Explosion-proof valve, battery cell and battery pack

Abstract

The invention belongs to the technical field of batteries, and particularly relates to an anti-explosion valve, a battery cell and a battery pack. The anti-explosion valve comprises an opening face and a skirt edge. A nick is arranged on one end surface, far away from the pole group, of the opening surface; an opening surface body is defined by one side of the nick, and a transition part is formed on the other side of the nick; the skirt edge is arranged around the periphery of the transition part; partition grooves are annularly formed in the peripheries of the nicks; in the thickness direction of the anti-explosion valve, the partition groove is formed between the side, away from the opening face body, of the nick and the outer side wall of the skirt edge, and the partition groove is formed in the transition part and / or the end face, close to the pole group, of the skirt edge. The explosion-proof valve disclosed by the invention has good heat dissipation and heat insulation effects, and can well avoid the influence of welding heat on the structural strength of the explosion-proof valve when the explosion-proof valve is welded, so that the structural stability and consistency of the explosion-proof valve are improved, and a battery cell has higher safety performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a kind of explosion-proof valve, battery cell and battery pack. BACKGROUND

[0002] The explosion-proof valve on the battery cell is mainly used for pressure relief and exhaust, due to mechanical impact, internal abnormal lap joint short circuit and other reasons, the battery cell is prone to thermal runaway, and the high-temperature gas in the battery cell is released through the directional release of the explosion-proof valve, which can prevent the explosion of the battery pack.

[0003] At present, in order to improve the capacity of the battery pack, the space utilization of the battery cell will be improved, so that the thickness of the single battery cell will be reduced; as a result, the size of the explosion-proof valve is very small, and when the explosion-proof valve is welded with the cover plate, due to unreasonable design of various parameters of the explosion-proof valve, the overall opening pressure of the cover plate is unstable after the explosion-proof valve is welded, which affects the safety performance of the battery cell. SUMMARY

[0004] In view of the above technical problems, the purpose of the present application at least solves one of the technical problems in the related art to some extent. To this end, the present application provides an explosion-proof valve, a battery cell and a battery pack, which can have good heat dissipation and heat insulation effects, and can well avoid the influence of welding heat on the structural strength of the explosion-proof valve when the explosion-proof valve is welded, so that the structural stability and consistency of the explosion-proof valve are improved, and the battery cell has higher safety performance.

[0005] In order to solve the above technical problems, the present application is realized as follows:

[0006] According to a first aspect of the present application, the present application provides an explosion-proof valve, comprising:

[0007] An opening surface is provided with a notch on the end surface away from the pole group; one side of the notch is surrounded to form an opening surface body, and the other side of the notch forms a transition part;

[0008] A skirt is arranged around the periphery of the transition part;

[0009] The periphery of the notch is provided with a separation groove; in the thickness direction of the explosion-proof valve, the separation groove is arranged between the side of the notch away from the opening surface body and the outer side wall of the skirt, and the separation groove is arranged on the end surface of the transition part and / or the skirt close to the pole group.

[0010] In an optional embodiment, in the length or width direction of the explosion-proof valve, the width of the separation groove is W2, and the W2 satisfies: 0.15mm≤W2≤0.25mm;

[0011] And / or, in the thickness direction of the explosion-proof valve, the depth of the separation groove is B, and the B satisfies: 0.2mm≤B≤0.4mm.

[0012] In an alternative embodiment, the score includes a continuous section and an opening section;

[0013] In the thickness direction of the explosion-proof valve, the thickness of the opening section is less than the thickness of the continuous section;

[0014] The thickness of the opening section is C, and the C satisfies: 0.06mm≤C≤0.15mm.

[0015] In an alternative embodiment, in the thickness direction of the explosion-proof valve, the opening surface body is provided as a convex surface away from the pole group direction;

[0016] The total area of the projection of the opening surface in the thickness direction of the explosion-proof valve is S1, and the upper surface area of the opening surface body is S2, and the S1 and S2 respectively satisfy: 150mm 2 ≤S1≤600mm 2 , 85mm 2 ≤S2≤470mm 2 .

[0017] In an alternative embodiment, in the thickness direction of the explosion-proof valve, the skirt thickness is A, and the A satisfies: 0.4mm≤A≤0.7mm;

[0018] In the length or width direction of the explosion-proof valve, the distance from the outer side wall of the skirt to the side of the score away from the opening surface body is W1, and the W1 satisfies: 1.5mm≤W1≤2.5mm.

