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

Abstract

The application relates to a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network, and belongs to the technical field of batteries. The electrode assembly in the battery monomer comprises first and second polar opposite tabs; the electrode terminal comprises first and second polar opposite electrode terminals, the first electrode terminal is connected with the first tab to form a first lead-out assembly, and the second electrode terminal is connected with the second tab to form a second lead-out assembly; a pressure relief mechanism is arranged in a shell; a protection module is connected between a first target piece and a second target piece, the first target piece is one of the first lead-out assembly, the second lead-out assembly and the pressure relief mechanism, the second target piece is the other one, and the protection module is used for balancing a voltage difference. The battery monomer, the battery device, the energy storage device, the energy storage system and the charging network provided by the application aim to reduce the risk of explosion and fire of the battery monomer in thermal runaway through the mode of actively clamping the voltage difference, and the reliability is higher.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, energy storage device, energy storage system and charging network. Background Technology

[0002] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] In the development of battery technology, in addition to improving the performance of individual battery cells, their reliability is also a crucial consideration. Therefore, how to improve the reliability of individual battery cells is a pressing issue that needs to be addressed in battery technology. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, battery device, energy storage device, energy storage system and charging network, which can reduce the risk of deflagration and fire of battery cells during thermal runaway by actively clamping voltage difference, and has higher reliability.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, electrode terminals, a pressure relief mechanism, and a protection module. The casing has a receiving cavity; the electrode assembly is received within the receiving cavity and includes a first electrode tab and a second electrode tab with opposite polarities; the electrode terminals are disposed on the casing and include a first electrode terminal and a second electrode terminal with opposite polarities, the first electrode terminal being connected to the first electrode tab to form a first lead-out assembly, and the second electrode terminal being connected to the second electrode tab to form a second lead-out assembly; the pressure relief mechanism is disposed on the casing; and the protection module is connected between a first target component and a second target component, the first target component being one of the first lead-out assembly, the second lead-out assembly, and the pressure relief mechanism, and the second target component being the other of the first lead-out assembly, the second lead-out assembly, and the pressure relief mechanism. The protection module is configured to balance the voltages on the first target component and the second target component.

[0006] In the technical solution of this application embodiment, a protection module is provided between the first target component and the second target component. The first target component is one of the first lead-out component, the second lead-out component, and the pressure relief mechanism, and the second target component is the other of the first lead-out component, the second lead-out component, and the pressure relief mechanism. In the event of thermal abuse testing or thermal runaway causing changes in the battery cell structure, the protection module can actively clamp the voltage difference between the first target component and the second target component to a voltage difference that can break down air. This reduces the risk of tip discharge between the first target component and the second target component, which helps to mitigate thermal runaway events and improves the reliability of the battery cell.

[0007] In some embodiments, the protection module includes a capacitor and a resistor connected in sequence. The capacitor stores charge when a voltage difference arises between the first and second target components, and the resistor dissipates the charge when the capacitor discharges. The protection module includes a capacitor and a resistor, wherein the capacitor acts as a DC blocking device, making the protection module open-circuit under normal battery cell operation, and collects and stores the charge generated between the first and second target components when the insulation fails, clamping the voltage difference between them below the minimum voltage difference required to break down air, thus reducing the risk of tip discharge on the component with the lower potential. The resistor dissipates the charge and converts it into heat energy when the capacitor discharges, achieving a "soft landing" of energy.

[0008] In some embodiments, the time constant of the protection module is greater than the ripple period of the battery cell during charging and discharging, and less than the failure time of the battery cell's casing when thermal abuse or thermal runaway occurs. The time constant is configured to characterize the product of the capacitance of the capacitor and the resistance of the resistor in the protection module. The time constant reflects the response speed of the protection module. By setting the time constant to be greater than the ripple period of the battery cell during charging and discharging, the protection module has a good bypass effect on the AC ripple during normal operation of the battery cell, reducing the risk of the protection module burdening the DC circuit during normal battery cell operation. Simultaneously, setting the time constant to be less than the failure time of the casing during thermal runaway allows the protection module to actively operate before the casing fails, proactively clamping the voltage between the first and second target components in advance.

[0009] In some embodiments, the capacitance of the capacitor is between 0.1 μF and 10 μF; the resistance of the resistor is between 10 Ω and 1000 Ω. This allows the specific parameters of the capacitor and resistor to be designed according to product specifications, improving the applicability of the protection module in individual battery cells.

[0010] In some embodiments, the resistor is a thick-film resistor or a wire-wound resistor. Both thick-film resistors and wire-wound resistors have good high-temperature resistance, which reduces the impact of high temperature on the protection module during thermal abuse testing of individual battery cells or in the event of thermal runaway, allowing the resistor to maintain the dissipation of the capacitor at high temperatures.

[0011] In some embodiments, the housing includes an end cap assembly and a shell, the end cap assembly and the shell together forming a receiving cavity; the end cap assembly includes an end cap body and an insulating member connected together, the end cap body is connected to a pressure relief mechanism, and the insulating member insulates the end cap body from the electrode terminals and the electrode assembly; the first target member may also be one of a first lead-out assembly, a second lead-out assembly, and the end cap body, and the second target member may be the other of the first lead-out assembly, the second lead-out assembly, and the end cap body. In these embodiments of the present application, since the end cap body is connected to the pressure relief mechanism, their potentials in the battery cell are consistent. At this time, placing the protection module between the end cap body and the first lead-out assembly or between the second lead-out assembly can balance the voltage difference between the pressure relief mechanism and the end cap body, reduce the risk of tip discharge of the pressure relief mechanism, and at the same time, provide new possibilities for the setting of the protection module, which is beneficial to further optimize the structure of the battery cell.

[0012] In some embodiments, the protection module is disposed within a housing cavity. This housing cavity provides a more stable operating environment for the protection module, further improving the reliability of the individual battery cells.

[0013] In some embodiments, the protection module is disposed outside the housing cavity. This reduces the difficulty of setting up the protection module, helps to reduce the occupation of the housing cavity, and helps to improve the energy density of the battery cell.

[0014] In some embodiments, the protection module is bonded to the insulating component. This simplifies the positioning of the protection module, and the bonding method between the protection module and the insulating component can further improve the structural stability of the protection module and enhance the vibration and drop resistance of the battery cells.

