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

Abstract

This application discloses a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network. The battery cell includes a casing, an electrode assembly, and electrode terminals. The casing includes a wall portion. The electrode assembly is disposed within the casing and includes an electrode body and a tab. The electrode body and the wall portion are arranged along a first direction. The tab is located on the side of the electrode body near the wall portion. The tab includes an extension section and a connecting section. The connecting section is connected to the end of the extension section away from the electrode body and is bent relative to the extension section. The electrode terminals are disposed in the wall portion and include a receiving cavity and a fixing portion. At least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity. The connecting section is accommodated in the receiving cavity. Along the first direction, at least a portion of the surface of the connecting section away from the electrode body contacts and connects with the fixing portion.

Description

Technical Field

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

[0002] In recent years, batteries have made great strides and can be widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power plants, as well as in electric vehicles, power tools, military equipment and aerospace.

[0003] Improving the energy density and reliability of batteries is an important research direction in the field of batteries. Utility Model Content

[0004] This application provides a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network, which can improve energy density and reliability.

[0005] In a first aspect, embodiments of this application provide a battery cell including a housing, an electrode assembly, and electrode terminals. The housing includes a wall portion. The electrode assembly is disposed within the housing and includes an electrode body and a tab. The electrode body and the wall portion are arranged along a first direction. The tab is located on the side of the electrode body near the wall portion. The tab includes an extension section and a connecting section. The connecting section is connected to the end of the extension section away from the electrode body and is bent relative to the extension section. The electrode terminals are disposed in the wall portion and include a receiving cavity and a fixing portion. At least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity. The connecting section is accommodated in the receiving cavity. Along the first direction, at least a portion of the surface of the connecting section away from the electrode body contacts and connects with the fixing portion.

[0006] In the above scheme, the electrode body and the wall portion are arranged along a first direction, and the electrode terminal is disposed on the wall portion, which includes a receiving cavity and a fixing portion. In the first direction, at least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity. Therefore, the extension section of the tab extending from the side of the electrode body near the wall portion can extend approximately in a straight line along the first direction and pass through the wall portion to extend into the receiving cavity without having to undergo multiple bends. This helps to reduce the tab space inside the battery cell, reduce the tab's occupation of the battery cell's internal space, and improve the energy density of the battery cell. Furthermore, by reducing the number of bends of the tab, it also helps to reduce the assembly difficulty of the tab, improve the assembly efficiency of the battery cell, and reduce the risk of damage to the tab due to multiple bends during assembly, thereby improving the production yield of the battery cell.

[0007] In some embodiments, the battery cell further includes a first insulating member disposed between the wall portion and the electrode body along a first direction. The first insulating member has a guide hole that extends through the first direction. Along the first direction, the guide hole is disposed opposite to and communicates with the receiving cavity, and an extension portion passes through the guide hole.

[0008] In the above solution, the extension section does not need to be bent as it passes through the guide hole to reach the receiving cavity, which helps to shorten the length of the extension section and reduce the space occupied by the electrode tab. Furthermore, the inner wall of the guide hole can also provide support and positioning for the extension section, which helps to reduce the risk of the extension section tipping over and improves the assembly accuracy of the electrode tab.

[0009] In some embodiments, the receiving cavity forms a first opening at one end facing the electrode body; the battery cell also includes a support member, at least a portion of which is located on the side of the receiving cavity near the electrode body and covers the first opening; the support member has a first through hole, which is disposed opposite to and communicates with the receiving cavity along a first direction, and an extension passes through the support member.

[0010] Using a support member to support the electrode terminals can improve their stability and reliability. Furthermore, because the support member covers the first opening of the receiving cavity and has a first through hole that is opposite to and communicates with the receiving cavity along a first direction, the extension segment does not need to be bent as it passes through the first through hole and extends into the receiving cavity. This helps to shorten the length of the extension segment and reduce the space occupied by the electrode tab. The inner wall of the first through hole also provides support and positioning for the extension segment, helping to reduce the risk of tipping over and improving the assembly accuracy and stability of the electrode tab.

[0011] In some embodiments, the support is an insulating structure. The support can isolate the electrode terminals and conductive structures located within the housing to a certain extent, and can also isolate the electrode terminals and the walls, reducing the risk of short circuits in individual battery cells.

[0012] In some embodiments, in the first direction, at least a portion of the support is located between the wall and the electrode terminal. The wall restricts the movement of the support in the direction close to the electrode body, improving the support effect of the support on the electrode terminal and thus improving the structural stability of the electrode terminal.

[0013] In some embodiments, the wall portion is provided with a second through hole, at least a portion of the electrode terminal is disposed in the second through hole, and at least a portion of the receiving cavity and at least a portion of the support member are located in the second through hole.

[0014] By creating a second through-hole in the wall, at least a portion of the electrode terminal, at least a portion of the receiving cavity, and at least a portion of the support member are all disposed within the second through-hole. This allows for a more compact structure of the electrode terminal, wall, and support member, helping to reduce the space occupied by the electrode terminal and support member within the housing. Furthermore, when the extension of the tab passes through the first through-hole of the support member and extends into the receiving cavity, a portion of the extension and the connecting section are located within the second through-hole, thus further reducing the space occupied by the tab within the housing.

[0015] In some embodiments, the inner wall of the second through hole is provided with a first recess, a portion of the electrode terminal is embedded in the first recess, and the support includes a first support portion and a second support portion. A portion of the first support portion is located on the side of the receiving cavity near the electrode body and forms the first through hole, and the second support portion is located between the electrode terminal and the wall portion.

[0016] In the above scheme, a first recess is formed on the inner wall of the second through hole. A portion of the electrode terminal and at least a portion of the second support of the support member are embedded in the first recess. This makes the structure between the electrode terminal, the support member and the wall more compact and the connection tighter. This helps to reduce the overall space occupied by the electrode terminal, the support member and the wall, and improve the structural stability of the electrode terminal and the support member.

[0017] In some embodiments, the electrode tab further includes a folding section that connects the extension section and the electrode body. Along a second direction, the size of the folding section is larger than the size of the connecting section, and the second direction intersects with the first direction.

[0018] During the manufacturing process of the electrode assembly, the tab layers drawn from the electrode body are gathered and pressed together to form the corresponding tabs, without having to bend the tabs multiple times. This helps to shorten the length of the tabs, reduce the space occupied by the tabs in the casing, and increase the energy density of the battery cell. At the same time, it also helps to reduce the difficulty of bending the tabs, reduce the risk of damage to the tabs due to multiple bends during assembly, and improve the production yield and assembly efficiency of the battery cell.

[0019] In some embodiments, the battery cell further includes a second insulating member, at least a portion of which is connected to the convergence section. The second insulating member provides insulation and isolation between the convergence section and other surrounding conductive structures, reducing the risk of short circuits in the battery cell.

[0020] In some embodiments, a portion of the second insulating member is connected to the retracting section, and another portion is connected to the extension section. On the one hand, the second insulating member can simultaneously insulate and isolate the retracting section and the extension section; on the other hand, the second insulating member can support the extension section to a certain extent, thereby reducing the risk of the extension section tipping over, deforming, or being inserted upside down, which helps to improve the reliability and positional accuracy of the extension section, thereby improving the assembly effect between the connecting section and the electrode terminals, and improving the reliability of the battery cell.

[0021] In some embodiments, there are multiple electrode bodies, and one tab connects to at least one electrode body. The electrode body includes a wound positive electrode plate, a negative electrode plate, and a separator. One tab can connect to one or more electrode bodies, and the number of tabs can be set according to the actual situation of the electrode assembly, which helps to improve the space utilization within the battery cell and the current transmission performance of the battery cell.

[0022] In some embodiments, the extension section is provided with a welding portion. The welding portion can be used to weld the tab layers corresponding to the extension section together, which on the one hand reduces the possibility of the tab layers corresponding to the extension section loosening to the surroundings, making the structure of the extension section more compact and reducing the risk of interference between the extension section and other surrounding structures, and on the other hand also helps to improve the structural strength of the extension section and reduce the risk of the extension section tilting or bending.

