Energy storage element and production method

Abstract

To provide an energy storage element and a production method.SOLUTION: An energy storage element 100 includes an air-tight and liquid-tight enclosed housing and an electrode-separator assembly 104 disposed therein, and an opening of a metal cup-shaped housing portion 101 having a circumferential sidewall and a terminal opening is sealed by a lid assembly 102. The lid assembly includes a metal cover plate 102a, and a terminal pole 102b guided through an aperture in the cover plate and electrically isolated from the cover plate. The terminal pole is placed directly on a contact sheet metal member 111 and connected to it by welding. Additionally, the terminal pole is electrically isolated from the cover plate by a hardened potting compound 113 of an electrically insulating plastic material.SELECTED DRAWING: Figure 3A-B

Description

[Technical Field]

[0001] The present invention, described below, relates to an energy storage element and a method for producing it. [Background technology]

[0002] Electrochemical energy storage elements can convert stored chemical energy into electrical energy through redox reactions. The simplest form of an electrochemical energy storage element is the electrochemical cell. An electrochemical cell includes a positive electrode, a negative electrode, and a separator between them. During discharge, electrons are released from the negative electrode as a result of the oxidation process. This creates an electron flow that can be drawn out by an external electrical consuming device, to which the electrochemical cell acts as an energy source. Simultaneously, an ionic current is generated within the cell corresponding to the electrode reaction. This ionic current crosses the separator and is enabled by the ion-conducting electrolyte. Thus, the separator prevents direct contact between the electrodes, but at the same time allows for charge equalization between the electrodes.

[0003] A battery is considered a secondary battery if its discharge is reversible, meaning that the conversion of chemical energy to electrical energy that occurred during discharge can be reversed to recharge the battery. The terms "anode" (negative electrode) and "cathode" (positive electrode), commonly used for secondary batteries, refer to the discharge function of the electrochemical battery.

[0004] Secondary lithium-ion batteries are used as energy storage elements in many applications because they can provide high current and are characterized by relatively high energy density. They are based on the use of lithium, which can move between the electrodes of the battery in the form of ions. The negative and positive electrodes of lithium-ion batteries are generally formed by so-called composite electrodes, which include not only electrochemically active components but also electrochemically inert components.

[0005] In principle, any material capable of absorbing and releasing lithium ions can be used as an electrochemically active component (active material) for a secondary lithium-ion battery. For the negative electrode, for example, carbon-based particles such as graphite carbon are used. The active material for the positive electrode may be, for example, lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4), or derivatives thereof. Electrochemically active materials are generally contained within the electrode in the form of particles. As an electrochemically inert component, the composite electrode generally includes a flat and / or strip-shaped current collector, such as metal foil, which acts as a carrier for each active material. The negative electrode current collector (anode current collector) may be made of, for example, copper or nickel, and the positive electrode current collector (cathode current collector) may be made of, for example, aluminum.

[0006] Furthermore, the electrodes may include an electrode binder (e.g., polyvinylidene fluoride (PVDF) or another polymer, e.g., carboxymethylcellulose), additives to improve conductivity, and other additives as electrochemically inert components. The electrode binder ensures the mechanical stability of the electrodes and, in many cases, the adhesion of the active material to the current collector. As an electrolyte, lithium-ion batteries typically contain a solution of a lithium salt, such as lithium hexafluoride phosphate (LiPF6), dissolved in an organic solvent (e.g., carbonate ether and carbonate ester).

[0007] Composite electrodes are generally combined with one or more separators during the production of lithium-ion batteries to form an electrode-separator assembly. In this process, the electrodes and separators are often connected under pressure, and sometimes by lamination or bonding, although this is often not essential. The basic functionality of the battery can then be established by impregnating the assembly with an electrolyte.

[0008] In many embodiments, the electrode-separator assembly is formed or manufactured in the form of a wound body. In the first case, for example, a ribbon-shaped positive electrode, a ribbon-shaped negative electrode, and at least one ribbon-shaped separator are supplied separately to a winding machine and wound spirally in the order of positive electrode / separator / negative electrode to form a wound body. In the second case, the ribbon-shaped positive electrode, a ribbon-shaped negative electrode, and at least one ribbon-shaped separator are first combined to form an electrode-separator assembly, for example, using the aforementioned pressure. The assembly is then wound in a further step.

[0009] For applications in the automotive sector, such as e-bikes or other applications with high energy requirements, such as tools, lithium-ion batteries are needed that have the highest possible energy density while also being able to handle high current loads during charging and discharging. Batteries in these applications are often designed as cylindrical batteries with a form factor of, for example, 21 × 70 mm (diameter * height). This type of battery always includes an assembly in the form of a wound body. Modern lithium-ion batteries of this form factor can achieve energy densities of up to 270 Wh / kg.

[0010] (Patent Document 1) describes an electrode-separator assembly and a cylindrical battery in which the electrodes are ribbon-shaped and in the form of a wound body. Each electrode includes a current collector loaded with electrode material. Electrodes polarized to opposite polarities are arranged in the electrode-separator assembly with an offset from each other, so that the longitudinal edge of the positive electrode current collector protrudes from one side of the wound body and the longitudinal edge of the negative electrode current collector protrudes from the other side of the wound body. For electrical contact with the current collectors, the battery has a contact sheet metal member, which is placed on the end face of the wound body and connected to one end face of the current collector by welding. This enables electrical contact with the current collector and therefore electrical contact with each electrode along its entire length. This significantly reduces the internal resistance in the described battery. Subsequently, it is possible to absorb the generation of large currents much better and to dissipate heat from the wound body more effectively.

[0011] Cylindrical batteries, such as those described in Patent Document 1, are typically used as part of a battery group in which several batteries are connected together in series and / or parallel. To tap the voltage, it is often desirable to have the batteries in contact with only one of their end faces. Therefore, it is advantageous to provide both the terminal connected to the positive electrode and the terminal connected to the negative electrode of the battery on only one of the battery's end faces.

[0012] A circular lithium-ion battery, known from (Patent Document 2), includes an electrode-separator assembly formed as a winding within a cylindrical housing. The housing includes a cylindrical metal housing cup, the opening of which is closed by a metal lid assembly. The bottom of the housing cup is electrically connected to the positive electrode of the winding, and thus the housing cup is positively polarized. Since both housing components are in direct contact with each other, the lid assembly is also positively polarized. A positive metal terminal pole is welded onto the lid assembly. On the other hand, the negative electrode of the winding is connected to a negative metal terminal pole, which is guided through the aperture of the lid assembly and electrically insulated from the lid assembly. Thus, the positive and negative terminal poles are positioned adjacent to each other on the same plane of the battery, and as a result, the battery can be easily incorporated into a battery group via the corresponding current conductors.

[0013] In addition to its excellent contact properties, the battery described in (Patent Document 2) is also characterized by the incorporation of overpressure protection. For this purpose, the bottom has a central circular region, which is separated from the rest of the annular region of the bottom by a circumferential weakening line, to which a bent arrester strip is welded to the inner surface, through which the electrical contact of the bottom with the positive electrode of the winding body exists. If the inside of the housing becomes overpressurized, the circular region can be blown off from the bottom. The annular insulator ensures that the rest of the annular area does not come into any contact with the electrode-separator assembly formed as a winding body, thereby preventing electrical contact between the positive electrode and the rest of the annular area and all components that are electrically in contact with that area (including the positive terminal pole).

[0014] The negative electrode of the winding is electrically contacted via multiple bent arrester strips, the upper end of which is coupled to the negative terminal pole. From an energy standpoint, the battery design described in (Patent Document 2) is not optimal. Dead volume exists at both ends of the winding, and therefore the aforementioned arrester strips must fill this dead volume. This negatively affects the energy density of the battery. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] International Publication No. 2017 / 215900A1 Pamphlet [Patent Document 2] U.S. Patent Application Publication No. 2006 / 0019150A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0016] The object of the present invention was to provide an energy storage element which is characterized by an improved energy density compared to the prior art and which can be processed efficiently to form a battery group. Furthermore, the energy storage element should also be characterized by improved safety. This object is achieved by an energy storage element having the features of claim 1. A production process having the features of claim 11 is also an object of the present invention. Preferred embodiments of the energy storage element according to the invention and of the method according to the invention are defined in the dependent claims.

Means for Solving the Problems

[0017] The energy storage element according to the present invention The energy storage element according to the present invention has the features a to o described immediately below. a. The energy storage element includes a hermetically and liquid-tightly sealed housing and an electrode-separator assembly disposed therein. b. The housing includes a metal cup-shaped housing portion having a housing bottom, a circumferential side wall, and a terminal opening. c. The housing includes a lid assembly that closes the terminal opening of the cup-shaped housing portion. d. The lid assembly includes a metal cover plate and terminal poles that are guided through apertures in the cover plate and are electrically insulated from the cover plate. e. The electrode-separator assembly includes a first flat terminal end face and a second flat terminal end face. f. The electrode-separator assembly includes an anode having an anode current collector having a first edge and a second edge parallel thereto. g. The anode current collector includes a main region loaded with a layer of negative electrode material and a free end strip along its first edge that is not loaded with electrode material and extends along the first edge. h. The electrode-separator assembly includes a cathode having a cathode current collector having a first edge and a second edge parallel thereto. i. The cathode current collector includes a main region loaded with the layer of the positive electrode material and a free-end strip extending along the first edge thereof and not loaded with the electrode material. j. The anode and the cathode are arranged in the electrode-separator assembly such that the first edge of the anode current collector protrudes from the first terminal end face of the electrode-separator assembly and the first edge of the cathode current collector protrudes from the second terminal end face. k. The energy storage element includes a contact sheet metal member placed directly on the first edge of the anode current collector or the first edge of the cathode current collector. l. The contact sheet metal member is electrically connected to the terminal pole passing through the aperture of the cover plate. m. The first edge of the cathode current collector or the anode current collector that does not contact the contact sheet metal member directly is electrically connected to the housing bottom. n. The terminal pole is placed directly on the contact sheet metal member and connected thereto by welding. o. The terminal pole is electrically insulated from the cover plate by a cured potting compound of an electrically insulating plastic material.

