End cover assembly, battery monomer and battery

Abstract

The utility model relates to an end cover assembly, a battery monomer and a battery. The end cover assembly comprises a base body which is provided with a mounting hole in a penetrating manner along the thickness direction; the electrode terminal comprises a body part and a first flanging part which are connected, the body part is arranged in the mounting hole in a penetrating manner and is in sealed connection with the mounting hole, and the first flanging part is arranged on the side, back on to the interior of the shell, of the base body; the riveting piece is arranged on the side, back on to the interior of the shell, of the base body and connected between the first flanging part and the base body in a sealed mode, a riveting groove is formed in the side, facing the first flanging part, of the riveting piece, and at least part of the first flanging part is contained and limited in the riveting groove. According to the end cover assembly, the battery monomer and the battery provided by the invention, the use safety can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to an end cover assembly, a battery cell and a battery. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] A battery includes battery cells. In the related art, the safety of using battery cells is not high, resulting in a reduced user experience. Summary of the Utility Model

[0004] Based on this, in view of the above problems, it is necessary to provide an end cover assembly, a battery cell and a battery that can improve the safety of use.

[0005] An end cover assembly, the end cover assembly includes:

[0006] A base body, which is provided with a mounting hole penetrating along its thickness direction;

[0007] An electrode terminal, including a connected body portion and a first flanging portion, the body portion is inserted through the mounting hole and is hermetically connected to the mounting hole, and the first flanging portion is arranged on the side of the base body facing away from the inside of the housing; and

[0008] A riveting member, which is arranged on the side of the base body facing away from the inside of the housing and is hermetically connected between the first flanging portion and the base body. A riveting groove is formed on the side of the riveting member facing the first flanging portion, and at least a part of the first flanging portion is received and limited in the riveting groove.

[0009] In some embodiments, the riveting groove is an annular groove and is arranged around the outer periphery of the body portion; the first flanging portion includes a first ring portion, an intermediate ring portion and a second ring portion. The intermediate ring portion is connected between the first ring portion and the second ring portion. The second ring portion sinks towards the base body compared with the first ring portion, and the intermediate ring portion and the second ring portion are received in the riveting groove.

[0010] In some embodiments, a groove is defined among the body portion, the first ring portion and the intermediate ring portion;

[0011] The riveting part includes an inner riveting part, an intermediate riveting part, and an outer riveting part that are connected in sequence. The inner riveting part is fitted into the groove. The intermediate riveting part is connected between the inner riveting part and the outer riveting part, and the intermediate riveting part sinks towards the base relative to the inner riveting part and the outer riveting part. The top surface of the intermediate riveting part, the outer side surface where the inner riveting part is connected to the top surface of the intermediate riveting part, and the inner side surface where the outer riveting part is connected to the top surface of the intermediate riveting part define the riveting groove.

[0012] In some embodiments, the inner riveting part sinks towards the base relative to the outer riveting part, and the height difference between the top surface of the inner riveting part and the top surface of the intermediate riveting part is L, where 0.2 mm ≤ L ≤ 2 mm.

[0013] In some embodiments, the inner riveting part sinks towards the base relative to the outer riveting part, the first ring part overlaps on the inner riveting part, and the top surface of the first ring part is lower than or flush with the top surface of the outer riveting part. The top surface of at least one of the first ring part and the outer riveting part is connected to the current collecting component.

[0014] In some embodiments, the maximum thickness of the riveting part is H, where H > 1 mm;

[0015] The first ring part and the inner riveting part are welded along the thickness direction of the base to form a first molten pool, and the penetration depth of the first molten pool is H1, where 1H / 5 < H1 < 2H / 3 and H1 > 0.2 mm; and / or

[0016] The second ring part and the intermediate riveting part are welded along the thickness direction of the base to form a second molten pool, and the penetration depth of the second molten pool is H2, where 1H / 5 < H2 < 2H / 3 and H2 > 0.2 mm; and / or

[0017] The outer side surface of the second ring part and the inner side surface of the outer riveting part are welded along the thickness direction of the base to form a third molten pool, and the penetration depth of the third molten pool is H3, where 0.3 mm < H3 < 1.5 mm and H3 > 0.2 mm.

[0018] In some embodiments, the weld width of at least one of the first molten pool, the second molten pool, and the third molten pool is W, where 0.2 mm < W < 2 mm.

[0019] In some embodiments, a rounded corner is provided at the connection between the top surface of the inner riveting part and the outer side surface of the inner riveting part, and the radius of the rounded corner is r, where 0.2 mm < r < 1 mm.

[0020] In some of these embodiments, the outer diameter of the body portion is D1, the outer diameter of the second ring portion is D2, and the thickness of the first ring portion is L1; 1.5L1 ≤ (D2 - D1) / 2 ≤ 8L1.

[0021] In some of these embodiments, the electrode terminal includes a second flanging portion, and the second flanging portion is disposed on a side of the base facing the interior of the housing and is arranged around the outer periphery of the body portion;

[0022] The thickness of the first ring portion is L1, and the thickness of the second flanging portion is L2, 1 ≤ L2 / L1 ≤ 3, 0.5 mm ≤ L2 ≤ 2 mm.

[0023] In some of these embodiments, the outer diameter of the body portion is D1, and the outer diameter of the second flanging portion is D3, 1.5L2 ≤ (D3 - D1) / 2 ≤ 10L2.

