Cover plate assembly and battery cell

Abstract

The utility model relates to the technical field of batteries, in particular to a cover plate assembly and a battery cell, the cover plate assembly comprises a cover plate and an explosion-proof valve, a mounting through hole penetrating in a first preset direction is formed in the cover plate, and an annular auxiliary mounting part is formed on the inner wall of the mounting through hole; the mounting through hole is divided into a first mounting through hole and a second mounting through hole in the first preset direction; a groove is formed in at least one side of the annular auxiliary mounting part in the first preset direction; the explosion-proof valve is arranged in the second installation through hole, an installation protruding part is formed on the explosion-proof valve and inserted into the groove, the explosion-proof valve is subjected to first welding on the outer bottom wall of the groove, and second welding is conducted on the matching edge of the second installation through hole and the explosion-proof valve. Therefore, the explosion-proof valve is welded twice, the welded structure is more stable and firmer, the air tightness of the battery cell is greatly improved, and the first welding seam is positioned outside the battery cell and is not in contact with electrolyte, so that corrosion failure is avoided.

Description

Technical Field

[0001] The present application relates to the field of battery cell technology, and in particular to a cover plate assembly and a battery cell. Background Art

[0002] At present, the battery cell top cover is a key component in the battery cell manufacturing process, integrating many safety-related functions, especially the explosion-proof valve parts in the assembly. Currently, the explosion-proof valve and the cover plate mostly use a single welding process, which is unreliable in structure and extremely prone to air leakage. In other words, there is a major hidden danger to the airtightness of the battery cell. Moreover, the weld is located inside the battery cell and is always in contact with the electrolyte, which is extremely easy to be corroded, resulting in problems such as failure of the explosion-proof valve. Utility Model Content

[0003] The purpose of this application is to provide a cover plate assembly and a battery cell, which to a certain extent solves the technical problems existing in the prior art that for the battery cell top cover, the explosion-proof valve and the cover plate are mostly welded in one process, the structure is unreliable, and it is extremely easy to leak, which poses a great hidden danger to the airtightness of the battery cell. Moreover, the weld is located inside the battery cell and is always in contact with the electrolyte, which is extremely easy to be corroded, thereby causing technical problems such as failure of the explosion-proof valve.

[0004] The present application provides a cover plate assembly, comprising: a cover plate and an explosion-proof valve; wherein the cover plate is formed with mounting holes extending through both sides thereof along a first preset direction, and an annular auxiliary mounting portion is formed on the inner wall of the mounting hole to separate the mounting hole into a first mounting hole and a second mounting hole along the first preset direction;

[0005] Along the first preset direction, a groove is formed on at least one side of the annular auxiliary mounting portion, and the groove is communicated with the second mounting through hole; the explosion-proof valve is arranged in the second mounting through hole, and the explosion-proof valve is formed with a mounting protrusion, the mounting protrusion is inserted into the groove, and the explosion-proof valve is welded for the first time at the outer bottom wall of the groove, and a second welding is performed at the mating edge of the second mounting through hole and the explosion-proof valve.

[0006] In the above technical solution, further, along the first preset direction, grooves are formed on the opposite sides of the annular auxiliary mounting portion, and are respectively a first groove and a second groove, and the first groove is connected to the first mounting through hole, the second groove is connected to the second mounting through hole, and the mounting protrusion is inserted in the second groove.

[0007] In any of the above technical solutions, further, along the first preset direction, the depth of the first groove is h1, the depth of the first mounting hole is h2, the thickness of the cover plate is H, and h1+h2=1 / 3H; along the first preset direction, the depth of the second groove is h3, and h3=1 / 3H.

[0008] In any of the above technical solutions, further, 0.2mm≤h1≤0.5mm.

[0009] In any of the above technical solutions, further, 1.5mm≤H≤2.5mm.

[0010] In any of the above technical solutions, further, the cover plate is formed with an auxiliary pressure relief blind hole.

[0011] In any of the above technical solutions, further, the edge of the bottom wall of the auxiliary pressure relief blind hole is provided with notches.

[0012] In any of the above technical solutions, further, the opening of the auxiliary pressure relief blind hole is arranged toward the electrode group side of the battery cell.

