Explosion-proof valve, cell, and battery pack

Abstract

The application belongs to the technical field of batteries, and particularly relates to an explosion-proof valve, a battery cell and a battery pack. The disclosed explosion-proof valve comprises an opening surface and a skirt. The 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. The skirt is circumferentially arranged on the periphery of the transition part. A separation groove is circumferentially arranged on 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 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. The explosion-proof valve has good 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, so that the battery cell has higher safety performance.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to an explosion-proof valve, a battery cell, and a battery pack. Background Technology

[0002] The explosion-proof valve on the battery cell is mainly used for pressure relief and gas exhaust. Because the battery cell is prone to thermal runaway due to mechanical impact, abnormal internal short circuits, etc., the high-temperature gas inside the battery cell can be released in a directional manner through the explosion-proof valve to prevent the battery pack from exploding.

[0003] Currently, in order to increase the capacity of battery packs, the space utilization rate of battery cells is improved, which reduces the thickness of a single battery cell. As a result, the size of the explosion-proof valve is very small. When welding the explosion-proof valve to 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 welding, which affects the safety performance of the battery cell. Summary of the Invention

[0004] In view of the above-mentioned technical problems, the present invention aims to at least partially solve one of the technical problems in the related art. To this end, the present invention provides an explosion-proof valve, a battery cell, and a battery pack, which can have good heat dissipation and insulation effects. This effectively avoids the welding heat affecting the structural strength of the explosion-proof valve during welding, thereby improving the structural stability and consistency of the explosion-proof valve, and consequently giving the battery cell higher safety performance.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

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

[0007] 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;

[0008] A skirt-like hem surrounds the periphery of the transition section;

[0009] 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.

[0010] In one optional implementation, the width of the partition groove in the length or width direction of the explosion-proof valve is W2, wherein W2 satisfies: 0.15mm≤W2≤0.25mm;

[0011] 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.

[0012] In one alternative implementation, the notch 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 connecting section;

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

[0015] In one alternative implementation, the opening surface body of the explosion-proof valve is configured as a convex surface away from the direction of the pole group in the thickness direction.

[0016] The total projected area of ​​the opening surface along 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 .

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

[0018] 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.

[0019] In one optional implementation, A, B, C, W1, and W2 further satisfy: 0.4 ≤ B / A ≤ 0.7, 0.3 ≤ C / B ≤ 0.45, and 0.05 ≤ W2 / W1 ≤ 0.15.

[0020] In one optional embodiment, 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;

[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. a and b satisfy the following conditions: 0.8mm≤a≤1.0mm and 0.25mm≤b≤0.6mm, respectively.

[0022] In one optional implementation, the welding area is formed by laser welding, wherein the welding power is 400W to 700W and the welding speed is 25m / s to 50m / s during the laser welding process.

[0023] According to a second aspect of the present invention, the present invention also provides a battery cell comprising: a cover plate, an electrode assembly, and an explosion-proof valve as described in any embodiment of the first aspect of the present invention disposed on the cover plate.

[0024] According to a third aspect of the present invention, the present invention also provides a battery pack, comprising: an explosion-proof valve as described in any embodiment of the first aspect of the present invention; and / or, a battery cell as described in any embodiment of the second aspect of the present invention.

[0025] The explosion-proof valve, battery cell, and battery pack provided by this invention also have at least the following beneficial effects:

[0026] This invention provides an explosion-proof valve, which includes an opening surface and a skirt. A notch is provided on the opening surface away from the electrode assembly. One side of the notch forms the opening surface body, and the other side forms a transition portion. A skirt surrounds the periphery of the transition portion. A groove is provided around the periphery of the notch. In the thickness direction of the explosion-proof valve, the groove is located between the side of the notch away from the opening surface body and the outer sidewall of the skirt, and the groove is located on the transition portion and / or the end face of the skirt near the electrode assembly. This explosion-proof valve has excellent heat dissipation and insulation effects, effectively preventing welding heat from affecting the structural strength of the explosion-proof valve during welding, thus improving the structural stability and consistency of the explosion-proof valve, and consequently giving the battery cell higher safety performance. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] Figure 1 The diagram shows the structure of the explosion-proof valve provided by this invention. Figure 1 ;