[0018] Such a designed lid assembly ensures that there is essentially no dead volume between the electrode-separator assembly and the metal cover plate. The potting compound can be filled into any space between the contact sheet metal member, the terminal pole, the cover plate and, if applicable, the O-ring-shaped insulating washer. The lid assembly having the above characteristics can be constructed very compactly. Furthermore, such an energy storage element has the advantage that it can make electrical contact with both the anode and the cathode via the lid assembly.

[0019] Preferred Embodiment of the Lid Assembly In a preferred embodiment, the energy storage element according to the present invention has at least one of the features a and b described immediately below. a. There is an annular gap filled with a potting compound between the cover plate and the contact sheet metal member. b. The annular gap is surrounded radially outward by an O-ring shaped insulating washer made of an electrically insulating plastic material. Particularly preferably, the energy storage element according to the present invention is characterized by a combination of both features a and b described above.

[0020] In many cases, it is preferable that the cup-shaped housing portion is positively polarized and the terminal pole is a negative terminal pole. In these cases, the energy storage element according to the present invention is characterized by feature a described immediately below, and optionally by a combination with at least one more of features b to e described immediately below. a. The cup-shaped housing portion is electrically connected to the cathode. b. The contact sheet metal member rests on the first edge of the anode current collector and is connected to it by welding. c. The cup-shaped housing portion is made of aluminum or an aluminum alloy. d. The cover plate is made of aluminum or an aluminum alloy. e. The contact sheet metal member is in direct contact with the terminal poles guided through the aperture of the cover plate and is preferably connected to them by welding. Particularly preferably, features a to e described immediately above are realized in combination.

[0021] In this embodiment, the substantial portion of the housing of the energy storage element is made of aluminum or an aluminum alloy. This offers several advantages. If the outer surface of the battery comes into contact with moisture, the formation of localized batteries is eliminated. The housing itself can essentially act as a positive terminal on all sides. However, it is particularly preferable that it contacts the battery exclusively via a lid assembly, where the negative terminal pole is also located. For this purpose, the diverter can be welded directly to the cover plate, or alternatively, fixed to a separate terminal pole, for example, by welding. Suitable aluminum alloys for the cup-shaped housing portion and cover plate are, for example, Al alloys of the types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg are also suitable. The aluminum content of the alloy is preferably greater than 99.5%.

[0022] In further cases, it may be preferable that the cup-shaped housing portion is negatively polarized and the terminal pole is a positive terminal pole. In these cases, the energy storage element according to the present invention has feature a described immediately below, and, where appropriate, a combination of at least one more of features b to e described immediately below. a. The cup-shaped housing portion is electrically connected to the anode. b. The contact sheet metal member is placed on the first edge of the cathode current collector and connected to it by welding. c. The cup-shaped housing portion is made of copper or nickel, or a copper or nickel alloy or steel, or nickel-plated steel. d. The cover plate is made of copper or nickel, or a copper or nickel alloy or steel, or nickel-plated steel. e. The contact sheet metal member is in direct contact with the terminal poles guided through the aperture of the cover plate and is preferably connected to them by welding. Particularly preferably, features a to e described immediately above are realized in combination.

[0023] In this embodiment, the substantial portion of the housing of the energy storage element consists of copper or nickel, or a copper or nickel alloy or steel, or nickel-plated steel. Suitable stainless steels include, for example, stainless steel of type 1.4303 or 1.4404, stainless steel of type SUS304, or nickel-plated steel. Specifically, as the copper alloy, a material of type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used. Nickel alloys of type NiFe, NiCu, CuNi, NiCr, and NiCrFe are particularly suitable.

[0024] In an advanced form of the energy storage element according to the present invention, in which the cup-shaped housing portion has positive polarity and the terminal pole is a negative terminal pole, the energy storage element is characterized by features a to d described immediately below. a. The contact sheet metal member is made of nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel. b. The terminal pole is a bimetallic terminal pole and includes a pole base made of nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel, and a pole upper part made of aluminum or an aluminum alloy. c. The pole base portion is welded to the contact sheet metal member. d. The pole base, contact sheet metal component, and anode current collector are made of the same material. Particularly preferably, the energy storage element according to the present invention is characterized by all combinations of features a to d described above.

[0025] Accordingly, in this embodiment, the energy storage element according to the present invention is characterized by terminal poles comprising two different metallic materials: on the one hand, nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel, and on the other hand, aluminum or an aluminum alloy. Thus, it is possible to construct an energy storage element according to the present invention in which the outer surface of its housing is formed entirely from aluminum or an aluminum alloy.

[0026] The upper part of the pole can be accessed from the outside and, for example, welded to an aluminum current conductor. Such energy storage elements offer the significant advantage of being easily incorporated into a battery group. In this case, the poles of several energy storage elements are interconnected via a common current conductor. From a production technology standpoint, it may be advantageous to weld the battery poles to the current conductors by laser. This is generally only problematic if the materials being welded are the same. For example, welding a copper terminal pole to an aluminum current conductor using a laser is difficult or impossible. On the other hand, if the upper part of the pole is made of aluminum or an aluminum alloy, welding can be performed without any problems. Thus, even the negative terminal pole of a battery can be connected by laser via a common aluminum current conductor.

[0027] Suitable aluminum alloys include, for example, Al alloys of the types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg are also suitable. The aluminum content of the alloys is preferably above 99.5%. Suitable stainless steels include, for example, stainless steel of the type 1.4303 or 1.4404, stainless steel of the type SUS304, or nickel-plated steel. Specifically, as copper alloys, materials of the type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used. Nickel alloys of the types NiFe, NiCu, CuNi, NiCr, and NiCrFe are particularly suitable.

[0028] In a further developed form of the energy storage element according to the present invention, in which the cup-shaped housing portion has negative polarity and the terminal pole is a positive terminal pole, the energy storage element has features a to c described immediately below. a. The contact sheet metal member is made of aluminum or an aluminum alloy. b. The terminal poles are made of aluminum or an aluminum alloy. c. The contact sheet metal member, the terminal pole, and the cathode current collector are made of the same material. Particularly preferably, the energy storage element according to the present invention is characterized by all combinations of features a to c described above.

[0029] Therefore, in this embodiment, it is also possible to construct an energy storage element according to the present invention in which the outer surface of the housing is formed entirely from aluminum or an aluminum alloy.

[0030] Preferred embodiment of the contact sheet metal member / Connection between the contact sheet metal member and the anode current collector and the negative terminal or connection between the contact sheet metal member and the cathode current collector and the positive terminal The contact sheet metal member is electrically connected to the terminal pole, which passes through the aperture of the cover plate, and to the anode current collector or cathode current collector. Specifically, the contact sheet metal member is directly welded to the terminal pole and / or their respective current collectors.

[0031] In a particularly preferred embodiment of the present invention, where the cup-shaped housing portion has positive polarity and the terminal pole is a negative terminal pole, the contact sheet metal member electrically connected to the negative terminal pole has at least one of the features described immediately below. a. The contact sheet metal member is made of nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel, such as stainless steel of type 1.4303 or 1.4404, stainless steel of type SUS304, or nickel-plated copper. b. The contact sheet metal member is made of the same material as the negative terminal pole or the pole base portion of the negative terminal pole. c. The contact sheet metal member is made of the same material as the anode current collector. Features a and b described immediately above, and especially features a to c, are preferably realized in combination with each other.

[0032] In a particularly preferred embodiment of the present invention, where the cup-shaped housing portion has negative polarity and the terminal pole is a positive terminal pole, the contact sheet metal member electrically connected to the positive terminal pole has at least one of the features a to c described immediately below. a. The contact sheet metal member is made of aluminum or an aluminum alloy. b. The contact sheet metal member is made of the same material as the positive terminal. c. The contact sheet metal member is made of the same material as the cathode current collector. Features a and b described immediately above, preferably features a to c, are particularly preferably realized in combination with each other.

[0033] If the contact sheet metal member is made of the same material as the positive terminal and / or cathode current collector, welding of these components can be performed without problems. Suitable aluminum alloys for the contact sheet metal member include Al alloys of the types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg are also suitable. The aluminum content of the alloy is preferably greater than 99.5%.

[0034] In a possible preferred evolution of the present invention, the contact sheet metal member has at least one of the features a to f described immediately below. a. The contact sheet metal member preferably has a uniform thickness in the range of 50 μm to 600 μm, and more preferably in the range of 150 μm to 350 μm. b. The contact sheet metal member has two opposing flat surfaces and extends substantially in only one dimension. c. The contact sheet metal member is a disc or a polygonal plate. d. The contact sheet metal member is sized such that it covers at least 40%, preferably at least 60%, and particularly preferably at least 80% of the protruding edge of the current collector on which it rests. e. The contact sheet metal member has at least one bead, which appears as an elongated recess on one flat surface of the contact sheet metal member and as an elongated convex on the opposite flat surface, and the contact sheet metal member rests on the first edge of the anode current collector or the first edge of the cathode current collector by its flat surface supporting the elongated convex. f. The contact sheet metal member is welded to the first edge of the anode current collector or the first edge of the cathode current collector in the region from the bead. Features a to c described immediately above, and especially preferably features a to d described immediately above, are particularly preferably implemented in combination with each other. In a preferred embodiment, features a to d are implemented in combination with features e and f.

[0035] Regarding thermal management of the energy storage element according to the present invention, it is important to cover the end faces over as large an area as possible. The larger the coverage, the higher the likelihood of contact with the first edge of each current collector (and, if possible, along its entire length). Therefore, the heat generated in the electrode-separator assembly can be effectively dissipated through the contact sheet metal member.

