclined relative to both the first outer surface 1337 and the third outer surface 1341. The second outer surface 1339 mates with the chamfered surface 11131.

[0073] Specifically, a chamfer 1113 is provided on the second side 1102 of the first through hole 111 near the top cover. The chamfer 1113 can be formed by one or more of the following methods, including but not limited to turning, milling, grinding, laser processing, and electrochemical processing. The chamfer 1113 includes a chamfered surface 11131 connecting the inner peripheral wall of the first through hole 111 and the second side 1102 of the top cover. The chamfered surface 11131 forms a certain angle with the first direction L to achieve a guiding function. The chamfer 1113 can reduce burrs at the part where the second side 1102 of the first through hole 111 near the top cover mates with the second side 1301 of the collector plate, reduce stress concentration during the assembly process of the top cover 11 and the collector plate 13, and avoid scratching the collector plate 13.

[0074] The outer peripheral wall of the protrusion 133 includes a first outer side surface 1337, a second outer side surface 1339, and a third outer side surface 1341. These three outer side surfaces are sequentially distributed from the protrusion 133 toward the top cover 11, and are connected in pairs. The first outer side surface 1337 contacts the outer peripheral wall of the rib 1111, such that the first outer side surface 1337 is circumferentially opposite and spaced from the inner peripheral wall of the first through hole 111. The second outer side surface 1339 is disposed between the first outer side surface 1337 and the third outer side surface. The second outer side surface 1339 is connected to the first outer side surface 1337 in the positive direction L1 of the first direction, and connected to the third outer side surface 1341 in the negative direction L2 of the first direction. The second outer surface 1339 is inclined relative to both the first outer surface 1337 and the third outer surface 1341. The included angle between the second outer surface 1339 and the first outer surface 1337 can be greater than, less than, or equal to the included angle between the second outer surface 1339 and the third outer surface 1341. The second outer surface 1339 mates with the chamfered surface 11131 and serves as a guide when the protrusion 133 is installed into the first through hole 111.

[0075] In the above technical solution, the inner peripheral wall of the chamfer 1113 corresponds to the protrusion 133 extending into the first through hole 111, and the chamfer surface 11131 cooperates with the second outer surface 1339 of the protrusion 133. It can also play a guiding role when the protrusion 133 is assembled into the first through hole 111 of the top cover 11. At the same time, it reduces stress concentration when the top cover 11 is assembled with the protrusion 133, and avoids the possibility of scratching the appearance of the outer surface of the protrusion 133 due to the presence of burrs in the contact part.

[0076] Furthermore, as an optional technical solution, the hardness of the rib 1111 is less than that of the top cover 11. The material of the rib 1111 can be different from that of the top cover 11; for example, the rib 1111 can be made of pure aluminum, which has lower hardness, while the top cover 11 can be made of an aluminum alloy, which has higher hardness than the rib 1111. Since the hardness of the rib 1111 is less than that of the top cover 11, when the collector plate 13 is assembled into the top cover 11, the rib 1111 will not scratch the outer peripheral wall of the protrusion 133, ensuring the smoothness of the outer peripheral wall of the protrusion 133 and the fit between the protrusion 133 and the rib 1111, while also making the collector plate 13 aesthetically pleasing.

[0077] Please see Figure 7As an optional technical solution of this application, the free end of the rib 1111 near the second side 1102 of the top cover includes a guide surface 11113. In the direction from the second side 1102 of the top cover to the first side 1101 of the top cover, the distance between the guide surface 11113 and the inner peripheral wall (i.e., the limiting surface 11111) of the rib 1111 gradually increases in the second direction W, and the second direction W is perpendicular to the first direction L.

[0078] Specifically, the free end of the rib 1111 is chamfered and forms a guide surface 11113. The distance between the guide surface 11113 and the inner peripheral wall (i.e., the limiting surface 11111) of the rib 1111 in the second direction W gradually increases, that is, the guide surface 11113 forms an acute angle with the first direction L. The guide surface 11113 plays a guiding role when the protrusion 133 of the collector plate 13 is assembled into the first through hole 111.

