Cover plate assembly and battery cell

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate assembly and a battery cell, and the cover plate assembly comprises a plate body provided with an anti-explosion valve; at least part of the insulating part is attached to the plate body, the insulating part is provided with a convex hull extending away from the plate body, and the convex hull is sunken to form a containing groove; the stop piece is contained in the containing groove, the stop piece is made of a high-temperature-resistant and electrolyte-resistant material, and the projection of the stop piece and the projection of the anti-explosion valve are not overlapped in the direction perpendicular to the plate body; the stopping piece protrudes towards the plate body to form a limiting part, the plate body is sunken corresponding to the limiting part to form a clamping groove, and the limiting part is suitable for being clamped into the clamping groove so as to limit the stopping piece to move in the direction parallel to the plane where the plate body is located; a buckle is further formed on the insulating part and is suitable for limiting the stopping part from being disengaged from the containing groove. According to the cover plate assembly provided by the utility model, after the insulating part is melted, the backstop part is ensured to be abutted between the plate body and the pole group, and the pole group is prevented from moving towards the side of the anti-explosion valve.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cover plate assembly and a battery core. Background Art

[0002] With the advancement of science and technology, batteries have been widely used in many fields, and battery safety has gradually become a crucial research topic in the battery field. The battery cell usually includes a shell, an end cap arranged on the shell, a pole group arranged inside the shell, and an insulating component. The insulating component plays an insulating role between the end cap and the pole group. The end cap is provided with an explosion-proof valve. When thermal runaway occurs inside the battery cell, the internal temperature can reach more than 600°C in a short time. The high-temperature and high-pressure gas generated inside the battery cell needs to be discharged from the explosion-proof valve in time to avoid the risk of explosion of the battery cell and ensure battery safety.

[0003] However, in the related technology, the insulating components are often made of plastic. When the battery cell experiences thermal runaway, the internal plastic material will quickly melt and fail. At this time, the melted insulating component loses its supporting effect on the electrode group. Under the action of high-temperature and high-pressure gas, the electrode group is likely to lose balance and drive the electrode group to move. The electrode group can easily block or clog the explosion-proof valve, so that the high-temperature and high-pressure gas inside the battery cell cannot be discharged from the explosion-proof valve in time, which can easily cause the battery cell to catch fire or even explode, posing a major safety hazard. Utility Model Content

[0004] In view of this, the utility model provides a cover plate assembly and a battery cell to solve the problem that after thermal runaway of the existing battery cell occurs, the pole group moves and easily blocks the explosion-proof valve due to the melting of the plastic parts.

[0005] In a first aspect, the utility model provides a cover plate assembly, comprising:

[0006] The plate body is provided with an explosion-proof valve;

[0007] The insulating member is at least partially disposed in close contact with the plate body, and the insulating member has a convex bump extending away from the plate body, and a receiving groove is formed in the convex bump;

[0008] A stopper is contained in the containing groove, the stopper is made of a high temperature resistant and electrolyte resistant material, and along a direction perpendicular to the plate body, the stopper and the projection of the explosion-proof valve do not overlap;

[0009] The stopper protrudes toward the plate body to form a limiting portion, and the plate body is recessed to form a slot corresponding to the limiting portion, and the limiting portion is suitable for being snapped into the slot to limit the movement of the stopper in a direction parallel to the plane where the plate body is located;

[0010] The insulating member is also formed with a buckle, which is suitable for limiting the stopper from escaping from the accommodating groove.

[0011] Beneficial effect: The cover plate assembly provided by the embodiment of the utility model is provided with a stopper, and the stopper is made of high temperature resistant and electrolyte resistant material. In the direction perpendicular to the plate body, the stopper and the projection of the explosion-proof valve do not overlap, so that after the insulating part of the battery cell melts due to thermal runaway, the stopper can be ensured to exist, and can abut between the plate body and the pole group to prevent the pole group from moving toward the explosion-proof valve and blocking the explosion-proof valve, thereby ensuring that an exhaust channel is left between the plate body and the pole group, effectively improving the exhaust and heat dissipation effect of the explosion-proof valve, and greatly improving the safety performance of the battery.

