Battery pole and battery

Abstract

The invention discloses a battery pole and a battery. The battery pole comprises a pole body and an external circuit connecting part, one end of the pole body comprises a connecting cavity, and one end of the connecting cavity is electrically connected with an external circuit connecting part; a weak part is arranged at the position where the connecting cavity is connected with the external circuit connecting part; an extrusion assembly is arranged in the connecting cavity and is used for extruding the external circuit connecting part and the fracture weak part when the battery pole is in thermal runaway, so that the electric connection between the pole body and the external circuit connecting part is disconnected; the method has the beneficial effects that when the temperature reaches the preset abnormal set value, the action is triggered immediately, a response signal is direct, and delay caused by waiting for accumulation of internal pressure of the battery in a traditional scheme is avoided, so that abnormal current can be cut off earlier, and thermal runaway is prevented.

Description

Technical Field

[0001] This invention relates to the field of new energy batteries, and more particularly to a battery terminal and a battery. Background Technology

[0002] With the widespread application of energy storage devices such as lithium-ion batteries, battery safety has always been a key focus of the industry. If the circuit cannot be cut off in time when batteries experience abnormal operating conditions such as overcharging, short circuits, or overloads, serious safety problems such as thermal runaway, fire, or even explosion can easily occur.

[0003] Currently, commonly used circuit-breaking protection devices for individual battery cells mainly include thermal fuses and pressure-sensing circuit-breaking structures. Although these devices theoretically possess circuit-breaking capabilities, they still have the following drawbacks in practical applications: To ensure circuit-breaking functionality, traditional structures often introduce additional connection points or materials, leading to increased internal resistance of the battery during normal operation, affecting the battery's energy efficiency and power output; some circuit-breaking devices rely on the rise in internal battery pressure as a trigger signal, resulting in a delayed response and inability to act promptly in the early stages of temperature anomalies, increasing the risk of battery thermal runaway; during long-term use, due to material aging, structural loosening, or sealing failure, the circuit-breaking device may malfunction or fail, affecting the overall lifespan and safety of the battery. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to solve the technical problems in the prior art and to provide a battery terminal and a battery.

[0005] Technical solution:

[0006] In a first aspect, this application proposes a battery terminal, comprising: a terminal body and an external circuit connection portion;

[0007] One end of the pole body includes a connecting cavity, and one end of the connecting cavity is electrically connected to an external circuit connection part;

[0008] The connection point between the connecting cavity and the external circuit connection part is provided with a weak part;

[0009] The connecting cavity is equipped with a compression assembly, which is used to compress the weak part of the external circuit connection when the battery terminal experiences thermal runaway, so as to disconnect the electrical connection between the terminal body and the external circuit connection.

[0010] Preferably, the external circuit connection part is provided with a cylindrical structure, and a first sealing ring is provided on the outer side of the external circuit connection part to abut against the inner wall of the connecting cavity. The external circuit connection part includes a sealing ring fixing area provided on the outer side of the external circuit connection part and an external circuit contact area provided at the end of the external circuit connection part away from the connecting cavity, wherein the first sealing ring is sleeved on the sealing ring fixing area.

[0011] Preferably, the extrusion assembly includes a piston with a U-shaped structure;

[0012] The interior of the connecting cavity is provided with an I-shaped groove, which includes a pressure medium receiving cavity located on the side near the external circuit connection part, a piston extrusion cavity located on the side away from the external circuit connection part, and a connecting cavity connecting the pressure medium receiving cavity and the piston extrusion cavity.

[0013] The piston is located in the piston extrusion chamber and the connecting chamber, and can slide along the inner wall of the piston extrusion chamber and the connecting chamber. When the piston slides along the inner wall of the piston extrusion chamber, it can extrude the pressure medium receiving chamber, the external circuit connection part, and the fracture weak part.

[0014] Preferably, the extrusion assembly further includes a support and a fixing body;

[0015] The support is fixedly installed on the side of the piston near the pressure medium receiving cavity and is connected to the piston and the inner wall of the piston extrusion cavity.

[0016] The fixing body is located on the side of the piston away from the support body and is connected to the piston and the inner wall of the piston compression chamber to prevent the piston from detaching from the connecting chamber; so as to fix the piston by means of the support body and the fixing body.

[0017] The support is made of a material that can transform into a liquid state at the high temperatures generated during battery thermal runaway, so that the piston can slide within the connecting cavity.

