End cap assembly, battery cell, battery module, and device

Abstract

The embodiment of the present application provides a kind of end cap assembly, battery cell, battery module and device, end cap assembly is used for battery cell, end cap assembly includes: end cap;Electrode terminal is set to end cap;Insulating piece is used to insulate electrode terminal and end cap, is sleeved on electrode terminal;Wherein, insulating piece and electrode terminal abut, at least one of insulating piece and electrode terminal is provided with stress release slot, stress release slot is configured to absorb the stress generated when electrode terminal and insulating piece abut each other.The embodiment of the present application is provided with stress release slot on insulating piece and / or electrode terminal, the stress generated when electrode terminal and insulating piece abut each other can be absorbed by stress release slot, to reduce the stress received by insulating piece, to avoid the cracking of insulating piece, to affect the safety performance of end cap assembly, so the embodiment of the present application can improve the safety performance of end cap assembly.

Description

[0001] This application is a divisional application based on the invention with application number 202010306786.5, application date April 17, 2020, applicant CATL, and invention title "End Cap Assembly, Battery Cell, Battery Module and Device". Technical Field

[0002] This invention relates to the field of energy storage equipment technology, and in particular to an end cap assembly, a battery cell, a battery module, and a device. Background Technology

[0003] With the development of science and technology, rechargeable battery cells are being used in an increasingly wide range of fields, such as automobiles, electric bicycles, and wireless power tools. At the same time, the safety performance requirements for battery cells are also becoming increasingly stringent.

[0004] Currently, existing battery cells typically include a casing, an electrode assembly located inside the casing, and an end cap assembly covering the opening of the casing. The end cap assembly is equipped with components such as insulating parts and electrode terminals. The safety performance of the end cap assembly directly affects the safety performance of the entire battery cell.

[0005] Therefore, there is an urgent need for a new end cap assembly, battery cell, battery module, and device. Summary of the Invention

[0006] This invention provides an end cap assembly, a battery cell, a battery module, and a device, aiming to improve the safety performance of the end cap assembly.

[0007] One embodiment of the present invention provides an end cap assembly for a battery cell. The end cap assembly includes: an end cap including a connecting hole; an electrode terminal riveted to the end cap and disposed in the connecting hole; and an insulating member for insulating the electrode terminal from the end cap. The insulating member has a through hole, and the electrode terminal includes a columnar portion that is fitted into the through hole and abuts against at least a portion of the hole wall. The insulating member includes a main body and a positioning portion connected to the main body, and the positioning portion is disposed in the connecting hole. The insulating member abuts against the electrode terminal, and a stress relief groove is provided on the hole wall of the insulating member. The stress relief groove is disposed circumferentially along the through hole to absorb the radial stress generated by the abutment between the columnar portion and the hole wall.

[0008] According to one aspect of the present invention, the stress relief groove is disposed on the wall of the through hole, and the stress relief groove is correspondingly disposed on the main body, or the stress relief groove extends from the main body to the positioning part.

[0009] According to one aspect of the invention, Stress relief grooves are formed by recesses in the bore wall; Alternatively, a portion of the hole wall protrudes to form two or more protrusions that abut against the columnar portion. The two or more protrusions are distributed circumferentially along the columnar portion to form a stress relief groove between two adjacent protrusions.

[0010] According to one aspect of the present invention, there are multiple stress relief grooves, which are symmetrically arranged circumferentially along the through hole.

[0011] According to one aspect of the invention, the stress relief groove has a V-shaped, U-shaped or arc-shaped cross-section in the axial direction.

[0012] According to one aspect of the invention, The stress relief groove is formed by a recess on the surface of the insulating component away from the end cap; And / or, stress relief grooves are formed by recesses in the surface of the insulating element toward the end cap.

[0013] According to one aspect of the invention, the stress relief groove is annular and surrounds the electrode terminal; Alternatively, there may be multiple stress relief grooves, which are distributed at intervals around the electrode terminals.

[0014] On the other hand, embodiments of the present invention also provide a battery cell, including a housing, an electrode assembly located inside the housing, and an end cap assembly covering the opening of the housing, wherein the end cap assembly is the end cap assembly described above.

