Battery cell, manufacturing method and apparatus for bottom tray, system, and charging network

Abstract

Provided in the present application are a battery cell, a manufacturing method and apparatus for a bottom tray, a system, and a charging network. The battery cell comprises an electrode assembly, a casing and a bottom tray, wherein the bottom tray is located between the electrode assembly and the inner wall of the casing and used for supporting the electrode assembly; the bottom tray comprises a first insulating layer, a support layer, and a second insulating layer arranged in the thickness direction of the bottom tray, the first insulating layer being located on the side surface of the support layer facing the electrode assembly, and the second insulating layer being located on the side surface of the support layer facing away from the electrode assembly. The embodiments of the present application can improve the reliability of pressure relief of the battery cell.

Description

Battery cell, base plate manufacturing method, apparatus, system and charging network

[0001] Cross-referencing

[0002] This application incorporates Chinese Patent Application No. 202510494332.8, filed on April 18, 2025, entitled “Battery Cell, Base Plate Preparation Method, Apparatus, System and Charging Network”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a method, apparatus, system and charging network for preparing a battery cell and a base plate. Background Technology

[0004] Energy conservation and emission reduction are key to sustainable social development. Rechargeable batteries, with their ability to store and release energy as needed, are widely used in various electrical devices and energy storage systems, and are an important component in promoting energy transition and sustainable development. For the new energy industry, battery technology is a crucial factor in its development.

[0005] The bottom of the battery casing is usually equipped with a base plate to support the electrode assembly. However, when the battery experiences a safety malfunction (such as overcharging or thermal runaway), the base plate may melt due to high temperature, thus failing to support the electrode assembly. This causes the electrode assembly to collapse and block the venting channel at the bottom, thereby affecting the pressure relief of the battery cells. Summary of the Invention

[0006] This application aims to at least address one of the technical problems existing in the background art. Therefore, one objective of this application is to provide a method, apparatus, system, and charging network for manufacturing a battery cell and a base plate, thereby improving the reliability of battery cell pressure relief.

[0007] An embodiment of the first aspect of this application provides a battery cell including an electrode assembly, a housing, and a base plate; the housing has a receiving cavity for accommodating the electrode assembly; the base plate is located between the electrode assembly and the inner wall of the housing and is used to support the electrode assembly; wherein the base plate includes a first insulating layer, a support layer, and a second insulating layer disposed along the thickness direction of the base plate, the first insulating layer being located on the side surface of the support layer facing the electrode assembly, and the second insulating layer being located on the side surface of the support layer facing away from the electrode assembly.

[0008] In the technical solution of this application embodiment, by setting the bottom support plate as a multi-layer composite structure, the support capacity of the bottom support plate can be effectively improved, thereby supporting the electrode assembly more reliably. This is conducive to maintaining the unobstructed venting channel between the bottom support plate and the housing, and improving the reliability of battery cell pressure relief.

[0009] In some embodiments, the first insulating layer and the second insulating layer are connected along the outer periphery of the support layer to completely enclose the support layer between the first insulating layer and the second insulating layer. By completely enclosing the support layer in the insulating layer, the support layer can be separated from the electrode assembly and the housing, especially the edge of the support layer can be separated from the inner wall of the housing. This can prevent scratching and the generation of metal particles that could cause micro-short circuits in the battery cells, thus improving the insulation effect.

[0010] In some embodiments, the support layer has at least one first groove extending through the support layer along the thickness direction of the base plate, and the first insulating layer and the second insulating layer are connected at the location of the first groove. By creating the first groove in the support layer and connecting the first insulating layer and the second insulating layer through the first groove, the number of connection points between the first insulating layer and the second insulating layer can be increased, thereby improving the overall stability of the base plate structure. In addition, the presence of the first groove will create a structure with multiple pits on the surface of the base plate facing the electrode assembly, which can provide more venting channels and electrolyte wetting channels for the electrode assembly.

[0011] In some embodiments, the receiving cavity has an opening, and the housing includes a bottom wall facing the opening; the battery cell also includes an explosion-proof valve disposed on the bottom wall, and a bottom support plate is located between the bottom wall and the electrode assembly; wherein, the support layer of the bottom support plate has a second groove disposed opposite to the explosion-proof valve, and the second groove penetrates the support layer along the thickness direction of the support layer. By providing a second groove on the support layer opposite to the explosion-proof valve, the structural strength of the bottom support plate at the position opposite the explosion-proof valve can be weakened. When the internal pressure of the battery cell increases, gas can break through the second groove and be directly sprayed towards the explosion-proof valve. This is more conducive to the gas generated at the electrode assembly passing through the bottom support plate to reach the explosion-proof valve, thereby improving the pressure relief efficiency.

[0012] In some embodiments, the orthographic projection of the explosion-proof valve falls entirely within the orthographic projection range of the second groove in a plane perpendicular to the thickness direction of the base plate. Setting the explosion-proof valve to fall entirely within the orthographic projection range of the second groove can shorten the gas exhaust path and improve exhaust efficiency.

[0013] In some embodiments, a third groove is provided on the first insulating layer, extending through the first insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the third groove falls completely within the orthographic projection range of the second groove.

[0014] In some embodiments, a fourth groove is provided on the second insulating layer, extending through the second insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the fourth groove falls completely within the orthographic projection range of the second groove.

[0015] By setting through slots corresponding to the second slots of the support layer on the first or second insulating layer, the local strength of the base plate in the area where the second slot is located can be further reduced, thereby reducing the resistance that the airflow needs to overcome to break through the base plate, which is conducive to directional guidance of gas ejection and improves the reliability and accuracy of pressure relief.

[0016] In some embodiments, a third groove is provided on the first insulating layer, penetrating the first insulating layer along the thickness direction of the base plate, and a fourth groove is provided on the second insulating layer, penetrating the second insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projections of both the third and fourth grooves fall completely within the orthographic projection range of the second groove, and the orthographic projections of the third and fourth grooves are staggered. By providing staggered third and fourth grooves on the first and second insulating layers respectively, the strength of the base plate at the location of the second groove can be weakened, reducing the resistance of gas breaking through the second groove, while also maintaining the structural integrity of the base plate and reducing the risk of leakage.

[0017] In some embodiments, the side surface of the base plate facing away from the electrode assembly has a first protrusion. The first protrusion abuts against the bottom wall, thereby forming an airflow channel between the base plate and the bottom wall that communicates with the location of the explosion-proof valve. By providing the first protrusion, the base plate can directly contact the bottom wall, allowing the bottom wall to more reliably support the base plate. Furthermore, the first protrusion can better guide the airflow to the location of the explosion-proof valve, thus facilitating exhaust.

[0018] In some embodiments, a first protrusion is formed by raising a portion of the support layer on the side facing away from the electrode assembly, and a second insulating layer covers the surface of the protrusion. Raising the support layer on the side facing the bottom wall to form the first protrusion strengthens the support layer's support capacity, and the first protrusion also allows the base plate to more reliably support the electrode assembly, improving the base plate's support capacity. Furthermore, the first protrusion, through the second insulating layer, abuts against the bottom wall, providing insulation and cushioning.

[0019] In some embodiments, the surface of the bottom wall facing the base plate is provided with a second protrusion, which abuts against the base plate, thereby forming an airflow channel between the base plate and the bottom wall that communicates with the location of the explosion-proof valve. By providing the second protrusion, a reliable exhaust channel can be formed while supporting the base plate, improving the reliability of exhaust.

[0020] In some embodiments, the orthographic projection of the support layer at least partially overlaps with the orthographic projection of the second protrusion in a plane perpendicular to the thickness direction of the base plate. This at least partial overlap of the orthographic projection of the support layer with the orthographic projection of the second protrusion allows the support layer to be supported by the second protrusion, reducing the risk of electrode assembly collapse and airflow channel blockage, and improving the reliability of battery cell venting and depressurization.

