Battery cover plate assembly, battery monomer with battery cover plate assembly, battery pack and electric equipment

Abstract

The invention discloses a battery cover plate assembly, a battery monomer with the battery cover plate assembly, a battery pack and electric equipment, and relates to the technical field of batteries. The battery cover plate assembly comprises a cover plate which is provided with a through hole and comprises a buffer structure arranged on the inner circumference of the through hole; the lead-out piece is arranged at the through hole and is used for conducting current; and the sealing element is arranged in the through hole and is positioned between the buffer structure and the leading-out element so as to realize sealing insulation between the cover plate and the leading-out element. According to the battery cover plate assembly, the buffer structure is used for absorbing stress in the assembling and using processes, so that the risk that the sealing element is broken in the assembling and using processes is reduced, and the sealing and insulating reliability of the sealing element is improved. The buffering structure is arranged on the inner periphery of the through hole of the cover plate, the buffering structure and the sealing piece are arranged in the through hole in the radial direction, thickness increase caused by stacking in some traditional sealing structures can be avoided, the installation space can be saved, and the structure is more compact.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover assembly and a battery cell, a battery pack and an electrical device having the same. Background Art

[0002] In some existing battery cover assemblies, the terminal and current lead-out components often utilize riveted or ceramic assembly structures, requiring multiple insulating seals to achieve both sealing and electrical conductivity, resulting in complex structures and cumbersome assembly. While existing technologies have simplified the structure through integrated designs, the sealing surface runs along the thickness of the cover assembly, which to some extent limits the overall thickness of the battery cover.

[0003] Therefore, how to achieve reliable sealing while reducing the number of parts and avoiding increasing the overall thickness has become one of the problems that need to be solved in current battery cover plates. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, a first aspect of the present invention is to provide a battery cover assembly that has good sealing and insulation properties, a simple sealing structure, and a small number of parts, while avoiding an increase in overall thickness.

[0005] A second aspect of the present invention aims to provide a battery cell having the above-mentioned battery cover assembly.

[0006] A third aspect of the present invention is to provide a battery assembly having the above-mentioned battery cell.

[0007] A fourth aspect of the present invention aims to provide a battery pack having the above-mentioned battery assembly.

[0008] A fifth aspect of the present invention aims to provide an electrical device having the above-mentioned battery pack.

[0009] According to an embodiment of the present invention, a battery cover plate assembly includes: a cover plate, wherein the cover plate is provided with a through hole, and the cover plate includes a buffer structure arranged on the inner periphery of the through hole; a lead-out piece, which is arranged at the through hole and is used to conduct current; and a sealing piece, wherein the sealing piece is at least partially arranged in the through hole and is located between the buffer structure and the lead-out piece to achieve sealed insulation between the cover plate and the lead-out piece.

[0010] According to an embodiment of the present invention, a battery cover assembly is provided with a buffer structure within the inner periphery of the through-hole of the cover, utilizing the buffer structure to absorb stress during assembly and use, thereby reducing the risk of seal rupture during assembly and use and improving the sealing and insulation reliability of the seal. Furthermore, in the present application, the buffer structure is provided within the inner periphery of the through-hole of the cover, and the buffer structure and at least a portion of the seal are arranged radially within the through-hole. This avoids the increased thickness caused by the stacked arrangement in some traditional sealing structures, thus saving installation space and thereby avoiding an increase in the overall thickness of the cover assembly, resulting in a more compact structure.

[0011] In some embodiments, the buffer structure is an annular structure disposed around the center of the through hole.

[0012] In some embodiments, the buffer structure is a bending sheet, which includes at least two segments connected in sequence from the inner wall of the through hole to the center of the through hole. The extension directions of at least two of the segments are different, and a bending corner is formed between two adjacent segments.

[0013] Specifically, the cover plate includes a plate body, the through hole is provided through the plate body, and the segments include first segments and second segments alternately arranged from the inner wall of the through hole to the center of the through hole, the first segments and the second segments extending in opposite directions, and the outermost first segments connected to the plate body.

[0014] In some embodiments, the slices further include: at least one third slice, the third slice is arranged parallel to the plate body and connected between the first slice and the second slice.

[0015] Furthermore, the buffer structure is provided with a first groove, and the first groove is located at the segment or the bending corner to form a buffer zone.

[0016] In some embodiments, a second groove is provided at the connection between the outermost slice and the plate body to form another buffer zone.

[0017] Specifically, the thickness of the bending piece is smaller than the thickness of the plate body.

[0018] Optionally, the thickness of the outermost first slice gradually decreases in a direction from the inner wall of the through hole to the center of the through hole.

[0019] In some embodiments, the buffer structure is integrally formed on the cover plate.

[0020] In some embodiments, the battery cover assembly further includes: a spacer, which is an insulating member and is located on a side of the cover facing the battery cell, and one end of the spacer is connected to the buffer structure.

[0021] Specifically, the spacer member includes: a spacer ring, which is arranged around the center of the through hole and one end of the spacer ring is connected to the bending corner; a spacer plate, which is connected to the other end of the spacer ring and has a first tab perforation.

[0022] Specifically, the first tab perforation includes: a first hole segment, which is arranged adjacent to the cover plate; and a second hole segment, which is connected to an end of the first hole segment away from the cover plate, and the circumference of the second hole segment gradually decreases in the direction toward the first hole segment.

[0023] In some embodiments, the opposite surfaces of the cover plate are the front and back surfaces of the plate, respectively, with the back surface facing the battery cell. The buffer structure has at least one bent corner protruding toward the front surface of the plate. The innermost circle of the buffer structure is an inner segment, which is inclined toward the center of the through hole in the direction from the front surface to the back surface of the plate. The seal is provided on the inner segment.

[0024] Specifically, the lead-out member is block-shaped and is located in the through hole, and the sealing member is annular and is arranged around the lead-out member.

[0025] Specifically, the lead-out piece includes: a tapered section, the width of which gradually decreases in a direction from the front side of the plate to the back side of the plate.

[0026] Furthermore, the circumference of the inner circumferential surface of the seal gradually decreases in the direction from the front side of the plate to the back side of the plate, and the inner circumferential surface of the seal includes: an inner circumferential first section surface and an inner circumferential second section surface, and the inner circumferential first section surface is located on the side of the inner circumferential second section surface adjacent to the front side of the plate; the angle between the inner circumferential first section surface and the axis of the through hole is greater than the angle between the inner circumferential second section surface and the axis of the through hole.

[0027] Optionally, the inner circumferential section surface contacts the tapered section surface, and solder is filled between the inner circumferential section surface and the tapered section.

[0028] Specifically, the circumference of the outer peripheral surface of the seal gradually decreases in the direction from the front side of the plate to the back side of the plate, and the outer peripheral surface of the seal includes: an outer peripheral first section surface and an outer peripheral second section surface, and the outer peripheral first section surface is located on the side of the outer peripheral second section surface adjacent to the front side of the plate; the angle between the outer peripheral first section surface and the axis of the through hole is smaller than the angle between the outer peripheral second section surface and the axis of the through hole.

[0029] Optionally, the outer circumferential section surface contacts the inner slice surface, and solder is filled between the outer circumferential section surface and the inner slice.

[0030] Specifically, the seal is located in the through hole, and the opposite side surfaces of the seal are respectively a sealing front and a sealing back, and the sealing back is arranged toward the battery cell. The lead-out piece includes a lead-out piece arranged on the sealing front, and the seal is provided with a matching hole; the matching hole is used to assemble the pole ear, and / or the lead-out piece also includes an inner lead portion connected to the lead-out piece and the matching hole is used to assemble the inner lead portion.

[0031] In some embodiments, the seal is block-shaped, a mating groove is provided at the center of the front face of the seal, a first mating boss is provided on the lead-out piece and is located in the mating groove, and the first mating boss is connected to the inner wall of the mating groove in surface contact.

[0032] In some embodiments, the sealing member is an annular sheet, and the matching hole formed after the sealing member surrounds the sheet constitutes a liquid injection hole.

[0033] Specifically, the liquid injection hole includes: a funnel hole segment, and the circumference of the funnel hole segment gradually decreases in the direction toward the sealed back surface.

[0034] Optionally, the lead-out piece is provided with a second mating boss located in the funnel hole section.

[0035] Furthermore, the inner lead portion is an annular sheet provided on the inner circumference of the liquid injection hole, and at least a portion of the inner circumference of the inner lead portion constitutes the tab connection surface.

[0036] Optionally, the inner lead portion is provided with a liquid leakage notch on a side facing the back side of the seal, and the liquid leakage notch is arranged opposite to the tab connection surface.

