Cover plate, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate, a battery cell and a battery pack, and the cover plate comprises a cover plate body, a first insulating part and a pole. The thickness of the cover plate and the bottom plate of the structure can meet the strength requirement and the welding requirement of the lug, so that the pole material can be saved; according to the cover plate, the plurality of buffer ribs are arranged on the side wall of one side, facing the middle area of the cover plate, of the short-edge convex part, so that the inclined plane buffer section is established in the height difference area between the short-edge convex part and the bottom plate, and when a welding copper nozzle is used for pressing and welding a tab, the inclined planes of the buffer ribs support the tab, so that the tab can be buffered. Meanwhile, H and L meet the conditions that H is larger than 0 and smaller than or equal to 1 mm, and L is larger than or equal to 0.8 mm, so that the inclined plane is the inclined plane with a slow gradient, the supporting and buffering effects of the inclined plane on the tab can be ensured, and the tab can be effectively prevented from being crushed by the welding copper nozzle and torn.

Description

Technical Field

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

[0002] like Figure 1 As shown, the cover includes components such as a cover body 1', a pole and a first insulating member 2', wherein the pole includes a base plate 31' and a column portion 32' provided on the base plate, and the column portion 32' passes through the first insulating member 2' and the cover body 1'. After the cover is assembled, the pole lug 71' of the pole group 7' is welded to the pole base plate. The first insulating member is provided on one side surface of the cover body facing the inner side of the cover, and the two ends of the first insulating member in the width direction are provided with a short side protrusion 22' and a long side protrusion 21' extending toward the inner side of the cover, and the length of the long side protrusion extending toward the inner side of the cover body is greater than the length of the short side protrusion extending toward the inner side of the cover body.

[0003] In order to facilitate the welding of the pole ear and the base plate, usually the side surface of the pole base plate facing the inner side of the cover plate needs to be flush with the side surface of the short side protrusion facing the inner side of the cover plate, or the side surface of the pole base plate facing the inner side of the cover plate needs to protrude from the side surface of the short side protrusion facing the inner side of the cover plate, which results in a larger thickness of the base plate and increased pole material cost; if the side surface of the pole base plate facing the inner side of the cover plate is retracted from the side surface of the short side protrusion facing the inner side of the cover plate, the welding tooling may easily crush the pole ear during the welding process, causing the pole ear to tear. Summary of the Invention

[0004] In view of this, the present invention provides a cover plate, a battery cell and a battery pack to solve the problem in the prior art that the thickness of the pole bottom plate of the cover plate is relatively thick and / or the welding tooling is prone to crushing the pole tab during welding.

[0005] In a first aspect, the present invention provides a cover plate, comprising:

[0006] Cover plate body;

[0007] a first insulating member, provided on a side surface of the cover plate body facing the inner side of the cover plate; a long side protrusion and a short side protrusion protruding toward the inner side of the cover plate are respectively provided at both ends in the width direction of the side surface of the first insulating member facing the inner side of the cover plate, the length of the long side protrusion protruding toward the inner side of the cover plate being greater than the length of the short side protrusion protruding toward the inner side of the cover plate; a plurality of buffer ribs are provided at intervals in the length direction of the side wall of one side of the short side protrusion facing the middle area of ​​the cover plate along the width direction of the cover plate, the side surface of the buffer rib facing the inner side of the cover plate is an inclined surface, and the side of the inclined surface close to the short side protrusion is connected to the side surface of the short side protrusion facing the inner side of the cover plate;

[0008] The pole includes a base plate and a column portion provided on the base plate, wherein the column portion passes through the first insulating member and the cover plate body; the base plate is located between the long-side raised portion and the buffer rib, and the side surface of the base plate facing the inner side of the cover plate is retracted from the side surface of the short-side raised portion facing the inner side of the cover plate; along the height direction of the cover plate, the distance between the side surface of the base plate facing the inner side of the cover plate and the side surface of the short-side raised portion facing the inner side of the cover plate is H, and the distance between the short-side raised portion and the facing side of the base plate is L, 0<H≤1mm, L≥0.8mm.