[0021] In some embodiments, the base plate has at least one through hole extending through the base plate along its thickness direction. The through hole is configured to allow fluid communication between the spaces on both sides of the base plate. By providing the through hole, the base plate can be positioned during installation, and gas communication can be achieved, thereby providing more airflow discharge paths and improving the reliability of battery cell depressurization.

[0022] In some embodiments, the battery cell further includes an insulating film disposed on the surface of the electrode assembly portion; wherein the portion of the insulating film facing the bottom wall serves as a first insulating layer or a second insulating layer of the base plate. Using the insulating film as the first or second insulating layer of the base plate can save one layer of insulating film and simplify the subsequent assembly steps of the battery cell.

[0023] In some embodiments, the thickness T1 of the support layer satisfies: 0.1mm ≤ T1 ≤ 5mm, and in some embodiments, 0.1mm ≤ T1 ≤ 2mm. Appropriately selecting the thickness of the support layer can balance the support performance of the base plate with the space arrangement requirements within the battery cell, thereby improving the overall performance of the battery.

[0024] In some embodiments, the thickness T2 of the first insulating layer satisfies: 0.1mm ≤ T2 ≤ 2mm. In some embodiments, the thickness T3 of the second insulating layer satisfies: 0.1mm ≤ T3 ≤ 2mm. Appropriately selecting the thicknesses of the first and second insulating layers can balance the insulation performance of the base plate with the space arrangement requirements within the battery cells, thereby improving the overall performance of the battery.

[0025] In some embodiments, the melting point of the support layer is higher than that of the first insulating layer and the second insulating layer. Increasing the melting point of the support layer above the melting points of the first and second insulating layers improves the high-temperature support capability of the base plate, thereby enhancing the reliability of battery cell pressure relief.

[0026] In some embodiments, the Young's modulus of the support layer is higher than that of the first insulating layer and the second insulating layer. Setting the Young's modulus of the support layer to be higher than that of the first insulating layer and the second insulating layer can improve the support capacity of the base plate.

[0027] In some embodiments, the support layer is made of metal, such as aluminum, aluminum alloy, or steel. Selecting a suitable metal material for the support layer can balance the support strength and high-temperature resistance of the base plate, thereby improving the reliability of the base plate support.

[0028] In some embodiments, the first insulating layer is made of PP, PI, or PET. In some embodiments, the second insulating layer is made of PP, PI, or PET. When the support layer can provide support, selecting a suitable insulating material can reduce the manufacturing cost of the base plate while meeting insulation requirements.

[0029] In some embodiments, the electrode assembly comprises an active material of lithium phosphate salt. The use of a multi-layered composite base plate in these battery cells reduces the risk of electrode assembly collapse and blockage of venting channels, thereby improving the reliability of venting and depressurization in the battery cell.

[0030] In some embodiments, the capacity of a single battery cell is greater than 400Ah. Using the aforementioned base plate can better meet the support requirements of such large-capacity battery cells, reduce the risk of electrode assembly collapse and blockage of venting channels, and improve the reliability of pressure relief and venting of the battery cell.

[0031] An embodiment of the second aspect of this application provides a method for preparing a base plate. The method includes: providing a first insulating layer, a second insulating layer, and a support layer; stacking the first insulating layer, the support layer, and the second insulating layer along the thickness direction of the support layer; and connecting the first insulating layer and the second insulating layer to obtain the base plate. By inserting a support layer between two insulating layers to prepare the base plate, the support capacity of the base plate can be enhanced, thereby reducing the risk of electrode assembly collapse due to base plate deformation during thermal runaway of the battery cell, and thus improving the reliability of battery cell depressurization.

[0032] In some embodiments, connecting the first insulating layer and the second insulating layer to obtain the base plate includes: continuously heat-melting the first insulating layer and the second insulating layer along the outer periphery of the support layer, so that the support layer completely covers the space between the first insulating layer and the second insulating layer. By heat-melting the first insulating layer and the second insulating layer along the outer periphery of the support layer, the support layer can be completely covered within the insulating layer, which can reduce the risk of metal particles generated by the support layer scraping the inner wall of the casing, causing micro-short circuits in the battery cells, and thus improves the insulation effect.

[0033] In some embodiments, the support layer has at least one first groove penetrating the support layer along its thickness direction; and the connection of the first insulating layer and the second insulating layer to obtain the base plate further includes: thermally fusing the first insulating layer and the second insulating layer at the location of the first groove. By forming the first groove on the support layer and thermally fusing the first insulating layer and the second insulating layer through the first groove, the number of connection points between the first insulating layer and the second insulating layer can be increased, improving the overall structural stability of the base plate. Furthermore, the presence of the first groove allows the surface of the base plate facing the electrode assembly to form a structure with multiple recesses, thus providing more venting channels and electrolyte wetting channels for the electrode assembly.

[0034] In some embodiments, the first insulating layer or the second insulating layer is part of an insulating film disposed on the surface of the electrode assembly. This reduces the number of insulating film layers between the electrode assembly and the housing, and allows the base plate to be used directly for assembly after preparation, thereby improving the assembly efficiency of subsequent battery cells.

[0035] An embodiment of the third aspect of this application provides a battery device comprising the battery cell described in the above embodiments.

[0036] An embodiment of the fourth aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0037] An embodiment of the fifth aspect of this application provides an energy storage device, which includes a plurality of battery cells or battery devices as described in the above embodiments, wherein the battery cells or battery devices are used to store or provide electrical energy.

[0038] An embodiment of the sixth aspect of this application provides an energy storage system, which includes a power conversion device and the energy storage device in the above embodiments. The power conversion device is used to electrically connect the power generation device and the energy storage device.

[0039] An embodiment of the seventh aspect of this application provides a charging network, the charging network including: charging piles: such as the above-mentioned energy storage device or the above-mentioned energy storage system, the energy storage device being used to provide electrical energy to the charging piles.

[0040] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0041] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0042] Figure 1 is an exploded structural diagram of a battery according to some embodiments of this application;

[0043] Figure 2 is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0044] Figure 3 is a schematic diagram of the structure of an energy storage system according to some embodiments of this application;

[0045] Figure 4 is a schematic diagram of the structure of a charging network according to some embodiments of this application;

[0046] Figure 5 is an exploded structural diagram of the base plate of some embodiments of this application;

[0047] Figure 6 is a top view of the base plate of some embodiments of this application;

[0048] Figure 7 is a cross-sectional view of Figure 6 along the AA direction;

[0049] Figure 8 is a bottom view of Figure 2 along direction B;

[0050] Figure 9 is a flowchart of a method for preparing a base plate according to some embodiments of this application.

[0051] Explanation of reference numerals in the attached drawings: Battery device 100, housing 10, first part 11, second part 12; battery cell 20, end cap 21, electrode terminal 21a, shell 22, bottom wall 221, explosion-proof valve 2211, electrode assembly 23, tab 23a; bottom support plate 24, first insulating layer 241, support layer 242, second insulating layer 243, first groove 2421, second groove 2422, third groove 2411, fourth groove 2431, through hole 244, first protrusion 245, second protrusion 2212, insulating film 25; energy storage device 200, power conversion device 300, power generation device 400, charging pile 500, connector 600. Detailed Implementation

[0052] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0053] 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, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of this application, technical terms such as "first" and "second" 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.

[0055] 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.

[0056] 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 have an "or" relationship.

[0057] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0058] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0059] 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0060] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, the market demand is also constantly increasing.

[0061] A base plate can be installed inside the battery casing to support the electrode assembly, allowing it to avoid the corners and bends of the casing and creating an airflow channel for gas release during depressurization. However, in the event of a battery safety malfunction (such as overcharging or thermal runaway), the internal pressure of the battery cell rises. The base plate is typically made of insulating materials like PP or PI, which melt at high temperatures. This can cause the electrode assembly to collapse due to insufficient support, further damaging the assembly and blocking the venting channel within the casing. Consequently, the gas inside the battery cell cannot escape in time, affecting the reliability of the battery cell depressurization.