[0013] In any of the above technical solutions, further, along the second preset direction, the auxiliary pressure relief blind hole is formed on at least one side of the cover plate and close to the edge.

[0014] In any of the above technical solutions, further, the cover plate assembly also includes an insulating component, and along the first preset direction, the insulating component is arranged on the side of the cover plate close to the pole group of the battery cell, and along the first preset direction, the insulating component is formed with a first exhaust groove opening toward the cover plate side, and the first exhaust groove is located directly below the auxiliary pressure relief blind hole, and the bottom wall and / or side wall of the first exhaust groove are formed with multiple first exhaust through holes.

[0015] In any of the above technical solutions, further, along the first preset direction, the projection of the first exhaust groove completely covers the projection of the auxiliary pressure relief blind hole, and there is a preset gap between the outer edges of the two projections.

[0016] In any of the above technical solutions, further, one of the insulating component and the cover plate is formed with a positioning protrusion, and the other one is formed with a positioning groove, and the positioning protrusion is inserted into the positioning groove.

[0017] In any of the above technical solutions, further, the insulating component is formed with a second exhaust groove opening toward the side of the cover plate, the bottom wall of the second exhaust groove is formed with a first auxiliary exhaust hole, the side wall of the second exhaust groove is formed with a second auxiliary exhaust hole, and one end of the second auxiliary exhaust hole extends to the bottom wall of the second exhaust groove, and the other opposite end of the second auxiliary exhaust hole extends to the cover plate structure located outside the open end of the second exhaust groove.

[0018] In any of the above technical solutions, further, the distance between two of the second auxiliary exhaust holes located on both sides of the center line of the cover plate set along the second preset direction is X, and the distance between any two adjacent second auxiliary exhaust holes among the remaining multiple second auxiliary exhaust holes is Y, and X>Y.

[0019] In any of the above technical solutions, further, the mounting protrusion is interference-fitted with the groove to form a snap-fit ​​structure.

[0020] This application also provides a battery cell comprising a housing, an electrode group, and a cover plate assembly according to any of the above technical solutions, wherein the electrode group is disposed within the housing, and the cover plate assembly is disposed at an open end of the housing. Therefore, all the beneficial technical effects of the cover plate assembly are achieved, and further description is omitted here.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The present application provides a new type of cover plate assembly, which includes a cover plate and an explosion-proof valve. During the assembly of the explosion-proof valve and the cover plate, the explosion-proof valve is first installed in the second mounting hole on the cover plate, and the mounting protrusion on the explosion-proof valve is inserted into the groove. After the explosion-proof valve and the cover plate are assembled in place, the mounting protrusion on the explosion-proof valve and the annular auxiliary mounting portion on the cover plate can be welded for the first time on the outer bottom wall of the groove, and then the seam welding is performed at the matching edge of the explosion-proof valve and the second mounting through hole, that is, the second welding is performed. It can be seen that the explosion-proof valve is welded twice, and the structure after welding is more stable and stronger, which greatly improves the airtightness of the battery cell. Moreover, the first welding seam is located outside the battery cell and does not contact the electrolyte, that is, it is isolated from the electrolyte, so corrosion failure will not occur, further avoiding failure of the explosion-proof valve, and greatly improving the airtightness of the battery cell, thereby improving the safety and reliability of the battery cell during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 An exploded view of the cover assembly provided in an embodiment of the present application;

[0025] Figure 2 An assembly diagram of a cover plate assembly provided in an embodiment of the present application;

[0026] Figure 3 Another assembly diagram of the cover plate assembly provided in an embodiment of the present application;

[0027] Figure 4 A schematic diagram of the structure of the cover plate provided in an embodiment of the present application;

[0028] Figure 5 for Figure 4 Schematic diagram of the enlarged structure at A;

[0029] Figure 6 Another structural schematic diagram of the cover plate provided in an embodiment of the present application;

[0030] Figure 7 for Figure 6 A schematic diagram of the enlarged structure at B;

[0031] Figure 8 Another structural schematic diagram of the cover plate provided in an embodiment of the present application;

[0032] Figure 9 for Figure 8 Cross-sectional view along CC section;

