Energy storage element and battery

Abstract

A secondary energy storage element (100) includes, as electrodes, a cathode (108) and an anode (105), which are parts of an assembly (104), which are separated by a separator or a solid electrolyte layer (116), and which are arranged in the assembly in the order of cathode (108) / separator or solid electrolyte layer (116) / anode (105). The cathode (108) comprises a cathode current collector (109) and a positive electrode material (110), and the anode (105) comprises an anode current collector (106) and a negative electrode material (107). The cathode current collector (109) has a main region loaded with a layer of positive electrode material (110) on both sides and a free edge strip (109b) extending along an edge of the cathode current collector (109) and not loaded with the positive electrode material (110). Alternatively or simultaneously, the anode current collector (106) has a main region loaded with a layer of negative electrode material (107) on both sides and a free edge strip (106b) extending along an edge of the anode current collector (106) and not loaded with the negative electrode material (107). The cathode (108) and the anode (105) are formed and / or arranged in the fitting (104) in such a way that a free edge strip (109b) of the cathode current collector (109) protrudes from one side (104b) of the fitting (104) and / or a free edge strip (106b) of the anode current collector (106) protrudes from the other side (104a) of the fitting (104). The energy storage element includes a first contact metal sheet (112) in direct contact with one of the free edge strips (106b) and / or a second contact metal sheet (101a) in direct contact with the other of the free edge strips (109b). The electrodes (105, 108) comprise at least one ion type selected from the group comprising sodium ions, potassium ions, calcium ions, magnesium ions, and aluminum ions which are exchanged between the cathode (108) and the anode (105) during charging and discharging of the secondary energy storage element (100).

Description

Technical Field

[0001] The present invention relates to an energy storage element suitable for providing very high current, and a method for manufacturing such an energy storage element. Background Technology

[0002] Application areas and existing technologies Electrochemical energy storage elements can convert stored chemical energy into electrical energy through redox reactions. One of the simplest forms of electrochemical energy storage elements is the electrochemical cell. It consists of a positive electrode and a negative electrode, which are separated from each other, for example, by a separator. During discharge, electrons are released at the negative electrode due to oxidation. This results in an electron current that can be drawn out by an external electrical device (the electrochemical cell serves as the energy source for this device). Simultaneously, an ionic current corresponding to the electrode reaction appears within the cell. This ionic current passes through the separator and is typically achieved by an ion-conducting electrolyte.

[0003] If the discharge is reversible, meaning that the process of converting chemical energy into electrical energy during discharge can be reversed and the monomer can be recharged, then the monomer is called a secondary monomer. In a secondary monomer, designating the negative electrode as the anode and the positive electrode as the cathode refers to the discharge function of the electrochemical monomer.

[0004] Secondary lithium-ion monomers are used as energy storage elements in many applications today because they can provide high current and have relatively high energy density. They are based on the use of lithium, which can migrate back and forth between the electrodes of the monomer in ionic form. The negative and positive electrodes of lithium-ion monomers are often formed by so-called composite electrodes, which include electrochemically inert components in addition to electrochemically active components.

[0005] In principle, any material capable of absorbing and releasing lithium ions can be used as the electrochemically active component (active material) of secondary lithium-ion monomers. For the negative electrode, carbon-based particles such as graphite carbon can be used. Lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4), or their derivatives can be used as active materials for the positive electrode. Electrochemically active materials are typically contained in the electrode in particulate form.

[0006] As an electrochemically inert component, composite electrodes typically include flat and / or strip-shaped current collectors, such as metal foil, which serve as a carrier for the corresponding active material. The current collector for the negative electrode (anode current collector) can be made of, for example, copper or nickel, while the current collector for the positive electrode (cathode current collector) can be made of, for example, aluminum. Furthermore, as an electrochemically inert component, the electrode may include electrode binders (e.g., polyvinylidene fluoride (PVDF) or other polymers such as carboxymethyl cellulose), conductivity-enhancing additives, and other additives. The electrode binder ensures the mechanical stability of the electrode and typically also ensures adhesion between the active material and the current collector.

[0007] As an electrolyte, lithium-ion monomers typically consist of a solution of lithium salts (such as lithium hexafluorophosphate (LiPF6)) in an organic solvent (e.g., carbonate ethers and carbonates).

[0008] In the manufacturing process of lithium-ion monomers, composite electrodes are combined with one or more spacers to form an assembly. The electrodes and spacers are typically bonded under pressure, but may also be bonded through lamination or adhesive bonding. The basic functionality of the monomer is then established by impregnating the assembly with an electrolyte.

[0009] In many embodiments, the assembly is formed or processed as a winding. Alternatively, the assembly may also be a stack of electrodes.

[0010] Similar to lithium-ion monomers, sodium-ion monomers (using sodium ions of alkali metal), potassium-ion monomers (using potassium ions of alkali metal), calcium-ion monomers (using calcium ions of alkali metal), magnesium-ion monomers (using magnesium ions of alkali metal), and aluminum-ion monomers (using aluminum ions of alkali metal) can be produced. For monomers with these alternative monomer chemistry compositions, the structure of the composite electrode and its further processing can typically be carried out in a 1:1 ratio, thereby using current collector materials, electrode materials, electrolytes, and separators tailored to the corresponding monomer chemistry composition.

[0011] In particular, sodium-ion monomers have reached practical maturity during this period. Unlike lithium-ion technology, the production of sodium-ion monomers is not limited by scarce resources. However, their average energy density is lower than that of lithium-ion monomers.

[0012] Due to their high energy density, lithium-ion cells are particularly suitable as power sources for electric motors in the automotive industry, and are also suitable for electric bicycles or other applications with high energy requirements, such as power tools. This requires optimizing lithium-ion cells to withstand high currents during charging and discharging.

[0013] Traditionally, electrodes contact the wound assembly, particularly via metal strips (tongues), which are welded to the current collector and protrude from the end face of the wound assembly, as in US 2005 / 0277019 A1. Figure 1 and Figure 2 As shown. This can be detrimental when high currents are present. Both the tabs and electrochemically active components of conventional lithium-ion monomers have limited high current capacity, especially in the charging direction and at low temperatures (<10°C). Elevation gradients and thermal gradients will occur. Mechanically, the wound assembly will also be affected by the tabs, which can lead to unfavorable pressure conditions.

[0014] Cylindrical lithium-ion cells are known from WO 2017 / 215900 A1, in which the assembly is formed of strip electrodes and exists in the form of a winding. Each electrode has a current collector loaded with electrode material. Electrodes of opposite polarity are arranged offset from each other within the assembly such that the longitudinal edge of the current collector of the positive electrode protrudes from the winding on one side, and the longitudinal edge of the current collector of the negative electrode protrudes from the winding on the other side. For electrical contact with the current collector, the cell has a contact plate instead of a tab, which is placed on the end face of the winding and welded to the longitudinal edge of the current collector. This makes it possible to electrically contact the current collector, and thus also the associated electrode along its entire length. This significantly reduces the internal resistance within the cell. Therefore, large currents can be absorbed better, and heat can be dissipated more effectively from the winding.

[0015] Similar monolithic designs can be found in EP 3916841 A1, EP 3916828 A1, EP 3916827 A1, EP3916829 A1, EP 3916870 A1, EP 3916869 A1, EP 3916877 A1, EP 3965196 A1, and EP3916868 A1.

[0016] Lithium-ion batteries have not yet established themselves in the market as starter batteries for motor vehicles equipped with internal combustion engines or other specialized applications. Lead-acid batteries remain primarily used for these applications, with electrodes made of lead or lead dioxide and an electrolyte made of dilute sulfuric acid. Lead-acid batteries can provide high current for short periods and perform well even at low temperatures. Furthermore, their production is relatively inexpensive.

[0017] However, an alternative is urgently needed for environmental reasons, as lead is extremely toxic. Although many countries have efficient battery deposition systems, lead release is sometimes difficult to avoid during lead mining and subsequent processing, as well as lead recycling. Summary of the Invention

[0018] Objectives and Solutions The purpose of this invention is to provide an energy storage element that performs no less than a lead-acid battery at low temperatures, but is cheaper than a lithium-ion cell, and can absorb high current during charging and deliver high current during discharging.

[0019] This objective is achieved by an energy storage element having the features of independent claim 1. A battery having the features of claim 13 also contributes to solving the problem. Preferred embodiments of the invention are defined in the dependent claims.

[0020] Energy storage element according to the present invention The energy storage element according to the present invention has the following features a. to g.: a. It includes a cathode and an anode as electrodes, which are part of the assembly in which they reside, and are separated by a separator or solid electrolyte layer in the order of cathode / separator or solid electrolyte layer / anode. b. The cathode includes the cathode current collector and the positive electrode material. c. The anode includes the anode current collector and the negative electrode material. d. The cathode current collector has - The main region, with layers of positive electrode material loaded on both sides, and - Free edge strips that extend along the edge of the cathode current collector and are not loaded with positive electrode material. and / or Anode current collector has - The main region, with layers of negative electrode material loaded on both sides, and - Free edge strips that extend along the edge of the anode current collector and are not loaded with negative electrode material. e. The cathode and anode are formed and / or arranged relative to each other within the assembly such that the free edge strip of the cathode current collector protrudes from one side of the assembly and / or the free edge strip of the anode current collector protrudes from the other side, and f. The energy storage element includes a first contact metal sheet in direct contact with one of the free edge strips and / or a second contact metal sheet in direct contact with the other of the free edge strips. in g. The electrode comprises at least one ion type selected from the group consisting of sodium ions, potassium ions, calcium ions, magnesium ions, and aluminum ions, which are exchanged between the cathode and anode during the charging and discharging of the secondary energy storage element.

[0021] Therefore, in its simplest embodiment, the energy storage element according to the invention is a sodium ion monomer, potassium ion monomer, calcium ion monomer, magnesium ion monomer, or aluminum ion monomer. Among these variations, according to the invention, an energy storage element having the chemical properties of a sodium ion monomer is particularly preferred.

[0022] In situations involving very high currents and / or low temperatures, it is essential to minimize any electrical, thermal, and ionic gradients across all electrochemically active components of the monomer. Avoiding ohmic losses plays a crucial role. The lowest possible gradient across the entire assembly, including the electrolyte space, is critical to lifetime and current-carrying capacity.

[0023] Along the entire length of the wound assembly, the first and / or second contact metal tabs ensure uniform electrical and thermal connections for the assembly's electrodes, thereby improving performance and extending service life. The contact metal tabs eliminate the need for tabs used for electrode contact. Therefore, under thermomechanical stress, no potentially problematic mechanical interference occurs within the wound assembly.

[0024] Surprisingly, it has been found that the design of the energy storage element according to the invention enables particularly efficient connection of the assembly's electrodes, especially for sodium-ion systems (but also applicable to other post-lithium systems, such as those based on sodium, potassium, calcium, magnesium, and aluminum ions as described above). Therefore, high-performance sodium-ion materials can be charged and discharged at rates up to 100 C. Furthermore, sodium-ion systems, in particular, can be designed to withstand deep discharge.

[0025] Energy storage element with wound assembly The assembly of the energy storage element according to the invention can be formed as a winding or an electrode stack. In the winding variant, it has the following characteristics a. to e.: a. The electrodes, current collectors, and the layer made of the electrode material are strip-shaped. b. It includes at least one strip-shaped separator or at least one strip-shaped solid electrolyte layer. c. The assembly is in the form of a winding, wherein the electrode and at least one separator are wound around a winding shaft, wherein the assembly includes first and second terminal end faces and a winding housing, and the free edge strip of the cathode current collector protrudes from the first end face and / or the free edge strip of the anode current collector protrudes from the second end face. d. It includes an enclosure, particularly a metal enclosure, comprising the enclosure shell or sidewalls, and the bottom and cover at the end faces, and e. The assemblies formed as windings are aligned in the housing such that the winding housing abuts against the inside or sidewall of the housing.

[0026] Strip-shaped separators form a separation layer in the assembly.

[0027] In this embodiment, the assembly preferably includes a strip-shaped divider or two strip-shaped dividers, each divider having first and second longitudinal edges and two ends.

[0028] The windings and housing are particularly preferably cylindrical. The housing then preferably has a circumferential housing shell and a circular bottom and cover. Within the cylindrical housing, the assemblies formed as cylindrical windings are preferably axially aligned.

[0029] The electrodes and at least one separator are preferably spirally wound around the winding axis.

[0030] Symmetrical and asymmetric winding contacts The winding-type assembly can have symmetrical and asymmetrical contact.

[0031] Symmetrical contact means - The cathode and anode of the energy storage element are formed and / or arranged within the assembly such that the free edge strip of the cathode current collector protrudes from one end face of the assembly, and the free edge strip of the anode current collector protrudes from the other end face of the assembly, and - The energy storage element includes a first contact metal sheet that is in direct contact with one of the free edge strips and a second contact metal sheet that is in direct contact with the other of the free edge strips.

[0032] Therefore, the two electrodes are in contact at the two end faces of the winding via contact metal sheets.

[0033] Asymmetric contact means - The cathode and anode of the energy storage element are formed and / or arranged within the assembly such that only the free edge strip of the cathode current collector or only the free edge strip of the anode current collector protrudes from one end face of the assembly, and - The energy storage element consists of only one contact metal sheet that is in direct contact with the free edge strip of the cathode current collector or anode current collector protruding from the assembly.

[0034] In this embodiment, only one electrode is in contact with one of the two end faces of the assembly via a contact metal plate. Preferably, at least one metal conductor strip (latch) is fixed to the current collector of the other electrode, which protrudes from the other terminal end face of the assembly.

[0035] In the case of asymmetric contact, the energy storage element according to the invention has one of the following features a to c immediately following: a. At least one metal conductor strip is welded to the cover or a metal post passing through the cover, while a free edge strip protruding from one of the end faces is welded to the bottom or placed directly on the metal sheet at the bottom of the housing (Variant A). or b. At least one metal conductor strip is welded to the bottom, while a free edge strip protruding from one of the end faces is welded to the cap or a column passing through the cap (Variant B). or c. At least one metal conductor strip is welded to the bottom, while a free edge strip protruding from one of its end faces is welded to a column passing through the cover or placed on the free edge strip and electrically coupled to the cover or column (Variant C).

[0036] In variant B, the bottom of the housing acts as a contact metal plate, which may be particularly advantageous because optimal heat dissipation can be achieved for the electrodes coupled via the free edge strip in this embodiment.

