Battery cell, battery device, electric device, and energy storage device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and a power utilization device. The battery cell includes a housing, an electrode terminal, an electrical connection structure, and a seal. At least one side of the housing along the first direction is provided with a mounting hole. The electrode terminals are arranged in the mounting holes in a penetrating mode. The electric connection structure is arranged in the shell, and the electric connection structure is connected with the electrode terminal in a welding mode to form a welding mark. The equivalent diameter of the projection of the welding mark on the first plane is L1, L1 is larger than or equal to 3.5 mm, and the first plane is perpendicular to the first direction. The sealing member sleeves the peripheral side of the electrode terminal and is clamped between the electrode terminal and the housing. And projecting on the first plane, wherein the projection of the welding mark is located in the projection range of the hollow area of the sealing element. The size of the sealing element is correspondingly increased by increasing the welding print area between the electric connection structure and the electrode terminal, so that the projection of the welding print is located in the projection range of the hollow area of the sealing element, a heat transfer path between the welding print and the sealing element is favorably increased, and the problem of burn failure of the sealing ring is solved.

Description

Technical Field

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

[0002] This section is intended to provide background or context for embodiments of this application. The description herein is not intended to imply that it is prior art simply because it is included in this section.

[0003] In new energy vehicles equipped with battery devices, the battery device can provide all or part of the power. The tabs of the battery cells are typically connected to the electrode terminals via adapter plates. These tabs are usually welded to the adapter plates, and the weld marks formed by this welding can affect the current-carrying capacity of the battery cells. To improve the current-carrying capacity, the weld mark area needs to be increased. However, in related technologies, increasing the weld mark area can lead to the problem of sealing ring burn-out and failure. Utility Model Content

[0004] In view of this, the embodiments of this application aim to provide a battery cell, battery device, power consumption device, and energy storage device that can improve the problem of seal ring burn failure after the solder area is increased.

[0005] To achieve the above objectives, a first aspect of this application provides a battery cell, comprising:

[0006] The housing has mounting holes on at least one side along a first direction;

[0007] Electrode terminals, wherein the electrode terminals are disposed in the mounting holes;

[0008] An electrical connection structure is disposed within the housing. The electrical connection structure is welded to the electrode terminal to form a solder mark. The equivalent diameter of the projection of the solder mark on the first plane is L1, where L1 is greater than or equal to 3.5 mm. The first plane is perpendicular to the first direction.

[0009] A sealing element is fitted around the periphery of the electrode terminal and sandwiched between the electrode terminal and the housing. When projected onto the first plane, the projection of the solder mark is located within the projection range of the hollow region of the sealing element.

[0010] The battery cell provided in this application includes a casing, electrode terminals, an electrical connection structure, and a seal. The electrode terminals are electrically connected to the tabs of the electrode assembly of the battery cell via an adapter, and the electrical connection structure is welded to the electrode terminals to form a solder mark. The seal is sleeved around the electrode terminals and sandwiched between the electrode terminals and the casing to achieve sealing and insulation between the electrode terminals and the casing. By setting the equivalent diameter of the solder mark projection on the first plane to be greater than or equal to 3.5 mm, the solder mark area can be increased, thereby improving the current carrying capacity and power of the battery cell. At the same time, the size of the seal is correspondingly increased so that the projection of the solder mark is located within the projection range of the hollow area of ​​the seal, which helps to increase the heat transfer path between the solder mark and the seal, thereby improving the problem of seal ring burn failure.

[0011] In some embodiments, the equivalent diameter of the projection of the hollow region of the seal onto the first plane is L2; ​​L1 is greater than or equal to half of L2.

[0012] While further improving the overcurrent capacity and power of individual battery cells, the heat transfer path between the solder and the seal is further increased, thereby further improving the problem of seal ring burn failure.

[0013] In some embodiments, L1 is greater than or equal to 7 mm and less than or equal to 12 mm.

[0014] The equivalent diameter of the solder mark within this range can improve the current carrying capacity and power of the battery cell, while also increasing the heat transfer path between the solder mark and the seal, thereby improving the problem of seal ring burn failure and improving the performance of the battery cell.

[0015] In some embodiments, the equivalent diameter of the projection of the hollow region of the seal onto the first plane is L2; ​​and the minimum gap between the solder mark and the sidewall of the hollow region of the seal in a direction perpendicular to the first direction is L3, where L3 is greater than or equal to 0 and less than or equal to half of L2.

[0016] This ensures that the projection of the solder mark on the first plane does not overlap with the projection of the seal on the first plane, which helps to increase the heat transfer path between the solder mark and the seal.

[0017] In some embodiments, L3 is greater than or equal to one-sixth of L2 and less than or equal to one-quarter of L2.

[0018] This further ensures that the projection of the solder mark on the first plane does not overlap with the projection of the seal on the first plane, which is beneficial to further increase the heat transfer path between the solder mark and the seal.

[0019] In some embodiments, the equivalent diameter of the projection of the hollow region of the seal onto the first plane is L2; ​​L2 is greater than 0 mm and less than or equal to 50 mm.

[0020] Within this range, the inner diameter of the seal is appropriate, which can increase the heat transfer path between the solder and the seal. Even if the solder area is increased to improve the current carrying capacity and power of the battery cell, there can still be a sufficient heat transfer path between the solder and the seal, thereby improving the problem of seal ring burn failure and improving the performance of the battery cell.

