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

Abstract

The invention relates to a single battery, a battery device, an energy storage device, an energy storage system and a charging network. The single battery comprises a shell, an electrode assembly and an insulating structure. The electrode assembly is contained in the shell, the shell comprises a first shell wall and a protruding part which protrudes towards the electrode assembly and supports the electrode assembly, and the protruding part forms a concave part on the surface, opposite to the electrode assembly, of the first shell wall; the insulating structure comprises a first insulating part, the first insulating part covers the surface, opposite to the electrode assembly, of the first shell wall, and a part of the first insulating part is attached to the inner wall of the concave part. In the single battery, the first insulating part covers the surface, opposite to the electrode assembly, of the first shell wall, so that the bottom of the single battery is insulated and protected. As one part of the first insulating part is attached to the inner wall of the concave part, the first insulating part is tightly attached to the concave part of the first shell wall, so that no gap is generated between the first insulating part and the inner wall of the concave part, the insulating property of the bottom of the battery monomer is effectively improved, and the service life of an insulating material is effectively prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, battery devices, energy storage devices, energy storage systems and charging networks. Background Art

[0002] With the rapid development of battery technology, the reliability requirements for battery cells are getting higher and higher. In order to effectively prevent the explosion of the battery cell at the bottom, a part of the bottom of the shell is usually concave to form a protrusion protruding inward to raise the electrode assembly inside the battery cell. However, due to the design of the battery structure, it is easy to reduce the insulation performance at the bottom of the battery cell and the life of the insulation material. Summary of the invention

[0003] Based on this, it is necessary to provide a battery cell, a battery device, an energy storage device, an energy storage system and a charging network to effectively improve the insulation performance of the bottom of the battery cell and the life of the insulation material.

[0004] In a first aspect, the present application provides a battery cell, which includes: an outer shell, which includes a first shell wall and a protrusion; an electrode assembly, which is accommodated in the outer shell, the protrusion is formed on the surface of the first shell wall facing the electrode assembly, and the protrusion forms a recess on the surface of the first shell wall facing away from the electrode assembly; an insulating structure, including a first insulating member, the first insulating member covers the surface of the first shell wall facing away from the electrode assembly, and a portion of the first insulating member is attached to the inner wall of the recess.

[0005] In the above-mentioned battery cell, the first insulating member covers the surface of the first shell wall facing away from the electrode assembly, so that the bottom of the battery cell is insulated and protected. Since a part of the first insulating member is attached to the inner wall of the recess, the first insulating member is tightly attached to the recess of the first shell wall, so that no gap is generated between the first insulating member and the inner wall of the recess, reducing the possibility of local discharge at the recess, and effectively improving the insulation performance of the bottom of the battery cell and the life of the insulating material.

[0006] In some embodiments, the first insulating member includes a fitting portion and a peripheral portion located outside the fitting portion, the fitting portion is fitted to the inner wall of the recess, and the peripheral portion is fitted to the area on the first shell wall except the recess. In this design, the first insulating member is designed as a fitting portion and a peripheral portion, so that the first insulating member can be better fitted on the surface of the first shell wall facing away from the electrode assembly, which not only improves the bonding strength between the first insulating member and the first shell wall; but also improves the insulation protection of the first shell wall, thereby improving the insulation performance of the battery cell and the service life of the insulation material.

[0007] In some embodiments, the fitting portion fits the inner wall of the recess, and a groove is formed on a side of the fitting portion that faces away from the recess. In this design, the groove is provided on the side of the fitting portion that faces away from the recess, which is convenient for increasing the specific surface area of ​​the first insulating member, improving the bonding strength of the surface of the first insulating member, and facilitating improving the stability of the battery cell in the battery device.

[0008] In some embodiments, the inner wall of the recess includes a first wall and second walls respectively disposed on opposite sides of the first wall, the fitting portion includes a first sub-portion and second sub-portions respectively disposed on opposite sides of the first sub-portion, the two second sub-portions and the first sub-portion enclose to form a recess, the first sub-portion fits the first wall, and the second sub-portion fits the second wall. In this design, the recess is designed as a first wall and two second walls, and the fitting portion is designed as a first sub-portion and two second sub-portions, so that when the fitting portion fits in the recess, a recess is formed on the side of the fitting portion that faces away from the recess.

[0009] In some embodiments, the first insulating member includes a covering portion, and the housing further includes a second shell wall disposed around the first shell wall, and the covering portion is configured to cover at least a portion of the second shell wall. With such a design, the covering portion of the first insulating member is extended to cover the second shell wall, thereby improving the insulation protection effect of the first insulating member on the first shell wall; at the same time, it also reduces the creepage discharge phenomenon on the second shell wall when the insulation of the first shell wall is tested.

[0010] In some embodiments, the fitting parts and the recessed parts each include a plurality of fitting parts and the recessed parts are arranged one to one, and the peripheral part is located at the periphery of each fitting part. In this design, multiple fitting parts and recessed parts are introduced to further improve the bonding strength between the first insulating member and the first shell wall, thereby achieving more effective insulation protection for the first shell wall.

[0011] In some embodiments, the thickness of the first insulating member is recorded as h, where 50 mm ≤ h ≤ 300 mm. With such a design, the thickness of the first insulating member is controlled between 50 mm and 300 mm, which reduces the space occupied in the height direction while improving the insulation protection of the first shell wall as much as possible, thereby improving the insulation performance of the battery cell.

[0012] In some embodiments, the thickness h also satisfies the condition: 60 mm ≤ h ≤ 80 mm. With such a design, the thickness of the first insulating member is controlled between 60 mm and 80 mm, further effectively taking into account the space occupied in the height direction and the insulation performance of the battery cell.

[0013] In some embodiments, the insulation structure further includes a second insulation member, which is coated on the side of the shell surrounding the outer periphery of the first shell wall and connected to the first insulation member. In this design, the introduction of the second insulation member makes the insulation protection of the shell more effective and reliable, and further improves the insulation performance of the battery cell.

