Battery cover plate and battery

Abstract

Disclosed in the present application are a battery cover plate and a battery. The battery cover plate comprises a cover plate body and a terminal post, wherein the cover plate body is provided with a terminal post through hole, and the terminal post passes through the terminal post through hole and is provided with a connecting recess, a tab being welded in the connecting recess; the connecting recess is provided with a first inner wall and a second inner wall on two sides in a first direction; the distance dimension between the first inner wall and the second inner wall is A, and the distance dimension between the first inner wall and the side of the tab close to the first inner wall in the first direction is B, satisfying 0.5 mm≤B≤(A / 3) mm. Inserting the tab into the connecting recess for welding reduces the occupied space, enabling an increase in the volume of a battery cell electrode assembly, improving energy density; in addition, the dimensional limitation on the distance dimension B between the first inner wall and the side of the tab close to the first inner wall in the first direction facilitates welding while increasing the connection area and ensuring welding quality.

Description

Battery cover plate and battery

[0001] Cross Reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. CN202411354835.7, filed on September 27, 2024, and entitled "Battery cover plate and battery", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery cover plate and a battery. BACKGROUND

[0004] The battery generally comprises a battery cover plate, a battery shell and a battery cell pole group. The battery shell is a single-edge open shell structure. The battery cover plate is arranged at the opening of the battery shell to form a storage space. The battery cell pole group is arranged in the storage space and electrolyte is injected into the storage space.

[0005] The battery cover plate has the functions of fixation and sealing, current conduction, pressure relief and fuse protection. The current conduction is achieved by welding the pole of the battery cover plate with the tab of the battery cell pole group.

[0006] However, the traditional riveting cover plate has many parts and complex assembly process. The bottom of the pole occupies a large space inside the battery. In addition, space for welding with the tab is also needed. Due to the volume of the battery cover plate and the space reserved for welding with the tab, a large amount of storage space inside the battery shell is occupied, so the volume of the battery cell pole group needs to be reduced to meet the assembly requirements, resulting in low battery energy density. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a battery cover plate and a battery with high space utilization, small space occupation and high battery energy density.

[0008] In a first aspect, the present application provides a battery cover plate, comprising:

[0009] a cover plate body, wherein a pole through hole is formed in the cover plate body;

[0010] a pole, wherein the pole is arranged in the pole through hole and a connecting groove is formed in the pole, and the tab of the battery cell pole group is welded in the connecting groove;

[0011] The first inner wall and the second inner wall are provided on both sides of the connecting groove along the first direction, the distance between the first inner wall and the second inner wall is A, the distance between the side of the tab close to the first inner wall along the first direction and the first inner wall is B, and 0.5mm≤B≤(A / 3)mm is satisfied.

[0012] Beneficial effects: By opening the connecting groove on the pole of the battery cover plate, the tab connected with the pole can be inserted into the connecting groove to realize connection, thereby saving the space reserved for realizing the connection of the tab and the pole, improving the space utilization, reducing the occupied space, and saving the space for increasing the volume of the battery cell pole group, thereby improving the energy density. By limiting the distance size B between the side of the tab close to the first inner wall along the first direction and the first inner wall to satisfy 0.5mm≤B≤(A / 3)mm, the area of the tab covering the connecting groove is increased while facilitating assembly, thereby ensuring the welding quality.

[0013] In an optional embodiment, the distance between the end face of the side close to the second inner wall on the bent end of the tab along the first direction and the second inner wall is C, and 2mm≤C≤(A / 3)mm is satisfied.

[0014] In an optional embodiment, the third inner wall and the fourth inner wall are provided on both sides of the connecting groove along the second direction, the distance between the third inner wall and the fourth inner wall is D, the distance between the side of the tab close to the third inner wall along the second direction and the third inner wall is E1, and 0.5mm≤E1≤(0.3D)mm is satisfied.

[0015] And / or, the distance between the side of the tab close to the fourth inner wall along the second direction and the fourth inner wall is E2, and 0.5mm≤E2≤(0.3D)mm is satisfied.