[0033] Figure 10 for Figure 9 Schematic diagram of the enlarged structure at D;

[0034] Figure 11 A schematic diagram of the structure of the explosion-proof valve provided in an embodiment of the present application;

[0035] Figure 12 A cross-sectional view of the assembly structure of the cover plate and the explosion-proof valve provided in an embodiment of the present application;

[0036] Figure 13 for Figure 12 Schematic diagram of the enlarged structure at E;

[0037] Figure 14 for Figure 12 Schematic diagram of the enlarged structure at F;

[0038] Figure 15 Another assembly diagram of the cover plate assembly provided in an embodiment of the present application;

[0039] Figure 16 for Figure 15 Cross-sectional view along section GG;

[0040] Figure 17 for Figure 16 A schematic diagram of the enlarged structure at I;

[0041] Figure 18 Another assembly diagram of the cover plate assembly provided in an embodiment of the present application;

[0042] Figure 19 for Figure 18 Schematic diagram of the enlarged structure at J.

[0043] Reference numerals:

[0044] 1-cover plate, 11-mounting through hole, 111-first mounting through hole, 112-middle through hole, 113-second mounting through hole, 12-annular auxiliary mounting portion, 121-first groove, 122-second groove, 13-auxiliary pressure relief blind hole, 14-notch, 15-positioning groove, 2-explosion-proof valve, 21-mounting protrusion, 3-insulating member, 31-first exhaust groove, 32-first exhaust through hole, 33-positioning protrusion, 34-second exhaust groove, 35-first auxiliary exhaust hole, 36-second auxiliary exhaust hole, 4-explosion-proof valve patch, 5-pole assembly. DETAILED DESCRIPTION

[0045] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0046] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application.

[0047] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0048] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0050] Refer to the following Figures 1 to 19 The present invention describes a cover assembly and a battery cell according to some embodiments of the present application.

[0051] Example 1

[0052] See also Figures 1 to 14 As shown, an embodiment of the present application provides a cover plate assembly, which is applied to a battery cell. The cover plate assembly includes: a cover plate 1 and an explosion-proof valve 2; wherein, along a first preset direction a, the cover plate 1 is formed with a mounting through hole 11 running through both sides thereof, and an inner wall of the mounting through hole 11 is formed with an annular auxiliary mounting portion 12 to separate the mounting through hole 11 into a first mounting through hole 111 and a second mounting through hole 113 along the first preset direction a, that is, an intermediate through hole 112 respectively connected to the first mounting through hole 111 and the second mounting through hole 113 is further provided between the first mounting through hole 111 and the second mounting through hole 113, that is, the mounting through hole 11 includes a first mounting through hole 111, an intermediate through hole 112 and a second mounting through hole 113 sequentially arranged along the first preset direction a, the first mounting through hole 111 is close to the outer side of the cover plate 1, that is, the outer side of the battery cell, and the second mounting through hole 113 is close to the inner side of the cover plate 1, that is, close to the pole group side of the battery cell;

[0053] Along the first preset direction a, a groove is formed on at least one side of the annular auxiliary mounting portion 12, and the groove is communicated with the second mounting through hole 113; the explosion-proof valve 2 is arranged in the second mounting through hole 113, and the explosion-proof valve 2 is formed with a mounting protrusion 21, the mounting protrusion 21 is inserted into the groove, and the first welding is performed on the explosion-proof valve 2 at the outer bottom wall of the groove, and the second welding is performed at the matching edge of the second mounting through hole 113 and the explosion-proof valve 2.

[0054] According to the structure described above, the present application provides a new type of cover plate assembly, which includes a cover plate 1 and an explosion-proof valve 2. In the process of assembling the explosion-proof valve 2 and the cover plate 1, the explosion-proof valve 2 is first installed in the second mounting through hole 113 on the cover plate 1, and the mounting protrusion 21 on the explosion-proof valve 2 is inserted into the groove. After the explosion-proof valve 2 and the cover plate 1 are assembled in place, the mounting protrusion 21 on the explosion-proof valve 2 and the annular auxiliary mounting portion 12 on the cover plate 1 can be welded for the first time on the outer bottom wall of the groove, and then the explosion-proof valve 2 is assembled into the second mounting through hole 113 on the cover plate 1. The valve 2 is welded at the mating edge with the second mounting through hole 113, that is, the second welding is performed. It can be seen that the explosion-proof valve 2 is welded twice, and the structure after welding is more stable and stronger, which greatly improves the airtightness of the battery cell. Moreover, the first welding seam is located outside the battery cell and does not contact the electrolyte, that is, it is isolated from the electrolyte, so corrosion failure will not occur, further avoiding the failure of the explosion-proof valve 2, and greatly improving the airtightness of the battery cell, thereby improving the safety and reliability of the battery cell during use.

