Top cover assembly, energy storage device and electric equipment

Abstract

The utility model provides a top cover assembly, an energy storage device and electric equipment. The top cover assembly comprises a top cover, lower plastic and a pole. The top cover comprises a first side and a second side which are opposite to each other in the thickness direction, and a first through hole is formed in the top cover. The lower plastic is arranged on the second side of the top cover and comprises a first side and a second side which are opposite to each other in the thickness direction, the first side of the lower plastic is opposite to the second side of the top cover, the second side of the lower plastic is provided with a mounting groove, and the lower plastic is further provided with a through second through hole. The pole comprises a pole body and a welding ring, the pole body penetrates through the first through hole and the second through hole and comprises a first end and a second end which are opposite, the first end of the pole body protrudes relative to the first side of the top cover, the second end of the pole body protrudes relative to the bottom face of the mounting groove, and the welding ring is fixed to the peripheral wall of the second end of the pole body. The value range of the minimum distance between the welding ring and the inner circumferential wall of the mounting groove is larger than or equal to 1 mm and smaller than or equal to 11 mm.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a top cover assembly, an energy storage device, and an electrical device. 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. In current battery cell top-cover assemblies, the terminal typically consists of a terminal body and a welding ring. After the terminal body passes through the top cover and lower plastic, the welding ring is fixedly connected to the outer peripheral wall of the terminal body protruding from the lower plastic. However, during the process of fixing the welding ring to the terminal body, energy can easily be transferred through the welding ring to the lower plastic, causing damage to the lower plastic and resulting in a low yield rate for the top-cover assembly. Utility Model Content

[0003] In view of the above problems, this application provides a top cover assembly, an energy storage device, and an electrical device.

[0004] In a first aspect, this application provides a top cover assembly. The top cover assembly includes a top cover, a lower plastic component, and an electrode post. The top cover includes a first side and a second side opposite to each other in the thickness direction, and is provided with a first through hole, the first through hole penetrating the first side and the second side of the top cover. The lower plastic component is disposed on the second side of the top cover and includes a first side and a second side opposite to each other in the thickness direction. The first side of the lower plastic component is opposite to the second side of the top cover, and the second side of the lower plastic component is provided with a mounting groove. The lower plastic component is also provided with a second through hole, the second through hole penetrating the bottom surface of the mounting groove and the first side of the lower plastic component. The pole post includes a pole body and a welding ring. The pole body passes through the first through hole and the second through hole, and includes a first end and a second end opposite to each other. The first end of the pole body protrudes relative to the first side of the top cover, and the second end of the pole body protrudes relative to the bottom surface of the mounting groove. The welding ring is welded to the outer peripheral wall of the second end of the pole body and is spaced apart from the inner peripheral wall of the mounting groove. The minimum distance between the welding ring and the inner peripheral wall of the mounting groove is greater than or equal to 1 mm and less than or equal to 11 mm.

[0005] The top cover assembly of the above technical solution utilizes the gap between the welding ring and the inner peripheral wall of the mounting groove, with the gap value ranging from greater than or equal to 1 mm to less than or equal to 11 mm. On the one hand, the gap can block the energy generated when the welding ring is fixed to the outer peripheral wall of the pole body protruding from the lower plastic, preventing the energy from being transmitted to the lower plastic through the welding ring. Therefore, compared with technical solutions where the welding ring and the inner peripheral wall of the mounting groove are in contact everywhere or where there is a gap between them but the gap is not within the above-mentioned size range, the lower plastic in the top cover assembly of this technical solution is usually not damaged due to the fixing operation of the pole body, thus ensuring the yield of the top cover assembly. On the other hand, the gap within the above-mentioned size range will not affect the layout of other components on the top cover (such as the injection hole and the explosion-proof valve).

[0006] As an optional technical solution of this application, the inner peripheral wall of the mounting groove is provided with multiple ribs. These ribs protrude from the inner peripheral wall of the mounting groove towards the center of the mounting groove and are configured to contact the welding ring to define the position of the welding ring within the mounting groove. The ribs on the inner peripheral wall of the mounting groove can define the position of the welding ring when it is fitted onto the pole piece for welding, preventing misalignment of the welding ring and ensuring the yield rate of the top cover assembly.

[0007] As an optional technical solution of this application, in the thickness direction of the lower plastic, the contact height between the rib and the welding ring is at least 1 / 3 of the thickness of the welding ring, and the rib does not extend beyond the mounting groove.

[0008] In the thickness direction of the lower plastic, the contact height between the raised rib and the welding ring is at least 1 / 3 of the thickness of the welding ring, and the raised rib does not extend beyond the mounting groove. On the one hand, the raised rib can effectively limit the welding ring, preventing it from skewing during assembly, thereby ensuring the yield of the top cover assembly. On the other hand, the raised rib will not affect the assembly of other components (current collectors or electrode assemblies), ensuring a more aesthetically pleasing second side of the lower plastic.

[0009] As an optional technical solution of this application, the protruding rib includes a limiting surface that faces away from the inner peripheral wall of the mounting groove and towards the center of the mounting groove, and the welding ring includes an outer surface; the outer surface is configured as a plane, and the limiting surface is configured as a plane, so that the limiting surface contacts the outer surface. The contact between the outer surface of the welding ring and the limiting surface increases the degree of contact between the protruding rib and the welding ring. The protruding rib can effectively limit the welding ring, preventing it from skewing during assembly, thereby further ensuring the yield of the top cover assembly.

[0010] As an optional technical solution of this application, the rib includes a limiting surface that is away from the inner peripheral wall of the mounting groove and faces the center of the mounting groove, and the welding ring includes an outer surface; at least one of the outer surface and the limiting surface is configured as a curved surface, and the limiting surface contacts the outer surface line.

[0011] The limiting surface contacts the outer side line, which not only satisfies the contact degree between the rib and the welding ring, but also reduces the friction between the rib and the welding ring when the welding ring is assembled into the mounting groove, thus avoiding excessive friction that could cause scratches on the outer surface of the welding ring.

[0012] As an optional technical solution of this application, the hardness of the raised rib is less than that of the lower plastic. Because the hardness of the raised rib is less than that of the lower plastic, the raised rib will not scratch the welding ring when it is assembled into the mounting groove, thus ensuring an aesthetically pleasing appearance.