[0029] Figure 2 The figure shown is a schematic diagram of the planar structure of the explosion-proof valve provided by the present invention;

[0030] Figure 3 The present invention is shown. Figure 2 A schematic diagram of the XX' cross-section structure of the provided explosion-proof valve;

[0031] Figure 4 The diagram shows the structure of the explosion-proof valve provided by this invention. Figure 2 ;

[0032] Figure 5 The diagram shows the cover plate structure of the battery cell provided by the present invention. Figure 1 ;

[0033] Figure 6 The diagram shows the cover plate structure of the battery cell provided by the present invention. Figure 2 ;

[0034] Figure 7 The diagram shows the cover plate structure of the battery cell provided by the present invention. Figure 3 ;

[0035] Figure 8 The diagram shown is a cross-sectional view of the cover plate structure of the battery cell provided by the present invention. Figure 1 ;

[0036] Figure 9 The present invention is shown. Figure 8 A magnified view of a portion of the image;

[0037] Figure 10 The diagram shown is a cross-sectional view of the cover plate structure of the battery cell provided by the present invention. Figure 2 ;

[0038] Figure 11 The present invention is shown. Figure 10 A magnified view of a portion of the image;

[0039] Figure 12 The diagram shown is a schematic diagram of the battery cell structure provided by the present invention.

[0040] Explanation of reference numerals in the attached figures:

[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 section; 140 - Groove;

[0043] 20-Cover plate; 210-Cover plate body; 220-Mounting hole; 230-Countertop; 240-Pole post; 250-Plastic part; 260-Welding area; 270-Through hole;

[0044] 30 - Electrode group; 40 - Housing.

[0045] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0046] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0047] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

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

[0049] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0050] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0051] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0052] Explosion-proof valves have pressure relief and venting functions, ensuring good safety performance for the battery cells. Battery cells are prone to thermal runaway due to mechanical impacts, internal abnormal connections, and short circuits. The directional release of high-temperature gases inside the cell through the explosion-proof valve can prevent the battery pack from exploding. Currently, to increase battery pack capacity, space utilization of the cells is improved, resulting in thinner individual cells. This leads to very small explosion-proof valves. During the welding of the explosion-proof valve to the cover plate, the heat generated during welding is transferred. If the welding power is too high, the resulting heat can affect the structural strength of the explosion-proof valve, thereby impacting the safety performance of the battery pack.

[0053] In view of the above-mentioned technical problems, the present invention provides an explosion-proof valve, a battery cell, and a battery pack, which have excellent heat dissipation and heat insulation effects. This can effectively prevent the welding heat from affecting the structural strength of the explosion-proof valve during welding, thereby improving the structural stability and consistency of the explosion-proof valve and thus enabling the battery cell to have higher safety performance.

[0054] The specific technical solution of the present invention is as follows:

[0055] In some embodiments of the present invention, an explosion-proof valve is provided, comprising: an opening surface 130 and a skirt 110; the opening surface 130 has a notch 120 on one end face away from the electrode assembly 30; an opening surface body 131 is formed on one side of the notch 120, and a transition portion 132 is formed on the other side of the notch 120; the skirt 110 is surrounded around the periphery of the transition portion 132; a groove 140 is provided around the periphery of the notch 120; in the thickness direction of the explosion-proof valve 10, the groove 140 is provided between the side of the notch 120 away from the opening surface body 131 and the outer sidewall of the skirt 110, and the groove 140 is provided on the end face of the transition portion 132 and / or the skirt 110 near the electrode assembly 30.

[0056] refer to Figure 1 and Figure 2 The explosion-proof valve 10 can be made of metal materials such as aluminum alloy and stainless steel. Furthermore, the planar structure of the explosion-proof valve 10 can be rectangular, square, elliptical, circular, or other irregular shapes. Those skilled in the art can adjust the design based on the present invention according to actual conditions. The explosion-proof valve 10 is mounted on the cover plate 20. The opening surface 130 of the explosion-proof valve 10 has a notch 120 on the end face away from the electrode assembly 30. In the width or length direction of the explosion-proof valve 10, one side of the notch 120 forms the opening surface body 131, and the other side forms the transition portion 132. That is, the notch 120 surrounds the opening surface 130, dividing the opening surface 130 into the opening surface body 131, the transition portion 132, etc.