[0015] In another aspect, embodiments of the present invention also provide a battery module, including the aforementioned battery cell.

[0016] In another aspect, embodiments of the present invention also provide an apparatus including the aforementioned battery cell, wherein the battery cell is used to provide electrical energy.

[0017] In the end cap assembly of this invention, the end cap assembly includes an end cap, electrode terminals, and an insulating member. The insulating member is used to insulate the electrode terminals and the end cap, and the insulating member is sleeved on the electrode terminals. When the insulating member is sleeved on the electrode terminals, the insulating member and the electrode terminals abut against each other. When the electrode terminals deform or shake, the insulating member is prone to cracking. This invention provides stress relief grooves on the insulating member and / or the electrode terminals. The stress relief grooves can absorb the stress generated when the electrode terminals abut against the insulating member, thereby reducing the stress on the insulating member and preventing it from cracking, which would affect the safety performance of the end cap assembly. Therefore, this invention can improve the safety performance of the end cap assembly. Attached Figure Description

[0018] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar features.

[0019] Figure 1 This is a schematic diagram of the structure of a vehicle provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a battery pack structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a battery module provided in an embodiment of the present invention; Figure 4 This is a three-dimensional structural diagram of a battery cell provided in an embodiment of the present invention; Figure 5 yes Figure 4 A schematic diagram of the exploded structure; Figure 6 yes Figure 4 Exploded view of the top cover assembly; Figure 7 This is a three-dimensional structural diagram of a battery cell provided in another embodiment of the present invention; Figure 8 yes Figure 7 A schematic diagram of the exploded structure; Figure 9 yes Figure 7 Exploded view of the top cover assembly; Figure 10 yes Figure 7 Top view of the top cover assembly; Figure 11 yes Figure 10 Sectional view at point AA; Figure 12 This is a top view of an insulating component of a top cover assembly provided in an embodiment of the present invention; Figure 13 yes Figure 12 Sectional view at point BB; Figure 14 This is a bottom view of an insulating component of a top cover assembly provided in an embodiment of the present invention; Figure 15 This is a perspective view of an insulating component of a top cover assembly provided in an embodiment of the present invention; Figure 16 This is a top view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 17 yes Figure 16 Sectional view at CC; Figure 18 This is a bottom view of an insulating component of a top cover assembly provided in another embodiment of the present invention; Figure 19 This is a top view of an insulating component of a top cover assembly provided in another embodiment of the present invention; Figure 20 This is a top view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 21 This is a top view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 22 yes Figure 21 Sectional view at point DD; Figure 23 This is a bottom view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 24 yes Figure 22 A magnified schematic diagram of the local structure at point I; Figure 25 This is a top view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 26 yes Figure 25 Sectional view at EE; Figure 27 This is a bottom view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 28 This is a perspective view of an insulating component of a top cover assembly provided in another embodiment of the present invention; Figure 29 This is a top view of an insulating member of a top cover assembly provided in another embodiment of the present invention; Figure 30 This is a schematic diagram of the structure of the electrode terminals of a top cover assembly provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Battery pack; 10. Battery cell; 11. Battery module; 12. Housing; 2. Vehicle body; 100. End cap assembly; 110. End cap; 111. Connecting hole; 120, First insulating element; 120a, Main body; 120b, Positioning part; 121, Through hole; 121a, First through hole; 121b, Second through hole; 122, Hole wall; 123, Protrusion; 130, Electrode terminal; 130a, First electrode terminal; 130b, Second electrode terminal; 131, Columnar portion; 140. Stress relief groove; 150. Adapter plate; 160. Second insulating component; 170. Sealing ring; 180. Connecting end plate; 200. Shell; 300. Electrode assembly; 310. First electrode tab; 320. Second electrode tab; X: Thickness direction; Y: Width direction; Z: Height direction. Detailed Implementation

[0021] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. In the accompanying drawings and the following description, at least some well-known structures and techniques have not been shown in order to avoid unnecessarily obscuring the invention; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0022] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this invention 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, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the embodiments of the present invention. It should also be noted in the description of the present invention that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0024] To better understand this invention, the following is combined with... Figures 1 to 30 The end cap assembly, battery cell, battery module, and device of the present invention will be described in detail.

