Contact plate and energy storage element

Abstract

The invention relates to a contact plate and an energy storage element. The contact plate comprises: a first contact section having a top side and a bottom side, the first end contact section being arranged for contact with a first component of the energy storage element; and a second contact section having a top side and a bottom side, the second end contact section being arranged for contact with a second member of the energy storage element. Between the first contact section and the second contact section, the contact plate comprises a connection section having a top side and a bottom side, with the top side of the connection section facing the bottom side of the first contact section and the bottom side of the connection section facing the top side of the second contact section. The first contact section and the connection section are connected to each other via a first bending region in which the contact plate is bent along at least one bending line. The second contact section and the connection section are connected to each other via a second bending region in which the contact plate is bent along at least one bending line.

Description

Technical Field

[0001] The invention described below relates to a contact plate and an energy storage element provided with the contact plate. Background Art

[0002] Electrochemical energy storage elements are capable of converting stored chemical energy into electrical energy through redox reactions. The simplest form of an electrochemical energy storage element is an electrochemical cell. An electrochemical cell comprises a positive electrode and a negative electrode with a diaphragm arranged therebetween. During discharge, electrons are released at the negative electrode through an oxidation process. This generates an electron flow that can be drawn by an external consumer, for which the electrochemical cell serves as an energy supplier. At the same time, an ion flow corresponding to the electrode reaction is generated inside the cell. This ion flow passes through the diaphragm and is achieved due to the ion-conducting electrolyte. Therefore, the diaphragm prevents direct contact of the electrodes. However, the diaphragm can also achieve charge balance between the electrodes.

[0003] If the discharge is reversible, i.e. the conversion of chemical energy into electrical energy during discharge can be reversed again and the cell can be charged again, then it is called a secondary cell. In secondary cells, the negative electrode is usually called the anode and the positive electrode is called the cathode, which refers to the discharge function of the electrochemical cell.

[0004] Nowadays, for many applications, secondary lithium-ion battery cells are used as energy storage elements, since they can supply large currents and are distinguished by a relatively high energy density. Secondary lithium-ion battery cells are based on the use of lithium, which can migrate back and forth between the electrodes of the battery cell in the form of ions. The negative and positive electrodes of lithium-ion battery cells usually consist of so-called composite electrodes, which, in addition to the electrochemically active components, also include non-electrochemically active components.

[0005] As electrochemically active components (active materials) of secondary lithium-ion battery cells, suitable materials are in principle all materials that can absorb and release lithium ions again. For the negative electrode, for example, carbon-based particles, such as graphite-type carbon, are used for this purpose. As active materials for the positive electrode, for example, lithium cobalt oxide (LiCoO 2 ), lithium manganese oxide (LiMn 2 O 4 ), lithium iron phosphate (LiFePO 4 ) or its derivatives. The electrochemically active material is generally contained in the electrode in the form of particles.

[0006] As a non-electrochemically active component, the composite electrode generally includes a planar and / or strip current collector, such as a metal foil used as a carrier of the corresponding active material. The current collector of the negative electrode (anode current collector) can be formed, for example, of copper or nickel, while the current collector of the positive electrode (cathode current collector) is formed, for example, of aluminum.

[0007] In addition, the electrode may include an electrode binder (e.g., polyvinylidene fluoride (PVDF) or other polymers, such as carboxymethyl cellulose), conductivity-improving additives and other additives as electrochemically inactive components. The electrode binder ensures the mechanical stability of the electrode and generally also ensures the adhesion of the active material to the current collector.

[0008] Lithium-ion battery cells usually contain a lithium salt solution as the electrolyte, such as lithium hexafluorophosphate (LiPF4) in an organic solvent (e.g., ethers and esters of carbonic acid). 6 ).

[0009] When producing lithium-ion battery cells, composite electrodes are usually combined with one or more separators to form an electrode-separator composite. In this case, the electrodes and separators are usually, but not necessarily, connected to each other under pressure, and if necessary, also by lamination or bonding. The basic functions of the battery cell can then be produced by soaking the composite with an electrolyte.

[0010] In many embodiments, the electrode-separator complex is formed in the form of a jelly roll or is processed into a jelly roll. In the first case, for example, a strip-shaped positive electrode and a strip-shaped negative electrode and at least one strip-shaped separator are supplied separately to a winder and spirally wound into a jelly roll with a positive electrode / separator / negative electrode sequence in the winder. In the second case, for example, the aforementioned pressure is applied to first combine the strip-shaped positive electrode and the strip-shaped negative electrode and at least one strip-shaped separator into an electrode-separator complex. Subsequently, in a further step, the complex is wound up.

[0011] For the automotive sector, electric bicycles or other applications with a high energy demand (eg power tools), lithium-ion battery cells are required that have the highest possible energy density and at the same time be able to carry large currents during charging and discharging.

[0012] Typically, battery cells for the above-mentioned applications are designed as cylindrical round battery cells, for example with a form factor of 21×70 (diameter times height in mm). Battery cells of this type always include a composite body in the form of a jellyroll. Modern lithium-ion battery cells of this form factor can achieve energy densities of up to 270 Wh / kg.

[0013] A cylindrical round battery cell is described in WO 2017 / 215900A1, in which the electrode-diaphragm complex and its electrodes are designed as strips and exist in the form of a winding body. Each electrode has a current collector loaded with electrode material. Electrodes of opposite polarity are arranged offset from each other inside the electrode-diaphragm complex so that the longitudinal edge of the current collector of the positive electrode on one side and the longitudinal edge of the current collector of the negative electrode on the other side extend out of the winding body. In order to make electrical contact with the current collector, the battery cell has a contact plate, which is sleeved on the end face of the winding body and connected to the longitudinal edge of one of these current collectors by welding. It can be achieved that the current collector and therefore the electrode associated with the current collector are electrically contacted over its entire length. This significantly reduces the internal resistance in the battery cell. Therefore, the occurrence of large currents can be better prevented, and heat can also be better extracted from the winding body.

[0014] Depending on the construction of the energy storage element, it may be necessary to connect the contact plate to a portion of its housing. Figure 1 This is shown in FIG. 1 , in which a current conductor 107 is used to bridge the distance in the housing, namely the distance between the contact plate 105 and the cover 102. In this case, a dead volume is inevitably produced, which has a negative impact on the energy density of the energy storage element shown.

[0015] EP 3916891A1 discloses a contact plate which is present in the finished cell in an S-shaped fold and not only contacts the electrode-diaphragm assembly over a large area but also bridges the gap to the multi-part cover. By using such a contact component, the dead volume mentioned above can be reduced. Summary of the invention

[0016] The basic object of the present invention is to provide energy storage elements which are distinguished by a high energy density. The basic object of the present invention is, in particular, to further improve a contact plate as mentioned in EP 3916891 A1.

[0017] This object is achieved by a contact plate having the features of claim 1. An energy storage element having the features of claim 9 is also the subject of the invention. Preferred embodiments of the invention are given in the dependent claims 2 to 8 and 10 to 13.