[0016] In an optional embodiment, the battery cover plate further comprises an upper insulating member, the upper insulating member is provided on the side of the cover plate body away from the battery cell pole group, and a first through hole is provided and communicates with the pole through hole, and the pole is arranged in the first through hole.

[0017] And / or, the surface of the pole away from the battery cell pole group is higher than the surface of the upper insulating member away from the battery cell pole group, the difference is H, and 0.1mm≤H≤2mm is satisfied.

[0018] In an alternative embodiment, the upper insulating member is provided with a mounting groove on the side away from the cover plate body, and the first through hole is formed in the mounting groove, and the battery cover plate further comprises a support provided with a mounting through hole in communication with the first through hole, and the support is sleeved on the pole and located in the mounting groove.

[0019] In an alternative embodiment, the wall thickness of the support is T, and T≥1mm is satisfied.

[0020] In an alternative embodiment, the depth of the connecting groove is M, and 0.01mm≤M≤4mm is satisfied.

[0021] In an alternative embodiment, the tab and the pole are laser welded, and a plurality of spaced-apart welding marks are formed on the area of the tab covering the connecting groove.

[0022] In an alternative embodiment, the welding mark is strip-shaped or circular.

[0023] In a second aspect, the application provides a battery comprising the battery cover plate as claimed in any one of the above, and the battery further comprises the cell pole group and a battery shell, and the battery cover plate is arranged on the battery shell to form a receiving cavity for placing the cell pole group.

[0024] Beneficial effects: the battery uses the above-mentioned battery cover plate to increase the volume of the cell pole group by saving space, thereby having a higher energy density and enhanced energy supply capacity, and the improved welding quality also ensures the reliability of the battery quality. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0026] Fig. 1 is a schematic diagram of the connection relationship between the battery cover plate and the cell pole group provided by the present application;

[0027] Fig. 2 is an exploded view of the structure of the battery cover plate provided by the present application;

[0028] Fig. 3 is a sectional view of the battery cover plate provided by the present application;

[0029] Fig. 4 is an enlarged view of the structure of part I in Fig. 3;

[0030] Fig. 5 is a schematic diagram of the cooperation size relationship between the battery cover plate and the pole lug after the pole lug is bent in the battery pole group provided by the present application;

[0031] Fig. 6 is a schematic diagram of the cooperation size relationship between the battery cover plate and the pole lug before the pole lug is bent in the battery pole group provided by the present application;

[0032] Fig. 7 is a schematic diagram of the structure of the upper insulating piece in the battery cover plate provided by the present application.

[0033] Reference signs: 100, battery pole group; 200, pole lug; 1, cover plate body; 11, pole post through hole; 12, mounting hole; 13, liquid injection hole; 2, pole post; 21, connecting groove; 211, first inner wall; 212, second inner wall; 213, third inner wall; 214, fourth inner wall; 3, explosion-proof valve; 4, protective film; 5, sealing ring; 6, upper insulating piece; 61, first through hole; 62, mounting groove; 7, lower insulating piece; 8, support piece; 81, mounting through hole. DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0035] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to the same reference numerals and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the applicability of other processes and / or the use of other materials.

[0036] The battery generally includes a battery cover plate, a battery shell, and a battery pole group. The battery shell is a single-edge open shell structure. By covering the battery cover plate at the opening of the battery shell, a storage space is formed. The battery pole group is arranged in the storage space and electrolyte is injected into the storage space.

[0037] The battery cover plate has the functions of fixation and sealing, current conduction, pressure relief, and fuse protection. The current conduction is achieved by welding the pole post on the battery cover plate with the pole lug of the battery pole group, thereby realizing the function of current conduction.

[0038] However, the traditional riveting cover plate has many parts, the assembly process is complex, the bottom of the pole occupies a large space inside the battery, and space for welding with the tab also needs to be reserved. Due to the volume of the battery cover plate and the space reserved for welding with the tab, a large amount of storage space inside the battery shell is occupied, so the volume of the battery cell pole group needs to be reduced to meet the assembly requirements, resulting in low battery energy density.