[0037] According to variant B, it is particularly advantageous if the anode current collector is directly connected to the bottom, while the cathode current collector is connected via a tab. Using conductor strips simultaneously on the end face of the winding facing the cover, while connecting the anode via, ideally, the entire longitudinal edge of its current collector, provides a volume advantage, which is particularly beneficial in energy-optimized cells. Simultaneously, good anode connection has a positive impact, thereby improving the performance and lifespan of the cell of the present invention. In particular, uniform electrical and thermal connection of the anode is beneficial for improving fast charging capability. In this case, it should be specifically mentioned that sodium-ion electrolytes generally have higher conductivity than lithium-ion electrolytes, thus offering advantages in thick or high-load electrodes, fast charging (>2 C), and low-temperature performance (<0 °C).

[0038] A preferred further embodiment of an energy storage element having a wound assembly. In energy storage elements with wound fittings, one or more contact metal sheets are preferably laid flat on one or both end faces, preferably in such a way that the free edge strips contact the contact metal sheets along their entire length. However, in practice, this is often not feasible.

[0039] The energy storage element with a wound assembly according to the invention is particularly preferred because it has the following feature a: a. The metal housing includes a cup-shaped or cylindrical housing portion having a terminal opening, preferably a circular opening, and a cap that closes the terminal opening of the cup-shaped housing portion.

[0040] In many preferred embodiments, the cover includes several components. For example, the cover may include a rupture membrane and / or be equipped with a CID function (CID = Current Interruption Device).

[0041] The lid preferably has a circular circumference and is arranged in such a way that its edge abuts against the inner side of the cup-shaped outer shell portion along the circumferential contact area, wherein the edge of the lid is connected to the cup-shaped outer shell portion by a circumferential weld. In this case, the two outer shell portions preferably have the same polarity, thus electrically coupled to either a positive or negative electrode. In this case, the shell also includes a cylindrical sleeve for electrical contact with an electrode not electrically connected to the shell.

[0042] In an alternative embodiment, an electrically insulating seal is mounted on the edge of the lid, electrically isolating the lid from the cup-shaped housing portion. In this case, the housing is typically sealed by a crimp closure.

[0043] The height of the energy storage element, which is formed into a cylindrical circular cell, is preferably in the range of 50 mm to 150 mm. The diameter of the cylindrical circular cell is preferably in the range of 15 mm to 100 mm.

[0044] In embodiments where the energy storage element according to the invention is a cylindrical circular unit, the anode current collector, the cathode current collector, and one or more separators or solid electrolyte layers preferably have the following dimensions: - Lengths range from 0.3 meters to 25 meters. - Width ranges from 30 mm to 145 mm.

[0045] In this embodiment, the contact metal sheet preferably has a circular basic shape.

[0046] Prismatic embodiment In the prismatic embodiment, the energy storage element according to the invention has the following features a. to c. immediately following each other, and particularly preferably features a. to d. immediately following each other: a. The assembly is in the form of a prismatic stack, wherein the cathode and anode are stacked together with other cathodes and anodes.

[0047] b. The electrodes and current collectors, as well as the layers made of electrode material, are formed in polygonal, particularly rectangular, shapes.

[0048] c. It includes at least one strip or polygon, particularly a rectangular separator, or at least one strip or polygon, particularly a rectangular solid electrolyte.

[0049] d. The stack is surrounded by a prismatic shell.

[0050] In a stack, adjacent electrodes with opposite polarities are always separated from each other by separators or a solid electrolyte layer.

[0051] The prismatic housing is preferably composed of a cup-shaped housing portion having terminal openings and a lid. In this embodiment, the bottom and lid of the cup-shaped housing portion are preferably polygonal, and particularly preferably have a rectangular base region. The shape of the terminal openings of the cup-shaped housing portion corresponds to the shape of the bottom and lid. Furthermore, the housing includes several, preferably four, rectangular side portions that connect the bottom and lid to each other.

[0052] Prismatic monomers can also be constructed as so-called pouch cells. A composite film is used instead of a metal outer shell, and the composite film is shaped appropriately using a deep-drawing process. Current conductors are led out to the outside through thermally welded / sealed partitions in the composite film.

[0053] The separation layer can be formed by several spacers, each arranged between adjacent electrodes. However, strip spacers can also separate stacked electrodes from each other. In the case of several spacers between the anode and cathode, the spacers preferably also have polygonal, particularly rectangular, base regions.

[0054] In this embodiment, the contact metal sheet preferably has a rectangular shape.

[0055] In some preferred variations of the prismatic embodiment, the energy storage element according to the invention has at least one of the following features a. and b. immediately following: a. The free edge strip of the cathode current collector of the stacked cathodes protrudes from one side of the stack and makes direct contact with the first contact metal sheet.

[0056] b. The free edge strip of the anode current collector of the stacked anodes protrudes from the other side of the stack and makes direct contact with the second contact metal sheet.

[0057] Preferably, features a and b that immediately follow each other are combined to achieve this.

[0058] In a further preferred variant of the prismatic embodiment, the energy storage element according to the invention has at least one of the following features a. and b. immediately following.

[0059] a. The free edge strips of the cathode current collector are arranged parallel to each other.

[0060] b. The free edge strips of the anode current collector are arranged parallel to each other.

[0061] Features a and b that immediately follow are preferably implemented in combination with each other.

[0062] Preferred electrochemical embodiments and electrolytes In another particularly preferred embodiment of the invention, the energy storage element according to the invention has one of the following features: a. The energy storage element is a sodium ion monomer.

[0063] b. The energy storage element includes sodium ion monomers.

[0064] c. The energy storage element includes one of the following electrolytes: - NaClO4, dissolved in at least one organic solvent, particularly in PC or in a mixture of carbonates selected from the group including EC / DEC / FEC and PC / FEC.

[0065] The concentration of NaClO4 in the electrolyte is preferably 0.3-5M, and particularly preferably 0.7M-1.7M.

[0066] In the EC / DEC / FEC mixture, the three components are preferably contained in the electrolyte in a volume ratio ranging from 1:2 to 2:1, and particularly in a volume ratio of 1:1:0.5.

[0067] In the case of a mixture containing EC / DEC, the components are preferably contained in the electrolyte in a volume ratio in the range of 1:2 to 2:1.

[0068] - NaPF6 and / or NaTFSI (sodium bis(trifluoromethanesulfonyl)imide), dissolved in at least one organic solvent, particularly in PC or in a mixture of carbonates selected from the group including EC / DEC / FEC, EC / PC, EC / DEC, FEC / EMC, and PC / FEC, or in a mixture of ethers such as THF / mTHF.

[0069] The concentration of NaPF6 and / or NaTFSI in the electrolyte is preferably 0.3-5M, and particularly preferably 0.7M-1.7M.

[0070] In the EC / PC mixture, the two components are preferably present in the electrolyte in a volume ratio ranging from 1:2 to 2:1.

[0071] In an EC / DEC mixture, the two components are preferably present in the electrolyte in a volume ratio ranging from 1:2 to 2:1.

[0072] In the FEC / EMC mixture, the two components are preferably contained in the electrolyte in a volume ratio ranging from 1:2 to 2:1, and particularly in a ratio of 3:7.

[0073] If necessary, the electrolyte can contain up to 10% FEC.

[0074] - NaFSI and / or NaTFSI and / or NaTDI, dissolved in at least one organic solvent, particularly in 1,4-dioxane (DX) and / or 1,3-dioxolane (DOL) and / or dimethyl ether (DME).

[0075] The concentration of NaFSI and / or NaTFSI and / or NaNDI in the electrolyte is preferably 0.3-5M, and particularly preferably 0.7M-1.7M.

[0076] - NaFSI and / or NaTFSI and / or NaNDI, dissolved in at least one organic solvent, particularly in dimethyl carbonate (DX) and / or tri(2,2,2-trifluoroethyl) phosphate (TFP).

[0077] The concentration of NaFSI and / or NaTFSI and / or NaNDI in the electrolyte is preferably 0.5-2.5 M, and particularly preferably 1 M-2 M.

[0078] In the EC / PC mixture, the components are preferably contained in the electrolyte in a volume ratio in the range of 1:2 to 2:1.

[0079] The liquid components are preferably contained in the electrolyte at a volume ratio in the range of 1:2 to 2:1.

[0080] - NaN(SO2F)2, dissolved in at least one organic solvent, particularly in 1,4-dioxane (DX) and / or 1,3-dioxolane (DOL) and / or dimethyl ether (DME).

[0081] The concentration of NaN(SO2F)2 in the electrolyte is preferably 0.3-5M, and particularly preferably 0.7M-1.7M.

[0082] In the DX / DOL mixture, the components are preferably contained in the electrolyte in a volume ratio in the range of 1:2 to 2:1.

[0083] - NaBF4, dissolved in at least one organic solvent, particularly in tetraethylene glycol dimethyl ether (TEGDME) and / or ACN and / or PC and / or GBL.

[0084] The concentration of NaBF4 in the electrolyte is preferably 0.3-5M, and particularly preferably 0.7-17M.

[0085] The electrolyte containing NaBF4 in TEGDME is particularly suitable for monomers with sodium metal anodes (see below).

[0086] Features a and c, as well as features b and c, are particularly preferred when combined with each other.

[0087] Feature a. Particularly relates to the embodiments of the energy storage element according to the invention as a cylindrical, circular monomer. In this embodiment, the energy storage element preferably comprises exactly one electrochemical monomer.

[0088] Feature b. Particularly relates to the prismatic embodiment of the energy storage element according to the present invention described above. In this embodiment, the energy storage element may further comprise more than one electrochemical cell.

[0089] Preferably, the sodium-ion-based energy storage element according to the present invention further includes an electrolyte comprising at least one of the following solvents and at least one of the following conductive salts: The preferred solvent is: - Carbonates: propylene carbonate (PC), ethylene carbonate-propylene carbonate (EC-PC), dimethyl acrylate-ethyl carbonate (PC-DMC-EMC), diethyl carbonate-diethyl carbonate (EC-DEC), ethylene carbonate-dimethyl carbonate (EC-DMC), ethylene carbonate-ethyl methyl carbonate (EC-EMC), ethylene carbonate-dimethyl carbonate-ethyl carbonate (EC-DMC-EMC), ethylene carbonate / dimethyl carbonate / diethyl carbonate (EC-DMC-DEC).

[0090] - Ethers: Tetrahydrofuran (THE), 2-methyltetrahydrofuran, dimethyl ether (DME), 1,4-dioxane (DX), 1,3-dioxolane (DOL), diethylene glycol dimethyl ether (DEGDME), tetraethylene glycol dimethyl ether (TEGDME).

[0091] - Nitriles: Acetonitrile (ACN), adiponitrile (AON), γ-butyrolactone (GBL).

[0092] Trimethyl phosphate (TMP) and tri(2,2,2-trifluoroethyl) phosphate (TFP) can also be considered.

[0093] The preferred conductive salt is: NaPF6, sodium difluoro(oxalate)borate (NaBOB), NaBF4, sodium bis(fluorosulfonyl)imide (NaFSI), sodium 2-trifluoromethyl-4,5-dicyanimidazolium (NaTDI), sodium bis(trifluoromethanesulfonyl)imide (NaNFSI), NaAsF6, NaBF4, NaClO4, NaB(C2O4)2, NaP(C6H4O2)3, NaCF3SO3, sodium trifluoromethanesulfonate (NaTf), and Et4NBF4.

[0094] Like solvents, conductive salts can also be used as mixtures of two or more main salts.

[0095] In a preferred embodiment, the additive can be added to the electrolyte. Examples of preferred additives, particularly those for stabilization, are as follows: Vinyl fluorocarbonate (FEC), trans-difluorovinyl carbonate (DFEC), vinyl sulfite (ES), vinyl carbonate (VC), bis(2,2,2-trifluoroethyl) ether (BTFE), sodium 2-trifluoromethyl-4,5-dicyanimidazolium (NaTDI), sodium bis(fluorosulfonyl)imide (NaFSI), aluminum chloride (AI-CI(3)), vinyl sulfate (DTD), sodium difluorophosphate (NaPO2F2), disodium oxalate (NaODFB), sodium difluorobisoxalate phosphate (NaDFOP), and tri(trimethylsilyl) borate (TMSB).

[0096] Ionic liquids can also be used instead of liquid electrolytes containing the above-mentioned conductive salts, such as 0.8 mol / L sodium bis(fluorosulfonyl)imide (Na-TFSI) in 1-methyl-1-propylpyrrolidone bis(trifluoromethylsulfonyl)imide (PMPyrr-TFSI).

[0097] Sodium polymer electrolytes are another option, such as polymer electrolytes based on polyethylene oxide (PEO) or polyvinylidene fluoride hexafluoropropylene, such as P(EO)8NaCF3SO3 or hydroxyethyl cellulose polyethylene oxide.

[0098] In addition to organic solvent-based liquid electrolytes, electrolytes containing OH- can also be used in specific applications. - NO3 - CI - and SO4 2- Sodium electrolytes containing anions of the group, or aqueous solutions of NaFSI, NaTDI, or NaTFSI.

[0099] Preferred embodiments of electrode materials The negative electrode material of the energy storage element according to the present invention based on sodium ions is preferably at least one of the following materials: - Carbon, especially hard carbon (pure carbon or with nitrogen and / or phosphorus doping) or soft carbon or graphene-based materials (nitrogen doping), carbon nanotubes, graphite; - Phosphorus or sulfur (conversion anode); - Polyanionic: Na2Ti3O7, Na3Ti2(PO4)3, TiP2O7, TiNb2O7, Na-Ti-(PO4)3, Na-V-(PO4)3 or Na-M-PO4-P2O7, where M = V, Ti, Fe, Co, Ni, Mn, or a mixture of 3d transition metals and added dopants (such as Al, Cu, Zn); - Na4M3(PO4)2(P2O7), M=Na, Zn, Al, Mg, or Ca; - Sn or Sb-based materials, such as Sn(Na)15 Sn4), Sb(Na3Sb), SnO2, Sb2O3; - Prussian blue: low-sodium variant (for systems with aqueous electrolytes); - Transition metal oxides: V2O5, MnO2, TiO2, Nb2O5, Fe2O3, Na2Ti3O7, NaCrTiO4, Na4Ti5O 12 ; - MXenes where M = Ti, V, Cr, Mo, or Nb, A = Al, Si, and Ga, X = C and / or N, e.g., Ti3C2; - Organic substances: e.g., sodium terephthalate (Na2C8H2O4).