[0021] In some embodiments, the equivalent diameter of the projection of the hollow region of the seal onto the first plane is L2; ​​L2 is greater than or equal to 13 mm and less than or equal to 16 mm.

[0022] The appropriate inner diameter of the seal within this range can further increase the heat transfer path between the solder and the seal. Even by increasing the solder area to improve the current carrying capacity and power of the battery cell, there can still be a sufficient heat transfer path between the solder and the seal, thereby further improving the problem of seal ring burn failure and improving the performance of the battery cell.

[0023] In some embodiments, the electrode terminal includes a connecting body and a connecting flange connected to one end of the connecting body. The connecting body passes through the mounting hole, and the connecting flange is disposed inside the housing. The electrical connection structure is welded to the side of the connecting flange opposite to the connecting body. In a direction perpendicular to the first direction, the size of the connecting flange is greater than or equal to the size of the connecting body.

[0024] In this embodiment, by setting the electrode terminal to include a connecting body and a connecting flange, and setting the size of the connecting flange to be greater than or equal to the size of the connecting body, it is beneficial to prevent the electrode terminal from coming out of the housing from the mounting hole, and also facilitates the welding between the electrode terminal and the electrical connection structure.

[0025] In some embodiments, the seal includes a sealing body and a sealing flange connected to one end of the sealing body, the sealing flange being sandwiched between the connecting flange and the housing, and the sealing body being sandwiched between the connecting body and the housing in a direction perpendicular to the first direction.

[0026] In this embodiment, by configuring the seal to include a sealing body and a sealing flange, it is further beneficial to achieve sealing and insulation between the electrode terminal and the housing, and also to facilitate the assembly of the seal.

[0027] In some embodiments, the dimension of the connecting flange in the first direction is L4, where L4 is greater than or equal to 2.5 mm and less than or equal to 6 mm.

[0028] The appropriate size of the connecting flange within this range not only increases the heat transfer path between the solder and the seal, improving the problem of seal ring burn failure, but also helps to make the battery cell have a better structural compactness, thereby improving the performance of the battery cell.

[0029] In some embodiments, the minimum gap between the solder mark and the sidewall of the hollow region of the seal is L3, the dimension of the connecting flange in the first direction is L4, and L4 / L3 is greater than or equal to 0.1 and less than or equal to 10.

[0030] In this embodiment, by setting the ratio of the dimension of the connecting flange in the first direction to the gap between the inner diameter of the solder and the seal to be greater than 0.1 and less than or equal to 10, the heat transfer path between the solder and the seal in the first direction is increased, thereby improving the problem of seal ring burn failure. At the same time, it also helps to make the battery cell have better structural compactness, thereby improving the performance of the battery cell.

[0031] In some embodiments, L4 / L3 is greater than or equal to 0.4 and less than or equal to 0.8.

[0032] In this embodiment, by setting the ratio of the dimension of the connecting flange in the height direction of the battery cell to the gap between the solder and the inner diameter of the seal to be greater than 0.4 and less than or equal to 0.8, the heat transfer path between the solder and the seal in the height direction of the battery cell is further increased, thereby further improving the problem of seal ring burn failure. At the same time, it is also beneficial to further improve the structural compactness of the battery cell, thereby improving the performance of the battery cell.

[0033] In some embodiments, the dimension of the connecting flange in the first direction is L4, and the penetration depth of the solder is L5, where L5 is greater than or equal to 10 μm and less than or equal to L4.

[0034] In this embodiment, by setting the weld penetration depth to be greater than or equal to 10 μm and less than or equal to the dimension of the connecting flange in the first direction, the weld penetration depth meets the requirements, which is beneficial to improving the reliability of the welding connection between the electrical connection structure and the electrode terminal.

[0035] In some embodiments, L5 is greater than or equal to 400 μm and less than or equal to L4.

[0036] In this embodiment, by setting the weld penetration depth to be greater than or equal to 400 μm and less than or equal to the dimension of the connecting flange in the first direction, the weld penetration depth meets the requirements, which is beneficial to further improve the reliability of the welding connection between the electrical connection structure and the electrode terminal.

[0037] In some embodiments, the edge of the connecting flange facing the electrical connection structure is thinned to form a groove, and the groove is spaced apart from the electrical connection structure.

[0038] In this embodiment, a groove is formed by thinning the edge of the connecting flange facing the electrical connection structure. The groove is spaced apart from the electrical connection structure, which helps to reduce the heat transferred to the seal, thereby improving the problem of seal ring burn failure.

[0039] In some embodiments, the battery cell includes an electrode assembly, and the electrode assembly includes tabs;

[0040] The battery cell includes an adapter plate, which, together with the electrode tab, forms the electrical connection structure. The electrode terminals are electrically connected to the electrode tab via the adapter plate, and the electrode terminals are soldered to the adapter plate to form the solder mark; or...

[0041] The tab is constructed as the electrical connection structure, and the electrode terminal is welded to the tab to form the solder mark.

[0042] A second aspect of this application provides a battery device including at least one of the battery cells described above.

