Battery cell, battery device, energy storage device, energy storage system, and charging network

Abstract

The embodiment of the application discloses a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network, and relates to the battery field. The battery monomer comprises a shell, an electrode assembly and a connecting piece, the shell comprises an end cover, the connecting piece is located on the side of the end cover facing the electrode assembly, the connecting piece comprises a first surface and a second surface oppositely arranged along a first direction, the first surface is away from the electrode assembly relative to the second surface; the projection area of the first surface along the first direction is smaller than the projection area of the second surface along the first direction, and the projection of the first surface along the first direction falls within the projection range of the second surface along the first direction, and the first direction is the thickness direction of the end cover. The battery monomer can reduce the risk of melting of the end cover when the battery monomer is in thermal runaway, and improve the safety performance of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network. Background Technology

[0002] In a single battery cell, the reliability of the electrical connection between the tabs of the electrode assembly and the electrode terminals on the end cap is a key factor affecting battery performance and safety. Currently, when a battery cell experiences thermal runaway, the top cap is prone to contact with the connection between the tabs and the electrode terminals, causing a short circuit. This short circuit not only exacerbates the thermal runaway reaction but may also lead to serious safety accidents such as bulging, leakage, or even fire and explosion of the battery cell, posing a threat to the overall safety of the battery device. Utility Model Content

[0003] This application provides a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network, which can reduce the risk of end cap melt-through when a battery cell experiences thermal runaway and improve the safety performance of the battery cell.

[0004] In a first aspect, this application provides a battery cell, including a housing with a receiving cavity, the housing including an end cap with an electrode terminal mounted on it; an electrode assembly including a tab and housed in the receiving cavity; and a connector located on the side of the end cap facing the electrode assembly and electrically connecting the electrode terminal and the tab, the connector including a first surface and a second surface disposed opposite to each other along a first direction, the first surface being farther away from the electrode assembly relative to the second surface; wherein the orthographic projection area of ​​the first surface along the first direction is smaller than the orthographic projection area of ​​the second surface along the first direction, and the orthographic projection of the first surface along the first direction falls within the orthographic projection range of the second surface along the first direction, the first direction being the thickness direction of the end cap.

[0005] In the technical solution of this application embodiment, by designing the connector with a first surface projection area smaller than the second surface and completely falling within the projection range of the second surface, when the battery thermal runaway end cap deforms due to gas generation, resulting in a higher center and lower sides, the spatial difference between the first and second surfaces of the connector provides a buffer space for the end cap deformation, preventing the end cap edge from rapidly overlapping with the connector and causing a local short circuit. This delays the continuous heat generation process caused by the short circuit, buys time for the battery management system to activate protective measures, reduces the risk of end cap meltdown, and improves the safety performance of the battery cell.

[0006] In some embodiments of the first aspect, the orthographic projection edge of the first surface along the first direction is spaced apart from the orthographic projection edge of the second surface along the first direction.

[0007] In this embodiment, by designing the orthographic projection edge of the first surface of the connector along the first direction to be spaced apart from the orthographic projection edge of the second surface along the first direction, more space can be provided for the deformation of the end cap, which is higher in the middle and lower on both sides, during thermal runaway. The spaced structure can reduce the possibility of local short circuits caused by rapid contact between the deformed edge of the end cap and the connector from all directions, delay the escalation of thermal runaway, reduce the risk of end cap melt-through, and enhance the safety performance and operational stability of the battery cell.

[0008] In some embodiments of the first aspect, the distance between the orthographic projection edge of the first surface along the first direction and the orthographic projection edge of the second surface along the first direction is equal.

[0009] In this embodiment of the application, by setting the edges of the first and second surfaces of the connector to be orthogonally projected along the first direction at equal intervals, it can provide uniform and sufficient clearance space for the edge of the end cap when the thermal runaway end cap undergoes deformation with a high center and low sides, avoiding the risk of short circuit due to insufficient local gaps. It can also ensure that the contact area between the connector and the tab is uniformly distributed, improve welding stability and conductivity, and enhance the safety performance and operational reliability of the battery cell.

[0010] In some embodiments of the first aspect, the connector further includes a third surface that connects the first surface and the second surface, the third surface being a plane.

[0011] In this embodiment, the connector connects the first and second surfaces through the third plane, which reduces the processing difficulty. While meeting the electrical connection requirements, the size can be reduced to reserve space for avoidance, reducing the possibility of short circuit between the end cap and the connector during thermal runaway, and improving the structural reliability and safety performance of the battery cell.

[0012] In some embodiments of the first aspect, the connector further includes a third surface connecting the first surface and the second surface, the connection between the third surface and the first surface having a rounded corner.

[0013] In this embodiment, the connector has a rounded corner at the connection between the third surface and the first surface. This allows for the dispersion of stress through a rounded transition while reserving a certain space for end cap deformation. This prevents the connector from cracking or deforming due to stress concentration during processing, assembly, and use. It also reduces scratch damage to surrounding components, protects the integrity of the insulation layer and end cap structure, reduces the risk of electric field concentration under extreme operating conditions, and improves the structural reliability of the connector and the safety performance of the battery cell.

[0014] In some embodiments of the first aspect, the radius of the fillet is r, and the thickness of the connector is h1, wherein 0.25h1≤r≤h1.

[0015] In this embodiment, the fillet radius r is limited to 0.25 to 1 times the thickness h1 of the connector. This ensures that a certain space is reserved for the deformation of the end cap by a radius not less than 0.25h1, reducing the possibility of short circuit caused by the overlap between the end cap and the connector. At the same time, the radius not exceeding h1 prevents structural redundancy from reducing the effective connection area or causing assembly interference, while also adapting to the assembly requirements of the end cap.

[0016] In some embodiments of the first aspect, the radius r of the fillet satisfies: 1 ≤ r ≤ 3 mm.

[0017] In this embodiment, a radius range of 1mm to 3mm allows the edge of the connector to form a smooth curved surface, providing adequate buffer space for end cap deformation. Simultaneously, it prevents excessive rounding from occupying too much internal space, ensuring that while reserving space for end cap deformation, the rounding size does not compress the layout space of other necessary internal structures of the battery cell. This allows for reasonable movement allowance during end cap deformation, reducing the risk of short circuits caused by deformation contact between the end cap and the connector, and improving the safety redundancy of the battery cell under extreme operating conditions.

[0018] In some embodiments of the first aspect, the connector further includes an insulating layer covering rounded corners, the insulating layer being made of a high-temperature resistant material.

[0019] In this embodiment, the connector is provided with an insulating layer covering the rounded corners, and the insulating layer is made of high-temperature resistant material, which reduces the risk of short circuit caused by exposed rounded corners. It can maintain stable insulation performance in high-temperature scenarios such as battery thermal runaway due to its high-temperature resistant characteristics, thereby improving the insulation reliability of the connector and the safe heat resistance of the battery cell.

[0020] In some embodiments of the first aspect, the material of the insulating layer includes: polyphenylene sulfide, polyimide, or polyether ether ketone.

