Battery monomer, battery device, energy storage device and power utilization device

Abstract

The utility model discloses a battery monomer, a battery device, an energy storage device and a power utilization device, the battery monomer comprises a shell and at least one electrode assembly arranged in an accommodating cavity of the shell, the shell comprises a shell and a body cover, the accommodating cavity is formed in the shell, an opening is formed in one end of the shell in a first direction, and the opening is communicated with the accommodating cavity; the end cover seals the opening and is in laser welding with the shell; at least part of the end cover stretches into the shell through the opening and is in clearance fit with the shell, one of the outer circumferential face of the part, stretching into the shell, of the end cover and the inner side face of the shell is provided with a protruding structure, and the other one of the outer circumferential face of the part, stretching into the shell, of the end cover and the inner side face of the shell is provided with a concave structure matched with the protruding structure. The battery monomer, the battery device, the energy storage device and the power utilization device provided by the utility model have high capacitance.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to battery cells, battery devices, energy storage devices, and power consumption devices. Background Technology

[0002] The application of new energy batteries in daily life and industry is becoming increasingly widespread. For example, new energy vehicles equipped with batteries are already widely used, and batteries are also increasingly being applied in energy storage. In new energy vehicles equipped with batteries, the batteries can provide all or part of the power. In the field of energy storage, batteries can be installed in energy storage boxes or directly on the user side.

[0003] With the continuous development of battery technology, the industry is constantly putting forward higher requirements for battery capacity. Utility Model Content

[0004] To address the aforementioned technical problems, this application provides a battery cell, battery device, energy storage device, and power consumption device that can increase the capacitance.

[0005] This application is achieved through the following technical solution.

[0006] A first aspect of this application provides a battery cell, including a housing and at least one electrode assembly disposed within a receiving cavity of the housing. The housing includes: a shell having the receiving cavity formed therein, an opening formed at one end of the shell in a first direction, the opening communicating with the receiving cavity; and an end cap closing the opening and laser-welded to the shell. At least a portion of the end cap extends into the shell through the opening and is clearance-fitted with the shell. Of the portion of the end cap extending into the shell, one of the outer peripheral surface and the inner surface of the shell has a protruding structure, and the other has a recessed structure that mates with the protruding structure.

[0007] In the technical solution provided in this application, the end cap and the housing have a gap fit, which reduces the squeezing effect of the end cap on the housing opening and reduces the probability of the housing opening expanding outwards. This results in better dimensional consistency between the housing at the opening and the parts away from the opening, thereby increasing the number of battery cells that can be accommodated within a certain size of space, and thus increasing the capacity. In addition, the end cap and the housing are fitted together by protruding and recessed structures, so that the gap between the end cap and the housing does not extend in a straight line along the first direction, but has a bent portion at the position of the protruding and recessed structures. Since laser transmission is in a straight line, during laser welding of the end cap and the housing in the embodiments of this application, the laser is less likely to enter the accommodating cavity through the gap between the end cap and the housing, making it less likely for the laser to damage the electrode components and electrolyte, thereby improving the capacity of the battery cells.

[0008] In some embodiments, the protruding structure is an annular structure extending circumferentially along the end cap; the recessed structure is an annular structure extending circumferentially along the end cap.

[0009] The end cap is welded to the shell in a ring along its outer periphery. This means that laser welding is required at all points on the outer periphery of the end cap. Therefore, both the protruding and recessed structures are designed as ring structures, so that there are bent portions in the ring gap between the end cap and the shell. This makes it difficult for the laser to enter the cavity at the welding position, and makes it less likely for the laser to damage the electrode components and electrolyte, thereby improving the capacity of the battery cell.

[0010] In some embodiments, the surface of the protruding structure includes a convex arcuate surface, the inner wall of the recessed structure includes a concave arcuate surface, and / or, the surface of the protruding structure includes at least one first plane, and the inner wall of the recessed structure includes at least one second plane.

[0011] By setting the protruding and recessed structures into various different shapes, it is possible to block the laser from entering the receiving cavity, and it also helps to improve assembly efficiency and the reliability of the connection between the end cap and the housing.

[0012] In some embodiments, the end cap surface facing the electrode assembly includes a first inner surface, and the end cap is formed with a first protrusion protruding toward the electrode assembly relative to the first inner surface. A raised structure or a recessed structure is formed on the side of the first protrusion facing the inner side of the housing, and the first protrusion is clearance-fitted with the housing.

[0013] Thus, the first protrusion is located near the outer peripheral edge of the end cap. The first protrusion protrudes towards the electrode assembly relative to the first inner surface, resulting in a relatively large dimension of the first protrusion along the first direction. This allows for the arrangement of raised or recessed structures, thereby achieving the function of blocking the laser from entering the receiving cavity. Furthermore, by providing the first protrusion, the strength of the end cap can be improved, reducing its resistance to deformation during processing and further enhancing the dimensional consistency of the battery cells.

[0014] In some embodiments, an adapter piece is provided between the end cap and the electrode assembly, and the adapter piece abuts against the first protrusion.

[0015] By abutting the first protrusion against the electrode assembly, the connection strength between the end cap and the adapter plate is improved, and the gap between the adapter plate and the electrode assembly is reduced, further enhancing the connection strength between them. Additionally, the weldable area between the end cap and the adapter plate is increased, improving the current-carrying capacity between them.

[0016] In some embodiments, the end cap is further formed with at least one second protrusion protruding toward the electrode assembly relative to the first inner surface, the second protrusion being located on the side of the first protrusion facing the center of the end cap, and each second protrusion abutting against the adapter piece.

[0017] By forming the second protrusion, the strength of the end cap is improved, which is beneficial for improving the dimensional consistency of the battery cells. Furthermore, the second protrusion abuts against the adapter plate, increasing the connection strength between the end cap and the adapter plate, and also helping to reduce the gap between the adapter plate and the electrode assembly, thus improving the connection strength between them. In addition, it increases the weldable area between the end cap and the adapter plate, enhancing the current-carrying capacity between them.

[0018] In some embodiments, the second protrusion is an annular structure with the center of the end cap as the center, or the second protrusion is a circular structure with the center of the end cap as the center.

[0019] Thus, the second protrusion abuts against the near-middle portion of the adapter piece, which helps to improve the connection strength between the adapter piece and the end cap and electrode assembly. In addition, it can increase the solderable area between the end cap and the adapter piece, thereby improving the current carrying capacity between the end cap and the adapter piece.

[0020] In some embodiments, the end cap has a first outer surface at a position corresponding to the first inner surface on the surface facing away from the electrode assembly, and a first recess is formed at a position corresponding to the first protrusion on the surface facing away from the electrode assembly. The first recess is recessed relative to the side of the first outer surface facing the electrode assembly.

[0021] Thus, by providing the first recess, the end cap gains a certain degree of elasticity, allowing it to release stress through deformation during installation. This reduces the compressive and frictional forces between the end cap and the housing during assembly, lowering the risk of housing deformation. Furthermore, the first recess reduces material usage, thus lowering material costs.

[0022] In some embodiments, a second recess is formed at a position corresponding to the second protrusion on the surface of the end cap facing away from the electrode assembly, and the second recess is recessed relative to the side of the first outer surface facing the electrode assembly.

[0023] Thus, by providing a second recess, the end cap gains a degree of elasticity, allowing it to release stress through deformation during installation. This reduces the compressive and frictional forces between the end cap and the housing during assembly, lowering the risk of housing deformation. Furthermore, the second recess reduces material usage, thus lowering material costs.

[0024] In some embodiments, a portion of the concave surface of the recessed structure blocks the side of the protruding structure facing away from the electrode assembly along the first direction.

[0025] The concave surface of the recessed structure blocks the side of the protruding structure facing away from the electrode assembly in the first direction, thus restricting the movement of the end cap facing away from the electrode assembly in the first direction, improving the limiting effect between the end cap and the housing, facilitating the welding operation of the end cap and the housing, and thereby improving the assembly efficiency of the two.

[0026] In some embodiments, the portion of the inner surface of the housing located on the side of the protrusion structure facing away from the electrode assembly along the first direction is laser-welded to the portion of the outer peripheral surface of the end cap located on the side of the protrusion structure facing away from the electrode assembly along the first direction.

[0027] In this way, the weld formed by welding the inner side of the housing to the outer peripheral surface of the end cap is located on the side of the raised structure facing away from the electrode assembly along the first direction. This not only makes the housing and the end cap welded together, but also further improves the connection strength between them by mutually limiting each other through the raised structure and the recessed structure.