[0043] The battery cell of the battery device provided in this application embodiment includes a casing, electrode terminals, an electrical connection structure, and a seal. The electrode terminals are electrically connected to the tabs of the electrode assembly of the battery cell via an adapter, and the electrical connection structure is welded to the electrode terminals to form a solder mark. The seal is sleeved around the electrode terminals and sandwiched between the electrode terminals and the casing to achieve sealing and insulation between the electrode terminals and the casing. By setting the equivalent diameter of the solder mark projection on the first plane to be greater than or equal to 3.5 mm, the solder mark area can be increased, thereby improving the current carrying capacity and power of the battery cell. At the same time, the size of the seal is correspondingly increased so that the projection of the solder mark is located within the projection range of the hollow area of ​​the seal, which helps to increase the heat transfer path between the solder mark and the seal, thereby improving the problem of seal ring burn failure.

[0044] A third aspect of this application provides an electrical device including the battery device described above, the battery device being used to provide electrical energy.

[0045] The battery device of the electrical device provided in this application embodiment includes a battery cell, which includes a casing, electrode terminals, an electrical connection structure, and a seal. The electrode terminals are electrically connected to the tabs of the electrode assembly of the battery cell via an adapter, and the electrical connection structure is welded to the electrode terminals to form a solder mark. The seal is sleeved around the electrode terminals and sandwiched between the electrode terminals and the casing to achieve sealing and insulation between the electrode terminals and the casing. By setting the equivalent diameter of the solder mark projection on the first plane to be greater than or equal to 3.5 mm, the solder mark area can be increased, thereby improving the current carrying capacity and power of the battery cell. At the same time, the size of the seal is correspondingly increased so that the projection of the solder mark is located within the projection range of the hollow area of ​​the seal, which helps to increase the heat transfer path between the solder mark and the seal, thereby improving the problem of seal ring burn failure. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0047] Figure 2 An exploded view of a battery device provided in an embodiment of this application;

[0048] Figure 3 A cross-sectional view of a battery cell provided in the first embodiment of this application;

[0049] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0050] Figure 5 for Figure 3 Enlarged view of point B in the middle.

[0051] Explanation of reference numerals in the attached figures

[0052] 10. Battery cell; 11. Adapter plate; 12. Housing; 121. Shell; 122. End cap; 13. Electrode terminal; 131. Connecting body; 132. Connecting flange; 133. Groove; 14. Electrode assembly; 15. Seal; 151. Sealing body; 152. Sealing flange; 16. Weld mark; 17. Upper plastic; 18. Lower plastic; 21. Housing; 211. First housing; 212. Second housing; 100. Battery assembly; 200. Controller; 300. Motor; 1000. Vehicle. Detailed Implementation

[0053] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0054] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0055] With the development of clean energy, more and more devices are using electricity as their driving force, leading to the rapid development of power batteries, such as lithium-ion batteries, which can store a large amount of electrical energy and can be repeatedly charged and discharged. These power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields.

[0056] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0057] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0058] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. 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. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0059] 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.

[0060] 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.

[0061] 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, 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.).

[0062] As an example, the positive electrode active material 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 battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may 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 oxide may 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 0.3 O2 (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.

[0063] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0064] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0065] 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, titanium, or silver. The composite current collector may include a polymer material substrate 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.).

[0066] 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.

[0067] 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.

[0068] As an example, the negative electrode active material 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 for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0069] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0070] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0071] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0072] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0073] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0074] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0075] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0077] Liquid electrolytes include electrolyte salts and solvents.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0082] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0083] 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.

[0084] 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-sulfur, sulfosilium-germanium), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0085] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0086] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0087] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0088] In some implementations, the electrode assembly is a stacked structure.

[0089] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0090] 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.

[0091] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0092] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0093] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0094] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0095] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0096] 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.

[0097] As an example, the 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. This application does not have any particular limitations.

[0098] In new energy vehicles equipped with battery devices, the battery device can provide all or part of the power. The tabs of the battery cells are typically connected to the electrode terminals via adapter plates. The tabs of the battery cells are usually welded to the adapter plates, or the tabs of the battery cells are directly welded to the electrode terminals. The weld marks formed by welding affect the current-carrying capacity of the battery cells. To improve the current-carrying capacity, the weld mark area needs to be increased. In related technologies, increasing the weld mark area leads to increased heat generated during welding or use. Simultaneously, the heat transfer path between the weld mark and the seal is shortened, potentially causing the seal ring to burn and fail.

[0099] In view of this, in order to improve the problem of sealing ring burn failure after increasing the solder area, this application provides a battery cell. The battery cell includes a casing, electrode terminals, an electrical connection structure, and a seal. The casing has a mounting hole on at least one side along a first direction. The electrode terminals pass through the mounting hole. The electrical connection structure is disposed inside the casing and is welded to the electrode terminals to form a solder mark. The equivalent diameter of the projection of the solder mark onto a first plane is L1, where L1 is greater than or equal to 3.5 mm, and the first plane is perpendicular to the first direction. The seal is sleeved around the electrode terminals and sandwiched between the electrode terminals and the casing. The projection of the solder mark onto the first plane is within the projection range of the hollow region of the seal.

[0100] The battery cell provided in this application includes a casing, electrode terminals, an electrical connection structure, and a seal. The electrode terminals are electrically connected to the tabs of the electrode assembly of the battery cell via an adapter, and the electrical connection structure is welded to the electrode terminals to form a solder mark. The seal is sleeved around the periphery of the electrode terminals and sandwiched between the electrode terminals and the casing to achieve sealing and insulation between the electrode terminals and the casing. By setting the equivalent diameter of the solder mark projection on the first plane to be greater than or equal to 3.5 mm, the solder mark area can be increased, thereby improving the current carrying capacity and power of the battery cell. At the same time, the size of the seal is correspondingly increased so that the equivalent diameter of the solder mark is less than or equal to the inner diameter of the seal, which helps to increase the heat transfer path between the solder mark and the seal, thereby improving the problem of seal ring burn failure.