[0025] like Figure 1 As shown, the present invention first provides a vehicle, which includes a battery pack 1 and a vehicle body 2, with the battery pack 1 disposed on the vehicle body 2.

[0026] The vehicle is a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, and can be a two-wheeled or three-wheeled electric vehicle. The vehicle body 2 is equipped with a drive motor, which is electrically connected to the battery pack 1 and powered by the battery pack 1. The drive motor is connected to the wheels on the vehicle body 2 through a transmission mechanism, thereby driving the vehicle. For example, the battery pack 1 can be horizontally mounted at the bottom of the vehicle body 2.

[0027] Please refer to the following: Figure 2 There are various ways to set up the battery pack 1. In some optional embodiments, the battery pack 1 includes a housing 12 and a battery module 11 disposed in the housing 12.

[0028] The number of battery modules 11 is one or more, and multiple battery modules 11 are arranged inside the housing 12. The type of housing 12 is not limited. The housing 12 can be a frame-shaped housing, a disc-shaped housing, or a box-shaped housing, etc. Specifically, the housing 12 may include a lower housing for accommodating the battery modules and an upper housing that covers the lower housing.

[0029] Please refer to the following: Figure 3 There are various ways to arrange the battery module 11. In some optional embodiments, the battery module 11 includes a receiving portion (not shown in the figure) and a plurality of battery cells 10 located in the receiving portion, with the battery cells 10 arranged side by side in the receiving portion.

[0030] There are various ways to arrange the housing. For example, the housing includes a shell and a cover plate covering the shell; or, the housing includes a side plate and an end plate that are connected in succession; or, the housing includes an end plate that is disposed opposite to each other and a band that surrounds the end plate and the battery cell; or, the housing includes a side plate, an end plate and a band.

[0031] It is understood that the battery cell 10 can be used not only in vehicles but also in other devices. This invention also provides a device that uses the battery cell 10 as a power source; the device can be, but is not limited to, vehicles, ships, or aircraft.

[0032] There are various ways to arrange the battery cell 10. Please refer to some optional embodiments as well. Figures 4 to 5 , Figure 4 A three-dimensional structural schematic diagram of a battery cell 10 provided in an embodiment of the present invention; Figure 5 yes Figure 4 A schematic diagram of the exploded structure. According to an embodiment of the present invention, a battery cell 10 is provided, wherein the battery cell 10 is a prismatic battery cell 10.

[0033] In other alternative embodiments, please refer to [the document / reference]. Figure 7 and Figure 8 , Figure 7This is a three-dimensional structural diagram of a battery cell 10 according to another embodiment of the present invention. Figure 8 yes Figure 7 A schematic diagram of the exploded structure. According to another embodiment of the present invention, the battery cell 10 is a cylindrical battery cell 10.

[0034] Please refer to the following: Figure 6 and Figure 9 , Figure 6 This is an exploded structural diagram of the top cover assembly of the prismatic battery cell 10 according to an embodiment of the present invention. Figure 9 This is an exploded structural diagram of the top cover assembly of a cylindrical battery cell 10 according to another embodiment of the present invention. According to the battery cell 10 provided in this embodiment of the present invention, both the prismatic battery cell 10 and the cylindrical battery cell 10 include a housing 200, an electrode assembly 300 located within the housing 200, and an end cap assembly 100 covering the opening of the housing 200.

[0035] The electrode assembly 300 includes a tab, which is connected to the electrode terminal 130 on the end cap assembly 100 via an adapter piece 150, thereby outputting the electrical energy generated by the electrode assembly 300 to the outside.

[0036] For example, there are two electrodes, namely a first electrode 310 and a second electrode 320. For example, there are two electrode terminals 130, namely a first electrode terminal 130a and a second electrode terminal 130b. The first electrode terminal 130a and the second electrode terminal 130b are respectively connected to the first electrode 310 and the second electrode 320.