[0019] In an alternative embodiment, the A, B, C, W1 and W2 also satisfy: 0.4≤B / A≤0.7, 0.3≤C / B≤0.45, 0.05≤W2 / W1≤0.15.

[0020] In an alternative embodiment, in the length or width direction of the explosion-proof valve, the side of the skirt away from the opening surface is provided with a welding area, and the explosion-proof valve is connected with the cover body through the welding area;

[0021] In the thickness direction of the explosion-proof valve, the cross-sectional width of the welding area is a, and the cross-sectional depth of the welding area is b, and the a and b respectively satisfy: 0.8mm≤a≤1.0mm, 0.25mm≤b≤0.6mm.

[0022] In an alternative embodiment, the welding area is formed by laser welding, and in the laser welding process, the welding power is 400W-700W, and the welding speed is 25m / s-50m / s.

[0023] According to a second aspect of the present application, the present application further provides an electric cell, comprising: a cover plate, a pole group, and the explosion-proof valve according to any one of the embodiments of the first aspect of the present application.

[0024] According to a third aspect of the present application, the present application further provides a battery pack, comprising: the explosion-proof valve according to any one of the embodiments of the first aspect of the present application; and / or, the electric cell according to any one of the embodiments of the second aspect of the present application.

[0025] The explosion-proof valve, the electric cell and the battery pack provided by the present application have at least the following beneficial effects:

[0026] The explosion-proof valve provided by the present application has the following beneficial effects: the opening surface and the skirt are arranged; the notch is arranged on the opening surface far away from the opening surface end face of the pole group; the opening surface body is arranged on one side of the notch, and the transition part is arranged on the other side of the notch; the skirt is arranged around the periphery of the transition part; the separation groove is arranged around the periphery of the notch; in the thickness direction of the explosion-proof valve, the separation groove is arranged between the side of the notch far away from the opening surface body and the outer side wall of the skirt, and the separation groove is arranged on the end face of the transition part and / or the skirt close to the pole group; the explosion-proof valve has excellent heat dissipation and heat insulation effects, can well avoid the influence of welding heat on the structural strength of the explosion-proof valve when the explosion-proof valve is welded, and can improve the structural stability and consistency of the explosion-proof valve, thereby improving the safety performance of the electric cell. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0028] Figure 1 The structure of the explosion-proof valve provided by the present application is shown Figure 1 ;

[0029] Figure 2 The plane structure schematic diagram of the explosion-proof valve provided by the present application is shown

[0030] Figure 3 The X-X` cross-sectional structure schematic diagram of the explosion-proof valve provided by the present application is shown Figure 2

[0031] Figure 4 The structure of the explosion-proof valve provided by the present application is shown Figure 2 ;

[0032] Figure 5 The cover plate structure schematic diagram of the electric cell provided by the present application is shown Figure 1 ;

[0033] Figure 6 The cover plate structure schematic diagram of the electric cell provided by the present application is shown Figure 2 ;​

[0034] Figure 7 Fig. 1 shows a schematic view of a cover plate structure of the battery cell according to the present application; Figure 3

[0035] Figure 8 Fig. 2 shows a schematic view of a cover plate cross-section structure of the battery cell according to the present application; Figure 1

[0036] Figure 9 Fig. 3 shows a partial enlarged view of the battery cell according to the present application; Figure 8

[0037] Figure 10 Fig. 4 shows a schematic view of a cover plate cross-section structure of the battery cell according to the present application; Figure 2

[0038] Figure 11 Fig. 5 shows a partial enlarged view of the battery cell according to the present application; Figure 10

[0039] Figure 12 Fig. 6 shows a schematic view of a battery cell structure according to the present application.

[0040] Legend of reference signs:

[0041] 10 - explosion-proof valve;

[0042] 110 - skirt; 120 - score; 121 - connecting section; 122 - opening section; 130 - opening surface; 131 - opening surface body; 132 - transition portion; 140 - partition groove;

[0043] 20 - cover plate; 210 - cover plate body; 220 - mounting hole; 230 - sink; 240 - pole; 250 - plastic part; 260 - welding area; 270 - through hole;

[0044] 30 - pole group; 40 - housing.

[0045] The specific embodiments of the present application have been shown in the above-described drawings, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the inventive concept by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0046] The technical solutions of the present application and how the technical solutions of the present application solve the above-described technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0047] ​​​​​The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as implicitly split by the language of the specification. The endpoints of the ranges and any values are to be interpreted as approximately or about the value it describes. For values which are less than one, the value of zero is also included. For values which are fractions or decimals, the value of zero is also included. For values which are greater than one, the value of one is also included. For ranges, use of 'between' and 'from' and 'to' include the values that are implicitly called out directly above the range, and that the method includes each and every value in between other values, or one or more values in between other values. For values which are less than one, the value of zero is included in the range. For values which are fractions or decimals, the value of zero is included in the range. For values which are greater than one, the value of one is included in the range.