[0037] In some embodiments, a portion of the lead-out member forms an explosion-proof valve disc.

[0038] Specifically, the lead-out piece is provided with a notch on the surface facing away from the sealing member, so that the portion of the lead-out piece surrounded by the notch constitutes the explosion-proof valve piece; and the projection of the notch on the front face of the seal is located within the range of the matching hole.

[0039] In some embodiments, the matching hole is used to penetrate the tab, and the lead-out piece is provided with a corresponding second tab penetration hole.

[0040] In some embodiments, the lead-out member is an integral stamped part, or the lead-out member is formed by connecting two metal strips through vacuum diffusion welding.

[0041] According to an embodiment of the present invention, a battery cell includes: a shell, wherein a accommodating cavity with an opening is provided in the shell; a battery cell is arranged in the accommodating cavity, and the battery cell includes a tab; the battery cover assembly described in the above embodiment, wherein the battery cover assembly is arranged at the opening, the cover is connected to the shell, and the lead-out piece is connected to the tab.

[0042] A battery assembly according to an embodiment of the present invention includes: at least two battery cells as described in the above embodiment; and a connecting piece connected to the lead-out pieces of at least two of the battery cells.

[0043] In some embodiments, the connecting piece includes: a first connecting piece, wherein at least two first connecting pieces are connected to the lead-out piece in a one-to-one correspondence; and a second connecting piece, wherein the second connecting piece is connected between two adjacent first connecting pieces, and at least a portion of the second connecting piece is a curved section.

[0044] Optionally, at least one third groove is provided on the curved section to form another buffer zone.

[0045] A battery pack according to an embodiment of the present invention includes the battery assembly described in the above embodiment.

[0046] An electric device according to an embodiment of the present invention includes the battery pack described in the above embodiment.

[0047] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0049] Figure 1 A cross-sectional view of a battery cover assembly on a width side in some embodiments of the present invention;

[0050] Figure 2 for Figure 1 a cross-sectional view of the middle cover;

[0051] Figure 3 for Figure 1 A cross-sectional view of the middle lead-out member;

[0052] Figure 4 for Figure 1 a cross-sectional view of the middle seal;

[0053] Figure 5 sectional views of the battery cover assembly on the width side in other embodiments of the present invention;

[0054] Figure 6sectional views of the battery cover assembly on the width side in other embodiments of the present invention;

[0055] Figure 7 sectional views of the battery cover assembly on the width side in other embodiments of the present invention;

[0056] Figure 8 A cross-sectional view of the assembly of the cover plate and the spacer ring in some embodiments of the present invention;

[0057] Figure 9 To adopt Figure 8 A cross-sectional view of the battery cover assembly of the scheme on the width side;

[0058] Figure 10 sectional views of the battery cover assembly on the width side in other embodiments of the present invention;

[0059] Figure 11 for Figure 10 A cross-sectional view of the middle lead-out member;

[0060] Figure 12 sectional views of cover plates on the width side in some other embodiments of the present invention;

[0061] Figure 13 A front perspective view of a cover plate in some embodiments of the present invention;

[0062] Figure 14 A rear perspective view of a cover plate in some embodiments of the present invention;

[0063] Figure 15 A front view of a cover plate in some embodiments of the present invention;

[0064] Figure 16 for Figure 15 Middle section view along AA direction;

[0065] Figure 17 A cross-sectional view of a battery cover assembly on a width side in some embodiments of the present invention;

[0066] Figure 18 for Figure 17 A cross-sectional view of the middle battery cover assembly on the length side;

[0067] Figure 19 for Figure 17 A cross-sectional view of the middle battery cover assembly with the cover hidden;

[0068] Figure 20 A cross-sectional view of a battery cover assembly on a width side in some other embodiments of the present invention;

[0069] Figure 21 for Figure 20 A cross-sectional view of the middle battery cover assembly with the cover hidden;

[0070] Figure 22 A cross-sectional view of a battery cover assembly on a width side in some other embodiments of the present invention;

[0071] Figure 23 for Figure 22 A cross-sectional view of the middle battery cover assembly with the cover hidden;

[0072] Figure 24 This is a cross-sectional view of a structure in which battery cells are connected via connecting sheets in some embodiments of the present invention.

[0073] Reference numerals:

[0074] Battery cover assembly 100,

[0075] Cover plate 10, plate front 11, plate back 12, through hole 13, plate body 14,

[0076] Buffer structure 15, slice 151, first slice 1511, second slice 1512, third slice 1513, inner slice 1514, bending corner 155, first groove 1561, second groove 1562,

[0077] Lead-out piece 30, lead-out front 301, lead-out back 302, lead-out peripheral surface 303, tapered section 31, equal width section 32, lead-out piece 33, second tab perforation 331, first matching boss 332, second matching boss 334, inner lead portion 34, tab connection surface 341, leakage notch 342, explosion-proof valve piece 35, notch 36, first lead-out block 37, second lead-out block 38,

[0078] Sealing member 50, inner circumference section 511, inner circumference section 512, outer circumference section 521, outer circumference section 522, sealing front face 531, sealing back face 532, matching hole 540, injection hole 541, funnel hole section 5411, matching groove 55, spacer 60, spacer ring 61, spacer plate 62, first tab through-hole 63, first hole section 631, second hole section 632, solder 70,

[0079] connecting piece 200, first connecting piece 210, second connecting piece 220, curved section 221, third groove 223,

[0080] Tab 400. DETAILED DESCRIPTION

[0081] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0082] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", "radial", "circumferential", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation and be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0083] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0084] The following describes a battery cover assembly 100 according to a first embodiment of the present invention with reference to the accompanying drawings.

[0085] like Figure 1-Figure 4 As shown, a battery cover plate assembly 100 according to an embodiment of the present invention includes: a cover plate 10, a lead-out member 30, and a sealing member 50. The cover plate 10 serves as the basic structure of the entire assembly, which is used to provide physical protection for the internal environment of the battery, and the cover plate 10 also supports the installation and fixation of the lead-out member 30 and the sealing member 50.

[0086] Reference Figure 2 The cover plate 10 is provided with a through hole 13 , and the cover plate 10 includes a buffer structure 15 provided on the inner periphery of the through hole 13 .

[0087] Lead member 30 is provided at through hole 13 and is used to conduct current. When the battery is discharging, lead member 30 is used to conduct the current within the battery to an external circuit. In some optional embodiments, the battery can also be charged, and lead member 30 is used to conduct the current outside the battery into the battery. Optionally, lead member 30 is a metal member, for example, aluminum.

[0088] The sealing member 50 is disposed in the through hole 13 and located between the buffer structure 15 and the lead-out member 30 to achieve insulation isolation between the cover plate 10 and the lead-out member 30 and seal the gap between the lead-out member 30 and the cover plate 10 .

[0089] According to the battery cover plate assembly 100 of the embodiment of the present invention, a buffer structure 15 is provided on the inner periphery of the through hole 13 of the cover plate 10. The buffer structure 15 is used to absorb stress during assembly and use, thereby reducing the risk of rupture of the seal 50 during assembly and use, and improving the sealing and insulation reliability of the seal 50. Moreover, in the present application, the buffer structure 15 is provided on the inner periphery of the through hole 13 of the cover plate 10. The buffer structure 15 and the seal 50 are arranged radially in the through hole 13. This can avoid the increase in thickness caused by the stacking arrangement in some traditional sealing structures, which helps save installation space, thereby avoiding an increase in the overall thickness of the battery cover plate assembly 100 and making the structure more compact.

[0090] It should be noted that, in this application, the radial direction of the through hole 13 refers to the direction from the inner periphery of the through hole 13 toward the center of the through hole 13. The radial direction of the through hole 13 is generally perpendicular to the axial direction of the through hole 13. The cover plate 10 has a width and a length, and the radial direction of the through hole 13 is perpendicular to both the width and length directions of the cover plate 10.

[0091] In some embodiments, the sealing member 50 may be a ceramic member, a carbon fiber member, etc. The sealing member 50 is preferably a ceramic member, which is more adaptable to harsh environments such as high temperature, high pressure, and strong corrosion.

[0092] In some embodiments, the buffer structure 15 is an annular structure arranged around the center of the through hole 13. In this way, the seal 50 can be buffered at all angles of 360 degrees, and the buffering protection effect is better.

[0093] Of course, the present application solution may not be limited thereto. For example, the buffer structure 15 may be divided into at least two substructures, and the at least two substructures are spaced apart along the circumference of the through hole 13 , and a portion of the seal 50 is filled and sealed between two adjacent substructures.