[0015] In some embodiments, the protection module is embedded within an insulating member. By molding the insulating member together with it during molding, the insulating member can provide good protection for the protection module.

[0016] In some embodiments, when the first target component and the second target component are respectively the first lead-out assembly and the second lead-out assembly, the protection module is connected between the first electrode terminal and the second electrode terminal; and / or, between the first electrode terminal and the second tab; and / or, between the first tab and the second electrode terminal; and / or, between the first tab and the second tab. The above configuration of the protection module can be freely selected according to product needs, providing a variety of different configuration methods for the protection module.

[0017] In some embodiments, the number of protection modules is at least two, and the first target component and the second target component connected to any two protection modules are not exactly the same. Multiple protection modules operate independently to reduce the risk of tip discharge between different first target components and different second target components in the event of thermal runaway, further improving the reliability of the battery cell.

[0018] In some embodiments, the protection module is welded to the first target component and the second target component. This arrangement helps to further improve the connection stability between the protection module and the first and second target components.

[0019] Secondly, embodiments of this application also provide a battery device, which includes a battery cell as provided in any of the foregoing embodiments.

[0020] Thirdly, embodiments of this application also provide an energy storage device, which includes a battery device as provided in any of the foregoing embodiments.

[0021] Fourthly, embodiments of this application also provide an energy storage system, which includes an energy storage converter and an energy storage device as provided in any of the foregoing embodiments. The energy storage converter is used to electrically connect the power generation device and the energy storage device.

[0022] Fifthly, embodiments of this application also provide a charging network, which includes charging piles and an energy storage device as provided in any of the foregoing embodiments, the energy storage device being used to provide electrical energy to the charging piles.

[0023] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a charging network provided in some embodiments of this application;

[0026] Figure 2 This application provides schematic diagrams of the structure of an energy storage system according to some embodiments.

[0027] Figure 3 This is a schematic diagram of the structure of an energy storage device provided in some embodiments of this application;

[0028] Figure 4 This is a three-dimensional structural schematic diagram of a battery device provided in some embodiments of this application;

[0029] Figure 5An exploded view of the three-dimensional structure of a single battery cell provided in some embodiments of this application;

[0030] Figure 6 This application provides schematic diagrams of the electrical connection structure between the protection module and other components in a battery cell, as shown in some embodiments.

[0031] Figure 7 This is a schematic diagram of the structure of the battery cell end cap assembly provided in an embodiment of this application.

[0032] Explanation of reference numerals in the attached diagram: 1. Charging network; 2. Energy storage system; 3. Power generation device;

[0033] 2000, Energy storage device; 210, Energy storage enclosure; 3000, Charging pile; 4000, Energy storage converter; 1000, Battery device; 200, Enclosure; 201, First part; 202, Second part;

[0034] 100. Battery cell; 10. Housing; 11. End cap assembly; 111. End cap body; 112. Insulator; 12. Housing; 20. Electrode assembly; 21. First electrode tab; 22. Second electrode tab; 30. Electrode terminal; 31. First electrode terminal; 32. Second electrode terminal; 40. Pressure relief mechanism; 50. Protection module; 51. Capacitor; 52. Resistor;

[0035] 101. Receiving cavity; 102. First target component; 103. Second target component. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, where the term "and / or" appears, "and / or" merely describes 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, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. Where the terms "first" and "second" appear, these terms are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" can explicitly or implicitly include at least one of those features. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0042] Compared to other types of batteries such as lead-acid and nickel-cadmium batteries, lithium-ion batteries have advantages such as high specific capacity, high operating voltage, fast charging speed, wide operating temperature range, long cycle life, small size, and light weight. They are widely used not only in portable electronic devices such as mobile phones, digital camcorders, and laptops, but also in large and medium-sized electric equipment such as electric vehicles, electric bicycles, and power tools. However, the safety of lithium batteries is a significant factor affecting their development.

[0043] The positive electrode materials of lithium-ion batteries generally include lithium-rich manganese-based, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, and lithium iron phosphate; the negative electrode is generally a graphite or silicon-carbon composite material. During charging, lithium ions are extracted from the positive electrode material, pass through the electrolyte and separator, and then embed into the negative electrode material. In a fully charged state, the positive electrode of a lithium-ion battery exhibits strong oxidizing properties, while the negative electrode exhibits strong reducing properties. The electrolyte used is typically LiPF6, which is easily decomposed by heat and is sensitive to water. The electrolyte solvent is generally a carbonate-based organic solvent with a low flash point. Under conditions of overcharging, over-discharging, or overheating, thermal runaway may occur inside the battery, leading to combustion or even explosion.

[0044] In related technologies, when thermal runaway occurs during thermal abuse testing or use of a battery cell, the insulating component, being a structure with a lower melting point, will melt first under the influence of heat. This melting inevitably affects other components within the battery cell that rely on the insulating component for fixation, altering their relative positions. When the insulating component fails, the air gap between components at high and low potentials within the battery cell changes. Due to the voltage difference between the two components, when the gap narrows, there is a risk of air breakdown and corona discharge or spark discharge, which could ignite electrolyte vapors within the containment cavity, exacerbating the thermal runaway situation.

[0045] In battery cells using related technologies, flame retardants and fire extinguishing agents are typically placed in the containment cavity to extinguish fires after thermal runaway escalates; or the material of the insulating components is changed to increase their melting point to reduce the risk of escalating thermal runaway. However, these methods are all passive protection measures against thermal runaway and cannot control the risk of thermal runaway at its source.

[0046] Based on this situation, this application provides a battery cell comprising a casing, an electrode assembly, electrode leads, a pressure relief mechanism, and a protection module. The casing has a receiving cavity; the electrode assembly is housed within the receiving cavity and includes a first electrode tab and a second electrode tab with opposite polarities; electrode terminals are disposed on the casing and include a first electrode terminal and a second electrode terminal with opposite polarities, the first electrode terminal being connected to the first electrode tab to form a first lead assembly, and the second electrode terminal being connected to the second electrode tab to form a second lead assembly; the pressure relief mechanism is disposed on the casing; and the protection module is connected between a first target component and a second target component, the first target component being one of the first lead assembly, the second lead assembly, and the pressure relief mechanism, and the second target component being the other of the first lead assembly, the second lead assembly, and the pressure relief mechanism. The protection module is configured to balance the voltages on the first target component and the second target component.

