Battery cell cap bottom plate comprising injection hole structure, sealing structure, battery cell, vehicle, method of manufacturing a bottom plate, and use of injection hole structure

Abstract

Embodiments of the present disclosure relate to a battery cell cap base plate comprising a injection hole structure, a sealing structure, a battery cell, a vehicle, a method of manufacturing a base plate and use of the injection hole structure. The invention relates to a battery cell cap substrate (2) comprising a injection hole structure (1) comprising an upper surface (3) comprising a recess (4), a bottom surface (5) opposite the upper surface (3), wherein the bottom surface (5) comprises a protrusion (6) opposite the recess (4) of the upper surface (3) and a groove (7) surrounding the protrusion (6), and a through hole (8), wherein the through hole (8) is coaxial with the recess (4), the groove (7) and the protrusion (6) and extends from the recess (4) through the protrusion (6).

Description

Technical Field

[0001] This invention relates to a battery cell cap substrate including an injection hole structure, a sealing structure, a battery cell including a battery cell cap, wherein the battery cell cap includes a substrate, a vehicle including an energy storage device (including a battery cell), a method for manufacturing the substrate, a substrate obtainable by the method, and the use of the injection hole structure for welding the injection hole cap. Background Technology

[0002] A battery cell housing, particularly an auxiliary battery cell housing, includes a cell can, such as a square cell can, and two caps (a positive cap at the cathode and a negative cap at the anode), which hermetically seal the battery cell. Each cap includes a substrate. The substrate is part of the cap sealed to the can by welding, for example, laser welding. The substrate of the positive cap includes an injection hole, which is used to inject electrolyte after the cell can and the two caps are welded together. Once electrolyte injection is complete, the injection hole is sealed with a rubber pin and an injection hole cap to prevent electrolyte leakage. The injection hole cap is thus welded to the injection hole by laser welding.

[0003] In industrial applications, aluminum is primarily used as a can and substrate material due to its low density and good corrosion resistance. However, aluminum also has a very low melting point, which can cause the material to melt during thermal runaway. This is particularly important for high-energy battery chemical reactions, as temperatures during thermal runaway can reach as high as 1000°C.

[0004] A primary goal in battery cell development is to increase the energy density of the battery cell while maintaining and / or improving its safety performance. A possible strategy to achieve this goal is to reduce the weight and / or volume of passive materials in the battery cell, such as the can and / or cap. For the cell cap, the wall thickness can be reduced by selecting a material with higher stiffness and / or hardness than commonly used aluminum, such as stainless steel.

[0005] However, depending on the cap's structure, the substrate design, and especially the injection hole structure, the choice of material must be adapted. Harder materials generally tend to have lower deformation capacity. Therefore, the common injection hole design, where the bottom structure is manufactured independently of the top structure, can no longer be used. This means that during stamping, the hard material is displaced and only slightly compressed.

[0006] Many attempts have been made to provide substrates with new injection hole structures and manufacturing processes for injection hole structures.

[0007] WO 2024032225 A1 discloses a top cover assembly for a prismatic battery cell, which includes a stepped liquid injection port. The injection port is located at the positive electrode and includes a sealing section and a positioning hole connected sequentially from bottom to top. After the electrolyte injection operation is completed, a cylindrical sealing pin is driven into the liquid injection port by external force, deforming the inner wall of the injection port. This seals the liquid injection port. The top cover is made of aluminum or an aluminum alloy.

[0008] CN 110048037A discloses a battery top cover, including a top cover sheet with an injection hole. The injection hole has a stepped structure.

[0009] CN 221201337U discloses a battery cover, including an electrode substrate and an electrode stop frame. The electrode substrate is attached to the front side of the electrode stop frame. The electrode stop frame is provided with an injection hole for electrolyte injection, and the injection hole has a stepped structure at the lower part of the substrate.

[0010] CN 206313033U discloses a battery cover, including an injection hole. The injection hole includes an annular groove and a flanged hole.

[0011] CN 219779174U discloses a cover plate assembly including a liquid injection hole. The liquid injection hole is a stepped cylindrical hole and includes a large-diameter hole and a small-diameter hole.

[0012] A common thread in all the literature is that the structure of the injection port is insufficient to achieve optimal welding results with the liquid injection port cap, especially when using hard and / or high-rigidity substrate materials. Therefore, in the aforementioned literature, a gap exists between the injection port cap and the substrate, necessitating the use of welding aids.

[0013] Considering sustainability, energy conservation, and safety concerns, there is an urgent need to develop battery cap assemblies, such as battery cells with reduced weight and volume. This can be achieved by using materials with higher stiffness and / or hardness than commonly used aluminum, such as stainless steel. Summary of the Invention

[0014] Surprisingly, a specific design structure for injection holes included in the substrate of a positive electrode substrate has been discovered. This structure includes a recess on the upper surface of the injection hole structure, a protrusion opposite the recess on the bottom surface, and a circular groove surrounding the protrusion. It is compatible with high-rigidity and hard metals, such as stainless steel, and the manufacturing process for this injection hole structure requires minimal energy and time. Furthermore, the specific design structure of the injection hole exhibits improved properties, such as perfect fit with the injection hole cap and high mechanical resistance during welding with the injection hole cap, resulting in enhanced overall safety of the battery cell. The specific arrangement of the recess, groove, and protrusion ensures uniform strength and stability of the injection hole, preventing cracking and minimizing deformation during welding. The groove distributes welding stress evenly around the substrate, reducing weak points and potential crack areas during welding. Because the injection hole cap is perfectly aligned with the injection hole, no additional welding aids are required, thus avoiding the disadvantages associated with welding aids mentioned above.

[0015] The object of the present invention is to provide a battery cell cap substrate including an injection hole structure, a sealing structure, a battery cell, a vehicle, a method of manufacturing a substrate including an injection hole structure, and the use of the injection hole structure, which at least partially overcome the above-mentioned disadvantages.

[0016] This objective is achieved through the use of the substrate including the injection hole structure according to claim 1, the sealing structure according to claim 9, the battery cell according to claim 10, the vehicle according to claim 11, the method according to claim 12, the injection hole structure according to claim 14, and the use of the injection hole structure according to claim 15.

[0017] Further advantageous embodiments of the invention are derived from the dependent claims and the following description of preferred embodiments of the invention.

[0018] A first aspect of the present invention relates to a battery cell cap substrate, which includes an injection hole structure comprising...

[0019] - Upper surface, which includes a recess;

[0020] - A bottom surface opposite the upper surface, wherein the bottom surface includes a protrusion opposite the recess of the upper surface and a groove surrounding the protrusion; and

[0021] - Through hole, wherein the through hole is coaxial with the recess, groove and protrusion, and extends from the recess through the protrusion.

[0022] In this invention, a "battery cell" refers to a device that generates electrical energy. A battery cell may include an anode (negative electrode), a cathode (positive electrode), an electrolyte, and a battery cell casing. The electrolyte facilitates ion movement between the electrodes.

[0023] In the context of this invention, "battery" refers to a device comprising one or more battery cells. A battery can be a single cell, such as an AA battery, or multiple cells, such as those used in laptops or electric vehicles.

[0024] In this invention, "battery cap" refers to a portion of a battery cell housing. The battery cell housing may include two caps (a positive cap at the positive electrode and a negative cap at the negative electrode) and a cell canister, such as a square cell canister. The two caps can hermetically seal the cell canister, thereby preventing electrolyte leakage. In some examples, the cap may include terminals, an upper insulating portion, a substrate, a lower insulating portion, rivets, and sealing rings.