[0079] Please see Figure 3 As an optional technical solution of this application, a first guide member 1311 is provided on the first side 1301 of the main body 131, and a second guide member 113 is provided on the second side 1102 of the top cover. One of the first guide member 1311 and the second guide member 113 is a protrusion, and the other is a groove. The protrusion includes a first guide surface 13111, and the groove includes a second guide surface 1133. The first guide surface 13111 and the second guide surface 1133 are both inclined relative to the first direction L, and the inclination angles are the same. The protrusion is engaged in the groove, and the first guide surface 13111 and the second guide surface 1133 are in cooperation.

[0080] Specifically, please combine Figure 5A first guide member 1311, disposed on the first side 1301 of the main body 131, corresponds to a second guide member 113, disposed on the second side 1102 of the top cover, in the first direction L. The area of ​​the projection of the first guide member 1311 onto a projection plane perpendicular to the first direction L is smaller than the area of ​​the projection of the main body 131 onto a projection plane perpendicular to the first direction L. The shape of the projection plane of the first guide member 1311 onto a projection plane perpendicular to the first direction L can be, but is not limited to, one or more combinations of shapes such as rectangle, circle, annulus, semi-annulus, and irregular shapes. The area of ​​the projection of the second guide member 113 onto a projection plane perpendicular to the first direction L is smaller than the area of ​​the projection of the top cover 11 onto a projection plane perpendicular to the first direction L. The shape of the projection plane of the second guide member 113 onto a projection plane perpendicular to the first direction L can be, but is not limited to, one or more combinations of shapes such as rectangle, circle, annulus, semi-annulus, and irregular shapes. The number, shape, and size of the first guide members 1311 correspond to the number, shape, and size of the second guide members 113. One of the first guide member 1311 and the second guide member 113 is a protrusion, and the other is a groove. That is, when the first guide member 1311 is a protrusion, the second guide member 113 is a groove; when the second guide member 113 is a protrusion, the first guide member 1311 is a groove. The above two technical solutions achieve the same effect in realizing the cooperation between the first guide member 1311 and the second guide member 113.

[0081] Figure 5 The design is illustrated by showing only the first guide member 1311 as a protrusion and the second guide member 113 as a groove. Regardless of the specific technical solution described above, the first guide member 1311 includes a first guide surface 13111, and the second guide member 113 includes a second guide surface 1133. When the first guide member 1311 is a protrusion and the second guide member 113 is a groove, the first guide surface 13111 is the outer surface of the protrusion, and the second guide surface 1133 is the inner surface of the groove. When the first guide member 1311 is a groove and the second guide member 113 is a protrusion, the first guide surface 13111 is the inner surface of the groove, and the second guide surface 1133 is the outer surface of the protrusion. The protrusion engages with the groove, allowing the first guide surface 13111 and the second guide surface 1133 to mate. The first guide surface 13111 and the second guide surface 1133 are both inclined relative to the first direction L, and the inclination angles are the same. The above two technical solutions achieve the same effect when the first guide surface 13111 and the second guide surface 1133 are matched.

[0082] In the above technical solution, the first guide 1311 and the second guide 113 play a guiding role when the collector plate 13 is assembled with the top cover 11. At the same time, they can make the assembled collector plate 13 and the top cover 11 basically coaxial, avoiding serious one-sided gap problems.

[0083] Please see Figure 3 As an optional technical solution of this application, the protrusion 133 is provided with a second through hole 1343 extending through the thickness direction. The second through hole 1343 includes a first sub-cavity 13431 and a second sub-cavity 13433 that communicate with each other. In the projection plane perpendicular to the first direction L, the size of the first sub-cavity 13431 is larger than the size of the second sub-cavity 13433, and the first sub-cavity 13431 is closer to the first side 1101 of the top cover than the second sub-cavity 13433. The top cover assembly 10 also includes a plastic nail 15 and a sealing member 17. The plastic nail 15 is installed in the second sub-cavity 13433, and the sealing member 17 is installed in the first sub-cavity 13431 and welded to the top cover 11.