[0100] An exemplary overview of suitable anode materials can also be found in the publication by Zhang et al., "Sodium-ion battery anodes: Status and future trends" (EnergyChem 1, 100012 (2019), 2019, page 19, Table 2).

[0101] Alternatively, a sodium metal anode can also be used on the anode side. Metallic sodium is preferably embedded in a porous conductive matrix structure with good sodium wettability. Here, minimal electrical, thermal, and mechanical gradients are very important; in the monomers of the present invention, these functions are achieved through a design characterized by face-side contact of the electrode windings.

[0102] The positive electrode material of the sodium-ion-based energy storage element according to the present invention is preferably at least one of the following materials: - Polyanions: NaFePO4 (triphylite type), Na2Fe-(P2O7), Na4Fe3(PO4)2(P2O7), Na2FePO4F, Na / Na2[Fe 1 / 2 Mn 1 / 2 PO4F, Na3V2(PO4)2F3, Na3V2(PO4)3, Na4(CoMnNi)3(PO4)2P2O7, NaCoPO4, Na2CoPO4F; - Silicates: Na2MnSiO4, Na2FeSiO4; - Prussian blue / white: Prussian blue (PB) exists in the form of A x Fe[Fe(CN)6] 1-y *nH2O, A = alkali metal, 0 < x < 2 and y < 1, Prussian white (Na~2), exists in the form of Na2Fe[Fe(CN)6], KFe2(CN)6, MnFe(CN)6, Fe2(CN)6; - Layered oxides: NaCoO2, NaFeO2, NaNiO2, NaCrO2, NaVO2, NaTiO2, Na(FeCo)O2, Na(NiFeCo)3O2, Na(NiFeMn)O2, and Na(NiFeCoMn)O2, Na(NiMnCo)O2.

[0103] A mixture of the above-mentioned positive electrode materials is also acceptable.

[0104] Furthermore, the electrodes of the energy storage element according to the invention preferably comprise electrode binders and / or additives to improve conductivity. The active material is preferably embedded in the matrix of the electrode binder, wherein the active material is preferably used in particulate form, and adjacent particles in the matrix are preferably in direct contact with each other. The conductive agent has the function of improving the conductivity of the electrode. Conventional electrode binders are based on, for example, polyvinylidene fluoride (PVDF), polyacrylate (Na), styrene-butadiene rubber, alginate (Na), or carboxymethyl cellulose, or mixtures of different binders. Conventional conductive agents are carbon black, fine graphite, carbon fibers, carbon nanotubes, and metal powders.

[0105] For sodium-ion-based energy storage devices, the following material combinations are particularly preferred: - Positive electrode: Na3V2(PO4)3 Negative electrode: Hard carbon Electrolyte: preferably NaPF6 in EC:PC:DMC (45:45:10 volume percentage) - Positive electrode: Na 2 / 3 (Ni 1 / 3 Mn 2 / 3 O2 Negative electrode: Hard carbon - Positive electrode: Na2Fe[Fe(CN)6] Negative electrode: Hard carbon Electrolyte: Preferably NaPF6 in EC:PC Ion deposition The functionality of sodium, potassium, calcium, magnesium, or aluminum ion monomers is based on the availability of sufficient mobile ions (in the case of sodium ion monomers, for example, mobile sodium ions) to balance the extracted current by migration between the anode and cathode or between the negative and positive electrodes. In the context of this application, mobile ions are understood to refer to ions that can be used in the storage and extraction processes in the electrodes during the discharge and charging of the energy storage element according to the invention, or ions that can be activated for this purpose. During the discharge and charging process of, for example, sodium ion monomers, mobile sodium is lost over time. These losses are the result of various generally unavoidable side reactions. Loss of mobile sodium has already occurred during the first charge and discharge cycle of the sodium ion monomer. During the first charge and discharge cycle, a capping layer is typically formed on the surface of the electrochemically active component at the negative electrode. This capping layer, referred to as a solid electrolyte interphase (SEI), typically consists primarily of electrolyte decomposition products and a certain amount of sodium, which is firmly bound within the layer.

[0106] To compensate for these losses, the sodium-ion-based energy storage element according to the present invention, in a preferred embodiment, is characterized by at least one of the following features a. and b.: a. The energy storage element includes a deposit of sodium or sodium-containing material not surrounded by a positive electrode and / or a negative electrode, through which the loss of sodium due to movement during operation can be compensated.

[0107] b. The deposit comes into contact with the electrolyte of the energy storage element.

[0108] It is particularly preferred that the preceding features a. and b. are combined with each other.

[0109] Particularly suitable sodium-containing materials are, for example, Na3N, Na2C2O4, Na2S, Na2C4O4, Na2C6O6, EDTA-4Na, DPTA-5Na, Na3P, or C. 12 H9Na (sodium biphenyl). For example, these materials can be added to electrode active materials. The additional sodium source can increase capacity or extend cycle life.

[0110] It is also conceivable that the electrodes could be pre-charged with an excess of sodium ions.

[0111] This also applies to embodiments of energy storage elements based on potassium, calcium, magnesium, or aluminum ions according to the present invention.

[0112] Preferred embodiment of sodium metal anode As described above, sodium metal anodes can also be used on the anode side, wherein metallic sodium is preferably embedded in a conductive matrix structure.

[0113] In a further embodiment, preferably, the energy storage element according to the invention is characterized by at least one of the following features: a. The anode comprises a matrix with depressions and / or pores in which metallic sodium is stored.

[0114] b. The matrix adheres to the surface of the anode current collector.

[0115] c. The matrix consists of carbon particles and binders.

[0116] d. The matrix includes conductive agents and / or fillers.

[0117] e. The substrate is the rough surface of the anode current collector.

[0118] It is particularly preferred that the features immediately preceding them, a. to d., or a. and d., are combined with each other.

[0119] Carbon particles, conductive agents, or fillers may be, for example, hard carbon, activated carbon, conductive graphite, carbon black, carbon nanotubes, graphene, or graphene oxide, or finely dispersed metals such as Ag, Cu, Al, Ni, or Pt. For example, the carbon particles may contain 20-80% (by weight) hard carbon, 80-20% (by weight) carbon black, and 0-10% (by weight) silver, preferably, the total weight percentage of the components is 100%.

[0120] The adhesive can be virtually any adhesive that is also suitable for producing composite electrodes for lithium-ion batteries. Suitable examples include polyvinylidene fluoride (PVDF) or another polymer, such as carboxymethyl cellulose or its derivatives.

[0121] Carbon-based matrices may include dopants such as boron, oxygen, fluorine, or nitrogen.

[0122] The thickness of the carbon-based matrix is ​​preferably 500 nm to 250 µm.

[0123] The surface of the anode current collector can be roughened by, for example, laser treatment.

[0124] Furthermore, preferably, the energy storage element according to the present invention is characterized by at least one of the following features: a. The anode includes a nucleation layer, which, in particular, replaces the matrix, in which metallic sodium is stored and / or deposited on the nucleation layer.

[0125] b. The nucleation layer is essentially composed of at least one material selected from the group consisting of tin, silver, gold, germanium, carbon, platinum, zinc, aluminum, magnesium, and silicon.

[0126] c. The nucleation layer has been deposited on the surface of the anode current collector by PVD (physical vapor deposition) or CVD (chemical vapor deposition).

[0127] Nucleation layers made of tin, silver, gold, germanium, and / or carbon facilitate sodium deposition. Carbon, silver, gold, platinum, zinc, aluminum, magnesium, tin, and silicon reduce overvoltage.

[0128] The nucleation layer may also include dopants such as boron, oxygen, fluorine, or nitrogen.

[0129] The thickness of the nucleation layer is preferably 100 nm to 50 µm.

[0130] Preferably, the matrix and / or nucleation layer account for less than 30% (weight percentage) of the dry weight of the negative electrode, and more preferably less than 5% (weight percentage).

[0131] To fabricate an electrode with a matrix or nucleation layer, it is preferable to use an anode current collector that has a matrix or nucleation layer but does not contain any metallic sodium. During the initial charging process, sodium is preferably deposited in and / or on the matrix or nucleation layer. The required sodium is preferably supplied through the cathode. For example, Na3V2(PO4)3 can be used as the positive electrode material for this purpose. Alternatively, sodium deposition can also be performed by pre-alkalization. This procedure prevents dendrite growth. Furthermore, it ensures that there is no unwanted excess sodium in the electrode.

[0132] Providing a degassing option during the first charging process may be useful so that excessive pressure does not accumulate in the housing of the energy storage element according to the invention.

[0133] Particularly preferred is that the ratio of anode capacity to cathode capacity is in the range of 0.7 to 1.2.

[0134] The energy storage element according to the invention is particularly preferred because it has the following immediately following features: Particularly preferred is that the nucleation layer and / or matrix are covered with a capping layer. Therefore, the negative electrode preferably comprises the following layer sequence: - Metal current collector - Matrix or nucleation layer - Overlay Therefore, the matrix or nucleation layer is arranged between the capping layer and the current collector.

[0135] The thickness of the capping layer is preferably in the range of 300 nm to 30 µm.

[0136] The coating layer is preferably formed of or includes a ceramic material. Preferred ceramic materials include alumina (Al₂O₃), aluminum hydroxide or aluminum hydroxyaluminate (AlOOH), silicon oxide (SiOx, where x is >1 and ≤2), titanium oxide (TiO₂), titanium nitride (TiN), titanium aluminum nitride (TiAlN), or titanium carbonitride (TiCN).

[0137] In a further possible preferred embodiment, the coating layer is made of Na1+x Zr2Si x P 3-x O 12 A superionic conductor of 0 < x < 3 is formed or includes such an ionic conductor.

[0138] In a further possible preferred embodiment, the covering layer is formed from a polymer, in particular polysiloxane, polyethylene oxide, perfluoropolyether, or polyacrylonitrile, or contains such a polymer.

[0139] If the covering layer includes a ceramic material, in a preferred embodiment it also includes an adhesive. The adhesive can basically be an adhesive that is also suitable as an adhesive for the active material, such as carboxymethyl cellulose.

[0140] Preferred embodiments of separators and solid electrolytes One or more separators are preferably formed from an electrically insulating plastic film. Preferably, the separator can be penetrated by the electrolyte. For this purpose, the plastic film used can, for example, have micropores. The film can consist of, for example, polyolefin or polyether ketone. Non-woven fabrics and fabrics made of plastic materials or other electrically insulating planar structures can also be used as separators. Separators with a preferred thickness in the range of 5 µm to 50 µm are preferred.

[0141] Separators made of cellulose-based materials can also be used. These materials have good wettability and high-temperature stability.

[0142] Especially in the prismatic embodiment of the energy storage element, one or more separators of the assembly can also be one or more layers of solid electrolyte.

[0143] The solid electrolyte can be, for example, a polymer solid electrolyte based on a polymer conductive salt complex, which exists in a single phase and does not contain any liquid components. As the polymer matrix, the polymer solid electrolyte can include, for example, polyacrylic acid (PAA), polyethylene glycol (PEG), or polymethyl methacrylate (PMMA), especially polyethylene oxide (PEO). In the case of sodium ion monomers, sodium conductive salts such as sodium bis(trifluoromethane)sulfonimide (NaTFSI), sodium hexafluorophosphate (NaPF6), and sodium tetrafluoroborate (NaBF4) can exist in a dissolved form.

[0144] Ceramic reinforcement of separators In individual cases, other preferred designs of the separator may be suitable. The energy storage element according to the invention preferably also has at least one of the following features a. and b. immediately following: a. In the case of an energy storage element with a wound assembly, the free edge strip of the cathode current collector or the free edge strip of the anode current collector is formed by the edge of the separator on the side of the assembly from which it protrudes, especially the longitudinal edge of the separator.

[0145] b. The edges or longitudinal edges of the partition forming this side, especially the end face, are reinforced with ceramic.

[0146] In a preferred further embodiment, the energy storage element according to the invention has the following feature a: a. The ceramic reinforcement is achieved by at least one particulate ceramic material, particularly at least one particulate ceramic filler material in the spacer.

[0147] Therefore, the separator can preferably be an electrically insulating plastic film in which particulate filler material is embedded. Preferably, the plastic film can be permeated with electrolyte (e.g., because it has micropores). The film can be made of, for example, polyolefins or polyetherketones. As mentioned above, nonwoven fabrics and textiles made of such plastic materials can also be used. In some cases, these may also be preferred.

[0148] The proportion of particulate filler material in the separator is preferably at least 40% (by weight), and particularly preferably at least 60% (by weight).

[0149] In a further preferred embodiment, the energy storage element according to the invention has the following feature a: a. The ceramic reinforcement is achieved by at least one particulate ceramic material, which exists as a coating on the surface of one or more separators.

[0150] Therefore, the separator can also preferably be a plastic film coated with ceramic material, or a nonwoven fabric, a woven fabric, or any other electrically insulating sheet.

[0151] In some embodiments, only one side of the flat structure, particularly the plastic film, is coated with ceramic material. In further embodiments, the flat structure, particularly the plastic film, is preferably coated with ceramic material on both sides.

[0152] If desired, the separator may preferably include ceramic material as a filler material and the same or different ceramic material as a coating.

[0153] In a further possible preferred embodiment, the energy storage element according to the invention has at least one of the following features a to e: a. At least one ceramic material / filler is or includes an electrically insulating material.

[0154] b. At least one ceramic material / filler is or includes at least one material selected from the group comprising glass-ceramic materials and glass.

[0155] c. At least one ceramic material / filler is or includes a sodium ion-conducting ceramic material, such as Na5AlO4*Na4SiO4 or NaAlSi2O6 or β-Al2O3, or NASICON materials, such as Na3Zr2Si2PO4. 12 .

[0156] d. At least one ceramic material / filler is or includes an oxide material, particularly a metal oxide.

[0157] e. The ceramic or oxidizing material is alumina (Al2O3), silicon oxide (SiOx), especially silicon dioxide (SiO2), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), silicon oxide, especially silicon dioxide (SiO2), or titanium carbonitride (TiCN).

