Electrochemical energy storage element

Abstract

To provide an electrochemical energy storage element characterized in a high energy density.SOLUTION: An electrochemical energy storage element includes an electrode-separator assembly in which at least one anode 105 and at least one cathode as an electrode and at least one separator or at least one solid electrolyte are included in an order of the anode 105 / the separator, or a solid electrolyte / a cathode. An anode collector includes: a main area 106c where a layer of negative electrode material is mounted on both side surfaces; and an end portion area 106b which is extended along an end portion in a strip type, and in which the negative electrode material is not mounted. The electrode includes an end portion 106a in which the collector is projected from a side surface, and has a first average thickness D1 in the main area 106c of the collector, and includes the maximum thickness D2 in the end portion area 106b coated by a layer of a support material 133. In the electrochemical energy storage element, the equation D2≤D1 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Application fields and prior art The invention described below relates to an electrochemical energy storage element that includes an electrode-separator assembly. [Background technology]

[0002] Electrochemical energy storage elements are capable of converting stored chemical energy into electrical energy by means of oxidation-reduction reactions. The simplest form of electrochemical energy storage element is the electrochemical cell. It comprises a positive electrode and a negative electrode, between which a separator is placed. During discharge, electrons are released at the negative electrode as a result of an oxidation process. This results in an electronic current that can be extracted by an external electrical consumer, and thus the electrochemical cell acts as an energy supplier. At the same time, an ionic current corresponding to the electrode reactions is generated in the cell. This ionic current is made possible by an ion-conducting electrolyte.

[0003] If the discharge is reversible, i.e., the conversion of chemical energy to electrical energy during discharge can be reversed and the cell charged again, it is called a secondary cell. The common designation of the negative electrode as the anode and the positive electrode as the cathode in secondary cells refers to the discharge function of the electrochemical cell.

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

[0005] In principle, any material capable of absorbing and releasing lithium ions can be used as the electrochemically active component (active material) of a secondary lithium-ion cell. For example, carbon-based particles such as graphitic carbon are used in the negative electrode. The active material of the positive electrode can be, for example, lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4), or derivatives thereof. The electrochemically active material is generally contained in the electrode in particulate form.

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

[0007] In addition, the electrode may contain an electrode binder (e.g., polyvinylidene fluoride (PVDF) or another polymer, e.g., carboxymethyl cellulose), additives to improve conductivity, and other additives as electrochemically inactive components. The electrode binder ensures the mechanical stability of the electrode and often also the adhesion of the active material to the current collector.

[0008] As an electrolyte, lithium-ion cells usually contain a solution of a lithium salt, such as lithium hexafluorophosphate (LiPF6), in an organic solvent, such as ethers and esters of carbonic acid.

[0009] During the manufacture of lithium-ion cells, the composite electrode is typically combined with one or more separators to form an electrode-separator assembly.

[0010] In many embodiments, the electrode-separator assembly is formed in the form of a winding or processed into a winding. In the first case, for example, the ribbon-type positive electrode and the ribbon-type negative electrode, and at least one ribbon-type separator are separately fed into a winding device and spirally wound into a winding in the order of positive electrode / separator / negative electrode. In the second case, the ribbon-type positive electrode and the ribbon-type negative electrode, and at least one ribbon-type separator are first combined, for example by applying the aforementioned pressure, to form an electrode-separator assembly. In a further step, this assembly is then wound.

[0011] For applications in the automotive sector, e-bikes or other applications with high energy requirements, such as power tools, lithium-ion cells with the highest possible energy density are required that can also withstand high currents during charging and discharging.

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

[0013] In the patent application EP 1 239 633 A1, a cylindrical round cell is described in which the electrode-separator assembly and its electrodes are in the form of a ribbon-type winding. Each electrode has a current collector on which the electrode material is mounted. The electrodes of opposite polarity are arranged offset from each other in the electrode-separator assembly, so that the longitudinal end of the positive current collector protrudes from the winding on one side and the longitudinal end of the negative current collector protrudes from the winding on the other side. For electrical contact of the current collectors, the cell has a contact sheet metal member, which is on one end face of the winding and is connected by welding to one longitudinal end of the current collector. This allows electrical contact with the current collector and therefore also with the associated electrode over its entire length. This significantly reduces the internal resistance in the cell. As a result, the generation of high currents can be much better mitigated and also allows heat to be dissipated well from the winding.

[0014] However, a problem associated with the cell described in the '639 patent is that it is difficult to weld the longitudinal ends and the contact sheet metal members together. Relative to the contact sheet metal members, the current collectors of the electrodes are very thin. The end regions of the current collectors are therefore mechanically weak and may be subject to unintended deformation or melting during the welding process. Furthermore, the separator of the electrode-separator assembly may melt when the contact sheet metal member is welded onto it. In extreme cases, this may result in a short circuit.

[0015] It is known from US Pat. No. 5,399,633 to coat the edges of the surface of a current collector with a support material that is more thermally stable than the surface coated with the support material. Such a support material is able to stabilize the edge regions of the current collector and insulates it in particularly critical areas.