[0084] Specifically, please combine Figure 4 The protrusion 133 has a second through hole 1343 in the first direction L. The second through hole 1343 penetrates the first side 1301 and the second side 1302 of the collector plate. The central axis of the second through hole 1343 is the central axis of the collector plate 13. The second through hole 1343 is the liquid injection hole of the top cover assembly 10. Liquid can be injected into the battery cell 100 through the second through hole 1343. After the liquid injection is completed, the second through hole 1343 is sealed. The second through hole 1343 includes a first sub-cavity 13431 and a second sub-cavity 13433 that are connected. The central axis of the first sub-cavity 13431 coincides with the central axis of the second sub-cavity 13433. The cavity shape of the first sub-cavity 13431 can be a cylinder, a hexahedron, or a frustum, etc. The cavity shape of the first sub-cavity 13431 and the second sub-cavity 13433 can be the same or different. The cross-sectional area of ​​the first sub-cavity 13431 is larger than that of the second sub-cavity 13433. The first sub-cavity 13431 is closer to the first side 1101 of the top cover than the second sub-cavity 13433.

[0085] The plastic pin 15 is a component in the top cover assembly 10 used to seal the second through hole 1343. The plastic pin 15 is installed inside the second sub-cavity 13433, and the fit between the plastic pin 15 and the second sub-cavity 13433 is an interference fit, whereby the plastic pin 15 is snapped into the second sub-cavity 13433 to achieve positional fixation. The plastic pin 15 is made of insulating material, including but not limited to polypropylene, polyethylene, polyvinylidene fluoride, and polycarbonate. The plastic pin 15 has good sealing performance, preventing leakage of electrolyte inside the battery cell 100.

[0086] To further prevent electrolyte leakage inside the battery cell 100, the top cover assembly 10 is also provided with a sealing element 17. The sealing element 17 is installed inside the first sub-cavity 13431 and welded to the top cover 11. The compression of the sealing element 17 can be controlled by welding, ensuring that the compression of the sealing element 17 is within a suitable range and guaranteeing the sealing effect of the sealing element 17. On the top cover assembly 10, plastic nails 15 are provided on the sealing element 17 in the negative direction L2 along the first direction. The plastic nails 15 are connected to the sealing element 17, or they are not connected to the sealing element 17. Thus, the sealing element 17 and the plastic nails 15 work together to provide a good sealing effect, preventing electrolyte leakage inside the battery cell 100, and also preventing external moisture and impurities from entering the battery cell 100.

[0087] Furthermore, the top cover 11 is also provided with an explosion-proof hole 115. The explosion-proof hole 115 is a through hole penetrating the first side 1101 and the second side 1102 of the top cover, and the explosion-proof hole 115 is spaced apart from the first through hole 111. Correspondingly, the top cover 11 also includes an explosion-proof valve 117, which is installed in the explosion-proof hole 115. When the internal chemical system of the battery cell 100 reacts abnormally and the internal environment begins to accumulate reaction gas, when the gas pressure accumulates to the threshold of the explosion-proof valve 117, the explosion-proof valve 117 bursts open and releases internal pressure, thereby ensuring the safety of the battery cell 100 in use.

[0088] In the above technical solution, the second through hole 1343 is the electrolyte injection hole of the battery cell 100. The plastic nail 15 fills the second sub-cavity 13433, initially sealing the second through hole 1343. The sealing element 17 is welded to the top cover 11 to further seal the second through hole 1343. The plastic nail 15 and the sealing element 17 together provide a good sealing effect for the top cover 11, preventing leakage of electrolyte inside the battery cell 100 on the one hand, and preventing external moisture and impurities from entering the battery cell 100 on the other hand.

[0089] Please see Figure 8 and Figure 9 The second aspect of this application provides an energy storage device. The energy storage device includes the top cover assembly 10 of any of the above embodiments.

