Contact sheet metal member and energy storage element

Abstract

To provide a contact sheet metal member and an energy storage element.SOLUTION: A contact sheet metal member 200 comprises: a. a first contact section 201 which is provided for being in contact with a first constituent of an energy storage element and includes a top face 201a, and a bottom face; b. a second contact section 202 which is provided for being in contact with a second constituent of the energy storage element and includes a top face 202a and a bottom face 202b; and c. a connection section 203 which is between the first contact section 201 and the second contact section 202 and includes a top face 203a and a bottom face 203b, in the connection section 203, the top face 203a of the connection section 203 being opposed to the bottom face of the first contact section 201 and the bottom face 203b of the connection section 203 being opposed to the top face 202a of the second contact section 202.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The invention described below relates to contact sheet metal members and energy storage elements provided therewith. [Background technology]

[0002] Electrochemical energy storage elements are capable of converting stored chemical energy into electrical energy via redox reactions. The simplest form of electrochemical energy storage element is the electrochemical cell. An electrochemical cell comprises a positive electrode and a negative electrode, between which a separator is placed. During discharge, as a result of an oxidation process, electrons are released at the negative electrode. The result is an electron flow that can be absorbed by an external consumer, for which the electrochemical cell serves as an energy source. At the same time, an ionic current corresponding to the electrode reactions is generated in the cell. This ionic current passes through the separator and is made possible by the ionically conductive electrolyte. The separator thus prevents direct contact between the electrodes. At the same time, however, the separator allows charge equalization between the electrodes.

[0003] If the discharge is reversible, i.e., it is possible to reverse the conversion of chemical energy to electrical energy during discharge and recharge the cell, the cell is called a secondary cell. In secondary cells, the common designation of the negative electrode as the anode and the positive electrode as the cathode refers to the discharge function of the electrochemical cell.

[0004] Secondary lithium-ion cells are used today in many applications as energy storage elements, since they can supply high currents and are characterized by a relatively high energy density. Secondary lithium-ion cells are based on the use of lithium, which can be transported back and forth in the form of ions between the electrodes of the cell. The negative and positive electrodes of lithium-ion cells are generally formed by so-called composite electrodes, which contain an electrochemically inactive component as well as an electrochemically active component.

[0005] In principle, all materials capable of absorbing and releasing lithium ions can be used as electrochemically active components (active materials) for secondary lithium-ion cells. For example, carbon-based particles such as graphitic carbon are used for the negative electrode. The active material for the positive electrode is, for example, lithium cobalt oxide (LiCoO 2 ), lithium manganese oxide (LiMn 2 O 4 ), lithium iron phosphate (LiFePO 4 ), or derivatives thereof. The electrochemically active material is generally contained in the electrode in particulate form.

[0006] As electrochemically inactive components, composite electrodes generally comprise flat and / or strip-shaped current collectors, e.g. metal foils, which act as carriers for the respective active materials: the current collector for the negative electrode (anode current collector) can be made, for example, of copper or nickel, the current collector for the positive electrode (cathode current collector) can be made, for example, of aluminum.

[0007] Additionally, the electrode may contain, as electrochemically inactive components, an electrode binder (e.g., polyvinylidene fluoride (PVDF) or another polymer, such as carboxymethylcellulose), conductivity improving additives, and other additives. The electrode binder ensures the mechanical stability of the electrode and, in many cases, the adhesion of the active material to the current collector.

[0008] As an electrolyte, lithium-ion cells typically use a lithium salt solution, such as lithium hexafluorophosphate (LiPF ), in an organic solvent (e.g., ethers and esters of carbonic acid). 6 ).

[0009] In manufacturing lithium-ion cells, a composite electrode is typically combined with one or more separators to form an electrode-separator assembly. The electrodes and separators are usually bonded together under pressure, optionally by lamination or bonding. The assembly can then be impregnated with an electrolyte to establish basic functionality of the cell.

[0010] In many embodiments, the electrode-separator assembly is formed in the form of a winding or processed into a winding. In the first case, for example, the ribbon-shaped positive and negative electrodes and at least one ribbon-shaped separator are fed separately to a winding machine and spirally wound into a winding having a positive electrode / separator / negative electrode sequence. In the second case, the ribbon-shaped positive and negative electrodes and at least one ribbon-shaped separator are first combined to form the electrode-separator assembly, for example by applying pressure as described above. Then, in a further step, the assembly is wound.

[0011] Applications in the automotive sector, for electric bicycles or other applications with high energy requirements, such as electric tools, require lithium-ion cells with the highest possible energy density that are also able to withstand high currents during charging and discharging.

[0012] Cells for the aforementioned applications are often designed as cylindrical round cells, with a form factor of, for example, 21 x 70 (diameter x height, in mm). This type of cell always comprises an assembly in the form of a wound body. Modern lithium-ion cells with this form factor are able to achieve energy densities of up to 270 Wh / kg.

[0013] EP 1 339 633 A1 discloses an electrode-separator assembly and a cylindrical circular cell whose electrodes are ribbon-like and in the form of a winding. Each electrode has a current collector provided with an electrode material. The electrodes with opposite polarity are arranged offset from each other in the electrode-separator assembly, so that the longitudinal edge of the current collector of the positive electrode protrudes from one side of the winding and the longitudinal edge of the current collector of the negative electrode protrudes from the other side of the winding. For electrical contact of the current collectors, the cell has a contact sheet metal member that rests on one end face of the winding and is connected by welding to the longitudinal edge of one of the current collectors. This allows the current collector, and therefore also the associated electrode, to be electrically contacted over its entire length. This significantly reduces the internal resistance in the described cell. As a result, high currents can be absorbed much better and also the heat can be dissipated better from the winding.

[0014] Depending on the design of the energy storage element, it may be necessary to connect the contact sheet metal member to a part of its housing. This is shown, for example, in FIG. 1 of (US Pat. No. 5,399,323), where a current conductor 107 is used to bridge the distance in the housing, i.e. the distance between the contact sheet metal member 105 and the lid 102. This inevitably leads to dead volumes, which have a negative effect on the energy density of the energy storage element shown.

[0015] Contact sheet metal elements are known from US Pat. No. 5,399,363, which are present in the finished cell as S-shaped folds and which not only make a large-area contact with the electrode-separator assembly but also simultaneously bridge the distance to the multi-part lid. By using such contact elements, the above-mentioned dead volumes can be reduced. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] International Publication No. 2017 / 215900A1 Brochure [Patent Document 2] International Publication No. 2021 / 239490A1 Brochure [Patent Document 3] European Patent Application Publication No. 3916891A1 Summary of the Invention [Problem to be solved by the invention]

[0017] The object of the present invention is to provide an energy storage element characterized by a high energy density. In particular, the present invention is based on the task of further improving contact sheet metal parts, as described in WO 2005 / 023366. [Means for solving the problem]

[0018] This object is achieved by a contact sheet metal part having the features of claim 1. An object of the invention is also an energy storage element having the features of claim 9. Preferred embodiments of the invention are defined in the dependent claims 2 to 8 and 10 to 13.