[0028] In some embodiments, the outer peripheral edge of the end cap is formed with a flange, which overlaps the end face of the housing with an opening and is laser welded to the end face.

[0029] In this way, the flange is overlapped and welded with the end face of the casing with an opening, which improves the pressure resistance of the battery cell in the first direction and reduces the probability of damage to the battery cell.

[0030] In some embodiments, the housing has a recessed structure, one end of the concave surface of the recessed structure extends along a first direction and is connected to the end face of the housing with an opening.

[0031] This structure allows the end cap to extend into the housing without elastic deformation, making it easy to assemble the end cap with the housing and improving the efficiency of the assembly process.

[0032] In some embodiments, a portion of the concave surface of the recessed structure extending along a first direction is laser-welded to the convex structure.

[0033] In this way, laser welding of the end cap and the housing is achieved, which improves the reliability of the connection between the two and reduces the probability of the laser entering the cavity, making it less likely for the laser to damage the electrode components and electrolyte, thereby increasing the capacity of the battery cell.

[0034] In some embodiments, the difference between the diameter of the inner surface of the housing and the diameter of the outer circumferential surface of the end cap is in the range of 0 to 0.2 mm.

[0035] Thus, the aforementioned dimensional settings ensure a proper fit between the end cap and the casing, improving the dimensional consistency of the battery cells and facilitating an increase in capacity within a given space. Furthermore, these dimensional settings prevent the gap between the end cap and the casing from becoming too large, thus improving the quality of their sealing weld.

[0036] In some embodiments, the outer peripheral surface of the portion of the end cap extending into the housing is provided with a protruding structure, and the inner surface of the housing is provided with a recessed structure. The outer diameter of the end cap at the protruding structure is smaller than the inner diameter of the housing at the recessed structure; the outer diameter of the end cap at the protruding structure is not smaller than the diameter of the inner surface of the housing.

[0037] By setting the outer diameter of the end cap at the protruding structure to be smaller than the inner diameter of the housing at the recessed structure, a clearance fit is achieved between the protruding structure of the end cap and the recessed structure of the housing, reducing the possibility of the housing expanding outward and thus improving the capacity within a given space. Furthermore, by setting the outer diameter of the end cap at the protruding structure to be no less than the diameter of the inner surface of the housing, the gap formed between the protruding structure and the housing does not extend linearly along the first direction, reducing the probability of laser light entering the housing through the gap. This makes it less likely for the laser to damage the electrode components and electrolyte, thereby increasing the capacity of the individual battery cells.

[0038] In some embodiments, the difference between the inner diameter of the housing at the recessed structure and the outer diameter of the end cap at the raised structure is in the range of 0 to 0.3 mm.

[0039] Thus, by setting the aforementioned difference, the raised structure of the end cap and the recessed structure of the housing are fitted with a clearance, reducing the possibility of the housing expanding outward and facilitating an increase in capacitance within a given space. Furthermore, by setting the aforementioned difference, the clearance between the raised structure of the end cap and the recessed structure of the housing is appropriate, preventing the gap from being too large and affecting the reliability of the connection between the end cap and the housing.

[0040] In some embodiments, the difference between the outer diameter of the end cap at the protruding structure and the diameter of the inner surface of the housing is in the range of 0 to 0.3 mm.

[0041] Thus, by setting the aforementioned difference, the protruding structure extends at least partially into the recessed structure, further enhancing the effect of preventing the laser from entering the housing. Furthermore, by setting the aforementioned difference, the protruding structure will not extend too deeply into the recessed structure, thus preventing the housing from expanding outwards.

[0042] In some embodiments, the outer peripheral surface of the portion of the end cap extending into the housing has a recessed structure, and the inner surface of the housing has a protruding structure. The outer diameter of the end cap at the recessed structure is smaller than the inner diameter of the housing at the protruding structure; the diameter of the outer peripheral surface of the end cap is not smaller than the inner diameter of the housing at the protruding structure.

[0043] By setting the outer diameter of the end cap at the recessed structure to be smaller than the inner diameter of the housing at the protruding structure, a clearance fit is achieved between the protruding structure of the end cap and the recessed structure of the housing, reducing the possibility of the housing expanding outward and thus improving the capacity within a given space. Furthermore, by setting the diameter of the outer circumferential surface of the end cap to be no less than the inner diameter of the housing at the protruding structure, the gap formed between the protruding structure and the end cap does not extend linearly along the first direction, reducing the probability of laser light entering the housing through the gap. This makes it less likely for the laser to damage the electrode components and electrolyte, thereby increasing the capacity of the individual battery cells.

[0044] In some embodiments, the difference between the inner diameter of the housing at the protruding structure and the outer diameter of the end cap at the recessed structure is in the range of 0 to 0.3 mm.

[0045] Thus, by setting the aforementioned difference, the recessed structure of the end cap and the protruding structure of the housing are fitted with a clearance, reducing the possibility of the housing expanding outward and facilitating an increase in capacitance within a given accommodating space. Furthermore, by setting the aforementioned difference, the clearance between the recessed structure of the end cap and the protruding structure of the housing is appropriate, preventing the gap from being too large and affecting the reliability of the connection between the end cap and the housing.

[0046] In some embodiments, the difference between the diameter of the outer peripheral surface of the end cap and the inner diameter of the housing at the protrusion structure is in the range of 0 to 0.3 mm.

[0047] Thus, by setting the aforementioned difference, the protruding structure extends at least partially into the recessed structure, further enhancing the effect of preventing the laser from entering the housing. Furthermore, by setting the aforementioned difference, the protruding structure will not extend too deeply into the recessed structure, thus preventing the housing from expanding outwards.

[0048] In some embodiments, the surface of the end cap facing the electrode assembly is connected to the outer peripheral surface via a convex arcuate surface.

[0049] Thus, the convex arc surface design allows for a smooth transition between the end cap's surface facing the electrode assembly and the end cap's outer peripheral surface, serving as a guide and facilitating the smooth insertion of the end cap into the housing along the first direction. This improves assembly efficiency and reduces friction between the end cap and the housing, thus minimizing wear on the housing.

[0050] A second aspect of this application provides a battery device comprising a plurality of battery cells provided in the first aspect.

[0051] Because the battery cells provided in the first aspect have a high capacity and can accommodate a large number of battery cells within a certain size of space, the battery device including multiple battery cells provided in the first aspect has a large capacity.

[0052] A third aspect of this application provides an energy storage device, which includes a plurality of battery cells provided in the first aspect or a plurality of battery devices provided in the second aspect.

[0053] Since the battery cells provided by the first aspect have a high capacity and can accommodate a large number of battery cells within a certain size of space, and the battery device provided by the second aspect has a high capacity, the energy storage device including multiple battery cells provided by the first aspect or multiple battery devices provided by the second aspect has a large capacity.

[0054] A fourth aspect of this application provides an electrical device comprising a plurality of battery cells provided in the first aspect or a plurality of battery devices provided in the second aspect.

[0055] Since the battery cells provided by the first aspect have a large capacity and can accommodate a large number of battery cells within a certain size of space, and the battery device provided by the second aspect has a high capacity, the power-consuming device including multiple battery cells provided by the first aspect or multiple battery devices provided by the second aspect has a large capacity.

[0056] The beneficial effects of the embodiments disclosed herein include: this application provides a battery cell, battery device, energy storage device, and power consumption device that can increase the capacitance. Attached Figure Description

[0057] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. 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:

[0058] Figure 1 This is a schematic diagram of the structure of a vehicle according to one or more embodiments;

[0059] Figure 2 This is an exploded perspective view of a battery device according to one or more embodiments;

[0060] Figure 3 This is an exploded perspective view of a battery module according to one or more embodiments;

[0061] Figure 4 This is an exploded perspective view of a battery cell according to one or more embodiments;

[0062] Figure 5 A front view of a battery cell according to one or more embodiments;

[0063] Figure 6 for Figure 5 Sectional view at point AA;

[0064] Figure 7 for Figure 6 A magnified view of the first structure at point B in the middle section;

[0065] Figure 8 for Figure 6 A magnified view of the second structure at point B in the middle section;

[0066] Figure 9 for Figure 6A magnified view of the third structure at point B in the middle section;

[0067] Figure 10 for Figure 6 A magnified view of the fourth structure at point B in the middle section;

[0068] Figure 11 for Figure 10 A schematic diagram of the structure before welding (welds not shown);

[0069] Figure 12 for Figure 6 A magnified view of a section at point C;

[0070] Figure 13 for Figure 6 A schematic diagram of the fifth structure at point B before welding (weld not shown).