[0090] Specifically, the energy storage device can be a single battery cell 100 ( Figure 8 As shown), it can also be a battery pack 1000 composed of one or more battery cells 100. Figure 9As shown, energy storage devices serve various functions, including but not limited to energy storage, energy dispatch, and energy storage power stations. Specifically, in some applications, energy storage devices can convert electrical energy into chemical energy for storage to meet peak energy demand, thus fulfilling the function of energy storage. In other applications, energy storage devices 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 be integrated into 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.

[0091] Please see Figure 9 When 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.

[0092] Please see Figure 1 and Figure 9 The battery cell 100 includes a top cover assembly 10, a housing 30, and a battery cell (not shown, but including at least an electrode assembly). The housing 30 has an opening, and the top cover assembly 10 is mounted on 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 and non-metals, wherein metals include aluminum, iron, steel, aluminum alloys, or iron alloys, and non-metals include, but are not limited to, plastics. In this application, the cross-section of the housing 30 is circular, which facilitates integration into a circular battery cell 100. The material of the housing 30 is aluminum alloy, which, while ensuring rigidity, also makes the battery cell 100 lighter and easier to transport.

[0093] A battery cell (not shown) is the core structure of a single battery cell 100 that converts electrical energy into chemical energy through a chemical reaction for charging and discharging. A battery cell is generally made by winding electrode components onto a core rod. The electrode components (not shown) mainly include a negative electrode, a positive electrode, and a separator. In one possible design, the negative electrode, separator, and positive electrode are sequentially stacked and attached to the core rod by adhesive or thermal fusion, and then wound to form the battery cell. After formation, the battery cell has gaps through which electrolyte can enter. The electrolyte is used to wet the battery 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. The separator is located between adjacent negative and positive electrodes to separate them.

[0094] The battery box 300 is a structure for holding individual 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. In this application, the cross-section of the battery box 300 is rectangular. The material of the battery box 300 is aluminum alloy, thus, while ensuring strength, it also makes the battery pack 1000 lighter and easier to transport.

[0095] The battery box 300 includes a box body 310 and a cover 330. The box body 310 and the cover 330 are combined to form a receiving cavity, in which a battery cell 100 is received. The box body 310 is the component in the battery box 300 that loads and supports the battery cell 100. One end of the box body 310 is closed, and the other end has an opening for the battery cell 100 to be inserted into the receiving cavity. The cover 330 is the component in the battery box 300 that covers the opening. The connection between the box body 310 and the 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-detachable connections include, but are not limited to, glued connections, welded connections, or a combination of glued connections and welded connections. In this application, the box body 310 and the cover 330 are detachably connected.

[0096] 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.

[0097] In the energy storage device described above, the top cover assembly 10 uses a rib 1111 to contact the outer peripheral wall of the protrusion 133. The rib 1111 can limit the position of the protrusion 133 when it passes through the first through hole 111 of the top cover 11, thus avoiding a one-sided gap between the collector 13 and the top cover 11. By providing the rib 1111 in the top cover assembly 10, the problem of enlarged injection holes caused by welding to cover one-sided gaps can be avoided. On the other hand, the protrusion 133 can be prevented from getting stuck and worn when it passes through the first through hole 111, ensuring the appearance yield of the top cover assembly 10.

[0098] Please see Figure 9 and Figure 10 This application provides an electrical appliance 10000. The electrical appliance 10000 includes an energy storage device.

[0099] 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.

[0100] 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.

[0101] In the electrical equipment 10000 described above, the top cover assembly 10 uses a rib 1111 to contact the outer peripheral wall of the protrusion 133. The rib 1111 can limit the position of the protrusion 133 when it passes through the first through hole 111 of the top cover 11, thus avoiding a one-sided gap between the collector 13 and the top cover 11. By providing the rib 1111 in the top cover assembly 10, the problem of enlarged injection holes caused by welding to cover one-sided gaps can be avoided. On the other hand, the protrusion 133 can be prevented from getting stuck and worn when it passes through the first through hole 111, ensuring the appearance yield of the top cover assembly 10.