[0024] In some of these embodiments, the bottom surface of the second flanging portion and the body portion facing the interior of the housing are flush.

[0025] In some of these embodiments, the body portion is a hollow structure with one end open and the other end closed, and the opening of the body portion is located on the end face of the body portion facing away from the interior of the housing.

[0026] In some of these embodiments, the electrode terminal includes a second flanging portion, and the second flanging portion is disposed on a side of the base facing the interior of the housing and is arranged around the outer periphery of the body portion;

[0027] The end cap assembly further includes a first insulating member and a second insulating member. The first insulating member is disposed on a side of the base facing away from the interior of the housing, and the first insulating member is sealingly connected between the riveting member and the base. The second insulating member is disposed on a side of the base facing the interior of the housing, and the second insulating member is sealingly connected between the second flanging portion and the base.

[0028] In some of these embodiments, the first insulating member has a limiting groove, and a plurality of limiting protrusions are formed by the protrusion of the groove bottom wall of the limiting groove. All the limiting protrusions are arranged around the outer periphery of the body portion;

[0029] A plurality of limiting recesses are formed on a side of the riveting member facing the first insulating member. The limiting recesses correspond to the limiting protrusions one by one. The riveting member is limited in the limiting groove, and the limiting protrusions are fitted with the corresponding limiting recesses.

[0030] In some of these embodiments, the electrode terminal includes a second flanging portion, and the second flanging portion is disposed on a side of the base facing the interior of the housing and is arranged around the outer periphery of the body portion;

[0031] The end cap assembly further includes a seal, the seal is disposed through the mounting hole, and the seal seals between the hole wall of the mounting hole and the outer side wall of the body portion.

[0032] A battery cell, the battery cell includes:

[0033] A housing, which is a hollow structure with at least one open end; and

[0034] The end cap assembly as described in any one of the above embodiments, the base of the end cap assembly covers the opening of the housing.

[0035] A battery, including the battery cell as described in the above embodiments.

[0036] For the above end cap assembly, battery cell and battery, by designing a riveting groove on the riveting part, at least part of the first flanging part is received and limited in the riveting groove, which increases the contact area between the riveting part and the first flanging part, and can improve the stability and reliability of the cooperation between the riveting part and the first flanging part. Moreover, the electrode terminal is also more closely matched with the riveting part, so that the risk of relative rotation between the motor terminal and the riveting part is reduced. In this way, external water vapor is also difficult to enter the housing through the gap between the riveting part and the first flanging part, and the electrolyte inside the housing cannot leak to the outside through the gap between the riveting part and the first flanging part, thus finally achieving the purpose of improving the safety of the battery cell. In addition, the design of the riveting groove also increases the heat dissipation area of the riveting part. Therefore, when the heat inside the battery cell is transferred to the riveting part through the tab and the electrode terminal, the heat can be dissipated in a timely and rapid manner through the riveting part, and the heat dissipation effect is good, reducing the risk of thermal runaway of the battery cell and further improving the safety of using the battery cell. Description of the Drawings

[0037] Figure 1 It is an exploded view of an end cap assembly cooperating with a housing with two open ends in an embodiment of the present application;

[0038] Figure 2 It is Figure 1 The exploded view of the end cap assembly shown;

[0039] Figure 3 It is Figure 1 The sectional view of the end cap assembly shown after cooperation and in the first perspective;

[0040] Figure 4 It is Figure 3 The marked drawing of the end cap assembly shown;

[0041] Figure 5 It is an exploded view of an end cap assembly cooperating with a housing with one open end and one closed end in an embodiment of the present application;

[0042] Figure 6 for Figure 5 a bottom view of the end cap assembly shown;

[0043] Figure 7 for Figure 5 A cross-sectional view of the end cap assembly after assembly and at a first viewing angle is shown;

[0044] Figure 8 for Figure 2 or Figure 5 A cross-sectional view of an electrode terminal in the end cap assembly shown in a first viewing angle;

[0045] Figure 9 for Figure 8 A labeled diagram of the electrode terminals shown;

[0046] Figure 10 for Figure 2 or Figure 5 The rivet in the end cap assembly is shown in a cross-sectional view at a first viewing angle.

[0047] Figure Number:

[0048] 1. Battery monomer;

[0049] 10. end cover assembly; 20. housing;

[0050] 11. substrate; 111. mounting hole; 12. electrode terminal; 121. main body; 122. first flange portion; 1221. first ring portion; 1222. intermediate ring portion; 1223. second ring portion; 1224. groove; 123. second flange portion; 13. rivet; 131. rivet groove; 132. inner rivet portion; 133. intermediate rivet portion; 134. outer rivet portion; 135. limiting recess; 14. first insulating member; 141. limiting groove; 142. limiting convex portion; 15. second insulating member; 16. sealing member; 17. pressure relief mechanism. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0052] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "periphery", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0053] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0054] In the present application, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0055] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0056] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0057] Currently, from the perspective of the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of batteries, the market demand is also continuously increasing.

[0058] Please refer to Figure 1 , the battery includes battery cells 1. In the battery, the battery cells 1 can be one or more. When there are multiple battery cells 1, the multiple battery cells 1 can be connected in series, parallel or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 1. The multiple battery cells 1 can be directly connected in series, parallel or in a mixed connection together; of course, the battery can also be in the form that multiple battery cells 1 are first connected in series, parallel or in a mixed connection to form battery modules, and then the multiple battery modules are connected in series, parallel or in a mixed connection to form an integral body.

