A battery cell, a battery device, and an electric device
By incorporating an elastic capsule shell inside the battery cell to release fire extinguishing media and phase change materials, the problems of battery thermal runaway and electrode assembly expansion and deformation are solved, thereby achieving battery safety and extended lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
- Filing Date
- 2024-12-02
- Publication Date
- 2026-06-02
Smart Images
Figure CN122136532A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and electrical equipment. Background Technology
[0002] With the development of new energy technologies, batteries are being used more and more widely. Besides performance requirements, safety is also a crucial issue that cannot be ignored during battery use. During cycling, the internal materials of a battery undergo exothermic chemical reactions, releasing a large amount of heat, which may lead to thermal runaway and other problems, affecting the battery's safety performance. Summary of the Invention
[0003] Therefore, it is necessary to provide a battery cell, battery device, and electrical equipment that can effectively suppress thermal runaway of the battery, thereby improving the battery's safety performance.
[0004] In a first aspect, this application provides a battery cell, including a shell and a capsule, the capsule being disposed inside the shell and including a capsule shell and a fire extinguishing medium disposed inside the capsule shell, the capsule shell being elastic and capable of elastic deformation under external force;
[0005] The capsule shell is configured to release the extinguishing medium inside when the external force reaches a first threshold or when the internal temperature of the shell reaches a second threshold.
[0006] With the above structure, when the battery cell is cycling normally, the capsule shell can provide deformation space for the electrode assembly, which can effectively extend the service life of the battery cell; when thermal runaway occurs inside the battery cell, the capsule shell can quickly release fire extinguishing medium to rapidly cool the battery cell, reduce the severity of thermal runaway, and thus improve the safety performance of the battery cell.
[0007] In some embodiments, the battery cell further includes at least one electrode assembly disposed inside the housing, a capsule disposed between at least one electrode assembly and the housing, and / or, a capsule disposed between two adjacent electrode assemblies.
[0008] Therefore, the capsule can not only provide some support for the electrode assembly, but also provide deformation space for the electrode assembly when it expands and deforms, so that the electrode assembly can be used more efficiently and the service life of the battery cell can be improved.
[0009] In some embodiments, a weak zone is provided on the side surface of the capsule shell facing the corresponding electrode assembly, and the weak zone is configured to rupture before other areas of the capsule shell and release the extinguishing medium.
[0010] With the above structure, when the electrode assembly experiences thermal runaway, the capsule shell can preferentially release the extinguishing medium from the weak area, allowing the extinguishing medium to act more accurately on the electrode assembly, effectively cooling the electrode assembly and thus reducing the severity of thermal runaway.
[0011] In some embodiments, the capsule shell has a contact surface that contacts the electrode assembly or the outer shell, the area of the contact surface is S1, the area of the side surface of the electrode assembly that contacts the capsule shell is S2, and the area of the side surface of the outer shell that contacts the capsule shell is S3, wherein S3>S1≥S2.
[0012] Therefore, the contact surface of the capsule shell can provide good support for the electrode assembly, making the electrode assembly more stable within the cavity.
[0013] In some embodiments, the capsule shell includes a substrate and a plurality of receiving portions, each receiving portion protruding from the substrate toward the electrode assembly and / or the outer shell, and each receiving portion having a first cavity formed inside, wherein the extinguishing medium is contained in each first cavity.
[0014] By setting multiple receiving parts, more stable support can be formed at different positions of the electrode assembly, further improving the support stability.
[0015] In some embodiments, the capsule shell material includes one or more of polypropylene, polyethylene, polyethylene terephthalate, and polyimide.
[0016] With the above structure, the capsule shell can be stably set inside the battery cell, providing stable support for the electrode assembly and providing a certain deformation space when the electrode assembly expands and deforms.
[0017] In some embodiments, the extinguishing medium includes one or more of sodium bicarbonate, sodium carbonate, calcium carbonate, and inert gas.
[0018] With the above structure, when a battery cell experiences thermal runaway, the extinguishing medium is released from the capsule shell and can quickly act on the electrode assembly to cool it down, effectively reducing the severity of the thermal runaway.