[0036] In some embodiments, it has proven advantageous to pre-treat the edges of each current collector on which the contact sheet metal member is to be placed before positioning the contact sheet metal member. Specifically, the edges may be folded to form at least one recess corresponding to at least one bead or elongated protrusion on the flat surface of the contact sheet metal member facing the first terminal end face. The edges of the current collector may also be oriented by the pre-treatment. For example, the edges of the current collector may be bent in a defined direction.

[0037] In some particularly preferred embodiments, the contact sheet metal member is pressed against the end face of the winding. In this case, at least one bead is unnecessary. In these cases, the contact sheet metal member is preferably polygonal or strip-shaped and covers preferably at least 40%, particularly preferably at least 60%, and especially at least 80% of the end face to be pressed.

[0038] Primary and secondary protection In a particularly preferred embodiment of the present invention, the energy storage element according to the present invention is characterized by the following features a and b. a. The bottom of the cup-shaped housing portion has primary protection against internal overpressure in the form of an aperture closed by a metal film. b. The bottom of the cup-shaped housing portion has secondary protection against internal overpressure in the form of at least one groove on its inner or outer surface.

[0039] The primary fuse has the function of providing pressure control compensation when an unacceptable overpressure occurs that exceeds a defined threshold. In this case, the pressure causes the diaphragm to rupture or blow out, allowing the gas generated inside the housing to escape through the aperture at the bottom of the housing.

[0040] A secondary fuse is provided if pressure equalization is not achieved quickly via the primary fuse. In this case, excessive pressure along a groove, which is merely a weakening structure at the bottom of the housing, causes the bottom of the housing to tear open, creating an outlet opening with a relatively large cross-section through which the gas generated inside the housing can escape. Such protective solutions are already known. With proper design of the groove and membrane, it is possible to precisely set the pressure at which the protection is triggered.

[0041] These safety features are not integrated into the lid assembly as in many conventional batteries (they are instead integrated into the bottom of the housing), allowing for the construction of an extremely compact lid assembly. Pre-assembly of the lid assembly is also unnecessary. Instead, the lid assembly can be manufactured during the assembly of the housing, as described in more detail below.

[0042] In a particularly preferred embodiment, the energy storage element according to the present invention has at least one of the features a to e described immediately below. a. The cover plate is welded to the terminal opening of the cup-shaped housing portion. b. The contact sheet metal member is assembled to the first edge of the anode current collector or the first edge of the cathode current collector by welding. c. The first edge of the anode or cathode current collector that does not directly contact the contact sheet metal member is placed directly on the bottom of the housing. d. The first edge of the anode or cathode current collector that does not directly contact the contact sheet metal member is connected to the bottom of the housing by welding. e. At least one groove is visible on the inner surface of the bottom of the housing. Preferably, features a to d described immediately above, and especially preferably features a to e described immediately above, are realized in combination.

[0043] In another particularly preferred embodiment of the present invention, the energy storage element according to the present invention is characterized by the following feature a. a. The metal film is fixed to the bottom of the cup-shaped housing portion by welding.

[0044] The bottom of the cup-shaped housing portion may have a shallow recess into which the membrane is inserted to prevent it from curling. Preferably, the membrane is connected to the bottom via a circular weld seam extending around the bottom aperture. The thickness of the membrane can be adjusted to match the pressure under which the protection is activated.

[0045] Preferred design of the housing bottom In a preferred embodiment, the energy storage element according to the present invention has at least one of the features a to f described immediately below. a. The bottom of the housing has at least one bead, which appears as an elongated recess on the outer surface of the bottom of the housing and as an elongated convex on the inner surface of the bottom of the housing, and the first edge of the anode current collector or the first edge of the cathode current collector is placed on the inner surface. b. The bottom of the housing is welded to the first edge of the anode current collector or the first edge of the cathode current collector in the region from the bead. c. The aperture is positioned at the center of the bottom of the housing. d. At least one bead includes multiple straight beads, specifically three beads, arranged in a star configuration around the aperture. e. At least one groove includes multiple straight subsections arranged in a star-shaped configuration around the aperture. f. At least one groove extends around the aperture and includes subsections that interconnect the star-shaped linear subsections. Preferably, features a and b, c and d, and c, e, and f described immediately prior to this are realized in combination. Particularly preferably, features a to f described immediately prior to this are realized in combination.

[0046] As a result of welding in the bead region, preferably one or more weld seams are visible in the latter. Each of the star-shaped bead and the star-shaped straight section of the groove preferably forms an angle of 120°. In some embodiments, it has proven advantageous to pre-treat the edge of the current collector that rests on the inner surface of the housing bottom to improve contact between the housing bottom and the current collector. Specifically, the edge can be folded to form at least one recess corresponding to at least one bead or elongated protrusion on the inner surface of the housing bottom. The edge of the current collector may also be directionally formed by the pre-treatment. For example, the edge of the current collector can be bent in a defined direction. In some embodiments, the bottom of the cup-shaped housing portion is welded and therefore manufactured separately and joined to the sidewall by welding. However, in most cases, the cup-shaped housing portion is manufactured by deep drawing.

[0047] Prismatic embodiment Preferably, the energy storage element according to the present invention is designed as a cylindrical battery or a button battery. However, in some preferred embodiments, the energy storage element according to the present invention may also be prismatic. In the latter case, the housing is prismatic. In this embodiment, the bottom and lid assembly of the cup-shaped housing portion preferably has a polygonal, particularly preferably rectangular, base. The shape of the terminal opening of the cup-shaped housing portion matches the shape of the bottom and lid assembly. Furthermore, the housing includes a plurality, preferably four, rectangular side portions connecting the bottom and lid assembly.

[0048] In this embodiment, the electrode-separator assembly is also preferably prismatic. In this case, the electrode-separator assembly is preferably a prismatic stack of several anodes, cathodes and at least one separator, and the electrode-separator assembly in the stack always includes anode / separator / cathode in this order. At least the anode and cathode preferably have a rectangular base surface, and each of the anode and cathode current collectors has a first edge and a second edge parallel thereto, and each has a free end strip along its first edge that is not coated with the respective electrode material.

[0049] If multiple separators are present between the anode and cathode, the separators also preferably have a rectangular footprint. However, ribbon-shaped separators can also be used to separate some anodes and cathodes in a stack. For example, the first and second flat terminal end faces of the stack are two opposing or adjacent faces of the stack. The first edge of the anode current collector protrudes from one of these end faces, and the first edge of the cathode current collector protrudes from the other. Contact sheet metal members rest on the first edges of the anode current collectors and are connected to them by welding.

[0050] Design as a cylindrical or button cell battery In embodiments of the energy storage element according to the present invention as a cylindrical battery or a button battery, the energy storage element according to the present invention preferably has at least one of the features a to p described immediately below. a. The terminal opening of the cup-shaped housing portion is circular in shape, and the circumferential side wall of the cup-shaped housing portion includes or forms a cylindrical housing shell. b. The lid assembly that closes the circular opening of the cup-shaped housing portion has a circular circumference. c. The electrode-separator assembly is in the form of a cylindrical wound body and has a wound body shell located between the end faces, in addition to first and second flat terminal end faces. d. Within the housing, the electrode-separator assembly is axially aligned so that the wound shell abuts against the inner surface of the cylindrical housing shell. e. The anode and anode current collector are ribbon-shaped, and the anode current collector has a first longitudinal edge, a second longitudinal edge, and two ends. f. The first edge and the parallel second edge of the anode current collector are the longitudinal edges of the ribbon-shaped anode current collector. g. The main strip-shaped region of the anode current collector is loaded with a layer of negative electrode material. h. The free end strip extends along the first longitudinal edge of the anode current collector. i. The cathode and cathode current collector are ribbon-shaped, and the cathode current collector has a first longitudinal edge, a second longitudinal edge, and two ends. j. The first edge and the parallel second edge of the cathode current collector are the longitudinal edges of the ribbon-shaped cathode current collector. k. The main strip-shaped region of the cathode current collector is loaded with a layer of positive electrode material. l. The free end strip extends along the first longitudinal edge of the cathode current collector. m. One or more separators in the electrode-separator assembly are ribbon-shaped. n. The anode and cathode are positioned within the electrode-separator assembly such that the first edge of the anode current collector protrudes from the first terminal end face of the electrode-separator assembly, and the first edge of the cathode current collector protrudes from the second terminal end face. o. The contact sheet metal member is placed on the first longitudinal edge of the anode current collector or the first edge of the cathode current collector and assembled by welding. p. The first longitudinal edge of the anode or cathode current collector that does not directly contact the contact sheet metal member is electrically connected to the bottom of the housing. Particularly preferably, the energy storage element according to the present invention is characterized by a combination of all the features a to p described above.

[0051] In this embodiment, the electrode-separator assembly preferably includes one ribbon-shaped separator or two ribbon-shaped separators, each having first and second longitudinal edges and two ends. The electrode-separator assembly always includes the electrode and separator in the order anode / separator / cathode.

[0052] Preferably, in this embodiment, a lid assembly having a circular periphery is positioned in the circular opening of the cup-shaped housing portion such that its periphery abuts against the inner surface of the cup-shaped housing portion along a circumferential contact zone, and the periphery of the lid assembly is connected to the cup-shaped housing portion by a circumferential weld seam. Preferably, the height of the energy storage element designed according to the present invention as a cylindrical battery is in the range of 50 mm to 150 mm. The diameter of the cylindrical battery is preferably in the range of 15 mm to 60 mm. Cylindrical batteries having these form factors are particularly suitable for supplying power to the electric drive unit of an automobile. When the energy storage element according to the present invention is designed as a button battery, it preferably has a maximum diameter of 25 mm and a maximum height of 15 mm.