[0018] Preferably, the piston includes a first piston head and a second piston head;

[0019] A second sealing ring is provided on the outer side of the first piston head;

[0020] A third sealing ring is provided on the outer side of the second piston head;

[0021] The first piston head can slide within the communicating cavity;

[0022] The second piston head can slide within the piston compression chamber.

[0023] Preferably, the pressure medium receiving cavity is filled with hydraulic fluid.

[0024] Preferably, one end of the connecting cavity is closed when connected to the external circuit connection part;

[0025] The interior of the connecting cavity is filled with a gas generator so that when the electrode body experiences thermal runaway, the high temperature generated heats the gas generator, causing the gas to compress the external circuit connection and break weak parts.

[0026] Preferably, the gas generator comprises citric acid, sodium carbonate, and water coated with paraffin or polyethylene wax film;

[0027] When the temperature reaches the preset melting point of the coating film, carbon dioxide gas can be generated.

[0028] This application also proposes a battery including battery terminals as described in the above embodiments.

[0029] Beneficial effects: Both schemes directly sense the terminal temperature through temperature-sensitive elements (low-melting-point support in Scheme 1 and gas generator in Scheme 2). When the temperature reaches the preset abnormal setting value (such as 65~130℃), the action is triggered immediately. The response signal is direct, avoiding the delay caused by waiting for the internal pressure of the battery in the traditional scheme. This allows the abnormal current to be cut off earlier, preventing thermal runaway.

[0030] During normal operation, the current flows through the "external circuit connection part, weak part, and terminal body". This path is made of a highly conductive material (such as copper or aluminum) that is integrally formed or firmly welded. There is no need to introduce additional series contacts or materials. Therefore, the internal resistance in the path is extremely low, which reduces the energy consumption of the battery and improves the charging and discharging efficiency.

[0031] By mechanically breaking the weak point, a physical hard disconnection of the circuit is achieved, which is non-recoverable and fundamentally prevents the circuit from reconnecting before the fault is eliminated.

[0032] The sealing ring is designed to ensure that even if the connection part shifts after a weak point breaks, it can effectively prevent the broken part from falling back and contacting the electrode body through its own sealing effect or expansion deformation, thus avoiding the risk of secondary conductivity.

[0033] Both schemes have their actuation mechanisms (pressure transmission medium chamber and gas generator chamber) sealed inside the terminal post. During operation, the electrolyte or high-temperature gas inside the battery will not leak out, and external contaminants will not enter the battery. This completely eliminates secondary safety hazards such as fire and corrosion caused by leakage. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the pole post structure in Embodiment 2 of the present invention;

[0035] Figure 2 This is a schematic diagram of the external circuit connection part of the present invention;

[0036] Figure 3 This is a schematic diagram of the connecting cavity structure in Embodiment 2 of the present invention;

[0037] Figure 4 This is a schematic diagram of the piston structure of the present invention;

[0038] Figure 5 This is a schematic diagram of the pole structure in Embodiment 3 of the present invention.

[0039] Reference numerals in the attached drawings: 1. Pole post body; 2. External circuit connection part; 2.1. First sealing ring; 2.2. Sealing ring fixing area; 2.3. External circuit contact area; 3. Weak part; 4. Piston; 4.1. Second piston head; 4.2. First piston head; 4.3. Third sealing ring; 4.4. Second sealing ring; 5. Connecting cavity; 5.1. Pressure medium receiving cavity; 5.2. Piston extrusion cavity; 5.3. Communicating cavity; 6. Support body; 7. Fixing body. Detailed Implementation

[0040] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0043] Example 1 addresses the problems existing in the prior art, such as... Figure 1-5 As shown, a battery terminal is proposed, comprising: a terminal body 1 and an external circuit connection part 2;

[0044] One end of the pole body 1 includes a connecting cavity 5, and one end of the connecting cavity 5 is electrically connected to the external circuit connection part 2;

[0045] A weak part 3 is provided at the position where the connecting cavity 5 is connected to the external circuit connection part 2. The structural strength of the weak part 3 is lower than that of the connecting cavity 5 and the external circuit connection part 2.

[0046] The connecting cavity 5 is provided with a compression assembly, which is used to compress the weak part 3 of the external circuit connection part 2 when the battery terminal thermally runs away, so as to disconnect the electrical connection between the terminal body 1 and the external circuit connection part 2.