[0021] In this embodiment, the material exhibits excellent insulation properties, with slow attenuation of insulation performance over long-term use. It effectively isolates the third surface of the connector from the end cap, reducing the risk of short circuits caused by accidental contact. All three materials can withstand the normal operating high temperatures during battery charging and discharging, as well as short-term high temperatures under abnormal conditions. They will not soften, melt, or experience a decrease in insulation performance due to high temperatures, thus solving the problem of insufficient temperature resistance in ordinary insulating materials, improving insulation reliability in high-temperature environments, and enhancing the safety of individual battery cells.

[0022] In some embodiments of the first aspect, the thickness of the insulating layer is h2, wherein 0.5 mm ≤ h2 ≤ 0.8 mm.

[0023] In this embodiment, the thickness of the insulation layer is set to 0.5mm≤h2≤0.8mm. This thickness range enables the insulation layer to have insulation and isolation performance, avoids the risk of leakage or short circuit between different components inside the battery cell, and also avoids the waste of internal space of the battery cell due to excessive thickness. Under the premise of meeting the insulation requirements, the compactness and safety of the battery cell are taken into account.

[0024] In some embodiments of the first aspect, the connection between the insulating layer and the connector includes adhesive bonding, electrophoresis, or electroplating.

[0025] In this embodiment, the connection between the insulation layer and the connector is achieved by using adhesive bonding, electrophoresis, or electroplating, which can significantly improve the bonding strength between the two, prevent the insulation layer from falling off under conditions such as vibration and high temperature, and ensure that the rounded corners are always covered. The three methods are suitable for different materials and structures, which can improve the connection strength between the insulation layer and the connector, and enhance the reliability and safety of battery insulation protection.

[0026] In some embodiments of the first aspect, the end cap further includes a groove located on the side of the end cap facing the electrode assembly, a connector is received in the groove, and a cavity is formed between the third surface of the connector and the groove, the cavity being filled with plastic.

[0027] In this embodiment, the end cap has a groove on the side facing the electrode assembly to accommodate the connector, thereby positioning and limiting the connector and preventing loosening of the connection caused by external force. The cavity between the third side of the connector and the groove is filled with plastic, which not only forms an insulating barrier to prevent short circuits, but also optimizes the utilization of internal space and comprehensively improves the structural stability, insulation performance and safety reliability of the battery cell.

[0028] In some embodiments of the first aspect, the connector is integrally formed with the electrode terminal.

[0029] In this embodiment, one-piece molding enables a seamless transition between the connector and the electrode terminal, avoiding the overlap allowance or welding protrusion required for separate welding. This helps reduce the overall volume of both components and lowers the possibility of short circuits caused by improper welding between the end cap and the connector. One-piece molding reduces the need for separate processing, positioning, and welding of the connector and electrode terminal, allowing them to be manufactured in a single molding process, shortening the production flow and reducing production costs.

[0030] Secondly, this application provides a battery device, including a housing; and a battery cell as described in the first aspect, the battery cell being housed within the housing.

[0031] Thirdly, this application provides an energy storage device, including a battery cell as described in the first aspect, or a battery device as described in the second aspect; wherein the battery cell or battery device is used to store electrical energy.

[0032] Fourthly, this application provides an energy storage system, including a power conversion device; and the energy storage device in the third aspect; wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0033] Fifthly, this application provides a charging network, including a charging pile; and an energy storage device as described in the third aspect or an energy storage system as described in the fourth aspect; wherein the energy storage device or energy storage system is used to provide electrical energy to the charging pile. Attached Figure Description

[0034] Figure 1 This is a structural diagram of an energy storage container according to an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the battery device according to an embodiment of this application;

[0036] Figure 3 This is a structural diagram of a battery cell according to an embodiment of this application;

[0037] Figure 4 This is an exploded view of a single battery cell according to an embodiment of this application;

[0038] Figure 5 This is a structural diagram of the connector according to an embodiment of this application;

[0039] Figure 6 This is a cross-sectional view of the connector according to an embodiment of this application;

[0040] Figure 7 This is a cross-sectional view of the end cap according to an embodiment of this application;

[0041] Figure 8 This is a partial cross-sectional view of the end cap according to an embodiment of this application;

[0042] Figure 9 This is another partial cross-sectional view of the end cap according to an embodiment of this application;

[0043] Figure 10 This is a structural diagram of the energy storage system according to an embodiment of this application;

[0044] Figure 11 This is a structural diagram of the charging network according to an embodiment of this application.

[0045] The accompanying drawings are not drawn to scale.

[0046] Figure label:

[0047] 1000 - Energy storage container; 100 - Battery unit; 10 - Container body; 101 - First container section; 102 - Second container section; 20 - Battery cell; 21 - Shell; 211 - Opening; 22 - End cap; 23 - Electrode terminal; 24 - Pressure relief mechanism; 25 - Electrode assembly; 251 - Tab; 26 - Connector; 261 - First side; 262 - Second side; 263 - Third side; 27 - Groove; 28 - Shell; 200 - Electrical cabinet; 300 - Energy storage system; 310 - Power conversion device; 320 - Power generation device; 400 - Charging network; 410 - Charging pile; 420 - Connector; 500 - Energy storage device. Detailed Implementation

[0048] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0051] In this application, the reference to "embodiment" means that a specific 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 mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0054] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0055] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0056] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0057] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the occurrence of short circuits while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0062] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0063] As an example, the positive current collector can be made of metal foil, conductive polymer material, carbon material or composite current collector.

[0064] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0065] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0066] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0067] As an example, the negative electrode current collector can be made of metal foil, conductive polymer material, carbon material or composite current collector.

[0068] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0069] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0070] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells.

[0071] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0072] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0073] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0074] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0075] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0076] Liquid electrolytes include electrolyte salts and solvents.

[0077] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0078] In some implementations, the electrode assembly is a stacked structure.

[0079] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0080] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0081] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0082] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0083] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0084] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0085] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0086] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0087] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0088] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0089] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0090] In some embodiments, a pressure relief mechanism is provided on the casing. The pressure relief mechanism is used to release the internal gas of the battery cell.

[0091] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0092] As an example, the pressure relief mechanism can be integrally molded with the housing.

[0093] As an example, the pressure relief mechanism can also be separately installed and connected to the housing.

[0094] The term "actuation" as used in this application refers to the activation or actuation of the pressure relief mechanism to a certain state, thereby releasing the internal pressure and temperature of the battery cell. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the mechanism to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the mechanism, etc. When the pressure relief mechanism is activated, the high-temperature, high-pressure substances inside the battery cell are discharged as waste from the activated portion. This method allows for pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby reducing the likelihood of potentially more serious accidents.

[0095] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for venting gas inside the battery cell.

[0096] The emissions from battery cells mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0097] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0098] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0099] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0100] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0101] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0102] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0103] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure for housing the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0104] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0105] In some embodiments, the energy storage device may include one or more battery clusters to increase the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0106] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices.

[0107] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0108] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet.

[0109] In some embodiments, the energy storage device 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.

[0110] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device via piping to regulate the temperature of the individual battery cells.

[0111] 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.

