Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a metal end cover, a shell, an electrode assembly, a plastic part and a heat absorption layer. The metal end cover is connected with the shell and cooperates with the shell to form an accommodating space. The electrode assembly is arranged in the accommodating space, and the plastic part is arranged on one side of the metal end cover facing the electrode assembly. The heat absorption layer is arranged on one side of the plastic part facing the electrode assembly. In this way, the heat absorption layer can absorb the heat transferred from the electrode assembly to the plastic part, so as to reduce the melting loss of the plastic part.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular to a battery cell, battery device, and power-consuming device. Background Technology

[0002] To reduce the probability of short circuits caused by electrical contact between the electrode assembly and the metal end cap, most battery cells have a lower plastic layer between the metal end cap and the electrode assembly to electrically isolate them. However, existing lower plastic layers have high melting loss at high temperatures, which can easily lead to the failure of the lower plastic layer's electrical isolation between the metal end cap and the electrode assembly, thus affecting the safety of the battery cell. Utility Model Content

[0003] This application provides a battery cell, a battery device, and an electrical device, aiming to solve the technical problem of large melting loss of the plastic under the bottom of existing battery cells under high temperature environment.

[0004] To address the aforementioned problems, this application provides a battery cell comprising: a metal end cap, a housing, an electrode assembly, a plastic component, and a heat-absorbing layer; the metal end cap is connected to the housing and together with the housing forms an accommodating space; the electrode assembly is disposed within the accommodating space; the plastic component is disposed on the side of the metal end cap facing the electrode assembly; and the heat-absorbing layer is disposed on the side of the plastic component facing the electrode assembly.

[0005] In the above scheme, by setting a heat-absorbing layer on the side of the plastic part facing the electrode assembly, the heat-absorbing layer can absorb the heat transferred from the electrode assembly to the plastic part, thereby delaying the time for the plastic part to reach the melting point temperature, thus reducing the melting loss of the plastic part under high temperature environment, which is beneficial to improving the reliability of the battery cell.

[0006] In one embodiment, a heat insulation layer is provided between the plastic part and the heat-absorbing layer.

[0007] Therefore, the heat insulation layer can be used to reduce the efficiency of heat transfer from the heat-absorbing layer to the plastic part, thereby further delaying the time it takes for the plastic part to reach its melting point temperature, and thus reducing the melting loss of the plastic part under high temperature conditions.

[0008] In one embodiment, a heat-conducting layer is provided on the side of the heat-absorbing layer opposite to the plastic part.

[0009] Therefore, the heat absorption efficiency of the heat-absorbing layer can be improved by using the heat-conducting layer, thereby reducing the heat transferred from the electrode assembly to the plastic part.

[0010] In one embodiment, there are multiple heat-absorbing layers, and the multiple heat-absorbing layers are distributed at different positions on the side of the plastic part facing the electrode assembly.

[0011] Therefore, multiple heat-absorbing layers can be used to absorb heat transferred to different parts of the plastic part, thereby reducing melting loss at different parts of the plastic part under high temperature conditions.

[0012] In one embodiment, a plurality of the heat-absorbing layers are disposed on the edge of the plastic part away from the center.

[0013] Therefore, multiple heat-absorbing layers can specifically absorb heat at the edges of plastic parts that are prone to melting, thereby reducing melting at the edges of plastic parts.

[0014] In one embodiment, the heat-absorbing layer includes a phase change material layer disposed on the side of the plastic part facing the electrode assembly.

[0015] Therefore, the phase change material layer can be used to absorb the heat transferred from the electrode assembly to the plastic part, thereby delaying the time it takes for the plastic part to reach its melting point temperature and reducing the melting loss of the plastic part under high temperature conditions.

[0016] In one embodiment, the heat-absorbing layer has a thickness of at least 1 mm and a width of at least 10 mm.

[0017] Therefore, by setting the thickness of the heat-absorbing layer to be at least 1 mm and the width to be at least 10 mm, the heat-absorbing layer can have a better heat absorption effect, so that the heat-absorbing layer can absorb the heat transferred from the electrode assembly to the plastic part.

[0018] In one embodiment, the volumetric energy density of the electrode assembly is greater than or equal to 370 Wh / L.

[0019] Therefore, the heat-absorbing layer can absorb the heat transferred from the high volumetric energy density electrode components to the plastic parts, thereby delaying the time it takes for the plastic parts to reach their melting point temperature, thus reducing the melting loss of the plastic parts under high temperature conditions, which is beneficial to improving the reliability of the battery cells.

[0020] In one embodiment, the plastic part is made of polyethylene terephthalate or polybutylene terephthalate.

[0021] Therefore, plastic parts can be made heat resistant to reduce melting loss in high-temperature environments.