[0047] When thermal runaway occurs inside the battery, the extrusion device can trigger the extrusion force, thereby extruding the external circuit connection part 2 and breaking the weak part 3.

[0048] In some specific embodiments, the weak point 3 can be achieved by thinning the connection point between the external circuit connection part 2 and the pole body 1, or by adjusting the strength of the connection interface between the external circuit connection part 2 and the pole body 1. For example, if the connection is made by laser welding, the weak point 3 can be manufactured by adjusting the strength of the weld and its surrounding heat-affected zone.

[0049] In some specific embodiments, the electrode body 1 is preferably made of copper, aluminum, or aluminum alloys.

[0050] In some specific embodiments, the electrode body 1 is connected to the tab or connecting piece of the internal electrode core, and electronic conduction is achieved.

[0051] In some specific embodiments, the external circuit connection part 2 is a circuit connection port between the battery and an external power supply or charging device. The external charging or power supply device achieves electronic communication with the electrode body 1 through the external circuit connection part 2, and is preferably made of copper, aluminum, or aluminum alloy.

[0052] In some specific embodiments, the external circuit connection part 2 is provided with a cylindrical structure. The outer side of the external circuit connection part 2 is provided with a first sealing ring 2.1 that abuts against the inner wall of the connecting cavity 5. The external circuit connection part 2 includes a sealing ring fixing area 2.2 provided on the outer side of the external circuit connection part 2 and an external circuit contact area 2.3 provided at the end of the external circuit connection part 2 away from the connecting cavity 5. The first sealing ring 2.1 is sleeved on the sealing ring fixing area 2.2.

[0053] In some specific embodiments, the first sealing ring 2.1 is a high-temperature resistant insulating elastic sealing ring. The temperature resistance of the first sealing ring 2.1 should meet the long-term temperature resistance requirements during normal battery use and the short-term temperature resistance requirements during device operation in case of abnormality. Typical examples include fluororubber and perfluoroether rubber sealing rings.

[0054] In some specific embodiments, the external circuit connection part 2 is electrically connected to the pole body 1, and the connection strength meets the requirements of product operating conditions. It is also a sealed connection, which further prevents leakage of gas or liquid inside the connection cavity 5 and protects the sealing ring 2.1 of the external circuit connection part 2. Laser welding is generally preferred, but riveting, threading, or other methods can also be used.

[0055] Example 2, a battery terminal according to claim 1, wherein the extrusion assembly includes a piston 4 with a U-shaped structure;

[0056] The connecting cavity 5 is provided with an I-shaped groove inside, which includes a pressure medium receiving cavity 5.1 located on the side close to the external circuit connection part 2, a piston extrusion cavity 5.2 located on the side away from the external circuit connection part 2, and a connecting cavity 5.3 connecting the pressure medium receiving cavity 5.1 and the piston extrusion cavity 5.2.

[0057] The piston 4 is located in the piston extrusion chamber 5.2 and the connecting chamber 5.3, and can slide along the inner wall of the piston extrusion chamber 5.2 and the connecting chamber 5.3. When the piston 4 slides along the inner wall of the piston extrusion chamber 5.2, it can extrude the pressure medium receiving chamber 5.1, the external circuit connection part 2, and the fracture weak part 3.

[0058] Based on Pascal's law, a liquid pressure transmission medium is filled in the pressure medium receiving cavity 5.1 to transmit the pressure generated by the piston 4 to all parts of the pressure transmission medium receiving cavity 5.1 in equal value. Because the area of ​​the external circuit connection part 2 subjected to the force of the liquid pressure transmission medium (filled in the pressure medium receiving cavity 5.1) in the direction of the piston 4 pressure is greater than the pressurization area of ​​the piston 4, the pressure of the piston 4 can be amplified and applied to the external circuit connection part 2, thereby making the weak part 3 more effectively disconnected.

[0059] In some specific embodiments, the extrusion assembly further includes a support 6 and a fixing body 7;

[0060] The support 6 is fixedly disposed on the side of the piston 4 near the pressure medium receiving cavity 5.1 and is connected to the inner wall of the piston 4 and the piston extrusion cavity 5.2;

[0061] The fixing body 7 is located on the side of the piston 4 away from the support body 6 and is connected to the piston 4 and the inner wall of the piston extrusion chamber 5.2 to prevent the piston 4 from detaching from the connecting chamber 5; so as to fix the piston 4 by the support body 6 and the fixing body 7.