[0023] In some embodiments, the tabs include multiple tab layers stacked together, and the connecting segment includes a portion of each tab layer, which helps to reduce the internal resistance of the connecting segment and improve the current transmission performance between the connecting segment and the electrode terminal.

[0024] In some embodiments, the connecting segment includes a plurality of sub-sections, each sub-section being connected to an extension segment and each sub-section being connected to an electrode terminal; the plurality of sub-sections include a first sub-section and a second sub-section, which protrude from opposite sides of the extension segment along a second direction.

[0025] In the first direction, at least a portion of the surface of each sub-part away from the electrode body can contact and connect with the fixing part, thereby helping to further increase the connection area between the connecting section and the fixing part and further enhance the connection strength between them. The first and second sub-parts are bent in opposite directions, which, while increasing the connection area between the connecting section and the fixing part, also helps to improve the uniformity of stress distribution on the connection surfaces of the connecting section and the fixing part.

[0026] In some embodiments, the plurality of sub-parts further includes a third sub-part that protrudes from the extension along a third direction, with the first direction, the second direction, and the third direction being perpendicular to each other.

[0027] The third sub-section bends in the third direction relative to the extension section, which helps to further increase the connection area between the connecting section and the fixed part.

[0028] In some embodiments, the multiple sub-parts are distributed circumferentially along the extension, which helps to further increase the connection area between the connecting section and the fixing part.

[0029] In some embodiments, the electrode terminal includes a terminal body and a fixing part. The terminal body has a terminal through hole, and the fixing part covers the end of the terminal through hole away from the electrode body and defines a receiving cavity with the terminal body. This helps to reduce the molding difficulty of the electrode terminal and improve the production efficiency of the battery cell.

[0030] Secondly, embodiments of this application provide a battery device including any of the above-mentioned battery cells.

[0031] Thirdly, embodiments of this application also provide an energy storage device, including a plurality of battery cells or a plurality of the above-mentioned battery devices, wherein the battery cells or battery devices are used to store or provide electrical energy.

[0032] Fourthly, embodiments of this application also provide an energy storage system, including an energy conversion system and the aforementioned energy storage device. The energy conversion system is connected to the energy storage device to convert the current input to the energy storage device or output from the energy storage device into energy.

[0033] Fifthly, embodiments of this application also provide a charging network, including a charging pile and the aforementioned energy storage device or energy storage system, wherein the energy storage device or energy storage system is used to provide electrical energy to the charging pile.

[0034] 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

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application 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.

[0036] Figure 1 This is a schematic diagram of the structure of a charging network provided in some embodiments of this application;

[0037] Figure 2 These are schematic diagrams of the energy storage system provided in some embodiments of this application;

[0038] Figure 3 This is a schematic diagram of the structure of an energy storage device provided in some embodiments of this application;

[0039] Figure 4 Exploded views of battery devices provided in some embodiments of this application;

[0040] Figure 5 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0041] Figure 6 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0042] Figure 7 This is a cross-sectional schematic diagram of a battery cell provided in some embodiments of this application;

[0043] Figure 8 yes Figure 7 A magnified view of section AA;

[0044] Figure 9 yes Figure 8 A magnified view of the area at BB;

[0045] Figure 10 This is a cross-sectional schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application;

[0046] Figure 11 This is a cross-sectional schematic diagram of the electrode assembly of a battery cell provided in other embodiments of this application.

[0047] The attached icons are numbered as follows:

[0048] 1. Energy storage device; 2. Energy conversion system; 3. Power generation equipment; 4. Charging pile; 5. Connector;

[0049] Battery assembly 100; housing 10; first housing section 101; second housing section 102; battery cell 20; electrode assembly 21; electrode body 211; electrode tab 212; extension section 2121; connecting section 2122; retracting section 2123; welding section 2124; sub-section 2125; first sub-section 2125a; second sub-section 2125b; outer shell 22; end cap 221; housing 222; peripheral wall 2221; end wall 2222; wall section 223; second through hole 2231; first recess 2232; wall body 223 3; Cover plate 2234; Electrode terminal 23; Receiving cavity 231; Fixing part 232; First opening 233; Terminal body 234; Terminal through hole 2341; Limiting part 235; First insulating member 24; Guide hole 241; Support member 25; First through hole 251; First support part 252; Second support part 253; First part 2531; Second part 2532; Second recess 254; Third insulating member 26; First insulating section 261; Second insulating section 262; Third insulating section 263; Second insulating member 27;

[0050] First wall S1; Second wall S2; Third wall S3; First direction Z; Second direction X; Third direction Y. Detailed Implementation

[0051] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0053] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0054] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0055] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0056] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0057] A single battery cell typically includes an electrode assembly. The electrode assembly consists of a positive electrode and a negative electrode. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes.

[0058] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0059] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0060] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0061] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

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

[0063] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0064] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0065] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0066] In some implementations, the electrode assembly is a stacked structure.

[0067] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0068] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0069] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0070] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0071] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0072] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0073] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0074] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0075] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte may include an electrolyte salt and a solvent.

[0077] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0078] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0079] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0080] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0081] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0082] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0083] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0084] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0085] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0086] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0087] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0088] The technical solutions described in the embodiments of this application are applicable to various energy storage devices that use individual battery cells, such as energy storage containers or energy storage cabinets.

[0089] In a battery cell, a tab extends from at least one end of the electrode assembly. It is typically bent multiple times before being connected to the electrode terminal via an adapter, or directly contacts and connects to the surface of the electrode terminal. However, when the aforementioned tab, after multiple bends, is connected to the electrode terminal, it occupies a significant amount of internal space in the battery cell, which is detrimental to improving the energy density of the battery cell. Furthermore, the connection strength between the tab and the electrode terminal is relatively low, affecting the reliability of the battery cell.

[0090] To address at least some of the aforementioned problems, embodiments of this application provide a battery cell including a housing, an electrode assembly, and electrode terminals. The housing includes a wall portion; the electrode assembly is disposed within the housing and includes an electrode body and a tab, the electrode body and the wall portion are arranged along a first direction, the tab is located on the side of the electrode body near the wall portion, the tab includes an extension section and a connecting section, the connecting section is connected to the end of the extension section away from the electrode body and is bent relative to the extension section; the electrode terminals are disposed in the wall portion, the electrode terminals include a receiving cavity and a fixing portion, at least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity, the connecting section is accommodated in the receiving cavity, and along the first direction, at least a portion of the surface of the connecting section away from the electrode body contacts and connects with the fixing portion.

[0091] In this embodiment, the electrode body and the wall portion are arranged along a first direction. The electrode terminal is disposed on the wall portion, which includes a receiving cavity and a fixing portion. In the first direction, at least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity. Therefore, the extension section of the tab extending from the side of the electrode body near the wall portion can extend approximately in a straight line along the first direction and pass through the wall portion to extend into the receiving cavity without needing to undergo multiple bends. This helps to reduce the tab space occupied by the tab inside the battery cell, reduce the tab's occupation of the battery cell's internal space, and improve the energy density of the battery cell. Furthermore, by reducing the number of bends of the tab, it also helps to reduce the assembly difficulty of the tab, improve the assembly efficiency of the battery cell, and reduce the risk of damage to the tab due to multiple bends during assembly, thereby improving the production yield of the battery cell. The connecting section is connected to the fixing portion within the receiving cavity. The connecting section and a portion of the extension section are both accommodated in the receiving cavity without occupying the internal space of the battery cell, which helps to further improve the energy density of the battery cell. Furthermore, the connecting section is bent relative to the extension section. In the first direction, at least a portion of the surface of the connecting section away from the electrode body can contact and connect with the portion of the fixing part located in the receiving cavity away from the electrode body. Compared to connecting the connecting section with the fixing part through the surface of the connecting section near the electrode body, the area of ​​the surface of the connecting section away from the electrode body is larger than the area of ​​the surface of the connecting section near the electrode body. This helps to increase the connection area between the connecting section and the fixing part, improve the connection strength between the two, and thus improve the reliability of the battery cell.