[0022] This application also provides a battery device comprising at least one of the aforementioned battery cells.

[0023] Therefore, the safety of battery devices can be improved by utilizing highly reliable battery cells.

[0024] This application also provides an electrical device, which includes the battery device described above.

[0025] Therefore, it is possible to use highly safe battery devices to power electrical devices. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0027] Figure 1 This is a schematic diagram of the structure of the electrical device provided in the embodiments of this application;

[0028] Figure 2 yes Figure 1 Exploded view of the battery device;

[0029] Figure 3 yes Figure 2 A schematic diagram of the structure of a single battery cell;

[0030] Figure 4 yes Figure 3 A schematic diagram of the exploded structure of a single battery cell;

[0031] Figure 5 yes Figure 4 Schematic diagram of the connection structure between the plastic parts and multiple heat-absorbing layers;

[0032] Figure 6 yes Figure 3 A schematic diagram of the cross-sectional structure of a single battery cell along section line V-V;

[0033] Figure 7 yes Figure 3 A schematic diagram of a partial cross-sectional structure of a single battery cell along section line V-V in another embodiment.

[0034] The attached figures are labeled as follows:

[0035] Electrical device 1, battery device 10, controller 20, motor 30, battery cell assembly 100, battery cell 110, metal end cap 111, housing 112, electrode assembly 113, plastic part 114, heat-absorbing layer 115, phase change material layer 1151, heat insulation layer 116, heat-conducting layer 118, housing assembly 200, first housing 210, second housing 220, accommodating space 1101, pole post 1111, pole tab 1131, adapter 1132. Detailed Implementation

[0036] It should be noted that, unless otherwise specified, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed descriptions in the specific implementation should be understood as explanations of the purpose of this application and should not be regarded as undue limitations on this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having” and any variations thereof are intended to cover non-exclusive inclusion.

[0038] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0041] In the description of the embodiments of this application, the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", "height direction", "first direction", "second direction", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0042] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0043] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0044] In some designs, battery cells typically include plastic components to isolate the electrode assembly and the metal end cap, preventing short circuits caused by electrical contact between the two. However, due to the large amount of heat generated by the electrode assembly during operation, the plastic components are prone to melting under high temperatures. This undoubtedly increases the risk of failure of the plastic components and is detrimental to improving the reliability of the battery cell.

[0045] To address the aforementioned technical problems, this application provides a battery cell that incorporates a heat-absorbing layer on the side of the plastic component facing the electrode assembly. This heat-absorbing layer absorbs the heat transferred from the electrode assembly to the plastic component, thereby delaying the time it takes for the plastic component to reach its melting point temperature. This reduces the melting loss of the plastic component under high-temperature conditions, which is beneficial for improving the reliability of the battery cell.

[0046] The battery device designed in this application can be used in energy storage devices or electrical devices. When used in an energy storage device, the energy storage device can be an energy storage container or energy storage cabinet, and the battery device can be installed as an energy storage element within the energy storage device. When used in an electrical device, the electrical device can be a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, vehicle, ship, spacecraft, or other electrical equipment, and the battery device can be installed as a power source within the electrical device.

[0047] Furthermore, the energy storage device may include: an energy storage body and a battery device as described in the context, wherein the energy storage body may be a frame structure for mounting the battery device. For example, the energy storage body may be an energy storage rack, an energy storage cabinet, or an energy storage box, etc. Similarly, the electrical device may include: an electrical device and a battery device as described in the context, wherein the electrical device may be a frame structure for mounting the electrical device. For example, when the electrical device is a vehicle, the electrical device may be the vehicle body, and when the electrical device is a ship, the electrical device may be the ship hull.

[0048] It is understood that the aforementioned electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Classified by power source, vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Classified by drive method, vehicles can be front-wheel drive cars, rear-wheel drive cars, or four-wheel drive cars.

[0049] Please see Figures 1 to 2 , Figure 1 This is a schematic diagram of the structure of the electrical device 1 provided in the embodiment of this application. Figure 2 yes Figure 1 An exploded view of the battery device 10.

[0050] The following description uses the battery device 10 used in the electrical device 1 as an example. The electrical device 1 provided in this embodiment can be a vehicle, and the battery device 10 can be installed inside the electrical device 1. Figure 1 As shown, the battery device 10 can be located at the bottom, head, or tail of the electrical device 1, and the battery device 10 can serve as the operating power source for the electrical device 1. For example, the electrical device 1 may also include a controller 20 and a motor 30. The controller 20 is used to control the battery device 10 to supply power to the motor 30 to meet the power requirements of the electrical device 1 during startup, navigation, and driving. Of course, the battery device 10 can not only serve as the operating power source for the electrical device 1, but also as the driving power source for the electrical device 1, to replace or partially replace fuel oil or natural gas to provide driving power for the electrical device 1.