[0053] In embodiments of the present invention where the battery is a cylindrical battery, the anode current collector, the cathode current collector, and one or more separators preferably have the following dimensions. - Lengths ranging from 0.5m to 25m - Width in the range of 30mm to 145mm

[0054] In these cases, the free end strip extending along the first longitudinal edge and not loaded with electrode material preferably has a width of 5000 μm or less. Particularly preferably, the anode current collector has a free end strip having a width in the range of 1000 to 2000 μm, particularly preferably about 1500 μm. Particularly preferably, the cathode current collector has a free end strip having a width in the range of 2000 to 4000 μm, particularly preferably about 3000 μm.

[0055] Preferred Embodiment of Separator Preferably, one or more separators are formed from an electrically insulating plastic film. The separator is preferably permeable to the electrolyte. For this purpose, the plastic film used may, for example, have micropores. The foil may consist of, for example, polyolefin or polyetherketone. Nonwoven fabrics and textiles or other electrically insulating sheet structures made of plastic materials can also be used as separators. Preferably, separators having a thickness in the range of 5 μm to 50 μm are used. In some particularly preferred embodiments, separators are used that are coated on one or both sides with ceramic particles (e.g., Al2O3 or SiO2) or impregnated with ceramic particles (e.g., Al2O3 or SiO2). Specifically, in embodiments where the energy storage element is prismatic, one or more separators in the assembly may also be one or more layers of the solid electrolyte.

[0056] Preferred structure of electrode-separator assembly formed as a wound body The ribbon-shaped anode, ribbon-shaped cathode, and ribbon-shaped separator are preferably helically wound around an electrode-separator assembly in the form of a wound body. To produce the electrode-separator assembly, the ribbon-shaped electrodes are preferably supplied together with the ribbon-shaped separator to a winding device, where they are preferably helically wound around the winding body axis. In some embodiments, the electrodes and separators are wound for this purpose on a cylindrical or hollow cylindrical winding body core, which is placed on a winding mandrel and remains on the winding body after winding. The winding body shell can be formed, for example, from a plastic film or adhesive tape. The winding body shell can also be formed from one or more separator winding bodies.

[0057] Preferred electrochemical embodiment In another particularly preferred embodiment of the present invention, the energy storage element according to the present invention has features a and b described immediately below. a. The energy storage element is a lithium-ion battery. b. The energy storage element includes a lithium-ion battery. Feature a specifically refers to the described embodiment of the energy storage element according to the invention as a cylindrical battery or a button battery. In this embodiment, the energy storage element preferably includes exactly one electrochemical cell or is exactly one electrochemical cell. Feature b specifically refers to the described prismatic embodiment of the energy storage element according to the invention. In this embodiment, the energy storage element may also include a plurality of electrochemical cells.

[0058] Basically, as the electrodes of the energy storage element, all electrode materials known for secondary lithium-ion batteries can be used. As the active material of the negative electrode, preferably in the form of particles, carbon-based particles such as graphite-like carbon or non-graphite carbon materials capable of intercalating lithium can be used. Alternatively or in addition, preferably, lithium titanate (Li4Ti5O 12 ) or its derivatives can be included in the negative electrode in the form of particles. Further, the negative electrode includes, as the active material, at least one material from the group including silicon, aluminum, tin, antimony, or compounds or alloys of these materials capable of reversibly depositing and removing lithium, such as silicon oxide (specifically SiO x , 0 < x < 2), which can optionally be combined with a carbon-based active material. Tin, aluminum, antimony, and silicon can form intermetallic phases with lithium. The capacity to absorb lithium, especially in the case of silicon, far exceeds that of graphite or equivalent materials. In many cases, a mixture of silicon and a carbon-based storage material is used. A thin anode made of metallic lithium is also suitable.

[0059] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds (such as LiCoO2 and LiFePO4). Further, the chemical formula LiNi x Mn y Co zLithium nickel manganese cobalt oxide (NMC) with O2 (where x + y + z is typically 1), lithium manganese spinel (LMO) with the chemical formula LiMn2O4, or LiNi x Co y Al z Lithium nickel cobalt aluminate (NCA) with O2 (where x + y + z is typically 1) is particularly well - suited. Its derivatives, such as, for example, the chemical formula Li 1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 Lithium nickel manganese cobalt aluminate (NMCA) with O2 or the Li 1+x M - O compounds and / or mixtures of the above materials can also be used. The cathode active material is also preferably used in the form of particles.

[0060] In addition, the electrodes of the energy storage element according to the present invention preferably contain an electrode binder and / or an additive to improve conductivity. The active material is preferably embedded in the matrix of the electrode binder, and adjacent particles of the matrix preferably contact each other directly. The conductive agent has the function of increasing the conductivity of the electrode. Common electrode binders are based on, for example, polyvinylidene fluoride (PVDF), lithium polyacrylate, styrene - butadiene rubber, carboxymethyl cellulose, or mixtures of different binders. Common conductive agents are carbon black, particulate graphite, carbon fiber, carbon nanotubes, and metal powders.

[0061] The energy storage element according to the present invention preferably comprises an electrolyte, and in the case of a lithium-ion battery, specifically an electrolyte based on at least one lithium salt, such as lithium hexafluoride phosphate (LiPF6), dissolved in an organic solvent (e.g., an organic carbonate or a mixture of cyclic ethers such as THF or nitrile). Other lithium salts that can be used include lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalato)borate (LiBOB).

[0062] The nominal capacity of the lithium-ion energy storage element according to the present invention, designed as a cylindrical battery, is preferably up to 15,000 mAh. In a 21 × 70 form factor, the energy storage element in one embodiment as a lithium-ion battery preferably has a nominal capacity in the range of 1,500 mAh to 7,000 mAh, and particularly preferably in the range of 3,000 to 5,500 mAh. In an 18 × 65 form factor, the battery in one embodiment as a lithium-ion battery preferably has a nominal capacity in the range of 1,000 mAh to 5,000 mAh, and particularly preferably in the range of 2,000 to 4,000 mAh.

[0063] In the European Union, manufacturers are strictly regulated in providing information regarding the nominal capacity of secondary batteries. For example, information regarding the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to IEC / EN61951-1 and IEC / EN60622 standards, information regarding the nominal capacity of secondary nickel-metal hydride batteries must be based on measurements according to IEC / EN61951-2 standards, information regarding the nominal capacity of secondary lithium batteries must be based on measurements according to IEC / EN61960 standards, and information regarding the nominal capacity of secondary lead-acid batteries must be based on measurements according to IEC / EN61056-1 standards. Any information regarding nominal capacity in this application is preferably based on these standards.

[0064] Sodium ion-based embodiment In further embodiments, the energy storage element according to the present invention may be a sodium-ion battery, a potassium-ion battery, a calcium-ion battery, a magnesium-ion battery, or an aluminum-ion battery. Among these variations, an energy storage battery having the chemical properties of a sodium-ion battery according to the present invention is particularly preferred.

[0065] Preferably, the sodium ion-based energy storage element of the present invention comprises an electrolyte comprising at least one of the following solvents and at least one of the following conductivity salts. Suitable solvents specifically include organic carbonates, ethers, nitriles, and mixtures thereof. Preferred examples are as follows: - Carbonates: Propylene carbonate (PC), ethylene carbonate-propylene carbonate (EC-PC), propylene carbonate-dimethyl carbonate-ethylmethyl carbonate (PC-DMC-EMC), ethylene carbonate-diethyl carbonate (EC-DEC), ethylene carbonate dimethyl carbonate (EC-DMC), ethylene carbonate ethylmethyl carbonate (EC-EMC), ethylene carbonate dimethyl carbonate ethylmethyl carbonate (EC-DMC-EMC), ethylene carbonate dimethyl carbonate diethyl carbonate (EC-DMC-DEC). - Ethers: tetrahydrofuran (THE), 2-methyltetrahydrofuran, dimethyl ether (OME), 1,4-dioxane (DX), 1,3-dioxolane (DOL), diethylene glycol dimethyl ether (DEGDME), tetraethylene glycol dimethyl ether (TEGDME). - Nitriles: Acetonitrile (ACN), adiponitrile (AON), γ-butyrolactone (GBL). Furthermore, trimethyl phosphate (TMP) and tris(2,2,2-trifluoroethyl) phosphate (TFP) are also possible.

[0066] Preferred conductivity salts are as follows: NaPF6, sodium difluoro(oxalato)borate (NaBOB), NaBF4, sodium bis(fluorosulfonyl)imide (NaFSI), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), NaAsF6, NaBF4, NaClO4, NaB(C2O4)2, NaP(C6H4O2)3, NaCF3SO3, sodium triflate (NaTf), and Et4NBF4. In preferred embodiments, additives can be added to the electrolyte. Examples of preferred additives, particularly for stabilization, include: fluoroethylene carbonate (FEC), transdifluoroethylene carbonate (DFEC), ethylene sulfite (ES), vinylene carbonate (VC), bis(2,2,2-trifluoroethyl) ether (BTFE), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(fluorosulfonyl)imide (NaFSI), aluminum chloride (AICI3), ethylene sulfate (DTD), sodium difluorophosphate (NaPO2F2), sodium difluoro(oxalato)borate (NaODFB), sodium difluorobisoxalatophosphate (NaDFOP), and tris(trimethylsilyl)borate (TMSB).

[0067] The negative electrode material for the sodium ion-based energy storage element according to the present invention is preferably at least one of the following materials. - Carbon: Particularly preferably hard carbon (pure or nitrogen and / or phosphorus-doped) or soft carbon or graphene-based material (N-type doped), carbon nanotubes, graphite - Phosphorus or sulfur (conversion anode) - Polyanions: Na2Ti3O7, Na3Ti2(PO4)3, TiP2O7, TiNb2O7, Na-Ti-(PO4)3, Na-V-(PO4)3 - Prussian blue: Low sodium variant (for aqueous electrolyte systems) - Transition metal oxides: V2O5, MnO2, TiO2, Nb2O5, Fe2O3, Na2Ti3O7, NaCrTiO4, Na4Ti5O 12 - MXene: M=Ti, V, Cr, Mo or Nb, A=Al, Si and Ga, X=C and / or N (e.g., Ti3C2) - Organic substances: For example, sodium terephthalate (Na2C8H2O4) Alternatively, a Na metal anode can be used on the anode side.