[0092] Please see Figure 1 This application provides a charging network including a charging pile 4 and an energy storage device 1. The charging pile 4 is electrically connected to the energy storage device 1, and the energy storage device 1 provides electrical energy to the charging pile 4. The charging pile 4 is electrically connected to a battery device in the energy storage device 1 via a cable, and the battery device can provide its stored electrical energy to the charging pile 4. The charging pile 4 has one or more connectors 5 for connecting to electrical equipment (such as a vehicle), thereby enabling the charging of electrical equipment.

[0093] Energy storage devices can be located inside the charging pile (e.g., an integrated energy storage and charging unit) or outside the charging pile.

[0094] Please see Figure 2In some embodiments, the energy storage system may include one or more energy storage devices 1 and a power conversion system 2 (PCS). The power conversion system 2 is used to connect the power generation device 3, the power grid, or the load to the energy storage device 1. The power generation device 3 generates electrical energy, the energy storage device 1 stores electrical energy, and the power conversion system 2 converts the current input to the energy storage device 1 or the current output from the energy storage device 1 into energy. The electrical energy generated by the power generation device 3 can be stored in the energy storage device 1 through the power conversion system 2, and the electrical energy stored in the energy storage device 1 can also be output to the load or the power grid through the power conversion system 2. As an example, the power generation device 3 may specifically be a solar panel, a hydroelectric power generation device, a thermal power generation device, a wind power generation device, etc. The specific type of the power generation device 3 is not limited in this application.

[0095] Please see Figure 3 The energy storage device 1 mentioned in this application embodiment may include one or more battery clusters to increase the voltage and capacity of the energy storage device 1. A battery cluster may include multiple battery devices 100, which are connected in series via a busbar to increase the voltage of the energy storage device 1. When the energy storage device 1 includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device 1.

[0096] The energy storage device 1 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device 1 can store electrical energy as needed and output it when appropriate. For example, the energy storage device 1 can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires the use of the energy storage device 1.

[0097] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0098] In some embodiments, the energy storage device 1 may include a cabinet and one or more battery clusters, with the battery clusters housed in the cabinet.

[0099] In some embodiments, the energy storage device 1 may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0100] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device via piping to regulate the temperature of the individual battery cells.

[0101] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0102] As an example, the central control module can serve as the battery management unit for energy storage device 1, used to monitor and manage it. The central control module can monitor information such as current, voltage, power, state of charge, and temperature of energy storage device 1. For example, it can control the charging and discharging current and voltage of energy storage device 1. 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.

[0103] As an example, a fire protection system includes control panels, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in energy storage systems.

[0104] As an example, the power distribution device can be used to distribute power to the power consumption modules of the energy storage device 1.

[0105] Please refer to Figure 4 , Figure 4 This is an exploded view of a battery device provided in some embodiments of this application. The battery device 100 includes a housing 10 and a battery cell 20. In some embodiments, the housing 10 may include a first housing portion 101 and a second housing portion 102, which overlap each other, and together define a receiving cavity for accommodating the battery cell 20. The second housing portion 102 may be a hollow structure with one end open, and the first housing portion 101 may be a plate-like structure, with the first housing portion 101 covering the open side of the second housing portion 102 so that the first housing portion 101 and the second housing portion 102 together define the receiving cavity; the first housing portion 101 and the second housing portion 102 may also be hollow structures, both open on one side, with the open side of the first housing portion 101 covering the open side of the second housing portion 102. Either the first housing portion 101 or the second housing portion 102 may include a bottom plate, and at least one of the first housing portion 101 and the second housing portion 102 may include a frame. Of course, the battery box formed by the first box section 101 and the second box section 102 can be of various shapes, such as cylinder, cuboid, etc.

[0106] Figure 5for Figure 4 The diagram shows the structure of a single battery cell assembly. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or a combination thereof. A combination thereof means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or a combination thereof to form battery modules, and then these battery modules are connected in series, parallel, or a combination thereof to form a whole, which is then housed within the housing 10.

[0107] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0108] Figure 6 This is an exploded structural diagram of the battery cell 20 according to some embodiments of this application. For example... Figure 6 As shown, the battery cell 20 includes an electrode assembly 21 and a housing 22. The housing 22 includes an end cap 221 and a casing 222. The casing 222 has an opening, and the end cap 221 is a component that closes onto the opening of the casing 222 to isolate the internal environment of the battery cell 20 from the external environment. The casing 222 may have one or more openings. The end cap 221 may also be provided in one or more ways.

[0109] Regardless of the specific type, the shape of the end cap 221 can be adapted to the shape of the housing 222 to fit the housing 222. Optionally, the end cap 221 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 221 is not easily deformed when subjected to compression and impact, so that the battery cell 20 can have higher structural strength and the safety performance can also be improved.

[0110] The end cap 221 may be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly 21 for outputting or inputting electrical energy to the battery cell 20. The electrode terminals can be directly connected to the tabs or indirectly connected to the tabs via an adapter. The electrode terminals can be provided on the end cap 221 or on the housing 222.

[0111] Please see Figures 6-8In a first aspect, embodiments of this application provide a battery cell 20, including a housing 22, an electrode assembly 21, and electrode terminals 23. The housing 22 includes a wall portion 223. The electrode assembly 21 is disposed within the housing 22 and includes an electrode body 211 and a tab 212. The electrode body 211 and the wall portion 223 are arranged along a first direction Z. The tab 212 is located on the side of the electrode body 211 near the wall portion 223. The tab 212 includes an extension section 2121 and a connecting section 2122. The connecting section 2122 is connected to the extension section 2121. The end of segment 2121 away from the electrode body 211 is bent relative to the extension segment 2121; the electrode terminal 23 is disposed on the wall portion 223, the electrode terminal 23 includes a receiving cavity 231 and a fixing portion 232, at least a portion of the fixing portion 232 is located on the side of the receiving cavity 231 away from the electrode body 211 and participates in defining the receiving cavity 231, the connecting segment 2122 is accommodated in the receiving cavity 231, and along the first direction Z, at least a portion of the surface of the connecting segment 2122 away from the electrode body 211 contacts and connects with the fixing portion 232.

[0112] The first direction Z can be either the height direction of the battery cell 20 or the thickness direction of the wall 223.

[0113] The housing 22 is a component used to encapsulate and protect structures such as the electrode assembly 21. The housing 22 includes a shell 222 and an end cap 221. Optionally, the shell 222 may include a peripheral wall 2221 and an end wall 2222. The peripheral wall 2221 is disposed around the electrode assembly 21, and the end cap 221 and the end wall 2222 are disposed opposite to each other and connected to the two ends of the peripheral wall 2221. A wall portion 223 is part of the housing 22. In some examples, the end cap 221 of the housing 22 may be a wall portion 223. In some examples, the end wall 2222 of the housing 22 may be a wall portion 223.

[0114] Electrode assembly 21 is a component in battery cell 20 used for electrochemical reactions. Electrode assembly 21 is disposed inside housing 22 and includes electrode body 211 and tab 212. Electrode body 211 has a wall portion 223 on the side along the first direction Z, and tab 212 is led out from the side of electrode body 211 along the first direction Z near the wall portion 223.

[0115] In the tab 212, the connecting segment 2122 is connected to the end of the extension segment 2121 away from the electrode body 211, and it is used to connect the electrode terminal 23. The connecting segment 2122 is bent relative to the extension segment 2121, that is, the extension direction of the connecting segment 2122 may intersect with or be perpendicular to the extension direction of the extension segment 2121.