[0158] Particularly preferred is that the features immediately preceding them, a. to c., or features immediately preceding them, a. and b. and d., or features immediately preceding them, a. and b. and e., are combined with each other.

[0159] Among the materials, aluminum oxide (Al2O3), aluminum hydroxide (Al(OH)3), aluminum hydroxyoxide (AlOOH), titanium oxide (TiO2), and silicon dioxide (SiO2) are particularly preferred as coating materials.

[0160] In a further possible preferred embodiment, the energy storage element according to the invention has at least one of the following features a. and b. immediately following: a. One or more separators may include at least one ceramic material only in certain areas.

[0161] b. One or more separators have edge strips along the edge forming the first side, particularly the first end face, wherein they comprise at least one ceramic material as a coating and / or particulate filler material.

[0162] It is particularly preferred that the preceding features a. and b. are combined with each other.

[0163] It is not necessary for the separator to include uniformly distributed ceramic material or to be uniformly coated all over. Rather, it may even be more preferable that the separator does not contain ceramic material in certain areas, such as the main area described above. In this area, the increase in thermal resistance of the separator is not as necessary as at the edges of the separator. Furthermore, ceramic material may cause an undesirable increase in the internal resistance of the energy storage element according to the invention, especially in this partition.

[0164] However, in many embodiments, the separator is preferably reinforced or coated with a ceramic material on its entire surface, i.e., between the anode and the cathode.

[0165] The front electrode area without an active material coating can be fully or partially coated with ceramic material to reduce the risk of short circuits.

[0166] More details about coating the separators with ceramic materials can be found in WO 2021 / 255238 A1.

[0167] Preferred embodiment of the current collector The current collector of the electrode of the energy storage element according to the invention has the function of electrically contacting the electrochemically active components contained in the corresponding electrode material over the largest possible area. Preferably, the current collector is composed of metal or at least metallized on its surface.

[0168] In particular, in the case of sodium-ion based energy storage elements according to the invention, aluminum or aluminum alloys are suitable as metallic materials for both the anode and cathode current collectors. Sodium-ion systems with current collectors made of aluminum or aluminum alloys on both the anode and cathode sides have proven to be particularly resistant to the effects of deep discharge.

[0169] Suitable aluminum alloys for cathode current collectors include, for example, 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55 type aluminum alloys. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, Al-CuTiMg, and AlMg are also suitable. The aluminum content of these alloys should preferably be higher than 99.5%.

[0170] The anode current collector and / or cathode current collector are preferably strip metal foils with a thickness in the range of 4µm to 30µm.

[0171] However, in addition to foil, other strip-shaped substrates (such as metal or metallized nonwoven fabric or open-cell metal foam or expanded metal) can also be used as current collectors.

[0172] The current collector is preferably equipped with corresponding electrode materials on both sides.

[0173] Edge enhancement of (one or more) current collectors The energy storage element according to the invention preferably further comprises at least one of the following features a to c: a. In the free edge strips of the cathode current collector and / or the free edge strips of the anode current collector, the surfaces of the cathode current collector and / or the anode current collector are coated with a support material that is more heat-resistant than the surface coated thereon.

[0174] b. Non-metallic materials are ceramic materials, microcrystalline glass materials, or glass.

[0175] c. The ceramic material is alumina (Al2O3), aluminum hydroxide (Al(OH)3), aluminum hydroxyaluminate (AlOOH), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), or titanium carbonitride (TiCN).

[0176] "Heat resistance" means that the supporting material remains solid at the temperature at which the surface melts. Therefore, it either has a higher melting point than the surface, is in a subclimate state, or decomposes only at the temperature at which the surface has already melted.

[0177] Preferably, the free edge strips of both the cathode current collector and the anode current collector are coated with a support material. It is particularly preferred to use the same support material in each case.

[0178] The contact metal sheet in direct contact with one or more free edge strips is preferably connected to the edge strips by welding. This can lead to problems such as unintentional pressure or melting of the current collector's edge strip. Support material counteracts these problems. It mechanically supports the current collector's edge strip and prevents melting, especially when both sides of the edge strip are coated with support material. Furthermore, the support material also prevents short circuits caused by melting of the separators in the aforementioned assembly. The support material electrically insulates the free area it covers. Therefore, in a preferred embodiment, it is formed to be electrically insulating.

[0179] More details about suitable support materials can be found in WO 2020 / 239512 A1.

[0180] In a particularly preferred embodiment, the support material covers not only the edge strip or a portion of the edge strip of the anode current collector, but also the electrode material disposed on the anode current collector in the main region. Therefore, the support material layer can also serve as a capping layer, for example, covering the aforementioned matrix or the aforementioned nucleation layer. This is preferred when the support material is one of the aforementioned ceramic materials.

[0181] The support layer may also include an adhesive, for example, which holds the ceramic particles of the support layer together.

[0182] Preferred embodiment of the assembly To prevent direct contact between oppositely polarized electrodes at the axial ends of the winding or stack, it is preferable to use a separator that is slightly wider than the electrodes to be separated. Therefore, in an energy storage element with a wound assembly, in a preferred embodiment, the assembly terminates at its axial end at a separator protrusion that correspondingly forms an end face.

[0183] In the case of the prismatic configuration, preferably, the edges of one or more separators form stacked sides from which the free edge strip of the current collector protrudes.

[0184] More preferably, the free edge strip of the current collector protruding from the terminal end face of the winding or the side of the stack does not exceed 5500µm from the end face or side, and preferably does not exceed 4000µm.

[0185] Particularly preferred is that the free edge strip of the anode current collector protrudes no more than 3000µm from the side of the stack or the end face of the winding, and more preferably no more than 2000µm. Particularly preferred is that the free edge strip of the cathode current collector protrudes no more than 4000µm from the side of the stack or the end face of the winding, and more preferably no more than 3000µm.

[0186] In the wound assembly, the strip anode, strip cathode, and one or more strip spacers are preferably wound in a spiral configuration. To produce this assembly, the strip electrode is preferably fed into a winding apparatus along with one or more strip spacers and is preferably spirally wound around a winding shaft therein. In some embodiments, for this purpose, the electrode and one or more spacers are wound on a cylindrical or hollow cylindrical winding core, which is placed on a winding mandrel and remains wound after winding.

[0187] The winding housing can be formed, for example, from a plastic film or tape. The winding housing may also be formed from one or more spacer windings.

[0188] Preferred embodiments of the first and / or second contact metal sheets One or more contact metal plates are preferably welded to the respective current collectors in direct contact with them. Particularly preferred are they welded directly to the free edge strip of the anode current collector.

[0189] In a preferred embodiment, the contact metal sheets are made of the same material as the current collectors to which they are welded.

[0190] In a particularly preferred embodiment, the contact metal sheet (especially in the case of the sodium ion-based energy storage element according to the invention) is composed of aluminum or an aluminum alloy.

[0191] The same alloy mentioned in relation to current collectors made of aluminum alloy is suitable as an aluminum alloy.

[0192] In other preferred embodiments, the contact metal sheet is composed of, for example, nickel, copper, titanium, nickel alloy, copper alloy, titanium alloy, or stainless steel.

[0193] In a further particularly preferred embodiment of the invention, the first contact metal sheet has at least one of the following features a to g: a. The contact metal sheet has a preferred uniform thickness, in the range of 50µm to 600µm, preferably in the range of 150µm to 350µm.

[0194] b. The contact metal sheet has two opposing flat sides and extends essentially in only one dimension.

[0195] c. The contact metal sheet is a disc or preferably a rectangular plate.

[0196] d. The size of the contact metal sheet is designed to cover at least 60%, preferably at least 70%, and particularly preferably at least 80% of the free edge strip of the corresponding current collector to which it is connected from its exposed side or end face.

[0197] e. The contact metal sheet has at least one hole, particularly at least one crater and / or at least one slit.

[0198] f. The contact metal sheet has at least one bead that appears as an elongated recess on one flat side of the contact metal sheet and as an elongated protrusion on the opposite flat side, wherein the contact metal sheet rests against the free edge strip of the corresponding current collector, and the flat side supports the elongated protrusion.

[0199] g. Contact metal sheets are welded to the free edge strip of the current collector in the area of ​​the weld bead, particularly through one or more welds and / or weld points arranged in the weld bead.

[0200] Particularly preferred is that features a., b., and d. immediately preceding each other are combined. In a preferred embodiment, features a., b., and d. are combined with one of features c. or e., or features f. and g. Particularly preferred is that all features a. to g. are combined with each other.

[0201] Extensive coverage of the end face is important for thermal management of the energy storage element according to the invention. A larger coverage area facilitates contact with the first edge of the current collector along its entire length. Therefore, heat generated within the assembly can be effectively dissipated via the contact metal sheet.

[0202] A particular advantage is that the contact metal sheet is in direct contact with all the windings of the winding, that is, in direct contact with the innermost and outermost windings of the winding.

[0203] For example, it may be useful to contact at least one hole in the metal sheet so that the assembly can be soaked in an electrolyte.

[0204] Electrical connections of (one or more) contact metal sheets Contact metal sheet is - Electrically connected to the casing, or - Connected to a contact post, which is guided through the housing and electrically insulated from the housing, or - The contact metal piece is part of the casing, such as the bottom of a cup-shaped casing or the lid of such a cup-shaped casing.

[0205] Electrical contact with the housing or contact posts can be achieved, specifically, by welding or mechanical connection. If necessary, electrical connections can also be made using separate electrical conductors.

[0206] To achieve optimal connection between the contact metal sheet and the current collector, it is preferable to perform mechanical pretreatment on the sides or end faces. For example, as described above, the edge of the current collector protruding from the end face of the electrode winding can be deformed to form a suitable container for the protrusion of the contact metal sheet having at least one weld bead.

[0207] Preferred design of the outer casing Regardless of its shape (e.g., prismatic or cylindrical), the housing of the energy storage element according to the invention is preferably a metal housing. It particularly preferably includes a cup-shaped housing portion and a lid.

[0208] In a preferred embodiment of the invention, the energy storage element according to the invention has at least one of the following features a. and b. immediately following: a. The cup-shaped outer shell is made of aluminum, aluminum alloy, nickel, copper, stainless steel, or nickel-plated steel.

[0209] b. The lid is made of aluminum, aluminum alloy, nickel, copper, stainless steel, or nickel-plated steel.

[0210] The combination of features a and b immediately preceding them is particularly preferred.

[0211] In some embodiments, it is desirable to directly attach the free edge strip of one of the current collectors to the housing. For this purpose, the free edge strip of the current collector can be welded to the bottom of the cup-shaped housing portion, for example, by laser. In this case, the bottom serves as a contact plate.

[0212] Conversely, in some embodiments, a contact plate may be provided as a cover, i.e., as part of the housing.

[0213] Especially in the case of sodium ion monomers, in a particularly preferred embodiment, both the cup-shaped outer shell and the lid are made of aluminum or aluminum alloy.

[0214] Suitable aluminum alloys for the cup-shaped outer casing are, for example, 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55 type aluminum alloys. AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg are also suitable. The aluminum content of these alloys is preferably higher than 99.5%.

[0215] In some embodiments, the bottom of the cup-shaped outer shell portion is welded, meaning it is manufactured separately and connected to one or more sidewalls by welding. However, in most cases, the cup-shaped outer shell portion is manufactured by deep drawing.

[0216] Preferred nominal capacity of energy storage elements The nominal capacity of the energy storage element according to the invention, designed as a cylindrical spherical monomer, is preferably up to 10,000 mAh. In one embodiment, the form factor of the energy storage element, which is a sodium ion monomer, is 21 x 70, and its nominal capacity is preferably in the range of 1,000 mAh to 5,000 mAh. Insulation of internal conductors In a particularly preferred embodiment, the energy storage element according to the invention has the following features a. to g. immediately following: a. It includes an airtight and liquid-tight housing having a metal cup-shaped housing portion with a bottom and a circular opening for terminals, and a lid with a circular edge that closes the circular opening for terminals.

[0217] b. The fittings are axially aligned in the cup-shaped outer shell, with the first end face pointing towards the lid and the second end face pointing towards the bottom, and in direct contact with the bottom if necessary.

[0218] c. It includes an annular seal made of an electrically insulating material that surrounds the circular edge of the lid and electrically insulates the cup-shaped outer shell portion and the lid from each other.

[0219] d. The cup-shaped outer shell includes an inner side and an outer side, and axially continuously includes a bottom, a central portion, and a closing portion, wherein... - The central part is cylindrical, and within the central part, the winding shell of the assembly forming the winding contacts the inner side of the cup-shaped outer shell portion, and - In the closure section, the annular seal is pressed against the inside of the lid and cup-shaped outer shell portion.

[0220] e. The central part and the closed part are separated by an indentation that circumferentially surrounds the outside of the cup-shaped outer shell part.

[0221] f. The contact metal sheet is electrically connected by welding to the free edge strip of the current collector protruding from the end face of the first terminal, and preferably also to the cover by welding.

[0222] g. The energy storage element includes at least one insulating element made of an electrically insulating material that protects the contact metal sheet and / or the first longitudinal edge of the current collector protruding from the first terminal end face and / or a separate electrical conductor fixed to the contact metal sheet so that it does not come into direct contact with the inside of the cup-shaped housing portion, particularly in the area of ​​the notch.

[0223] This measure ensures a reduction in the risk of short circuits in the internal contact areas of individual cells. For example, axial forces associated with high alignment typically no longer result in direct contact between battery assemblies with opposite polarities. These are prevented by at least one insulating element.

[0224] In a further preferred embodiment of this preferred development, the energy storage element according to the invention has at least one of the following features a to c: a. At least one insulating element is or includes an insulating strip that is applied to the edge of the defined end face and protects it from direct contact with the inside.

[0225] b. At least one insulating element is or includes an annular molded portion made of plastic, preferably having an L-shaped cross-section, which is applied to the edge of the defining end face and protects it from direct contact with the inside.

[0226] c. The thickness of the ring-shaped molded portion made of insulating tape or plastic ranges from 10µm to 200µm.

[0227] Preferably, the features a. and c. and b. and c. that immediately follow are combined.

[0228] The insulating tape can be, for example, Kapton / polyimide tape.

[0229] The annular plastic molding portion, preferably having an L-shaped cross-section, can be manufactured, for example, by injection molding, and can be pushed onto the edge to be protected. For example, it can be composed of Teflon or polyamide.