[0062] To improve the reliability of battery cell pressure relief, this application provides a battery cell including an electrode assembly, a housing, and a base plate. The housing has a receiving cavity for accommodating the electrode assembly. The base plate is located between the electrode assembly and the inner wall of the housing and supports the electrode assembly. The base plate may include a first insulating layer, a support layer, and a second insulating layer disposed along the thickness direction of the base plate. The first insulating layer is located on the side of the support layer facing the electrode assembly, and the second insulating layer is located on the side of the support layer facing away from the electrode assembly. By adding a support layer between the two insulating layers, the support capacity of the base plate can be improved, thereby reducing the risk of electrode assembly collapse, helping to maintain the unobstructed venting channel inside the housing, and improving the reliability of battery cell pressure relief.

[0063] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices or energy storage devices such as vehicles, ships, or aircraft. A power system comprising the electrical device or energy storage device can be constructed using the battery cells and batteries disclosed in this application, which helps to improve the reliability of battery cell pressure relief.

[0064] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0065] This application also provides an energy storage device that uses a battery as a power source. The energy storage device can be, but is not limited to, an energy storage container, an energy storage cabinet, an energy storage power station, an energy storage battery pack, or a portable energy storage system.

[0066] For ease of explanation, the following embodiments use a battery device according to an embodiment of this application as an example.

[0067] Please refer to Figure 1, which is an exploded structural diagram of a battery provided in some embodiments of this application. The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space. Alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0068] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel connections. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0069] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0070] Please refer to Figure 2, which is an exploded structural diagram of a battery cell provided in some embodiments of this application. A battery cell 20 refers to the smallest unit that makes up a battery. As shown in Figure 2, the battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0071] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. In some embodiments, end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 21 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with electrode assembly 23 for outputting or inputting electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0072] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 closes the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The housing 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0073] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode plates without active material each constitute a tab 23a. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs 23a connect to the electrode terminals to form a current loop.

[0074] Please refer to Figure 3, which is a schematic diagram of the structure of an energy storage system provided in some embodiments of this application. Embodiments of this application provide an energy storage device 200, including one or more battery clusters to increase the voltage and capacity of the energy storage device 200. A battery cluster may include multiple battery devices 100, which are connected in series via a busbar to increase the voltage of the energy storage device 200. When the energy storage device 200 includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device 200. The energy storage device 200 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device 200 can store electrical energy as needed and output electrical energy at appropriate times. For example, the energy storage device 200 can store electrical energy during off-peak hours and provide electrical energy to relevant users or electrical equipment during peak hours. The energy storage system provided in this application can be any power system that requires the energy storage device 200. In some embodiments, the energy storage device 200 is an energy storage container or an energy storage cabinet.

[0075] In some embodiments, the energy storage device 200 may include a cabinet and one or more battery clusters housed in the cabinet.

[0076] In some embodiments, the energy storage device 200 may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0077] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device 100 via piping to regulate the temperature of the individual battery cells 20.

[0078] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0079] As an example, the central control module can serve as the battery management unit of the energy storage device 200, used to monitor and manage the energy storage device 200. The central control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device 200. For example, it can control the charging and discharging current and voltage of the energy storage device 200. As an example, the central control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0080] As an example, a fire protection system includes control panels, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in energy storage systems.

[0081] As an example, the power distribution unit can be used to distribute power to the power modules of the energy storage device 200.

[0082] In some embodiments, the energy storage system may include one or more energy storage devices 200 and a power converter system (PCS), wherein the power converter system 300 is connected between the power generation device 400 and the energy storage device 200. The power generation device 400 generates electrical energy, which can be stored in the energy storage device 200 through the power converter system 300, and the electrical energy stored in the energy storage device 200 can be released back to the power generation device 400 through the power converter system 300. As an example, the power generation device 400 may specifically be a power grid, a solar panel, a hydroelectric power generation device 400, a thermal power generation device 400, a wind power generation device 400, etc. The specific type of the power generation device 400 is not limited in this application.

[0083] Please refer to Figure 4, which is a schematic diagram of the structure of a charging network provided in some embodiments of this application. This application provides a charging network including a charging pile 500 and an energy storage device 200. The charging pile 500 is electrically connected to the energy storage device 200, which provides electrical energy to the charging pile 500. The charging pile 500 is electrically connected to a battery device 100 in the energy storage device 200 via a cable, and the battery device 100 can provide its stored electrical energy to the charging pile 500. The charging pile 500 has one or more connectors 600 for connecting to electrical equipment (such as a vehicle), thereby providing energy to the electrical equipment.

[0084] The energy storage device 200 can be located inside the charging pile 500 (e.g., an integrated energy storage and charging unit) or outside the charging pile 500.

[0085] Please refer to Figures 2 and 5-7. Figure 5 is an exploded structural diagram of the base plate provided in some embodiments of this application. Figure 6 is a top view of the base plate in some embodiments of this application. Figure 7 is a cross-sectional view of Figure 6 along the AA direction.

[0086] This application provides a battery cell 20, which includes a housing 22, an electrode assembly 23, and a bottom support plate 24; the housing 22 has a receiving cavity for accommodating the electrode assembly; the bottom support plate 24 is located between the electrode assembly 23 and the inner wall of the housing 22 and is used to support the electrode assembly 23.

[0087] The base plate 24 includes a first insulating layer 241, a support layer 242 and a second insulating layer 243 disposed along the thickness direction of the base plate 24. The first insulating layer 241 is located on the side surface of the support layer 242 facing the electrode assembly 23, and the second insulating layer 243 is located on the side surface of the support layer 242 away from the electrode assembly 23.

[0088] The base plate 24 has a multi-layer composite structure. Specifically, the first insulating layer 241, the support layer 242, and the second insulating layer 243 are all planar thin plate structures. They are stacked along the thickness direction of the base plate 24, i.e., the X direction shown in Figure 5. The first insulating layer 241 is located on the upper surface of the support layer 242 and contacts the bottom of the electrode assembly 23. The second insulating layer 243 is located on the lower surface of the support layer 242 and can directly or indirectly contact the inner wall of the housing.

[0089] In this way, the support layer 242 is sandwiched between the first insulating layer 241 and the second insulating layer 243, which can provide stronger support and thus improve the support capacity of the base plate 24. Furthermore, the first insulating layer 241 and the second insulating layer 243 can separate the support layer 242 from the electrode assembly 23 and the housing 22. Thus, the support layer 242 located in the middle can be made of a suitable material to enhance its support capacity as needed, such as a metal material.

[0090] The first insulating layer 241 and the second insulating layer 243 can be made of the same insulating material or different insulating materials.

[0091] In some embodiments, the first insulating layer 241, the support layer 242, and the second insulating layer 243 can be fixed to each other by any feasible connection method, such as by bonding or fusion bonding, thereby forming an integral component and installing it between the housing and the electrode assembly.

[0092] In some embodiments, other functional layers, such as adhesive layers, may be provided between the first insulating layer 241 and the support layer 242, and between the second insulating layer 243 and the support layer 242 as needed.

[0093] In this embodiment, by setting the base plate 24 as a multi-layer composite structure, the support capacity of the base plate 24 can be effectively improved, thereby supporting the electrode assembly 23 more reliably. This helps to maintain the unobstructed venting channel between the base plate 24 and the housing 22, and improves the reliability of the battery cell 20 pressure relief.

[0094] According to some embodiments of this application, the first insulating layer 241 and the second insulating layer 243 are connected along the outer periphery of the support layer 242 so as to completely cover the support layer 242 between the first insulating layer 241 and the second insulating layer 243.