[0018] The contact plate is provided for use in an energy storage element which comprises an electrode-diaphragm complex in a housing. The contact plate is used to electrically contact the electrode of the electrode-diaphragm complex and is intended to connect the electrode to a metal part of the housing or an electrode guided through the housing. The contact plate always has the following features a. to e.:

[0019] a. The contact plate comprises a first contact section having a top side and a bottom side, the first contact section being configured to make contact with a first component of an energy storage element.

[0020] b. The contact plate comprises a second contact section having a top side and a bottom side, the second contact section being configured to make contact with a second component of the energy storage element.

[0021] c. The contact plate comprises a connecting section having a top side and a bottom side between the first contact section and the second contact section, wherein the top side of the connecting section faces the bottom side of the first contact section and the bottom side of the connecting section faces the top side of the second contact section.

[0022] d. The first contact section and the connecting section are connected to one another via a first bending region, in which the contact plate is bent along at least one bending line, preferably along the first bending line.

[0023] e. The second contact section and the connecting section are connected to one another via a second bending region, in which the contact plate is bent along at least one bending line, preferably along a second bending line.

[0024] The contact plate is particularly unique in the following features f.:

[0025] f. The second contact section has a recess or a through-hole which forms a receptacle for the first bending region.

[0026] In the sense of a dead volume that is as small as possible, it is desirable that the contact plate requires as little space as possible in the housing. It is therefore expedient to press the first contact section, the connecting section and the second contact section against one another during assembly so that the spacing between the first contact section and the second contact section and thus the spacing between the bottom side of the first contact section and the top side of the connecting section and the spacing between the top side of the second contact section and the bottom side of the connecting section are as small as possible. In the ideal case, the bottom side of the first contact section and the top side of the connecting section are in direct contact, and the top side of the second contact section and the bottom side of the connecting section are in direct contact.

[0027] During this process, the bending zone, especially the first bending zone, can be problematic. When a sheet is bent, it always springs back a little. In order to bend the sheet at the desired angle, it is usually necessary to bend the sheet beyond the desired angle. This becomes more difficult as the bending angle approaches 180°.

[0028] The recess / through-hole ensures that during production of the contact plate part or its assembly, the first bending region can be pressed, if necessary permanently, into the plane of the second contact section and thus temporarily or permanently simplifies compaction of the contact plate and reduces dead volumes.

[0029] In a preferred embodiment, the contact plate is characterized by at least one of the following features a. to c.:

[0030] a. The first contact section is oriented parallel to the second contact section.

[0031] b. The connecting section is oriented parallel to the first contact section and / or the second contact section.

[0032] c. The connecting section encloses an angle in the range of -10° to +30° with the first contact section and / or the second contact section.

[0033] It is particularly preferred to realize the features a. and b. just mentioned above or the features a. and c. just mentioned above in combination with one another. Feature b. is preferred when the above-mentioned ideal situation occurs, i.e. the bottom side of the first contact section and the top side of the connecting section are in direct contact and the top side of the second contact section and the bottom side of the connecting section are in direct contact. However, more often, in particular also before the contact plate is assembled, there is no direct contact, so that the connecting section encloses the above-mentioned angle in the range of -10° to +30° with the first contact section and / or the second contact section.

[0034] In the described relationship, the parallel orientation of the contact sections is to be understood as meaning that the bottom side of the first contact section and the top side of the second contact section are evenly spaced apart from one another. When the bottom side of the first contact section and the top side of the connecting section are oriented parallel and the top side of the second contact section and the bottom side of the connecting section are oriented parallel, the spacing is usually zero.

[0035] It is also preferred that the contact plate is characterized by at least one of the following features a. and b.:

[0036] a. The contact plate has a uniform thickness in each of the first contact section, the second contact section and the connecting section.

[0037] b. The contact plate has the same thickness in the connecting section as in the first contact section and / or the second contact section.

[0038] It is particularly preferred to implement the features a. and b. just mentioned above in combination.

[0039] In some embodiments, the contact plate is unique in that:

[0040] a. The contact plate has at least one bead in the second contact section, which at least one bead is in the form of a depression on the top side and a projection on the bottom side of the second contact section.

[0041] Such a crimped edge can help to form a good welding contact with the electrode, which will be described in detail below.

[0042] In a further preferred embodiment, the contact plate is distinguished by at least one of the following features a. to c.:

[0043] a. The contact plate in the first contact section comprises only a region extending in the flat layer.

[0044] b. The contact plate in the second contact section comprises only a region extending in the flat layer.

[0045] c. The contact plate in the connecting section only includes a region extending in a flat layer.

[0046] It is particularly preferred if the features a. to c. just mentioned above are implemented in combination.

[0047] In the case where the first contact section is oriented parallel to the second contact section, the flat layer in which the regions of the first contact section and the second contact section extend is correspondingly also oriented parallel to one another. The flat layer in which the region of the connecting section extends can intersect the other two flat layers, i.e. when the connecting section is not oriented parallel to the first contact section and the second contact section. This is usually always the case before the contact plate is assembled.

[0048] In an alternative preferred embodiment, the contact plate is characterized by at least one of the following features a. to c.:

[0049] a. The contact plate in the first contact section comprises only a region extending in the flat layer.

[0050] b. The contact plate comprises in the second contact section a first region extending in a planar layer and at least one second region not extending in this planar layer.

[0051] c. The contact plate in the connecting section only includes a region extending in a flat layer.

[0052] It is particularly preferred if the features a. to c. just mentioned above are implemented in combination.

[0053] These alternative preferred embodiments are particularly relevant when the contact plate has at least one bead in the second contact section. In this case, the at least one second region comprises a region of the depression or the elevation that does not extend in the plane of the first region.

[0054] In the case where the second contact section has at least one bead, it is particularly preferred if the first contact section is oriented parallel to the first region of the second contact section.

[0055] In the above relationship, a flat layer is understood to be a non-bend layer with a uniform thickness, which preferably exceeds the thickness of the contact plate in the corresponding section by no more than 10%. Particularly preferably, the thickness of the flat layer corresponds to the thickness of the contact plate in the corresponding section.

[0056] The through-hole or the recess is preferably located in the planar layer in which the regions or the first region of the second contact section extend. In the case of a through-hole, the through-hole is surrounded by the regions or the first region.

[0057] The contact plate is preferably characterized by at least one of the following features a. and b.:

[0058] a. The first contact section is the end contact section.

[0059] b. The second contact section is the terminal contact section.

[0060] It is particularly preferred to realize the features a. and b. just mentioned above in combination. Before the bending of the contact plate along the mentioned bending line, the two contact sections are respectively end pieces of the contact plate.

[0061] In another preferred embodiment, the contact plate is characterized by the following features a.:

[0062] a. The first contact section and the second contact section and the connecting section each have a through-hole which overlaps one another in a direction perpendicular to the second contact section and forms a passage, preferably a straight passage, through these sections of the contact plate.

[0063] The lead-through facilitates the filling with electrolyte. Thus, the electrode-separator assembly can be flooded with electrolyte at the end.

[0064] Every energy storage element comprising a contact plate as described above is a subject of the present invention.