[0019] In some embodiments, the capsule further includes a phase change material disposed inside the capsule shell, the capsule shell being configured to release the extinguishing medium and / or phase change material when the applied external force reaches a first threshold or when the internal temperature of the shell reaches a second threshold.
[0020] By incorporating phase change materials, heat can be absorbed inside the battery cell, thereby reducing the risk of thermal runaway or mitigating its severity, and further improving the safety performance of the battery cell.
[0021] In some embodiments, the phase change material includes paraffin and / or crystalline hydrated salt phase change materials. This effectively absorbs heat, reducing the risk of thermal runaway or mitigating its severity.
[0022] In some embodiments, the capsule further includes a poisoning agent disposed inside the capsule shell, the capsule shell being configured to release a fire extinguishing medium and / or a phase change material and / or a poisoning agent when the applied external force reaches a first threshold or when the internal temperature of the shell reaches a second threshold.
[0023] When the poisoning agent is released from the capsule shell, it can mix with the electrolyte inside the battery cell to form a non-flammable or non-flammable mixture, thereby suppressing the thermal runaway of the battery cell.
[0024] In some embodiments, the poisoning agent includes aluminum sulfate and phloroglucinol.
[0025] In some embodiments, the capsule shell has a second cavity inside, and the capsule also includes a phase change material and a poisoning agent. The extinguishing medium, the phase change material, and the poisoning agent are all disposed in the second cavity.
[0026] When thermal runaway occurs inside a single battery cell, fire extinguishing media, phase change materials, and poisoning agents can be released simultaneously from the capsule shell, acting on the location of thermal runaway at the same time, further improving the suppression effect of thermal runaway.
[0027] In some embodiments, the capsule shell has multiple independent third cavities inside, and the capsule also includes a phase change material and a poisoning agent, with the extinguishing medium, phase change material and poisoning agent respectively disposed in the independent third cavities.
[0028] This allows the extinguishing medium, phase change material, and poisoning agent to be released separately during thermal runaway, thus enabling each to play its role.
[0029] Secondly, this application also provides a battery device, including the battery cell as described above.
[0030] Thirdly, this application also provides an electrical device, including the battery device described above.
[0031] In the aforementioned battery cell, battery device, and electrical equipment, the capsule is disposed inside the outer shell of the battery cell, and the capsule shell is elastic. When the battery cell is cycling normally, the electrode assembly inside the battery cell will expand and deform during the cycle. At this time, the capsule shell can provide a certain expansion and deformation space for the electrode assembly, thereby improving the cycle life of the battery cell. When the battery cell experiences thermal runaway, when the pressure on the capsule shell reaches a first threshold or the internal temperature of the outer shell reaches a second threshold, the capsule shell can release a fire extinguishing medium to rapidly cool the battery cell, reduce the severity of the thermal runaway, and thus improve the safety performance of the battery cell. Attached Figure Description
[0032] Figure 1 This is a schematic diagram of the structure of a battery cell according to one or more embodiments.
[0033] Figure 2 This is a schematic diagram of the structure of a capsule shell according to one or more embodiments.
[0034] Explanation of reference numerals in the attached drawings: 100, battery cell; 10, outer casing; 20, capsule; 30, electrode assembly; 21, capsule shell; 22, weak area; 211, substrate; 212, receiving part. Detailed Implementation
[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0036] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0037] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0038] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0039] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0040] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0041] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.
[0042] A battery cell is the smallest unit that makes up a battery. A battery cell typically includes a casing and an electrode assembly disposed inside the casing. The casing includes a housing and a top cover. The housing has an opening, and the top cover is a sealing cover disposed at the opening of the housing. The top cover and the housing together enclose a cavity in which the electrode assembly is placed.
[0043] During battery cycling, the electrochemical reactions primarily occur in the electrode components, generating a significant amount of heat. As the battery cell is used, the accumulation of internal heat can easily lead to thermal runaway, affecting its safety performance.