[0012] In an optional embodiment, the convex bump surrounds a local area of ​​the accommodating groove to form a notch, and the buckle is formed in the notch and extends from the bottom of the notch toward a direction close to the board body;

[0013] Along the direction perpendicular to the plate body, the end of the buckle on one side away from the bottom of the notch forms a hook head, and the hook head overlaps at least part of the projection of the receiving groove;

[0014] The length of the buckle extending from the bottom of the notch toward the direction close to the board body is a, and satisfies: 0.3b≤a≤b, where b is the depth of the accommodating groove.

[0015] Beneficial effect: By making the length a of the clip extending from the bottom of the notch toward the direction close to the plate body less than or equal to the depth b of the accommodating groove, the clip is prevented from protruding from the upper surface of the insulating member and from interfering with the plate body. At the same time, by limiting the lower limit of a to be greater than 0.3b, it can ensure that the clip can be bent smoothly, facilitate the stopper to enter the accommodating groove, and prevent the clip from breaking. At the same time, by limiting the lower limit of a to be greater than 0.3b, it can ensure that the stopper has a sufficient size, avoiding the exhaust passage between the plate body and the pole group being too narrow due to the stopper being too small.

[0016] In an optional embodiment, the hook head is partially inclined toward one side of the plate body to form a guide portion, and the guide portion is suitable for guiding the stopper to be inserted into the receiving groove;

[0017] The thickness of the hook is t1, and satisfies: 0.6t≤t1≤1.2t, where t is the wall thickness of the convex hull.

[0018] Beneficial effect: By limiting the lower limit of the thickness t1 of the hook head, it is possible to avoid the weak strength caused by the thin thickness of the hook head and avoid the hook head from breaking. And by limiting the upper limit of the thickness t1 of the hook head, it is possible to avoid the waste of space caused by the excessive thickness of the hook head.

[0019] In an optional embodiment, the buckles are located on both sides of the convex bump along the length direction of the insulating member;

[0020] Along the width direction of the insulating member, the gap between the buckle in the notch and the convex bump is B, the width of the buckle is A, and the following conditions are satisfied: 0.5mm≤B≤5mm; 1mm≤A≤5mm.

[0021] In an optional embodiment, along the direction perpendicular to the plate body, the length of the overlapping area between the projection of the hook in the length direction of the insulating part and the accommodating groove is W2; the size of the stopper in the length direction of the insulating part is W1, and the size of the accommodating groove in the length direction of the insulating part is W, and it satisfies: 0.5mm≤W1-(W-2*W2)≤2mm.

[0022] Beneficial effect: Thus, it can be ensured that the stopper can be smoothly installed in the receiving groove, and after the stopper is installed in the receiving groove, it can be effectively clamped by the hook head to prevent the stopper from falling out of the receiving groove.

[0023] In an optional embodiment, the height of the convex hull extending from the surface of the stopper toward the plate body is d, and satisfies:

[0024] 0<d-t1<i, wherein t1 is the thickness of the hook and i is the depth of the slot.

[0025] Beneficial effect: By making d-t1<i, it can be ensured that after the insulating part and the plate body are assembled, the stopper can be snapped into the slot, and there will be no situation where the stopper is too high to lift the slot, ensuring smooth assembly. At the same time, by making 0<d-t1, it can be ensured that after the insulating part and the plate body are assembled, the stopper can be snapped into the slot smoothly and will not fall out of the slot, ensuring effective snapping.

[0026] In an optional implementation, the groove depth i of the groove satisfies: 0.3T≤i≤0.6T, wherein T is the thickness of the plate body.

[0027] Beneficial effect: By reasonably setting the depth of the card slot, the structural strength of the board body can be ensured, while avoiding the occurrence of a poor card connection effect caused by the card slot being too shallow.

[0028] In an optional embodiment, the plate body is formed with an explosion-proof valve groove suitable for accommodating the explosion-proof valve, and the explosion-proof valve is placed in the explosion-proof valve groove and is welded and fixed to the plate body;

[0029] Along the length direction of the plate body, the minimum spacing between the edge of the card slot and the edge of the explosion-proof valve slot is j, and j≥3mm.

