Thermal runaway exhaust structure and battery cell
By using a needle puncture unit in the battery cell to contact the explosion-proof valve and control its starting pressure, the problem that the existing explosion-proof valve of the battery cell cannot accurately control the air-relief pressure, improve the response speed and reduce the pressure relief hysteresis , ensuring the safety of the battery.
Patent Information
- Application Number
- CN202323320089.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-05
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2033-12-05
AI Technical Summary
The existing battery cell explosion-proof valves are difficult to achieve sufficient consistency in structure, resulting in the inability to accurately control the starting pressure of deflation and pressure relief, and there is a pressure relief hysteresis, which can easily lead to battery explosion.
The needle puncture unit is adopted, and the thimble formed by the plate body is in contact with the explosion-proof valve, so that the explosion-proof valve is opened smoothly in the inflatable state, and the thickness and spacing of the explosion-proof valve are controlled to accurately control the starting pressure, improve the response speed, and reduce the pressure relief hysteresis.
Accurate control of deflation and pressure relief is achieved, the response speed is improved, the pressure relief hysteresis is reduced, and the battery safety is ensured.
Smart Images
Figure CN222191061U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and in particular to a thermal runaway exhaust structure and a battery core. Background Art
[0002] The exhaust structure of the energy storage cell thermal runaway is particularly important to the safety of the cell. When the cell thermal runaway occurs, the gas inside the cell expands, causing the internal pressure to increase. When the pressure increases to a certain level, the explosion-proof valve ruptures to release gas and pressure, thereby preventing the cell from exploding.
[0003] Most of the existing explosion-proof valves for battery cells are notched. However, the notched explosion-proof valve needs to be stamped and then welded, and the manufacturing process is relatively complicated, which makes it difficult to achieve sufficient consistency in the structure of the notched explosion-proof valve, and the starting pressure of the gas release and pressure relief cannot be accurately controlled. In addition, the starting pressure of the gas release and pressure relief of the notched explosion-proof valve is large, and the gas release and pressure relief cannot be immediately released when the battery is abnormal, which can easily cause the battery to explode. Utility Model Content
[0004] In view of this, the utility model provides a thermal runaway exhaust structure and a battery cell to solve the problem that the explosion-proof valve cannot accurately control the starting pressure of the air release and pressure relief and there is a pressure relief hysteresis.
[0005] In a first aspect, the utility model provides a thermal runaway exhaust structure, comprising:
[0006] An explosion-proof valve is provided on the housing and / or cover of the battery cell;
[0007] The acupuncture unit includes a plate body and at least one ejector pin formed on the plate body, wherein the ejector pin protrudes from one side of the plate body toward the explosion-proof valve;
[0008] The explosion-proof valve has an initial state in which it is spaced apart from the ejector pin, and an inflated state in which it bulges toward the ejector pin after being deformed by pressure;
[0009] In the inflated state, the explosion-proof valve is adapted to contact the ejector pin so that the ejector pin punctures the explosion-proof valve.
[0010] Beneficial effect: The thermal runaway exhaust structure provided by the embodiment of the utility model is provided with a puncture unit, so that the plate body of the puncture unit protrudes toward one side of the explosion-proof valve to form a ejector pin, and when the explosion-proof valve is in an inflated state, as the inflation proceeds, the explosion-proof valve is brought into contact with the ejector pin, so that the ejector pin punctures the explosion-proof valve, thereby ensuring the smooth opening of the explosion-proof valve. There is no need to use a large air pressure value to puncture the explosion-proof valve, and there is no need to use a complicated process to produce a notched explosion-proof valve. The starting pressure when the explosion-proof valve bulges can be guaranteed by controlling the thickness of the explosion-proof valve, and the starting pressure of the air release and pressure relief can be accurately controlled, thereby improving the response speed of the air release and pressure relief, reducing the pressure relief hysteresis, and ensuring the safety of the battery.
[0011] In an optional embodiment, in the initial state, the minimum distance between the puncture unit and the explosion-proof valve is a, wherein a satisfies 0.3 mm≤a≤0.5 mm.
