Battery cover plate and battery

Abstract

The present invention belongs to the technical field of batteries, and discloses a battery cover plate and a battery. The battery cover plate includes a cover plate body and a pole column. A pole column through hole is formed in the cover plate body. The pole column is inserted into the pole column through hole and is provided with a connection groove. The pole ear is welded in the connection groove. The two sides of the connection groove along the first direction are provided with a first inner wall and a second inner wall. The distance dimension between the first inner wall and the second inner wall is A, and the distance dimension between the side of the pole ear close to the first inner wall along the first direction and the first inner wall is B, and 0.5 mm ≤ B ≤ (A / 3) mm is satisfied. By welding the pole ear into the connection groove, the occupied space is reduced, the volume of the battery cell pole group is increased, and the energy density is improved. Moreover, by limiting the distance dimension B between the side of the pole ear close to the first inner wall along the first direction and the first inner wall, while facilitating welding, the connection area is increased and the welding quality is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery cover plate and a battery. Background Art

[0002] A battery generally includes a battery cover plate, a battery housing, and an electrode assembly of an electric core. The battery housing is a housing structure with an open side. By covering the battery cover plate on the open port of the battery housing, a storage space is formed. The electrode assembly of the electric core is arranged in the storage space, and an electrolyte is injected into the storage space.

[0003] Among them, the battery cover plate has the functions of fixing and sealing, current conduction, pressure relief, and fuse protection. The current conduction is achieved by welding the pole column on the battery cover plate to the tab of the electrode assembly of the electric core, so as to achieve the function of current conduction.

[0004] However, the traditional riveted cover plate has more parts, complex process assembly, the bottom of the pole column occupies more internal space of the battery, and a space for welding with the tab needs to be reserved. Due to the superposition of the volume of the battery cover plate itself and the space reserved for welding with the tab, a large amount of internal storage space of the battery housing will be occupied, so the volume of the electrode assembly of the electric core needs to be reduced to meet the assembly requirements, resulting in a low energy density of the battery. Summary of the Invention

[0005] The purpose of the present invention is to provide a battery cover plate and a battery, which have high space utilization rate, small occupied space, and high battery energy density.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] On the one hand, a battery cover plate is provided, and the battery cover plate includes:

[0008] A cover plate body, and a pole column through hole is opened on the cover plate body;

[0009] A pole column, which is arranged in the pole column through hole and is provided with a connection groove, and the tab of the electrode assembly of the electric core is welded in the connection groove;

[0010] The two sides of the connection groove along a first direction are provided with a first inner wall and a second inner wall, the distance dimension between the first inner wall and the second inner wall is A, the distance dimension between the tab and the first inner wall on the side close to the first inner wall along the first direction is B, and 0.5 mm ≤ B ≤ (A / 3) mm is satisfied.

[0011] Optionally, the distance dimension between the end face on the side close to the second inner wall of the bent end of the tab along the first direction and the second inner wall is C, and 2 mm ≤ C ≤ (A / 3) mm is satisfied.

[0012] Optionally, third inner wall and fourth inner wall are provided on two sides of the connecting groove along the second direction, the distance dimension between the third inner wall and the fourth inner wall is D, the distance dimension between one side of the tab along the second direction close to the third inner wall and the third inner wall is E1, and 0.5 mm ≤ E1 ≤ (0.3D) mm is satisfied;

[0013] And / or, the distance dimension between one side of the tab along the second direction close to the fourth inner wall and the fourth inner wall is E2, and 0.5 mm ≤ E2 ≤ (0.3D) mm is satisfied.

[0014] Optionally, the battery cover plate further includes an upper insulating member, the upper insulating member is provided on a side of the cover plate body facing away from the battery cell electrode group, and a first through hole communicating with the pole column through hole is opened, and the pole column is inserted into the first through hole;

[0015] And / or, the surface of the pole column facing away from the battery cell electrode group is higher than the surface of the upper insulating member facing away from the battery cell electrode group, and the difference value is H, and 0.1 mm ≤ H ≤ 2 mm is satisfied.

[0016] Optionally, an installation groove is provided on a side of the upper insulating member facing away from the cover plate body, the first through hole is opened in the installation groove, the battery cover plate further includes a support member, an installation through hole communicating with the first through hole is opened on the support member, the support member is sleeved on the pole column and is located in the installation groove.