[0039] Therefore, in order to improve the space utilization, increase the volume of the battery cell pole group, and improve the energy density of the battery, the embodiment provides a battery cover plate.

[0040] As shown in FIGS. 1-7, the battery cover plate includes a cover plate body 1 and a pole 2, the cover plate body 1 is provided with a pole through hole 11, the pole 2 is arranged in the pole through hole 11, and a connecting groove 21 is provided. The tab 200 of the battery cell pole group 100 is welded in the connecting groove 21, the first inner wall 211 and the second inner wall 212 are arranged on both sides of the connecting groove 21 along the first direction, the distance between the first inner wall 211 and the second inner wall 212 is A, the distance between the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is B, and 0.5mm≤B≤(A / 3)mm is satisfied.

[0041] By providing the connecting groove 21 on the pole 2 of the battery cover plate, the tab 200 connected with the pole 2 can be inserted into the connecting groove 21 to realize connection, thereby saving the space reserved for realizing the connection between the tab 200 and the pole 2, improving the space utilization, reducing the occupied space, and saving the space for increasing the volume of the battery cell pole group 100, thereby improving the energy density. By limiting the distance B between the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 to 0.5mm≤B≤(A / 3)mm, the area of the tab 200 covering the connecting groove 21 is increased while facilitating assembly, thereby ensuring the welding quality.

[0042] In the embodiment, in order to improve the protection performance of the battery cover plate, the battery cover plate further includes an explosion-proof valve 3 and a protective film 4, an installation hole 12 for placing the explosion-proof valve 3 is provided on the cover plate body 1, the explosion-proof valve 3 is installed in the installation hole 12, and the protective film 4 is attached to the outer surface of the explosion-proof valve 3. In addition, in order to facilitate the injection of electrolyte, the cover plate body 1 is also provided with a liquid injection hole 13 for electrolyte injection, and in order to improve the sealing performance of the battery cover plate, a sealing ring 5 is arranged between the pole 2 and the pole through hole 11 of the cover plate body 1.

[0043] Optionally, as shown in FIG. 2 and FIG. 5, the distance between the folded end of the tab 200 close to the second inner wall 212 along the first direction and the side of the second inner wall 212 is C, and satisfies 2mm≤C≤(A / 3)mm. By limiting the distance C between the folded end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212, it is ensured that the tab 200 has sufficient connection area after being bent, and the folded end of the tab 200 and the second inner wall 212 have sufficient gap, which is convenient for subsequent welding operation. The distance B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 and the distance C between the folded end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 are matched with each other, so that the tab 200 has sufficient connection area, and the tab 200 and the first inner wall 211 and the second inner wall 211 of the connecting groove 21 have sufficient gap, thereby facilitating the welding operation.

[0044] As shown in Table 1, in order to verify the rationality of the distance B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 and the distance C between the folded end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212, eight groups of examples and four groups of comparative examples are selected for verification.

[0045] Table 1

[0046] In Example 1, the distance A between the first inner wall 211 and the second inner wall 212 is set to 30mm, the distance B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is set to 0.5mm, which satisfies 0.5mm≤B≤(A / 3)mm, and the distance C between the folded end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 is set to 2mm, which satisfies 2mm≤C≤(A / 3)mm. After welding test, the press-fit welding of the tab 200 has no problem, and the tab 200 is not damaged during the press-fit welding. After laser welding, no welding quality problem is found.

[0047] In Example 2, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 3 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 4 mm, which satisfies 2 mm≤C≤(A / 3) mm. After welding test, the press-fit welding of the tab 200 has no problem, and no damage to the tab 200 occurs during the press-fit welding. After laser welding, no welding quality problem is found.

[0048] In Example 3, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 5 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 6 mm, which satisfies 2 mm≤C≤(A / 3) mm. After welding test, the press-fit welding of the tab 200 has no problem, and no damage to the tab 200 occurs during the press-fit welding. After laser welding, no welding quality problem is found.