[0094] When the buffer structure 15 is an annular structure disposed around the center of the through hole 13, the overall shape of the buffer structure 15 is consistent with the shape of the through hole 13. For example, when the through hole 13 is a circular hole, the buffer structure 15 is an annular shape. When the through hole 13 is a racetrack-shaped hole, the buffer structure 15 is a racetrack-shaped hole.

[0095] In some embodiments, as Figure 2 As shown, the buffer structure 15 is a bent sheet, which includes at least two segments 151 connected in sequence from the inner wall of the through hole 13 to the center of the through hole 13. The at least two segments 151 extend in different directions, and a bent corner 155 is formed between two adjacent segments 151. In other words, the at least two segments 151 of the bent sheet are connected in sequence along the radial direction of the through hole 13. When the bent sheet is annular, each segment 151 is an annular segment.

[0096] In this way, the expansion and contraction between two adjacent segments 151 can realize deformation to absorb the impact force, and can also realize buffering by deforming layer by layer and consuming energy step by step, and can also prolong the impact time, disperse the impact force, and ultimately reduce the damage to the protected object.

[0097] Specifically, if Figure 2 As shown, the cover plate 10 includes a plate body 14, and a through hole 13 is set through the plate body 14. The two opposite surfaces of the plate body 14 are the plate front surface 11 and the plate back surface 12 respectively, and the through hole 13 is set through from the plate front surface 11 to the plate back surface 12.

[0098] From the inner wall of through-hole 13 to the center of through-hole 13, segments 151 include alternating first segments 1511 and second segments 1512. These segments 1511 and 1512 extend in opposite directions, with the outermost first segment 1511 connected to plate body 14. Thus, first segments 1511 and second segments 1512 form a generally V-shaped structure. The V-shaped structure has a relatively small angle, allowing it to easily return to its original shape after impact and return the lead-out member 30 and seal 50 to their original positions. Furthermore, the V-shaped structure is highly responsive to impact and requires a relatively small width dimension of cover plate 10, avoiding excessive width that would make seal 50 too narrow.

[0099] Here, the first slice 1511 is arranged to be tilted along the direction from the back side 12 of the board to the front side 11 of the board, and the second slice 1512 is arranged to be tilted along the direction from the front side 11 of the board to the back side 12 of the board.

[0100] In some specific embodiments, Figure 5 As shown, the segment 151 further includes: at least one third segment 1513, which is arranged parallel to the plate body 14 and connected between the first segment 1511 and the second segment 1512. This arrangement can increase the number of bending corners 155 within a smaller width range, thereby increasing the cushioning capacity.

[0101] by Figure 2 、 Figure 5-Figure 6 For example, in Figure 1 In the embodiment, the buffer structure 15 includes a first segment 1511 and a second segment 1512 . A bending corner 155 is formed at the connection between the first segment 1511 and the second segment 1512 , serving as a buffer zone.

[0102] exist Figure 5 In the embodiment, the buffer structure 15 includes a first segment 1511, a second segment 1512, and a third segment 1513. The third segment 1513 is connected between the first segment 1511 and the second segment 1512 to form two bent corners 155. In this way, the buffer structure 15 can have two buffer zones, which are distributed along the radial direction of the through hole 13.

[0103] exist Figure 6 In the embodiment, the buffer structure 15 includes a first segment 1511, a second segment 1512, another first segment 1511, and another second segment 1512 arranged radially from the outside to the inside. A bend 155 is formed at the junction of every two segments 151. In this way, the buffer structure 15 can have three buffer zones, which are distributed radially along the through hole 13.

[0104] In addition to setting the number of buffers using the number of slices 151 , other buffers may also be set on the buffer structure 15 .

[0105] For example, in some specific embodiments, Figure 7 As shown, the buffer structure 15 is provided with a first groove 1561, and the first groove 1561 is located at the segment 151 or the bending corner 155 to form a buffer zone. Figure 7 In the example, a first groove 1561 is provided at the bend corner 155 where the first segment 1511 connects to the third segment 1513, serving as a buffer zone. By removing material at the first groove 1561, the structure is guided to deform preferentially at the groove under impact loads, preventing disordered failure of the entire structure while dissipating energy during the deformation process.

[0106] In some specific embodiments, Figure 2 and Figure 7 As shown, a second groove 1562 is provided at the junction of the outermost first segment 1511 and the plate body 14 to form another buffer zone. This can absorb impacts on the plate body 14. By cutting material at the second groove 1562, the guide structure deforms preferentially at the groove under impact loads, preventing excessive deformation of the plate body 14 and preventing deformation of the plate body 14 from affecting the sealing connection with the battery housing.

[0107] That is to say, in order to enhance the buffering function of the cover plate 10 in this application, the cover plate 10 may be designed with multiple layers of buffering, such as Figure 5-Figure 6 The figure shows a secondary buffer mechanism designed based on the original cover plate buffer area. The definition of a secondary buffer zone is to increase the buffer area without thinning the local area of ​​the cover plate, expanding the original single buffer area to more than two. Figure 5 The structure shown is to set the original buffer angle to a plane, thereby increasing the original buffer area from one to two. Figure 6 The structure shown is a structure in which the flat bottom area of ​​the first structure is set at an opposite angle, thereby increasing the number of secondary buffer areas to 3. Based on the above design, the number of secondary buffer areas can be further increased.

[0108] Furthermore, the addition of the secondary buffer must meet the following requirements:

[0109] The thickness of the secondary buffer should be smaller than that of the cover plate, so that the buffer zone can fully absorb the strain transmitted to the cover plate when the battery cell is working;

[0110] The increase in the number of secondary buffer zones must be based on the premise that the current lead-out components (metal blocks) and the welding area between the cover edge and the shell are not encroached upon;

[0111] The more secondary buffer zones there are, the better. Increasing the number of secondary buffer zones will increase the displacement of the center area of ​​the cover along the length of the cell under cell working conditions. The design should be based on conditions such as the cover material and thickness.

[0112] On the basis of the secondary buffer zone, a tertiary buffer zone can be added to further increase the buffering capacity of the cover plate to the external load, such as Figure 7 As shown. The third-level buffer area is defined as a localized thinning process on the original second-level buffer area. Compared to increasing the number of second-level buffer areas, the advantage of the third-level buffer design is that it can achieve enhanced buffering capacity without encroaching on the cover plate space. At the same time, due to the smaller size of the third-level buffer, it is less likely to aggravate the deformation of the cover plate along the length of the battery cell.

[0113] Furthermore, the design of the three-level buffer must meet the following requirements:

[0114] The thickness of the tertiary buffer zone should be greater than the thickness of the shell, because the buffer zone will bear greater strain than the shell. If the thickness of the tertiary buffer zone is less than or equal to the thickness of the shell, this area will be most susceptible to damage during the use of the battery cell.

[0115] The tertiary buffer area should be designed at the corner of the secondary buffer area. If it is designed in a straight area, the buffer effect will not be effectively improved. In other words, the tertiary buffer area is an enhancement of the buffer effect of the secondary buffer area.

[0116] The third level buffer area should avoid the brazing area, i.e. Figure 7 The secondary buffer zone 1 is shown. Because the strength of the brazing zone is relatively low, if the tertiary buffer zone is set near the brazing zone, it will be prone to damage to the brazing zone due to the high deformation it will bear.

[0117] In some embodiments, as Figure 2 As shown, the thickness of the bent piece is less than that of the plate body 14. This arrangement not only facilitates processing and prevents the bent piece from occupying too much volume and affecting the arrangement of the seal 50, but also utilizes a thinner bent piece, which is more easily deformed when subjected to force, reducing rigidity and extending the deformation range, so that the force applied to the plate body 14 is more concentrated on the buffer structure 15.

[0118] Optionally, the thickness of the outermost first segment 1511 gradually decreases from the inner wall of the through hole 13 to the center of the through hole 13. In this way, the outermost first segment 1511 is thicker at the connection with the plate body 14, thereby achieving a high structural strength at the connection between the outermost first segment 1511 and the plate body 14 and preventing stress concentration and breakage at this location when bearing load.

[0119] The thickness of the outermost first slice 1511 gradually decreases from the outside to the inside in the radial direction, so that when subjected to external force, the stress is gradually guided to the bending corner 155, and the stress is consumed by the folding and expansion between adjacent slices 151.

[0120] Optionally, the thickness of the remaining slices 151 is uniform, which facilitates processing and avoids breakage.