[0014] In some embodiments, a portion of the first insulating member is wrapped around the side of the housing that is arranged around the outer periphery of the first housing wall, and an end of the second insulating member close to the first housing wall is wrapped around the surface of the second insulating member that faces away from the housing. In this design, the second insulating member and the first insulating member are overlapped on the side of the housing, which not only facilitates the connection between the two, but also helps to improve the insulation protection of the housing and enhance the insulation effect.

[0015] In some embodiments, the second insulating member is configured to be coated on the side of the housing around the first housing wall in a film-layer attachment manner. In this design, attaching the second insulating member to the side of the housing in a film-layer attachment manner not only simplifies the process, but also improves the insulation protection of the side of the housing.

[0016] In some embodiments, the first insulating member is constructed to have a structure having one or more of epoxy material, polyimide material, and acrylic material. With such a design, using at least one of epoxy material, polyimide material, and acrylic material as the material of the first insulating member is not only conducive to improving insulation, but also conducive to the first insulating member being attached to the inner wall of the recess, eliminating the gap between the first insulating member and the recess, and reducing the risk of partial discharge.

[0017] In some embodiments, the housing includes a shell and an end cap disposed on the shell, and the end of the shell away from the end cap includes a first shell wall. With such a design, the end cap and the shell are introduced to facilitate sealing the electrode assembly and provide a closed environment for it.

[0018] In some embodiments, the first insulating member is configured to be formed on the inner wall of the recess and the surface of the first shell wall facing away from the electrode assembly by coating or electrophoresis. Such a design, using coating or electrophoresis, is conducive to improving the insulation performance on the first shell wall; at the same time, it also reduces the possibility of a gap between the first insulating member and the recess, reducing the probability of partial discharge.

[0019] In some embodiments, the battery cell further includes a pressure relief mechanism, which is disposed on the first shell wall. In this design, the pressure relief mechanism and the protrusion are both disposed on the first bottom wall, so that the pressure relief in the pressure relief mechanism is stably performed, which is beneficial to improving the reliability of the battery cell.

[0020] In some embodiments, the pressure relief mechanism includes a notch, which is recessed on the surface of the first shell wall facing and / or facing away from the electrode assembly. With such a design, the notch is introduced to facilitate directional pressure relief from the first shell wall during thermal runaway, thereby improving the reliability of the battery cell.

[0021] In a second aspect, the present application provides a battery device, the battery device comprising any of the above battery cells.

[0022] In a third aspect, the present application provides an electrical device, which includes the above battery device.

[0023] In a fourth aspect, the present application provides an energy storage device, which includes the above battery device.

[0024] In a fifth aspect, the present application provides an energy storage system, which includes a power conversion device and an energy storage device as described above, wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0025] In a sixth aspect, the present application provides a charging network, which includes: charging piles: such as the above energy storage device or the above energy storage system, the energy storage device is used to provide electrical energy for the charging piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An exploded view of a battery device provided in accordance with some embodiments of the present application.

[0027] Figure 2 A schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application.

[0028] Figure 3 A schematic diagram of the structure of an energy storage system provided in some embodiments of the present application.

[0029] Figure 4 A schematic diagram of the structure of a charging network provided for some embodiments of the present application.

[0030] Figure 5 A cross-sectional view of the local structure after the housing and the insulating structure are matched in some embodiments of the present application.

[0031] Figure 6 A cross-sectional view of a partial structure of a housing provided in some embodiments of the present application.

[0032] Figure 7 A schematic structural diagram of the surface of the first shell wall facing away from the electrode assembly provided in some embodiments of the present application.

[0033] Figure 8 A cross-sectional view of the local structure after the shell and the insulation structure are matched with each other in some other embodiments of the present application.

[0034] Fig. 9 for Figure 6 Enlarged view of the structure at point A in the middle circle.

[0035] Fig.10 for Figure 5 Enlarged view of the structure at point B in the middle circle.

[0036] 100, battery device; 10, battery cell; 20, casing; 201, first part; 202, second part; 1, outer shell; 1a, shell; 1a1, opening; 1b, end cap; 11, first shell wall; 12, protrusion; 13, recess; 131, first wall; 132, second wall; 14, second shell wall; 2, electrode assembly; 3, insulating structure; 31, first insulating member; 311, fitting part; 31a, first sub-section; 31b, second sub-section; 312, outer part; 313, covering part; 314, groove; 32, second insulating member; 4, pressure relief mechanism; 41, notched part; X, height direction; 200, energy storage device; 300, power conversion equipment; 400, power generation equipment; 500, charging pile; 600, connector. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0038] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0039] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0041] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, 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 implementation method.

[0043] The battery device generally includes a box body and a battery cell contained in the box body. In order to improve the reliability of the battery cell, the battery cell generally includes a pressure relief mechanism. Taking the bottom explosion-proof as an example, a part of the bottom of the shell is usually concave to form a protrusion protruding inward, and the protrusion is used to support the electrode assembly, and the electrode assembly is raised, so that there is a pressure relief airway between the electrode assembly and the bottom of the battery cell to achieve effective explosion-proof. However, when the insulating blue film wraps the outside of the battery cell, since the protrusion forms a concave portion on the outer surface of the bottom of the battery cell, after the insulating blue film is wrapped, a certain gap will be formed at the concave portion, resulting in the gap being subjected to voltage when the battery cell is working. Under the action of voltage, local discharge occurs at the gap, and the impact of charged particles generated by local discharge will increase the local temperature, and the heat accumulation will cause the insulating blue film to overheat or even carbonize and lose its insulation ability. At the same time, compounds such as ozone and nitrogen oxides generated by local discharge will corrode the insulating material, resulting in a shortened life of the insulating material.

[0044] Based on this, in order to solve the problem of reduced insulation performance and life of insulation materials at the bottom of traditional battery cells, the present application provides a battery cell, in which a first insulating member covers the surface of the first shell wall facing away from the electrode assembly, so that the bottom of the battery cell is insulated and protected. Since a portion of the first insulating member is attached to the inner wall of the recess, the first insulating member is tightly attached to the recess of the first shell wall, so that no gap is generated between the first insulating member and the inner wall of the recess, reducing the possibility of local discharge at the recess, and effectively improving the insulation performance of the bottom of the battery cell and the life of the insulation material.