[0059] In some embodiments, the battery may further include other structures. For example, the battery may further include a busbar component for connecting the multiple battery cells 1 to achieve electrical connection among the multiple battery cells 1.

[0060] Among them, each battery cell 1 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 1 can be in the shape of a cuboid, a cylinder, a prism or other shapes.

[0061] Please refer to again Figure 1 , the battery cell 1 includes an end cap assembly 10, a housing 20, an electrode assembly and other functional components.

[0062] The housing 20 is a component for cooperating with the end cap assembly 10 to form the internal environment of the battery cell 1, wherein the formed internal environment can be used to accommodate the electrode assembly, the electrolyte and other components. The housing 20 is a hollow structure with at least one open end. Without limitation, the housing 20 is a hollow structure with one open end and one closed end, or the housing 20 is a hollow structure with two open ends. The end cap assembly 10 corresponds to the openings of the housing 20 one by one, and the end cap assembly 10 covers the corresponding openings of the housing 20. The housing 20 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 20 can be determined according to the specific shape and size of the electrode assembly. The material of the housing 20 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations on this.

[0063] The electrode assembly is a component in the battery cell 1 where electrochemical reactions occur. The housing 20 can contain one or more electrode assemblies. The electrode assembly is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and usually a separator is provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet having active substances constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active substances respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab can be located at one end of the main body together or at both ends of the main body respectively. During the charge and discharge process of the battery, the positive active substance and the negative active substance react with the electrolyte, and the electrode tabs are connected to the electrode terminals 12 to form a current loop.

[0064] Please refer to Figures 2 to 7 , the end cap assembly 10 includes a base body 11, electrode terminals 12, riveting parts 13, a first insulating part 14, a second insulating part 15 and a sealing potting part.

[0065] The base body 11 refers to a component that covers the opening of the housing 20 to isolate the internal environment of the battery cell 1 from the external environment. The housing 20 and the base body 11 can be independent components. An opening can be provided on the housing 20, and the base body 11 covers the opening to form the internal environment of the battery cell 1. Without limitation, the base body 11 and the housing 20 can also be integrated. Specifically, the base body 11 and the housing 20 can first form a common connection surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 20, the base body 11 is then made to cover the housing 20. Without limitation, the shape of the base body 11 can be adapted to the shape of the housing 20 to cooperate with the housing 20. Optionally, the base body 11 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the base body 11 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 1 to have higher structural strength and the safety performance can also be improved. In some embodiments, a pressure relief mechanism 17 for releasing the internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold can also be provided on the base body 11. The material of the base body 11 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. The base body 11 is provided with an installation hole 111 penetrating along its thickness direction.

[0066] The electrode terminal 12 is used for electrically connecting with the tab of the electrode assembly to output or input electrical energy outward or inward. The positive electrode terminal 12 is electrically connected to the positive tab, and the negative electrode terminal 12 is electrically connected to the negative tab. It can be understood that when the positive tab and the negative tab are located at one end of the main body part, the housing 20 has only one opening, the end cap assembly 10 is one, the base body 11 covers the opening of the housing 20, and both the positive electrode terminal 12 and the negative electrode terminal 12 are located on the same base body 11; when the positive tab and the negative tab are located at opposite ends of the main body part, openings are respectively provided at opposite ends of the housing 20, the end cap assembly 10 is in two groups, the base bodies 11 of the two groups of end cap assemblies 10 respectively cover different openings, the positive electrode terminal 12 is arranged on the base body 11 of one group of end cap assemblies 10, and the negative electrode terminal 12 is arranged on the base body 11 of the other group of end cap assemblies 10.

[0067] Combined Figure 1 、 Figure 2 and Figure 3 , the electrode terminal 12 includes a main body part 121, a first flanging part 122 and a second flanging part 123. The main body part 121 passes through the installation hole 111 and is hermetically connected to the installation hole 111. The first flanging part 122 is arranged on the side of the base body 11 facing away from the interior of the housing 20 and is connected to the base body 11. The second flanging part 123 is arranged on the side of the base body 11 facing the interior of the housing 20 and is arranged around the outer periphery of the main body part 121, and the second flanging part 123 is connected to the main body part 121.

[0068] Specifically, the body portion 121 can be a solid structure or a hollow structure. For example, the body portion 121 is a hollow structure with one end open and the other end closed, and the opening of the body portion 121 is located on the end face of the body portion 121 facing away from the interior of the housing 20. Designing the body portion 121 as a hollow structure makes the electrode terminal 12 light in weight and low in cost, which is beneficial to reducing the mass of the electrode terminal 12 and enabling the battery cell 1 to have a higher energy density. In addition, the electrode terminal 12 with a hollow structure is a thin-walled structure, and the wall thickness of the body portion 121 is relatively thin. Therefore, when the battery cell 1 is working, the heat inside it can easily pass through the side wall of the body portion 121 and diffuse to the outside, enhancing the heat dissipation effect.