[0009] Beneficial effect: The thickness of the bottom plate of the cover plate of this structure is set to meet the strength requirements and the welding requirements with the pole ear. The side surface of the bottom plate facing the inner side of the cover plate is retracted into the side surface of the short side protrusion facing the inner side of the cover plate, which can save pole material; the cover plate is provided with multiple buffer ribs on the side wall of the short side protrusion facing the middle area of ​​the cover plate, and the side surface of the buffer rib facing the inner side of the cover plate is an inclined surface, and the two sides of the inclined surface respectively support the side surface of the short side protrusion facing the inner side of the cover plate and the side surface of the bottom plate facing the inner side of the cover plate, thereby establishing an inclined surface buffer section in the height difference area between the short side protrusion and the bottom plate. When welding the pole ear, the pole group is located outside one side of the short side protrusion, and the pole ear close to the pole group side gradually tilts along the inclined surface to transition to the bottom plate and then is laid on the bottom plate parallel to the bottom plate. When using a welding copper nozzle to press and weld the pole ear, the inclined surface of the buffer rib supports the pole ear, which can play a buffering role for the pole ear. At the same time, the distance H between the side surface of the bottom plate facing the inner side of the cover plate and the side surface of the short side protrusion facing the inner side of the cover plate, as well as the distance L between the short side protrusion and the opposite side of the bottom plate satisfy 0<H≤1mm, L≥0.8mm. This setting can make the inclined surface a slope with a gentle slope, which can ensure the support and buffering effect of the inclined surface on the pole ear, and can effectively prevent the welding copper nozzle from crushing the pole ear and prevent the pole ear from tearing.

[0010] In an optional embodiment, a surface of the bottom plate facing the inner side of the cover plate protrudes from a side of the inclined surface close to the bottom plate.

[0011] Beneficial effect: This arrangement allows the side of the inclined surface close to the bottom plate to transition better to the side surface of the bottom plate facing the inner side of the cover plate. The tab can gradually transition from the inclined surface to the bottom plate, which can prevent the tab from contacting the sharp corners of the buffer rib, improve the support and buffering effect of the buffer rib on the tab, and avoid the tab from tearing.

[0012] In an optional embodiment, a section of the inclined surface close to the short-side raised portion is a first arc surface, and the first arc surface smoothly transitions to the inner surface of the short-side raised portion.

[0013] Beneficial effect: In this way, the bending area of ​​the tab can be supported by a smooth arc surface, which can better support the tab, further improve the buffering effect on the tab, and prevent the tab from being damaged.

[0014] In an optional embodiment, a sealing ring is further included, which is sleeved on the column portion. The sealing ring includes a parallel portion, and a side surface of the parallel portion facing the inner side of the cover plate abuts against a side surface of the bottom plate facing the outer side of the cover plate. Along the width direction of the cover plate, before the sealing ring is compressed, the distance between the parallel portion and the side wall facing the buffer rib is a, 0.3mm≤a≤0.5mm.

[0015] Beneficial effects: This arrangement can ensure the spacing between the side walls facing the buffer ribs, prevent the spacing between the two from being too small, prevent the side walls of the parallel part from exceeding the side walls of the bottom plate before the sealing ring is compressed, ensure that the bottom plate completely presses the parallel part, ensure the compression effect on the parallel part, and ensure the sealing of the sealing ring; at the same time, it can avoid the spacing between the parallel part and the side walls facing the buffer ribs from being too large, and ensure that the parallel part abuts against the first insulating part after compression, thereby ensuring sealing.

[0016] In an optional embodiment, one end of the buffer rib toward the outer side of the cover plate extends to the root of the short side protrusion, and the side wall of the bottom plate facing the buffer rib abuts against the buffer rib.

[0017] Beneficial effect: This arrangement can increase the contact area between the side wall of the buffer rib and the side wall of the bottom plate, and the bottom plate can be limited in the width direction by the buffer rib, which can ensure the limiting effect of the buffer rib on the pole; in addition, the pole bottom plate is limited by the buffer rib, compared with the limiting method of limiting the bottom plate in the width direction by the short side protrusion, the multiple buffer ribs on the side of the bottom plate are arranged at intervals. When welding the pole ear and the bottom plate, the welding heat can be dissipated through the gap between the buffer ribs, which can prevent heat accumulation at the short side protrusion and cause the short side protrusion to melt due to heat, and can improve the heat dissipation effect during pole ear welding.

[0018] In an optional embodiment, along the length direction of the cover plate, among the buffer ribs abutting against the bottom plate, the spacing between adjacent buffer ribs is W, and 2mm≤W≤5mm.