[0062] Among them, the support body 6 is made of a material that can change its physical properties to liquid at high temperatures generated during battery thermal runaway, so that the piston 4 can slide within the connecting cavity 5.

[0063] In some specific embodiments, the fixing body 7 is a rigid solid, fixed in or around the piston compression chamber 5.2 of the electrode body 1, and outside the second piston head 4.1, to prevent the piston 4 from falling off the electrode body 1. The contact area with the second piston head 4.1 can be appropriately reduced to increase the area of ​​action of the gas inside the cell on the second piston head 4.1 before the piston 4 moves.

[0064] In some specific embodiments, the piston 4 includes a first piston head 4.2 and a second piston head 4.1;

[0065] A second sealing ring 4.4 is provided on the outer side of the first piston head 4.2;

[0066] A third sealing ring 4.3 is provided on the outer side of the second piston head 4.1;

[0067] The first piston head 4.2 is capable of sliding within the communicating cavity 5.3;

[0068] The second piston head 4.1 can slide within the piston compression chamber 5.2.

[0069] The second piston head 4.1 bears the internal pressure of the battery cell. After the temperature reaches the abnormal set temperature value, the support body 6 fails. Under the action of the internal air pressure of the battery cell, the entire piston 4 moves towards the external circuit connection part 2. The first piston head 4.2 squeezes the liquid pressure transmission medium (filled in the pressure medium accommodating cavity 5.1), and the liquid pressure transmission medium further squeezes the external circuit connection part 2, causing the weak part 3 to break.

[0070] In some specific embodiments, the support 6 is an object with a melting point equal to an abnormal set temperature value. Before the temperature reaches the abnormal set temperature value, it is a rigid solid with low deformation under pressure, providing support. After the temperature reaches the abnormal set temperature value, it melts and no longer provides support. Typical examples include low-melting-point alloys made of metallic elements such as bismuth, lead, tin, and cadmium, which also have the characteristic of adjustable melting points.

[0071] The support 6 can be designed as a ring. This is used to prevent the piston 4 from moving towards the external circuit connection 2 before the temperature reaches the abnormal set temperature value, thus squeezing the liquid pressure transmission medium (filled in the pressure medium receiving cavity 5.1), and then squeezing the external circuit connection 2, damaging the weak part 3.

[0072] When the temperature reaches the abnormal set temperature value, the support body 6 melts and no longer blocks the piston 4 from moving towards the external circuit connection part 2. Under the pressure inside the battery cell, the piston 4 squeezes the liquid pressure transmission medium (filled in the pressure medium accommodating cavity 5.1), thereby squeezing the external circuit connection part 2 and destroying the weak part 3.

[0073] In some specific embodiments, the pressure medium receiving cavity 5.1 is filled with hydraulic fluid.

[0074] 1. Under normal battery cell conditions:

[0075] When the battery cell is working normally, current flows forward or backward from the circuit interface of the charging or power-consuming device to the external circuit connection part 2, then through the weak part 3 and the terminal body 1 to the inside of the battery, realizing the conduction of the internal and external circuits of the battery. At this time, the support body 6 is solid, preventing the piston 4 from moving towards the external circuit connection piece 2, thus avoiding squeezing the liquid pressure conduction medium (filled in the pressure medium receiving cavity 5.1), which would then squeeze the external circuit connection piece 2 and damage the weak part 3, ensuring normal circuit conduction.

[0076] 2. Under abnormal operating conditions:

[0077] 2.1 When the battery experiences abnormalities such as overcharging, short circuit, or overload, the temperature and internal pressure of various parts of the battery rise. When the temperature of the terminal block rises to the abnormal temperature set value (the melting point of the support 6), the support 6 melts and no longer obstructs the piston 4 from moving towards the external circuit connection piece 2. The piston 4 then begins to squeeze the liquid pressure transmission medium (filled in the pressure medium receiving cavity 5.1) under the pressure of the gas pressure inside the battery cell.

[0078] The abnormal temperature setpoint is determined based on the battery characteristics; generally, for lithium iron phosphate / graphite lithium-ion batteries, the preferred setting is 65~130℃. The lowest possible value should be chosen without affecting the reliability of the battery cell's normal operation, to cut off the abnormal current circuit as early as possible and ensure battery safety.