[0045] In addition, a portion of the first insulating member is fitted into the recess, so that the bonding area of ​​the first insulating member on the outer surface of the first shell wall is increased, which is conducive to improving the bonding strength between the first insulating member and the shell, and improving the structural stability of the battery cell. At the same time, it is also convenient to meet the bonding strength requirements of the battery cell in the battery device.

[0046] The battery cells disclosed in the embodiments of the present application can be used in, but not limited to, energy storage systems, and can also be used in electrical equipment such as vehicles, ships, or aircraft. The power supply system of the electrical equipment can be composed of the battery cells, battery devices, etc. disclosed in the present application.

[0047] The battery disclosed in the embodiment of the present application can be used in, but not limited to, energy storage systems, and can also be used in electrical devices such as vehicles, ships, or aircraft. The power supply system of the electrical equipment can be composed of the battery cells, intermediate batteries, etc. disclosed in the present application. Please refer to Figure 1 , Figure 1 An exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 includes a box body 20 and a battery cell 10, and the battery cell 10 is contained in the box body 20. Among them, the box body 20 is used to provide a storage space for the battery cell 10, and the box body 20 can adopt a variety of structures. In some embodiments, the box body 20 may include a first part 201 and a second part 202, and the first part 201 and the second part 202 cover each other, and the first part 201 and the second part 202 jointly define a storage space for accommodating the battery cell 10. The second part 202 may be a hollow structure with an opening 1a1 at one end, and the first part 201 may be a plate-like structure, and the first part 201 covers the opening 1a1 side of the second part 202, so that the first part 201 and the second part 202 jointly define a storage space; the first part 201 and the second part 202 may also be hollow structures with an opening 1a1 on one side, and the opening 1a1 side of the first part 201 covers the opening 1a1 side of the second part 202. Of course, the box body 20 formed by the first part 201 and the second part 202 can be in various shapes, such as a cylinder, a cuboid, etc.

[0048] In the battery device 100, there may be multiple battery cells 10, and the multiple battery cells 10 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 10 are both connected in series and in parallel. The multiple battery cells 10 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 10 is accommodated in the box 20; of course, the battery device 100 may also be a battery module formed by connecting multiple battery cells 10 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 20. The battery device 100 may also include other structures, for example, the battery device 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 10.

[0049] Each battery cell 10 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 10 may be cylindrical, flat, rectangular, or in other shapes.

[0050] Please refer to Figure 2 , Figure 2 The schematic diagram of the exploded structure of the battery cell 10 provided in some embodiments of the present application. The battery cell 10 refers to the smallest unit constituting the battery device 100. Figure 3 The battery cell 10 includes an end cover 1b, a shell 1a, an electrode assembly 2 and other functional components.

[0051] The end cap 1b refers to a component that covers the opening 1a1 of the shell 1a to isolate the internal environment of the battery cell 10 from the external environment. Without limitation, the shape of the end cap 1b can be adapted to the shape of the shell 1a to match the shell 1a. Optionally, the end cap 1b can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 1b is not easily deformed when squeezed and collided, so that the battery cell 10 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals can be provided on the end cap 1b. The electrode terminal can be used to electrically connect to the electrode assembly 2 for outputting or inputting electrical energy of the battery cell 10. In some embodiments, the end cap 1b can also be provided with a pressure relief mechanism 4 for releasing the internal pressure when the internal pressure or temperature of the battery cell 10 reaches a threshold. The material of the end cap 1b can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this. In some embodiments, an insulating member may be provided inside the end cap 1b, and the insulating member may be used to isolate the electrical connection components in the housing 1a from the end cap 1b to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, or the like.

[0052] The shell 1a is a component used to cooperate with the end cap 1b to form the internal environment of the battery cell 10, wherein the formed internal environment can be used to accommodate the electrode assembly 2, the electrolyte and other components. The shell 1a and the end cap 1b can be independent components, and an opening 1a1 can be set on the shell 1a, and the internal environment of the battery cell 10 is formed by covering the opening 1a1 with the end cap 1b at the opening 1a1. Without limitation, the end cap 1b and the shell 1a can also be integrated. Specifically, the end cap 1b and the shell 1a can form a common connection surface before other components are put into the shell, and when the interior of the shell 1a needs to be encapsulated, the end cap 1b is covered with the shell 1a. The shell 1a can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 1a can be determined according to the specific shape and size of the electrode assembly 2. The material of the shell 1a can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0053] The electrode assembly 2 is a component in the battery cell 10 where electrochemical reactions occur. One or more electrode assemblies 2 may be contained in the housing 1a. The electrode assembly 2 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 2, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery device 100, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0054] Please refer to Figure 3 , Figure 3A schematic diagram of the structure of an energy storage system provided in some embodiments of the present application. An embodiment of the present application provides an energy storage device 200, including one or more battery clusters (Battery Cluster) to increase the voltage and capacity of the energy storage device 200. The battery cluster may include multiple battery devices 100, and the multiple battery devices 100 are connected in series through a busbar to increase the voltage of the energy storage device 200. When the energy storage device 200 includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device 200. The energy storage device 200 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device 200 can store electrical energy as needed and output electrical energy at an appropriate time. For example, the energy storage device 200 can store electrical energy when electricity consumption is low, and provide electrical energy to relevant users or electrical equipment during peak electricity consumption. The energy storage system provided in the embodiment of the present application can be any power system that requires the use of the energy storage device 200. In some embodiments, the energy storage device 200 is an energy storage container or an energy storage cabinet.

[0055] In some embodiments, the energy storage device 200 may include a cabinet and one or more battery clusters, wherein the battery clusters are housed in the cabinet.

[0056] In some embodiments, the energy storage device 200 may include modules such as a thermal management module, a main control module, a master control module, a power distribution module, and a fire protection module.