[0044] Furthermore, the electrode assembly expands and deforms during the reaction process. As batteries become increasingly widely used, the requirements for their energy density are also rising. Therefore, current batteries have high energy density, which limits the deformable space of the electrode assembly, thus hindering the extension of the battery cell's lifespan.
[0045] Based on the above considerations, in order to solve the problem of thermal runaway in batteries and improve battery safety performance, one or more embodiments of this application provide a battery cell with a capsule disposed inside the battery cell's outer shell. The capsule shell is elastic. During normal battery cell cycling, the electrode components inside the battery cell expand and deform during cycling. At this time, the capsule shell can provide a certain expansion and deformation space for the electrode components, thereby improving the cycle life of the battery cell. When thermal runaway occurs in the battery cell, if the pressure on the capsule shell reaches a first threshold or the internal temperature of the outer shell reaches a second threshold, the capsule shell can release a fire extinguishing medium to rapidly cool the battery cell, reducing the severity of thermal runaway and thus improving the safety performance of the battery cell.
[0046] It should be noted that the battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.
[0047] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.
[0048] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.
[0049] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.
[0050] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.
[0051] See Figure 1 One embodiment of this application provides a battery cell 100, including a housing 10 and a capsule 20. The capsule 20 is disposed inside the housing 10 and includes a capsule shell 21 and a fire extinguishing medium (not shown) disposed inside the capsule shell 21. The capsule shell 21 is elastic and capable of elastic deformation under external force. Furthermore, the capsule shell 21 is configured to release the fire extinguishing medium inside when the applied external force reaches a first threshold or when the internal temperature of the housing 10 reaches a second threshold.
[0052] It should be noted that the outer casing 10 may include a housing and a top cover, with the top cover sealed at the opening of the housing, and the two together enclosing a cavity capable of accommodating the electrode assembly 30 and other functional components. Therefore, the outer casing 10 refers to a structure that can provide accommodating space for other structures of the battery cell 100, such as the electrode assembly 30 or other functional components, and provide a certain degree of protection.
[0053] Capsule 20 refers to a structure inside the battery cell 100 that provides deformation space for the expansion and deformation of the electrode assembly 30 and effectively improves the thermal runaway problem of the battery cell 100. The capsule 20 is disposed inside the outer shell 10, that is, within the receiving cavity. The capsule 20 includes a capsule shell 21 and a fire extinguishing medium. The capsule shell 21 is hollow and contains the fire extinguishing medium.
[0054] The extinguishing medium refers to a substance that can act on the electrode assembly 30 or other structures inside the battery cell 100 to rapidly cool the battery cell 100, thereby reducing the severity of thermal runaway. The extinguishing medium can be gaseous, liquid, or in other states. When the extinguishing medium is gaseous, it can be rapidly sprayed out after being released from the capsule shell 21, allowing it to act more quickly on the location of thermal runaway.
[0055] Furthermore, the capsule shell 21 is elastic, meaning it can undergo elastic deformation under external force. As the battery cell 100 is used cyclically, the electrode assembly 30 will expand. When the electrode assembly 30 does not expand, the capsule shell 21 provides support within the cavity. When the electrode assembly 30 expands, the capsule shell 21 undergoes elastic deformation under the compression of the electrode assembly 30, providing deformation space for the electrode assembly 30. This facilitates the cyclic use of the electrode assembly 30 and effectively extends the service life of the battery cell 100.
[0056] Furthermore, the first threshold refers to the critical pressure that the capsule shell 21 can withstand. That is, when the external pressure on the capsule shell 21 is greater than or equal to the first threshold, the capsule shell 21 will rupture, thereby releasing the fire extinguishing medium inside. The second threshold refers to the melting point of the capsule shell 21. That is, when the temperature inside the cavity is greater than or equal to the second threshold, the capsule shell 21 will melt, thereby releasing the fire extinguishing medium inside. In other words, as long as either the temperature inside the battery cell 100 or the pressure on the capsule shell 21 reaches the threshold, the capsule shell 21 can release the fire extinguishing medium inside, effectively controlling the thermal runaway of the battery cell 100.