[0112] As an example, the central control module can serve as the battery management unit for an energy storage device, used to monitor and manage the device. The central control module can monitor information such as the energy storage device's current, voltage, power, state of charge, or temperature. For instance, it can control the charging and discharging current and voltage of the energy storage device. 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.

[0113] 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.

[0114] As an example, the power distribution unit can be used to distribute power to the power modules of the energy storage device.

[0115] In some embodiments, the energy storage system may include one or more energy storage devices and a power converter system (PCS), which is connected between the power generation device and the energy storage device. The power generation device generates electrical energy, which can be stored in the energy storage device through the power converter. For example, the power generation device may specifically be a solar panel, a hydroelectric power generation device, a thermal power generation device, a wind power generation device, etc. The specific type of power generation device is not limited in this application.

[0116] In some embodiments, the charging network may include charging piles and energy storage devices. The charging piles are electrically connected to the energy storage devices, which provide power to the charging piles. The charging piles are electrically connected to a battery device in the energy storage device via cables, and the battery device can provide its stored electrical energy to the charging piles. The charging piles have one or more connectors for connecting to electrical devices, thereby enabling the charging of power to the devices.

[0117] Energy storage devices can be located inside the charging pile (e.g., an integrated energy storage and charging unit) or outside the charging pile.

[0118] In a single battery cell, the reliability of the electrical connection between the tabs of the electrode assembly and the electrode terminals on the end cap is a key factor affecting battery performance and safety. Currently, when a battery cell experiences thermal runaway, the top cap is prone to contact with the connection between the tabs and the electrode terminals, causing a short circuit. This short circuit not only exacerbates the thermal runaway reaction but may also lead to serious safety accidents such as bulging, leakage, or even fire and explosion of the battery cell, posing a threat to the overall safety of the battery device.

[0119] Based on the above considerations, this application provides a battery cell that can reduce the risk of end cap meltdown during thermal runaway and improve the safety performance of the battery cell. The battery cell provided in this application includes a casing, an electrode assembly, and a connector. The casing forms a receiving cavity and includes an end cap on which electrode terminals are mounted. The electrode assembly includes tabs and is housed within the receiving cavity. The connector is located on the side of the end cap facing the electrode assembly and electrically connects the electrode terminals and the tabs. The connector includes a first surface and a second surface disposed opposite each other along a first direction, with the first surface being farther away from the electrode assembly than the second surface. The orthographic projection area of ​​the first surface along the first direction is smaller than the orthographic projection area of ​​the second surface along the first direction, and the orthographic projection of the first surface along the first direction falls within the orthographic projection range of the second surface along the first direction. The first direction is the thickness direction of the end cap.

[0120] In this embodiment, by designing the connector with a first surface projection area smaller than the second surface and completely falling within the projection range of the second surface, when the battery thermal runaway end cap deforms due to gas generation, resulting in a higher center and lower sides, the spatial difference between the first and second surfaces of the connector provides a buffer space for the end cap deformation, preventing the end cap edge from rapidly overlapping with the connector and causing a local short circuit. This delays the continuous heat generation process caused by the short circuit, buys time for the battery management system to activate protective measures, reduces the risk of end cap meltdown, and improves the safety performance of the battery cell.

[0121] Figure 1 This is a structural diagram of an energy storage container according to an embodiment of this application. Figure 1 As shown, the energy storage container 1000 is a relatively highly integrated energy storage device. The interior of the energy storage container 1000 is a hollow structure, which can include multiple compartments, for example, to accommodate multiple electrical cabinets 200.

[0122] In some embodiments, the energy storage container 1000 may include a plurality of electrical cabinets 200, each of which may include a cabinet body and at least one electrical box.

[0123] The battery cabinet 200 is used to encapsulate one or more battery devices 100. Multiple battery devices 100 can be connected in parallel, in series, or in a series-parallel connection.

[0124] In some embodiments, the storage container may include a battery compartment for accommodating batteries. In addition, the interior of the energy storage container 1000 can be divided into multiple functional compartments according to actual needs. Each functional compartment is equipped with other functional equipment components for managing or assisting the operation of the multiple batteries, such as: a busbar component, a main control component, a thermal management component, etc.

[0125] In some embodiments, the thermal management component may include an air conditioning assembly, a fan assembly, water-cooled pipes, etc., which can be used to perform thermal management on the interior of the energy storage container 1000 to adjust the temperature inside the energy storage container 1000.

[0126] In some embodiments, the energy storage container 1000 may also include a fire protection system for fire protection treatment of the energy storage container 1000, such as alarm, cooling or fire extinguishing.

[0127] In some embodiments, the energy storage container 1000 can be a regular cuboid structure, which facilitates the fixed placement and transportation of the energy storage container 1000.

[0128] It should be understood that Figure 1 The components shown are merely examples. In practical applications, these components may have different names, or they may be modified according to actual needs. Figure 1 You can add or delete components in the system.

[0129] Figure 2 This is a schematic diagram of the battery device according to an embodiment of this application. Figure 2 As shown, the battery device 100 of this application embodiment may include a plurality of battery cells 20 to meet different power usage needs. It should be understood that, as Figure 2 As shown, the battery device 100 in this embodiment may further include a housing 10.

[0130] The housing 10 may include two parts, referred to herein as a first housing part 101 and a second housing part 102, which are fastened together. The shapes of the first housing part 101 and the second housing part 102 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of multiple battery cells 20 housed inside. At least one of the first housing part 101 and the second housing part 102 has an opening. For example, the first housing part 101 and the second housing part 102 can both be hollow cuboids with one face as an opening. The openings of the first housing part 101 and the second housing part 102 are arranged opposite to each other, and the first housing part 101 and the second housing part 102 are fastened together to form a housing 10 with a closed cavity, which can be used to house multiple battery cells 20. Multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing 10 formed by the fastening of the first housing part 101 and the second housing part 102.

[0131] For example, one of the first housing portion 101 and the second housing portion 102 may be a hollow cuboid with an opening, while the other is plate-shaped to cover the opening. Taking the second housing portion 102 as a hollow cuboid with one opening, and the first housing portion 101 as a plate-shaped example, then the first housing portion 101 covers the opening of the second housing portion 102 to form a housing 10 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0132] Figure 3 This is a structural diagram of a battery cell according to an embodiment of this application. Figure 4 This is an exploded view of a single battery cell according to an embodiment of this application. Figure 3 , Figure 4 As shown, the battery cell 20 in this embodiment may include a housing 21, electrode terminals 23, a pressure relief mechanism 24, and an electrode assembly 25. The housing 21 includes a shell 28 and an end cap 22.

[0133] The housing 28 is a hollow structure with an opening 211. The electrode assembly 25 is housed within the housing 28, and the shape of the housing 28 can be determined according to the specific shape of the electrode assembly 25. For example, if the electrode assembly 25 is a cuboid structure, the housing 28 can also be a cuboid structure. Figure 3 and Figure 4 An example is shown where the housing 28 and electrode assembly 25 are square.

[0134] The shell 28 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not limit this.