[0013] As an optional technical solution of this application, a plurality of the ribs are arranged around the axis of the pole body, and at least one rib is corresponding to each of the four sides of the welding ring. On the one hand, since there is a rib on each side of the welding ring, the ribs on all four sides can limit the welding ring when it is positioned, thus ensuring that the welding ring will not be skewed to the greatest extent. On the other hand, due to the existence of the gaps, when the welding ring is welded to the outer peripheral wall of the second end of the pole body, the heat generated by welding can still be blocked by the gaps and cannot be transferred to the lower plastic through the welding ring, thus preventing the lower plastic from melting and ensuring that the top cover assembly has a high yield.

[0014] As an optional technical solution of this application, with one rib corresponding to each side of the welding ring, the plurality of ribs are evenly distributed around the center of the mounting groove. In this way, the restraining force exerted by the ribs on the perimeter of the welding ring is uniform, which better ensures that the welding ring will not be skewed.

[0015] As an optional technical solution of this application, when at least two ribs are provided on each side of the welding ring, the at least two ribs on each side form a group, and multiple groups of ribs are evenly distributed around the center of the mounting groove. With at least two ribs provided on each side of the inner circumferential wall of the mounting groove, the restraining force applied by the ribs on each side to the corresponding side of the welding ring is more stable and uniform, thus better ensuring that the welding ring will not be skewed.

[0016] As an optional technical solution of this application, the free end of the rib away from the bottom surface of the mounting groove includes a guide surface. In the direction from the second side of the lower plastic to the bottom surface of the mounting groove, the distance between the guide surface and the inner peripheral wall gradually increases along the length of the top cover. The free end of the rib is chamfered. The guide surface acts as a guide when the welding ring is assembled into the mounting groove. Furthermore, when welding the welding ring to the first end of the pole piece, the chamfer prevents the rib from melting and being extruded from the second side of the lower plastic, thus avoiding significant aesthetic defects.

[0017] As an optional technical solution of this application, the first end of the pole piece is provided with a protrusion; the top cover assembly further includes an upper plastic and a sealing element. The upper plastic is sleeved on the pole piece and includes a first sub-part and a second sub-part that are in contact. The first sub-part is disposed on the first side of the top cover, and at least a portion of the first sub-part is sandwiched between the top cover and the protrusion in the thickness direction of the top cover. The second sub-part passes through the first through hole and the second through hole, and forms a receiving cavity with the inner wall of the second through hole. The sealing element surrounds the second sub-part and is received in the receiving cavity. In the thickness direction of the top cover, the sealing element is sandwiched between the top cover and the welding ring.

[0018] In the above technical solution, the top plastic has good insulation properties, which can prevent internal short circuits in the battery cell and improve the safety of the battery cell. The sealant can provide a good sealing effect, preventing electrolyte leakage from inside the battery cell, and also preventing external moisture and impurities from entering the battery cell.

[0019] Secondly, this application provides an energy storage device. The energy storage device includes the top cover assembly described in any of the above embodiments.

[0020] In the energy storage device of the above technical solution, the top cover assembly utilizes the gap between the welding ring and at least a portion of the inner peripheral wall of the mounting groove to block the energy generated when the welding ring is fixed to the outer peripheral wall of the pole body protruding from the lower plastic. This prevents the energy from being transferred to the lower plastic through the welding ring. Therefore, compared with the technical solution where the welding ring is in contact with the inner peripheral wall of the mounting groove at all points, the lower plastic in the top cover assembly of this technical solution is usually not damaged due to the fixing operation of the pole body, thereby ensuring the yield of the top cover assembly.

[0021] Thirdly, this application provides an electrical appliance. The electrical appliance includes the energy storage device described in any of the above embodiments.

[0022] In the electrical equipment described above, the top cover assembly utilizes the gap between the welding ring and at least a portion of the inner peripheral wall of the mounting groove to block the energy generated when the welding ring is fixed to the outer peripheral wall of the pole body protruding from the lower plastic. This prevents the energy from being transmitted to the lower plastic through the welding ring. Therefore, compared to technical solutions where the welding ring is in contact with the inner peripheral wall of the mounting groove at every point, the lower plastic in the top cover assembly of this technical solution is generally not damaged due to the fixing operation of the pole body, thus ensuring the yield of the top cover assembly.

[0023] 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

[0024] 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:

[0025] Figure 1 This is a three-dimensional assembly diagram of the top cover assembly according to some embodiments of this application;

[0026] Figure 2 for Figure 1 An exploded perspective view of the top cover assembly shown.

[0027] Figure 3 for Figure 1 An exploded perspective view of the top cover assembly shown below;

[0028] Figure 4 for Figure 3 Enlarged diagram of point IV in the middle;

[0029] Figure 5 for Figure 1 A top view of the top cover assembly shown;

[0030] Figure 6 for Figure 5 A cross-sectional view of the top cover assembly along line VI-VI is shown.

[0031] Figure 7 for Figure 6 Enlarged diagram of point VII in the middle;

[0032] Figure 8 for Figure 1 The top cover assembly shown is a bottom view.

[0033] Figure 9 for Figure 8 Enlarged view of point IX in the middle;

[0034] Figure 10 This is a three-dimensional assembly diagram of a battery cell according to some embodiments of this application;

[0035] Figure 11 for Figure 10 The diagram shows a three-dimensional exploded view of a single battery cell;

[0036] Figure 12 This is a three-dimensional structural diagram of a battery pack according to some embodiments of this application;

[0037] Figure 13 This is a schematic diagram of the planar structure of an electrical device according to some embodiments of this application.

[0038] The reference numerals in the detailed embodiments are as follows:

[0039] 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;

[0040] Top cover 11; First through hole 110; First side of top cover 111; Second side of top cover 113; First explosion-proof hole 115;

[0041] Lower plastic 12; second through hole 120; first side of lower plastic 121; second side of lower plastic 123; second explosion-proof hole 125; mounting groove 126; bottom surface 1261; inner peripheral wall 1263; gap 127; first inner side 12631; second inner side 12633; third inner side 12635; fourth inner side 12637; protruding rib 1265; guide surface 12651; limiting surface 12653;

[0042] 13 pole post; 131 pole post body; 1311 first end; 1313 second end; 1315 outer peripheral wall; 133 welding ring; 1330 outer surface; 1331 first outer side; 1333 second outer side; 1335 third outer side; 1337 fourth outer side; 135 protrusion;

[0043] 15mm plastic top; 155mm perforation; 151mm first sub-section; 153mm second sub-section; 150mm receiving cavity;

[0044] 16. Seal; 17. Explosion-proof valve; 30. Housing; 300. Battery box; 310. Box body; 330. Length direction X; Width direction Y; Thickness direction Z. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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).