[0068] The positive electrode material of the sodium ion-based energy storage element according to the present invention may be, for example, at least one of the following materials. - Polyanions: NaFePO4 (trifil type), Na2Fe(P2O7), Na4Fe3(PO4)2(P2O7), Na2FePO4F, Na / Na2[Fe 1 / 2 Mn 1 / 2 ]PO4F, Na3V2(PO4)2F3, Na3V2(PO4)3, Na4(CoMnNi)3(PO4)2P2O7, NaCoPO4, Na2CoPO4F - Silicates: Na2MnSiO4, Na2FeSiO4 - Layered oxides: NaCoO2, NaFeO2, NaNiO2, NaCrO2, NaVO2, NaTiO2, Na(FeCo)O2, Na(NiFeCo)3O2, Na(NiFeMn)O2, and Na(NiFeCoMn)O2, Na(NiMnCo)O2, NaCoO2, NaFeO2, NaNiO2, NaCrO2, NaVO2, NaTiO2, Na(FeCo)O2, Na(NiFeCo)3O2, Na(NiFeMn)O2, and Na(NiFeCoMn)O2, Na(NiMnCo)O2

[0069] In addition, the electrodes of the energy storage element according to the present invention preferably include an electrode binder and / or additives to improve conductivity. The active material is preferably embedded in the matrix of the electrode binder, and the active material is preferably used in the form of particles, and adjacent particles in the matrix are preferably in direct contact with each other. Conductive agents have the function of increasing the conductivity of the electrodes. Common electrode binders are based on, for example, polyvinylidene fluoride (PVDF), sodium polyacrylate, styrene-butadiene rubber, sodium alginate, or carboxymethylcellulose, or mixtures of different binders. Common conductive agents are carbon black, fine-particle graphite, carbon fibers, carbon nanotubes, and metal powders.

[0070] Particularly preferred, in the energy storage element according to the present invention based on sodium ion technology, both the anode current collector and the cathode current collector are made of aluminum or an aluminum alloy. Not only the housing and contact plates, but also any further current conductors present within the housing may be made of aluminum or an aluminum alloy.

[0071] Preferred Embodiment of a Current Collector The current collector of the energy storage element has the function of making electrical contact with the electrochemically active components contained in each electrode material over the largest possible area. Preferably, the current collector is made of metal or at least its surface is metallized.

[0072] In the case of the energy storage element according to the present invention designed as a lithium-ion battery, suitable metals for the anode current collector are, for example, copper or nickel or other conductive materials (specifically, copper or nickel alloys or nickel-coated metals). Specifically, as copper alloys, materials of the type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used. Nickel alloys of the type NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable. In principle, stainless steel of the type 1.4303 or 1.4404 or SUS304 is also possible.

[0073] For the energy storage element according to the present invention, designed as a lithium-ion battery, aluminum or other conductive materials (including aluminum alloys) are particularly suitable as the metal for the cathode current collector. Suitable aluminum alloys for the cathode current collector include Al alloys of the types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg are also suitable. The aluminum content of the alloy is preferably greater than 99.5%.

[0074] Preferably, each of the anode current collector and / or cathode current collector is a metal foil with a thickness in the range of 4 μm to 30 μm, and in the described configuration of the energy storage element as a cylindrical battery, it is a ribbon-shaped metal foil with a thickness in the range of 4 μm to 30 μm. In some preferred embodiments, the foil may be perforated. However, in addition to the foil, other ribbon-shaped substrates such as metal nonwoven fabric or metallized nonwoven fabric, perforated metal foam, or expanded metal can be used as current collectors. Preferably, the current collectors have the respective electrode materials supported on both sides. In the described configuration of the energy storage element as a cylindrical battery, the longitudinal edge of the separator preferably forms the end face of the electrode-separator assembly formed as a wound body. In the prismatic configuration of the energy storage element described, the edge of the separator preferably forms the end face of the stack where the edge of the current collector appears.

[0075] The longitudinal edges or margins of the anode current collector and / or cathode current collector protruding from the terminal surface of the winding or the surface of the stack are preferably 5000 μm or less, more preferably 3500 μm or less. Particularly preferably, the edges or longitudinal edges of the anode current collector protrude only 2500 μm or less, particularly preferably 1500 μm or less, from the surface of the stack or the end surface of the winding. Particularly preferably, the edges or longitudinal edges of the cathode current collector protrude only 3500 μm or less, particularly preferably 2500 μm or less, from the surface of the stack or the end surface of the winding.

[0076] Preferred embodiment of the housing portion In a further particularly preferred embodiment of the present invention, the energy storage element according to the present invention has at least one of the features a to c described immediately below. a. The bottom of the cup-shaped housing portion has a thickness in the range of 200 μm to 2000 μm. b. The side walls of the cup-shaped housing portion have a thickness ranging from 150 μm to 2000 μm. c. The lid assembly, specifically the cover plate of the lid assembly, has a thickness in the range of 200 μm to 2000 μm. Particularly preferably, features a to c described immediately above are realized in combination.

[0077] The method according to the present invention The production method according to the present invention is used to produce an energy storage element according to the present invention and is characterized by steps a to e according to the present invention. According to the present invention, the circumferential side wall and terminal opening, b. A step of providing an electrode-separator assembly, wherein the electrode-separator assembly is - A cathode having a cathode current collector having a first edge and a second edge parallel thereto, - An anode including an anode current collector having a first edge and a second edge parallel thereto, - A first flat terminal end face and a second flat terminal end face Includes, - The anode current collector includes a main region loaded with a layer of negative electrode material and a free end strip extending along its first edge, which is not loaded with electrode material. - The cathode current collector includes a main region loaded with a layer of positive electrode material and a free end strip extending along its first edge, which is not loaded with electrode material. - The anode and cathode are positioned within the electrode-separator assembly such that the first edge of the anode current collector protrudes from the first terminal end face of the electrode-separator assembly, and the first edge of the cathode current collector protrudes from the second terminal end face. c. Inserting the electrode-separator assembly into the cup-shaped housing portion such that the first edge of the anode current collector or the first edge of the cathode current collector is positioned at the bottom of the housing. d. A cover plate having an aperture for the terminal pole (102b) is inserted into the terminal opening of the cup-shaped housing portion (101). e. A step in which the gap remaining between the cover plate (102a) and the contact sheet metal member (111) is filled with a potting compound (113), wherein, once cured, the potting compound (113) electrically insulates the cover plate (102a) from the terminal pole (102b) and from the contact sheet metal member (111).

[0078] All components used in the method relating to the energy storage element according to the present invention have been described. Hereinafter, the corresponding descriptions are referred to. Steps d and e form the housing of the energy storage element, simultaneously sealing its upper portion. Preferably, a cover plate is welded to the cup-shaped housing portion before step e. This measure, combined with the application of the potting compound in step e, ensures a liquid-tight and airtight seal of the housing.

[0079] As described above, it is preferable that the first edge of the anode current collector or the first edge of the cathode current collector be placed directly on the bottom of the housing. Furthermore, it is preferable that the edge that rests on the bottom of the housing be fixed to the bottom of the housing by welding. The welding connection between the first edge that rests on the bottom of the housing and the bottom of the housing is preferably made from the outside by welding, specifically by laser welding.

[0080] In a preferred embodiment, the method includes at least one of steps a and b described immediately below. a. A contact sheet metal member is positioned on a first edge of the anode current collector or a first edge of the cathode current collector that is not placed on the bottom of the housing, and is fixed to this edge by welding. b. The terminal pole is fixed to the contact sheet metal member. Preferably, the method according to the present invention includes both steps a and b.

[0081] Steps a and b can be performed before or after inserting the electrode-separator assembly into the housing cup. The terminal poles are fixed to the contact sheet metal member by welding. In a particularly preferred embodiment, an O-ring shaped insulating washer made of the electrically insulating plastic material mentioned above is placed on the contact sheet metal member before the cover plate is inserted. The O-ring shaped insulating washer radially separates the gap into which the potting compound is filled. The electrode-separator assembly can be impregnated with the appropriate electrolyte through the aperture at the bottom of the housing of the metal cup-shaped housing portion. The aperture can then be sealed with a metal film.

[0082] In a preferred embodiment, the method includes step a, which is described immediately afterward. a. At the bottom of the cup-shaped housing portion, - Primary protection against internal overpressure in the form of an aperture closed by a metal film, and - Secondary protection against internal overpressure in the form of at least one groove on the inner surface of the housing bottom or the outer surface of the housing bottom The step in which it is incorporated.