[0030] Beneficial effect: Since the explosion-proof valve needs to be fixed to the plate body by welding, the welding heat will cause the force change in the area near the welding position. By making the minimum distance j ≥ 3mm between the edge of the slot and the edge of the explosion-proof valve slot, the deformation of the slot caused by welding heat can be reduced, ensuring the effective clamping of the slot to the limit part. In addition, it can also prevent the force change caused by the forming process of the slot from affecting the plate body, avoiding affecting the welding of the explosion-proof valve and the plate body, and avoiding affecting the opening pressure of the explosion-proof valve.

[0031] In an optional embodiment, along the length direction of the plate body, the slot width of the card slot is h; along the width direction of the plate body, the slot length of the card slot is g; and the conditions are as follows: e<h; f<g;

[0032] Among them, e is the dimension of the limiting portion along the length direction of the plate body, and f is the dimension of the limiting portion along the width direction of the plate body.

[0033] In a second aspect, the utility model further provides a battery cell, comprising:

[0034] A housing having an opening;

[0035] and a cover plate assembly as described above, which is arranged to cover the opening, and the cover plate assembly and the shell are combined to form a closed cavity;

[0036] The pole group is arranged in the closed cavity. When the battery cell has thermal runaway, the pole group abuts against the stopper so that an exhaust passage is left between the pole group and the explosion-proof valve.

[0037] Because the battery cell includes a cover plate assembly, it has the same effect as the cover plate assembly and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 This is a schematic diagram of the disassembled state of the cover assembly of the utility model in a front view;

[0040] Figure 2 for Figure 1 A partial enlarged view of

[0041] Figure 3 This is a schematic diagram of the disassembled state of the cover assembly of the utility model in an inverted perspective;

[0042] Figure 4 for Figure 3 A partial enlarged view of

[0043] Figure 5 It is a top view of the cover plate assembly of the utility model;

[0044] Figure 6 for Figure 5 Schematic diagram of the AA section;

[0045] Figure 7 for Figure 6 A partial enlarged view of

[0046] Figure 8 for Figure 6 Schematic diagram of the BB section;

[0047] Fig. 9 A schematic diagram of a stopper;

[0048] Fig.10 A top view of the insulating member and the stopper in an installed state;

[0049] Fig.11 is a schematic diagram from a first perspective showing the insulating member and the stopper member in an installed state;

[0050] Fig.12 It is a schematic diagram from a second perspective showing the insulating member and the stop member in an installed state.

[0051] Description of reference numerals:

[0052] 1. Plate body; 11. Explosion-proof valve; 12. Slot; 15. Protective sheet; 2. Insulator; 21. Accommodating groove; 22. Bump; 23. First through hole; 24. Buckle; 241. Hook; 242. Guide; 3. End plate; 31. Displacement portion; 32. Second through hole; 4. Stopper; 41. Limiting portion. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0054] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0055] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0057] Combine the following Figures 1 to 12 , describing an embodiment of the utility model.

[0058] According to an embodiment of the present utility model, on the one hand, a cover plate assembly is provided, comprising:

[0059] The plate body 1 is provided with an explosion-proof valve 11;

[0060] The insulating member 2 is at least partially disposed in close contact with the board body 1 , and has a convex bump 22 extending away from the board body 1 , and a receiving groove 21 is formed in the convex bump 22 ;

[0061] The stopper 4 is accommodated in the accommodating groove 21. The stopper 4 is made of a high temperature resistant and electrolyte resistant material. In a direction perpendicular to the plate body 1, the stopper 4 and the explosion-proof valve 11 do not overlap in projection.

[0062] The stopper 4 protrudes toward the plate body 1 to form a limiting portion 41, and the plate body 1 is recessed to form a slot 12 corresponding to the limiting portion 41. The limiting portion 41 is suitable for being snapped into the slot 12 to limit the movement of the stopper 4 in a direction parallel to the plane where the plate body 1 is located;

[0063] The insulating member 2 is further formed with a buckle 24 , which is suitable for limiting the stopper 4 from escaping from the receiving groove 21 .