[0016] It is also known from US Pat. No. 5,399,633 to coat the end regions of the current collector with a ceramic material. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] International Publication No. 2017 / 215900 A1 Brochure [Patent Document 2] International Publication No. 2020 / 239512 A1 Brochure [Patent Document 3] US Patent Application Publication No. 2020 / 0144676 A1 Summary of the Invention [Problem to be solved by the invention]

[0018] Objectives and Solutions It was the object of the present invention to provide an energy storage element which is characterized by a high energy density. In particular, the present invention was based on the task of further improving the solution described in WO 2005 / 023366. [Means for solving the problem]

[0019] This object is achieved by an electrochemical energy storage element having the features of claim 1. A method having the features of claim 10 is also part of the invention. Preferred embodiments of the invention can be found in the dependent claims 2 to 9 and 11.

[0020] The electrochemical energy storage element features an electrode-separator assembly within a housing, the assembly being characterized by: a. The assembly comprises at least one anode and at least one cathode as electrodes, and at least one separator or at least one solid electrolyte, in the order anode / separator or solid electrolyte / cathode. b. The anode comprises an anode current collector, which is preferably a thin, electrically conductive substrate having a top side, a bottom side, and an edge. c. The cathode includes a cathode current collector, which is preferably a thin, electrically conductive substrate having a top side, a bottom side, and an edge. d. the anode current collector includes a main area on both sides of which a layer of negative electrode material is carried, and end areas extending in strip form along the ends and not carrying negative electrode material; and / or The cathode current collector includes a main area carrying layers of positive electrode material on both sides thereof and end areas extending in strip form along the ends and not carrying any positive electrode material. e. The assembly has one side from which the anode current collector end or the cathode current collector end protrudes. f. The end region extending along the laterally projecting edge is partially or completely coated with an electrically non-conductive layer of support material. g. The electrode, whose current collector includes a laterally protruding end portion, has a first average thickness D1 in the main area of ​​the current collector and a maximum thickness D2 in the end area where the layer of support material is coated. h. D2≦D1.

[0021] Feature h. in combination with feature g. ensures that there are no problems in the electrode-separator assembly in the area of ​​the end regions where the support material is coated. If an electrode becomes thicker in the area of ​​the end regions where the support material is coated than in the main area where the electrode material is mounted, the thickness increase can accumulate, for example in the case of spirally wound electrodes, which can lead to mechanical stresses.

[0022] The aforementioned average thickness D1 can be determined by thickness measurements. For this purpose, thickness measurements are performed at several measurement points along a cross section perpendicular to the strip-shaped main area passing through the main area coated with the electrode material. D1 is determined by adding up the measurement results and dividing by the number of measurements. Preferably, at least six measurements are performed at six measurement points. It is further preferred that the two end measurement points are 2 mm away from the two ends of the cut, respectively, and that the remaining measurement points divide the distance between the two end measurement points equally.

[0023] The "cross section" is preferably not a mechanical cut. Rather, the average thickness is determined using a cross-sectional image, which can be obtained by CT (Computer Tomography) analysis. This means that a homogenous electrode can be tested that is part of an electrode-separator assembly placed in a closed metal housing.

[0024] With regard to the coating with the support material, there are four particularly preferred variants of the invention.

[0025] Variant 1 is characterized by at least one of the following features a. to c: a. An end region extending along the laterally protruding edge is partially coated with a layer of support material. b. The end region extending along the edge protruding from the side is further divided into a first strip-shaped subregion that does not contain support material, a second strip-shaped subregion that has support material coated on both sides, and a third strip-shaped subregion that also does not contain support material. c. the third strip-type subregion is a terminal strip-type subregion, the first strip-type subregion is immediately adjacent to the main region of the current collector, and the second subregion separates the first strip-type subregion from the second strip-type subregion. Preferably, the immediately above features a. to c. are implemented in combination.

[0026] Variant 2 is characterized by at least one of the following features a. to c: a. An end region extending along the laterally protruding edge is partially coated with a layer of support material. b. The end region extending along the edge protruding from the side is divided into a first strip-shaped subregion having support material coated on both sides and a second strip-shaped subregion that does not include support material. c. The second strip-shaped subregion is an end strip-shaped subregion, and the first strip-shaped subregion is immediately adjacent to the main region of the current collector and separates the main region from the second strip-shaped subregion. Preferably, the immediately above features a. to c. are implemented in combination.

[0027] Variant 3 is characterized by at least one of the following features a. to c.: a. An end region extending along the laterally protruding edge is completely coated with a layer of support material. b. An end region extending along the laterally protruding edge is coated on both sides with a layer of support material. Preferably, features a. and b. immediately above are realised in combination.

[0028] Variant 4 is characterized by at least one of the following features a. to d: a. An end region extending along the laterally protruding edge is partially coated with a layer of support material. b. The end region extending along the edge protruding from the side is divided into a first strip-shaped subregion having support material coated on both sides and a second strip-shaped subregion that does not include support material. c. The second strip-shaped subregion is an end strip-shaped subregion, and the first strip-shaped subregion is immediately adjacent to the main region of the current collector and separates the main region from the second strip-shaped subregion. d. The major area is partially or completely coated with an electrically non-conductive layer of a support material. Preferably, features a. and b. immediately above are realised in combination.