[0049] In Example 4, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 7 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 8 mm, which satisfies 2 mm≤C≤(A / 3) mm. After welding test, the press-fit welding of the tab 200 has no problem, and no damage to the tab 200 occurs during the press-fit welding. After laser welding, no welding quality problem is found.

[0050] In Embodiment 5, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 10 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 10 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, the press-fit welding of the tab 200 does not have any problems, no damage to the tab 200 occurs during the press-fit welding, and no welding quality problems are found after the laser welding.

[0051] In Embodiment 6, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 8 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 1 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 2 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, the press-fit welding of the tab 200 does not have any problems, no damage to the tab 200 occurs during the press-fit welding, and no welding quality problems are found after the laser welding.

[0052] In Embodiment 7, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 60 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 4 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 6 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, the press-fit welding of the tab 200 does not have any problems, no damage to the tab 200 occurs during the press-fit welding, and no welding quality problems are found after the laser welding.

[0053] In Example 8, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 80 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is set to 4 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 is set to 8 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, the press-fit welding of the tab 200 is not problematic, and no damage to the tab 200 occurs during the press-fit welding. After laser welding, no welding quality problems are found.

[0054] From the above Examples 1 to 8, when the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 satisfies 2 mm≤C≤(A / 3) mm, the press-fit welding of the tab 200 can be ensured to proceed smoothly, and the tab 200 will not be damaged, ensuring the quality after welding.

[0055] In Comparative Example 1, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is set to 0.2 mm, which is less than the minimum value in the range of 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 is set to 4 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, since the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is less than the specified range, the press-fit of the tab 200 is extremely difficult, which leads to poor fitting of the tab 200 with the connecting groove 21 on the pole 2, resulting in problems such as popping, virtual welding, and other undesirable problems during welding.

[0056] In Comparative Example 2, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 1 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 1 mm, which is less than the minimum value in the range of 2 mm≤C≤(A / 3) mm. After the welding test, since the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is less than the specified range, the connecting area of the tab 200 to the pole 2 in the first direction is small, which leads to the tearing of the tab 200 when the tab 200 is press-fitted.

[0057] In Comparative Example 3, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set to 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is set to 7 mm, which satisfies 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is set to 12 mm, which is greater than the maximum value in the range of 2 mm≤C≤(A / 3) mm. After the welding test, since the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 in the first direction and the second inner wall 212 is greater than the specified range, and the distance dimension B between the side of the tab 200 close to the first inner wall 211 in the first direction and the first inner wall 211 is in the specified range, in order to realize the cooperation of the tab 200 with the connecting groove 21 on the pole 2, the width dimension of the pole 2 in the first direction is increased, which increases the volume of the pole 2, leading to the increase of the size of other components cooperating with the pole 2, thereby increasing the cost.

[0058] In the comparative example 4, the distance dimension A between the first inner wall 211 and the second inner wall 212 is set as 30 mm, the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is set as 12 mm, which is greater than the maximum value in the range of 0.5 mm≤B≤(A / 3) mm, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 is set as 8 mm, which satisfies 2 mm≤C≤(A / 3) mm. After the welding test, since the distance dimension B between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 is greater than the specified range, and the distance dimension C between the bent end of the tab 200 close to the second inner wall 212 along the first direction and the second inner wall 212 is in the specified range, in order to realize the cooperation between the tab 200 and the connecting groove 21 on the pole 2, the width dimension of the pole 2 along the first direction is increased, thereby increasing the volume of the pole 2, which leads to the increase of the size of other components cooperating with the pole 2, thereby increasing the cost.

[0059] Optionally, as shown in FIG. 2 and FIG. 6, the connecting groove 21 is provided with a third inner wall 213 and a fourth inner wall 214 on both sides along the second direction, the distance dimension between the third inner wall 213 and the fourth inner wall 214 is D, the distance dimension between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 is E1, and satisfies 0.5 mm≤E1≤(0.3D) mm, and the distance dimension between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 is E2, and satisfies 0.5 mm≤E2≤(0.3D) mm.