[0019] The contact sheet metal part is intended for use in an energy storage element comprising an electrode-separator assembly in a housing. The contact sheet metal part is used to electrically contact the electrodes of the electrode-separator assembly and is intended to connect said electrodes to a metal part of the housing or to an electric pole passing through the housing. The contact sheet metal part always has the following characteristics a. to e.: a. The contact sheet metal member includes a first contact section having a top surface and a bottom surface adapted to contact a first component of the energy storage element. b. The contact sheet metal member includes a second contact section having a top surface and a bottom surface adapted to contact a second component of the energy storage element. c. The contact sheet metal member includes a connection section between the first contact section and the second contact section, the connection section having a top surface and a bottom surface, the top surface of the connection section facing the bottom surface of the first contact section and the bottom surface of the connection section facing the bottom surface of the second contact section. d. the first contact section and the connecting section are connected to one another via a first bending zone, and the contacting sheet metal members are bent along at least one bend line, preferably along a first bend line. e. the second contact section and the connecting section are connected to one another via a second bending zone, and the contacting sheet metal members are bent along at least one bend line, preferably along a second bend line.

[0020] The contact sheet metal part is characterized in particular by the following features f.: f. The second contact section has a recess or aperture that forms a receiving portion for the first bending zone.

[0021] In order to minimize the dead volume, it is desirable for the contact sheet metal parts to occupy as little space as possible in the housing. It is therefore advantageous to press the first contact section, the connection section and the second contact section together during assembly so that the distance between the first and second contact sections, and therefore the distance between the bottom surface of the first contact section and the top surface of the connection section, and between the top surface of the second contact section and the bottom surface of the connection section, are as small as possible. Ideally, the bottom surface of the first contact section and the top surface of the connection section, as well as the top surface of the second contact section and the bottom surface of the connection section, are in direct, preferably flat contact with each other.

[0022] The bending zones, especially the first bending zone, can create problems during this process. When sheet metal is bent, it always bounces back a little. Therefore, in order to bend the sheet metal at a desired angle, the sheet metal must generally be bent slightly beyond the desired angle. The closer the desired bend angle is to 180°, the more difficult the bend will be.

[0023] The recess / aperture ensures that the first bending zone can be forced, permanently if necessary, into the plane of the second contact section during manufacture of the contact sheet metal member or during assembly of the energy storage element, thus facilitating temporary or permanent compression of the contact sheet and reduction of dead volume.

[0024] In a preferred embodiment, the contact sheet metal member is characterized by at least one of the following features a. to c.: a. The first contact section is aligned parallel to the second contact section. b. The connection section is aligned parallel to the first contact section and / or the second contact section. c. The connection section is at an angle in the range of -10° to +30° relative to the first contact section and / or the second contact section.

[0025] It is particularly preferred that the immediately preceding features a. and b. or the immediately preceding features a. and c. are realized in combination with one another. Feature b. is preferred when the above-mentioned ideal case occurs, in which the bottom surface of the first contact section and the top surface of the connection section, as well as the top surface of the second contact section and the bottom surface of the connection section, are in direct, preferably flat contact with one another. However, in many cases, in particular before the contact sheet metal parts are attached, there is no direct contact, so that the connection section forms the above-mentioned angle in the range of -10° to +30° with the first contact section and / or the second contact section.

[0026] In the described context, parallel alignment of the contact sections means that the bottom surface of the first contact section and the top surface of the second contact section are uniformly spaced apart. When the bottom surface of the first contact section and the top surface of the connection section, and the top surface of the second contact section and the bottom surface of the connection section are aligned in parallel, the distance is approximately zero.

[0027] It is further preferred that the contact sheet metal member is characterized by at least one of the following features a.-b.: a. The contact sheet metal member has a uniform thickness in the first contact section, the second contact section, and the connecting section. b. The contact sheet metal members have a thickness in the connection section that is the same as a thickness in the first contact section and / or the second contact section.

[0028] The immediately preceding features a. and b. are particularly preferably realised in combination.

[0029] In some embodiments, the contact sheet metal member is characterized by the following features a. a. The contacting sheet metal member has at least one bead in the second contact section, the bead appearing as a depression on the top surface and a protrusion on the bottom surface of the second contact section.

[0030] Such a bead can be useful in making a good weld contact with the electrode, as will be described in more detail below.

[0031] In a further preferred embodiment, the contact sheet metal member is characterized by at least one of the following features a. to c.: In the first contact section, the contacting sheet metal members only have areas that extend within the same planar layer. b. In the second contact section, the contacting sheet metal members only have areas that extend within the same planar layer. c. In the connection section, the contacting sheet metal members only have areas which extend within the same planar layer.

[0032] The immediately preceding features a to c are particularly preferably realized in combination.

[0033] In the aforementioned case where the first contact section is aligned parallel to the second contact section, the flat layers on which the areas of the first and second contact sections extend are also aligned parallel to each other accordingly. That is, if the connection section is not aligned parallel to the first and second contact sections, the flat layer on which the area of ​​the connection section extends may cross the other two flat layers. In general, this is always the case before the contact sheet metal members are attached.

[0034] In an alternative preferred embodiment, the contact sheet metal member is characterized by at least one of the following features a. to c.: In the first contact section, the contacting sheet metal members only have areas that extend within the same planar layer. b. In the second contact section, the contacting sheet metal member has a first region that extends in the planar layer and at least one second region that does not extend in the planar layer. c. In the connection section, the contacting sheet metal members only have areas which extend within the same planar layer.

[0035] The immediately preceding features a to c are particularly preferably realized in combination.

[0036] These alternative preferred embodiments are particularly suitable when the contact sheet metal member comprises at least one bead in the second contact section, in which case the at least one second region comprises a recessed or raised region, which does not actually extend in the plane of the first region.

[0037] If the second contact section comprises at least one bead, it is particularly preferred that the first contact section is aligned parallel to the first region of the second contact section.

[0038] In the above context, a flat layer is preferably understood as a non-bent layer having a uniform thickness, which preferably does not exceed the thickness of the contact sheet metal part in the corresponding section by more than 10%. Particularly preferably, the thickness of the flat layer corresponds to the thickness of the contact sheet metal part in the corresponding section.

[0039] The aperture or recess is preferably located in the planar layer through which the region of the second contact section or the first region extends. In the case of an aperture, the aperture is surrounded by the region or the first region.

[0040] The contact sheet metal member is preferably characterized by at least one of the following features a. to b.: a. The first contact section is a terminal contact section. b. The second contact section is a terminal contact section.

[0041] The immediately preceding features a. and b. are particularly preferably realised in combination. Before the contacting sheet metal parts are bent along the above-mentioned bending lines, the two contact sections are preferably ends of the contacting sheet metal parts.

[0042] In a further preferred embodiment, the contact sheet metal member is characterized by the following feature a. a. The first and second contact sections and the connecting section each have apertures, the apertures overlapping each other in a direction perpendicular to the second contact section and / or forming a path, preferably a straight path, through the sections of the contacting sheet metal member.

[0043] The pathways facilitate electrolyte filling, allowing the electrode-separator assembly to be impregnated with electrolyte at the ends.

[0044] Any energy storage element comprising contact sheet metal members as described above is an object of the present invention.