[0029] The electrode-separator assembly can have a cylindrical or substantially cylindrical shape, or a prismatic or substantially prismatic shape.

[0030] If it has a cylindrical or essentially cylindrical shape, it is preferably characterized by at least one of the features a. to g. immediately below: a. The electrode-separator assembly is a wound body, including an anode and a cathode, and at least one separator or at least one layer of solid electrolyte, each in a ribbon-type form, wound in a spiral shape. b. The wound electrode-separator assembly has first and second end faces and a winding shell therebetween. c. The anode current collector is ribbon-shaped with its main and end sections parallel to each other, whereby the main section is strip-shaped as are the end sections. d. The cathode current collector is ribbon-shaped with its main and end sections parallel to each other, whereby the main and end sections are strip-shaped. e. An end of the anode current collector protrudes from one end face and an end of the cathode current collector protrudes from the other end face. f. A contact sheet metal member is secured to the first and / or second end surface. g. A contacting sheet metal member or members are welded to an end or ends protruding from each end face. Preferably, the immediately above features a. and e. are realised in combination. Particularly preferably, the electrode-separator assembly is characterised by features a. to f. or features a. to g.

[0031] Thus, when the electrode-separator assembly is cylindrical, the side from which the end of the anode current collector or the end of the cathode current collector protrudes is the first or second end face. The end of the anode current collector according to feature e. immediately above is the longitudinal end of the anode current collector. The end of the cathode current collector according to feature e. immediately above is the longitudinal end of the cathode current collector.

[0032] In a typical case, the spirally wound electrode ribbon and at least one separator ribbon preferably have the following dimensions: - Lengths ranging from 0.5m to 25m - Width in the range of 40mm~145mm

[0033] To produce a wound electrode-separator assembly consisting of an electrode ribbon and at least one ribbon-type separator, the ribbon-type electrodes and at least one separator are typically fed to a winding device, where they are preferably spirally wound around a winding axis. Bonding or contacting at high temperature of the electrodes and separators is usually not required. In some embodiments, the electrodes and at least one separator are wound onto a cylindrical or hollow cylindrical winding core, which is placed on a winding mandrel and remains in the winding body after winding.

[0034] The winding shell can be formed, for example, by a plastic film or an adhesive tape. The winding shell can also be formed by one or more separator windings.

[0035] When the electrode-separator assembly has an essentially prismatic shape, it is preferably characterized by at least one of the features a. to f. immediately below: a. The electrode-separator assembly comprises a plurality of anodes and a plurality of cathodes in a stack form, in which adjacent electrodes of opposite polarity in the stack are separated by at least one separator or at least one layer of solid electrolyte. b. Each of the anode current collectors of the anode includes a main area carrying a layer of negative electrode material on both sides thereof, and end areas extending into strips along the ends and not carrying negative electrode material. c. Each of the cathode current collectors of the cathode includes a main area carrying a layer of positive electrode material on both sides thereof and end areas extending into strips along the ends and not carrying positive electrode material. d. The stack is prismatic and has a first side from which an end of an anode current collector protrudes and a second side from which an end of a cathode current collector protrudes. e. A contact sheet metal member is secured to the first and / or second sides. f. A contacting sheet metal member or members are welded to the ends protruding from each side.

[0036] Preferably, the immediately above features a. and d. are realised in combination. Particularly preferably, the electrode-separator assembly is characterised by features a. to e. or features a. to f.

[0037] In an essentially prismatic electrode-separator assembly, the current collector ends of the positive and negative electrodes can also protrude from two or more sides of the electrode-separator assembly. For example, each positive electrode having a rectangular basic shape can have two strip-shaped end sections without electrode material, which extend along one end of the respective current collector and protrude from two adjacent sides of the electrode-separator assembly. In this case, the contact sheet metal members can be, for example, L-shaped and arranged on both sides from which the respective ends protrude. Or two contact sheet metal members can be used.

[0038] If prismatic, the electrode-separator assembly preferably includes a plurality of electrodes having a rectangular basic shape.

[0039] Additionally, the electrode-separator assembly can be formed as a flat coil with a helically wound ribbon-type electrode, or can have an essentially prismatic shape.

[0040] The electrodes are preferably composite structures comprising electrochemically active and electrochemically inactive components, the basic structure of which has already been explained in the introduction section.

[0041] The current collector serves to electrically contact the electrochemically active components contained in the respective electrode materials over as large an area as possible. Preferably, the current collector is made of a metal or is at least metallized on its surface.

[0042] In the case of the electrode material of lithium-ion cells, suitable metals for the anode current collector include copper or nickel or another electrically conductive material, in particular an alloy of copper and nickel or a metal coated with nickel. In particular, materials of the type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used as the copper alloy. Alloys of the type NiFe, NiCu, CuNi, NiCr, and NiCrFe are particularly suitable as the nickel alloy. Alloys of the type NiFe, NiCu, CuNi, NiCr, and NiCrFe are particularly suitable as the nickel alloy. Stainless steels, for example of the type 1.4303 or 1.4404 or SUS304, can also be considered.