[0017] Optionally, the wall thickness dimension of the support member is T, and T ≥ 1 mm is satisfied.

[0018] Optionally, the depth dimension of the connecting groove is M, and 0.01 mm ≤ M ≤ 4 mm is satisfied.

[0019] Optionally, the tab and the pole column are laser welded, and a plurality of weld marks are formed at intervals in a region where the tab covers the connecting groove.

[0020] Optionally, the weld marks are strip-shaped or circular.

[0021] On the other hand, a battery is provided, the battery includes the battery cover plate as described in any one of the above, the battery further includes the battery cell electrode group and a battery housing, and the battery cover plate is covered on the battery housing to form an accommodation chamber for placing the battery cell electrode group.

[0022] Advantages of the present invention:

[0023] The present invention provides a battery cover plate. By providing a connection groove on the pole column of the battery cover plate, the tab connected to the pole column can extend into the connection groove to achieve connection, thereby saving the space reserved for connecting the tab to the pole column, improving the space utilization rate, reducing the occupied space, enabling the saved space to be used to increase the volume of the battery cell pole group, thereby increasing the energy density. And by defining the dimension B of the distance between the side of the tab close to the first inner wall in the first direction and the first inner wall, making it satisfy 0.5mm ≤ B ≤ (A / 3)mm, while facilitating assembly, the area of the tab covering the connection groove is increased, thereby ensuring the welding quality.

[0024] The present invention also provides a battery. By applying the above battery cover plate, the volume of the battery cell pole group is increased by using the saved space, thereby having a higher energy density, enhancing the power supply capacity. And due to the improvement of the welding quality, the reliability of the battery quality is also ensured. Brief Description of the Drawings

[0025] Figure 1 is a schematic diagram of the connection relationship between the battery cover plate provided by the present invention and the battery cell pole group;

[0026] Figure 2 is an exploded view of the structure of the battery cover plate provided by the present invention;

[0027] Figure 3 is a sectional view of the battery cover plate provided by the present invention;

[0028] Figure 4 is Figure 3 an enlarged view of the structure of part Ⅰ in ;

[0029] Figure 5 is a schematic diagram of the matching dimension relationship after the tab in the battery cover plate provided by the present invention and the battery cell pole group is bent;

[0030] Figure 6 is a schematic diagram of the matching dimension relationship before the tab in the battery cover plate provided by the present invention and the battery cell pole group is bent;

[0031] Figure 7 is a schematic diagram of the structure of the upper insulating part in the battery cover plate provided by the present invention.

[0032] In the figure:

[0033] 100, battery cell pole group; 200, tab;

[0034] 1, cover plate body; 11, pole column through hole; 12, mounting hole; 13, liquid injection hole;

[0035] 2. Terminal; 21. Connecting groove; 211. First inner wall; 212. Second inner wall; 213. Third inner wall; 214. Fourth inner wall;

[0036] 3. Explosion-proof valve;

[0037] 4. Protective film;

[0038] 5. Sealing ring;

[0039] 6. Upper insulating part; 61. First through hole; 62. Mounting groove;

[0040] 7. Lower insulating part;

[0041] 8. Support part; 81. Mounting through hole. Detailed implementation manners

[0042] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0043] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above and over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below and under", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the first feature has a lower horizontal height than the second feature.

[0045] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", etc. are based on the orientation or positional relationships shown in the drawings. They are only for the convenience of description and simplifying operations, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0046] A battery generally includes a battery cover plate, a battery case, and an electrode group of the battery cell. The battery case is a housing structure with an open side. By covering the battery cover plate on the open part of the battery case, a storage space is formed. The electrode group of the battery cell is arranged in the storage space, and electrolyte is injected into the storage space.

[0047] Among them, the battery cover plate has the functions of fixing and sealing, current conduction, pressure relief, and fuse protection. The current conduction is achieved by welding the pole column on the battery cover plate to the tab of the electrode group of the battery cell, thereby realizing the current conduction function.