[0045] Particularly preferably, the energy storage element according to the invention has the following characteristics a. to c.: a. The energy storage element includes an electrode-separator assembly having an anode / separator / cathode sequence. b. The energy storage element comprises an air-tight and liquid-tight housing in which the electrode-separator assembly is disposed. c. The electrode-separator assembly is electrically connected via a contact sheet metal member to a part of the housing or to an electrical pole that passes through the housing.

[0046] The energy storage element may have a prismatic or cylindrical housing. The electrode-separator assembly therefore also preferably has an essentially prismatic or cylindrical shape. In the case of a prismatic shape, the electrode-separator assembly preferably comprises a stack of electrodes, for example electrodes having a rectangular shape. In the case of a cylindrical or essentially cylindrical shape, the electrode-separator assembly preferably comprises a spirally wound ribbon electrode. Preferably, a separator or a layer of solid electrolyte is arranged between the oppositely polarized electrodes. In the case of a separator, the separator and the electrodes are preferably impregnated with an electrolyte.

[0047] Particularly preferably, the energy storage element is a cylindrical round cell and thus preferably comprises an anode and a cathode in the form of a ribbon. Furthermore, the energy storage element preferably comprises one ribbon-shaped separator or two ribbon-shaped separators. In these preferred embodiments, the energy storage element is characterized by the following features a to f: a. The electrode-separator assembly is in the form of a cylindrical winding having a first terminal end face and a second terminal end face and a winding shell therebetween. b. The anode of the electrode-separator assembly comprises an anode current collector having a first longitudinal edge and a parallel second longitudinal edge. c. The anode current collector has a main area provided with a layer of negative electrode material and a free edge strip extending along a first longitudinal edge free of negative electrode material. d. The cathode of the electrode-separator assembly comprises a cathode current collector having a first longitudinal edge and a parallel second longitudinal edge. e. A cathode current collector having a main area provided with a layer of positive electrode material and a free edge strip extending along a first longitudinal edge free of electrode material. f. The anode and cathode are positioned within the electrode-separator assembly such that a first longitudinal edge of the anode current collector protrudes from a first terminal end face and a first longitudinal edge of the cathode current collector protrudes from a second terminal end face of the electrode-separator assembly.

[0048] The end face is preferably bounded by a circular edge.

[0049] In particularly preferred embodiments, the energy storage element is further characterized by the following features a to c: The housing includes a metal housing cup having a terminal circular opening and a lid assembly having a circular edge that closes the circular opening. b. The top surface of the first contact section is secured to the lid assembly, preferably welded to the lid assembly. c. A bottom surface of the second contact section is fixed, preferably welded, to a longitudinal edge of one of the current collectors protruding from one of the end faces of the electrode-separator assembly.

[0050] Thus, the first component of the energy storage element described above in connection with the description of the contact sheet metal members may be the lid assembly, and thus the second component of the energy storage element described above may be the electrode-separator assembly described.

[0051] In some embodiments, it may be preferred to weld an additional separate sheet metal part onto a longitudinal edge of one of the current collectors protruding from one of the end faces of the electrode-separator assembly, and to fasten, preferably by welding, the bottom surface of the second contact section to this additional sheet metal part, which then electrically connects the longitudinal edge to a contact sheet metal member, which in turn electrically connects the additional sheet metal part to a housing part or to an electric pole passing through the housing.

[0052] The lid assembly is preferably characterized by the following features a. to j.: The lid assembly includes a pole cap having a circular edge. b. The lid assembly includes a first metal disk having a circular edge. c. The lid assembly includes a second metal disk having a circular edge. d. The lid assembly includes an annular seal. e. The lid assembly includes an annular insulator. f. The first metal disc is disposed between the pole cap and the second metal disc. g. The annular insulator electrically insulates the first metal disc and the second metal disc from each other. h. The first metal disk is in direct contact with the pole cap. i. An annular seal is mounted on the pole cap and / or the circular edge of the first metal disc. j. The top surface of the first contact section is welded to a second metal disc.

[0053] In particularly preferred embodiments, the energy storage element is further characterized by the following features a. to c., preferably by the following features a. to d.: The housing cup comprises, in axial sequence, a bottom section, a center section, and a closure section. b. The central section is cylindrical, where the wound shell of the electrode-separator assembly contacts the inside of the housing cup. c. In the closed section, the annular seal of the lid assembly presses against the edge of the pole cap and / or the edge of the first metal disc and the inside of the housing cup. d. In the closure section, the housing cup has an opening edge defining a circular opening, the opening edge bent radially inwardly over an edge of the pole cap and / or first metal disk surrounded by the seal to securely secure the lid assembly, including the seal, within the circular opening of the housing cup.

[0054] The term "edge of the pole cap and / or the first metal disc" includes embodiments in which the diameters of the pole cap and the metal disc are different or the same. For crimping, the component with the larger diameter is important because the seal is in contact with that component.

[0055] As already mentioned above, the recess / aperture ensures that the first bending zone can be pressed into the plane of the second contact section during manufacture of the contact sheet metal part and / or during assembly of the energy storage element.

[0056] In some embodiments, the first bending zone only remains temporarily in the recess or aperture. However, this process may also result in the contact sheet metal member having the first bending zone or a part of the first bending zone permanently protruding into the recess or aperture, and thus preferably into the above-mentioned flat layer through which the second contact section region or the first region extends. Such an arrangement is particularly efficient for reducing the above-mentioned dead volume.

[0057] The electrode-separator assembly is preferably in direct contact with the inner surface of the housing cup. It is particularly preferred that the electrode-separator assembly is in direct contact with the inner surface of the housing cup. However, in some embodiments, electrical insulation of the inner surface may be provided, for example by a plastic film. In this case, the electrode-separator assembly is preferably in contact with the inner wall via the film.

[0058] The bottom of the housing cup is preferably circular. The housing cup is usually formed by deep drawing. However, it is also possible to form the cup by welding the bottom into the tubular half-piece.

[0059] The height of the energy storage elements according to the invention, preferably designed as cylindrical round cells, is in the range of 50 mm to 150 mm. Their diameter is preferably in the range of 15 mm to 60 mm. Cylindrical round cells with these form factors are suitable for powering electric drives, for example in automobiles.

[0060] Lithium-Ion Energy Storage Element Embodiment In a particularly preferred embodiment of the invention, the energy storage element according to the invention is based on lithium-ion technology.

[0061] Essentially all electrode materials known for secondary lithium-ion cells can be used for the electrodes for the energy storage element.

[0062] Carbon-based particles such as graphite carbon, or preferably also in particulate form, non-graphite carbon materials capable of intercalating lithium can be used as the active material in the negative electrode. Alternatively or in addition, lithium titanate (Li 4 Ti 5 O 12 ) or derivatives thereof can also preferably be included in the negative electrode, also in particulate form. Furthermore, the negative electrode contains, as the active material, at least one material from the group consisting of silicon, aluminum, tin, antimony, or compounds or alloys of these materials, which can reversibly store or release lithium, for example silicon oxide (specifically, SiO x , 0 < x < 2), optionally in combination with a carbon-based active material. Tin, aluminum, antimony, and silicon can form intermetallic phases with lithium. The capacity of the lithium storage part is many times higher than that of graphite or equivalent materials, especially in the case of silicon. Mixtures of silicon and carbon-based storage materials are often used. Thin anodes made of metallic lithium are also suitable.