[0055] Further, preferably, the first preset direction a is the thickness direction of the cover plate 1 , but is certainly not limited thereto.

[0056] In this embodiment, preferably, Figures 4 to 13 As shown, along the first preset direction a, grooves are formed on the opposite sides of the annular auxiliary mounting portion 12, which are the first groove 121 and the second groove 122 respectively, and the first groove 121 is connected to the first mounting through hole 111, the second groove 122 is connected to the second mounting through hole 113, and the mounting protrusion 21 is inserted into the second groove 122.

[0057] It should be noted that an explosion-proof valve patch 4 is also pasted on the outside of the first mounting hole 111. When the battery cell is baked or at high temperature, when the glue on the edge of the explosion-proof valve 2 overflows, the retaining groove is provided to avoid damage to the explosion-proof diaphragm.

[0058] According to the structure described above, on the one hand, the bottom wall of the first groove 121 can be used as a laser welding point to facilitate welding; on the other hand, an explosion-proof valve patch 4 is also pasted on the outside of the first mounting hole 111. When the battery cell is baked or at a high temperature, the glue around the explosion-proof valve patch 4 will overflow. At this time, the side wall of the first groove 121 can block the glue and prevent the glue from flowing onto the explosion-proof valve 2 below, thereby protecting the explosion-proof valve 2.

[0059] In this embodiment, preferably, Figure 10As shown, along the first preset direction a, the depth of the first groove 121 is h1, the depth of the first mounting hole 111 is h2, the thickness of the cover plate 1 is H, and h1+h2=1 / 3H; along the first preset direction a, the depth of the second groove 122 is h3, and h3=1 / 3H.

[0060] According to the structure described above, the thickness of the solid area between the first groove 121 and the second groove 122 is 1 / 3H to avoid being too thin, which may cause deformation during groove processing.

[0061] Furthermore, preferably, 0.2 mm ≤ h1 ≤ 0.5 mm, where h1 is the height of the sidewall of the first groove 121. If the height is too small, it will not block the glue. If the height is too large, it may extend outside the first mounting hole 111, affecting the assembly of the explosion-proof valve patch 4 or even puncturing the explosion-proof valve patch 4. Of course, the value of h1 is not limited to this and can also be less than 0.2 mm or greater than 0.5 mm.

[0062] Furthermore, preferably, 1.5 mm ≤ H ≤ 2.5 mm. If the cover plate 1 is too thin, the strength is insufficient and it is inconvenient to process the corresponding mounting holes 11 and grooves thereon. If the cover plate 1 is too thick, it takes up a lot of space and wastes materials. Of course, the value of H is not limited to this and can also be less than 1.5 mm or greater than 2.5 mm.

[0063] In this embodiment, preferably, Figure 6 and Figure 14 As shown, the cover plate 1 is formed with an auxiliary pressure relief blind hole 13 .

[0064] According to the structure described above, when the battery cell has thermal runaway and needs to release pressure and exhaust, the main pressure relief channel at the explosion-proof valve 2 may be blocked by other molten materials in the battery cell. Therefore, when the main pressure relief channel is blocked, the auxiliary pressure relief hole on the cover plate 1 will release pressure and exhaust when the air pressure exceeds the strength of the set notch 14, thereby reducing the risk of battery cell explosion and improving the safety and reliability of the battery cell during use.

[0065] In this embodiment, preferably, Figure 14 As shown, the edge of the bottom wall of the auxiliary pressure relief blind hole 13 is provided with a notch 14 .

[0066] According to the structure described above, the auxiliary pressure relief blind hole 13 on the cover plate 1 will release pressure and exhaust when the air pressure exceeds the strength of the set notch 14, thereby reducing the risk of battery cell explosion.

