Battery assembly, battery pack and power equipment

Abstract

The invention discloses a battery assembly, a battery pack and power equipment, and the battery assembly comprises: a housing, in which an accommodating cavity is formed, and on which an explosion-proof valve communicating with the accommodating cavity is formed; the battery cell is accommodated in the accommodating cavity; the protective layer wraps at least part of the periphery of the battery cell, a guide channel extending towards the anti-explosion valve is formed in the side, close to the outer surface of the battery cell, of the protective layer, the outlet end and the inlet end of the guide channel communicate with the containing cavity, and the outlet end of the guide channel right faces at least part of the anti-explosion valve. According to the battery assembly disclosed by the invention, the guide channel extending towards the anti-explosion valve is arranged on the protective layer, so that high-pressure and high-temperature gas generated in the battery assembly can flow to the anti-explosion valve through the guide channel and is discharged from the anti-explosion valve, and the accident that the gas in the battery assembly cannot be discharged due to the fact that the protective layer shields the anti-explosion valve is effectively prevented; and the safety and the reliability of the battery assembly during operation are improved.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a battery assembly, a battery pack and a power device. Background Art

[0002] Among the related technologies, lithium-ion power batteries are an important part of the new energy industry. In recent years, with the increasing global awareness of sustainable development, the lithium battery industry has ushered in an unprecedented wave of rapid development. In order to improve the energy density of lithium-ion batteries while ensuring safety, a series of innovative technical routes have emerged in the industry, such as blade batteries and bottom-opening valve batteries.

[0003] Blade batteries are known for their unique long and thin shape. Although this inherent property gives them many performance advantages, it also limits the explosion-proof valve to the structure of the cover plate and can only be set at both ends of the battery cell. As a result, in the event of thermal runaway, the exhaust path is too long and the explosion-proof valve cannot open quickly. Eventually, too much gas accumulates inside the battery cell, causing it to expand and rupture in the middle of the shell, causing serious safety problems.

[0004] In the bottom-opening valve battery cell design, the internal winding core naturally tends to stick to the bottom of the shell due to the influence of gravity. At the critical moment when exhaust is required, the Mylar film and other materials may block the position of the explosion-proof valve, and the internal high-temperature and high-pressure materials cannot be discharged in time, causing the battery cell to overheat, expand or even explode, increasing safety risks. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a battery assembly. The battery assembly according to the present invention provides a guide channel extending toward the explosion-proof valve on the protective layer, so that the high-pressure and high-temperature gas generated inside the battery assembly can flow to the explosion-proof valve through the guide channel and be discharged from the explosion-proof valve, effectively preventing the protective layer from blocking the explosion-proof valve, resulting in the accident that the gas inside the battery assembly cannot be discharged, thereby improving the safety and reliability of the battery assembly during operation.

[0006] The present invention also provides a battery pack having the above battery assembly.

[0007] The present invention also provides a power device having the battery pack.

[0008] The battery assembly according to the present invention comprises: a shell having a accommodating cavity formed therein, and an explosion-proof valve connected to the accommodating cavity formed on the shell; a battery cell, the battery cell being accommodated in the accommodating cavity; a protective layer, the protective layer wrapping at least a portion of the outer circumference of the battery cell, a guide channel extending toward the explosion-proof valve being formed on a side of the protective layer close to the outer surface of the battery cell, the outlet end and the inlet end of the guide channel being respectively connected to the accommodating cavity, and the outlet end of the guide channel being arranged opposite to at least a portion of the explosion-proof valve.

[0009] According to the battery assembly of the present invention, a guide channel is arranged on the protective layer, the guide channel extends toward the explosion-proof valve, both ends of the guide channel are connected to the accommodating cavity, and the outlet end of the guide channel is directly opposite to at least part of the explosion-proof valve. The design of the guide channel helps the gas generated inside the battery assembly to flow more smoothly toward the explosion-proof valve through the guide channel when a thermal reaction occurs in the battery assembly, effectively preventing the protective layer from blocking the explosion-proof valve, resulting in an accident in which the gas inside the battery assembly cannot be discharged. When the pressure near the explosion-proof valve exceeds a certain value, the explosion-proof valve will open to release the internal pressure of the battery assembly, reduce the pressure inside the battery assembly, and improve the safety of the battery assembly during operation.

[0010] According to some embodiments of the present invention, a cross-sectional area of ​​the guide channel gradually increases in a direction from the bottom of the shell toward the explosion-proof valve.

[0011] According to some embodiments of the present invention, the guide channels are configured as a plurality of guide channels and are arranged at intervals on the protective layer.