[0063] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds, such as LiCoO 2 and LiFePO 4 . Lithium nickel manganese cobalt oxide (NMC) having the chemical formula LiNi x Mn y Co z O 2 (where x + y + z is typically 1), lithium manganese spinel (LMO) having the chemical formula LiMn 2 O 4 , or lithium nickel cobalt aluminum oxide (NCA) having the chemical formula LiNi x Co y Al z O 2 (where x + y + z is typically 1) are also particularly suitable. Derivatives thereof, for example, the chemical formula Li 1.11 (Ni 0.40 Mn 0.39 Co0.16 Al 0.05 ) 0.89 O 2 Lithium nickel manganese cobalt aluminum oxide (NMCA), or Li 1+x Mixtures of MO compounds and / or materials mentioned above may also be used. The cathode active material is also preferably used in particulate form.

[0064] In addition, the electrodes of the energy storage element preferably contain an electrode binder and / or additives to improve electrical conductivity. The active material is preferably embedded in the matrix of the electrode binder, and adjacent particles in the matrix are preferably in direct contact with each other. The conductive agent has the function of increasing the electrical conductivity of the electrode. Common electrode binders are, for example, based on polyvinylidene fluoride (PVDF), (Li-) polyacrylate, styrene butadiene rubber, or carboxymethyl cellulose, or a mixture of different binders. Common conductive agents are carbon black, fine graphite, carbon fibers, carbon nanotubes, and metal powders.

[0065] The energy storage element preferably comprises an electrolyte, in the case of a lithium-ion cell, in particular at least one lithium salt, such as lithium hexafluorophosphate (LiPF ), dissolved in an organic solvent (for example in a mixture of organic carbonates or cyclic ethers, such as THF or nitriles). 6 Other usable lithium salts include, for example, lithium tetrafluoroborate (LiBF 4 ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalato)borate (LiBOB).

[0066] The nominal capacity of the lithium-ion based energy storage element designed as a cylindrical round cell is preferably up to 15000 mAh. In the case of a 21x70 form factor, the circular cell in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1500 mAh to 7000 mAh, particularly preferably in the range of 3000 to 5500 mAh. In the case of a 18x65 form factor, the circular cell in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1000 mAh to 5000 mAh, particularly preferably in the range of 2000 to 4000 mAh.

[0067] In the European Union, manufacturer information on the nominal capacity of secondary batteries is highly regulated. For example, information on the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to the IEC / EN 61951-1 and IEC / EN 60622 standards, information on the nominal capacity of secondary nickel-hydrogen hybrid batteries must be based on measurements according to the IEC / EN 61951-2 standard, information on the nominal capacity of secondary lithium batteries must be based on measurements according to the IEC / EN 61960 standard, and information on the nominal capacity of secondary lead-acid batteries must be based on measurements according to the IEC / EN 61056-1 standard. Any information on nominal capacity in the present application is preferably based on these standards.

[0068] Sodium Ion Energy Storage Element Embodiment In further embodiments, the energy storage element may be a sodium-ion cell, a potassium-ion cell, a calcium-ion cell, a magnesium-ion cell, or an aluminum-ion cell. Among these variations, energy storage elements having a sodium-ion cell chemistry are particularly preferred. Preferably, the sodium-ion based energy storage element according to the present invention comprises an electrolyte comprising at least one of the following solvents and at least one of the following conductive salts:

[0069] Organic carbonates, ethers, nitriles and mixtures thereof are particularly suitable as solvents. Preferred examples are: Carbonates: Propylene carbonate (PC), Ethylene carbonate-propylene carbonate (EC-PC), Propylene carbonate-dimethyl carbonate-ethyl methyl carbonate (PC-DMC-EMC), Ethylene carbonate-diethyl carbonate (EC-DEC), Ethylene carbonate-dimethyl carbonate (EC-DMC), Ethylene carbonate-ethyl methyl carbonate (EC-EMC), Ethylene carbonate-dimethyl carbonate-ethyl methyl carbonate (EC-DMC-EMC), Ethylene carbonate-dimethyl carbonate-diethyl carbonate (EC-DMC-DEC) Ethers: Tetrahydrofuran (THF), 2-methyltetrahydrofuran, dimethyl ether (OME), 1,4-dioxane (DX), 1,3-dioxolane (DOL), diethylene glycol dimethyl ether (DEGDME), tetraethyl glycol dimethyl ether (TEGDME) · Nitriles: Acetonitrile (ACN), Adiponitrile (AON), y-butyrolactone (GBL).

[0070] Trimethyl phosphate (TMP) and tris(2,2,2-trifluoroethyl) phosphate (TFP) can also be used.

[0071] A preferred conductive salt is NaPF 6 , sodium difluoro(oxalato)borate (NaBOB), NaBF 4 , sodium bis(fluorosulfonyl)imide (NaFSI), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), NaAsF 6 , NaBF 4 , NaClO 4 , NaB(C 2 O 4 ) 2 , NaP(C 6 H4 O 2 ) 3 , NaCF 3 SO 3 , sodium triflate (NaTf), and Et 4 NBF 4 It is.

[0072] In a preferred embodiment, additives may be added to the electrolyte. Examples of preferred additives, especially for stabilization, are:

[0073] Fluoroethylene carbonate (FEC), trans-difluoroethylene 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 (AlCl 3 ), ethylene sulfate (DTD), sodium difluorophosphate (NaPO 2 F 2 ), sodium difluoro(oxalato)borate (NaODFB), sodium difluorobisoxalatophosphate (NaDFOP) and tris(trimethylsilyl)borate (TMSB).

[0074] The negative electrode material of the sodium ion based energy storage element is preferably at least one of the following materials: Carbon: in particular hard carbon (pure or doped with nitrogen and / or phosphorus) or soft carbon, or graphene-based materials (N-doped), carbon nanotubes, graphite Phosphorus or sulfur (conversion anode) Polyanion: Na 2 Ti 3 O 7 , Na 3 Ti 2 (PO 4 ) 3 , TiP 2 O 7 , TiNb 2 O7 , Na-Ti-(PO 4 ) 3 , Na-V-(PO 4 ) 3 Prussian Blue: low sodium variant (for aqueous electrolyte systems) ·Transition metal oxide:V 2 O 5 , MnO 2 , TiO 2 , Nb 2 O 5 , Fe 2 O 3 , Na 2 Ti 3 O 7 , NaCrTiO 4 , Na 4 Ti 5 O 12 MXene: M=Ti, V, Cr, Mo or Nb, A=Al, Si and Ga, X=C and / or N, e.g. Ti 3 C 2 Organic substances: For example, sodium terephthalate (Na 2 C 8 H 2 O 4 )

[0075] Alternatively, a sodium metal anode can be used on the anode side.