[0025] In this invention, a "terminal" is a conductive component that provides an electrical connection point from a battery cell to an external circuit or device. It facilitates the transfer of current from the battery to the device it powers.

[0026] A battery cell may have two terminals: a positive terminal (cathode) from which current flows out, and a negative terminal (anode) from which current flows in. The positive and negative terminals ensure a secure and effective connection to the device being powered. The terminals may comprise conductive materials selected from the group consisting of stainless steel, copper, brass, or aluminum.

[0027] In the context of this invention, "upper insulating portion" and "lower insulating portion" refer to components that provide electrical insulation and mechanical protection.

[0028] The upper insulating portion can be an assembly located between the positive terminal of the battery cell and the substrate of the positive cap, and / or between the negative terminal of the battery cell and the substrate of the negative cap. The upper insulating portion can prevent electrical short circuits by insulating the positive or negative terminal from the cell housing, and / or provide a barrier to protect internal components from mechanical stress or damage.

[0029] The lower insulation portion may be an assembly located between the sealing ring of the positive or negative terminal cap and the rivet of the positive or negative terminal cap. The lower insulation portion can prevent electrical short circuits by insulating the positive or negative terminal from the unit housing, and / or provide a barrier to protect internal components from mechanical stress or damage.

[0030] The upper and / or lower insulating portions may be made of plastics selected from the group consisting of polypropylene, polyethylene, polycarbonate, polyamide and / or polyvinyl chloride.

[0031] In this invention, a "sealing ring" refers to the circular component of the cap, designed to fit precisely between the substrate and the lower plastic insulation portion to prevent electrolyte leakage. The sealing ring can be made of an elastic material, such as nitrile rubber, silicone rubber, fluoroelastomers, ethylene propylene diene monomer, and neoprene rubber.

[0032] In the context of this invention, "rivet" refers to a mechanical component used to securely connect active battery components, such as electrodes and terminals, to the battery cap and maintain a tight seal to prevent electrolyte leakage. Rivets may be made of materials selected from the group consisting of aluminum, aluminum alloys, copper, or composite materials made therefrom.

[0033] The substrate can be made of a material selected from the group including steel, stainless steel, aluminum alloy, or aluminum. In industrial applications, aluminum or aluminum alloys are primarily used as the material for both the can and the substrate. The can can be joined to the substrate by welding, particularly laser welding.

[0034] The substrate can have a shape selected from rectangular, circular, or square. In some examples, the substrate can be rectangular.

[0035] In some examples, the substrate may have a rectangular or square shape, with a diagonal length of 100-200 mm. The diagonal of a rectangle or square is a line segment connecting two opposite corners of the rectangle or square. In some examples, the substrate may have a rectangular or square shape, with a perimeter of 200-400 mm.

[0036] In some examples, the substrate may have a rectangular shape with an aspect ratio of 1:1 to 50:1. In some embodiments, the substrate may have a rectangular shape with an aspect ratio of 1-30 cm.

[0037] A substrate with a rectangular or square shape can be used in a square battery cell.

[0038] The substrate includes a top surface, a bottom surface opposite the top surface, and an injection hole structure. The top surface of the substrate can be positioned opposite the battery cell canister. The bottom surface can be positioned facing the battery cell canister.

[0039] In some examples, the surface area of ​​the upper surface can be equal to the surface area of ​​the lower surface. In some other examples, the surface area of ​​the upper surface can be less than the surface area of ​​the lower surface. In some still examples, the surface area of ​​the upper surface can be greater than the surface area of ​​the lower surface.

[0040] The substrate may include equal wall thicknesses. The wall thickness can be the distance between the upper and lower surfaces of the substrate. A constant, equal distance can be observed from every point on the upper surface to the lower surface. The substrate wall thickness can be 0.4–2.5 mm. Only at the injection hole structure may the substrate not include equal wall thicknesses.

[0041] The substrate may comprise a material selected from the group consisting of steel, stainless steel, aluminum, or aluminum alloys. In some examples, the substrate may be made of stainless steel.

[0042] The substrate may also include a central hole. This hole may be an opening for the battery cell electrode (anode or cathode) and may be closed by terminals and / or metal caps.

[0043] In this invention, the center of a rectangular or square substrate refers to the point or area where the diagonals of the substrate intersect. The center can be equidistant from all four corners.

[0044] In addition, the wall thickness of the unit tank can be less than the wall thickness of the substrate.

[0045] In some examples, the substrate may have a hardness of 20 to 90 HRC, measured according to DIN ENISO 6508-1. In some embodiments, the substrate may have a hardness of 40 to 90 HRC, measured according to DIN ENISO 6508-1. In some examples, the hardness of the substrate may be higher than that of aluminum or aluminum alloys, measured according to DIN ENISO 6508-1.

[0046] In some examples, the substrate can have a tensile strength of 280 MPa to 1200 MPa, measured according to DIN EN 10088-3. The material thickness for which the tensile strength is measured according to DIN EN 10088-3 can be 100 mm to 500 mm.

[0047] In some examples, the substrate can have an elastic limit of 200 to 1000 MPa. In some examples, the substrate can have an elastic limit of 210 to 900 MPa, measured according to DIN EN 10088-3. The material thickness for which the elastic limit is measured according to DIN EN 10088-3 can be from 100 mm to 500 mm.

[0048] In some examples, the substrate may have an elongation at break of 20% to 50% in the longitudinal direction and / or 20% to 50% in the transverse direction, as measured according to DIN EN 10088-3. The material thickness for which the fracture strain is measured according to DIN EN 10088-3 may be from 100 mm to 500 mm.

[0049] The substrate may also include rounded or pointed edges. These rounded or pointed edges can perfectly fit and align with the rounded or pointed edges of the can. Therefore, flush assembly with the can is ensured to guarantee a tight seal against leaks.

[0050] The aforementioned substrate may be particularly suitable for materials with high rigidity and hardness, such as stainless steel, which helps to reduce the weight and volume of the battery cap.

[0051] The substrate of the positive electrode cap may include injection holes.

[0052] In the context of this invention, an "injection hole" refers to an opening or port through which electrolyte can be introduced into the battery cell after the cell can and two caps have been welded together.

[0053] The injection port can be airtightly sealed using a rubber pin and an injection port cap.

[0054] The rubber pin can be positioned in the through hole of the injection hole structure.

[0055] The injection port cap can be welded to the injection port structure to provide a strong and leak-proof seal.

[0056] The rubber pin may comprise a material selected from the group consisting of ethylene propylene diene monomer, fluoroelastomer, silicone rubber, nitrile rubber, or neoprene rubber. The injection port cap may comprise a material selected from the group consisting of steel or stainless steel. In some examples, the injection port cap may be made of stainless steel.

[0057] The injection port cap may not include aluminum or aluminum alloy.

[0058] In this invention, "injection hole structure" refers to the form of an injection hole and surrounding structural features included in the substrate of the positive electrode cap. The structural features of the injection hole can surround the injection hole in an area of ​​3 to 30 mm. The injection hole structure includes a recessed upper surface, a raised bottom surface opposite the recess, a groove surrounding the raised surface, and a through hole that can extend coaxially through the raised surface.

[0059] The injection hole structure enables precise electrolyte injection, which is crucial in this invention. Furthermore, the injection hole structure ensures that the injection hole cap is flush with the injection hole structure, which enhances the solderability of the battery cell and the overall structural integrity.