[0121] In the present embodiment, the buffer structure 15 is integrally formed on the cover plate 10. Specifically, the plate body 14 and the buffer structure 15 are integrally formed, with no gap between them. This avoids potential risks associated with the joint and provides a more robust structure for the cover plate 10. Alternatively, the cover plate 10 is a metal component, and the integrally formed metal plate has no welds or mechanical connection points. In other embodiments, the plate body 14 and the buffer structure 15 are welded together. In this case, the weld is relatively weak and requires reinforcement, such as by increasing the thickness.

[0122] In some embodiments, as Figure 8 and Figure 9 The battery cover assembly 100 further includes a spacer 60, which is an insulating member and is located on the side of the cover 10 facing the battery cell. One end of the spacer 60 is connected to the buffer structure 15. The spacer 60 is provided to maintain the insulation isolation between the tab 400 and the cover 10, reduce the movement of the tab 400, and improve the safety and reliability of the battery.

[0123] In some specific embodiments, the spacer 60 may be annular and disposed around the tab 400, or in other words, around the center of the through hole 13. Alternatively, the spacer 60 is a plate disposed on the side of the cover 10 facing the battery cell, and the spacer 60 is provided with a tab through hole for passing the tab 400.

[0124] In other specific embodiments, Figure 8 As shown, the spacer 60 includes a spacer ring 61 and a spacer plate 62. The spacer ring 61 is arranged around the center of the through hole 13, and one end of the spacer ring 61 is connected to the bent corner 155. The spacer plate 62 is connected to the other end of the spacer ring 61, and the spacer plate 62 is provided with a first tab through-hole 63.

[0125] In this configuration, the spacer ring 61 can surround the tab 400 and separate the spacer plate 62 from the cover plate 10, maintaining a safe distance. The spacer plate 62 separates the battery body 14 from the battery cell, improving the protective spacing and reducing the chance of the battery cell contacting the cover plate 10.

[0126] Connecting one end of the spacer ring 61 to the bent corner 155 utilizes the characteristics of the bent corner 155 to increase the contact area between the two, thereby improving the connection stability of the spacer ring 60. Furthermore, when the bent corner 155 protrudes toward the direction of the plate front 11, the spacer ring 61 can be configured longer, which not only facilitates processing and connection, but also provides a certain cushioning and protective effect.

[0127] Specifically, if Figure 8 As shown, the first tab through-hole 63 includes a first hole segment 631 and a second hole segment 632. The first hole segment 631 is located adjacent to the cover plate 10, and the second hole segment 632 is connected to the end of the first hole segment 631 away from the cover plate 10. The circumference of the second hole segment 632 gradually decreases in the direction toward the first hole segment 631. In other words, the second hole segment 632 gradually decreases in the direction toward the first hole segment 631, which facilitates guiding the tab 400 toward the first hole segment 631 when inserting the tab 400. The first hole segment 631 is relatively narrow, which effectively constrains the tab 400 and makes it easier to connect the tab 400 to the lead member 30.

[0128] Alternatively, as Figure 8 As shown, the edges of the spacer plates 62 have transition angles.

[0129] In some embodiments, as Figure 1 and Figure 2 As shown, the buffer structure 15 has at least one bent corner 155 that protrudes toward the board front surface 11. The innermost circle of the buffer structure 15 is an inner segment 1514. The inner segment 1514 is arranged obliquely toward the center of the through hole 13 in the direction from the board front surface 11 to the board back surface 12. The seal 50 is provided on the inner segment 1514. In this way, the seal 50 or the lead-out member 30 located in the through hole 13 has a wedge shape with a wide outer side and a narrow inner side. This facilitates increasing the contact area between the buffer structure 15 and the seal 50, or increasing the contact area between the seal 50 and the lead-out member 30, thereby increasing the reliability of the connection.

[0130] Furthermore, the aforementioned structure allows the lead-out member 30 to have a larger area for connection to external structures at the outward end (i.e., the end where the front surface 11 of the board is located). For example, the lead-out member 30 can connect to the connecting piece 200 with a larger contact area, increasing the effective contact area for current flow, thereby reducing contact resistance, minimizing the risk of local overheating, and improving the reliability of the electrical connection.

[0131] In some embodiments, as Figure 1 As shown, the lead-out member 30 is block-shaped and positioned within the through-hole 13, while the seal 50 is annular and disposed around the lead-out member 30. The lead-out member 30 has a front lead-out face 301 and a back lead-out face 302 facing each other, with a peripheral lead-out face 303 connected between the front lead-out face 301 and the back lead-out face 302. The front lead-out face 301 and the front plate 11 are located on the same side, while the back lead-out face 302 and the back plate 12 are located on the same side. The seal 50 is annular, with its outer peripheral surface connected to the buffer structure 15 and its inner peripheral surface connected to the peripheral lead-out face 303 of the lead-out member 30. With this arrangement, the upper cover plate 10, seal 50, and lead-out member 30 of the battery cover plate assembly 100 are completely radially distributed, further facilitating a reduction in the thickness of the battery cover plate assembly 100. Furthermore, with this arrangement, the cross-sectional dimensions of the lead-out member 30 at all locations along the thickness direction can be guaranteed, shortening the current transmission path, reducing contact resistance, and improving current carrying capacity.

[0132] Specifically, if Figure 3 As shown, the lead-out member 30 includes a tapered section 31, the width of which gradually decreases from the front surface 11 to the back surface 12 of the plate. In this way, the outer peripheral surface of the tapered section 31 can be used to increase the contact area with the sealing member 50, thereby improving the connection reliability.

[0133] Alternatively, as Figure 3 As shown, the lead-out member 30 further includes a uniform width section 32 connected to the end of the tapered section 31 facing the lead-out front 301. In other words, the lead-out member 30 has a uniform width at the end outside the battery, which prevents the lead-out member 30 from forming sharp corners at the edge of the lead-out front 301, which could be easily damaged.

[0134] In some optional embodiments, the circumference of the inner peripheral surface of the sealing member 50 gradually decreases in the direction from the front surface 11 to the back surface 12 of the plate. Figure 4 As shown, the inner circumference of the seal 50 includes: an inner circumference section 511 and an inner circumference section 512. The inner circumference section 511 is located on the side of the inner circumference section 512 adjacent to the plate front face 11. The angle between the inner circumference section 511 and the axis of the through hole 13 is greater than the angle between the inner circumference section 512 and the axis of the through hole 13. This arrangement facilitates the seal 50 to achieve contact with the lead-out circumference 303 of the lead-out member 30 at the inner circumference section 512, reducing the gap between the two. With the arrangement of the inner circumference section 511, the gap between the inner circumference section 511 and the lead-out circumference 303 gradually increases in the direction toward the lead-out front face 301, which facilitates assembly and also facilitates the formation of a filler gap between the two.

[0135] Alternatively, as Figure 1As shown, the inner circumferential surface 512 is in contact with the tapered section 31, and solder 70 is filled between the inner circumferential surface 511 and the tapered section 31. In other words, the inner circumferential surface 512 and the outer circumferential surface of the tapered section 31 each form an equal angle with the axis of the through hole 13. This ensures contact area and improves sealing.

[0136] In some optional embodiments, such as Figure 4 As shown, the circumference of the outer peripheral surface of the seal 50 gradually decreases in the direction from the front surface 11 of the plate to the back surface 12 of the plate. The outer peripheral surface of the seal 50 includes: an outer peripheral section 521 and an outer peripheral section 522. The outer peripheral section 521 is located on the side of the outer peripheral section 522 adjacent to the front surface 11 of the plate. The angle between the outer peripheral section 521 and the axis of the through hole 13 is smaller than the angle between the outer peripheral section 522 and the axis of the through hole 13. This arrangement facilitates the seal 50 to achieve contact with the inner segment 1514 at the outer peripheral section 522, reducing the gap between the two. With the arrangement of the outer peripheral section 521, the gap between the outer peripheral section 521 and the inner segment 1514 gradually increases in the direction toward the lead-out front surface 301, which facilitates assembly and also facilitates the formation of a filler gap between the two.

[0137] Alternatively, as Figure 1 As shown, the outer circumferential surface 522 is in contact with the inner segment 1514, and solder 70 is filled between the outer circumferential surface 521 and the inner segment 1514. In other words, the outer circumferential surface 522 and the inner circumferential surface of the inner segment 1514 each form an equal angle with the axis of the through hole 13. This ensures contact area and improves sealing.

