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

Abstract

The present application applies to the technical field of batteries. Provided are a battery cell (1), a related device, an energy storage system (1000) and a charging network (2000). The battery cell (1) comprises an electrode assembly (11) and a casing (12). At least part of the electrode assembly (11) is arranged within the casing (12). The casing (12) comprises an end wall (121), a side wall (122) and a first transition portion (123), wherein the side wall (122) comprises a main wall (1221) and a first thickened portion (1222), the wall thickness of the first thickened portion (1222) being greater than the wall thickness of the main wall (1221), and the first transition portion (123) is connected between the end wall (121) and the first thickened portion (1222). The end wall (121) is provided with a first inner surface (1201) facing the electrode assembly (11), and a first groove (1202) is formed on the periphery of the first inner surface (1201), the first groove (1202) extending to the first transition portion (123). In this way, the problem of the weakness of the first transition portion (123) and the vicinity thereof can be ameliorated.

Description

Battery cells, related devices, energy storage systems and charging networks Technical Field

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

[0002] In related technologies, a battery cell typically includes a housing and an electrode assembly, with at least a portion of the electrode assembly disposed within the housing. The housing generally includes an end wall and a side wall connected to the end wall, with a transition portion provided at the connection between the end wall and the side wall.

[0003] In some cases, the inner surface of the end wall can be recessed at its perimeter to form a clearance groove, which can be used to avoid electrode assemblies. However, the presence of the clearance groove results in a thinner wall thickness in the transition section and its surrounding area, making it weaker and reducing structural strength. Summary of the Invention

[0004] In view of the above problems, the purpose of this application is to provide a battery cell, related devices, energy storage system and charging network that can improve the technical problem of weak transition section and its surrounding area.

[0005] The technical solution adopted in the embodiments of this application is:

[0006] In a first aspect, embodiments of this application provide a single battery cell, comprising:

[0007] Electrode assembly;

[0008] The housing includes at least a portion of the electrode assembly disposed within it; the housing includes an end wall, a side wall, and a first transition portion, the end wall being disposed at one end of the side wall along a first direction; the side wall includes a main wall arranged along the first direction and a first thickened portion, the wall thickness of the first thickened portion being greater than the wall thickness of the main wall, and the first transition portion connecting the end wall and the first thickened portion; the end wall has a first inner surface facing the electrode assembly, and a first groove is formed on the outer periphery of the first inner surface, the first groove extending to the first transition portion.

[0009] The battery cell provided in this application embodiment has an end wall disposed at one end of a side wall along a first direction. The side wall includes a main wall and a first thickened portion arranged along the first direction. The wall thickness of the first thickened portion is greater than the wall thickness of the main wall, and a first transition portion connects the end wall and the first thickened portion. This results in the side wall being thickened in the end region near the first transition portion. Furthermore, the first transition portion connects the first thickened portion and the end wall, thereby increasing the wall thickness of the first transition portion. In this way, the wall thickness of the first transition portion and its surrounding area can be increased, increasing the structural strength and thus improving the weakness of the first transition portion and its surrounding area. This helps to improve the structural strength of the casing, and consequently, improves the structural strength and reliability of the battery cell.

[0010] In some embodiments, the inner surface of the first thickened portion protrudes from the main body wall.

[0011] By having the inner surface of the first thickened portion protrude from the main body wall, the wall thickness of the first thickened portion is increased. This allows the inner surface of the first transition portion to protrude correspondingly to the inner surface of the first thickened portion, thereby increasing the wall thickness of the first transition portion. This helps to mitigate the weakness of the first transition portion and its surrounding area caused by the first groove formed by the inner surface depression of the end wall, reducing the weakness of the first transition portion and its surrounding area, and improving the structural strength of the first transition portion and its surrounding area.

[0012] In some embodiments, in a first direction, at least a portion of the wall thickness of the first thickened portion is gradually increased from the main body wall toward the first transition portion.

[0013] By adopting the above technical solution, a smooth transition can be achieved between the first thickened part and the main body wall. This helps to improve the stress concentration problem at the connection between the first thickened part and the main body wall caused by the increased wall thickness, and makes the connection between the first thickened part and the main body wall have greater structural strength.

[0014] In some embodiments, the inner surface of the first transition portion is rounded.

[0015] By using rounded corners on the inner surface of the first transition section, a smooth transition is achieved between the inner surface of the first thickened section and the wall of the first groove, which can alleviate the stress concentration problem in the first transition section and its surrounding area. Furthermore, since the wall thickness of the first thickened section is greater than that of the main body wall, the rounded corners on the inner surface of the first transition section allow for a greater wall thickness in the first transition section and its surrounding area, thereby contributing to improved structural strength.

[0016] In some embodiments, a first dividing line is provided between the first transition portion and the first thickened portion. The first dividing line passes through the center of the inner surface of the first transition portion and is parallel to the wall thickness direction of the main body wall. The wall thickness of the main body wall is H1, and the maximum wall thickness of the first thickened portion is H2, where (H2-H1) / H1∈(0, 0.5).

[0017] By adopting the above technical solution, the increase in the wall thickness of the first thickened portion is kept within a certain range. On the one hand, this allows the first thickened portion to have a larger wall thickness, thereby enabling the first transition portion and its surrounding area to have a larger wall thickness, and thus greater structural strength. On the other hand, it can improve the interference problem between the first thickened portion and the electrode assembly. Furthermore, it is also beneficial for increasing the energy density of the battery cell.

[0018] In some embodiments, (H2-H1) / H1∈(0, 1 / 3).

[0019] By adopting the above technical solution, on the one hand, the first thickened portion has a larger wall thickness, thereby resulting in a larger wall thickness for the first transition portion and its surrounding area. On the other hand, it can improve the interference problem between the first thickened portion and the electrode assembly. Furthermore, it is beneficial to increase the energy density of the battery cell.

[0020] In some embodiments, the first direction is parallel to the wall thickness direction of the end wall, and in the first direction, the distance between the end of the first thickened portion away from the first transition portion and the outer surface of the end wall is H3, where H3 ∈ [2 mm, 5 mm].

[0021] By using H3∈[2mm, 5mm], the first thickened portion has a certain dimensional range in the first direction. On the one hand, the setting of the first thickened portion allows for an increase in the wall thickness of the first transition portion and its surrounding area, resulting in a larger wall thickness for the first transition portion and its surrounding area. On the other hand, it can improve the interference problem between the first thickened portion and the electrode assembly. Furthermore, it is also beneficial for increasing the energy density of the battery cell.

[0022] In some embodiments, H3∈[3mm, 4mm].

[0023] This design allows for increased wall thickness in the first transition section and its vicinity, resulting in a thicker wall. It also mitigates interference between the thickened section and the electrode assembly. Furthermore, it contributes to improved energy density in the individual battery cells.

[0024] In some embodiments, the first transition portion surrounds the outer periphery of the first groove; the number of sidewalls is multiple, and the multiple sidewalls include two first sidewalls disposed opposite to each other along a second direction and two second sidewalls disposed opposite to each other along a third direction. The two first sidewalls and the two second sidewalls together surround the outer periphery of the end wall and are all connected to the first transition portion.

[0025] At least one first sidewall includes a main wall and a first thickened portion, wherein the wall thickness of the first thickened portion is greater than the wall thickness of the main wall; and / or, at least one second sidewall includes a main wall and a first thickened portion, wherein the wall thickness of the first thickened portion is greater than the wall thickness of the main wall.

[0026] Among them, the first direction, the second direction, and the third direction intersect each other in pairs.

[0027] By adopting the above technical solution, four sidewalls are arranged to surround the outer periphery of the end wall, and at least one sidewall includes the main wall, a second thickened portion, and a first thickened portion. That is, the wall thickness of at least one sidewall is increased in the end region near the first transition portion along the first direction, thereby increasing the structural strength of the region of the first transition portion corresponding to the at least one sidewall, which is beneficial to improving the reliability of the battery cell.

[0028] In some embodiments, the surface area of ​​the first sidewall is greater than the surface area of ​​the second sidewall. The first sidewall includes a main wall and a first thickened portion, and the wall thickness of the first thickened portion is greater than the wall thickness of the main wall.

[0029] Because the surface area of ​​the first sidewall is larger than that of the second sidewall, the region of the first transition section corresponding to the first sidewall is more prone to weakness. Furthermore, by having a thicker first section in the first sidewall than the main body wall, the structural strength of the region of the first transition section corresponding to the first sidewall and its vicinity can be increased, thus helping to improve the reliability of the battery cell.

[0030] In some embodiments, the minimum wall thickness of the first sidewall is less than the minimum wall thickness of the second sidewall. The first sidewall includes a main wall and a first thickened portion, and the wall thickness of the first thickened portion is greater than the wall thickness of the main wall.

[0031] Because the minimum wall thickness of the first sidewall is less than the minimum wall thickness of the second sidewall, the area of ​​the first transition portion corresponding to the first sidewall is more prone to weakness. However, by having the wall thickness of the first thickened portion of the first sidewall greater than the wall thickness of the main body wall, the structural strength of the area of ​​the first transition portion corresponding to the first sidewall and its vicinity can be increased, which helps improve the reliability of the battery cell.

[0032] In some embodiments, the second sidewall includes a main wall and a first thickened portion, wherein the thickness of the first thickened portion is greater than the thickness of the main wall.

[0033] This helps to increase the structural strength of the first transition section in the area surrounding the first groove and its vicinity, thereby helping to improve the reliability of the battery cell.

[0034] In some embodiments, a second transition portion is formed at the junction of the first sidewall and the second sidewall.

[0035] By adopting the above technical solution, the first transition portion is also thickened in the area corresponding to the second thickened portion and the first thickened portion, which helps to improve the overall structural strength of the casing and improve the reliability of the battery cell.