[0116] The extension segment 2121 is used to connect the electrode body 211 and the connecting segment 2122. The extension segment 2121 can be directly connected to the electrode body 211, or indirectly connected to the electrode body 211 through other structures. The extension segment 2121 can extend approximately in a straight line; for example, the extension segment 2121 can extend in a straight line along a first direction Z.

[0117] The electrode tab 212 may include a positive electrode tab and a negative electrode tab, and the electrode terminal 23 includes a positive electrode terminal 23 and a negative electrode terminal 23. The positive electrode tab is connected to the positive electrode terminal 23, and the negative electrode tab is connected to the negative electrode terminal 23.

[0118] The electrode body 211 may include a positive electrode sheet, a separator, and a negative electrode sheet stacked together, with the separator separating the positive and negative electrode sheets. The positive electrode sheet includes a positive electrode base and a positive electrode film layer disposed on at least one side of the positive electrode base, and the positive electrode base is connected to a positive electrode tab. The negative electrode sheet includes a negative electrode base and a negative electrode film layer disposed on at least one side of the negative electrode base, and the negative electrode base is connected to a negative electrode tab. In the battery cell 20, the number of electrode assemblies 21 may be one or more.

[0119] Electrode terminals 23 are conductive structures used to realize the current input or output of the battery cell 20. There are various ways to connect the electrode terminals 23 to the wall portion 223. In one example, the electrode terminal 23 can be embedded in the wall portion 223 along a first direction Z. In this case, a portion of the electrode terminal 23 can be exposed on the side of the wall portion 223 away from the electrode body 211 for connection with an external electrical connector, and another portion can be exposed on the side of the wall portion 223 near the electrode assembly 21 for connection with the tab 212. In another example, the electrode terminal 23 can be located on the side of the wall portion 223 away from the electrode body 211 along the first direction Z, and the tab 212 can pass through the wall portion 223 and connect to the electrode terminal 23. There can be multiple electrode terminals 23, which may include positive electrode terminals 23 and negative electrode terminals 23.

[0120] The electrode terminal 23 includes a receiving cavity 231 and a fixing part 232. The receiving cavity 231 is formed inside the electrode terminal 23. The receiving cavity 231 may have an opening on the side of the receiving cavity 231 near the electrode body 211 along the first direction Z so that the tab 212 can pass through.

[0121] The fixing part 232 may participate in defining the receiving cavity 231 in whole or in part, that is, at least a portion of the fixing part 232 is exposed inside the receiving cavity 231, and the tab 212 can be connected from inside the receiving cavity 231 to at least a portion of the fixing part 232.

[0122] At least a portion of the fixing part 232 is located on the side of the receiving cavity 231 away from the electrode body 211, and at least a portion of its surface faces the electrode body 211 in the first direction Z, so as to facilitate contact and connection with the surface of the bent connecting section 2122. All of the fixing part 232 may be located on the side of the receiving cavity 231 away from the electrode body 211, or a portion of the fixing part 232 may be located on the side of the receiving cavity 231 away from the electrode body 211, with the remaining portion located on the other sides of the receiving cavity 231.

[0123] In this embodiment, the electrode body 211 and the wall portion 223 are arranged along the first direction Z. The electrode terminal 23 is disposed on the wall portion 223, which includes a receiving cavity 231 and a fixing portion 232. In the first direction Z, at least a portion of the fixing portion 232 is located on the side of the receiving cavity 231 away from the electrode body 211 and participates in defining the receiving cavity 231. Therefore, the extension segment 2121 of the tab 212 extending from the side of the electrode body 211 near the wall portion 223 can extend approximately in a straight line along the first direction Z and pass through the wall portion 223 to extend into the receiving cavity 231 without having to bend multiple times. This helps to reduce the tab 212 space inside the battery cell 20, reduce the tab 212's occupation of the internal space of the battery cell 20, and improve the energy density of the battery cell 20. Furthermore, by reducing the number of bends of the tab 212, it is also beneficial to reduce the assembly difficulty of the tab 212, improve the assembly efficiency of the battery cell 20, and at the same time reduce the risk of damage to the tab 212 due to multiple bends during the assembly process, thereby improving the production yield of the battery cell 20.

[0124] The connecting section 2122 is connected to the fixing part 232 within the receiving cavity 231. Both the connecting section 2122 and a part of the extension section 2121 are accommodated in the receiving cavity 231 without occupying the internal space of the battery cell 20, which is beneficial to further improve the energy density of the battery cell 20.

[0125] Furthermore, the connecting segment 2122 is bent relative to the extension segment 2121. In the first direction Z, at least a portion of the surface of the connecting segment 2122 away from the electrode body 211 can contact and connect with the portion of the fixing part 232 located in the receiving cavity 231 away from the electrode body 211. Compared to connecting the connecting segment 2122 with the fixing part 232 through the surface of the connecting segment 2122 near the electrode body 211, the area of ​​the surface of the connecting segment 2122 away from the electrode body 211 is larger than the area of ​​its surface near the electrode body 211. This helps to increase the connection area between the connecting segment 2122 and the fixing part 232, improve the connection strength between the two, and thus improve the reliability of the battery cell 20.

[0126] Please see Figure 8In some embodiments, the battery cell 20 further includes a first insulating member 24. Along the first direction Z, the first insulating member 24 is disposed between the wall portion 223 and the electrode body 211. The first insulating member 24 has a guide hole 241 that extends along the first direction Z. Along the first direction Z, the guide hole 241 is disposed opposite to and communicates with the receiving cavity 231. The extension section 2121 passes through the guide hole 241.

[0127] The first insulating member 24 serves as an insulating structure separating the wall portion 223 from the conductive structure located within the housing 22. In the first direction Z, the first insulating member 24 is disposed between the wall portion 223 and the electrode body 211, achieving insulation isolation between the wall portion 223 and the electrode body 211. The first insulating member 24 can be connected to the wall portion 223; for example, it can be connected to the wall portion 223 by means of adhesion, snap-fit, or other methods.

[0128] The first insulating member 24 is provided with a guide hole 241, which extends along the first direction Z and penetrates the first insulating member 24. In the first direction Z, the end of the guide hole 241 near the electrode body 211 is connected to the interior of the outer shell 22, and the end of the guide hole 241 away from the electrode body 211 can be connected to the receiving cavity 231.

[0129] In the same plane perpendicular to the first direction Z, the orthographic projection of the guide hole 241 and the orthographic projection of the receiving cavity 231 overlap at least partially, so that the guide hole 241 and the receiving cavity 231 can be arranged opposite each other along the first direction Z.

[0130] In the above solution, a first insulating member 24 is provided between the wall portion 223 and the electrode body 211. The first insulating member 24 has a guide hole 241 extending along the first direction Z. Along the first direction Z, the guide hole 241 is opposite to and communicates with the receiving cavity 231. Therefore, the extension segment 2121 does not need to be bent during its extension through the guide hole 241 to the receiving cavity 231, which helps to shorten the length of the extension segment 2121 and reduce the space occupied by the electrode tab 212. Furthermore, the inner wall of the guide hole 241 can also provide support and positioning for the extension segment 2121, which helps to reduce the risk of the extension segment 2121 tipping over and improves the assembly accuracy of the electrode tab 212.

[0131] Optionally, the volume resistivity of the first insulating element 24 is greater than or equal to 10¹³ Ω·cm, and the dielectric strength is 15kV / mm to 20kV / mm, which helps to suppress leakage current and micro-short circuits and improve the reliability of the battery cell 20.

[0132] Please see Figure 8In some embodiments, the receiving cavity 231 forms a first opening 233 at one end facing the electrode body 211; the battery cell 20 also includes a support member 25, at least a portion of which is located on the side of the receiving cavity 231 near the electrode body 211 and covers the first opening 233; the support member 25 is provided with a first through hole 251, which is disposed opposite to and communicates with the receiving cavity 231 along the first direction Z, and the extension 2121 passes through the support member 25.

