Blocking device, battery cap and battery

Abstract

The present invention discloses a blocking device that is mounted above an explosion-proof valve in a battery cap. The explosion-proof valve includes a hollow mounting portion and an explosion portion mounted within the mounting portion. The blocking device is capable of abutting the explosion portion and is provided with a vent. The present invention also discloses an end cap and a battery including the blocking device. The present invention has the beneficial effect that when a battery cell experiences thermal runaway, the blocking device can prevent the explosion portion in the explosion-proof valve from moving upward, thereby delaying or preventing the release of substances within the battery, reducing or avoiding the hazards caused by leakage of chemical substances within the battery, and improving the safety performance of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a blocking device, a battery cap and a battery. Background Art

[0002] Lithium batteries are increasingly used in various digital devices, including laptops, digital cameras, and mobile phones. They also have broad applications in electric vehicles, bicycles, mobile base stations, and energy storage base stations. In this context, batteries are no longer used singly, as in mobile phones, but are increasingly used in series or parallel battery packs. Users are increasingly concerned about improving battery range and safety. Currently, these improvements are primarily achieved through increasing capacity and the volumetric energy density of battery cells. However, these improvements in range and energy density also pose safety risks to the battery cells themselves, such as overheating, fire, and explosion. Safety incidents are common, posing a direct threat to consumers' personal and property safety.

[0003] In traditional lithium-ion battery technology, in order to prevent abnormal situations such as overcharging, over-discharging and short circuit, a protection board is installed on the outside of the lithium-ion battery cell. The protection board is equipped with a protection circuit for controlling the battery voltage and current. However, there is basically no protection circuit inside the battery cell. When the battery cell is short-circuited or heated, the temperature rises instantly, and the electrolyte decomposes and bulges. Due to the short time, the external protection device has not yet fully taken effect, and the internal temperature of the battery cell will rise and bulge, causing fire and explosion.

[0004] After years of development, the manufacturing process of cylindrical batteries has become very mature. In addition to greatly improved performance, its safety is also very complete. In order to avoid the explosion of the sealed metal shell, cylindrical batteries are now equipped with a safety valve on the top. The safety valve is standard for every cylindrical battery and is also the most important explosion-proof barrier. When the internal pressure of the battery is too high, the positive electrode solder joint will be broken first. If the internal pressure continues to rise, the top safety valve will crack to exhaust and reduce pressure to avoid explosion. However, after the safety valve cracks, the chemical substances leaked from the battery will still react chemically with the oxygen in the air under high temperature conditions, and there is still a possibility of fire, posing a safety hazard. Summary of the Invention

[0005] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a blocking device capable of preventing or delaying leakage of substances inside a battery, as well as an end cover and a battery including the blocking device.

[0006] The technical solutions of the present invention are as follows:

[0007] The first aspect of the present invention is to provide a blocking device, which is installed in the battery cap and arranged above the explosion-proof valve in the battery cap. The explosion-proof valve includes a hollow mounting portion and an explosion portion installed in the mounting portion. The blocking device can abut against the explosion portion, and the blocking device is provided with a ventilation hole.

[0008] As an optimal technical solution, the blasting part has a first station protruding downward and a second station protruding upward. The blasting part can be flipped from the first station to the second station, and the blocking device can abut against the blasting part located at the second station.

[0009] As an optimal technical solution, the blocking device includes a hollow outer frame and a blocking piece installed in the outer frame. The blocking device abuts against the blasting part located at the second workstation through the blocking piece, and the air vent is formed between the outer frame and the blocking piece.

[0010] As a preferred technical solution, the blocking sheet can be deformed and / or broken under the pressure of the bursting part.

[0011] As a preferred technical solution, the blocking piece includes a first blocking piece, a second blocking piece, and an intermediate connecting piece connected between the first blocking piece and the second blocking piece, and the intermediate connecting piece can be broken under the pressure of the bursting part.

[0012] As a preferred technical solution, the first blocking piece and the second blocking piece can be deformed under the pressure of the bursting part.