[0036] In some embodiments, the inner surface of the second transition portion is rounded.

[0037] In this way, on the one hand, the stress concentration problem at the connection between the first and second sidewalls can be improved. On the other hand, it allows the second transition portion to be thickened in the area corresponding to the first thickened portion, which helps to improve the overall structural strength of the casing and the reliability of the battery cell.

[0038] In some embodiments, in a first direction, the first groove is provided with a bottom wall; the end wall is also provided with a second inner surface connected between the bottom wall and the first inner surface, the bottom wall is connected to the first transition portion, and the connection between the first inner surface and the second inner surface is a rounded transition.

[0039] This allows the junction of the first inner surface and the second inner surface to be smoothly set, thereby improving the problem of the electrode assembly being punctured at the junction of the first inner surface and the second inner surface, and achieving a protective effect on the electrode assembly.

[0040] In some embodiments, the connection between the first inner surface and the second inner surface is transitioned by a rounded corner.

[0041] This allows the junction of the first inner surface and the second inner surface to be smoothly set, thereby improving the problem of the electrode assembly being punctured at the junction of the first inner surface and the second inner surface, and achieving a protective effect on the electrode assembly.

[0042] In some embodiments, the first direction is parallel to the wall thickness direction of the end wall, and in the first direction, the distance between the first inner surface and the outer surface of the end wall is H4, the first groove is provided with a groove bottom wall, and the maximum distance between the groove bottom wall and the first inner surface is H5, where H5 / H4∈[1 / 20, 1 / 3].

[0043] This design allows the first groove to have a certain depth in the first direction. This serves two purposes: firstly, it allows the first groove to avoid interference with the electrode assembly, reducing interference between the electrode assembly and the first transition section; secondly, it allows the end wall to have a relatively large wall thickness despite the presence of the first groove, thus providing structural strength.

[0044] In some embodiments, H5 / H4∈[1 / 10, 1 / 4].

[0045] In this way, on the one hand, the first groove can avoid the electrode assembly, improving the interference problem between the electrode assembly and the first transition section. On the other hand, the end wall has a relatively large wall thickness even with the first groove, thus providing a certain structural strength.

[0046] In some embodiments, the sidewall further includes a second thickened portion, the first thickened portion and the second thickened portion are respectively disposed at both ends of the main body wall along the first direction, and the wall thickness of the second thickened portion is greater than the wall thickness of the main body wall.

[0047] By setting the wall thickness of the second thickened portion to be greater than that of the main wall, the end region of the side wall away from the end wall along the first direction is thickened. This allows the side wall to be welded to the end cap via the second thickened portion, thereby increasing the welding strength between the end cap and the side wall, as well as the fatigue strength of the weld seam. This reduces the weakness at the weld point between the end cap and the side wall, improves the structural strength of the casing, and ultimately enhances the structural strength and reliability of the battery cell.

[0048] In some embodiments, the wall thickness of the main body is H1, and the maximum wall thickness of the second thickened portion is H6, where (H6-H1) / H1∈(0, 0.5).

[0049] This approach allows for a larger wall thickness in the second thickened section, thereby increasing the welding strength between the second thickened section and the end cap, as well as the fatigue strength of the weld, thus improving the reliability of the battery cell. Furthermore, it facilitates an increase in the energy density of the battery cell.

[0050] In some embodiments, (H6-H1) / H1∈(0, 1 / 3).

[0051] This approach allows for a larger wall thickness in the second thickened section, thereby increasing the welding strength between the second thickened section and the end cap, as well as the fatigue strength of the weld, thus improving the reliability of the battery cell. Furthermore, it facilitates an increase in the energy density of the battery cell.

[0052] In some embodiments, the battery cell further includes an end cap, which is welded to a second thickened portion.

[0053] By making the wall thickness of the second thickened part greater than that of the main body wall, and by welding the end cap to the second thickened part, the welding strength of the second thickened part and the end cap and the fatigue strength of the weld formed by the welding can be improved, thereby improving the reliability of the battery cell.

[0054] Secondly, embodiments of this application provide a battery device, including a single battery cell.

[0055] The battery device provided in this application, by employing the aforementioned battery cells, helps to improve the reliability of the battery device.

[0056] Thirdly, embodiments of this application provide an electrical device, including a single battery cell or a battery device.

[0057] The electrical device provided in this application, by employing the aforementioned battery cells or battery devices, helps to improve the reliability of the electrical device.

[0058] Fourthly, embodiments of this application provide an energy storage device, including a single battery cell or a battery assembly.

[0059] The energy storage device provided in this application, by employing the aforementioned battery cells or battery devices, helps to improve the reliability of the energy storage device.

[0060] Fifthly, embodiments of this application provide an energy storage system, including a power conversion device and an energy storage device, wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0061] The energy storage system provided in this application, by employing the energy storage devices described above, helps to improve the reliability of the energy storage system.

[0062] Sixthly, embodiments of this application provide a charging network, including charging piles, and including an energy storage device or energy storage system, wherein the energy storage device is used to provide electrical energy to the charging piles.

[0063] The charging network provided in this application embodiment, by employing the energy storage device or energy storage system mentioned above, helps to improve the reliability of the charging network.

[0064] 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

[0065] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies 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.

[0066] Figure 1 is a schematic diagram of an energy storage system provided in some embodiments of this application;

[0067] Figure 2 is a schematic diagram of a charging network provided in some embodiments of this application;

[0068] Figure 3 is a schematic diagram of a vehicle provided in some embodiments of this application;

[0069] Figure 4 is an exploded view of a battery device provided in some embodiments of this application;

[0070] Figure 5 is a three-dimensional structural diagram of a battery cell provided in some embodiments of this application;

[0071] Figure 6 is a cross-sectional view of Figure 5 along AA;

[0072] Figure 7 is an enlarged view of point B in Figure 6;

[0073] Figure 8 is an enlarged view of point C in Figure 6;

[0074] Figure 9 is a perspective structural diagram of the housing of a battery cell provided in some embodiments of this application;

[0075] Figure 10 is an enlarged view of point D in Figure 9;

[0076] Figure 11 is an enlarged view of point E in Figure 9.

[0077] In the figure, the following labels are used: 1000-Energy storage system; 1100-Power conversion device; 1200-Power generation device; 2000-Charging network; 2100-Charging pile; 2200-Connector; 3000 - Vehicle; 3100 - Controller; 3200 - Motor; 100 - Energy storage device; 10 - Battery device; 1 - Battery cell; 101 - Receiving cavity; 11 - Electrode assembly; 12 - Housing; 1201 - First inner surface; 1202 - First groove; 1203 - Groove bottom wall; 1204 - Second inner surface; 121 - End wall; 122 - Side wall; 122a - First side wall; 122b - Second side wall; 1221 - Main body wall; 1222 - First thickened part; 1223 - Second thickened part; 123 - First transition part; 124 - Second transition part; 13 - End cap; 2 - Housing; 21 - First part; 22 - Second part; O - Center; L1 - First dividing line; L2 - Second dividing line; Z - First direction; Y - Second direction; X - Third direction. Detailed Implementation

[0078] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0079] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0080] Unless otherwise specified, all technical features and optional technical features of the embodiments of this application can be combined with each other to form new technical solutions.

[0081] In the description of the embodiments of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0082] Furthermore, the terms "first" and "second" 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. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0083] In the description of the embodiments of this application, "multiple" means two or more, and unless otherwise explicitly specified, "two or more" includes two. Correspondingly, "multiple groups" means two or more groups, including two groups.

[0084] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "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. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0085] In the description of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three possibilities: A exists, A and B exist simultaneously, and B exists. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0086] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0087] In related technologies, a battery cell typically includes a housing and an electrode assembly, with at least a portion of the electrode assembly disposed within the housing. The housing generally includes an end wall and a side wall connected to the end wall, with a transition portion provided at the junction of the end wall and the side wall. The end wall, side wall, and transition portion enclose a receiving cavity, within which at least a portion of the electrode assembly is received.

[0088] The inner surface of this transition section is generally rounded.

[0089] A base plate is typically installed between the end wall and the electrode assembly. The base plate elevates the electrode assembly to reduce interference between it and the transition section, thereby lowering the risk of damage caused by the electrode assembly being squeezed by the transition section. However, the base plate occupies internal space within the battery cell, which is detrimental to increasing the energy density of the battery cell.

[0090] In some cases, the inner surface of the end wall can be recessed at its perimeter to form a clearance groove. This groove can be used to avoid electrode assemblies, improving interference between the electrode assemblies and the transition section. Understandably, the portion of the end wall without the clearance groove can replace a base plate, thus eliminating the need for a base plate. Due to the clearance groove, the transition section needs to undergo adaptive deformation; that is, it needs to adapt to the recessed inner surface of the end wall at its perimeter to achieve a natural transition between the clearance groove and the sidewall. However, this results in a relatively thin wall thickness in the transition section and its surrounding area, leading to a weaker structure and lower structural strength. Consequently, this affects the overall structural strength and reliability of the battery cell.

[0091] Based on the above considerations, embodiments of this application provide a battery cell, related devices, an energy storage system, and a charging network. An end wall is disposed at one end of a side wall along a first direction. The side wall includes a main wall arranged along the first direction and a first thickened portion. The wall thickness of the first thickened portion is greater than the wall thickness of the main wall, and a first transition portion connects the end wall and the first thickened portion. This results in a thickened wall thickness in the end region of the side wall near the first transition portion. Furthermore, the first transition portion connects the first thickened portion and the end wall, increasing the wall thickness of the first transition portion. In this way, the wall thickness of the first transition portion and its surrounding area can be increased, thereby increasing the structural strength and addressing the weakness in the first transition portion and its surrounding area. This helps improve the structural strength of the casing, and ultimately improves the structural strength and reliability of the battery cell.