[0079] 2.2 According to the mechanical analysis, P1*S11=P2*S2, P2=P1*S11 / S2. Since the design value of S11 is greater than S2, the internal pressure P1 of the cell is amplified by S11 / S2 times, forming pressure P2.

[0080] Wherein, P1: internal air pressure of the battery; P2: pressure exerted by the liquid pressure transmission medium (filled in the pressure medium container 5) on the first piston head 4.2.

[0081] S11: The area of ​​action of the gas inside the cell on the first piston head 4.2 (before the piston 4 moves, due to the contact between the fixed body 7 and the second piston head 4.1, S11 is equal to the piston head area S1 minus the area of ​​close contact between the fixed body 7 and the piston head 4.1; after the piston 4 moves, the second piston head 4.1 is no longer in contact with the fixed body 7, and S11 is equal to S1).

[0082] S2: The interaction area between the liquid pressure transmission medium (filled in the pressure medium container 5) and the first piston head 4.2 is equal to the area of ​​the first piston head 4.2.

[0083] For ease of explanation, the above calculation product is simplified, ignoring the effects of non-major forces such as friction, the resistance of the support ring to the movement of piston 4 after the temperature reaches the set abnormal value, and the pressure resistance of the gas inside the piston extrusion chamber 5.2.

[0084] 2.3 According to Pascal's Law, the force exerted by the liquid pressure transmission medium (filled in the pressure medium container 5) on the external circuit connection part 2 in the weak part 3 along the piston movement direction is F1 = P2*S3 = P1*S11*S3 / S2. Compared to the internal air pressure P1 acting directly on S3, the force is amplified by a factor of S11 / S2. This force will be transmitted to the weak part 3, causing the weak part 3 to break, thereby disconnecting the internal and external circuits.

[0085] The amplified force accelerates the fracture of weak point 3, thus enabling a more timely response. Furthermore, it prevents the conductivity of the terminal and battery reliability from being affected by excessively low strength settings for the weak point. Simultaneously, it avoids the risk of internal gas leakage from the terminal and subsequent fire.

[0086] Note: S3: The area of ​​the liquid pressure transmission medium (filled in the pressure medium container cavity 5.1) acting on the external circuit connection part 2 in the weak part along the piston movement direction. The pressure in this area will be transmitted to the weak part 3.

[0087] 2.4. When the weak part 3 breaks, if the first sealing ring 2.1 of the external circuit connection part 2 is not completely detached from the pole body 1, the liquid pressure transmission medium (filled in the pressure medium container cavity 5.1) will not leak and can still provide pressure support for the broken external circuit connection part 2, preventing the external circuit connection part 2 from falling back and causing the conductive part to overlap with the pole body 1 and continue to conduct electricity. If the first sealing ring 2.1 of the external circuit connection part 2 is partially detached from the pole body 1 at this time, the detached part will expand and become larger, which can provide additional resistance to prevent the external circuit connection part 2 from falling back.

[0088] If the first sealing ring 2.1 of the external circuit connection part 2 is completely detached from the restraint of the pole body 1, the pressure conducting medium (liquid) filled in the pressure medium receiving cavity 5.1 will leak, and will not be able to effectively provide pressure to prevent the external circuit connection part 2 from falling back and overlapping. However, at this time, the first sealing ring 2.1 of the external circuit connection part 2, which is completely detached from the restraint, will expand and become larger, providing support resistance to prevent the external circuit connection part 2 from falling back, causing the conductive part to overlap with the pole body 1 and continue to conduct electricity.

[0089] In some specific embodiments, the abnormal temperature setpoint is set according to the battery characteristics; generally, for lithium iron phosphate / graphite lithium-ion batteries, it is preferably 65~130℃. The lowest possible value should be chosen without affecting the reliability of the cell's normal operation, so as to cut off the abnormal current circuit as early as possible and ensure battery safety.

[0090] In Example 3, one end of the connecting cavity 5 is closed when connected to the external circuit connection part 2;

[0091] The interior of the connecting cavity 5 is filled with a gas generator so that when the electrode body 1 experiences thermal runaway, the high temperature generated by the gas generator will compress the external circuit connection part 2 and the weak part 3.