[0101] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0102] Please refer to Figure 1 The vehicle 1000 may contain a controller 200, a motor 300, and a battery device 100. The controller 200 controls the battery device 100 to supply power to the motor 300. For example, the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, it can serve as the operating power source for the vehicle 1000's electrical system, such as for the power requirements of starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000 but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle 1000.

[0103] This application provides an energy storage device, including multiple battery cells 10 or battery devices 100 according to any embodiment of this application, wherein the battery cells 10 or battery devices 100 are used to store or provide electrical energy.

[0104] 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, an energy storage device 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 energy storage devices.

[0105] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0106] Please see Figures 3 to 5 This application provides a battery cell 10. The battery cell 10 includes a housing 12, electrode terminals 13, an electrical connection structure, and a sealing element 15. The housing 12 has a mounting hole on at least one side along a first direction. The electrode terminals 13 pass through the mounting hole. The electrical connection structure is disposed within the housing 12, and an adapter piece 11 is welded to the electrode terminals 13, forming a solder mark 16. The equivalent diameter of the projection of the solder mark 16 onto a first plane is L1, where L1 is greater than or equal to 3.5 mm, and the first plane is perpendicular to the first direction. The sealing element 15 is sleeved around the periphery of the electrode terminals 13 and sandwiched between the electrode terminals 13 and the housing 12. Projected onto the first plane, the projection of the solder mark 16 lies within the projection range of the hollow region of the sealing element 15.

[0107] For example, the first direction can be the height direction of the battery cell 10, or it can be a direction perpendicular to the height direction of the battery cell 10. This application embodiment uses the height direction of the battery cell 10 as an example for description.

[0108] For example, the electrical connection structure is connected to the electrode terminal 13 by laser welding.

[0109] In some embodiments, the battery cell 10 includes an electrode assembly 14, which includes tabs that can conduct current from the electrode assembly 14. The tabs include a positive tab and a negative tab.

[0110] Electrode terminal 13 is electrically connected to electrode tab. Electrode terminal 13 can be directly connected to electrode tab, or it can be indirectly connected to electrode tab through current collector components such as adapter plate 11.

[0111] Exemplarily, the battery cell 10 includes an adapter piece 11, which is electrically connected to the electrode tab. The electrode terminal 13 is electrically connected to the electrode tab via the adapter piece 11. The electrode terminal 13 is soldered to the adapter piece 11, forming a solder mark 16. This application uses an electrical connection structure...

[0112] For example, the tab is constructed as an electrical connection structure, with the electrode terminal 13 welded to the tab to form a solder mark 16.

[0113] In some embodiments, the housing 12 includes an end cap 122 and a housing 121, the housing 121 having an opening, and the end cap 122 covering the opening. The housing 121 may have one or more openings. The end cap 122 may also have one or more.

[0114] In some embodiments, at least one electrode terminal 13 is provided on the housing 12, and the electrode terminal 13 is electrically connected to the electrode tab via an adapter piece 11. The electrode terminal 13 may be provided on the end cap 122 or on the housing 121.

[0115] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell 10 assemblies for providing voltage and capacity. A battery cell 10 assembly may include multiple battery cells 10, which are connected in series, parallel, or mixed connections via busbars.

[0116] In some embodiments, the battery cell assembly is typically formed by arranging multiple battery cells 10.

[0117] As an example, the battery cell 10 assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 10 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 10 together with cable ties.

[0118] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 21 and one or more battery cell 10 assemblies housed in the housing 21.

[0119] As an example, the battery cell 10 assembly can be a battery module, and the battery cell 10 assembly can be housed in the housing 21 by fixing the battery module in the housing 21.

[0120] As an example, the battery cell 10 assembly can also be housed in the housing 21 by directly fixing multiple battery cells 10 to the housing 21.

[0121] For example, please refer to Figure 2 The housing 21 may include a first housing 211 and a second housing 212. The first housing 211 and the second housing 212 are fastened together to form a closed space inside the housing 21 to house the battery cells 10. Here, "closed" refers to covering or closing, which can be sealed or unsealed. The first housing 211 may be a top cover or a bottom plate.

[0122] As an example, the housing 21 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 21 forms an enclosed space to accommodate the battery cells 10 assembly.

[0123] In some embodiments, the housing 21 may be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 21 may be at least a portion of the floor of the vehicle 1000, or a portion of the housing 21 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1000.

[0124] As an example, seal 15 is, for example, a sealing ring.

[0125] The sealing element 15 is sleeved around the electrode terminal 13 and sandwiched between the electrode terminal 13 and the housing 12 to achieve sealing and insulation between the electrode terminal 13 and the housing 12.

[0126] For example, please refer to Figure 4 and Figure 5 The battery cell 10 includes an upper plastic 17, which is disposed on the outside of the housing 12 and located between the electrode terminal 13 and the housing 12, for the purpose of achieving insulation between the electrode terminal 13 and the housing 12.

[0127] As an example, the battery cell 10 includes a lower plastic 18 disposed inside the housing 12 and located between the electrode terminal 13 and the housing 12, for achieving insulation between the electrode terminal 13 and the housing 12; in addition, the lower plastic 18 is also located between the electrode terminal 13 and the adapter piece 11, for achieving insulation between the electrode terminal 13 and the adapter piece 11.