[0051] 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.

[0052] 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.

[0053] Please refer to the following: Figures 1 to 3 The first aspect of this application provides a top cover assembly 10. The top cover assembly 10 includes a top cover 11, a lower plastic part 12, and a pole post 13. The top cover 11 includes a first side 111 and a second side 113 opposite to each other in the thickness direction Z, and is provided with a first through hole 110, which penetrates the first side 111 and the second side 113 of the top cover. The lower plastic part 12 is disposed on the second side 113 of the top cover, and includes a first side 121 and a second side 123 opposite to each other in the thickness direction Z. The first side 121 of the lower plastic part is opposite to the second side 113 of the top cover. The second side 123 of the lower plastic part is provided with a mounting groove 126. The lower plastic part 12 also has a second through hole 120, which penetrates the bottom surface 1261 of the mounting groove 126 and the first side 121 of the lower plastic part. The pole post 13 includes a pole post body 131 and a welding ring 133. The pole post body 131 has a first through hole 110 and a second through hole 120, and includes a first end 1311 and a second end 1313 opposite to each other. The first end 1311 of the pole post body 131 protrudes from the first side 111 of the top cover, and the second end 1313 of the pole post body 131 protrudes from the bottom surface 1261 of the mounting groove 126. The welding ring 133 is fixed to the outer peripheral wall 1315 of the second end 1313 of the pole post body 131 and is spaced apart from the inner peripheral wall 1263 of the mounting groove 126. The minimum distance between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 is greater than or equal to 1 mm and less than or equal to 11 mm.

[0054] Please combine Figure 10 and Figure 11The top cover assembly 10 is a component that covers the top opening of the housing 30 of the battery cell and provides a sealed space for the electrode assembly and electrolyte located inside the housing 30. The electrical energy of the electrode assembly can be led out to the outside through the top cover assembly 10.

[0055] Please refer to the following: Figure 2 , Figure 3 and Figure 11 The top cover 11 refers to a component that covers the opening of the housing 30 to isolate the internal environment of the battery cell from the external environment. In any case, 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 (the plane intercepted by a plane perpendicular to the thickness direction Z) 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 circular, square, polygonal, or other 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. This application uses a top cover 11 with a square cross-sectional shape for illustration. Optionally, the top cover 11 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the top cover 11 is less prone to deformation under pressure and impact, enabling the battery cell to have higher structural strength and higher safety performance. The first side 111 of the top cover faces the outside of the housing 30, and the second side 113 of the top cover faces the inside of the housing 30. The thickness direction Z of the top cover 11 refers to the direction in which the first side 111 of the top cover points to the second side 113 of the top cover, or vice versa. The thickness direction Z of the top cover 11 is also the height direction of the battery cell 100. The top cover 11 has a first through hole 110 that extends through the first side 111 and the second side 113 of the top cover along the thickness direction Z.

[0056] Please refer to the following: Figures 2 to 4 ,and Figure 11The lower plastic 12 is a component in the top cover assembly 10 that provides insulation. The lower plastic 12 is made of an insulating material, including but not limited to polypropylene, polyethylene, polyvinylidene fluoride, or polycarbonate. The lower plastic 12 is disposed on the second side 113 of the top cover. The lower plastic 12 includes a first side 121 and a second side 123 opposite to each other in the thickness direction Z. The first side 121 of the lower plastic faces the outside of the housing 30, and the second side 123 faces the inside of the housing 30. Therefore, the first side 121 of the lower plastic is opposite to the second side 113 of the top cover. The lower plastic 12 has good insulation properties, which can prevent internal short circuits in the battery cell 100 and improve the safety of the battery cell 100. More specifically, the lower plastic 12 is provided with a mounting groove 126 and a second through hole 120. The mounting groove 126 is recessed from the second side 123 of the lower plastic to the first side 121 of the lower plastic, and the second through hole 120 penetrates the bottom surface 1261 of the mounting groove 126 and the first side 121 of the lower plastic.

[0057] The terminal 13 is an external circuit used to conduct current from the electrode assembly to the outside of the battery cell 100 to output electrical energy from the electrode assembly, and also a functional component used to input electrical energy from outside the battery cell 100 into the electrode assembly. The terminal 13 passes through the top cover 11 from inside the battery cell 100 and extends to the outside of the top cover 11. The terminal 13 can be a positive terminal or a negative terminal.

[0058] Please refer to the following: Figure 2 , Figure 3 , Figures 5 to 7 In some embodiments, the pole post 13 includes a pole body 131 and a welding ring 133 connected to each other. The pole body 131 passes through a first through hole 110 and a second through hole 120, and includes a first end 1311 and a second end 1313 opposite to each other. The first end 1311 protrudes from a first side 111 opposite to the top cover. The second end 1313 extends from the second through hole 120 in a direction away from the top cover 11, and protrudes from the bottom surface 1261 of the mounting groove 126. The welding ring 133 is fixed to the outer peripheral wall 1315 of the second end 1313 and is spaced apart from the inner peripheral wall 1263 of the mounting groove 126. In other words, the welding ring 133 does not contact the inner peripheral wall 1263 of the mounting groove 126, and there is a gap 127 between them.

[0059] The welding ring 133 is a ring-shaped component used for electrical connection. The welding ring 133 can be a circular ring, a square ring, or other irregularly shaped ring structure; that is, the welding ring 133 has a hole in the middle, and its outer contour is circular, square, or other irregularly shaped. It should be noted that "irregularly shaped" in this application refers to an irregular shape, that is, a shape different from traditional regular shapes, such as circles, ellipses, squares (including rectangles and squares), isosceles triangles, equilateral triangles, regular pentagons, or regular hexagons. For example, an "irregularly shaped" shape can be an irregular pentagon (…). Figure 3 As shown), the shape can be an irregular hexagon or an irregular heptagon, etc. Correspondingly, the cross-section of the mounting groove 126 (the plane intercepted by the thickness direction Z perpendicular to the top cover 11) can also be circular, square, or other irregular shapes. In this application, the shape of the welding ring 133 is adapted to the shape of the cross-section of the mounting groove 126 to make the overall appearance of the top cover assembly 10 more aesthetically pleasing.