[0048] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0049] Unless otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0050] Unless otherwise specified, all steps of the present application can be performed in sequence or randomly, and are preferably performed in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, the method also comprises step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0051] Unless otherwise specified, the "includes" and "contains" mentioned in the present application mean open or closed. For example, the "includes" and "contains" can mean that other components not listed can also be included or contained, or only the listed components can be included or contained.

[0052] The explosion-proof valve has the function of pressure relief and exhaust, so that the battery cell has good safety performance. The battery cell is prone to thermal runaway due to mechanical impact, internal abnormal lap joint short circuit and other reasons. The directional release of high temperature gas in the battery cell through the explosion-proof valve can avoid explosion of the battery pack. At present, in order to improve the capacity of the battery pack, the space utilization of the battery cell will be improved, so that the thickness of the single battery cell will be reduced. As a result, the size of the explosion-proof valve is very small. When the explosion-proof valve is welded with the cover plate, the heat generated by welding will be transferred. If the welding power is too large and the heat generated is high, the structural strength of the explosion-proof valve will be affected, thereby affecting the safety performance of the battery pack.

[0053] In view of the above-mentioned technical problems, the present application provides an explosion-proof valve, a battery cell and a battery pack, which have excellent heat dissipation and heat insulation effects, can well avoid the influence of welding heat on the structural strength of the explosion-proof valve during welding of the explosion-proof valve, improve the structural stability and consistency of the explosion-proof valve, and further improve the safety performance of the battery cell.

[0054] The technical scheme of the present application is as follows:

[0055] In some embodiments of the present application, an explosion-proof valve is provided, comprising: an opening surface 130 and a skirt 110; the opening surface 130 is provided with a notch 120 on the end surface away from the pole group 30; one side of the notch 120 is surrounded to form an opening surface body 131, and the other side of the notch 120 forms a transition part 132; the skirt 110 is circumferentially arranged on the periphery of the transition part 132; a separation groove 140 is circumferentially arranged on the periphery of the notch 120; in the thickness direction of the explosion-proof valve 10, the separation groove 140 is arranged between the side of the notch 120 away from the opening surface body 131 and the outer side wall of the skirt 110, and the separation groove 140 is arranged on the end surface of the transition part 132 and / or the skirt 110 close to the pole group 30.

[0056] Reference Figure 1 and Figure 2 The material of the explosion-proof valve 10 can be made of aluminum alloy, stainless steel and other metal materials, and the planar structure shape of the explosion-proof valve 10 can be rectangular, square, oval, circular or other irregular shape, and those skilled in the art can adjust and design on the basis of the present application according to the actual situation. The explosion-proof valve 10 is arranged on the cover plate 20, and the opening surface 130 in the explosion-proof valve 10 is provided with a notch 120 on the end surface away from the pole group 30; in the width or length direction of the explosion-proof valve 10, one side of the notch 120 is surrounded to form an opening surface body 131, and the other side of the notch 120 is surrounded to form a transition part 132; that is, the notch 120 is circumferentially arranged on the opening surface 130, and the notch 120 divides the opening surface 130 into the opening surface body 131, the transition part 132 and the like.

[0057] Reference Figure 3, the circumferential ring of the notch 120 is provided with a groove 140, that is, on the spatial structure of the explosion-proof valve 10, the outer periphery of the notch 120 is provided with a groove 140, the groove 140 can be provided on the same side as the notch 120 or not on the same side; in the thickness direction of the explosion-proof valve 10, the groove 140 is arranged between the notch 120 away from the opening surface body 131 to the outer side wall of the skirt 110, the number of grooves 140 can be one, two or more than three, the cross-sectional shape of the groove 140 can be rectangular, trapezoidal, triangular, circular arc or other irregular arbitrary figure, etc.; in some preferred embodiments, the groove 140 can be arranged on the transition part 132 and / or the end face of the skirt 110 close to the pole group 30. By arranging the groove 140 between the notch 120 away from the opening surface body 131 to the outer side wall of the skirt 110, a good heat dissipation and heat insulation effect can be achieved for the explosion-proof valve 10. When the explosion-proof valve 10 is welded to the cover plate 20, a certain position of the skirt 110 is welded to the cover plate 20, and during the welding process, the heat generated by the welding will be transmitted to the side close to the opening surface 130, and the heat transmission path will be lengthened when the heat is transmitted to the groove 140, thereby achieving good heat dissipation, thereby greatly reducing the influence of welding on the stability of the explosion-proof valve 10.