[0060] The injection hole structure can be included in the substrate of the positive electrode cell cap. The injection hole structure can be circular in shape, i.e., circular when viewed from a top view. In some examples, the injection hole structure can be circular in shape with a diameter of 3-30 mm.

[0061] In some embodiments, the injection hole structure may have a circular shape, wherein the ratio of the outer diameter to the radius is 0.1-2.

[0062] In other examples, the injection hole structure can have a shape selected from a group including rectangles, quadratic shapes, ellipses, or triangles.

[0063] In some examples, the injection hole structure may have a stepped form in the cross-sectional view.

[0064] The injection hole structure may include an upper surface and a bottom surface opposite to the upper surface.

[0065] In the context of this invention, "surface" refers to the outermost layer or boundary of the injection hole structure exposed to the surrounding environment.

[0066] The upper surface of the injection port structure can be positioned opposite the battery cell tank and electrolyte. The bottom surface can be positioned facing the battery cell tank and electrolyte.

[0067] In some examples, the surface area of ​​the upper surface can be equal to the surface area of ​​the lower surface. In some other examples, the surface area of ​​the upper surface can be less than the surface area of ​​the lower surface. In some still examples, the surface area of ​​the upper surface can be greater than the surface area of ​​the lower surface.

[0068] The upper surface of the injection hole structure includes a recess. In some examples, the upper surface of the injection hole structure consists of a recess.

[0069] In some examples, the recess may be located at the center of the upper surface of the injection hole structure.

[0070] In the context of this invention, the center of a circular material, such as an injection hole structure, refers to a point or region equidistant from all points on the circumference of the circular material.

[0071] In the context of this invention, the center of a rectangular or quadrilateral material, such as an injection hole structure, refers to the point or region at the intersection of the diagonals of the rectangular or quadrilateral material. The center can be equidistant from all four corners.

[0072] The recess can be located at the center of the upper surface of the injection hole structure. The center of the recess can be at the same location as the center of the injection hole structure, meaning the recess can be arranged coaxially with the upper surface of the injection hole structure. The center of the injection hole structure can be at the same location as the center of the upper surface.

[0073] Viewed from a top view, the recess can be circular, rectangular, triangular, or quadrilateral. In most examples, the recess can be circular.

[0074] In some examples, the recess includes a trapezoidal structure in the cross-sectional view.

[0075] In some embodiments, the recess includes a recess bottom width and a recess opening width, wherein the ratio of the recess bottom width to the recess opening width can be 0.1-5.

[0076] In this invention, "bottom width of the recess" refers to the horizontal distance passing through the bottom surface of the recess. It is a measurement of the width at the deepest part of the recess. When the recess has a circular shape, the bottom width can be the diameter of the recess at its bottom surface. When the recess has a rectangular or square shape, the bottom width can correspond to the diagonal of the recess at its bottom surface.

[0077] In this invention, "recess opening width" refers to the horizontal distance through the entrance of the recess. It is a measurement of the width at the highest point of the recess. When the recess has a circular shape, the recess opening width can be the diameter of the recess at the entrance. When the recess has a rectangular or square shape, the recess opening width can correspond to the diagonal of the recess at the entrance.

[0078] The width of the recessed bottom can be 0.1-5mm. The width of the recessed opening can be 0.1-5mm. In some examples, the width of the recessed opening can be greater than the width of the recessed bottom. In some other examples, the width of the recessed opening can be equal to the width of the recessed bottom. In some other examples, the width of the recessed opening can be less than the width of the recessed bottom.

[0079] In some examples, the recess may have a circular shape, wherein the bottom width (diameter) of the recess at the bottom surface of the recess is 0.1-5 mm, the opening width (diameter) of the recess at the inlet is 0.1-5 mm, the radius at the bottom surface of the recess is 0.05-2 mm, and the radius at the inlet of the first groove is 0.05-2 mm.

[0080] In some examples, the recess includes a recess bottom width and a recess opening width, wherein the ratio of the recess bottom width to the recess opening width is 0.1-5, and wherein the recess opening width may be greater than the recess bottom width.

[0081] In some examples, the width of the recessed groove can decrease continuously from the width of the recessed opening to the width of the recessed bottom.

[0082] The recessed entrance may terminate on the upper surface of the substrate. The substrate may include an upper surface and a lower surface. The upper surface of the substrate may be positioned opposite the cell tank and the electrolyte. The lower surface of the substrate may be positioned facing the cell tank and the electrolyte.

[0083] In some examples, the recess may also include an inner wall. The inner wall of the recess may be located between the entrance of the recess and the bottom of the recess. When viewed in a cross-sectional view, the inner wall of the recess may form four corners at its intersection. Therefore, in some examples, the recess may include a first corner, a second corner, a third corner, and a fourth corner in a cross-sectional view. The first and second corners may be located at the intersection of the inner wall of the recess and the bottom surface of the substrate. The third and fourth corners may be located at the intersection of the inner wall of the recess and the bottom of the recess. The first and second corners may include angles of 90°. The third and fourth corners may include angles of 90°. In some other examples, the first and second corners may include angles greater than 90°. In some other examples, the third and fourth corners may include angles greater than 90°.

[0084] In some examples, the recessed first and second corners may have rounded edges in the cross-sectional view. In some other examples, the recessed first and second corners may have pointed edges in the cross-sectional view. In some examples, the recessed third and fourth corners may have rounded edges in the cross-sectional view. In some other examples, the recessed third and fourth corners may have pointed edges in the cross-sectional view.

[0085] In some examples, the recess also includes a bottom surface of the recess. The bottom surface of the recess can be the recessed surface at the bottom of the recess.

[0086] The depression may have a first depth of 0.1-2 mm. The first depth may be the distance between the bottom of the depression and the entrance of the depression.

[0087] The bottom surface of the injection hole structure includes a protrusion opposite to the depression on the upper surface and a groove surrounding the protrusion.

[0088] In some examples, the protrusion can be circular. In other examples, the protrusion can be a rectangle, trapezoid, triangle, ellipse, or square. In some examples, the protrusion can have the same shape as the depression.

[0089] The protrusion can be located at the center of the bottom surface of the injection hole structure. The center of the protrusion, the center of the recess, and the center of the injection hole structure are located at the same position. The center of the injection hole structure and the center of the bottom surface are located at the same position.

[0090] The protrusion can be circular, rectangular, trapezoidal, or square. In most examples, the protrusion can be circular.

[0091] The protrusion can have a height of 0.1-2 mm. The height can be the distance between the top surface of the protrusion and the bottom surface of the substrate.

[0092] The circular protrusion may have a radius of 1.5-12 mm, a diameter of 3-24 mm, and an outer diameter of 3-24 mm at its top surface.

[0093] In some embodiments, the protrusion may include a bottom width and a top width, wherein the ratio of the bottom width to the top width may be 6.0-1.0. "Top width" in this invention refers to the diameter of the protrusion at its top surface. "Bottom width" refers to the diameter of the protrusion at its base, where the protrusion terminates in a groove.

[0094] The protrusion may also include an outer wall. The outer wall may be located between the top surface of the protrusion and the groove surrounding the protrusion. When viewed in a cross-sectional view, the outer wall of the protrusion may form four corners at its intersection. Therefore, in some examples, the protrusion may include a first corner, a second corner, a third corner, and a fourth corner in a cross-sectional view. The first and second corners may be located at the intersection of the outer wall of the protrusion and the top surface of the protrusion. The third and fourth corners may be located at the intersection of the outer wall of the protrusion and the bottom of the groove. The first and second corners may include angles of 90°. The third and fourth corners may include angles of 90°. In some other examples, the first and second corners may include angles greater than 90°. In some other examples, the third and fourth corners may include angles greater than 90°.