[0051] The battery device 10 can be used to power the electrical device 1, and the battery device 10 may include: a battery cell assembly 100 and a housing assembly 200. For example... Figure 2As shown, the battery cell assembly 100 can be disposed within the housing assembly 200, and the battery cell assembly 100 can be used to supply power to the electrical device 1. The housing assembly 200 can accommodate the battery cell assembly 100 and can be used to connect the electrical device 1 to its main body to fix the battery device 10 to the electrical device 1. For example, when the electrical device 1 is a vehicle, the housing assembly 200 can be connected to the vehicle body of the electrical device 1, so that the battery device 10 can be fixed to the vehicle body of the electrical device 1 as a whole.

[0052] The battery cell assembly 100 may include at least one battery cell 110, and the battery cell 110 can be used to store or release electrical energy to power the electrical device 1 when needed. The battery cell 110 can be a rechargeable battery, meaning a battery cell 110 that can be recharged after discharge to activate its active materials and continue to be used. Furthermore, the battery cell 110 may include, but is not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0053] Furthermore, when there are multiple battery cells 110, the multiple battery cells 110 can be electrically connected by at least one of the following methods: series connection, parallel connection, and mixed connection via a busbar component, and can be connected together by bundling to be placed as a whole within the housing assembly 200. Of course, the multiple battery cells 110 can also be divided into multiple groups according to a preset number and bundled together, and are not limited to being bundled into one group.

[0054] In some embodiments, the connection method of the multiple battery cells 110 is not limited to bundling; the multiple battery cells 110 may also be connected in other ways. In some embodiments, the multiple battery cells 110 are not limited to being bundled together and placed as a whole inside the housing assembly 200; the multiple battery cells 110 may also be placed independently inside the housing assembly 200.

[0055] The enclosure assembly 200 can be used to house and protect the battery cell assembly 100, and can be connected to the power-consuming body of the electrical device 1. For example... Figure 2 As shown, the housing assembly 200 may include a first housing 210 and a second housing 220. The first housing 210 can be connected to the second housing 220 and together they can enclose a receiving space to house the battery cell assembly 100. Simultaneously, at least one of the first housing 210 and the second housing 220 can be connected to the power-consuming body of the electrical device 1, allowing the battery device 10 to be fixed to the electrical device 1.

[0056] Furthermore, the first housing 210 and the second housing 220 overlap each other to jointly enclose and form the aforementioned receiving space. For example, the second housing 220 can be a hollow structure with one open end, and the first housing 210 can be a plate-like structure. The first housing 210 covers the open side of the second housing 220 to jointly enclose and form the receiving space. Alternatively, the first housing 210 and the second housing 220 can both be hollow structures with one open end, with the open side of the first housing 210 covering the open side of the second housing 220, so that the first housing 210 and the second housing 220 jointly enclose and form the receiving space.

[0057] Furthermore, the first housing 210 and the second housing 220 can be fixed together by welding or screwing. For example, the first housing 210 can be made of metal, the second housing 220 can be made of plastic, and the edges of the first housing 210 and the second housing 220 can be bolted together. Alternatively, both the first housing 210 and the second housing 220 can be made of metal, and the edges of the first housing 210 and the second housing 220 can be welded together.

[0058] In some embodiments, the connection method of the first housing 210 and the second housing 220 may not be limited to the scheme shown in the above embodiments, and the connection method of the first housing 210 and the second housing 220 can be selected according to requirements. Similarly, the materials of the first housing 210 and the second housing 220 may be the same or different, and may not be limited to metal or plastic shown in the above embodiments. These will not be listed in detail here.

[0059] In some embodiments, the housing assembly 200 may also be part of the electrical device 1. For example, when the electrical device 1 is a vehicle, the housing assembly 200 may also be part of the vehicle's chassis. That is, a portion of the housing assembly 200 may be at least a portion of the vehicle's floor, or a portion of the housing assembly 200 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0060] Please see Figures 3 to 6 , Figure 3 yes Figure 2 A schematic diagram of the structure of the 110 battery cell. Figure 4 yes Figure 3 A schematic diagram of the exploded structure of the 110 cell in the middle section. Figure 5 yes Figure 4 A schematic diagram of the connection structure between the plastic part 114 and the multiple heat-absorbing layers 115. Figure 6 yes Figure 3 A schematic diagram of the cross-sectional structure of the 110 cell along section line V-V.