[0133] The support member 25, either wholly or partially, may be located on the side of the electrode terminal 23 near the electrode body 211, and may be used to support the electrode terminal 23 from the side of the electrode terminal 23 near the electrode body 211. The support member 25 may be connected to the wall portion 223, or may be spaced apart from the wall portion 223.

[0134] The support member 25 is disposed in whole or in part on the side of the receiving cavity 231 near the electrode body 211 and covers the first opening 233 of the receiving cavity 231, so that the receiving cavity 231 is relatively sealed.

[0135] The support member 25 may be provided with a first through hole 251. The first through hole 251 penetrates the support member 25 along the first direction Z. In the first direction Z, the end of the first through hole 251 near the electrode body 211 is connected to the inside of the outer shell 22, and the end of the first through hole 251 away from the electrode body 211 is connected to the receiving cavity 231. The extension section 2121 can enter the receiving cavity 231 through the first opening 233 after passing through the first through hole 251.

[0136] The support member 25 may not have the first insulating member 24 on the side near the electrode body 211, and the end of the first through hole 251 near the electrode body 211 may be directly connected to the interior of the outer shell 22. Alternatively, the support member 25 may have the first insulating member 24 on the side near the electrode body 211, with a portion of the support member 25 supported between the electrode terminal 23 and the first insulating member 24. The first through hole 251 and the guide hole 241 of the first insulating member 24 may be arranged opposite to each other along the first direction Z and communicate with each other. The end of the first through hole 251 near the electrode body 211 may be connected to the interior of the outer shell 22 through the guide hole 241.

[0137] In the same plane perpendicular to the first direction Z, the orthographic projection of the first through hole 251 and the orthographic projection of the receiving cavity 231 overlap at least partially, so that the first through hole 251 and the receiving cavity 231 are arranged opposite to each other along the first direction Z.

[0138] In the above solution, at least a portion of a support member 25 is provided on the side of the electrode terminal 23 near the electrode body 211 to support the electrode terminal 23, thereby improving the stability and reliability of the electrode terminal 23. The support member 25 covers the first opening 233 of the receiving cavity 231 and has a first through hole 251. Along the first direction Z, the first through hole 251 is opposite to and communicates with the receiving cavity 231. Therefore, the extension segment 2121 does not need to be bent during its extension through the first through hole 251 to the receiving cavity 231, which helps to shorten the length of the extension segment 2121 and reduce the space occupied by the tab 212. Furthermore, the inner wall of the first through hole 251 can also provide support and positioning for the extension segment 2121, which helps to reduce the risk of the extension segment 2121 tipping over and improves the assembly accuracy and stability of the tab 212.

[0139] In some embodiments, the support member 25 is an insulating structure. The support member 25 can isolate the electrode terminals 23 and the conductive structures located within the housing 22 to a certain extent, and can also isolate the electrode terminals 23 and the wall 223, reducing the risk of short circuit in the battery cell 20.

[0140] Please see Figure 8 In some embodiments, at least a portion of the support member 25 is located between the wall portion 223 and the electrode terminal 23 in the first direction Z. The wall portion 223 restricts the movement of the support member 25 in the direction close to the electrode body 211, thereby improving the support effect of the support member 25 on the electrode terminal 23 and thus improving the structural stability of the electrode terminal 23.

[0141] In the first direction Z, a portion of the wall portion 223 may abut against at least a portion of the support member 25 on the side near the electrode body 211, and at least a portion of the support member 25 is supported between a portion of the wall portion 223 and the electrode terminal 23. In the first direction Z, the entirety or a portion of the support member 25 is located between the wall portion 223 and the electrode terminal 23.

[0142] In other directions perpendicular to the first direction Z, the side of the support member 25 may or may not have a wall portion 223, and the side of the electrode terminal 23 may or may not have a wall portion 223.

[0143] A portion of the electrode terminal 23 may be provided with a portion of the wall portion 223 on the side away from the electrode body 211 along the first direction Z. In this case, a portion of the electrode terminal 23 is located between a portion of the wall portion 223 and the support member 25. Alternatively, the electrode terminal 23 may not be provided with the wall portion 223 on the side away from the electrode body 211 along the first direction Z.

[0144] Please see Figure 8In some embodiments, the wall portion 223 is provided with a second through hole 2231, at least a portion of the electrode terminal 23 is disposed in the second through hole 2231, and at least a portion of the receiving cavity 231 and at least a portion of the support member 25 are located in the second through hole 2231.

[0145] The second through hole 2231 penetrates the wall portion 223 along the first direction Z. The entirety or a portion of the electrode terminal 23 is located within the second through hole 2231, the entirety or a portion of the receiving cavity 231 is located within the second through hole 2231, and the entirety or a portion of the support member 25 is located within the second through hole 2231. Furthermore, when the extension segment 2121 of the tab 212 passes through the first through hole 251 of the support member 25 and extends to the receiving cavity 231, a portion of the extension segment 2121 and the connecting segment 2122 are located within the second through hole 2231.

[0146] In some examples, a portion of the wall 223 protrudes from the inner wall of the second through hole 2231 and presses against the side of the support 25 near the electrode body 211, such that at least a portion of the support 25 is located between the wall 223 and the electrode terminal 23 along the first direction Z.

[0147] In other examples, the inner wall of the second through hole 2231 may be formed with a recess into which at least a portion of the support 25 and a portion of the electrode terminal 23 may be embedded, such that at least a portion of the support 25 is located between the wall portion 223 and the electrode terminal 23 along the first direction Z.

[0148] In this embodiment, by opening a second through hole 2231 in the wall portion 223, at least a portion of the electrode terminal 23, at least a portion of the receiving cavity 231, and at least a portion of the support member 25 are all disposed in the second through hole 2231. This makes the structure of the electrode terminal 23, the wall portion 223, and the support member 25 more compact, which helps to reduce the space occupied by the electrode terminal 23 and the support member 25 in the inner and outer space of the housing 22. Furthermore, when the extension section 2121 of the tab 212 passes through the first through hole 251 of the support member 25 and extends to the receiving cavity 231, a portion of the extension section 2121 and the connecting section 2122 are located in the second through hole 2231, which also helps to reduce the space occupied by the tab 212 in the interior of the housing 22.

[0149] Please see Figure 8 and Figure 9 In some embodiments, the inner wall of the second through hole 2231 is provided with a first recess 2232, a portion of the electrode terminal 23 is embedded in the first recess 2232, and the support member 25 includes a first support portion 252 and a second support portion 253. A portion of the first support portion 252 is located on the side of the receiving cavity 231 near the electrode body 211 and forms the first through hole 251. The second support portion 253 is located between the electrode terminal 23 and the wall portion 223.

[0150] The first recess 2232 is formed by the inner wall of the second through hole 2231 recessed in a direction away from the center line of the second through hole 2231. The first recess 2232 may include a first wall S1, a second wall S2 and a third wall S3. The first wall S1 and the second wall S2 are arranged at intervals relative to each other along the direction from the electrode body 211 to the wall portion 223, and the third wall S3 connects the first wall S1 and the second wall S2.

[0151] The electrode terminal 23 may include a terminal body 234, a fixing part 232, and a limiting part 235, both of which are connected to the terminal body 234. In the first direction Z, the limiting part 235 is embedded between the first wall S1 and the second wall S2, and the terminal body 234 is located outside the first recess 2232. The first wall S1 and the second wall S2 can directly or indirectly restrict the movement of the limiting part 235 in the first direction Z, thereby restricting the movement of the electrode terminal 23 in the first direction Z. Optionally, the limiting part 235 and the terminal body 234 may be an integrally formed structure.

[0152] In the support member 25, a portion of the first support portion 252 is located on the side of the receiving cavity 231 near the electrode body 211, covering the first opening 233 of the receiving cavity 231, and the other portion can be disposed opposite to and connected to the terminal body 234 in the first direction Z. The first support portion 252 forms a first through hole 251 for the extension 2121 of the tab 212 to pass through, which can provide support and positioning for the extension 2121 of the tab 212.