[0037] When the battery cell 10 is a prismatic battery cell 10, the electrode assembly 300 of the prismatic battery cell 10 includes, for example, a first electrode, a second electrode, and a separator (not shown in the figure), with the first electrode and the second electrode insulated from each other by the separator. The first electrode, the second electrode, and the separator can be formed into the electrode assembly 300 by winding or stacking, and the electrode assembly 300 generates electrical energy through a chemical reaction with the electrolyte. The first electrode is, for example, a positive electrode, and the second electrode is, for example, a negative electrode. Positive active material can be coated on the coated area of ​​the positive electrode, and negative active material can be coated on the coated area of ​​the negative electrode. The uncoated portion extending from the coated area of ​​the positive electrode serves as a positive electrode tab, for example, the first tab 310 can be a positive electrode tab; the uncoated portion extending from the coated area of ​​the negative electrode serves as a negative electrode tab, for example, the second tab 320 can be a negative electrode tab. The first electrode is electrically connected to the first electrode terminal 130a via the first electrode tab 310, and the second electrode is electrically connected to the second electrode terminal 130b via the second electrode tab 320, thereby outputting the generated electrical energy to the outside. The first electrode terminal 130a and the second electrode terminal 130b are both disposed on the end plate assembly 100.

[0038] The first tab 310 and the second tab 320 of the prismatic battery cell 10 are, for example, respectively disposed in the width direction of the battery cell 10. Figure 5 On both sides in the Y direction of the prismatic battery cell 10. It can be understood that the first tab 310 and the second tab 320 of the prismatic battery cell 10 may also be disposed, for example, in the height direction of the battery cell 10 (in the Y direction). Figure 5 On one side of the cylindrical battery cell 10 in the Z direction. The first tab 310 and the second tab 320 can, for example, be respectively disposed in the height direction of the battery cell 10 (in the Z direction). Figure 8 On both sides of the Z direction in the middle.

[0039] The cylindrical battery cell 10 may include, for example, two end cap assemblies 100, which are disposed on opposite sides of the cylindrical battery cell 10 in the height direction. It is understood that the cylindrical battery cell 10 may also include only one end cap assembly 100.

[0040] In some alternative embodiments, the end cap assembly 100 further includes an end cap 110 and an insulating member 1, with an electrode terminal 130 disposed on the end cap 110, and the insulating member used to insulate the electrode terminal 130 from the end cap 110, and the insulating member sleeved on the electrode terminal 130.

[0041] The location of the insulating element is not limited. For example, the insulating element may be a first insulating element 120 disposed on the side of the end cap 110 away from the electrode assembly 300, or a second insulating element 160 disposed on the side of the end cap 110 facing the electrode assembly 300. Alternatively, the insulating element may include both the first insulating element 120 and the second insulating element 160. In this embodiment of the invention, the concept of the invention is illustrated using the first insulating element 120 as an example.

[0042] When the first insulating element 120 is sleeved on the electrode terminal 130, the first insulating element 120 and the electrode terminal 130 abut against each other. When the electrode terminal 130 deforms or shakes, the first insulating element 120 is prone to cracking. For example, when the electrode terminal 130 is fixed to the end cap 110 by riveting, the electrode terminal 130 will expand during the riveting process, causing the electrode terminal 130 to squeeze the first insulating element 120. The first insulating element 120 may deform and crack under stress. When the first insulating element 120 cracks and forms a fissure, metal particles may fall into the fissure, thereby reducing the creepage distance between the electrode terminal 130 and the end cap 110, causing a short circuit in the end cap assembly 100, and affecting the safety performance of the end cap assembly 100.

[0043] The invention concept is illustrated below using a cylindrical end cap assembly 100 as an example. Please refer to the following: Figure 10 and Figure 11 , Figure 10 This is a top view of an end cap assembly 100 provided in an embodiment of the present invention. Figure 11 for Figure 10 Sectional view at point AA.

[0044] According to an embodiment of the present invention, an end cap assembly 100 includes: an end cap 110; an electrode terminal 130 disposed on the end cap 110; and a first insulating member 120 for insulating the electrode terminal 130 from the end cap 110 and sleeved on the electrode terminal 130; wherein the first insulating member 120 and the electrode terminal 130 abut against each other, and at least one of the first insulating member 120 and the electrode terminal 130 is provided with a stress relief groove 140, which is configured to absorb the stress generated by the abutment between the electrode terminal 130 and the insulating member.