[0128] The equivalent diameter of the projection of solder mark 16 onto the first plane is L1. Here, the equivalent diameter refers to the diameter of a circle when the area of ​​a non-circular object is equal to the area of ​​a circle.

[0129] Here, the first direction, namely the height direction of the battery device, is used... Figure 3 X in the figure represents...

[0130] Projected onto the first plane, the equivalent diameter of the projected hollow region of the seal 15 is L2.

[0131] Here, the specific cross-sectional shape of the hollow region of the seal 15 in the section perpendicular to the first direction is not limited; for example, it can be circular, elliptical, polygonal, or other shapes. This embodiment of the application uses a circular cross-sectional shape for the hollow region of the seal 15 as an example for description.

[0132] The housing 12 has a mounting hole on at least one side along the first direction. This can mean that the housing 12 has a mounting hole on one side along the first direction, or that the housing 12 has mounting holes on both sides along the first direction.

[0133] Of course, in other embodiments, the housing 12 may also have mounting holes on sides other than the first direction. Here, L1 is greater than or equal to 3.5 mm and is projected on the first plane. The projection of the solder mark 16 is located within the projection range of the hollow region of the seal 15. That is, the equivalent diameter of the projection of the solder mark 16 on the first plane is greater than or equal to 3.5 mm and less than or equal to the inner diameter of the seal 15, which increases the area of ​​the solder mark 16. This is beneficial to improving the current carrying capacity and power of the battery cell 10.

[0134] It should be noted that if the inner diameter of the seal 15 increases, the outer diameter of the corresponding electrode terminal 13 will also increase, so that the seal 15 can be sleeved on the periphery of the electrode terminal 13.

[0135] Here, when projected onto the first plane, the projection of the weld mark 16 is located within the projection range of the hollow region of the seal 15. That is, L1 is less than or equal to L2. The ratio of the equivalent diameter of the projection of the weld mark 16 onto the first plane to the inner diameter of the seal 15 is greater than 0 and less than or equal to 1. In other words, the equivalent diameter of the projection of the weld mark 16 onto the first plane is less than or equal to the inner diameter of the seal 15.

[0136] L1 / L2 can be any one of the following values: 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or any value between the two.

[0137] The battery cell 10 provided in this embodiment includes a housing 12, electrode terminals 13, an electrical connection structure, and a sealing element 15. The electrode terminals 13 are electrically connected to the tabs of the electrode assembly 14 of the battery cell 10 via an adapter, and the electrical connection structure is welded to the electrode terminals 13 to form a solder mark 16. The sealing element 15 is sleeved around the periphery of the electrode terminals 13 and sandwiched between the electrode terminals 13 and the housing 12 to achieve sealing and insulation between the electrode terminals 13 and the housing 12. By setting the equivalent diameter of the projection of the solder mark 16 on the first plane to be greater than or equal to 3.5 mm, the area of ​​the solder mark 16 can be increased, thereby improving the current carrying capacity and power of the battery cell 10. At the same time, correspondingly increasing the size of the sealing element 15 and projecting it on the first plane so that the projection of the solder mark 16 is within the projection range of the hollow area of ​​the sealing element 15, is beneficial to increasing the heat transfer path between the solder mark 16 and the sealing element 15, thereby improving the problem of sealing ring burn failure. In summary, the battery cell 10 provided in this application improves the current carrying capacity and power of the battery cell 10 by simultaneously increasing the area of ​​the solder 16 and the inner diameter of the seal 15, while also increasing the heat transfer path between the solder 16 and the seal 15, thereby improving the problem of seal ring burn failure.

[0138] In some embodiments, please refer to Figure 5 L1 is greater than or equal to half of L2.

[0139] In other words, the ratio of the equivalent diameter of the projection of the weld mark 16 onto the first plane to the inner diameter of the seal 15 is greater than or equal to 0.5 and less than or equal to 1.

[0140] For example, L1 / L2 can be a point value of any one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or 1, or a point value between any two of them.

[0141] In this embodiment, by setting the equivalent diameter of the projection of the solder mark 16 on the first plane to be greater than or equal to half the inner diameter of the seal 15, the current carrying capacity and power of the battery cell 10 are further improved, while the heat transfer path between the solder mark 16 and the seal 15 is further increased, thereby further improving the problem of seal ring burn failure.

[0142] In some embodiments, please continue reading Figures 4 to 5 L1 is greater than or equal to 7 mm and less than or equal to 12 mm.

[0143] In other words, the equivalent diameter of the projection of solder mark 16 on the first plane is greater than or equal to 7 mm and less than or equal to 12 mm.

[0144] For example, the equivalent diameter of the projection of the solder mark 16 on the first plane can be any one of 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm or any combination thereof.

[0145] In this embodiment, by setting the equivalent diameter of the projection of the solder mark 16 on the first plane to be greater than or equal to 7 mm and less than or equal to 12 mm, the solder mark 16 with an equivalent diameter within this range can improve the current carrying capacity and power of the battery cell 10, while also increasing the heat transfer path between the solder mark 16 and the seal 15, thereby improving the problem of seal ring burn failure and improving the performance of the battery cell 10.