[0230] In a second preferred further development of this preferred embodiment, the energy storage element according to the invention has at least one of the following features a to c: a. At least one insulating element is or includes an annular insulating element made of plastic, which abuts against the inside of the cup-shaped housing portion in the notched partition and protects it from direct contact with the contact metal sheet. b. The annular insulating element is a section of the annular seal.

[0231] c. The thickness of the ring-shaped insulating element made of plastic is between 20µm and 400µm.

[0232] Preferably, features a and b that immediately follow are implemented in combination. When implemented in combination, features a through c are particularly preferred.

[0233] The annular insulating element can also be a molded part, like an annular seal. The thickness of the insulating element is preferably in the range of 20µm to 400µm.

[0234] The ring-shaped insulating element can be composed of, for example, Teflon, polyamide, polybutylene terephthalate, or perfluoroalkoxy polymer.

[0235] In a third preferred further development of this preferred embodiment, the energy storage element according to the invention has at least one of the following features a. to d. immediately following: a. At least one insulating element is or includes an annular plastic portion that surrounds the contact metal sheet and protects it from direct contact with the interior of the cup-shaped housing component in the notched partition.

[0236] b. The annular plastic part is a hollow cylinder, including a sheath, and is defined by a perimeter at the end face.

[0237] c. The annular plastic part is a hollow cylinder, including a sheath, defined at the end face by a circumferential edge, one of which is formed as an outwardly pointing annular collar and placed on the contact metal sheet.

[0238] d. The thickness of the annular plastic portion ranges from 20µm to 600µm.

[0239] Preferably, the features immediately preceding them a. and b., and particularly preferably features a., b., and d., are combined. Features immediately preceding them a., c., and d. are particularly preferably combined.

[0240] The annular plastic portion can also be a molded portion. The thickness of the plastic portion is preferably in the range of 20µm to 600µm.

[0241] The plastic part can be made of, for example, Teflon, polyamide, polybutylene terephthalate, or perfluoroalkoxy polymers.

[0242] In a fourth preferred further development of this preferred embodiment, the energy storage element according to the invention has at least one of the following features a. and b.: a. At least one insulating element is or includes an electrically insulating plastic coating that surrounds the edge of the contact metal sheet and protects it from direct contact with the interior of the cup-shaped housing component, particularly in the area of ​​the notch.

[0243] b. The electrically insulating coating is formed by overmolding the edges of the contact metal sheet.

[0244] Preferably, features a and b that immediately follow are combined.

[0245] In principle, all thermoplastics with electrical insulating properties are suitable for overmolding the edges of contact metal sheets. Polyamides, for example, are suitable.

[0246] The invention also includes combinations of the four particularly preferred development schemes described. An energy storage element is particularly preferred when it has a combination of two or more of the following four features a. to d.: a. At least one insulating element comprises an insulating tape or annular molded portion made of plastic, which is applied to the edge defining the end face and protects it from direct contact with the inside, i.e., according to the first particularly preferred development scheme, an insulating tape or circular molded part, and / or b. At least one insulating element comprises an annular insulating element that abuts against the inner side of the cup-shaped housing component in the notched partition and protects it from direct contact with the contact metal sheet, i.e., the annular insulating element according to the second particularly preferred development embodiment; and / or c. At least one insulating element includes an annular plastic portion that surrounds the contact metal sheet and protects it from direct contact with the interior of the cup-shaped housing component within the notched partition, i.e., the annular plastic portion according to the third particularly preferred development embodiment, and / or d. At least one insulating element is or includes an electrically insulating plastic coating that surrounds the edge of the contact metal sheet and protects it from direct contact with the interior of the cup-shaped housing component, particularly in the notched partition, i.e., the plastic coating according to the fourth particularly preferred development scheme.

[0247] Preferably, the energy storage element according to the invention has at least one of the following features a. or b.: a. The cup-shaped outer casing component has the same maximum outer diameter at the center and at the closure.

[0248] b. In the region of the gap, the outer diameter of the cup-shaped outer shell portion is reduced by 4 to 20 times the wall thickness of the cup-shaped outer shell portion in that partition.

[0249] Preferably, features a and b that immediately follow are combined.

[0250] Monomer sealing through casting of compounds In a particularly preferred embodiment, the energy storage element according to the invention has the following following features: a. It includes a gas-tight and liquid-tight housing having a metal cup-shaped housing portion and a lid, the cup-shaped housing portion having a bottom and a terminal opening, the lid closing the terminal opening.

[0251] b. The cover includes a metal cover plate and a connecting post that is guided through a hole in the cover plate and electrically insulated from the cover plate.

[0252] c. The fittings are arranged in the cup-shaped outer shell portion, with one side facing the lid and the second side facing the bottom, optionally in direct contact with the bottom.

[0253] d. The cathode and anode are formed and / or arranged in the assembly such that the free edge strip of the cathode current collector protrudes from one side of the assembly, and the free edge strip of the anode current collector protrudes from one side of the assembly. e. The contact metal sheet is placed directly on the free edge strip of a current collector protruding from one side of the assembly and is connected to the latter by welding.

[0254] f. The contact metal sheet is electrically connected to the connecting post passing through the hole in the cover plate, preferably directly welded to the connecting post, or the connecting post is part of the contact metal sheet.

[0255] g. The connecting post is electrically insulated from the cover plate by a hardened casting compound made of electrically insulating plastic material.

[0256] This design ensures that there is virtually no dead volume between the fittings and the metal cover. Any space between the contact metal sheet, connecting post, and cover can be filled with casting compound. A cover with these features can be constructed very compactly.

[0257] Furthermore, the advantage of energy storage elements having the features a. to g. immediately preceding them is that they can be electrically contacted with the anode and cathode via the cover.

[0258] In a preferred further development of this embodiment, the energy storage element according to the invention has the following feature a: a. The edge strip of the cathode current collector or anode current collector, which does not directly contact the contact metal sheet, is electrically connected to the bottom of the housing, preferably directly welded to the bottom of the housing.

[0259] In many cases, preferably in this embodiment, the cup-shaped outer casing portion is positively polarized, and the connecting post is a negatively polarized connecting post. In these cases, the energy storage element according to the invention has the following feature a immediately following, optionally combined with at least one of the following features b and c: a. The cup-shaped outer shell is electrically connected to the cathode.

[0260] b. The cup-shaped outer shell is made of aluminum or aluminum alloy.

[0261] c. The cover plate is made of aluminum or aluminum alloy.

[0262] The combination of features a to c immediately preceding them is particularly preferred.

[0263] In this embodiment, the housing of the energy storage element is primarily composed of aluminum or an aluminum alloy. This has several advantages. It prevents the formation of localized components when the exterior of the cell comes into contact with moisture. The housing itself essentially serves as the positive electrode connection post on all sides. However, it is particularly preferred that the cell is exclusively contacted only through the cover, with the negative connection post also located on the cover. For this purpose, the current conductor can be directly welded to the cover plate, or, for example, fixed to a separate connection post by welding.

[0264] In other cases, the cup-shaped outer casing portion is preferably negatively polarized, and the connecting post is preferably a positively polarized connecting post. In these cases, the energy storage element according to the invention has the following feature a immediately following, optionally combined with at least one of the following features b and c: a. The cup-shaped outer shell portion is electrically connected to the anode.

[0265] b. The cup-shaped outer shell is made of aluminum or aluminum alloy.

[0266] c. The cover plate is made of aluminum or aluminum alloy.

[0267] The combination of features a to c immediately preceding them is particularly preferred.

[0268] In a preferred embodiment, the energy storage element according to the invention has at least one of the following features a and b immediately following: a. There is an annular gap between the cover plate and the contact metal sheet, and the annular gap is filled with a casting compound.

[0269] b. The annular gap is defined radially outward by an O-shaped annular insulating disc made of electrically insulating plastic material.

[0270] In a further particularly preferred embodiment, the energy storage element according to the invention has at least one of the following features a to c: a. The contact metal sheet is made of aluminum or an aluminum alloy.

[0271] b. The connecting column is made of aluminum or aluminum alloy.

[0272] c. The contact metal sheet, connecting post, and cathode current collector are made of the same material.

[0273] In embodiments where the connecting post is the portion of the contact metal plate, the contact metal plate serves simultaneously as a conductor and electrode for the current from the anode or cathode current collector. Therefore, a separate electrical conductor, as is typically arranged between the cover or cover assembly and the contact plate, is not required, as described in WO 2017 / 215900 A1.

[0274] In this embodiment, the contact metal sheet preferably includes a flat section and a protrusion. The flat section is placed directly on the free edge strip of one of the current collectors protruding from one side of the assembly and is connected to the latter by welding. The protrusion points away from that side. The protrusion serves as a connecting post and is preferably guided through a hole in the cover plate.

[0275] The contact metal sheet has at least one of the following features a. and b. immediately following: a. The protrusion of the metal part facing away from the end face of the first terminal is shaped into a cup.

[0276] b. The contact metal sheet, including the protrusion, is a one-piece molded component.

[0277] Preferably, features a and b that immediately follow are combined.

[0278] The contact metal sheet with the cup-shaped protrusion can be produced, for example, in a deep drawing process, in which case it is preferably integrally formed. However, it can also be produced, for example, by forming or machining a metal workpiece or by 3D printing.

[0279] In a particularly preferred embodiment of the invention, the energy storage element according to the invention has the following features a. and b.: a. The bottom of the cup-shaped outer casing has a primary safety device in the form of a hole sealed by a metal membrane to prevent internal overpressure.

[0280] b. The bottom of the cup-shaped housing portion has a secondary safety device to prevent internal overpressure, which is in the form of at least one groove on its inner or outer side.

[0281] When an unacceptable overpressure exceeding a specified threshold occurs, the primary safety device functions to achieve controlled pressure equalization. In this situation, the membrane is pressure-ruptured or blown away, and the gas formed inside the housing can escape through the vent at the bottom of the housing.

[0282] The secondary safety device is designed for situations where pressure equalization via the primary safety device is not fast enough. In such cases, the bottom of the casing may tear along a groove due to overpressure, which is simply a weakening of the bottom structure of the casing, creating an outlet with a relatively large cross-section through which gas formed inside the casing can escape.

[0283] This safety solution is known in itself. Through proper design of the grooves and membrane, the pressure required to trigger the safety device can be precisely adjusted.

[0284] Because the aforementioned safety features are not integrated into the cover like many traditional single-piece designs, but rather integrated into the bottom of the housing, the cover can be constructed in an extremely compact manner. Pre-assembly of the cover is also not absolutely necessary. Instead, the cover can be manufactured during the housing assembly process.

[0285] In a particularly preferred embodiment, the energy storage element according to the invention has at least one of the following features a to e: a. The cover plate is welded to the terminal opening of the cup-shaped outer shell.

[0286] b. The contact metal sheet is welded to the contact metal sheet of the anode current collector or the free edge strip of the cathode current collector.

[0287] c. Free edge strips that do not directly contact the contact metal sheet are placed directly on the bottom of the casing.

[0288] d. Free edge strips that do not directly contact the contact metal sheet are welded to the bottom of the housing.

[0289] e. At least one groove is located on the inside of the bottom of the housing.

[0290] The preceding features a. to d. are preferably implemented in combination, and the following features a. to e. are particularly preferably implemented in combination.

[0291] In a further particularly preferred embodiment of the invention, the energy storage element according to the invention has the following feature a.

[0292] a. The metal film is fixed to the bottom of the cup-shaped outer shell by welding.

[0293] The bottom of the cup-shaped outer shell may have a flat recess into which the membrane is inserted so that it does not protrude. It is preferably connected to the bottom by a circular weld around a hole in the bottom.

[0294] The thickness of the membrane can be adjusted to the pressure that triggers the safety device.

[0295] In a preferred embodiment, the energy storage element according to the invention has at least one of the following features a to g: a. The bottom of the housing has at least one weld bead, which is an elongated recess on its outer side and an elongated protrusion on its inner side, wherein the edge strip of the cathode current collector or anode current collector that does not directly contact the contact metal sheet is located on the inner side.

[0296] b. The edge strip of the cathode current collector or anode current collector, which does not directly contact the contact metal sheet, is electrically connected to the bottom of the housing, preferably directly welded to the bottom of the housing.

[0297] c. The bottom of the casing is welded to the free edge strip of the anode current collector or the free edge strip of the cathode current collector in the weld bead partition. d. The hole is located at the center of the bottom of the casing.

[0298] e. At least one weld bead comprises multiple linear weld beads, particularly three weld beads, which are arranged in a star shape around the hole.

[0299] f. At least one weld bead comprises multiple linear sections arranged in a star shape around the hole.

[0300] g. At least one weld bead includes a section extending around the hole, which connects the star-shaped linear sections to each other.

[0301] Features a. and b., c. and d., c. and e., and f. that immediately follow are preferably implemented in combination. Features a. to g. that immediately follow are particularly preferably implemented in combination.

[0302] As a result of welding in the weld bead partition, one or more welds are preferably found there. The star-shaped linear sections of the star-shaped weld bead and the groove preferably form an angle of 120° with each other.

[0303] In some embodiments, it has been shown to be advantageous to pre-treat the free edge strip of the current collector placed on the inner side of the bottom of the housing to improve the contact between the bottom of the housing and the current collector. In particular, at least one pressure-reducing element corresponding to at least one weld bead can be folded into the edge.

[0304] The edges of the current collector may also have undergone orientation pre-treatment. For example, it can be bent in a specified direction.

[0305] The battery according to the present invention The energy storage element according to the present invention, particularly the energy storage element based on sodium ion technology, not only provides high power density but also fast charging speed, good performance at low temperatures, and excellent cycle stability. Furthermore, for example, the supply of sodium is virtually unlimited.

[0306] For all these reasons, the energy storage element according to the invention, especially the energy storage element based on sodium ion technology, is well-suited for use in starter batteries that can replace lead-acid batteries, for example in motor vehicles.

[0307] Therefore, the invention described herein includes - Any battery comprising two or more energy storage elements according to the invention, particularly, sodium-ion technology-based energy storage elements connected in series and / or in parallel.

[0308] The battery according to the invention particularly includes a plurality of energy storage elements according to the invention, which are connected to each other, such that the battery provides a voltage of 12 volts or 24 volts.