[0019] Beneficial effect: This arrangement can prevent the spacing between adjacent buffer ribs from being too large, and can further improve the supporting and positioning effect of the buffer ribs on the base plate.

[0020] In an optional embodiment, along the width direction of the cover plate, a plurality of limiting ribs are provided at intervals in the length direction of the side wall of one side of the long side protrusion toward the middle area of ​​the cover plate, and the side of the bottom plate facing the long side protrusion abuts against the limiting ribs.

[0021] Beneficial effects: The limiting ribs and the buffer ribs cooperate to abut against the two long sides of the base plate respectively to limit the width direction of the base plate. The limiting ribs and the buffer parts are arranged at intervals along the length direction of the base plate. When welding the tabs, heat can flow and dissipate from the gaps between adjacent limiting ribs and adjacent buffer ribs, which can improve the heat dissipation effect when welding the tabs.

[0022] In an optional embodiment, the plurality of limiting ribs and the plurality of buffer ribs on both sides of the bottom plate in the width direction are arranged opposite to each other.

[0023] In a second aspect, the present invention further provides a battery cell comprising a housing and a cover plate as described above, wherein the housing has an opening and the cover plate is disposed over the opening. The battery cell including the cover plate has the same technical effects as the cover plate and will not be further described here.

[0024] In a third aspect, the present invention further provides a battery pack comprising the aforementioned battery cell. The battery pack includes a cover plate, which has the same technical effects as the cover plate and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic diagram of the welding of the cover plate and the tab described in the background technology of the present invention;

[0027] Figure 2 A top view of a cover plate according to an embodiment of the present invention;

[0028] Figure 3 for Figure 2 AA section view (including dimension marks);

[0029] Figure 4 for Figure 2 AA section view (excluding dimension marks);

[0030] Figure 5 for Figure 4 A partial enlarged view of part A;

[0031] Figure 6 for Figure 2 BB cross-sectional view;

[0032] Figure 7 for Figure 2A schematic diagram of the three-dimensional structure of the cover plate shown;

[0033] Figure 8 for Figure 7 The schematic diagram of the pole after the cover is removed is shown;

[0034] Figure 9 for Figure 2 Bottom view of the cover shown.

[0035] Description of reference numerals:

[0036] 1', cover body; 2', first insulating member; 21', long side protrusion; 22', short side protrusion; 31', bottom plate; 32', column; 7', pole group; 71', pole ear;

[0037] 1. Cover plate body; 2. First insulating part; 21. Long side raised part; 22. Short side raised part; 23. Buffer rib; 231. Inclined surface; 2311. First arc surface; 24. Limiting rib; 3. Pole; 31. Bottom plate; 32. Column; 4. Sealing ring; 41. Parallel part; 5. Second insulating part; 6. Riveted block. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0039] like Figure 1 As shown, the cover in the related art includes components such as a cover body 1', a pole and a first insulating member 2', wherein the pole includes a base plate 31' and a column portion 32' provided on the base plate, and the column portion 32' passes through the first insulating member 2' and the cover body 1'. After the cover is assembled, the pole lug 71' of the pole group 7' is welded to the pole base plate. The first insulating member is provided on one side surface of the cover body facing the inner side of the cover, and the two ends of the first insulating member in the width direction are provided with a short side protrusion 22' and a long side protrusion 21' extending toward the inner side of the cover, and the length of the long side protrusion protruding toward the inner side of the cover body is greater than the length of the short side protrusion protruding toward the inner side of the cover body.

[0040] like Figure 1As shown, when welding the tab to the electrode assembly, the tab passes over the short-side protrusion and is placed flush with the base plate. The tab and cover plate are secured with a fixture, and the welding nozzle presses the tab and welds the tab to the base plate. If the side of the base plate facing the inner side of the cover plate is indented behind the side of the short-side protrusion facing the inner side of the cover plate, the tab will bend at a large angle between the short-side protrusion and the base plate due to the height difference between the short-side protrusion and the base plate. This can easily cause the tab to be crushed and tear under the pressure of the welding nozzle. In order to facilitate the welding of the pole ear and the base plate and avoid the pole ear from tearing, usually the side surface of the pole base plate facing the inner side of the cover plate needs to be flush with the side surface of the short side protrusion facing the inner side of the cover plate, or the side surface of the pole base plate facing the inner side of the cover plate needs to protrude from the side surface of the short side protrusion facing the inner side of the cover plate, which results in a larger thickness of the base plate and increased pole material cost; if the side surface of the pole base plate facing the inner side of the cover plate is retracted from the side surface of the short side protrusion facing the inner side of the cover plate, the welding tooling may easily crush the pole ear during the welding process, causing the pole ear to tear.