[0095] The first insulating layer 241 and the second insulating layer 243 can be configured to have an outer periphery larger than that of the support layer 242, so that a portion of the first insulating layer 241 extends beyond the support layer 242, and the portion of the first insulating layer 241 extending beyond the support layer 242 can directly contact the portion of the second insulating layer 243 extending beyond the support layer 242 for connection.

[0096] The connection along the outer periphery of the support layer 242 refers to a continuous connection around the outer edge of the support layer 242, so that the support layer can completely cover the space between the first insulating layer 241 and the second insulating layer 243. The specific connection method can be set as needed. For example, it can be achieved by heat fusion or adhesive bonding. Alternatively, the first insulating layer 241 and the second insulating layer 243 can be set as insulating layers located on both sides of the support layer 242, formed by folding an insulating film layer along a set crease. In this way, the first insulating layer 241 and the second insulating layer 243 can be connected through the folding position.

[0097] By completely enclosing the support layer 242 within the insulating layer, the support layer 242 can be separated from the electrode assembly 23 and the housing 22. In particular, the edge of the support layer 242 is separated from the inner wall of the housing 22. This can prevent scratching and the generation of metal particles that could cause micro-short circuits in the battery cells 20, thus improving the insulation effect.

[0098] According to some embodiments of this application, as shown in FIG7, the support layer 242 is provided with at least one first groove 2421 extending through the support layer 242 along the thickness direction of the bottom plate 24, and the first insulating layer 241 and the second insulating layer 243 are connected at the position of the first groove 2421.

[0099] The first groove 2421 is a through groove that penetrates the support layer 242. The shape of the first groove 2421 can be arbitrarily set as needed, for example, it can be circular, elliptical, or polygonal. The number of first grooves 2421 can be one or more, and this application does not limit this. As shown in Figures 5 and 6, the support layer 242 includes a plurality of elongated first grooves 2421 extending in different directions and spaced apart along the length direction of the support layer 242.

[0100] The first insulating layer 241 and the second insulating layer 243 are both thin film layers. They can contact each other and connect to each other at the location of the first groove 2421. The specific connection method can be any feasible connection method, such as heat fusion connection or bonding.

[0101] By creating a first groove 2421 on the support layer 242 and connecting the first insulating layer 241 and the second insulating layer 243 through the first groove 2421, the number of connection points between the first insulating layer 241 and the second insulating layer 243 can be increased, thereby improving the overall structural stability of the base plate 24. Furthermore, the presence of the first groove 2421 creates a structure with multiple recesses on the surface of the base plate 24 facing the electrode assembly, providing more venting channels and electrolyte wetting channels for the electrode assembly 23.

[0102] Please refer to Figure 8, which is a bottom view of Figure 2 along direction B.

[0103] According to some embodiments of this application, the housing 22 has an opening in its receiving cavity, and the housing 22 includes a bottom wall 221 facing the opening; the battery cell 20 also includes an explosion-proof valve 2211 disposed on the bottom wall 221, and the bottom support plate 24 is located between the bottom wall 221 and the electrode assembly 23; wherein, the support layer 242 of the bottom support plate 24 is provided with a second groove 2422 disposed facing the explosion-proof valve 221, and the second groove 2422 penetrates the support layer 242 along the thickness direction of the support layer 242.

[0104] The housing 22 can be formed into an open receiving cavity by stamping, and the end cap 21 can be connected to the housing 22 by covering the opening, thereby forming a closed receiving cavity for accommodating the electrode assembly.

[0105] The housing 22 includes a bottom wall 221 facing the opening and a side wall adjacent to the opening. The bottom wall 221 and the side wall are bent together, and the bottom support plate 24 is engaged at the bend to prevent the electrode assembly 23 from being squeezed by the bend. A small cavity that allows airflow can be formed between the bottom support plate 24 and the bottom wall 221. The explosion-proof valve 2211 is disposed on the bottom wall 221. When the internal pressure of the battery cell is too high, the gas can flow through the space between the bottom support plate 24 and the bottom wall 221 to the location of the explosion-proof valve 2211, causing the explosion-proof valve 2211 located on the bottom wall 221 to break open and allow the gas to be ejected, thereby achieving pressure relief.

[0106] The explosion-proof valve 2211 can be an independent explosion-proof valve welded into the mounting hole of the bottom wall 221, or it can be an integrated explosion-proof valve directly installed on the bottom wall 221 and integrated with the bottom wall 221. For example, a groove can be provided on the surface of the bottom wall 221 to serve as an explosion-proof valve that can release pressure.

[0107] The second groove 2422 can be a through groove of any shape. In some embodiments, the shape of the second groove 2422 can correspond to that of the explosion-proof valve 2211, for example, the two have the same shape and size. The second groove 2422 being directly opposite the explosion-proof valve 2211 means that, along the direction perpendicular to the surface of the bottom wall 221, the orthographic projection of the second groove 2422 on the upper surface of the bottom wall 221 at least partially overlaps with the orthographic projection of the explosion-proof valve 2211 on the upper surface of the bottom wall 221.

[0108] In some embodiments, as shown in FIG6, the first insulating layer 241 and the second insulating layer 243 may also be connected at the position of the second groove 2422. The specific connection method may be the same as or different from the connection method at the first groove 2421, for example, it may be heat-fused or bonded.

[0109] In some embodiments, the second groove 2422 only penetrates the support layer 242, while the first insulating layer 241 and the second insulating layer 243 can be complete and continuous at the position of the second groove 2422. In other embodiments, at least one of the first insulating layer 241 and the second insulating layer 243 may also have some weak structures at the position corresponding to the second groove 2422, which is more conducive to the gas breaking through the bottom support plate 24 and reaching the explosion-proof valve 2211. The weak structure can be a partially recessed groove or a notch, or it can be a completely penetrating groove.

[0110] By setting a second groove 2422 on the support layer 242 that is directly opposite to the explosion-proof valve 2211, the structural strength of the bottom plate at the position directly opposite the explosion-proof valve 2211 can be weakened. When the internal pressure of the battery cell increases, the gas can break through the second groove 2422 and spray directly onto the explosion-proof valve 2211. This makes it easier for the gas generated at the electrode assembly 23 to pass through the bottom plate 24 and reach the explosion-proof valve 2211, thus improving the pressure relief efficiency.

[0111] According to some embodiments of this application, as shown in FIG8, in a plane perpendicular to the thickness direction of the base plate 24, the orthogonal projection of the explosion-proof valve 2211 falls completely within the orthogonal projection range of the second groove 2422.

[0112] In some examples, the plane perpendicular to the thickness direction of the base plate 24 is any plane perpendicular to the X direction. The projected area of ​​the second groove 2422 in the plane perpendicular to the thickness direction of the base plate 24 is greater than the projected area of ​​the explosion-proof valve 2211 in the plane, and the projected pattern of the explosion-proof valve 2211 is completely within the range of the projected pattern of the second groove 2422.

[0113] As shown in Figure 8, the explosion-proof valve 2211 is an "H" shaped pattern formed by the grooves on the bottom wall 221, and the second groove 2422 is a rectangular groove. When viewed from the outside of the bottom wall 221 of the housing 22, the explosion-proof valve 2211 is completely located within the projection range of the second groove 2422.

[0114] Setting the explosion-proof valve 2211 to fall completely within the orthogonal projection range of the second slot 2422 can shorten the gas exhaust path and improve exhaust efficiency.

[0115] According to some embodiments of this application, a third groove is provided on the first insulating layer 241, which extends through the first insulating layer 241 along the thickness direction of the base plate 24. In a plane perpendicular to the thickness direction of the base plate 24, the orthographic projection of the third groove 2411 falls completely within the orthographic projection range of the second groove 2422.