[0071] Explanation of reference numerals in the attached figures

[0072] 1000 Vehicle; 100 Battery Unit; 200 Controller; 300 Motor; 10 Housing; 101 First Housing; 102 Second Housing; 20 Battery Cell; 30 Battery Module; 1 Shell; 11 End Cap; 111 Protruding Structure; 1111 Convex Arc Surface; 1112 First Plane; 112 First Inner Surface; 113 First Protrusion; 114 Second Protrusion; 115 First Outer Surface; 116 First Recess; 117 Second Recess; 118 Flanged Edge; 119 Outer Peripheral Surface; 12 Housing; 121 Recessed Structure; 122 Inner Surface; 123 Annular Sidewall; 124 Bottom Wall; 13 Terminal Post; 131 Injection Hole; 2 Electrode Assembly; 21 Positive Electrode Tab; 22 Negative Electrode Tab; 3 Adapter Plate; 4 Sealing Pin. Detailed Implementation

[0073] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0075] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0076] In this document, the term "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 throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0077] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0078] In the description of the embodiments of this application, the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0079] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0080] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0081] The following is a detailed description of this application.

[0082] Currently, new energy batteries are being used more and more widely in daily life and industry. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of the application areas of power batteries, the market demand is also constantly increasing.

[0083] A larger battery capacity stores more electrical energy, enabling the device to operate for longer periods, thus significantly extending battery life. Furthermore, a larger capacity battery means fewer charging cycles, reducing the inconvenience of frequent charging for users and contributing to longer battery lifespan. Additionally, a larger capacity battery reduces the risk of device interruption due to low power, improving user experience and satisfaction. Therefore, increasing battery capacity is one of the key research topics in the industry.

[0084] The inventors of this application have discovered that currently, some battery cell end caps and housing openings are interference-fitted to meet the requirements of connection stability. However, due to this interference fit, the housing opening expands outward under the squeezing action of the end cap, resulting in poor dimensional consistency between the housing at the opening and the end furthest from the end cap. Consequently, the number of battery cells that can be accommodated within a given space is limited, leading to a smaller capacity. Furthermore, when the battery cell end cap and housing are connected by laser welding, the laser can easily penetrate the gap between the outer circumference of the end cap and the inner surface of the housing during the welding process, entering the battery cell's interior. This laser can damage the internal structure of the battery cell, such as the electrodes, separator, or electrolyte, thereby reducing the battery cell's capacity.

[0085] The inventors of this application discovered through research that changing the interference fit between the end cap and the housing opening to a clearance fit reduces the squeezing effect of the end cap on the housing, improves the dimensional consistency of the battery cells, and thus increases the number of battery cells that can be accommodated within a given space, thereby increasing the capacity. Furthermore, the protrusions and grooves between the end cap and the housing create a gap that is not linear but has bends at the points where the protrusions and grooves meet. Since laser transmission is linear, during laser welding of the end cap and housing, the laser is less likely to penetrate the housing through the gap, thus reducing the risk of damage to the electrode components and electrolyte, thereby increasing the capacity of the battery cells.

[0086] Based on this design concept, the inventors of this application have designed a battery cell, which includes a housing and at least one electrode assembly disposed in a cavity within the housing. The housing includes a shell and an end cap. The shell forms a cavity, and an opening is formed at one end of the shell in a first direction, which communicates with the cavity. The end cap closes the opening and is laser-welded to the shell. At least a portion of the end cap extends into the shell through the opening and is clearance-fitted with the shell. Of the outer peripheral surface of the portion of the end cap extending into the shell and the inner surface of the shell, one is provided with a protruding structure, and the other is provided with a recessed structure that mates with the protruding structure.

[0087] In this design, the end cap and housing have a gap fit, reducing the squeezing effect of the end cap on the housing opening and ensuring better dimensional consistency between the opening and the area away from the opening. This allows for a greater number of battery cells to be accommodated within a given space, thus increasing the battery capacity. Furthermore, the outer circumference of the end cap and the inner surface of the housing are fitted together by protruding and recessed structures. This means the gap between the end cap and housing does not extend linearly along the first direction, but rather has a bend at the point where the protruding and recessed structures meet. Since laser transmission is linear, during laser welding of the end cap and housing in this design, the laser is less likely to penetrate the gap between the end cap and housing into the cavity, minimizing damage to the electrode components and electrolyte, thereby improving the battery cell capacity.

[0088] The battery cells provided in this application embodiment can be used, but are not limited to, in battery devices. A battery device may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0089] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0090] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0091] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0092] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0093] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0094] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0095] 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.

[0096] 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.

[0097] As an example, the battery cell can be a cylindrical battery, a prismatic battery, a pouch battery, or a battery of other shapes. Prismatic batteries include square-shell batteries, blade-shaped batteries, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0098] A single battery cell includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During the charging and discharging process of the 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.

[0099] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a layer of positive active material disposed on at least one surface of the positive current collector.

[0100] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0101] 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.).

[0102] As an example, the positive electrode active material layer 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 material layers in batteries may also be used. These positive electrode active material layers 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0103] 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 have a positive electrode active material layer. As an example, a positive electrode active material layer is filled and / or deposited within the foamed metal.

[0104] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0105] 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.).

[0106] As an example, the negative electrode sheet may include a negative current collector and a layer of negative active material disposed on at least one surface of the negative current collector.

[0107] 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 layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0108] As an example, the negative electrode active material layer may employ a type of negative electrode active material layer known in the art for use in battery cells. As an example, the negative electrode active material layer 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 material layers in battery cells may also be used. These negative electrode active material layers may be used alone or in combination of two or more.

[0109] In some embodiments, the negative electrode can be made of 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 layer, although a negative electrode active material layer may or may not be present.

[0110] As an example, a layer of negative electrode active material can be filled or / and deposited inside the negative electrode current collector.

[0111] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0112] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0117] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0118] In some implementations, the electrode assembly is a stacked structure.

[0119] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0120] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0121] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0122] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0123] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0124] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0125] 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.

[0126] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells or battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0127] The technical solutions described in the embodiments of this application are applicable to various energy storage devices that use battery cells or battery devices, such as energy storage containers or energy storage cabinets.

[0128] In the following embodiments, for ease of explanation, a vehicle 1000 is used as an example of an electrical device according to an embodiment of this application. The description is as follows with reference to the accompanying drawings.

[0129] Figure 1 This is a structural schematic diagram of a vehicle 1000 according to one or more embodiments.

[0130] Vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended vehicles, etc. For example... Figure 1 As shown, a battery device 100 is installed inside the vehicle 1000. The battery device 100 can 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, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0131] In some embodiments 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 for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0132] Figure 2 This is an exploded perspective view of a battery device 100 according to one or more embodiments.

[0133] like Figure 2 As shown, the battery device 100 includes a housing 10 and at least one battery cell 20. Figure 2 (Not shown in the image), the housing 10 has a receiving space, in which at least one battery cell 20 is received.

[0134] In some embodiments of this application, the housing 10 may include a first housing 101 and a second housing 102. The first housing 101 and the second housing 102 are fastened together, forming an accommodating space inside the housing 10 to accommodate the battery cell 20. This accommodating space may be sealed or unsealed.

[0135] The second box 102 can be a hollow structure with one end open, and the first box 101 can be a plate-like structure. The first box 101 covers the open side of the second box 102 so that the first box 101 and the second box 102 together define the accommodating space. Alternatively, the first box 101 and the second box 102 can both be hollow structures with one side open, and the open side of the first box 101 covers the open side of the second box 102. Of course, the box 10 formed by the first box 101 and the second box 102 can be of various shapes, such as a cylinder, a cuboid, etc.

[0136] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is placed in the receiving space formed by the second housing 102 and the first housing 101. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form battery modules 30, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is then housed in the receiving space formed by the second housing 102 and the first housing 101. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0137] Figure 3 This is an exploded perspective view of a battery module according to one or more embodiments.