[0013] As a preferred technical solution, the shape of the hollow portion of the outer frame is the same as that of the bursting portion, and the inner diameter of the outer frame is larger than the outer diameter of the bursting portion.

[0014] As a preferred technical solution, the blocking device is a PCB board.

[0015] A second aspect of the present invention provides a battery cap comprising the above-mentioned blocking device.

[0016] As an optimal technical solution, it also includes:

[0017] A top cover is arranged above the blocking device, and is provided with a plurality of vent holes;

[0018] An explosion-proof valve is disposed below the blocking device, comprising a hollow mounting portion and a bursting portion mounted within the mounting portion, the bursting portion having a first position protruding downward and a second position protruding upward, the bursting portion being capable of flipping from the first position to the second position, a blocking piece in the blocking device abutting against the bursting portion at the second position, and the blocking piece being capable of deforming under pressure from the bursting portion;

[0019] A bottom plate is provided below the explosion-proof valve, the bottom plate has a plurality of vent holes, and the bottom plate is welded to the explosion part to form a positive electrode welding point;

[0020] The sealing ring, the top cover, the blocking device, the explosion-proof valve and the bottom plate are sequentially arranged in the sealing ring.

[0021] A third aspect of the present invention provides a battery, comprising the above-mentioned battery cap.

[0022] The beneficial effects of the present invention are as follows: the high-temperature resistant blocking device of the present invention is used in a battery end cap. When a battery cell experiences thermal runaway, the blocking device can block the upward movement of the burst portion in the explosion-proof valve, thereby delaying or preventing the outflow of the battery's internal substances, reducing or avoiding the hazards caused by leakage of chemical substances within the battery, and improving the safety performance of the battery. When the pressure within the battery further increases, the explosion-proof valve ruptures and squeezes the blocking sheet in the blocking device, causing it to break and deform, thereby allowing some of the battery's internal substances to flow out from the rupture of the explosion-proof valve and the vents on the blocking device, without causing an explosion due to excessive internal pressure in the battery due to the inability of the battery's internal substances to flow out. At the same time, the blocking of the first and second blocking sheets can further delay the outflow of the battery's internal substances, providing a secondary protective effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a blocking device in a preferred embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of a battery in a preferred embodiment of the present invention;

[0025] Figure 3 Schematic diagram of an explosion of a battery in a preferred embodiment of the present invention;

[0026] Numbers in the figure: 1. Top cover; 2. Sealing ring; 3. Blocking device; 31. Air vent; 32. Outer frame; 33. First blocking piece; 34. Second blocking piece; 35. Intermediate connecting piece; 4. Explosion-proof valve; 41. Mounting part; 42. Explosion part; 5. Bottom plate; 6. Outer shell; 7. Positive electrode welding point. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to specific examples, but the present invention is not limited to the following specific examples.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0030] like Figures 1 and 2 As shown, a blocking device in this embodiment is used to be installed in the battery cap and is arranged above the explosion-proof valve 4 in the battery cap. The blocking device includes a hollow outer frame 32 and a blocking piece installed in the outer frame 32, and a vent 31 is formed between the outer frame 32 and the blocking piece; the explosion-proof valve 4 includes a hollow mounting portion 41 and a bursting portion 42 installed in the mounting portion 41, the bursting portion 42 has a first position protruding downward and a second position protruding upward, and the bursting portion can be flipped from the first position to the second position. When the bursting portion 42 is at the first position, the blocking piece is spaced apart from the bursting portion 42. When the bursting portion 42 is at the second position, the blocking piece and the bursting portion 42 abut against each other. In this embodiment, the blocking piece is used in conjunction with the explosion-proof valve 4 to block the bursting portion 42 from moving upward, thereby delaying or preventing the internal material of the battery from rushing out. Therefore, the blocking device is used on the battery to improve the safety performance of the battery. In this embodiment, the blocking device 3 is a PCB board that is resistant to high temperatures and has a flame retardant effect, so that the blocking device 3 itself is not prone to fire.