[0043] For lithium-ion cells, aluminum or another electrically conductive material, such as an aluminum alloy, is particularly suitable as the cathode current collector metal.

[0044] Suitable aluminum alloys for the cathode current collector are, for example, Al alloys of the 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series) and GM55 type. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg and AlMg. The aluminum content of these alloys is preferably greater than 99.5%.

[0045] Preferably, the anode current collector and / or the cathode current collector are each a metal foil having a thickness in the range of 4 μm to 30 μm.

[0046] However, in addition to films, other substrates such as metallic or metallized nonwoven fabrics, or open pore metal foams, or expanded metals, can also be used as current collectors, preferably also having a thickness in the range of 4 μm to 30 μm.

[0047] The separator is preferably formed from an electrically insulating plastic film. It preferably has pores that allow the liquid electrolyte to pass through. The plastic film may consist of, for example, polyolefin or polyetherketone. However, nonwoven fabrics or cloths made of plastic materials or other electrically insulating cloths can also be used as separators. Separators with a thickness in the range of 5 to 50 μm are preferred. The separator is impregnated with a suitable electrolyte, like the electrodes.

[0048] A layer of the aforementioned solid electrolyte can also be used instead of the separator, especially in the case of prismatic electrode-separator assemblies. The solid electrolyte has inherent ionic conductivity and does not need to be impregnated with a liquid electrolyte. The solid electrolyte can be, for example, a polymer solid electrolyte based on a polymer-conductive salt complex that exists in a single phase without any liquid component. The polymer solid electrolyte can have polyacrylic acid (PAA), polyethylene glycol (PEG), or polymethylmethacrylate (PMMA) as the polymer matrix. Lithium conductive salts such as lithium bis-(trifluoromethane)sulfonylimide (LiTFSI), lithium hexafluorophosphate (LiPF6), and lithium tetrafluoroborate (LiBF4) can be present therein.

[0049] The side of the electrode-separator assembly from which one or more ends protrude with the strip-shaped end area is preferably formed by the end of the separator or solid electrolyte layer. For example, when a ribbon-shaped separator is placed between ribbon-shaped electrodes of opposite polarity in a wound cylindrical electrode-separator assembly, the longitudinal end of this separator forms the end face of the cylindrical electrode-separator assembly. In general, the distance between adjacent windings of the windings is very small. Ideally, the longitudinal end extends to the flat surface from which the longitudinal end of one current collector protrudes.

[0050] With respect to electrochemistry, the electrode-separator assembly is not limited to a particular cell type. In a particularly preferred embodiment, it includes a lithium-ion based electrode. In another embodiment, it includes an electrode based on sodium-ion, potassium-ion, calcium-ion, magnesium-ion, or aluminum-ion technology. Of these alternatives, electrodes using sodium-ion cell chemistry are particularly preferred.

[0051] As is known, cells using lithium-ion technology are based on the use of lithium, which in the form of ions, can be shuttled between the electrodes of an energy storage element.

[0052] In principle, any material capable of absorbing and releasing lithium ions can be used as the electrochemically active component (active material) of a lithium-ion cell. For example, carbon-based particles such as graphitic carbon can be used in the negative electrode of the electrode-separator assembly. Suitable active materials for the positive electrode include lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4), or derivatives thereof. The electrochemically active material is generally included in the electrode in particulate form.

[0053] The active material is generally the main component of the layer applied to the current collector. The current collector is an electrochemically inactive component of the energy storage element. Metal foils are particularly suitable as current collectors. The negative current collector (anode current collector) of a lithium-ion cell may be made of, for example, copper or nickel, and the positive current collector (cathode current collector) may be made of, for example, aluminum. In addition, the electrode may contain an electrode binder (for example polyvinylidene fluoride (PVDF) or another polymer, for example carboxymethyl cellulose), an additive that improves the conductivity, and another additive as an electrochemically inactive component. The electrode binder ensures the mechanical stability of the layer on the current collector and in many cases also the adhesion of the layer to the current collector. Common conductivity-improving additives are carbon black, fine graphite, carbon fibers, carbon nanotubes, and metal powders.

[0054] As electrolytes for lithium-ion cells, solutions of lithium salts such as lithium hexafluorophosphate (LiPF6) in organic solvents (eg ethers and esters of carbonic acid) are particularly suitable.

[0055] Cells using sodium-ion technology are known to be based on the use of sodium, which in ionic form can be shuttled between the electrodes of an energy storage element.