[0116] In some embodiments, the second insulating layer 243 is provided with a fourth groove 2431 that penetrates the second insulating layer 243 along the thickness direction of the base plate 24. In a plane perpendicular to the thickness direction of the base plate 24, the orthographic projection of the fourth groove 2431 falls completely within the orthographic projection range of the second groove 2422.

[0117] The third slot 2411 and the fourth slot 2431 are both through slots that penetrate their respective insulating layers. The shape and number of the third slot 2411 and the fourth slot 2431 can be set according to actual needs, and this application does not impose any restrictions.

[0118] By providing through slots corresponding to the second groove 2422 of the support layer 242 on the first insulating layer 241 or the second insulating layer 243 respectively, the local strength of the bottom plate in the area where the second groove 2422 is located can be further reduced, thereby reducing the resistance that the airflow needs to overcome to break through the bottom plate 24, which is conducive to directional guidance of gas ejection and improving the reliability and accuracy of pressure relief.

[0119] According to some embodiments of this application, a third groove 2411 is provided on the first insulating layer 241, which penetrates the first insulating layer 241 along the thickness direction of the base plate 24, and a fourth groove 2431 is provided on the second insulating layer 243, which penetrates the second insulating layer 243 along the thickness direction of the base plate 24; wherein, in a plane perpendicular to the thickness direction of the base plate 24, the orthographic projections of the third groove 2411 and the fourth groove 2431 both fall completely within the orthographic projection range of the second groove 2422, and the orthographic projections of the third groove 2411 and the fourth groove 2431 are staggered and spaced apart from each other.

[0120] The third groove 2411 and the fourth groove 2431 are both located within the area where the first insulating layer 241 and the second insulating layer 243 are connected to each other in the second groove 2422. The third groove 2411 and the fourth groove 2431 are staggered and spaced apart from each other. This means that the third groove 2411 and the fourth groove 2431 are not connected along the thickness direction of the bottom support plate 24, i.e., the X direction. In this way, the bottom support plate 24 can still maintain structural integrity at the position of the second groove 2422, and the presence of the third groove 2411 and the fourth groove 2431 will not cause the two sides of the bottom support plate 24 to be directly connected.

[0121] By setting mutually staggered third grooves 2411 and fourth grooves 2431 on the first insulating layer 241 and the second insulating layer 243 respectively, the strength of the bottom support plate 24 at the location of the second groove 2422 can be weakened, the resistance of gas breaking through the second groove 2422 can be reduced, and the structural integrity of the bottom support plate 24 can be maintained, reducing the risk of leakage.

[0122] According to some embodiments of this application, the side surface of the bottom support plate 24 facing away from the electrode assembly 23 is provided with a first protrusion 245. The first protrusion 245 is used to abut against the bottom wall 221 so that an airflow channel communicating with the location of the explosion-proof valve 2211 is formed between the bottom support plate 24 and the bottom wall 221.

[0123] The first protrusion 245 is disposed on the lower surface of the base plate 24, that is, the surface facing away from the electrode assembly 23 and facing the bottom wall 221. The first protrusion 245 protrudes towards the bottom wall 221 relative to other positions on the lower surface of the base plate 24, and during assembly, the lower surface of the first protrusion 245 can directly abut against the bottom wall 221, so that the entire base plate 24 can be directly supported on the bottom wall 221.

[0124] Due to the presence of the first protrusion 245, an airflow channel for gas circulation can be formed between the base plate 24 and the bottom wall 221. In some examples, this airflow channel can be connected to the location of the explosion-proof valve 2211, thereby guiding the gas to be discharged to the location of the explosion-proof valve 2211.

[0125] For the base plate 24 of the multi-layer composite structure, the first protrusion 245 may be formed by one or more layers protruding towards the side where the bottom wall 221 is located.

[0126] The number of first protrusions 245 can be one or more, and this embodiment does not limit this. As shown in FIG6, the bottom support plate 24 is provided with first protrusions 245 on both sides of the second groove 2422 along its length direction, and multiple first protrusions 245 spaced apart along the width direction of the bottom support plate 24 can be provided on each side, and an airflow channel connecting to the location of the second groove 2422 can be formed between adjacent first protrusions 245.

[0127] By setting the first protrusion 245, the bottom support plate 24 can directly contact the bottom wall 221, so that the bottom wall 221 can more reliably support the bottom support plate 24, and the first protrusion 245 can better guide the airflow to the location of the explosion-proof valve 2211, which is conducive to exhaust.

[0128] According to some embodiments of this application, a first protrusion 245 is formed on a portion of the surface of the support layer 242 facing away from the electrode assembly 23, and a second insulating layer 243 covers the surface of the first protrusion 245.

[0129] The first protrusion 245 can be a rib formed by a local position of the support layer 242 protruding towards the side where the bottom wall 221 is located. Specifically, the first protrusion 245 can be a part of the support layer 242. For example, the support layer 242 can be processed into several parts with different thicknesses, among which the thicker part that protrudes towards the bottom wall 221 is the first protrusion 245.

[0130] The second insulating layer 243 covers the surface of the first protrusion 245, for example, it can be pasted on the surface of the first protrusion 245, so that the first protrusion 245 can abut against the bottom wall 221 through the second insulating layer 243.

[0131] The support layer 242 is raised on one side of the surface facing the bottom wall to form a first protrusion 245. On the one hand, the support layer 242 has a stronger supporting capacity, and the first protrusion 245 can also make the bottom plate 24 support the electrode assembly 23 more reliably, thus improving the supporting capacity of the bottom plate 24. On the other hand, the first protrusion 245 abuts against the bottom wall 221 through the second insulating layer 243, which can play an insulating and buffering role.

[0132] According to some embodiments of this application, the surface of the bottom wall 221 facing the bottom support plate 24 is provided with a second protrusion 2212, which abuts against the bottom support plate 24, so that an airflow channel communicating with the location of the explosion-proof valve 2211 is formed between the bottom support plate 24 and the bottom wall 221.

[0133] The second protrusion 2212 can be a protrusion structure provided on the surface of the bottom wall 221. The second protrusion 2212 can be integrally formed by stamping the bottom wall 221, or it can be connected to the surface of the bottom wall 221 by other possible connection methods, such as welding or bonding.

[0134] The second protrusion 2212 can directly abut against the lower surface of the base plate 24, thereby supporting the base plate 24 and forming an airflow channel between the base plate 24 and the bottom wall 221. As shown by the arrow in Figure 8, this indicates the direction of gas flow in the airflow channel during exhaust. This guides the gas flow to the location of the explosion-proof valve 2211 for easy discharge. It is understood that since the second protrusion 2212 is located on the bottom wall 221, even if the base plate 24 is deformed or melted by heat, the second protrusion 2212 can, to a certain extent, prevent complete blockage of the airflow channel, thus achieving reliable exhaust and pressure relief.

[0135] The shape and number of the second protrusion 2212 can be set as needed, and this application does not impose any restrictions on this.

[0136] In some embodiments, the battery cell 20 may have a second protrusion 2212 on the bottom wall 221 or a first protrusion 245 on the lower surface of the bottom support plate 24. The first protrusion 245 and the second protrusion 2212 together or separately define an airflow channel communicating with the location of the explosion-proof valve 2211.

[0137] By setting the second protrusion 2212, a reliable exhaust channel can be formed while supporting the bottom support plate 24, thereby improving the reliability of exhaust.

[0138] According to some embodiments of this application, in a plane perpendicular to the thickness direction of the base plate 24, the orthographic projection of the support layer 242 at least partially overlaps with the orthographic projection of the second protrusion 2212.

[0139] Along the X direction, the orthographic projection of the support layer 242 at least partially overlaps with the orthographic projection of the second protrusion 2212, which means that the support layer 242 with strong support capacity in the base plate 24 can be directly located above the second protrusion 2212 and can be supported by the second protrusion 2212.