[0135] End cap 22 is used to seal opening 211 to form a sealed mounting space for accommodating electrode assembly 25. The mounting space is also used to accommodate electrolyte, such as electrolyte solution. Electrode terminals 23 are mounted on end cap 22 for connection to electrode assembly 25, i.e., electrode terminals 23 are connected to tabs 251 of electrode assembly 25.

[0136] The end cap 22 is also equipped with a pressure relief mechanism 24. When the internal pressure of the battery cell 20 rises abnormally, the pressure relief mechanism 24 can be activated in time to release the excessive pressure inside the battery cell 20, thereby reducing the possibility of dangerous situations such as the battery cell 20 exploding.

[0137] It should be understood that the shape of the battery cell 20 in this application embodiment can be flexibly set according to actual application, that is, the outer shell 21 of the battery cell 20 can be any polyhedral structure, for example, it can be set as a cuboid or a cylinder, etc.

[0138] Figure 5 This is a structural diagram of the connector according to an embodiment of this application. Figure 6 This is a cross-sectional view of the connector according to an embodiment of this application. Figure 7 This is a cross-sectional view of the end cap according to an embodiment of this application. Figures 5 to 7 As shown, the battery cell 20 may include a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is received in the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite to each other along a first direction. The first surface 261 is farther away from the electrode assembly 25 relative to the second surface 262. The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction falls within the orthographic projection range of the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22.

[0139] The outer casing 21 is used to form a receiving space for the battery cell 20, and a receiving cavity is formed inside it to receive the core battery components such as the electrode assembly 25 and the electrolyte. The outer casing 21 includes a housing 28 and an end cap 22, wherein the housing 28 can be a hollow structure with an opening 211 at one end, and the end cap 22 closes to the opening of the housing 28 to seal the receiving cavity.

[0140] An electrode terminal 23 is installed on the end cap 22. The electrode terminal 23 may include a positive terminal and a negative terminal, which are used to connect the battery cell 20 to the positive and negative terminals of an external circuit, respectively.

[0141] The electrode assembly 25 is housed in the receiving cavity of the housing 21. The end of the electrode assembly 25 has a tab 251 extending out. The tab 251 is close to the end cover 22 and is used to make an electrical connection with the corresponding electrode terminal 23.

[0142] The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25, i.e., on the inner side of the end cap 22. It serves as an electrical connection device between the electrode terminal 23 and the tab 251, enabling a conductive connection between the two. Specifically, one end of the connector 26 is electrically connected to the electrode terminal 23, and the other end is electrically connected to the tab 251. The connector 26 can be welded to both the electrode terminal 23 and the tab 251, thereby conducting the current generated by the electrode assembly 25 to the electrode terminal 23 through the tab 251 and the connector 26, or conducting external current to the electrode assembly 25 through the electrode terminal 23, the connector 26, and the tab 251.

[0143] The connector 26 includes a first surface 261 and a second surface 262 disposed opposite to each other along a first direction. The first surface 261 is the side of the connector 26 that is away from the electrode assembly 25 relative to the second surface 262, i.e., the side that is close to the end cap 22. The second surface 262 is the side of the connector 26 that is close to the electrode assembly 25 relative to the first surface 261, i.e., the side that is close to the tab 251.

[0144] The first direction is the thickness direction of the end cap 22, that is, the direction in which the end cap 22 extends from the side away from the receiving cavity to the side closer to the receiving cavity, or vice versa.

[0145] The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction completely falls within the orthographic projection range of the second surface 262 along the first direction. That is, when viewed from the thickness direction of the end cap 22, the projected outline of the first surface 261 of the connector 26 near the end cap 22 is completely located inside the projected outline of the second surface 262 near the tab 251, and the projected size of the first surface 261 is smaller than the projected size of the second surface 262. In other words, in the cross-section of the connector 26 along the first direction, the first side corresponding to the first surface 261 is smaller than the second side corresponding to the second surface 262, meaning the upper side of the cross-section is shorter and the lower side is longer.

[0146] The orthographic projection of the first surface 261 along the first direction falls entirely within the orthographic projection range of the second surface 262 along the first direction. This structure results in the connector 26 forming a stepped or sloping profile that is narrower at the top and wider at the bottom in the first direction, and the second surface 262 has a larger size than the first surface 261.

[0147] In some embodiments, the connector 26 can be a welding pad, that is, the connector 26 can connect the electrode terminal 23 and the tab 251 by welding. Specifically, the first side 261 is welded to the electrode terminal 23, and the second side 262 is welded to the tab 251.

[0148] In some embodiments, the shapes of the first surface 261 and the second surface 262 may be the same or different, and can be designed according to the solder marks of the connector 26 and the tab 251 and the connection with the electrode terminal 23.

[0149] In some embodiments, the connector 26 can also be connected to the electrode terminal 23 and the tab 251 by means of mechanical connection, conductive adhesive connection or crimping, etc., which is not limited in this application.

[0150] When the battery cell 20 experiences thermal runaway, the lower plastic insulation between the connector 26 and the end cap 22 melts, and the electrode assembly 25 generates gas violently, causing the end cap 22 to deform. The deformed end cap 22 is higher in the middle and lower on both sides, making it prone to overlapping with the edge of the connector 26, causing a localized short circuit. Continued heat generation will melt through the end cap 22, posing a safety hazard to the battery cell 20. The design of the first surface 261 of the connector 26 being smaller than the second surface 262 provides some space for the deformation of the end cap 22. When thermal runaway causes the end cap 22 to deform with a higher middle and lower sides, because the projected area of ​​the first surface 261 of the connector 26 is smaller and falls entirely within the projected area of ​​the second surface 262, a buffer zone is formed between the second surface 262 and the first surface 261.

[0151] In this embodiment, by designing the connector 26 such that the projected area of ​​the first surface 261 is smaller than that of the second surface 262 and falls entirely within the projected area of ​​the second surface 262, when the battery thermal runaway end cap 22 deforms due to gas generation, resulting in a higher center and lower sides, the spatial difference between the first surface 261 and the second surface 262 of the connector 26 provides a buffer space for the deformation of the end cap 22, preventing the edge of the end cap 22 from rapidly overlapping with the connector 26 and causing a local short circuit. This delays the continuous heat generation process caused by the short circuit, buys time for the battery management system to activate protective measures, reduces the risk of the end cap 22 melting through, and improves the safety performance of the battery cell 20.

[0152] In this embodiment of the application, the orthographic projection edge of the first surface 261 along the first direction is spaced apart from the orthographic projection edge of the second surface 262 along the first direction.

[0153] "Separated" means that in the first direction, when orthographically projecting the first surface 261 and the second surface 262, there is a certain distance between the projected outline edges of the first surface 261 and the projected outline edges of the second surface 262. They do not touch, overlap, or intersect. In other words, there is a non-overlapping area between the outermost edge of the projection of the first surface 261 and the outermost edge of the projection of the second surface 262.

[0154] The gap is formed because the orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 falls completely within the orthographic projection area of ​​the second surface 262. This results in the projection of the second surface 262 forming a ring around the projection of the first surface 261 that does not contact the edge of the projection of the first surface 261 when viewed from the first direction.