[0067] In this embodiment, preferably, Figure 14As shown, the opening of the auxiliary pressure relief blind hole 13 is arranged toward the electrode group side of the battery cell.

[0068] According to the structure described above, the opening of the auxiliary pressure relief blind hole 13 is set toward the battery cell, that is, toward the inside of the battery cell, which can ensure that the surface of the cover plate 1 is flat. Of course, it is not limited to this. The opening of the auxiliary pressure relief blind hole 13 can also be set toward the side away from the battery cell, that is, toward the outside of the battery cell. The specific selection is based on actual needs.

[0069] In this embodiment, preferably, Figure 6 As shown, along the second preset direction b, auxiliary pressure relief blind holes 13 are formed on two opposite sides of the cover plate 1 and close to the edges.

[0070] According to the structure described above, the auxiliary pressure relief blind hole 13 is set at the edge position of the cover plate 1, so that when the main air leakage channel of the explosion-proof valve 2 at the center is blocked, the air can be exhausted from both sides, and the auxiliary pressure relief blind hole 13 is set close to the edge of the cover plate 1, so that the exhaust channel below it can effectively avoid the structure such as the pole ear of the open pole group, and preferably, multiple auxiliary pressure relief blind holes 13 are provided on each side, and the multiple auxiliary pressure relief blind holes 13 can be arranged in sequence along the third preset direction c.

[0071] Furthermore, preferably, the second preset direction b is the length direction of the cover plate 1 , and the third preset direction c is the width direction of the cover plate 1 . Of course, it is not limited thereto and can be selected according to actual needs.

[0072] It should be noted that: it is not limited to forming auxiliary pressure relief blind holes 13 on both opposite sides of the cover plate 1 and close to the edges along the second preset direction b. Auxiliary pressure relief blind holes 13 can also be provided on only one side of the cover plate 1 along the second preset direction b. The specific selection is based on actual needs.

[0073] In this embodiment, preferably, Figures 15 to 19 As shown, the cover assembly also includes an insulating component 3, and along the first preset direction a, the insulating component 3 is arranged on the side of the cover 1 close to the pole group of the battery cell, and along the first preset direction a, the insulating component 3 is formed with a first exhaust groove 31 with an opening toward the side of the cover 1, and the first exhaust groove 31 is located directly below the auxiliary pressure relief blind hole 13, and the bottom wall of the first exhaust groove 31 is formed with a plurality of first exhaust through holes 32. Of course, it is not limited to this, and only the side wall of the first exhaust groove 31 can be formed with a plurality of first exhaust through holes 32, or the bottom wall and side wall of the first exhaust groove 31 can be formed with a plurality of first exhaust through holes 32, depending on actual needs.

[0074] According to the structure described above, when the battery cell experiences thermal runaway, the high-temperature and high-pressure gas generated inside it will enter the auxiliary pressure relief blind hole 13 through the first exhaust groove 31, and the auxiliary pressure relief blind hole 13 will release pressure and exhaust when the air pressure exceeds the strength of the set notch 14, thereby reducing the risk of battery cell explosion.

[0075] Furthermore, preferably, the insulating component 3 may be a plastic component, and thus may be referred to as lower plastic, but is not limited thereto.

[0076] In this embodiment, preferably, Figure 17 As shown, along the first preset direction a, the projection of the first exhaust groove 31 completely covers the projection of the auxiliary pressure relief blind hole 13 , and a preset gap exists between the outer edges of the two projections.

[0077] According to the structure described above, the size of the first vent groove 31 is larger than that of the auxiliary pressure relief blind hole 13, thereby not reducing the pressure of the high-temperature, high-pressure gas generated during thermal runaway of the battery cell. This allows the high-temperature, high-pressure gas to quickly break through the notches 14 around the bottom of the auxiliary pressure relief blind hole 13, thereby quickly releasing the pressure and exhausting the gas. Of course, this is not limited to this. The projection of the first vent groove 31 along the first predetermined direction a can also completely overlap the outer edge of the projection of the auxiliary pressure relief blind hole 13, etc., and the specific selection is based on actual needs.