[0057] As an example, the thermal management module may include a liquid cooling unit that provides cooling liquid for regulating the temperature of the battery cells 10 to each battery device 100 through a pipeline.

[0058] As an example, the main control module can be used as a battery management unit of a battery cluster 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 example, the charging and discharging current and voltage of the battery cluster can be controlled. The main control module includes a slave battery management unit SBMU (Slave Battery Management Unit, SBMU), a fusion switch and other modules.

[0059] As an example, the master control module can be used as a battery management unit of the energy storage device 200 to monitor and manage the energy storage device 200. The master control module can monitor information such as the current, voltage, power, state of charge or temperature of the energy storage device 200. For example, the charge and discharge current, voltage, etc. of the energy storage device 200 can be controlled. As an example, the master control module includes an insulation monitoring module IMM (Insulation Monitoring Module, abbreviated as IMM), a master battery management unit MBMU (Master Battery Management Unit, MBMU), Ethernet ETH (Ether Net, ETH) and a fiber optic conversion module.

[0060] As an example, the fire protection system includes a control panel, detectors, alarm devices, etc., which are used to detect, alarm or extinguish fire in the energy storage system.

[0061] As an example, the power distribution device may be used to distribute power to the power modules of the energy storage device 200 .

[0062] In some embodiments, the energy storage system may include one or more energy storage devices 200 and a power conversion device 300 (Power Converter System, PCS for short), and the power conversion device 300 is used to connect between the power generation device 400 and the energy storage device 200. The power generation device 400 is used to generate electric energy, and the electric energy generated by the power generation device 400 can be stored in the energy storage device 200 through the power conversion device 300, and the electric energy stored in the energy storage device 200 can be released to the power generation device 400 through the power conversion device 300. As an example, the power generation device 400 can specifically be a power grid, a solar panel, a hydroelectric power generation device 400, a thermal power generation device 400, a wind power generation device 400, etc. Among them, the specific type of the power generation device 400 is not limited in this application.

[0063] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of a charging network provided for some embodiments of the present application. An embodiment of the present application provides a charging network, including a charging pile 500 and an energy storage device 200, wherein the charging pile 500 is electrically connected to the energy storage device 200, and the energy storage device 200 is used to provide electrical energy to the charging pile 500. The charging pile 500 is electrically connected to the battery device 100 in the energy storage device 200 via a cable, and the battery device 100 can provide its stored electrical energy to the charging pile 500. The charging pile 500 has one or more connectors 600, and the connector 600 is used to connect to an electrical device (such as a vehicle), so that energy can be replenished to the electrical device.

[0064] The energy storage device 200 may be located inside the charging pile 500 (eg, an integrated storage and charging device), or may be located outside the charging pile 500 .

[0065] According to some embodiments of this application, please refer to Figure 5 and Figure 6 The present application provides a battery cell 10, which includes: a shell 1, an electrode assembly 2 and an insulating structure 3. The shell 1 includes a first shell wall 11 and a protrusion 12; the electrode assembly 2 is accommodated in the shell 1, the protrusion 12 is formed on the surface of the first shell wall 11 facing the electrode assembly 2, and the protrusion 12 forms a recess 13 on the surface of the first shell wall 11 facing away from the electrode assembly 2. The insulating structure 3 includes a first insulating member 31, the first insulating member 31 covers the surface of the first shell wall 11 facing away from the electrode assembly 2, and a part of the first insulating member 31 is attached to the inner wall of the recess 13.

[0066] The outer shell 1 refers to a structure that provides a closed environment for the electrode assembly 2, which may be a structure without end covers, such as: the outer shell 1 is a closed aluminum shell, etc.; it may also be a combination of a shell 1a and an end cover 1b. The first shell wall 11 refers to a side wall of the outer shell 1, which may be the bottom wall, side wall or top wall of the outer shell 1. Specifically in some embodiments, the first shell wall 11 is the bottom wall of the outer shell 1 in the vertical direction. At the same time, a protrusion 12 protruding toward the inside of the outer shell 1 is provided on the first shell wall 11, so that the protrusion 12 forms a pressure relief airway on the first shell wall 11 toward the electrode assembly 2. In this way, when thermal runaway occurs in the battery cell 10, the air pressure will break through the first shell wall 11 from the pressure relief airway to achieve effective bottom explosion protection. Among them, a pressure relief mechanism 4 is provided on the first shell wall 11 to allow the air pressure to be discharged from the pressure relief mechanism 4. For details, please refer to Figure 7 In addition, the shape of the protrusion 12 can be designed in many ways, and is not limited to Figure 4 For example, the cross-sectional shape of the protrusion 12 may be, but is not limited to, a truncated cone, a hemispherical shape, or the like.

[0067] At the same time, the protrusion 12 forms a recess 13 on the surface of the first shell wall 11 facing away from the electrode assembly 2. In this way, when preparing the protrusion 12 on the first shell wall 11, the protrusion 12 can be directly formed integrally on the first shell wall 11 by stamping or the like, thereby simplifying the preparation process of the protrusion 12 and reducing the processing cost.

[0068] The first insulating member 31 refers to a structure that can provide insulation protection for the outer surface of the first shell wall 11, and its material can be but is not limited to insulating paint, insulating rubber, etc. When the first insulating member 31 covers the surface of the first shell wall 11 facing away from the electrode assembly 2, if there is a gap between the first insulating member 31 and the recess 13, local discharge will occur in the gap after the voltage is applied. Local discharge produces charged particles that impact, causing the local temperature of the gap to increase, and the accumulation of heat causes the first insulating member 31 to overheat or even carbonize and lose its insulation ability; at the same time, compounds such as ozone and nitrogen oxides generated by local discharge will corrode the insulating material, shorten the insulation life, and make the insulating structure 3 fail to meet the insulation requirements.