[0061] The battery cell 110 can be used to store or release electrical energy to power the electrical device 1 when needed, and the battery cell 110 may include: a metal end cap 111, a housing 112, an electrode assembly 113, a plastic part 114, and a heat-absorbing layer 115. For example... Figures 3 to 4 As shown, the metal end cap 111 can be connected to the housing 112 and together with the housing 112 can form an accommodating space 1101. The electrode assembly 113 can be disposed within the accommodating space 1101, and the plastic part 114 can be disposed on the side of the metal end cap 111 facing the electrode assembly 113. The heat-absorbing layer 115 can be disposed on the side of the plastic part 114 facing the electrode assembly 113.

[0062] The housing 112 can be a hollow structure with an opening at one end, and the metal end cap 111 can cover the opening side of the housing 112, forming an accommodating space 1101 together with the housing 112. The metal end cap 111 can be made of a metal material with high hardness and strength, such as aluminum alloy, while the housing 112 can be made of a metal material such as aluminum alloy, or a non-metallic material such as plastic. Furthermore, the metal end cap 111 and the housing 112 can be connected together by one or more fixing methods such as bonding, welding, snap-fitting, or screwing.

[0063] Furthermore, a terminal post 1111 may be inserted through the metal end cap 111, and the terminal post 1111 may be electrically isolated from the metal end cap 111. Simultaneously, there may be two terminals 1111, and the two terminals 1111 may be the positive and negative terminals of the battery cell 110, respectively. One end of the terminal post 1111 may protrude from the side of the metal end cap 111 facing away from the electrode assembly 113 and may be electrically connected to the aforementioned external conductive structure such as the current collector. The other opposite end of the terminal post 1111 may protrude from the side of the metal end cap 111 facing the electrode assembly 113 and may be electrically connected to the electrode assembly 113.

[0064] In some embodiments, in addition to the terminal post 1111, an explosion-proof valve may also be installed on the metal end cap 111, and the explosion-proof valve can control whether the accommodating space 1101 is connected to the outside world, so as to realize the pressure relief function of the battery cell 110. Of course, in addition to the terminal post 1111 and the explosion-proof valve, other functional structures required for the battery cell 110 may also be installed on the metal end cap 111, which will not be listed and described in this embodiment.

[0065] Electrode assembly 113 is the component in the battery cell 110 where the electrochemical reaction occurs, and the housing 112 may contain one or more electrode assemblies 113. The electrode assembly 113 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is typically provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab 1131, and the two tabs 1131 may be located together on the side of the main body facing the metal end cap 111. During the charging and discharging process of the battery cell 110, the positive and negative active materials can react with the electrolyte in the housing 112, and the two tabs 1131 are connected to two terminals 1111 to form a current loop.

[0066] In some embodiments, an adapter 1132 may be provided between the electrode assembly 113 and the metal end cap 111, and the number of adapters 1132 may also be two, which may be respectively provided with two tabs 1131 and two posts 1111. Specifically, the adapter 1132 may be a metal adapter piece, and the adapter 1132 may be electrically connected to both the tabs 1131 and the posts 1111 to achieve electrical conductivity between them. Compared to the scheme where the tabs 1131 are directly electrically connected to the posts 1111, the presence of the adapter 1132 can reduce the restrictions on the posts 1111 and the tabs 1131, which is beneficial to improving the layout flexibility of the posts 1111 and the tabs 1131.

[0067] like Figures 4 to 5 As shown, the plastic component 114 can be disposed on the side of the metal end cap 111 facing the electrode assembly 113, and can electrically isolate the metal end cap 111 and the electrode assembly 113. For example, in the direction of the metal end cap 111 facing the electrode assembly 113, the orthographic projection of the metal end cap 111 can be located within the coverage area of ​​the orthographic projection of the plastic component 114, so that the plastic component 114 can shield the metal end cap 111 to maintain the electrical isolation between the metal end cap 111 and the electrode assembly 113. The plastic component 114 can be connected to the metal end cap 111 and can be fixed to the side of the metal end cap 111 facing the electrode assembly 113.

[0068] Furthermore, the plastic part 114 can be made of PP (Polypropylene), and the melting point of the plastic part 114 is greater than or equal to 160°C. The PP plastic part 114, after high-temperature testing, generally experiences melting loss within 10mm in the width direction at its edges, exposing a portion of the corresponding area of ​​the metal end cap 111. When the electrode assembly 113 moves towards the metal end cap 111 along with the opening of the battery cell 110, the exposed portion of the metal end cap 111 is prone to contact with the electrode assembly 113, causing a short circuit. In this embodiment, the aforementioned width direction can be the direction from the edge of the plastic part 114 towards the center.

[0069] In some embodiments, the material of the plastic part 114 is not limited to PP material, and the material of the plastic part 114 can also be selected according to design requirements, as long as the plastic part 114 has a certain high temperature resistance. This embodiment will not list them one by one.