[0138] like Figure 3 As shown, there are multiple battery cells 20. These multiple battery cells 20 are first connected in series, parallel, or in a mixed manner to form a battery module 30. The multiple battery modules 30 are then connected in series, parallel, or in a mixed manner to form a whole, which is housed in the housing 10.

[0139] Multiple battery cells 20 in the battery module 30 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 20 in the battery module 30.

[0140] Below, refer to Figures 4 to 13 Some embodiments of this application will be described in detail.

[0141] Figure 4This is an exploded perspective view of a battery cell according to one or more embodiments; Figure 5 A front view of a battery cell according to one or more embodiments; Figure 6 for Figure 5 Sectional view at point AA; Figure 7 for Figure 6 A magnified view of the first structure at point B in the middle section; Figure 8 for Figure 6 A magnified view of the second structure at point B in the middle section; Figure 9 for Figure 6 A magnified view of the third structure at point B in the middle section; Figure 10 for Figure 6 A magnified view of the fourth structure at point B in the middle section; Figure 11 for Figure 10 A schematic diagram of the structure before welding (welds not shown); Figure 12 for Figure 6 A magnified view of a section at point C; Figure 13 for Figure 6 A schematic diagram of the fifth structure at point B before welding (weld not shown).

[0142] The first aspect of this application provides a battery cell 20, such as Figures 4 to 9 As shown, the battery cell 20 includes a housing 1 and at least one electrode assembly 2 disposed in the receiving cavity of the housing 1. The housing 1 includes a shell 12 and an end cap 11. The shell 12 forms a receiving cavity, and an opening is formed at one end of the shell 12 in a first direction X, which communicates with the receiving cavity. The end cap 11 closes the opening and is laser welded to the shell 12. At least a portion of the end cap 11 extends into the shell 12 through the opening and is clearance-fitted with the shell 12. One of the outer peripheral surface of the portion of the end cap 11 extending into the shell 12 and the inner surface of the shell 12 are provided with a protruding structure 111, and the other is provided with a recessed structure 121 that cooperates with the protruding structure 111.

[0143] Electrode assembly 2 is the component in the battery cell 20 where the electrochemical reaction occurs. The casing 1 may contain one or more electrode assemblies 2. Electrode assembly 2 includes a positive electrode, a negative electrode, and a separator, with the separator disposed between the negative and positive electrode. During the charging and discharging process of the battery cell 20, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator, disposed between the positive and negative electrode, prevents short circuits between the positive and negative electrodes while allowing active ions to pass through. The positive electrode includes a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector. The positive active material layer is coated on the surface of the positive current collector; at least a portion of the positive current collector is not coated with the positive active material layer, and the uncoated portion of the positive current collector serves as a positive electrode tab 21. The negative electrode sheet includes a negative current collector and a negative active material layer disposed on at least one surface of the negative current collector, the negative active material layer being coated on the surface of the negative current collector; at least a portion of the negative current collector is not coated with the negative active material layer, and the portion of the negative current collector not coated with the negative active material layer serves as the negative electrode tab 22.

[0144] The outer casing 1 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film. In some embodiments, the outer casing 1 can be a sealed structure or a non-sealed structure. As an example, when the outer casing 1 is a non-sealed structure, it serves to protect the electrode assembly 2, and a sealing bag is also included between the outer casing 1 and the electrode assembly 2. The sealing bag is used to encapsulate the electrode assembly 2 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the outer casing 1 is a sealed structure, it is used to encapsulate the electrode assembly 2 and electrolyte components. Exemplarily, the outer casing 1 can be cylindrical or prismatic. Prismatic shapes include square shells, blade shapes, and polygonal prisms, such as hexagonal prisms, etc., and there are no particular limitations in this application. The housing 12 and the end cap 11 can be made of the same material or different materials.

[0145] The housing 12 is a hollow structure with an opening on one side. The end cap 11 closes to the opening of the housing 12 to form a sealed connection, creating a cavity for accommodating the electrode assembly 2 and the electrolyte. The housing 12 is hollow, with an internal space for accommodating the electrode assembly 2. The housing 12 can have various shapes, such as a cylinder or a cuboid. The shape of the housing 12 can be determined based on the specific shape of the electrode assembly 2. For example, if the electrode assembly 2 is a cylinder, a cylindrical housing can be used; if the electrode assembly 2 is a cuboid, a cuboid housing can be used.

[0146] The housing 12 can be positively charged, negatively charged, or uncharged. When the housing 12 needs to be charged, it can be directly connected to the tabs of the electrode assembly 2, or it can be electrically connected to the tabs through other conductive components.

[0147] For example, the end cap 11 and the housing 12 can be connected by welding, so that the end cap 11 and the housing 12 can have substantially the same potential. For example, when the housing 12 needs to be positively charged, the end cap 11 can be used to electrically connect the housing 12 to the positive electrode tab 21; when the housing 12 needs to be negatively charged, the end cap 11 can be used to electrically connect the housing 12 to the negative electrode tab 22. Of course, the housing 12 can also be connected to the tab through other conductive structures, and this embodiment does not limit this. The end cap 11 can be electrically connected to the electrode assembly 2, or it can be insulated from the electrode assembly 2.

[0148] The portion of the end cap 11 extending into the housing 12 has a clearance fit with the housing 12, meaning that in any direction perpendicular to the first direction X, the size of the opening of the housing 12 is larger than the size of the portion of the end cap 11 extending into the housing 12, resulting in a gap between the portion of the end cap 11 extending into the housing 12 and the inner wall of the housing 12. For example, the outer shell 1 is cylindrical, the end cap 11 is a circular plate structure, the receiving cavity of the housing 12 is a cylindrical cavity, and the inner diameter of the housing 12 is larger than the diameter of the portion of the end cap 11 extending into the housing 12. For example, the outer shell 1 is a square shell, the end cap 11 is a square plate structure, the receiving cavity of the housing 12 is a cubic cavity, the length of the end cap 11 is greater than the length of the receiving cavity of the housing 12, the width of the end cap 11 is greater than the width of the receiving cavity of the housing 12, the length direction and the width direction are mutually perpendicular to the first direction X, and the length of the end cap 11 is greater than or equal to the width of the end cap 11, and the length of the receiving cavity is greater than or equal to the width of the receiving cavity.

[0149] In this embodiment, the end cap 11 and the housing 12 are fitted with an opening gap, reducing the squeezing effect of the end cap 11 on the opening of the housing 12 and decreasing the probability of the opening of the housing 12 expanding outwards. This results in better dimensional consistency between the opening and the portion of the housing 12 away from the opening, thereby increasing the number of battery cells 20 that can be accommodated within a certain size of space, and thus increasing the capacity. Furthermore, the end cap 11 and the housing 12 are fitted together by a protruding structure 111 and a recessed structure 121. The gap between the end cap 11 and the housing 12 does not extend linearly along the first direction X, but rather has a bent portion at the location where the protruding structure 111 and the recessed structure 121 fit together. Since laser transmission is linear, during laser welding of the end cap 11 and the housing 12 in this embodiment, the laser is less likely to enter the accommodating cavity through the gap between the end cap 11 and the housing 12, making it less likely for the laser to damage the electrode assembly 2 and the electrolyte, thereby increasing the capacity of the battery cell 20.

[0150] In some embodiments of this application, such as Figures 4 to 6As shown, the housing 12 includes a bottom wall 124 and an annular sidewall 123 surrounding the bottom wall 124. The bottom wall 124 is connected to one end of the annular sidewall 123 along the first direction X, forming a receiving cavity with an opening at the other end of the annular sidewall 123. The end cap 11 closes the opening. The bottom wall 124 is provided with an electrode post 13. An adapter piece 3 is welded to one end of the electrode post 13 that extends into the receiving cavity. The adapter piece 3 is welded to the negative electrode tab 22 of the electrode assembly 2. A positive electrode tab 21 is formed on the other side of the electrode assembly 2 along the first direction X opposite to the positive electrode tab 21. Another adapter piece 3 is welded between the positive electrode tab 21 and the end cap 11. In this way, the housing 1 is positively charged and the electrode post 13 is negatively charged.

[0151] For example, the housing 12 is a one-piece molded structure.

[0152] For example, the housing 12 is formed by welding a bottom wall 124 and an annular sidewall 123.

[0153] In some embodiments of this application, the protruding structure 111 is an annular structure extending circumferentially along the end cap 11; the recessed structure 121 is an annular structure extending circumferentially along the end cap 11.