[0102] 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 cap assembly, characterized by, The collector includes: a top cover including a first side and a second side opposite to each other in a first direction, and provided with a first through hole penetrating the first side of the top cover and the second side of the top cover, an inner peripheral wall of the first through hole being provided with at least three protrusions extending from the inner peripheral wall of the first through hole towards a center of the first through hole; and a collector plate including a body portion and a protruding portion, the body portion including a first side and a second side opposite to each other in the first direction, the first side of the body portion being closer to the second side of the top cover than the second side of the body portion, the protruding portion protruding from the first side of the body portion towards the top cover, the protruding portion being at least partially accommodated in the first through hole, and the at least three protrusions being configured to be in contact with an outer peripheral wall of the protruding portion.

2. The roof assembly of claim 1, wherein, The protruding portion is coaxial with the first through hole.

3. The roof assembly of claim 1 or 2, wherein, The protruding portion includes a first sub-portion, a second sub-portion and a third sub-portion successively connected to each other, the third sub-portion extending from the first side of the body portion, and the first sub-portion being at least partially inserted into the first through hole and in contact with the protrusions; in the first direction, a contact size of the protrusions with the first sub-portion is at least 1 / 3 of a size of the first sub-portion.

4. The roof assembly of claim 1 or 2, wherein, The protrusions include a limiting surface facing away from the inner peripheral wall of the first through hole and towards the center of the first through hole, and the outer peripheral wall of the protruding portion includes a first outer side surface; The first outer side surface is configured as a plane, and the limiting surface is configured as a plane, so that the limiting surface is in surface contact with the first outer side surface; or At least one of the first outer side surface and the limiting surface is configured as a curved surface, and the limiting surface is in linear contact with the first outer side surface.

5. The roof assembly of claim 1 or 2, wherein, The first through hole is provided with a chamfer near an opening of the second side of the top cover, and the chamfer is provided with a chamfer surface connecting the inner peripheral wall of the first through hole and the second side of the top cover; the outer peripheral wall of the protruding portion includes a first outer side surface, a second outer side surface and a third outer side surface successively connected to each other, the first outer side surface being in contact with the outer peripheral wall of the protrusions, the third outer side surface being connected to the first side of the body portion, the second outer side surface being connected between the first outer side surface and the third outer side surface and being inclined relative to both the first outer side surface and the third outer side surface, and the second outer side surface being matched with the chamfer surface.

6. The roof assembly of claim 1 or 2, wherein, A free end of the protrusions near the second side of the top cover includes a guide surface, and in a direction from the second side of the top cover to the first side of the top cover, a distance between the guide surface and the inner peripheral wall of the protrusions in a second direction gradually increases, the second direction being perpendicular to the first direction.

7. The roof assembly of claim 1 or 2, wherein, The first side of the body portion is provided with a first guide member, and the second side of the top cover is provided with a second guide member, one of the first guide member and the second guide member being a protrusion and the other being a groove, the protrusion including a first guide surface, the groove including a second guide surface, the first guide surface and the second guide surface being inclined relative to the first direction and having the same inclination angle, the protrusion being engaged in the groove, and the first guide surface and the second guide surface being matched.

8. The roof assembly of claim 1 or 2, wherein, The protrusion is provided with a second through hole penetrating in the thickness direction, the second through hole comprises a first sub-cavity and a second sub-cavity which are communicated, in a projection plane perpendicular to the first direction, the size of the first sub-cavity is greater than the size of the second sub-cavity, and the first sub-cavity is closer to the first side of the top cover than the second sub-cavity. The top cover assembly further comprises: A plastic nail is installed in the second sub-cavity; And A sealing member is installed in the first sub-cavity and welded with the top cover.

9. An energy storage device, characterized by, The energy storage device comprises the top cover assembly according to any one of claims 1-8.

10. An electric device, characterized by The electric device comprises the energy storage device according to claim 9.

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