[0047] According to the battery cell of this application, by setting a protection module between a first target component and a second target component, wherein the first target component is one of a first lead-out assembly, a second lead-out assembly, and a pressure relief mechanism, and the second target component is the other of the first lead-out assembly, the second lead-out assembly, and the pressure relief mechanism, the protection module can actively clamp the voltage difference between the first target component and the second target component to a voltage difference that can break down air when thermal abuse testing or thermal runaway occurs and the battery cell structure changes. This reduces the risk of tip discharge of the component with the lower potential, which helps to mitigate thermal runaway events and improves the reliability of the battery cell.

[0048] The battery cells disclosed in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft.

[0049] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0050] The battery device disclosed in this application can be applied to energy storage devices such as energy storage containers or energy storage cabinets.

[0051] The battery device 1000 will be described below with reference to the accompanying drawings.

[0052] Please refer to Figure 1 and Figure 3 , Figure 1 This is a schematic diagram of the structure of the charging network 1 provided in some embodiments of this application. Figure 3This is a schematic diagram of the structure of an energy storage device 2000 provided in some embodiments of this application. Embodiments of this application provide a charging network 1, which includes a charging pile 3000 for charging electrical equipment. The charging network 1 may also include an energy storage device 2000, which is electrically connected to the charging pile 3000 and provides power to the charging pile 3000.

[0053] It should be noted that the charging pile 3000 and the battery cells in the energy storage device 2000 are electrically connected via cables. The battery cells can supply their stored electrical energy to the charging pile 3000. The charging pile 3000 has connectors that can be connected to electrical equipment, thereby replenishing the equipment's energy. The application of the energy storage device 2000 in this charging network 1 can effectively improve the safety of the charging network 1 and also help to improve the flexibility of the charging network 1 during deployment.

[0054] In a charging network 1, there can be one charging pile 3000, and the energy storage device 2000 provides power to the one charging pile 3000; there can also be multiple charging piles 3000, and the energy storage device 2000 provides power to multiple charging piles 3000.

[0055] As an example, such as Figure 1 As shown, the charging network 1 includes an energy storage device 2000 and two charging piles 3000, with the energy storage device 2000 providing power to the two charging piles 3000.

[0056] The energy storage device 2000 may include a battery device 1000, which is electrically connected to the charging pile 3000 so that the battery device 1000 can provide power to the charging pile 3000.

[0057] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of an energy storage system 2 provided in some embodiments of this application. Embodiments of this application provide an energy storage system 2. The energy storage system 2 includes an energy storage converter 4000, which can be electrically connected to a generator 3 to convert the electrical power provided by the generator 3. The energy storage system 2 may also include an energy storage device 2000, which is electrically connected to the energy storage converter 4000. The energy storage converter 4000 converts the electrical energy provided by the generator 3 and stores it in the energy storage device 2000.

[0058] A power conversion device is used to connect the power generation device 3 and the energy storage device 2000. The power generation device 3 generates electrical energy and stores the generated electrical energy in the energy storage device 2000 via the power conversion device. The use of the energy storage device 2000 in the energy storage system 2 effectively improves the operational safety of the energy storage system 2. In specific implementations, the power generation equipment can be solar panels, hydroelectric power generation equipment, thermal power generation equipment, etc. This application does not limit the specific type of power generation equipment.

[0059] As an example, such as Figure 2 As shown, the energy storage system 2 includes an energy storage device 2000 and an energy storage converter 4000. The two power generation devices 3 respectively transmit the generated electrical energy to the energy storage converter 4000, and the energy storage converter 4000 introduces the electrical energy into the energy storage device 2000 for storage.

[0060] Please refer to Figure 3 The energy storage device 2000 includes an energy storage box 210, and a battery device 1000 is installed inside the energy storage box 210.

[0061] As an example, the energy storage device 2000 can be an energy storage container, an energy storage cabinet, etc.

[0062] As an example, the energy storage device 2000 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 power stations can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. Wind power generation systems collect wind energy from wind turbines, convert it into electricity, and store it in the energy storage device 2000. Solar power generation systems can convert solar energy into electricity, store it in the energy storage device 2000, and supply it to users as needed. Mobile power systems can supply power to relevant electrical equipment in areas where the mains power supply cannot reach, such as remote mountainous areas and isolated wilderness areas. Temporary power supply systems can provide power to users when there is insufficient power.

[0063] Please refer to Figure 4 , Figure 4This is a perspective structural diagram of a battery device according to an embodiment of this application. The battery device 1000 includes a housing 200 and a battery cell 100, with the battery cell 100 housed within the housing 200. The housing 200 provides a accommodating space for the battery cell 100, and the housing 200 can adopt various structures. In some embodiments, the housing 200 may include a first portion 201 and a second portion 202, which overlap each other, jointly defining a accommodating space for accommodating the battery cell 100. The second portion 202 may be a hollow structure with one open end, and the first portion 201 may be a plate-like structure, with the first portion 201 covering the open side of the second portion 202, so that the first portion 201 and the second portion 202 jointly define the accommodating space; alternatively, the first portion 201 and the second portion 202 may both be hollow structures with one open side, with the open side of the first portion 201 covering the open side of the second portion 202. Of course, the box 200 formed by the first part 201 and the second part 202 can be of various shapes, such as cylinder, cuboid, etc.

[0064] In the battery device 1000, there can be multiple battery cells 100, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 100 are connected in both series and parallel configurations. Multiple battery cells 100 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 100 is housed within the housing 200. Alternatively, the battery device 1000 can also consist of multiple battery cells 100 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 200. The battery device 1000 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 100.

[0065] Each battery cell 100 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 100 can be cylindrical, flat, cuboid, or other shapes.

[0066] Please refer to Figure 5 , Figure 5 An exploded perspective view of a battery cell provided in one embodiment of this application. The battery cell 100 refers to the smallest unit comprising the battery device 1000. For example... Figure 5 The battery cell 100 includes a housing 10 (including an end cap assembly 11 and a housing 12) and an electrode assembly 20.