[0070] The heat-absorbing layer 115 can be disposed on the side of the plastic part 114 facing the electrode assembly 113, and can be used to absorb the heat transferred from the electrode assembly 113 to the plastic part 114. The heat-absorbing layer 115 can be connected to the plastic part 114 and can be fixed to the side of the plastic part 114 facing the electrode assembly 113. Simultaneously, the heat-absorbing layer 115 can be disposed at the edge of the plastic part 114 to protect the edges of the plastic part 114 that are prone to melting, thereby reducing melting at the edges of the plastic part 114.

[0071] In some embodiments, the heat-absorbing layer 115 may be disposed at other locations on the plastic part 114, except for the edge locations. That is, the heat-absorbing layer 115 may be disposed at any location on the side of the plastic part 114 facing the electrode assembly 113, so that the heat-absorbing layer 115 can cover most of the area of ​​the plastic part 114 facing the electrode assembly 113, so that the heat-absorbing layer 115 can absorb the heat transferred from the electrode assembly 113 to the plastic part 114.

[0072] In the above solution, by providing a heat-absorbing layer 115 on the side of the plastic part 114 facing the electrode assembly 113, the heat-absorbing layer 115 can absorb the heat transferred from the electrode assembly 113 to the plastic part 114, thereby delaying the time for the plastic part 114 to reach the melting point temperature, thus reducing the melting loss of the plastic part 114 under high temperature environment, which is beneficial to improving the reliability of the battery cell 110.

[0073] In some embodiments, the volumetric energy density of the electrode assembly 113 is greater than or equal to 370 Wh / L.

[0074] Electrode assembly 113 can be a high volumetric energy density battery cell, and the volumetric energy density of electrode assembly 113 can be greater than or equal to 370Wh / L. For example, electrode assembly 113 can be a high-energy-density lithium iron phosphate (LiFePO4) battery cell. Of course, there can be many other types of electrode assembly 113, as long as the volumetric energy density of electrode assembly 113 is greater than or equal to 370Wh / L. This embodiment will not list them all.

[0075] In the above solution, the heat-absorbing layer 115 can absorb the heat generated by the high volumetric energy density electrode assembly 113, thereby delaying the time it takes for the plastic part 114 to reach its melting point temperature. This reduces the melting loss of the plastic part 114 under high-temperature conditions, which is beneficial to improving the reliability of the battery cell 110. That is, the heat-absorbing layer 115 can be applied to the high volumetric energy density battery cell 110 to reduce the probability of short circuits caused by large melting loss of the plastic part 114.

[0076] In some embodiments, the plastic part 114 is made of polyethylene terephthalate or polybutylene terephthalate.

[0077] The plastic part 114 can be made of polyethylene terephthalate, and this type of material can have a melting point temperature greater than or equal to 255°C, thus giving the plastic part 114 high-temperature resistance. Alternatively, the plastic part 114 can be made of polybutylene terephthalate, and this type of material can have a melting point temperature greater than or equal to 225°C, thus giving the plastic part 114 high-temperature resistance.

[0078] In the above solution, by setting the material of the plastic part 114 to polyethylene terephthalate or polybutylene terephthalate, the plastic part 114 can have high temperature resistance, thereby reducing the melting loss of the plastic part 114 under high temperature environment.

[0079] like Figure 5 As shown, there can be multiple heat-absorbing layers 115, and these multiple heat-absorbing layers 115 can be distributed at different positions on the side of the plastic part 114 facing the electrode assembly 113.

[0080] To cover most of the plastic part 114, multiple heat-absorbing layers 115 can be used, and these multiple heat-absorbing layers 115 can be arranged at different positions on the side of the plastic part 114 facing the electrode assembly 113, so as to absorb the heat transferred from the electrode assembly 113 to different positions on the plastic part 114. The arrangement of the multiple heat-absorbing layers 115 on the side of the plastic part 114 facing the electrode assembly 113 can be selected according to requirements, as long as the multiple heat-absorbing layers 115 can cover as much of the plastic part 114 as possible.

[0081] Furthermore, the areas occupied by the multiple heat-absorbing layers 115 on the side of the plastic part 114 facing the electrode assembly 113 can be different. That is, the size of the multiple heat-absorbing layers 115 can be adaptively adjusted according to the actual placement position of the plastic part 114, which helps to improve the placement flexibility of the multiple heat-absorbing layers 115.

[0082] In the above scheme, by setting the number of heat-absorbing layers 115 to multiple, and the multiple heat-absorbing layers 115 can be set at different positions on the side of the plastic part 114 facing the electrode assembly 113, the multiple heat-absorbing layers 115 can absorb the heat transferred from the electrode assembly 113 to different positions of the plastic part 114, so as to reduce the melting loss of different positions of the plastic part 114 under high temperature environment.