[0092] This terminal features an independently designed gas generator, allowing for higher gas pressure values. Compared to traditional circuit breaking schemes that rely on the battery's own gas pressure, the fracture strength of its weak points can be designed to be higher (eliminating concerns about failure to break due to insufficient gas pressure), increasing the terminal's conductivity and the battery's reliability during normal operation. Furthermore, because the gas generator is independently designed, it does not utilize the gas pressure generated when the battery overheats. Compared to traditional circuit breaking schemes that rely on the battery's own gas pressure, this allows for a more timely response to abnormal battery temperatures. It eliminates the need to wait for the battery pressure to rise, thus reducing the risk of battery malfunctions.

[0093] In some specific embodiments, the gas generator includes citric acid, sodium carbonate, and water coated with paraffin or polyethylene wax film;

[0094] When the temperature reaches the preset melting point of the coating film, carbon dioxide gas can be generated.

[0095] Once the temperature reaches the melting point of the coating, the coating ruptures, releasing citric acid and sodium carbonate into the water, which react to produce carbon dioxide gas. Before the temperature reaches the melting point of the coating, the water remains more stable due to the protective effect of the coating.

[0096] Specifically, the gas generator is sealed and stored in the connecting cavity 5. It can quickly generate gas after the temperature of the electrode column rises to the set temperature point (abnormal temperature set value), increase the gas pressure in the connecting cavity 5, damage the weak part 3, disconnect the circuit connection between the external circuit connection part 2 and the electrode column body 1, thereby disconnecting the circuit connection between the battery and the external power supply and charging device.

[0097] The abnormal temperature setpoint is determined based on the battery characteristics; generally, for lithium iron phosphate / graphite lithium-ion batteries, the preferred setting is 65~130℃. The lowest possible value should be chosen without affecting the reliability of the battery cell's normal operation, to cut off the abnormal current circuit as early as possible and ensure battery safety.

[0098] The gas generator should remain stable during normal battery operation, producing no gas or only a limited amount of gas, to avoid damaging vulnerable parts of the battery during normal operation. Furthermore, the gas produced by the gas generator should be non-flammable and non-toxic.

[0099] The gas generator can be a single component or a multi-component component. Coating methods can be used to improve its stability under normal conditions and its compatibility with the electrode (to prevent corrosion of the electrode).

[0100] 1. When the battery is working normally, the current flows from the circuit interface of the charging or power-consuming device to the external circuit connection part 2 in the forward or reverse direction, and then through the weak part 3 and the terminal body 1 to the inside of the battery, so as to realize the conduction of the internal and external circuits of the battery.

[0101] At this time, the gas generator (filled in the connecting cavity 5) will not produce gas (or will produce a limited amount of gas) to damage the weak part 3, ensuring that the circuit can conduct normally.

[0102] 2. Under abnormal operating conditions:

[0103] When the battery experiences abnormalities such as overcharging, short circuit, or overload, the temperature of various parts of the battery rises. When the temperature of the terminal post rises to the abnormal temperature setpoint (the temperature at which the gas generator in the connecting cavity 5 begins to produce gas), the gas generator (filled in the connecting cavity 5) begins to produce gas, and the gas pressure inside the connecting cavity 5 increases. This pressure compresses the external circuit connection part 2. When the pressure generated by the gas reaches the critical point that the weak part 3 can withstand, the weak part 3 breaks, and the circuit connection between the external circuit connection part 2 and the terminal post body 1 is disconnected, thereby disconnecting the circuit connection between the battery and the charging or power-consuming device and ensuring battery safety.

[0104] When the weak part 3 breaks, if the first sealing ring 2.1 of the external circuit connection part 2 is not completely freed from the restraint of the pole body 1, the gas in the connection cavity 5 will not leak. It can still provide pressure support for the broken external circuit connection part 2, preventing the external circuit connection part 2 from falling back and causing the conductive part to overlap with the pole body 1 and continue to conduct electricity. If the first sealing ring 2.1 of the external circuit connection part 2 is partially freed from the restraint of the pole body 1 at this time, the freed part will expand and become larger, which can provide additional resistance to prevent the external circuit connection part 2 from falling back.

[0105] If the first sealing ring 2.1 of the external circuit connection part 2 is completely detached from the restraint of the pole body 1, the gas in the connection cavity 5 will leak and cannot effectively provide pressure to prevent the external circuit connection part 2 from falling back and overlapping. However, at this time, the first sealing ring 2.1 of the external circuit connection part 2, which is completely detached from the restraint, will expand and become larger, providing support resistance to prevent the external circuit connection part 2 from falling back, thus avoiding the conductive part from overlapping with the pole body 1 and continuing to conduct electricity.