[0095] In some examples, the first and second protruding corners may have rounded edges in the cross-sectional view. In some other examples, the first and second protruding corners may have pointed edges in the cross-sectional view. In some examples, the third and fourth protruding corners may have rounded edges in the cross-sectional view. In some other examples, the third and fourth protruding corners may have pointed edges in the cross-sectional view.

[0096] The groove surrounds the protrusion.

[0097] In some examples, the groove can be an annular groove surrounding the protrusion. In other examples, the groove can be a rectangular groove, trapezoidal groove, triangular groove, elliptical groove, or square groove surrounding the protrusion.

[0098] In some examples, the groove can be a continuous groove without any interruption.

[0099] In some examples, the bottom surface of the injection hole structure includes a central circular protrusion and a second annular groove surrounding the protrusion.

[0100] In some examples, the groove includes a groove bottom width and a groove opening width, wherein the ratio of the groove bottom width to the groove opening width is 0.1-1.

[0101] In this invention, "groove bottom width" refers to the horizontal distance of the bottom surface of the groove. It is a measurement of the width at the deepest part of the groove. "Groove opening width" in this invention refers to the horizontal distance through the entrance of the groove. It is a measurement of the width at the highest part of the groove.

[0102] In some examples, the groove opening width may be greater than the groove bottom width. In some other examples, the groove opening width is equal to the groove bottom width. In some still examples, the groove opening width is less than the groove bottom width.

[0103] In some examples, the groove width can decrease continuously from the groove opening width to the groove bottom width.

[0104] The groove may also include an outer wall and an inner wall. The outer wall may be adjacent to the substrate. The inner wall may be adjacent to the protrusion.

[0105] In some examples, the inner wall may have a contact angle >90° with the bottom surface of the groove. In some examples, the outer wall may have a contact angle >90° with the bottom surface of the groove. In some examples, the contact angles of the inner and outer walls may be equal.

[0106] The groove may include a second depth of 0.1-2 mm. The second depth may be the distance between the bottom surface of the groove and the entrance of the groove.

[0107] In the case of the first annular groove, the distance from the midpoint of the bottom width of the groove to the center of the protrusion can be equal.

[0108] In some embodiments, the recess includes a first depth, and the groove includes a second depth, wherein the ratio of the first depth to the second depth may be 0.1-1.

[0109] In some examples, the protrusion may be circular in shape. In some embodiments, the width of the recessed opening may be greater than or equal to the width of the top of the protrusion, i.e., the diameter at the top surface of the protrusion.

[0110] The injection hole structure includes a through-hole, which is coaxial with recesses, grooves, and protrusions, and extends from the recesses through the protrusions. The through-hole can be cylindrical in shape.

[0111] In this invention, "coaxial" means that the through-holes, recesses, grooves, and protrusions have a common axis, that is, these structural features are aligned along the same axis. The through-hole can be located at the center of the top surface of the protrusion and the center of the bottom surface of the recess.

[0112] In the context of this invention, "extending from the recess through the protrusion" means that, viewed from above, the through-hole can begin at the bottom surface of the recess and end at the top surface of the protrusion. Therefore, the through-hole can pass through the protrusion on the bottom surface of the injection hole structure.

[0113] In some examples, the through-hole may include a height of 0.01-10 mm. The height of the through-hole may be equal to the wall thickness of the protrusion. In some examples, the through-hole may also include a radius of 0.01-10 mm.

[0114] In some embodiments, the through hole may be cylindrical and may include a through hole radius and a through hole height, wherein the ratio of the through hole radius to the through hole height may be 1-100.

[0115] In some embodiments, the ratio of via height to recess depth can be 0.01-100. In some other examples, the ratio of via height to recess depth can be 0.0001-1.

[0116] In a cross-sectional view, a through-hole may include four corners: a first corner and a second corner at the intersection of the through-hole and the recessed bottom surface, and a third corner and a fourth corner at the intersection of the through-hole and the raised top surface. The angles of the first, second, third, and fourth corners of the through-hole may be equal to 90°. The first, second, third, and fourth corners may have sharp edges. In other examples, the first, second, third, and fourth corners may have rounded edges.

[0117] The injection hole structure can have a stepped structure through recesses, grooves, and protrusions.

[0118] The inner wall of the recess may be inclined toward the bottom surface of the first protrusion. The outer wall of the protrusion may also be inclined toward the top surface of the protrusion. "Oriented toward" in the context of this invention means that the wall may be angled or inclined relative to a reference plane. In the case of the inner wall, the reference plane may be the bottom surface of the recess. The angle between the inner wall and the bottom surface of the recess, i.e., the aforementioned third and fourth angles of the recess in the cross-sectional view, may be greater than 90°. In the case of the outer wall, the reference plane may be the top surface of the protrusion. The angle between the outer wall and the top surface of the protrusion, i.e., the aforementioned first and second angles of the protrusion in the cross-sectional view, may be greater than 90°.

[0119] The aforementioned structural features (recesses, grooves, protrusions) of the injection port structure allow for quick and easy filling of the battery cell with electrolyte and enable flush assembly with the injection port cover, while leaving sufficient space to accommodate the rubber pin.

[0120] The aforementioned injection hole structure may be particularly suitable for materials with high rigidity and hardness, such as stainless steel, thereby helping to reduce the weight and volume of the battery cap.

[0121] By utilizing the structural features of the injection hole structure, high leakage tightness (high sealing efficiency), high battery safety, and prevention of welding cracks can be achieved in the injection hole after electrolyte injection and injection hole cap welding.

[0122] Specifically, compared to the existing injection hole structures described above, this structural feature ensures equal strength and stability throughout the entire injection hole structure. Specifically, the groove prevents cracking during welding because it ensures a uniform distribution of welding stress within the injection hole structure, thereby enhancing structural integrity and reducing the risk of weaknesses.

[0123] After the electrolyte is added, the injection port structure is sealed with a rubber pin and an injection port cap. The injection port cap can be connected to the injection port structure by welding, such as laser welding.

[0124] The aforementioned structural features (grooves, recesses, and protrusions) of the injection port structure allow for flush assembly with the injection port cap and rubber pin. The injection port cap can be perfectly fitted into the recess on the bottom surface of the injection port structure. The rubber pin can also be perfectly fitted into the through hole and the volume formed between the injection port cap and the bottom surface of the recess.

[0125] A second aspect of the invention relates to a sealing structure comprising a substrate including an injection hole structure, an injection hole cap, and a rubber pin.

[0126] The rubber pin can be positioned within the through-hole and can point into the recess. An injection port cap can cover the rubber pin, which can seal the through-hole. The injection port cap can be laser-welded to the substrate.

[0127] The injection port cap can be as described above. The injection port cap can be made of a material selected from stainless steel, steel, and aluminum. In some examples, the injection port cap can be made of stainless steel or steel.

[0128] The rubber pin can be as described above, and can be made of the materials described above.

[0129] The gap after inserting the injection port cap into the injection port structure can be in the range of 0 mm to 0.1 mm. To ensure proper alignment of the injection port cap and the injection port structure, no other materials, such as welding aids or gap fillers for filling the gap between the injection port cap and the injection port structure, are required.

[0130] There may be no gap between the injection port cover and the injection port structure; that is, in some examples, the gap can be 0 mm.