[0067] End cap assembly 11 refers to a component that covers the opening of housing 12 to isolate the internal environment of battery cell 100 from the external environment. Not limited to this, the shape of end cap assembly 11 may be adapted to the shape of housing 12 to fit housing 12.

[0068] The end cap assembly 11 includes an end cap body 111 and an insulating component 112. Optionally, the end cap body 111 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap assembly 11 is less likely to deform when subjected to compression and impact, so that the battery cell 100 can have higher structural strength and improved safety performance.

[0069] The end cap assembly 11 may be provided with functional components such as electrode terminals 30. The electrode terminals 30 can be electrically connected to the electrode assembly 20 for outputting or inputting electrical energy into the battery cell 100. In some embodiments, the end cap assembly 11 may also be provided with a pressure relief mechanism 40 for releasing internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. The end cap body 111 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose any special limitations on this.

[0070] The insulating component 112 in the battery cell 100 mainly undertakes the functions of electrical insulation and sealing. The insulating component 112 may be, but is not limited to, made of polypropylene, polyphenylene ether, nylon and other plastics that have excellent chemical corrosion resistance and insulation properties.

[0071] Generally, the insulating component 112 can be divided into an upper plastic and a lower plastic. The upper plastic is usually located between the riveting block and the housing 12 to isolate the riveting block and the housing 12, prevent short circuits, and improve the electrical reliability of the battery cell 100. Structurally, the upper plastic usually has through holes to cooperate with the riveting block, terminal posts, and other structures, playing a role in positioning, fixing, and simplifying assembly, which helps to improve the compactness and stability of the battery cell 100. The lower plastic is usually located between the end cap body 111 and the electrode assembly 20, mainly used to isolate the terminal posts, busbars, etc., from the housing 12 to prevent internal short circuits. At the same time, the lower plastic usually has an injection hole and is equipped with a one-way conduction valve structure to allow electrolyte to be injected into the housing while preventing liquid backflow or leakage, improving injection efficiency and reliability. In these embodiments of this application, only the lower plastic is used as an example of the insulating component 112.

[0072] The housing 12 is a component used to cooperate with the end cap assembly 11 to form the internal environment of the battery cell 100. This internal environment can accommodate the electrode assembly 20, electrolyte, and other components. The housing 12 and the end cap assembly 11 can be independent components. An opening can be provided on the housing 12, and the end cap assembly 11 can close the opening to form the internal environment of the battery cell 100. Alternatively, the end cap assembly 11 and the housing 12 can be integrated. Specifically, the end cap assembly 11 and the housing 12 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 12, the end cap assembly 11 closes the housing 12. The housing 12 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 12 can be determined according to the specific shape and size of the electrode assembly 20. The material of the housing 12 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0073] Electrode assembly 20 is the component in the battery cell 100 where electrochemical reactions occur. The casing 12 may contain one or more electrode assemblies 20. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the cell assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0074] Figure 6 This application provides schematic diagrams of the electrical connection structure between the protection module and other components in a battery cell, as shown in some embodiments. Figure 7 This is a schematic diagram of the structure of the battery cell end cap assembly provided in an embodiment of this application.

[0075] Please refer to the reference. Figures 1 to 7This application provides a battery cell 100, which includes a housing 10, an electrode assembly 20, electrode terminals 30, a pressure relief mechanism 40, and a protection module 50. The housing 10 has a receiving cavity 101; the electrode assembly 20 is received in the receiving cavity 101 and includes a first electrode tab 21 and a second electrode tab 22 with opposite polarities; the electrode terminals 30 are disposed on the housing 10 and include a first electrode terminal 31 and a second electrode terminal 32 with opposite polarities. The first electrode terminal 31 is connected to the first electrode tab 21 to form a first lead-out assembly. (Unlabeled), the second electrode terminal 32 is connected to the second electrode tab 22 to form a second lead-out assembly (unlabeled); the pressure relief mechanism 40 is disposed in the housing 10; the protection module 50 is connected between the first target component 102 and the second target component 103, the first target component 102 being one of the first lead-out assembly, the second lead-out assembly and the pressure relief mechanism 40, and the second target component 103 being the other of the first lead-out assembly, the second lead-out assembly and the pressure relief mechanism 40, and the protection module 50 is configured to balance the respective voltages on the first target component 102 and the second target component 103.

[0076] The outer casing 10 is a covering structure for the battery cell 100, used to provide a relatively sealed and stable working environment for the electrode assembly 20 disposed therein. The outer casing 10 has a receiving cavity 101, which means that the outer casing 10 is a hollow, fully enclosed structure, and the hollow area of ​​the outer casing 10 is the receiving cavity 101.

[0077] The outer contour of the outer shell 10 can be designed as needed. For example, in these embodiments of this application, the outer contour of the outer shell 10 can be, but is not limited to, a rectangle, a cylinder, a prism, etc.

[0078] The electrode assembly 20 is the component in the battery cell 100 that is actually used to store or release electrical energy. The electrode assembly 20 is housed in the receiving cavity 101. When immersed in the electrolyte, electrons can pass through the separator and move between the positive and negative electrode plates to realize the charging and discharging of the battery cell 100.

[0079] The electrode assembly 20 includes a first tab 21 and a second tab 22 with opposite polarities. That is, one of the first tab 21 and the second tab 22 is connected to the positive electrode plate in the electrode assembly 20 as a positive tab, and the other is connected to the negative electrode plate in the electrode assembly 20 as a negative tab.

[0080] Electrode terminals 30 are disposed on the housing 10 and include a first electrode terminal 31 and a second electrode terminal 32 with opposite polarities. The function of the electrode terminals 30 is to lead out the electrode assembly 20 so that the electrode assembly 20 can be connected to an external charging or discharging device through the electrode terminals 30. The first electrode terminal 31 and the second electrode terminal 32 have opposite polarities, meaning that one of them serves as the positive electrode terminal of the battery cell 100, and the other serves as the negative electrode terminal.

[0081] The first electrode terminal 31 is connected to the first tab 21 to form a first lead-out assembly, and the second electrode terminal 32 is connected to the second tab 22 to form a second lead-out assembly. In this way, the first lead-out assembly and the second lead-out assembly cooperate with each other to lead out the electrode assembly 20, and connect to the positive and negative terminals of an external charging or discharging device during use, so that the battery cell 100 and the external device form an electrical circulation loop to realize the corresponding charging or discharging function.