[0138] In some embodiments, as Figure 3 As shown, the lead-out member 30 is a one-piece stamped and formed part. Optionally, the lead-out member 30 is a one-piece metal block. This one-piece metal block has no joint gaps, which avoids potential risks at the joints and makes the overall structure of the lead-out member 30 more robust. Furthermore, since this one-piece metal block has no welds or mechanical connection points, it avoids the increase in resistance that could result from these connection points, thereby ensuring stable current flow capacity.

[0139] In other embodiments, Figure 10 and Figure 11As shown, the lead-out member 30 includes a first lead-out block 37 and a second lead-out block 38 connected together, and the two lead-out blocks are made of different materials. Optionally, the first lead-out block 37 and the second lead-out block 38 are both made of metal sheets, and the lead-out member 30 is formed by connecting the two metal sheets by vacuum diffusion welding. Optionally, during the manufacturing process, metal sheets of different materials can be vacuum diffusion welded. Welding the lead-out member 30 by welding two metal sheets can reduce material usage, which is beneficial for reducing costs and achieving lightweight goals, and can also meet the electrical conductivity requirements of different ends of the lead-out member 30. For example, the first lead-out block 37 of the lead-out member 30 at the end where the front side 301 is located is made of aluminum sheet, which is wide but has relatively low conductivity. The second lead-out block 38 of the lead-out member 30 at the end where the back side 302 is located is made of copper sheet, which is narrow but has relatively high conductivity.

[0140] For ease of understanding, the following Figures 1-12 The structure of the battery cover assembly 100 in the first category of specific embodiments is described.

[0141] Depend on Figure 1 As shown, the battery cover assembly 100 is composed of three parts, namely the cover 10, the lead-out member 30 and the sealing member 50. The sealing member 50 is a ceramic ring, and the lead-out member 30 is a metal pole.

[0142] Compared with the traditional light cover, Figure 1 The inner side of the middle cover plate 10 has a buffer structure 15. Based on this feature, the traditional structure of the lamination structure can be eliminated, and the buffer structure 15 of the cover plate 10 itself can absorb the stress during welding and use. In addition, the buffer structure 15 can be directly welded to the ceramic part, and the inner side of the ceramic ring is then welded to the pole. The bottom of the pole is then welded to the tab 400. The above cover plate 10, ceramic ring, and pole are connected by brazing. To this end, preferably, the connecting surface of each component is set as an inclined surface to facilitate the insertion of the brazing material.

[0143] Figure 1 The specific assembly sequence of the battery cover assembly 100 shown is to match the outer solder with the cover 10, then install the ceramic ring, then put the inner solder, and finally put the terminal. The assembled components are placed in the brazing equipment to keep warm until the welding is completed. Figure 3 The pole has an inclination angle θ1. A larger angle decreases the bottom width c of the pole, reducing the weld surface area with the tab 400. However, if this dimension is too small, it will increase the difficulty of matching with the inner solder. Preferably, the angle θ1 can be set between 10° and 30°. Furthermore, the top of the pole is a vertical platform that extends beyond the top of the cover plate 10. Its top surface is connected to the connecting piece 200 between the battery cells. To ensure a gap between the connecting piece 200 and the cover plate 10 and to minimize material and space, the height b is set to 1 to 2 mm.

[0144] For the buffer area of ​​the cover plate 10, refer to Figure 2 If the bevel angle θ2 in the middle area and the bevel angle θ3 in the edge area are too large, the space occupied will be too large, and the space left for the pole will be compressed; if they are too small, the buffering effect and the coordination with the solder will be affected. Therefore, it is preferred that θ2 and θ3 are set at 10 to 30 degrees. The thickness a of the step inside the buffer zone needs to ensure strength and brazing. To ensure strength, it needs to be greater than the thickness of the battery cell shell. To ensure brazing, the thickness a needs to be greater than 0.5mm. Because the thickness of the battery cell shell is generally less than 0.5mm, the thickness b can be greater than 0.5mm, and to ensure space for the pole, the thickness b should be as small as possible.

[0145] Figure 1 and Figure 2 The cross-section of the cover plate buffer area shown is a straight design. The advantage of this design is its simple structure. However, in order to achieve the matching between the brazing material, the ceramic ring and the cover plate 10 during brazing, it is necessary to set the slope of the ceramic ring cross-section. The slope of the ceramic ring on one side is different, and it is divided into two sections. Figure 4 The slope of the upper outer section is θ4, and the slope of the lower section is θ7. θ7 is equal to θ2 to ensure that the lower section of the ceramic ring is completely aligned with the inner side of the cover plate buffer structure 15. θ4 must be smaller than θ2 to ensure clearance for soldering. Similarly, the inner side of the ceramic ring is divided into upper and lower sections. The slope of the lower inner section, θ6, matches the slope of the terminal, θ1, while the slope of the upper inner section, θ5, is greater than θ1 to ensure clearance for soldering between the terminal and the ceramic ring. The height of the lower side of the ceramic ring is b1.

[0146] For the negative electrode, the following combination Figure 10-11 The structures of the battery cover assembly 100 in other specific embodiments are described.

[0147] Reference Figure 10 and Figure 11 , copper-aluminum composite poles can be used. In existing negative electrode covers, copper-aluminum composites are often machined from copper-aluminum composite rolled sheets to obtain copper-aluminum composite poles, which are more expensive. However, due to the characteristics of ceramics themselves, the present invention Figure 10 The structural design in the scheme shown does not require the use of copper-aluminum composite panels. The copper-aluminum composite pole cover can be assembled through simple steps and materials:

[0148] 1. Press the copper block, aluminum block, ceramic ring, cover plate 10, solder and other related components Figure 10 The structures are assembled together.

[0149] 2. Then place the above components in a heating furnace, apply vertical pressure to the aluminum block, and keep it warm for a period of time to complete the diffusion welding connection between the copper block and the aluminum block.

[0150] 3. Then increase the temperature to melt the brazing material and complete the connection between the ceramic ring and the aluminum metal on both sides.

[0151] As can be seen from the above, the assembly and welding process of the battery cover assembly 100 requires only a single assembly and heating step, resulting in high efficiency and low cost. The first heating temperature is approximately 550°C to complete the copper-aluminum diffusion bonding. The outer and inner solders are made of solid silver-aluminum solder with a melting point above 600°C to ensure that the solder does not melt during the copper-aluminum diffusion bonding process.

[0152] In addition, Figure 11 As shown, the copper block height in the copper-aluminum composite terminal is b1, aligned with the height of the ceramic ring's underside. If it is higher than the ceramic ring's underside, the aluminum block's positioning will be affected, potentially leading to misalignment during diffusion welding. If it is lower than the ceramic ring's underside, the aluminum block's sides must be designed with a dual-section structure similar to the ceramic ring's to avoid gaps. This can also cause poor contact during diffusion welding.

[0153] In some embodiments, as Figure 2 As shown, at least one slice 151 is a flat slice, which is convenient for processing. Figure 12 As shown, at least one of the segments 151 is a wavy segment, which can increase the contact area with the seal 50 or increase the solder contact area between the two. In another embodiment, the buffer structure 15 includes both straight segments 151 and wavy segments 151.

[0154] That is to say, the buffer zone of the cover plate 10 has the flat design as described above. Figure 13-15 As shown, it can also be designed as a stepped type, such as Figure 12 As shown. Its advantage is that it can increase the brazing area and avoid the problem that the straight brazing surface in a single direction is prone to stress concentration when subjected to tangential stress along the surface, and the cracks are prone to rapid expansion. For the stepped cover buffer, there are two main parameter characteristics, such as Figure 12 As shown, there are two characteristic angles θ8 and θ9 that make up the steps, where θ8 can be 1 to 5 degrees, which is convenient for demolding during the preparation of the battery cover assembly 100, as well as the assembly of the cover 10 and the solder. The larger θ9 is, the more conducive it is to increase the welding area, but it will make it difficult for the solder at different steps to flow, which is not conducive to welding. Therefore, θ9 can be between 30 and 60 degrees.

[0155] The current carrying capacity of the pole depends on its width and length. The width is limited by the width of the cover 10 itself and the space occupied by the buffer structure 15 and the ceramic ring, so the range of variation is not large. Figure 16, is determined by the D1 and D2 of the cover buffer, but if D1 and D2 are too large, it will make the ceramic ring more difficult to prepare and more susceptible to damage. Preferably, D1 is the buffer width W (such as Figure 2 In addition, the height H of the buffer zone will affect the height of the pole, and H is the thickness of the cover plus the height h of the buffer zone protrusion. The protrusion height should be the thickness a of the buffer zone (as shown). Figure 2 3 times (or more than 1.5 mm) of the thickness shown in the figure to avoid stress concentration in this area.