[0048] However, the traditional riveted cover plate has more components, complex process assembly, the bottom of the pole column occupies more internal space of the battery, and a space for welding with the tab needs to be reserved. Due to the superposition of the volume of the battery cover plate itself and the space reserved for welding with the tab, a large amount of internal storage space of the battery case will be occupied, so the volume of the electrode group of the battery cell needs to be reduced to meet the assembly requirements, resulting in a low energy density of the battery.

[0049] Therefore, in order to improve the space utilization rate, increase the volume of the electrode group of the battery cell, and improve the energy density of the battery, this embodiment provides a battery cover plate.

[0050] As Figures 1 to 7 shown, the battery cover plate includes a cover plate body 1 and a pole column 2. A pole column through hole 11 is formed on the cover plate body 1. The pole column 2 is inserted into the pole column through hole 11, and a connection groove 21 is formed. The tab 200 of the electrode group 100 of the battery cell is welded in the connection groove 21. First inner wall 211 and second inner wall 212 are provided on both sides of the connection groove 21 along the first direction. The distance dimension between the first inner wall 211 and the second inner wall 212 is A, and the distance dimension between the tab 200 and the first inner wall 211 on the side close to the first inner wall 211 along the first direction is B, and 0.5mm ≤ B ≤ (A / 3)mm is satisfied.

[0051] By providing a connection groove 21 on the terminal post 2 of the battery cover plate, the tab 200 connected to the terminal post 2 can extend into the connection groove 21 to achieve connection, thus saving the space reserved for connecting the tab 200 to the terminal post 2, improving the space utilization rate, reducing the occupied space, and enabling the saved space to be used to increase the volume of the battery cell stack 100, thereby increasing the energy density. And by defining the dimension B of the distance between the side of the tab 200 close to the first inner wall 211 along the first direction and the first inner wall 211 to satisfy 0.5 mm ≤ B ≤ (A / 3) mm, while facilitating assembly, the area where the tab 200 covers the connection groove 21 is increased, thus ensuring the welding quality.

[0052] In this embodiment, 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. After the explosion-proof valve 3 is installed in the installation hole 12, a protective film 4 is pasted on its outer surface. In addition, to facilitate the injection of the electrolyte, a liquid injection hole 13 for injecting the electrolyte is also provided on the cover plate body 1. And to improve the sealing performance of the battery cover plate, a sealing ring 5 is further provided between the terminal post 2 and the terminal post through hole 11 of the cover plate body 1.

[0053] Optionally, as Figure 2 、 Figure 5 shown, the dimension of the distance between the end face on the side close to the second inner wall 212 of the bent end of the tab 200 along the first direction and the second inner wall 212 is C, and it satisfies 2 mm ≤ C ≤ (A / 3) mm. By defining the dimension C of the distance between the bent end of the tab 200 along the first direction close to the second inner wall 212 and the second inner wall 212, after the tab 200 is bent, it has both sufficient connection area and sufficient clearance between the bent end of the tab 200 and the second inner wall 212, facilitating subsequent welding operations. Among them, the dimension B of the distance 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 dimension C of the distance between the bent end of the tab 200 along the first direction close to the second inner wall 212 and the second inner wall 212 cooperate with each other, so that while the tab 200 has sufficient connection area, there is also sufficient clearance between the tab 200 and both the first inner wall 211 and the second inner wall 211 of the connection groove 21, thus facilitating the welding operation.

[0054] As shown in Table 1, to verify the rationality of the dimension ranges of the dimension B of the distance 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 dimension C of the distance between the bent end of the tab 200 along the first direction close to the second inner wall 212 and the second inner wall 212, eight groups of examples and four groups of comparative examples are selected for verification.

[0055] Table 1

[0056]

[0057] In Embodiment 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 in the first direction and the first inner wall 211 is set to 0.5 mm, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0058] In Embodiment 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0059] In Embodiment 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0060] In Embodiment 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0061] 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0062] 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0063] 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0064] In Embodiment 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 in the first direction and the first inner wall 211 is set to 4 mm, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0065] As can be seen from the above Embodiments 1 to 8, when 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 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 satisfies 2 mm ≤ C ≤ (A / 3) mm, the smooth progress of the press-fit welding of the tab 200 can be ensured, and the tab 200 will not be damaged, ensuring the quality after welding.