[0060] The minimum distance between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 is greater than or equal to 1 mm and less than or equal to 11 mm. That is, the gap 127 is greater than or equal to 1 mm and less than or equal to 11 mm. Specifically, the gap 127 can be any one or any two of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and 11 mm. If the gap is less than 1 mm, the gap is too small, and when the welding ring is welded and fixed to the outer peripheral wall of the pole body protruding from the lower plastic, the energy generated by welding will be transferred to the lower plastic and melt it. If the gap is greater than 11 mm, the gap is too large, which will make the entire mounting groove too large and affect the layout of other components on the top cover 11 (such as the injection hole and the explosion-proof valve).

[0061] In this technical solution, the top cover assembly 10 utilizes the gap 127 between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126. The value of the gap 127 is greater than or equal to 1 mm and less than or equal to 11 mm. On the one hand, the gap 127 can block the energy generated when the welding ring 133 is fixed to the outer peripheral wall 1315 of the pole piece 131 protruding from the lower plastic 12, so that the energy cannot be transmitted to the lower plastic 12 through the welding ring 133. Compared with technical solutions where the welding ring and the inner peripheral wall of the mounting groove are in contact everywhere or there is a gap between them but the gap is not within the above-mentioned size range, the lower plastic 12 in the top cover assembly 10 of this technical solution is usually not damaged due to the fixing operation of the pole piece 131, thereby ensuring the yield of the top cover assembly 10. On the other hand, the gap 127 within the above-mentioned size range will not affect the layout of other components on the top cover 11 (such as the injection hole and the explosion-proof valve).

[0062] As an optional technical solution of this application, all areas of the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 are spaced apart. In this way, the welding ring 133 does not contact the inner peripheral wall 1263 of the mounting groove 126 around its periphery. The energy generated when the welding ring 133 is fixed to the outer peripheral wall 1315 protruding from the lower plastic 12 by the pole post 131 can be completely blocked, which can protect the lower plastic 12 from damage due to the fixing operation of the pole post 131 to the greatest extent, thereby maximizing the yield of the top cover assembly 10.

[0063] Please see Figure 2 , Figure 6 and Figure 7 As an optional technical solution of this application, the welding ring 133 is welded to the outer peripheral wall 1315 of the second end 1313 of the pole body 131. In this way, a complete circle of weld marks is formed on the outer peripheral wall 1315 of the second end 1313 of the pole body 131.

[0064] The electrode post 131 and the welding ring 133 can be two independent single structures, connected together by a specific fixing connection method. There are many specific fixing connection methods, such as detachable fixing connections like threaded connections or snap-fit ​​connections, and non-detachable fixing connections like adhesive bonding, integral molding, or welding. This application uses welding to fix the welding ring 133 and the electrode post 131. This ensures the bonding strength between the welding ring 133 and the electrode post 131, preventing them from easily separating. Furthermore, since the electrode post 13 is used to transmit current, welding ensures the overall current transmission capacity of the electrode post 13. Moreover, compared to threaded or snap-fit ​​connections, the structure of the electrode post 131 is relatively simple, saving manufacturing costs. Compared to integral molding, the electrode post 13 is easier to insert into the top cover 11 and the lower plastic 12, facilitating the assembly of the top cover assembly 10.

[0065] Since the welding ring 133 is welded to the outer peripheral wall 1315 of the second end 1313 of the pole post 131, the energy generated when the welding ring 133 is fixed to the outer peripheral wall 1315 protruding from the lower plastic 12 of the pole post 131 is the heat generated during the welding process. During the welding process, the heat is blocked by the gap 127 between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126, and cannot be transferred to the lower plastic 12 through the welding ring 133. This can prevent the lower plastic 12 from melting and ensure that the top cover assembly 10 has a high yield.

[0066] Please refer to the following as well. Figure 2 , Figure 6 and Figure 7 As an optional technical solution of this application, the pole post 13 may further include a protrusion 135, which is fixed to the outer peripheral wall 1315 of the first end 1311 of the pole post 131. In this case, both the protrusion 135 and the welding ring 133 protrude outward relative to the pole post 131 along the radial direction of the pole post 131. In the thickness direction Z, the protrusion 135 protrudes from the first side 111 of the top cover.

[0067] The protrusion 135 is also a ring-shaped component that serves as an electrical connection. Similar to the welding ring 133, the protrusion 135 can also be a circular ring structure, a square ring structure, or other irregularly shaped ring structures. The pole body 131 and the protrusion 135 can also be two independent single structures connected together by a specific fixing connection method, which has been explained previously and will not be repeated here. Of course, the pole body 131 and the protrusion 135 can also be made of the same raw material and formed into two interconnected parts by stamping or cold forging processes. This results in a pole 13 with protruding ends and a concave middle.

[0068] Furthermore, the top cover assembly 10 also includes a current collector, which is a functional component used to electrically connect the electrode assembly and the terminal 13 inside the battery cell 100, so as to conduct the current in the electrode assembly to the outside of the battery cell 100 or to introduce external current into the battery cell 100. Typically, the current collector is made of a conductive material to facilitate current conduction. The current collector can be made of metals such as aluminum and copper, or other conductive materials such as aluminum alloys and copper alloys. The current collector includes a positive current collector and a negative current collector. The positive current collector is used to electrically connect the positive terminal 13 and the electrode tab of the electrode assembly, and the negative current collector is used to electrically connect the negative terminal 13 and the electrode tab of the electrode assembly. Additionally, the current collector in this application can be a bent current collector or a non-bent current collector. A bent current collector includes at least one bend, and its extension direction lies in multiple planes; for example, an S-shaped current collector has three extension planes. Non-bending manifolds do not contain bends, and their extension direction lies in a plane, such as disc-shaped manifolds.