[0082] The pressure relief mechanism 40 is located on the outer casing 10 and is designed to work when thermal runaway of the battery cell 100 causes the temperature and pressure inside the containment cavity 101 to rise. This breaks the relatively sealed environment between the containment cavity 101 and the outside, allowing the gas inside the containment cavity 101 to escape to the outside, thereby relieving the internal pressure of the battery cell 100 under thermal runaway conditions and reducing the risk of the battery cell 100 exploding or burning.

[0083] The protection module 50 is connected between the first target component 102 and the second target component 103, wherein the first target component 102 is one of the first lead-out component, the second lead-out component and the pressure relief mechanism 40, and the second target component 103 is the other of the first lead-out component, the second lead-out component and the pressure relief mechanism 40.

[0084] In some embodiments, the protection module 50 may be disposed between the first lead-out component and the second lead-out component, and / or between the first lead-out component and the pressure relief mechanism 40, and / or between the second lead-out component and the pressure relief mechanism 40. That is, the protection module 50 may be disposed between the positive lead-out side of the battery cell 100 and the pressure relief mechanism 40, and / or between the negative lead-out side and the pressure relief mechanism 40, and / or between the positive lead-out side and the negative lead-out side, i.e., the protection module 50 is disposed between components that may generate a voltage difference after the insulation of the housing 10 fails.

[0085] The protection module 50 is configured to balance the voltages on the first target 102 and the second target 103, that is, the protection module 50 can be used to reduce the voltage difference between the first target 102 and the second target 103, thereby reducing the risk of tip discharge of the first target 102 or the second target 103 due to the presence of voltage difference.

[0086] It should be noted that in these embodiments of this application, the first target component 102 and the second target component 103 can be relatively insulated from each other by the outer casing 10. However, during the thermal abuse test of the battery cell 100 or when the battery cell 100 is in a thermal runaway state, the structure of the outer casing 10 changes due to heat. This causes the relative positional relationship between some components directly or indirectly disposed on the outer casing 10, such as the first tab 21, the second tab 22, the first electrode terminal 31, the second electrode terminal 32, and the pressure relief mechanism 40, to change. This causes the insulation between some components to fail and generate a large voltage difference, which can easily break down the air and generate an extremely high-temperature electric arc. There is a risk that the electric arc may ignite the electrolyte vapor or other flammable gases generated, exacerbating the thermal runaway situation.

[0087] The protection module 50 is disposed between the first target component 102 and the second target component 103. The first target component 102 and the second target component 103 are any two components that may generate a voltage difference when the insulation of the housing 10 fails. The two are connected through the protection module 50 so as to balance the voltage of each component when the insulation of the housing 10 fails, reduce the voltage difference between them, thereby reducing the risk of arcing and sparking, and facilitating the control of thermal runaway events.

[0088] According to the battery cell 100 provided in the embodiments of this application, a protection module 50 is provided between the first target component 102 and the second target component 103. The first target component 102 is one of the first lead-out component, the second lead-out component, and the pressure relief mechanism 40, and the second target component 103 is the other of the first lead-out component, the second lead-out component, and the pressure relief mechanism 40. When the structure of the battery cell 100 changes due to thermal abuse testing or thermal runaway, the protection module 50 can actively clamp the voltage difference between the first target component 102 and the second target component 103 to a voltage difference that can break down air. This reduces the risk of tip discharge between the first target component 102 and the second target component 103, which helps to mitigate thermal runaway events and improves the reliability of the battery cell 100.

[0089] In some embodiments, the protection module 50 includes a capacitor 51 and a resistor 52 connected in sequence. The capacitor 51 is used to store charge when a voltage difference is generated between the first target 102 and the second target 103, and the resistor 52 is used to dissipate charge when the capacitor 51 discharges.

[0090] Capacitor 51 stores charge when a voltage difference arises between the first target component 102 and the second target component 103. It is understood that, due to the "DC blocking and AC passing" characteristic of capacitor 51, under normal operating conditions of the battery cell 100, the protection module 50 (capacitor-resistor circuit) is in an open-circuit state and will not affect the normal operation of the battery cell 100. However, when the insulation of the casing 10 fails, causing a voltage difference between the first target component 102 and the second target component 103, capacitor 51 in the protection module 50 begins to collect and store charge, enabling the protection module 50 to open-circuit under normal operating conditions of the battery cell 100 and actively intervene when the insulation of the casing 10 fails.

[0091] The function of resistor 52 is to consume the charge stored in capacitor 51 so that electrical energy is converted into heat energy when capacitor 51 discharges, so that capacitor 51 and resistor 52 together clamp the voltage difference between the first target 102 and the second target 103 within a suitable range, reducing the risk of tip discharge and arcing between the first target 102 and the second target 103.

[0092] It should be noted that the heat generated by resistor 52 is much lower than the temperature of electric arc spark. Therefore, in these embodiments of this application, resistor 52 is mainly used to make the energy between the first target 102 and the second target 103 "soft land" when thermal runaway occurs in the battery cell 100, thereby reducing the risk of tip discharge and generation of electric arc spark.

[0093] In some embodiments, resistor 52 may be replaced with other loads that can convert electrical energy when capacitor 51 is discharging. For example, in some embodiments, resistor 52 may be replaced with an alarm so that the alarm operates when capacitor 51 is discharging, converting electrical energy into light energy and mechanical energy (vibration generates sound) to warn of thermal runaway in battery cell 100.

[0094] In some embodiments, the alarm can also be connected in series in the capacitor-resistor circuit of the protection module 50 so that the resistor 52 and the alarm together consume the charge stored in the capacitor 51. At the same time, the alarm can be used to remind the user of the battery cell 100 to warn of the risk of thermal runaway of the battery cell 100.

[0095] In some embodiments, the time constant of the protection module 50 is greater than the ripple period of the battery cell 100 during charging and discharging, and the time constant of the protection module 50 is less than the failure time of the casing 10 of the battery cell 100 when thermal abuse or thermal runaway occurs; wherein, the time constant is configured to characterize the product of the capacitance of the capacitor 51 and the resistance of the resistor 52 in the protection module 50.