[0057] With the above structure, when the battery cell 100 is in normal operation, the capsule shell 21 can provide deformation space for the electrode assembly 30, which can effectively extend the service life of the battery cell 100. When thermal runaway occurs inside the battery cell 100, the capsule shell 21 can quickly release the fire extinguishing medium to rapidly cool down the battery cell 100, reduce the severity of thermal runaway, and thus improve the safety performance of the battery cell 100.
[0058] In some embodiments, the battery cell 100 further includes at least one electrode assembly 30, each electrode assembly 30 being disposed inside the housing 10, and a capsule 20 being disposed between at least one electrode assembly 30 and the housing 10, and / or, the capsule 20 being disposed between two adjacent electrode assemblies 30.
[0059] Specifically, the electrode assembly 30 is the component in the battery cell 100 where the actual electrochemical reaction occurs. The electrode assembly 30 can be either a stacked type or a wound type. A stacked type means that the positive electrode, separator, and negative electrode in the electrode assembly 30 are stacked in sequence, while a wound type means that the positive electrode, separator, and negative electrode in the electrode assembly 30 are stacked and then wound.
[0060] Each battery cell 100 may include one or more electrode assemblies 30. When one electrode assembly 30 is disposed in the receiving cavity, the capsule 20 is disposed between the electrode assembly 30 and the inner wall of the outer shell 10. When two or more electrode assemblies 30 are disposed in the receiving cavity, the capsule 20 may be disposed between the electrode assembly 30 and the inner wall of the outer shell 10, or it may be disposed between adjacent electrode assemblies 30.
[0061] Therefore, capsule 20 can not only provide a certain support for electrode assembly 30, but also provide deformation space for electrode assembly 30 when it expands and deforms, so that electrode assembly 30 can be used more efficiently and the service life of battery cell 100 can be improved.
[0062] In some embodiments, a weak region 22 is provided on the side surface of the capsule shell 21 facing the corresponding electrode assembly 30. The weak region 22 is configured to rupture before other areas of the capsule shell 21 and release the extinguishing medium.
[0063] Specifically, the weak zone 22 refers to the area where the capsule shell 21 can preferentially rupture or melt when subjected to external pressure or when the temperature is too high, so that the extinguishing medium can be preferentially released from the weak zone 22.
[0064] When the capsule shell 21 is disposed between the inner wall of the electrode assembly 30 and the outer shell 10, a weak area 22 may be provided on the side surface of the capsule shell 21 that contacts the electrode assembly 30. When the capsule shell 21 is disposed between adjacent electrode assemblies 30, weak areas 22 may be provided on the two sides surface of the capsule shell 21 that respectively contact the corresponding electrode assembly 30.
[0065] With the above structure, when the electrode assembly 30 experiences thermal runaway, the capsule shell 21 can preferentially release the extinguishing medium from the weak area 22, so that the extinguishing medium can act more accurately on the electrode assembly 30, effectively cooling the electrode assembly 30 and thus reducing the severity of thermal runaway.
[0066] In some embodiments, the capsule shell 21 has a contact surface (not shown) that contacts the electrode assembly 30 or the outer shell 10, the area of the contact surface is S1, the area of the side surface of the electrode assembly 30 that contacts the capsule shell 21 is S2, and the area of the side surface of the outer shell 10 that contacts the capsule shell 21 is S3, wherein S3 > S1 ≥ S2.
[0067] Specifically, the capsule shell 21 is disposed between the inner wall of the electrode assembly 30 and the outer shell 10, or between adjacent electrode assemblies 30. The surface of the capsule shell 21 is fitted to the inner wall of the electrode assembly 30 or the outer shell 10, and this surface is the contact surface of the capsule shell 21.
[0068] Therefore, the contact surface of the capsule shell 21 can provide good support for the electrode assembly 30, making the electrode assembly 30 more stable in the cavity.
[0069] Furthermore, the surface of the electrode assembly 30 that contacts the capsule shell 21 can be the larger surface area of the electrode assembly 30, that is, the surface with the largest area in the electrode assembly 30. Similarly, the surface of the outer shell 10 that contacts the capsule shell 21 can be the larger surface area of the outer shell 10, that is, the surface with the largest area in the outer shell 10. This further increases the contact area between the electrode assembly 30 and the capsule shell 21, thereby improving the supporting effect of the capsule shell 21 on the electrode assembly 30.