[0069] The first flanging portion 122 and the second flanging portion 123 cooperate with the base body 11 to prevent the electrode terminal 12 from falling off from the mounting hole 111. Among them, the second flanging portion 123 is flush with the top surface of the body portion 121 facing the interior of the housing 20, so that the bottom surface of the electrode terminal 12 is relatively flat to facilitate welding with the tab of the electrode assembly. Among them, the tab can be welded to the bottom surface of the second flanging portion 123 and / or the body portion 121. When the battery cell 1 is working properly, the heat generated will be transferred to the electrode terminal 12 through the tab and diffuse to the outside through the electrode terminal 12, which is beneficial to preventing the thermal runaway problem caused by the failure to transfer heat in time.

[0070] The riveting member 13 refers to the component used to fix the electrode terminal 12. Both the riveting member 13 and the electrode terminal 12 are made of conductive materials. Specifically, the riveting member 13 is arranged on the side of the base body 11 facing away from the interior of the housing 20 and is hermetically connected between the first flanging portion 122 and the base body 11. A riveting groove 131 is formed on the side of the riveting member 13 facing the first flanging portion 122, and at least part of the first flanging portion 122 is received and limited in the riveting groove 131. The setting of the riveting groove 131 increases the contact area between the electrode terminal 12 and the riveting member 13, making the cooperation between the riveting member 13 and the electrode terminal 12 more stable and reliable, thereby reducing the risk of the electrode terminal 12 falling off.

[0071] The first insulating member 14 is provided on the side of the base body 11 facing away from the interior of the housing 20, and the first insulating member 14 is sealingly connected between the riveting member 13 and the base body 11. The second insulating member 15 is provided on the side of the base body 11 facing the interior of the housing 20, and the second insulating member 15 is sealingly connected between the second flanging portion 123 and the base body 11. The first insulating member 14 is used to achieve insulation between the riveting member 13 and the base body 11, and the second insulating member 15 is used to achieve insulation between the second flanging portion 123 and the base body 11. In this design, during the charging and discharging process, the current only passes through the tab of the electrode assembly, the electrode terminal 12 and the current collecting member, and will not leak to the base body 11, thereby improving the safety of the battery during operation. In addition, the first insulating member 14 is sealingly connected between the riveting member 13 and the base body 11, and the second insulating member 15 is sealingly connected between the second flanging portion 123 and the base body 11. Therefore, it is difficult for external water vapor to enter the housing 20 through the gaps between the riveting member 13 and the base body 11, and between the second flanging portion 123 and the base body 11, and it is also difficult for the electrolyte in the housing 20 to leak to the outside through the gaps between the second flanging portion 123 and the base body 11, and between the riveting member 13 and the base body 11, improving the use safety.

[0072] Specifically, the first insulating member 14 and the second insulating member 15 can be plastics, rubber or other insulating components, and the manufacturing materials of the first insulating member 14 and the second insulating member 15 can be set according to requirements and are not limited here.

[0073] In some alternative embodiments, the first insulating member 14 has a limiting groove 141, and a plurality of limiting protrusions 142 are formed by the protrusion of the groove bottom wall of the limiting groove 141. All the limiting protrusions 142 are arranged around the outer periphery of the body portion 121; a plurality of limiting recesses 135 are formed on the side of the riveting member 13 facing the first insulating member 14. The limiting recesses 135 correspond to the limiting protrusions 142 one by one. The riveting member 13 is limited in the limiting groove 141, and the limiting protrusions 142 are fitted with the corresponding limiting recesses 135. The cooperation of the limiting protrusions 142 and the limiting recesses 135 can position and assemble the first insulating member 14 and the riveting member 13, prevent the riveting member 13 and the first insulating member 14 from rotating relative to each other, has a good anti-rotation effect, and improves the torsional resistance of the electrode terminal 12.

[0074] Among them, the first insulating member 14 and the riveting member 13 can be separately formed and later assembled and combined into a whole, or, after the riveting member 13 is formed, the first insulating member 14 can be injection molded and formed on the riveting member 13.

[0075] The seal 16 is inserted through the mounting hole 111 and sealed between the hole wall of the mounting hole 111 and the outer side wall of the body portion 121. Exemplarily, the seal 16 can be rubber, silica gel, plastic, etc. The seal 16 functions as a seal between the base 11 and the body portion 121 of the electrode terminal 12. The provision of the seal 16 helps to prevent the electrolyte in the housing 20 from leaking to the outside through the gap between the base 11 and the body portion 121, and can also reduce the risk of external water vapor and the like entering the housing 20 through this gap.

[0076] In the battery cell 1 in the related art, the first flanging portion 122 of the electrode terminal 12 and the riveting member 13 are stacked, which may cause relative rotation between the electrode terminal 12 and the riveting member 13 and form a gap. When the seal 16 fails to seal, external water vapor easily enters the housing 20 through the gap between the riveting member 13 and the first flanging portion 122, and the gap between the base 11 and the electrode terminal 12. Or, the electrolyte in the housing 20 may also leak to the outside through the gap between the base 11 and the electrode terminal 12, and the gap between the riveting member 13 and the first flanging portion 122, resulting in corrosion of the bus bar component. Both of the above situations may reduce the safety of the battery cell 1 during use.