[0045] In this embodiment of the invention, stress relief grooves 140 are provided on the first insulating member 120 and / or the electrode terminal 130. The stress relief grooves 140 can absorb the stress generated when the electrode terminal 130 comes into contact with the first insulating member 120, thereby reducing the stress on the first insulating member 120 and preventing the first insulating member 120 from cracking. This avoids cracks affecting the safety performance of the end cap 110. Therefore, this embodiment of the invention can improve the safety performance of the end cap assembly 100.

[0046] It is understood that when the second insulating member 160 is fitted onto the electrode terminal 130, at least one of the second insulating member 160 and the electrode terminal 130 is provided with a stress relief groove 140.

[0047] Please refer to the following: Figures 12 to 15 , Figure 12 This is a top view of a first insulating member 120 provided in an embodiment of the present invention. Figure 13 yes Figure 12 Sectional view at point BB. Figure 14 This is a bottom view of a first insulating member 120 provided in an embodiment of the present invention. Figure 15 This is a perspective view of a first insulating member 120 provided in an embodiment of the present invention.

[0048] According to some embodiments of the present invention, when the electrode terminal 130 includes a first electrode terminal 130a and a second electrode terminal 130b, the first electrode terminal 130a and the second electrode terminal 130b can be sleeved by the same first insulating member 120.

[0049] It is understood that, in some alternative embodiments, the end cap assembly 100 may be respectively fitted onto the first electrode terminal 130a and the second electrode terminal 130b by two first insulating members 120. At least one of the two first insulating members 120, the first electrode terminal 130a, and the second electrode terminal 130b is provided with a stress relief groove 140 to absorb the stress generated by the contact between the electrode terminal 130 and the first insulating member 120. Optionally, each pair of cooperating first insulating members 120 and electrode terminals 130 is provided with a stress relief groove 140 to absorb the stress applied by each electrode terminal 130.

[0050] In some optional embodiments, the end cap assembly 100 further includes a connecting end plate 180 disposed on the side of the first insulating member 120 opposite to the end cap 110, and the electrode terminal 130 is connected to the connecting end plate 180. For example, the connecting end plate 180 is provided with a riveting hole, and one end of the electrode terminal 130 is located in the riveting hole.

[0051] For example, electrode terminal 130 extends into the first insulating member 120 from the side facing the end cover 110, and then the electrode terminal 130 continues to extend into the riveting hole of the connecting end plate 180, performing a riveting operation to rivet the electrode terminal 130 into the riveting hole. Because the first insulating member 120 is pressed between the connecting end plate 180 and the end cover 110, it is prone to cracking when subjected to stress generated by the electrode terminal 130 abutting against it, making it difficult to guarantee the creepage distance between the connecting end plate 180 and the end cover 110. This embodiment of the invention, by providing a stress relief groove 140, can prevent the first insulating member 120 from cracking, causing a short circuit in the end cover assembly 100 and affecting the safety performance of the end cover 110.

[0052] In some optional embodiments, the first insulating member 120 is provided with a through hole 121, and the electrode terminal 130 includes a columnar portion 131, which is sleeved in the through hole 121 and abuts against at least a portion of the hole wall 122 of the through hole 121. The hole wall 122 of the through hole 121 refers to the wall surface of the first insulating member 120 facing the through hole 121.

[0053] The stress relief groove 140 can be positioned in various ways. In some optional embodiments, the stress relief groove 140 is arranged circumferentially along the through hole 121 to absorb the radial stress generated by the contact between the columnar portion 131 and the hole wall 122. The radial direction is perpendicular to the axial direction of the through hole 121, which is the height direction, and the radial direction is, for example, the width direction or the thickness direction.

[0054] In these alternative embodiments, the columnar portion 131 abuts against at least a portion of the hole wall 122, and the columnar portion 131 provides radial stress to the hole wall 122. The stress relief groove 140 is disposed on the periphery of the through hole 121 so that the stress relief groove 140 can absorb the radial stress, thereby preventing the first insulating member 120 from cracking.