[0069] To this end, in this embodiment, a portion of the first insulating member 31 is attached to the inner wall of the recess 13, so that no gap is generated between the first insulating member 31 and the inner wall of the recess 13, thereby reducing the possibility of local discharge at the recess 13. When a portion of the first insulating member 31 is attached to the inner wall of the recess 13, the first insulating member 31 can fill the recess 13 completely; or a structure with uniform thickness can be formed on the inner wall of the recess 13, so that the portion of the first insulating member 31 located in the recess 13 also has a corresponding concave structure, for example, the first insulating member 31 is coated on the inner wall of the recess 13 by electrophoresis, spraying, printing, etc.

[0070] With such a design, the first insulating member 31 fits tightly on the recess 13 of the first shell wall 11, so that no gap is generated between the first insulating member 31 and the inner wall of the recess 13, thereby reducing the possibility of local discharge at the recess 13 and effectively improving the insulation performance of the bottom of the battery cell 10 and the life of the insulation material.

[0071] According to some embodiments of the present application, optionally, please refer to Figure 5 The first insulating member 31 includes a fitting portion 311 and a peripheral portion 312 located at the periphery of the fitting portion 311 . The fitting portion 311 fits the inner wall of the recess 13 , and the peripheral portion 312 fits the area of ​​the first shell wall 11 except the recess 13 .

[0072] The fitting portion 311 refers to the structure in which the first insulating member 31 fits in the recess 13, and the peripheral portion 312 is the structure in which the first insulating member 31 fits in the area other than the recess 13. The peripheral portion 312 is arranged around the periphery of the fitting portion 311 and connected to the fitting portion 311 to form a complete first insulating member 31. When there are multiple recesses 13, there are also multiple fitting portions 311, and the fitting portions 311 and the recesses 13 are arranged one-to-one. At the same time, the peripheral portion 312 is arranged around the periphery of each fitting portion 311.

[0073] At the same time, when the fitting portion 311 fits on the inner wall of the recess 13, its thickness can be kept uniform, so that the surface of the fitting portion 311 facing away from the recess 13 can also form a concave structure. Of course, in some embodiments, the fitting portion 311 can also fill the recess 13 so that no gap is generated between the fitting portion 311 and the inner wall of the recess 13. In this case, the surface of the fitting portion 311 facing away from the recess 13 is a plane. For details, please refer to Figure 8 .

[0074] In this way, the first insulating member 31 is designed to be a fitting portion 311 and a peripheral portion 312, so that the first insulating member 31 can better fit on the surface of the first shell wall 11 facing away from the electrode assembly 2, which not only improves the bonding strength between the first insulating member 31 and the first shell wall 11; but also improves the insulation protection of the first shell wall 11, thereby improving the insulation performance of the battery cell 10 and the service life of the insulation material.

[0075] According to some embodiments of the present application, optionally, please refer to Figure 5 The fitting portion 311 fits against the inner wall of the recess 13 , and a groove 314 is formed on a side of the fitting portion 311 facing away from the recess 13 .

[0076] It can be known that there are many ways to form a groove 314 on the side of the fitting portion 311 facing away from the recess 13, such as forming a layer of fitting portion 311 on the inner wall of the recess 13 by spraying, electrophoresis or printing. Since the side of the fitting portion 311 facing away from the recess 13 has a groove 314, when the battery cell 10 is bonded to the battery device 100, the glue can penetrate into the groove 314, increasing the bonding area with the first insulating member 31, which is conducive to improving the bonding strength. Among them, the shape of the groove 314 can be consistent with the shape of the recess 13, or it can be inconsistent.

[0077] With such a design, a groove 314 is provided on the side of the fitting portion 311 facing away from the recess 13 , so as to increase the specific surface area of ​​the first insulating member 31 and improve the bonding strength of the surface of the first insulating member 31 , thereby improving the stability of the battery cell 10 in the battery device 100 .

[0078] According to some embodiments of the present application, optionally, please refer to Fig. 9 and Fig.10 The inner wall of the recess 13 includes a first wall 131 and a second wall 132 respectively arranged on two opposite sides of the first wall 131. The fitting portion 311 includes a first sub-portion 31a and a second sub-portion 31b respectively arranged on two opposite sides of the first sub-portion 31a. The two second sub-portions 31b and the first sub-portion 31a are enclosed to form a groove 314. The first sub-portion 31a is fitted to the first wall 131, and the second sub-portion 31b is fitted to the second wall 132.

[0079] It should be noted that the recess 13 can be understood as a structure formed by the surface of the first shell wall 11 being recessed inwardly, and a notch is formed on the surface of the first shell wall 11 facing away from the electrode assembly 2. At this time, the first wall 131 is an inner wall of the recess 13 facing the notch, and the two second walls 132 are respectively located on the inner walls on both sides of the notch. Each second wall 132 can be inclined relative to the first wall 131, for example: the angle between the second wall 132 and the first wall 131 can be a right angle or an obtuse angle.

[0080] Meanwhile, the two second sub-portions 31b refer to structures in which the fitting portion 311 is respectively connected to the peripheral portion 312, and the angle between the second sub-portion 31b and the first sub-portion 31a may be the same as or different from the angle between the first wall 131 and the second wall 132. Specifically, in some embodiments, the two second walls 132 are inclined relative to the first wall 131 in directions away from each other, and the two second sub-portions 31b are inclined relative to the first sub-portion 31a in directions away from each other.

[0081] In this way, the recess 13 is designed as a first wall 131 and two second walls 132, and the fitting portion 311 is designed as a first sub-portion 31a and two second sub-portions 31b, so that when the fitting portion 311 is fitted in the recess 13, a groove 314 is formed on the side facing away from the recess 13.

[0082] According to some embodiments of the present application, optionally, please refer to Figure 5 The first insulating member 31 includes a covering portion 313 , and the housing 1 further includes a second shell wall 14 arranged around the outer periphery of the first shell wall 11 . The covering portion 313 is configured to cover at least a portion of the second shell wall 14 .