[0092] It should be noted that the relevant devices may include battery devices, power-consuming devices, and energy storage devices.

[0093] The battery cell involved in the embodiments of this application refers to the smallest unit used for storing and outputting electrical energy. The battery cell can be a secondary battery or a primary battery. A secondary battery is a battery cell that can be recharged after discharge to activate the active materials and continue to be used.

[0094] The battery cells can be cylindrical, flat, cuboid, or other shapes. Battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0095] The battery device involved in the embodiments of this application can be a single physical module comprising one or more battery cells, used to provide voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in a mixed connection via a busbar. A mixed connection refers to multiple battery cells being connected in both series and parallel configurations.

[0096] In some embodiments, the battery device can be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. As an example, multiple battery cells can be fixed to form a battery module by cable ties or the like. As an example, multiple battery cells can also be fixed to form a battery module by end plates, side plates, or the like.

[0097] In some embodiments, the battery device can be a battery pack, which may include a housing and individual battery cells. As an example, individual battery cells may be directly housed within the housing. As another example, multiple individual battery cells may first be assembled into one or more battery modules and then housed within the housing.

[0098] The battery cells and battery devices involved in the embodiments of this application can be used in energy storage devices that use battery cells or battery devices as energy storage elements.

[0099] The energy storage device involved in the embodiments of this application can be an energy storage container or an energy storage cabinet.

[0100] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours.

[0101] The energy storage device may include one or more battery clusters, and the battery clusters may include multiple battery devices.

[0102] In some embodiments, multiple battery devices in a battery cluster can be connected in series via a busbar to increase the voltage of the energy storage device.

[0103] In some embodiments, when the energy storage device includes multiple battery clusters, the multiple battery clusters can be connected in parallel to increase the capacity of the energy storage device.

[0104] In some embodiments, the energy storage device may further include a cabinet in which the battery clusters are housed.

[0105] In some embodiments, the energy storage device may further include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0106] In some embodiments, the thermal management module may include a liquid cooling unit that provides coolant to each battery device via piping for regulating the temperature of individual battery cells.

[0107] In some embodiments, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For example, the main control module can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0108] In some embodiments, the central control module can serve as the battery management unit of the energy storage device, used for monitoring and managing the energy storage device. The central control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device. For example, the central control module can control the charging and discharging current and voltage of the energy storage device. As an example, the central control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0109] In some embodiments, the fire protection module may include a control panel, detectors, alarm devices, etc., for detecting, alarming, or extinguishing fires in the energy storage device.

[0110] In some embodiments, the power distribution module can be used to distribute power to modules in the energy storage device that require electricity.

[0111] The energy storage system involved in the embodiments of this application can be any power system that requires energy storage devices.

[0112] In some embodiments, please refer to FIG1, which is a schematic diagram of an energy storage system 1000 provided in some embodiments of this application. The energy storage system 1000 involved in the embodiments of this application may include an energy storage device 100 and a power converter system (PCS) 1100, which is connected between a power generation device 1200 and the energy storage device 100. The power generation device 1200 generates electrical energy, which can be stored in the energy storage device 100 through the power converter system 1100. The number of energy storage devices 100 may be one or more.

[0113] As an example, the power generation device 1200 can specifically be a solar panel, a hydroelectric power generation device, a thermal power generation device, a wind power generation device, etc.

[0114] In some embodiments, please refer to FIG2, which is a schematic diagram of a charging network 2000 provided in some embodiments of this application. The charging network 2000 involved in the embodiments of this application may include a charging pile 2100 and an energy storage device 100. The charging pile 2100 is electrically connected to the energy storage device 100, and the energy storage device 100 is used to provide electrical energy to the charging pile 2100.

[0115] The charging pile 2100 and the battery device in the energy storage device 100 can be electrically connected by a cable, and the battery device can provide the electrical energy stored in it to the charging pile 2100.

[0116] The charging pile 2100 may have one or more connectors 2200, which are used to connect to electrical devices (such as vehicles) so as to provide power to the electrical devices.

[0117] The energy storage device 100 can be located inside the charging pile 2100 (e.g., an integrated energy storage and charging unit) or outside the charging pile 2100.

[0118] The battery cell and battery device provided in this application embodiment can also be used in electrical devices that use the battery cell or battery device as a power source.

[0119] Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, vehicles, 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. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft. Based on the power source, vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Based on the drive method, vehicles can be front-wheel drive vehicles, rear-wheel drive vehicles, or four-wheel drive vehicles.

[0120] For ease of description, this application uses a vehicle as an example to illustrate the embodiments of the electrical device.

[0121] In some embodiments, please refer to FIG3, which is a schematic diagram of a vehicle 3000 provided in some embodiments of this application. A battery device 10 is disposed inside the vehicle 3000, and the battery device 10 may be located at the bottom, front, or rear of the vehicle 3000. The battery device 10 can be used to power the vehicle 3000; for example, the battery device 10 can serve as the operating power source for the vehicle 3000. The vehicle 3000 may also include a controller 3100 and a motor 3200. The controller 3100 is used to control the battery device 10 to supply power to the motor 3200, for example, to meet the power requirements of the vehicle 3000 during startup, navigation, and driving.

[0122] In some embodiments, the battery device 10 can not only serve as the operating power source for the vehicle 3000, but also as the driving power source for the vehicle 3000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 3000.

[0123] In some embodiments, please refer to FIG4, which is an exploded view of a battery device 10 provided in some embodiments of this application. The battery device 10 may include a housing 2 and a battery cell 1. The housing 2 is a structure with internal space, and the internal space of the housing 2 is used to accommodate the battery cell 1.

[0124] The housing 2 can adopt various structures. In some embodiments, the housing 2 may include a first part 21 and a second part 22, which overlap each other and jointly define the internal space of the housing 2, which is a closed space. Here, "closed" means covered or shut off; it can be sealed or unsealed. That is, the housing 2 can be a sealed structure or an unsealed structure. Referring to Figure 4, both the first part 21 and the second part 22 can be hollow structures with an opening at one end. The open side of the first part 21 overlaps the open side of the second part 22, so that the first part 21 and the second part 22 jointly define the internal space of the housing 2. Alternatively, the first part 21 can be a hollow structure with an opening at one end, and the second part 22 can be a plate-like structure. The second part 22 overlaps the open side of the first part 21, so that the first part 21 and the second part 22 jointly define the internal space of the housing 2. The housing 2 composed of the first part 21 and the second part 22 can be of various shapes, such as a cylinder, a cuboid, etc.

[0125] In some embodiments, multiple battery cells 1 can be connected in series, parallel, or mixed to form a whole, and then the whole formed by the multiple battery cells 1 is directly housed in the internal space of the housing 2. In other embodiments, multiple battery cells 1 can also be connected in series, parallel, or mixed to form a battery module, and the battery module is housed in the internal space of the housing 2. In still other embodiments, multiple battery cells 1 can also be connected in series, parallel, or mixed to form multiple battery modules, and the multiple battery modules can then be connected in series, parallel, or mixed to form a whole, and housed in the internal space of the housing 2.

[0126] In some embodiments, referring to Figures 3 and 4, the housing 2 of the battery device 10 can be part of the chassis structure of the vehicle 3000. For example, a portion of the housing 2 can be at least a portion of the floor of the vehicle 3000, or a portion of the housing 2 can be at least a portion of the crossbeams and longitudinal beams of the vehicle 3000.

[0127] In some embodiments, please refer to Figures 5 and 6 together, and in conjunction with other accompanying drawings. Figure 5 is a perspective structural diagram of a battery cell provided in some embodiments of this application, and Figure 6 is a cross-sectional view of Figure 5 along line AA. The battery cell 1 provided in the embodiments of this application may include an electrode assembly 11 and a housing.

[0128] The electrode assembly is the component in the battery cell 1 where the electrochemical reaction takes place. The electrode assembly is mainly formed by winding or stacking positive and negative electrode sheets, with a separator between them. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, while the portions without active material each constitute a tab. The tab of the positive electrode sheet is called the positive tab, and the tab of the negative electrode sheet is called the negative tab. The positive and negative tabs can be located together at one end of the main body; alternatively, they can be located at opposite ends of the main body.

[0129] In a single battery cell 1, the number of electrode components can be one or more.

[0130] In some contexts, electrode assemblies may also be referred to as bare cells, wound bodies, laminates, etc.

[0131] In some embodiments, the battery cell 1 may further include an electrolyte, which acts as a conductor of ions between the positive and negative electrode plates. The electrolyte described in this application embodiment may be liquid, gel-like, or solid.

[0132] The housing is used to define the internal environment of the battery cell 1 and to house the electrode assembly and electrolyte.

[0133] In some embodiments, please refer to Figures 5 and 6 together, and in conjunction with other figures. The housing may include a housing 12 and an end cap 13, which are components used to jointly define the internal environment of the battery cell 1. The internal environment defined by the housing 12 and the end cap 13 is used to house the electrode assembly and the electrolyte. The housing 12 and the end cap 13 may be separate components. Specifically, the housing 12 has an opening, and the end cap 13 is disposed over the opening of the housing 12 to jointly define the internal environment of the battery cell 1 and isolate the internal environment of the battery cell 1 from the external environment.

[0134] The outer casing can be either a sealed or unsealed structure. As an example, when the outer casing is sealed, it protects the electrode assembly and, to some extent, prevents leakage such as electrolyte leakage. As another example, when the outer casing is unsealed, it still protects the electrode assembly, and a sealing bag may be included between the outer casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating structure, an aluminum-plastic film, etc.

[0135] The number of end caps 13 can be one, and the end cap 13 is located at one end of the housing 12.

[0136] The housing 12 can be cylindrical, square, or other shapes, depending on the specific shape and size of the electrode assembly.