[0140] The orthographic projection of the support layer 242 along the X direction overlaps at least partially with the orthographic projection of the second protrusion 2212 along the X direction. In this way, the support layer 242 can be supported by the second protrusion 2212, which can reduce the risk of the electrode assembly 23 collapsing and the airflow channel being blocked, and improve the reliability of battery cell venting and depressurization.

[0141] According to some embodiments of this application, as shown in Figures 6 and 7, the base plate 24 is provided with at least one through hole 244 extending through the base plate 24 along the thickness direction of the base plate 24, and the through hole 244 is configured to allow fluid communication between the spaces on both sides of the base plate 24.

[0142] The through-hole 244 penetrates the first insulating layer 241, the support layer 242, and the second insulating layer 243 along the thickness direction of the base plate 24. The number of through-holes 244 can be one or more, depending on actual needs.

[0143] The shape of the through hole 244 can be any shape, such as a circle, an ellipse or a polygon.

[0144] In some embodiments, the position of the through hole 244 can be adapted to the position of the airflow channel between the base plate 24 and the bottom wall 221. For example, the through hole 244 can be fluidly connected to an airflow channel defined by the first protrusion 245 or the second protrusion 2212 between the base plate 24 and the bottom wall 221. In this way, the gas generated by the electrode assembly 23 can reach the location of the explosion-proof valve 2211 and be discharged through the through hole 244 and the airflow channel.

[0145] By setting through holes 244, the bottom support plate 24 can be positioned during installation, and gas can be connected, thereby providing more airflow discharge paths and improving the reliability of battery cell pressure relief.

[0146] According to some embodiments of this application, the battery cell 20 further includes an insulating film 25 disposed on a portion of the surface of the electrode assembly 23; wherein the portion of the insulating film 25 facing the bottom wall 221 serves as a first insulating layer 241 or a second insulating layer 243 of the bottom support plate 24.

[0147] The insulating film 25 may be a mylar film, which covers the outer surface of the electrode assembly, including the side surface of the electrode assembly and the end face away from the tab. The electrode assembly 23 encapsulated within the insulating film 25 may be one or more.

[0148] The portion of the insulating film 25 covering the end face of the electrode assembly is directly opposite the bottom wall 221, while the bottom support plate 24 is in direct contact with the insulating film 25. In this embodiment, the insulating film 25 can be directly used as either the first insulating layer 241 or the second insulating layer 243.

[0149] Using the insulating film 25 as the first insulating layer 241 or the second insulating layer 243 of the base plate 24 can save one layer of insulating film. On the other hand, the base plate 24 can be pre-processed with the insulating film 25 into an integral component before the material arrives, and then the material is assembled with the electrode assembly 23 and the housing 22, simplifying the subsequent assembly steps.

[0150] According to some embodiments of this application, as shown in FIG7, the thickness T1 of the support layer 242 satisfies: 0.1 mm ≤ T1 ≤ 5 mm, and in some embodiments, 0.1 mm ≤ T1 ≤ 2 mm.

[0151] The support layer 242 is flat, and its thickness T1 can be determined according to the support requirements and material type. In some embodiments, the thickness T1 of the support layer 242 can be any value between 0.1mm and 5mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, and 5mm.

[0152] In some embodiments, the thickness T1 of the support layer 242 can be any value between 0.1 mm and 2 mm.

[0153] By appropriately selecting the thickness of the support layer 242, the support performance of the bottom support plate 24 and the space arrangement requirements within the battery cell 20 can be balanced, thereby improving the overall performance of the battery.

[0154] According to some embodiments of this application, as shown in FIG7, the thickness T2 of the first insulating layer satisfies: 0.1mm ≤ T2 ≤ 2mm. In some embodiments, the thickness T3 of the second insulating layer satisfies: 0.1mm ≤ T3 ≤ 2mm.

[0155] The thickness T2 of the first insulating layer can be any value between 0.1mm and 2mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, and 2mm.

[0156] The thickness T3 of the second insulating layer can be any value between 0.1mm and 2mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, and 2mm.

[0157] The thickness T2 of the first insulating layer and the thickness T3 of the second insulating layer can be the same or different; this embodiment does not impose any restrictions on this.

[0158] In some embodiments, in the base plate 24, the thickness T2 of the first insulating layer and the thickness T3 of the second insulating layer are both less than the thickness of the support layer 242.

[0159] By rationally selecting the thickness T2 of the first insulating layer and the thickness T3 of the second insulating layer, the insulation performance of the base plate and the space arrangement requirements within the battery cell can be balanced, thereby improving the overall performance of the battery.

[0160] According to some embodiments of this application, the melting point of the support layer 242 is higher than the melting point of the first insulating layer 241 and the melting point of the second insulating layer 243.

[0161] Melting point is the temperature at which a substance changes from a solid to a liquid state. In some embodiments, the base plate is made of an insulating material (such as polypropylene). In the event of a battery safety failure, the internal temperature of the battery is high, which may exceed the melting point of some materials, such as polypropylene, causing the base plate to melt.

[0162] In the embodiments of this application, since the supporting layer 242 has a stronger supporting capacity than the first insulating layer 241 and the second insulating layer 243, and the melting point of the supporting layer is set to be higher than the melting point of the first insulating layer 241 and the second insulating layer 243, the bottom plate 24 can still maintain a certain degree of structural integrity in a high-temperature environment, thereby maintaining the supporting function of the bottom plate 24.

[0163] By making the melting point of the support layer 242 higher than that of the first insulating layer 241 and the second insulating layer 243, the high-temperature support capacity of the base plate 24 can be improved, thereby enhancing the reliability of the battery cell pressure relief.

[0164] According to some embodiments of this application, the Young's modulus of the support layer 242 is higher than that of the first insulating layer 241 and the second insulating layer 243.

[0165] Young's modulus is a physical quantity that describes the ability of a solid material to resist elastic deformation; it is also called the tensile modulus. Young's modulus reflects the rigidity or elasticity of a material. A larger Young's modulus means the material is less prone to elastic deformation, i.e., the "harder" the material; a smaller Young's modulus means the material is more prone to elastic deformation, i.e., the "softer" the material. For example, steel has a large Young's modulus, indicating that it is not easily deformed under stress and has high strength and rigidity; while materials such as polypropylene and polyimide have smaller Young's moduli and are more prone to large elastic deformation.

[0166] In this embodiment, a material with a high Young's modulus can be used to prepare the support layer 242, thereby improving the deformation resistance and support capacity of the base plate 24. Furthermore, using a material with a high Young's modulus to prepare the support layer 242 can further reduce its thickness, thus reducing the overall thickness of the base plate 24.

[0167] Setting the Young's modulus of the support layer 242 to be higher than that of the first insulating layer 241 and the second insulating layer 243 can improve the support capacity of the base plate 24 and optimize the thickness of the base plate 24, which is more conducive to improving the volumetric energy density of the battery cells.

[0168] According to some embodiments of this application, the support layer 242 is made of metal, which in some embodiments may be aluminum, aluminum alloy or steel.

[0169] The support layer 242 can be made of a metal material that meets the support requirements, such as aluminum, aluminum alloy, or steel. Since the support layer 242 is covered by an insulating layer, it will not directly contact the electrode assembly 23 and the housing 22, so a metal material can be used without worrying about the risk of short circuit.

[0170] Using a suitable metal material to prepare the support layer 242 can balance the support strength and high temperature resistance of the base plate, thereby improving the reliability of the base plate support.

[0171] According to some embodiments of this application, the material of the first insulating layer 241 includes PP (Polypropylene), PI (Polyimide), or PET (Polyethylene Terephthalate).

[0172] In some embodiments, the material of the second insulating layer 243 includes PP, PI, or PET.