[0055] The stress relief groove 140 may be provided on the first insulating member 120 and / or the columnar portion 131 to absorb the radial stress generated by the contact between the columnar portion 131 and the first insulating member 120.

[0056] In some alternative embodiments, the stress relief groove 140 is disposed on the first insulating member 120. When the stress relief groove 140 is disposed on the first insulating member 120, the stress relief groove 140 may be disposed on the hole wall 122, or the stress relief groove 140 may be disposed on the surface of the first insulating member 120 facing the end cap 110, or the stress relief groove 140 may be disposed on the surface of the first insulating member 120 away from the end cap 110.

[0057] For example, a stress relief groove 140 is provided in the hole wall 122, and the stress relief groove 140 is formed by a recess in the hole wall 122. This can reduce the contact area between the hole wall 122 and the columnar portion 131, and the stress relief groove 140 can provide a certain deformation space to the first insulating member 120, thereby preventing the first insulating member 120 from cracking.

[0058] In other alternative embodiments, please refer to [the document / reference]. Figures 16 to 18 , Figure 16 This is a top view of a first insulating member 120 provided in another embodiment of the present invention. Figure 17 for Figure 16 Sectional view at CC, Figure 18 This is a bottom view of a first insulating member 120 provided in another embodiment of the present invention.

[0059] According to another embodiment of the present invention, a portion of the hole wall 122 has two or more protrusions 123 that abut against the columnar portion 131. The protrusions 123 are distributed circumferentially along the electrode terminal 130 to form a stress relief groove 140 between adjacent protrusions 123. The abutment between the columnar portion 131 and the protrusions 123 further reduces the contact area between the columnar portion 131 and the first insulating member 120. The stress relief groove 140 formed between adjacent protrusions 123 provides deformation space for deformation of the protrusions 123 and other parts of the first insulating member 120, thereby preventing the first insulating member 120 from cracking.

[0060] When the stress relief groove 140 is provided on the columnar portion 131 and / or the hole wall 122, there are various distribution patterns for the stress relief groove 140. Please refer to the following for details. Figure 19 and Figure 20 The number of stress relief grooves 140 can be one, and one stress relief groove 140 is located on the periphery of the through hole 121.

[0061] In some alternative embodiments, there are multiple stress relief grooves 140, which are symmetrically distributed circumferentially around the through hole 121. The multiple symmetrically distributed stress relief grooves 140 can ensure that the first insulating member 120 is subjected to more balanced stress, and prevent the first insulating member 120 from cracking due to excessive local stress.

[0062] The stress relief groove 140 can be configured in various shapes. When the stress relief groove 140 is disposed on the hole wall 122 or the columnar portion 131, the cross-section of the stress relief groove 140 in the axial direction is V-shaped, U-shaped, or arc-shaped. The cross-section of the stress relief groove 140 in the axial direction can also be other shapes, as long as the stress relief groove 140 can absorb the stress when the electrode terminal 130 and the first insulating member 120 come into contact.

[0063] In some optional embodiments, the end cap 110 is provided with a connection hole 111, and the electrode terminal 130 is disposed in the connection hole 111, for example, the columnar portion 131 is disposed through the connection hole 111. The first insulating member 120 includes a main body portion 120a and a positioning portion 120b connected to the main body portion 120a, the positioning portion 120b being disposed within the connection hole 111. This increases the creepage distance between the columnar portion 131 and the end cap 110, improving the safety performance of the end cap assembly 100.

[0064] In some optional embodiments, the end cap assembly 100 may further include a sealing ring 170, which is sleeved on the columnar portion 131 and located on the side of the positioning portion 120b away from the main body portion 120a, thereby further improving the safety performance of the end cap assembly 100.

[0065] The positioning part 120b is, for example, cylindrical, and the through hole 121 includes a first through hole 121a located in the main body part 120a and a second through hole 121b located in the positioning part 120b.

[0066] The dimensions of the first through hole 121a and the second through hole 121b are not limited. In some optional embodiments, such as... Figure 17 As shown, the second through hole 121b has the same radial dimension as the first through hole 121a.