[0058] The explosion-proof valve provided by the application has the advantages that: the opening surface and the skirt are arranged; the notch is arranged on the end face of the opening surface away from the pole group; the opening surface body is arranged on one side of the notch, and the transition part is arranged on the other side of the notch; the skirt is arranged around the periphery of the transition part; the groove is arranged around the periphery of the notch; in the thickness direction of the explosion-proof valve, the groove is arranged between the notch away from the opening surface body to the outer side wall of the skirt, and the groove is arranged on the end face of the transition part and / or the skirt close to the pole group; the explosion-proof valve has excellent heat dissipation and heat insulation effects, can well avoid the influence of welding heat on the structural strength of the explosion-proof valve during welding, and can improve the structural stability and consistency of the explosion-proof valve, thereby improving the safety performance of the battery cell.

[0059] In some embodiments, in the length or width direction of the explosion-proof valve 10, the width of the groove 140 is W2, and W2 satisfies: 0.15mm≤W2≤0.25mm;

[0060] Reference Figure 8 and Figure 9In the length or width direction of the explosion-proof valve 10, the maximum width W2 of the partition groove 140 can be any one or any point between any two of 0.15 mm, 0.16 mm, 0.18 mm, 0.20 mm, 0.21 mm, 0.22 mm, 0.24 mm or 0.25 mm; by limiting the width of the partition groove 140, the explosion-proof valve can have more excellent heat dissipation and heat insulation performance, thereby the stability and consistency of the explosion-proof valve are good, and the opening pressure of the explosion-proof valve is stable; if the width of the partition groove 140 is less than the above range, the heat dissipation effect cannot be good, and the heat generated during welding of the explosion-proof valve 10 and the cover plate 20 cannot be effectively dispersed, which easily leads to poor consistency of the explosion-proof valve 10; if it is greater than the above range, the mechanical strength of the explosion-proof valve 10 will be reduced, especially the mechanical strength at the position of the partition groove 140 will be reduced, which easily damages the explosion-proof valve 10.

[0061] In some embodiments, in the thickness direction of the explosion-proof valve 10, the depth of the partition groove 140 is B, and B satisfies: 0.2 mm≤B≤0.4 mm.

[0062] Reference Figure 8 and Figure 9 In the thickness direction of the explosion-proof valve 10, the depth B of the partition groove 140 can be any one or any point between any two of 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.9 mm or 2.0 mm; for the same reason, by limiting the depth of the partition groove 140, the explosion-proof valve 10 can have more excellent heat dissipation and heat insulation performance, thereby the stability and consistency of the explosion-proof valve 10 are good, and the opening pressure of the explosion-proof valve 10 is stable; if it is less than the above range, the temperature transfer path can not be long enough to cause poor heat dissipation effect during welding, which makes the structural strength of the explosion-proof valve 10 unstable, and the consistency of the explosion-proof valve 10 is poor; if it is greater than the above range, the explosion-proof valve 10 is easily broken or cracked at the position of the partition groove 140, and the explosion-proof valve 10 is easily damaged.

[0063] In some embodiments, the notch 120 includes a connecting section 121 and an opening section 122; in the thickness direction of the explosion-proof valve 10, the thickness of the opening section 122 is less than the thickness of the connecting section 121; the thickness of the opening section 122 is C, and C satisfies: 0.06 mm≤C≤0.15 mm.

[0064] Reference Figure 8 and Figure 9The score 120 surrounding the periphery of the opening face body 131 includes a connecting section 121 and an opening section 122, wherein the thickness of the opening section 122 is less than the thickness of the connecting section 122 in the thickness direction of the explosion-proof valve 10; the thickness of the opening section 122 is very thin, and the explosion-proof valve 10 will be reversed along the connecting section 121 when the battery cell is in thermal runaway, and the explosion-proof valve 10 is opened to release pressure; the thickness C of the opening section 122 can be any one of 0.06mm, 0.065mm, 0.07mm, 0.0.86mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.14mm, 0.145mm or 0.15mm or any point value between any two of them; by limiting the thickness of the opening section 122, the opening pressure of the explosion-proof valve 10 can be well guaranteed; if it is greater than the above range, the explosion-proof valve 10 may not be able to effectively open to release pressure when the battery cell is in thermal runaway, and there is a risk of explosion; if it is less than the above range, the explosion-proof valve 10 may be opened when the thermal runaway does not occur, making it unstable.