[0078] In this embodiment, preferably, Figure 6 and Figure 18 As shown, the cover plate 1 is formed with a positioning protrusion 33 , the insulating member 3 is formed with a positioning groove 15 , and the positioning protrusion 33 is inserted into the positioning groove 15 .

[0079] According to the structure described above, the cooperation between the positioning protrusion 33 and the positioning groove 15 can realize the rapid positioning and assembly of the insulating component 3 and the cover plate 1, thereby improving the convenience of operation and strengthening the bonding strength between the insulating component 3 and the cover plate 1.

[0080] It should be noted that the above structure is not limited thereto. The insulating component 3 may be formed with a positioning protrusion 33 , the cover plate 1 may be formed with a positioning groove 15 , and the positioning protrusion 33 may be inserted into the positioning groove 15 . The specific selection is based on actual needs.

[0081] In this embodiment, preferably, Figure 13 As shown, the mounting protrusion 21 is interference-fitted with the groove to form a snap-fit ​​structure, which improves the stability and firmness of the explosion-proof valve 2 and the cover plate 1 after assembly, thereby helping to improve the airtightness of the battery cell.

[0082] In this embodiment, preferably, Figure 18 and Figure 19As shown, the insulating member 3 is formed with a second exhaust groove 34 that opens toward the side of the cover plate 1, the bottom wall of the second exhaust groove 34 is formed with a first auxiliary exhaust hole 35, which is a longitudinal exhaust hole, and the side wall of the second exhaust groove 34 is formed with a second auxiliary exhaust hole 36, which is a transverse exhaust hole, and one end of the second auxiliary exhaust hole 36 extends to the bottom wall of the second exhaust groove 34, and the other opposite end of the second auxiliary exhaust hole 36 extends to the cover plate 1 structure located outside the open end of the second exhaust groove 34.

[0083] According to the structure described above, when the battery cell needs to be exhausted, the transverse exhaust holes provided in the insulating component 3 can quickly discharge the gas in other parts of the battery cell to that place. In addition, when the longitudinal exhaust holes (main exhaust holes) are blocked by reactants, the transverse exhaust holes can assist in exhausting, thereby providing safety and reliability of the battery cell during use.

[0084] In this embodiment, preferably, Figure 18 and Figure 19 As shown, along the second preset direction b, a plurality of second auxiliary exhaust holes 36 are provided on both sides of the second exhaust groove 34, and the plurality of second auxiliary exhaust holes 36 are sequentially spaced along the third preset direction c;

[0085] The distance between two second auxiliary exhaust holes 36 located on both sides of the center line of the cover plate 1 set along the second preset direction b is X, and the distance between any two adjacent second auxiliary exhaust holes 36 among the remaining multiple second auxiliary exhaust holes 36 is Y, and X>Y.

[0086] According to the structure described above, the central area of ​​the cover plate 1 plays the role of fixing the battery cell. Therefore, the distance between the two second auxiliary exhaust holes 36 in the middle area is set to be larger, so that the physical structure area between the two is larger, which helps to improve the fixing effect of the battery cell, and the second auxiliary exhaust holes 36 on both sides can be set relatively densely to increase the exhaust effect during thermal runaway.

[0087] It should be noted that: it is not limited to "along the second preset direction b, multiple second auxiliary exhaust holes 36 are provided on both sides of the second exhaust groove 34", and multiple second auxiliary exhaust holes 36 can also be provided only on one side of the second exhaust groove 34, which is selected according to actual needs.

[0088] In this embodiment, preferably, Figure 1 and Figure 2 As shown, the cover plate assembly also includes a pole assembly 5, which are existing structures and will not be described in detail here.

[0089] Example 2

[0090] Embodiment 2 of the present application further provides a battery cell, comprising the cover plate assembly described in the above-mentioned embodiment 1, and thus has all the beneficial technical effects of the cover plate assembly, and the same technical features and beneficial effects are not repeated here.

[0091] In this embodiment, preferably, the battery cell further includes a housing and a pole group (not shown in the figure); wherein the pole group is disposed in the housing, and the cover assembly is disposed at the open end of the housing.