[0069] The current is transmitted from the inside of the battery cell 100 to the outside in the following order: the current of the electrode assembly is transmitted to the current collector through the tab, the current collector is transmitted to the second end 1313 of the terminal 131 and the welding ring 133, and the terminal 131 and the welding ring 133 are transmitted to the external circuit through the bump 135 or the first end 1311 of the terminal 131 to realize the discharge of the battery cell 100 to the outside; the current is transmitted from the outside of the battery cell 100 to the inside in the following order: the current of the external circuit is transmitted to the second end 1313 of the terminal 131 through the bump 135 or the first end 1311 of the terminal 131, and the current of the second end 1313 of the terminal 131 and / or the welding ring 133 is transmitted to the tab through the current collector, thereby reaching the electrode assembly to realize the charging of the battery cell 100.

[0070] The external circuit of the battery cell 100 is typically made of aluminum to reduce cost and weight. Therefore, the connection between the external circuit and the battery cell 100 generally uses aluminum sheets. In one embodiment, inside the battery cell 100, the positive current collector is made of aluminum foil, and the negative current collector is made of copper foil. Therefore, the positive electrode post 13 must be made of aluminum and the negative electrode post 13 of copper to ensure the performance of the battery cell 100. Based on this requirement, the positive electrode post 13 can be made entirely of aluminum. The negative electrode post 13 can be a composite post 13 formed of copper and aluminum, with the copper portion of the negative electrode post 13 closer to the side with the current collector to ensure conductivity with it, while the aluminum portion is closer to the side away from the current collector. Aluminum is cheaper than copper, and the copper-aluminum composite negative electrode post 13 has a lower cost.

[0071] Please see Figure 2 , Figure 6 and Figure 7 As an optional technical solution in this application, the welding ring 133 is made of the same material as the second end 1313 of the electrode 131. When the electrode 13 is a positive electrode, the second end 1313 of the electrode 131 is made of aluminum, and therefore the welding ring 133 is also made of aluminum. When the electrode 13 is a negative electrode, the second end 1313 of the electrode 131 is made of copper, and therefore the welding ring 133 is also made of copper. The fact that the welding ring 133 is made of the same material as the second end 1313 of the electrode 131 ensures the overall current carrying capacity of the electrode 13, thereby guaranteeing its overcurrent capability.

[0072] Please see Figure 4 As an optional technical solution of this application, the inner peripheral wall 1263 of the mounting groove 126 is provided with a plurality of protruding ribs 1265. The plurality of protruding ribs 1265 protrude from the inner peripheral wall 1263 of the mounting groove 126 toward the center of the mounting groove 126. The plurality of protruding ribs 1265 are configured to contact the welding ring 133 to limit the position of the welding ring 133 in the mounting groove 126.

[0073] The rib 1265 is a protruding structure that protrudes from the inner peripheral wall 1263 of the mounting groove 126 toward the center of the mounting groove 126. As mentioned above, since the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 are spaced apart, if the gap 127 between them is too large, when the welding ring 133 is fitted onto the outer peripheral wall 1315 of the second end 1313 of the pole piece 131 for welding, assembly misalignment is likely to occur, resulting in poor appearance of the top cover assembly 10. In this embodiment, the inner peripheral wall 1263 of the mounting groove 126 is provided with a rib 1265. The rib 1265 can limit the position of the welding ring 133 when it is fitted onto the pole piece 131 for welding, which can prevent the welding ring 133 from being assembled misaligned and ensure the yield of the top cover assembly 10.

[0074] Please continue reading. Figure 4 As an optional technical solution of this application, in the thickness direction Z of the lower plastic 12, the contact height between the rib 1265 and the welding ring 133 is at least 1 / 3 of the thickness of the welding ring 133, and the rib 1265 does not exceed the mounting groove 126.

[0075] As mentioned earlier, the rib 1265 is used to define the position of the welding ring 133 in the mounting groove 126, and since the rib 1265 is in contact with the welding ring 133, the degree of contact between the two plays a crucial role in defining the position. If the contact height between the rib 1265 and the welding ring 133 in the thickness direction Z of the lower plastic 12 is less than 1 / 3 of the thickness of the welding ring 133, the degree of contact is too low, and the rib 1265 cannot define the welding ring 133, thus failing to ensure that the welding ring 133 does not become misaligned during assembly. Simultaneously, the dimension of the rib 1265 in the thickness direction Z of the lower plastic 12 cannot be too large. If it is too large, for example, if the rib 1265 extends beyond the mounting groove 126 (with a protruding portion from the mounting groove 126), the rib 1265 will affect the assembly of other components (current collectors or electrode assemblies), and the second side 123 of the lower plastic will also be aesthetically unpleasing.

[0076] Therefore, in the thickness direction Z of the lower plastic 12, the contact height between the rib 1265 and the welding ring 133 is at least 1 / 3 of the thickness of the welding ring 133, and the rib 1265 does not extend beyond the mounting groove 126. On the one hand, the rib 1265 can effectively limit the welding ring 133, preventing it from skewing during assembly, thus ensuring the yield of the top cover assembly. On the other hand, the rib 1265 will not affect the assembly of other components (current collectors or electrode assemblies), ensuring a more aesthetically pleasing second side 123 of the lower plastic.

[0077] Please see Figure 2 and Figure 4As an optional technical solution of this application, the rib 1265 includes a limiting surface 12653 that faces away from the inner peripheral wall 1263 of the mounting groove 126 and towards the center of the mounting groove 126, and the welding ring 133 includes an outer surface 1330. In some embodiments, the outer surface 1330 is configured as a plane, and the limiting surface 12653 is configured as a plane, so that the limiting surface 12653 contacts the outer surface 1330. For example, if the rib 1265 is a cuboid structure and the welding ring 133 is a square ring structure, then the outer surface 1330 is a rectangular or rectangular plane, and the limiting surface 12653 is a rectangular or rectangular plane.

[0078] The outer surface 1330 of the welding ring 133 contacts the limiting surface 12653, which can increase the contact degree between the rib 1265 and the welding ring 133. The rib 1265 can effectively limit the welding ring 133, which can prevent the welding ring 133 from being skewed during assembly, thereby further ensuring the yield of the top cover assembly.