[0173] The material of the first insulating layer 241 can be the same as or different from that of the second insulating layer 243.

[0174] If the support layer can provide support, selecting appropriate insulation materials can reduce the manufacturing cost of the base plate while meeting insulation requirements.

[0175] According to some embodiments of this application, electrode assembly 23 includes lithium phosphate as an active material.

[0176] Electrode assembly 23 includes a positive electrode active material and a negative electrode active material. The positive electrode active material may include lithium phosphate salts, such as one or more of lithium iron phosphate, lithium manganese phosphate, lithium manganese iron phosphate, lithium cobalt phosphate, and lithium vanadium phosphate. The negative electrode active material may be an active material compatible with the above-mentioned positive electrode active material, such as graphite. When a battery cell containing lithium phosphate active material experiences thermal runaway, the continuous heating time is long, which will cause the base plate to be in a high-temperature environment for a long time, increasing the risk of electrode assembly collapse. Therefore, it is more necessary for such battery cells to adopt the multi-layer composite structure base plate proposed in the embodiments of this application, which can reduce the risk of electrode assembly collapse and blockage of venting channels, and improve the reliability of battery cell venting and pressure relief.

[0177] According to some embodiments of this application, the capacity of the battery cell 20 is greater than 400Ah.

[0178] The capacity of a battery cell refers to the total amount of charge that a battery cell can release under certain discharge conditions, usually expressed in ampere-hours (Ah) or milliampere-hours (mAh).

[0179] It is understood that the capacity claimed in the embodiments of this application refers to the rated capacity of a single battery cell. For example, for lithium batteries, the rated capacity can be determined with reference to the provisions of Chinese standard GB / T18287-2000, or it can be determined according to the minimum capacity tested under the IEC61960 standard test conditions.

[0180] Large-capacity batteries experience more dramatic temperature rises during thermal runaway. The base plate used in this application embodiment can better meet the support requirements of such large-capacity battery cells, reduce the risk of electrode assembly collapse and blockage of exhaust channels, and improve the reliability of battery cell pressure relief and exhaust.

[0181] Please refer to Figure 9, which is a flowchart of a method for preparing a base plate according to some embodiments of this application.

[0182] This application provides a method for preparing a base plate, the method comprising:

[0183] S1. Provide a first insulating layer, a second insulating layer, and a support layer;

[0184] S2. The first insulating layer, the support layer, and the second insulating layer are stacked along the thickness direction of the support layer.

[0185] S3. Connect the first insulating layer and the second insulating layer to obtain the base plate.

[0186] The first insulating layer, the second insulating layer, and the support layer are all planar thin film or flat plate structures.

[0187] In step S3, the first insulating layer and the second insulating layer can be connected in any feasible way, such as heat fusion connection, bonding, etc., and this embodiment does not limit this.

[0188] By inserting a support layer between two insulating layers to prepare a base plate, the support capacity of the base plate can be enhanced, thereby reducing the risk of electrode assembly collapse due to base plate deformation during thermal runaway of the battery cell, and thus improving the reliability of battery cell depressurization.

[0189] According to some embodiments of this application, step S3 includes: continuously heat-melting the first insulating layer and the second insulating layer along the outer periphery of the support layer so that the support layer completely covers the space between the first insulating layer and the second insulating layer.

[0190] The outer periphery of the support layer refers to the area around the edge of the support layer in the plane it is located on.

[0191] Understandably, the dimensions of the first and second insulating layers need to be larger than the dimensions of the support layer, so that they can extend beyond the edge of the support layer to facilitate interconnection.

[0192] Thermal fusion bonding refers to the process of applying heat to the first and second insulating layers that are in contact with each other, causing them to melt and bond together at a high temperature.

[0193] By thermally fusing the first and second insulating layers to the outer periphery of the support layer, the support layer can be completely encapsulated within the insulating layer. This reduces the risk of metal particles generated when the support layer scrapes against the inner wall of the casing, which could cause micro-short circuits in the battery cells, and improves the insulation effect.

[0194] According to some embodiments of this application, the support layer is provided with at least one first groove penetrating the support layer along the thickness direction of the support layer; and wherein step S3 further includes: thermally fusing the first insulating layer and the second insulating layer at the position of the first groove.

[0195] The number of first slots on the support layer can be one or more, and the position of the first slots can be arranged as needed. For example, multiple first slots can be evenly spaced.

[0196] By creating a first groove in the support layer and thermally fusing the first and second insulating layers together through the first groove, the number of connection points between the first and second insulating layers can be increased, improving the overall stability of the base plate structure. Furthermore, the presence of the first groove creates multiple recesses on the surface of the base plate facing the electrode assembly, providing more venting channels and electrolyte wetting channels for the electrode assembly.

[0197] According to some embodiments of this application, the first insulating layer or the second insulating layer is part of an insulating film disposed on the surface of the electrode assembly.

[0198] In step S1, the insulating film used to cover the surface of the electrode assembly can be used as the first insulating layer or the second insulating layer, and thermal fusion connection can be performed in step S3.

[0199] This embodiment can reduce one insulating film layer between the electrode assembly and the housing, and the base plate can be directly used for assembly after preparation, thereby improving the assembly efficiency of subsequent battery cells.

[0200] This application provides a battery device that includes the battery cell described in the above embodiments.

[0201] The battery device in this embodiment uses the same battery cells as in the above embodiments, and therefore has the same technical effect, which will not be described again here.

[0202] This application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0203] The power device in this embodiment uses the battery device in the above embodiment, and therefore has the same technical effect, which will not be described again here.

[0204] This application provides an energy storage device, which includes multiple battery cells or battery devices as described in the above embodiments. The battery cells or battery devices are used to store or provide electrical energy.

[0205] The energy storage device in this embodiment has the same technical effect as the battery cells or battery devices in the above embodiments, and will not be described again here.

[0206] This application provides an energy storage system, which includes a power conversion device and the energy storage device in the above embodiments. The power conversion device is used to electrically connect the power generation device and the energy storage device.

[0207] The energy storage system in this embodiment has the same technical effect as the energy storage device in the above embodiment, and will not be described again here.

[0208] This application provides a charging network, which includes: charging piles: such as the above-mentioned energy storage devices or above-mentioned energy storage systems, wherein the energy storage devices are used to provide electrical energy to the charging piles.

[0209] The charging network in this embodiment has the same technical effect as the energy storage device or above energy storage system in the above embodiments, and will not be described again here.

[0210] The present application will be further described below with reference to a specific embodiment.

[0211] As shown in Figures 2 and 5-8, the battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, a bottom support plate 24, and an insulating film 25.

[0212] The housing 22 has an opening in the receiving cavity; the housing 22 includes a bottom wall 221 facing the opening and a side wall adjacent to the opening; an explosion-proof valve 2211 is provided on the bottom wall 221, wherein the explosion-proof valve 2211 may be formed by a groove provided on the outer surface of the bottom wall 221.

[0213] The electrode assembly 23 includes an active material of lithium phosphate; specifically, the positive electrode active material of the electrode assembly 23 is lithium phosphate. The electrode assembly 23 is disposed within the receiving cavity of the housing 22.

[0214] The base plate 24 is located between the electrode assembly 23 and the inner wall of the housing 22 and is used to support the electrode assembly 23. The base plate 24 includes a first insulating layer 241, a support layer 242 and a second insulating layer 243 disposed along the thickness direction of the base plate 24. The first insulating layer 241 is located on the side surface of the support layer 242 facing the electrode assembly 23, and the second insulating layer 243 is located on the side surface of the support layer 242 away from the electrode assembly 23.

[0215] The support layer 242 is made of metal, and in some embodiments, it can be aluminum, aluminum alloy, or steel. The first insulating layer 241 and the second insulating layer 243 are made of PP, PI, or PET.