[0137] The shell 12 and end cap 13 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0138] Please refer to Figures 5 through 8, and in conjunction with other accompanying drawings. Figure 7 is an enlarged view of point B in Figure 6, and Figure 8 is an enlarged view of point C in Figure 6. In Figure 8, the main body wall 1221 and the second thickened portion 1223 are separated by a dashed line. The battery cell 1 provided in this embodiment includes an electrode assembly 11 and a housing 12. At least a portion of the electrode assembly 11 is disposed within the housing 12. The housing 12 includes an end wall 121, a side wall 122, and a first transition portion 123. The end wall 121 is disposed at one end of the side wall 122 along a first direction Z. The side wall 122 includes a main body wall 1221 and a first thickened portion 1222. The first thickened portion 1222 and the main body wall 1221 are arranged along the first direction Z. The first transition portion 123 connects the end wall 121 and the first thickened portion 1222. The wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main body wall 1221. The end wall 121 is provided with a first inner surface 1201, which faces the electrode assembly 11. A first groove 1202 is formed on the outer periphery of the first inner surface 1201, which extends to the first transition portion 123.

[0139] Both end wall 121 and side wall 122 are solid walls of the shell 12.

[0140] The fact that end wall 121 is located at one end of side wall 122 along the first direction Z does not mean that end wall 121 and side wall 122 must be distributed along the first direction Z. It can be understood that the solid wall of housing 12 at one end along the first direction Z is end wall 121. As an example, the wall thickness direction of end wall 121 is parallel to the first direction Z.

[0141] The main wall 1221 and the first thickened portion 1222 are two parts of the side wall 122 arranged along the first direction Z. The main wall 1221 is the main part of the side wall 122. The first thickened portion 1222 is located at one end of the main wall 1221 along the first direction Z. Specifically, the first thickened portion 1222 is located at the end of the main wall 1221 along the first direction Z near the end wall 121, and the end wall 121 is located at the end of the first thickened portion 1222 away from the main wall 1221 along the first direction Z. The first thickened portion 1222 is the end region of the side wall 122 along the first direction Z near the first transition portion 123.

[0142] The first transition portion 123 refers to the part of the housing 12 used to achieve the transition effect between the side wall 122 and the end wall 121. Specifically, the first transition portion 123 is disposed between the end wall 121 and the side wall 122, and connects the end wall 121 and the side wall 122 to achieve the transition between them. More specifically, the first transition portion 123 is connected between the end wall 121 and the first thickened portion 1222, meaning that the first transition portion 123 is disposed between the first thickened portion 1222 of the side wall 122 and the end wall 121, and connects the first thickened portion 1222 and the end wall 121, so that the first transition portion 123 achieves the transition between the first thickened portion 1222 of the side wall 122 and the end wall 121.

[0143] The side wall 122, end wall 121, and first transition portion 123 can be configured to form a receiving cavity 101, which is the internal environment of the battery cell 1, and at least a portion of the electrode assembly 11 is disposed within the receiving cavity 101. Specifically, the main body wall 1221, the first thickened portion 1222, the end wall 121, and the first transition portion 123 can be configured to form the receiving cavity 101.

[0144] The sidewall 122, endwall 121, and first transition portion 123 may each have an inner surface and an outer surface. The inner surface of the endwall 121 refers to the surface of the endwall 121 facing the receiving cavity 101, specifically the surface of the endwall 121 facing the receiving cavity 101 along the first direction Z. The outer surface of the endwall 121 refers to the surface of the endwall 121 away from the receiving cavity 101, specifically the surface of the endwall 121 away from the receiving cavity 101 along the first direction Z. The inner surface of the first transition portion 123 is the surface of the first transition portion 123 facing the receiving cavity 101, and the outer surface of the first transition portion 123 is the surface of the first transition portion 123 away from the receiving cavity 101. The inner surface of the sidewall 122 is the surface of the sidewall 122 facing the receiving cavity 101, and the outer surface of the sidewall 122 is the surface of the sidewall 122 away from the receiving cavity 101. Specifically, the inner surface of the first thickened portion 1222 is the surface of the first thickened portion 1222 facing the receiving cavity 101, the outer surface of the first thickened portion 1222 is the surface of the first thickened portion 1222 away from the receiving cavity 101, the inner surface of the main body wall 1221 is the surface of the main body wall 1221 facing the receiving cavity 101, and the outer surface of the main body wall 1221 is the surface of the main body wall 1221 away from the receiving cavity 101.

[0145] The first inner surface 1201 is a part of the inner surface of the end wall 121. The outer periphery of the first inner surface 1201 is formed with a first groove 1202, which means that the inner surface of the end wall 121 forms a first groove 1202 at a position surrounding the outer periphery of the first inner surface 1201. In other words, the inner surface of the end wall 121 is recessed to form the first groove 1202, and the first groove 1202 surrounds the outer periphery of the first inner surface 1201.

[0146] The first groove 1202 refers to the groove structure used to avoid the electrode assembly 11.

[0147] The first groove 1202 extends to the first transition portion 123, meaning that the groove wall of the first groove 1202 extends to the first transition portion 123 so that the groove wall of the first groove 1202 and the first transition portion 123 are connected. Understandably, the first groove 1202 extends to the four edges of the end wall 121.

[0148] Understandably, the first transition portion 123 is disposed between the first groove 1202 and the first thickened portion 1222, and is connected to the groove wall of the first groove 1202 and the first thickened portion 1222, so as to realize the transition between the first groove 1202 and the first thickened portion 1222.

[0149] The battery cell 1 provided in this application embodiment has a first groove 1202 formed by a recess in the inner surface of the end wall 121, and the first groove 1202 is disposed around the outer periphery of the first inner surface 1201 of the end wall 121, so that the electrode assembly 11 can be disposed on the first inner surface 1201, while the first transition portion 123 is avoided by the first groove 1202. In this way, the first inner surface 1201 can replace the bottom support plate to support and raise the electrode assembly 11, which can improve the interference problem between the first transition portion 123 and the electrode assembly 11 and achieve protection for the electrode assembly 11. Furthermore, the bottom support plate is eliminated, which is beneficial to improving the energy density of the battery cell 1.

[0150] An end wall 121 is provided at one end of the side wall 122 along the first direction Z. The side wall 122 includes a main wall 1221 and a first thickened portion 1222 arranged along the first direction Z. The wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221. A first transition portion 123 connects the end wall 121 and the first thickened portion 1222, thereby thickening the end region of the side wall 122 near the first transition portion 123 along the first direction Z. Furthermore, the first transition portion 123 facilitates the transition between the first thickened portion 1222 and the end wall 121, allowing the first transition portion 123 to adapt to the thickened portion 1222 by undergoing adaptive deformation, thereby increasing the wall thickness of the first transition portion 123. In this way, the wall thickness of the first transition portion 123 and its surrounding area can be increased, thereby increasing the structural strength. This can improve the problem of the weakness of the first transition portion 123 and its surrounding area caused by the setting of the first groove 1202, that is, reduce the weakness of the first transition portion 123 and its surrounding area. This helps to improve the structural strength of the housing 12, and thus improve the structural strength and reliability of the battery cell 1.

[0151] In some embodiments, please refer to FIG7, and in conjunction with other figures. The inner surface of the first thickened portion 1222 protrudes from the main body wall 1221.

[0152] Understandably, the inner surface of the first thickened portion 1222 protrudes from the inner surface of the main body wall 1221 toward the receiving cavity 101, so that the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main body wall 1221.

[0153] The inner surface of the first thickened portion 1222 protrudes from the main body wall 1221, thereby increasing the wall thickness of the first thickened portion 1222. This allows the inner surface of the first transition portion 123 to protrude correspondingly to the inner surface of the first thickened portion 1222, thus increasing the wall thickness of the first transition portion 123. This helps to mitigate the weakness of the first transition portion 123 and its surrounding area caused by the first groove 1202 formed by the recess on the inner surface of the end wall 121, reducing the weakness of the first transition portion 123 and its surrounding area, and improving the structural strength of the first transition portion 123 and its surrounding area. Consequently, this contributes to improving the structural strength of the casing 12, and further improves the structural strength and reliability of the battery cell 1.

[0154] In addition, by having the inner surface of the first thickened portion 1222 protrude from the main body wall 1221, the wall thickness of the first thickened portion 1222 is increased, which can maintain the smoothness of the outer surface of the shell 12 and help to ensure the consistency of the shape of the battery cell 1 to a certain extent.

[0155] In some embodiments, the outer surface of the first thickened portion 1222 may also protrude from the main body wall 1221 so that the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main body wall 1221.

[0156] In some embodiments, please refer to FIG7, and in conjunction with other figures. In the first direction Z, at least a portion of the wall thickness of the first thickened portion 1222 is gradually increased from the main body wall 1221 toward the first transition portion 123.

[0157] Therefore, when the inner surface of the first thickened portion 1222 protrudes from the main body wall 1221, at least a portion of the inner surface of the first thickened portion 1222 can gradually protrude from the main body wall 1221, so that the inner surface of the first thickened portion 1222 and the inner surface of the main body wall 1221 can achieve a smooth transition. When the outer surface of the first thickened portion 1222 protrudes from the main body wall 1221, at least a portion of the outer surface of the first thickened portion 1222 can gradually protrude from the main body wall 1221, so that the outer surface of the first thickened portion 1222 and the outer surface of the main body wall 1221 can achieve a smooth transition.

[0158] In some possible designs, as shown in Figure 7, the wall thickness of the first thickened portion 1222 gradually increases from the main body wall 1221 toward the first transition portion 123 in the first direction Z.