[0070] S3>S1≥S2, meaning that the larger surface area of the outer shell 10 is greater than the contact surface of the capsule shell 21, which is greater than or equal to the larger surface area of the electrode assembly 30. Thus, the capsule shell 21 provides more stable support between the electrode assembly 30 and the outer shell 10, making the electrode assembly 30 more stably positioned within the cavity.
[0071] like Figure 2 As shown, in some embodiments, the capsule shell 21 includes a base plate 211 and a plurality of receiving portions 212. Each receiving portion 212 protrudes from the base plate 211 toward the electrode assembly 30 and / or the outer shell 10, and each receiving portion 212 forms a first cavity (not shown in the figure) inside, in which the fire extinguishing medium is contained.
[0072] Specifically, substrate 211 refers to a plate-like structure that can provide a supporting base for housing 212. Placing substrate 211 between electrode assembly 30 and housing 10 or between adjacent electrode assemblies 30 can provide good support for electrode assembly 30.
[0073] The receiving portion 212 refers to a protrusion disposed on the substrate 211. The shape of the receiving portion 212 can be circular, elongated, or other shapes. Each receiving portion 212 is a protrusion on the substrate 211, and the receiving portions 212 are independent of each other and spaced apart from each other. The interior of each receiving portion 212 forms a first cavity. By uniformly distributing the receiving portions 212 on the substrate 211, a stable support can be provided for the electrode assembly 30, and deformation space can be provided for the electrode assembly 30.
[0074] The extinguishing medium is contained in each first cavity. Thus, each containing part 212 can not only support the electrode assembly 30, but also release the extinguishing medium in the first cavity when the electrode assembly 30 experiences thermal runaway, thereby rapidly cooling the electrode assembly 30.
[0075] By providing multiple receiving portions 212, more stable support can be formed at different positions of the electrode assembly 30, further improving the support stability.
[0076] In some embodiments, the material of the capsule shell 21 includes one or more of polypropylene, polyethylene, polyethylene terephthalate, and polyimide.
[0077] Specifically, the capsule shell 21 can be made of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), or polyimide (PI). These materials are not only elastic but also do not react with the electrolyte, allowing them to be more stably disposed inside the battery cell 100.
[0078] With the above structure, the capsule shell 21 can be stably set inside the battery cell 100, and provide stable support for the electrode assembly 30, as well as provide a certain deformation space when the electrode assembly 30 expands and deforms.
[0079] In some embodiments, the extinguishing medium includes one or more of sodium bicarbonate, sodium carbonate, calcium carbonate, and inert gas.
[0080] Specifically, the extinguishing medium can be sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), or calcium carbonate (CaCO3), which can produce carbon dioxide (CO2) when heated. The CO2 can act on the electrode assembly 30 or other locations where thermal runaway occurs, and rapidly cool them down.
[0081] In addition, the extinguishing medium can also be an inert gas. When the capsule shell 21 ruptures and releases the inert gas, the inert gas can suppress thermal runaway and reduce the severity of thermal runaway.
[0082] With the above structure, when the battery cell 100 experiences thermal runaway, the fire extinguishing medium is released from the capsule shell 21, which can quickly act on the electrode assembly 30 to cool down the electrode assembly 30 and effectively reduce the severity of thermal runaway.
[0083] In some embodiments, the capsule 20 further includes a phase change material (not shown) disposed inside the capsule shell 21, which is configured to release the extinguishing medium and / or phase change material when the applied external force reaches a first threshold or when the internal temperature of the outer shell 10 reaches a second threshold.
[0084] Specifically, a phase change material can also be provided inside the capsule shell 21. The phase change material can absorb heat, thereby reducing the risk of thermal runaway or reducing the severity of thermal runaway.
[0085] In actual use, the extinguishing medium and the phase change material can be released from the capsule shell 21 either individually or simultaneously, depending on the actual situation, which will not be elaborated here.