[0216] The support layer 242 is provided with a first groove 2421 and a second groove 2422. The second groove 2422 is positioned opposite to the explosion-proof valve 2211. The first insulating layer 241 and the second insulating layer 243 are heat-fused together along the circumference of the support layer 242 and at the locations of the first groove 2421 and the second groove 2422.

[0217] The first insulating layer 241 is provided with a third groove 2411 that penetrates the first insulating layer 241 along the thickness direction of the base plate 24, and the second insulating layer 243 is provided with a fourth groove 2431 that penetrates the second insulating layer 243 along the thickness direction of the base plate 24; wherein, in a plane perpendicular to the thickness direction of the base plate 24, the orthographic projections of the third groove 2411 and the fourth groove 2431 are completely within the orthographic projection range of the second groove 2422, and the orthographic projections of the third groove 2411 and the fourth groove 2431 are staggered and spaced apart from each other.

[0218] The inner surface of the bottom wall 221 facing the bottom support plate 24 is provided with a second protrusion 2212, which abuts against the bottom support plate 24 and forms an airflow channel between the bottom wall 221 and the bottom support plate 24, communicating with the location of the explosion-proof valve 2211. In a plane perpendicular to the thickness direction of the bottom support plate 24, the orthographic projection of the support layer 242 at least partially overlaps with the orthographic projection of the second protrusion 2212.

[0219] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: Electrode assembly; The housing has a receiving cavity for accommodating the electrode assembly; A base plate is located between the electrode assembly and the inner wall of the housing and is used to support the electrode assembly; The base plate includes a first insulating layer, a support layer, and a second insulating layer disposed along the thickness direction of the base plate. The first insulating layer is located on the side surface of the support layer facing the electrode assembly, and the second insulating layer is located on the side surface of the support layer facing away from the electrode assembly.

2. The battery cell according to claim 1, wherein, The first insulating layer and the second insulating layer are connected along the outer periphery of the support layer so as to completely cover the support layer between the first insulating layer and the second insulating layer.

3. The battery cell according to claim 1, wherein, The support layer has at least one first groove that runs through the support layer along the thickness direction of the base plate, and the first insulating layer and the second insulating layer are connected at the position of the first groove.

4. The battery cell according to any one of claims 1-3, wherein, The receiving cavity has an opening, and the housing includes a bottom wall directly opposite the opening; The battery cell also includes an explosion-proof valve disposed on the bottom wall, and the bottom support plate is located between the bottom wall and the electrode assembly; The base plate has a second groove in its support layer that is directly opposite the explosion-proof valve, and the second groove penetrates the support layer along its thickness direction.

5. The battery cell according to claim 4, wherein, In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the explosion-proof valve falls completely within the orthographic projection range of the second groove.

6. The battery cell according to claim 4 or 5, wherein, The first insulating layer has a third groove penetrating the first insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the third groove falls completely within the orthographic projection range of the second groove, or The second insulating layer is provided with a fourth groove that penetrates the second insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the fourth groove falls completely within the orthographic projection range of the second groove.

7. The battery cell according to claim 4 or 5, wherein, The first insulating layer has a third groove that penetrates the first insulating layer along the thickness direction of the base plate, and the second insulating layer has a fourth groove that penetrates the second insulating layer along the thickness direction of the base plate. In a plane perpendicular to the thickness direction of the base plate, the orthographic projections of the third groove and the fourth groove both fall completely within the orthographic projection range of the second groove, and the orthographic projections of the third groove and the fourth groove are staggered and spaced apart from each other.

8. The battery cell according to any one of claims 4-7, wherein, The bottom support plate has a first protrusion on the side surface facing away from the electrode assembly. The first protrusion is used to abut against the bottom wall so that an airflow channel is formed between the bottom support plate and the bottom wall, which is connected to the location of the explosion-proof valve.

9. The battery cell according to claim 8, wherein, The support layer has a raised portion on the side facing away from the electrode assembly to form the first protrusion, and the second insulating layer covers the surface of the protrusion.

10. The battery cell according to any one of claims 4-7, wherein, The bottom wall has a second protrusion on the surface facing the bottom support plate. The second protrusion abuts against the bottom support plate, so that an airflow channel is formed between the bottom support plate and the bottom wall, which is connected to the location of the explosion-proof valve.

11. The battery cell according to claim 10, wherein, In a plane perpendicular to the thickness direction of the base plate, the orthographic projection of the support layer at least partially overlaps with the orthographic projection of the second protrusion.

12. The battery cell according to any one of claims 1-11, wherein, The base plate has at least one through hole extending through the base plate along its thickness direction, the through hole being configured to allow fluid communication between the spaces on both sides of the base plate.

13. The battery cell according to any one of claims 1-12, wherein, The battery cell also includes an insulating film sleeved on the surface of the electrode assembly portion; The portion of the insulating film facing the bottom wall serves as either the first insulating layer or the second insulating layer of the base plate.

14. The battery cell according to any one of claims 1-13, wherein, The thickness T1 of the support layer satisfies: 0.1mm≤T1≤5mm, preferably 0.1mm≤T1≤2mm.

15. The battery cell according to any one of claims 1-14, wherein, The thickness T2 of the first insulating layer satisfies: 0.1mm≤T2≤2mm, and / or the thickness T3 of the second insulating layer satisfies: 0.1mm≤T3≤2mm.

16. The battery cell according to any one of claims 1-15, wherein, The melting point of the support layer is higher than that of the first insulating layer and the second insulating layer.

17. The battery cell according to any one of claims 1-16, wherein, The Young's modulus of the support layer is higher than that of the first insulating layer and the second insulating layer.

18. The battery cell according to any one of claims 1-17, wherein, The support layer is made of metal, preferably aluminum, aluminum alloy or steel.

19. The battery cell according to any one of claims 1-18, wherein, The material of the first insulating layer includes PP, PI or PET, and / or the material of the second insulating layer includes PP, PI or PET.

20. The battery cell according to any one of claims 1-19, wherein, The electrode assembly includes lithium phosphate as the active material.

21. The battery cell according to any one of claims 1-20, wherein, The capacity of the battery cell is greater than 400Ah.

22. A method for preparing a base plate, comprising: A first insulating layer, a second insulating layer, and a support layer are provided; The first insulating layer, the support layer, and the second insulating layer are stacked along the thickness direction of the support layer; The first insulating layer and the second insulating layer are connected to obtain the base plate.

23. The preparation method according to claim 22, wherein, The step of connecting the first insulating layer and the second insulating layer to obtain the base plate includes: The first insulating layer and the second insulating layer are continuously heat-fused together along the outer periphery of the support layer, so that the support layer completely covers the space between the first insulating layer and the second insulating layer.

24. The preparation method according to claim 22 or 23, wherein, The support layer is provided with at least one first groove that penetrates the support layer along the thickness direction of the support layer; Furthermore, the step of connecting the first insulating layer and the second insulating layer to obtain the base plate further includes: The first insulating layer and the second insulating layer are thermally fused together at the position of the first groove.

25. The preparation method according to any one of claims 22-24, wherein, The first insulating layer or the second insulating layer is part of an insulating film applied to the surface of the electrode assembly.

26. A battery device comprising a battery cell as claimed in any one of claims 1-25.

27. An electrical device comprising a battery device as described in claim 26, the battery device being used to provide electrical energy.

28. An energy storage device comprising a plurality of battery cells according to claims 1-21 or a plurality of battery devices according to claim 26, wherein the battery cells or the battery devices are used to store or provide electrical energy.

29. An energy storage system comprising a power conversion device and an energy storage device as claimed in claim 28, wherein the power conversion device is used to electrically connect a power generation device and the energy storage device.

30. A charging network comprising a charging pile and an energy storage device as claimed in claim 28 or an energy storage system as claimed in claim 29, the energy storage device or the energy storage system being used to provide electrical energy to the charging pile.

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