[0106] This application also proposes a battery including battery terminals as described in the above embodiments.

[0107] The above description is merely a specific implementation of the embodiments of the present invention, but the protection scope of the embodiments of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of the present invention should be covered within the protection scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention should be determined by the protection scope of the claims.

Claims

1. A battery terminal, characterized in that, include: The pole body (1) and the external circuit connection part (2); One end of the pole body (1) includes a connecting cavity (5), and one end of the connecting cavity (5) is electrically connected to the external circuit connection part (2); The connection cavity (5) is provided with a weak part (3) at the position where it connects to the external circuit connection part (2); The connecting cavity (5) is provided with a compression assembly, which is used to compress the weak part (3) of the external circuit connection part (2) when the battery terminal thermally runs away, so as to disconnect the electrical connection between the terminal body (1) and the external circuit connection part (2).

2. A battery terminal according to claim 1, characterized in that, The external circuit connection part (2) is provided with a cylindrical structure. The outer side of the external circuit connection part (2) is provided with a first sealing ring (2.1) that abuts against the inner wall of the connecting cavity (5). The external circuit connection part (2) includes a sealing ring fixing area (2.2) provided on the outer side of the external circuit connection part (2) and an external circuit contact area (2.3) provided at the end of the external circuit connection part (2) away from the connecting cavity (5). The first sealing ring (2.1) is fitted onto the sealing ring fixing area (2.2).

3. A battery terminal according to claim 1, characterized in that, The extrusion assembly includes a piston (4) with a U-shaped structure. The connecting cavity (5) is provided with an I-shaped groove inside, which includes a pressure medium receiving cavity (5.1) located on the side close to the external circuit connection part (2), a piston extrusion cavity (5.2) located on the side away from the external circuit connection part (2), and a connecting cavity (5.3) connecting the pressure medium receiving cavity (5.1) and the piston extrusion cavity (5.2). The piston (4) is located in the piston extrusion chamber (5.2) and the connecting chamber (5.3) and can slide along the inner wall of the piston extrusion chamber (5.2) and the connecting chamber (5.3). When the piston (4) slides along the inner wall of the piston extrusion chamber (5.2), it can extrude the pressure medium receiving chamber (5.1) and the external circuit connection part (2) to break the weak part (3).

4. A battery terminal according to claim 3, characterized in that, The extrusion assembly also includes a support (6) and a fixing body (7); The support (6) is fixedly disposed on the side of the piston (4) near the pressure medium receiving cavity (5.1) and connected to the inner wall of the piston (4) and the piston extrusion cavity (5.2); The fixing body (7) is located on the side of the piston (4) away from the support body (6) and is connected to the inner wall of the piston (4) and the piston extrusion chamber (5.2) to prevent the piston (4) from detaching from the connecting chamber (5); so as to fix the piston (4) through the support body (6) and the fixing body (7). Among them, the support (6) is a material that can change its physical properties to liquid at high temperatures generated during battery thermal runaway, so that the piston (4) can slide in the connecting cavity (5).

5. A battery terminal according to claim 3, characterized in that, The piston (4) includes a first piston head (4.2) and a second piston head (4.1). A second sealing ring (4.4) is provided on the outer side of the first piston head (4.2). A third sealing ring (4.3) is provided on the outer side of the second piston head (4.1). The first piston head (4.2) is capable of sliding within the communicating cavity (5.3); The second piston head (4.1) is able to slide within the piston extrusion chamber (5.2).

6. A battery terminal according to claim 3, characterized in that, The pressure medium receiving cavity (5.1) is filled with hydraulic fluid.

7. A battery terminal according to claim 1, characterized in that, When one end of the connecting cavity (5) is connected to the external circuit connection part (2), it is closed; The interior of the connecting cavity (5) is filled with a gas generator so that when the electrode body (1) undergoes thermal runaway, the high temperature generated heats the gas generator, causing the gas to squeeze the external circuit connection part (2) and break the weak part (3).

8. A battery terminal according to claim 7, characterized in that, The gas generator includes citric acid, sodium carbonate, and water coated with paraffin or polyethylene wax film; When the temperature reaches the preset melting point of the coating film, carbon dioxide gas can be generated.

9. A battery, characterized in that, Includes the battery terminals as described in any one of claims 1-8.

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