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

Abstract

The utility model provides a battery cell, a battery device, an energy storage device, an energy storage system and a charging network. The battery cell includes a housing including a first wall, an electrode terminal disposed on the first wall, an electrode assembly disposed on the first wall, and a support member. At least part of the electrode assembly is contained in the shell, the electrode assembly comprises an electrode main body and a tab, the tab extends out from one end, facing the electrode terminal, of the electrode main body, and the supporting piece and the tab are welded to form a first welding part. Wherein a groove is formed in the side, facing the tab, of the electrode terminal, at least part of the first welding part is contained in the groove, and the supporting piece, the tab and the bottom wall of the groove are welded to form a second welding part. According to the invention, the energy density of the battery monomer can be effectively improved.

Description

Technical Field

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

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

[0003] In the development of battery technology, improving the energy density of individual battery cells is a continuous research direction. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, an energy storage device, an energy storage system, and a charging network, which can effectively improve the energy density of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, electrode terminals, an electrode assembly, and a support member. The casing includes a first wall, and the electrode terminals are disposed on the first wall. At least a portion of the electrode assembly is housed within the casing. The electrode assembly includes an electrode body and a tab, with the tab extending from the end of the electrode body facing the electrode terminal. The support member is welded to the tab to form a first weld portion. A groove is provided on the side of the electrode terminal facing the tab, and at least a portion of the first weld portion is accommodated in the groove. The support member, the tab, and the bottom wall of the groove are welded to form a second weld portion.

[0006] By providing a groove to accommodate at least part of the first weld portion, the dimensions of the support, tabs, and electrode terminals along the thickness direction of the first wall can be reduced, thereby effectively improving the volumetric energy density of the battery cell. Furthermore, the introduction of the groove also reduces the overall weight of the electrode terminals, which not only lowers costs but also increases the gravimetric energy density of the battery cell.

[0007] The groove can also relieve stress, reducing the risk of cracking of the electrode terminals due to excessive thermal stress during the welding process.

[0008] In some embodiments of the first aspect, the first welded portion is directly connected to the second welded portion.

[0009] During the operation of a single battery cell, current can be directly transmitted between the first and second welded parts, thereby shortening the conductive path, reducing resistance, improving overcurrent capacity, and reducing heat generation.

[0010] In some embodiments of the first aspect, the first welded portion includes a first part and a second part connected together, wherein the first part is directly connected to the second welded portion, and the second part is not directly connected to the second welded portion.

[0011] The above technical solution can shorten the conductive path and reduce the thermal stress on the tabs during the entire welding process, thereby reducing the risk of tab tearing.

[0012] In some embodiments of the first aspect, the second portion is disposed around the second weld portion.

[0013] The above technical solution can further increase the flow area between the first weld and the second weld, reduce resistance, shorten the conductive path, improve flow capacity, and reduce heat generation.

[0014] In some embodiments of the first aspect, in the same plane perpendicular to the thickness direction of the first wall, the first area S1 of the orthographic projection of the first weld and the second area S2 of the orthographic projection of the second weld satisfy the relationship: 1≤S1 / S2≤12.

[0015] Limiting S1 / S2 to greater than or equal to 1 can reduce welding difficulty, improve yield, and reduce costs; limiting S1 / S2 to less than or equal to 12 can increase the flow area between the first and second welded parts, reduce resistance, shorten the conductive path, improve flow capacity, and reduce heat generation.

[0016] In some embodiments of the first aspect, the first area S1 and the second area S2 satisfy the relationship: 1.2 ≤ S1 / S2 ≤ 6. This can further improve the balance between welding difficulty and flow capacity.

[0017] In some embodiments of the first aspect, at least a portion of the support member is located between the bottom wall and the electrode lug in the thickness direction of the first wall, and is welded to the electrode lug and the bottom wall respectively.

[0018] By placing the support between the bottom wall and the tab, at least a portion of the support can be located within the groove, and the inner wall of the groove can limit the support, making it less likely for the support to move.

[0019] In some embodiments of the first aspect, at least a portion of the tab is accommodated within a groove.

[0020] It can further reduce the overall dimensions of the support, tabs, and electrode terminals along the thickness direction of the first wall, thereby further improving the volumetric energy density of the battery cell.

[0021] In some embodiments of the first aspect, at least a portion of the support member is located on the side of the tab facing away from the bottom wall in the thickness direction of the first wall, and the tab is directly welded to the bottom wall.

[0022] By placing the support on the side of the tab facing away from the bottom wall, the tab can be directly welded to the bottom wall. This not only provides support for the tab and reduces tab cracking during laser welding, but also further shortens the current path between the tab and the electrode terminal, improves current carrying capacity, reduces heat generation, and thus improves the electrical performance of the battery cell.

[0023] In some embodiments of the first aspect, at least a portion of the support is received within a groove.

[0024] This design allows for a further reduction in the overall dimensions of the support, tabs, and electrode terminals along the thickness of the first wall, thereby further improving the volumetric energy density of the battery cell. Simultaneously, the inner wall of the groove provides a certain degree of restraint to the support, preventing it from shifting.

[0025] In some embodiments of the first aspect, the support includes a first region and a second region, the second region being disposed circumferentially along the first region, and at least one of the two opposite surfaces of the first region along the thickness direction of the first wall having a greater surface roughness than the second region, and the electrode lug being welded to the first region to form a first welded portion.