[0057] refer to Figure 3The periphery of the notch 120 is provided with a groove 140. That is, in the spatial structure of the explosion-proof valve 10, the notch 120 is provided with a groove 140 around its outer periphery. The groove 140 can be located on the same side as the notch 120 or on a different side. In the thickness direction of the explosion-proof valve 10, the groove 140 is located between the side of the notch 120 away from the opening surface body 131 and the outer sidewall of the skirt 110. The number of grooves 140 can be one, two, three or more. The cross-sectional shape of the groove 140 can be rectangular, trapezoidal, triangular, arc-shaped or other irregular arbitrary shapes. In some preferred embodiments, the groove 140 can be located on the end face of the transition portion 132 and / or the skirt 110 near the pole group 30. By setting a groove 140 between the side of the notch 120 away from the opening surface body 131 and the outer sidewall of the skirt 110, the explosion-proof valve 10 can achieve a good heat dissipation and heat insulation effect. 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. During the welding process, the heat generated by welding will be transferred to the side closer to the opening surface 130 and transferred to the groove 140, which makes the heat transfer path longer and thus can dissipate heat well, thereby greatly reducing the impact of welding on the stability of the explosion-proof valve 10.

[0058] This invention provides an explosion-proof valve, which includes an opening surface and a skirt. A notch is provided on the opening surface away from the electrode assembly. One side of the notch forms the opening surface body, and the other side forms a transition portion. A skirt surrounds the periphery of the transition portion. A groove is provided around the periphery of the notch. In the thickness direction of the explosion-proof valve, the groove is located between the side of the notch away from the opening surface body and the outer sidewall of the skirt, and the groove is located on the transition portion and / or the end face of the skirt near the electrode assembly. This explosion-proof valve has excellent heat dissipation and insulation effects, effectively preventing welding heat from affecting the structural strength of the explosion-proof valve during welding, thus improving the structural stability and consistency of the explosion-proof valve, and consequently giving the battery cell higher safety performance.

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

[0060] refer to 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 of 0.15mm, 0.16mm, 0.18mm, 0.20mm, 0.21mm, 0.22mm, 0.24mm, or 0.25mm, or any value between any two. By limiting the width of the partition groove 140, the explosion-proof valve can have better heat dissipation and insulation performance, thereby improving the stability and consistency of the explosion-proof valve and ensuring stable opening pressure. If the width of the partition groove 140 is less than the above range, it cannot achieve good heat dissipation. When welding the explosion-proof valve 10 and the cover plate 20, the heat generated during welding cannot be effectively dissipated, which can easily lead to poor consistency of the explosion-proof valve 10. If it is greater than the above range, it will reduce the mechanical strength of the explosion-proof valve 10, especially the mechanical strength at the location of the partition groove 140, which can easily damage the explosion-proof valve 10.

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

[0062] refer to 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 of 0.2mm, 0.3mm, 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.9mm, or 2.0mm, or any value between any two. Similarly, by limiting the depth of the partition groove 140, the explosion-proof valve 10 can have better heat dissipation and insulation performance, thereby making the explosion-proof valve 10 more stable and consistent, and the opening pressure of the explosion-proof valve 10 more stable. If it is less than the above range, the temperature transfer path may not be long enough during welding, resulting in poor heat dissipation, unstable structural strength of the explosion-proof valve 10, and poor consistency of the explosion-proof valve 10. If it is greater than the above range, the explosion-proof valve 10 is prone to breakage or cracking at the partition groove 140 position, 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, where C satisfies: 0.06mm≤C≤0.15mm.