[0155] The size of the interval can be set according to actual design requirements. It can be a uniform interval, that is, the distance from the projection edge of the first surface 261 to the projection edge of the second surface 262 is equal in all directions; or it can be a non-uniform interval, with different interval distances in different directions.

[0156] In this embodiment, by designing the first surface 261 of the connector 26 to be spaced apart from the orthographic projection edge of the second surface 262 along the first direction, more space can be provided for the deformation of the end cap 22, which is higher in the middle and lower on both sides, during thermal runaway. The spaced structure can reduce the possibility of local short circuits caused by rapid contact between the deformation edge of the end cap 22 and the connector 26 from all directions, delay the escalation of thermal runaway, reduce the risk of the end cap 22 melting through, and enhance the safety performance and operational stability of the battery cell 20.

[0157] In this embodiment of the application, the distance between the orthographic projection edge of the first surface 261 along the first direction and the orthographic projection edge of the second surface 262 along the first direction is equal.

[0158] Equal interval distances mean that, within the orthographic projection plane in the first direction, the shortest distance from each edge point of the first surface 261 projection profile to the corresponding edge point of the second surface 262 projection profile remains consistent.

[0159] For example, when the projections of the first surface 261 and the second surface 262 are both circular, the two circles are concentric and the distance between their edges is the difference in their radii; when the projections are square and the edges are parallel, the parallel spacing between each side of the projection of the first surface 261 and the corresponding side of the projection of the second surface 262 is equal.

[0160] In this embodiment, by setting the edges of the first surface 261 and the second surface 262 of the connector 26 to be equidistant along the first direction, it can provide uniform and sufficient clearance space for the edge of the end cap 22 when the thermal runaway end cap 22 undergoes deformation with a high center and low sides, avoiding the risk of short circuit due to insufficient local gaps. It can also ensure that the contact area between the connector 26 and the tab 251 is uniformly distributed, improving welding stability and conductivity, and enhancing the safety performance and operational reliability of the battery cell 20.

[0161] Figure 8 This is a partial cross-sectional view of the end cap according to an embodiment of this application. Figure 8 As shown, the connector 26 also includes a third surface 263 that connects the first surface 261 and the second surface 262, and the third surface 263 is a plane.

[0162] The connector 26 includes a third surface 263 for connecting the first surface 261 and the second surface 262, and the third surface 263 is a planar structure, that is, the cross section of the connector 26 along the first direction is trapezoidal.

[0163] The third surface 263 is an inclined surface at a certain angle relative to the first surface 261 and the second surface 262, forming a gradually expanding connection.

[0164] Compared to complex curved or irregular surfaces, the third surface 263 of a plane is easier to achieve in the manufacturing process, which can effectively reduce the processing difficulty and cost. It can be accurately formed through conventional stamping, cutting and other processes, which is conducive to improving production efficiency and product consistency.

[0165] Inside the battery cell 20, the planar third surface 263 facilitates and stabilizes the assembly of the connector 26 with surrounding components. In the event of thermal runaway in the battery cell 20 and deformation of the end cap 22, the planar third surface 263 helps to evenly distribute the pressure applied by the end cap 22, preventing damage to the connector 26 due to localized stress concentration, and ensuring the battery cell 20 maintains stable performance under extreme conditions.

[0166] In this embodiment, the connector 26 connects the first surface 261 and the second surface 262 through the third surface 263 of the plane, which can reduce the processing difficulty. While meeting the electrical connection requirements, the size can be reduced to reserve space for avoidance, reducing the possibility of short circuit between the end cap 22 and the connector 26 during thermal runaway, and improving the structural reliability and safety performance of the battery cell 20.

[0167] In one embodiment, the third surface 263 is a plane perpendicular to the first surface 261 and the second surface 262, forming a straight-wall connection. Compared to the original connector 26, which was prone to short circuits due to overlap between the end cap 22 and the connector 26 during thermal runaway, the redundant side dimensions that may exist in the traditional structure are eliminated. While ensuring electrical connection performance, the lateral dimension of the connector 26 is smaller than before, which can reserve some space and reduce the risk of contact short circuits.

[0168] In some embodiments, the third surface 263 can be composed of multiple planes of different heights forming a stepped structure to achieve multi-level transitions.

[0169] Figure 9 This is another partial cross-sectional view of the end cap according to an embodiment of this application. (See attached image.) Figure 9 As shown, the connector 26 also includes a third surface 263 that connects the first surface 261 and the second surface 262, and the connection between the third surface 263 and the first surface 261 has a rounded corner.

[0170] The connector 26 includes a first surface 261, a second surface 262, and a third surface 263 connecting the two. The connection between the third surface 263 and the first surface 261 adopts a rounded corner design, that is, the connection is replaced by a right angle or bevel by a rounded transition.

[0171] In some embodiments, the rounded corner forms a continuous curved surface with a certain radius, one end of which is smoothly connected to the first surface 261. If the radius of the rounded corner is equal to the thickness of the connector 26, the rounded corner connects the first surface 261 and the second surface 262. If the radius of the rounded corner is less than or greater than the welding thickness, a plane can be appropriately added according to the connection situation to achieve a natural connection between the rounded corner and the second surface 262.

[0172] In some embodiments, the rounded corners can be formed by stamping, grinding, or CNC machining. In the stamping process, the rounded corners can be formed in one stamping process during the forming of the connector 26 by the rounded corner design of the die, ensuring the consistency and precision of the structure; if the grinding process is used, the initially formed right-angled edges can be finely ground to form a smooth arc surface at the junction.

[0173] Rounded corners reduce the risk of scratches between the connector 26 and surrounding components. When the connector 26 is accommodated in the groove 27 of the end cap 22 or assembled with other components, the right-angled edge can easily cause wear to the end cap 22, insulating plastic and other surrounding components, and may even scratch the insulation layer, leading to leakage or short circuit; while the smooth transition structure of the rounded corners can reduce interference problems during assembly, protect the integrity of surrounding components, and reduce the safety hazard of operators being scratched by sharp edges during assembly.

[0174] In this embodiment, the connector 26 has a rounded corner at the connection between the third surface 263 and the first surface 261. This allows for the provision of space for the deformation of the end cap 22, while also dispersing stress through a rounded transition. This prevents the connector 26 from cracking or deforming due to stress concentration during processing, assembly, and use. It also reduces scratch damage to surrounding components, protects the insulation layer and the structural integrity of the end cap 22, and reduces the risk of electric field concentration under extreme conditions. This improves the structural reliability of the connector 26 and the safety performance of the battery cell 20.

[0175] The battery cell 20 has a rounded corner radius of r and a connector 26 with a thickness of h1, where 0.25h1≤r≤h1.

[0176] The rounded corner serves as the structure at the connection between the third surface 263 and the first surface 261 of the connector 26. Its radius r needs to be reasonably matched with the thickness h1 of the connector 26, that is, the distance between the first surface 261 and the second surface 262 in the thickness direction.