[0146] In some embodiments, please refer to Figures 4 to 5 In a direction perpendicular to the first direction, the minimum gap between the weld mark 16 and the sidewall of the hollow region of the seal 15 is L3, where L3 is greater than or equal to 0 and less than or equal to half of L2.

[0147] For example, the first direction is the height direction of the battery cell 10, and the direction perpendicular to the first direction is the radial direction of the seal 15.

[0148] Here, L3 is greater than or equal to 0 and less than or equal to half of L2. That is to say, the minimum gap between the weld mark 16 and the side wall of the hollow region of the seal 15 is greater than or equal to 0 and less than or equal to half of the inner diameter of the seal 15. In this way, the projection of the weld mark 16 on the first plane and the projection of the seal 15 on the first plane do not overlap, which is beneficial to increasing the heat transfer path between the weld mark 16 and the seal 15.

[0149] In some embodiments, please refer to Figures 4 to 5 L3 is greater than or equal to one-sixth of L2 and less than or equal to one-quarter of L2.

[0150] Here, L3 is greater than or equal to one-sixth of L2 and less than or equal to one-quarter of L2. That is to say, the minimum gap between the solder mark 16 and the sidewall of the hollow region of the seal 15 is greater than or equal to one-sixth of the equivalent diameter of the projection of the hollow region of the seal 15 and less than or equal to one-quarter of the equivalent diameter of the projection of the hollow region of the seal 15. In this way, the projection of the solder mark 16 on the first plane and the projection of the seal 15 on the first plane will not overlap, which is beneficial to further increase the heat transfer path between the solder mark 16 and the seal 15.

[0151] In some embodiments, please refer to Figures 4 to 5 L2 is greater than 0 mm and less than or equal to 50 mm.

[0152] Here, L2 is greater than 0 mm and less than or equal to 50 mm. That is, the inner diameter of the seal 15 is greater than or equal to the equivalent diameter of the projection of the solder mark 16 on the first plane and less than or equal to 50 mm. In other words, by increasing the size of the seal 15, the heat transfer path between the solder mark 16 and the seal 15 is increased.

[0153] In this embodiment, by setting the inner diameter of the seal 15 to be greater than or equal to the equivalent diameter of the projection of the solder mark 16 on the first plane and less than or equal to 50 mm, the inner diameter of the seal 15 within this range is appropriate, which can increase the heat transfer path between the solder mark 16 and the seal 15. Even if the area of ​​the solder mark 16 is increased to improve the current carrying capacity and power of the battery cell 10, there can still be a sufficient heat transfer path between the solder mark 16 and the seal 15, thereby improving the problem of seal ring burn failure and improving the performance of the battery cell 10.

[0154] In some embodiments, please continue reading Figures 4 to 5 L2 is greater than or equal to 13mm and less than or equal to 16mm.

[0155] In other words, the inner diameter of seal 15 is greater than or equal to 13mm and less than or equal to 16mm.

[0156] For example, the inner diameter of the seal 15 can be any one of 13mm, 13.5mm, 13.8mm, 14mm, 14.2mm, 14.5mm, 15mm, 15.5mm, 15.8mm, and 16mm, or any combination thereof.

[0157] In this embodiment, by setting the inner diameter of the seal 15 to be greater than or equal to 13 mm and less than or equal to 16 mm, the appropriate inner diameter of the seal 15 within this range can further increase the heat transfer path between the solder mark 16 and the seal 15. Even by increasing the area of ​​the solder mark 16 to improve the current carrying capacity and power of the battery cell 10, there can still be a sufficient heat transfer path between the solder mark 16 and the seal 15, thereby further improving the problem of seal ring burn failure and improving the performance of the battery cell 10.

[0158] In some embodiments, please continue reading Figures 4 to 5 The electrode terminal 13 includes a connecting body 131 and a connecting flange 132 connected to one end of the connecting body 131. The connecting body 131 passes through a mounting hole, and the connecting flange 132 is disposed within the housing 12. The electrical connection structure is welded to the side of the connecting flange 132 opposite to the connecting body 131. In a direction perpendicular to the first direction, the size of the connecting flange 132 is greater than or equal to the size of the connecting body 131.

[0159] Here, the connecting body 131 and the connecting flange 132 can be an integral structure or a separate structure.

[0160] The connecting flange 132 is disposed inside the housing 12 for electrical connection with the electrical connection structure and can prevent the electrode terminal 13 from coming out of the housing 12 from the mounting hole.

[0161] In this embodiment, by setting the electrode terminal 13 to include a connecting body 131 and a connecting flange 132, and setting the size of the connecting flange 132 to be greater than or equal to the size of the connecting body 131, it is beneficial to prevent the electrode terminal 13 from coming out of the housing 12 from the mounting hole, and also facilitates the welding between the electrode terminal 13 and the electrical connection structure.

[0162] In some embodiments, please continue reading Figures 4 to 5 The sealing element 15 includes a sealing body 151 and a sealing flange 152 connected to one end of the sealing body 151. The sealing flange 152 is sandwiched between the connecting flange 132 and the outer shell 12. In a direction perpendicular to the first direction, the sealing body 151 is sandwiched between the connecting body 131 and the outer shell 12.

[0163] Here, the sealing body 151 and the sealing flange 152 can be an integral structure or a separate structure.