[0083] like Figure 5 As shown, multiple heat-absorbing layers 115 can be arranged on the edge of the plastic part 114 away from the center.

[0084] As mentioned above, since the edges of the plastic part 114 are more prone to melting, multiple heat-absorbing layers 115 can be arranged at the edges of the plastic part 114 facing the electrode assembly 113 to reduce the degree of melting in the edge areas of the plastic part 114. In this way, multiple heat-absorbing layers 115 can provide targeted protection for the edges of the plastic part 114. Compared to a solution that covers all areas with heat-absorbing layers 115, the number of heat-absorbing layers 115 used can be reduced, thereby reducing the cost of the battery cell 110.

[0085] In some embodiments, the side of the plastic part 114 facing the electrode assembly 113 can be rectangular, the number of heat-absorbing layers 115 can be 6, and two heat-absorbing layers 115 can be respectively arranged on the two short sides of the side of the plastic part 114 facing the electrode assembly 113, while the remaining four heat-absorbing layers 115 can be divided into two groups of two, so as to be respectively arranged on the two long sides of the side of the plastic part 114 facing the electrode assembly 113.

[0086] It is understood that the above embodiments are merely illustrative examples, and the side of the plastic part 114 facing the electrode assembly 113 may not be limited to being rectangular, and the number of heat-absorbing layers 115 may not be limited to 6. For example, the side of the plastic part 114 facing the electrode assembly 113 may also be square or circular, and the number of heat-absorbing layers 115 may be less than 6 or more than 6, such as 4, 5, 7 or 8, etc.

[0087] In the above solution, by arranging multiple heat-absorbing layers 115 on the edge of the plastic part 114 away from the center, the multiple heat-absorbing layers 115 can provide targeted protection for the edge of the plastic part 114 that is prone to melting, so as to reduce the melting damage at the edge of the plastic part 114.

[0088] like Figure 5 As shown, the thickness of the heat-absorbing layer 115 is at least greater than 1 mm, and the width is at least greater than 10 mm.

[0089] The heat-absorbing layer 115 has a thickness of at least 1 mm in the direction facing the plastic part 114, and can specifically be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm, to ensure that the heat-absorbing layer 115 has sufficient heat absorption performance. Simultaneously, the width of the heat-absorbing layer 115 in the aforementioned width direction is at least 10 mm, and can specifically be 10 mm, 11 mm, 12 mm, or 13 mm, to ensure that the heat-absorbing layer 115 can cover the edges of the plastic part 114 that are prone to melting. Furthermore, the length of the heat-absorbing layer 115 can be adaptively adjusted according to the placement of the heat-absorbing layer 115 and the actual size of the plastic part 114, as long as the heat-absorbing layer 115 can cover as much of the plastic part 114 as possible.

[0090] In the above solution, by setting the thickness of the heat-absorbing layer 115 to be at least greater than 1 mm, the heat-absorbing layer 115 can have sufficient heat absorption performance. Furthermore, by setting the width of the heat-absorbing layer 115 to be at least greater than 10 mm, the heat-absorbing layer 115 can cover the edges of the plastic part 114 that are prone to melting. Thus, the heat-absorbing layer 115 can have a good heat absorption effect, facilitating the absorption of heat transferred from the electrode assembly 113 to the plastic part 114, thereby reducing the melting loss of the plastic part 114 under high temperature conditions.

[0091] like Figure 6 As shown, in order to realize the heat absorption function of the heat absorption layer 115, the heat absorption layer 115 may include a phase change material layer 1151, and the phase change material layer 1151 may be disposed on the side of the plastic part 114 facing the electrode assembly 113.

[0092] The phase change material layer 1151 can be disposed on the side of the plastic part 114 facing the electrode assembly 113, and can absorb the heat transferred from the electrode assembly 113 to the plastic part 114. The phase change material layer 1151 can include any one of solid-solid phase change materials, solid-liquid phase change materials, and composite phase change materials. Composite phase change materials refer to composite phase change materials in which one or more functional additives (such as coolants, binders, or curing agents) are added to solid-solid or solid-liquid phase change materials.

[0093] Furthermore, the phase change material layer 1151 can be a heat-absorbing block made of solid-solid phase change material or its composite phase change material, and can be fixed to the plastic part 114 by adhesive bonding. Alternatively, the phase change material layer 1151 can be a heat-absorbing coating sprayed or applied onto the plastic part 114 by solid-solid phase change material or its composite phase change material. Or, the phase change material layer 1151 can be a heat-absorbing film made of an encapsulation film and solid-liquid phase change material or its composite phase change material filled within the encapsulation film, and can be fixed to the plastic part 114 by adhesive bonding.