[0012] According to some embodiments of the present invention, the battery assembly further includes: an auxiliary exhaust membrane, which is connected to at least a portion of the protective layer and is located on a side of the protective layer facing the explosion-proof valve, and the auxiliary exhaust membrane is suitable for shrinking when heated and separating from the protective layer.

[0013] According to some embodiments of the present invention, the battery assembly further includes: a protective plate, wherein the protective plate is disposed between the battery cell and the shell, an exhaust port is formed on the bottom protective plate, the exhaust port is disposed opposite to the explosion-proof valve, and the exhaust port is suitable for the gas in the accommodating cavity and the auxiliary exhaust membrane that has shrunk due to heat to pass through.

[0014] According to some embodiments of the present invention, the protective plate is formed with a wetting hole penetrating in the thickness direction, and the wetting hole is suitable for the passage of electrolyte.

[0015] According to some embodiments of the present invention, the protective layer is configured as a polyester film layer.

[0016] According to some embodiments of the present invention, the thickness of the protective layer is h, and satisfies: 100 μm≤h≤200 μm.

[0017] The battery pack according to the present invention is briefly described below.

[0018] The battery pack according to the present invention is provided with the battery assembly described in any one of the above embodiments. Since the battery pack according to the present invention is provided with the battery assembly described in any one of the above embodiments, the gas generated by the battery assembly arranged in the battery pack when thermal runaway occurs can be discharged from the exhaust valve immediately, thereby reducing the risk of explosion of the battery assembly and improving the safety and reliability of the battery pack during operation.

[0019] The power device according to the present invention is briefly described below.

[0020] The power equipment according to the present invention is provided with a battery pack as described in any one of the above embodiments. Since the power equipment according to the present invention is provided with a battery pack as described in any one of the above embodiments, the power equipment according to the present application has better safety and higher reliability.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a schematic structural diagram of a battery assembly according to an embodiment of the present invention;

[0024] Figure 2 is a front view of a protective layer according to one embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of the end structure of a protective layer according to an embodiment of the present invention;

[0026] Figure 4 is a schematic structural diagram of a guide channel according to an embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of the structure of a battery assembly according to another embodiment of the present invention.

[0028] Reference numerals:

[0029] 100. Battery assembly;

[0030] 11. Shell; 12. Battery cell; 13. Protective layer; 14. Cover plate; 15. Explosion-proof valve;

[0031] 21. Guide channel; 22. Guard plate; 23. Exhaust port; 24. Wetting hole. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] Among the related technologies, lithium-ion power batteries are an important part of the new energy industry. In recent years, with the increasing global awareness of sustainable development, the lithium battery industry has ushered in an unprecedented wave of rapid development. In order to improve the energy density of lithium-ion batteries while ensuring safety, a series of innovative technical routes have emerged in the industry, such as blade batteries and bottom-opening valve batteries.

[0034] Blade batteries are known for their unique long and thin shape. Although this inherent property gives them many performance advantages, it also limits the explosion-proof valve to the structure of the cover plate and can only be set at both ends of the battery cell. As a result, in the event of thermal runaway, the exhaust path is too long and the explosion-proof valve cannot open quickly. Eventually, too much gas accumulates inside the battery cell, causing it to expand and rupture in the middle of the shell, causing serious safety problems.

[0035] In the bottom-opening valve battery cell design, the internal winding core naturally tends to stick to the bottom of the shell due to the influence of gravity. At the critical moment when exhaust is required, the Mylar film and other materials may block the position of the explosion-proof valve, and the internal high-temperature and high-pressure materials cannot be discharged in time, causing the battery cell to overheat, expand or even explode, increasing safety risks.

[0036] Reference below Figure 1-Figure 5 A battery assembly according to an embodiment of the present invention is described.

[0037] The battery assembly 100 according to the present invention includes: a shell 11, a battery cell 12 and a protective layer 13, wherein a receiving cavity is formed in the shell 11, and an explosion-proof valve 15 connected to the receiving cavity is formed on the shell 11; the battery cell 12 is accommodated in the receiving cavity; the protective layer 13 is wrapped around at least part of the periphery of the battery cell 12, and a guide channel 21 extending toward the explosion-proof valve 15 is formed on one side of the protective layer 13 close to the outer surface of the battery cell 12, wherein the outlet end and the inlet end of the guide channel 21 are respectively connected to the receiving cavity, and the outlet end of the guide channel 21 is arranged opposite to at least part of the explosion-proof valve 15.