[0077] In this application, by designing a riveting groove 131 on the riveting member 13, at least a part of the first flanging portion 122 is received and limited in the riveting groove 131, which increases the contact area between the riveting member 13 and the first flanging portion 122, and can improve the stability and reliability of the cooperation between the riveting member 13 and the first flanging portion 122. Moreover, the electrode terminal 12 and the riveting member 13 are more closely matched, so that the risk of relative rotation between the motor terminal and the riveting member 13 is reduced. In this way, when the seal 16 fails, it is also difficult for external water vapor to enter the housing 20 through the gap between the riveting member 13 and the first flanging portion 122, and the electrolyte inside the housing 20 cannot leak to the outside through the gap between the riveting member 13 and the first flanging portion 122, thus ultimately achieving the purpose of improving the safety of the battery cell 1. In addition, the design of the riveting groove 131 also increases the heat dissipation area of the riveting member 13. Therefore, when the heat inside the battery cell 1 is transferred to the riveting member 13 through the tab and the electrode terminal 12, the heat can be dissipated in a timely and rapid manner through the riveting member 13, and the heat dissipation effect is good, reducing the risk of thermal runaway of the battery cell 1 and further improving the safety of the battery cell 1 during use.

[0078] Further, in some alternative embodiments, the riveting groove 131 is an annular groove and is disposed around the outer periphery of the body portion 121; the first flanging portion 122 includes a first ring portion 1221, an intermediate ring portion 1222, and a second ring portion 1223. The first ring portion 1221 is disposed around the outer periphery of the body portion 121, the intermediate ring portion 1222 is disposed around the outer periphery of the first ring portion 1221, the second ring portion 1223 is disposed around the outer periphery of the intermediate ring portion 1222, and the intermediate ring portion 1222 is connected between the first ring portion 1221 and the second ring portion 1223. The second ring portion 1223 sinks towards the base body 11 compared with the first ring portion 1221, and the intermediate ring portion 1222 and the second ring portion 1223 are received in the riveting groove 131.

[0079] It can be understood that for two components, if one component sinks towards the base body 11 compared with the other component, then the top surface of the sunken component is closer to the base body 11 than the top surface of the other component.

[0080] By designing the riveting groove 131 as an annular groove and the first flanging portion 122 includes a first ring portion 1221, an intermediate ring portion 1222, and a second ring portion 1223, a larger contact area is provided between the riveting member 13 and the first flanging portion 122. Circumferential connection and sealing can be performed between the riveting groove 131 and the first flanging portion 122, and heat can be dissipated quickly, which is beneficial to further improving the safety of the battery cell 1 during use.

[0081] Of course, in some other embodiments, there may be a plurality of riveting grooves 131 which are arranged at intervals along the outer periphery of the body portion 121, and there are a plurality of first flanging portions 122. The first flanging portions 122 correspond to the riveting grooves 131 one by one, and the intermediate ring portion 1222 and the second ring portion 1223 of the first flanging portion 122 are received in the corresponding riveting grooves 131.

[0082] Please refer to again Figure 3 and at the same time refer to Figures 8 to 10 , in some alternative embodiments, a groove 1224 is defined among the body portion 121, the first ring portion 1221, and the intermediate ring portion 1222; the riveting member 13 includes an inner riveting portion 132, an intermediate riveting portion 133, and an outer riveting portion 134 which are connected in sequence. The inner riveting portion 132 is fitted in the groove 1224, the intermediate riveting portion 133 is connected between the inner riveting portion 132 and the outer riveting portion 134, and the intermediate riveting portion 133 sinks towards the base body 11 relative to the inner riveting portion 132 and the outer riveting portion 134. The top surface of the intermediate riveting portion 133, the outer side surface where the inner riveting portion 132 is connected to the top surface of the intermediate riveting portion 133, and the inner side surface where the outer riveting portion 134 is connected to the top surface of the intermediate riveting portion 133 define the riveting groove 131.

[0083] Among them, the top surface of the intermediate riveting portion 133 (such as Figure 10The surface pointed by arrow b in ) constructs the bottom wall of the riveting groove 131, and the outer side surface where the inner riveting portion 132 is connected to the top surface of the intermediate riveting portion 133 (such as Figure 10 The surface pointed by arrow e in ) constructs the groove side wall with a smaller radial dimension of the riveting groove 131, and the inner side surface where the outer riveting portion 134 is connected to the top surface of the intermediate riveting portion 133 (such as Figure 10 The surface pointed by arrow d in ) constructs the groove side wall with a larger radial dimension of the riveting groove 131.

[0084] In this embodiment, the inner riveting portion 132 is fitted into the groove 1224, so that the inner riveting portion 132, the first ring portion 1221 and the intermediate ring portion 1222 cooperate to form a reinforcing rib structure, improving the overall structural strength after the riveting member 13 is fitted with the first flanging portion 122, and enabling a greater riveting force between the riveting member 13 and the first flanging portion 122.

[0085] Combined Figure 10 , in some alternative embodiments, the inner riveting portion 132 sinks towards the base 11 relative to the outer riveting portion 134, and the top surface of the inner riveting portion 132 (such as Figure 10 The surface pointed by arrow a in ) and the top surface of the intermediate riveting portion 133 (such as Figure 10 The surface pointed by arrow b in ) has a height difference of L, where 0.2 mm (millimeter) ≤ L ≤ 2 mm. When L < 0.2 mm, the depth of the riveting groove 131 is relatively shallow and the riveting force is small. Moreover, in this case, the depth of the formed groove 1224 is also relatively shallow, and the overall structural strength improvement after the riveting member 13 is fitted with the first flanging portion 122 is small. When L > 2 mm, the dimension of the body portion 121 in the thickness direction of the base 11 is large, and the battery energy density is reduced.