[0056] For the electrodes of the electrode-separator assembly based on sodium ion technology, for example the following materials can be used on the anode side: - carbon, in particular hard carbon (pure or doped with nitrogen and / or phosphorus) or soft carbon or graphene-based materials (e.g. doped with nitrogen); carbon nanotubes, graphite - Polyanions, e.g. Na2Ti3O7, Na3Ti2(PO4)3, TiP2O7, TiNb2O7, Na-Ti-(PO4)3, Na-V-(PO4)3 - Transition metal oxides: V2O5, MnO2, TiO2, Nb2O5, Fe2O3, Na2Ti3O7, NaCrTiO4, Na4Ti5O 12

[0057] On the cathode side, for example, the following materials can be considered: - Polyanions: NaFePO4(Triphylit-Typ), Na2Fe(P2O7), Na4Fe3(PO4)2(P2O7), Na2FePO4F, Na / Na2[Fe 1 / 2 Mn 1 / 2 ]PO4F, Na3V2(PO4)2F3, Na3V2(PO4)3, Na4(CoMnNi)3(PO4)2P2O7, NaCoPO4, Na2CoPO4F - Silicates: Na2MnSiO4, Na2FeSiO4 - Layered oxides: NaCoO2, NaFeO2, NaNiO2, NaCrO2, NaVO2, NaTiO2, Na(FeCo)O2, Na(NiFeCo)3O2, Na(NiFeMn)O2, Na(NiFeCoMn)O2, Na(NiMnCo)O2

[0058] Additionally, the electrodes of the sodium ion based electrode-separator assembly preferably include an electrode binder and / or additives that improve conductivity and / or other additives.

[0059] In a sodium-ion energy storage cell, both the anode and cathode current collectors are preferably made of aluminum or an aluminum alloy.

[0060] Energy storage elements based on sodium ion technology preferably have an electrolyte having at least one solvent and at least one conductive salt.

[0061] Particularly suitable as solvents are organic carbonates, ethers, nitriles, and mixtures thereof.

[0062] Preferred conductive salts are NaPF6, sodium difluoro(oxalato)borate (NaBOB), NaBF4, sodium bis(fluorosulfonyl)imide (NaFSI), 2 trifluoromethyl-4,5-dicycloimidazole sodium (NaTDI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), NaAsF6, NaBF4, NaClO4, NaB(C2O4)2, NaP(C6H4O2)3; NaCF3SO3, sodium triflate (NaTf), and Et4NBF4.

[0063] The contacting sheet metal members of the electrode-separator assembly are preferably characterized by the following further features: a. The contact sheet metal member preferably has a uniform thickness in the range of 50 μm to 600 μm, especially in the range of 100 μm to 500 μm, preferably 200 μm or 300 μm.

[0064] A thickness of the contact sheet metal member of approximately 200 μm is particularly suitable for making contact with an anode or negative electrode, and a thickness of the contact sheet metal member of approximately 300 μm is particularly suitable for making contact with a cathode or positive electrode.

[0065] In particularly preferred embodiments, the contact sheet metal member is characterized by the following further features: a. The contact sheet metal member has at least one bead formed as an elongated depression on one flat side of the contact sheet metal member and as an elongated raised portion on the other flat side, the contact sheet metal member facing the electrode-separator assembly having the flat side with the elongated raised portion.

[0066] Furthermore, in preferred embodiments, the electrode-separator assembly may be characterized by at least one of the following additional features: a. The contact sheet metal member is welded to the electrode-separator assembly in the area of ​​at least one bead. b. The weld is straight. c. The weld seam is formed by two or more parallel weld lines per bead.

[0067] Preferably, the above features a. and b., and particularly preferably, the above features a. to c. are realized in combination with one another.

[0068] The stability of the weld, and generally of the welded contact with the electrode, can be further improved by welding a contact sheet metal member in the area of ​​at least one bead to a stack end, or to several such ends, protruding from one side of the electrode-separator assembly.

[0069] Preferably the contact sheet metal members have two, or three or more beads.

[0070] The central area of ​​the contact sheet metal member may have an opening, for example in the form of a circular hole, which opening in the contact sheet metal member may be used when impregnating the electrode-separator assembly with electrolyte liquid.

[0071] In some embodiments, it has been found to be advantageous to pretreat the edge of the current collector that protrudes from one side of the electrode-separator assembly before placing the contact sheet metal member on top. In particular, at least one recess can be folded over into one or more edges, the position of which corresponds to the position of at least one bead or an elongated raised portion on the flat side of the contact sheet metal member that faces the electrode-separator assembly.

[0072] An end of the current collector or ends of the current collector may also be subjected to directionally shaping, such as bending in a defined direction, as part of the pre-treatment.

[0073] The contact sheet metal member can be electrically connected to the anode current collector of the electrode-separator assembly or the cathode current collector of the electrode-separator assembly. As explained in U.S. Patent No. 5,999,933, the use of contact sheet metal members provides the advantage that the electrodes contact the contact sheet metal members along their respective edges. This generally allows the energy storage element to have a lower internal resistance, which allows it to mitigate the generation of high currents much better than conventional energy storage elements.

[0074] A contact sheet metal member providing electrical connection to the anode current collector of an electrode-separator assembly, particularly an electrode-separator assembly suitable for lithium-ion cells, can be characterized by at least one of the following features: a. The contact sheet metal members are made of nickel or copper or titanium, or an alloy of nickel or copper or titanium, or stainless steel, for example of the 1.4303 or 1.4404 type or of the SUS304 type, or nickel-plated copper. b. The contact sheet metal member and the anode current collector are made of the same material.