[0065] In some embodiments, in the thickness direction of the explosion-proof valve 10, the opening face body 131 is set as a convex surface away from the direction of the pole group 30; the projection area of the opening face 130 in the thickness direction of the explosion-proof valve 10 is S1, and the upper surface area of the opening face body 131 is S2, S1 and S2 respectively satisfy: 150mm 2 ≤S1≤600mm 2 , 85mm 2 ≤S2≤470mm 2 .

[0066] Referring to Figure 4 , Figure 8 and Figure 9 , in the thickness direction of the explosion-proof valve 10, the opening face body 131 can be set as a convex surface away from the direction of the pole group 30, which can further improve the directional exhaust pressure relief performance of the explosion-proof valve 10; the projection area S1 of the opening face 130 in the thickness direction of the explosion-proof valve 10 can be any one of 150mm 2 , 200mm 2 , 250mm 2 , 300mm 2 , 400mm 2 , 500mm 2 or 600mm 2 or any point value between any two of them; the upper surface area S2 of the opening face body 131 can be 85mm 2 , 90mm 2 , 100mm 2 , 200mm 2 , 300mm 2 , 400mm 2 , 500mm2 Or 570mm 2 The value of any one or any two of the above; by limiting the above area, it can be ensured that the explosion-proof valve 10 has better directional exhaust and pressure relief performance, and that the opening surface body 131 in the middle of the explosion-proof valve 10 can break first, thereby making the explosion strength of the explosion-proof valve 10 small and not easy to damage the entire cover plate 20. If it is not within the above range, it may affect the stability and consistency of the explosion-proof valve 10.

[0067] In some embodiments, in the thickness direction of the explosion-proof valve 10, the thickness of the skirt 110 is A, where A satisfies: 0.4mm≤A≤0.7mm; in the length or width direction of the explosion-proof valve 10, the distance from the outer sidewall of the skirt 110 to the side of the notch 120 away from the opening surface body 131 is W1, where W1 satisfies: 1.5mm≤W1≤2.5mm.

[0068] refer to Figure 8 and Figure 9 The thickness A of the skirt 110 can be any one of 0.4mm, 0.5mm, 0.55mm, 0.6mm, or 0.7mm, or any value between any two of these. In the length or width direction of the explosion-proof valve 10, the distance W1 from the outer sidewall of the skirt 110 to the side of the notch 120 away from the opening surface body 131 can be 1.5mm, 1.6mm, 1.65mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.4mm, or 2. The value of any one of 5mm or any point between any two; by limiting the range of A and W1 mentioned above, the explosion-proof valve 10 and the cover plate 20 can be firmly connected. If the thickness of the skirt 110 is too thin, it may be broken through during the welding process, damaging the explosion-proof valve 10. Moreover, limiting the range of W1 can minimize the impact of the heat generated by welding on the opening surface body 131 and ensure the stability of the explosion-proof valve 10. If W1 is not within this range, it may not affect the consistency of the explosion-proof valve 10.

[0069] In some embodiments, A, B, C, W1, and W2 also satisfy: 0.4 ≤ B / A ≤ 0.7, 0.3 ≤ C / B ≤ 0.45, and 0.05 ≤ W2 / W1 ≤ 0.15.

[0070] refer to Figure 8, the ratio of B / A can be any one of 0.4, 0.5, 0.55, 0.6 or 0.7 or any point value between any two of them; the ratio of C / B can be any one of 0.3, 0.32, 0.35, 0.38, 0.40, 0.42, 0.44 or 0.45 or any point value between any two of them; the ratio of W2 / W1 can be any one of 0.05, 0.06, 0.08, 0.09, 0.1, 0.12, 0.13 or 0.15 or any point value between any two of them; by limiting the above ratios, the opening pressure of the explosion-proof valve 10 can be well guaranteed to be stable and consistent, and the structural design of the explosion-proof valve 10 is more reasonable. If any of the above ratios is not within the range, it may partially or completely affect the structural rationality of the explosion-proof valve 10, and when the explosion-proof valve 10 is welded, it may affect the structural strength of the explosion-proof valve 10, thereby affecting the stability and consistency of the explosion-proof valve 10.