[0083] The second shell wall 14 refers to an annular structure surrounding the first shell wall 11, and its shape can be various, such as but not limited to a cylindrical shape, a quadrangular prism, etc. When the covering portion 313 of the first insulating member 31 covers the outer surface of the first shell wall 11, it can also cover at least a portion of the second shell wall 14, which is more effective for the insulation protection of the first shell wall 11; at the same time, it also reduces the creepage discharge phenomenon on the second shell wall 14 when the insulation test of the first shell wall 11 is performed.

[0084] The covering portion 313 refers to the structure in which the first insulating member 31 covers the second shell wall 14, wherein in some embodiments, the covering height of the covering portion 313 on the second shell wall 14 may be greater than or equal to 10 mm; of course, considering the insulation protection cost, the covering height of the first insulating member 31 on the second shell wall 14 is minimized while satisfying the creepage safety during the test. In addition, when the first insulating member 31 further includes a fitting portion 311 and a peripheral portion 312 located at the periphery of the fitting portion 311, the covering portion 313 is disposed around the periphery of the peripheral portion 312.

[0085] With this design, the covering portion 313 of the first insulating member 31 is extended to cover the second shell wall 14, thereby improving the insulation protection effect of the first insulating member 31 on the first shell wall 11; at the same time, it also reduces the creepage discharge phenomenon on the second shell wall 14 when testing the insulation of the first shell wall 11.

[0086] According to some embodiments of the present application, optionally, please refer to Figure 5 The fitting portion 311 and the recessed portion 13 each include a plurality of fitting portions 311 , and the two are arranged one to one, and the outer portion 312 is located at the outer periphery of each fitting portion 311 .

[0087] It can be seen that when the first insulating member 31 covers the surface of the first shell wall 11 facing away from the electrode assembly 2, each fitting portion 311 fits in the corresponding recess 13; at the same time, the outer portion 312 fits in the area of ​​the first shell wall 11 except the recesses 13.

[0088] With such a design, a plurality of fitting portions 311 and recessed portions 13 are introduced to further improve the bonding strength between the first insulating member 31 and the first shell wall 11 , thereby achieving more effective insulation protection for the first shell wall 11 .

[0089] According to some embodiments of the present application, optionally, please refer to Figure 5 The thickness of the first insulating member 31 is denoted as h, wherein 50 mm ≤ h ≤ 300 mm.

[0090] If the thickness of the first insulating member 31 is designed to be too small, the insulation protection of the first shell wall 11 may be reduced; if the thickness of the first insulating member 31 is designed to be too large, it will occupy too much space of the battery cell 10 in the height direction X. Therefore, the thickness of the first insulating member 31 is controlled between 50 mm and 300 mm, for example, but not limited to 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, etc.

[0091] With such a design, the thickness of the first insulating member 31 is controlled between 50 mm and 300 mm, which reduces the space occupied in the height direction X and improves the insulation protection of the first shell wall 11 as much as possible, thereby improving the insulation performance of the battery cell 10 .

[0092] According to some embodiments of the present application, optionally, the thickness h also satisfies the condition: 60 mm ≤ h ≤ 80 mm.

[0093] The thickness of the first insulating member 31 may also be controlled between 60 mm and 80 mm, for example, but not limited to, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, etc.

[0094] With such a design, the thickness of the first insulating member 31 is controlled between 60 mm and 80 mm, further effectively taking into account both the space occupied in the height direction X and the insulation performance of the battery cell 10 .

[0095] According to some embodiments of the present application, optionally, please refer to Figure 5 The insulating structure 3 further includes a second insulating member 32 , which is coated on a side surface of the housing 1 surrounding the outer periphery of the first housing wall 11 and connected to the first insulating member 31 .

[0096] The second insulating member 32 is coated on the side of the housing 1, the first insulating member 31 is coated on the first shell wall 11, and the second insulating member 32 is connected to the first insulating member 31, which means that the first insulating member 31 and the second insulating member 32 can form a complete protective structure, so that the housing 1 is effectively insulated and protected. There are many ways to connect the second insulating member 32 to the first insulating member 31, such as: the second insulating member 32 covers the side of the first insulating member 31 facing away from the housing 1; or the end of the second insulating member 32 is spliced ​​with the end of the first insulating member 31. Among them, the second insulating member 32 can be an insulating paint or a blue film, such as a PET (Polyethylene terephthalate) film.

[0097] For specific embodiments, please refer to Figure 5 The housing 1 further includes a second housing wall 14 surrounding the first housing wall 11 , a second insulating member 32 at least covers the second housing wall 14 , and one end of the second insulating member 32 is flush with a surface of the first housing wall 11 facing away from the electrode assembly 2 .

[0098] With such a design, the second insulating member 32 is introduced, so that the insulation protection of the housing 1 is more effective and reliable, and the insulation performance of the battery cell 10 is further improved.

[0099] According to some embodiments of the present application, optionally, please refer to Figure 5 A portion of the first insulating member 31 is covered on the side surface of the housing 1 surrounding the outer periphery of the first housing wall 11 , and an end of the second insulating member 32 close to the first housing wall 11 is covered on the surface of the second insulating member 32 facing away from the housing 1 .

[0100] It can be seen that the first insulating member 31, in addition to covering the first shell wall 11, also covers the side of the shell 1. When a portion of the first insulating member 31 covers the side of the shell 1, the second insulating member 32 covers the side of the shell 1, and one end of the second insulating member 32 also covers the surface of the first insulating member 31 facing away from the shell 1, so that the two are connected to each other to form a complete protective structure.

[0101] For specific embodiments, please refer to Figure 5The first insulating member 31 also includes a covering portion 313 arranged around the outer periphery of the outer portion 312, and the housing 1 also includes a second shell wall 14 arranged around the outer periphery of the first shell wall 11, and the covering portion 313 covers at least a portion of the second shell wall 14; one end of the second insulating member 32 is covered on the surface of the covering portion 313 facing away from the second shell wall 14.

[0102] With such a design, the second insulating member 32 and the first insulating member 31 are overlapped on the side of the housing 1, which not only facilitates the connection between the two, but also helps to improve the insulation protection of the housing 1 and enhance the insulation effect.