[0164] In a direction perpendicular to the first direction, the sealing body 151 is sandwiched between the connecting body 131 and the outer shell 12 to achieve sealing and insulation between the connecting body 131 and the outer shell 12. The sealing flange 152 is sandwiched between the connecting flange 132 and the outer shell 12 to achieve sealing and insulation between the connecting flange 132 and the outer shell 12.

[0165] In this embodiment, by configuring the seal 15 to include a sealing body 151 and a sealing flange 152, it is further beneficial to achieve sealing and insulation between the electrode terminal 13 and the housing 12, and to facilitate the assembly of the seal 15.

[0166] In some embodiments, please continue reading Figures 4 to 5 The connecting flange 132 has a dimension of L4 in the first direction, which is greater than or equal to 2.5 mm and less than or equal to 6 mm.

[0167] That is, the dimension of the connecting flange 132 in the first direction is greater than or equal to 2.5 mm and less than or equal to 6 mm.

[0168] Here, the larger the dimension of the connecting flange 132 in the first direction, the greater the heat transfer path between the solder mark 16 and the seal 15.

[0169] For example, the dimension of the connecting flange 132 in the first direction can be a point value of any one of 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, and 6mm, or a point value between any two of them.

[0170] In this embodiment, by setting the dimension of the connecting flange 132 in the first direction to be greater than or equal to 2.5 mm and less than or equal to 6 mm, the dimension of the connecting flange 132 within this range is appropriate. This increases the heat transfer path between the solder mark 16 and the seal 15, improves the problem of seal ring burn failure, and also helps to make the battery cell 10 have better structural compactness, thereby improving the performance of the battery cell 10.

[0171] In some embodiments, please continue reading Figures 4 to 5 The minimum gap between the weld mark 16 and the sidewall of the hollow area of ​​the seal 15 is L3, and the dimension of the connecting flange 132 in the first direction is L4. L4 / L3 is greater than or equal to 0.1 and less than or equal to 10.

[0172] That is, the ratio of the dimension of the connecting flange 132 in the first direction to the minimum gap between the weld 16 and the sidewall of the hollow region of the seal 15 is greater than or equal to 0.1 and less than or equal to 10.

[0173] For example, L4 / L3 can be any one of the following point values: 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, or any point value between the two.

[0174] Here, the larger the ratio of the dimension of the connecting flange 132 in the first direction to the minimum gap between the solder mark 16 and the sidewall of the hollow region of the seal 15, the larger the heat transfer path between the solder mark 16 and the seal 15 in the first direction.

[0175] In this embodiment, by setting the ratio of the dimension of the connecting flange 132 in the first direction to the minimum gap between the solder mark 16 and the sidewall of the hollow region of the seal 15 to be greater than 0.1 and less than or equal to 10, the heat transfer path between the solder mark 16 and the seal 15 in the first direction is increased, thereby improving the problem of seal ring burn failure. At the same time, it also helps to make the battery cell 10 have better structural compactness, thereby improving the performance of the battery cell 10.

[0176] In some embodiments, please continue reading Figures 4 to 5 The L4 / L3 ratio is greater than or equal to 0.4 and less than or equal to 0.8.

[0177] That is, the ratio of the dimension of the connecting flange 132 in the first direction to the gap between the weld 16 and the inner diameter of the seal 15 is greater than or equal to 0.4 and less than or equal to 0.8.

[0178] For example, L4 / L3 can be a point value of any one of 0.4, 0.42, 0.45, 0.48, 0.5, 0.55, 0.58, 0.6, 0.63, 0.65, 0.67, 0.7, 0.75, 0.8 or a point value between any two.

[0179] In this embodiment, by setting the ratio of the dimension of the connecting flange 132 in the first direction to the minimum gap between the solder mark 16 and the sidewall of the hollow region of the seal 15 to be greater than 0.4 and less than or equal to 0.8, the heat transfer path between the solder mark 16 and the seal 15 in the first direction is further increased, thereby further improving the problem of seal ring burn failure. At the same time, it is also beneficial to further improve the structural compactness of the battery cell 10, thereby improving the performance of the battery cell 10.

[0180] In some embodiments, please continue reading Figures 4 to 5 The dimension of the connecting flange 132 in the first direction is L4, and the penetration depth of the solder 16 is L5, where L5 is greater than or equal to 10μm and less than or equal to L4.

[0181] In other words, the penetration depth of the solder mark 16 is greater than or equal to 10 μm and less than or equal to the dimension of the connecting flange 132 in the first direction.

[0182] It should be noted that weld penetration refers to the distance between the deepest point of the molten portion of the base metal and the surface of the base metal. That is, in a butt weld, the distance from the end face of the connecting flange 132 to the deepest point of the molten zone.

[0183] In this embodiment, by setting the penetration depth of the solder mark 16 to be greater than or equal to 10 μm and less than or equal to the dimension of the connecting flange 132 in the first direction, the penetration depth of the solder mark 16 meets the requirements, which is beneficial to improving the reliability of the welding connection between the electrical connection structure and the electrode terminal 13.

[0184] In some embodiments, please continue reading Figures 4 to 5 L5 is greater than or equal to 400 μm and less than or equal to L.

[0185] In other words, the penetration depth of the solder mark 16 is greater than or equal to 400 μm and less than or equal to the dimension of the connecting flange 132 in the height direction of the battery cell 10.

[0186] In this embodiment, by setting the penetration depth of the solder mark 16 to be greater than or equal to 400 μm and less than or equal to the dimension of the connecting flange 132 in the first direction, the penetration depth of the solder mark 16 meets the requirements, which is beneficial to further improve the reliability of the welding connection between the electrical connection structure and the electrode terminal 13.