[0096] The time constant of the protection module 50 is equal to the product of the capacitance of the capacitor 51 and the resistance of the resistor 52, and can be used to characterize the response rate of the protection module 50 to thermal runaway.

[0097] In these embodiments of the present application, by setting the time constant of the protection module 50 to be greater than the ripple period of the battery cell 100 during charging and discharging, the protection module 50 can have a good bypass effect on the AC ripple of the battery cell 100 during normal operation, reducing the risk of the protection module 50 causing a burden on the DC circuit.

[0098] Meanwhile, by setting the time constant of the protection module 50 to be less than the failure time of the casing 10 when the battery cell 100 experiences thermal abuse or thermal runaway, the protection module 50 can intervene before the casing 10 fails, balancing and clamping the voltage between the first target component 102 and the second target component 103, reducing the risk of tip discharge and arcing between the first target component 102 and the second target component 103.

[0099] It should be noted that in these embodiments of this application, the capacitance parameters of the capacitor 51 and the resistance parameters of the resistor 52 in the protection module 50 can be adjusted and set according to the specific parameters of the battery cell 100 (such as the voltage of the battery cell 100 and the size of the end cap assembly 11 in the casing 10).

[0100] In some embodiments, the capacitance of capacitor 51 is between 0.1 μF and 10 μF. The capacitance of capacitor 51 needs to be set appropriately so that it can store enough charge to neutralize the potential of the first target 102 or the second target 103 exposed due to insulation failure of the casing 10. The capacitance should be selected to ensure that the amount of charge stored is much greater than the amount of charge that may accumulate due to electric field distortion between the first target 102 and the second target 103, so that the protection module 50 can effectively reduce the voltage difference between the first target 102 and the second target 103.

[0101] Exemplary examples in these embodiments of the present application may include, but are not limited to, setting the capacitance of capacitor 51 to 0.5μF, 1μF, 3μF, 5μF, or 8μF. Capacitor 51 may include, but is not limited to, ceramic capacitors or film capacitors with good insulation and heat resistance.

[0102] The resistance of resistor 52 is between 10Ω and 1000Ω. Resistor 52 has two main functions. One is to limit the leakage current generated by the charging and discharging circuit of capacitor 51 when the battery cell 100 is operating normally, so as to limit the leakage current to a minimum and reduce the impact on the normal operation and cycle performance of the battery cell 100. At the same time, when capacitor 51 discharges after the insulation of the casing 10 fails, resistor 52 can be used to limit the instantaneous current peak, reducing the risk of generating new sparks or impacting the electrode assembly 20.

[0103] For example, the resistance value of resistor 52 may be, but is not limited to, 50Ω, 100Ω, 300Ω, 500Ω or 800Ω.

[0104] In these embodiments of the present application, when selecting the capacitance of capacitor 51 and the resistance of resistor 52, the influence of protection module 50 on the normal operation of battery cell 100 and the response speed (i.e., time constant) of protection module 50 in the event of thermal runaway should be taken into account.

[0105] For example, the capacitance of capacitor 51 can be selected to be 1μF and the resistance of resistor 52 can be selected to be 100Ω, so that the protection module 50 can reduce the impact on battery cell 100 when the battery cell 100 is operating normally, and respond quickly when the insulation of the casing 10 fails (at which time the time constant τ=0.1 ms), actively intervene and adjust the voltage difference between the first target component 102 and the second target component 103, thereby reducing the risk of thermal runaway escalation.

[0106] In some embodiments, resistor 52 is a thick-film resistor or a wire-wound resistor. This improves the high-temperature resistance of resistor 52, enabling it to maintain good operating conditions even in the event of thermal runaway.

[0107] In some embodiments, after the capacitor 51 and resistor 52 are connected, a protective cover can be provided on the outer layer of both to cover and fix the capacitor 51 and resistor 52, thereby improving the consistency between the capacitor 51 and resistor 52.

[0108] In some embodiments, the housing 10 includes an end cap assembly 11 and a housing 12, the end cap assembly 11 and the housing 12 together forming a receiving cavity 101; the end cap assembly 11 includes an end cap body 111 connected to an insulating member 112, the end cap body 111 is connected to a pressure relief mechanism 40, and the insulating member 112 insulates the end cap body 111 from the electrode terminal 30 and the electrode assembly 20; the first target member 102 may also be one of the first lead-out assembly, the second lead-out assembly and the end cap body 111, and the second target member 103 may be the other of the first lead-out assembly, the second lead-out assembly and the end cap body 111.

[0109] The outer casing 10 includes an end cap assembly 11 and a housing 12. The end cap assembly 11 and the housing 12 together form a receiving cavity 101. This means that during the manufacturing process of the outer casing 10, the end cap assembly 11 and the housing 12 are formed separately and then assembled together to form the receiving cavity 101. A possible implementation is that the housing 12 is a semi-enclosed structure with one open end. During assembly, the end cap assembly 11 covers the open end of the housing 12 and together forms the receiving cavity 101.

[0110] The end cap assembly 11 includes an end cap body 111 and an insulating member 112 connected to each other. The end cap body 111 is connected to the pressure relief mechanism 40. The end cap body 111 is a metal member to improve the structural strength of the end cap assembly 11. The connection between the end cap body 111 and the pressure relief mechanism 40 makes the end cap body 111 and the pressure relief mechanism 40 equipotential.

[0111] At this time, the first target component 102 can also be one of the first lead-out component, the second lead-out component, and the end cap body 111, and the second target component 103 can be the other of the first lead-out component, the second lead-out component, and the end cap body 111. In this way, more possibilities are provided for the setting of the protection module 50, so that the protection module 50 can adjust the voltage difference between the pressure relief mechanism 40 and the first lead-out component or the second lead-out component through the end cap body 111.

[0112] In some embodiments, the protection module 50 is disposed inside the receiving cavity 101, and / or the protection module 50 is disposed outside the receiving cavity 101.

[0113] The protection module 50 is located within the receiving cavity 101, meaning that the structure of the protection module 50 is located within the receiving cavity 101. This allows the receiving cavity 101 to provide a relatively stable and sealed working environment for the protection module 50, further improving the structural reliability of the battery cell 100.