[0076] The positive electrode material of the sodium ion based energy storage element can include or be at least one of the following materials: Polyanion: NaFePO 4 (Triphyllite type), Na 2 Fe(P 2 O 7 ), Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ), Na 2 FePO 4 F, Na / Na 2 [Fe1 / 2 Mn 1 / 2 ]PO 4 F, Na 3 V 2 (PO 4 ) 2 F 3 , Na 3 V 2 (PO 4 ) 3 , Na 4 (CoMnNi) 3 (PO 4 ) 2 P 2 O 7 , NaCoPO 4 , Na 2 CoPO 4 F ·Silicate: Na 2 MnSiO 4 , Na 2 FeSiO 4 Layered oxide: NaCoO 2 , NaFeO 2 , NaNiO 2 , NaCrO 2 , NaVO 2 , NaTiO 2 , Na(FeCo)O 2 , Na(NiFeCo) 3 O 2 , Na(NiFeMn)O 2 , and Na(NiFeCoMn)O 2 , Na(NiMnCo)O 2 .

[0077] In addition, the electrode of the energy storage element according to the present invention preferably comprises an electrode binder and / or additives to improve electrical 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. The conductive agent has the function of increasing the electrical conductivity of the electrode. Common electrode binders are, for example, based on polyvinylidene fluoride (PVDF), (Na) polyacrylate, styrene butadiene rubber, (Na) alginate or carboxymethyl cellulose, or a mixture of different binders. Common conductive agents are carbon black, fine graphite, carbon fibers, carbon nanotubes and metal powders.

[0078] In particularly preferred energy storage elements based on sodium-ion technology, both the anode and cathode current collectors are constructed of aluminum or an aluminum alloy. The housing and contact plates, as well as any other current conductors within the housing, can also be constructed of aluminum or an aluminum alloy.

[0079] Preferred housing design Particularly preferably, the energy storage element according to the invention is characterized by at least one of the following features a. to c.: a. The center section and the closed section are separated by a recess that circumferentially surrounds the outer surface of the housing cup. b. The housing cup has the same maximum outside diameter in the center section and the closed section. c. In the region of the recess, the outer diameter of the housing cup is reduced by an amount between 4 and 12 times the wall thickness of the housing cup in this region.

[0080] It is preferable that at least the immediately preceding features a and b be realized in combination. It is particularly preferable that all three of the immediately preceding features a to c be realized in combination with one another.

[0081] Preferably, the annular seal is compressed in the closed section, the annular seal preferably being radially pressed against the circular edge of the pole cap and / or the first metal disc.

[0082] Contact Sheet Metal Member Embodiments In principle, the contact sheet metal member may be electrically connected to either the anode current collector or the cathode current collector.

[0083] In a particularly preferred embodiment of the invention, the contact sheet metal member electrically connected to the anode current collector is characterized by at least one of the following features a. and b.: a. The contact sheet metal members are constructed of nickel or copper or titanium, or nickel or copper or titanium alloys, or stainless steel, for example type 1.4303 or 1.4404, or type SUS304, or nickel plated copper. b. The contact sheet metal member is constructed from the same material as the anode current collector.

[0084] In another particularly preferred embodiment of the invention, the contact sheet metal member electrically connected to the cathode current collector is characterized by at least one of the following features a. and b.: a. The contact sheet metal member is constructed from aluminum or an aluminum alloy. b. The contact sheet metal member is constructed from the same material as the anode current collector.

[0085] Particularly preferably, the contact sheet metal member electrically connected to the anode current collector and / or the contact sheet metal member electrically connected to the cathode current collector is characterized by at least one of the two features a. and b. immediately below: a. The contact sheet metal member has a preferably uniform thickness in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm. b. The contact sheet metal member is dimensioned to cover at least 40%, preferably at least 70%, particularly preferably at least 80% of the first terminal end face or of the second terminal end face.

[0086] It is particularly preferred that the immediately preceding features a. and b. are realised in combination with one another.

[0087] Covering as much of the end surface as possible is important for the thermal management of the energy storage element according to the invention. The larger the coverage, the easier it is to contact the majority of the first longitudinal edge of the corresponding current collector, or even over its entire length. Thus, the heat generated in the electrode-separator assembly can be better dissipated through the contact sheet metal members.

[0088] Preferably, the bottom surface of the second contact section of the contact sheet metal member rests flat on the first longitudinal edge of the current collector to which it is welded, and ideally it contacts the longitudinal edge over most or all of its length.

[0089] In some embodiments, it has been found to be advantageous to subject the longitudinal edges of the current collector to a pretreatment before the contact sheet metal member is placed thereon. In particular, at least one recess can be folded into the longitudinal edges, which corresponds to at least one bead or elongated ridge on the bottom surface of the second contact section of the contact sheet metal member.

[0090] The longitudinal edges of the current collector may be pre-formed to have a directional shape, for example, the longitudinal edges may be bent in a predetermined direction.

[0091] Particularly preferably, the contact sheet metal element is welded to a first longitudinal edge of the corresponding current collector in the region of the bead, in particular via one or more weld seams or weld spots in the bead.

[0092] Preferred embodiments of the current collector and separator The anode current collector, cathode current collector, and separator of the energy storage element according to the present invention preferably have the following dimensions: Length ranging from 0.5m to 25m Width ranging from 40mm~145mm.

[0093] When the electrode-separator assembly is formed as a winding, the ribbon-shaped anode, ribbon-shaped cathode, and ribbon-shaped separator are preferably wound helically. To produce the electrode-separator assembly, the ribbon-shaped electrode and ribbon-shaped separator are generally fed to a winding device, where they are wound helically, preferably around a winding axis. It is generally not necessary to bond or contact the electrodes and separators at high temperatures. In some embodiments, the electrodes and separator(s) are wound on a cylindrical or hollow cylindrical winding core, which is seated on a winding mandrel and remains in the winding after winding.

[0094] The rolling shell can be formed, for example, by a plastic film or an adhesive tape. The rolling shell can also be formed by one or more turns of the separator.

[0095] The current collector of the energy storage element according to the invention serves to electrically contact the electrochemically active components contained in the corresponding electrode material over as large an area as possible. Preferably, the current collector is made of metal or at least has a metallized surface.

[0096] In the case of the lithium-ion cell of the present invention, the preferred metal for the anode current collector is copper or nickel, or other conductive materials, in particular alloys of copper and nickel, or nickel-coated metals. In particular, materials of the type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used as copper alloys. Alloys of the type NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable as nickel alloys. Alloys of the type NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable as nickel alloys. Stainless steels, such as type 1.4303 or 1.4404 or type SUS304, can also be considered.

[0097] For lithium-ion cells, aluminum or other conductive materials, including aluminum alloys, are particularly suitable as metals for the cathode current collector.

[0098] Suitable aluminum alloys for the cathode current collector include, for example, Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg. The aluminum content of these alloys is preferably greater than 99.5%.

[0099] Preferably, the anode current collector and / or the cathode current collector are each a ribbon-shaped metal foil having a thickness in the range of 4 μm to 30 μm.

[0100] However, in addition to foils, other strip-shaped substrates such as metallic or metallized nonwoven fabrics, or open-pore metal foams, or expanded metals can also be used as current collectors.

[0101] The current collector is preferably provided on both sides with a corresponding electrode material.

[0102] Preferably, the longitudinal edges of the separator(s) form the end faces of the electrode-separator assembly.