[0083] Further features and advantages of the present invention will become apparent from the following description of the claims and preferred examples of embodiments of the invention, in conjunction with the drawings. Each of the individual features can be realized separately or in combination with one another. [Brief explanation of the drawing]

[0084] [Figure 1] This is a schematic diagram of an electrode ribbon and its arrangement to show the structure of an electrode-separator assembly for an energy storage battery according to the present invention. [Figure 2A-C] These are external and longitudinal cross-sectional views of an embodiment of an energy storage battery according to the present invention. [Figure 3A-B] This is a detailed view of the upper and lower end face regions in a longitudinal cross-section of an embodiment of the energy storage battery according to the present invention. [Figure 4A-B] Detailed views of a terminal pole in a top perspective and a cross-sectional view for a preferred embodiment of an energy storage battery according to the present invention. [Figure 5A-B] Detailed views of an insulating washer for a preferred embodiment of the energy storage battery according to the present invention, in a top perspective view and a cross-sectional view. [Figure 6A-B] Detailed views of a contact sheet metal member for a preferred embodiment of the energy storage battery according to the present invention, in a top perspective view and a bottom perspective cross-sectional view. [Figure 7] This is a detailed view of the bottom of the housing of a preferred embodiment of the energy storage battery according to the present invention. [Figure 8A-C] This is an exploded view of various components of a preferred embodiment of the energy storage battery according to the present invention. [Figure 9A-B] This is a detailed view from the upper end face region of a preferred embodiment of an energy storage battery according to the present invention, illustrating a production process for an energy storage battery. [Figure 10] This is a diagonally elevated view of the bottom of the housing of a preferred embodiment of an energy storage battery according to the present invention, illustrating the production process for the energy storage battery. [Figure 11A-B] This is a cross-sectional view of an alternative embodiment of a contact sheet metal member to which terminal poles are attached and its installation in a preferred embodiment of the energy storage battery according to the present invention. [Modes for carrying out the invention]

[0085] The electrode-separator assembly shown in Figures 1A to D includes a ribbon-shaped anode 105 (Figure 1A) having a ribbon-shaped anode current collector 106 having a first longitudinal edge 106a and a second longitudinal edge parallel thereto. The anode current collector 106 is preferably copper or nickel foil. The anode current collector 106 includes a strip-shaped main region loaded with a layer of negative electrode material 107 and a free-end strip 106b extending along its first longitudinal edge 106a, which is not loaded with electrode material 107. Furthermore, the electrode-separator assembly includes a ribbon-shaped cathode 108 (Figure 1B) having a ribbon-shaped cathode current collector 109 having a first longitudinal edge 109a and a second longitudinal edge parallel thereto. The cathode current collector 109 is preferably aluminum foil. The cathode current collector 109 includes a strip-shaped main region loaded with a layer of positive electrode material 110, and a free-end strip 109b extending along a first longitudinal edge 109a, which is not loaded with electrode material 110. Both electrodes are shown separately in their unwound state in Figures 1A and B.

[0086] The anode 105 and cathode 108 are offset from each other within the electrode-separator assembly, so that the first longitudinal edge 106a of the anode current collector 106 protrudes from the first terminal end face 104a, and the first longitudinal edge 109a of the cathode current collector 109 protrudes from the second terminal end face 104b of the electrode-separator assembly 104. The offset arrangement can be seen in Figure 1C. Figure 1C also shows two ribbon-shaped separators 116 and 117 that separate electrodes 105 and 108 in the winding. Figure 1D shows the electrode-separator assembly in the form of a winding that can be used in an energy storage element according to the present invention. The electrode edges 106a and 109a protruding from the end faces 104a and 104b are clearly visible. The outer winding shell 104c is formed of a plastic film.

[0087] Figures 2A-C show preferred embodiments of the energy storage battery according to the present invention in a top perspective view (Figure 2A), a longitudinal section (Figure 2B), and a bottom perspective view (Figure 2C). The energy storage battery 100 is in the form of a cylindrical battery. The housing of the energy storage battery 100 is formed by a cup-shaped housing portion 101 and a lid assembly. In this regard, the lid assembly includes a cover plate 102a having the shape of an opening plate and a terminal pole 102b located in the center of the lid assembly.

[0088] As can be seen in the cross-sectional view of Figure 2B, inside the energy storage battery 100 there is a wound electrode-separator assembly 104 formed by wound electrode ribbons and separator ribbons between them.

[0089] Figure 2C shows the underside of the energy storage battery 100 formed by the housing bottom 101a. In the housing bottom 101a, three weld embossments are arranged in a star shape in the form of beads 101d, appearing as recesses on the outer surface and as elongated protrusions on the inner surface. The longitudinal edges of each current collector are placed on the inner surface of these beads 101d, and in the region from these beads, the current collector is preferably welded directly to the housing bottom. The material used for the housing bottom 101a and the entire cup-shaped housing portion 101 is preferably aluminum.

[0090] In this example, the housing bottom 101a incorporates two protective features. Firstly, there is an aperture at the center of the housing bottom 101a, which is closed by a metal film 114. If overpressure occurs due to a battery malfunction, this film 114 equalizes the pressure, in which case the film is either ruptured and opened or blown off by the pressure. In this way, any gas that may be generated within the battery can escape through the aperture (primary protection device) of the housing bottom 101a.

[0091] In addition, the housing bottom 101a is provided with further protection, which is implemented by three grooves 101c arranged in a star shape. These grooves 101c represent a weakening structure of the housing bottom 101a and thus form a predetermined point of failure in the event of overpressure in the battery (secondary protection). In this exemplary embodiment, the grooves are located on the inner surface of the housing bottom 101a and are therefore shown as dashed lines in Figure 2C. Specifically, the grooves 101c can be implemented as three scribed lines. Furthermore, partial circular connections of the scribed lines or grooves 101c further form the scribed lines in a star shape. Under moderately high overpressure, the housing bottom 101a tears open along the grooves 101c and the partial circular connections of these grooves, forming an outlet opening with a relatively large cross-section through which any gas generated in the housing can be quickly released.

[0092] Figures 3A and 3B show enlarged views of the end face region of the energy storage battery 100. From Figure 3A, details of the end face having the lid assembly 102 are evident. The lid assembly 102 includes a cover plate 102a having a central aperture and a terminal pole 102b positioned at the center of the cover plate 102a. In this exemplary embodiment, the terminal pole 102b forms the negative pole, and the peripheral cover plate 102a forms the positive pole of the energy storage battery 100.

[0093] A contact sheet metal member 111 is located below the terminal pole 102b, and the contact sheet metal member 111 is placed on the free end strip 106b of the spirally arranged anode current collector of the negative electrode and welded to it. Specifically, the contact sheet metal member 111 is electrically connected to the terminal pole 102b, which is formed from two metal components, by welding in this case as well. With respect to the contact sheet metal member 111, the cover plate 102a is electrically insulated by an O-ring shaped insulating washer 112. Furthermore, an electrically insulating potting compound 113 is located in the gap between the terminal pole 102b and the cover plate 102a.

[0094] Figure 3B shows details of the opposite end face of the energy storage battery 100, which is formed by the housing bottom 101a. The free end strip 109b of the cathode current collector is electrically connected directly to (specifically welded to) the housing bottom 101a at this end face of the energy storage battery 100. Electrical contact exists with the metal cover plate 102a at the opposite end face via the jacket of the cup-shaped housing portion 101, and thus the positive potential of the battery can also be tapped at the upper end face of the energy storage battery 100.

[0095] The lower end face of the energy storage battery 100 shown in Figure 3B demonstrates the preferred overpressure protection function of the battery according to the present invention. Primary protection is formed by a metal film 114 that closes the central circular aperture 101b of the housing bottom 101a. Secondary protection is formed by grooves 101c, and in this embodiment, one of three star-shaped grooves 101c is visible in the cross-section. The grooves 101c located on the inner surface of the housing bottom 101a provide a defined weakening structure at the housing bottom, so that if relatively high overpressure occurs in the battery, these structures can open and release the gas.

[0096] The preferred design of the energy storage battery 100 according to the present invention, as shown in Figure 3, allows for a reduction in the number of components in the upper region of the energy storage battery (Figure 3A), where the negative and positive terminals of the battery are located. Specifically, this design eliminates the need for additional arresters by integrally fabricating the terminal pole 102b.

[0097] Direct contact of one longitudinal edge of the electrode ribbon at the bottom of the housing (partial figure 3B) also contributes to making the battery particularly compact, eliminating the need for dead volume for various battery functions. Direct contact of the longitudinal edges of the electrode ribbon also improves heat dissipation and reduces internal resistance. In addition, this battery design generally allows for the formation of longer windings in the resulting energy storage battery, and therefore higher energy density.

[0098] In this embodiment, the upper end face of the energy storage battery 100 is as compact as possible. In the event of gas generation within the battery, which would result in an increase in pressure, these gases are inevitably conducted to the lower region of the battery, where safety features for pressure equalization are located. Thus, overall, such a battery has a very good level of safety.

[0099] Figures 4A and 4B show detailed views of the terminal pole 102b in a top perspective view (Figure 4A) and a cross-sectional view (Figure 4B). In this preferred embodiment, the terminal pole 102b is composed of two metal components. The upper region (top of the pole) 1020 is preferably made of aluminum, and the lower region (bottom of the pole) 1021 is preferably made of copper. The upper region 1020 has a chamfered circumferential upper edge. As shown in the cross-sectional view in Figure 4B, the lower region 1021 includes an outer circumferential weld point shoulder 1021a and a central downward projection pin 1021b. The pin 1021b engages with a recess provided, for convenience, corresponding to the center of the contact sheet metal member 111, thereby ensuring a good fit of the terminal pole 102b.

[0100] Such terminal poles 102b can be formed from, for example, a bimetallic strip material of aluminum and copper. For example, for this purpose, a circular blank is stamped from the bimetal. The upper region 1020 having chamfered edges and the base region 1021 having a central pin 2021b and a circumferential welded shoulder 1021a can be formed by cold forming.

[0101] Copper is particularly suitable for the base region 1021 of the terminal pole 102b, especially when the terminal pole 102b is provided to contact the anode current collector via a contact sheet metal member 111. Since this copper material is particularly suitable for the terminal pole, the anode current collector is also typically made of copper. In this case, preferably, the contact sheet metal member 111 is also made of copper.

[0102] Forming the upper portion 1020 of the terminal pole 102b from aluminum has the particular advantage that, in this case, the cup-shaped housing portion 101 is also generally made of aluminum, so the entire housing of the energy storage battery can be formed from aluminum. The cathode current collector that electrically contacts the housing bottom 101a is also often made of aluminum. Naturally, if the energy storage battery 100 is constructed with reverse polarity, it is also possible to make different choices of metal materials for the housing and / or terminal poles.