[0154] It is understood that the ring structure can be, but is not limited to, circular rings, square rings, hexagonal rings, etc. The specific shape is determined by the shape of the end cap 11 and the shell 12, and is not specifically limited here.

[0155] The end cap 11 is circumferentially welded to the housing 12, meaning that laser welding is required at all points on the outer periphery of the end cap 11. Therefore, both the protruding structure 111 and the recessed structure 121 are designed as annular structures, so that there are bent portions in the annular gap between the end cap 11 and the housing 12. This makes it difficult for laser to enter the cavity at the welding position, and makes it less likely for laser to damage the electrode assembly 2 and the electrolyte, thereby improving the capacity of the battery cell 20.

[0156] In some embodiments of this application, such as Figure 7 and Figure 8 As shown, the surface of the protruding structure 111 includes a convex arcuate surface 1111, and the inner wall of the groove of the recessed structure 121 includes a concave arcuate surface, and / or, as shown... Figure 9 and Figure 10 As shown, the surface of the protruding structure 111 includes at least one first plane 1112, and the inner wall of the groove of the recessed structure 121 includes at least one second plane.

[0157] For example, such as Figure 7 and Figure 8As shown, the cross-section of the protruding structure 111 is semi-circular, meaning the cross-section is formed by cutting through a plane perpendicular to the circumferential direction of the protruding structure 111. The outer surface of the protruding structure 111 is a convex arc-shaped surface 1111. The cross-section of the recessed structure 121 is also semi-circular, meaning the cross-section is formed by cutting through a plane perpendicular to the circumferential direction of the recessed structure 121. The inner wall surface of the recessed structure 121 is a concave arc-shaped surface. Thus, the combination of the convex arc-shaped surface 1111 and the concave arc-shaped surface improves the smoothness of the end cap 11 entering the opening of the housing 12, thereby increasing assembly efficiency.

[0158] For example, such as Figure 9 and Figure 10 As shown, the protruding structure 111 is an approximately cubic structure, and each plane on the outer surface of the protruding structure 111 is a first plane 1112. The recessed structure 121 forms a cubic space, and each plane on the inner wall surface of the recessed structure 121 is a second plane. This improves the reliability of the engagement between the protruding structure 111 and the recessed structure 121, and enhances the structural strength of the outer shell 1.

[0159] By setting the protruding structure 111 and the recessed structure 121 into various different shapes, the function of blocking the laser from entering the receiving cavity can be achieved. Moreover, it is beneficial to improve assembly efficiency and the reliability of the connection between the end cap 11 and the housing 12.

[0160] In some embodiments of this application, such as Figures 7 to 10 As shown, the surface of the end cap 11 facing the electrode assembly 2 includes a first inner surface 112. The end cap 11 has a first protrusion 113 that protrudes toward the electrode assembly 2 relative to the first inner surface 112. A protruding structure 111 or a recessed structure 121 is formed on the side of the first protrusion 113 facing the inner side of the housing 12. The first protrusion 113 is clearance-fitted with the housing 12.

[0161] For example, the first protrusion 113 is an annular structure that surrounds the center of the end cap 11.

[0162] Thus, the first protrusion 113 is located near the outer peripheral edge of the end cap 11. The first protrusion 113 protrudes towards the electrode assembly 2 relative to the first inner surface 112, making the size of the first protrusion 113 along the first direction X relatively large. This allows for the arrangement of the protruding structure 111 or the recessed structure 121, thereby achieving the function of blocking the laser from entering the receiving cavity. In addition, by providing the first protrusion 113, the strength of the end cap 11 can be improved, the resistance to deformation during processing can be reduced, and the dimensional consistency of the battery cell 20 can be further improved.

[0163] In some embodiments of this application, such as Figures 7 to 10As shown, an adapter plate 3 is provided between the end cap 11 and the electrode assembly 2, and the surface of the adapter plate 3 facing away from the electrode assembly 2 abuts against the first protrusion 113.

[0164] For example, the adapter 3 is connected to the tabs of the electrode assembly 2 and the end cap 11 by laser welding or other means.

[0165] For example, the electrode assembly 2 is a cylindrical structure with its axial direction aligned with the first direction X. In other words, the electrode assembly 2 is a wound structure wound around a central axis extending along the first direction X. The positive electrode current collector at one end of the positive electrode sheet extending beyond the separator along the first direction X serves as the positive electrode tab 21, and the negative electrode current collector at the other end of the negative electrode sheet extending beyond the separator along the first direction X serves as the negative electrode tab 22. The adapter piece 3 abutting against the first protrusion 113 is welded to either the positive electrode tab 21 or the negative electrode tab 22.

[0166] By abutting the first protrusion 113 against the electrode assembly 2, the connection strength between the end cap 11 and the adapter piece 3 is improved, and the gap between the adapter piece 3 and the electrode assembly 2 is reduced, thus increasing the connection strength between them. Additionally, the weldable area between the end cap 11 and the adapter piece 3 is increased, enhancing the current-carrying capacity between them.

[0167] In some embodiments of this application, such as Figure 6 and Figure 12 As shown, the end cap 11 also has at least one second protrusion 114 that protrudes toward the electrode assembly 2 relative to the first inner surface 112. The second protrusion 114 is located on the side of the first protrusion 113 facing the center of the end cap 11, and each second protrusion 114 abuts against the adapter piece 3.

[0168] By forming the second protrusion 114, the strength of the end cap 11 is improved, which is beneficial to improving the dimensional consistency of the battery cells 20. Furthermore, the second protrusion 114 abuts against the adapter piece 3, improving the connection strength between the end cap 11 and the adapter piece 3, and also helps to reduce the gap between the adapter piece 3 and the electrode assembly 2, thereby improving the connection strength between the adapter piece 3 and the electrode assembly 2. In addition, it can increase the weldable area between the end cap 11 and the adapter piece 3, improving the current-carrying capacity between them.

[0169] For example, the second protrusion 114 is a circular structure with the center of the end cap 11 as the center.

[0170] For example, such as Figure 4 As shown, the second protrusion 114 is a ring structure with the center of the end cap 11 as the center.

[0171] Thus, the second protrusion 114 abuts against the middle portion of the adapter piece 3, which helps to improve the connection strength between the adapter piece 3 and the end cap 11 and the electrode assembly 2. In addition, when the adapter piece 3 and the end cap 11 are connected by welding, the weldable area between the end cap 11 and the adapter piece 3 can be increased, thereby improving the current carrying capacity between the end cap 11 and the adapter piece 3.

[0172] In some embodiments of this application, such as Figures 7 to 10 As shown, the end cap 11 has a first outer surface 115 at a position corresponding to the first inner surface 112 on the surface facing away from the electrode assembly 2, and a first recess 116 is formed at a position corresponding to the first protrusion 113 on the surface facing away from the electrode assembly 2. The first recess 116 is recessed relative to the first outer surface 115 toward the side facing the electrode assembly 2.

[0173] Thus, by providing the first recess 116, the end cap 11 can have a certain degree of elasticity, allowing it to release stress through elastic deformation during installation. This reduces the squeezing and frictional forces between the end cap 11 and the housing 12 during assembly, lowering the risk of deformation of the housing 12. Furthermore, the first recess 116 reduces material usage, thus lowering material costs.

[0174] In some embodiments of this application, such as Figure 12 As shown, a second recess 117 is formed on the surface of the end cap 11 facing away from the electrode assembly 2 at a position corresponding to the second protrusion 114. The second recess 117 is recessed relative to the first outer surface 115 toward the side facing the electrode assembly 2.

[0175] Thus, by providing the second recess 117, the end cap 11 can have a certain degree of elasticity, allowing it to release stress through elastic deformation during installation. This reduces the squeezing and frictional forces between the end cap 11 and the housing 12 during assembly, lowering the risk of deformation of the housing 12. Furthermore, the second recess 117 reduces material usage, thus lowering material costs.

[0176] In some embodiments of this application, such as Figures 7 to 9 As shown, a portion of the concave surface of the recessed structure 121 blocks the protruding structure 111 on the side opposite to the electrode assembly 2 along the first direction X.

[0177] For example, such as Figure 7 and Figure 8 As shown, the recessed structure 121 forms a semi-cylindrical space, and the half-arc surface of the recessed structure 121 located at its lowest point away from the receiving cavity blocks the side of the protruding structure 111 facing away from the electrode assembly 2 along the first direction X.