[0103] Preferred Embodiments of the Lid Assembly The energy storage element according to the invention is preferably characterized by the fact that the CID function is integrated in the lid assembly, which ensures that in case of too high pressure in the cell, the pressure can escape from the housing, while at the same time the electrical contact between the lid assembly and the electrode-separator assembly is interrupted. Particularly preferably, the energy storage element according to the invention is characterized by at least one of the following features a. and b.: A first metal disc of the lid assembly includes a metal membrane that bulges outwardly or bursts when a certain excess pressure occurs inside the housing. b. A first metal disk including a membrane is in direct contact with an upper surface of a first contact section of a contacting sheet metal member.

[0104] Preferably, features a. and b. immediately preceding are implemented in combination.

[0105] Anticipated design of the seal The energy storage element according to the invention is preferably characterized by at least one of the following characteristics a. and b.: a. The seal is made of a plastic material having a melting point above 200°C, preferably above 300°C, and particularly preferably above 300°C and below 350°C. b. The plastic material is polyetheretherketone (PEEK), polyimide (PI), polyphenylene sulfide (PPS), or polytetrafluoroethylene (PTFE).

[0106] Preferably, features a. and b. immediately preceding are implemented in combination. [Brief description of the drawings]

[0107] Further features and advantages of the invention are apparent from the claims and from the following description of preferred embodiments of the invention taken in conjunction with the drawings. The illustrated features may be realized individually or in combination with other features. [Figure 1] 1 shows a diagram of a first embodiment of a contact sheet metal part according to the invention; [Diagram 2] 2 shows a second embodiment of a contact sheet metal member according to the present invention. [Diagram 3] 3 shows a third embodiment of a contact sheet metal member according to the present invention. [Figure 4] 1 illustrates an electrode-separator assembly that may be part of an energy storage element according to the present invention, and its components. [Diagram 5] 1 shows a portion of a cross section through a lid assembly that can be used in accordance with the present invention. [Figure 6] FIG. 1 is a general view (cross-sectional view) of an embodiment of an energy storage element according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0108] 1 shows a preferred embodiment of a contact sheet metal part 200 according to the invention in top view (upper figure) and bottom view (middle figure). Furthermore, a cross-sectional view of the contact sheet metal part 200 along line S is shown (lower figure). The contact sheet metal part 200 comprises a first terminal contact section 201 having a top surface 201a and a bottom surface 201b, which is provided for contacting a first component of an energy storage element; and a second terminal contact section 202 having a top surface 202a and a bottom surface 202b, which is provided for contacting a second component of the energy storage element. Between the first contact section 201 and the second contact section 202, the contact sheet metal piece 200 comprises a connection section 203 having a top surface 203a and a bottom surface 203b. As a result of the bending process, the top surface 203a of the connection section 203 now faces the bottom surface 201b of the first contact section 201, and the bottom surface 203b of the connection section 203 faces the top surface 202a of the second contact section 202. The first contact section 201 and the connection section 203 are connected to each other via a first bending zone 204, and the contact sheet metal piece 200 is bent along a first bending line. The second contact section 202 and the connection section 203 are connected to each other via a second bending zone 205, and the contact sheet metal part 200 is bent along a second bending line. As a result of the above-mentioned bending process, the connection section 203 is aligned parallel to the second contact section 202 and forms an angle in the range of -10° to +30° with respect to the first contact section 201. The contact sheet metal part 200 has the same thickness in the connection section 203 as it does in the first contact section 201 and in the second contact section 202. This may be, for example, in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0109] The contact sheet metal part 200 comprises only an area extending in a flat layer in each of the first contact section 201, the second contact section 202 and the connection section 203. This flat layer is a non-curved layer having a uniform thickness, which essentially corresponds to the thickness of the contact sheet metal part 200 in the respective section. Since the connection section 203 is not parallel to the first contact section 201, the flat layer in which the area of ​​the connection section 203 extends typically intersects along a bend line the flat layer in which the area of ​​the first contact section extends.

[0110] The second contact section 202 has a recess 206 that forms a receiving portion for the first bending zone 204. The first bending zone 204 can be pressed into this receiving portion, for example during installation of the contact sheet metal member 200. The receiving portion 206 is formed by two legs 202c and 202d that are connected to each other by a cross member 202e. The cross member is long enough so that the first bending zone 204 can be pressed into the receiving portion without contacting one of the legs 202c and 202d.

[0111] The recess 206 is located in the same flat layer as the area of ​​the second contact section 202 or the first area extends. The first contact section 201 has an aperture 209. Along a line 210, the contact sheet metal member 200 can be welded, for example, to an edge of a current collector protruding from an end face of the electrode-separator assembly.

[0112] Fig. 2 shows a further preferred embodiment of a contact sheet metal part 200 according to the invention in top view (upper figure) and bottom view (middle figure). Furthermore, a cross-section of the contact sheet metal part 200 along the line S is shown (lower figure). The contact sheet metal part 200 comprises a first terminal contact section 201 with a top surface 201a and a bottom surface 201b, intended for contacting a first component of the energy storage element, and a second terminal contact section 202 with a top surface 202a and a bottom surface 202b, intended for contacting a second component of the energy storage element. Between the first contact section 201 and the second contact section 202, the contact sheet metal part 200 comprises a connection section 203 with a top surface 203a and a bottom surface 203b. As a result of the bending process, the top surface 203a of the connection section 203 faces the bottom surface 201b of the first contact section 201, and the bottom surface 203b of the connection section 203 faces the top surface 202a of the second contact section 202. The first contact section 201 and the connection section 203 are connected to each other via a first bending zone 204, and the contact sheet metal member 200 is bent along a first bending line. The second contact section 202 and the connection section 203 are connected to each other via a second bending zone 205, and the contact sheet metal member 200 is bent along a second bending line. As a result of the above-mentioned bending process, the connection section 203 is aligned parallel to the first contact section 201 and the second contact section 202. The contact sheet metal member 200 has the same thickness in the connection section 203 as it has in the first contact section 201 and the second contact section 202. This may typically be in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0113] The contact sheet metal part 200 comprises only a region extending in a flat layer in each of the first contact section 201, the second contact section 202 and the connection section 203. This flat layer is a non-curved layer having a uniform thickness, which essentially corresponds to the thickness of the contact sheet metal part 200 in the respective section. Since the connection section 203 is parallel to the contact sections 201 and 202, the flat layer in which the connection section 203 and the regions of the contact sections 201 and 202 extend is also not crossed.

[0114] The second contact section 202 has an elliptical aperture 207 that forms a receptacle for the first bending zone 204. The first bending zone 204 can be pressed into this receptacle, for example, during installation of the contact sheet metal member 200. The aperture 207 is large enough so that the first bending zone 204 can be pressed into the receptacle without contacting the edges of the aperture.

[0115] The aperture 207 is located in the same planar layer through which the region or first region of the second contact section 202 extends and is defined by this region or first region.

[0116] Along line 210, for example, contact sheet metal member 200 may be welded to an edge of a current collector protruding from an end face of the electrode-separator assembly.