[0153] Optionally, when the battery cell 20 includes the first insulating member 24, in the first direction Z, a portion of the first support portion 252 is located between the receiving cavity 231 and the first insulating member 24, and another portion is supported between the terminal body 234 and the first insulating member 24.

[0154] The second support part 253 is connected to the first support part 252. The second support part 253 and the first support part 252 can be integrally formed or separate formed.

[0155] The second support portion 253 is located between the electrode terminal 23 and the wall portion 223 to isolate the electrode terminal 23 and the wall portion 223. The entirety or a portion of the second support portion 253 may be embedded in the first recess 2232. In the first direction Z, the portion of the second support portion 253 embedded in the first recess 2232 is located between the limiting portion 235 of the electrode terminal 23 and the first wall S1 of the first recess 2232.

[0156] In the above scheme, a first recess 2232 is formed on the inner wall of the second through hole 2231. A portion of the electrode terminal 23 and at least a portion of the second support portion 253 of the support member 25 are embedded in the first recess 2232. This makes the structure between the electrode terminal 23, the support member 25 and the wall portion 223 more compact and the connection tighter. This helps to reduce the overall space occupied by the electrode terminal 23, the support member 25 and the wall portion 223, and improve the structural stability of the electrode terminal 23 and the support member 25.

[0157] Optionally, along the direction of the wall portion 223 pointing towards the electrode body 211, the first support portion 252 may be recessed relative to the first wall S1 of the first recess 2232. A second recess 254 is formed on the side of the first support portion 252 away from the electrode body 211, and the first support portion 252 may serve as the bottom wall of the second recess 254 to define the second recess 254. The second support portion 253 includes a first portion 2531 and a second portion 2532. The first portion 2531 is embedded in the first recess 2232, and the second portion 2532 connects the first support portion 252 and the first portion 2531 and is located outside the first recess 2232. The second portion 2532 may serve as the side wall of the second recess 254 to define the second recess 254. A portion of the terminal body 234 of the electrode terminal 23 may be located in the second recess 254, which helps to increase the contact area between the support member 25 and the electrode terminal 23 and improve the support strength of the support member 25 for the electrode terminal 23. The surface of electrode terminal 23 near electrode body 211 contacts the surface of first support portion 252 away from electrode body 211, and the second portion 2532 of second support portion 253 is radially supported between terminal body 234 and wall portion 223 along second through hole 2231. A portion of receiving cavity 231 is located in second recess 254, which helps to increase the size of receiving cavity 231 along the first direction Z, facilitating the accommodation of connecting section 2122 and part of extension section 2121 of electrode tab 212.

[0158] In other examples, in the first direction Z, the surface of the first support 252 away from the electrode body 211 may be flush with the surface of the second support 253 away from the electrode body 211. The entire second support 253 is disposed in the recess and located between the electrode terminal 23 and the first wall S1 of the recess. In this case, the support member 25 may be approximately a flat plate structure extending radially.

[0159] Optionally, in the radial direction of the second through hole 2231, the size of the second wall S2 is smaller than that of the first wall S1, so that the diameter of the second through hole 2231 at the second wall S2 is larger than its diameter at the first wall S1, which helps to reduce the difficulty of embedding a part of the electrode terminal 23 into the first recess 2232.

[0160] Optionally, the first recess 2232 can be arranged in a circumferential manner along the second through hole 2231, and the first wall S1 and the second wall S2 can both extend continuously along the circumferential direction of the second through hole 2231. A portion of the electrode terminal 23 can be embedded in the first recess 2232 in the circumferential direction to improve the stability of the electrode terminal 23.

[0161] Optionally, the battery cell 20 further includes a third insulating member 26, which includes a first insulating segment 261 and a second insulating segment 262. The first insulating segment 261 is located in the first recess 2232 and isolates at least a portion of the inner wall of the first recess 2232 from the limiting portion 235. The second insulating segment 262 is located on the side of the first insulating segment 261 away from the electrode body 211 and isolates the inner wall of the second through hole 2231 from the terminal body 234, thereby achieving insulation isolation between the wall portion 223 and the electrode terminal 23.

[0162] Optionally, a portion of the first insulating section 261 isolates the second wall S2 from the limiting portion 235, and another portion isolates the third wall S3 from the limiting portion 235.

[0163] Optionally, another portion of the first insulating segment 261 covers the end face of the second support portion 253 away from the first support portion 252.

[0164] Optionally, the third insulating member 26 further includes a third insulating segment 263 connected to the second insulating segment 262, and the third insulating segment 263 covers at least a portion of the surface of the wall portion 223 away from the electrode body 211.

[0165] Optionally, the wall portion 223 includes a wall body 2233 and a cover plate 2234. The cover plate 2234 is disposed on the side of the wall body 2233 away from the electrode body 211. Both the cover plate 2234 and the wall body 2233 are disposed around the second through hole 2231. A portion of the cover plate 2234 is connected to the side of the wall body 2233 away from the electrode body 211, and another portion is bent in a direction away from the electrode body 211 to define a first recess 2232 together with the wall body 2233. In the first direction Z, the first recess 2232 is located between a portion of the cover plate 2234 and the wall body 2233.

[0166] Optionally, a portion of the wall body 2233 is disposed around the cover plate 2234.

[0167] Please see Figure 8 and Figure 10 In some embodiments, the tab 212 further includes a retractable section 2123, which connects the extension section 2121 and the electrode body 211. Along the second direction X, the size L1 of the retractable section 2123 is larger than the size L2 of the connecting section 2122, and the second direction X intersects the first direction Z.

[0168] In the electrode assembly 21, the tab 212 may include multiple tab layers, which are disposed along a second direction X. Specifically, the positive tab may include multiple positive tab layers, and the negative tab may include multiple negative tab layers. The second direction X can be any direction intersecting the first direction Z; optionally, the second direction X can be any direction perpendicular to the first direction Z. For example, the second direction X can be the thickness direction of the battery cell 20.

[0169] During the manufacturing process of electrode assembly 21, multiple tab layers extending from electrode body 211 are gathered along the second direction X, and a portion of each gathered tab layer is pressed to form tab 212. The extension section 2121 and the connecting section 2122 both include the pressed portion of each tab layer, while the gathering section 2123 includes the unpressed portion of each tab layer, such that the dimension of the gathering section 2123 along the second direction X is larger than the dimension of the extension section 2121 along the second direction X.

[0170] It should be noted that, in the embodiments of this application, the dimension of the gathering section 2123 along the second direction X can be the sum of the thickness of each tab layer and the distance between the lead-out ends of each adjacent tab layer, wherein the lead-out end is the end of the tab layer near the electrode body 211.

[0171] The tab layer of the converging segment 2123 can extend in a straight line or in a curve. The tab layer of the extending segment 2121 can be bent relative to at least a portion of the tab layer of the converging segment 2123.

[0172] The converging section 2123 connects the electrode body 211 and the extension section 2121. Its dimension along the second direction X is larger than that of the extension section 2121 along the second direction X. During the manufacturing process of the electrode assembly 21, the tabs drawn from the electrode body 211 are converging and pressed to form corresponding tabs 212 without having to bend the tabs 212 multiple times. This helps to shorten the length of the tabs 212, reduce the space occupied by the tabs 212 in the housing 22, and increase the energy density of the battery cell 20. At the same time, it also helps to reduce the difficulty of bending the tabs 212, reduce the risk of damage to the tabs 212 due to multiple bends during assembly, and improve the production yield and assembly efficiency of the battery cell 20.

[0173] Please see Figure 10 In some embodiments, the battery cell 20 further includes a second insulating member 27, at least partially connected to the retractable section 2123. The second insulating member 27 can achieve insulation and isolation between the retractable section 2123 and other surrounding conductive structures, reducing the risk of short circuit in the battery cell 20.