[0066] 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 in the first direction and the first inner wall 211 is set to 0.2 mm. At this time, the distance dimension B is less than the minimum value within the range of 0.5 mm ≤ B ≤ (A / 3) mm. 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, so that 2 mm ≤ C ≤ (A / 3) mm is satisfied. After the welding test, since 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 less than the specified range, the pressing of the tab 200 is extremely difficult, resulting in poor fitting between the tab 200 and the connection groove 21 on the pole column 2, and causing poor problems such as explosion points and false soldering during welding.

[0067] 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, so that 0.5 mm ≤ B ≤ (A / 3) mm is satisfied. 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. At this time, the distance dimension C is less than the minimum value within 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 connection area of the tab 200 and the pole column 2 in the first direction is small, resulting in the tearing of the tab 200 when the tab 200 is pressed.

[0068] 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, such that 0.5 mm ≤ B ≤ (A / 3) mm. 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. At this time, the distance dimension C is greater than the maximum value within the range of 2 mm ≤ C ≤ (A / 3) mm. After welding tests, 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 within the specified range, in order to achieve the fit between the tab 200 and the connection groove 21 on the terminal 2, the width dimension of the terminal 2 in the first direction is increased, thereby increasing the volume of the terminal 2, resulting in an increase in the dimensions of other components that cooperate with the terminal 2, and thus leading to an increase in cost.

[0069] In Comparative 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 12 mm. At this time, the distance dimension B is greater than the maximum value within the range of 0.5 mm ≤ B ≤ (A / 3) mm. 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, such that 2 mm ≤ C ≤ (A / 3) mm. After welding tests, since 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 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 in the first direction and the second inner wall 212 is within the specified range, in order to achieve the fit between the tab 200 and the connection groove 21 on the terminal 2, the width dimension of the terminal 2 in the first direction is increased, thereby increasing the volume of the terminal 2, resulting in an increase in the dimensions of other components that cooperate with the terminal 2, and thus leading to an increase in cost.

[0070] Optionally, as Figure 2 、 Figure 6As shown, on both sides of the connecting groove 21 along the second direction, there are a third inner wall 213 and a fourth inner wall 214. 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 it satisfies 0.5mm ≤ E1 ≤ (0.3D)mm. 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 it satisfies 0.5mm ≤ E2 ≤ (0.3D)mm.

[0071] By setting the dimension ranges 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, the distance dimension E1 satisfies 0.5mm ≤ E1 ≤ (0.3D)mm, and the distance dimension E2 satisfies 0.5mm ≤ E2 ≤ (0.3D)mm. Thus, sufficient gaps are left between both 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, facilitating subsequent welding operations. At the same time, the width of the tab 200 along the second direction is ensured, so that there is sufficient connection area between the tab 200 and the pole 2 in the second direction, thereby ensuring the connection strength after welding. The numerical 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.

[0072] As shown in Table 2, taking the case where 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 is the same as 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 an example, in order to verify the rationality of the dimension ranges 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.

[0073] Table 2

[0074]

[0075] 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 in 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 in the second direction and the fourth inner wall 214 are set to 0.5 mm, so that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0076] 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 in 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 in the second direction and the fourth inner wall 214 are set to 2 mm, so that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0077] 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 in 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 in the second direction and the fourth inner wall 214 are set to 4 mm, so that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0078] In Example 12, 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 in 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 in the second direction and the fourth inner wall 214 are set to 6 mm, so that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, there are no problems with the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 is not damaged. After laser welding, no welding quality problems are found.

[0079] In Embodiment 13, 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 in 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 in the second direction and the fourth inner wall 214 are set to 8 mm, such that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0080] In Embodiment 14, 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 in 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 in the second direction and the fourth inner wall 214 are set to 10 mm, such that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0081] In Embodiment 15, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 10 mm. The distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are set to 1 mm, such that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0082] In Embodiment 16, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 50 mm. The distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are set to 3 mm, such that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding tests, no problems occurred in the press-fit welding of the tab 200. During the press-fit welding process, the tab 200 was not damaged. After laser welding, no welding quality problems were found.

[0083] In Embodiment 17, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 80 mm. The distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are set to 3 mm, such that 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm is satisfied. After welding tests, no problems occurred in the press-fitting welding of the tab 200. During the press-fitting welding process, the tab 200 was not damaged, and after laser welding, no welding quality problems were found.