[0067] Alternatively, in some other alternative embodiments, please refer to [the following text is also provided]. Figures 21 to 24 , Figure 21 This is a top view of a first insulating member 120 provided in another embodiment of the present invention. Figure 22 yes Figure 21 Sectional view at DD in the middle. Figure 23This is a bottom view of a first insulating member 120 provided in another embodiment of the present invention. Figure 24 yes Figure 22 A magnified schematic diagram of the structure at point I in the middle.

[0068] According to another embodiment of the present invention, the radial dimension of the second through hole 121b is larger than the radial dimension of the first through hole 121a, such that the hole wall 122 of the second through hole 121b and the columnar portion 131 are spaced by a predetermined distance, which can prevent the columnar portion 131 from squeezing the positioning portion 120b when it expands, deforms or shakes, thus preventing the positioning portion 120b from cracking.

[0069] When the stress relief groove 140 is provided on the hole wall 122, the stress relief groove 140 can be correspondingly provided on the main body 120a, or the stress relief groove 140 can extend from the main body 120a to the positioning part 120b. The stress relief groove 140 provided on the positioning part 120b can prevent the positioning part 120b from cracking under stress.

[0070] like Figure 22 As shown, the stress relief groove 140 is provided on the hole wall 122 of the through hole 121, and the stress relief groove 140 is correspondingly provided on the main body 120a, or, as... Figures 14 to 16 As shown, the stress relief groove 140 extends from the main body 120a to the positioning part 120b.

[0071] In some alternative embodiments, please refer to [the document / reference]. Figures 25 to 28 , Figure 25 This is a top view of a first insulating member 120 provided in another embodiment of the present invention. Figure 26 yes Figure 25 Sectional view at EE, Figure 27 This is a bottom view of a first insulating member 120 provided in another embodiment of the present invention. Figure 28 This is a three-dimensional structural schematic diagram of a first insulating member 120 provided in another embodiment of the present invention.

[0072] According to another embodiment of the present invention, a stress relief groove 140 is disposed on the surface of the first insulating member 120 facing the end cap 110, and the stress relief groove 140 is formed by a recess in the surface of the first insulating member 120 facing the end cap 110. It is understood that the stress relief groove 140 can also be disposed on the surface of the first insulating member 120 away from the end cap 110, and the stress relief groove 140 is formed by a recess in the surface of the first insulating member 120 away from the end cap 110. Alternatively, stress relief grooves 140 are provided on both the surface of the first insulating member 120 facing the end cap 110 and the surface away from the end cap 110. In these optional embodiments, the stress relief groove 140 can provide deformation space to the first insulating member 120, thereby preventing the first insulating member 120 from cracking.

[0073] When the stress relief groove 140 is provided on the surface of the first insulating member 120 facing the end cover 110 and the surface away from the end cover 110, the stress relief groove 140 is, for example, annular. The annular stress relief groove 140 is provided around the through hole 121, and the stress relief groove 140 can absorb stress at different positions around the through hole 121.

[0074] Or please refer to them together. Figure 29 In some alternative embodiments, there are multiple stress relief grooves 140, which are symmetrically distributed circumferentially around the through hole 121, making the stress on the first insulating member 120 more uniform. Figure 29 There are four stress relief grooves 140, which are symmetrically distributed circumferentially in the through hole 121.

[0075] Please refer to the following: Figure 30 In some alternative embodiments, a stress relief groove 140 is disposed on the electrode terminal 130, and the stress relief groove 140 is formed by a recess in the outer wall of the columnar portion 131. That is, the columnar portion 131 abuts against the hole wall 122 through at least a portion of its outer wall. The stress relief groove 140 is disposed on the outer wall, which can reduce the contact area between the columnar portion 131 and the hole wall 122, and can reduce the deformation of the columnar portion 131, thereby reducing the radial force exerted by the columnar portion 131 on the hole wall 122, and preventing the first insulating member 120 from cracking as a result.