[0026] When the first region with a higher surface roughness is welded to the electrode tab, the two are less likely to move relative to each other, thus helping to improve the weld quality. In addition, by increasing the roughness, the risk of material stacking due to electrostatic adsorption between multiple supports can be reduced, thereby improving production efficiency.

[0027] In some embodiments of the first aspect, the dimension of the support member along the thickness direction of the first wall is 0.1mm-1.5mm.

[0028] Limiting the dimension of the support member along the thickness direction of the first wall to greater than or equal to 0.1 mm can improve the strength of the support member and reduce the risk of tearing. Limiting the dimension of the support member along the thickness direction of the first wall to less than or equal to 1.5 mm can reduce the difficulty of welding, reduce welding heat generation, reduce thermal stress on the tab, and reduce the risk of tab tearing.

[0029] In some embodiments of the first aspect, the first weld portion is welded to the bottom wall of the groove to form a second weld portion.

[0030] The above technical solution can further increase the flow area between the first weld and the second weld, reduce resistance, shorten the conductive path, improve flow capacity, and reduce heat generation.

[0031] In some embodiments of the first aspect, the electrode tab and the support are ultrasonically welded to form a first welded portion, and / or the support, the electrode tab, and the bottom wall of the groove are laser welded to form a second welded portion.

[0032] During ultrasonic welding, the electrode tabs experience less heat impact; after welding, the portion of the electrode tabs near the first weld joint is less prone to tearing. Laser welding can reduce welding difficulty and increase the strength of the resulting second weld joint.

[0033] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0034] Thirdly, this application provides an energy storage device, which includes a plurality of battery cells provided in any embodiment of the first aspect or a plurality of battery devices provided in any embodiment of the second aspect, wherein the battery cells or battery devices are used to store or provide electrical energy.

[0035] Fourthly, this application provides an energy storage system, which includes a power conversion device and an energy storage device provided in any embodiment of the third aspect, wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0036] Fifthly, this application provides a charging network, which includes a charging pile and an energy storage device provided in any embodiment of the third aspect or an energy storage system provided in any embodiment of the fourth aspect, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0037] 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

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a schematic diagram of the charging network structure in some embodiments of this application;

[0040] Figure 2 This is a schematic diagram of the energy storage system in some embodiments of this application;

[0041] Figure 3 This is a schematic diagram of the structure of the energy storage device in some embodiments of this application;

[0042] Figure 4 This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0044] Figure 6 A three-dimensional structural schematic diagram of a battery cell provided in some embodiments of this application;

[0045] Figure 7 This is a top view of a single battery cell provided in some embodiments of this application;

[0046] Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure along AA;

[0047] Figure 9 for Figure 8 A magnified schematic diagram of the structure at point M;

[0048] Figure 10 This is a top view of another battery cell provided in some embodiments of this application;

[0049] Figure 11 for Figure 10 Schematic diagram of the cross-sectional structure along BB;

[0050] Figure 12 for Figure 11 A magnified schematic diagram of the local structure at point N;

[0051] Figure 13 This is a three-dimensional structural diagram of a support member for a battery cell provided in some embodiments of this application.

[0052] The reference numerals in the detailed embodiments are as follows:

[0053] 1000, Charging network; 2000, Energy storage system; 3000, Power generation device;

[0054] 100. Battery device;

[0055] 200. Energy storage device; 210. Energy storage container;

[0056] 300, charging piles;

[0057] 400. Energy storage converter;

[0058] 5. Housing; 5a. First housing; 5b. Second housing; 6. Battery module; 7. Battery cell;

[0059] 10. Outer shell; 11. First wall;

[0060] 20. Electrode terminal; 21. Groove;

[0061] 30. Electrode assembly; 31. Electrode body; 32. Tab;

[0062] 40. Support component; 41. First region; 42. Second region;

[0063] W1, First welded part; W11, First section; W12, Second section; W2, Second welded part;

[0064] Z, thickness direction. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0066] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0067] In this application, the reference to "embodiment" means that a particular 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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0068] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0069] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0070] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0071] In this application, "multiple" means two or more (including two).

[0072] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0073] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0074] In the development of battery technology, improving the energy density of individual battery cells is a continuous research direction.

[0075] A battery cell typically includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are also housed within the housing. The electrode assembly includes tabs that are electrically connected to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to an external circuitry of the battery cell to enable charging or discharging of the battery cell.

[0076] In related technologies, tabs can be directly connected to electrode terminals via welding, and current can be transmitted at the weld joint between the tab and the electrode terminal. However, the tabs are relatively thin, and when the battery cell is subjected to external impact, the part of the tab near the weld joint is prone to tearing, thereby reducing the current carrying capacity between the tab and the electrode terminal, increasing heat generation, and even causing the connection between the tab and the electrode terminal to fail, affecting the reliability of the battery cell.

[0077] In practical applications, support components are typically used to connect the tabs and electrode terminals to reduce the risk of connection failure and improve the reliability of the battery cell. However, the introduction of support components occupies internal space within the battery cell, affecting its energy density.

[0078] Based on the above considerations, this application designs a battery cell, which includes a casing, electrode terminals, an electrode assembly, and a support member. The casing includes a first wall, and the electrode terminals are disposed on the first wall. At least a portion of the electrode assembly is housed within the casing. The electrode assembly includes an electrode body and a tab, with the tab extending from the end of the electrode body facing the electrode terminal. The support member is welded to the tab to form a first welded portion. A groove is provided on the side of the electrode terminal facing the tab, and at least a portion of the first welded portion is accommodated in the groove. The support member, the tab, and the bottom wall of the groove are welded to form a second welded portion.