[0159] Alternatively, in some other possible designs, the first thickened portion 1222 may include a first segment and a second segment connected along a first direction Z, wherein, in the first direction Z, the end of the first segment away from the second segment is connected to the main body wall 1221, and the end of the second segment away from the first segment is connected to the first transition portion 123. Thus, the first transition portion 123 serves to achieve a transition connection between the second segment and the end wall 121. In the first direction Z, the wall thickness of the first segment gradually increases from the main body wall 1221 towards the second segment.

[0160] By adopting the above technical solution, a smooth transition can be achieved between the first thickened part 1222 and the main body wall 1221. This helps to improve the stress concentration problem at the connection between the first thickened part 1222 and the main body wall 1221 caused by the increased wall thickness of the first thickened part 1222, and makes the connection between the first thickened part 1222 and the main body wall 1221 have greater structural strength.

[0161] In some embodiments, the first thickened portion 1222 and the first transition portion 123 are smoothly transitioned. Specifically, the inner surface of the first thickened portion 1222 and the inner surface of the first transition portion 123 can be smoothly transitioned, for example, but not limited to, through a concave arc surface. Specifically, the outer surface of the first thickened portion 1222 and the outer surface of the first transition portion 123 can be smoothly transitioned, for example, but not limited to, through a concave arc surface.

[0162] In some embodiments, please refer to FIG7, and in conjunction with other figures. The inner surface of the first transition portion 123 has rounded corners.

[0163] By rounding the inner surface of the first transition portion 123, a smooth transition is achieved between the inner surface of the first thickened portion 1222 and the wall of the first groove 1202, which can alleviate the stress concentration problem in the first transition portion 123 and its surrounding area. Furthermore, since the wall thickness of the first thickened portion 1222 is greater than that of the main body wall 1221, the rounded inner surface of the first transition portion 123 allows for a greater wall thickness in the first transition portion 123 and its surrounding area, thereby improving the structural strength of the first transition portion 123 and its surrounding area and mitigating the weakness in this area.

[0164] It should be noted that the inner surface of the first transition portion 123 is rounded, so that the inner surface of the first transition portion 123 and the inner surface of the first thickened portion 1222 can be smoothly transitioned, and the inner surface of the first transition portion 123 and the groove wall of the first groove 1202 can be smoothly transitioned.

[0165] In some embodiments, please refer to FIG7 and other figures. A first dividing line L1 is provided between the first transition portion 123 and the first thickened portion 1222. The first dividing line L1 passes through the center O of the inner surface of the first transition portion 123 and is parallel to the wall thickness direction of the main body wall 1221.

[0166] The first dividing line L1 refers to the dividing line between the first transition part 123 and the first thickened part 1222, and is a virtual line.

[0167] The inner surface of the first transition portion 123 is rounded, so that the circle containing the inner surface of the first transition portion 123 has a center. The first dividing line L1 passes through the center O, is parallel to the wall thickness direction of the main body wall 1221, and is perpendicular to the first direction Z.

[0168] As an example, as shown in Figure 7, the wall thickness direction of the first sidewall 122a referred to below is along the second direction Y. In the first sidewall 122a, the first dividing line L1 passes through the center O of the inner surface of the first transition portion 123 on the first sidewall 122a and is parallel to the second direction Y.

[0169] As another example, as shown in Figure 9, the wall thickness direction of the second sidewall 122b referred to below is the third direction X. In the second sidewall 122b, the first dividing line L1 passes through the center O of the inner surface of the first transition portion 123 on the second sidewall 122b and is parallel to the third direction X.

[0170] In some embodiments, please refer to FIG7, and in conjunction with other figures. The wall thickness of the main body wall 1221 is H1, and the maximum wall thickness of the first thickened portion 1222 is H2, (H2-H1) / H1∈(0,0.5).

[0171] Wherein, (H2-H1) / H1 can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0172] By adopting the above technical solution, the increase in wall thickness of the first thickened portion 1222 is kept within a certain range. This allows the first thickened portion 1222 to have a larger wall thickness, resulting in a larger wall thickness for the first transition portion 123 and its surrounding area, thus increasing structural strength and mitigating the weakness of the first transition portion 123 and its surrounding area. Furthermore, it reduces interference between the first thickened portion 1222 and the electrode assembly 11. Additionally, it contributes to increasing the energy density of the battery cell 1.

[0173] In some embodiments, please refer to Figure 7, and in conjunction with other figures. (H2-H1) / H1∈(0, 1 / 3).

[0174] Wherein, (H2-H1) / H1 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 1 / 3, etc.

[0175] By adopting the above technical solution, on the one hand, the first thickened portion 1222 has a larger wall thickness, thereby giving the first transition portion 123 and its surrounding area a larger wall thickness, and thus greater structural strength. On the other hand, it can improve the interference problem between the first thickened portion 1222 and the electrode assembly 11. In addition, it is also beneficial to improve the energy density of the battery cell 1.

[0176] In some embodiments, please refer to FIG7 and other figures. A second dividing line L2 is provided between the end wall 121 and the first transition portion 123. The second dividing line L2 passes through the center O of the inner surface of the first transition portion 123 and is parallel to the first direction Z.

[0177] The second dividing line L2 refers to the dividing line between the first transition section 123 and the end wall 121, and is a virtual line.

[0178] In some embodiments, please refer to FIG7 and other figures. The first direction Z is parallel to the wall thickness direction of the end wall 121. In the first direction Z, the distance between the end of the first thickened portion 1222 away from the first transition portion 123 and the outer surface of the end wall 121 is H3, where H3 ∈ [2 mm, 5 mm].

[0179] H3 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0180] By using H3∈[2mm, 5mm], the first thickened portion 1222 has a certain dimensional range in the first direction Z. On the one hand, due to the provision of the first thickened portion 1222, the wall thickness of the first transition portion 123 and its surrounding area can be increased, thereby giving the first transition portion 123 and its surrounding area a larger wall thickness and thus greater structural strength. On the other hand, it can improve the interference problem between the first thickened portion 1222 and the electrode assembly 11. In addition, it is also beneficial to improve the energy density of the battery cell 1.

[0181] In some embodiments, please refer to Figure 7, and in conjunction with other figures. H3∈[3mm, 4mm].

[0182] H3 can be 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, etc.

[0183] This design allows for increased wall thickness in the first transition section 123 and its surrounding area, resulting in greater structural strength. It also mitigates interference between the first thickened section 1222 and the electrode assembly 11. Furthermore, it contributes to improved energy density in the battery cell 1.

[0184] In some embodiments, the battery cell 1 is a cylindrical battery. Specifically, the casing 12 is cylindrical, and the sidewalls 122 are cylindrical. Therefore, the first direction Z can be the axial direction of the battery cell 1.

[0185] In some embodiments, please refer to Figures 5 to 11 together, and in conjunction with other figures. Figure 9 is a perspective view of the housing 12 of a battery cell 1 according to some embodiments of this application; Figure 10 is an enlarged view of point D in Figure 9; and Figure 11 is an enlarged view of point E in Figure 9. A first transition portion 123 surrounds the outer periphery of the first groove 1202. Multiple sidewalls 122 are present, collectively surrounding the outer periphery of the end wall 121, and each sidewall 122 is connected to the end of the first transition portion 123 away from the end wall 121. The multiple sidewalls 122 include two first sidewalls 122a and two second sidewalls 122b. The two first sidewalls 122a are arranged opposite each other along a second direction Y, and the two second sidewalls 122b are arranged opposite each other along a third direction X. The two first sidewalls 122a and the two second sidewalls 122b together surround the outer periphery of the end wall 121. Furthermore, both the first sidewalls 122a and the second sidewalls 122b are connected to the first transition portion 123. Wherein, the first direction Z intersects with the second direction Y, the first direction Z intersects with the third direction X, and the second direction Y intersects with the third direction X.

[0186] The first transition portion 123 surrounds the outer periphery of the first groove 1202, meaning that the first transition portion 123 surrounds the outer periphery of the end wall 121 and is connected to the end wall 121. Specifically, the first transition portion 123 is connected to the groove wall of the first groove 1202.

[0187] Understandably, each first sidewall 122a is connected to two second sidewalls 122b on both sides along the third direction X, and each second sidewall 122b is connected to two first sidewalls 122a on both sides along the second direction Y, so that the first sidewalls 122a and the second sidewalls 122b are arranged alternately in the circumferential direction, thereby causing the two first sidewalls 122a and the two second sidewalls to be arranged together around the outer periphery of the end wall 121. The end wall 121, the first transition portion 123, and the four sidewalls 122 together form the aforementioned receiving cavity 101.

[0188] The first sidewall 122a is connected to the first transition portion 123, so that the first transition portion 123 can realize the transition between the first sidewall 122a and the first groove 1202 of the end wall 121. The second sidewall 122b is connected to the first transition portion 123, so that the first transition portion 123 can realize the transition between the second sidewall 122b and the first groove 1202 of the end wall 121.

[0189] The intersection of the first direction Z and the second direction Y means that the first direction Z and the second direction Y can form an angle greater than 0° and less than 180°, that is, the first direction Z and the second direction Y are not parallel. The first direction Z and the second direction Y can be perpendicular to each other or not perpendicular. The first direction Z and the second direction Y can be directions intersecting on the same plane, or directions on planes that are skew to each other, and the projection of the second direction Y onto the plane containing the first direction Z can intersect the first direction Z. Correspondingly, the meaning of the intersection of the first direction Z and the third direction X, and the intersection of the second direction Y and the third direction X, can be explained in the same way, and will not be repeated here. As an example, the first direction Z and the second direction Y are perpendicular, the first direction Z is perpendicular to the third direction X, and the second direction Y is perpendicular to the third direction X. In some cases, the first direction Z can be the length direction or height direction of the battery cell 1, the second direction Y can be the thickness direction of the battery cell 1, and the third direction X can be the width direction of the battery cell 1.