[0012] Beneficial effect: By ensuring that the acupuncture unit and the explosion-proof valve are always in a spaced state, the acupuncture unit can be prevented from accidentally puncturing the explosion-proof valve, ensuring the safety of the explosion-proof valve in a normal state. And by reducing the distance between the acupuncture unit and the explosion-proof valve as much as possible, the contact efficiency between the acupuncture unit and the explosion-proof valve can be ensured, and the response speed can be improved.
[0013] In an optional implementation, the thickness of the explosion-proof valve is H, wherein H satisfies 0.05 mm ≤ a ≤ 0.3 mm.
[0014] Beneficial effect: By limiting the upper limit of the thickness of the explosion-proof valve, the deformation pressure of the explosion-proof valve can be ensured to be small, which facilitates the bulging of the explosion-proof valve, thereby ensuring the smooth opening of the explosion-proof valve, improving the response speed of air release and pressure relief, reducing the pressure relief hysteresis, and ensuring battery safety.
[0015] In an optional embodiment, at least one hollow portion is further provided on the plate body; along the opening direction of the explosion-proof valve, a projection of the at least one hollow portion overlaps with the explosion-proof valve.
[0016] Beneficial effect: By opening at least one hollow portion on the plate body, after the explosion-proof valve is opened, exhaust can be exhausted outward through the hollow portion, reducing the influence of the puncture unit on the exhaust efficiency. At the same time, along the opening direction of the explosion-proof valve, the projection of at least one hollow portion overlaps with the explosion-proof valve, which can reduce the interference of the puncture unit on the exhaust path of the explosion-proof valve.
[0017] In an optional embodiment, the hollow portions are arranged in multiple rows side by side, and at least one hollow portion and at least one ejector pin are arranged in sequence and at intervals.
[0018] Beneficial effect: By arranging the ejector pins in a multi-row structure and providing a plurality of ejector pins in each row, the puncturing efficiency of the ejector pins on the explosion-proof valve can be increased.
[0019] In an optional embodiment, the puncture unit further includes a support portion, and the support portion is fixedly connected to the housing of the battery cell, or the support portion is fixedly connected to the cover plate of the battery cell.
[0020] Beneficial effect: The acupuncture unit is fixed by providing a support part, which can ensure that the acupuncture unit is firmly fixed and avoid accidental falling.
[0021] In an optional embodiment, at least a partial area of the explosion-proof valve is formed with notches.
[0022] Beneficial effect: By forming notches in at least part of the explosion-proof valve, the explosion path of the explosion-proof valve can be limited. Through the dual cooperation of the puncture unit and the notches, the opening efficiency of the explosion-proof valve can be improved, ensuring the smooth opening of the explosion-proof valve, which is more conducive to achieving explosion.
[0023] In an optional embodiment, the melting point temperature of the pricking unit is lower than the exhaust temperature of the explosion-proof valve.
[0024] Beneficial effect: By making the melting point of the puncture unit lower than the exhaust temperature of the explosion-proof valve, the puncture unit can be melted by the high-temperature medium discharged from the battery cell after the explosion-proof valve is opened, thereby increasing the exhaust area and avoiding interference of the puncture unit with the exhaust path.
[0025] In an optional implementation, the explosion-proof valve has a deformation pressure P, where P satisfies 0.6MPa≤P≤1.2MPa.
[0026] Beneficial effect: When the pressure is reached, the explosion-proof valve can be pushed outward by the air pressure, deforming from the initial state to the inflated state, so that the starting pressure of the deflation and pressure relief can be accurately controlled.
[0027] In a second aspect, the utility model further provides a battery cell, comprising:
[0028] Shell and cover plate; and the thermal runaway exhaust structure as described above, the explosion-proof valve is opened on the shell and / or cover plate.
[0029] Because the battery cell includes a thermal runaway exhaust structure, it has the same effect as the thermal runaway exhaust structure and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] 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.
[0031] Figure 1 It is a schematic diagram of the battery cell of the utility model;
[0032] Figure 2 This is a schematic diagram of the disassembled state of the battery cell of the utility model;
[0033] Figure 3 This is a schematic diagram of the cover plate and the acupuncture unit of the utility model from a first perspective;
[0034] Figure 4 This is a schematic diagram of the cover plate and the acupuncture unit of the utility model from a second viewing angle;
[0035] Description of reference numerals:
[0036] 1. Shell; 2. Cover plate; 3. Pole; 4. Explosion-proof valve; 41. Notch; 5. Puncture unit; 51. Hollow part; 52. Ejector pin; 53. Support part; 54. Plate body. DETAILED DESCRIPTION
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] Combine the following Figures 1 to 4 , describing an embodiment of the utility model.