[0177] From a structural strength perspective, when the fillet radius r is not less than 0.25h1, it ensures that the arc transition has a sufficient radius of curvature, forming a certain volume space between it and the end cap 22. If the radius is too small (less than 0.25h1), the space is too small, and when the end cap 22 bends, it is easy to overlap with the third surface 263, failing to achieve the effect of reducing the possibility of short circuits. If r exceeds h1, the fillet may excessively occupy the effective space of the connector 26, or even cause the actual effective area of ​​the first surface 261 to shrink, affecting the connection reliability of the connector 26 with the electrode terminal 23 and the tab 251, or causing assembly interference with surrounding components.

[0178] In this embodiment, the fillet radius r is limited to 0.25 to 1 times the thickness h1 of the connector 26. This ensures that a certain space is reserved for the deformation of the end cap 22 by a radius not less than 0.25h1, reducing the possibility of short circuit caused by the overlap between the end cap 22 and the connector 26. At the same time, the radius not exceeding h1 prevents structural redundancy from reducing the effective connection area or causing assembly interference, while also adapting to the assembly requirements of the end cap 22.

[0179] In this embodiment of the application, the radius r of the fillet satisfies: 1≤r≤3mm.

[0180] In some embodiments, the radius r of the fillet can be in the range of 0.5mm ≤ r ≤ 4mm.

[0181] In some embodiments, the radius r of the fillet can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, or 4mm.

[0182] In some embodiments, the radius r of the fillet is associated with the thickness h1 of the connector 26, and the thickness h1 of the connector 26 satisfies: 2≤r≤3mm.

[0183] In some embodiments, the thickness h1 of the connector 26 satisfies: 1≤r≤4mm.

[0184] The thickness h1 of the connector 26 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, or 4mm.

[0185] In some embodiments, a radius range of 1 mm to 3 mm can play a positive role in extreme conditions such as thermal runaway. When the end cap 22 deforms and comes into contact with the connector 26, the rounded corner of this size can reduce the risk of electric field concentration and tip discharge by smoothing the surface, avoiding sparks or short circuits caused by local charges, and providing additional protection for battery safety.

[0186] In this embodiment, a radius range of 1mm to 3mm allows the edge of the connector 26 to form a smooth curved surface, providing adequate buffer space for the deformation of the end cap 22. Simultaneously, it prevents excessive rounding from occupying too much internal space, ensuring that while reserving space for the deformation of the end cap 22, the rounding size does not compress the layout space of other necessary structures inside the battery cell 20. This allows for reasonable movement allowance when the end cap 22 deforms, reducing the risk of short circuits caused by deformation contact between the end cap 22 and the connector 26, and improving the safety redundancy of the battery cell 20 under extreme operating conditions.

[0187] In this embodiment, the connector 26 further includes an insulating layer, which covers rounded corners, and the insulating layer is made of a high-temperature resistant material.

[0188] An insulating layer is wrapped around the outer surface of the rounded corner to form an insulating barrier. When the battery cell 20 experiences thermal runaway and the end cap 22 deforms due to heat, it further reduces the possibility of direct contact between the rounded corner and the end cap 22.

[0189] In some embodiments, the insulating layer may cover the entire connector 26.

[0190] High-temperature resistant materials refer to materials that can maintain stable insulation properties (volume resistivity ≥ 10) even at temperatures above 80℃. 14 Materials that are Ω·cm in size and do not undergo significant deformation or decomposition.

[0191] The insulation layer, made of high-temperature resistant materials, can maintain a stable physical form and insulation performance in environments with normal operating high temperatures (such as 40-60℃) generated by battery charging and discharging, and even short-term high temperatures (such as 80-150℃) under abnormal operating conditions, and will not fail due to high temperature.

[0192] In this embodiment, the connector 26 is provided with an insulating layer covering the rounded corners, and the insulating layer is made of a high-temperature resistant material, which reduces the risk of short circuit caused by exposed rounded corners. It can maintain stable insulation performance in high-temperature scenarios such as battery thermal runaway due to its high-temperature resistant properties, thereby improving the insulation reliability of the connector 26 and the safe heat resistance of the battery cell 20.

[0193] In the embodiments of this application, the materials of the insulating layer include: polyphenylene sulfide, polyimide, or polyether ether ketone.

[0194] Polyphenylene sulfide (PPS) can withstand long-term temperatures above 200°C and short-term temperatures up to 260°C. It has good chemical corrosion resistance, does not easily react with battery electrolytes, and has high mechanical strength and good dimensional stability.

[0195] Polyimide (PI) exhibits excellent temperature resistance, with a long-term operating temperature range of -200℃ to 260℃, and can withstand short-term temperatures above 400℃. It also possesses excellent insulation properties (volume resistivity ≥10).14 It has a strength of Ω·cm and also possesses good radiation resistance and mechanical toughness.

[0196] Polyetheretherketone (PEEK) has a long-term operating temperature of about 250°C and a short-term temperature resistance of over 300°C. It has excellent chemical corrosion resistance, fatigue resistance and insulation stability, and can maintain high mechanical strength at high temperatures.

[0197] In this embodiment, the material exhibits excellent insulation properties, and its insulation performance degrades slowly over long-term use. It can isolate the third surface 263 of the connector 26 from the end cap 22, reducing the risk of short circuits caused by accidental contact. All three materials can withstand the normal operating high temperatures during battery charging and discharging, as well as short-term high temperatures under abnormal conditions. They will not soften, melt, or experience a decrease in insulation performance due to high temperatures, solving the problem of insufficient temperature resistance in ordinary insulating materials, improving insulation reliability in high-temperature environments, and enhancing the safety of the battery cell 20.

[0198] In this embodiment of the application, the thickness of the insulating layer is h2, wherein 0.5mm≤h2≤0.8mm.

[0199] In some embodiments, the thickness h2 of the insulating layer can be in the range of 0.3mm ≤ h2 ≤ 1mm.

[0200] In some embodiments, the thickness h2 of the insulating layer can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0201] In some embodiments, a thickness of 0.5 mm or more can provide the insulation layer with sufficient insulation strength to withstand the voltage difference that may exist inside the battery cell 20, reducing the risk of short circuit due to insulation layer breakdown; this thickness can cover the surface undulations of the rounded corners, so that the rounded corners have no weak points with insufficient local thickness, achieving comprehensive insulation isolation.

[0202] In some embodiments, a thickness of 0.5mm-0.8mm gives the insulation layer good mechanical strength and wear resistance, making it less prone to breakage or peeling under insertion and removal, vibration, or slight friction during long-term use during battery assembly. When faced with external impact, the thickness can also buffer stress, protect the rounded corner area from mechanical damage, and extend the service life of the insulation layer.

[0203] A thickness not exceeding 0.8mm can effectively control the volume of the insulation layer, avoiding an increase in the overall size of the connector 26 due to excessive thickness, and adapting to the compact internal structure design of the battery cell 20.

[0204] In this embodiment, the thickness of the insulation layer is set to 0.5mm≤h2≤0.8mm. This thickness range enables the insulation layer to have insulation and isolation performance, avoids the risk of leakage or short circuit between different components inside the battery cell 20, and also avoids the waste of internal space of the battery cell 20 due to excessive thickness. Under the premise of meeting the insulation requirements, the compactness and safety of the battery cell 20 are taken into account.

[0205] In this embodiment of the application, the connection method between the insulating layer and the connector 26 includes: adhesive bonding, electrophoresis, or electroplating.