[0131] A precise fit between the injection port cap and the injection port structure is crucial for the overall safety and / or performance of the battery cell. A precise fit between the injection port structure and the injection port cap eliminates the need for additional welding materials. This precise fit results in high connection strength between the injection port cap and the injection port structure. Because additional welding materials are not required, issues related to insufficient gap filling and potential connection cracking are avoided.

[0132] The battery cell canister can be connected to a substrate by welding, such as laser welding. After the substrate is welded to the canister, the injection port of the injection port structure can be hermetically sealed by a rubber pin and an injection port cap. The injection port cap can be welded to the substrate, providing a robust and leak-proof seal. The rubber pin can include materials selected from the group consisting of ethylene propylene diene monomer, fluoroelastomer, silicone rubber, nitrile rubber, or neoprene rubber. The injection port cap can include materials selected from the group consisting of steel, stainless steel, aluminum, or aluminum alloys.

[0133] In some examples, the injection port cap may be made of stainless steel. The injection port cap may not include aluminum or aluminum alloy.

[0134] A third aspect of the present invention relates to a battery cell including the above-described sealed structure.

[0135] Therefore, the battery cell may include the battery cell cap substrate with the injection hole structure described above.

[0136] Battery cells can be cylindrical, prismatic, pouch, or button cells. Battery cells can be auxiliary battery cells. Battery cells can be lithium-ion, nickel-cadmium, nickel-metal hydride, lithium-sulfur, or flow batteries.

[0137] The battery cell can be as described above. Therefore, the battery cell can include two caps: a positive cap located at the cathode and a negative cap located at the anode. The positive cap can include an injection hole structure. In some examples, the battery cell cap can also include terminals, an upper insulating portion, a lower insulating portion, rivets, and a sealing ring.

[0138] The terminals, upper insulating portion, substrate, lower insulating portion, rivets, and sealing rings are as described above.

[0139] The substrate of the positive electrode cap may include a central hole and the aforementioned injection hole structure. The injection hole can be hermetically sealed by the aforementioned rubber pin and the aforementioned injection hole cap.

[0140] The substrate can be soldered onto the unit tank to provide a robust and leak-proof seal.

[0141] In some examples, the gap between the substrate and the unit tank can be 0 mm to 0.1 mm before welding.

[0142] Another aspect of the present invention relates to a vehicle including an energy storage device comprising the aforementioned battery cell.

[0143] The vehicle can be, for example, a trackless and / or chainless land vehicle, particularly a passenger car or commercial vehicle.

[0144] An energy storage device may include one or more of the aforementioned battery cells. An energy storage device may also be a battery module.

[0145] Energy storage devices can be connected to control units, such as battery management systems. The battery management system can monitor the state of the energy storage device, such as its state of charge or health, the charging or discharging process, and can diagnose faults and / or anomalies in the battery cells, such as defective cells or connection problems.

[0146] In some examples, the control unit may include a computer system and a computer-readable storage medium system, which includes instructions that, when executed by the computer, cause the computer to analyze and manage the battery.

[0147] Another aspect of the present invention is a method for manufacturing the above-described injection hole structure, comprising:

[0148] - Punch or punch basic through holes on the base battery cell cap substrate;

[0149] - A foundation groove is formed on the bottom surface of the stamped base substrate, wherein the foundation groove coaxially surrounds the foundation through hole;

[0150] - Further stamping is performed on the upper surface of the stamped substrate, wherein a base recess and a base protrusion opposite the base recess and located at the center of the base groove are formed; and

[0151] -Imprinting and / or shaping of base grooves, base depressions and base protrusions, wherein the above-mentioned injection hole structure is formed.

[0152] In the context of this invention, "basic" refers to the initial form of the through-hole, battery cap substrate, groove, recess, and protrusion, rather than the final form. In the basic form, the aforementioned structural features of the through-hole, battery cap substrate, groove, recess, and protrusion may be visible, but the final structure may not yet be formed (e.g., the sharp or rounded edges of the aforementioned recesses and grooves, the through-hole structure, the specific dimensions of the recesses and grooves, etc.).

[0153] The base battery cell cap substrate, also known as the base substrate, may not include the aforementioned injection hole structure. The aforementioned injection hole structure can be formed in the base battery cell cap substrate that forms the aforementioned substrate through stamping, forming, and shaping processes.

[0154] In the context of this invention, "stamping" refers to the process in which a metal sheet, such as a base substrate, can be placed into a stamping press, wherein a die shapes the metal sheet into a desired shape.

[0155] In the context of this invention, "punching" refers to the process of creating a hole in a metal sheet, such as a base substrate, by pushing a punch through the sheet.

[0156] In some examples, "sheet" can refer to a flexible (continuous) sheet that can be rolled up, embossed, and / or stamped to at least some extent.

[0157] The base substrate material can be selected from steel, stainless steel, aluminum, or aluminum alloy.

[0158] For stamping, punches and die blocks can be used.

[0159] In this invention, a "punch" refers to a tool used to apply force to a material, such as a sheet of metal, to shape and / or cut the material. A punch can be a hard metal bar with a tip having a specific shape that corresponds to a desired shape or hole to be formed in the material. A punch can be used to stamp a sheet of metal to form the aforementioned injection port caps, including protrusions, recesses, and grooves. The stamping process can represent a mature and stable industrial process.

[0160] The punch may have a shape at its tip corresponding to the shape of the through hole described above. The tip of the punch may have a shape including a circular shape.

[0161] The tip of the punch can have the same dimensions as the aforementioned through hole.

[0162] In this invention, a "die block" refers to a tool used in conjunction with a punch to shape or cut material. A die typically provides a cavity or anvil upon which the punch presses a sheet of material to create a desired shape, i.e., a through-hole. A die block can hold a sheet of metal in place and provide the necessary support and shape to form the aforementioned through-hole when the punch is pressed against it.

[0163] A stamped base substrate, including basic through-holes, can be formed through a stamping process. The basic through-holes can begin on the upper surface of the base substrate and terminate on the bottom surface. The bottom surface can be positioned facing the cell can, while the upper surface can be positioned on the opposite side of the cell can. Therefore, the basic through-holes can penetrate the base substrate.

[0164] The upper surface of the base substrate can be positioned opposite the punch. The bottom surface can be positioned facing the punch.

[0165] In a further step, a foundation groove is formed on the bottom surface of the stamped base substrate, wherein the foundation groove coaxially surrounds the foundation through hole.

[0166] In the sense of this invention, “forming” may include a further stamping step and / or a milling step using another die block and another punch.

[0167] When the forming step can be a stamping step, the shape of the punch ensures the structure of the base groove. The upper surface of the base substrate can be positioned opposite the punch. The bottom surface can be positioned facing the punch.

[0168] In a further step, the substrate is stamped onto the upper surface of the stamped substrate, forming a base recess and a base protrusion opposite the base recess and located at the center of the base groove. During this stamping step, the base groove can be folded, thus forming a small ring on the opposite side of the base recess. This small ring may be necessary because the gap between the injection port cap and the substrate needs to be as small as possible to ensure laser solderability. The stamping step can result in a base injection port structure including the base recess and base groove, through-hole, and base protrusion. When viewed in a cross-sectional view, a specific stepped structure of the base injection port structure can be formed, thereby ensuring that the injection port cap is flush with the substrate.

[0169] The tip of the punch used in the second or third stamping step may have a rounded shape. The upper surface of the base substrate may be positioned toward the punch. The bottom surface may be positioned toward the die block.