[0042] According to an embodiment of the present utility model, on the one hand, a thermal runaway exhaust structure is provided, comprising:
[0043] An explosion-proof valve 4 is provided on the housing 1 and / or the cover plate 2 of the battery cell;
[0044] The acupuncture unit 5 includes a plate body 54 and at least one ejector pin 52 formed on the plate body 54. The ejector pin 52 is formed by protruding from one side of the plate body 54 toward the explosion-proof valve 4;
[0045] The explosion-proof valve 4 has an initial state in which it is spaced apart from the ejector pin 52, and an inflated state in which it bulges toward the ejector pin 52 after being deformed by pressure;
[0046] In the inflated state, the explosion-proof valve 4 is adapted to contact the ejector pin 52 so that the ejector pin 52 punctures the explosion-proof valve 4 .
[0047] The puncture unit 5 includes a plate body 54 and at least one ejector pin 52 formed on the plate body 54. The ejector pin 52 has a tip with a smaller diameter at one end away from the plate body 54, so that when the explosion-proof valve 4 bulges toward the ejector pin 52 after being deformed by pressure, the ejector pin 52 can be used to puncture the explosion-proof valve 4.
[0048] The explosion-proof valve 4 has an initial state in which it is spaced apart from the ejector pin 52 . In the initial state, there is a gap between the explosion-proof valve 4 and the ejector pin 52 , which prevents the ejector pin 52 from accidentally triggering the explosion-proof valve 4 , thereby ensuring the safety of the explosion-proof valve 4 in normal use.
[0049] The explosion-proof valve 4 may be disposed on the housing 1 of the battery cell, or the explosion-proof valve 4 may be disposed on the cover plate 2 of the battery cell.
[0050] The starting pressure value of the explosion-proof valve 4 is relatively small. When the battery cell has thermal runaway, gas is generated inside the battery cell, causing the explosion-proof valve 4 to deform from an initial state to an inflated state under pressure. After further inflation, the explosion-proof valve 4 contacts the ejector pin 52, so that the ejector pin 52 pierces the explosion-proof valve 4, thereby ensuring the smooth opening of the explosion-proof valve 4, improving the response speed of air release and pressure relief, reducing the pressure relief hysteresis, and ensuring battery safety.
[0051] The explosion-proof valve 4 can follow the pressure change inside the battery cell to achieve concave-convex deformation. The explosion-proof valve 4 can be smoothly opened by contacting the explosion-proof valve 4 with the ejector pin 52 using the concave-convex deformation.
[0052] The thermal runaway exhaust structure provided by the embodiment of the utility model is provided with a puncture unit 5, so that the plate body 54 of the puncture unit 5 protrudes toward one side of the explosion-proof valve 4 to form a ejector pin 52, and when the explosion-proof valve 4 is in an inflated state, as the inflation proceeds, the explosion-proof valve 4 is brought into contact with the ejector pin 52, so that the ejector pin 52 punctures the explosion-proof valve 4, thereby ensuring the smooth opening of the explosion-proof valve 4, without the need for a large air pressure value to puncture the explosion-proof valve 4, and without the need to produce a notched explosion-proof valve through a complex process. The starting pressure when the explosion-proof valve 4 bulges can be guaranteed by controlling the thickness of the explosion-proof valve 4, and the starting pressure of the air release and pressure relief can be accurately controlled, thereby improving the response speed of the air release and pressure relief, reducing the pressure relief hysteresis, and ensuring the safety of the battery.
[0053] In some embodiments, in the initial state, the minimum distance between the acupuncture unit 5 and the explosion-proof valve 4 is a, wherein a satisfies 0.3 mm≤a≤0.5 mm.
[0054] By ensuring that the puncture unit 5 and the explosion-proof valve 4 are always in a spaced state, the puncture unit 5 can be prevented from accidentally puncturing the explosion-proof valve 4, and the safety of the explosion-proof valve 4 in a normal state can be ensured. In addition, by reducing the distance between the puncture unit 5 and the explosion-proof valve 4 as much as possible, the contact efficiency between the puncture unit 5 and the explosion-proof valve 4 can be ensured, and the response speed can be improved.