[0060] The distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 are set in the range, so that the distance dimension E1 satisfies 0.5 mm≤E1≤(0.3D) mm, and the distance dimension E2 satisfies 0.5 mm≤E2≤(0.3D) mm. Thus, there is enough gap between the two sides of the tab 200 along the second direction and the third inner wall 213 and the fourth inner wall 214 of the connecting groove 21, thereby facilitating subsequent welding operation, and at the same time, the width of the tab 200 along the second direction is ensured, so that the tab 200 and the pole 2 have enough connection area in the second direction, thereby ensuring the connection strength after welding. The values of the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 can be the same or different.

[0061] As shown in Table 2, taking the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 as examples, in order to verify the rationality of the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214, nine groups of examples and two groups of comparative examples are selected for verification.

[0062] Table 2

[0063] In Example 9, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 30 mm, the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 are set to 0.5 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 does not have problems, and in the process of press-fit welding, the tab 200 is not damaged, and after laser welding, no welding quality problems are found.

[0064] In Example 10, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 30 mm, the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 are set to 2 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 does not have problems, and in the process of press-fit welding, the tab 200 is not damaged, and after laser welding, no welding quality problems are found.

[0065] In Example 11, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 30 mm, the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 along the second direction and the third inner wall 213 and the distance dimension E2 between the side of the tab 200 close to the fourth inner wall 214 along the second direction and the fourth inner wall 214 are set to 4 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 does not have problems, and in the process of press-fit welding, the tab 200 is not damaged, and after laser welding, no welding quality problems are found.

[0066] In Example 12, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 30 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 6 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have problems, and during the press-fit welding, the tab 200 did not have damage, and after laser welding, no welding quality problems were found.

[0067] In Example 13, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 30 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 8 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have problems, and during the press-fit welding, the tab 200 did not have damage, and after laser welding, no welding quality problems were found.

[0068] In Example 14, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 30 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 10 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have problems, and during the press-fit welding, the tab 200 did not have damage, and after laser welding, no welding quality problems were found.

[0069] In Example 15, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 10 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 1 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have problems, and during the press-fit welding, the tab 200 did not have damage, and after laser welding, no welding quality problems were found.

[0070] In Example 16, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 50 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 3 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have any problem, and during the press-fit welding, the tab 200 was not damaged, and after laser welding, no welding quality problem was found.

[0071] In Example 17, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 80 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 3 mm, so as to satisfy 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, the press-fit welding of the tab 200 did not have any problem, and during the press-fit welding, the tab 200 was not damaged, and after laser welding, no welding quality problem was found.

[0072] From the above Examples 9 to 17, it can be seen that when the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 satisfy 0.5 mm≤E1(E2)≤(0.3D) mm, the press-fit welding of the tab 200 can be ensured to proceed smoothly, and the tab 200 will not be damaged, and the quality after welding is ensured.

[0073] In Comparative Example 5, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 was set to 30 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were set to 0.2 mm, so as to not satisfy the range of 0.5 mm≤E1(E2)≤(0.3D) mm. After welding test, since the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 were less than the specified range, the press-fit of the tab 200 was extremely difficult, which led to poor fit of the tab 200 with the connecting groove 21 on the pole 2, and caused problems such as blowhole, false welding and the like during welding.

[0074] In the comparative example 6, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set as 30 mm, the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 are set as 12 mm, which does not satisfy the range of 0.5 mm≤E1(E2)≤(0.3D) mm. After the welding test, since the distance dimension E1 between the tab 200 along the second direction close to one side of the third inner wall 213 and the third inner wall 213 and the distance dimension E2 between the tab 200 along the second direction close to one side of the fourth inner wall 214 and the fourth inner wall 214 are greater than the specified range, the connection area of the tab 200 and the pole 2 is reduced, and the problem of tearing of the tab 200 during the press fitting occurs.