[0086] Thus, by designing 0.2 mm ≤ L ≤ 2 mm, on the premise of being able to increase the riveting force between the first flanging portion 122 and the riveting member 13 and enabling the overall formed by their riveting to have a greater structural strength, the battery energy density can also be increased.

[0087] Please refer to again Figures 8 to 10 , in some alternative embodiments, the inner riveting portion 132 sinks towards the base 11 relative to the outer riveting portion 134, the first ring portion 1221 overlaps on the inner riveting portion 132, and the top surface of the first ring portion 1221 is lower than or flush with the top surface of the outer riveting portion 134 (such as Figure 10 The surface pointed by arrow c in ), and the top surface of at least one of the first ring portion 1221 and the outer riveting portion 134 is connected to the bus bar component. In this way, the end cap assembly 10 has a relatively flat top surface, facilitating the welding of the bus bar component to the top surface of the first ring portion 1221 and / or the outer riveting portion 134, and the welding effect is good.

[0088] Please refer toFigure 3 , Figure 4 , Figure 8 and Figure 10 , in some alternative embodiments, the maximum thickness of the riveting member 13 is H, where H > 1 mm; the first ring portion 1221 and the inner riveting portion 132 are welded along the thickness direction of the base body 11 to form a first molten pool (as indicated by X in Figure 4 ), the penetration depth of the first molten pool is H1, where 1H / 5 < H1 < 2H / 3 and H1 > 0.2 mm; and / or, the second ring portion 1223 and the intermediate riveting portion 133 are welded along the thickness direction of the base body 11 to form a second molten pool (as indicated by Y in Figure 4 ), the penetration depth of the second molten pool is H2, where 1H / 5 < H2 < 2H / 3 and H2 > 0.2 mm; and / or, the outer side surface of the second ring portion 1223 (the surface indicated by the arrow g in Figure 8 ) and the inner side surface of the outer riveting portion 134 (the surface indicated by the arrow d in Figure 10 ) are welded along the thickness direction of the base body 11 to form a third molten pool (as indicated by Z in Figure 4 ), the penetration depth of the third molten pool is H3, where 0.3 mm < H3 < 1.5 mm and H3 > 0.2 mm.

[0089] The bottom surface of the riveting member 13 is a plane, and the maximum thickness of the riveting member 13 refers to the thickness between the top surface of the outer riveting portion 134 and the bottom surface of the riveting member 13.

[0090] Among them, the welding method mentioned above can be penetration welding.

[0091] By means of welding, the risk of relative rotation between the riveting member 13 and the electrode terminal 12 to form a gap is reduced, which is beneficial to improving the safety of the battery cell 1 during use. In addition, welding can also improve the structural stability of the whole formed by riveting the riveting member 13 and the electrode terminal 12.

[0092] Among them, if H1, H2 and H3 are too small, the welding and sealing strength is low, and the welding between the first flanging portion 122 and the riveting member 13 is not firm. If H1, H2 and H3 are too large, the thermal influence on the first insulating member 14 is greater, and it is easy to cause thermal deformation of the first insulating member 14. Therefore, by designing 1H / 5 < H1 < 2H / 3, and / or, 1H / 5 < H2 < 2H / 3, and / or, 0.3 mm < H3 < 1.5 mm, while improving the welding strength, the thermal influence of welding on the first insulating member 14 can be reduced, making the welding effect better.

[0093] In some alternative embodiments, the weld width of at least one of the first molten pool, the second molten pool and the third molten pool is W, where 0.2 mm < W < 2 mm.

[0094] For example, when forming the first molten pool and the second molten pool by welding, the weld width of at least one of the first molten pool and the second molten pool satisfies the condition: 0.2 mm < W < 2 mm. With the weld width within this range, the welding is firm and the welding effect is good.

[0095] In some alternative embodiments, a chamfered corner is provided at the connection between the top surface of the inner riveting portion 132 and the outer side surface of the inner riveting portion 132, and the radius of the chamfered corner is r, where 0.2 mm < r < 1 mm. The provision of the chamfered corner facilitates the better fitting of the first flanging portion 122 with the riveting groove 131 of the riveting member 13 when the first flanging portion 122 is riveted to the riveting groove 131, reduces the stress concentration between the riveting groove 131 of the riveting member 13 and the first flanging portion 122 here, and prevents the first flanging portion 122 from cracking due to excessive stress during riveting.

[0096] To further reduce the occurrence of the problem of cracking of the first flanging portion 122 caused by stress concentration and to reduce the processing difficulty, chamfered corners are provided at the connection between the outer side surface of the inner riveting portion 132 and the top surface of the intermediate riveting portion 133, and at the connection between the top surface of the intermediate riveting portion 133 and the inner side surface of the outer riveting portion 134, and the radius of the chamfered corner is also r, where 0.2 mm < r < 1 mm.