[0156] The above-mentioned cover plate structure transfers the sealing and buffer zone to the side of the cover plate 10, thereby greatly reducing the use of structural parts, and the top spacer is also removed. However, in the traditional battery cover plate structure, the inner spacer needs to be buckled with the top spacer to prevent the inner spacer from moving. For this reason, in the present invention, the inner spacer is improved and changed into a spacer member 60. A protrusion is set on the upper surface of the spacer member 60, and the position of the protrusion just matches the corner of the buffer zone. Relying on the restriction of the corner on the spacer member 60, the spacer member 60 is prevented from moving, such as Figure 8 As shown. The protrusion spacing L2 on both sides of the spacer 60 should be greater than the spacing between the corner vertices of the buffer zone on both sides, so that after assembly, the cover 10 will form a restraining force on the spacer 60. In addition, the curvature R1 of the top of the protrusion of the spacer 60 must be greater than the R angle R2 of the buffer zone, that is, to ensure that there is a gap between the two to prevent the protrusion of the spacer from affecting the buffering effect of the buffer zone, as shown. Figure 9 shown.

[0157] In some embodiments, as Figure 17 and Figure 18 As shown, the seal 50 is located in the through hole 13, and the opposite side surfaces of the seal 50 are respectively a sealing front side 531 and a sealing back side 532, and the sealing back side 532 is arranged toward the battery cell. The lead-out member 30 includes a lead-out piece 33 arranged on the sealing front side 531, and a matching hole 540 is provided on the seal 50.

[0158] The fitting hole 540 is used to assemble the tab 400 , and / or the lead-out member 30 further includes an inner lead-out portion 34 connected to the lead-out piece 33 , and the fitting hole 540 is used to assemble the inner lead-out portion 34 .

[0159] That is to say, the sealing member 50 is provided at the through hole 13 and can be provided to be close to a solid block. The lead-out member 30 ensures the contact area with the external structure (such as the connecting piece 200) through the lead-out piece 33 provided on the sealing front 531. At this time, it is necessary to provide a matching hole 540 on the sealing member 50. The matching hole 540 can allow a part of the lead-out member 30 to pass through to connect to the tab 400, or the tab 400 can be directly passed through to connect to the lead-out member 30, or a part of the lead-out member 30 and the tab 400 can be extended into the matching hole 540 for connection. Such a setting provides more than one kind of lead-out method for the lead-out member 30, and the structural selection is multiple and flexible.

[0160] In some specific embodiments, Figure 17 and Figure 19 As shown, the seal 50 is block-shaped, with a mating groove 55 defined in the center of the sealing front face 531. The lead-out piece 33 is provided with a first mating boss 332 positioned within the mating groove 55. The first mating boss 332 is connected to the inner wall of the mating groove 55 by surface contact. This increases the contact area between the lead-out piece 33 and the seal 50, improving the reliability of the connection between the two.

[0161] Specifically, if Figure 19 and Figure 17 As shown, the seal 50 is provided with a mating hole 540, one end of which is in the mating groove 55. The mating hole 540 is used to pass the tab 400. The lead sheet 33 is provided with a corresponding second tab through-hole 331, one end of which is at the first mating boss 332. In this way, the joint between the two holes is strengthened by the mating surface of the groove and boss.

[0162] Of course, in some specific embodiments, even without the first mating protrusion 332 and the mating groove 55 , the mating hole 540 can still be used to penetrate the tab 400 , and the lead-out piece 33 is provided with a corresponding second tab through-hole 331 .

[0163] In other specific embodiments, Figures 21 to 23 As shown, the seal 50 is an annular piece, and the mating hole 540 formed by the seal 50 surrounding it constitutes the liquid injection hole 541. This integrates the function of the liquid injection hole into the seal 50, achieving dual functions. Furthermore, the annular shape of the seal 50 ensures that the liquid injection hole 541 has a large diameter for convenient liquid injection. This eliminates the need for a separate liquid injection hole on the cover plate 10, fully utilizing the existing space, reducing assembly steps, and lowering costs.

[0164] It should be noted that, when assembling the battery, liquid may be injected first, and then the lead-out piece 33 may be fixed to the sealing front face 531 to achieve sealing of the liquid injection hole 541 .

[0165] Specifically, if Figure 21As shown, the liquid injection hole 541 includes a funnel section 5411, the circumference of which gradually decreases toward the sealed back surface 532. This effectively utilizes the characteristics of the buffer structure 15, giving the liquid injection hole 651 a funnel shape. Even if there is leakage during external injection, the liquid can flow into the housing through the funnel, thereby reducing injection losses.

[0166] Alternatively, as Figure 21 As shown, the lead-out piece 33 is provided with a second mating protrusion 334 positioned within the funnel hole section 5411. It is understood that after the funnel-shaped liquid injection hole 541 is formed in the seal 50, the funnel opening is large and relatively weak. Providing the second mating protrusion 334 within the funnel hole section 5411 on the lead-out piece 33 increases the structural strength of this area and reduces the gap for liquid flow within the funnel hole.

[0167] In some other specific embodiments, Figure 22 and Figure 23 As shown, the inner lead portion 34 is an annular piece provided on the inner circumference of the injection hole 541. At least a portion of the inner circumference of the inner lead portion 34 constitutes the tab connection surface 341. In other words, the mating hole 540 on the sealing member 50 is used to accommodate the inner lead portion 34 of the lead member 30 and to allow the tab 400 to extend therein. The tab 400 is connected to the lead member 30 in the mating hole 540, and the connection is protected by the sealing member 50.

[0168] Specifically, the diameter of the liquid injection hole 541 is relatively large, and the inner lead portion 34 is connected to the tab 40 here. The liquid injection hole 541 serves two purposes, and the structure is highly compact.

[0169] In some optional embodiments, such as Figure 22 and Figure 23 As shown, the inner lead portion 34 is provided with a leakage notch 342 on the side facing the sealing back surface 532, and the leakage notch 342 is arranged opposite to the tab connection surface 341. In this way, the tab 400 is located without blocking the injection, thereby improving the liquid permeability.

[0170] In some embodiments, as Figure 20 and Figure 22 As shown, a portion of the lead-out member 30 forms an explosion-proof valve plate 35. In this way, the lead-out member 30 integrates the explosion-proof function, improves the safety of the battery, and at the same time reduces the number of holes on the cover plate 10, facilitates sealing, and also ensures the overall structural strength of the cover plate 10.

[0171] Specifically, if Figure 20 and Figure 22 As shown, the lead-out piece 33 is provided with a notch 36 on the surface facing away from the sealing member 50, so that the portion of the lead-out piece 33 surrounded by the notch 36 constitutes the explosion-proof valve piece 35. The projection of the notch 36 on the sealing front face 531 is located within the range of the matching hole 540.

[0172] That is to say, by pre-forming notches (shallow annular or cross-shaped grooves) in the area corresponding to the matching hole 540 of the lead-out piece 33, a weak link is formed, which will preferentially rupture / open when the internal pressure of the battery exceeds the standard, releasing gas to avoid explosion.

[0173] Alternatively, the lead tab 33 may be formed with notches 36 by laser engraving or mechanical stamping, or may be pre-formed with notches 36 by hot pressing, both without the need for complex equipment. Alternatively, the notches 36 may be completed simultaneously during the stamping and stretching steps of the lead tab 33, without adding any additional steps.

[0174] For ease of understanding, the following Figure 17-Figure 19 The structure of the battery cover assembly 100 in the second category of specific embodiments is described.

[0175] Figure 17 The main structural features of this type of battery cover assembly 100 are shown. As can be seen from the figure, compared with the first type of structure, the structure of the cover 10 in the second type has not changed, and the buffer structure 15 is integrated on the inside. One of the differences is that the ceramic parts in the second type are not annular parts, but are close to solid, with only an opening in the middle, namely the matching hole 540, to pass the pole ear 400. In addition, the second type does not contain poles, but a metal sheet is set on the upper surface of the ceramic, and the current is extracted through the cooperation of the pole ear 400 and the metal sheet. Preferably, the metal sheet can be set as a central protrusion to ensure cooperation with the ceramic block. The metal sheet and the ceramic are also connected by brazing.

[0176] During assembly, the tab 400 passes directly through the battery cover assembly 100 and is then welded. The portion of the tab 400 that extends beyond the battery cover assembly 100 can be directly used as a connecting piece for series connection between battery cells. By connecting the positive and negative tabs that extend beyond the battery cover assembly 100 through welding or hot pressing, the battery cells can be connected in series. Compared to the traditional connecting piece solution, this solution can achieve flexible connection between battery cells in series without the need for additional connecting pieces, thereby reducing costs and simplifying the process. However, the tab 400 can also be made not to exceed the upper surface of the metal sheet. Under this structure, the existing connecting piece can be welded to the metal sheet to achieve connection between battery cells.