[0065] Particularly preferably, the energy storage element according to the invention has the following features a. to c.:

[0066] a. The energy storage element comprises an electrode-separator complex having an anode / separator / cathode sequence.

[0067] b. The energy storage element comprises a gas-tight and liquid-tight housing in which the electrode-diaphragm complex is arranged.

[0068] c. The electrode-diaphragm complex is electrically connected to a part of the housing or to an electrode guided through the housing via a contact plate.

[0069] The energy storage element can have a prismatic housing or a cylindrical housing. Correspondingly, the electrode-diaphragm complex preferably also has a substantially prismatic shape or a substantially cylindrical shape. In the case of a prismatic shape, the electrode-diaphragm complex preferably comprises a plurality of electrodes in a stacked form, for example electrodes having a rectangular basic shape. When the electrode-diaphragm complex has a substantially cylindrical shape, it is preferably composed of a spirally wound strip electrode. Here, a diaphragm or a layer formed by a solid electrolyte is arranged between electrodes of opposite polarity. In the case of a diaphragm, the diaphragm and the electrodes are preferably immersed in an electrolyte.

[0070] Particularly preferably, the energy storage element is a cylindrical round battery cell and comprises an anode and a cathode, preferably in the form of a strip. In addition, the electrode-diaphragm complex preferably comprises a strip-shaped diaphragm or two strip-shaped diaphragms. In these preferred embodiments, the energy storage element is characterized by the following features a. to f.:

[0071] a. The electrode-separator assembly is in the form of a cylindrical jellyroll having a first end face and a second end face and a jellyroll side face located therebetween.

[0072] b. The anode of the electrode-separator complex includes an anode current collector having a first longitudinal edge and a second longitudinal edge parallel thereto.

[0073] c. The anode current collector comprises a main area loaded with a layer made of negative electrode material and a free edge strip extending along a first longitudinal edge thereof and not loaded with negative electrode material.

[0074] d. The cathode of the electrode-separator complex includes a cathode current collector having a first longitudinal edge and a second longitudinal edge parallel thereto.

[0075] e. The cathode current collector comprises a main area loaded with a layer made of positive electrode material and a free edge strip extending along its first longitudinal edge and not loaded with electrode material.

[0076] f. The anode and cathode are arranged offset from each other in the electrode-separator assembly so that a first longitudinal edge of the anode current collector extends from a first end face of the electrode-separator assembly and a first longitudinal edge of the cathode current collector extends from a second end face of the electrode-separator assembly.

[0077] The end faces are preferably defined by rounded edges.

[0078] In a particularly preferred embodiment, the energy storage element is also characterized by the following features a. to c.:

[0079] a. The housing comprises a metal housing cup having a circular opening at the end and a cover assembly having a circular edge, the cover assembly closing the circular opening.

[0080] b. The top side of the first contact section is fixed to the cover component, preferably welded to the cover component.

[0081] c. The bottom side of the second contact section is fixed by welding to a longitudinal edge of one of the current collectors protruding from one of the end faces of the electrode-separator assembly.

[0082] Thus, the first component of the energy storage element mentioned in the description of the contact plate can be the cover component and the second component of the energy storage element mentioned can be the described electrode-diaphragm assembly.

[0083] In principle, it is also possible to weld an additional sheet metal part to the longitudinal edge of one of the current collectors protruding at one of the end faces of the electrode-diaphragm assembly, and to fix the bottom side of the second contact section to the additional sheet metal part by welding. In this case, the additional sheet metal part electrically connects the longitudinal edge to the contact plate, and the contact plate electrically connects the additional sheet metal part to a part of the housing or to an electrode guided through the housing.

[0084] The lid assembly is preferably unique in the following features a. to j.:

[0085] a. The cover assembly includes a polar cap having a rounded edge.

[0086] b. The cover assembly includes a first metal disk having a rounded edge.

[0087] c. The cover assembly includes a second metal disk having a rounded edge.

[0088] d. The cover assembly includes an annular seal.

[0089] e. The cover assembly includes an annular insulator.

[0090] f. The first metal disk is arranged between the pole cap and the second metal disk.

[0091] g. The annular insulator electrically insulates the first metal disk and the second metal disk from each other.

[0092] h. The first metal disk is in direct contact with the pole cap.

[0093] i. The annular seal is pulled onto the circular edge of the pole cap and / or the first metal disk.

[0094] j. The top side of the first contact section is welded to the second metal disk.

[0095] In a particularly preferred embodiment, the energy storage element is also characterized by the following features a. to c., preferably by the following features a. to d.:

[0096] a. The housing cup includes a bottom, a middle section and a closed section in order in the axial direction.

[0097] b. The middle section is cylindrical and in the middle section the jellyroll side of the electrode-separator assembly designed as a jellyroll is in contact with the inner side of the housing cup.

[0098] c. In the closed section, the annular seal of the cover assembly is in pressure contact with the edge of the pole cap and / or the edge of the first metal disk and the inside of the housing cup.

[0099] d. The housing cup has an opening edge defining a circular opening in the closed section, the opening edge is bent radially inward beyond the edge of the pole cap and / or the first metal disk surrounded by the seal, and the opening edge fixes the cover assembly including the seal in the circular opening of the housing cup in a form-fitting manner.

[0100] The term "edge of the pole cap and / or the first metal disk" includes embodiments in which the pole cap and the metal disk have different or identical diameters. The component with the larger diameter is decisive for the pressure contact because the seal rests against it.

[0101] As already mentioned above, the recess / through-hole ensures that the first bending region can be pressed into the plane of the second contact section during production of the contact plate and / or during assembly thereof.

[0102] In some embodiments, the first bending region only temporarily remains in the recess or through-hole. However, the process can also result in a contact plate in which the first bending region or a part of the first bending region permanently extends into the recess or through-hole and thus preferably also into the mentioned regions of the second contact section or the flat layer in which the first region extends. Such a configuration is particularly advantageous for reducing dead volumes.

[0103] The electrode-diaphragm complex is preferably in direct contact with the inner side of the housing cup. Particularly preferably, the complex directly adjoins the inner side of the housing cup. However, in some embodiments, it can be provided that the inner side is electrically insulated, for example by means of a foil. In this case, the electrode-diaphragm complex is in contact with the inner wall via the foil.

[0104] The bottom of the housing cup is preferably designed to be round. 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.

[0105] Preferably, the height of the cylindrical circular battery cell of the energy storage element according to the invention is in the range from 50 mm to 150 mm. Its diameter is preferably in the range from 15 mm to 60 mm. Cylindrical circular battery cells with these form factors are suitable, for example, for powering the electric drive of a motor vehicle.

[0106] Implementation as a lithium-ion energy storage element

[0107] In a particularly preferred embodiment of the invention, the energy storage element according to the invention is based on lithium-ion technology.

[0108] Basically all electrode materials known for secondary lithium-ion battery cells can be used for the electrodes of the energy storage element.