[0064] refer to Figure 8 and Figure 9The notch 120 surrounding the opening surface body 131 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 122. The opening section 122 is very thin, and in the event of thermal runaway of the battery cell, it will rupture along this area, causing the explosion-proof valve 10 to reverse along the connecting section 121 and open to release pressure. The thickness C of the opening section 122 can be 0.06mm, 0.065mm, 0.07mm, 0.086mm, or 0. The thickness of the opening section 122 can be limited to any one of 0.9mm, 0.1mm, 0.11mm, 0.12mm, 0.14mm, 0.145mm, or 0.15mm, or any point between any two of these values. By limiting the thickness of the opening section 122, the opening pressure of the explosion-proof valve 10 can be well guaranteed to be stable. If it is greater than the above range, the explosion-proof valve 10 may not be able to open effectively to relieve pressure in the event of thermal runaway of the battery cell, which may lead to an explosion risk. If it is less than the above range, the explosion-proof valve 10 may open even before thermal runaway occurs, making it unstable.

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

[0066] refer to Figure 4 , Figure 8 and Figure 9 In the thickness direction of the explosion-proof valve 10, the opening surface body 131 can be set as a convex surface away from the pole group 30, which can further improve the directional exhaust and pressure relief performance of the explosion-proof valve 10; the projected area S1 of the opening surface 130 in the thickness direction of the explosion-proof valve 10 can be 150mm². 2 200mm 2 250mm 2 300mm 2 400mm 2 500mm 2 Or 600mm 2 The value of any one of or any two of them; the upper surface area S2 of the open surface body 131 can be 85mm². 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 8The ratio of B / A can be any one of 0.4, 0.5, 0.55, 0.6, or 0.7, or any value between any two; 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 value between any two; 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 value between any two. By limiting the above ratios, the opening pressure of the explosion-proof valve 10 can be well guaranteed to be relatively stable and consistent, and the structural design of the explosion-proof valve 10 can be more reasonable. If any of the above ratios is outside this range, it may partially or completely affect the structural rationality of the explosion-proof valve 10. During welding, the structural strength of the explosion-proof valve 10 may be affected, 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, a welding area 260 is provided on the side of the skirt 110 away from the opening surface 130, and the explosion-proof valve 10 is connected to 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, where a and b satisfy: 0.8mm≤a≤1.0mm, 0.25mm≤b≤0.6mm respectively.

[0072] refer to Figure 10 and Figure 11 Along the length or width of the explosion-proof valve 10, a welding area 260 is provided on the side of the skirt 110 away from the opening surface 130. This welding area 260 can be the area where the explosion-proof valve 10 and the cover plate 20 are welded together. That is, 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 formed by laser welding. Along the thickness direction of the explosion-proof valve 10, the cross-sectional width 'a' of the welding area 260 can be 0.8mm, 0.82mm, 0.85mm, or 0. The cross-sectional depth b of the welding area 260 can be any one of 0.9mm, 0.95mm, or 1mm, or any value between any two; 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 value between any two; 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 impact of welding on the explosion-proof valve 10 can be 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, during which the welding power is 400W to 700W and the welding speed is 25m / s to 50m / s.

[0074] refer to Figure 7 and Figure 9 The welding area 260 can be formed by laser welding, and the welding area 260 surrounds the outer side of the skirt 110. In order to minimize the impact on the explosion-proof valve 10 during the welding process and ensure that the explosion-proof valve 10 has excellent stability and consistency, the welding power can be any one of 400W, 450W, 500W, 600W or 700W or any value between any two; the welding speed can be any one of 25m / s, 28m / s, 30m / s, 35m / s, 40m / s, 45m / s or 50m / s or any value between any two. By limiting the welding power and welding speed, the explosion-proof valve can be firmly connected to the cover plate 20, and the impact of the heat generated by welding on the explosion-proof valve 10 can be reduced, so that the explosion-proof valve has good stability and consistency.

[0075] In some embodiments of the present invention, a battery cell is also provided, comprising: a cover plate, an electrode assembly, and an explosion-proof valve as described in any of the above embodiments disposed on the cover plate.