[0170] The base recess can have a trapezoidal structure. The base circular groove can have a ring-shaped structure. The recess and groove can control the outer radius of the injection hole structure.

[0171] In some embodiments, a base recess can be punched at the location of a base through-hole. This means that during the punching process, a punch can widen a portion of the base through-hole on the upper surface of the base substrate to form a base recess, for example, widening it to 70% of the length of the base through-hole. The length of the base through-hole can correspond to the wall thickness of the base substrate, i.e., the distance between the upper and lower surfaces of the base substrate.

[0172] In a further step, the base grooves, base depressions, and base protrusions are embossed and / or shaped to form the aforementioned injection hole structure.

[0173] After the basic injection hole structure, including basic protrusions, basic recesses, basic grooves, and basic through holes, can be formed, the embossing and / or shaping steps may include refining the shape and / or upper and / or bottom surfaces of the basic injection hole structure. "Embossing" refers to a precise stamping process that further defines the structure of the injection hole. This step ensures that the injection hole structure has the correct dimensions and surface characteristics as described above, such as the dimensions of the aforementioned protrusions, recesses, and grooves.

[0174] In some examples, the method may include a further step of trimming and / or punching a section of the base substrate surrounding a region where an injection hole structure may be formed. This step may include removing excess material from the base substrate around the area of ​​the sheet that will form the injection hole cap. Trimming refers to removing unwanted material, while punching involves creating a hole and / or shape by applying force with a punch. This step prepares the sheet for the stamping process by ensuring that only the necessary material of the sheet is retained.

[0175] This method may include the further step of cutting a base substrate from a metal sheet. For cutting, for example, scissors, a laser cutter, a waterjet cutter, or a die-cutting machine can be used. During the cutting process, the edges of the base substrate may be sharpened. If sharp edges cannot be obtained, further sharpening processes may be applied, for example, by grinding, milling with a rotary cutting tool, polishing with an abrasive material, or electrochemical machining using an electric current.

[0176] In some examples, the method may also include deburring and / or cleaning the injection hole structure. During the deburring and / or cleaning step, any burrs and / or sharp edges that may have been generated during previous steps can be removed. Furthermore, during the cleaning process, any residual material can be removed, such as dust or dirt from previous steps, thereby ensuring that the injection hole structure / substrate is ready for use in the battery cell cap.

[0177] The specific structure of the injection hole can be adapted to materials with high rigidity and hardness, such as stainless steel or steel.

[0178] In some embodiments, during stamping, the aforementioned protrusions on the bottom surface of the injection hole structure / substrate and the aforementioned recesses on the upper surface of the injection hole structure / substrate opposite to the bottom surface can be formed simultaneously. "Simultaneously" in the context of this invention means at the same time. This means that the aforementioned protrusions and recesses can be formed at the same time, rather than staggered or with a time offset.

[0179] The above method enables the continuous fabrication of injection hole structures. The base substrate can be conveyed on a conveyor belt and subjected to the above-described stamping and further process steps.

[0180] In some examples, the method for manufacturing the above-described injection hole structure may include:

[0181] - Trim and / or stamp the area surrounding the base substrate where an injection hole structure can be formed;

[0182] - Punch or punch holes in the base substrate to create basic through-holes;

[0183] - A foundation groove is formed on the bottom surface of the stamped base substrate, wherein the foundation groove coaxially surrounds the foundation through hole;

[0184] - The substrate is further stamped on the upper surface of the stamped substrate, wherein a base recess and a base protrusion opposite to the base recess and located at the center of the base groove are formed.

[0185] -Imprinting and / or shaping of base grooves, base depressions and base protrusions, wherein the above-mentioned injection hole structure is formed;

[0186] - Deburr and / or clean the injection hole structure.

[0187] Specifically, by using an injection hole structure made of stainless steel with the aforementioned structural features (secondary recess and protrusion), the welding stress and weld deformation typically observed during and after the laser welding process of the injection hole cap may become unobservable. Furthermore, due to the small gap between the injection hole cap and the injection hole structure / substrate, for example, 0 mm to 0.1 mm, the injection hole cap can be flush-mounted within the recess of the injection hole structure. This small gap ensures laser weldability. Therefore, when using the aforementioned injection hole structure, a strong seal can be achieved, thereby enhancing the overall performance stability and safety of the battery.

[0188] On the other hand, the present invention relates to an injection hole structure that can be obtained by the above method.

[0189] The injection hole structure obtained by the above method can have the above structural features, especially depressions, grooves and protrusions.

[0190] On the other hand, the present invention relates to the use of the injection hole structure according to the invention for sealing the injection hole in a battery cell cap.

[0191] This invention can be used in the automotive industry. Furthermore, it can be used in all fields utilizing batteries and energy storage systems, particularly in areas where large amounts of data are available, such as industry, agriculture, mobility, power supply, and heat supply. For example, this invention can be used in large-scale industrial energy storage systems, small-scale home storage systems, commercial vehicles, laptops, etc.

[0192] Specifically, this invention can be used in fields requiring lightweight design, such as electric aircraft or electric vehicles. Attached Figure Description

[0193] Embodiments of the present invention are described by way of example and with reference to the accompanying drawings, wherein:

[0194] Figure 1 A schematic cross-sectional view of the injection hole structure according to the present invention is shown;

[0195] Figure 2 A substrate including an injection hole structure is schematically shown in a cross-sectional view;

[0196] Figure 3 A substrate including an injection hole structure is schematically shown in top view;

[0197] Figure 4a The top surface of the substrate, including the injection hole structure, is schematically shown in top view.

[0198] Figure 4bThe upper surface of the injection hole structure is schematically shown;

[0199] Figure 5a The bottom surface of the substrate, including the injection hole structure, is schematically shown in top view;

[0200] Figure 5b The bottom surface of the injection hole structure is schematically shown;

[0201] Figure 6 A battery cell cap substrate including an injection hole structure according to the present invention is schematically shown;

[0202] Figure 7 The structure of the vehicle according to the present invention is schematically shown;

[0203] Figure 8 The method according to the invention is illustrated schematically;

[0204] Figure 9 The basic groove is schematically shown; and

[0205] Figure 10 The sealing structure according to the invention is shown schematically. Detailed Implementation

[0206] Figure 1 A schematic cross-sectional view of the injection hole structure 1 according to the present invention is shown. The injection hole structure is located in the substrate 2 of the positive electrode battery cap.

[0207] The injection hole structure 1 is the form of the injection through hole 8 and the surrounding structural features included in the substrate 2 of the positive electrode cap.

[0208] The injection hole structure 1 has a circular shape in the top view. In the cross-sectional view, the injection hole structure 1 has a stepped shape.

[0209] The injection port structure 1 includes an upper surface 3 and a bottom surface 5 opposite to the upper surface 3. The upper surface 3 of the injection port structure 1 is positioned opposite the battery cell tank and the electrolyte. The bottom surface 5 is positioned facing the battery cell tank and the electrolyte.

[0210] The recess 4 is located at the center of the upper surface 3 of the injection hole structure 1. The center of the recess 4 is at the same position as the center of the injection hole structure 1, that is, the recess and the upper surface 3 of the injection hole structure 1 are arranged coaxially. The recess 4 is circular in shape. In a cross-sectional view, the recess 4 is a trapezoidal structure. The recess 4 includes a bottom width wg1 and an opening width wo1, wherein the ratio of the bottom width wg1 to the opening width wo1 is 0.1-5. The bottom width wg1 is 0.1-5 mm. The opening width wo1 is 0.1-5 mm. The opening width wo1 is greater than the bottom width. The groove width of the recess 4 decreases continuously from the opening width wo1 to the bottom width wg1. The entrance of the recess 4 terminates at the upper surface 23 of the substrate 2.