[0174] Optionally, the second insulator 27 can be a flexible structure to reduce the risk of damage to the tab 212. Of course, in other examples, the second insulator 27 can also be a rigid structure.

[0175] Optionally, the second insulating element 27 may be insulating tape.

[0176] Please see Figure 10 In some embodiments, a portion of the second insulating member 27 is connected to the retracting section 2123, and another portion is connected to the extension section 2121. On the one hand, the second insulating member 27 can simultaneously insulate and isolate the retracting section 2123 and the extension section 2121. On the other hand, the second insulating member 27 can support the extension section 2121 to a certain extent, thereby reducing the risk of the extension section 2121 tipping over, deforming, or being inserted upside down. This helps to improve the reliability and positional accuracy of the extension section 2121, thereby improving the assembly effect between the connecting section 2122 and the electrode terminal 23, and improving the reliability of the battery cell 20.

[0177] Optionally, a portion of the second insulating member 27 may be disposed around the retractable section 2123, and another portion may be disposed around the extension section 2121, to increase its insulating protection effect on the retractable section 2123 and the extension section 2121. Of course, in other embodiments, the second insulating member 27 may also include a plurality of insulating portions arranged circumferentially along the tab 212, that is, the second insulating member 27 is a discontinuous structure arranged circumferentially along the tab 212.

[0178] Please see Figure 7 In some embodiments, there are multiple electrode bodies 211, and one tab 212 connects to at least one electrode body 211. The electrode body 211 includes a wound positive electrode, a negative electrode, and a separator. One tab 212 can connect to one or more electrode bodies 211. The number of tabs 212 can be set according to the actual situation of the electrode assembly 21, which helps to improve the space utilization within the battery cell 20 and the current transmission performance of the battery cell 20.

[0179] The electrode assembly 21 has a wound structure, in which the positive electrode, negative electrode, and separator of the electrode body 211 are wound together. The battery cell 20 can be cylindrical, flat, or other shapes.

[0180] The term "tab 212 connecting to electrode body 211" can mean that the tab 212 can be composed of tab layers of the same polarity drawn from the corresponding electrode body 211.

[0181] In some examples, a tab 212 connects to an electrode body 211, and the tab 212 is formed by the convergence of tab layers of the same polarity extending from the electrode body 211. In other examples, a tab 212 connects to two electrode bodies 211, and the tab 212 is formed by the convergence of tab layers of the same polarity extending from the two electrode bodies 211. Of course, in other examples, a tab 212 may also connect to more than two electrode bodies 211.

[0182] Please see Figure 10 In some embodiments, the extension 2121 is provided with a welding portion 2124.

[0183] The welding part 2124 can be used to weld the tab layers corresponding to the extension 2121 of the tab 212 together. On the one hand, it reduces the possibility of the tab layers corresponding to the extension 2121 loosening to the surroundings, making the structure of the extension 2121 more compact and reducing the risk of interference between the extension 2121 and other surrounding structures. On the other hand, it also helps to improve the structural strength of the extension 2121 and reduce the risk of the extension 2121 tilting or bending.

[0184] During the forming process of tab 212, the tab layers after being gathered can be pre-welded to form a welded part 2124, and then the connecting section 2122 of tab 212 and electrode terminal 23 can be connected.

[0185] In some embodiments, tab 212 includes a plurality of tab layers (not shown) stacked together, and connection segment 2122 includes a portion of each tab layer, which helps to reduce the internal resistance of connection segment 2122 and improve the current transmission performance between connection segment 2122 and electrode terminal 23.

[0186] The connecting segment 2122 may consist of a portion of each tab layer that is away from the electrode body 211 and is drawn from the corresponding electrode body 211.

[0187] Please see Figure 11 In some embodiments, the connecting segment 2122 includes a plurality of sub-segments 2125, which are respectively connected to the extension segment 2121 and each sub-segment 2125 is respectively connected to the electrode terminal 23; the plurality of sub-segments 2125 include a first sub-segment 2125a and a second sub-segment 2125b, which protrude from opposite sides of the extension segment 2121 along the second direction X.

[0188] Each sub-section 2125 may include at least one tab layer, and different sub-sections 2125 may include different tab layers.

[0189] Each sub-section 2125 can be bent relative to the extension 2121. At least some of the sub-sections 2125 are bent in different directions relative to the extension 2121. In the first direction Z, at least a portion of the surface of each sub-section 2125 away from the electrode body 211 can contact and connect with the fixing part 232, thereby helping to further increase the connection area between the connecting part 2122 and the fixing part 232, and further enhance the connection strength between them.

[0190] In some examples, the bending direction of all sub-parts 2125 is different. Of course, in other examples, the bending direction of some sub-parts 2125 can be the same.

[0191] The plurality of sub-parts 2125 include a first sub-part 2125a and a second sub-part 2125b. In the second direction X, the first sub-part 2125a and the second sub-part 2125b protrude from opposite sides of the extension section 2121, that is, the first sub-part 2125a and the second sub-part 2125b are both bent relative to the extension section 2121 in the second direction X, and the first sub-part 2125a and the second sub-part 2125b are bent in opposite directions. This increases the connection area between the connecting section 2122 and the fixing part 232, and also helps to improve the uniformity of stress distribution on the connection surface between the connecting section 2122 and the fixing part 232.

[0192] In some embodiments, the plurality of sub-parts 2125 further includes a third sub-part (not shown in the figure), which protrudes from the extension 2121 along a third direction Y, and the first direction Z, the second direction X and the third direction Y are perpendicular to each other.

[0193] The third direction Y is perpendicular to the first direction Z and the second direction X. For example, the third direction Y can be the width direction of the battery cell 20.

[0194] The third sub-part protrudes from the extension section 2121 along the third direction Y, that is, the third sub-part bends relative to the extension section 2121 along the third direction Y, which is beneficial to further increase the connection area between the connecting section 2122 and the fixing part 232.

[0195] Optionally, there may be two third sub-parts. In the third direction Y, the two third sub-parts may protrude from opposite sides of the extension section 2121 to further improve the uniformity of stress distribution on the connection surface between the connecting section 2122 and the fixing part 232.

[0196] In some embodiments, the plurality of sub-parts 2125 are distributed circumferentially along the extension 2121, which helps to further increase the connection area between the connecting section 2122 and the fixing part 232.

[0197] For example, multiple sub-sections 2125 may be distributed in a radiating pattern with the extension segment 2121 as the center.

[0198] Please see Figure 8 and Figure 9 In some embodiments, the electrode terminal 23 includes a terminal body 234 and a fixing part 232. The terminal body 234 has a terminal through hole 2341. The fixing part 232 covers the end of the terminal through hole 2341 away from the electrode body 211 and defines a receiving cavity 231 with the terminal body 234. This helps to reduce the molding difficulty of the electrode terminal 23 and improve the production efficiency of the battery cell 20.

[0199] In some alternative embodiments, the fixing part 232 may be connected to the end of the terminal body 234 away from the electrode body 211 and cover the terminal through hole 2341.

[0200] In some alternative embodiments, the fixing part 232 can be embedded in the terminal body 234 along the first direction Z. On the one hand, this can increase the connection area between the fixing part 232 and the terminal body 234 and improve the connection strength between the two. On the other hand, it can make the structure of the terminal body 234 and the fixing part 232 more compact, which is beneficial to reduce the volume and space occupation of the electrode terminal 23.

[0201] For example, a third recess is formed at the end of the terminal body 234 away from the electrode body 211. Along the direction from the electrode body 211 to the wall portion 223, the terminal through hole 2341 is arranged opposite to and communicates with the third recess. In the same plane perpendicular to the first direction Z, the projected area of ​​the terminal through hole 2341 is smaller than the projected area of ​​the bottom surface of the third recess. A fixing portion 232 is embedded in the third recess, wherein a portion of the terminal body 234 surrounds the fixing portion 232, another portion of the terminal body 234 abuts against a portion of the surface of the fixing portion 232 near the electrode body 211, and a portion of the fixing portion 232 covers the end of the terminal through hole 2341 away from the electrode body 211.