[0076] like Figure 5 and Figure 6 The cover plate 20 on the battery cell includes a cover plate body 210. A mounting hole 220 is provided on the cover plate body 210. A countersunk platform 230 is provided on the end of the mounting hole 220 near the electrode group. An explosion-proof valve 10 is installed on the countersunk platform 230 of the mounting hole 220. A plastic part 250 is also provided on the side of the cover plate body 210 near the electrode group 30. A through hole 270 is also provided on the cover plate body 210. An electrode post 240 is provided in the through hole 270.

[0077] like Figure 12 As shown, the battery cell may include a cover plate 20, an electrode assembly 30, and a housing 40. The electrode assembly 30 is disposed in the housing 40. One end of the housing 40 is provided with the cover plate 20, and an explosion-proof valve 10 is provided on the cover plate 20, or an explosion-proof valve 10 is provided on any side wall of the housing 40. The electrode assembly 30 also includes a shell, a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. For example, the positive electrode plate includes a current collector made of copper foil or aluminum foil, and the current collector is provided with active materials such as lithium iron phosphate or ternary materials. Similarly, the current collector of the negative electrode plate is provided with active materials such as graphite. The specific structure of the battery cell described above is well known in the art and will not be described in detail here.

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

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

[0080] The present application will be described in detail below with reference to the accompanying drawings and examples. However, the implementation and protection of the present invention are not limited thereto. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0081] Example 1

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

[0083] Example 2

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

[0085] Example 3

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

[0087] Example 4

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

[0089] Example 5

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

[0091] Example 6

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

[0093] Example 7

[0094] The only difference in Example 7 is 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, and W2 / W1 = 0.11.

[0095] Example 8

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

[0097] Example 9

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

[0099] Example 10

[0100] The only difference in Example 10 is 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, and W2 / W1 = 0.10.

[0101] Example 11

[0102] The only difference in Example 11 is 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, and W2 / W1 = 0.07.

[0103] Example 12

[0104] The only difference in Example 12 is 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, and W2 / W1 = 0.06.

[0105] Comparative Example 1

[0106] In Comparative Example 1, the only differences are 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, and W2 / W1 = 0.16.

[0107] Comparative Example 2

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

[0109] Comparative Example 3

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

[0111] Comparative Example 4

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

[0113] Performance testing:

[0114] To verify the design effectiveness of the explosion-proof valves in Examples 1-12 and Comparative Examples 1-4, explosion-proof discs of 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 meet the following conditions: 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 has good consistency. In contrast, the explosion-proof valves in Comparative Examples 1 to 4 do not meet the above equations, and the opening pressure consistency and stability of the explosion-proof valves after laser welding are poor.

[0120] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0121] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0122] It should be noted that the terms "and / or" or " / " used herein are merely descriptions of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The singular forms "a," "described," and "the" used in the embodiments of the invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0123] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain 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 invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

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 portion and / or the end face of the skirt near the pole assembly. Wherein, in the length or width direction of the explosion-proof valve, the width of the groove is W2, 0.15mm≤W2≤0.25mm; the distance from the outer sidewall of the skirt to the side of the groove away from the opening surface body is W1, 1.5mm≤W1≤2.5mm; The notch includes a connecting section and an opening section; in the thickness direction of the explosion-proof valve, the depth of the groove is B, 0.2mm≤B≤0.4mm; the thickness of the opening section is less than the thickness of the connecting section; the thickness of the opening section is C, 0.06mm≤C≤0.15mm; the opening surface body is configured as a convex surface away from 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, wherein S1 and S2 respectively satisfy: 150mm 2 ≤S1≤600mm 2 85mm 2 ≤S2≤470mm 2 The thickness of the skirt hem is A, where 0.4mm ≤ A ≤ 0.7mm; 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.

2. 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.

3. The explosion-proof valve according to claim 2, characterized in that, The welding area is formed by laser welding. During the laser welding process, the welding power is 400W~700W and the welding speed is 25m / s~50m / s.

4. A battery cell, characterized in that, include: Cover plate, electrode assembly, and explosion-proof valve as described in any one of claims 1 to 3 disposed on the cover plate.

5. A battery pack, characterized in that, include: The explosion-proof valve according to any one of claims 1 to 3; And / or, the battery cell according to claim 4.

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