[0103] According to some embodiments of the present application, optionally, the second insulating member 32 is configured to be coated on the side surface of the housing 1 surrounding the outer periphery of the first housing wall 11 in a film layer attachment manner.

[0104] The film layer attachment method refers to attaching the surface of the second insulating member 32 to the side of the housing 1, so that the second insulating member 32 is tightly wrapped on the housing 1. In some examples, the second insulating member 32 can be a blue film.

[0105] With such a design, the second insulating member 32 is attached to the side surface of the housing 1 by film layer attachment, which not only simplifies the process but also improves the insulation protection of the side surface of the housing 1 .

[0106] According to some embodiments of the present application, optionally, the first insulating member 31 is constructed to have a structure having one or more of epoxy material, polyimide material, and acrylic material.

[0107] The material of the first insulating member 31 can be one of epoxy material, polyimide material, and acrylic material; meanwhile, during construction, the first insulating member 31 can be formed on the first shell wall 11 by electrophoresis, spraying, or printing.

[0108] Such a design, using at least one of epoxy material, polyimide material, and acrylic material as the material of the first insulating member 31, is not only beneficial to improving the insulation; it is also beneficial for the first insulating member 31 to fit against the inner wall of the recess 13, eliminating the gap between the first insulating member 31 and the recess 13, and reducing the risk of local discharge.

[0109] According to some embodiments of the present application, optionally, please refer to Figure 3 The housing 1 comprises a shell 1a and an end cover 1b disposed on the shell 1a. One end of the shell 1a away from the end cover 1b comprises a first shell wall 11.

[0110] It can be seen that the end cap 1b cooperates with the shell 1a to form a space for accommodating the electrode assembly 2. At this time, the first shell wall 11 is located at the end of the shell 1a opposite to the end cap 1b. At the same time, in some embodiments, the shell 1a also includes a second shell wall 14 surrounding the outer periphery of the first shell wall 11.

[0111] Such a design, with the introduction of the end cover 1b and the shell 1a, facilitates the sealing of the electrode assembly 2 and provides a closed environment for it.

[0112] According to some embodiments of the present application, optionally, the first insulating member 31 is configured to be formed on the inner wall of the recess 13 and the surface of the first shell wall 11 facing away from the electrode assembly 2 by coating or electrophoresis.

[0113] When the first insulating member 31 is coated or electrophoretically formed on the inner wall of the recess 13 and the surface of the first shell wall 11, its thickness can maintain a certain uniformity, which is beneficial to improving the insulation performance on the first shell wall 11. At the same time, the coating and electrophoresis methods make it easier for the first insulating member 31 to fit on the inner wall of the recess 13, reducing the possibility of a gap between the first insulating member 31 and the recess 13.

[0114] Such a design, using coating or electrophoresis, is beneficial to improving the insulation performance of the first shell wall 11; at the same time, it also reduces the possibility of a gap between the first insulating member 31 and the recess 13, and reduces the probability of partial discharge.

[0115] According to some embodiments of the present application, optionally, please refer to Figure 7 The battery cell 10 further includes a pressure relief mechanism 4 , which is disposed on the first shell wall 11 .

[0116] It can be seen that the pressure relief mechanism 4 and the protrusion 12 are both arranged on the first shell wall 11, so that the protrusion 12 protrudes toward the inside of the shell 1, so that the first shell wall 11 forms a pressure relief airway on the surface of the electrode assembly 2, so that the air pressure can be stably relieved from the pressure relief mechanism 4 on the first shell wall 11 when thermal runaway occurs in the battery cell 10. When the first shell wall 11 is the bottom wall of the shell 1, the pressure relief method of the battery cell 10 is bottom pressure relief.

[0117] The pressure relief mechanism 4 may have various structures, such as but not limited to an explosion-proof membrane, a pressure relief valve, etc.

[0118] With such a design, the pressure relief mechanism 4 and the protrusion 12 are both arranged on the first bottom wall, so that the pressure relief in the pressure relief mechanism 4 is stably performed, which is beneficial to improving the reliability of the battery cell 10 .

[0119] According to some embodiments of the present application, optionally, please refer to Figure 7The pressure relief mechanism 4 includes a notched portion 41 , which is recessed on the surface of the first shell wall 11 facing toward and / or facing away from the electrode assembly 2 .

[0120] The notch 41 refers to a concave structure on the first shell wall 11. When thermal runaway occurs, the gas pressure can break through the notch 41 to achieve effective pressure relief. In some specific examples, a carving knife can be used to carve at least one surface of the first shell wall 11 to form a thinner weak structure, for example: the thickness of the first shell wall 11 on the notch 41 is less than the thickness of the first shell wall 11 except the notch 41.

[0121] The notched portion 41 may be disposed on a surface of the first shell wall 11 facing the electrode assembly 2, or may be disposed on a surface of the first shell wall 11 facing away from the electrode assembly 2; of course, the notched portion 41 may be disposed on both surfaces of the first shell wall 11. When the notched portions 41 are disposed on both surfaces of the first shell wall 11, the notched portions 41 on the two surfaces are opposite to each other along the thickness direction of the first shell wall 11. At the same time, the number of notched portions 41 may be one or more. When the number of notched portions 41 is more than one, there are various distributions of all notched portions 41, for example, all notched portions 41 may form a cross-shaped structure, an H-shaped structure, etc.

[0122] With such a design, the notch portion 41 is introduced to facilitate directional pressure relief from the first shell wall 11 during thermal runaway, thereby improving the reliability of the battery cell 10 .

[0123] According to some embodiments of the present application, the present application provides a battery device 100 , and the battery device 100 includes any of the above battery cells 10 .

[0124] According to some embodiments of the present application, the present application provides an electric device, and the electric device includes the above battery device 100.

[0125] According to some embodiments of the present application, the present application provides an energy storage device, which includes the above battery device.

[0126] According to some embodiments of this application, please refer to Figure 3 The present application provides an energy storage system, which includes a power conversion device and an energy storage device as described above, wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0127] According to some embodiments of this application, please refer to Figure 4 The present application provides a charging network, which includes charging piles and the above energy storage devices or the above energy storage systems, and the energy storage devices are used to provide electrical energy for the charging piles.