[0190] In some possible designs, please refer to Figures 5 to 11 together, and in conjunction with other figures. At least one first sidewall 122a includes the aforementioned main wall 1221 and the aforementioned first thickened portion 1222, and in the first sidewall 122a, the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221.

[0191] Understandably, the wall thickness of the first thickened portion 1222 of the first sidewall 122a is greater than the wall thickness of the main body wall 1221 of the first sidewall 122a. That is, the wall thickness of the end region of the first sidewall 122a near the first transition portion 123 along the first direction Z is all thickened.

[0192] In the first sidewall 122a, the wall thickness of the main wall 1221 is approximately the dimension of the main wall 1221 along the second direction Y, and the wall thickness of the first thickened portion 1222 is approximately the dimension of the first thickened portion 1222 along the second direction Y.

[0193] As an example, as shown in Figures 5 to 11, both first sidewalls 122a include the aforementioned main wall 1221 and the first thickened portion 1222.

[0194] In some possible designs, please refer to Figures 5 through 11 together, and in conjunction with other figures. At least one second sidewall 122b includes the aforementioned main wall 1221 and the aforementioned first thickened portion 1222, and in the second sidewall 122b, the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221.

[0195] Understandably, the wall thickness of the first thickened portion 1222 of the second sidewall 122b is greater than the wall thickness of the main body wall 1221 of the second sidewall 122b. That is, the wall thickness of the end region of the second sidewall 122b near the first transition portion 123 along the first direction Z is all thickened.

[0196] In the second sidewall 122b, the wall thickness of the main wall 1221 is approximately the size of the main wall 1221 along the third direction X, and the wall thickness of the first thickened portion 1222 is approximately the size of the first thickened portion 1222 along the third direction X.

[0197] As an example, as shown in Figures 5 to 11, both second sidewalls 122b include the aforementioned main wall 1221 and the first thickened portion 1222.

[0198] By adopting the above technical solution, four sidewalls 122 are arranged around the outer periphery of the end wall 121, and at least one sidewall 122 includes the main wall 1221 and the first thickened portion 1222. That is, the wall thickness of at least one sidewall 122 near the end region of the first transition portion 123 along the first direction Z is increased, thereby increasing the structural strength of the region of the first transition portion 123 corresponding to the at least one sidewall 122, which is beneficial to improving the structural strength of the casing 12, and thus improving the structural strength and reliability of the battery cell 1.

[0199] In some embodiments, please refer to Figures 5 to 11 together, and in conjunction with other figures. The surface area of ​​the first sidewall 122a is greater than the surface area of ​​the second sidewall 122b. The first sidewall 122a includes the main wall 1221 and the first thickened portion 1222, and the wall thickness of the first thickened portion 1222 in the first sidewall 122a is greater than the wall thickness of the main wall 1221.

[0200] The surface area of ​​the first sidewall 122a refers to the surface area of ​​one side of the first sidewall 122a along the second direction Y, and the surface area of ​​the second sidewall 122b is the surface area of ​​one side of the second sidewall 122b along the third direction X.

[0201] Because the surface area of ​​the first sidewall 122a is larger than that of the second sidewall 122b, the area of ​​the first transition portion 123 corresponding to the first sidewall 122a is more prone to weakness. Furthermore, because the wall thickness of the first thickened portion 1222 in the first sidewall 122a is greater than the wall thickness of the main body wall 1221, the structural strength of the area of ​​the first transition portion 123 corresponding to the first sidewall 122a and its vicinity can be increased, which helps to improve the structural strength of the casing 12, and thus improves the structural strength and reliability of the battery cell 1.

[0202] In some embodiments, the minimum wall thickness of the first sidewall 122a is less than the minimum wall thickness of the second sidewall 122b. The first sidewall 122a includes the main wall 1221 and the first thickened portion 1222, and the wall thickness of the first thickened portion 1222 in the first sidewall 122a is greater than the wall thickness of the main wall 1221.

[0203] Because the minimum wall thickness of the first sidewall 122a is less than the minimum wall thickness of the second sidewall 122b, the area of ​​the first transition portion 123 corresponding to the first sidewall 122a is more prone to weakness. However, because the wall thickness of the first thickened portion 1222 in the first sidewall 122a is greater than the wall thickness of the main body wall 1221, the structural strength of the area of ​​the first transition portion 123 corresponding to the first sidewall 122a and its vicinity can be increased, which helps to improve the structural strength of the casing 12, and thus improves the structural strength and reliability of the battery cell 1.

[0204] In some embodiments, the second sidewall 122b includes the main wall 1221 and the first thickened portion 1222, and the wall thickness of the first thickened portion 1222 in the second sidewall 122b is greater than the wall thickness of the main wall 1221.

[0205] By adopting the above technical solution, the first sidewall 122a includes the main wall 1221 and the first thickened portion 1222, and the second sidewall 122b also includes the main wall 1221 and the first thickened portion 1222. In the first sidewall 122a, the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221. Furthermore, in the second sidewall 122b, the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221. This helps to increase the structural strength of the first transition portion 123 in the area surrounding the first groove 1202 and its vicinity, thereby helping to improve the structural strength of the casing 12, and further improving the structural strength and reliability of the battery cell 1.

[0206] In some embodiments, please refer to Figures 9 to 11 together, and in conjunction with other figures. A second transition portion 124 is formed at the connection between the first sidewall 122a and the second sidewall 122b.

[0207] The second transition portion 124 refers to the portion formed between the first sidewall 122a and the second sidewall 122b, used to realize the transition between the first sidewall 122a and the second sidewall 122b.

[0208] Wherein, based on the first sidewall 122a including the main wall 1221 and the first thickened portion 1222, the second transition portion 124 can realize the transition between the main wall 1221 and the second sidewall 122b, as well as the transition between the first thickened portion 1222 and the second sidewall 122b, so that the area of ​​the second transition portion 124 corresponding to the first thickened portion 1222 is also thickened.

[0209] Based on the fact that both the first sidewall 122a and the second sidewall 122b include the aforementioned main wall 1221 and the first thickened portion 1222, the second transition portion 124 can realize the transition between the main wall 1221 of the first sidewall 122a and the main wall 1221 of the second sidewall 122b, as well as the transition between the first thickened portion 1222 of the first sidewall 122a and the first thickened portion 1222 of the second sidewall 122b, thereby enabling the area of ​​the second transition portion 124 corresponding to the first thickened portion 1222 of each sidewall 122 to also be thickened.

[0210] By adopting the above technical solution, the first transition portion 123 is also thickened in the area corresponding to the first thickened portion 1222, which helps to improve the overall structural strength of the casing 12 and the structural strength and reliability of the battery cell 1.

[0211] In some embodiments, please refer to Figures 9 to 11 together, and in conjunction with other figures. The inner surface of the second transition portion 124 has rounded corners.

[0212] By rounding the inner surface of the second transition portion 124, the inner surfaces of the first sidewall 122a and the second sidewall 122b can transition smoothly through the rounded corners. This improves stress concentration at the connection between the first and second sidewalls 122a and 122b. Furthermore, the second transition portion 124 can be thickened in the area corresponding to the first thickened portion 1222, which enhances the overall structural strength of the casing 12 and improves the structural strength and reliability of the battery cell 1.

[0213] In some embodiments, please refer to Figures 7 and 10 together, and in conjunction with other figures. In the first direction Z, the first groove 1202 is provided with a groove bottom wall 1203. The end wall 121 is also provided with a second inner surface 1204, which connects the groove bottom wall 1203 and the first inner surface 1201. The groove bottom wall 1203 is connected to a first transition portion 123, and the connection between the first inner surface 1201 and the second inner surface 1204 is a rounded transition.

[0214] Understandably, one side of the first groove 1202 along the first direction Z is the bottom wall 1203 of the first groove 1202. The bottom wall 1203 and the second inner surface 1204 are both groove walls of the first groove 1202.

[0215] The second inner surface 1204 being connected between the bottom wall 1203 of the tank and the first inner surface 1201 means that the second inner surface 1204 is located between the bottom wall 1203 of the tank and the first inner surface 1201, and the second inner surface 1204 is connected between the bottom wall 1203 of the tank and the first inner surface 1201.

[0216] The arc transition at the junction of the first inner surface 1201 and the second inner surface 1204 means that the junction of the first inner surface 1201 and the second inner surface 1204 is provided with an arc surface. Specifically, the arc surface at the junction of the first inner surface 1201 and the second inner surface 1204 is raised.

[0217] This allows the junction of the first inner surface 1201 and the second inner surface 1204 to be smoothly positioned, thereby improving the problem of the electrode assembly 11 being punctured at the junction of the first inner surface 1201 and the second inner surface 1204, and achieving a protective effect on the electrode assembly 11.

[0218] In some embodiments, please refer to Figures 7 and 10 together, and in conjunction with other figures. The connection between the first inner surface 1201 and the second inner surface 1204 is transitioned by a rounded corner.

[0219] Understandably, the junction of the first inner surface 1201 and the second inner surface 1204 is provided with rounded corners. Specifically, the rounded corners at the junction of the first inner surface 1201 and the second inner surface 1204 are provided with protrusions.

[0220] This allows the junction of the first inner surface 1201 and the second inner surface 1204 to be smoothly positioned, thereby improving the problem of the electrode assembly 11 being punctured at the junction of the first inner surface 1201 and the second inner surface 1204, and achieving a protective effect on the electrode assembly 11.

[0221] In some embodiments, please refer to FIG7 and other figures. The first direction Z is parallel to the wall thickness direction of the end wall 121. In the first direction Z, the distance between the first inner surface 1201 and the outer surface of the end wall 121 is H4. In the first direction Z, the first groove 1202 is provided with a groove bottom wall 1203. In the first direction Z, the maximum distance between the groove bottom wall 1203 and the first inner surface 1201 is H5. Wherein, H5 / H4∈[1 / 20, 1 / 3].