[0064] The plate body 1 is made of metal material, for example, aluminum, aluminum alloy, steel, etc.

[0065] An explosion-proof valve 11 is provided on the board body 1. When thermal runaway occurs in the battery cell, the high-temperature and high-pressure gas generated inside the battery cell needs to be discharged from the explosion-proof valve in time.

[0066] An insulating part 2 is also provided on the side of the plate body 1 facing the pole group of the battery cell. The insulating part 2 can insulate the plate body 1 from the pole group. The insulating part 2 is made of plastic. When thermal runaway occurs in the battery cell, the insulating part 2 will quickly melt and fail. The insulating part 2 loses its support for the pole group, causing the pole group to move toward the explosion-proof valve under the action of high-temperature and high-pressure gas.

[0067] The cover plate assembly provided by the embodiment of the utility model is provided with a stopper 4, and the stopper 4 is made of a high temperature resistant and electrolyte resistant material. In the direction perpendicular to the plate body 1, the stopper 4 and the projection of the explosion-proof valve 11 do not overlap, so that after the insulating part 2 melts due to thermal runaway of the battery cell, the stopper 4 can be ensured to exist, and can abut between the plate body 1 and the pole group to prevent the pole group from moving toward the explosion-proof valve side to block the explosion-proof valve, thereby ensuring that an exhaust channel is left between the plate body 1 and the pole group, effectively improving the exhaust and heat dissipation effect of the explosion-proof valve, and greatly improving the safety performance of the battery.

[0068] In addition, after thermal runaway occurs, the accommodating groove 21 of the insulating member 2 for accommodating the stop member 4 will also lose its restraint on the stop member 4, causing the stop member 4 to move horizontally in a direction parallel to the plate body 1. The stop member 4 of this embodiment protrudes toward the plate body 1 to form a limiting portion 41, and the plate body 1 is recessed to form a slot 12 corresponding to the limiting portion 41. The limiting portion 41 is suitable for snapping into the slot 12 to limit the movement of the stop member 4 in a direction parallel to the plane where the plate body 1 is located; thereby, the stop member 4 can be maintained in a suitable abutting position, and the explosion-proof valve 11 will not be blocked, which also avoids the stop member 4 from being ejected from the explosion-proof valve 11.

[0069] When thermal runaway occurs, the pole group will move toward the board body 1 driven by air pressure, which can tighten the stopper 4 to prevent the limiting portion 41 from escaping from the slot 12. The position of the stopper 4 is maintained unchanged by squeezing the pole group.

[0070] The stopper 4 is made of a high temperature resistant and electrolyte resistant material, such as ceramics, aluminum alloy, etc., which can ensure that the stopper 4 has a certain strength.

[0071] The shape of the stopper 4 is not limited. For example, the cross section of the stopper 4 can be square, rectangular, T-shaped, cross-shaped, I-shaped, etc.

[0072] The shape of the limiting portion 41 formed on the stopper 4 can be various forms, such as rectangular, circular, waist-shaped or triangular, etc. Correspondingly, the shape of the card slot 12 matching the limiting portion 41 can also be various forms, such as rectangular, circular, waist-shaped or triangular, etc.

[0073] Optionally, the stopper 4 is formed with a plurality of limiting portions 41, and the corresponding plate body 1 is recessed to form a plurality of clamping grooves 12 corresponding to the limiting portions 41, so as to increase the clamping strength and prevent the stopper 4 from shaking.

[0074] Optionally, the stopper 4 is accommodated in the receiving groove 21, which can be set at any position of the insulating member 2. Preferably, the stopper 4 does not overlap with the projection of the explosion-proof valve 11. If the stopper 4 overlaps with the projection of the explosion-proof valve 11, it is necessary to ensure that the width of the stopper 4 is greater than the opening width of the explosion-proof valve, so as to prevent the stopper 4 from being ejected from the explosion-proof valve 11.