[0094] Furthermore, the phase change material layer 1151 can have a phase change temperature lower than the melting point temperature of the plastic part 114, allowing the phase change material layer 1151 to absorb heat before the plastic part 114 reaches its melting point, thereby delaying the time it takes for the plastic part 114 to reach its melting point and reducing the melting loss of the plastic part 114. For example, the phase change material of the phase change material layer 1151 can be sodium hydride borane, and the phase change temperature of the phase change material layer 1151 can be 140°C, which allows the phase change temperature of the phase change material layer 1151 to be lower than the melting point temperature (160°C) of the plastic part 114.

[0095] In some embodiments, the heat-absorbing layer 115 may include, in addition to the phase change material layer 1151, a film layer for performing other functions. For example, the heat-absorbing layer 115 may also include an adhesive layer disposed between the phase change material layer 1151 and the plastic part 114, so that the phase change material layer 1151 can be bonded to the plastic part 114 by the adhesive layer. And / or, the heat-absorbing layer 115 may also include a protective layer disposed on the side of the phase change material layer 1151 opposite to the plastic part 114, so as to protect the phase change material layer 1151 by means of the protective layer.

[0096] In the above scheme, the heat-absorbing layer 115 may include a phase change material layer 1151, and the phase change material layer 1151 may be disposed on the side of the plastic part 114 facing the electrode assembly 113, so that the phase change material layer 1151 can absorb the heat transferred from the electrode assembly 113 to the plastic part 114, so as to realize the heat absorption function of the heat-absorbing layer 115.

[0097] In some embodiments, in addition to using a phase change material layer 1151 to achieve the heat absorption function, the heat absorption layer 115 can also use other films or structures with heat absorption functions to achieve the heat absorption function. As long as the heat absorption layer 115 has heat absorption capacity, it is sufficient. This embodiment will not list them one by one.

[0098] Please see Figure 7 , Figure 7 yes Figure 3 A schematic diagram of a partial cross-sectional structure of the battery cell 110 along section line V-V in another embodiment.

[0099] like Figure 7 As shown, a heat insulation layer 116 is provided between the plastic part 114 and the heat-absorbing layer 115.

[0100] The heat insulation layer 116 can be made of a material with low thermal conductivity, and it can be used to reduce the efficiency of heat transfer from the heat-absorbing layer 115 to the plastic part 114. The heat insulation layer 116 can be a heat insulation block and can be fixed between the plastic part 114 and the heat-absorbing layer 115 by means of adhesive bonding or the like. Alternatively, the heat insulation layer 116 can be a heat-insulating coating and can be formed between the plastic part 114 and the heat-absorbing layer 115 by means of spraying or the like.

[0101] Furthermore, the orthographic projection of the heat-absorbing layer 115 onto the plastic part 114 can be located within the coverage area of ​​the orthographic projection of the heat-insulating layer 116 onto the plastic part 114. For example, the area of ​​the orthographic projection of the heat-insulating layer 116 onto the plastic part 114 can be greater than or equal to the area of ​​the orthographic projection of the heat-absorbing layer 115 onto the plastic part 114, so that the heat-insulating layer 116 can completely cover the heat-absorbing layer 115.

[0102] In the above solution, by providing a heat insulation layer 116 between the plastic part 114 and the heat-absorbing layer 115, the efficiency of heat transfer from the heat-absorbing layer 115 to the plastic part 114 can be reduced. Thus, even when the heat-absorbing layer 115 reaches its maximum heat absorption capacity and transfers heat to the plastic part 114, the heat insulation layer 116 can delay the time it takes for the plastic part 114 to reach its melting point temperature, thereby reducing the melting loss of the plastic part 114 under high-temperature conditions.

[0103] like Figure 7 As shown, a heat-absorbing layer 115 has a heat-conducting layer 118 on the side opposite to the plastic part 114.

[0104] The thermally conductive layer 118 can be made of a material with high thermal conductivity, and it can be used to improve the efficiency of the heat-absorbing layer 115 in absorbing the heat transferred by the electrode assembly 113. The thermally conductive layer 118 can be a thermally conductive block or thermally conductive adhesive, and can be fixed to the side of the heat-absorbing layer 115 facing away from the plastic part 114 by means of bonding or other methods. Alternatively, the thermally conductive layer 118 can be a thermally conductive coating or thermally conductive silicone grease, and can be formed on the side of the heat-absorbing layer 115 facing away from the plastic part 114 by spraying or coating.