[0109] In the negative electrode, carbon-based particles (such as graphite-type carbon) or non-graphite carbon materials (preferably also in particulate form) capable of being used for lithium intercalation can be used as the active material. Alternatively or additionally, lithium titanate (Li 4 Ti 5 O 12 ) or its derivatives (preferably also in particulate form) can also be included in the negative electrode. Furthermore, as the active material, the negative electrode can comprise at least one material selected from the group consisting of silicon, aluminum, tin, antimony or compounds or alloys of these materials capable of reversibly embedding and de-embedding lithium, such as silicon oxide (in particular SiO x , where 0 < x < 2), optionally in combination with a carbon-based active material. Tin, aluminum, antimony and silicon are capable of forming intermetallic phases with lithium. Here, especially in the case of silicon, the ability to absorb lithium is many times greater than that of graphite or similar materials. Mixtures of silicon-based and carbon-based storage materials are usually used. In addition, thin anodes made of metallic lithium are also suitable.

[0110] For the positive electrode, for example, lithium-metal oxide compounds and lithium-metal phosphate compounds (such as LiCoO 2 and LiFePO 4 ) are considered as the active material. Furthermore, lithium nickel manganese cobalt oxide (NMC) of the general formula LiNi x Mn y Co z O 2 (where x + y + z is usually 1), lithium manganese spinel (LMO) of the general formula LiMn 2 O 4 or lithium nickel cobalt aluminum oxide (NCA) of the general formula LiNi x Co y Al z O 2 (where x + y + z is usually 1) are particularly suitable. Derivatives thereof can also be used, for example of the general formula Li1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 O 2 Lithium nickel manganese cobalt aluminum oxide (NMCA) or Li 1+x MO compounds and / or mixtures of the abovementioned materials. The cathode active material is preferably also used in particulate form.

[0111] In addition, the electrode of the energy storage element preferably includes an electrode binder and / or an additive for improving conductivity. The active material is preferably embedded in a matrix made of an electrode binder, wherein adjacent particles in the matrix are preferably in direct contact with each other. The conductive agent is used to improve the conductivity of the electrode. Common electrode binders are based on polyvinylidene fluoride (PVDF), polyacrylate (lithium), styrene-butadiene rubber or carboxymethyl cellulose or a mixture of different binders. Common conductive agents include carbon black, fine graphite, carbon fiber, carbon nanotubes and metal powders.

[0112] The energy storage element preferably comprises an electrolyte, in the case of lithium-ion battery cells in particular an electrolyte based on at least one lithium salt, for example lithium hexafluorophosphate (LiPF4) dissolved in an organic solvent, for example a mixture of organic carbonates or a cyclic ether such as THF or a nitrile. 6 Other lithium salts that can be used include lithium tetrafluoroborate (LiBF 4 ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(oxalato)borate (LiBOB).

[0113] The rated capacity of the lithium-ion-based energy storage element designed as cylindrical round battery cell is preferably up to 15000 mAh. In the embodiment as lithium-ion battery cell, the round battery cell with a 21×70 form factor preferably has a rated capacity in the range of 1500 mAh to 7000 mAh, particularly preferably in the range of 3000 to 5500 mAh. In the embodiment as lithium-ion battery cell, the round battery cell with a 18×65 form factor preferably has a rated capacity in the range of 1000 mAh to 5000 mAh, particularly preferably in the range of 2000 to 4000 mAh.

[0114] In the European Union, manufacturer information about the rated capacity of secondary batteries is strictly regulated. For example, information about the rated capacity of secondary nickel-cadmium batteries should be based on measurements according to standards IEC / EN 61951-1 and IEC / EN 60622, information about the rated capacity of secondary nickel-metal hydride batteries should be based on measurements according to standard IEC / EN 61951-2, information about the rated capacity of secondary lithium batteries should be based on measurements according to standard IEC / EN 61960, and the rated capacity of secondary lead-acid batteries should be based on measurements according to standard IEC / EN 61056-1. Any information about the rated capacity in this application is preferably also based on these standards.

[0115] Sodium-based implementation

[0116] In other embodiments, the energy storage element can also be a sodium ion battery cell, a potassium ion battery cell, a calcium ion battery cell, a magnesium ion battery cell or an aluminum ion battery cell. Among these variants, energy storage elements with a sodium ion battery chemistry are particularly preferred.

[0117] Preferably, the sodium ion-based energy storage element comprises an electrolyte comprising at least one of the following solvents and at least one of the following conductive salts:

[0118] In particular, organic carbonates, ethers, nitriles and mixtures thereof come into consideration as solvents. Preferred examples are:

[0119] -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)

[0120] -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)

[0121] -Nitrile: acetonitrile (ACN), adiponitrile (AON), y-butyrolactone (GBL)

[0122] Furthermore, trimethyl phosphate (TMP) and tris(2,2,2-trifluoroethyl)phosphate (TFP) may also be considered.

[0123] Preferred conductive salts are:

[0124] NeA 6 , sodium difluoro(oxalato)borate (NaBOB), NaBF 4 、Sodium bis(fluorosulfonyl)imide (NaFSI), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(trifluoromethylsulfonyl)imide (NaTFSI), NaAsF 6 , NaBF 4 、NaClO 4 、NaB(C 2 O 4 ) 2 、NaP(C 6 H 4 O 2 ) 3 ;NaCF 3 SO 3 , sodium trifluoromethanesulfonate (NaTf) and Et 4 NBF 4 .

[0125] In a preferred embodiment, additives may be added to the electrolyte. Examples of preferred additives, particularly additives for stabilization, are as follows:

[0126] Fluorinated ethylene carbonate (FEC), trans-difluoroethylene carbonate (DFEC), ethylene sulfite (ES), ethylene carbonate (VC), bis(2,2,2-trifluoroethyl) ether (BTFE), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(fluorosulfonyl)imide (NaFSI), aluminum chloride (AICl3), ethylene sulfate (DTD), sodium difluorophosphate (NaPO 2 F 2 ), sodium difluoro(oxalato)borate (NaODFB), sodium difluorobis(oxalato)phosphate (NaDFOP), and tris(trimethylsilyl)borate (TMSB).

[0127] The negative electrode material of the sodium ion-based energy storage element is preferably at least one of the following materials:

[0128] - carbon, particularly preferably hard carbon (pure or with nitrogen and / or phosphorus doping) or soft carbon or graphene-based materials (with N doping); carbon nanotubes, graphite

[0129] - Phosphorus or sulfur (conversion anode)

[0130] -Polyanions: Na 2 Ti 3 O 7 、Na 3 Ti2 (PO 4 ) 3 、TiP 2 O 7 、TiNb 2 O 7 、Na-Ti-(PO 4 ) 3 、Na-V-(PO 4 ) 3

[0131] -Prussian Blue: Low sodium variant (for systems with aqueous electrolytes)

[0132] - Transition metal oxides: 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

[0133] -MXene, where M = Ti, V, Cr, Mo or Nb, and A = Al, Si and Ga, and X = C and / or N, such as Ti 3 C 2

[0134] -Organic: such as sodium terephthalate (Na 2 C 8 H 2 O 4 )

[0135] Alternatively, it is in principle also possible to use a Na metal anode on the anode side.