[0178] For example, such as Figure 9As shown, the recessed structure 121 forms a cubic space, and the plane furthest from the receiving cavity on the concave surface of the recessed structure 121 blocks the side of the protruding structure 111 facing away from the electrode assembly 2 along the first direction X.

[0179] The concave surface of the recessed structure 121 blocks the protruding structure 111 on the side facing away from the electrode assembly along the first direction X, thus restricting the movement of the end cap 11 facing away from the electrode assembly 2 along the first direction X, improving the limiting effect between the end cap 11 and the housing 12, facilitating the welding operation of the end cap 11 and the housing 12, thereby improving the assembly efficiency of the two.

[0180] In some embodiments of this application, such as Figure 7 and Figure 9 As shown, the portion of the inner side of the housing 12 located on the side of the protrusion 111 facing away from the electrode assembly 2 along the first direction X is laser-welded to the portion of the outer peripheral surface of the end cap 11 located on the side of the protrusion 111 facing away from the electrode assembly 2 along the first direction X.

[0181] In some embodiments, the inner surface of the housing 12 refers to the portion of the inner surface of the housing 12 surrounding the end cap 11 excluding the surface of the protruding structure 111 or the recessed structure 121.

[0182] In this way, the weld formed by welding the inner side of the housing 12 to the outer peripheral surface of the end cap 11 is located on the side of the protruding structure 111 facing away from the electrode assembly 2 along the first direction X. This not only makes the housing 12 and the end cap 11 welded together, but also mutually restrained by the protruding structure 111 and the recessed structure 121, further improving the connection strength between the two.

[0183] In some embodiments of this application, such as Figure 8 As shown, the outer peripheral edge of the end cap 11 is formed with a flange 118, which is attached to the end face of the housing 12 with an opening and is laser welded to the end face.

[0184] It is understandable that the flange 118 is folded to the side opposite to the center of the end cover 11, and the flange 118 is laser welded to the end face of the housing 12 with an opening, so that the end cover 11 and the housing 12 are welded from the outer peripheral side, thereby improving the welding stability and welding quality.

[0185] For example, such as Figure 8 As shown, a raised structure 111 or a recessed structure 121 is formed on the side of the first protrusion 113 of the end cap 11 away from the center of the end cap 11. A flange 118 is connected to the side of the first protrusion 113 of the end cap 11 away from the center of the end cap 11. The flange 118 is connected to the position of the first protrusion 113 away from the electrode assembly 2, so that the raised structure 111 or the recessed structure 121 is located on the side of the flange 118 facing the electrode assembly 2.

[0186] In this way, the flange 118 is connected and welded to the end face of the housing 12 with an opening, which improves the pressure resistance of the battery cell 20 along the first direction X and reduces the probability of damage to the battery cell 20.

[0187] In some embodiments of this application, such as Figure 10 and Figure 11 As shown, the housing 12 is provided with a recessed structure 121. One end of the concave surface of the recessed structure 121 extends along the first direction X and is connected to the end face of the housing 12 with an opening.

[0188] It is understood that the housing 12 has a recessed structure 121, and the end cap 11 has a protruding structure 111. For example... Figure 11 As shown, the recessed structure 121 of the housing 12 forms a stepped structure, and the movement of the protruding structure 111 away from the electrode assembly 2 along the first direction X is not constrained by the recessed structure 121.

[0189] This structure ensures that the assembly process of the housing 12 and the end cap 11 does not interfere with each other. The end cap 11 can extend into the housing 12 without elastic deformation, making it easy to assemble with the housing 12 and improving the efficiency of the assembly. Furthermore, the structure of the end cap 11 and the housing 12 is relatively simple to manufacture and easy to implement. Moreover, welding from above the end cap 11 reduces the impact of weld reinforcement on the diameter of the housing 1.

[0190] In some embodiments of this application, such as Figure 10 and Figure 11 As shown, the portion of the concave surface of the recessed structure 121 extending along the first direction X is laser welded to the portion of the protruding structure 111 extending along the first direction X.

[0191] In this way, laser welding of end cap 11 and housing 12 is achieved, improving the reliability of the connection between the two and reducing the probability of laser entering the cavity, making it less likely for the laser to damage the electrode assembly 2 and electrolyte, thereby increasing the capacity of battery cell 20.

[0192] In some embodiments of this application, such as Figure 11 As shown, the difference between the diameter D1 of the inner side surface 122 of the housing 12 and the diameter D2 of the outer peripheral surface 119 of the end cap 11 is in the range of 0 to 0.2 mm.

[0193] It should be noted that the inner surface of the housing 12 refers to the inner surface of the housing 12 that serves as a reference reference for the recessed structure 121 or the protruding structure 111; the outer peripheral surface of the end cap 11 refers to the outer surface of the end cap 11 that serves as a reference reference for the recessed structure 121 or the protruding structure 111. For example, as Figure 11As shown, the inner side 122 of the housing 12 is provided with a recessed structure 121, which is recessed towards the outer side of the housing 12 relative to the inner side 122 of the housing 12. The outer peripheral surface 119 of the end cap 11 is provided with a protruding structure 111, which protrudes towards the outer side of the housing 12 relative to the outer peripheral surface 119 of the end cap 11.

[0194] For example, the difference between the diameter D1 of the inner surface 122 of the housing 12 and the diameter D2 of the outer peripheral surface 119 of the end cap 11 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, and 0.2mm.

[0195] Thus, the aforementioned dimensional settings ensure a proper fit between the end cap 11 and the housing 12, improving the dimensional consistency of the battery cells 20 and facilitating an increase in capacity within a given space. Furthermore, these dimensional settings prevent the gap between the end cap 11 and the housing 12 from becoming too large, thereby improving their sealing performance and welding quality.

[0196] In some embodiments of this application, such as Figure 11 As shown, the outer peripheral surface of the portion of the end cap 11 that extends into the housing 12 is provided with a protruding structure 111, and the inner surface of the housing 12 is provided with a recessed structure 121. The outer diameter D3 of the end cap 11 at the protruding structure 111 is smaller than the inner diameter D4 of the housing 12 at the recessed structure 121; the outer diameter D3 of the end cap 11 at the protruding structure 111 is not smaller than the diameter D1 of the inner surface 122 of the housing 12.

[0197] It is understandable that "outer diameter D3 is not less than diameter D1" means that outer diameter D3 is greater than or equal to diameter D1.

[0198] By setting the outer diameter D3 of the end cap 11 at the protrusion 111 to be smaller than the inner diameter D4 of the housing 12 at the recess 121, a clearance fit is achieved between the protrusion 111 of the end cap 11 and the recess 121 of the housing 12, reducing the possibility of the housing 12 expanding outward and thus improving the capacity within a certain accommodating space. Furthermore, by setting the outer diameter D3 of the end cap 11 at the protrusion 111 to be no smaller than the diameter D1 of the inner surface of the housing 12, the gap between the end cap 11 and the housing 12 does not extend linearly along the first direction X, reducing the probability of laser light entering the interior of the housing 1 through the gap. This makes it less likely for the laser light to damage the electrode assembly 2 and the electrolyte, thereby increasing the capacity of the battery cell 20.

[0199] In some embodiments of this application, such as Figure 11 As shown, the difference between the inner diameter D4 of the housing 12 at the recessed structure 121 and the outer diameter D3 of the end cap 11 at the raised structure 111 is in the range of 0 to 0.3 mm.

[0200] For example, the difference between the inner diameter D4 of the housing 12 at the recessed structure 121 and the outer diameter D3 of the end cap 11 at the protruding structure 111 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.3mm.

[0201] Thus, by setting the aforementioned difference, the protruding structure 111 of the end cap 11 and the recessed structure 121 of the housing 12 are properly fitted, reducing the possibility of the housing 12 expanding outward and improving the capacitance within a certain accommodating space. Furthermore, by setting the aforementioned difference, the gap between the protruding structure 111 of the end cap 11 and the recessed structure 121 of the housing 12 is appropriate, preventing the gap from being too large and affecting the reliability of the connection between the end cap 11 and the housing 12.

[0202] In some embodiments of this application, such as Figure 11 As shown, the difference between the outer diameter D3 of the end cap 11 at the protruding structure 111 and the diameter D1 of the inner side surface 122 of the housing 12 is in the range of 0 to 0.3 mm.

[0203] For example, the difference between the outer diameter D3 of the end cap 11 at the protrusion structure 111 and the diameter D1 of the inner surface 122 of the housing 12 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.3mm.