[0092] It should be noted that the housing may have one open end, in which case the aforementioned cover assembly is provided. The housing may also have two open ends, in which one or both of the open ends are provided with the aforementioned cover assembly, depending on actual needs.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate and an explosion-proof valve; wherein, along a first preset direction, the cover plate is formed with mounting holes extending through both sides thereof, and an annular auxiliary mounting portion is formed on the inner wall of the mounting hole to separate the mounting hole into a first mounting hole and a second mounting hole along the first preset direction; Along the first preset direction, a groove is formed on at least one side of the annular auxiliary mounting portion, and the groove is communicated with the second mounting through hole; the explosion-proof valve is arranged in the second mounting through hole, and the explosion-proof valve is formed with a mounting protrusion, the mounting protrusion is inserted into the groove, and the explosion-proof valve is welded for the first time at the outer bottom wall of the groove, and a second welding is performed at the mating edge of the second mounting through hole and the explosion-proof valve.

2. The cover plate assembly according to claim 1, wherein: Along the first preset direction, grooves are formed on the opposite sides of the annular auxiliary mounting portion, which are the first groove and the second groove respectively, and the first groove is connected to the first mounting through hole, the second groove is connected to the second mounting through hole, and the mounting protrusion is inserted in the second groove.

3. The cover plate assembly according to claim 2, wherein: Along the first preset direction, the depth of the first groove is h1, the depth of the first mounting hole is h2, the thickness of the cover plate is H, and h1+h2=1 / 3H; along the first preset direction, the depth of the second groove is h3, and h3=1 / 3H.

4. The cover plate assembly according to claim 3, wherein: 0.2mm≤h1≤0.5mm; and / or 1.5mm≤H≤2.5mm.

5. The cover plate assembly according to claim 1, wherein: The cover plate is formed with an auxiliary pressure relief blind hole.

6. The cover plate assembly according to claim 5, wherein: The edge of the bottom wall of the auxiliary pressure relief blind hole is provided with notches; and / or The opening of the auxiliary pressure relief blind hole is arranged toward the electrode group side of the battery cell; and / or Along the second preset direction, the auxiliary pressure relief blind hole is formed on at least one side of the cover plate and close to the edge.

7. The cover plate assembly according to claim 5, wherein: The cover plate assembly also includes an insulating component, and along the first preset direction, the insulating component is arranged on the side of the cover plate close to the pole group of the battery cell, and along the first preset direction, the insulating component is formed with a first exhaust groove opening toward the cover plate side, and the first exhaust groove is located directly below the auxiliary pressure relief blind hole, and the bottom wall and / or side wall of the first exhaust groove are formed with multiple first exhaust through holes.

8. The cover plate assembly according to claim 7, wherein: Along the first preset direction, the projection of the first exhaust groove completely covers the projection of the auxiliary pressure relief blind hole, and there is a preset gap between the outer edges of the two projections; and / or A positioning protrusion is formed on one of the insulating component and the cover plate, and a positioning groove is formed on the other of the insulating component and the cover plate, and the positioning protrusion is inserted into the positioning groove.

9. The cover plate assembly according to claim 7, wherein: The insulating component is formed with a second exhaust groove that opens toward the side of the cover plate, the bottom wall of the second exhaust groove is formed with a first auxiliary exhaust hole, the side wall of the second exhaust groove is formed with a second auxiliary exhaust hole, and one end of the second auxiliary exhaust hole extends to the bottom wall of the second exhaust groove, and the other opposite end of the second auxiliary exhaust hole extends to the cover plate structure located outside the open end of the second exhaust groove.

10. The cover plate assembly according to claim 9, wherein: The distance between two second auxiliary exhaust holes on both sides of the center line of the cover plate set along the second preset direction is X, and the distance between any two adjacent second auxiliary exhaust holes among the remaining multiple second auxiliary exhaust holes is Y, and X>Y.

11. The cover plate assembly according to any one of claims 1 to 10, characterized in that: The mounting protrusion is interference-fitted with the groove to form a clamping structure.

12. A battery cell, characterized in that: It comprises a shell, a pole group and a cover plate assembly according to any one of claims 1 to 11; wherein the pole group is arranged in the shell, and the cover plate assembly is arranged at the open end of the shell.

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