[0206] In some embodiments, the insulating layer and the connector 26 are connected by adhesive. Specifically, the insulating layer is adhered to the rounded corner surface of the connector 26 by a high-temperature resistant adhesive, such as epoxy high-temperature resistant adhesive or silicone high-temperature resistant adhesive, and a firm connection is formed after curing.

[0207] In some embodiments, the insulating layer and the connector 26 are connected by electrophoresis. Specifically, the connector 26 is placed as an electrode in the electrophoresis tank of the insulating material, and the insulating material particles are uniformly deposited on the rounded corner surface by the action of an electric field. After curing, an insulating layer is formed, and an integrated connection with the connector 26 is achieved.

[0208] In some embodiments, the insulating layer and the connector 26 are connected by electroplating. Specifically, for conductive high-temperature resistant insulating materials, the material is deposited on the rounded corner surface by electroplating and then sintered at high temperature to form a dense insulating layer, which forms a metallurgical bond or a chemical bond with the surface of the connector 26.

[0209] In this embodiment, the connection between the insulation layer and the connector 26 is achieved by using adhesive bonding, electrophoresis, or electroplating, which can significantly improve the bonding strength between the two, prevent the insulation layer from falling off under conditions such as vibration and high temperature, and ensure that the rounded corners are always covered. The three methods are suitable for different materials and structures, which can improve the connection strength between the insulation layer and the connector 26 and enhance the reliability and safety of battery insulation protection.

[0210] Combination Figure 9 As shown, the end cap 22 also includes a groove 27 located on the side of the end cap 22 facing the electrode assembly 25. The connector 26 is accommodated in the groove 27, and there is a cavity between the third surface 263 of the connector 26 and the groove 27, which is filled with plastic.

[0211] On the side of the end cap 22 facing the electrode assembly 25, there is a groove 27. The shape and size of the groove 27 can be adapted to the connector 26. The connector 26 is fully accommodated in the groove 27, which realizes the positioning and limiting of the connector 26 on the end cap 22, and makes reasonable use of the space inside the battery cell 20, thereby improving the space utilization rate of the battery cell 20.

[0212] A cavity is reserved between the third surface 263 of the connector 26 and the inner wall of the groove 27. This cavity can provide deformation space for the end cap 22 during thermal runaway deformation.

[0213] The cavity is filled with plastic material. As an insulating material, the plastic can form an insulating barrier between the connector 26 and the end cap 22, reducing the risk of leakage or short circuit caused by direct contact between the connector 26 and the end cap 22.

[0214] The combination of groove 27 and plastic filler optimizes the internal space utilization of the battery cell 20. By embedding the connector 26 into the groove 27 of the end cap 22 and filling it with plastic, the connector 26 is prevented from protruding from the surface of the end cap 22 and occupying extra space, making the internal structure of the battery cell 20 more compact and improving the energy density of the battery cell 20. At the same time, the plastic filler layer can fill the gap between the connector 26 and the groove 27, reducing the air residue inside the battery cell 20, reducing the additional pressure on the end cap 22 caused by the thermal expansion of air, and indirectly improving the battery's resistance to thermal runaway.

[0215] In this embodiment, the end cap 22 has a groove 27 on the side facing the electrode assembly 25 to accommodate the connector 26, thereby positioning and limiting the connector 26 and preventing loosening of the connection caused by external force. The cavity between the third surface 263 of the connector 26 and the groove 27 is filled with plastic, which not only forms an insulating barrier to prevent short circuits, but also optimizes the utilization of internal space and comprehensively improves the structural stability, insulation performance and safety reliability of the battery cell 20.

[0216] In this embodiment, the connector 26 and the electrode terminal 23 are integrally formed.

[0217] In some embodiments, the connector 26 and the electrode terminal 23 can be made of the same metal material and are integrally formed by an integrated process, such as stamping, forging, casting, machining or powder metallurgy, with no splicing seam or welding interface between them, forming a continuous conductive path.

[0218] In the integrally formed structure, one end of the electrode terminal 23 extends to the outside of the end cover 22 for external electrical connection, and the other end is directly connected to the connector 26 on the inside of the end cover 22. The second surface 262 of the connector 26 is welded to the tab 251, realizing a complete path for current to be conducted outward from the tab 251 through the connector 26 and the electrode terminal 23.

[0219] It should be understood that the structure of the first surface 261, the second surface 262, and the third surface 263 of the connector 26 is still the same as the structure in any of the above embodiments, only the connection method of the two is changed from separate welding to integral molding.

[0220] In some embodiments, the battery cell 20 may include an electrode terminal structure, which includes an electrode terminal 23 and a connector 26, wherein the electrode terminal 23 and the connector 26 are integrally formed. The structure of the first surface 261, the second surface 262, and the third surface 263 of the connector 26 remains the same as in any of the above embodiments, that is, the first surface 261 includes a portion connected to the electrode terminal 23.

[0221] In this embodiment, the one-piece molding achieves a seamless transition between the connector 26 and the electrode terminal 23, avoiding the overlap allowance or welding protrusion required for separate welding. This helps reduce the overall volume of both components and lowers the possibility of short circuits caused by improper welding between the end cap 22 and the connector 26. One-piece molding reduces the need for separate processing, positioning, and welding of the connector 26 and the electrode terminal 23, allowing for manufacturing in a single process, shortening the production flow, and reducing production costs.

[0222] This application provides a battery device 100, including a housing 10 and a battery cell 20, with the battery cell 20 housed in the housing 10. The battery cell 20 may include a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is housed in the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite each other along a first direction. The first surface 261 is farther from the electrode assembly 25 than the second surface 262. The projected area of ​​the first surface 261 along the first direction is smaller than the projected area of ​​the second surface 262 along the first direction, and the projected area of ​​the first surface 261 along the first direction falls within the projected area of ​​the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22.

[0223] It should be understood that the battery cell 20 may also include the battery cell 20 in any of the above embodiments.

[0224] This application provides an energy storage device 500, including a battery cell 20 or a battery device 100, wherein the battery cell 20 or the battery device 100 is used to store electrical energy.

[0225] In some embodiments, the battery cell 20 may include: a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is received in the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite to each other along a first direction. The first surface 261 is farther away from the electrode assembly 25 relative to the second surface 262. The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction falls within the orthographic projection range of the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22.

[0226] It should be understood that the battery cell 20 may also include the battery cell 20 in any of the above embodiments.

[0227] In some embodiments, the battery device 100 includes a housing 10 and a battery cell 20, wherein the battery cell 20 is housed in the housing 10.

[0228] Figure 10 This is a structural diagram of an energy storage system according to an embodiment of this application. Figure 10 As shown, this application provides an energy storage system 300, including a power conversion device 310 and an energy storage device 500; wherein, the power conversion device 310 is used to electrically connect the power generation device 320 and the energy storage device 500.

[0229] The energy storage device 500 may include a battery cell 20, which may include a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is housed in the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite each other along a first direction. The first surface 261 is farther away from the electrode assembly 25 than the second surface 262. The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction falls within the orthographic projection range of the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22.