[0309] Typically, the sodium-ion-based energy storage element according to the invention provides a nominal voltage in the range of 1.5 volts to 4.8 volts, preferably 2.4 volts to 4 volts. Therefore, a battery with a nominal voltage of 12V according to the invention preferably comprises 3 to 5 energy storage elements according to the invention connected in series.

[0310] Other features and advantages of the invention will be apparent from the claims and the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings. Each feature can be implemented individually or in combination with each other. Attached Figure Description

[0311] The attached diagram schematically shows Figure 1 This is a first embodiment (cross-sectional view) of the sodium-ion energy storage element according to the present invention. Figure 2 This is a second embodiment of the sodium-ion energy storage element according to the present invention. Figure 3 A third embodiment (cross-sectional view) of the sodium-ion energy storage element according to the present invention is shown. Figure 4 Several embodiments of a contact metal sheet are shown, which is adapted to contact the first longitudinal edge (perspective view) of a current collector protruding from the first terminal end face of a sodium-ion energy storage element according to the invention. Figure 5 The assembly and its components (top view and perspective view) are shown as part of the sodium-ion energy storage element according to the present invention. Figure 6 A further embodiment of a contact metal sheet is shown, which is adapted to contact the first longitudinal edge (perspective view) of a current collector protruding from the first terminal end face of a sodium-ion energy storage element according to the invention. Figure 7 This is a representation of the external longitudinal cross-section of an embodiment of the energy storage element according to the present invention. Figure 8 This is a detailed longitudinal cross-sectional view of the upper and lower end face sections according to an embodiment of the energy storage element of the present invention. Figure 9 A, Figure 9 B is a detailed view of the connecting column of a preferred embodiment of the energy storage element according to the present invention, viewed from a certain angle and in cross-sectional view. Figure 10 A, 10B is as follows Figures 7 to 9Detailed views of the insulating disk of a preferred embodiment of the energy storage element according to the present invention, viewed from a certain angle and in cross-sectional view. Figure 11 A, 11B are Figure 7 The diagram shows a detailed representation of the contact metal sheet of a preferred embodiment of the energy storage element according to the present invention, viewed from above a certain angle and a cross-sectional view viewed from below a certain angle. Figure 12 Is it like this? Figure 7 A detailed view of the bottom of the housing of a preferred embodiment of the energy storage element according to the present invention is shown. Figure 13 A-13C is shown in exploded view as follows Figure 7 The illustration shows various components of a preferred embodiment of an energy storage element according to the present invention. Figure 14 A and 14B are detailed views of the upper surface partitions of a preferred embodiment of the energy storage element according to the present invention, illustrating possible methods for manufacturing the energy storage element. Figure 15 This is a view of the bottom of the casing from an oblique angle, showing a preferred embodiment of the energy storage element according to the present invention, and illustrating a method for manufacturing the energy storage element. Figure 16 A, 16B are cross-sectional views of alternative embodiments of the contact metal sheet in a preferred embodiment of the energy storage element according to the present invention, and the contact metal sheet has connecting posts, and Figure 17 Examples of lid fittings, such as... Figure 1 , Figure 2 ,or Figure 3 As shown, it can be installed as a cover in the energy storage element according to the present invention. Detailed Implementation

[0312] Figure 1 An energy storage element 100 according to the invention is shown, having a sealed housing to prevent the ingress of air and liquid. The housing includes a metallic cup-shaped housing portion 101 with a circular opening for terminals and a cap 102 with a circular edge 102a that closes the circular opening. The energy storage element also includes an annular seal 103 made of an electrically insulating material, which surrounds the circular edge 102a of the cap 102 and electrically insulates the cup-shaped housing portion 101 and the cap 102 from each other.

[0313] The lid is only shown in the form of a disc. However, multi-part lid assemblies are often used as lids, for example... Figure 17 As shown.

[0314] The cup-shaped outer shell portion 101 includes, in axial order, a bottom 101a, a central portion 101b, and a closing portion 101c. The central portion 101b is cylindrical. In the central portion 101b, a winding shell 104c, forming a winding assembly 104, contacts the inner side 101d of the cup-shaped outer shell portion 101. In the closing portion 101c, an annular seal 103 is pressed against the cover 102 and the inner side of the cup-shaped outer shell portion 101. The central portion 101b and the closing portion 101c are separated by a notch 111, which circumferentially surrounds the outer side 101e of the cup-shaped outer shell portion 101.

[0315] The assembly 104, with its cylindrical winding configuration in an anode / separator / cathode sequence, is not shown in detail here. Only the longitudinal edge 106a of the anode current collector 106, protruding from end face 104a of the assembly 104, and the longitudinal edge 109a of the cathode current collector 109, protruding from end face 104b of the assembly 104, are visible. The longitudinal edge 109a is preferably welded directly to the bottom of the housing 101a along its entire length. The longitudinal edge 106a is preferably welded directly to the contact metal plate 112 along its entire length. The contact metal plate 112 is then connected to the cover 102 via an electrical conductor 133.

[0316] The energy storage element 100 preferably has a height in the range of 60 mm to 100 mm, and its diameter is preferably in the range of 20 mm to 50 mm. The wall thickness of the cup-shaped outer casing portion 101 in the central portion 101b is typically in the range of 0.1 mm to 0.3 mm.

[0317] The energy storage element includes an electrically insulating plastic coating 180 as an insulating element, which surrounds the edge of the contact metal sheet 112 and protects it from direct contact with the inner side 101d of the cup-shaped housing portion 101 (particularly in the region of the notch 111). The electrically insulating coating 180 is formed by overmolding the edge of the contact metal sheet 112. Furthermore, the energy storage element 100 includes an annular plastic portion 170 as an insulating element, which surrounds the individual electrical conductor 133 fixed to the contact metal sheet and protects it from direct contact with the inner side 101d of the cup-shaped housing portion 101 in the region of the notch 111.

[0318] As a result, even when the outer casing is deformed due to external mechanical forces, the energy storage element 100 is well protected from short circuits.

[0319] Figure 2An energy storage element 100 according to the invention is shown, having a hermetically and liquidally sealed housing. The housing includes a metallic cup-shaped housing portion 101 with a circular terminal opening and a cap 102 with a circular edge 102a that closes the circular opening. The energy storage element also includes an annular seal 103 made of an electrically insulating material, which surrounds the circular edge 102a of the cap 102 and electrically insulates the cup-shaped housing portion 101 and the cap 102 from each other.

[0320] The lid is only shown in the form of a disc. However, multi-part lid assemblies are often used as lids, for example... Figure 17 As shown.

[0321] The cup-shaped outer shell portion 101 continuously includes a bottom 101a, a central portion 101b, and a closing portion 101c in the axial direction. The central portion 101b is cylindrical. In the central portion 101b, the winding shell 104c of the assembly 104, which is formed as a winding, contacts the inner side 101d of the cup-shaped outer shell portion 101. (Note: For clarity, the assembly 104 shown here is spaced apart from the inner side 101d, but it actually presses against the inner side 101d, such as...) Figure 1 As shown), in the closure portion 101c, the annular seal 103 is pressed against the inside of the cover 102 and the cup-shaped outer shell portion 101. The central portion 101b and the closure portion 101c are separated by a notch 111, which circumferentially surrounds the outer side 101e of the cup-shaped outer shell portion 101.

[0322] The assembly 104, with its cylindrical winding configuration in an anode / separator / cathode sequence, is not shown in detail here. Only the longitudinal edge 106a of the anode current collector 106, protruding from end face 104a of the assembly 104, and the longitudinal edge 109a of the cathode current collector 109, protruding from end face 104b of the assembly 104, are visible. The longitudinal edge 109a is preferably welded directly to the bottom of the housing 101a along its entire length. The longitudinal edge 106a is preferably welded directly to the contact metal plate 112 along its entire length. The contact metal plate 112 is then connected to the cover 102 via an electrical conductor 133.

[0323] The energy storage element 100 preferably has a height in the range of 60 mm to 100 mm, and its diameter is preferably in the range of 20 mm to 50 mm. The wall thickness of the cup-shaped outer casing portion 101 in the central portion 101b is typically in the range of 0.1 mm to 0.3 mm.

[0324] The energy storage element includes an annular molded portion 150 made of plastic and having an L-shaped cross-section, which serves as an insulating element. This annular molded portion is applied to the edge defining the end face 104a and protects it from direct contact with the inner side 101d of the cup-shaped housing portion 101. Furthermore, the energy storage element includes an annular insulating element 160 made of plastic, which abuts against the inner side 101d of the cup-shaped housing portion 101 in the partition of the notch 111 and protects it from direct contact with the electrical conductor 133. This could also be a section of an annular seal 103 with a height sufficient to cover the notch 111 from the inside.

[0325] As a result, even when the outer casing is deformed due to external mechanical forces, the energy storage element 100 is well protected from short circuits.

[0326] Instead of the annular plastic molding portion 150 with an L-shaped cross-section, the edge defining the end face 104a can also be covered with an insulating tape, such as Kapton tape 150. Ideally, this can be applied to the edge during winding formation and effectively protect the edge from direct contact with the inner side 101d.

[0327] Figure 3 An energy storage element 100 according to the invention is shown, having a hermetically and liquidally sealed housing. The housing includes a metallic cup-shaped housing portion 101 with a circular terminal opening and a cap 102 with a circular edge 102a that closes the circular opening. The energy storage element also includes an annular seal 103 made of an electrically insulating material, which surrounds the circular edge 102a of the cap 102 and electrically insulates the cup-shaped housing portion 101 and the cap 102 from each other.

[0328] The lid is only shown in the form of a disc. However, multi-part lid assemblies are often used as lids, for example... Figure 17 As shown.

[0329] The cup-shaped outer shell portion 101 continuously includes a bottom 101a, a central portion 101b, and a closing portion 101c in the axial direction. The central portion 101b is cylindrical. In the central portion 101b, a winding shell 104c of an assembly 104 designed as a winding contacts the inner side 101d of the cup-shaped outer shell portion 101. In the closing portion 101c, an annular seal 103 presses against the cover 102 and the inner side of the cup-shaped outer shell portion 101. The central portion 101b and the closing portion 101c are separated by a notch 111, which circumferentially surrounds the outer side 101e of the cup-shaped outer shell portion 101.

[0330] The assembly 104, with its cylindrical winding configuration in an anode / separator / cathode sequence, is not shown in detail here. Only the longitudinal edge 106a of the anode current collector 106, protruding from end face 104a of the assembly 104, and the longitudinal edge 109a of the cathode current collector 109, protruding from end face 104b of the assembly 104, are visible. The longitudinal edge 109a is preferably directly welded to the contact metal sheet 134 along its entire length. The contact metal sheet 134 is in turn welded to the bottom 101a. The longitudinal edge 106a is preferably directly welded to the contact metal sheet 112 along its entire length. The contact metal sheet 112 is in turn connected to the cover 102 via an electrical conductor 133.

[0331] The energy storage element 100 preferably has a height in the range of 60 mm to 100 mm, and its diameter is preferably in the range of 20 mm to 50 mm. The wall thickness of the cup-shaped outer casing portion 101 in the central portion 101b is typically in the range of 0.1 mm to 0.3 mm.

[0332] The energy storage element includes an annular plastic portion 170 as an insulating element, which laterally surrounds the electrical conductor 133 and protects it from direct contact with the inner side 101d of the cup-shaped housing portion 101 within the partition of the notch 111. The annular plastic portion 170 is designed as a hollow cylinder and includes a sheath 171 perpendicular to the contact metal plate 112. One edge of the sheath is formed as an outwardly pointing annular loop 171 and rests on the contact metal plate 112.

[0333] As a result, even when the outer casing is deformed due to external mechanical forces, the energy storage element 100 is well protected from short circuits.

[0334] Figure 4 Several embodiments of the contact metal sheet 112 are shown, which is adapted to contact the first longitudinal edge 106a of the current collector 106 protruding from the first terminal end face 104a of the energy storage element 100 according to the invention.

[0335] Example A shows a circular and substantially flat metal disc with a circumferential edge 102a, serving as a contact metal sheet 112. It is characterized by a central hole 142 and three offset weld beads 141. This assembly can be used according to… Figures 1 to 3 In the energy storage element, it serves as the electrical contact for the edge 106a of the anode current collector 106. However, it is also suitable for use as... Figure 3 The contact metal sheet 134 in the energy storage element. When using this metal disc to contact the longitudinal edge 106a, it is typically required... Figures 1 to 3 The individual conductor 133 shown is used to bridge the distance to the contact metal plate 102.

[0336] This is not the case in Embodiment B. Here, the contact metal sheet 112 includes a first segment 112a, which can lie flat on the first longitudinal edge of the current collector protruding from the first terminal end face 104a and then extend parallel to the end face 104a. However, it also includes a second segment 112b, which is connected to the first segment 112a at an angle, and the first segment 112a is electrically connected to the cover 102 through the second segment 112b. When using this contact metal sheet, a separate conductor 133 is not required. Another feature of the contact metal sheet 112 is the hole 142 and two weld beads 141. The contact metal sheet is preferably welded to the longitudinal edge of the corresponding current collector in these weld beads.

[0337] The difference between Embodiments C and D and Embodiment B is that segment 112a includes three or four strips extending in different directions. Each strip has a weld bead 141. Furthermore, each sheet portion has two holes 142.

[0338] The structure of assembly 104 is as follows Figure 5 As shown. Assembly 104 includes a strip anode 105 and a strip anode current collector 106, the strip anode current collector 106 having a first longitudinal edge 106a and a second longitudinal edge parallel thereto. The anode current collector 106 is a foil made of aluminum. It includes a strip-shaped main region and a free edge strip 106b, the strip-shaped main region being loaded with a layer of negative electrode material 107, the free edge strip extending along its first longitudinal edge 106a without being loaded with electrode material 107. Furthermore, assembly 104 includes a strip cathode 108 and a strip cathode current collector 109, the strip cathode current collector 109 having a first longitudinal edge 109a and a second longitudinal edge parallel thereto. The cathode current collector 109 is also an aluminum foil. It includes a strip-shaped main region and a free edge strip 109b, the strip-shaped main region being loaded with a layer of positive electrode material 110, the free edge strip extending along its first longitudinal edge 109a without being loaded with electrode material 110. Both electrodes are shown in an unwound state.