[0079] In other embodiments, at least one of the outer surface 1330 and the limiting surface 12653 of the welding ring 133 is configured as a curved surface, and the limiting surface 12653 is in line contact with the outer surface 1330. In one example, the limiting surface 12653 is a curved surface, and the outer surface 1330 can be either a plane or a curved surface. For example, the rib 1265 is a cylindrical structure, and the limiting surface 12653 is the circumferential surface of the cylinder. As another example, the rib 1265 is a semi-cylindrical structure, and the limiting surface 12653 is the circumferential surface of the semi-cylindrical structure. In this case, the welding ring 133 can be the aforementioned circular ring structure, square ring structure, or other irregular ring structure. In another example, the outer surface 1330 is a curved surface, and the limiting surface 12653 can be either a plane or a curved surface. For example, the welding ring 133 is a circular ring structure, and the outer surface 1330 is the circumferential surface of the circular ring structure. At this time, the limiting surface 12653 can be the aforementioned rectangular plane, triangular plane, or other polygonal plane.

[0080] The limiting surface 12653 is in line contact with the outer surface 1330. While satisfying the contact degree between the rib 1265 and the welding ring 133, it can also reduce the friction between the rib 1265 and the welding ring 133 when the welding ring 133 is assembled into the mounting groove 126, and avoid excessive friction causing scratches on the appearance of the outer surface 1330 of the welding ring 133.

[0081] As an optional technical solution in this application, the hardness of the raised rib 1265 is less than the hardness of the lower plastic 12. The material of the raised rib 1265 can be different from that of the lower plastic 12; for example, the raised rib 1265 can be made of soft rubber, while the lower plastic 12 is made of hard plastic. Because the hardness of the raised rib 1265 is less than that of the lower plastic 12, the raised rib 1265 will not scratch the welding ring 133 when it is assembled into the mounting groove 126, thus ensuring an aesthetically pleasing appearance.

[0082] Please see Figure 8 and Figure 9 As an optional technical solution of this application, a plurality of ribs 1265 are arranged around the axis of the pole body 131, and at least one rib 1265 is respectively arranged around the perimeter of the welding ring 133.

[0083] If we establish a coordinate system with its center as the center point, the length direction of the top cover 11 as the X-axis, and the width direction of the top cover 11 as the Y-axis, then the perimeter of the welding ring 133 refers to the two sides opposite each other along the X-axis and the two sides opposite each other along the Y-axis. Specifically, regardless of the shape of the outer contour of the welding ring 133, the perimeter of the welding ring 133 corresponds to a first outer side 1331, a second outer side 1333, a third outer side 1335, and a fourth outer side 1337. The first outer side 1331 and the third outer side 1335 are opposite sides of the welding ring 133 along the length direction X of the top cover 11, and the first outer side 1331 is closer to the edge of the top cover 11 than the third outer side 1335. The second outer side 1333 and the fourth outer side 1337 are opposite sides of the welding ring 133 along the width direction Y of the top cover 11. Correspondingly, the mounting groove 126 has a first inner side 12631, a second inner side 12633, a third inner side 12635, and a fourth inner side 12637 around its perimeter. The first inner side 12631 and the third inner side 12635 are opposite sides of the mounting groove 126 in the length direction X of the top cover 11, and the first inner side 12631 is closer to the edge of the top cover 11 than the third inner side 12635. The second inner side 12633 and the fourth inner side 12637 are opposite sides of the welding ring 133 in the width direction Y of the top cover 11. The first inner side 12631 is opposite to the first outer side 1331, the second inner side 12633 is opposite to the second outer side 1333, the third inner side 12635 is opposite to the third outer side 1335, and the fourth inner side 12637 is opposite to the fourth outer side 1337. At least one raised rib 1265 is provided on each of the four sides of the welding ring 133. That is, at least one raised rib 1265 is provided on the first inner side 12631, the second inner side 12633, the third inner side 12635 and the fourth inner side 12637 of the mounting groove 126. The first outer side 1331, the second outer side 1333, the third outer side 1335 and the fourth outer side 1337 of the welding ring 133 correspond to the raised rib 1265 of the first inner side 12631, the second inner side 12633, the third inner side 12635 and the fourth inner side 12637 respectively.

[0084] In one example, "corresponding" means that the first outer side 1331, the second outer side 1333, the third outer side 1335, and the fourth outer side 1337 of the welding ring 133 are respectively spaced from the ribs 1265 of the first inner side 12631, the second inner side 12633, the third inner side 12635, and the fourth inner side 12637. At this time, on the one hand, each of the four sides of the welding ring 133 corresponds to a rib 1265. When the welding ring 133 is limited, the ribs 1265 on all four sides play a limiting role in the welding ring 133, which can ensure that the welding ring 133 will not be skewed to the greatest extent. On the other hand, due to the existence of the gap, when the welding ring 133 is welded to the outer peripheral wall 1315 of the second end 1313 of the pole piece 131, the heat generated by welding can still be blocked by the gap and cannot be transferred to the lower plastic 12 through the welding ring 133, which can still prevent the lower plastic 12 from melting and ensure that the top cover assembly 10 has a high yield. In another example, "corresponding" means that the first outer side 1331, the second outer side 1333, the third outer side 1335, and the fourth outer side 1337 of the welding ring 133 respectively abut against the ribs 1265 of the first inner side 12631, the second inner side 12633, the third inner side 12635, and the fourth inner side 12637. At this point, on the one hand, the welding ring 133 is in contact with a rib 1265 on all four sides. At the beginning of assembling the welding ring 133 to the outer peripheral wall 1315 of the first end 1311 of the pole piece 131, the ribs 1265 on all four sides can restrict the assembly space, ensuring that the welding ring 133 will not be skewed during the installation process. On the other hand, although the welding ring 133 is in contact with the ribs 1265 on all four sides, there are still gaps in the area of ​​the inner peripheral wall 1263 of the mounting groove 126 other than the ribs 1265. When the welding ring 133 is welded to the outer peripheral wall 1315 of the second end 1313 of the pole piece 131, these gaps can still prevent the heat generated by welding from being transferred to the lower plastic 12 through the welding ring 133, which can reduce the probability of the lower plastic 12 melting and ensure that the top cover assembly 10 has a high yield.