[0211] The recess 4 also includes an inner wall iw1. The inner wall iw1 is located between the entrance and the bottom of the recess. When viewed in a cross-sectional view, the inner wall iw1 forms four corners c11, c12, c13, and c14 at its intersection. Therefore, the recess 4 in the cross-sectional view includes a first corner c11, a second corner c12, a third corner c13, and a fourth corner c14. Corners c11, c12, c13, and c14 each include an angle greater than 90° and each includes a rounded edge. The recess 4 includes a first depth d1 of 0.1-2 mm.

[0212] The protrusion 6 is circular in shape. It is located at the center of the bottom surface 5 of the injection hole structure 1 and has a height 24 of 0.1-2 mm. The protrusion 6 includes a top surface 26, a radius of 1.5-12 mm, a diameter of 3-24 mm, and an outer diameter of 3-24 mm. The protrusion 6 also includes a bottom width bgw and a top width btw, with the ratio of the bottom width bgw to the top width btw being 6.0-1.0. The protrusion 6 also includes an outer wall bow. The outer wall bow is located between the top surface 26 and the groove 7 surrounding the protrusion 6. In a cross-sectional view, the outer wall bow forms four corners: bc1 (first corner), bc2 (second corner), bc3 (third corner), and bc4 (fourth corner). When viewed in a cross-sectional view, the angles at corners bc1 and bc2 are greater than 90° and have rounded edges.

[0213] The groove 7 surrounds the protrusion 7 in a circular shape. The groove 7 includes a bottom width wg2 and an opening width wo2, wherein the ratio of the bottom width wg2 to the opening width wo2 is 0.1-1. The recess 4 includes a first depth d1, and the groove 7 includes a second depth d2, wherein the ratio of the first depth d1 to the second depth d2 is 0.1-1.

[0214] The injection hole structure 1 includes a through hole 8, which is coaxial with the recess 4, groove 7, and protrusion 6, and extends from the recess 4 through the protrusion to the top surface 26 of the protrusion. The through hole 8 is cylindrical in shape and includes a through hole radius 11 and a through hole height 12, wherein the ratio of the through hole radius 11 to the through hole height 12 is 0.01-100. The ratio of the through hole height 12 to the recess depth d1 is 0.01-100. In a cross-sectional view, the through hole 8 includes four corners ch1, ch2, ch3, and ch4, wherein the four corners form 90° and are sharp edges.

[0215] The aforementioned structural features of the injection hole structure (recess 4, groove 7, protrusion 6) allow for rapid and easy filling of the battery cell 13 with electrolyte and enable flush assembly with the injection hole cover. Furthermore, the structural characteristics of the injection hole structure 1 achieve high leakage tightness (high sealing efficiency) of the injection through-hole 8 after electrolyte injection and injection hole cover welding, high safety of the battery cell 13, and prevention of welding cracks.

[0216] Figure 2 A substrate 2, including the injection hole structure 1, is schematically shown in cross-sectional view. A protrusion 6 protrudes outward from the bottom surface 22 of the substrate 1. A recess 4 is located on the upper surface 23 of the substrate 2. The substrate 2 and the injection hole structure 1 are made of steel.

[0217] Figure 3 A substrate 2, including an injection hole structure 1, is schematically shown in top view. The substrate 2 also includes a hole 24 at its center. Hole 24 is an opening for the positive electrode and cathode. The substrate 2 and the injection hole structure 1 are made of steel. The injection hole structure 1 is located at the intersection point i of the shorter side of the substrate.

[0218] Figure 4a The upper surface 23 of the substrate 2, including the injection hole structure 1, is schematically shown. The upper surface 23 of the substrate 2 is shown. Circles indicate the locations of the injection hole structure 1. The substrate 2 and the injection hole structure 1 are made of steel.

[0219] Figure 4b schematically shown Figure 4a The injection hole structure 1, indicated by the middle circle, specifically its upper surface 3. The upper surface 3 includes a recess 4. At the center of the recess, a through-hole 8 is provided, which passes through the substrate 2 and the protrusion 6. The recess 4 also includes a bottom surface sg1. The bottom surface of the recess can be the surface of the recess at the bottom of the recess. The ratio of the outer diameter 9 to the radius 10 of the injection hole structure 1 is 0.1-2.

[0220] Figure 5a The bottom surface 22 of the substrate 2, including the injection hole structure 1, is schematically shown. Circles indicate the location of the injection hole structure 1. The substrate 2 and the injection hole structure 1 are made of steel.

[0221] Figure 5b schematically shown Figure 5a The injection hole structure 1 is indicated by the middle circle, particularly its bottom surface 5. A groove 7 surrounds a protrusion 6. A through hole 8 is located at the center of both the protrusion 6 and the bottom surface 5 of the injection hole structure 1.

[0222] Figure 6 The structure of battery cell 13 is schematically shown, including battery cell cap 14, wherein battery cell cap 14 includes Figure 6 Battery cell cap substrate 2.

[0223] Figure 7 The structure of a vehicle 15 according to the present invention is schematically shown. The vehicle 15 includes an energy storage device 16, which includes... Figure 7 Battery cell 13.

[0224] Figure 8 A method 100 according to the present invention is illustrated schematically. The method includes the following steps:

[0225] Step 106: Trim and / or punch the area of ​​the base substrate 18 surrounding the region where the injection hole structure 1 will be formed. This step involves removing excess material from the base substrate 18 around the region where the injection hole structure 1 will be formed. Trimming refers to removing unwanted material, while punching refers to creating a hole or shape by applying force with a punch. This step prepares the base substrate 18 for forming the injection hole structure 1 by ensuring that only the necessary material of the base substrate 18 is retained.

[0226] Step 101: Punch or punch foundation through holes 17 on the base substrate 18.

[0227] Step 102: A foundation groove 19 is formed on the bottom surface 20 of the base substrate 18 after stamping or punching, wherein the foundation groove 19 is coaxially surrounding the foundation through hole 17. The foundation groove 19 is formed by stamping.

[0228] Step 103: On the upper surface 21 of the stamped or punched substrate 18, the substrate 18 is further stamped, wherein a base recess and a base protrusion opposite to the base recess and located at the center of the base groove 19 are formed.

[0229] During the stamping process, the base groove 19 will fold and thus form an annular groove on the bottom surface 20 of the base substrate 18, opposite to the base recess on the upper surface 21. This formed annulus is necessary because the gap between the injection hole cap and the substrate 2 / injection hole structure 1 needs to be as small as possible (0 mm to 0.1 mm) to ensure laser solderability.

[0230] Step 104: Imprint and / or shape the base groove, base depression, and base protrusion, thereby forming the injection hole structure 1. This step ensures that the injection hole structure has the correct dimensions and surface characteristics required for its function, namely the protrusion 6, the depression 4, and the groove 7.

[0231] Step 105: Deburr and / or clean the injection hole structure 1 to obtain a clean injection hole structure 1. This removes any burrs and / or sharp edges that may have been generated during previous steps. Furthermore, during the cleaning process 106, any residual material, such as dust or dirt from previous steps, is removed, ensuring that the injection hole structure 1 is ready for use in the battery cap 2.