[0204] Thus, by setting the above difference, the protruding structure 111 extends at least partially into the recessed structure 121, further improving the effect of preventing the laser from entering the housing 1. Furthermore, by setting the above difference, the protruding structure 111 will not extend too deeply into the recessed structure 121, thus preventing the housing 1 from expanding outwards.

[0205] In some embodiments of this application, such as Figure 11 As shown, the surface of the end cap 11 facing the electrode assembly 2 is connected to the outer peripheral surface 119 of the end cap 11 by a convex arc-shaped surface 1111.

[0206] For example, the surface of the first protrusion 113 of the end cap 11 facing the electrode assembly 2 is connected to the outer peripheral surface 119 of the end cap 11 via a convex arcuate surface 1111l.

[0207] Thus, the convex arc surface 1111 allows for a smooth transition between the surface of the end cap 11 facing the electrode assembly 2 and the outer peripheral surface 119 of the end cap 11, which serves as a guide and facilitates the smooth insertion of the end cap 11 into the housing 12 along the first direction X. This improves assembly efficiency and reduces friction between the end cap 11 and the housing 12, thereby reducing wear on the housing 12.

[0208] In some embodiments of this application, such as Figure 13 As shown, the outer peripheral surface of the portion of the end cap 11 that extends into the housing 12 is provided with a recessed structure 121, and the inner surface of the housing 12 is provided with a protruding structure 111. The outer diameter D3 of the end cap 11 at the recessed structure 121 is smaller than the inner diameter D4 of the housing 12 at the protruding structure 111; the diameter D2 of the outer peripheral surface of the end cap 11 is not smaller than the inner diameter D4 of the housing 12 at the protruding structure 111.

[0209] It is understandable that "diameter D2 is not less than inner diameter D4" means that diameter D2 is greater than or equal to inner diameter D4.

[0210] By setting the outer diameter D3 of the end cap 11 at the recessed structure 121 to be smaller than the inner diameter D4 of the housing 12 at the protruding structure 111, a clearance fit is achieved between the protruding structure 111 of the end cap 11 and the recessed structure 121 of the housing 12, reducing the possibility of the housing 12 expanding outward and thus improving the capacity within a certain accommodating space. Furthermore, by setting the diameter D2 of the outer circumferential surface of the end cap 11 to be no smaller than the inner diameter D4 of the housing 12 at the protruding structure 111, the gap formed between the housing 12 and the end cap 11 does not extend linearly along the first direction X, reducing the probability of laser light entering the interior of the housing 1 through the gap. This makes it less likely for the laser light to damage the electrode assembly 2 and the electrolyte, thereby increasing the capacity of the battery cell 20.

[0211] In some embodiments of this application, such as Figure 13As shown, the difference between the inner diameter D4 of the housing 12 at the protruding structure 111 and the outer diameter D3 of the end cap 11 at the recessed structure 121 is in the range of 0 to 0.3 mm.

[0212] For example, the difference between the inner diameter D4 of the housing 12 at the protruding structure 111 and the outer diameter D3 of the end cap 11 at the recessed structure 121 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.3mm.

[0213] Thus, by setting the aforementioned difference, the recessed structure 121 of the end cap 11 and the protruding structure 111 of the housing 12 are properly fitted with a clearance, reducing the possibility of the housing 12 expanding outward and improving the capacitance within a certain accommodating space. Furthermore, by setting the aforementioned difference, the gap between the recessed structure 121 of the end cap 11 and the protruding structure 111 of the housing 12 is appropriate, preventing the gap from being too large and affecting the reliability of the connection between the end cap 11 and the housing 12.

[0214] In some embodiments of this application, such as Figure 13 As shown, the difference between the diameter D2 of the outer circumferential surface of the end cap 11 and the inner diameter D4 of the housing 12 at the protrusion structure 111 is in the range of 0 to 0.3 mm.

[0215] For example, the difference between the diameter D2 of the outer peripheral surface of the end cap 11 and the inner diameter D4 of the housing 12 at the protrusion structure 111 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.3mm.

[0216] Thus, by setting the above difference, the protruding structure 111 extends at least partially into the recessed structure 121, further improving the effect of preventing the laser from entering the housing 1. Furthermore, by setting the above difference, the protruding structure 111 will not extend too deeply into the recessed structure 121, thus preventing the housing 1 from expanding outwards.

[0217] The second aspect of this application provides a battery device 100, which includes a plurality of battery cells 20 provided in the first aspect.

[0218] Since the battery cell 20 provided in the first aspect has a large capacity and can accommodate a large number of battery cells 20 in a certain size space, the battery device 100 including multiple battery cells 20 provided in the first aspect has a large capacity.

[0219] A third aspect of this application provides an energy storage device comprising a plurality of battery cells 20 provided in a first aspect or a plurality of battery devices 100 provided in a second aspect for providing electrical energy.

[0220] Since the battery cell 20 provided by the first aspect has a large capacity and can accommodate a large number of battery cells 20 within a certain size of space, and the battery device 100 provided by the second aspect has a large capacity, the energy storage device including multiple battery cells 20 provided by the first aspect or multiple battery devices 100 provided by the second aspect has a large capacity.

[0221] A fourth aspect of this application provides an electrical device comprising a plurality of battery cells 20 provided in a first aspect or a plurality of battery devices 100 provided in a second aspect for providing electrical energy.

[0222] Since the battery cell 20 provided by the first aspect has a large capacity and can accommodate a large number of battery cells 20 within a certain size of space, and the battery device 100 provided by the second aspect has a large capacity, the power-consuming device including a plurality of battery cells 20 provided by the first aspect or a plurality of battery devices 100 provided by the second aspect has a large capacity.

[0223] The following describes specific examples of some embodiments of this application with reference to the accompanying drawings.

[0224] As a specific example, a battery cell structure (cell 20) is provided, including an end cap 11, a housing 12, an electrode assembly 2, an adapter plate 3, and a sealing pin 4. The housing 12 has an opening, and the edge of the opening has a step (recessed structure 121) or a groove (recessed structure 121) to mate with a protruding position (protruding structure 111) of the end cap 11. The groove can be arc-shaped, rectangular, etc., and its size is smaller than the thickness of the housing 12. The housing 12 is made of metal, such as steel or aluminum, possessing a certain degree of toughness, and can recover its shape after plastic deformation under external force. The electrode assembly 2 is housed within the housing 12, enabling the battery cell structure to efficiently store and release electrical energy. Both sides of the electrode assembly 2 are connected to adapter plates 3. The adapter plate 3 on one side of the electrode assembly 2 is connected to the housing 12, and the adapter plate 3 on the other side of the electrode assembly 2 is connected to the electrode post 13 located on the end cap 11. The adapter plate 3 can be stably connected to the electrode assembly 2, the housing 12, and the electrode post 13 by laser welding or other methods, so that the current generated by the electrode assembly 2 can be conducted from the adapter plate 3 to the housing 12 or the electrode post 13. The electrode post 13 has a liquid injection hole 131, and a sealing pin 4 is located on the electrode post 13 and is connected to the electrode post 13 by laser welding or other methods to seal the liquid injection hole 131 and ensure the airtightness of the battery cell. End cap 11 is used to cover the opening of housing 12. There is a protrusion (protrusion structure 111) on the outside of end cap 11. After assembly, it cooperates with the step (recessed structure 121) or groove (recessed structure 121) of housing 12 to ensure that the laser is blocked from entering housing 12 during the cell sealing welding process. At the same time, it reduces the probability of assembly expansion, improves the consistency of cell diameter size, meets the grouping requirements between cells, and improves the safety of cells at the battery pack level. There is an arc-shaped chamfer (convex arc surface 1111) on the bottom of the outside of end cap 11. It can play a guiding role during the assembly of housing 12 and end cap 11. The diameter of the protrusion (protrusion structure 111) on the outside of end cap 11 is larger than the inner diameter of the opening of housing 12. During the assembly process, the protrusion will cause plastic deformation of the opening of the housing. When the protrusion of end cap 11 is assembled to the step (recessed structure 121) or groove (recessed structure 121) of housing 12, the expansion deformation of housing 12 returns to the original size, and the end cap 11 and housing 12 are assembled. The end cap 11 has recesses (first protrusion 113 and second protrusion 114) around its perimeter and center. The recesses contact the adapter piece 3 and can be connected together by laser welding or other methods to allow current to be conducted outward from the electrode assembly 2. The inner and outer recesses design can increase the weldable area and improve the current carrying capacity. There are grooves (first recess 116 and second recess 117) on both the inner and outer sides to contact the adapter piece 3, which can prevent uneven deformation of the adapter piece 3 caused by the pressure of the recesses on one side, reduce the assembly gap between the end cap 11 and the adapter piece 3, and improve the welding quality and weld reliability.