[0177] Figure 18A cross-sectional view of the battery cover assembly 100 in the length direction is shown. As can be seen from the figure, the length D4 of the middle opening of the metal sheet is smaller than the ceramic block D3, and the value of D4 should be slightly larger than the length of the tab 400 to facilitate the insertion of the tab 400 into the opening. In addition, the upper side of the opening of the metal sheet can be chamfered. One of the purposes is to form a hanging feature in the weld after welding, thereby improving the strength of the weld. However, it should be noted that the bevel is only designed in the length direction. If the bevel is set in the width direction, the amount of metal in the molten pool during welding will be significantly reduced, and there may be problems with non-fusion. The second is to reduce the difficulty of the tab 400 penetrating the opening. In addition, the bottom of the metal sheet opening should be chamfered to reduce the difficulty of the tab 400 penetrating.

[0178] Figure 19 A cross-sectional view of the battery cover assembly 100 in the width direction is shown. As can be seen from the figure, the width w1 of the metal sheet opening must also be smaller than the width w2 of the ceramic opening in the width direction. w1 should be slightly larger than the thickness of the tab 400. The gap formed will be filled by the metal melted from the metal sheet during welding. The bottom of the metal sheet needs to be chamfered to facilitate the insertion of the tab 400. The thickness of the thin area of ​​the metal sheet is h1, which must meet the thickness of the metal and ceramic brazing and must be greater than 0.5mm. h2 is the height of the thick area of ​​the metal sheet, which must be greater than 1mm to form a sufficiently deep molten pool between the tab 400 and it during welding to avoid defects such as gaps.

[0179] On the basis of the above second category, new designs can be made to further enhance the functional integration of the battery cover assembly 100 and form a third category of structures.

[0180] For ease of understanding, the following Figure 20-23 The structure of the battery cover assembly 100 in the third category of specific embodiments is described.

[0181] Figure 20 The design of integrated explosion-proof valve in metal sheet is shown. Its principle is to hollow out the ceramic block in the second category and increase the space of the central opening. Figure 21 As shown, the metal plate boss width is w3, the explosion-proof notch spacing is w4, and the ceramic ring opening width is w5. The relationship between the three is w5>w4>w3. w4>w3 is to facilitate the processing of the explosion-proof valve notch. The reason why w5 is greater than w4 is to ensure that the internal pressure of the battery cell acts directly on the notched area, thereby achieving the explosion-proof effect.

[0182] The above structure integrates the explosion-proof valve into the metal sheet, further simplifying the battery cover assembly 100. However, in addition to the explosion-proof valve, the battery cover assembly 100 also includes a liquid injection hole 541. Figure 17 The structure cannot integrate the function of the liquid injection hole 541. The reason is that Figure 17In the structure, the tab 400 needs to be inserted into the metal sheet. If the tab 400 is inserted into the metal sheet opening after the liquid is injected, and then the metal sheet and the ceramic are welded, the process is difficult to implement. Figure 20 As shown in the figure, the battery cover assembly 100 structure with the metal sheet integrated with the explosion-proof valve and the injection hole 541 function is Figure 17 Based on the structure shown, a metal ring is added. The metal ring, ceramic, and cover plate 10 are pre-connected by brazing, and then assembled with the battery cell. The tab 400 extends into the battery cover plate assembly 100 and is welded to the metal ring, and then liquid is injected into the metal ring. Finally, the metal sheet and the ceramic ring are connected by laser brazing. Figure 23 As shown, the inner spacing w6 of the metal ring must be larger than the spacing w4 of the explosion-proof notches (in Figure 21 In the same manner, preferably, the metal ring should be asymmetrically designed, and the height of the side connected to the tab 400 can be greater than the side not connected to the tab 400, and the height difference h3 between the two (in Figure 23 The larger the h3 is, the wider the injection channel will be. However, if it is too large, it will affect the fit between the metal ring and the ceramic. Therefore, h3 should be less than half of the total height of the metal ring. Figure 23 shown.

[0183] A battery cell according to an embodiment of the second aspect of the present invention comprises: a housing, a battery cell, and the battery cover assembly 100 according to the embodiment of the first aspect of the present invention. The housing has a receiving cavity with an opening. The battery cell is disposed in the receiving cavity and includes a tab 400. The battery cover assembly 100 is disposed at the opening, the cover 10 is connected to the housing, and the lead 30 is connected to the tab 400.

[0184] The battery cell of this embodiment utilizes the improved battery cover assembly 100, which not only facilitates electrical connection between the internal and external circuits of the battery cell but also, through the cooperation of the seal 50, ensures reliable insulation between the lead-out member 30 and the cover 10, preventing short circuits. Furthermore, the battery cover assembly 100 achieves sealing and insulation performance without adding additional space, resulting in a more compact overall structure. This helps improve the space utilization of the battery cell and supports the lightweighting of the battery cell.

[0185] The battery assembly according to the third embodiment of the present invention includes: at least two battery cells according to the second embodiment of the present invention and a connecting piece 200, wherein the connecting piece 200 is connected to the lead-out pieces 30 of the at least two battery cells.

[0186] The battery assembly utilizes connecting tabs 200 to connect multiple, reliably insulated battery cells in series, facilitating electrical connection within the battery assembly. Furthermore, the lead-out member 30 and the cover plate 10 provide excellent sealing and insulation, eliminating the need for additional insulation structures or protective components during external connections, effectively preventing the risk of short circuits caused by improper connection structure placement.

[0187] In some embodiments, the connecting piece 200 includes a first connecting piece 210 and a second connecting piece 220. There are at least two first connecting pieces 210, each connected to the lead-out member 30 in a one-to-one correspondence. A second connecting piece 220 is connected between two adjacent first connecting pieces 210, and at least a portion of the second connecting piece 220 is a curved section 221. The curved section 221 increases buffering capacity, absorbs impact loads, and absorbs internal stress, thereby improving protection for the battery cells.

[0188] Optionally, at least one third groove 223 is provided on the curved section 221 to form another buffer zone.

[0189] Specific as Figure 24 In the embodiment shown, after the cover plate 10 and the shell and other components are assembled into a single battery, the battery cells need to be connected in series through the connecting piece 200. During the use of the battery cells, the force on the cover plate 10 caused by the connecting piece 200 is an important part of the overall force of the battery cover plate assembly 100. Therefore, a buffer design is provided for the connecting piece 200 to reduce the load transferred from the connecting piece 200 to the cover plate 10. The buffer design of the connecting piece 200 is to set a buffer zone near the contact area between the connecting piece 200 and the pole, such as Figure 24 As shown. The buffer zone can be arc-shaped or bevel-shaped, so that the strain is concentrated in the buffer zone. The buffer zone is divided into a primary buffer zone and a secondary buffer zone. The secondary buffer zone is an area that is locally thinned in the primary buffer zone. The secondary buffer zone can further block the transmission of strain and thus achieve the buffering function. Preferably, the secondary buffer zone can adopt an arc structure. The reason is that the secondary buffer zone itself is small in size. When the strain is concentrated here, it may cause the stress in the local area to exceed the yield limit, thereby causing structural damage. The use of an arc design can make the strain distribution more dispersed and reduce stress concentration.

[0190] A battery pack according to an embodiment of a fourth aspect of the present invention includes a battery assembly according to an embodiment of the third aspect of the present invention.

[0191] The battery pack of this embodiment adopts an improved battery assembly, so that the battery pack has higher stability and reliability.

[0192] An electrical device according to an embodiment of a fifth aspect of the present invention includes a battery pack according to an embodiment of the fourth aspect of the present invention.

[0193] It should be noted that the electrical equipment referred to here includes but is not limited to new energy vehicles, power tools, ships, spacecraft, etc. Among them, new energy vehicles can be pure electric vehicles, extended-range vehicles, etc. Specifically, a battery pack is provided in the vehicle. Here, the battery pack can be used to power the vehicle, for example, the battery pack can be used as the operating power supply of the vehicle. The vehicle may also include a controller and a motor, and the controller is used to control the battery pack to power the motor, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery pack can not only serve as the operating power supply of the vehicle, but also as the driving power supply of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0194] By adopting the improved battery pack, the stability and reliability of electrical equipment can be improved.