[0222] Understandably, one side of the first groove 1202 along the first direction Z is the bottom wall 1203 of the first groove 1202. The bottom wall 1203 is a part of the groove wall of the first groove 1202.

[0223] In the first direction Z, the maximum distance between the bottom wall 1203 of the groove and the first inner surface 1201 is the depth of the first groove 1202.

[0224] H5 / H4 can be 1 / 20, 0.06, 0.07, 0.08, 0.09, 1 / 10, 0.11, 0.12, 0.13, 0.14, 3 / 20, 0.16, 0.17, 0.18, 0.19, 1 / 5, 0.21, 0.22, 0.23, 0.24, 1 / 4, 0.26, 0.27, 0.28, 0.29, 3 / 10, 0.31, 0.32, 0.33, 1 / 3, etc.

[0225] This configuration allows the first groove 1202 to have a certain depth in the first direction Z. This serves two purposes: firstly, it allows the first groove 1202 to avoid the electrode assembly 11, improving the interference problem between the electrode assembly 11 and the first transition portion 123; secondly, it allows the end wall 121 to have a relatively large wall thickness even with the first groove 1202, thus providing a certain structural strength.

[0226] In some embodiments, please refer to Figure 7, and in conjunction with other figures. H5 / H4∈[1 / 10, 1 / 4].

[0227] H5 / H4 can be 1 / 10, 0.11, 0.12, 0.13, 0.14, 3 / 20, 0.16, 0.17, 0.18, 0.19, 1 / 5, 0.21, 0.22, 0.23, 0.24, 1 / 4, etc.

[0228] In this way, on the one hand, the first groove 1202 can avoid the electrode assembly 11, improving the interference problem between the electrode assembly 11 and the first transition portion 123. On the other hand, the end wall 121 has a relatively large wall thickness under the arrangement of the first groove 1202, thus having a certain structural strength.

[0229] In some embodiments, please refer to Figures 5 to 11 together, and in conjunction with other figures. The sidewall 122 also includes a second thickened portion 1223. The first thickened portion 1222 and the second thickened portion 1223 are respectively disposed at both ends of the main body wall 1221 along the first direction Z. The wall thickness of the second thickened portion 1223 is greater than the wall thickness of the main body wall 1221.

[0230] The second thickened portion 1223 is the end region of the sidewall 122 located away from the first transition portion 123 along the first direction Z. The first thickened portion 1222 is located at the end of the main body wall 1221 near the first transition portion 123 along the first direction Z, and the second thickened portion 1223 is located at the end of the main body wall 1221 away from the first transition portion 123 along the first direction Z. It can be understood that the second thickened portion 1223, the main body wall 1221, and the first thickened portion 1222 are arranged sequentially along the first direction Z, and the main body wall 1221, the first thickened portion 1222, the second thickened portion 1223, the end wall 121, and the first transition portion 123 can enclose and form the aforementioned receiving cavity 101.

[0231] By setting the wall thickness of the second thickened portion 1223 to be greater than that of the main body wall 1221, the end region of the side wall 122 away from the end wall 121 along the first direction Z is thickened. This allows the side wall 122 to be welded to the end cap 13 via the second thickened portion 1223, thereby increasing the welding strength between the end cap 13 and the side wall 122 and the fatigue strength of the weld seam. This reduces the weakness at the weld position between the end cap 13 and the side wall 122, improves the structural strength of the casing, and ultimately enhances the structural strength and reliability of the battery cell 1.

[0232] It should be further explained that by making the wall thickness of the first thickened portion 1222 greater than that of the main body wall 1221, the structural strength of the first transition portion 123 and its surrounding area can be increased, thus improving the problem of the first transition portion 123 and its surrounding area being weak. Specifically, it can improve the problem that the first transition portion 123 and its surrounding area are weaker than the connection between the end cap 13 and the second thickened portion 1223 due to the provision of the second thickened portion 1223, so that the connection between the end cap 13 and the second thickened portion 1223 is still weaker than the first transition portion 123 and its surrounding area, which is beneficial to improving the reliability of the battery cell 1.

[0233] It should also be noted that, as shown in Figures 7 to 11, and in conjunction with other accompanying drawings, the first sidewall 122a, which includes the main wall 1221 and the first thickened portion 1222, may also include the second thickened portion 1223. Specifically, in the first sidewall 122a, the first thickened portion 1222 and the second thickened portion 1223 are respectively provided at both ends of the main wall 1221 along the first direction Z, so that the wall thickness of both ends of the first sidewall 122a along the first direction Z is thickened. Furthermore, the second sidewall 122b may also have a second thickened portion 1223 at its end region along the first direction Z away from the first transition portion 123, or it may not have a second thickened portion 1223.

[0234] Based on the aforementioned main wall 1221 and the first thickened portion 1222, the second sidewall 122b may further include the aforementioned second thickened portion 1223. Specifically, in the second sidewall 122b, the first thickened portion 1222 and the second thickened portion 1223 are respectively provided at both ends of the main wall 1221 along the first direction Z, so that the wall thickness of the second sidewall 122b at both ends along the first direction Z is thickened.

[0235] In some embodiments, please refer to Figures 8 and 11 together, and in conjunction with other figures. The inner surface of the second thickened portion 1223 protrudes from the main body wall 1221, such that the wall thickness of the second thickened portion 1223 is greater than the wall thickness of the main body wall 1221. The inner surface of the second thickened portion 1223 is the surface of the second thickened portion 1223 facing the receiving cavity 101.

[0236] This design maintains the smoothness of the outer surface of the casing 12, which helps to ensure the consistency of the shape of the battery cell 1 to a certain extent.

[0237] In some embodiments, please refer to Figures 8 and 11 together, and in conjunction with other figures. The wall thickness of the second thickened portion 1223 gradually increases from that of the main body wall 1221. This allows for a smooth transition between the second thickened portion 1223 and the main body wall 1221, which helps to alleviate stress concentration at the connection between the main body wall 1221 and the second thickened portion 1223, thereby improving the structural strength of the shell 12.

[0238] In some embodiments, please refer to FIG8, and in conjunction with other figures. The wall thickness of the main body wall 1221 is H1, and the maximum wall thickness of the second thickened portion 1223 is H6, (H6-H1) / H1∈(0,0.5).

[0239] Wherein, (H6-H1) / H1 can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0240] By adopting the above technical solution, the increase in wall thickness of the second thickened portion 1223 compared to the main wall 1221 is within a certain range. This allows the second thickened portion 1223 to have a larger wall thickness, thereby improving the welding strength between the second thickened portion 1223 and the end cap 13, as well as the fatigue strength of the weld, thus enhancing the structural strength and reliability of the battery cell 1. Furthermore, it facilitates an increase in the energy density of the battery cell 1.

[0241] In some embodiments, please refer to Figure 8, and in conjunction with other figures. (H6-H1) / H1∈(0, 1 / 3).

[0242] Wherein, (H6-H1) / H1 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 1 / 3, etc.

[0243] In this way, on the one hand, the second thickened portion 1223 can have a larger wall thickness, thereby improving the welding strength of the second thickened portion 1223 and the end cap 13 and the fatigue strength of the weld formed by the welding, thus improving the reliability of the battery cell 1. On the other hand, it is beneficial to improve the energy density of the battery cell 1.

[0244] In some embodiments, please refer to Figures 5, 6, and 8 together, and in conjunction with other figures. The battery cell 1 also includes an end cap 13, which is welded to the second thickened portion 1223.

[0245] The end cap 13 and the end wall 121 are disposed opposite each other along the first direction Z. In the first direction Z, the electrode assembly 11 is disposed between the end cap 13 and the end wall 121.

[0246] By making the wall thickness of the second thickened portion 1223 greater than that of the main body wall 1221, and by welding the end cap 13 to the second thickened portion 1223, the welding strength of the second thickened portion 1223 and the end cap 13 and the fatigue strength of the weld formed by the welding can be improved, thereby improving the reliability of the battery cell 1.

[0247] Please refer to Figure 4 and other accompanying drawings. The battery device 10 provided in this embodiment includes a battery cell 1. The battery cell 1 in this embodiment is the same as the battery cell 1 in the above embodiments; please refer to the relevant descriptions of the battery cell 1 in the above embodiments for details, which will not be repeated here.

[0248] The battery device 10 provided in this application adopts the battery cell 1 involved in the above embodiments, which makes the battery cell 1 have strong structural strength and reliability, thereby helping to improve the reliability of the battery device 10.

[0249] Please refer to Figure 3 and other accompanying drawings. The electrical device provided in this application embodiment includes a battery cell 1 or a battery device 10. The battery cell 1 and battery device 10 in this embodiment are the same as those in the above embodiments; please refer to the relevant descriptions of the battery cell 1 and battery device 10 in the above embodiments for details, which will not be repeated here.

[0250] The electrical device provided in this application embodiment, by employing the battery cell 1 or battery device 10 mentioned above, helps to improve the reliability of the electrical device.

[0251] The energy storage device 100 provided in this application embodiment includes a battery cell 1 or a battery device 10. The battery cell 1 and battery device 10 in this embodiment are the same as those in the above embodiments; please refer to the relevant descriptions of the battery cell 1 and battery device 10 in the above embodiments for details, which will not be repeated here.

[0252] The energy storage device 100 provided in this application embodiment can improve the reliability of the energy storage device 100 by adopting the battery cell 1 or battery device 10 mentioned above.

[0253] Referring to Figure 1, the energy storage system 1000 provided in this embodiment includes a power conversion device 1100 and an energy storage device 100. The power conversion device 1100 is used to electrically connect the power generation device 1200 and the energy storage device 100. The energy storage device 100 in this embodiment is the same as the energy storage device 100 in the above embodiments; please refer to the relevant descriptions of the energy storage device 100 in the above embodiments for details, which will not be repeated here.