[0225] like Figures 7 to 9As shown, the edge of the end cap 11 has a protrusion (protrusion structure 111). The outer diameter of the protrusion D3 is larger than the inner diameter D1 of the housing 12. At the same time, the outer diameter D3 of the protrusion is smaller than the inner diameter D4 of the groove of the housing 12. After the end cap 11 and the housing 12 are assembled, the protrusion of the end cap 11 is embedded in the groove of the housing 12, which can reduce the risk of the housing 12 popping out after the pressure of the end cap 11 is removed.

[0226] like Figure 7 and Figure 8 As shown, the end cap 11 protrusion is arc-shaped, and the corresponding groove of the housing 12 is an arc-shaped groove that matches the end cap 11 protrusion. The edges of this structure are all arc-shaped, which can reduce the scraping between the end cap 11 and the housing 12 during the assembly process and reduce the probability of metal chips falling off during the assembly process.

[0227] like Figure 8 As shown, the end cap 11 has a flange edge (flanged edge 118) on its edge. After the housing 12 and the end cap 11 are assembled, they can be welded from the side to improve welding stability and welding quality.

[0228] like Figure 10 and Figure 11 As shown, the edge of the end cap 11 has a step (protruding structure 111), and the shell opening of the housing 12 has a step (recessed structure 121) that matches the end cap 11. The outer diameter D3 of the step of the end cap 11 is larger than the inner diameter D1 of the housing 12. The step of the end cap 11 can rest on the step of the housing 12. During the laser welding process from above the housing 12, the laser can be blocked from entering the housing 12. At the same time, the outer diameter D3 of the step of the end cap 11 is smaller than the inner diameter D4 of the step of the housing 12. The assembly process of the housing 12 and the end cap 11 does not interfere with each other. After the end cap 11 and the housing 12 are assembled, the housing 12 will not expand outward. Moreover, the structure of the end cap 11 and the housing 12 is relatively simple to process and easy to implement. In addition, the welding is done from above the end cap 11, which can reduce the influence of the weld reinforcement on the diameter of the cell.

[0229] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. 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 all should be covered within the scope of the 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.

Claims

1. A battery cell, characterized by, Includes a housing and at least one electrode assembly disposed within a receiving cavity of the housing. The outer casing includes: The housing has the receiving cavity, and an opening is formed at one end of the housing in a first direction, the opening communicating with the receiving cavity; End cap, which closes the opening, is laser welded to the housing; At least a portion of the end cap extends into the housing through the opening and is clearance-fitted with the housing. One of the outer peripheral surface of the portion of the end cap extending into the housing and the inner surface of the housing are provided with a protruding structure, and the other is provided with a recessed structure that mates with the protruding structure.

2. The battery cell according to claim 1, characterized in that, The protruding structure is a ring-shaped structure extending circumferentially along the end cap; The recessed structure is a ring-shaped structure extending circumferentially along the end cap.

3. The battery cell according to claim 1 or 2, characterized in that, The surface of the protruding structure includes a convex arc-shaped surface, and the inner wall of the groove of the recessed structure includes a concave arc-shaped surface, and / or The surface of the protruding structure includes at least one first plane, and the inner wall of the groove of the recessed structure includes at least one second plane.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The end cap's surface facing the electrode assembly includes a first inner surface. The end cap has a first protrusion protruding toward the electrode assembly relative to the first inner surface. The first protrusion has a raised structure or a recessed structure on the side facing the inner side of the housing. The first protrusion is clearance-fitted with the housing.

5. The battery cell according to claim 4, characterized in that, An adapter plate is provided between the end cap and the electrode assembly, and the adapter plate abuts against the first protrusion.

6. The battery cell according to claim 5, characterized in that, The end cap also has at least one second protrusion that protrudes toward the electrode assembly relative to the first inner surface. The second protrusion is located on the side of the first protrusion facing the center of the end cap, and each second protrusion abuts against the adapter piece.

7. The battery cell according to claim 6, characterized in that, The second protrusion is an annular structure with the center of the end cap as the center, or the second protrusion is a circular structure with the center of the end cap as the center.

8. The battery cell according to any one of claims 6 or 7, characterized in that, The end cap has a first outer surface at a position corresponding to the first inner surface on the surface facing away from the electrode assembly, and a first recess is formed at a position corresponding to the first protrusion on the surface facing away from the electrode assembly. The first recess is recessed relative to the side of the first outer surface facing the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The end cap has a second recess formed on the surface opposite to the electrode assembly at a position corresponding to the second protrusion. The second recess is recessed relative to the side of the first outer surface facing the electrode assembly.

10. The battery cell according to any one of claims 1 to 9, characterized in that, The concave surface of the recessed structure partially blocks the protruding structure on the side facing away from the electrode assembly along the first direction.

11. The battery cell according to claim 10, characterized in that, The inner side of the housing located on the side of the protrusion structure facing away from the electrode assembly along the first direction is laser-welded to the outer peripheral surface of the end cap located on the side of the protrusion structure facing away from the electrode assembly along the first direction.

12. The battery cell according to claim 10, characterized in that, The outer peripheral edge of the end cap is formed with a flange, which overlaps the end face of the housing with the opening and is laser welded to the end face.

13. The battery cell according to any one of claims 1 to 9, characterized in that, The housing is provided with the recessed structure, one end of the concave surface of the recessed structure extends along the first direction and is connected to the end face of the housing with the opening.

14. The battery cell according to claim 13, characterized in that, The portion of the concave surface of the recessed structure extending along the first direction is laser-welded to the protruding structure.

15. The battery cell according to any one of claims 1 to 14, characterized in that, The difference between the diameter of the inner side of the housing and the diameter of the outer circumference of the end cap is in the range of 0 to 0.2 mm.

16. The battery cell according to any one of claims 1 to 12, characterized in that, The outer peripheral surface of the portion of the end cap that extends into the housing is provided with the protruding structure, and the inner surface of the housing is provided with the recessed structure. The outer diameter of the end cap at the protruding structure is smaller than the inner diameter of the housing at the recessed structure; The outer diameter of the end cap at the protruding structure is not less than the diameter of the inner surface of the housing.

17. The battery cell according to claim 16, characterized in that, The difference between the inner diameter of the housing at the recessed structure and the outer diameter of the end cap at the protruding structure is in the range of 0 to 0.3 mm.

18. The battery cell according to claim 16 or 17, characterized in that, The difference between the outer diameter of the end cap at the protruding structure and the diameter of the inner surface of the housing is in the range of 0 to 0.3 mm.

19. The battery cell according to any one of claims 1 to 15, characterized in that, The outer peripheral surface of the portion of the end cap that extends into the housing has the recessed structure, and the inner surface of the housing has the protruding structure. The outer diameter of the end cap at the recessed structure is smaller than the inner diameter of the housing at the protruding structure; The diameter of the outer circumferential surface of the end cap is not less than the inner diameter of the housing at the protruding structure.

20. The battery cell according to claim 19, characterized in that, The difference between the inner diameter of the housing at the protruding structure and the outer diameter of the end cap at the recessed structure is in the range of 0 to 0.3 mm.

21. The battery cell according to claim 19 or 20, characterized in that, The difference between the diameter of the outer circumferential surface of the end cap and the inner diameter of the housing at the protruding structure is in the range of 0 to 0.3 mm.

22. The battery cell according to any one of claims 1 to 21, characterized in that, The end cap surface facing the electrode assembly is connected to the outer peripheral surface by a convex arc-shaped surface.

23. A battery device, characterized in that, It includes a plurality of battery cells according to any one of claims 1 to 22.

24. An energy storage device, characterized in that, The energy storage device includes a plurality of battery cells according to any one of claims 1 to 22 or a plurality of battery devices according to claims 23 for providing electrical energy.

25. An electrical appliance, characterized in that, The electrical device includes a plurality of battery cells as described in any one of claims 1 to 22 or a plurality of battery devices as described in claim 23 for providing electrical energy.

Images