[0071] In some embodiments, in the length or width direction of the explosion-proof valve 10, the skirt 110 is provided with a welding area 260 away from one side of the opening face 130, and the explosion-proof valve 10 is connected with the cover plate body 210 through the welding area 260; in the thickness direction of the explosion-proof valve 10, the cross-sectional width of the welding area 260 is a, and the cross-sectional depth of the welding area 260 is b, which respectively satisfy: 0.8mm≤a≤1.0mm, 0.25mm≤b≤0.6mm.

[0072] Reference Figure 10 and Figure 11 In the length or width direction of the explosion-proof valve 10, the skirt 110 is provided with a welding area 260 away from one side of the opening face 130, which can be the area for welding connection of the explosion-proof valve 10 and the cover plate 20, i.e. the explosion-proof valve 10 is installed on the cover plate body 210, and then the skirt 110 and the cover plate body 210 are laser welded to form the welding area 260; in the thickness direction of the explosion-proof valve 10, the cross-sectional width a of the welding area 260 can be any one of 0.8mm, 0.82mm, 0.85mm, 0.9mm, 0.95mm or 1mm or any point value between any two of them; the cross-sectional depth b of the welding area 260 can be any one of 0.25mm, 0.3mm, 0.4mm, 0.5mm or 0.6mm or any point value between any two of them; by limiting the cross-sectional width and depth of the welding area 260, the explosion-proof valve 10 and the cover plate 20 can be firmly connected, and the influence on the explosion-proof valve 10 during welding is minimized, so that the explosion-proof valve 10 has excellent stability and consistency.

[0073] In some embodiments, the welding area 260 is formed by laser welding, and in the laser welding process, the welding power is 400-700 W, and the welding speed is 25-50 m / s.

[0074] With reference to Figure 7 and Figure 9 , the welding area 260 can be formed by laser welding, and the welding area 260 is arranged around the outer side of the skirt 110 part. In order to minimize the influence on the explosion-proof valve 10 during welding and ensure that the explosion-proof valve 10 has excellent stability and consistency, the welding power can be any one of 400 W, 450 W, 500 W, 600 W or 700 W or any point value between any two of them; the welding speed can be any one of 25 m / s, 28 m / s, 30 m / s, 35 m / s, 40 m / s, 45 m / s or 50 m / s or any point value between any two of them; by limiting the welding power and the welding speed, the explosion-proof valve can be stably connected to the cover plate 20, and the heat generated by welding can reduce the influence on the explosion-proof valve 10, so that the explosion-proof valve has good stability and consistency.

[0075] In some embodiments of the present application, an electric core is also provided, comprising: a cover plate, a pole group, and the explosion-proof valve in any of the above embodiments arranged on the cover plate.

[0076] As Figure 5 and Figure 6 , the cover plate 20 on the electric core comprises a cover plate body 210, and a mounting hole 220 is arranged on the cover plate body 210. The mounting hole 220 is arranged on the end close to the pole group, and a sink 230 is arranged on the sink 230 of the mounting hole 220. The explosion-proof valve 10 is arranged on the sink 230. The side of the cover plate body 210 close to the pole group 30 is also provided with a plastic part 250, and a through hole 270 is arranged on the cover plate body 210. The pole column 240 is arranged in the through hole 270.

[0077] As Figure 12 shown, the electric core can include a cover plate 20, a pole group 30 and a shell 40, wherein the pole group 30 is arranged in the shell 40, one end of the shell 40 is provided with the cover plate 20, the cover plate 20 is provided with the explosion-proof valve 10, or the explosion-proof valve 10 is arranged on any one side wall of the shell 40; the pole group 30 further comprises a shell, a positive plate, a negative plate, a diaphragm, an electrolyte and the like, for example: the positive plate comprises a current collector made of copper foil or aluminum foil, and the current collector is provided with active material such as lithium iron phosphate or ternary material, and the current collector of the negative plate is provided with active material such as graphite, and the specific structure of the above electric core is well known in the art, and will not be described in detail here.

[0078] In some embodiments of the present application, a battery pack is also provided, comprising: the explosion-proof valve in any of the above embodiments of the present application.

[0079] In some embodiments, the battery pack includes the cell of any of the above embodiments.

[0080] The application is further illustrated below in conjunction with the accompanying drawings and examples, but the implementation and protection of the application are not limited thereto, and the following examples are only part of the examples of the application, not a limitation of the application.

[0081] Example 1

[0082] In Example 1, the parameters of the explosion-proof valve are respectively set as A = 0.45 mm, B = 0.2 mm, C = 0.065 mm, W1 = 1.55 mm, W2 = 0.16 mm, B / A = 0.44, C / B = 0.33, W2 / W1 = 0.10.