[0038] In some specific embodiments, the battery assembly 100 is composed of a shell 11, a battery cell 12 and a protective layer 13. A accommodating cavity is formed in the shell 11. A cover plate 14 is provided on the shell 11. The cover plate 14 is suitable for closing the accommodating cavity. An installation position of an explosion-proof valve 15 is formed on the cover plate 14. The protective layer 13 wraps at least a portion of the periphery of the battery cell 12. The battery cell 12 and the protective layer 13 are accommodated in the accommodating cavity together. A guide channel 21 is provided on the protective layer 13. The guide channel 21 extends toward the explosion-proof valve 15. Both ends of the guide channel 21 are connected to the accommodating cavity, and the outlet end of the guide channel 21 is connected to the outlet end of the guide channel 21. At least part of the explosion-proof valve 15 is facing, and the design of the guide channel 21 helps the gas generated inside the battery assembly 100 to flow more smoothly toward the explosion-proof valve 15 through the guide channel 21 when a thermal reaction occurs in the battery assembly 100, effectively preventing the protective layer 13 from blocking the explosion-proof valve 15, resulting in an accident in which the gas inside the battery assembly 100 cannot be discharged. When the pressure near the explosion-proof valve 15 exceeds a certain value, the explosion-proof valve 15 will open to release the internal pressure of the battery assembly 100, reduce the internal pressure of the battery assembly 100, and improve the safety of the battery assembly 100 during operation.

[0039] According to the battery assembly 100 of the present invention, a guide channel 21 is set on the protective layer 13, and the guide channel 21 extends toward the explosion-proof valve 15. Both ends of the guide channel 21 are connected to the accommodating cavity, and the outlet end of the guide channel 21 is directly opposite to at least part of the explosion-proof valve 15. The design of the guide channel 21 helps the gas generated inside the battery assembly 100 to flow more smoothly toward the explosion-proof valve 15 through the guide channel 21 when a thermal reaction occurs in the battery assembly 100, effectively preventing the protective layer 13 from blocking the explosion-proof valve 15, resulting in an accident in which the gas inside the battery assembly 100 cannot be discharged. When the pressure near the explosion-proof valve 15 exceeds a certain value, the explosion-proof valve 15 will open to release the internal pressure of the battery assembly 100, reduce the internal pressure of the battery assembly 100, and improve the safety of the battery assembly 100 during operation.

[0040] According to some embodiments of the present invention, the cross-sectional area of ​​the guide channel 21 gradually increases in the direction from the bottom of the shell 11 toward the explosion-proof valve 15. This design can form a fluid dynamic characteristic similar to the Venturi effect, that is, as the cross-sectional area of ​​the channel gradually increases, the air flow velocity decreases and the pressure decreases, which helps the gas to flow to the explosion-proof valve 15 more quickly and smoothly and be discharged from the explosion-proof valve 15 during thermal runaway, thereby quickly reducing the pressure inside the battery and avoiding safety accidents caused by excessive pressure. The gradually increasing cross-section helps to reduce the resistance encountered during the gas flow process, especially when the gas carries tiny particles or steam. The larger outlet cross-section can reduce the possibility of these substances depositing in the channel, thereby reducing the risk of the channel being blocked. Compared with the design of uniform cross-section, the gradually expanding guide channel 21 can achieve better gas discharge effect in a limited space, while maintaining a compact structure and having a certain guiding effect on the flow of gas. When a short circuit or overheating occurs inside the battery, this design can discharge the generated harmful gas more quickly, reducing the risk of gas accumulation inside the battery assembly 100, playing a key role in preventing the battery assembly 100 from exploding, and improving the safety of the battery assembly 100.

[0041] According to some embodiments of the present invention, the guide channels 21 are constructed as multiple guide channels 21 and are arranged at intervals on the protective layer 13. The multiple guide channels 21 provide multiple gas discharge paths. Even if a channel is blocked for some reason, the other channels can still work normally, ensuring the continuous discharge of gas and improving the reliability and safety of the battery assembly 100. The multiple guide channels 21 can more evenly distribute the gas generated inside the battery to avoid excessive local pressure. This can reduce the risk of deformation or rupture of the shell 11 due to excessive local pressure, further improving the safety of the battery. The guide channels 21 at different positions can adapt to different failure modes. The design of multiple guide channels 21 provides greater design flexibility for the battery assembly 100. The number, position and shape of the channels can be adjusted according to specific application requirements and battery size to achieve optimal performance and safety.