[0114] In some embodiments, the protection module 50 is disposed outside the receiving cavity 101 to reduce the space occupied by the protection module 50 in the receiving cavity 101, which is beneficial to improving the energy density of the battery cell 100. At the same time, the arrangement of the protection module 50 outside the receiving cavity 101 also helps to reduce the difficulty of installing the protection module 50.

[0115] In some embodiments, the protection module 50 is bonded to the insulating member 112, and / or the protection module 50 is embedded in the insulating member 112.

[0116] The bonding of the protection module 50 to the insulating component 112 refers to the fact that the capacitor 51 and resistor 52 in the protection module 50 can be fixed to the insulating component 112 by adhesive, and the capacitor 51 and resistor 52 are connected sequentially by wires to form a capacitor-resistance circuit. The two ends of this capacitor-resistance circuit are electrically connected to the first target component and the second target component by welding, respectively. The adhesive bonding between the protection module 50 and the insulating component 112 is simple and easy to implement, which can improve the assembly efficiency of the protection module 50.

[0117] In some embodiments, the protection module 50 may be embedded within the insulating member 112. That is, the protection module 50 may be integrally formed with the insulating member 112 during the forming stage, using the insulating member 112 as the outer covering structure of the protection module 50. This arrangement helps to further improve the structural consistency between the protection module 50 and the insulating member 112, and further enhances the vibration and drop resistance of the battery cell 100.

[0118] It is understood that, in the embodiment where the protection module 50 is embedded in the insulating member 112, at least a portion of the wires located at both ends of the protection module 50 for connecting to the first target member 102 and the second target member 103 respectively are disposed outside the insulating member 112, so as to connect to the first target member 102 and the second target member 103 respectively.

[0119] In some embodiments, the number of protection modules 50 is at least two, and the first target component 102 and the second target component 103 connected to any two protection modules 50 are not exactly the same.

[0120] Multiple protection modules 50 are independent of each other and are respectively connected between different first target components 102 and different second target components 103, respectively, to balance the voltage difference between different first target components 102 and different second target components 103.

[0121] For example, in some embodiments, the number of protection modules 50 may be three. One protection module 50 is disposed between the first electrode terminal 31 and the pressure relief mechanism 40 to adjust the voltage difference between the first electrode terminal 31 and the pressure relief mechanism 40 when the battery cell 100 experiences thermal runaway. Another protection module 50 is disposed between the second electrode terminal 32 and the pressure relief mechanism 40 to adjust the voltage difference between the second electrode terminal 32 and the pressure relief mechanism 40 when the battery cell 100 experiences thermal runaway. A third protection module 50 is disposed between the first electrode terminal 31 and the second electrode terminal 32 to adjust the voltage difference between the first electrode terminal 31 and the second electrode terminal 32 when the battery cell 100 experiences thermal runaway.

[0122] In some embodiments, when the first target component 102 and the second target component 103 are respectively the first lead-out component and the second lead-out component, the protection module 50 is connected between the first electrode terminal 31 and the second electrode terminal 32; and / or, between the first electrode terminal 31 and the second electrode tab 22; and / or, between the first electrode tab 21 and the second electrode terminal 32; and / or, between the first electrode tab 21 and the second electrode tab 22.

[0123] In the structure of the battery cell 100, the polarity of the first tab 21 is the same as the polarity of the first electrode terminal 31, and the polarity of the second tab 22 is the same as the polarity of the second electrode terminal 32. Therefore, in these embodiments of the present application, the first lead-out assembly and the second lead-out assembly are respectively structures in the battery cell 100 used to lead out the positive and negative electrodes of the electrode assembly 20.

[0124] In this way, the first tab 21 and the first electrode terminal 31 are at the same potential, and the second tab 22 and the second electrode terminal 32 are at the same potential. In embodiments where the protection module 50 is disposed between the first lead assembly and the second lead assembly, the protection module 50 can be connected between the first electrode terminal 31 and the second electrode terminal 32, between the first electrode terminal 31 and the second tab 22, between the first tab 21 and the second electrode terminal 32, or between the first tab 21 and the second tab 22. Furthermore, in embodiments where there are multiple protection modules 50, multiple protection modules 50 can be simultaneously disposed between the first lead assembly and the second lead assembly to reduce the voltage difference between the two components in the event of thermal runaway of the battery cell 100.

[0125] It should be noted that in some embodiments of this application, the first tab 21 and the first electrode terminal 31, and the second tab 22 and the second electrode terminal 32, are connected by adapters to reduce the difficulty of connecting the tabs and the electrode terminals. It is understood that the adapter connecting the first tab 21 and the first electrode terminal 31 is a first adapter (not shown), and the potential of the first adapter is consistent with that of the first tab 21 and the first electrode terminal 31; the adapter connecting the second tab 22 and the second electrode terminal 32 is a second adapter (not shown), and the potential of the second adapter is consistent with that of the second tab 22 and the second electrode terminal 32. In this case, the protection module 50 can also be located between the first adapter and the second adapter to provide more options for optimizing the placement of the protection module 50.

[0126] In some embodiments, the protection module 50 is welded to the first target component 102 and the second target component 103. This means that the wires disposed at both ends of the protection module 50 are welded to the first target component 102 and the second target component 103 respectively, so as to further improve the structural consistency between the protection module 50 and the first target component 102 and the second target component 103, and thus improve reliability.

[0127] For example, in some embodiments of this application, the protection module 50 may be welded to the first target component 102 and the second target component 103 by laser welding.

[0128] This application also provides a battery device, which includes a battery cell 100 as provided in any of the foregoing embodiments.

[0129] This application also provides an energy storage device, which includes a battery device as provided in any of the foregoing embodiments.

[0130] This application also provides an energy storage system, which includes an energy storage converter and an energy storage device as provided in any of the foregoing embodiments. The energy storage converter is used to electrically connect the power generation device and the energy storage device.

[0131] This application also provides a charging network, which includes charging piles and an energy storage device as provided in any of the foregoing embodiments, the energy storage device being used to provide electrical energy to the charging piles.