[0086] By incorporating phase change materials, heat can be absorbed inside the battery cell 100, thereby reducing the risk of thermal runaway or the severity of thermal runaway, and further improving the safety performance of the battery cell 100.
[0087] In some embodiments, the phase change material includes paraffin and / or hydrated salt phase change materials.
[0088] Specifically, inorganic phase change materials can be selected, such as paraffin wax and hydrated salt phase change materials. This effectively absorbs heat, reducing the risk of thermal runaway or mitigating its severity.
[0089] In some embodiments, the capsule 20 further includes a poisoning agent (not shown) disposed inside the capsule shell 21, which is configured to release a fire extinguishing medium and / or a phase change material and / or a poisoning agent when the external force reaches a first threshold or the internal temperature of the outer shell 10 reaches a second threshold.
[0090] Specifically, the capsule shell 21 can contain fire extinguishing medium, phase change material and poisoning agent, and can be released from the capsule shell 21 one by one, or all at the same time.
[0091] When the poisoning agent is released from the capsule shell 21, it can mix with the electrolyte inside the battery cell 100 to form a non-flammable or non-flammable mixture, thereby suppressing the thermal runaway of the battery cell 100.
[0092] In some embodiments, the poisoning agent includes aluminum sulfate and phloroglucinol.
[0093] Therefore, when the battery cell 100 experiences thermal runaway, the poisoning agent can release substances such as ALSO4 that can react with the electrolyte when heated, thereby poisoning the battery cell 100 and suppressing the thermal runaway of the battery cell 100.
[0094] In some embodiments, the capsule shell 21 has a second cavity (not shown in the figure), and the capsule 20 also includes a phase change material and a poisoning agent. The extinguishing medium, the phase change material and the poisoning agent are all disposed in the second cavity.
[0095] Specifically, the interior of the capsule shell 21 can be configured as an integral second cavity, and the extinguishing medium, phase change material and poisoning agent are simultaneously placed in the second cavity. In this case, the extinguishing medium, phase change material and poisoning agent can be selected as substances that do not react with each other.
[0096] When thermal runaway occurs inside the battery cell 100, fire extinguishing medium, phase change material and poisoning agent can be released simultaneously from the capsule shell 21, which can act on the location of thermal runaway at the same time, further improving the suppression effect of thermal runaway.
[0097] In some embodiments, the capsule shell 21 has multiple independent third cavities (not shown in the figure), and the capsule 20 also includes a phase change material and a poisoning agent, with the extinguishing medium, phase change material and poisoning agent respectively disposed in the independent third cavities.
[0098] Understandably, when the extinguishing medium, phase change material and poisoning agent react with each other, multiple independent third cavities can be set inside the capsule shell 21, and the extinguishing medium, phase change material and poisoning agent can be placed in different third cavities, so that the extinguishing medium, phase change material and poisoning agent can be released separately in the event of thermal runaway, so that each can play its role.
[0099] Based on the same concept as the battery cell 100 described above, this application also provides a battery device including the battery cell 100 as described above.
[0100] Based on the same concept as the battery device described above, this application also provides an electrical device including the battery device described above.
[0101] According to one or more embodiments, in use, the capsule 20 is disposed between the electrode assembly 30 and the inner wall of the housing 10, or between two adjacent electrode assemblies 30. During the cycling process of the battery cell 100, the capsule housing 21 can provide a certain degree of support for the electrode assembly 30, making the placement of the electrode assembly 30 in the housing 10 more stable.
[0102] As the battery cell 100 cycles, the electrode assembly 30 expands and deforms. At this time, the capsule shell 21 undergoes elastic deformation under the compression of the electrode assembly 30, thereby providing a certain deformation space for the electrode assembly 30, enabling the electrode assembly 30 to cycle better and extending the service life of the battery cell 100.
[0103] Furthermore, when the electrode assembly 30 experiences thermal runaway, if the pressure applied by the electrode assembly 30 to the capsule shell 21 reaches a first threshold, or if the temperature inside the battery cell 100 reaches a second threshold, the capsule shell 21 will rupture or melt, thereby releasing the fire extinguishing medium, phase change material, and poisoning agent inside the capsule shell 21.