[0084] As can be seen from the above Embodiment 9 to Embodiment 17, when the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 satisfy 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm, the smooth progress of the press-fitting welding of the tab 200 can be ensured, and the tab 200 will not be damaged, ensuring the quality after welding.

[0085] In Comparative Example 5, 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 in 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 in the second direction and the fourth inner wall 214 are set to 0.2 mm, such that the range of 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm is not satisfied. After welding tests, since the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are less than the specified range, the press-fitting of the tab 200 is extremely difficult, resulting in poor fitting between the tab 200 and the connection groove 21 on the pole column 2, and causing problems such as explosion points and false soldering during welding.

[0086] In Comparative Example 6, the distance dimension D between the third inner wall 213 and the fourth inner wall 214 is set to 30 mm, and the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are set to 12 mm, so that it does not satisfy the range of 0.5 mm ≤ E1 (E2) ≤ (0.3D) mm. After welding testing, since the distance dimension E1 between the side of the tab 200 close to the third inner wall 213 in 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 in the second direction and the fourth inner wall 214 are greater than the specified range, the connection area between the tab 200 and the terminal 2 is reduced, resulting in the problem of tearing of the tab 200 during press-fitting.

[0087] Optionally, as Figure 2 、 Figure 4 shown, the battery cover plate further includes an upper insulating member 6. The upper insulating member 6 is disposed on the side of the cover plate body 1 facing away from the battery cell electrode group 100, and is provided with a first through hole 61 communicating with the terminal through hole 11. The terminal 2 is inserted into the first through hole 61. The surface of the terminal 2 facing away from the battery cell electrode group 100 is higher than the surface of the upper insulating member 6 facing away from the battery cell electrode group 100, and the difference therebetween is H, and 0.1 mm ≤ H ≤ 2 mm is satisfied.

[0088] By limiting the difference H between the surface of the terminal 2 facing away from the battery cell electrode group 100 and the surface of the upper insulating member 6 facing away from the battery cell electrode group 100 to satisfy 0.1 mm ≤ H ≤ 2 mm, on the one hand, it is avoided that the difference H is too small, which affects the welding of the bus bar and the terminal 2. On the other hand, it is avoided that the difference H is too large, which affects the height design of the terminal 2, increases the volume, and raises the manufacturing cost.

[0089] In this embodiment, the battery cover plate further includes a lower insulating member 7, which is respectively disposed on both sides of the cover plate body 1 with the upper insulating member 6, so as to improve the insulation performance of the battery cover plate. Both the upper insulating member 6 and the lower insulating member 7 are made of plastic material. Wherein, the difference H between the surface of the terminal 2 facing away from the battery cell electrode group 100 and the surface of the upper insulating member 6 facing away from the battery cell electrode group 100 can be any value between 0.1 mm and 2 mm or the range between any two values, such as 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. In this embodiment, the optimal value of the difference H between the surface of the terminal 2 facing away from the battery cell electrode group 100 and the surface of the upper insulating member 6 facing away from the battery cell electrode group 100 is 0.35 mm.

[0090] Optionally, as Figure 2 、 Figure 7As shown, on the side of the upper insulating part 6 facing away from the cover plate body 1, there is an installation groove 62, and the first through hole 61 is opened in the installation groove 62. The battery cover plate further includes a support part 8, and an installation through hole 81 communicating with the first through hole 61 is opened on the support part 8. The support part 8 is sleeved on the pole column 2 and is located in the installation groove 62. By providing the installation groove 62 on the upper insulating part 6, it is convenient to limit and fix the support part 8. In this embodiment, the support part 8 is of an annular structure and is welded to the pole column 2.

[0091] Furthermore, the wall thickness dimension of the support part 8 is T, and it satisfies T≥1mm. By limiting the wall thickness dimension T of the support part 8 to satisfy T≥1mm, it is avoided that the wall thickness dimension T of the support part 8 is too small, resulting in the melting of the upper insulating part 6 when the support part 8 is welded to the pole column 2, affecting the appearance and insulating performance of the battery.