[0136] The positive electrode material of the sodium ion-based energy storage element is, for example, at least one of the following materials:

[0137] -Polyanions: NaFePO 4 (lithium iron phosphate 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 [Fe 1 / 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

[0138] - Silicate: Na 2 MnSiO 4 、Na 2 FeSiO 4

[0139] - 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

[0140] In addition, the electrode of the energy storage element according to the present invention preferably includes an electrode binder and / or an additive for improving conductivity. The active material is preferably embedded in a matrix made of an electrode binder, wherein 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 is used to improve the conductivity of the electrode. Common electrode binders are based on polyvinylidene fluoride (PVDF), polyacrylate (sodium), styrene-butadiene rubber, alginate (sodium) or carboxymethyl cellulose or a mixture of different binders. Common conductive agents include carbon black, fine graphite, carbon fiber, carbon nanotubes and metal powders.

[0141] Particularly preferably, in energy storage elements based on sodium ion technology, both the anode current collector and the cathode current collector are made of aluminum or an aluminum alloy. The housing and the contact plates and, if necessary, further current conductors present in the housing can also be made of aluminum or an aluminum alloy.

[0142] Optimal design of the housing

[0143] Particularly preferably, the energy storage element according to the invention is distinguished by at least one of the following features a. to c.:

[0144] a. The intermediate section and the closed section are separated by a recess which annularly surrounds the outside of the housing cup.

[0145] b. The housing cup has the same maximum outer diameter in the middle section and the closed section.

[0146] c. In the region of the depression, the outer diameter of the housing cup is reduced by 4 to 12 times the wall thickness of the housing cup in this region.

[0147] Preferably, at least the features a. and b. mentioned just above are implemented in combination. Particularly preferably, all three features a. to c. mentioned just above are implemented in combination.

[0148] Preferably, the annular seal is present in a compressed form in the closed section.The annular seal is preferably pressed radially against the pole cap and / or the circular edge of the first metal disk.

[0149] Embodiments of the contact plate

[0150] In principle, the contact plate can be electrically connected to the anode current collector or the cathode current collector.

[0151] In a particularly preferred embodiment of the present invention, the contact plate electrically connected to the anode current collector is characterized by at least one of the following features a. and b.:

[0152] a. The contact plate is made of nickel or copper or titanium or nickel alloy or copper alloy or titanium alloy or stainless steel (for example, type 1.4303 or 1.4404 or SUS304) or nickel-plated copper.

[0153] b. The contact plate is made of the same material as the anode current collector.

[0154] In another particularly preferred embodiment of the present invention, the contact plate electrically connected to the cathode current collector is characterized by at least one of the following features a. and b.:

[0155] a. The contact plate is made of aluminum or aluminum alloy.

[0156] b. The contact plate is made of the same material as the anode current collector.

[0157] Particularly preferably, the contact plate connected to the anode current collector and / or the contact plate electrically connected to the cathode current collector is characterized by at least one of the following features a. to g.:

[0158] a. The contact plate has a preferably uniform thickness in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0159] b. The contact plate is dimensioned such that it covers at least 40%, preferably at least 70%, particularly preferably at least 80% of the first end face or the second end face.

[0160] It is particularly preferred to implement the features a. and b. just mentioned above in combination with one another.

[0161] The largest possible coverage of the end face is of great importance for the thermal management of the energy storage element according to the invention. The larger the coverage, the more likely it is that the longest possible section of the first longitudinal edge of the respective current collector will be in contact. As a result, the heat generated in the electrode-diaphragm complex can be dissipated well via the contact plate.

[0162] Preferably, the second contact section of the contact plate is placed flat with its bottom side on the first longitudinal edge of the current collector, to which the second contact section is welded. Ideally, the second contact section is in contact with the longitudinal edge over most of its length or over its entire length.

[0163] In some embodiments, it has proven to be advantageous to subject the longitudinal edges of the current collector to a pretreatment before the contact plate is fitted. In particular, at least one groove can be folded into the longitudinal edge, which corresponds to at least one bead or elongated projection on the bottom side of the second contact section of the contact plate.

[0164] The longitudinal edge of the current collector can also be subjected to directional deformation by pretreatment, for example, the longitudinal edge can be bent in a defined direction.

[0165] Particularly preferably, the contact plate is welded in the region of the bead, in particular via one or more weld seams arranged in the bead, to the first longitudinal edge of the respective current collector.

[0166] Optimal design of current collector and separator

[0167] The anode current collector, cathode current collector and the separator or separators of the battery cell according to the invention preferably have the following dimensions:

[0168] - Length ranges from 0.5m to 25m

[0169] -Width ranges from 40mm to 145mm

[0170] In an electrode-diaphragm complex designed as a winding body, a strip-shaped anode, a strip-shaped cathode and the strip-shaped diaphragm or diaphragms are preferably present in a spirally wound form. In order to manufacture the electrode-diaphragm complex, the strip-shaped electrode and the strip-shaped diaphragm or diaphragms are usually supplied to a winding device and are preferably spirally wound around a winding axis in the winding device. Here, bonding of the electrode and the diaphragm or contact at high temperatures is usually not required. In some embodiments, the electrode and the diaphragm or diaphragms are wound on a cylindrical or hollow cylindrical winding body core, which is sleeved on a winding bobbin and remains in the winding body after winding.

[0171] The jelly roll side can be formed, for example, by a plastic foil or an adhesive tape. It can also be realized that the jelly roll side is formed by one or more turns of a separator.

[0172] The current collector of the energy storage element according to the present invention is used to make electrical contact with 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 is metallized at least on the surface.

[0173] In the case of an energy storage element designed as a lithium-ion battery cell according to the invention, for example copper or nickel or other conductive materials, in particular copper alloys and nickel alloys or nickel-coated metals are suitable as the metal of the anode current collector. In particular, materials of the EN CW-004A or EN CW-008A type with a copper content of at least 99.9% can be used as copper alloys. NiFe, NiCu, CuNi, NiCr and NiCrFe type alloys are particularly suitable as nickel alloys. NiFe, NiCu, CuNi, NiCr and NiCrFe type alloys are particularly suitable as nickel alloys. Generally, stainless steel is also possible, for example 1.4303 or 1.4404 type or SUS304 type.

[0174] In the case of an energy storage element according to the invention designed as a lithium-ion battery cell, aluminum or other electrically conductive materials (including also aluminum alloys) are particularly suitable as the metal for the cathode current collector.

[0175] Aluminum alloys suitable for cathode current collectors are, for example, 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55 type aluminum alloys. In addition, AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg are also suitable. The aluminum content of the alloy is preferably higher than 99.5%.

[0176] Preferably, the anode current collector and / or the cathode current collector are each a strip-shaped metal foil having a thickness ranging from 4 μm to 30 μm.

[0177] In addition to foils, however, other strip-shaped substrates such as metal or metallized nonwovens or open-pore metal foams or expanded metals can also be used as current collectors.

[0178] The current collector is preferably loaded with the corresponding electrode material on both sides.

[0179] Preferably, the longitudinal edge or edges of the separator form the end faces of the electrode-separator assembly designed as a coil.