[0041] The following combination Figures 2 to 9 , describing embodiments of the present invention.

[0042] According to an embodiment of the present invention, in one aspect, a cover plate is provided, including a cover plate body 1 , a first insulating member 2 and a pole 3 .

[0043] Among them, the first insulating member 2 is arranged on one side surface of the cover body 1 facing the inner side of the cover; the first insulating member 2 is provided with a long side protrusion 21 and a short side protrusion 22 protruding toward the inner side of the cover at both ends in the width direction of the side surface facing the inner side of the cover, and the length of the long side protrusion 21 protruding toward the inner side of the cover is greater than the length of the short side protrusion 22 protruding toward the inner side of the cover; along the width direction of the cover, the short side protrusion 22 is provided with a plurality of buffer ribs 23 at intervals in the length direction of the side wall of one side facing the middle area of ​​the cover, and the side surface of the buffer rib 23 facing the inner side of the cover is a slope 231, and the side of the slope 231 close to the short side protrusion 22 is connected to the short side protrusion The side surface of the edge protrusion 22 faces the inner side of the cover; the pole 3 includes a base plate 31 and a column portion 32 provided on the base plate 31, and the column portion 32 passes through the first insulating member 2 and the cover body 1; the base plate 31 is located between the long side protrusion 21 and the buffer rib 23, and the side surface of the base plate 31 facing the inner side of the cover is retracted into the side surface of the short side protrusion 22 facing the inner side of the cover; along the height direction of the cover, the distance between the side surface of the base plate 31 facing the inner side of the cover and the side surface of the short side protrusion 22 facing the inner side of the cover is H, and the distance between the short side protrusion 22 and the facing side of the base plate 31 is L, 0<H≤1mm, L≥0.8mm.

[0044] The thickness of the cover plate of this structure is set so that it can meet the strength requirements and the welding requirements with the pole ear. The side surface of the bottom plate 31 facing the inner side of the cover plate is retracted inwardly from the side surface of the short side protrusion 22 facing the inner side of the cover plate, which can save the material of the pole 3; the cover plate is provided with a plurality of buffer ribs 23 on the side wall of the side of the short side protrusion 22 facing the middle area of ​​the cover plate, and the side surface of the buffer rib 23 facing the inner side of the cover plate is a slope 231, and the two sides of the slope 231 respectively receive the short side protrusion 22 facing the inner side of the cover plate. One side surface of the inner side of the cover plate and one side surface of the bottom plate 31 facing the inner side of the cover plate, thereby establishing a bevel buffer section in the height difference area between the short side protrusion 22 and the bottom plate 31. When welding the pole ear, the pole group is located outside one side of the short side protrusion 22, and the pole ear close to the side of the pole group gradually tilts along the bevel 231 to transition to the bottom plate 31 and then is laid on the bottom plate 31 parallel to the bottom plate 31. When using a welding copper nozzle to press and weld the pole ear, the bevel 231 of the buffer rib 23 supports the pole ear, which can play a buffering role on the pole ear. At the same time, the distance H between the side surface of the bottom plate 31 facing the inner side of the cover plate and the side surface of the short side protrusion 22 facing the inner side of the cover plate, as well as the distance L between the short side protrusion 22 and the opposite side of the bottom plate 31 satisfy 0<H≤1mm, L≥0.8mm. This setting can make the inclined surface 231 a slope with a gentle slope 231, which can ensure the support and buffering effect of the inclined surface 231 on the pole ear, and can effectively prevent the welding copper nozzle from crushing the pole ear and prevent the pole ear from tearing.

[0045] Cover plates with different H and L are designed. The pole group is located outside the short-side raised portion 22. A welding copper nozzle is used to weld the pole tab and the bottom plate 31 of the pole column 3. The state of the pole tab is observed after welding. The test results are shown in Table 1.