[0117] Fig. 3 shows a further preferred embodiment of a contact sheet metal part 200 according to the invention in top view (upper figure) and bottom view (middle figure). Furthermore, a cross-section of the contact sheet metal part 200 along the line S is shown (lower figure). The contact sheet metal part 200 comprises a first terminal contact section 201 with a top surface 201a and a bottom surface 201b, intended for contacting a first component of the energy storage element, and a second terminal contact section 202 with a top surface 202a and a bottom surface 202b, intended for contacting a second component of the energy storage element. Between the first contact section 201 and the second contact section 202, the contact sheet metal part 200 comprises a connection section 203 with a top surface 203a and a bottom surface 203b. As a result of the bending process, the top surface 203a of the connection section 203 faces the bottom surface 201b of the first contact section 201, and the bottom surface 203b of the connection section 203 faces the top surface 202a of the second contact section 202. The first contact section 201 and the connection section 203 are connected to each other via a first bending zone 204, and the contact sheet metal member 200 is bent along a first bending line. The second contact section 202 and the connection section 203 are connected to each other via a second bending zone 205, and the contact sheet metal member 200 is bent along a second bending line. As a result of the above-mentioned bending process, the connection section 203 is aligned parallel to the first contact section 201 and the second contact section 202. The contact sheet metal member 200 has the same thickness in the connection section 203 as it has in the first contact section 201 and the second contact section 202. This may typically be in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0118] The contact sheet metal member 200 has three star-shaped beads 208 in the second contact section 202, which appear as depressions on the top surface 202a and as bumps on the bottom surface 202b of the second contact section 202. It is at these beads 208 that the contact sheet metal member 200 can be welded to edges of current collectors protruding from an end face of the electrode-separator assembly.

[0119] In the first contact section 201 and in the connection section 203, the contact sheet metal parts 200 only comprise areas that extend in the same flat layer. In contrast, in the second contact section 202, the contact sheet metal parts 200 comprise a first area that extends in the flat layer and at least one second area that does not extend in this flat layer. That is to say, in the second contact section 202, the contact sheet metal parts 200 comprise three beads 208 and the at least one second area comprises in each case an area of ​​depression or protuberance that does not extend in the plane of the first area.

[0120] The second contact section 202 has a slot-like aperture 207 that forms a receiving portion for the first bending zone 204. The aperture 207 is present in and is shaped by the flat layer in which the area of ​​the second contact section 202 or the first area extends. The first bending zone 204 protrudes into the receiving portion and therefore also into the flat layer in which the area of ​​the second contact section 202 or the first area extends. The aperture 207 is sufficiently large so that the first bending zone 204 can be pressed into the receiving portion without contacting the edges of the aperture 207.

[0121] The first contact section 201 has an aperture 209. The second contact section 202 has an additional aperture 209.

[0122] FIG. 4 shows the structure of an electrode-separator assembly 104 that can be a component of an energy storage element according to the invention. The assembly 104 comprises a ribbon-shaped anode 105 with a ribbon-shaped anode current collector 106, the anode current collector having a first longitudinal edge 106a and a second longitudinal edge parallel thereto. The anode current collector 106 is a foil made of copper or nickel. The anode current collector comprises a strip-shaped main area provided with a layer of negative electrode material 107 and a free edge strip 106b extending along its first longitudinal edge 106a and not provided with electrode material 107. Furthermore, the assembly 104 comprises a ribbon-shaped cathode 108 with a ribbon-shaped cathode current collector 109, the cathode current collector 109 having a first longitudinal edge 109a and a second longitudinal edge parallel thereto. The cathode current collector 109 is an aluminum foil. The cathode current collector comprises a strip-shaped main area provided with a layer of positive electrode material 110 and a free edge strip 109b extending along its first longitudinal edge 109a which is free of electrode material 110. Both electrodes are shown individually in an unwound state.

[0123] The anode 105 and cathode 108 are offset from one another within the electrode-separator assembly 104 such that a first longitudinal edge 106a of the anode current collector 106 protrudes from a first terminal end face 104a and a first longitudinal edge 109a of the cathode current collector 109 protrudes from a second terminal end face 104b of the electrode-separator assembly 104. The offset configuration is visible in the bottom left view, which also shows two ribbon-like separators 156 and 157, which separate the electrodes 105 and 108 from one another in the windings.

[0124] In the bottom right image, the electrode-separator assembly 104 is shown in a wound form, as can be used, for example, in an energy storage cell according to Fig. 6. The electrode edges 106a and 109a protruding from the end faces 104a and 104b are clearly visible. The wound shell 104c is formed by a plastic film.

[0125] The lid assembly 102 shown in Figure 5 includes a pole cap 117, a first metal disc 113, a second metal disc 115, an annular seal 103, and an annular insulator 116. The first metal disc 113 is disposed between the pole cap 117 and the second metal disc 115. The annular insulator 116 electrically insulates the first metal disc 113 from the second metal disc 115, while the first metal disc 113 is in direct contact with the pole cap 117.

[0126] The annular seal 103 is mounted on the circular edge of a first metal disc 113 which is folded in a U-shape around the edge of the pole cap 117 .

[0127] The seal 103 comprises an outer annular segment 130 which is open at its lower end into an inwardly facing collar 131 which narrows the outer annular segment 130 at this end. The collar 131 has an inner edge 131a which merges into an inner annular segment 132 which has a smaller diameter than the outer annular segment 130.

[0128] FIG. 6 shows an energy storage cell 100 according to the invention, with a closed and liquid-tight housing comprising a metal housing cup 101 with a terminal circular opening and a lid assembly 102 with a circular edge 102a closing the circular opening. The lid assembly 102 has a structure similar to that of the lid assembly shown in FIG. 5. A seal 103 is made of an electrically insulating material and surrounds the circular edge 102a of the lid assembly 102, electrically insulating the housing cup 101 and the lid assembly 102 from each other. The housing cup 101 comprises, in axial sequence, a bottom 101a, a central section 101b, and a closed section 101c, the central section 101b being cylindrical, in which a wound shell 104c of an electrode-separator assembly 104 formed as a wound body contacts the inside of the housing cup 101, and in the closed section 101c, an annular seal 103 presses against the lid assembly 102 and the inside of the housing cup 101. In the closure section 101c, the housing cup 101 has an opening edge 101d defining a circular opening which is bent radially inwardly over an edge 102a of the lid assembly 102 surrounded by a seal 103 to securely fasten the lid assembly 102, including the seal 103, within the circular opening of the housing cup 101.

[0129] The cell 100 also comprises an electrode-separator assembly 104 in the form of a cylindrical winding in an anode / separator / cathode sequence, which is only shown here diagrammatically. The longitudinal edge 106a of the anode current collector 106 protrudes from the end face 104a of the electrode-separator assembly 104, and the longitudinal edge 109a of the anode current collector 109 protrudes from the end face 104b of the electrode-separator assembly 104. The longitudinal edge 106a is welded directly to the housing bottom 101a, preferably over its entire length. The longitudinal edge 109a is connected directly to the contact sheet metal member 200, preferably over its entire length, according to the embodiment shown in FIG. 2. The second contact section 202 then rests with its bottom face 202b on the longitudinal edge 109a. Preferably, the longitudinal edge 109a is welded to the bottom face 202b. The top surface 201a of the first contact section 201 rests directly on the second metal disc 115 and is connected thereto by welding.