[0031] In some embodiments, the barrier sheet includes a first barrier sheet 33, a second barrier sheet 34, and an intermediate connecting sheet 35 connected between the first and second barrier sheets 33, 34. The intermediate connecting sheet 35 is capable of breaking under the pressure of the bursting portion 42. The first and second barrier sheets 33, 34 are capable of slightly deforming upward under the pressure of the bursting portion 42. Therefore, if the pressure of the battery's internal materials is too high, the bursting portion 42 can automatically compress the intermediate connecting sheet 35 to break it. Simultaneously, the first and second barrier sheets 33, 34 can also slightly deform upward, allowing some of the battery's internal materials to flow out through the rupture point of the explosion-proof valve and between the first and second barrier sheets 33, 34, rather than causing an explosion due to excessive internal pressure. Furthermore, the blocking effect of the first and second barrier sheets 33, 34 can further delay the outflow of internal materials, providing secondary protection. In actual applications, the barrier sheet may only break or only deform, allowing the internal materials of the battery to be discharged through the rupture point or deformation point. The specific method can be determined by those skilled in the art based on actual conditions.

[0032] In some embodiments, the shape of the hollow portion of the outer frame 32 is the same as the shape of the bursting portion 42. In this embodiment, the hollow portion of the outer frame 32 and the bursting portion 42 are both circular, and the inner diameter of the outer frame 32 is larger than the outer diameter of the bursting portion 42. This allows the internal contents of the battery that exit from below the bursting portion 42 to flow out through the vents 31 formed in the hollow portion of the outer frame 32. In actual applications, the shape of the hollow portion of the outer frame 32 and the bursting portion 42 can also be oval, square, etc., and those skilled in the art can determine the specific shape based on actual conditions.

[0033] like Figures 2 and 3As shown, this embodiment also provides a battery cap, which includes the above-mentioned blocking device 3, and also includes a top cover 1, an explosion-proof valve 4, a bottom plate 5 and a sealing ring 2. The top cover 1 is arranged above the blocking device 3, and is provided with a plurality of vents on the top cover 1, through which the pressure inside the battery can flow out; the explosion-proof valve 4 is arranged below the blocking device 3, and the explosion-proof valve 4 includes a hollow mounting portion 41, a bursting portion 42 mounted in the mounting portion 41, and a protective line for connecting the mounting portion 41 and the bursting portion 42, the bursting portion 42 having a first position protruding downward and a second position protruding upward, and the bursting portion 42 can be flipped from the first position to the second position, and When the pressure inside the battery continues to increase, the protective line on the explosion-proof valve 4 can be broken, so that the material inside the battery can flow out from the rupture, and the blocking piece in the blocking device 3 abuts against the bursting part 42 located at the second workstation, and the blocking piece can be deformed under the squeezing of the bursting part 42; the bottom plate 5 is arranged below the explosion-proof valve 4, and has a plurality of vents on the bottom plate 5. The pressure inside the battery cell can be transmitted to the explosion-proof valve 4 through the vents, and then transmitted to the top cover 1 by the explosion-proof valve 4. The center of the bottom plate 5 is welded to the bursting part 42 to form a positive electrode welding point 7; the top cover 1, the blocking device 3, the explosion-proof valve 4 and the bottom plate 5 are arranged in the sealing ring 2 in sequence to form an end cover.