[0075] In some embodiments, in combination Fig.11 As shown, the convex bump 22 surrounds a local area of ​​the receiving groove 21 to form a notch, and the buckle 24 is formed in the notch and extends from the bottom of the notch toward the direction close to the board body 1;

[0076] Along the direction perpendicular to the plate body 1 , the end of the buckle 24 on one side away from the bottom of the notch forms a hook 241 , and the hook 241 at least partially overlaps with the projection of the receiving groove 21 ;

[0077] The length of the buckle 24 extending from the bottom of the notch toward the board body 1 is a, and satisfies: 0.3b≤a≤b, where b is the depth of the receiving groove 21 .

[0078] By making the length a of the clip 24 extending from the bottom of the notch toward the direction close to the plate body 1 less than or equal to the depth b of the accommodating groove 21, the clip 24 is prevented from protruding from the upper surface of the insulating member 2, and the clip 24 is prevented from interfering with the plate body 1. At the same time, by limiting the lower limit of a to be greater than 0.3b, it can be ensured that the clip 24 can be bent smoothly, and the stopper 4 can be conveniently entered into the accommodating groove 21 to prevent the clip 24 from breaking. At the same time, by limiting the lower limit of a to be greater than 0.3b, it can be ensured that the stopper 4 has a sufficient size, and the exhaust passage between the plate body 1 and the pole group is prevented from being too narrow due to the stopper 4 being too small.

[0079] In some embodiments, in combination Fig.10 , Fig.12 As shown, the hook head 241 is partially inclined toward one side of the plate body 1 to form a guide portion 242, and the guide portion 242 is suitable for guiding the stopper 4 to be inserted into the receiving groove 21;

[0080] The thickness of the hook 241 is t1 and satisfies: 0.6t≤t1≤1.2t, where t is the wall thickness of the convex hull 22 .

[0081] By limiting the lower limit of the thickness t1 of the hook head 241, the hook head 241 can be prevented from being too thin and weak in strength, and the hook head 241 can be prevented from being broken. By limiting the upper limit of the thickness t1 of the hook head 241, the space waste caused by the hook head 241 being too thick can be avoided.

[0082] In some embodiments, in combination Figure 1 , Fig.10 As shown, the buckles 24 are located on both sides of the convex 22 along the length direction of the insulating member 2;

[0083] Along the width direction of the insulating member 2 , the gap between the buckle 24 in the notch and the convex bump 22 is B, the width of the buckle 24 is A, and the following conditions are satisfied: 0.5 mm ≤ B ≤ 5 mm; 1 mm ≤ A ≤ 5 mm.

[0084] In some embodiments, in combination Figure 7 As shown, along the direction perpendicular to the plate body 1, the length of the overlapping area between the hook 241 and the projection of the accommodating groove 21 in the length direction of the insulating part 2 is W2; the dimension of the stopper 4 in the length direction of the insulating part 2 is W1, and the dimension of the accommodating groove 21 in the length direction of the insulating part 2 is W, and it satisfies: 0.5mm≤W1-(W-2*W2)≤2mm.

[0085] Thereby, it can be ensured that the stopper 4 is smoothly installed in the receiving groove 21 , and after the stopper 4 is installed in the receiving groove 21 , it can be effectively engaged by the hook head 241 to prevent the stopper 4 from escaping from the receiving groove 21 .

[0086] In some embodiments, in combination Fig. 9 As shown, the height of the convex bump 22 extending from the surface of the stopper 4 toward the plate body 1 is d, and satisfies:

[0087] 0<d-t1<i, wherein t1 is the thickness of the hook 241 , and i is the depth of the slot 12 .

[0088] By making d-t1<i, it can be ensured that after the insulating member 2 and the plate body 1 are assembled, the stopper 4 can be snapped into the slot 12, and there will be no situation where the stopper 4 is too high to lift up the slot 12, thereby ensuring smooth assembly. At the same time, by making 0<d-t1, it can be ensured that after the insulating member 2 and the plate body 1 are assembled, the stopper 4 can be snapped into the slot 12 smoothly, and will not fall out of the slot 12, thereby ensuring effective snapping.