[0130] The cell 100 has a height in the range of 60 mm to 10 mm, for example, its diameter is preferably in the range of 20 mm to 50 mm. The housing cup 101 generally has a wall thickness in the range of 0.1 mm to 0.3 mm in the central section 101b. The radially inwardly bent opening edge 101d of the housing cup 101 has a thickness in the range of 1.5 to 2 times that of the housing cup 101 in the central section 101b. The opening edge comprises an inner first surface in direct contact with the seal 103 and a second surface facing away from the seal 103. The second surface comprises an annular flat surface 101p. The flat surface is preferably characterized by an annular width in the range of 0.8 mm to 3 mm, preferably forming an angle of 90° with the wall of the housing cup 101 in the central section 101b. There is a maximum height difference of 0.08 mm between the highest and lowest points of the annular flat surface.

Claims

1. A contact sheet metal member (200), a. a first contact section (201) having a top surface (201a) and a bottom surface (201b) for contacting a first component of an energy storage element; b. a second contact section (202) having a top surface (202a) and a bottom surface (202b) for contacting a second component of the energy storage element; a connection section (203) having a top surface (203a) and a bottom surface (203b) between the first contact section (201) and the second contact section (202), the top surface (203a) of the connection section (203) facing the bottom surface (201b) of the first contact section (201) and the bottom surface (203b) of the connection section (203) facing the top surface (202a) of the second contact section (202); d. said first contact section (201) and said connection section (203) are connected to each other via a first bending zone (204) and said contact sheet metal member (200) is bent along at least one bend line; e. the second contact section (202) and the connection section (203) are connected to each other via a second bending zone (205), and the contact sheet metal member (200) is bent along at least one bend line; As a result, f. the second contact section (202) has a recess (206) or aperture (207) that forms a receiving portion for the first bending zone (204); A contact sheet metal member (200).

2. Additional features include: a. said first contact section (201) is aligned parallel to said second contact section (202); b. the connection section (203) is aligned parallel to the first contact section (201) and / or the second contact section (202); c) the connection section (203) is at an angle in the range of -10° to +30° relative to the first contact section (201) and / or the second contact section (202); 2. The contact sheet metal member of claim 1, comprising at least one of:

3. Additional features include: a. the contact sheet metal member (200) has a uniform thickness in the first contact section (201), the second contact section (202), and the connecting section (203); b. the contact sheet metal member (200) has a thickness in the connection section (203) that is the same as a thickness in the first contact section (201) and / or the second contact section (202); 3. The contact sheet metal member according to claim 1, further comprising at least one of:

4. Additional features include: a. the contact sheet metal member (200) has at least one bead (208) in the second contact section (202), the bead appearing as a depression on a top surface (202a) and as a protuberance on a bottom surface (202b) of the second contact section (202); The contact sheet metal member according to any one of claims 1 to 3, having

5. Additional features include: a. in said first contact section (201), said contact sheet metal member (200) only comprises areas extending within the same planar layer; b. in said second contact section (202), said contact sheet metal member (200) only comprises areas extending within the same planar layer; c. in said connection section (203), said contact sheet metal members (200) only comprise areas extending within the same planar layer; The contact sheet metal member according to any one of claims 1 to 4, comprising at least one of:

6. Additional features include: a. in said first contact section (201), said contact sheet metal member (200) only comprises areas extending within the same planar layer; b. in said second contact section (202), said contact sheet metal member (200) comprises a first region extending in said planar layer and at least one second region not extending in said planar layer; c. in said connection section (203), said contact sheet metal members (200) only comprise areas extending within the same planar layer; The contact sheet metal member according to any one of claims 1 to 4, comprising at least one of:

7. Additional features include: a. the first contact section (201) is a terminal contact section; b. the second contact section (202) is a terminal contact section; The contact sheet metal member according to any one of claims 1 to 6, comprising at least one of:

8. Additional features include: a. the first contact section (201) and the second contact section (202) and the connecting section (203) each have an aperture (209), the apertures overlapping each other in a direction perpendicular to the second contact section (202) and / or forming a path through the sections of the contact sheet metal member (200); The contact sheet metal part according to any one of claims 1 to 7, having

9. An energy storage element (100) comprising a contact sheet metal member (200) according to any one of the preceding claims.

10. Additional features include: a. the energy storage element (100) comprises an electrode-separator assembly (104) having an anode (105) / separator (116) / cathode (108) sequence; b. the energy storage element (100) comprises a housing that is airtight and liquid tightly closed and in which the electrode-separator assembly (104) is disposed; c) said electrode-separator assembly (104) is electrically connected via said contact sheet metal member (200) to a part of said housing or to an electric pole passing through said housing; The energy storage element of claim 9 , comprising at least one of:

11. Additional features include: a. the electrode-separator assembly (104) is in the form of a cylindrical winding having a first terminal end face (104a) and a second terminal end face (104b) and a winding shell (104c) therebetween; b. the anode (105) of the electrode-separator assembly (104) comprises an anode current collector (106) having a first longitudinal edge (106a) and a second longitudinal edge parallel thereto; c) said anode current collector (106) comprising a main area provided with a layer (107) of negative electrode material and a free edge strip extending along a first longitudinal edge (106a) thereof and free of said negative electrode material; d. the cathode (108) of the electrode-separator assembly (104) comprises a cathode current collector (109) having a first longitudinal edge (109a) and a second longitudinal edge parallel thereto; e. said cathode current collector (109) comprising a main area provided with a layer of positive electrode material (110) and a free edge strip extending along a first longitudinal edge (109a) thereof and free of said electrode material (110); f. the anode (105) and the cathode (108) are disposed within the electrode-separator assembly (104) such that the first longitudinal edge (106a) of the anode current collector (106) projects from the first terminal end face (104a) and the first longitudinal edge (109a) of the cathode current collector (108) projects from the second terminal end face (104b) of the electrode-separator assembly (104); The energy storage element according to claim 9 or 10, comprising at least one of:

12. Additional features include: a. the housing comprises a metal housing cup (101) having a terminal circular opening, and a lid assembly (102) having a circular edge (102a) closing the circular opening; b. the top surface (201a) of the first contact section (201) is secured to the lid assembly (102); c. the bottom surface (202b) of the second contact section (202) is fixed, preferably welded, to a longitudinal edge (106a or 109a) of one of the current collectors (106, 109) protruding from one of the end sides (104a or 104b) of the electrode-separator assembly (104); The energy storage element of claim 11 , comprising at least one of:

13. Additional features include: a. said lid assembly (102) comprising a pole cap (117) having a circular edge; b. said lid assembly (102) comprising a first metal disk (113) having a circular edge; c. the lid assembly (102) comprises a second metal disc (115) having a circular edge; d. said lid assembly (102) comprising an annular seal (103); e. the lid assembly (102) comprises an annular insulator (116); f. the first metal disc (113) is disposed between the pole cap (117) and the second metal disc (115); g. the annular insulator (116) electrically insulates the first metal disk (113) and the second metal disk (115) from each other; h. said first metal disk (113) is in direct contact with said pole cap (117); i. the annular seal (103) is mounted on the circular edge of the pole cap (117) and / or the first metal disc (113); j. the top surface (201a) of the first contact section (201) is welded to the second metal disc (115); The energy storage element of claim 12 , comprising at least one of:

Images