[0055] In some embodiments, the thickness of the explosion-proof valve 4 is H, wherein H satisfies 0.05 mm ≤ a ≤ 0.3 mm.
[0056] The explosion-proof valve 4 is thin and can be deformed inside and outside.
[0057] By limiting the upper thickness limit of the explosion-proof valve 4, the deformation pressure of the explosion-proof valve 4 can be ensured to be relatively small, which facilitates the bulging of the explosion-proof valve 4 and ensures the smooth opening of the explosion-proof valve 4, improves the response speed of air release and pressure relief, reduces the pressure relief hysteresis, and ensures battery safety.
[0058] By limiting the lower limit of the thickness of the explosion-proof valve 4 , it is possible to avoid insufficient structural strength due to the explosion-proof valve 4 being too thin, and to avoid accidental triggering.
[0059] As an optional embodiment, the explosion-proof valve 4 is welded to the cover plate.
[0060] Combination Figure 4 As shown, in the initial state, the explosion-proof valve 4 is recessed relative to the cover plate 2, and at this time, the explosion-proof valve 4 has no contact with the puncture unit 5. When the battery undergoes thermal runaway, the internal air pressure pushes up the explosion-proof valve 4, causing the explosion-proof valve 4 to bulge toward the puncture unit 5 and contact the puncture unit 5.
[0061] In some embodiments, in combination Figure 3 , Figure 4 As shown, at least one hollow portion 51 is further provided on the plate body 54 ; along the opening direction of the explosion-proof valve 4 , the projection of at least one hollow portion 51 overlaps with the explosion-proof valve 4 .
[0062] By providing at least one hollow portion 51 on the plate body 54, after the explosion-proof valve 4 is opened, exhaust can be discharged outward through the hollow portion 51, reducing the influence of the puncture unit 5 on the exhaust efficiency. At the same time, along the opening direction of the explosion-proof valve 4, the projection of at least one hollow portion 51 overlaps with the explosion-proof valve 4, which can reduce the interference of the puncture unit 5 on the exhaust path of the explosion-proof valve 4.
[0063] In some embodiments, in combination Figure 3 , Figure 4As shown, the hollow portions 51 are arranged in multiple rows side by side, and at least one hollow portion 51 and at least one ejector pin 52 are arranged in sequence and at intervals.
[0064] By arranging the ejector pins 52 in a multi-row structure with a plurality of ejector pins 52 in each row, the efficiency of the ejector pins 52 in puncturing the explosion-proof valve 4 can be increased.
[0065] The hollow parts 51 are arranged in multiple rows side by side, which can play a role similar to reinforcing ribs, thereby improving the rigidity of the acupuncture unit 5 and ensuring that the acupuncture unit 5 is not easily deformed.
[0066] In some embodiments, in combination Figure 3 As shown, the puncture unit 5 further includes a support portion 53, and the support portion 53 is fixedly connected to the housing 1 of the battery cell, or the support portion 53 is fixedly connected to the cover plate 2 of the battery cell.
[0067] The support portion 53 is provided to fix the acupuncture unit 5, so that the acupuncture unit 5 can be firmly fixed and prevented from accidentally falling.
[0068] In this embodiment, the pricking unit 5 is bonded or welded to the top of the cover plate 2. Correspondingly, a positioning groove corresponding to the support portion 53 may be provided on the cover plate 2 to facilitate the positioning of the support portion 53 and ensure that the ejector pin 52 is positioned accurately.
[0069] In some embodiments, in combination Figure 4 As shown, at least a partial area of the explosion-proof valve 4 is formed with notches 41 .
[0070] By forming notches 41 in at least a portion of the explosion-proof valve 4, the explosion path of the explosion-proof valve 4 can be limited. Through the dual cooperation of the puncture unit 5 and the notches 41, the opening efficiency of the explosion-proof valve 4 can be improved, ensuring the smooth opening of the explosion-proof valve 4, which is more conducive to achieving explosion.
[0071] Optionally, the tip position of at least part of the ejector pins 52 corresponds to the position of the notch 41 , so that the explosion-proof valve 4 can be opened more easily.