[0105] Furthermore, the orthographic projection of the heat-absorbing layer 115 onto the plastic part 114 can be located within the coverage area of ​​the orthographic projection of the heat-conducting layer 118 onto the plastic part 114. For example, the area of ​​the orthographic projection of the heat-conducting layer 118 onto the plastic part 114 can be greater than or equal to the area of ​​the orthographic projection of the heat-absorbing layer 115 onto the plastic part 114, so that the heat-conducting layer 118 can completely cover the heat-absorbing layer 115.

[0106] In the above solution, by providing a heat-conducting layer 118 on the side of the heat-absorbing layer 115 away from the plastic part 114, the efficiency of the heat-absorbing layer 115 in absorbing the heat transferred by the electrode assembly 113 can be improved by using the heat-conducting layer 118, so as to reduce the heat transferred from the electrode assembly 113 to the plastic part 114.

[0107] In some embodiments, except Figure 7 In addition to the embodiment shown where the heat insulation layer 116 and the heat conduction layer 118 coexist, the heat insulation layer 116 and the heat conduction layer 118 may also exist separately.

[0108] Finally, in some specific application scenarios, in order to solve the problem of large melting loss of the plastic under the existing battery cell in high temperature environment, the battery cell 110 provided in this application embodiment includes: a metal end cap 111, a housing 112, an electrode assembly 113, a plastic part 114, and a heat-absorbing layer 115; the metal end cap 111 is connected to the housing 112 and together with the housing 112 forms an accommodating space 1101; the electrode assembly 113 is disposed in the accommodating space 1101, and the plastic part 114 is disposed on the side of the metal end cap 111 facing the electrode assembly 113; the heat-absorbing layer 115 is disposed on the side of the plastic part 114 facing the electrode assembly 113.

[0109] Furthermore, the volumetric energy density of the electrode assembly 113 is greater than or equal to 370 Wh / L. The plastic part 114 is made of polyethylene terephthalate or polybutylene terephthalate. Multiple heat-absorbing layers 115 are distributed at different positions on the side of the plastic part 114 facing the electrode assembly 113. The thickness of the heat-absorbing layer 115 is at least greater than 1 mm, and the width is at least greater than 10 mm. The heat-absorbing layer 115 includes a phase change material layer 1151 disposed on the side of the plastic part 114 facing the electrode assembly 113. In addition, a heat insulation layer 116 is provided between the plastic part 114 and the heat-absorbing layer 115, and a thermally conductive layer 118 is provided on the side of the heat-absorbing layer 115 facing away from the plastic part 114.

[0110] The battery cell 110 provided in this application embodiment has a heat-absorbing layer 115 provided on the side of the plastic part 114 facing the electrode assembly 113. The heat-absorbing layer 115 can absorb the heat transferred from the electrode assembly 113 to the plastic part 114, thereby delaying the time for the plastic part 114 to reach the melting point temperature, thereby reducing the melting loss of the plastic part 114 in the high temperature environment. This is beneficial to improving the reliability of the battery cell 110.

[0111] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A battery cell, characterized in that, The battery cell includes: a metal end cap, a housing, an electrode assembly, a plastic part, and a heat-absorbing layer; The metal end cap is connected to the housing and together with the housing, they form an accommodating space; the electrode assembly is disposed within the accommodating space, and the plastic part is disposed on the side of the metal end cap facing the electrode assembly; the heat-absorbing layer is disposed on the side of the plastic part facing the electrode assembly.

2. The battery cell according to claim 1, characterized in that, A heat insulation layer is provided between the plastic part and the heat-absorbing layer.

3. The battery cell according to claim 1 or 2, characterized in that, The heat-absorbing layer has a heat-conducting layer on the side opposite to the plastic part.

4. The battery cell according to claim 1, characterized in that, The number of heat-absorbing layers is multiple, and the multiple heat-absorbing layers are distributed at different positions on the side of the plastic part facing the electrode assembly.

5. The battery cell according to claim 4, characterized in that, Multiple heat-absorbing layers are arranged on the edges of the plastic part away from the center.

6. The battery cell according to claim 1, characterized in that, The heat-absorbing layer includes a phase change material layer disposed on the side of the plastic part facing the electrode assembly.

7. The battery cell according to claim 1, characterized in that, The heat-absorbing layer has a thickness of at least 1 mm and a width of at least 10 mm.

8. The battery cell according to claim 1, characterized in that, The volumetric energy density of the electrode assembly is greater than or equal to 370Wh / L.

9. The battery cell according to claim 1, characterized in that, The plastic part is made of polyethylene terephthalate or polybutylene terephthalate.

10. A battery device, characterized in that, The battery device comprises: at least one battery cell as described in any one of claims 1-9.

11. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 10.

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