[0046] Table 1

[0047]

[0048] It can be seen from Examples 1 to 12 in Table 1 that when H and L satisfy 0<H≤1mm and L≥0.8mm, the tab is in good condition and undamaged after being welded to the bottom plate 31; it can be seen from Comparative Examples 1 to 4 in Table 1 that when 0<H≤1mm and L<0.8mm, the slope of the inclined surface 231 of the buffer rib 23 is relatively large, and the tab is cut after welding; it can be seen from Comparative Examples 5 and 6 that when L≥0.8mm and H>1mm, the distance H between the inner surface of the pole 3 and the inner surface of the short-side protrusion 22 is too large, and the height difference between the inner surface of the pole 3 and the inner surface of the short-side protrusion 22 is too large, resulting in serious cutting after the tab is welded.

[0049] like Figures 3 to 5As shown, along the width direction of the cover plate, the buffer rib 23 includes two oppositely arranged side walls, a slope 231 and a bottom wall. One side wall of the buffer rib 23 is attached to the short side protrusion 22, and the other side wall of the buffer rib 23 is abutted against the side wall of the bottom plate 31. The bottom wall and the slope 231 are arranged opposite to each other.

[0050] If the surface of the bottom plate 31 facing the inner side of the cover plate is retracted to the side of the inclined surface 231 close to the bottom plate, there will be an angle between the inclined surface 231 and the side wall of the buffer rib 23 and the bottom plate 31. The tab will extend along the inclined surface 231 and the angle to the bottom plate 31. The tab will contact the angle of the buffer rib 23, which may damage the tab. To avoid this problem, Figure 5 As shown, in some embodiments, the side surface of the bottom plate 31 facing the inner side of the cover plate protrudes from the side of the inclined surface 231 close to the bottom plate. This arrangement can make the side of the inclined surface 231 close to the bottom plate 31 better transition to the side surface of the bottom plate 31 facing the inner side of the cover plate. The tab can be gradually transitioned from the inclined surface 231 to the bottom plate 31, which can prevent the tab from contacting the sharp edges of the buffer rib 23, improve the support and buffering effect of the buffer rib 23 on the tab, and avoid the tab from tearing.

[0051] like Figure 5 As shown, in some embodiments, a section of the inclined surface 231 close to the short side protrusion 22 is a first arc surface 2311, and the first arc surface 2311 smoothly transitions to the inner surface of the short side protrusion 22. When welding the pole ear, the pole ear extends from the side surface of the short side protrusion 22 toward the inner side of the cover plate to the first arc surface 2311, and the first arc surface 2311 smoothly transitions to the side surface of the short side protrusion 22 toward the inner side of the cover plate. In this way, the bending area of ​​the pole ear can be supported by the smooth arc surface, which can better support the pole ear, further improve the buffering effect on the pole ear, and prevent the pole ear from being damaged.

[0052] In some embodiments, the inclined surface 231 is a straight inclined surface 231 . In other embodiments, the inclined surface 231 may also be a curved inclined surface.

[0053] like Figure 5 As shown, in some embodiments, arc chamfers are provided at both ends of the short side protrusion 22 in the thickness direction, the short side protrusion 22 between the two arc chamfers is a plane, and the first arc surface 2311 connects the plane section of the side surface of the short side protrusion 22 facing the inner side of the cover plate. This arrangement can prevent sharp edges from damaging the tabs.

[0054] like Figure 3 and Figure 4As shown, in some embodiments, the cover plate further includes a sealing ring 4, which is sleeved on the column portion 32. The sealing ring 4 includes a parallel portion 41, and a side surface of the parallel portion 41 facing the inner side of the cover plate abuts against a side surface of the bottom plate 31 facing the outer side of the cover plate. Along the width direction of the cover plate, before the sealing ring 4 is compressed, the distance between the parallel portion 41 and the side wall facing the buffer rib 23 is a, 0.3mm≤a≤0.5mm. The bottom plate 31 of the pole 3 needs to squeeze and compress the parallel portion 41 to form a seal between the bottom plate 31 and the cover plate body 1. Before the sealing ring 4 is compressed, the spacing a between the parallel portion 41 and the side walls facing the buffer rib 23 satisfies 0.3mm≤a≤0.5mm. This setting can ensure the spacing between the side walls facing the buffer rib 23, prevent the spacing between the two from being too small, and prevent the side walls of the parallel portion 41 from exceeding the side walls of the bottom plate 31 before the sealing ring is compressed. It can ensure that the bottom plate 31 completely presses the parallel portion 41, ensures the compression effect on the parallel portion 41, and ensures the sealing of the sealing ring 4; at the same time, it can avoid the spacing between the parallel portion 41 and the side walls facing the buffer rib 23 from being too large, and ensure that the parallel portion 41 abuts against the first insulating member 2 after compression, thereby ensuring sealing.