[0083] Example 2

[0084] In Example 2, the difference is only that A = 0.45 mm, B = 0.2 mm, C = 0.07 mm, W1 = 1.55 mm, W2 = 0.16 mm, B / A = 0.44, C / B = 0.35, W2 / W1 = 0.10.

[0085] Example 3

[0086] In Example 3, the difference is only that A = 0.45 mm, B = 0.25 mm, C = 0.075 mm, W1 = 1.6 mm, W2 = 0.16 mm, B / A = 0.56, C / B = 0.30, W2 / W1 = 0.10.

[0087] Example 4

[0088] In Example 4, the difference is only that A = 0.45 mm, B = 0.25 mm, C = 0.083 mm, W1 = 1.6 mm, W2 = 0.2 mm, B / A = 0.56, C / B = 0.33, W2 / W1 = 0.13.

[0089] Example 5

[0090] In Example 5, the difference is only that A = 0.5 mm, B = 0.3 mm, C = 0.089 mm, W1 = 1.8 mm, W2 = 0.25 mm, B / A = 0.60, C / B = 0.30, W2 / W1 = 0.14.

[0091] Example 6

[0092] In Example 6, the difference is only that A = 0.5 mm, B = 0.3 mm, C = 0.092 mm, W1 = 1.8 mm, W2 = 0.23 mm, B / A = 0.60, C / B = 0.31, W2 / W1 = 0.13.

[0093] Example 7

[0094] Example 7 differs only in that A = 0.55 mm, B = 0.3 mm, C = 0.098 mm, W1 = 1.8 mm, W2 = 0.2 mm, B / A = 0.55, C / B = 0.31, W2 / W1 = 0.11.

[0095] Example 8

[0096] Example 8 differs only in that A = 0.55 mm, B = 0.35 mm, C = 0.105 mm, W1 = 2.2 mm, W2 = 0.22 mm, B / A = 0.64, C / B = 0.30, W2 / W1 = 0.10.

[0097] Example 9

[0098] Example 9 differs only in that A = 0.55 mm, B = 0.35 mm, C = 0.13 mm, W1 = 2.2 mm, W2 = 0.22 mm, B / A = 0.64, C / B = 0.37, W2 / W1 = 0.10.

[0099] Example 10

[0100] Example 10 differs only in that A = 0.6 mm, B = 0.35 mm, C = 0.15 mm, W1 = 2.3 mm, W2 = 0.22 mm, B / A = 0.58, C / B = 0.43, W2 / W1 = 0.10.

[0101] Example 11

[0102] Example 11 differs only in that A = 0.6 mm, B = 0.4 mm, C = 0.14 mm, W1 = 2.3 mm, W2 = 0.16 mm, B / A = 0.67, C / B = 0.35, W2 / W1 = 0.07.

[0103] Example 12

[0104] Example 12 differs only in that A = 0.6 mm, B = 0.4 mm, C = 0.12 mm, W1 = 2.5 mm, W2 = 0.15 mm, B / A = 0.67, C / B = 0.30, W2 / W1 = 0.06.

[0105] Comparative Example 1

[0106] In Comparative Example 1, the only difference is that A = 0.5 mm, B = 0.3 mm, C = 0.089 mm, W1 = 1.8 mm, W2 = 0.28 mm, B / A = 0.60, C / B = 0.30, W2 / W1 = 0.16.

[0107] Comparative Example 2

[0108] In Comparative Example 2, the only difference is that A=0.6mm, B=0.3mm, C=0.15mm, W1=2.3mm, W2=0.22mm, B / A=0.50, C / B=0.50, W2 / W1=0.10.

[0109] Comparative Example 3

[0110] In Comparative Example 3, the only difference is that A=0.55mm, B=0.2mm, C=0.098mm, W1=2.2mm, W2=0.22mm, B / A=0.36, C / B=0.49, W2 / W1=0.10.

[0111] Comparative Example 4

[0112] In Comparative Example 4, the only difference is that A=0.6mm, B=0.23mm, C=0.065mm, W1=1.55mm, W2=0.16mm, B / A=0.38, C / B=0.28, W2 / W1=0.10.

[0113] Performance test:

[0114] In order to verify the design effect of the explosion-proof valve in Examples 1-12 and Comparative Examples 1-4, explosion-proof sheets with different design sizes were selected for welding verification (design opening pressure Cpk>1.67), and the results are shown in Table 1.