[0075] The contact sheet metal member by which electrical contact is made with the cathode current collector of an electrode-separator assembly, in particular an electrode-separator assembly suitable for lithium-ion cells, can preferably be characterized by at least one of the following features: a. The contact sheet metal members are made of aluminum or an aluminum alloy. b. The contact sheet metal member and the cathode current collector are made of the same material.

[0076] Suitable aluminum alloys for the contact sheet metal members include Al alloys of the following types: 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg. The aluminum content of these alloys is preferably greater than 99.5%.

[0077] Additionally, the contact sheet metal member may be characterized by at least one of features a.-c immediately below: a. The contact sheet metal members have two opposed flat sides and extend essentially in only one dimension. b. The contact sheet metal member is a disk or a polygonal plate. c. The contact sheet metal member is sized to cover at least 40%, preferably at least 50%, preferably at least 60%, preferably at least 70%, and particularly preferably at least 80% of the side or end surface of the electrode-separator assembly to which it is secured.

[0078] Preferably, the immediately above described features a. and b. or a. and c. or b. and c. or, particularly preferably, the immediately above described features a. to c. are realized in combination with one another.

[0079] It is advantageous for the thermal management of the electrode-separator assembly to cover as much of the side or end surface of the electrode-separator assembly as possible with the contact sheet metal member. This makes it easier to contact the longest possible portion of each electrode. Thus, heat generated in the electrode-separator assembly can be dissipated particularly well through the contact sheet metal member to the housing.

[0080] The support material of the electrode-separator assembly according to the present invention is preferably characterized by at least one of the features a. to c. immediately below: The support material is a ceramic material. b. The support material comprises ceramic particles and a binder. c. The ceramic material or particles is boehmite (AlO(OH) or γ-AlOOH).

[0081] Ceramic materials having a melting point higher than that of the respective material of the current collector supported by the ceramic material are preferred. Carbides, nitrides, oxides, silicides, or mixtures and derivatives of these compounds are suitable, especially in particulate form. In a preferred embodiment, the ceramic material is aluminum oxide (Al2O3), titanium oxide (TiO2), titanium nitride (TiN), titanium aluminum nitride (TiAlN), or titanium carbonitride (TiCN).

[0082] As an alternative to a ceramic material, the support material may be a glass-ceramic material or a glass. The term "glass-ceramic material" means in particular a material that contains crystalline particles embedded in an amorphous glass phase. The term "glass" basically means any inorganic glass that meets the thermal stability criteria defined above and is chemically stable towards any electrolyte that may be present.

[0083] According to the invention, the support material is particularly preferably formed according to characteristic c. immediately above.

[0084] The binder according to characteristic b. immediately above is preferably at least one binder from the group of compounds: polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyamide (PA), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), hydrogenated acrylonitrile butadiene rubber (HNBR), polyacrylic acid (PAA), polymethacrylate (PMA), polyacrylate (PA), polyvinyl acetate (PVA), polyacrylonitrile (PAN), polyethylene (PE), polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), polystyrene (PS), polyurethane (PU).

[0085] For example, fluorinated derivatives of the compounds described are also suitable.

[0086] The energy storage element according to the invention is particularly preferably characterized by the following features a. and b.: The energy storage element includes an air-tight and liquid-tight housing in which the electrode-separator assembly is disposed. b. The electrode-separator assembly is electrically connected via contact sheet metal members to an electrode that is part of or passes through the housing.

[0087] The housing in which the electrode-separator assembly is placed is preferably a housing that is air-tight and liquid-tight sealed.

[0088] The energy storage element can have a prismatic or cylindrical housing. In the case of a prismatic housing, the electrode-separator assembly preferably has a prismatic or essentially prismatic shape as described. In the case of a cylindrical housing, the electrode-separator assembly preferably has a cylindrical or substantially cylindrical shape as described.

[0089] The housing is preferably formed from a cup-shaped metallic housing part and a lid part which is at least partially made of metal. The cup-shaped housing part can be formed, for example, by a deep drawing process. However, it can also be produced, for example, by welding the bottom to a tubular housing part. The two housing parts can be assembled together by a seal which is electrically insulating and electrically insulates the two housing parts from each other. The two housing parts can also be joined together by welding. In this case, the insulated metallic electrode is generally brought out of the housing through an opening in the housing.

[0090] The electrical and thermal contact of the electrode with the housing or with at least one housing part is effected via a contact sheet metal part, which itself can be electrically connected to the housing part or to the metal electrode, for example, via a current conductor or by direct welding.

[0091] The housing part can consist of aluminum, aluminum alloys, or steel sheet, for example nickel-plated steel sheet. Suitable aluminum alloys for the cup-shaped metal housing part are, for example, Al-alloys of the type 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg. The aluminum content of these alloys is preferably more than 99.5%.