[0055] In some embodiments, the bottom plate 31 is a rectangular plate, and the length of the bottom plate 31 is greater than the width of the bottom plate 31 . The buffer rib 23 is disposed outside one long side of the bottom plate 31 .

[0056] One end of the buffer rib 23 toward the outside of the cover plate extends to the root of the short-side protrusion 22 , and the side wall of the bottom plate 31 facing the buffer rib 23 abuts against the buffer rib 23 . That is, the bottom wall of the buffer rib 23 is attached to the surface of the first insulating member 2 facing the inner side of the cover plate between the two protrusions. This arrangement can increase the contact area between the side wall of the buffer rib 23 and the side wall of the bottom plate 31, and the bottom plate 31 can be limited in the width direction by the buffer rib 23, so as to ensure the limiting effect of the buffer rib 23 on the pole 3; in addition, the bottom plate 31 of the pole 3 is limited by the buffer rib 23. Compared with the limiting method of limiting the bottom plate 31 in the width direction by the short side protrusion 22, the multiple buffer ribs 23 on the side of the bottom plate 31 are arranged at intervals. When welding the pole ear and the bottom plate 31, the welding heat can be dissipated through the gap between the buffer ribs 23, which can prevent heat from accumulating in the short side protrusion 22 and causing the short side protrusion 22 to melt due to heat, and can improve the heat dissipation effect during the welding of the pole ear.

[0057] like Figure 7 and Figure 8 As shown, in some embodiments, a plurality of buffer ribs 23 are spaced apart along the length direction of the cover plate, and the density of the spacing of the plurality of buffer ribs 23 on the side of the bottom plate 31 is greater than the density of the buffer ribs 23 in the area outside the bottom plate 31, thereby improving the supporting and positioning effect of the buffer ribs 23 on the bottom plate 31.

[0058] In some optional embodiments, such as Figure 9 As shown, along the length direction of the cover plate, among the buffer ribs 23 that abut against the bottom plate 31, the spacing between adjacent buffer ribs 23 is W, 2mm≤W≤5mm. This setting can prevent the spacing between adjacent buffer ribs 23 from being too large, and can further improve the supporting and positioning effect of the buffer ribs 23 on the bottom plate 31.

[0059] Cover plates with different W values ​​were designed. The position of the bottom plate 31 in the width direction of the first insulating member 2 was observed or measured using a two-dimensional measuring instrument to determine whether the bottom plate 31 was centered and whether the long side of the bottom plate 31 was parallel to the long side of the first insulating member 2. The test results are shown in Table 2.

[0060] Table 2

[0061]

[0062] It can be seen from Examples 1 to 9 in Table 2 that when W≤5mm is satisfied, the spacing between adjacent buffer ribs 23 is small, which can effectively ensure the supporting effect of the buffer ribs 23 on the bottom plate 31, and the position of the bottom plate 31 is accurate and without offset; it can be seen from Comparative Examples 1 to 4 that when W>5mm, the spacing between adjacent buffer ribs 23 is large, and it is difficult to ensure the supporting and positioning effect of the buffer ribs 23 on the bottom plate 31 of the pole 3, and the bottom plate 31 will be offset and twisted to a certain extent in the width direction; and as W increases, the offset and twisting degree of the bottom plate 31 will increase.

[0063] In some embodiments, as Figure 3 、 Figure 4 and Figure 9 As shown, a plurality of limiting ribs 24 are provided at intervals in the length direction of the side wall of one side of the long side protrusion 21 toward the middle area of ​​the cover plate, and the bottom plate 31 abuts against the limiting rib 24 on one side of the long side protrusion 21. The limiting rib 24 cooperates with the buffer rib 23 to abut against the two long sides of the bottom plate 31 respectively to limit the width direction of the bottom plate 31. The limiting rib 24 and the buffer are both arranged at intervals along the length direction of the bottom plate 31. When welding the pole ears, heat can flow and dissipate from the gap between adjacent limiting ribs 24 and adjacent buffer ribs 23, which can improve the heat dissipation effect when welding the pole ears.