[0085] Please see Figure 8 and Figure 9 As an optional technical solution of this application, with one rib 1265 corresponding to each side of the welding ring 133, the multiple ribs 1265 are evenly distributed around the center of the mounting groove 126. In this way, the restraining force applied by the ribs 1265 around the welding ring 133 is uniform, which can better ensure that the welding ring 133 will not be skewed.

[0086] Please see Figure 8 and Figure 9As an optional technical solution of this application, when at least two ribs 1265 correspond to each side of the welding ring 133, the at least two ribs 1265 on each side form a group, and multiple groups of ribs 1265 are evenly distributed around the center of the mounting groove 126. Figure 9 As shown, the first inner side 12631, the second inner side 12633, the third inner side 12635, and the fourth inner side 12637 of the mounting groove 126 are each provided with two protruding ribs 1265. The two protruding ribs 1265 of the first inner side 12631 are the first group of protruding ribs 1265, the two protruding ribs 1265 of the second inner side 12633 are the second group of protruding ribs 1265, the two protruding ribs 1265 of the third inner side 12635 are the third group of protruding ribs 1265, and the two protruding ribs 1265 of the fourth inner side 12637 are the fourth group of protruding ribs 1265. The first group of protruding ribs 1265, the second group of protruding ribs 1265, the third group of protruding ribs 1265, and the fourth group of protruding ribs 1265 are uniformly distributed around the center of the mounting groove 126 as a whole. Each side of the inner peripheral wall 1263 of the mounting groove 126 is provided with at least two ribs 1265, so that the restraining force applied by the ribs 1265 on the corresponding side of the welding ring 133 is more stable and uniform, and the welding ring 133 can be better guaranteed not to be skewed.

[0087] Please see Figure 4 As an optional technical solution of this application, the free end of the rib 1265 away from the bottom surface 1261 of the mounting groove 126 includes a guide surface 12651. In the direction from the second side 123 of the lower plastic to the bottom surface 1261 of the mounting groove 126 (upward in the thickness direction Z of the top cover 11), the distance between the guide surface 12651 and the inner peripheral wall 1263 gradually increases in the length direction of the top cover 11. That is, the free end of the rib 1265 is provided with a chamfer. The guide surface 12651 plays a guiding role when the welding ring 133 is assembled into the mounting groove 126. Moreover, when welding the welding ring 133 to the first end 1311 of the pole piece 131, the chamfer can prevent the rib 1265 from being melted and extruded from the second side 123 of the lower plastic, causing obvious appearance defects.

[0088] Please refer to the following: Figure 2 , Figure 6 and Figure 7As an optional technical solution of this application, the first end 1311 of the pole piece 131 is provided with a protrusion 135; the top cover assembly 10 also includes an upper plastic 15 and a sealing member 16. The upper plastic 15 is sleeved on the pole piece 131 and includes a first sub-part 151 and a second sub-part 153 that are in contact. The first sub-part 151 is disposed on the first side 111 of the top cover, and at least a portion of the first sub-part 151 is sandwiched between the top cover 11 and the protrusion 135 in the thickness direction Z of the top cover 11. The second sub-part 153 passes through the first through hole 110 and the second through hole 120, and forms a receiving cavity 150 between the second through hole 120 and the inner wall of the second through hole 120. The sealing member 16 surrounds the second sub-part 153 and is received in the receiving cavity 150. In the thickness direction Z of the top cover 11, the sealing member 16 is sandwiched between the top cover 11 and the welding ring 133.

[0089] The upper plastic 15 is a component in the top cover assembly 10 that provides insulation. The upper plastic 15 is made of an insulating material, including but not limited to polypropylene, polyethylene, polyvinylidene fluoride, or polycarbonate. The upper plastic 15 has good insulation properties, preventing internal short circuits in the battery cell 100 and improving the safety of the battery cell 100. Furthermore, the upper plastic 15 and the lower plastic 12 are both components in the top cover assembly 10 that provide insulation, but they can be made of the same insulating material or different insulating materials. The upper plastic 15 is disposed on the first side 111 of the top cover and sandwiched between the top cover 11 and the protrusion 135. That is, the upper plastic 15 is used to support the protrusion 135. In some embodiments, the upper plastic 15 includes two contiguous parts, a first sub-part 151 and a second sub-part 153, with the first sub-part 151 disposed on the first side 111 of the top cover. In addition, the upper plastic 15 has a through hole 155 that passes through the first sub-part 151 and the second sub-part 153, and the pole post 13 also passes through the through hole 155.

[0090] To prevent electrolyte leakage inside the battery cell 100, the top cover assembly 10 is also provided with a seal 16, which surrounds the second sub-part 153 and is housed in the receiving cavity 150. In the thickness direction Z of the top cover 11, the seal 16 is sandwiched between the top cover 11 and the welding ring 133. Therefore, the seal 16 provides 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.

[0091] The welding ring 133 is welded to the outer peripheral wall 1315 of the second end 1313 of the electrode post 131, thus forming a complete weld mark at the mating position of the welding ring 133 and the electrode post 131. Welding the welding ring 133 to the outer peripheral wall 1315 of the second end 1313 of the electrode post 131 allows for control of the compression of the seal 16, ensuring that the compression of the seal 16 is within a suitable range, guaranteeing the sealing effect of the seal 16, and thus ensuring the safety of the battery cell 100 in use.

[0092] Furthermore, the top cover 11 is also provided with a first explosion-proof hole 115, which is a through hole penetrating the first side 111 and the second side 113 of the top cover, and is spaced apart from the first through hole 110. The lower plastic 12 is also provided with a second explosion-proof hole 125, which is a through hole penetrating the first side 121 and the second side 123 of the lower plastic, and is spaced apart from the second through hole 120, and corresponds to and communicates with the first explosion-proof hole 115. Furthermore, the top cover assembly 10 also includes an explosion-proof valve 17, which is installed in the first 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, the explosion-proof valve 17 will burst open to release internal pressure when the gas pressure accumulates to the threshold of the explosion-proof valve 17, thereby ensuring the safety of battery use.

[0093] Please see Figures 10 to 12 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.

[0094] Specifically, the energy storage device can be a single battery cell 100 ( Figure 10 and Figure 11 As shown), it can also be a battery pack 1000 composed of one or more battery cells 100. Figure 12 As 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.