[0089] In some embodiments, in combination Figure 8As shown, the groove depth i of the clamping groove 12 satisfies: 0.3T≤i≤0.6T, where T is the thickness of the board body 1. By properly setting the groove depth of the clamping groove 12, the structural strength of the board body 1 can be ensured, while avoiding the situation where the clamping effect is poor due to the clamping groove 12 being too shallow.

[0090] In some embodiments, in combination Figure 7 As shown, the plate body 1 is formed with an explosion-proof valve groove suitable for accommodating the explosion-proof valve 11, and the explosion-proof valve 11 is placed in the explosion-proof valve groove and is welded and fixed to the plate body 1;

[0091] Along the length direction of the plate body 1 , the minimum distance between the edge of the clamping groove 12 and the edge of the explosion-proof valve groove is j, and j≥3 mm.

[0092] Since the explosion-proof valve 11 needs to be fixed to the plate body 1 by welding, the welding heat will cause the stress change in the area near the welding position. By making the minimum spacing j between the edge of the clamping groove 12 and the edge of the explosion-proof valve groove ≥ 3mm, the deformation of the clamping groove 12 caused by the welding heat can be reduced, and the effective clamping of the clamping groove 12 to the limiter 41 can be ensured. In addition, it can also prevent the stress change caused by the molding process of the clamping groove 12 from affecting the plate body 1, avoiding affecting the welding of the explosion-proof valve and the plate body 1, and avoiding affecting the opening pressure of the explosion-proof valve.

[0093] In some embodiments, in combination Figure 8 , Fig. 9 As shown, along the length direction of the plate body 1, the slot width of the slot 12 is h; along the width direction of the plate body 1, the slot length of the slot 12 is g; and the conditions are as follows: e<h; f<g;

[0094] Among them, e is the dimension of the limiting portion 41 along the length direction of the plate body 1 , and f is the dimension of the limiting portion 41 along the width direction of the plate body 1 .

[0095] This ensures that the limiting portion 41 and the slot 12 are assembled smoothly.

[0096] In some embodiments, in combination Figures 1 to 4 As shown, the cover plate assembly further includes: an end plate 3, which is arranged on the side of the insulating member 2 facing away from the plate body 1, and the end plate 3 is recessed to form a paving portion 31 suitable for accommodating the convex bump 22;

[0097] In a direction perpendicular to the board body 1, the convex 22 is penetrated by a first through hole 23, and the retracting portion 31 is penetrated by a second through hole 32. By connecting the first through hole 23 and the second through hole 32, the electrolyte can flow smoothly and prevent the electrolyte from accumulating in the containing groove 21.

[0098] According to an embodiment of the present utility model, on the other hand, a battery cell is provided, comprising:

[0099] A housing having an opening;

[0100] and a cover plate assembly as described above, which is arranged to cover the opening, and the cover plate assembly and the shell are combined to form a closed cavity;

[0101] The electrode group is arranged in the sealed cavity. When the battery cell has thermal runaway, the electrode group abuts against the stopper 4 so that an exhaust passage is left between the electrode group and the explosion-proof valve 11 .

[0102] In the battery cell provided by the embodiment of the utility model, when thermal runaway occurs in the battery cell, the pole group abuts against the stopper 4 so that an exhaust channel is left between the pole group and the explosion-proof valve 11. By providing the stopper 4, the stopper 4 is made of a high temperature resistant and electrolyte resistant material, and the projections of the stopper 4 and the explosion-proof valve 11 do not overlap in a direction perpendicular to the plate body 1. Therefore, after the insulating part 2 melts due to thermal runaway of the battery cell, the stopper 4 can be ensured to exist, abut between the plate body 1 and the pole group, prevent the pole group from moving toward the explosion-proof valve side to block the explosion-proof valve, ensure that an exhaust channel is left between the plate body 1 and the pole group, effectively improve the exhaust and heat dissipation effect of the explosion-proof valve, and greatly improve the safety performance of the battery.

[0103] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present utility model are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations are all within the scope defined by the present utility model.