[0103] Figures 5A and 5B show an O-ring shaped insulating washer 112 in a complete perspective view from above (Figure 5A) and a cross-section view (Figure 5B). In one embodiment, the insulating washer 112 has the function of electrically insulating the cover plate 102a, which preferably has positive polarity, from the components of the energy storage battery 100, which has negative polarity. In addition, the insulating washer 112 also provides liquid-tight and airtight sealing of the housing.

[0104] In the preferred example of the insulating washer 112 shown herein, the insulating washer is made of two different materials. The outer region 112a of the insulating washer 112 is preferably formed from a particularly rigid plastic material, such as PBT (polybutylene terephthalate). The inner region 112b is preferably formed from a plastic material that has a certain degree of flexibility and, more importantly, is particularly heat-resistant, such as PET (polyethylene terephthalate). Thus, the outer region 112a provides certain mechanical stability. The inner region 112b provides flexibility and, in particular, resistance to the potting compound 13 that is applied and heat-cured during the assembly of the energy storage battery. By certain advantages, the inner circumference of the O-ring shaped insulating washer 112 is thickened along the circumferential direction, thereby further supporting the stability of the components in the end face region of the assembled energy storage battery.

[0105] During the assembly of the energy storage battery, the insertion of the insulating washer 112 into the battery lid area achieves an initial temporary seal of the battery until the potting compound 113, which is later applied, hardens and completely seals the battery. Furthermore, the special shape of the insulating washer 112 allows for axial support of the wound electrode-separator assembly 104, for example, during battery testing. In addition, in the case of lateral deformation of the battery, the shape of the insulating washer 112 provides space for possible deformation of the contact sheet metal member 111. Finally, the shape of the insulating washer 112 allows for a reduction in the volume of the potting compound 113 and a reduction in the amount of air bubbles that may be trapped during potting when assembling the energy storage battery.

[0106] As a possible alternative to such insulating washers, for example, an insulating sealing bead corresponding to a silicone bead can be provided. This can also ensure a high level of sealing. However, in contrast, the insulating washer 112 offers various advantages, specifically as mentioned in the embodiments presented herein.

[0107] Figures 6A and 6B show preferred embodiments of a contact sheet metal member 111 provided to contact the free ends of the current collectors of each electrode in the upper region of the energy storage battery. Figure 6A shows a top view of the disk-shaped contact sheet metal member 111. Figure 6B shows a section of the contact sheet metal member 111 viewed from below, i.e., the surface of the contact sheet metal member that faces the electrode-separator assembly in the energy storage battery.

[0108] Similar to the bead 101d on the housing bottom 101a, the contact sheet metal member 111 also has three beads 111d arranged in a star shape, appearing as recesses on its outer surface (Figure 6A) and as elongated protrusions on its inner surface (Figure 6B). The beads 111d can be stamped, for example, and have a depth of, for example, 0.25 mm. When the battery is assembled, the beads 111d contact the respective longitudinal edges of the electrode ribbons of the electrode-separator assembly that contact their surfaces. The contact sheet metal member 111 is preferably welded to the respective longitudinal edges of the electrode ribbons via the beads 111d.

[0109] The recess 111e is located in the center of the contact sheet metal member 111. The recess 111e serves to receive the terminal pole 102b at the point where the central pin 1021b of the terminal pole 102b engages with the recess 111e. In this way, the terminal pole 102b can be easily positioned and fixed to the contact sheet metal member 111, and as a result, welding of the terminal pole 102b can be performed without problems.

[0110] Furthermore, in a particularly preferred embodiment of the contact sheet metal member 111 shown herein, additional star-shaped narrow recesses 111f are provided located on the inner surface of the contact sheet metal member 111. In this exemplary embodiment, a total of nine of these recesses 111f are provided as star-shaped narrow grooves. The grooves may have a depth of, for example, 0.1 mm. The grooves of the recesses 111f serve to improve the distribution of the electrolyte within the battery.

[0111] Furthermore, in this preferred embodiment, the contact sheet metal member 111 has an embossed circumferential edge 111g, which is positioned as a predetermined bending point, specifically a downward bulge. This predetermined buckling point facilitates the assembly of the energy storage battery housing. In the preferred embodiment, the contact sheet metal member 111 is made of a copper plate, for example, a copper plate with a material thickness of 0.3 mm. Copper is particularly advantageous when the contact sheet metal member is in contact with the longitudinal edge of an anode current collector, which is also preferably formed from copper.

[0112] Figure 7 shows a detailed view of the housing bottom 101a of the energy storage battery, which has inwardly projecting beads 101d arranged in a star shape, and the inwardly projecting beads 101d are specifically formed as weld embossings for contact with the wound electrode-separator assembly. The star-shaped arrangement of the three beads 101d is particularly advantageous for the assembly of the battery, especially due to its rotational symmetry.

[0113] The central aperture 101b at the bottom 101a of the housing is covered by a metal film 114, which serves as primary protection for the battery in case of overpressure. In this regard, the aperture 101b is particularly intended to be used to initially fill the battery with electrolyte during battery production before closing the aperture 101b with the metal film 114. A circumferential recess 1010b surrounding the central aperture 101b is preferably provided to receive the metal film 114 for closing the central aperture 101b.

[0114] Furthermore, in this embodiment, three star-shaped weakening structures are provided in the form of internal opening grooves 101c, which are connected by pitched circular connecting lines 1010c. These weakening structures 101c and 1010c serve as secondary protection against internal overpressure. Instead of mounting the weakening structures from the inside of the housing bottom, such weakening structures (e.g., marking lines) can also be mounted from the outside. The outer surface of the housing bottom 101a can further be provided with one or more nameplates 1010a that can be used to attach various inscriptions. Figures 8-10 below illustrate various details relating to the manufacture of an energy storage battery according to the present invention.

[0115] Figures 8A-8C show exploded views of various components of a preferred embodiment of the energy storage battery according to the present invention. Figure 8A shows the components of the housing, which includes a housing cup 101, terminals 102b, an O-ring-shaped insulating washer 112, a cover plate 102 having a central recess into which the terminals 102b engage, and a potting compound 113. Below the housing cup 101, a closure for the energy storage battery is shown in the form of a metal film 114, which adheres to the electrolyte 115 schematically shown here after it has been filled into the assembled battery.

[0116] Figure 8B shows an electrode-separator assembly 104 in the form of a wound body and a contact sheet metal member 111 attached thereto. The wound electrode-separator assembly 104 can be produced in a known manner by winding an electrode ribbon and a separator on a winding machine. To complete the wound body form, a preferred method is to use a conical pressure piece to bend the outermost winding turn inward, for example, 30° to 45°, so that the winding body form is stabilized. Then, for example, an adhesive tape 118 made of polypropylene (Figure 8C) is preferably attached to the outer surface of the wound body, which can perform an electrical insulation function in the battery in addition to its stabilization function. After this stabilization of the wound electrode-separator assembly 104, for example, a disc-shaped contact sheet metal member 111 made of copper can be lightly placed on the upper end face of the wound body and fixed with a particularly stable adhesive tape 119 made of polyimide, for example. For this purpose, for example, a Kapton® tape with a thickness of 50 μm can be used.

[0117] Next, the electrode-separator assembly 104 with the contact sheet metal member 111 attached is inserted into the cup-shaped housing portion 101. After aligning the beads with the bottom of the housing and the contact sheet metal member (which may be done with camera assistance), the assembly can be laser-welded by pressing it simultaneously or sequentially from above and below using an appropriate pressing tool to bring the longitudinal edges of the electrode ribbons into contact with the respective beads. After that, the terminal poles 102b can be placed on the contact sheet metal member 111 and welded.

[0118] Figures 9A and 9B show details of the fabrication of the battery cover assembly. Figure 9A shows a detailed view of the welding of the contact sheet metal member 102b onto the contact sheet metal member 111, where the laser can be applied obliquely or vertically, particularly in the area from the circumferential welding shoulder 1021a of the contact sheet metal member 102b. Figure 9B shows how insulating washers 112 can be inserted and pressed to the correct height before the cover plate 102a is positioned and welded from oblique, vertical, or horizontal directions to the cup-shaped housing portion, which is not shown here. Here, the terminal pole 102b can be pressed to the correct height relative to the battery shoulder formed by the upper surface of the cover plate 102a, if necessary. The gap provided for this purpose may be, for example, 1 mm between the top of the terminal pole 102b and the top of the cover plate 102a. The gap between the cover plate 102a and the terminal pole 102b is filled with a potting compound 113 to make this part of the energy storage battery airtight and liquid-tight. Next, the energy storage battery can be transferred to an oven to cure the potting compound 113, allowing any remaining moisture in the wound electrode-separator assembly to be baked out.

[0119] Figure 10 shows the final filling of the electrolyte 115, which is filled from the bottom (top in this embodiment) of the energy storage battery 100 through the aperture 101b at the bottom 101a of the housing. Finally, a metal film 114 is attached as a closure of the opening at the bottom 101a of the housing or as a closure of the central aperture 101b. For this purpose, for example, a vertical laser beam can be used.

[0120] Figure 11 shows an alternative method for mounting the lid assembly. Figure 11A shows a perspective cross-sectional view from below of the contact sheet metal member 111 to which the terminals 102b are attached. Figure 11B shows a longitudinal cross-section of the top portion of the battery. In this alternative manufacturing process, the terminal poles 102b are pre-welded to the contact sheet metal member 111. For this purpose, friction welding or friction stir welding can be used.

[0121] In this embodiment of the contact sheet metal member 111, the star-shaped bead 111d of the contact sheet metal member 111 can be shortened as needed, as it is covered by the terminal pole 102b during subsequent welding of the electrode-separator assembly. Thus, a relatively small welding area can be used to bring the longitudinal edges of each electrode ribbon into contact with the contact sheet metal member 111. However, this embodiment can offer advantages for assembly.