[0075] Optionally, as shown in FIG. 2 and FIG. 4, the battery cover plate further comprises an upper insulating piece 6, which is arranged on the side of the cover plate body 1 away from the cell pole group 100 and is provided with a first through hole 61 in communication with the pole column through hole 11, and the pole column 2 is arranged in the first through hole 61. The surface of the pole column 2 away from the cell pole group 100 is higher than the surface of the upper insulating piece 6 away from the cell pole group 100, and the difference is H, which satisfies 0.1 mm≤H≤2 mm.

[0076] By limiting the difference H between the surface of the pole column 2 away from the cell pole group 100 and the surface of the upper insulating piece 6 away from the cell pole group 100 to satisfy 0.1 mm≤H≤2 mm, on the one hand, it avoids affecting the welding of the bus bar and the pole column 2 due to the too small difference H, and on the other hand, it avoids affecting the height design of the pole column 2 due to the too large difference H, increasing the volume and increasing the manufacturing cost.

[0077] In the present embodiment, the battery cover plate further comprises a lower insulating piece 7, which is arranged on both sides of the cover plate body 1 together with the upper insulating piece 6, thereby improving the insulation performance of the battery cover plate, wherein the upper insulating piece 6 and the lower insulating piece 7 are both plastic materials. The difference H between the surface of the pole column 2 away from the cell pole group 100 and the surface of the upper insulating piece 6 away from the cell pole group 100 can be any value between 0.1 mm and 2 mm or a range between any two values, for example, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. In the present embodiment, the optimal value of the difference H between the surface of the pole column 2 away from the cell pole group 100 and the surface of the upper insulating piece 6 away from the cell pole group 100 is 0.35 mm.

[0078] Optionally, as shown in FIG. 2 and FIG. 7, the upper insulating piece 6 is provided with a mounting groove 62 on the side away from the cover plate body 1, and the first through hole 61 is arranged in the mounting groove 62. The battery cover plate further comprises a support 8, and the support 8 is provided with a mounting through hole 81 which is in communication with the first through hole 61. The support 8 is sleeved on the pole 2 and located in the mounting groove 62. By arranging the mounting groove 62 on the upper insulating piece 6, the support 8 can be conveniently limited and fixed. In this embodiment, the support 8 is in a ring structure and is welded with the pole 2.

[0079] Further, the wall thickness of the support 8 is T, and T≥1mm is satisfied. By limiting the wall thickness T of the support 8 to satisfy T≥1mm, it is avoided that the wall thickness T of the support 8 is too small, which causes the upper insulating piece 6 to melt when the support 8 is welded with the pole 2, thereby affecting the appearance and insulation performance of the battery.

[0080] Optionally, as shown in FIG. 2 and FIG. 4, the depth of the connecting groove 21 is M, and 0.01mm≤M≤4mm is satisfied. By limiting the depth M of the connecting groove 21 to satisfy 0.01mm≤M≤4mm, it is avoided that the depth M is too small, which causes the saved space to be limited and is not conducive to the improvement of the volume energy density of the battery, and it is also avoided that the depth M is too large, which causes the height of the pole 2 to increase and the manufacturing cost to increase.

[0081] In this embodiment, the depth M of the connecting groove 21 can be any value between 0.01mm and 4mm or a range between any two values, such as 0.01mm, 0.1mm, 1mm, 2mm, 3mm, 4mm, etc. In this embodiment, the optimal value of the difference H between the surface of the pole 2 away from the cell pole group 100 and the surface of the upper insulating piece 6 away from the cell pole group 100 is 2mm.

[0082] Optionally, the tab 200 and the pole 2 are laser welded, and a plurality of spaced-apart welding marks are formed on the area of the tab 200 covering the connecting groove 21. By using the discontinuous welding method of forming a plurality of spaced-apart welding marks, the deformation caused by long-time welding can be reduced, and the welding operation time can be shortened, thereby improving the welding operation efficiency. The welding marks are in a strip shape or a circular shape. In this embodiment, the welding marks are in a plurality of spaced-apart strip structures.