[0097] Please refer to Figure 8 and Figure 9 , in some alternative embodiments, the outer diameter of the main body portion 121 is D1, the outer diameter of the second ring portion 1223 is D2, and the thickness of the first ring portion 1221 is L1; 1.5L1 ≤ (D2 - D1) / 2 ≤ 8L1. When (D2 - D1) / 2 < 1.5L1, the width of the first flanging portion 122 in its radial direction is small, which is not suitable for forming the first ring portion 1221, the intermediate ring portion 1222, and the second ring portion 1223 that are bent in sequence, and the difficulty of riveting with the riveting groove 131 is also large. If (D2 - D1) / 2 > 8L1, it is likely to cause an increase in the consumption of the electrode terminal 12 and high costs. Thus, by designing 1.5L1 ≤ (D2 - D1) / 2 ≤ 8L1, while facilitating riveting, the manufacturing cost of the battery cell 1 can be reduced.

[0098] In some alternative embodiments, the thickness of the first ring portion 1221 is L1, and the thickness of the second flanging portion 123 is L2, where 1 ≤ L2 / L1 ≤ 3 and 0.5 mm ≤ L2 ≤ 2 mm. Since a reinforcing rib structure is formed between the first flanging portion 122 and the riveting member 13, even if the thickness of the first flanging portion 122 is less than that of the second flanging portion, it still has better structural strength. When the thickness of the second flanging portion 123 satisfies the conditions: 1 ≤ L2 / L1 ≤ 3 and 0.5 mm ≤ L2 ≤ 2 mm, the second flanging portion 123 has better structural strength and can support the second insulating member 15, which can reduce the risk of deformation under the extrusion of the second insulating member 15. Moreover, at this thickness, the second flanging portion 123 consumes less material, which can reduce the energy density and manufacturing cost of the battery.

[0099] In some alternative embodiments, the outer diameter of the main body portion 121 is D1, and the outer diameter of the second flanging portion 123 is D3, where 1.5L2 ≤ (D3 - D1) / 2 ≤ 10L2. In this design, the outer diameter size of the second flanging portion 123 is appropriate, which is convenient for riveting with the second insulating member 15 and the sealing member 16. In addition, the second flanging portion 123 consumes less material, which can reduce the energy density and manufacturing cost of the battery.

[0100] For the above-mentioned end cap assembly 10, battery cell 1 and battery, by designing a riveting groove 131 on the riveting member 13, at least a part of the first flanging portion 122 is received and limited in the riveting groove 131, which increases the contact area between the riveting member 13 and the first flanging portion 122, and can improve the stability and reliability of the cooperation between the riveting member 13 and the first flanging portion 122. Moreover, the electrode terminal 12 and the riveting member 13 are also more closely matched, so that the risk of relative rotation between the motor terminal and the riveting member 13 is reduced. In this way, external water vapor is also less likely to enter the housing 20 from the gap between the riveting member 13 and the first flanging portion 122, and the electrolyte inside the housing 20 cannot leak to the outside from the gap between the riveting member 13 and the first flanging portion 122, thus finally achieving the purpose of improving the safety of the battery cell 1. In addition, the design of the riveting groove 131 also increases the heat dissipation area of the riveting member 13. Therefore, when the heat inside the battery cell 1 is transferred to the riveting member 13 through the tab and the electrode terminal 12, the heat can be dissipated in a timely and rapid manner through the riveting member 13, and the heat dissipation effect is good, reducing the risk of thermal runaway of the battery cell 1 and further improving the safety of the battery cell 1 during use.

[0101] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0102] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. An end cap assembly, characterized in that: The end cap assembly comprises: The base body (11) is provided with a mounting hole (111) extending through the base body along the thickness direction thereof; The electrode terminal (12) comprises a main body (121) and a first flange portion (122) connected to each other, wherein the main body (121) is inserted into the mounting hole (111) and is sealedly connected to the mounting hole (111), and the first flange portion (122) is arranged on a side of the base (11) facing away from the inside of the housing (20); and A rivet (13) is arranged on a side of the base (11) facing away from the interior of the shell (20), and is sealed between the first flange portion (122) and the base (11); a rivet groove (131) is formed on a side of the rivet (13) facing the first flange portion (122), and the first flange portion (122) is at least partially accommodated and confined in the rivet groove (131).

2. The end cap assembly according to claim 1, characterized in that: The rivet groove (131) is an annular groove and is arranged around the outer circumference of the main body (121); the first flange portion (122) includes a first ring portion (1221), an intermediate ring portion (1222) and a second ring portion (1223); the intermediate ring portion (1222) is connected between the first ring portion (1221) and the second ring portion (1223); the second ring portion (1223) is sunken toward the base (11) compared to the first ring portion (1221); and the intermediate ring portion (1222) and the second ring portion (1223) are accommodated in the rivet groove (131).

3. The end cap assembly according to claim 2, characterized in that: A groove (1224) is defined between the main body (121), the first ring portion (1221) and the middle ring portion (1222); The riveted part (13) comprises an inner riveted part (132), an intermediate riveted part (133) and an outer riveted part (134) which are connected in sequence, the inner riveted part (132) is embedded in the groove (1224), the intermediate riveted part (133) is connected between the inner riveted part (132) and the outer riveted part (134), and the intermediate riveted part (133) is sunken toward the base body (11) relative to the inner riveted part (132) and the outer riveted part (134), the top surface of the intermediate riveted part (133), the outer side surface where the inner riveted part (132) is connected to the top surface of the intermediate riveted part (133), and the inner side surface where the outer riveted part (134) is connected to the top surface of the intermediate riveted part (133) define the riveted groove (131).