[0079] By providing a groove to accommodate at least part of the first weld portion, the dimensions of the support, tabs, and electrode terminals along the thickness direction of the first wall can be reduced, thereby effectively improving the volumetric energy density of the battery cell. Furthermore, the introduction of the groove also reduces the overall weight of the electrode terminals, which not only lowers costs but also increases the gravimetric energy density of the battery cell.

[0080] The groove can also relieve stress, reducing the risk of cracking of the electrode terminals due to excessive thermal stress during the welding process.

[0081] The battery device disclosed in this application can be applied to energy storage devices such as energy storage containers or energy storage cabinets.

[0082] The battery device is described below with reference to the accompanying drawings.

[0083] Please refer to Figure 1 and Figure 3 , Figure 1 This is a schematic diagram of the structure of a charging network 1000 provided in some embodiments of this application. Figure 3 This is a schematic diagram of the structure of an energy storage device 200 provided in some embodiments of this application. Embodiments of this application provide a charging network 1000, which includes a charging pile 300 for charging electrical equipment. The charging network 1000 may also include an energy storage device 200, which is electrically connected to the charging pile 300 and provides power to the charging pile 300.

[0084] It should be noted that the charging pile 300 and the battery cells in the energy storage device 200 are electrically connected via cables, and the battery cells can supply their stored electrical energy to the charging pile 300. The charging pile 300 has a connector that can be connected to electrical equipment, thereby replenishing the equipment's power. The application of the energy storage device 200 in this charging network 1000 can effectively improve the safety of the charging network 1000 and also help to enhance the flexibility of the charging network 1000 during deployment.

[0085] In a charging network 1000, there can be one charging pile 300, and the energy storage device 200 provides power to the one charging pile 300; there can also be multiple charging piles 300, and the energy storage device 200 provides power to multiple charging piles 300.

[0086] As an example, such as Figure 1 As shown, the charging network 1000 includes an energy storage device 200 and two charging piles 300, with the energy storage device 200 providing power to the two charging piles 300.

[0087] The energy storage device 200 may include a battery device 100, which is electrically connected to the charging pile 300 so that the battery device 100 can provide power to the charging pile 300.

[0088] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of an energy storage system 2000 provided in some embodiments of this application. Embodiments of this application provide an energy storage system 2000. The energy storage system 2000 includes an energy storage converter 400, which is electrically connected to a generator 3000 to convert the electrical power provided by the generator 3000. The energy storage system 2000 may also include an energy storage device 200, which is electrically connected to the energy storage converter 400. The energy storage converter 400 converts the electrical energy provided by the generator 3000 and stores it in the energy storage device 200.

[0089] A power conversion device is used to connect the power generation device 3000 and the energy storage device 200. The power generation device 3000 generates electrical energy and stores it in the energy storage device 200 via the power conversion device. The use of the energy storage device 200 in the energy storage system 2000 effectively improves its operational safety. In specific implementations, the power generation equipment can be solar panels, hydroelectric power generation equipment, thermal power generation equipment, etc. This application does not limit the specific type of power generation equipment.

[0090] As an example, such as Figure 2 As shown, the energy storage system 2000 includes an energy storage device 200 and an energy storage converter 400. The two power generation devices 3000 respectively transmit the generated electrical energy to the energy storage converter 400, and the energy storage converter 400 introduces the electrical energy into the energy storage device 200 for storage.

[0091] Please refer to Figure 3 The energy storage device 200 includes an energy storage box 210, and a battery device 100 is installed inside the energy storage box 210.

[0092] As an example, the energy storage device 200 can be an energy storage container, an energy storage cabinet, etc.

[0093] As an example, energy storage device 200 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage power stations can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. Wind power generation systems collect wind energy from wind turbines, convert it into electrical energy, and store it in energy storage device 200. Solar power generation systems can convert solar energy into electrical energy, store it in energy storage device 200, and supply it to users as needed. Mobile power systems can supply power to relevant electrical equipment in areas where the mains power supply cannot reach, such as remote mountainous areas and remote wilderness areas. Temporary power supply systems can provide power to users when there is insufficient power supply.

[0094] Figure 4 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0095] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0096] A battery cell assembly may include multiple battery cells ( Figure 4 (Not shown) Multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0097] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0098] As an example, a single 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.

[0099] As an example, a battery cell can be 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 battery cells, such as hexagonal prismatic battery cells.

[0100] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module 6, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module 6 can be formed by bundling multiple battery cells together with cable ties.

[0101] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 5 and one or more battery cell assemblies housed within the housing 5. As an example, the battery cell assembly may be a battery module 6, which can be housed within the housing by securing the battery module 6 to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0102] In some embodiments, the housing 5 is used to house individual battery cells, and the housing 5 can have various structures.

[0103] In some embodiments, the housing 5 may include a first housing 5a and a second housing 5b. The first housing 5a and the second housing 5b are fastened together to form a closed space inside the housing 5 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0104] In some embodiments, the housing 5 may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the housing to accommodate individual battery cells. As an example, the frame may include multiple side beams.

[0105] In some embodiments, the housing 5 may be part of the vehicle's chassis structure. For example, a portion of the housing 5 may be at least a portion of the vehicle's floor, or a portion of the housing 5 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0106] In some embodiments, the battery device 100 may be an energy storage device.