[0095] Please see Figure 12When 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.

[0096] Please see Figure 2 , Figure 3 , Figure 10 and Figure 11 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 (the plane intercepted by a plane perpendicular to the thickness direction Z) may, but is not limited to, be circular, elliptical, square, or other polygonal. The material of the housing 30 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 housing 30 is square, which facilitates integration into a square 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.

[0097] A battery cell 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 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 the 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.

[0098] The battery box 300 is a structure for holding individual battery cells 100. The cross-section of the battery box 300 (the plane intercepted by a plane perpendicular to the thickness direction Z) may, but is not limited to, be circular, elliptical, square, or other polygonal. 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.

[0099] 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, adhesive connections, welding, or a combination of adhesive connections and welding connections. In this application, the box body 310 and the cover 330 are detachably connected.

[0100] 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.

[0101] In the energy storage device of the above technical solution, the top cover assembly 10 utilizes the gap between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126, and the value of the gap 127 is greater than or equal to 1 mm and less than or equal to 11 mm. On the one hand, the gap 127 can block the energy generated when the welding ring 133 is fixed to the outer peripheral wall 1315 protruding from the lower plastic 12, so that the energy cannot be transmitted to the lower plastic 12 through the welding ring 133. Therefore, compared with the technical solution where the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 are in contact everywhere or there is a gap between them but the gap is not within the above size range, the lower plastic 12 in the top cover assembly 10 of this technical solution is usually not damaged due to the fixing operation of the pole 131, thereby ensuring the yield of the top cover assembly 10. On the other hand, the gap 127 within the above size range will not affect the layout of other components (such as injection holes and explosion-proof valves) on the top cover 11.

[0102] Please see Figure 2 , Figure 3 and Figure 13 This application provides an electrical appliance 10000. The electrical appliance 10000 includes an energy storage device.

[0103] 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.

[0104] 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.

[0105] In the electrical equipment 10000 of the above technical solution, the top cover assembly 10 utilizes the gap between the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126, and the value of the gap 127 is greater than or equal to 1 mm and less than or equal to 11 mm. On the one hand, the gap 127 can block the energy generated when the welding ring 133 is fixed to the outer peripheral wall 1315 protruding from the lower plastic 12, so that the energy cannot be transmitted to the lower plastic 12 through the welding ring 133. Therefore, compared with the technical solution where the welding ring 133 and the inner peripheral wall 1263 of the mounting groove 126 are in contact everywhere or there is a gap between them but the gap is not within the above-mentioned size range, the lower plastic 12 in the top cover assembly 10 of this technical solution is usually not damaged due to the fixing operation of the pole 131, thereby ensuring the yield of the top cover assembly 10. On the other hand, the gap 127 within the above-mentioned size range will not affect the layout of other components (such as injection holes and explosion-proof valves) on the top cover 11.

[0106] 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 the thickness direction, and is provided with a first through hole that penetrates the first side and the second side of the top cover; A lower plastic insert, disposed on the second side of the top cover, includes a first side and a second side opposite to each other in the thickness direction. The first side of the lower plastic insert is opposite to the second side of the top cover. The second side of the lower plastic insert has a mounting groove. The lower plastic insert also has a second through hole, which penetrates the bottom surface of the mounting groove and the first side of the lower plastic insert. The electrode post includes an electrode body and a welding ring. The electrode body passes through the first through hole and the second through hole, and includes a first end and a second end opposite to each other. The first end of the electrode body protrudes from the first side of the top cover, and the second end of the electrode body protrudes from the bottom surface of the mounting groove. The welding ring is welded to the outer peripheral wall of the second end of the electrode body and is spaced apart from the inner peripheral wall of the mounting groove. The minimum distance between the welding ring and the inner peripheral wall of the mounting groove is greater than or equal to 1 mm and less than or equal to 11 mm.

2. The top cover assembly according to claim 1, characterized in that, The inner peripheral wall of the mounting groove is provided with a plurality of ribs, which protrude from the inner peripheral wall of the mounting groove toward the center of the mounting groove. The plurality of ribs are configured to contact the welding ring to define the position of the welding ring in the mounting groove.

3. The top cover assembly according to claim 2, characterized in that, In the thickness direction of the lower plastic, the contact height between the rib and the welding ring is at least 1 / 3 of the thickness of the welding ring, and the rib does not extend beyond the mounting groove.

4. The top cover assembly according to claim 2, characterized in that, The rib includes a limiting surface that is away from the inner peripheral wall of the mounting groove and faces the center of the mounting groove, and the welding ring includes an outer surface. The outer surface is configured as a plane, and the limiting surface is configured as a plane such that the limiting surface contacts the outer surface; or, At least one of the outer surface and the limiting surface is configured as a curved surface, and the limiting surface contacts the outer surface line.

5. The top cover assembly according to claim 2, characterized in that, The hardness of the raised rib is less than the hardness of the lower plastic.

6. The top cover assembly according to claim 2, characterized in that, Multiple ribs are arranged around the axis of the pole body, and at least one rib corresponds to each of the four sides of the welding ring; With one rib corresponding to each side of the welding ring, the plurality of ribs are evenly distributed around the center of the mounting groove; or, With at least two ribs corresponding to each side of the welding ring, the at least two ribs on each side form a group, and multiple groups of ribs are evenly distributed around the center of the mounting groove.

7. The top cover assembly according to claim 2, characterized in that, The free end of the rib away from the bottom surface of the mounting groove includes a guide surface. In the direction from the second side of the lower plastic to the bottom surface of the mounting groove, the distance between the guide surface and the inner peripheral wall in the length direction of the top cover gradually increases.

8. The top cover assembly according to claim 1, characterized in that, The first end of the pole piece is provided with a protrusion; the top cover assembly further includes: A plastic sleeve is fitted onto the electrode body and includes a first sub-part and a second sub-part that are in contact with each other. The first sub-part is disposed on a first side of the top cover, and at least a portion of the first sub-part is sandwiched between the top cover and the protrusion in the thickness direction of the top cover. The second sub-part passes through the first through hole and the second through hole, and forms an accommodating cavity with the second through hole. A seal surrounds the second sub-part and is housed within the receiving cavity, the seal being sandwiched between the top cover and the welding ring in the thickness direction of the top cover.

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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