[0083] In this embodiment, a battery is also provided, which comprises the above-mentioned battery cover plate. The battery further comprises a cell pole group 100 and a battery shell. The battery cover plate is arranged on the battery shell to form a containing cavity for placing the cell pole group 100.

[0084] The battery has higher energy density, enhanced energy supply capacity and guaranteed battery quality reliability due to the improved welding quality by using the saved space to increase the volume of the battery cell pole group 100.

[0085] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents. Industrial applicability

[0086] By opening the connecting groove on the pole post of the battery cover plate, the tab connected with the pole post can be inserted into the connecting groove to realize connection, thereby saving the space reserved for realizing the connection between the tab and the pole post, thereby improving the space utilization, reducing the occupied space, and enabling the saved space to be used to increase the volume of the battery cell pole group, thereby improving the energy density; and by limiting the distance between the side of the tab close to the first inner wall along the first direction and the first inner wall in size, the area of the tab covering the connecting groove is increased while facilitating assembly, thereby ensuring the welding quality.

Claims

1. A battery cover plate, characterized by The battery cover plate comprises: a cover plate body, an electrode post through hole being formed in the cover plate body; an electrode post, the electrode post being arranged in the electrode post through hole and being provided with a connecting groove, and a tab of an electrode group being welded in the connecting groove; the connecting groove is provided with a first inner wall and a second inner wall on two sides in a first direction, a distance between the first inner wall and the second inner wall is A, a distance between a side of the tab close to the first inner wall in the first direction and the first inner wall is B, and 0.5mm≤B≤(A / 3)mm is satisfied.

2. The battery cover plate of claim 1, wherein, a distance between an end face of a bending end of the tab close to the second inner wall in the first direction and the second inner wall is C, and 2mm≤C≤(A / 3)mm is satisfied.

3. The battery cover plate of claim 1, wherein, the connecting groove is provided with a third inner wall and a fourth inner wall on two sides in a second direction, a distance between the third inner wall and the fourth inner wall is D, a distance between a side of the tab close to the third inner wall in the second direction and the third inner wall is E1, and 0.5mm≤E1≤(0.3D)mm is satisfied; and / or, a distance between a side of the tab close to the fourth inner wall in the second direction and the fourth inner wall is E2, and 0.5mm≤E2≤(0.3D)mm is satisfied.

4. The battery cover plate of claim 1, wherein, the battery cover plate further comprises an upper insulating piece, the upper insulating piece being arranged on a side of the cover plate body away from the electrode group and being provided with a first through hole in communication with the electrode post through hole, and the electrode post being arranged in the first through hole; and / or, a surface of the electrode post away from the electrode group is higher than a surface of the upper insulating piece away from the electrode group, a difference between the two surfaces is H, and 0.1mm≤H≤2mm is satisfied.

5. The battery cover plate of claim 4, wherein, a mounting groove is arranged on a side of the upper insulating piece away from the cover plate body, the first through hole is formed in the mounting groove, the battery cover plate further comprises a support piece, the support piece is provided with a mounting through hole in communication with the first through hole, the support piece is sleeved on the electrode post and is arranged in the mounting groove.

6. The battery cover plate of claim 5, wherein, a wall thickness of the support piece is T, and T≥1mm is satisfied.

7. The battery cover plate of claim 1, wherein, a depth of the connecting groove is M, and 0.01mm≤M≤4mm is satisfied.

8. The battery cover plate of claim 1, wherein, the tab and the electrode post are laser welded, and a plurality of interval distributed welding marks are formed on an area of the tab covering the connecting groove.

9. The battery cover plate of claim 8, wherein, the welding mark is in a strip shape or a circular shape.

10. A battery characterized by the battery comprises the battery cover plate according to any one of claims 1-9, the battery further comprises the electrode group and a battery shell, and the battery cover plate is arranged on the battery shell to form a containing chamber for placing the electrode group.

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