[0107] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0108] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0109] Figure 5 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0110] In some embodiments, such as Figure 5 As shown, there are multiple battery cells 7, which are first connected in series, parallel, or a combination of both to form a battery module 6. These battery modules 6 are then connected in series, parallel, or a combination of both to form a whole, which is housed within the casing.

[0111] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6. There can be one or more busbars, each used to electrically connect at least two battery cells 7.

[0112] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0113] In some embodiments, the outer casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0114] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0115] In some embodiments, the casing of the battery cell is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0116] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being connected to the housing and covering the opening;

[0117] The housing is a component used to fit the end cap to form the internal cavity of the battery cell. The formed internal cavity can be used to house the electrode assembly, electrolyte, and other components.

[0118] The housing and end cap can be separate components. For example, an opening can be provided on the housing, and the end cap can be used to close the opening to form an internal cavity for the battery cell.

[0119] The housing can come in various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, and aluminum alloy.

[0120] The shape of the end cap can be adapted to the shape of the housing to fit the housing. The material of the end cap can be the same as or different from that of the housing. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell to have higher strength and improve reliability.

[0121] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0122] The housing may be open at one end or at both ends. In some examples, the housing may be a structure with an opening on one side, with one end cap fitting over the housing. In other examples, the housing may be a structure with openings on both sides, with two end caps fitting over the two openings of the housing, respectively.

[0123] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0124] In some embodiments, the electrode assembly includes a positive electrode and a negative electrode, wherein the positive electrode and the negative electrode have opposite polarities.

[0125] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

[0126] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0127] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0128] As an example, the positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0129] In some embodiments, the negative electrode may include a negative current collector.

[0130] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0131] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0132] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0133] As an example, the negative electrode film layer includes a negative electrode active material, which may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0134] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0135] In some embodiments, the electrode assembly further includes a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0136] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0137] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0138] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0139] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0140] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0141] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0142] In some implementations, the electrode assembly is a stacked structure.

[0143] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0144] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0145] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0146] In some embodiments, the positive current collector may include a positive tab, and the negative current collector may include a negative tab. The positive and negative tabs can be used to transmit current. As an example, at least a portion of the positive tab is not coated with a positive film layer, and at least a portion of the negative tab is not coated with a negative film layer.

[0147] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0148] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0149] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of a positive current collector covered by the positive electrode film, a negative electrode film, and a portion of a negative current collector covered by the negative electrode film.

[0150] The positive and negative tabs can be drawn from the same end of the electrode body, or they can be drawn from opposite ends of the electrode body.

[0151] In some embodiments, a battery cell includes a positive electrode lead and a negative electrode lead, wherein the positive electrode lead is electrically connected to a positive electrode plate and the negative electrode lead is electrically connected to a negative electrode plate.

[0152] The positive and negative leads are used to connect to the external circuit to enable charging or discharging of the battery cells.

[0153] In some embodiments, the positive lead-out portion includes a positive terminal. At least a portion of the positive terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0154] As an example, the positive terminal may be a separately molded component that is mounted on the housing. Alternatively, the positive terminal may also be part of the housing.

[0155] In some examples, the positive terminal is directly connected to the positive plate; in other examples, the positive terminal and the positive plate are indirectly connected through other conductive structures, such as a positive adapter.

[0156] In some embodiments, the positive terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0157] In some embodiments, the negative lead-out portion includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0158] As an example, the negative terminal can be a separately molded component that is mounted on the housing. Alternatively, the negative terminal can also be part of the housing.

[0159] In some examples, the negative terminal is directly connected to the negative electrode plate; in other examples, the negative lead-out section also includes other conductive structures connecting the negative terminal and the negative electrode plate, such as a negative adapter.

[0160] In some embodiments, the negative terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0161] Figure 6 This is a three-dimensional structural diagram of a battery cell provided in some embodiments of this application. Figure 7 This is a top view schematic diagram of a single battery cell provided in some embodiments of this application. Figure 8 for Figure 7 A schematic diagram of the cross-sectional structure along AA. Figure 9 for Figure 8 A magnified schematic diagram of the structure at point M.

[0162] Continue to refer to Figures 6 to 9 This application provides a battery cell 7, which includes a housing 10, electrode terminals 20, electrode assemblies 30, and a support member 40. The housing 10 includes a first wall 11, and the electrode terminals 20 are disposed on the first wall 11. At least a portion of the electrode assembly 30 is housed within the housing 10. The electrode assembly 30 includes an electrode body 31 and a tab 32. The tab 32 extends from the end of the electrode body 31 facing the electrode terminal 20. The support member 40 is welded to the tab 32 to form a first welded portion W1. A groove 21 is provided on the side of the electrode terminal 20 facing the tab 32. At least a portion of the first welded portion W1 is housed in the groove 21. The support member 40, the tab 32, and the bottom wall of the groove 21 are welded to form a second welded portion W2.

[0163] In some examples, the first welded part W1 and the second welded part W2 can be directly connected. Exemplarily, during the operation of the battery cell 7, the current on the tab 32 can be conducted to the electrode terminal 20 through the first welded part W1 and the second welded part W2.

[0164] In other examples, the first welded portion W1 and the second welded portion W2 are spaced apart by a certain distance and are connected by a portion of the support member 40. Exemplarily, during the operation of the battery cell 7, a portion of the current on the tab 32 is conducted to the electrode terminal 20 through the second welded portion W2, and another portion of the current on the tab 32 can be conducted to the electrode terminal 20 via the first welded portion W1, the support member 40, and the second welded portion W2.