[0128] According to some embodiments of this application, please refer to Figures 5 to 10The present application provides a battery cell 10, which includes a shell 1, an electrode assembly 2 and an insulating structure 3. The insulating structure 3 includes a first insulating member 31 and a second insulating member 32. The first insulating member 31 is arranged on the first shell wall 11 of the shell 1 and fits with the inner wall of the recess 13 of the first shell wall 11. The second insulating member 32 is coated on the second shell wall 14 surrounding the outer periphery of the first shell wall 11 on the shell 1. Among them, the first insulating member 31 can be tightly fitted with the first shell wall 11 by electrophoresis, spraying, printing, etc., and the second insulating member 32 can be a blue film. That is, the blue film structure is eliminated on the first shell wall 11 of the shell 1, and the first insulating member 31 is fitted. In this way, while playing the role of insulation, the gap between the insulating structure 3 and the shell 1 is eliminated, reducing the probability of partial discharge, which is beneficial to improving the insulation performance of the battery cell 10 and extending the service life of the insulating material.

[0129] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0130] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A housing (1) comprising a first housing wall (11) and a protruding portion (12); An electrode assembly (2) is accommodated in the housing (1), the protrusion (12) is formed protruding from the surface of the first housing wall (11) facing the electrode assembly (2), and the protrusion (12) forms a recess (13) on the surface of the first housing wall (11) facing away from the electrode assembly (2); and The insulating structure (3) comprises a first insulating member (31), wherein the first insulating member (31) covers the surface of the first shell wall (11) facing away from the electrode assembly (2), and a portion of the first insulating member (31) is attached to the inner wall of the recess (13).

2. The battery cell according to claim 1, characterized in that: The first insulating member (31) comprises a fitting portion (311) and a peripheral portion (312) located on the periphery of the fitting portion (311), the fitting portion (311) being fitted to the inner wall of the recess (13), and the peripheral portion (312) being fitted to the area on the first shell wall (11) excluding the recess (13).

3. The battery cell according to claim 2, characterized in that: The fitting portion (311) fits against the inner wall of the recess (13), and a groove (314) is formed on a side of the fitting portion (311) that faces away from the recess (13).

4. The battery cell according to claim 3, characterized in that: The inner wall of the recess (13) comprises a first wall (131) and second walls (132) respectively arranged on two opposite sides of the first wall (131); the fitting portion (311) comprises a first sub-portion (31a) and second sub-portions (31b) respectively arranged on two opposite sides of the first sub-portion (31a); the two second sub-portions (31b) and the first sub-portion (31a) are combined to form the groove (314); the first sub-portion (31a) is fitted to the first wall (131), and the second sub-portion (31b) is fitted to the second wall (132).

5. The battery cell according to claim 1, characterized in that: The first insulating member (31) comprises a covering portion (313), and the housing (1) further comprises a second shell wall (14) arranged around the outer periphery of the first shell wall (11), and the covering portion (313) is arranged to cover at least a portion of the second shell wall (14).

6. The battery cell according to claim 2, characterized in that: The fitting portion (311) and the recessed portion (13) each include a plurality of portions, and the two are arranged one to one, and the peripheral portion (312) is located at the periphery of each fitting portion (311).

7. The battery cell according to any one of claims 1 to 6, characterized in that: The thickness of the first insulating member (31) is denoted as h, wherein 50 mm ≤ h ≤ 300 mm.

8. The battery cell according to claim 7, characterized in that: The thickness h also satisfies the condition: 60mm≤h≤80mm.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The insulating structure (3) further comprises a second insulating member (32), the second insulating member (32) being coated on the side surface of the outer shell (1) surrounding the outer periphery of the first shell wall (11) and being connected to the first insulating member (31).

10. The battery cell according to claim 9, characterized in that: A portion of the first insulating member (31) is wrapped around the side surface of the outer shell (1) surrounding the outer periphery of the first shell wall (11), and an end of the second insulating member (32) close to the first shell wall (11) is wrapped around the surface of the first insulating member (31) facing away from the outer shell (1).

11. The battery cell according to claim 9, characterized in that: The second insulating member (32) is arranged to be coated on the side surface of the outer shell (1) around the outer periphery of the first shell wall (11) in a film layer attachment manner.

12. The battery cell according to any one of claims 1 to 6, characterized in that: The first insulating member (31) is constructed to have a structure having one or more of epoxy material, polyimide material, and acrylic material.

13. The battery cell according to any one of claims 1 to 6, characterized in that: The housing (1) comprises a shell (1a) and an end cover (1b) disposed on the shell (1a); an end of the shell (1a) away from the end cover (1b) comprises the first shell wall (11).

14. The battery cell according to any one of claims 1 to 6, characterized in that: The first insulating member (31) is arranged to be formed on the inner wall of the recess (13) and the surface of the first shell wall (11) facing away from the electrode assembly (2) by coating or electrophoresis.

15. The battery cell according to any one of claims 1 to 6, characterized in that: The battery cell further comprises a pressure relief mechanism (4), and the pressure relief mechanism (4) is arranged on the first shell wall (11).

16. The battery cell according to claim 15, characterized in that: The pressure relief mechanism (4) comprises a notched portion (41), and the notched portion (41) is recessed on a surface of the first shell wall (11) facing towards and / or facing away from the electrode assembly (2).

17. A battery device, characterized in that: The battery device comprises the battery cell according to any one of claims 1-16.

18. An energy storage device, characterized in that: The energy storage device comprises the battery device of claim 17.

19. An energy storage system, characterized in that: The energy storage system comprises a power conversion device (300) and the energy storage device according to claim 18, wherein the power conversion device (300) is used to electrically connect a power generation device (400) and the energy storage device.

20. A charging network, characterized in that: The charging network includes: Charging piles (500); The energy storage device according to claim 18 or the energy storage system according to claim 19, wherein the energy storage device is used to provide electrical energy to the charging pile (500).

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