[0092] The present invention further includes a method for producing an electrochemical energy storage element having the electrode-separator assembly described above, the method comprising the steps of: a. applying a layer of electrode material within a major area of ​​a current collector having a top side, a bottom side, and an end and; b. applying a layer of support material in an end area of ​​the current collector extending in a strip along said edge and not carrying electrode material; c. Optionally, calendering the current collector coated with the layer of electrode material and the layer of support material; The method comprises the steps of: d. The layers of electrode material and support material are selected and applied so that the electrode produced has a first average thickness D1 in the main region and a maximum thickness D2 in the edge regions, where D2≦D1.

[0093] The final thicknesses D1 and D2 and their ratio to each other are determined by the amount of support material and electrode material applied per unit area and the compression of the layers during the calendering of the optional step c. This is generally done using rollers that generate pressure on the layers and compress them. The optimal settings of these parameters can be easily determined in practice by experimental tests.

[0094] In this manner, both the anode and cathode can be manufactured and processed in a subsequent step with the separator to form the electrode-separator assembly according to the present invention already described above.

[0095] Particularly preferably, the method is characterized by at least one of the features a. to g. immediately below: A layer of support material is applied using a suspension comprising the support material in particulate form and a suspending agent. b. The suspending agent comprises at least one material from the group consisting of water, N-methyl-pyrrolidone (NMP) and ethanol. c. The suspension includes a binder. d. The suspension includes a particulate support material having a d50 value in the range of 0.2 μm to 0.5 μm. e. The suspension does not contain any particles having a size >2 μm. f. The suspension contains additives which affect its processing properties. g. The suspension contains the following components in the following proportions: - Suspending agent 40-90% by weight - Particulate support material 10~60% by weight - Binder 1~20% by weight - Additives 0-5% by weight The components of feature g. total 100% by weight.

[0096] After the suspension is applied to the current collector, the suspending agent contained therein must be removed, for example by the application of heat and / or reduced pressure, which is typically followed by the calendaring process described above.

[0097] Further features and advantages of the invention will become apparent from the following description of preferred embodiments in conjunction with the drawings. In this context, it should be noted that the features of the preferred embodiments shown in the examples do not necessarily have to be related to each other and can also be realized independently of each other. [Brief description of the drawings]

[0098] The figures are shown diagrammatically. [Figure 1A] FIG. 2 is a cross-sectional view of the current collector of the anode of an electrode-separator assembly according to the invention having a preferred embodiment of coating with a support material (variant 1). [Figure 1B] FIG. 2 is a cross-sectional view of the current collector of the anode of an electrode-separator assembly according to the invention having a preferred embodiment of coating with a support material (variant 2). [Figure 1C] FIG. 2 is a cross-sectional view of the current collector of the anode of an electrode-separator assembly according to the invention having a preferred embodiment of coating with a support material (variant 3). [Figure 1D] FIG. 2 is a cross-sectional view of the current collector of the anode of an electrode-separator assembly according to the invention having a preferred embodiment of coating with a support material (variant 4). [Diagram 2] FIG. 2 is a detailed view (cross-section) of an end of an electrode of an electrode-separator assembly according to the present invention; [Diagram 3] 1 is a longitudinal section through an energy storage element according to the present invention having an electrode-separator assembly with contacting sheet metal members according to the present invention. [Figure 4] 1 is an embodiment of an electrode-separator assembly and its components according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0099] Detailed Description of the Preferred Embodiments 1A includes an end region 106b coated on both sides with a layer of support material 133 and a main region 106c coated on both sides with a layer of electrode material 107. The end region 106b is further divided into a first strip-shaped subregion 106ba that does not include support material 133, a second strip-shaped subregion 106bb that has support material 133 coated on both sides, and a third strip-shaped subregion 106bc that also does not include support material 133. The third strip-shaped subregion 106bc is an end strip-shaped subregion, with the first strip-shaped subregion 106ba immediately adjacent to the strip-shaped main region 106c of the current collector and the second subregion 106bb separating the first strip-shaped subregion 106ba from the second strip-shaped subregion 106bb.

[0100] In fact, in many embodiments, the depicted main region 106c, the depicted end region 106b, and the depicted subregions 106ba, 106bb, and 106bc do not have sharp boundaries with one another as shown in the drawings, with one possible path of the boundaries of each region being shown by dashed lines.

[0101] The current collector 106 of the anode 105 shown in FIG. 1B includes an end region 106b coated with a layer of support material 133 on both sides and a main region 106c coated with a layer of electrode material 107 on both sides. The end region 106b is coated with a layer of support material 133 only in some areas. It is further divided into a first strip-shaped subregion 106bd coated with support material 133 on both sides and a second strip-shaped subregion 106be that does not contain support material. The second strip-shaped subregion 106be is an end strip-shaped subregion, the first strip-shaped subregion 106bd being directly adjacent to the main region 106c of the current collector and separating the main region 106c from the second strip-shaped subregion 106be.

[0102] In fact, in many embodiments, the depicted main region 106c, the depicted end region 106b, and the depicted subregions 106bd and 106be do not have sharp boundaries with one another as shown in the drawings. One possible path of the boundaries of each region is shown by a dashed line.

[0103] 1C includes an end region 106b that is coated on both sides with a layer of support material 133, and a main region 106c that is coated on both sides with a layer of electrode material 107. The end region 106b is completely coated on both sides with a layer of support material 133.