[0165] The first welding part W1 can be one or more. The second welding part W2 can be one or more.

[0166] The first welded part W1 and the second welded part W2 can be formed by the same welding process or by different welding processes.

[0167] The area of ​​the first welded part W1 may be greater than, equal to or less than the area of ​​the second welded part W2.

[0168] Multiple conductive paths can be formed between the tab 32 and the electrode terminal 20 through the first weld portion W1 and the second weld portion W2, thereby improving the current carrying capacity between the tab 32 and the electrode terminal 20 and reducing heat generation. Compared with the second weld portion W2, the formation of the first weld portion W1 is independent of the electrode terminal 20, and the first weld portion W1 has a smaller impact on the tab 32 (for example, the thermal stress on the tab 32 is smaller), and the portion of the tab 32 near the first weld portion W1 is less prone to tearing.

[0169] For example, the first welded part W1 may be partially or entirely contained within the groove 21.

[0170] At least a portion of the second welded portion W2 is accommodated in the groove 21. Exemplarily, the second welded portion W2 may be partially or entirely accommodated in the groove 21.

[0171] The support 40 can reduce the cracking of the tab 32 during laser welding, while ensuring that there is still sufficient flow area when there is cracking in the laser welding area of ​​the tab 32.

[0172] Optionally, the support member 40 may be, but is not limited to, a plate-like structure, a column-like structure, or a block-like structure.

[0173] By providing a groove 21 to accommodate at least a portion of the first welded portion W1, the dimensions of the support member 40, the tab 32, and the electrode terminal 20 along the thickness direction Z of the first wall 11 can be reduced, thereby effectively increasing the volumetric energy density of the battery cell 7. Furthermore, the introduction of the groove 21 also reduces the overall weight of the electrode terminal 20, which not only lowers costs but also increases the gravimetric energy density of the battery cell 7.

[0174] The groove 21 can also play a stress-relieving role, which can reduce the risk of the electrode terminal 20 cracking due to excessive thermal stress during the welding process.

[0175] In some embodiments, the tab 32 includes multiple tab layers, which are stacked on top of each other. By providing multiple tab layers, the current carrying capacity of the tab 32 can be increased, the heat generation of the tab 32 can be reduced, and the risk of the tab 32 melting can be lowered.

[0176] In some embodiments, the portion of the tab 32 that is not welded to other components is directly connected to the first welding portion W1. Exemplarily, multiple tab layers of the tab 32 are directly connected to the first welding portion W1. Exemplarily, the thickness of the tab layer is 2μm-30μm. Optionally, the thickness of the tab layer is 5μm-15μm.

[0177] In some embodiments, the battery cell 7 further includes a buffer layer disposed on the sidewall of the groove 21, and the elastic modulus of the buffer layer is less than the elastic modulus of the electrode terminal 20.

[0178] For example, a buffer layer is connected to electrode terminal 20. The buffer layer can be detachably connected to electrode terminal 20 or fixedly disposed on electrode terminal 20. The buffer layer can be directly connected to electrode terminal 20 or constrained to electrode terminal 20 by other components. As an example, the connection method between the buffer layer and electrode terminal 20 can be, but is not limited to, bolt connection, snap-fit, riveting, or adhesive bonding.

[0179] The buffer layer has a small elastic modulus and a relatively soft texture, which can reduce the risk of damage to the tab 32 caused by rigid contact between the tab 32 and the sidewall of the groove 21.

[0180] Optionally, the buffer layer may be made of materials such as silicone, foam, or rubber.

[0181] As an example, the elastic modulus of electrode terminal 20 and buffer layer can be tested in accordance with the national standard GB / T 22315-2008 "Test Method for Elastic Modulus and Poisson's Ratio of Metallic Materials".

[0182] In some embodiments, the first welding part W1 is directly connected to the second welding part W2.

[0183] In some examples, the tab 32 is first welded to the support 40 to form a first welded part W1. A portion of the first welded part W1 is directly welded to the bottom wall of the groove 21 to form a second welded part W2. The second welded part W2 is directly connected to another portion of the first welded part W1 that is not directly welded to the bottom wall of the groove 21.

[0184] In other examples, the first weld portion W1 is disposed along the outer periphery of the second weld portion W2, and at least a portion of the outer periphery of the first weld portion W1 is directly connected to at least a portion of the outer periphery of the second weld portion W2. For example, the first weld portion W1 may extend along the outer periphery of the second weld portion W2 by 0.25 turns, 0.5 turns, 0.75 turns, or 1 turn.

[0185] During the operation of the battery cell 7, the current can be directly transmitted between the first welding part W1 and the second welding part W2, thereby shortening the conductive path, reducing resistance, improving overcurrent capacity, and reducing heat generation.

[0186] In some embodiments, at least a portion of the first weld portion W1 is disposed around the second weld portion W2.

[0187] For example, the entire first welded portion W1 may surround the second welded portion W2, or a portion of the first welded portion W1 may surround the second welded portion W2.

[0188] The above technical solution can reduce the distance difference between different parts of the first welded part W1 and the second welded part W2, improve the uniformity of the flow, and reduce heat generation.

[0189] In some embodiments, the first welding part W1 includes a first part W11 and a second part W12 connected together. The first part W11 is directly connected to the second welding part W2, while the second part W12 is not directly connected to the second welding part W2.

[0190] For example, in the thickness direction Z of the first wall 11, the portion of the first welded portion W1 that overlaps with the second welded portion W2 can be understood as the first portion W11, and the portion of the first welded portion W1 that does not overlap with the second welded portion W2 can be understood as the second portion W12.