[0064] like Figure 9 As shown, in some embodiments, multiple limiting ribs 24 and multiple buffer ribs 23 are arranged one by one on both sides of the width direction of the bottom plate 31, so that the buffer ribs 23 and the limiting ribs 24 respectively support and position the bottom plate 31 from opposite ends, which is conducive to further improving the limiting effect of the bottom plate 31 and ensuring that the pole 3 remains in the desired position.

[0065] In some embodiments, as Figure 3 and Figure 4As shown, the cross-section of the limiting rib 24 is rectangular, one side wall of the limiting rib 24 abuts against the long side protrusion 21, and the other side wall of the limiting rib 24 abuts against the bottom plate 31. The side surface of the limiting rib 24 facing the outside of the cover is provided on the first insulating member 2 between the two protrusions, and the side surface of the limiting rib 24 facing the inside of the cover is retracted inward from the side surface of the bottom plate 31 facing the inside of the cover.

[0066] In some embodiments, as Figure 3 、 Figure 4 and Figure 6 As shown, the cover plate further includes a second insulating member 5 and a rivet block 6. The second insulating member 5 is provided on a surface of the cover plate body 1 facing the outside of the cover plate, and the rivet block 6 is provided on the second insulating member 5. The column portion 32 passes through the first insulating member 2, the cover plate body 1, the second insulating member 5 and the rivet block 6 and is riveted to the rivet block 6.

[0067] In some embodiments, the cross-sectional area of ​​the bottom plate 31 is larger than the cross-sectional area of ​​the column portion 32 , and the cross-sectional area of ​​the column portion 32 is a runway shape with a rectangular middle and semicircular ends.

[0068] According to an embodiment of the present invention, on the other hand, a battery cell is provided, comprising a housing and the cover plate of the above embodiment, wherein the housing is provided with an opening, and the cover plate is provided on the opening.

[0069] In the battery cell of this structure, the thickness of the bottom plate 31 of the pole 3 on the cover plate is set to meet the strength requirements and the welding requirements with the pole ear. The side surface of the bottom plate 31 facing the inner side of the cover plate is retracted to the side surface of the short side protrusion 22 facing the inner side of the cover plate, which can save the material of the pole 3; the cover plate is provided with a plurality of buffer ribs 23 on the side wall of the short side protrusion 22 facing the middle area of ​​the cover plate, and the side surface of the buffer rib 23 facing the inner side of the cover plate is an inclined surface 231, and the two sides of the inclined surface 231 respectively bear the short side protrusion 2 2 toward the inner side of the cover plate and the side surface of the bottom plate 31 toward the inner side of the cover plate, thereby establishing a buffer section of the inclined surface 231 in the height difference area between the short-side raised portion 22 and the bottom plate 31. When welding the electrode tab, the electrode group is located outside one side of the short-side raised portion 22, and the electrode tab close to the electrode group gradually tilts along the inclined surface 231 to transition to the bottom plate 31 and then is laid on the bottom plate 31 parallel to the bottom plate 31. When using a welding copper nozzle to press and weld the electrode tab, the inclined surface 231 of the buffer rib 23 supports the electrode tab and can play a buffering role for the electrode tab. At the same time, the distance H between the side surface of the bottom plate 31 facing the inner side of the cover plate and the side surface of the short side protrusion 22 facing the inner side of the cover plate, as well as the distance L between the short side protrusion 22 and the opposite side of the bottom plate 31 satisfy 0<H≤1mm, L≥0.8mm. This setting can make the inclined surface 231 a slope with a gentle slope 231, which can ensure the support and buffering effect of the inclined surface 231 on the pole ear, and can effectively prevent the welding copper nozzle from crushing the pole ear and prevent the pole ear from tearing.

[0070] In some optional embodiments, the battery cell includes a blade battery cell, the blade battery cell includes a shell, and the two ends of the shell are open in the length direction. The cover plate includes a positive cover plate and a negative cover plate, a positive electrode column 3 is provided on the positive cover plate, and a negative electrode column 3 is provided on the negative cover plate. The positive cover plate and the negative cover plate are respectively provided on the openings at both ends of the shell.