Claims

1. A cover plate assembly, It is characterized in that include: The plate body is provided with an explosion-proof valve; An insulating member, at least partially disposed in close contact with the plate body, the insulating member having a convex bump extending away from the plate body, and a receiving groove formed in a recess in the convex bump; A stopper, contained in the containing groove, the stopper is made of a high temperature resistant and electrolyte resistant material, and along a direction perpendicular to the plate body, the stopper and the explosion-proof valve projection do not overlap; The stopper protrudes toward the plate body to form a limiting portion, and the plate body is recessed to form a slot corresponding to the limiting portion, and the limiting portion is suitable for being snapped into the slot to limit the movement of the stopper in a direction parallel to the plane where the plate body is located; The insulating member is further formed with a buckle, and the buckle is suitable for limiting the stopper from escaping from the accommodating groove.

2. The cover plate assembly according to claim 1, It is characterized in that The convex bump surrounds a local area of ​​the accommodating groove to form a notch, and the buckle is formed in the notch and extends from the bottom of the notch toward the direction close to the plate body; Along a direction perpendicular to the plate body, an end of the buckle on one side away from the bottom of the notch forms a hook, and the hook overlaps at least part of the projection of the receiving groove; The length of the buckle extending from the bottom of the notch toward the direction close to the plate body is a, and satisfies: 0.3b≤a≤b, where b is the depth of the accommodating groove.

3. The cover plate assembly according to claim 2, It is characterized in that The hook is partially inclined toward one side of the plate body to form a guide portion, and the guide portion is suitable for guiding the stopper to be inserted into the receiving groove; The thickness of the hook is t1, and satisfies: 0.6t≤t1≤1.2t, where t is the wall thickness of the convex hull.

4. The cover plate assembly according to claim 2, It is characterized in that The buckles are located on both sides of the convex bump along the length direction of the insulating member; Along the width direction of the insulating member, the gap between the buckle in the notch and the convex bump is B, the width of the buckle is A, and the following conditions are satisfied: 0.5mm≤B≤5mm; 1mm≤A≤5mm.

5. The cover plate assembly according to claim 2, It is characterized in that Along the direction perpendicular to the plate body, the length of the overlapping area between the projection of the hook and the accommodating groove in the length direction of the insulating part is W2; the dimension of the stopper in the length direction of the insulating part is W1, and the dimension of the accommodating groove in the length direction of the insulating part is W, and it satisfies: 0.5mm≤W1-(W-2*W2)≤2mm.

6. The cover plate assembly according to any one of claims 2 to 5, It is characterized in that The height of the convex bulge extending from the surface of the stopper toward the plate body is d, and satisfies: 0<d-t1<i, wherein t1 is the thickness of the hook head, and i is the depth of the slot.

7. The cover plate assembly according to claim 6, It is characterized in that The groove depth i of the groove satisfies: 0.3T≤i≤0.6T, wherein T is the thickness of the plate body.

8. The cover plate assembly according to any one of claims 1 to 5, It is characterized in that The plate body is formed with an explosion-proof valve groove suitable for accommodating the explosion-proof valve, and the explosion-proof valve is placed in the explosion-proof valve groove and is welded and fixed to the plate body; Along the length direction of the plate body, the minimum spacing between the edge of the clamping slot and the edge of the explosion-proof valve slot is j, and j≥3mm.

9. The cover plate assembly according to any one of claims 1 to 5, It is characterized in that Along the length direction of the plate body, the slot width of the card slot is h; along the width direction of the plate body, the slot length of the card slot is g; and the following conditions are satisfied: e<h; f<g; Among them, e is the dimension of the limiting portion along the length direction of the plate body, and f is the dimension of the limiting portion along the width direction of the plate body.

10. A battery cell, It is characterized in that include: A housing having an opening; and a cover plate assembly as claimed in any one of claims 1 to 9, which is arranged to cover the opening, wherein the cover plate assembly and the shell are combined to form a closed cavity; The pole group is arranged in the closed cavity. When the battery cell has thermal runaway, the pole group abuts against the stopper so that an exhaust passage is left between the pole group and the explosion-proof valve.

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