[0232] Figure 9 The diagram schematically shows a base groove 19 on the bottom surface 20 of the base substrate 18 after step 102. The upper surface 21 of the base substrate is opposite the base groove 19. The base groove 19 surrounds the center c of the base substrate. At the center c of the base substrate, a base through hole 17 (not shown) is provided.

[0233] Figure 10 The sealing structure 27 is schematically shown, which includes a substrate 2 containing an injection hole structure 1, an injection hole cover 28, and a rubber pin 29.

[0234] Rubber pin 29 seals the through hole 8 and points into the recess 4. Injection hole cap 28 covers the through hole 8 and the recess 3 sealed by rubber pin 29. The injection hole cap is welded to the substrate by laser welding.

[0235] The gap after inserting the injection port cap 28 into the injection port structure 1 is in the range of 0 mm to 0.1 mm. No other materials, such as welding aids or gap fillers for filling the gap between the injection port cap 28 and the injection port structure 1, are required for proper alignment of the injection port cap 28 and the injection port structure 1.

[0236] The precise fit of the injection port cap 28 is crucial for the overall safety and / or performance of the battery cell 13. The precise fit between the injection port structure 1 and the injection port cap 28 eliminates the need for additional welding auxiliary materials.

[0237] Due to the specific stepped injection hole structure 1 (recesses 4, protrusions 6, and grooves 7 on the bottom surface 5), the heat generated during welding is evenly distributed in the injection hole cap 28, and no localized stress is generated at the weld. Therefore, proper sealing of the through hole 8 is achieved, and electrolyte leakage is avoided.

[0238] List of reference numerals

[0239] 1. Injection Hole Structure

[0240] 2 Battery cell cap substrate

[0241] 3. Upper surface of the injection hole structure

[0242] 4 depressions

[0243] 5. Bottom surface of the injection hole structure

[0244] 6 protrusions

[0245] 7 grooves

[0246] 8 through holes

[0247] 9. Outer diameter of the injection hole structure

[0248] 10 Radius of the injection hole structure

[0249] 11 through hole radius

[0250] 12 through hole height

[0251] 13 battery cells

[0252] 14 Battery Cell Cap

[0253] 15 vehicles

[0254] 16 energy storage devices

[0255] 17 Basic Through Holes

[0256] 18-base battery cell cap substrate

[0257] 19 basic grooves

[0258] 20. Bottom surface of the base substrate

[0259] 21. Top surface of the base substrate

[0260] 22 The bottom surface of the substrate

[0261] 23 The upper surface of the substrate

[0262] 24 substrate holes

[0263] 25 protrusion height

[0264] 26 raised top surface

[0265] 27 Sealing Structure

[0266] 28 cover plate

[0267] 29 rubber pins

[0268] 100 Method for manufacturing injection hole structures

[0269] 101 stamping or punching base through hole

[0270] 102 forms the basic groove

[0271] 103 stamping base substrate

[0272] 104 Imprinting and / or Shaping

[0273] 105 trimming and / or punching

[0274] 106 Deburring and / or Cleaning

[0275] wg1 Recessed bottom width

[0276] wg2 groove bottom width

[0277] wo1 concave opening width

[0278] wo2 groove opening width

[0279] bgw raised bottom width

[0280] btw the width of the raised top

[0281] bow raised outer wall

[0282] iw1 recessed inner wall

[0283] bc1 protrudes from the first corner

[0284] bc2 protrusion at the second corner

[0285] bc3 protrusion at the third corner

[0286] bc4 protrusion at the fourth corner

[0287] d1 First Depth

[0288] d2 second depth

[0289] c base substrate center

[0290] I cross

[0291] c11 concave first corner

[0292] c12 concave second corner

[0293] c13 concave third corner

[0294] c14 concave fourth corner

[0295] sg1 concave bottom surface

[0296] ch1 through hole first corner

[0297] ch2 through hole second corner

[0298] CH3 through hole third corner

[0299] ch4 through hole fourth corner

Claims

1. A battery cell cap substrate (2) including an injection hole structure (1), the injection hole structure comprising... - Upper surface (3), the upper surface including a recess (4); - A bottom surface (5) opposite to the upper surface (3), wherein the bottom surface (5) includes a protrusion (6) opposite to the recess (4) of the upper surface (3) and a groove (7) surrounding the protrusion (6); and - Through hole (8), wherein the through hole (8) is coaxial with the recess (4), the groove (7) and the protrusion (6) and extends from the recess (4) through the protrusion (6).

2. The substrate (2) including the injection hole structure (1) according to claim 1, wherein the injection hole structure (1) has a circular shape and the ratio of the outer diameter (9) to the radius (10) of the injection hole structure is 0.1-2.

3. The substrate (2) including the injection hole structure (1) according to any one of the preceding claims, wherein the recess (4) includes a recess bottom width (wg1) and a recess opening width (wo1), wherein the ratio of the recess bottom width (wg1) to the recess opening width (wo1) is 0.1-5.

4. A substrate (2) comprising the injection hole structure (1) according to any one of the preceding claims, wherein the recess (4) comprises a first depth (d1) and the groove (7) comprises a second depth (d2), wherein the ratio of the first depth (d1) to the second depth (d2) is 0.1-1.

5. A substrate (2) comprising the injection hole structure (1) according to any one of the preceding claims, wherein the protrusion (6) comprises a bottom width (bgw) and a top width (btw), wherein the ratio of the bottom width (bgw) to the top width (btw) is 6.0 to 1.

0.

6. A substrate (2) comprising the injection hole structure (1) according to any one of the preceding claims, wherein the width of the recessed opening (wo1) is greater than or equal to the width of the protruding top (btw).

7. A substrate (2) comprising the injection hole structure (1) according to any one of the preceding claims, wherein the through hole (8) is cylindrical and comprises a through hole radius (11) and a through hole height (12), wherein the ratio of the through hole radius (11) to the through hole height (12) is 0.01-100.

8. A substrate (2) comprising the injection hole structure (1) according to any one of the preceding claims, wherein the ratio of the through hole height (12) to the recess depth (d1) is 0.01-100.

9. A sealing structure (27) comprising a substrate (2) including an injection hole structure (1) as described in any one of claims 1 to 8, an injection hole cap (28), and a rubber pin (29).

10. A battery cell (13) comprising a battery cell cap (14), wherein the battery cell cap (14) comprises a sealing structure (27) according to claim 9.

11. A vehicle (15) including an energy storage device (16) comprising a battery cell (13) according to claim 10.

12. A method (100) for manufacturing an injection hole structure (1) according to any one of claims 1 to 8, comprising: -(101) Punch or punch a basic through hole (17) on the basic battery cell cap substrate (18); -(102) A base groove (19) is formed on the bottom surface (20) of the stamped base substrate, wherein the base groove (19) is coaxially surrounding the base through hole (17); -(103) The base substrate is stamped on the upper surface (21) of the stamped base substrate, wherein a base recess and a base protrusion opposite to the base recess and located at the center of the base groove are formed; as well as - (104) Imprinting and / or shaping the base groove (19), the base recess, the base protrusion and the base through hole (17), wherein an injection hole structure (1) according to any one of claims 1 to 8 is formed.

13. The method according to claim 12, wherein in step (103), the base recess is punched at the location of the base through hole (17).

14. An injection hole structure (1) obtained by the method according to any one of claims 12 to 13.

15. Use of the injection hole structure (1) according to any one of claims 1 to 8 or 14 for sealing the injection hole in a battery cell cap (14).

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