[0115] Table 1. Test results:

[0116]

[0117]

[0118]

[0119] It can be seen that when the design parameters of the explosion-proof valve satisfy: 0.4≤B / A≤0.7, 0.3≤C / B≤0.45, 0.05≤W2 / W1≤0.15, the opening pressure of the explosion-proof valve is relatively stable, and the consistency is good; compared with the explosion-proof valves in Comparative Examples 1-4, which do not satisfy the above equations, the opening pressure consistency and stability of the explosion-proof valve after laser welding are poor.

[0120] The part of the application not described in detail is the technology known to those skilled in the art.

[0121] The above describes the basic principles of the present application in combination with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present application are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and are not limiting, and the above details do not limit the present application to the above specific details.

[0122] It should be noted that the term "and / or" or " / " used herein is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. The singular form "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural form, unless the context clearly indicates otherwise.

[0123] In the detailed description and in the claims, a list of items connected by the term "at least one of", "at least one", "at least one of", or other similar terms means any combination of the listed items. For example, if the items A, B are listed, the phrase "at least one of A, B" means A alone; B alone; or A and B. In another example, if the items A, B, C are listed, the phrase "at least one of A, B, C" means A alone; B alone; C alone; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A can include a single element or multiple elements. Item B can include a single element or multiple elements. Item C can include a single element or multiple elements.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An explosion-proof valve, characterized in that, include: An opening surface is provided with a groove on one end face away from the electrode group; one side of the groove forms the opening surface body, and the other side of the groove forms a transition portion; A skirt-like hem surrounds the periphery of the transition section; The periphery of the groove is provided with a partition groove; in the thickness direction of the explosion-proof valve, the partition groove is located between the side of the groove away from the opening surface body and the outer sidewall of the skirt, and the partition groove is located on the transition part and / or the end face of the skirt near the pole group.

2. The explosion-proof valve according to claim 1, characterized in that, In the length or width direction of the explosion-proof valve, the width of the partition groove is W2, and W2 satisfies: 0.15mm≤W2≤0.25mm; And / or, in the thickness direction of the explosion-proof valve, the depth of the groove is B, wherein B satisfies: 0.2mm≤B≤0.4mm.

3. The explosion-proof valve according to claim 1, characterized in that, The groove includes a continuous section and an opening section; In the thickness direction of the explosion-proof valve, the thickness of the opening section is less than the thickness of the connecting section; The thickness of the opening section is C, and C satisfies: 0.06mm≤C≤0.15mm.

4. The explosion-proof valve according to claim 1, characterized in that, In the thickness direction of the explosion-proof valve, the opening surface body is configured as a convex surface away from the direction of the pole group; The projected area of ​​the opening surface in the thickness direction of the explosion-proof valve is S1, and the upper surface area of ​​the opening surface body is S2. S1 and S2 respectively satisfy: 150mm² 2 ≤S1≤600mm 2 85mm 2 ≤S2≤470mm 2 .

5. The explosion-proof valve according to claim 1, characterized in that, In the thickness direction of the explosion-proof valve, the skirt thickness is A, and A satisfies: 0.4mm ≤ A ≤ 0.7mm; In the length or width direction of the explosion-proof valve, the distance from the outer sidewall of the skirt to the side of the notch away from the opening surface body is W1, and W1 satisfies: 1.5mm≤W1≤2.5mm.

6. The explosion-proof valve according to any one of claims 1 to 5, characterized in that, The A, B, C, W1 and W2 also satisfy: 0.4≤B / A≤0.7, 0.3≤C / B≤0.45, 0.05≤W2 / W1≤0.

15.

7. The explosion-proof valve according to claim 1, characterized in that, In the length or width direction of the explosion-proof valve, a welding area is provided on the side of the skirt away from the opening surface, and the explosion-proof valve is connected to the cover plate body through the welding area; In the thickness direction of the explosion-proof valve, the cross-sectional width of the welding area is a, and the cross-sectional depth of the welding area is b. a and b satisfy the following conditions: 0.8mm≤a≤1.0mm and 0.25mm≤b≤0.6mm, respectively.

8. The explosion-proof valve according to claim 7, characterized in that, The welding area is formed by laser welding. During the laser welding process, the welding power is 400W to 700W and the welding speed is 25m / s to 50m / s.

9. A battery cell, characterized in that, include: Cover plate, electrode assembly, and explosion-proof valve as described in any one of claims 1 to 8 disposed on the cover plate.

10. A battery pack, characterized in that, include: The explosion-proof valve according to any one of claims 1 to 8; And / or, the battery cell according to claim 9.

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