[0187] In some embodiments, please continue reading Figures 4 to 5 The edge of the connecting flange 132 facing the electrical connection structure is thinned to form a groove 133, and the groove 133 is spaced apart from the electrical connection structure.

[0188] The edge of the connecting flange 132 is thinned to form a groove 133, that is, the central region of the connecting flange 132 protrudes from the edge of the connecting flange 132. In this way, the central region of the connecting flange 132 can better contact and weld with the electrical connection structure.

[0189] For example, the electrical connection structure and the central region of the connection flange 132 also form a recessed region.

[0190] In this embodiment, by thinning the edge of the connecting flange 132 facing the electrical connection structure to form a groove 133, and the groove 133 being spaced apart from the electrical connection structure, it is beneficial to reduce the heat transferred to the seal 15, thereby improving the problem of seal ring burn failure.

[0191] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A battery cell, characterized in that, include: The housing has mounting holes on at least one side along a first direction; Electrode terminals, wherein the electrode terminals are disposed in the mounting holes; An electrical connection structure is disposed within the housing. The electrical connection structure is welded to the electrode terminal to form a solder mark. The equivalent diameter of the projection of the solder mark on the first plane is L1, where L1 is greater than or equal to 3.5 mm. The first plane is perpendicular to the first direction. A sealing element is fitted around the periphery of the electrode terminal and sandwiched between the electrode terminal and the housing. When projected onto the first plane, the projection of the solder mark is located within the projection range of the hollow region of the sealing element.

2. The battery cell according to claim 1, characterized in that, Projected onto the first plane, the equivalent diameter of the projection of the hollow region of the seal is L2; ​​in a direction perpendicular to the first direction, the minimum gap between the weld and the sidewall of the hollow region of the seal is L3, where L3 is greater than or equal to 0 and less than or equal to half of L2.

3. The battery cell according to claim 2, characterized in that, L3 is greater than or equal to one-sixth of L2 and less than or equal to one-quarter of L2.

4. The battery cell according to claim 1, characterized in that, Projected onto the first plane, the equivalent diameter of the projected hollow region of the seal is L2; ​​L1 is greater than or equal to half of L2.

5. The battery cell according to claim 1, characterized in that, L1 is greater than or equal to 7 mm and less than or equal to 12 mm.

6. The battery cell according to claim 1, characterized in that, The equivalent diameter of the projection of the hollow region of the seal onto the first plane is L2; ​​L2 is greater than 0 mm and less than or equal to 50 mm.

7. The battery cell according to claim 6, characterized in that, Projected onto the first plane, the equivalent diameter of the projected hollow region of the seal is L2; ​​L2 is greater than or equal to 13 mm and less than or equal to 16 mm.

8. The battery cell according to claim 1, characterized in that, The electrode terminal includes a connecting body and a connecting flange connected to one end of the connecting body. The connecting body passes through the mounting hole, and the connecting flange is disposed inside the housing. The electrical connection structure is welded to the side of the connecting flange opposite to the connecting body. In a direction perpendicular to the first direction, the size of the connecting flange is greater than or equal to the size of the connecting body.

9. The battery cell according to claim 8, characterized in that, The sealing element includes a sealing body and a sealing flange connected to one end of the sealing body. The sealing flange is sandwiched between the connecting flange and the outer shell. In a direction perpendicular to the first direction, the sealing body is sandwiched between the connecting body and the outer shell.

10. The battery cell according to claim 8, characterized in that, The dimension of the connecting flange in the first direction is L4, where L4 is greater than or equal to 2.5 mm and less than or equal to 6 mm.

11. The battery cell according to claim 10, characterized in that, The minimum gap between the weld mark and the sidewall of the hollow region of the seal is L3, and the dimension of the connecting flange in the first direction is L4. L4 / L3 is greater than or equal to 0.1 and less than or equal to 10.

12. The battery cell according to claim 11, characterized in that, The L4 / L3 ratio is greater than or equal to 0.4 and less than or equal to 0.

8.

13. The battery cell according to claim 8, characterized in that, The dimension of the connecting flange in the first direction is L4, and the penetration depth of the solder is L5, where L5 is greater than or equal to 10 μm and less than or equal to L4.

14. The battery cell according to claim 13, characterized in that, L5 is greater than or equal to 400 μm and less than or equal to L4.

15. The battery cell according to claim 8, characterized in that, The edge of the connecting flange facing the electrical connection structure is thinned to form a groove, and the groove is spaced apart from the electrical connection structure.

16. The battery cell according to any one of claims 1-15, characterized in that, The battery cell includes an electrode assembly, and the electrode assembly includes tabs; The battery cell includes an adapter plate, which, together with the electrode tab, forms the electrical connection structure. The electrode terminals are electrically connected to the electrode tab via the adapter plate, and the electrode terminals are soldered to the adapter plate to form the solder mark; or... The tab is constructed as the electrical connection structure, and the electrode terminal is welded to the tab to form the solder mark.

17. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1-16.

18. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-16 or a battery device according to claim 17, wherein the battery cell or the battery device is used to store or provide electrical energy.

19. An energy storage device, characterized in that, Includes a battery cell according to any one of claims 1-16 or a battery device according to claim 17, wherein the battery cell or the battery device is used to store or provide electrical energy.

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