[0122] Since it may be simpler to directly attach the terminals 102b to the contact sheet metal member 111 outside the housing cup assembly, the central recess of the contact sheet metal member and the corresponding pins of the terminals 102b may be unnecessary if required. Further assembly of the energy storage battery using terminal poles 102b already directly welded to the contact plate 111 is, in principle, no different from the manufacturing process previously described for the energy storage battery 100.

Claims

1. An energy storage element (100), characterized a. The energy storage element (100) includes an airtight and liquid-tight sealed housing and an electrode-separator assembly (104) disposed therein. b. The housing includes a metal cup-shaped housing portion (101) including a housing bottom (101a), a circumferential side wall, and a terminal opening. c. The housing includes a lid assembly (102) that closes the terminal opening of the cup-shaped housing portion (101), d. The lid assembly (102) includes a metal cover plate (102a) and a terminal pole (102b) that passes through the aperture of the cover plate (102a) and is electrically insulated from the cover plate (102a). e. The electrode-separator assembly (104) includes a first flat terminal end face (104a) and a second flat terminal end face (104b), f. The electrode-separator assembly (104) includes an anode (105) having an anode current collector (106) having a first edge (106a) and a second edge parallel thereto, g. The anode current collector (106) includes a main region loaded with a layer of negative electrode material (107) and a free end strip (106b) extending along its first edge (106a) that is not loaded with the electrode material (107). h. The electrode-separator assembly (104) includes a cathode (108) having a cathode current collector (109) having a first edge (109a) and a second edge parallel thereto. i. The cathode current collector (109) includes a main region on which a layer of positive electrode material (110) is loaded, and a free end strip (109b) extending along its first edge (109a) on which the electrode material (110) is not loaded. j. The anode (105) and the cathode (108) are arranged within the electrode-separator assembly (104) such that the first edge (106a) of the anode current collector (106) protrudes from the first terminal end face (104a) of the electrode-separator assembly (104), and the first edge (109a) of the cathode current collector (109) protrudes from the second terminal end face (104b). k. The energy storage element includes a contact sheet metal member (111) placed directly on the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109). l. The contact sheet metal member (111) is electrically connected to the terminal (102b) that passes through the aperture of the cover plate (102a). m. The first edges (109a, 106a) of the cathode current collector (109) or the anode current collector (106) that do not directly contact the contact sheet metal member (111) are electrically connected to the housing bottom (101a). n. The terminal pole (102b) rests directly on the contact sheet metal member (111) and is connected to it by welding. o. The terminal pole (102b) is electrically insulated from the cover plate (102) by a cured potting compound (113) of an electrically insulating plastic material. An energy storage element (100) having the following characteristics.

2. The following additional features: a. An annular gap exists between the cover plate (102) and the contact sheet metal member (111) in which the potting compound (113) is filled. b. The annular gap is surrounded radially outward by an O-ring shaped insulating washer (112) made of an electrically insulating plastic material. An energy storage element according to claim 1, having at least one of the following.

3. The following additional features: a. The cup-shaped housing portion (101) is electrically connected to the cathode. b. The contact sheet metal member (111) rests on the first edge (106a) of the anode current collector (106) and is joined to it by welding. c. The cup-shaped housing portion (101) is made of aluminum or an aluminum alloy. d. The cover plate (102a) shall be made of aluminum or an aluminum alloy. e. The contact sheet metal member (111) is in direct contact with the terminal pole (102b) which is guided through the aperture of the cover plate (102a). An energy storage element according to claim 1, having at least one of the following.

4. The following additional features: a. The cup-shaped housing portion (101) is electrically connected to the anode. b. The contact sheet metal member (111) is placed on the first edge (109a) of the cathode current collector (109) and is joined to it by welding. c. The cup-shaped housing portion (101) is made of copper or nickel, or a copper or nickel alloy or steel, or nickel-plated steel. d. The cover plate (102a) shall be made of copper or nickel, or a copper or nickel alloy or steel, or nickel-plated steel. e. The contact sheet metal member (111) is in direct contact with the terminal pole (102b) which is guided through the aperture of the cover plate (102a). An energy storage element according to claim 1, having at least one of the following.

5. The following additional features: a. The contact sheet metal member (111) is made of nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel. b. The terminal pole (102b) is a bimetallic terminal pole and includes a pole base portion (1021) made of nickel, copper, or titanium, or a nickel, copper, or titanium alloy, or stainless steel, and a pole upper portion (1020) made of aluminum or an aluminum alloy. c. The pole base portion (1021) is welded to the contact sheet metal member (111). d. The pole base portion (1021), the contact sheet metal member (111), and the anode current collector (106) are made of the same material. An energy storage element according to claim 1, having at least one of the following.

6. The following additional features: a. The contact sheet metal member (111) is made of aluminum or an aluminum alloy. b. The terminal pole (102b) shall be made of aluminum or an aluminum alloy. c. The contact sheet metal member (111), the terminal pole (102b), and the cathode current collector (109) are made of the same material. An energy storage element according to claim 1, having at least one of the following.

7. The following additional features: a. The contact sheet metal member (111) has a uniform thickness in the range of 50 μm to 600 μm. b. The contact sheet metal member (111) has two opposing flat surfaces and extends substantially in only one dimension. c. The contact sheet metal member (111) is a disc or a polygonal plate. d. The contact sheet metal member (111) shall be sized such that it covers at least 40% of the end faces (104a, 104b) on which the edges (106a, 109a) of the current collector (106, 109) on which it rests protrude. e. The contact sheet metal member (111) has at least one bead (111d), the at least one bead (111d) appears as an elongated recess on one flat surface of the contact sheet metal member (111) and as an elongated protrusion on the opposite flat surface, and the contact sheet metal member (111) rests on the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109) by the flat surface supporting the elongated protrusion. f. The contact sheet metal member (111) is welded in the region of the bead (111d) to the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109). An energy storage element according to claim 1, having at least one of the following.

8. The following additional features: a. The bottom portion (101a) of the cup-shaped housing portion (101) has primary protection against internal overpressure in the form of an aperture (101b) closed by a metal film (114), and b. The bottom portion (101a) of the cup-shaped housing portion (101) has secondary protection against internal overpressure in the form of at least one groove (101c) on its inner surface or outer surface. An energy storage element according to claim 1, having the following characteristics.

9. The following additional features: a. The metal film (114) is fixed to the bottom portion (101a) of the cup-shaped housing portion (101) by welding. An energy storage element according to claim 8, having the following characteristics.

10. The following additional features: a. The housing bottom (101a) has at least one bead (101d), the at least one bead (101d) appears as an elongated recess on the outer surface of the housing bottom (101a) and as an elongated protrusion on the inner surface of the housing bottom (101a), and the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109) is placed on the inner surface. b. The housing bottom (101a) is welded in the region of the bead (101d) to the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109). c. The aperture (101b) is positioned at the center of the housing bottom (101a). d. The at least one bead (101d) includes a plurality of straight beads, specifically three beads, arranged in a star configuration around the aperture (101b). e. The at least one groove (101c) includes a plurality of straight subsections arranged in a star configuration around the aperture (101b), f. The at least one groove (101c) extends around the aperture (101b) and includes a subsection (1010c) that interconnects the star-shaped linear subsections. An energy storage element according to claim 1, having at least one of the following.

11. A method for producing an energy storage element according to any one of claims 1 to 10, a. A step of providing a metal cup-shaped housing portion (101) including a housing bottom (101a), a circumferential side wall, and a terminal opening, b. Providing an electrode-separator assembly (104), wherein the electrode-separator assembly (104) is - A cathode (108) having a cathode current collector (109) having a first edge (109a) and a second edge parallel thereto, - Anode (105) including an anode current collector (106) having a first edge (106a) and a second edge parallel thereto. including and - First flat terminal end face (104a) and second flat terminal end face (104b) It has, - The anode current collector (106) includes a main region loaded with a layer of negative electrode material (107) and a free end strip (106b) extending along its first edge (106a) that is not loaded with the electrode material (107). - The cathode current collector (109) includes a main region loaded with a layer of positive electrode material (110) and a free end strip (109b) extending along its first edge (109a) that is not loaded with the electrode material (110). - The anode (105) and cathode (108) are arranged within the electrode-separator assembly (104) such that the first edge (106a) of the anode current collector (106) protrudes from the first terminal end face (104a) of the electrode-separator assembly (104), and the first edge (109a) of the cathode current collector (109) protrudes from the second terminal end face (104b), step, c. Inserting the electrode-separator assembly (104) into the cup-shaped housing portion (101) such that the first edge portions (106a, 109a) of the anode current collector (106) or the first edge portion (109a) of the cathode current collector (109) is placed on the housing bottom portion (101a), d. A cover plate (102a) having an aperture for the terminal pole (102b) is inserted into the terminal opening of the cup-shaped housing portion (101). e. A step in which the gap remaining between the cover plate (102a) and the contact sheet metal member (111) is filled with a potting compound (113), wherein, once cured, the potting compound (113) electrically insulates the cover plate (102a) from the terminal pole (102b) and the contact sheet metal member (111). A method that includes this.

12. The following additional steps: a. The contact sheet metal member (111) is positioned on the first edge (106a) of the anode current collector (106) or the first edge (109a) of the cathode current collector (109), which is not placed on the housing bottom (101a), and is assembled to the edges (106a, 109a) by welding. b. The terminal (102b) is fixed to the contact sheet metal member (111). A method for producing an energy storage element according to claim 11, comprising at least one of the following.

13. The following additional steps: a. A step of creating a welded joint between the first edge portions (106a, 109a) placed on the housing bottom portion (101a) and the housing bottom portion. b. At the bottom portion (101a) of the cup-shaped housing portion (101), - Primary protection against internal overpressure in the form of an aperture (101b) closed by a metal film (114), and - Secondary protection against internal overpressure in the form of at least one groove (101c) on the inner surface of the housing bottom (101a) or the outer surface of the housing bottom (101a) Steps that incorporate A method for producing the energy storage element according to claim 11, including the following:

Images