[0202] Secondly, embodiments of this application provide a battery device 100, including any of the above-mentioned battery cells 20.

[0203] Thirdly, embodiments of this application also provide an energy storage device 1, including a plurality of battery cells 20 or a plurality of the above-mentioned battery devices 100, wherein the battery cells 20 or battery devices 100 are used to store or provide electrical energy.

[0204] Fourthly, this application also provides an energy storage system, including an energy conversion system 2 and the aforementioned energy storage device 1. The energy conversion system 2 is connected to the energy storage device 1 to convert the current input to the energy storage device 1 or output from the energy storage device 1 into energy.

[0205] Fifthly, embodiments of this application also provide a charging network, including a charging pile 4 and the aforementioned energy storage device 1 or energy storage system, wherein the energy storage device 1 or energy storage system is used to provide electrical energy to the charging pile 4.

[0206] This application provides a battery cell 20, including a housing 22, an electrode assembly 21, and electrode terminals 23. The housing 22 includes a wall portion 223. The electrode assembly 21 is disposed within the housing 22 and includes an electrode body 211 and a tab 212. The electrode body 211 and the wall portion 223 are arranged along a first direction Z. The tab 212 is located on the side of the electrode body 211 near the wall portion 223. The tab 212 includes an extension section 2121 and a connecting section 2122, and the connecting section 2122 is connected to the extension section 2121. The extension segment 2121 is bent relative to the extension segment 2121 at one end away from the electrode body 211. The electrode terminal 23 is disposed in the wall portion 223 and includes a receiving cavity 231 and a fixing portion 232. At least a portion of the fixing portion 232 is located on the side of the receiving cavity 231 away from the electrode body 211 and participates in defining the receiving cavity 231. The connecting segment 2122 is accommodated in the receiving cavity 231. Along the first direction Z, at least a portion of the surface of the connecting segment 2122 away from the electrode body 211 contacts and connects with the fixing portion 232. The battery cell 20 also includes a first insulating member 24. Along the first direction Z, the first insulating member 24 is disposed between the wall portion 223 and the electrode body 211. The first insulating member 24 has a guide hole 241 that extends along the first direction Z. Along the first direction Z, the guide hole 241 is disposed opposite to and communicates with the receiving cavity 231. The extension segment 2121 passes through the guide hole 241. The receiving cavity 231 forms a first opening 233 at one end facing the electrode body 211. The battery cell 20 also includes a support member 25, at least a portion of which is located on the side of the receiving cavity 231 near the electrode body 211 and covers the first opening 233. The support member 25 has a first through hole 251, which is opposite to and communicates with the receiving cavity 231 along the first direction Z. The extension section 2121 passes through the support member 25. The tab 212 also includes a closing section 2123, which connects the extension section 2121 and the electrode body 211. Along the second direction X, the size of the closing section 2123 is larger than the size of the connecting section 2122. The second direction X intersects the first direction Z. There are multiple electrode bodies 211, and one tab 212 connects to at least one electrode body 211. The electrode body 211 includes a wound positive electrode, a negative electrode, and a separator.

[0207] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing, including the walls; An electrode assembly is disposed within the housing and includes an electrode body and a tab. The electrode body and the wall are arranged along a first direction. The tab is located on the side of the electrode body near the wall. The tab includes an extension section and a connecting section. The connecting section is connected to the end of the extension section away from the electrode body and is bent relative to the extension section. An electrode terminal is disposed on the wall portion. The electrode terminal includes a receiving cavity and a fixing portion. At least a portion of the fixing portion is located on the side of the receiving cavity away from the electrode body and participates in defining the receiving cavity. A connecting segment is accommodated in the receiving cavity. Along the first direction, at least a portion of the surface of the connecting segment away from the electrode body contacts and connects with the fixing portion.

2. The battery cell according to claim 1, characterized in that, The battery cell further includes a first insulating member, which is disposed between the wall portion and the electrode body along the first direction. The first insulating member has a guide hole extending along the first direction. Along the first direction, the guide hole is disposed opposite to and communicates with the receiving cavity, and the extension passes through the guide hole.

3. The battery cell according to claim 1, characterized in that, The receiving cavity forms a first opening at one end facing the electrode body; The battery cell also includes a support member, at least a portion of which is located on the side of the receiving cavity near the electrode body and covers the first opening; The support member is provided with a first through hole. Along the first direction, the first through hole is disposed opposite to and communicates with the receiving cavity, and the extension section passes through the support member.

4. The battery cell according to claim 3, characterized in that, The support component is an insulating structure.

5. The battery cell according to claim 3, characterized in that, In the first direction, at least a portion of the support is located between the wall and the electrode terminal.

6. The battery cell according to claim 5, characterized in that, The wall portion is provided with a second through hole, at least a portion of the electrode terminal is disposed in the second through hole, and at least a portion of the receiving cavity and at least a portion of the support member are located in the second through hole.

7. The battery cell according to claim 6, characterized in that, The inner wall of the second through hole is provided with a first recess, and a portion of the electrode terminal is embedded in the first recess. The support includes a first support portion and a second support portion. A portion of the first support portion is located on the side of the receiving cavity near the electrode body and forms the first through hole. The second support portion is located between the electrode terminal and the wall portion.

8. The battery cell according to any one of claims 1-7, characterized in that, The electrode tab also includes a folding section that connects the extension section and the electrode body. Along a second direction, the size of the folding section is larger than the size of the connecting section, and the second direction intersects the first direction.

9. The battery cell according to claim 8, characterized in that, The battery cell also includes a second insulating member, at least a portion of which is connected to the retracting section.

10. The battery cell according to claim 9, characterized in that, A portion of the second insulating element is connected to the retracting section, and another portion is connected to the extending section.

11. The battery cell according to any one of claims 1-7, characterized in that, The electrode body comprises multiple electrode bodies, with one electrode tab connected to at least one electrode body. The electrode body includes a positive electrode plate, a negative electrode plate, and an insulating element wound together.

12. The battery cell according to any one of claims 1-7, characterized in that, The extension section is equipped with a welding section.

13. The battery cell according to any one of claims 1-7, characterized in that, The electrode includes multiple electrode layers stacked together, and the connecting segment includes a portion of each electrode layer.

14. The battery cell according to any one of claims 1-7, characterized in that, The connecting segment includes multiple sub-sections, each of which is connected to the extension segment and each of which is connected to the electrode terminal. The plurality of said sub-parts includes a first sub-part and a second sub-part, which protrude from opposite sides of the extension along a second direction.

15. The battery cell according to claim 14, characterized in that, The plurality of sub-parts further includes a third sub-part that protrudes from the extension along a third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other.

16. The battery cell according to claim 14, characterized in that, The plurality of said sub-parts are distributed circumferentially along said extension.

17. The battery cell according to any one of claims 1-7, characterized in that, The electrode terminal includes a terminal body and the fixing part. The terminal body has a terminal through hole. The fixing part covers the end of the terminal through hole away from the electrode body and defines the receiving cavity with the terminal body.

18. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-17.

19. An energy storage device, characterized in that, It includes a plurality of battery cells according to any one of claims 1-17 or a plurality of battery devices according to claim 18, wherein the battery cells or the battery devices are used to store or provide electrical energy.

20. An energy storage system, characterized in that, It includes an energy conversion system and an energy storage device as described in claim 19, wherein the energy conversion system is connected to the energy storage device to convert the current input to or output from the energy storage device into energy.

21. A charging network, characterized in that, It includes a charging pile and an energy storage device as described in claim 19 or an energy storage system as described in claim 20, wherein the energy storage device or the energy storage system is used to provide electrical energy to the charging pile.

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