[0339] The anode 105 and cathode 108 are arranged offset from each other within the assembly 104, such that the first longitudinal edge 106a of the anode current collector 106 protrudes from the first terminal end face 104a of the assembly 104, and the first longitudinal edge 109a of the cathode current collector 109 protrudes from the second terminal end face 104b of the assembly 104. This offset arrangement is shown in the lower left figure. Two strip-shaped separators 116 and 117 are also shown in the figure, which separate the electrodes 105 and 108 from each other in the winding.

[0340] The diagram in the lower right corner shows the coiled assembly 104, as it can be used according to... Figures 1 to 4In one of the energy storage elements, the electrode edges 106a and 109a protruding from end faces 104a and 104b are clearly visible. The winding shell 104c is formed of a plastic film.

[0341] Figure 6 A further embodiment of the contact metal sheet 112 is shown, which is adapted to contact the first longitudinal edge 106a of the current collector 106 protruding from the first terminal end face 104a of the energy storage element 100 according to the invention.

[0342] The embodiments BD shown here are Figure 4 The main difference in the contact metal sheet shown in embodiment BD is that segment 112b is not folded into a Z-shape, but rather bent into a U-shape. This contact metal sheet can replace the one according to... Figures 1 to 3 The contact metal sheet 112 and the electrical conductor 133 in the energy storage element.

[0343] Figure 7 A-7C shows an view from above at a certain angle ( Figure 7 A) Viewed from the longitudinal section ( Figure 7 B), and observing from a low angle ( Figure 7 C) A preferred embodiment of the energy storage cell according to the present invention. The energy storage cell 100 has the shape of a cylindrical circular cell. The outer shell of the energy storage cell 100 is formed by a cup-shaped outer shell portion 101 and a cap. The cap includes a cover plate 102a having a perforated plate shape and a connecting post 102b located at the center of the cap assembly.

[0344] like Figure 7 As shown in the cross-sectional view of B, the winding assembly 104 is located inside the energy storage cell 100 and is formed by winding electrode strips with separation strips between the electrode strips.

[0345] Figure 7 C shows the bottom side of the energy storage cell 100 formed by the bottom of the housing 101a. Three weld embossings in the form of weld beads 161 are arranged in a star shape in the bottom of the housing 101a, appearing as recesses on the outer side and as elongated protrusions on the inner side. The longitudinal edges of the corresponding current collectors rest against these weld beads 161 on the inner side, and in the partitions of these weld beads, the current collectors are preferably welded directly to the bottom of the housing.

[0346] Aluminum is the preferred material for the bottom of the housing 101a and the entire cup-shaped housing portion 101.

[0347] In this example, two safety functions are integrated into the bottom of the housing 101a. Firstly, a hole is located at the center of the bottom of the housing 101a, which is sealed by a metal membrane 114. In the event of excessive pressure due to a monomer failure, this membrane 114 achieves pressure equalization by rupturing or breaking under pressure. Thus, any gas that may form inside the monomer can escape through the hole in the bottom of the housing 101a (primary safety device).

[0348] In addition, another safety function is provided in the bottom of the housing 101a, which is achieved by three star-shaped recesses 166. These recesses 166 weaken the structure of the bottom of the housing 101a, thereby creating a predetermined break point (secondary safety device) in the event of overpressure inside the unit. In this example, the recesses 166 are located on the inner side of the bottom of the housing 101a, therefore... Figure 7 C is shown as a dashed line. For example, groove 166 can be formed as three scratch lines. The star-shaped arrangement of the scratch lines is further formed by the partial circular connection of the scratch lines or groove 166. Under corresponding high overpressure, the bottom 101a of the housing tears along groove 166 and the partial circular connection of these grooves, thereby creating an outlet with a relatively large cross-section through which gas formed inside the housing can escape rapidly if necessary.

[0349] Figure 8 A and 8B show the results according to Figure 7 An enlarged view of the end face partition of an embodiment of the energy storage cell 100. Figure 8 A shows details of the end face with the cover 102. The cover 102 includes a cover plate 102a with a central hole and a connecting post 102b arranged at the center of the cover plate 102a. In this example, the connecting post 102b can form the negative electrode of the energy storage cell 100, while the surrounding cover plate 102a can form the positive electrode of the energy storage cell 100.

[0350] Below the connecting post 102b is a contact metal sheet 112, which is placed on and welded to the free edge strip 106b of the spirally arranged anode current collector of the negative electrode. The contact metal sheet 112 is electrically connected to the connecting post 102b, which is formed by two metal components, specifically also by welding. The cover plate 102a is electrically insulated from the contact metal sheet 112 by an O-ring insulating disc 177. Furthermore, an electrically insulating molding compound 113 is located in the gap between the connecting post 102b and the cover plate 102a.

[0351] Figure 8B shows details of the opposite end faces of the energy storage cell 100. The free edge strip 109b of the cathode current collector is electrically connected to this end face of the energy storage cell 100, specifically welded to the bottom of the housing 101a. Electrical contact is established between the sheath of the cup-shaped housing portion 101 and the metal cover plate 102a on the opposite end face, so that the positive potential of the cell can also be tapped on the upper end face of the energy storage cell 100.

[0352] Figure 8 The preferred overpressure protection function of the cell according to the invention can be seen on the lower end face of the energy storage cell 100 shown in Figure B. The primary safety device is formed by a metal membrane 114 that seals the central circular hole 155 in the bottom 101a of the outer casing. The secondary safety device is formed by grooves 166, one of which is visible in the cross-sectional view in this illustration. The grooves 166 located inside the bottom 101a of the outer casing represent a defining weakening structure at the bottom of the outer casing; therefore, when a relatively high overpressure accumulates inside the cell, these structures open, allowing gas to escape.

[0353] like Figure 8 As shown, the preferred design of the energy storage cell 100 according to the present invention allows for a reduction in the number of parts in the upper section of the energy storage cell. Figure 8 (A) In this upper section, the negative and positive electrode terminals of the individual are arranged. In particular, due to the integrated structure of the connecting post 102b, this design eliminates the need for additional conductors.

[0354] One of the electrode strips has its longitudinal edge in direct contact (partial) with the bottom side of the housing. Figure 8 B) It also contributes to the particularly compact design of the monomer, so that the various functions of the monomer do not require dead volume.

[0355] Direct contact with the longitudinal edge of the electrode strip also achieves improved heat dissipation and reduced internal resistance.

[0356] In addition, the design of this single cell typically allows for longer windings, resulting in a higher energy density in the final energy storage cell.

[0357] In this configuration, the upper surface of the energy storage cell 100 is designed to be as compact as possible. Any gas that might be generated inside the cell and cause a pressure increase is inevitably guided to the lower section of the cell, where a pressure equalization safety function is located. Therefore, overall, this cell has very good safety.

[0358] Figure 9 A and 9B show Figure 7 and Figure 8 Detailed top view of connecting column 102b ( Figure 9 A) and sectional view ( Figure 9B). The connecting post 102b may consist of two metal components. The upper section (upper part of the post) 1020 does not necessarily have to be made of the same metal as the lower section (lower part of the post) 1021. The upper section 1020 has a beveled circumferential edge. For example... Figure 4 As shown in the cross-sectional view of B, the lower portion 1021 has an outer peripheral weld shoulder 1021a and a downwardly protruding central pin 1021b. The pin 1021b readily engages in a corresponding recess in the center of the contact metal sheet 112, thereby ensuring a good fit with the connecting post 102b.

[0359] Figure 10 A and 10B show a complete top view of the O-ring insulating disk 177. Figure 10 A) and cross-sectional view ( Figure 10 B). The insulating disk 177 has the function of electrically insulating the preferred positively polarized cover plate 102a from the energy storage cell 100 having the opposite polarity. In addition, the insulating disk 177 also provides liquid-tight and gas-tight seals for the housing.

[0360] In a preferred example of the insulating disk 177 shown here, the insulating disk is made of two different materials. The outer partition 177a of the insulating disk 177 is preferably made of a particularly robust plastic material, such as PBT (polybutylene terephthalate). The inner partition 177b is preferably made of a slightly softer and, most importantly, particularly heat-resistant plastic, such as PET (polyethylene terephthalate). Thus, the outer partition 177a ensures specific mechanical stability. The inner partition 177b provides flexibility and is particularly heat-resistant to the casting compound 13 during the assembly of the energy storage cell.

[0361] The inner circumference of the O-ring insulating disk 177 has the special advantage of being circumferentially thickened, which further supports the stability of the components in the end face partitions of the installed energy storage cell.

[0362] When assembling the energy storage cell, the insulating disk 177 is inserted into the coverage area of ​​the cell to initially provide a temporary seal until the subsequently introduced sealing compound 113 hardens to completely seal the cell. Furthermore, for example, during cell testing, the specific shape of the insulating disk 177 allows for axial support of the winding assembly 104. If the cell deforms laterally, the shape of the insulating disk 177 also provides space for any deformation of the contact metal sheet 112. Finally, the shape of the insulating disk 177 allows for a reduction in the volume of the casting compound 113 and the number of any air bubbles trapped during the casting process when assembling the energy storage cell.

[0363] As a possible alternative to this insulating disc, an insulating sealant weld bead equivalent to a silicone weld bead can be applied. This also ensures a tight seal. However, the insulating disc 177, particularly in the embodiment shown here, offers all the aforementioned advantages.

[0364] Figure 11 A and 11B show a preferred embodiment of the contact metal sheet 112, which is used to contact the free edge of the current collector of the corresponding electrode in the upper part of the energy storage cell. Figure 11 A shows a top view of the disc-shaped contact metal sheet 112. Figure 11 B shows a cross-section of the contact metal sheet 112 as viewed from below, i.e., the side of the contact metal sheet facing the assembly 104 inside the energy storage cell.

[0365] Similar to the weld 161 on the bottom of the housing 101a, the contact metal sheet 112 also has three star-shaped welds 112d, which appear as recesses on the outer side. Figure 11 A), which appears as a slender protrusion on the inner side ( Figure 11 (B) For example, weld bead 112d can be knurled and has a depth of, for example, 0.25 mm. When the unit is assembled, weld bead 112d contacts the corresponding longitudinal edge of the electrode strip of the assembly to be contacted there. Contact metal sheet 112 is preferably welded to the corresponding longitudinal edge of the electrode strip via weld bead 112d.

[0366] A recess 112e is present in the center of the contact metal sheet 112. The recess 112e is used to receive the connecting post 102b, whereby the center pin 1021b of the connecting post 102b engages in the recess 112e. In this way, the connecting post 102b can be easily positioned and fixed on the contact metal sheet 112, so that the connecting post 102b can be welded without any problems.

[0367] Furthermore, in a particularly preferred embodiment of the contact metal sheet 112 shown herein, additional star-shaped narrow recesses 112f are provided on the inward-facing side of the contact metal sheet 122. In this example, a total of nine of these recesses 112f are configured as narrow channels arranged in a star shape. For example, the depth of the recesses can be 0.1 mm. The recesses 112f are used to improve the distribution of electrolytes within the monomer.

[0368] Furthermore, in this preferred embodiment, the contact metal sheet 112 has an embossed circumferential edge 112g, which is arranged with predetermined bending points, particularly with the burrs facing downwards. These predetermined bending points facilitate the assembly of the energy storage cell's housing.

[0369] In a preferred embodiment, the contact metal sheet 112 is made of aluminum, for example, an aluminum sheet with a material thickness of 0.3 mm.

[0370] Figure 12A detailed view of the bottom 101a of the housing of an energy storage cell with star-shaped inwardly projecting weld beads 161 is shown. The weld beads 161 are specifically formed as welding embossing for contact with the winding assembly. Due to its rotational symmetry, the star-shaped arrangement with three weld beads 161 is particularly advantageous for mounting the cell.

[0371] The central hole 155 in the bottom 101a of the housing is covered by a metal membrane 114 and serves as a primary safety device for the monomer in the event of overpressure. In particular, the hole 155 is first used to fill the monomer with electrolyte during the manufacturing process of the monomer before the metal membrane 114 is sealed.

[0372] In order to precisely accommodate the metal film 114 to close the central hole 155, a circumferential recess 1010b is preferably provided around the central hole 155.

[0373] Furthermore, in this embodiment, three star-shaped weakening structures are provided in the form of inwardly opening recesses 166, which are connected to each other by semi-circular connecting lines 1010c. These weakening structures 166 and 1010c serve as auxiliary safety protection against internal overpressure. As an alternative to connecting the weakening structures to the bottom of the housing from the inside, such weakening structures, such as scratches, can also be connected from the outside.

[0374] One or more label fields 1010a can also be set on the outside of the bottom of the shell 101a, which can be used to paste various written information.

[0375] Figure 13 A-13C shows an exploded view of various components of a preferred embodiment of an energy storage cell according to the present invention. Figure 13 A shows a housing comprising a housing cup 101, a connecting post 102b, an O-ring insulating disk 177, a cover plate 102 with a central recess engaging with the connecting post 102b, and a housing for casting compound 113. Below the housing cup 101, the closure of the energy storage cell is shown in the form of a metal membrane 114, which is attached after the assembled cell is filled with the electrolyte 115, schematically indicated herein.

[0376] Figure 13 B shows a wound electrode-separator assembly 104 and a contact metal sheet 112 to be attached thereto. The assembly 104 can be produced, particularly on a winding machine, in a manner known per se, by winding the electrode strip and the separator. To achieve the winding shape, it is preferable to use a tapered pressure member to bend the outermost winding turns inwards by 30° to 45° to stabilize the winding shape. Then, it is preferable to apply, for example, a tape 118 made of polypropylene (… Figure 13C) Applied to the outer peripheral surface of the winding, this tape, in addition to its stabilizing function, can also perform electrical insulation within the monomer if necessary. After the winding assembly 104 is stabilized, a disc-shaped contact metal sheet 112, for example made of aluminum, can be loosely placed on the upper end face of the winding and secured with a particularly stable tape 119, for example made of polyimide. For this purpose, for example, a 50µm thick Kapton tape can be used. ® adhesive tape.

[0377] The assembly 104 with the attached contact metal plate 112 can then be inserted into the cup-shaped housing portion 101. After aligning the weld beads in the bottom of the housing and the contact metal plate, if necessary, the arrangement can be pressed together using a suitable pressing tool with the aid of a camera, and laser welding can be performed from above and below to simultaneously or sequentially bring the longitudinal edges of the electrode strips into contact with the corresponding weld beads. The connecting post 102b can then be placed on the contact metal plate 112 and welded thereon.