[0132] Based on some embodiments of this application, please refer to the following: Figures 1 to 7 This application provides a battery cell 100, which includes a housing 10, an electrode assembly 20, electrode terminals 30, a pressure relief mechanism 40, and a protection module 50. The housing 10 has a receiving cavity 101; the electrode assembly 20 is received in the receiving cavity 101 and includes a first electrode tab 21 and a second electrode tab 22 with opposite polarities; the electrode terminals 30 are disposed on the housing 10 and include a first electrode terminal 31 and a second electrode terminal 32 with opposite polarities. The first electrode terminal 31 is connected to the first electrode tab 21 to form a first lead-out assembly. (Unlabeled), the second electrode terminal 32 is connected to the second electrode tab 22 to form a second lead-out assembly (unlabeled); the pressure relief mechanism 40 is disposed in the housing 10; the protection module 50 is connected between the first target component 102 and the second target component 103, the first target component 102 being one of the first lead-out assembly, the second lead-out assembly and the pressure relief mechanism 40, and the second target component 103 being the other of the first lead-out assembly, the second lead-out assembly and the pressure relief mechanism 40, and the protection module 50 is configured to balance the respective voltages on the first target component 102 and the second target component 103.

[0133] In these embodiments of this application, the first target component 102 is the positive electrode terminal, and the second target component 103 is the pressure relief mechanism 40. That is, the protection module 50 is disposed between the positive electrode terminal and the pressure relief mechanism 40. Under the normal working condition of the battery cell 100, the protection module 50 will not affect the normal working condition of the battery cell 100. However, when the battery cell 100 experiences thermal runaway, causing the insulation of the casing 10 to fail, the relative positional relationship between the positive electrode terminal and the pressure relief mechanism 40 changes. The positive electrode terminal is at a high potential, and the pressure relief mechanism 40 is at a low potential, resulting in a large voltage difference between the two. At the same time, since the structure of the pressure relief mechanism 40 is usually designed with sharp corners or edges with small radii of curvature (to meet the pressure requirements of precise explosion), under the action of a high voltage difference, sharp discharge phenomena are easily generated at these sharp corners or edges with small radii of curvature, thereby generating electric arc sparks.

[0134] At this time, the protection module 50 can automatically operate before the insulation of the housing 10 fails, balancing the voltage between the positive electrode terminal and the pressure relief mechanism 40, and reducing the risk of tip discharge.

[0135] In these embodiments of the present application, the two ends of the protection module 50 are respectively connected to the first target 102 and the second target 103, so that the capacitor 51 and the resistor 52 together clamp the voltage difference between the first target 102 and the second target 103 within a suitable range, thereby reducing the risk of tip discharge and arcing between the first target 102 and the second target 103.

[0136] In these embodiments of the present application, by setting the time constant of the protection module 50 to be greater than the ripple period of the battery cell 100 during charging and discharging, the protection module 50 can have a good bypass effect on the AC ripple of the battery cell 100 during normal operation, reducing the risk of the protection module 50 causing a burden on the DC circuit.

[0137] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly, housed in the receiving cavity, includes a first electrode tab and a second electrode tab with opposite polarities; An electrode terminal is disposed on the housing and includes a first electrode terminal and a second electrode terminal with opposite polarities. The first electrode terminal is connected to the first tab to form a first lead-out assembly, and the second electrode terminal is connected to the second tab to form a second lead-out assembly. A pressure relief mechanism is located in the outer casing; A protection module is connected between a first target component and a second target component and includes a capacitor and a resistor connected in sequence. The first target component is one of a first lead-out assembly, a second lead-out assembly, and a pressure relief mechanism. The second target component is the other of the first lead-out assembly, the second lead-out assembly, and the pressure relief mechanism. The protection module is configured to balance the voltages on the first target component and the second target component. The capacitor is used to store charge when a voltage difference is generated between the first target component and the second target component. The resistor is used to dissipate charge when the capacitor discharges.

2. The battery cell according to claim 1, characterized in that, The time constant of the protection module is greater than the ripple period of the battery cell during charging and discharging, and the time constant of the protection module is less than the failure time of the casing when the battery cell experiences thermal runaway. The time constant is configured to characterize the product of the capacitance of the capacitor and the resistance of the resistor in the protection module.

3. The battery cell according to claim 1, characterized in that, The capacitance of the capacitor is between 0.1 μF and 10 μF; And / or, the resistance of the resistor is between 10Ω and 1000Ω.

4. The battery cell according to claim 1, characterized in that, The resistor is a thick-film resistor or a wire-wound resistor.

5. The battery cell according to claim 1, characterized in that, The outer casing includes an end cap assembly and a housing, wherein the end cap assembly and the housing together form the receiving cavity; The end cap assembly includes an end cap body and an insulating component connected together. The end cap body is connected to the pressure relief mechanism, and the insulating component insulates the end cap body from the electrode terminals and the electrode assembly. The first target component may be one of the first lead-out component, the second lead-out component, and the end cap body, and the second target component may be the other of the first lead-out component, the second lead-out component, and the end cap body.

6. The battery cell according to claim 5, characterized in that, The protection module is disposed inside the receiving cavity, and / or the protection module is disposed outside the receiving cavity.

7. The battery cell according to claim 5, characterized in that, The protection module is bonded to the insulating component, and / or the protection module is embedded within the insulating component.

8. The battery cell according to claim 1, characterized in that, When the first target component and the second target component are respectively the first lead-out component and the second lead-out component, The protection module is connected between the first electrode terminal and the second electrode terminal; and / or between the first electrode terminal and the second tab; And / or, between the first electrode tab and the second electrode terminal; and / or, between the first electrode tab and the second electrode tab.

9. The battery cell according to any one of claims 1 to 8, characterized in that, The number of protection modules is at least two, and the first target component and the second target component connected to any two protection modules are not exactly the same.

10. The battery cell according to any one of claims 1 to 8, characterized in that, The protection module is welded to the first target component and the second target component.

11. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1 to 10.

12. An energy storage device, characterized in that, Includes the battery device as described in claim 11.

13. An energy storage system, characterized in that, It includes an energy storage converter and an energy storage device as described in claim 12, wherein the energy storage converter is used to electrically connect the power generation device and the energy storage device.

14. A charging network, characterized in that, It includes a charging pile and an energy storage device as described in claim 12, the energy storage device being used to provide electrical energy to the charging pile.

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