[0191] The above technical solution, by directly connecting a part of the first welding part W1 to the second welding part W2 and not directly connecting the other part to the second welding part W2, can shorten the conductive path and reduce the thermal stress on the tab 32 during the entire welding process, thereby reducing the risk of tearing of the tab 32.

[0192] In some embodiments, the second portion W12 is disposed around the second weld portion W2. In other words, the outer periphery of the second weld portion W2 is directly connected to the first weld portion W1.

[0193] For example, a portion of the first welded portion W1 is directly welded to the bottom wall of the groove 21 to form the second welded portion W2, such that the entire second welded portion W2 is located inside the first welded portion W1.

[0194] The above technical solution can further increase the current-carrying area between the first welding part W1 and the second welding part W2, reduce resistance, shorten the conductive path, improve current-carrying capacity, and reduce heat generation.

[0195] In some embodiments, in the same plane perpendicular to the thickness direction Z of the first wall 11, the first area S1 of the orthographic projection of the first welded part W1 and the second area S2 of the orthographic projection of the second welded part W2 satisfy the relationship: 1≤S1 / S2≤12.

[0196] For example, when the second part W12 is arranged around the second welded part W2, that is, when the entire second welded part W2 is located inside the first welded part W1, the ratio of the first area S1 to the second area S2 can characterize the relative size between the first welded part W1 and the second welded part W2.

[0197] It should be noted that in this embodiment, the second welded part W2 is formed on the basis of the first welded part W1, and the formation of the second welded part W2 will reduce the size of the first welded part W1. The first area S1 refers to the orthographic projection area of ​​the first welded part W1 before the formation of the second welded part W2, that is, the first area S1 refers to the original area size of the first welded part W1.

[0198] As an example, in the same plane perpendicular to the thickness direction Z of the first wall 11, the first area S1 of the orthographic projection of the first welded part W1 is the sum of the area of ​​the orthographic projection of the first part W11 and the area of ​​the orthographic projection of the second part W12.

[0199] As an example, S1 / S2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0200] Limiting S1 / S2 to greater than or equal to 1 can reduce welding difficulty, improve yield, and reduce costs; limiting S1 / S2 to less than or equal to 12 can increase the flow area between the first welded part W1 and the second welded part W2, reduce resistance, shorten the conductive path, improve flow capacity, and reduce heat generation.

[0201] In some embodiments, the first area S1 and the second area S2 satisfy the relationship: 1.2≤S1 / S2≤6, which can further improve the balance between welding difficulty and flow capacity.

[0202] As an example, S1 / S2 can be 1.2, 2, 2.5, 3.5, 4, 4.5, 5, 6, etc.

[0203] In some embodiments, at least a portion of the support member 40 is located between the bottom wall and the tab 32 in the thickness direction Z of the first wall 11, and is welded to the tab 32 and the bottom wall respectively.

[0204] For example, the support member 40 may be partially located between the bottom wall and the tab 32, or it may be entirely located between the bottom wall and the tab 32.

[0205] By placing the support member 40 between the bottom wall and the tab 32, at least a portion of the support member 40 can be located within the groove 21. The inner wall of the groove 21 can limit the support member 40 to a certain extent, making it difficult for the support member 40 to move.

[0206] For example, during the welding process, the sturdy support 40 can improve the welding quality; when the battery cell 7 is subjected to external impact, the sturdy support 40 can reduce the risk of the tab 32 tearing, thereby reducing the risk of the tab 32 failing to connect with the electrode terminal 20 and improving the reliability of the battery cell 7.

[0207] In some embodiments, at least a portion of the support member 40 is located between the bottom wall and the tab 32 in the thickness direction Z of the first wall 11, and is welded to the tab 32 and the bottom wall respectively, with the entire support member 40 accommodated within the groove 21. This further reduces the space occupied by the support member 40 within the battery cell 7.

[0208] In some embodiments, at least a portion of the support member 40 is located between the bottom wall and the tab 32 in the thickness direction Z of the first wall 11, and is welded to the tab 32 and the bottom wall respectively, with at least a portion of the tab 32 accommodated in the groove 21.

[0209] It can further reduce the overall dimensions of the support member 40, the tab 32, and the electrode terminal 20 along the thickness direction Z of the first wall 11, thereby further improving the volumetric energy density of the battery cell 7.

[0210] For example, the tab 32 may be partially or entirely contained within the groove 21.

[0211] Figure 10 This is a top view schematic diagram of another battery cell provided in some embodiments of this application. Figure 11 for Figure 10 A schematic diagram of the cross-sectional structure along BB. Figure 12 for Figure 11 A magnified schematic diagram of the structure at point N.

[0212] Continue to refer to Figures 8 to 10In some embodiments, at least a portion of the support member 40 is located on the side of the tab 32 facing away from the bottom wall in the thickness direction Z of the first wall 11, and the tab 32 is directly welded to the bottom wall.

[0213] For example, the support member 40 may be partially located on the side of the tab 32 facing away from the bottom wall, or it may be entirely located on the side of the tab 32 facing away from the bottom wall.

[0214] By placing the support member 40 on the side of the tab 32 facing away from the bottom wall, so that the tab 32 can be directly welded to the bottom wall, the support member 40 can provide support for the tab 32 to reduce the cracking of the tab 32 during laser welding, while further shortening the current path between the tab 32 and the electrode terminal 20, improving the current carrying capacity, reducing heat generation, and thus improving the electrical performance of the battery cell 7.