[0034] When the battery cell experiences thermal runaway, the internal gas pressure of the battery rises, causing the positive electrode welding point 7 between the bottom plate 5 and the explosion-proof valve 4 to be disconnected, thereby forming a short circuit state between the positive and negative electrodes; when the gas pressure in the battery cell continues to rise, the explosion-proof valve 4 flips over from the first station to the second station, and the explosion-proof valve 4 at the second station will abut against the blocking device 3 above. Since the blocking device 3 blocks the explosion-proof valve 4, it can prevent or delay the internal material of the battery from rushing out; when the gas pressure in the battery further increases, the protective line on the explosion-proof valve 4 ruptures, and the gas inside the battery passes through The liquid flows out of the rupture and flows out through the vent 31 on the blocking device 3, thereby achieving the purpose of pressure relief; when the air pressure in the battery further increases, the explosion-proof valve 4 squeezes the blocking piece to cause it to break and deform, so that the material in the battery can partially flow out, thereby avoiding explosion caused by excessive pressure of the material in the battery. At the same time, the blocking piece can further block the material flowing out of the battery and slow down the outflow speed, thereby reducing or avoiding the harm caused by leakage of chemical substances inside the battery. Therefore, the end cover used on the battery can improve the safety performance of the battery.

[0035] like Figures 2 and 3 As shown, this embodiment further provides a battery, which includes the above-mentioned cap, a battery cell and a shell 6, wherein the battery cell is installed in the shell 6 and the cap is installed on the shell 6. Since the battery has a cap that can slow down or prevent the outflow of substances in the battery, the safety performance of the battery is improved.

[0036] The above are only examples of the features of the present invention and do not constitute any limitation on the scope of protection of the present invention. Any technical solution formed by equivalent exchange or equivalent replacement falls within the scope of protection of the present invention.

Claims

1. A blocking device, characterized in that: The blocking device (3) is installed in the battery cap and is arranged above the explosion-proof valve (4) in the battery cap. The explosion-proof valve (4) includes a hollow mounting portion (41) and a bursting portion (42) installed in the mounting portion (41). The blocking device (3) can abut against the bursting portion (42). The blocking device (3) is provided with an air vent (31). The bursting portion (42) has a first position protruding downward and a second position protruding upward. The bursting portion can be flipped from the first position to the second position. The blocking device (3) can abut against the bursting portion (42) located at the second position. The blocking device (3) includes a hollow outer frame (32) and a bursting portion (42) installed in the outer frame (32). The blocking piece, the blocking device (3) is in contact with the bursting part (42) located at the second station through the blocking piece, the air vent (31) is formed between the outer frame (32) and the blocking piece, the blocking piece can be deformed and / or broken under the extrusion of the bursting part (42), the blocking piece includes a first blocking piece (33), a second blocking piece (34) and an intermediate connecting piece (35) connected between the first blocking piece (33) and the second blocking piece (34), the intermediate connecting piece (35) can be broken under the extrusion of the bursting part (42), the shape of the hollow part of the outer frame (32) is the same as the shape of the bursting part (42), and the inner diameter of the outer frame (32) is larger than the outer diameter of the bursting part (42).

2. A blocking device according to claim 1, characterized in that: The blocking device (3) is a PCB board.

3. A battery cap, characterized in that: It comprises the blocking device (3) according to any one of claims 1 to 2.

4. A battery cap according to claim 3, characterized in that: The device further comprises: a top cover (1) arranged above the blocking device (3), wherein the top cover (1) is provided with a plurality of vent holes; an explosion-proof valve (4) arranged below the blocking device (3), wherein the explosion-proof valve (4) comprises a hollow mounting portion (41) and an explosion portion (42) mounted in the mounting portion (41), wherein the explosion portion (42) has a first position protruding downward and a second position protruding upward, wherein the explosion portion (42) can be flipped from the first position to the second position, and the blocking device (3) is provided with a plurality of vent holes; and The blocking piece in the device (3) abuts against the explosion part (42) located at the second station, and the blocking piece can be deformed under the pressure of the explosion part (42); the bottom plate (5) is arranged below the explosion-proof valve (4), the bottom plate (5) has a plurality of vent holes, and the bottom plate (5) and the explosion part (42) are welded to form a positive electrode welding point (7); the sealing ring (2), the top cover (1), the blocking device (3), the explosion-proof valve (4) and the bottom plate (5) are arranged in sequence in the sealing ring (2).

5. A battery, characterized in that: The battery cap comprises the battery cap according to any one of claims 3 to 4.

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