[0042] According to some embodiments of the present invention, the battery assembly 100 further includes: an auxiliary exhaust membrane, which is connected to at least part of the protective layer 13 and is located on the side of the protective layer 13 facing the explosion-proof valve 15, and the auxiliary exhaust membrane is suitable for shrinking when heated and separating from the protective layer 13.

[0043] In some specific embodiments, an auxiliary exhaust membrane is further provided in the battery assembly 100. The auxiliary exhaust membrane is provided on the side of the protective layer 13 close to the explosion-proof valve 15. The auxiliary exhaust membrane is made of a heat-shrinkable material. When thermal runaway occurs in the battery assembly 100, the auxiliary exhaust membrane shrinks due to heat and separates from the protective layer 13 to form an additional gas exhaust path, so that the gas generated inside can be quickly discharged through the gap between the auxiliary exhaust membrane and the protective layer 13, thereby reducing the internal pressure and preventing the shell 11 from rupture or explosion due to pressure accumulation. The separation between the auxiliary exhaust membrane and the protective layer 13 provides multiple gas exhaust paths. Even if one place is blocked, other paths can still work normally, ensuring the continuity and reliability of gas exhaust. The thermal shrinkage characteristics of the auxiliary exhaust membrane enable the auxiliary exhaust membrane to automatically shrink and separate from the protective layer 13 under high temperature conditions, thereby reducing the resistance encountered during gas flow and reducing the risk of channel blockage.

[0044] According to some embodiments of the present invention, the battery assembly 100 also includes: a protective plate 22, which is arranged between the battery cell 12 and the shell 11, and an exhaust port 23 is formed on the bottom protective plate 22. The exhaust port 23 is arranged opposite to the explosion-proof valve 15, and the exhaust port 23 is suitable for accommodating the gas in the cavity and the auxiliary exhaust membrane that shrinks due to heat to pass through.

[0045] In some specific embodiments, the guard plate 22 is arranged between the battery cell 12 and the shell 11 to play a role of physical isolation, which can prevent external impact or foreign matter from directly contacting the battery cell 12, and protect the battery cell 12 from physical damage. The guard plate 22 can reduce the contact between the battery cell 12 and the shell 11 with metal chips or other conductive materials, and reduce the risk of internal short circuit of the battery assembly 100. An exhaust port 23 is formed on the guard plate 22, and the exhaust port 23 is arranged opposite to the explosion-proof valve 15 to ensure that when thermal runaway occurs in the battery, the gas generated inside can quickly flow toward the explosion-proof valve 15 through the exhaust port 23 and be discharged from the explosion-proof valve 15. The explosion valve 15 is used to discharge gas to reduce the internal pressure of the battery assembly 100. The design of the exhaust port 23 is matched with the thermal shrinkage characteristics of the auxiliary exhaust film. When the internal temperature of the battery rises, the auxiliary exhaust film shrinks due to the heat and separates from the protective layer 13. The gas can be discharged smoothly through the exhaust port 23 on the protective plate 22, thereby further improving the efficiency of gas discharge and ensuring the safety and reliability of the operation of the battery assembly 100. The presence of the protective plate 22 can enhance the overall structural stability of the battery assembly 100 and reduce the risk of deformation or rupture of the shell 11 due to changes in the internal pressure of the battery assembly 100 or external impacts.

[0046] According to some embodiments of the present invention, the protective plate 22 is formed with a wetting hole 24 penetrating in the thickness direction, and the wetting hole 24 is configured as a plurality of holes arranged at intervals. The wetting hole 24 allows the electrolyte to pass through the protective plate 22. After being injected from the top or side of the shell 11, it can be more evenly distributed to various parts of the battery cell 12, ensuring that the electrolyte can fully infiltrate the pole piece of the battery cell 12, improving the electrochemical performance of the battery assembly 100, and the electrolyte can reach the inside of the battery cell 12 more quickly through the wetting hole 24, shortening the injection time and improving the production efficiency. The uniform distribution of the electrolyte can ensure that the electrochemical reaction of various parts of the battery cell 12 is more uniform. The uniform distribution of the electrolyte also helps to uniformly distribute the temperature inside the battery assembly 100, avoid local overheating, and extend the service life of the battery assembly 100. In addition, by setting the wetting hole 24 on the protective plate 22, the electrolyte and gas can flow more freely, reducing the accumulation of local pressure, reducing the risk of excessive pressure inside the battery assembly 100, and improving the safety of the battery assembly 100. .