[0104] The extinguishing agent is rapidly sprayed onto the electrode assembly 30, quickly cooling it and effectively reducing the severity of thermal runaway. Simultaneously, the phase change material absorbs heat, thereby controlling the internal temperature of the battery cell 100. Furthermore, the poisoning agent mixes with the electrolyte inside the battery cell 100 to form a flame-retardant or non-flammable mixture, further suppressing thermal runaway of the battery cell 100.
[0105] Therefore, the above structure can cool down the thermally runaway electrode assembly 30 in a timely manner and reduce the severity of thermal runaway, effectively improving the safety performance of the battery cell 100.
[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A battery cell, characterized in that, include: shell; and The capsule is disposed inside the outer shell and includes a capsule shell and a fire extinguishing medium disposed inside the capsule shell. The capsule shell is elastic and can undergo elastic deformation under external force. The capsule shell is configured to release the extinguishing medium inside when the external force reaches a first threshold or when the internal temperature of the shell reaches a second threshold.
2. The battery cell according to claim 1, characterized in that, The battery cell further includes at least one electrode assembly, each of the electrode assemblies being disposed inside the housing, and the capsule being disposed between at least one of the electrode assemblies and the housing, and / or, the capsule being disposed between two adjacent electrode assemblies.
3. The battery cell according to claim 2, characterized in that, The capsule shell has a weak area on one side surface facing the corresponding electrode assembly. The weak area is configured to rupture before other areas of the capsule shell and release the extinguishing medium.
4. The battery cell according to claim 2 or 3, characterized in that, The capsule shell has a contact surface that contacts the electrode assembly or the outer shell, the area of the contact surface is S1, the area of the side surface of the electrode assembly that contacts the capsule shell is S2, and the area of the side surface of the outer shell that contacts the capsule shell is S3, wherein S3 > S1 ≥ S2.
5. The battery cell according to claim 2, characterized in that, The capsule shell includes a base plate and a plurality of receiving portions. Each of the receiving portions protrudes from the base plate toward the electrode assembly and / or the outer shell, and each of the receiving portions forms a first cavity inside, in which the fire extinguishing medium is contained.
6. The battery cell according to any one of claims 1-3, characterized in that, The capsule shell is made of one or more of the following materials: polypropylene, polyethylene, polyethylene terephthalate, and polyimide.
7. The battery cell according to any one of claims 1-3, characterized in that, The extinguishing medium includes one or more of sodium bicarbonate, sodium carbonate, calcium carbonate, and inert gases.
8. The battery cell according to claim 1, characterized in that, The capsule also includes a phase change material disposed inside the capsule shell, and the capsule shell is configured to release the extinguishing medium and / or the phase change material when the external force reaches the first threshold or when the internal temperature of the outer shell reaches the second threshold.
9. The battery cell according to claim 8, characterized in that, The phase change material includes paraffin and / or hydrated salt phase change materials.
10. The battery cell according to claim 8, characterized in that, The capsule also includes a poisoning agent disposed inside the capsule shell, the capsule shell being configured to release the extinguishing medium and / or the phase change material and / or the poisoning agent when the external force reaches the first threshold or when the internal temperature of the outer shell reaches the second threshold.
11. The battery cell according to claim 10, characterized in that, The poisoning agents include aluminum sulfate and phloroglucinol.
12. The battery cell according to claim 1, characterized in that, The capsule shell has a second cavity inside, and the capsule also includes a phase change material and a poisoning agent. The extinguishing medium, the phase change material, and the poisoning agent are all disposed in the second cavity.
13. The battery cell according to claim 1, characterized in that, The capsule shell has multiple independent third cavities inside. The capsule also includes a phase change material and a poisoning agent. The extinguishing medium, the phase change material, and the poisoning agent are respectively disposed in the independent third cavities.
14. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-13.
15. An electrical appliance, characterized in that, Includes the battery device as described in claim 14.