[0378] Figure 14 A and 14B show the production details of the individual cap assembly. Figure 14 A shows a detailed view of the connecting post 102b being welded to the contact metal sheet 112, where the laser can be applied at an angle or perpendicularly, particularly in the partition of the circumferential welding shoulder 1021a of the connecting post 102b. Figure 14 B illustrates how the insulating disc 177 is inserted and pressed to the correct height before the cover plate 102a is placed on top and welded at an angle, vertically, or horizontally to the cup-shaped housing portion (not shown here). Now, if needed, the connecting post 102b can be pressed to the correct height relative to the unit shoulder formed by the upper side of the cover plate 102a. The distance provided for this purpose could, for example, be 1 mm between the top side of the connecting post 102b and the top side of the cover plate 102a. The gap between the cover plate 102a and the connecting post 102b is filled with a casting compound 113 to seal this portion of the energy storage unit, making it both gas-tight and liquid-tight.

[0379] The energy storage unit can then be transferred to an oven to solidify the casting compound 113 and bake away any residual moisture in the winding assembly.

[0380] Figure 15 The final filling of electrolyte 115 is shown, which is filled from the bottom side (top in this figure) of energy storage cell 100 through hole 101b in bottom housing 101a. Finally, metal film 114 is applied as a closure for the opening in bottom housing 101a or as a closure for central hole 155. For this purpose, a vertical laser beam can be used, for example.

[0381] Figure 16 Another option for installing the cover assembly is shown. Figure 16A shows a cross-sectional view of the connecting post 102b attached to the contact metal sheet 112, viewed from below at a certain angle. Figure 16 B shows the longitudinal section of the upper surface region of the monomer.

[0382] In this alternative manufacturing process, the connecting post 102b is pre-welded to the contact metal sheet 112. Friction welding or friction stir welding can be used for this purpose.

[0383] In the design of the contact metal sheet 112 in this embodiment, the star-shaped weld beads 112d of the contact metal sheet 122 can be shortened if necessary because they are covered by the connecting posts 102b during subsequent welding of the electrode-separator assembly. Therefore, overall, the welding surface available for contacting the longitudinal edges of the respective electrode strips with the contact metal sheet 112 is slightly less. However, this design can provide advantages for the assembly.

[0384] Since it may be easier to attach the connecting post 102b directly to the contact metal plate 112 on the outside of the housing cup fitting, the central recess in the contact metal plate and the corresponding pin on the connecting post 102b can be omitted.

[0385] The further assembly of the energy storage cell with the connecting post 102b, which has been directly welded to the contact metal sheet 112, is in principle no different from the manufacturing method of the energy storage cell 100 described above.

[0386] Figure 17 An example of a lid assembly 202 is shown, which can be installed as a lid, such as... Figure 1 or Figure 2 or Figure 3 The energy storage element shown according to the present invention.

[0387] This includes a metal disc 213 with a metal membrane 214, which bulges outward or ruptures under overpressure within the housing. The metal disc 213 with the membrane 214 is in electrical and direct contact with a metal cap 217 that seals the cover assembly 202 to the outside. It is also in electrical contact with an internal metal contact disc 215, but only through the metal membrane 214. Otherwise, the metal disc 213 and the contact disc 215 are electrically insulated from each other by an annular insulator 216. If the membrane 214 bulges outward due to overpressure that can act directly on the membrane through the orifice 215a, the electrical contact between the metal disc 213 and the contact disc 215 is broken. Under high pressure, the membrane may also rupture. Figures 1 to 3 The conductor 113 of the shown unit can be soldered to the contact plate 213.

Claims

1. A secondary energy storage element (100) having the following characteristics: a. Includes a cathode (108) and an anode (105) as electrodes, wherein the cathode (108) and the anode (105) are part of the assembly (104), wherein, The cathode and the anode are separated by a separator or solid electrolyte layer (116) in the order of cathode (108) / separator or solid electrolyte layer (116) / anode (105). b. The cathode (108) includes a cathode current collector (109) and a positive electrode material (110). c. The anode (105) includes an anode current collector (106) and a negative electrode material (107). d. The cathode current collector (109) has - The main region, on both sides of which are layers of the positive electrode material (110), and - A free edge strip (109b) extends along the edge (109a) of the cathode current collector (109) and is not loaded with the positive electrode material (110). and / or The anode current collector (106) has - The main region, on both sides of which are layers of the negative electrode material (107), and - A free edge strip (106b) extends along the edge (106a) of the anode current collector (106) and is not loaded with the negative electrode material (107). e. The cathode (108) and the anode (105) are formed and / or arranged relative to each other within the assembly (104) such that the free edge strip (109b) of the cathode current collector (109) protrudes from one side (104b) of the assembly (104) and / or the free edge strip (106b) of the anode current collector (106) protrudes from the other side (104b) of the assembly (104), and f. The energy storage element includes a first contact metal sheet (112) that is in direct contact with one of the free edge strips (106b) and / or a second contact metal sheet (101a) that is in direct contact with the other of the free edge strips (109b). in g. The electrodes (105, 108) include at least one ion type selected from the group consisting of sodium ions, potassium ions, calcium ions, magnesium ions, and aluminum ions, which are exchanged between the cathode (108) and the anode (105) during the charging and discharging of the secondary energy storage element (100).

2. The energy storage element according to claim 1, having the following additional features: a. The electrodes (105, 108), the current collectors (106, 109), and the layer made of the electrode material (107, 110) are strip-shaped. b. The energy storage element includes at least one strip-shaped separator (116) or at least one strip-shaped solid electrolyte layer. c. The assembly (104) is in the form of a winding, wherein, The electrodes (105, 108) and the at least one separator (116) are wound around a winding shaft. The assembly (104) includes first and second terminal end faces (104a, 104b) and a winding housing (104c). The free edge strip (109b) of the cathode current collector (109) protrudes from the first end face (104b) and / or the free edge strip (106b) of the anode current collector (106) protrudes from the second end face (104a). d. The energy storage element includes a housing, particularly a metal housing, the housing comprising a housing shell or sidewalls and including a bottom (101a) and a cover (102) at the end face, and e. In the housing, the fitting (104) formed as a winding is aligned such that the winding housing (104c) rests against the inner side (101d) of the housing or the side wall.

3. The energy storage element according to claim 1, having the following additional features: a. The assembly (104) is in the form of a prismatic stack, wherein, The cathode (108) and the anode (105) are stacked together with other cathodes (108) and anodes (105). b. The electrodes (105, 108), the current collectors (106, 109), and the layer made of the electrode material are polygonal, particularly rectangular. c. The energy storage element comprises at least one strip-shaped or polygonal separator (116) or at least one strip-shaped or polygonal solid electrolyte, wherein the separator is particularly rectangular and the solid electrolyte is particularly rectangular. d. The stack is surrounded by a prismatic shell.

4. The energy storage element according to any one of the preceding claims, having at least one of the following additional features: a. The energy storage element (100) is a sodium ion monomer. b. The energy storage element comprises a sodium ion monomer. c. The energy storage element includes one of the following electrolytes: - NaClO4, dissolved in at least one organic solvent, particularly dissolved in PC or a mixture of carbonates selected from the group including EC / DEC / FEC and PC / FEC; - NaPF6 and / or NaTFSI, dissolved in at least one organic solvent, particularly dissolved in PC or a mixture of carbonates selected from the group including EC / DEC / FEC, EC / PC, EC / DEC, FEC / EMC, and PC / FEC, or a mixture of ethers such as THF / mTHF; - NaFSI and / or NaTFSI and / or NaNDI, dissolved in at least one organic solvent, particularly dissolved in 1,4-dioxane (DX) and / or 1,3-dioxolane (DOL) and / or dimethyl ether (DME); - NaFSI and / or NaTFSI and / or NaNDI, dissolved in at least one organic solvent, particularly in dimethyl carbonate (DX) and / or tri(2,2,2-trifluoroethyl) phosphate (TFP); - NaN(SO2F)2, dissolved in at least one organic solvent, particularly in 1,4-dioxane (DX) and / or 1,3-dioxolane (DOL) and / or dimethyl ether (DME); - NaBF4, dissolved in at least one organic solvent, particularly in tetraethylene glycol dimethyl ether (TEGDME) and / or ACN and / or PC and / or GBL.

5. The energy storage element according to any one of the preceding claims, having at least one of the following additional features: a. The anode comprises a matrix having depressions and / or pores, in which metallic sodium is stored. b. The matrix is ​​attached to the surface of the anode current collector. c. The matrix comprises carbon particles and a binder. d. The matrix includes a conductive agent and / or a filler. e. The substrate is the rough surface of the anode current collector.

6. The energy storage element according to any one of claims 1 to 4, having the following additional features: a. The anode includes a nucleation layer in which metallic sodium is stored and / or deposited on the nucleation layer. b. The nucleation layer is substantially composed of at least one material selected from the group consisting of: Tin, silver, gold, germanium, carbon, platinum, zinc, aluminum, magnesium, and silicon. c. The nucleation layer is deposited on the surface of the anode current collector by PVD (physical vapor deposition) or CVD (chemical vapor deposition).

7. The energy storage element according to claim 6, having at least one of the following additional features: a. The negative electrode comprises a layer sequence of a metal current collector / matrix or nucleation layer and a capping layer. b. The nucleation layer is therefore arranged between the capping layer and the current collector. c. The thickness of the capping layer is in the range of 300 nm to 30 µm. d. The covering layer is formed of or includes a ceramic material. e. The covering layer comprises aluminum oxide (Al2O3), aluminum hydroxide or aluminum hydroxyoxide (AlOOH), silicon oxide (SiOx, x in the range of >1 and ≤2), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), or titanium carbonitride (TiCN) or formed thereof.

8. The energy storage element according to any one of claims 2 or 4-7, having at least one of the following additional features: a. The energy storage element includes a gas-tight and liquid-tight housing, the housing having a metallic cup-shaped housing portion (101) and a cap (102) having a circular edge (102a), the cup-shaped housing portion having a bottom (101a) and a terminal circular opening, the cap closing the terminal circular opening. b. The fitting (104) is arranged axially aligned within the cup-shaped housing portion, with the first end face (104a) pointing toward the lid (102) and the second end face (104b) pointing toward the bottom (101a), optionally in direct contact with the bottom (101a). c. The energy storage element includes an annular seal (103) made of an electrically insulating material, the annular seal (103) surrounding the circular edge (102a) of the cover (102) and electrically insulating the cup-shaped outer shell portion (101) and the cover (102) from each other. d. The cup-shaped outer shell portion (101) includes an inner side (101d) and an outer side (101e), and axially continuously includes the bottom (101a), the central portion (101b), and the closing portion (101c), wherein - The central portion (101b) is cylindrical, and within the central portion (101b), the winding shell (104c) of the assembly (104), which is formed as a winding, contacts the inner side (101d) of the cup-shaped outer shell portion (101), and - In the closure portion (101c), the annular seal (103) is pressed against the inside of the cover (102) and the cup-shaped outer shell portion (101). e. The central portion (101b) and the closed portion (101c) are separated by a notch (111) that surrounds the outer side (101e) of the cup-shaped outer shell portion (101) circumferentially. f. The contact metal sheet (112) is electrically connected by welding to the free edge strip (106b) of the current collector protruding from the end face (104a) of the first terminal, and preferably also electrically connected by welding to the cover (102). g. The energy storage element includes at least one insulating element (150; 160; 170; 180) made of an electrically insulating material, the insulating element causing the free edge strips (106b, 109b) of the contact metal sheet (112) and / or the individual electrical conductor (133) fixed to the contact metal sheet (112) to not directly contact the inside (101d) of the cup-shaped housing portion (101), particularly in the region of the notch (111).

9. The energy storage element according to any one of claims 1 to 7, having at least one of the following additional features: a. The energy storage element includes a gas-tight and liquid-tight housing, the housing having a metal cup-shaped housing portion (101) and a cover (102), the cup-shaped housing portion having a bottom (101a) and a terminal opening, the cover (102) closing the terminal opening. b. The cover (102) includes a metal cover plate (102a) and a connecting post (102b), the connecting post (102b) being guided through a hole in the cover plate (102) and electrically insulated from the cover plate (102). c. The fitting (104) is arranged in the cup-shaped outer shell portion, with one side (104a) facing the lid (102) and the second side (104b) facing the bottom (101a), and optionally in direct contact with the bottom (101b). d. The cathode (108) and the anode (105) are formed and / or arranged within the assembly (104) such that the free edge strip (109b) of the cathode current collector (109) protrudes from one side (104b) of the assembly (104), and the free edge strip (106b) of the anode current collector (106) protrudes from one side (104a) of the assembly (104). e. The contact metal sheet (112) is placed directly on the free edge strip of one of the current collectors protruding from one side of the assembly and is connected thereto by welding. f. The contact metal sheet (112) is electrically connected to a connecting post (102b) passing through a hole in the cover plate (102a), preferably directly welded to the connecting post (102b), or the connecting post (102b) is part of the contact metal sheet (112). g. The connecting post (102b) is electrically insulated from the cover plate (102) by a hardened casting compound (113) made of electrically insulating plastic material.

10. The energy storage element according to claim 9, further comprising the following additional features: a. The edge strip of the cathode current collector (109) or the anode current collector (106) that does not directly contact the contact metal sheet (112) is electrically connected to the bottom of the housing (101a), preferably directly welded to the bottom of the housing (101b).

11. The energy storage element according to any one of claims 9 or 10, having at least one of the following additional features: a. An annular gap exists between the cover plate (102) and the contact metal sheet (112), and the casting compound (113) fills the annular gap. b. The annular gap is defined radially outward by an O-shaped annular insulating disk (177) made of electrically insulating plastic material.

12. The energy storage element according to any one of claims 9 to 11, having the following additional features: a. The bottom (101a) of the cup-shaped outer shell portion (101) has a primary safety device in the form of a hole (155) to prevent internal overpressure, the hole being sealed by a metal membrane (114). b. The bottom (101a) of the cup-shaped housing portion (101) has at least one secondary safety device in the form of a groove (166) on its inner or outer side to prevent internal overpressure.

13. A battery comprising at least two energy storage elements according to any one of the preceding claims, the energy storage elements being connected in parallel and / or in series.

14. The battery according to claim 13, characterized in that, Its nominal voltage is 12V or 24V.

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