[0215] In some embodiments, at least a portion of the support member 40 is located on the side of the tab 32 facing away from the bottom wall along the thickness direction Z of the first wall 11. The tab 32 is directly welded to the bottom wall, and the tab 32 is entirely accommodated within the groove 21. This allows for a further reduction in the overall dimensions of the support member 40, the tab 32, and the electrode terminal 20 along the thickness direction Z of the first wall 11, thereby further improving the volumetric energy density of the battery cell 7.

[0216] In some embodiments, in the thickness direction Z of the first wall 11, at least a portion of the support member 40 is located on the side of the tab 32 facing away from the bottom wall, the tab 32 is directly welded to the bottom wall, and at least a portion of the support member 40 is accommodated in the groove 21.

[0217] This allows for a further reduction in the overall dimensions of the support member 40, the tab 32, and the electrode terminal 20 along the thickness direction Z of the first wall 11, thereby further improving the volumetric energy density of the battery cell 7. Simultaneously, the inner wall of the groove 21 provides a certain degree of restraint to the support member 40, making it less prone to movement.

[0218] For example, the support member 40 may be partially or entirely contained within the groove 21.

[0219] Figure 13 This is a three-dimensional structural diagram of a support member for a battery cell provided in some embodiments of this application.

[0220] Continue to refer to Figure 13 In some embodiments, the support member 40 includes a first region 41 and a second region 42, the second region 42 being arranged circumferentially along the first region 41, and at least one of the two opposite surfaces of the first region 41 along the thickness direction Z of the first wall 11 having a surface roughness greater than that of the second region 42, and the tab 32 being welded to the first region 41 to form a first welded part W1.

[0221] For example, the surface roughness of one of the two opposite surfaces of the first region 41 along the thickness direction Z of the first wall 11 may be greater than the surface roughness of the second region 42, or the surface roughness of both opposite surfaces of the first region 41 along the thickness direction Z of the first wall 11 may be greater than the surface roughness of the second region 42.

[0222] When the first region 41 with a larger surface roughness is welded to the tab 32, the two are less likely to move relative to each other, which helps to improve the welding quality. In addition, by increasing the roughness, the risk of material stacking caused by electrostatic adsorption between multiple support members 40 can also be reduced, thereby improving production efficiency.

[0223] In some embodiments, a first region 41 with a larger surface roughness can be formed by embossing the support member 40, and the remaining unembossed region is the second region 42.

[0224] For example, the embossing depth can be 0.01mm-0.1mm.

[0225] In some embodiments, the support member 40 is provided with a positioning structure, which is used for positioning the support member 40 and the tab 32.

[0226] For example, the positioning structure may be, but is not limited to, a chamfered structure or a pattern mark, etc.

[0227] In some embodiments, the positioning structure is disposed in the second region 42.

[0228] In some embodiments, the dimension d1 of the support member 40 along the thickness direction Z of the first wall 11 is 0.1mm-1.5mm.

[0229] For example, the dimension d1 of the support member 40 along the thickness direction Z of the first wall 11 can be understood as the thickness of the support member 40.

[0230] As an example, the dimension d1 of the support member 40 along the thickness direction Z of the first wall 11 can be 0.1mm, 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm or 1.5mm.

[0231] Limiting the dimension d1 to greater than or equal to 0.1 mm can increase the strength of the support 40 and reduce the risk of tearing of the support 40; limiting the dimension d1 to less than or equal to 1.5 mm can reduce the welding difficulty, reduce welding heat generation, reduce thermal stress on the tab 32, and reduce the risk of tearing of the tab 32.

[0232] In some embodiments, the dimension d1 of the support member 40 along the thickness direction Z of the first wall 11 is 0.2mm-0.8mm.

[0233] In some embodiments, the first welded portion W1 is welded to the bottom wall of the groove 21 to form the second welded portion W2.

[0234] For example, the tab 32 is first welded to the support member 40 to form a first welded part W1, and then the first welded part W1 is welded to the bottom wall of the groove 21 to form a second welded part W2.

[0235] The above technical solution can further increase the current-carrying area between the first welding part W1 and the second welding part W2, reduce resistance, shorten the conductive path, improve current-carrying capacity, and reduce heat generation.

[0236] In some embodiments, the tab 32 and the support member 40 are ultrasonically welded to form a first welded portion W1. During ultrasonic welding, the tab 32 is less affected by heat; after welding, the portion of the tab 32 near the first welded portion W1 is less prone to tearing.

[0237] In some embodiments, the support 40, the tab 32, and the bottom wall of the groove 21 are laser-welded to form a second welded portion W2. Laser welding reduces the difficulty of welding and increases the strength of the second welded portion W2.

[0238] For example, laser welding is a welding method that uses a high-energy laser beam to irradiate a work surface, causing it to melt instantly and form a molten pool, thereby achieving a metal connection. Laser welding has advantages such as high welding speed, small heat-affected zone, and high welding quality.

[0239] According to some embodiments of this application, this application also provides a battery device 100, including a battery cell 7 of any of the above schemes.

[0240] According to some embodiments of this application, this application also provides an energy storage device, including multiple battery cells 7 or multiple battery devices 100 of any kind, wherein the battery cells 7 or battery devices 100 are used to store or provide electrical energy.