[0076] It should be noted that when stress relief grooves 140 are provided on the outer walls of both the hole wall 122 and the columnar portion 131, the stress relief grooves 140 on the outer walls of the hole wall 122 and the columnar portion 131 are arranged opposite to each other, so that the stress relief grooves 140 are hollow. For example, when a protrusion 123 is provided on the hole wall 122, the protrusion 123 on the hole wall 122 and the stress relief groove 140 on the outer wall of the columnar portion 131 are misaligned to avoid the protrusion 123 being located inside the stress relief groove 140 and affecting the function of the stress relief groove 140.

[0077] In some optional embodiments, stress relief grooves 140 are provided on both the first insulating member 120 and the electrode terminal 130. The stress relief grooves 140 on the first insulating member 120 are disposed on its surface facing and / or away from the end cap 110, and the stress relief grooves 140 on the electrode terminal 130 are disposed on its outer wall.

[0078] Alternatively, in some other optional embodiments, the first insulating member 120 is provided with a stress relief groove 140, the stress relief groove 140 including a first stress relief groove 140 disposed on the surface of the first insulating member 120 facing and / or away from the end cap 110, and a second stress relief groove 140 disposed on the hole wall 122.

[0079] This invention can be implemented in other specific forms without departing from its spirit and essential characteristics. For example, the algorithm described in a particular embodiment can be modified without departing from the basic spirit of the invention. Therefore, the present embodiments are to be regarded as exemplary rather than limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and all changes falling within the meaning and scope of the claims and their equivalents are thus included within the scope of the invention.

Claims

1. An end cap assembly for a battery cell, characterized in that, include: End cap; Electrode terminals are disposed on the end cap; An insulating element, used to insulate the electrode terminal and the end cap, and sleeved on the electrode terminal; The insulating component and the electrode terminal abut against each other. The insulating component is provided with a stress relief groove, which is configured to absorb the stress generated by the abutment between the electrode terminal and the insulating component.

2. The end cap assembly according to claim 1, characterized in that, The insulating component has a through hole, and the electrode terminal includes a columnar portion, which is sleeved in the through hole and abuts against at least a portion of the hole wall; The stress relief groove is provided along the circumference of the through hole to absorb the radial stress generated by the columnar portion abutting against the hole wall.

3. The end cap assembly according to claim 2, characterized in that, The stress relief groove is disposed on the insulating component; The stress relief groove is formed by the recess in the hole wall; Alternatively, a portion of the hole wall may protrude to form two or more protrusions that abut against the columnar portion. The two or more protrusions are distributed circumferentially along the columnar portion to form the stress relief groove between two adjacent protrusions.

4. The end cap assembly according to any one of claims 2-3, characterized in that, There are multiple stress relief grooves, which are symmetrically arranged circumferentially along the through hole.

5. The end cap assembly according to any one of claims 1-3, characterized in that, The stress relief groove has a V-shaped, U-shaped, or arc-shaped cross-section in the axial direction.

6. The end cap assembly according to claim 2, characterized in that, The stress relief groove is formed by a recess in the surface of the insulating element away from the end cap; And / or, the stress relief groove is formed by a recess in the surface of the insulating element toward the end cap.

7. The end cap assembly according to claim 6, characterized in that, The stress relief groove is annular and surrounds the electrode terminal; Alternatively, there may be multiple stress relief grooves, which are distributed at intervals around the electrode terminals.

8. The end cap assembly according to claim 2, characterized in that, The end cap includes a connection hole, and the electrode terminal is disposed in the connection hole; The insulating component includes a main body and a positioning part connected to the main body, and the positioning part is disposed in the connection hole.

9. The end cap assembly according to claim 8, characterized in that, The through hole extends through the positioning part and the main body part. The stress relief groove is disposed on the wall of the through hole. The stress relief groove is correspondingly disposed on the main body part, or the stress relief groove extends from the main body part to the positioning part.

10. A single battery cell, characterized in that, include: A housing, an electrode assembly located within the housing, and an end cap assembly covering the opening of the housing, wherein the end cap assembly is the end cap assembly as described in any one of claims 1-9.

11. A battery module, characterized in that, Includes the battery cell as described in claim 10.

12. An apparatus, characterized in that, Includes the battery cell of claim 10, the battery cell being used to provide electrical energy.

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