[0180] Possible designs of cover components

[0181] The energy storage element according to the invention is preferably characterized by the integration of a CID function in the cover assembly, which ensures that in the event of excessive pressure in the battery cell, the pressure can escape from the housing and at the same time the electrical contact between the cover assembly and the electrode-diaphragm assembly can be interrupted.

[0182] Particularly preferably, the energy storage element according to the present invention is characterized by at least one of the following features a. and b.:

[0183] a. The first metal disk of the cover assembly includes a metal diaphragm that bulges outward or ruptures when excess pressure exists within the housing.

[0184] b. The first metal disk of the cover assembly is in direct contact with the top side of the first contact section of the contact plate with the diaphragm.

[0185] It is preferred that the features a. and b. just mentioned above are implemented in combination.

[0186] Possible designs of seals

[0187] Preferably, the energy storage element according to the invention is characterized by at least one of the following features a. and b.:

[0188] a. The seal is made of a plastic material having a melting point >200°C, preferably >300°C, particularly preferably a melting point >300°C and <350°C.

[0189] b. The plastic material is polyetheretherketone (PEEK), polyimide (PI), polyphenylene sulfide (PPS) or polytetrafluoroethylene (PTFE).

[0190] It is preferred that the features a. and b. just mentioned above are implemented in combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0191] Other features and advantages of the present invention are derived from the claims and the following description of preferred embodiments of the present invention in conjunction with the accompanying drawings. Here, each feature can be implemented separately or in combination with each other.

[0192] In the accompanying drawings it is schematically shown:

[0193] - Figure 1 A view showing a first embodiment of a contact plate according to the invention;

[0194] - Figure 2 A view showing a second embodiment of a contact plate according to the invention;

[0195] - Figure 3 A view showing a third embodiment of a contact plate according to the invention;

[0196] - Figure 4 An electrode-diaphragm assembly and its components are shown, which is a component of the energy storage element according to the invention;

[0197] - Figure 5 shows a partial cross-section of a cap assembly according to the present invention; and

[0198] - Figure 6 An overall view (cross-sectional illustration) of an energy storage element according to the invention is shown. DETAILED DESCRIPTION

[0199] Figure 1A preferred embodiment of a contact plate 200 according to the invention is shown in a top view from above (upper illustration) and in a top view from below (middle illustration). In addition, a cross section of the contact plate 200 along the line S is shown (lower illustration). The contact plate 200 comprises: a first end contact section 201 with a top side 201a and a bottom side 201b, which is configured to contact a first component of an energy storage element; and a second end contact section 202 with a top side 202a and a bottom side 202b, which is configured to contact a second component of an energy storage element. Between the first contact section 201 and the second contact section 202, the contact plate 200 comprises a connecting section 203 with a top side 203a and a bottom side 203b. Due to the bending process, the top side 203a of the connecting section 203 is oriented toward the bottom side 201b of the first contact section 201, and the bottom side 203b of the connecting section 203 is oriented toward the top side 202a of the second contact section 202. The first contact section 201 and the connecting section 203 are connected to each other via a first bending zone 204, in which the contact plate 200 is bent along a first bending line. The second contact section 202 and the connecting section 203 are connected to each other via a second bending zone 205, in which the contact plate 200 is bent along a second bending line. Due to the mentioned bending process, the connecting section 203 is oriented parallel to the second contact section 202, while the connecting section and the first contact section 201 enclose an angle in the range of -10° to +30°. The contact plate 200 has the same thickness in the connecting section 203 as in the first contact section 201 and the second contact section 202. The thickness may typically be in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0200] The contact plate 200 includes only areas extending in a flat layer in the first contact section 201, the second contact section 202 and the connecting section 203. The flat layer is here a non-bending layer with a uniform thickness, which substantially corresponds to the thickness of the contact plate 200 in the corresponding section. Since the connecting section 203 is not parallel to the first contact section 201, the flat layer in which the area of ​​the connecting section 203 extends and the flat layer in which the area of ​​the first contact section extends typically intersect along a bending line.

[0201] The second contact section 202 has a recess 206 which forms a receptacle for the first bending region 204. For example, the first bending region 204 can be pressed into the receptacle when the contact plate 200 is assembled. The receptacle 206 is formed by two legs 202c and 202d, which are connected to each other via a connecting web 202e. The web is long enough so that the first bending region 204 can be pressed into the receptacle without contacting the legs 202c and 202d.

[0202] The recess 206 is located in the planar layer in which the regions or the first region of the second contact section 202 extend.

[0203] The first contact section 201 has a through-hole 209 .

[0204] For example, the contact plate 200 can be welded along the line 210 to the edge of the current collector that protrudes from the end face of the electrode-separator assembly.

[0205] Figure 2 Another preferred embodiment of the contact plate 200 according to the invention is shown in a top view from above (upper illustration) and in a top view from below (middle illustration). In addition, a cross section of the contact plate 200 along the line S is shown (lower illustration). The contact plate 200 comprises: a first end contact section 201 having a top side 201a and a bottom side 201b, which is configured to contact a first component of an energy storage element; and a second end contact section 202 having a top side 202a and a bottom side 202b, which is configured to contact a second component of an energy storage element. Between the first contact section 201 and the second contact section 202, the contact plate 200 comprises a connecting section 203 having a top side 203a and a bottom side 203b. Due to the bending process, the top side 203a of the connecting section 203 is oriented toward the bottom side 201b of the first contact section 201, and the bottom side 203b of the connecting section 203 is oriented toward the top side 202a of the second contact section 202. The first contact section 201 and the connecting section 203 are connected to each other via a first bending zone 204, in which the contact plate 200 is bent along a first bending line. The second contact section 202 and the connecting section 203 are connected to each other via a second bending zone 205, in which the contact plate 200 is bent along a second bending line. Due to the mentioned bending process, the connecting section 203 is oriented parallel to the first contact section 201 and the second contact section 202. The contact plate 200 has the same thickness in the connecting section 203 as in the first contact section 201 and the second contact section 202. The thickness may typically be in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0206] The contact plate 200 includes only areas extending in a flat layer in the first contact section 201, the second contact section 202 and the connecting section 203. A flat layer is here a non-bend layer with a uniform thickness, which corresponds substantially to the thickness of the contact plate 200 in the corresponding section. Since the connecting section 203 is parallel to the contact sections 201 and 202, the area of ​​the connecting section 203 does not intersect these flat layers in which the areas of the contact sections 201 and 202 extend.

[0207] The second contact section 202 has an oval through hole 207, which forms a receptacle for the first bending region 204. The first bending region 204 can be pressed into the receptacle, for example, when the contact plate 200 is assembled. The size of the through hole 207 is large enough so that the first bending region 204 can be pressed into the receptacle without contacting the edge of the through hole.

[0208] The through-hole 207 is located in a planar layer in which the regions or the first region of the second contact section 202 extend and is surrounded by the regions or the first region.

[0209] For example, the contact plate 200 can be welded along the line 210 to the edge of the current collector that protrudes from the end face of the electrode-separator assembly.