[0195] Other components of the battery cover assembly 100 according to the embodiment of the present invention, such as the cover 10 and the operation thereof, are well known to those skilled in the art and will not be described in detail here.

[0196] Throughout this specification, reference to terms such as "embodiment" or "example" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0197] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A battery cover assembly, characterized in that: include: A cover plate, wherein the cover plate is provided with a through hole, and the cover plate includes a buffer structure provided on an inner periphery of the through hole; A lead-out member, provided at the through hole and used for conducting current; A sealing member is at least partially disposed in the through hole and located between the buffer structure and the lead-out member to achieve sealing and insulation between the cover plate and the lead-out member.

2. The battery cover assembly according to claim 1, characterized in that: The buffer structure is an annular structure arranged around the center of the through hole.

3. The battery cover assembly according to claim 1, characterized in that: The buffer structure is a bending piece, which includes at least two segments connected in sequence from the inner wall of the through hole to the center of the through hole. The extension directions of at least two of the segments are different, and a bending corner is formed between two adjacent segments.

4. The battery cover assembly according to claim 3, characterized in that: The cover plate includes a plate body, and the through hole is provided through the plate body; In the direction from the inner wall of the through hole to the center of the through hole, the slices include first slices and second slices that are alternately arranged, the first slices and the second slices extend in opposite directions, and the outermost first slice is connected to the plate body.

5. The battery cover assembly according to claim 4, characterized in that: The slices further include: at least one third slice, which is arranged parallel to the plate body and connected between the first slice and the second slice.

6. The battery cover assembly according to claim 3, characterized in that: The buffer structure is provided with a first groove, and the first groove is located at the segment or the bending corner to form a buffer zone.

7. The battery cover assembly according to claim 4, characterized in that: A second groove is provided at the connection between the outermost slice and the plate body to form another buffer zone.

8. The battery cover assembly according to claim 4, characterized in that: The thickness of the bent piece is smaller than the thickness of the plate body, and the thickness of the outermost first segment gradually decreases in a direction from the inner wall of the through hole to the center of the through hole.

9. The battery cover assembly according to claim 3, characterized in that: At least one of the slices is a straight slice, and / or at least one of the slices is a wavy slice.

10. The battery cover assembly according to claim 1, characterized in that: The buffer structure is integrally formed on the cover plate.

11. The battery cover assembly according to claim 3, characterized in that: Also includes: The spacer is an insulating member and is located on the side of the cover plate facing the battery core, and one end of the spacer is connected to the buffer structure.

12. The battery cover assembly according to claim 11, characterized in that: The spacer member comprises: a spacer ring, the spacer being arranged around the center of the through hole, and one end of the spacer ring being connected to the bending corner; A spacer plate is connected to the other end of the spacer ring and is provided with a first tab through-hole.

13. The battery cover assembly according to claim 12, characterized in that: The first tab perforation comprises: a first hole section, the first hole section being disposed adjacent to the cover plate; The second hole segment is connected to an end of the first hole segment away from the cover plate, and the circumference of the second hole segment gradually decreases in a direction toward the first hole segment.

14. The battery cover assembly according to any one of claims 1 to 13, characterized in that: The two opposite surfaces of the cover plate are respectively a front side and a back side of the plate, and the back side of the plate is arranged toward the battery cell; The buffer structure has at least one bent corner protruding toward the front side of the plate. The innermost circle of the buffer structure is an inner split. The inner split is inclined toward the center of the through hole in the direction from the front side of the plate to the back side of the plate. The seal is arranged on the inner split.

15. The battery cover assembly according to claim 14, characterized in that: The lead-out piece is block-shaped and is located in the through hole, and the sealing piece is annular and is arranged around the lead-out piece.

16. The battery cover assembly according to claim 15, characterized in that: The lead-out member comprises: The tapered section has a width that gradually decreases from the front surface of the plate to the back surface of the plate.

17. The battery cover assembly according to claim 16, characterized in that: The circumference of the inner circumference of the sealing member gradually decreases in the direction from the front surface of the plate to the back surface of the plate, and the inner circumference of the sealing member includes: an inner circumference section and an inner circumference section, wherein the inner circumference section is located on a side of the inner circumference section adjacent to the front surface of the plate; The angle between the inner circumferential section and the axis of the through hole is greater than the angle between the inner circumferential section and the axis of the through hole.

18. The battery cover assembly according to claim 17, characterized in that: The inner circumferential section surface is in contact with the tapered section surface, and solder is filled between the inner circumferential section surface and the tapered section.

19. The battery cover assembly according to claim 16, wherein: The circumference of the outer peripheral surface of the sealing member gradually decreases in the direction from the front surface of the plate to the back surface of the plate, and the outer peripheral surface of the sealing member includes: an outer peripheral first segment surface and an outer peripheral second segment surface, and the outer peripheral first segment surface is located on a side of the outer peripheral second segment surface adjacent to the front surface of the plate; The angle between the outer peripheral section and the axis of the through hole is smaller than the angle between the outer peripheral section and the axis of the through hole.

20. The battery cover assembly according to claim 19, wherein: The outer circumferential section surface is in contact with the inner segment surface, and solder is filled between the outer circumferential section surface and the inner segment.

21. The battery cover assembly according to claim 14, characterized in that: The sealing member is located in the through hole, and the opposite surfaces of the sealing member are respectively a sealing front and a sealing back, the sealing back is arranged toward the battery cell, the lead-out member includes a lead-out piece arranged on the sealing front, and the sealing member is provided with a matching hole; The matching hole is used to assemble the tab, and / or the lead-out piece further includes an inner lead-out portion connected to the lead-out piece, and the matching hole is used to assemble the inner lead-out portion.

22. The battery cover assembly according to claim 21, wherein: The sealing member is block-shaped, a matching groove is provided at the center of the sealing front, a first matching boss is provided on the lead-out piece and is located in the matching groove, and the first matching boss is connected to the inner wall of the matching groove in surface contact.

23. The battery cover assembly according to claim 21, characterized in that: The sealing member is an annular sheet, and the matching hole formed after the sealing member surrounds the sheet constitutes a liquid injection hole.

24. The battery cover assembly according to claim 23, characterized in that: The liquid injection hole includes a funnel hole section, the circumference of which gradually decreases in a direction toward the sealed back surface.

25. The battery cover assembly according to claim 24, characterized in that: The lead-out piece is provided with a second matching boss located in the funnel hole section.

26. The battery cover assembly according to claim 23, characterized in that: The inner lead portion is an annular sheet provided on the inner circumference of the liquid injection hole, and at least a portion of the inner circumference of the inner lead portion constitutes a tab connection surface.

27. The battery cover assembly according to claim 26, characterized in that: The inner lead portion is provided with a liquid leakage notch on a side facing the sealing back surface, and the liquid leakage notch is arranged opposite to the tab connection surface.

28. The battery cover assembly according to claim 21, wherein: A portion of the lead-out piece forms an explosion-proof valve plate.

29. The battery cover assembly according to claim 28, characterized in that: The lead-out piece is provided with a notch on a surface facing away from the sealing member, so that the portion of the lead-out piece surrounded by the notch constitutes the explosion-proof valve piece; The projection of the notch on the sealing front is located within the range of the fitting hole.

30. The battery cover assembly according to claim 21, wherein: The matching hole is used for penetrating the tab, and the lead-out piece is provided with a corresponding second tab penetrating hole.

31. The battery cover assembly according to any one of claims 1 to 13, characterized in that: The lead-out piece is an integral stamped piece, or is formed by connecting two metal strips through vacuum diffusion welding.

32. A battery cell, characterized in that: include: a housing, wherein a receiving cavity with an opening is provided in the housing; A battery cell is disposed in the accommodating cavity, and the battery cell includes a tab; The battery cover assembly according to any one of claims 1-31, wherein the battery cover assembly is arranged at the opening, the cover is connected to the shell, and the lead-out piece is connected to the tab.

33. A battery assembly, characterized in that: include: at least two battery cells according to claim 32; A connecting piece is connected to the lead-out pieces of at least two of the battery cells.

34. The battery assembly according to claim 33, wherein: The connecting piece includes: a first connecting piece, wherein the first connecting piece is at least two and is connected to the lead-out piece in a one-to-one correspondence; The second connecting piece is connected between two adjacent first connecting pieces, and at least a portion of the second connecting piece is a curved section.

35. The battery assembly according to claim 34, wherein: At least one third groove is provided on the curved section to form another buffer zone.

36. A battery pack, characterized in that: Comprising a battery assembly according to any one of claims 33-35.

37. An electrical device, characterized in that: Comprising a battery pack according to claim 36.

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