[0047] According to some embodiments of the present invention, the protective layer 13 is constructed as a polyester film layer (such as Mylar film). The polyester film has high toughness and tear resistance, and can provide effective protection when the battery is subjected to external impact or vibration, reducing the risk of damage to the battery cell 12. The polyester film is not easily penetrated by sharp objects, and can effectively prevent external foreign matter from entering the interior of the battery, reducing the risk of internal short circuit. The polyester film has good corrosion resistance to most electrolytes and chemicals, and will not react with the chemical components inside the battery assembly 100, ensuring the long-term stability and safety of the battery assembly 100. The polyester film has good antioxidant properties, and can maintain stable physical and chemical properties during the charge and discharge cycle of the battery assembly 100, thereby extending the service life of the battery assembly 100. The polyester film has high insulation resistance, and can effectively isolate the electrical connection between the battery cell 12 and the shell 11, reducing the risk of leakage and short circuit. The polyester film can maintain good insulation properties at higher voltages, thereby improving the safety of the battery assembly 100 during operation.

[0048] According to some embodiments of the present invention, the thickness of the protective layer 13 is h and satisfies: 100 μm≤h≤200 μm. When the thickness h of the protective layer 13 is within the above range, it can provide sufficient protection for the battery cell 12 without increasing excessive weight and volume of the battery assembly 100.

[0049] The battery pack according to the present invention is briefly described below.

[0050] The battery pack according to the present invention is provided with the battery assembly 100 described in any one of the above embodiments. Since the battery pack according to the present invention is provided with the battery assembly 100 described in any one of the above embodiments, the gas generated by the battery assembly 100 arranged in the battery pack when thermal runaway occurs can be discharged from the exhaust valve immediately, thereby reducing the risk of explosion of the battery assembly 100 and improving the safety and reliability of the battery pack during operation.

[0051] The power device according to the present invention is briefly described below.

[0052] The power equipment according to the present invention is provided with a battery pack as described in any one of the above embodiments. Since the power equipment according to the present invention is provided with a battery pack as described in any one of the above embodiments, the power equipment according to the present application has better safety and higher reliability.

[0053] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0054] In the description of the present invention, "first feature" or "second feature" may include one or more of the features. In the description of the present invention, "plurality" means two or more.

[0055] In the description of the present invention, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0056] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0057] In the description of this specification, reference to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention.

[0058] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery assembly, characterized in that: include: A housing (11), wherein a receiving chamber is formed in the housing (11), and an explosion-proof valve (15) communicating with the receiving chamber is formed on the housing (11); A battery core (12), the battery core (12) being accommodated in the accommodation cavity; A protective layer (13), the protective layer (13) wrapping at least a portion of the outer periphery of the battery core (12), a guide channel (21) extending toward the explosion-proof valve (15) is formed on a side of the protective layer (13) close to the outer surface of the battery core (12), the outlet end and the inlet end of the guide channel (21) are respectively connected to the accommodating cavity, and the outlet end of the guide channel (21) is arranged opposite to at least a portion of the explosion-proof valve (15).

2. The battery assembly according to claim 1, characterized in that: The cross-sectional area of ​​the guide channel (21) gradually increases in a direction from the bottom of the housing (11) toward the explosion-proof valve (15).

3. The battery assembly according to claim 2, characterized in that: The guide channels (21) are structured as a plurality of guide channels and are arranged at intervals on the protective layer (13).

4. The battery assembly according to claim 1, characterized in that: The battery assembly further comprises: An auxiliary exhaust membrane is connected to at least a portion of the protective layer (13) and is located on a side of the protective layer (13) facing the explosion-proof valve (15), and the auxiliary exhaust membrane is suitable for shrinking under heat and being separated from the protective layer (13).

5. The battery assembly according to claim 4, characterized in that: The battery assembly further comprises: A protective plate (22), the protective plate (22) being arranged between the battery cell (12) and the shell (11), the protective plate (22) being provided with an exhaust port (23), the exhaust port (23) being arranged opposite to the explosion-proof valve (15), the exhaust port (23) being suitable for the gas in the accommodating cavity and the auxiliary exhaust membrane after heat shrinkage to pass through.

6. The battery assembly according to claim 5, characterized in that: The protective plate (22) is formed with a wetting hole (24) penetrating in the thickness direction, and the wetting hole (24) is suitable for the electrolyte to pass through.

7. The battery assembly according to claim 1, characterized in that: The protective layer (13) is configured as a polyester film layer.

8. The battery assembly according to claim 7, characterized in that: The thickness of the protective layer (13) is h, and satisfies: 100 μm≤h≤200 μm.

9. A battery pack, characterized in that: A battery assembly comprising any one of claims 1 to 8.

10. A power device, characterized in that: A battery pack comprising the battery pack of claim 9.

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