[0230] It should be understood that the battery cell 20 may also include the battery cell 20 in any of the above embodiments.

[0231] Figure 11 This is a structural diagram of the charging network according to an embodiment of this application. Figure 11As shown, a charging network 400 includes a charging pile 410 and an energy storage device or energy storage system 300, wherein the energy storage device or energy storage system 300 is used to provide electrical energy to the charging pile 410.

[0232] The energy storage system 300 may include an energy storage device 500, which may include a battery cell 20. The battery cell 20 may include a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is housed in the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite each other along a first direction. The first surface 261 is farther away from the electrode assembly 25 than the second surface 262. The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction falls within the orthographic projection range of the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22.

[0233] It should be understood that the battery cell 20 may also include the battery cell 20 in any of the above embodiments.

[0234] The charging pile 410 and the battery device 100 in the energy storage device 500 can be electrically connected via a cable, and the battery device 100 can supply its stored electrical energy to the charging pile 410. The charging pile 410 may have one or more connectors 420 for connecting to electrical equipment, thereby replenishing the energy of the equipment. The energy storage device 500 may be located inside the charging pile 410 (e.g., an integrated charging and energy storage unit) or outside the charging pile 410.

[0235] According to some embodiments of this application, see Figures 5 to 9This application provides a battery cell 20 that may include a housing 21, an electrode assembly 25, and a connector 26. The housing 21 forms a receiving cavity and includes an end cap 22 on which electrode terminals 23 are mounted. The electrode assembly 25 includes tabs 251 and is received within the receiving cavity. The connector 26 is located on the side of the end cap 22 facing the electrode assembly 25 and electrically connects the electrode terminals 23 and the tabs 251. The connector 26 includes a first surface 261 and a second surface 262 disposed opposite each other along a first direction. The first surface 261 is farther away from the electrode assembly 25 relative to the second surface 262. The orthographic projection area of ​​the first surface 261 along the first direction is smaller than the orthographic projection area of ​​the second surface 262 along the first direction, and the orthographic projection of the first surface 261 along the first direction falls within the orthographic projection area of ​​the second surface 262 along the first direction. The first direction is the thickness direction of the end cap 22. The orthographic projection edge of the first surface 261 along the first direction is spaced apart from the orthographic projection edge of the second surface 262 along the first direction. The distance between the orthographic projection edge of the first surface 261 along the first direction and the orthographic projection edge of the second surface 262 along the first direction is equal.

[0236] The connector 26 also includes a third surface 263 connecting the first surface 261 and the second surface 262, with a rounded corner at the connection between the third surface 263 and the first surface 261. The radius of the rounded corner is r, and the thickness of the connector 26 is h1, where 0.25h1≤r≤h1. The radius r of the rounded corner satisfies: 1≤r≤3mm. The connector 26 also includes an insulating layer covering the rounded corner, and the insulating layer is made of a high-temperature resistant material. The insulating layer material includes: polyphenylene sulfide, polyimide, or polyetheretherketone. The thickness of the insulating layer is h2, where 0.5mm≤h2≤0.8mm. The connection method between the insulating layer and the connector 26 includes: adhesive bonding, electrophoresis, or electroplating.

[0237] The end cap 22 also includes a groove 27 located on the side of the end cap 22 facing the electrode assembly 25. The connector 26 is accommodated in the groove 27, and a cavity is formed between the third surface 263 of the connector 26 and the groove 27, which is filled with plastic. The connector 26 is integrally formed with the electrode terminal 23.

[0238] 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 battery cell, characterized in that, include: The housing (21) has a receiving cavity and includes an end cap (22) on which an electrode terminal (23) is mounted. An electrode assembly (25) comprising tabs (251) and housed within the receiving cavity; A connector (26) is located on the side of the end cap (22) facing the electrode assembly (25) and electrically connects the electrode terminal (23) and the tab (251). The connector (26) includes a first surface (261) and a second surface (262) disposed opposite to each other along a first direction. The first surface (261) is away from the electrode assembly (25) relative to the second surface (262). Wherein, the orthographic projection area of ​​the first surface (261) along the first direction is smaller than the orthographic projection area of ​​the second surface (262) along the first direction, and the orthographic projection of the first surface (261) along the first direction falls within the orthographic projection range of the second surface (262) along the first direction, and the first direction is the thickness direction of the end cap (22).

2. The battery cell according to claim 1, characterized in that, The orthographic projection edge of the first surface (261) along the first direction is spaced apart from the orthographic projection edge of the second surface (262) along the first direction.

3. The battery cell according to claim 2, characterized in that, The distance between the orthographic projection edge of the first surface (261) along the first direction and the orthographic projection edge of the second surface (262) along the first direction is equal.

4. The battery cell according to claim 3, characterized in that, The connector (26) further includes a third surface (263) connecting the first surface (261) and the second surface (262), wherein the third surface (263) is a plane.

5. The battery cell according to claim 3, characterized in that, The connector (26) further includes a third surface (263) connecting the first surface (261) and the second surface (262), and the connection between the third surface (263) and the first surface (261) has a rounded corner.

6. The battery cell according to claim 5, characterized in that, The radius of the rounded corner is r, and the thickness of the connector (26) is h1, wherein 0.25h1≤r≤h1.

7. The battery cell according to claim 6, characterized in that, The radius r of the fillet must satisfy: 1≤r≤3mm.

8. The battery cell according to claim 5, characterized in that, The connector (26) also includes an insulating layer that covers the rounded corners, and the insulating layer is made of a high-temperature resistant material.

9. The battery cell according to claim 8, characterized in that, The insulating layer is made of materials including polyphenylene sulfide, polyimide, or polyether ether ketone.

10. The battery cell according to claim 9, characterized in that, The thickness of the insulating layer is h2, wherein 0.5mm≤h2≤0.8mm.

11. The battery cell according to claim 8, characterized in that, The connection methods between the insulating layer and the connector (26) include: adhesive bonding, electrophoresis, or electroplating.

12. The battery cell according to any one of claims 4 to 11, characterized in that, The end cap (22) further includes a groove (27) located on the side of the end cap (22) facing the electrode assembly (25), the connector (26) is accommodated in the groove (27), and there is a cavity between the third surface (263) of the connector (26) and the groove (27), the cavity being filled with plastic.

13. The battery cell according to any one of claims 1 to 11, characterized in that, The connector (26) is integrally formed with the electrode terminal (23).

14. A battery device, characterized in that, include: Box (10); The battery cell according to any one of claims 1 to 13 is housed in the housing (10).

15. An energy storage device, characterized in that, include: The battery cell according to any one of claims 1 to 13; or The battery device according to claim 14; The battery cell or the battery device is used to store electrical energy.

16. An energy storage system, characterized in that, include: Power conversion device (310); and The energy storage device according to claim 15; The power conversion device (310) is used to electrically connect the power generation device (320) and the energy storage device.

17. A charging network, characterized in that, include: Charging pile (410); and The energy storage device according to claim 15 or the energy storage system according to claim 16; wherein, The energy storage device or the energy storage system is used to provide electrical energy to the charging pile (410).

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