[0210] Figure 3 Another preferred embodiment of the contact plate 200 according to the invention is shown in a top view from above (upper illustration) and in a top view from below (middle illustration). In addition, a cross section of the contact plate 200 along the line S is shown (lower illustration). The contact plate 200 comprises: a first end contact section 201 having a top side 201a and a bottom side 201b, which is configured to contact a first component of an energy storage element; and a second end contact section 202 having a top side 202a and a bottom side 202b, which is configured to contact a second component of an energy storage element. Between the first contact section 201 and the second contact section 202, the contact plate 200 comprises a connecting section 203 having a top side 203a and a bottom side 203b. Due to the bending process, the top side 203a of the connecting section 203 is oriented toward the bottom side 201b of the first contact section 201, and the bottom side 203b of the connecting section 203 is oriented toward the top side 202a of the second contact section 202. The first contact section 201 and the connecting section 203 are connected to each other via a first bending zone 204, in which the contact plate 200 is bent along a first bending line. The second contact section 202 and the connecting section 203 are connected to each other via a second bending zone 205, in which the contact plate 200 is bent along a second bending line. Due to the mentioned bending process, the connecting section 203 is oriented parallel to the first contact section 201 and the second contact section 202. The contact plate 200 has the same thickness in the connecting section 203 as in the first contact section 201 and the second contact section 202. The thickness may typically be in the range of 50 μm to 600 μm, preferably in the range of 150 μm to 350 μm.

[0211] The contact plate 200 has three beads 208 arranged in a star shape in the second contact section 202, which are recessed on the top side 202a and raised on the bottom side 202b of the second contact section 202. At these beads 208, the contact plate 200 can be welded to the edge of the current collector protruding from the end face of the electrode-separator assembly.

[0212] The contact plate 200 includes only regions extending in the flat layer in the first contact section 201 and the connection section 203. In the second contact section 202, the contact plate 200 includes a first region extending in the flat layer and at least one second region not extending in the flat layer. That is, the contact plate 200 includes three curling edges 208 in the second contact section 202, and the at least one second region includes a region of the depression or the protrusion that does not extend in the plane of the first region.

[0213] The second contact section 202 has a slot-shaped through hole 207, which forms a receptacle for the first bending region 204. The through hole 207 is located in the flat layer in which the regions or the first regions of the second contact section 202 extend and is surrounded by the regions or the first regions. The first bending region 204 extends into this receptacle and thus into the flat layer in which the regions or the first regions of the second contact section 202 extend. The size of the through hole 207 is large enough so that the first bending region 204 can be pressed into the receptacle without contacting the edge of the through hole 207.

[0214] The first contact section 201 has a through-hole 209. The second contact section 202 has an additional through-hole 209.

[0215] Figure 4The structure of an electrode-diaphragm complex 104 is shown, which can be a component of an energy storage element according to the present invention. The complex 104 includes a strip-shaped anode 105 having a strip-shaped anode current collector 106, which has 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 foil includes a strip-shaped main area and a free edge strip 106b, the strip-shaped main area is loaded with a layer made of a negative electrode material 107, and the free edge strip extends along its first longitudinal edge 106a and does not load the electrode material 107. In addition, the complex 104 includes a strip-shaped cathode 108 having a strip-shaped cathode current collector 109, which has 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 region loaded with a layer made of positive electrode material 110 and a free edge strip 109b extending along its first longitudinal edge 109a and not loaded with electrode material 110. The two electrodes are shown separately in an unwound state.

[0216] The anode 105 and the cathode 108 are arranged offset from each other in the electrode-diaphragm complex 104, so that the first longitudinal edge 106a of the anode current collector 106 protrudes from the first end face 104a of the electrode-diaphragm complex 104, and the first longitudinal edge 109a of the cathode current collector 109 protrudes from the second end face 104b of the electrode-diaphragm complex. The offset arrangement can be seen from the illustration at the bottom left. Two strip-shaped separators 156 and 157 are also shown, which separate the electrodes 105 and 108 from each other in the winding body.

[0217] The lower right illustration shows an electrode-separator assembly 104 in a wound form, which can be Figures 1 to 4 The electrode edges 106a and 109a extending from the end faces 104a and 104b can be clearly seen. The winding body side 104c is composed of a plastic foil.

[0218] exist Figure 5 The cap assembly 102 shown in FIG. 1 includes a pole cap 117, a first metal disk 113, a second metal disk 115, an annular seal 103, and an annular insulator 116. The first metal disk 113 is arranged between the pole cap 117 and the second metal disk 115. The annular insulator 116 electrically insulates the first metal disk 113 from the second metal disk 115. The first metal disk 113 is in direct contact with the pole cap 117.

[0219] The annular seal 103 is pulled onto the circular edge of the first metal disk 113 , which surrounds the edge of the pole cap 117 in a U-shaped manner.

[0220] The seal 103 comprises an outer annular section 130 which merges at its lower end into an inwardly directed collar 131 which narrows the annular section 130 at this end. The collar 131 has an inner edge 131a which transitions into an inner annular section 132 which has a smaller diameter than the outer annular section 130.

[0221] Figure 6 An energy storage battery cell 100 according to the present invention is shown with a gas-tight and liquid-tight closed housing, the housing comprising a metal housing cup 101 with a circular opening at the end and a cover assembly 102 with a circular edge 102a, the cover assembly closing the circular opening. Figure 5 101 is constructed similarly to the cover assembly shown in . The seal 103 is made of an electrically insulating material and surrounds the circular edge 102a of the cover assembly 102, and electrically insulates the housing cup 101 and the cover assembly 102 from each other. The housing cup 101 includes a bottom 101a, a middle section 101b and a closed section 101c in the axial direction in sequence, wherein the middle section 101b is designed to be cylindrical, and in the middle section 101b, the winding body side 104c of the electrode-diaphragm composite 104 designed as a winding body is in contact with the inner side of the housing cup 101, and in the closed section 101c, the annular seal 103 is in pressure contact with the inner side of the cover assembly 102 and the housing cup 101. The housing cup 101 has an opening edge 101d defining a circular opening in the closed section 101c, which is bent radially inward beyond an edge 102a of the cover component 102 surrounded by the seal 103, and the opening edge fixes the cover component 102 including the seal 103 in the circular opening of the housing cup 101 in a shape-fitting manner.

[0222] The battery cell 100 further comprises an electrode-separator complex 104 in the form of a cylindrical winding with an anode / separator / cathode sequence, which is however only schematically shown here. Only the longitudinal edge 106a of the anode current collector 106 protruding from the end face 104a of the electrode-separator complex 104 and the longitudinal edge 109a of the anode current collector 109 protruding from the end face 104b of the electrode-separator complex 104 can be seen. The longitudinal edge 106a is preferably welded directly to the housing bottom 101a over its entire length. The longitudinal edge 109a is preferably welded directly to the housing bottom 101a over its entire length according to the embodiment of the present invention. Figure 2 The contact plate 200 of the embodiment shown is connected. Here, the second contact section 202 is placed with its bottom side 202b on the longitudinal edge 109a. Preferably, the longitudinal edge 109a is welded to the bottom side 202b. The first contact section 201 is directly against the second metal disk 115 with its top side 201a and is connected to it by welding.