4. The end cap assembly according to claim 3, characterized in that: The inner riveted portion (132) sinks toward the base (11) relative to the outer riveted portion (134), and a height difference between a top surface of the inner riveted portion (132) and a top surface of the middle riveted portion (133) is L, 0.2 mm≤L≤2 mm.

5. The end cap assembly according to claim 3, characterized in that: The inner riveted portion (132) sinks toward the base (11) relative to the outer riveted portion (134); the first ring portion (1221) overlaps the inner riveted portion (132); and the top surface of the first ring portion (1221) is lower than or flush with the top surface of the outer riveted portion (134); and the top surface of at least one of the first ring portion (1221) and the outer riveted portion (134) is connected to the conduit component.

6. The end cap assembly according to claim 3, characterized in that: The maximum thickness of the riveted part (13) is H, H>1 mm; The first ring portion (1221) and the inner riveted portion (132) are welded along the thickness direction of the base (11) to form a first molten pool, the molten depth of the first molten pool being H1, 1H / 5<H1<2H / 3, H1>0.2mm; and / or The second ring portion (1223) and the middle riveted portion (133) are welded along the thickness direction of the base (11) to form a second molten pool, the molten depth of the second molten pool being H2, 1H / 5<H2<2H / 3, H2>0.2mm; and / or The outer side surface of the second ring portion (1223) and the inner side surface of the outer riveted portion (134) are welded along the thickness direction of the base (11) to form a third molten pool, and the melting depth of the third molten pool is H3, 0.3mm<H3<1.5mm, H3>0.2mm.

7. The end cap assembly according to claim 6, characterized in that: The molten width of at least one of the first molten pool, the second molten pool and the third molten pool is W, and 0.2 mm<W<2 mm.

8. The end cap assembly according to claim 3, characterized in that: A chamfer is provided at a connection between the top surface of the inner riveted portion (132) and the outer side surface of the inner riveted portion (132), and the radius of the chamfer is r, 0.2 mm < r < 1 mm.

9. The end cap assembly according to claim 2, characterized in that: The outer diameter of the main body (121) is D1, the outer diameter of the second ring portion (1223) is D2, and the thickness of the first ring portion (1221) is L1; 1.5L1≤(D2-D1) / 2≤8L1.

10. The end cap assembly according to claim 2, characterized in that: The electrode terminal (12) comprises a second flange portion (123), wherein the second flange portion (123) is arranged on a side of the base (11) facing the inside of the housing (20) and is arranged around the outer circumference of the main body portion (121); The thickness of the first ring portion (1221) is L1, the thickness of the second flange portion (123) is L2, 1≤L2 / L1≤3, 0.5mm≤L2≤2mm.

11. The end cap assembly according to claim 10, characterized in that: The outer diameter of the main body (121) is D1, the outer diameter of the second flange portion (123) is D3, and 1.5L2≤(D3-D1) / 2≤10L2.

12. The end cap assembly according to claim 10, characterized in that: The second flange portion (123) and the main body portion (121) are flush with the bottom surface facing the interior of the shell (20).

13. The end cap assembly according to claim 1, wherein: The main body (121) is a hollow structure with one end open and the other end closed, and the opening of the main body (121) is located on the end surface of the main body (121) facing away from the interior of the shell (20).

14. The end cap assembly according to claim 1, wherein: The electrode terminal (12) comprises a second flange portion (123), wherein the second flange portion (123) is arranged on a side of the base (11) facing the inside of the housing (20) and is arranged around the outer circumference of the main body portion (121); The end cap assembly further comprises a first insulating member (14) and a second insulating member (15), wherein the first insulating member (14) is arranged on a side of the base (11) facing away from the interior of the shell (20), and the first insulating member (14) is sealedly connected between the rivet member (13) and the base (11), and the second insulating member (15) is arranged on a side of the base (11) facing the interior of the shell (20), and the second insulating member (15) is sealedly connected between the second flange portion (123) and the base (11).

15. The end cap assembly according to claim 14, characterized in that: The first insulating member (14) has a limiting groove (141), the bottom wall of the limiting groove (141) protrudes to form a plurality of limiting convex parts (142), and all the limiting convex parts (142) are arranged around the outer periphery of the main body (121); The rivet (13) is provided with a plurality of limiting recesses (135) on one side facing the first insulating member (14), the limiting recesses (135) corresponding to the limiting protrusions (142) one by one, the rivet (13) is limited in the limiting groove (141), and the limiting protrusions (142) are engaged with the corresponding limiting recesses (135).

16. The end cap assembly according to claim 1, wherein: The electrode terminal (12) comprises a second flange portion (123), wherein the second flange portion (123) is arranged on a side of the base (11) facing the inside of the housing (20) and is arranged around the outer circumference of the main body portion (121); The end cover assembly further comprises a sealing member (16), wherein the sealing member (16) is passed through the mounting hole (111), and the sealing member (16) is sealed between the hole wall of the mounting hole (111) and the outer side wall of the main body (121).

17. A battery cell, characterized in that: The battery cell comprises: The housing (20) is a hollow structure with at least one end open; and As described in any one of claims 1 to 16, the base (11) of the end cover assembly covers the opening of the shell (20).

18. A battery, characterized in that: Comprising the battery cell as claimed in claim 17 above.

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