[0254] The energy storage system 1000 provided in this application, by employing the energy storage device 100 involved in the above embodiments, helps to improve the reliability of the energy storage system 1000.

[0255] Referring to Figure 2, the charging network 2000 provided in this embodiment includes a charging pile 2100 and an energy storage device 100 or an energy storage system 1000. The energy storage device 100 is used to provide electrical energy to the charging pile 2100. The energy storage device 100 and energy storage system 1000 in this embodiment are the same as those in the above embodiments. For details, please refer to the relevant descriptions of the energy storage device 100 and energy storage system 1000 in the above embodiments, which will not be repeated here.

[0256] The charging network 2000 provided in this application embodiment, by employing the energy storage device 100 or energy storage system 1000 involved in the above embodiments, helps to improve the reliability of the charging network 2000.

[0257] As one embodiment of this application, as shown in Figures 5 to 11, the battery cell 1 includes an electrode assembly 11, a housing 12, and an end cap 13. The housing 12 includes an end wall 121, a first transition portion 123, and four side walls 122. The end wall 121 is located at one end of the side wall 122 along a first direction Z, and the end cap 13 is located at the other end of the side wall 122 along the first direction Z. The four side walls 122 include two first side walls 122a and two second side walls 122b. The two first side walls 122a are arranged opposite each other along a second direction Y, and the two second side walls 122b are arranged opposite each other along a third direction X. The two first side walls 122a and the two second side walls 122b together surround the end wall 121, and the surface area of ​​the first side wall 122a is larger than the surface area of ​​the second side wall 122b. The first transition portion 123 surrounds the outer periphery of the end wall 121 and connects the end wall 121 and each side wall 122. The inner surface of the first transition portion 123 is rounded to achieve the transition between each sidewall 122 and the end wall 121. The first sidewall 122a includes a main wall 1221, a second thickened portion 1223, and a first thickened portion 1222. The second thickened portion 1223 and the first thickened portion 1222 are respectively disposed at both ends of the main wall 1221 along the first direction Z, and the first transition portion 123 connects the end wall 121 and the first thickened portion 1222. The wall thickness of both the second thickened portion 1223 and the first thickened portion 1222 is greater than the wall thickness of the main wall 1221. The inner surface of the first thickened portion 1222 protrudes from the main wall 1221, so that the wall thickness of the first thickened portion 1222 is greater than the wall thickness of the main wall 1221. The end cap 13 is welded to the second thickened portion 1223 and to the end region of the second sidewall 122b away from the end wall 121 along the first direction Z.

[0258] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell (1), wherein, include: Electrode assembly (11); A housing (12), in which at least a portion of the electrode assembly (11) is disposed; the housing (12) includes an end wall (121), a side wall (122), and a first transition portion (123), the end wall (121) being disposed at one end of the side wall (122) along a first direction (Z); the side wall (122) including a main body wall (1221) arranged along the first direction (Z) and a first thickened portion (1222), the first thickened portion (1222) being... The wall thickness is greater than that of the main body wall (1221), and the first transition portion (123) is connected between the end wall (121) and the first thickened portion (1222); the end wall (121) is provided with a first inner surface (1201), the first inner surface (1201) faces the electrode assembly (11), and a first groove (1202) is formed on the outer periphery of the first inner surface (1201), the first groove (1202) extends to the first transition portion (123).

2. The battery cell (1) according to claim 1, wherein, The inner surface of the first thickened portion (1222) protrudes from the main body wall (1221).

3. The battery cell (1) according to claim 1 or 2, wherein, In the first direction (Z), at least a portion of the wall thickness of the first thickened portion (1222) is gradually increased from the main body wall (1221) toward the first transition portion (123).

4. The battery cell (1) according to any one of claims 1-3, wherein, The inner surface of the first transition portion (123) is rounded.

5. The battery cell (1) according to claim 4, wherein, A first dividing line (L1) is provided between the first transition portion (123) and the first thickened portion (1222). The first dividing line (L1) passes through the center (O) of the inner surface of the first transition portion (123) and is parallel to the wall thickness direction of the main body wall (1221). The wall thickness of the main body wall (1221) is H1, and the maximum wall thickness of the first thickened portion (1222) is H2, where (H2-H1) / H1∈(0,0.5).

6. The battery cell (1) according to claim 5, wherein, (H2-H1) / H1∈(0,1 / 3).

7. The battery cell (1) according to any one of claims 1-6, wherein, The first direction (Z) is parallel to the wall thickness direction of the end wall (121), and in the first direction (Z), the distance between the end of the first thickened portion (1222) away from the first transition portion (123) and the outer surface of the end wall (121) is H3, where H3 ∈ [2 mm, 5 mm].

8. The battery cell (1) according to claim 7, wherein, H3∈[3mm, 4mm].

9. The battery cell (1) according to any one of claims 1-8, wherein, The first transition portion (123) surrounds the outer periphery of the first groove (1202); the number of sidewalls (122) is multiple, and the multiple sidewalls (122) include two first sidewalls (122a) arranged opposite each other along the second direction (Y) and two second sidewalls (122b) arranged opposite each other along the third direction (X). The two first sidewalls (122a) and the two second sidewalls (122b) together surround the outer periphery of the end wall (121) and are all connected to the first transition portion (123); At least one first sidewall (122a) includes the main wall (1221) and the first thickened portion (1222), and in the first sidewall (122a), the wall thickness of the first thickened portion (1222) is greater than the wall thickness of the main wall (12221); and / or, at least one second sidewall (122b) includes the main wall (1221) and the first thickened portion (1222), and in the second sidewall (122b), the wall thickness of the first thickened portion (1222) is greater than the wall thickness of the main wall (1221); The first direction (Z), the second direction (Y), and the third direction (X) intersect each other in pairs.

10. The battery cell (1) according to claim 9, wherein, The surface area of ​​the first sidewall (122a) is greater than the surface area of ​​the second sidewall (122b). The first sidewall (122a) includes the main wall (1221) and the first thickened portion (1222). In the first sidewall (122a), the wall thickness of the first thickened portion (1222) is greater than the wall thickness of the main wall (1221).

11. The battery cell (1) according to claim 9 or 10, wherein, The minimum wall thickness of the first sidewall (122a) is less than the minimum wall thickness of the second sidewall (122b). The first sidewall (122a) includes the main wall (1221) and the first thickened portion (1222), and in the first sidewall (122a), the wall thickness of the first thickened portion (1222) is greater than the wall thickness of the main wall (1221).

12. The battery cell (1) according to claim 10 or 11, wherein, The second sidewall (122b) includes the main wall (1221) and the first thickened portion (1222), and in the second sidewall (122b), the wall thickness of the first thickened portion (1222) is greater than the wall thickness of the main wall (1221).

13. The battery cell (1) according to any one of claims 9-12, wherein, A second transition portion (124) is formed at the connection between the first sidewall (122a) and the second sidewall (122b).

14. The battery cell (1) according to claim 13, wherein, The inner surface of the second transition section (124) is rounded.

15. The battery cell (1) according to any one of claims 1-14, wherein, In the first direction (Z), the first groove (1202) is provided with a bottom wall (1203); the end wall (121) is also provided with a second inner surface (1204) connecting the bottom wall (1203) and the first inner surface (1201), the bottom wall (1203) is connected to the first transition portion (123), and the connection between the first inner surface (1201) and the second inner surface (1204) is a rounded transition.

16. The battery cell (1) according to claim 15, wherein, The connection between the first inner surface (1201) and the second inner surface (1204) is transitioned by a rounded corner.

17. The battery cell (1) according to any one of claims 1-16, wherein, The first direction (Z) is parallel to the wall thickness direction of the end wall (121), and the distance between the first inner surface (1201) and the outer surface of the end wall (121) in the first direction (Z) is H4. The first groove (1202) is provided with a groove bottom wall (1203), and the maximum distance between the groove bottom wall (1203) and the first inner surface (1201) is H5, where H5 / H4∈[1 / 20, 1 / 3].

18. The battery cell (1) according to claim 17, wherein, H5 / H4∈[1 / 10, 1 / 4].

19. The battery cell (1) according to any one of claims 1-18, wherein, The sidewall (122) further includes a second thickened portion (1223), the first thickened portion (1222) and the second thickened portion (1223) are respectively disposed at both ends of the main body wall (1221) along the first direction (Z), and the wall thickness of the second thickened portion (1223) is greater than the wall thickness of the main body wall (1221).

20. The battery cell (1) according to claim 19, wherein, The wall thickness of the main body wall (1221) is H1, and the maximum wall thickness of the second thickened part (1223) is H6, (H6-H1) / H1∈(0,0.5).

21. The battery cell (1) according to claim 20, wherein, (H6-H1) / H1∈(0,1 / 3).

22. The battery cell (1) according to any one of claims 19-21, wherein, The battery cell (1) also includes an end cap (13), which is welded to the second thickened portion (1223).

23. A battery device (10), wherein, Includes the battery cell (1) according to any one of claims 1-22.

24. An electrical appliance, wherein, It includes a battery cell (1) according to any one of claims 1-22; or, it includes a battery device (10) according to claim 23.

25. An energy storage device (100), wherein, It includes a battery cell (1) according to any one of claims 1-22; or, it includes a battery device (10) according to claim 23.

26. An energy storage system (1000), wherein, It includes a power conversion device (1100) and an energy storage device (100) according to claim 25, wherein the power conversion device (1100) is used to electrically connect the power generation device (1200) and the energy storage device (100).

27. A charging network (2000), wherein, It includes a charging pile (2100) and an energy storage device (100) according to claim 25 or an energy storage system (1000) according to claim 26, wherein the energy storage device (100) is used to provide electrical energy to the charging pile (2100).

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