[0223] The battery cell 100 has, for example, a height in the range of 60 mm to 10 mm, and 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 middle section 101 b. The radially inwardly curved opening edge 101 d of the housing cup 101 is thicker than the housing cup 101 in the middle section 101 b by a factor in the range of 1.5 to 2. The opening edge includes a first side surface located inside and in direct contact with the seal 103 and a second side surface facing away from the seal 103. The second side surface includes a flat surface 101 p in the shape of an annular ring. The flat surface preferably forms an annular ring with a width in the range of 0.8 mm to 3 mm and forms an angle of 90° with the wall of the housing cup 101 in the middle section 101 b. There is a maximum height difference of 0.08 mm between the highest point and the lowest point of the annular flat surface.

Claims

1. A contact plate (200), comprising: a. a first contact section (201) having a top side (201a) and a bottom side (201b), the first contact section being arranged for making contact with a first member of the energy storage element, and b. a second contact section (202) having a top side (202a) and a bottom side (202b), the second contact section being configured to make contact with a second member of the energy storage element, and c. a connecting section (203) between the first contact section (201) and the second contact section (202) having a top side (203a) and a bottom side (203b), wherein the top side (203a) of the connecting section (203) faces the bottom side (201b) of the first contact section (201), and the bottom side (203b) of the connecting section (203) faces the top side (202a) of the second contact section (202), and in d. the first contact section (201) and the connecting section (203) are connected to each other via a first bending zone (204), in which the contact plate (200) is bent along at least one bending line, and e. the second contact section (202) and the connecting section (203) are connected to each other via a second bending zone (205), in which the contact plate (200) is bent along at least one bending line, in f. The second contact section (202) has a recess (206) or a through hole (207), which forms a receptacle for the first bending region (204).

2. The contact plate according to claim 1, having at least one of the following additional features: a. the first contact section (201) is oriented parallel to the second contact section (202), b. the connecting section (203) is oriented parallel to the first contact section (201) and / or the second contact section (202), c. The connecting section (203) forms an angle in the range of -10° to +30° with the first contact section (201) and / or the second contact section (202).

3. The contact plate according to claim 1 or claim 2, having at least one of the following additional features: a. the contact plate (200) has a uniform thickness in the first contact section (201), the second contact section (202) and the connecting section (203), respectively; b. The contact plate (200) has the same thickness in the connecting section (203) as in the first contact section (201) and / or the second contact section (202).

4. The contact plate according to any of the preceding claims, having the following additional features: a. The contact plate (200) has at least one bead (208) in the second contact section (202), wherein the at least one bead is recessed on the top side (202a) of the second contact section (202) and is protruding on the bottom side (202b).

5. The contact plate according to claim 1 , having at least one of the following additional features: a. the contact plate (200) in the first contact section (201) only comprises a region extending in a flat layer, b. the contact plate (200) in the second contact section (202) only comprises a region extending in a flat layer, c. The contact plate (200) in the connecting section (203) only includes a region extending in a flat layer.

6. The contact plate according to any one of claims 1 to 4, having at least one of the following additional features: a. the contact plate (200) in the first contact section (201) only comprises a region extending in a flat layer, b. the contact plate (200) comprises in the second contact section (202) a first region extending in a flat layer and at least one second region not extending in the flat layer, c. The contact plate (200) in the connecting section (203) only includes a region extending in a flat layer.

7. The contact plate according to any of the preceding claims, having at least one of the following additional features: a. The first contact section (201) is an end contact section, b. The second contact section (202) is a terminal contact section.

8. The contact plate according to any of the preceding claims, having the following additional features: a. The first contact section (201) and the second contact section (202) as well as the connecting section (203) each have a through hole (209), which overlaps each other in a direction perpendicular to the second contact section (202) and forms a through-hole that passes through the section of the contact plate (200).

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

10. The energy storage element according to claim 9, having at least one of the following additional features: a. The energy storage element (100) comprises an electrode-diaphragm complex (104) having an anode (105) / diaphragm (116) / cathode (108) sequence, b. The energy storage element (100) comprises a gas-tight and liquid-tight closed housing, in which the electrode-diaphragm complex (104) is arranged, c. The electrode-diaphragm assembly (104) is electrically connected to a part of the housing or an electrode guided through the housing via the contact plate (200).

11. The energy storage element according to claim 9 or claim 10, having at least one of the following additional features: a. The electrode-diaphragm composite (104) is in the form of a cylindrical winding, wherein the winding has a first end face (104a) and a second end face (104b) and a winding side face (104c) located therebetween, b. the anode (105) of the electrode-separator complex (104) comprises an anode current collector (106), the anode current collector having a first longitudinal edge (106a) and a second longitudinal edge parallel thereto, c. the anode current collector (106) comprises a main region loaded with a layer (107) made of negative electrode material and a free edge strip extending along its first longitudinal edge (106a) and not loaded with the negative electrode material, d. The cathode (108) of the electrode-separator complex (104) comprises a cathode current collector (109), wherein the cathode current collector has a first longitudinal edge (109a) and a second longitudinal edge parallel thereto, e. the cathode current collector (109) comprises a main region loaded with a layer of positive electrode material (110) and a free edge strip extending along its first longitudinal edge (109a) and not loaded with the electrode material (110), f. The anode (105) and the cathode (108) are arranged in the electrode-diaphragm complex (104) so ​​that a first longitudinal edge (106a) of the anode current collector (106) extends from a first end face (104a) of the electrode-diaphragm complex (104), and a first longitudinal edge (109a) of the cathode current collector (108) extends from a second end face (104b) of the electrode-diaphragm complex.

12. The energy storage element according to claim 11, having at least one of the following additional features: a. The housing comprises a metal housing cup (101) having a circular opening at the end and a cover assembly (102) having a circular edge (102a), wherein the cover assembly closes the circular opening, b. The top side (201a) of the first contact section (201) is fixed on the cover assembly (102), c. The bottom side (202b) of the second contact section (202) is fixed by welding to a longitudinal edge (106a or 109a) of one of the current collectors (106, 109) extending from one of the end faces (104a or 104b) of the electrode-diaphragm assembly (104).

13. The energy storage element according to claim 12, having at least one of the following additional features: a. The cover assembly (102) comprises a polar cap (117) having a rounded edge, b. The cover assembly (102) comprises a first metal plate (113) having a circular edge, c. The cover assembly (102) comprises a second metal plate (115) having a rounded edge, d. The cover assembly (102) includes an annular seal (103), e. The cover assembly (102) includes an annular insulator (116), f. The first metal disk (113) is arranged between the pole cap (117) and the second metal disk (115), g. The annular insulator (116) electrically insulates the first metal disk (113) and the second metal disk (115) from each other, h. The first metal disk (113) is in direct contact with the pole cap (117), i. the annular seal (103) is pulled onto the circular edge of the pole cap (117) and / or the first metal disk (113), j. The top side (201a) of the first contact section (201) is welded to the second metal disk (115).

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