[0072] In some embodiments, the melting point temperature of the puncture unit 5 is lower than the exhaust temperature of the explosion-proof valve 4 .
[0073] By making the melting point of the puncture unit 5 lower than the exhaust temperature of the explosion-proof valve 4, the puncture unit 5 can be melted by the high-temperature medium discharged from the battery cell after the explosion-proof valve 4 is opened, thereby increasing the exhaust area and preventing the puncture unit 5 from interfering with the exhaust path.
[0074] In some embodiments, the deformation pressure P of the explosion-proof valve 4 satisfies 0.6 MPa≤P≤1.2 MPa.
[0075] Optionally, the opening pressure of the explosion-proof valve 4 is between 0.6MPa and 1.2MPa, that is, when the pressure is reached, the explosion-proof valve 4 can be pushed outward by the air pressure and deformed from the initial state to the inflated state, so that the starting pressure of the deflation and pressure relief can be accurately controlled.
[0076] According to an embodiment of the present utility model, on the other hand, a battery cell is provided, comprising:
[0077] The shell 1 and the cover plate 2; and the thermal runaway exhaust structure as described above, the explosion-proof valve 4 is opened on the shell 1 and / or the cover plate 2.
[0078] In some embodiments, the battery cell may adopt a method of having two-side output poles 3 , one side being the positive pole and the other side being the negative pole, and explosion-proof valves 4 are designed on both sides.
[0079] Additionally, the explosion-proof valve 4 can be designed at the top, bottom or side of the battery cell, and the explosion-proof valve 4 can be on the same plane as the pole or on a different plane from the pole.
[0080] Additionally, the number of explosion-proof valves 4 may be multiple.
[0081] In other embodiments, the battery cell may also adopt the method of having the poles 3 on the same side, and designing multiple explosion-proof valves 4 on other sides of the battery cell, so as to achieve thermal and electrical separation.
[0082] 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 thermal runaway exhaust structure, characterized in that: include: An explosion-proof valve is provided on the housing and / or cover of the battery cell; A needling unit, the needling unit comprising a plate body and at least one ejector pin formed on the plate body, the ejector pin protruding from one side of the plate body toward the explosion-proof valve; The explosion-proof valve has an initial state in which it is spaced apart from the ejector pin, and an inflated state in which it bulges toward the ejector pin after being deformed by pressure; In the inflated state, the explosion-proof valve is adapted to contact the ejector pin so that the ejector pin punctures the explosion-proof valve.
2. The thermal runaway exhaust structure according to claim 1, characterized in that: In the initial state, the minimum distance between the pricking unit and the explosion-proof valve is a, wherein a satisfies 0.3 mm≤a≤0.5 mm.
3. The thermal runaway exhaust structure according to claim 1, characterized in that: The thickness of the explosion-proof valve is H, wherein H satisfies 0.05mm≤a≤0.3mm.
4. The thermal runaway exhaust structure according to claim 1, characterized in that: At least one hollow portion is also formed on the plate body; along the opening direction of the explosion-proof valve, a projection of at least one of the hollow portions overlaps with the explosion-proof valve.
5. The thermal runaway exhaust structure according to claim 4, characterized in that: The hollow parts are arranged in multiple rows side by side, and at least one of the hollow parts and at least one of the ejector pins are arranged in sequence and at intervals.
6. The thermal runaway exhaust structure according to claim 4, characterized in that: The acupuncture unit further includes a support portion, and the support portion is fixedly connected to the shell of the battery cell, or the support portion is fixedly connected to the cover plate of the battery cell.
7. The thermal runaway exhaust structure according to any one of claims 1 to 6, characterized in that: At least a portion of the explosion-proof valve is formed with notches.
8. The thermal runaway exhaust structure according to any one of claims 1 to 6, characterized in that: The melting point temperature of the pricking unit is lower than the exhaust temperature of the explosion-proof valve.
9. The thermal runaway exhaust structure according to any one of claims 1 to 6, characterized in that: The explosion-proof valve has a deformation pressure P, wherein P satisfies 0.6MPa≤P≤1.2MPa.
10. A battery cell, characterized in that: include: A shell and a cover plate; and a thermal runaway exhaust structure as described in any one of claims 1 to 9 above, wherein an explosion-proof valve is provided on the shell and / or the cover plate.