[0071] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising the battery cell of the above embodiment.

[0072] In a battery pack with this structure, a buffer rib 23 is provided on the first insulating member 2 of the cover plate. When the tab is pressed and welded using a copper welding nozzle, the inclined surface 231 of the buffer rib 23 supports the tab, providing a buffering effect. Furthermore, the spacing H between the inner surface of the bottom plate 31 and the inner surface of the short-side raised portion 22, as well as the spacing L between the facing surfaces of the short-side raised portion 22 and the bottom plate 31, satisfies the conditions 0 < H ≤ 1 mm and L ≥ 0.8 mm. This configuration ensures that the inclined surface 231 has a relatively gentle slope, ensuring its support and buffering effect on the tab, effectively preventing the copper welding nozzle from crushing the tab and tearing it.

[0073] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate, characterized in that: include: Cover plate body; a first insulating member, provided on a side surface of the cover plate body facing the inner side of the cover plate; a long side protrusion and a short side protrusion protruding toward the inner side of the cover plate are respectively provided at both ends in the width direction of the side surface of the first insulating member facing the inner side of the cover plate, the length of the long side protrusion protruding toward the inner side of the cover plate being greater than the length of the short side protrusion protruding toward the inner side of the cover plate; a plurality of buffer ribs are provided at intervals in the length direction of the side wall of one side of the short side protrusion facing the middle area of ​​the cover plate along the width direction of the cover plate, the side surface of the buffer rib facing the inner side of the cover plate is an inclined surface, and the side of the inclined surface close to the short side protrusion is connected to the side surface of the short side protrusion facing the inner side of the cover plate; The pole includes a base plate and a column portion provided on the base plate, wherein the column portion passes through the first insulating member and the cover plate body; the base plate is located between the long-side raised portion and the buffer rib, and the side surface of the base plate facing the inner side of the cover plate is retracted from the side surface of the short-side raised portion facing the inner side of the cover plate; along the height direction of the cover plate, the distance between the side surface of the base plate facing the inner side of the cover plate and the side surface of the short-side raised portion facing the inner side of the cover plate is H, and the distance between the short-side raised portion and the facing side of the base plate is L, 0<H≤1mm, L≥0.8mm.

2. The cover plate according to claim 1, wherein: A surface of one side of the bottom plate facing the inner side of the cover plate protrudes from a side of the inclined surface close to the bottom plate.

3. The cover plate according to claim 1 or 2, characterized in that: A section of the inclined surface close to the short-side raised portion is a first arc surface, and the first arc surface smoothly transitions to the inner surface of the short-side raised portion.

4. The cover plate according to claim 1 or 2, characterized in that: It also includes a sealing ring, which is sleeved on the column portion. The sealing ring includes a parallel portion, and a side surface of the parallel portion facing the inner side of the cover plate abuts against a side surface of the bottom plate facing the outer side of the cover plate. Along the width direction of the cover plate, before the sealing ring is compressed, the distance between the parallel portion and the side wall facing the buffer rib is a, 0.3mm≤a≤0.5mm.

5. The cover plate according to claim 1 or 2, characterized in that: One end of the buffer rib toward the outer side of the cover plate extends to the root of the short-side protrusion, and the side wall of the bottom plate facing the buffer rib abuts against the buffer rib.

6. The cover plate according to claim 5, characterized in that: Along the length direction of the cover plate, the interval between adjacent buffer ribs in contact with the bottom plate is W, and 2mm≤W≤5mm.

7. The cover plate according to claim 5, characterized in that: Along the width direction of the cover plate, a plurality of limiting ribs are provided at intervals in the length direction of the side wall of one side of the long side protrusion facing the middle area of ​​the cover plate, and a surface of the bottom plate facing the long side protrusion abuts against the limiting ribs.

8. The cover plate according to claim 7, wherein: The plurality of limiting ribs and the plurality of buffer ribs on both sides of the bottom plate in the width direction are arranged opposite to each other.

9. A battery cell, characterized in that: The invention comprises a shell and the cover plate according to any one of claims 1 to 8, wherein the shell is provided with an opening, and the cover plate is arranged on the opening.

10. A battery pack, characterized in that: Including the battery cell according to claim 9.

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