[0241] According to some embodiments of this application, this application also provides an energy storage system, including a power conversion device and an energy storage device of any of the above schemes, wherein the power conversion device is used to electrically connect a power generation device and an energy storage device.

[0242] According to some embodiments of this application, this application also provides a charging network, including a charging pile and an energy storage device or an energy storage system of any of the above schemes, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0243] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. All technical features and optional technical features of this application can be combined to form new technical solutions.

[0244] To better understand the battery cell 7 provided in the embodiments of this application, based on the same inventive concept, an embodiment of the battery cell 7 in practical application is provided here for illustration.

[0245] This application provides a battery cell 7, which includes a housing 10, electrode terminals 20, electrode assemblies 30, and a support member 40. The housing 10 includes a first wall 11, and the electrode terminals 20 are disposed on the first wall 11. At least a portion of the electrode assembly 30 is housed within the housing 10. The electrode assembly 30 includes an electrode body 31 and a tab 32. The tab 32 extends from the end of the electrode body 31 facing the electrode terminal 20. The support member 40 is welded to the tab 32 to form a first welded portion W1. A groove 21 is provided on the side of the electrode terminal 20 facing the tab 32. At least a portion of the first welded portion W1 is housed in the groove 21. The support member 40, the tab 32, and the bottom wall of the groove 21 are welded to form a second welded portion W2. The outer periphery of the second welded portion W2 is directly connected to the first welded portion W1.

[0246] In the thickness direction Z of the first wall 11, at least a portion of the support member 40 is located on the side of the tab 32 facing away from the bottom wall, and the tab 32 is directly welded to the bottom wall.

[0247] By providing a groove 21 to accommodate at least a portion of the first welded portion W1, the dimensions of the support member 40, the tab 32, and the electrode terminal 20 along the thickness direction Z of the first wall 11 can be reduced, thereby effectively increasing the volumetric energy density of the battery cell 7. Furthermore, the introduction of the groove 21 also reduces the overall weight of the electrode terminal 20, which not only lowers costs but also increases the gravimetric energy density of the battery cell 7.

[0248] The groove 21 can also play a stress-relieving role, which can reduce the risk of the electrode terminal 20 cracking due to excessive thermal stress during the welding process.

[0249] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0250] 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 shell, including the first wall; Electrode terminals are disposed on the first wall; An electrode assembly, at least partially housed within the housing, the electrode assembly comprising an electrode body and a tab, the tab extending from one end of the electrode body facing the electrode terminal; A support member, which is welded to the electrode lug to form a first welded portion; The electrode terminal has a groove on the side facing the tab, at least a portion of the first welded part is accommodated in the groove, and the support, the tab and the bottom wall of the groove are welded together to form a second welded part.

2. The battery cell according to claim 1, characterized in that, The first welded part is directly connected to the second welded part.

3. The battery cell according to claim 1, characterized in that, The first welding part includes a first part and a second part connected together. The first part is directly connected to the second welding part, while the second part is not directly connected to the second welding part.

4. The battery cell according to claim 3, characterized in that, The second part is arranged around the second welded part.

5. The battery cell according to claim 4, characterized in that, In the same plane perpendicular to the thickness direction of the first wall, the first area S1 of the orthographic projection of the first welded part and the second area S2 of the orthographic projection of the second welded part satisfy the relationship: 1≤S1 / S2≤12.

6. The battery cell according to claim 5, characterized in that, The first area S1 and the second area S2 satisfy the relationship: 1.2≤S1 / S2≤6.

7. The battery cell according to claim 1, characterized in that, In the thickness direction of the first wall, at least a portion of the support is located between the bottom wall and the electrode lug, and is welded to the electrode lug and the bottom wall respectively.

8. The battery cell according to claim 7, characterized in that, At least a portion of the tab is accommodated within the groove.

9. The battery cell according to claim 1, characterized in that, In the thickness direction of the first wall, at least a portion of the support is located on the side of the electrode tab facing away from the bottom wall, and the electrode tab is directly welded to the bottom wall.

10. The battery cell according to claim 9, characterized in that, At least a portion of the support is accommodated within the groove.

11. The battery cell according to claim 1, characterized in that, The support includes a first region and a second region, the second region being arranged circumferentially along the first region, and at least one of the two surfaces of the first region opposite to each other along the thickness direction of the first wall having a greater surface roughness than the second region. The electrode tab is welded to the first region to form the first welded part.

12. The battery cell according to claim 1, characterized in that, The dimension of the support member along the thickness direction of the first wall is 0.1mm-1.5mm.

13. The battery cell according to claim 1, characterized in that, The first welded part is welded to the bottom wall of the groove to form the second welded part.

14. The battery cell according to any one of claims 1-13, characterized in that, The electrode tab and the support are ultrasonically welded to form the first welded part, and / or the support, the electrode tab, and the bottom wall of the groove are laser welded to form the second welded part.

15. A battery device, characterized in that, It includes multiple battery cells as described in any one of claims 1-14.

16. An energy storage device, characterized in that, It includes a plurality of battery cells as described in any one of claims 1 to 14 or a plurality of battery devices as described in claim 15, wherein the battery cells or the battery devices are used to store or provide electrical energy.

17. An energy storage system, characterized in that, It includes a power conversion device and an energy storage device as described in claim 16, wherein the power conversion device is used to electrically connect the power generation device and the energy storage device.

18. A charging network, characterized in that, It includes a charging pile and an energy storage device as described in claim 16 or an energy storage system as described in claim 17, wherein the energy storage device is used to provide electrical energy to the charging pile.

Images