[0092] Optionally, as Figure 2 、 Figure 4 shown, the depth dimension of the connection groove 21 is M, and it satisfies 0.01mm≤M≤4mm. By limiting the depth dimension M of the connection groove 21 to satisfy 0.01mm≤M≤4mm, it is avoided that the depth dimension M is too small, resulting in limited saved space and being unfavorable for improving the volume energy density of the battery, and it is also avoided that the depth dimension M is too large, resulting in an increase in the height dimension of the pole column 2 and an increase in the manufacturing cost.

[0093] In this embodiment, the depth dimension M of the connection groove 21 can be any value between 0.01mm and 4mm or the 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 column 2 facing away from the battery cell pole group 100 and the surface of the upper insulating part 6 facing away from the battery cell pole group 100 is 2mm.

[0094] Optionally, the pole ear 200 and the pole column 2 are laser welded, and a plurality of weld marks are formed in a spaced-apart manner in the area where the pole ear 200 covers the connection groove 21. By adopting the discontinuous welding method of forming a plurality of spaced-apart weld marks, the deformation caused by long-time welding can be reduced, and the welding operation time can be shortened, improving the welding operation efficiency. Among them, the weld marks are strip-shaped or circular. In this embodiment, the weld marks are a plurality of spaced-apart strip-shaped structures.

[0095] In this embodiment, a battery is also provided. This battery includes the above-mentioned battery cover plate. The battery further includes a battery cell pole group 100 and a battery housing. The battery cover plate is covered on the battery housing to form an accommodation chamber for placing the battery cell pole group 100.

[0096] By applying the above-mentioned battery cover plate, the battery increases the volume of the battery cell electrode group 100 by using the saved space, thereby having a higher energy density, enhancing the power supply capacity, and also ensuring the reliability of the battery quality due to the improvement of the welding quality.

[0097] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery cover, characterized in that: The battery cover comprises: A cover plate body, wherein a pole through hole is formed on the cover plate body; A pole, the pole is inserted into the pole through hole and is provided with a connection groove, and the pole lug of the battery cell pole group is welded in the connection groove; The connecting groove is provided with a first inner wall and a second inner wall on both sides 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 pole ear 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; The distance between the end surface of the bent end of the pole tab close to the second inner wall along the first direction and the second inner wall is C, and satisfies 2mm≤C≤(A / 3)mm; The connecting groove is provided with a third inner wall and a fourth inner wall on both sides along the second direction, the distance dimension between the third inner wall and the fourth inner wall is D, the distance dimension between the side of the pole ear 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; And / or, the distance between the side of the pole tab close to the fourth inner wall along the second direction and the fourth inner wall is E2, and satisfies 0.5 mm ≤ E2 ≤ (0.3D) mm; The battery cover plate also includes an upper insulating member, a mounting groove is provided on the side of the upper insulating member facing away from the cover plate body, a first through hole is opened in the mounting groove, the battery cover plate also includes a support member, a mounting through hole connected to the first through hole is opened on the support member, the support member is sleeved on the pole and located in the mounting groove, the support member is an annular structure, and is welded to the pole.

2. The battery cover according to claim 1, characterized in that: The upper insulating member is arranged on a side of the cover body away from the battery cell electrode group, and is provided with a first through hole connected to the pole through hole, and the pole is passed through the first through hole; And / or, the surface of the pole facing away from the battery cell electrode group is higher than the surface of the upper insulating member facing away from the battery cell electrode group, the difference is H, and 0.1 mm≤H≤2 mm is satisfied.

3. The battery cover according to claim 1, characterized in that: The wall thickness dimension of the support member is T, and satisfies T≥1mm.

4. The battery cover according to claim 1, characterized in that: The depth dimension of the connecting groove is M, and satisfies 0.01mm≤M≤4mm.

5. The battery cover according to claim 1, characterized in that: The pole tab and the pole column are welded by laser, and a plurality of weld marks distributed at intervals are formed on the area where the pole tab covers the connecting groove.

6. The battery cover according to claim 5, characterized in that: The welding mark is in the shape of a strip or a circle.

7. A battery, characterized in that The battery comprises the battery cover as described in any one of claims 1-6, and the battery also comprises the battery cell group and a battery shell, and the battery cover is arranged on the battery shell to form a accommodating chamber for placing the battery cell group.

Images