[0104] In reality, in many embodiments, the depicted main region 106c and the depicted end region 106b will not have a sharp boundary with one another as shown in the drawings. Instead, there may be some overlap. One possible path of the boundary between the regions is shown by the dashed line.

[0105] The current collector 106 of the anode 105 shown in FIG. 1D includes an end portion 106b coated on both sides with a layer of support material 133 and a main portion 106c coated on both sides with a layer of electrode material 107. The end portion 106b is partially coated with a layer of support material 133. It is further divided into a first strip-shaped subregion 106bf coated on both sides with support material 133 and a second strip-shaped subregion 106bg that does not include support material 133. The second strip-shaped subregion 106bg is an end strip-shaped subregion, the first strip-shaped subregion 106bf being directly adjacent to the main region 106c of the current collector and separating the main region 106c from the second strip-shaped subregion 106bg. Furthermore, the main region 106c is also completely coated with an electrically non-conductive layer of support material 133.

[0106] In fact, in many embodiments, the depicted main region 106c, the depicted end region 106b, and the depicted subregions 106bf and 106bg do not have sharp boundaries with one another as shown in the drawings, with one possible path of the boundaries of each region being shown by a dashed line.

[0107] FIG. 2 shows the electrode ends of an electrode-separator assembly according to the invention. The cathode 108 is placed between two anodes 105, which are connected to the anodes by separators 116 or by a separator 116. Each of the anodes 105 includes an anode current collector 106 coated with an electrode material 107 on both sides. The anode current collector 106 is a copper foil. The cathode 108 includes a cathode current collector 109, which is a thin aluminum foil. The end 116a of the separators or the separator is in a plane in which the end 109a of the current collector 109 protrudes. In this case, this plane is defined as the end face 104b. The protruding part of the end face of the current collector 109 has a length L3 in this case.

[0108] The cathode current collector 109 comprises a main region 109c on both sides of which is deposited a layer of positive electrode material 110, and an end region 109b extending in strip form along the end 109a and not carrying electrode material 110. The end region 109b is further divided into three strip-shaped directly adjacent subregions 109ba, 109bb, and 109bc, where subregion 109ba does not contain support material 133, subregion 109bb is coated on both sides with support material 133, and subregion 109bc also does not contain support material 133.

[0109] It should be emphasized that the separators 116 or one separator 116 has a protruding portion of length L2 relative to the negative electrode 105 to prevent direct contact with the cathode 106 in the end regions of the electrode 105.

[0110] It should also be emphasized that the negative electrodes have protrusions L1 relative to the main areas 109c, so that they completely overlap in the direction perpendicular to the current collector 109 with the subareas 109ba, which in this case have a preferred length L4.

[0111] It should also be emphasized that the sub-area 109bb, in this case having the preferred length L5, completely overlaps the separators 116 or the separator 116 in the direction perpendicular to the current collector 109. Only a portion of the sub-area 109bb overlaps the electrode 105 in the direction perpendicular to the current collector 109.

[0112] Representative preferred values ​​of lengths L1 to L5 are as follows: L1=0.5mm~1.5mm L2=0.25mm~1.25mm L3=0.75mm~1.75mm L4=0.1mm~0.9mm L5=0.5mm~1.5mm

[0113] FIG. 3 shows an example of an energy storage element 100 according to the invention having an electrode-separator assembly 104. The energy storage element 100 comprises a housing closed in an air-tight and liquid-tight manner and in which the electrode-separator assembly 104 is arranged. The housing comprises a cup-shaped metallic housing part 101 and a housing lid 102, between which an electrically insulating seal 103 is arranged. The electrode-separator assembly 104 is a winding and comprises anode 105 and cathode 108, which are each ribbon-shaped and spirally wound, and a separator 116. The electrode-separator assembly 104 is electrically connected to the housing by metallic contact sheet metal members 117 and 118. The anode 105 is connected to the bottom of the cup-shaped housing part 101 by the contact sheet metal member 117, which therefore serves as the negative electrode of the energy storage element 100. The cathode 108 is connected to the lid 102 by a contact sheet metal member 118 , which therefore functions as the positive terminal of the energy storage element 100 .

[0114] Contact sheet metal members 117 and 118 are welded to the longitudinal ends of current collectors 106 and 109. Current collectors 106 and 109 are formed as ribbons and each include a strip-shaped end section 106b and 109b that is coated with support material 133.

[0115] FIG. 4 shows the structure of an electrode-separator assembly 104 that may be a component of an energy storage element according to the invention. The assembly 104 comprises a ribbon-shaped anode 105 having a ribbon-shaped anode current collector 106 with a first longitudinal end 106a and a second longitudinal end parallel thereto. The anode current collector 106 is preferably a foil made of copper or nickel. It comprises a strip-shaped main area on which a layer of anode material 107 is mounted and a free end strip 106b extending along its first longitudinal end 106a on which no electrode material 107 is mounted but on which a support material 133 is instead mounted. Furthermore, the assembly 104 comprises a ribbon-shaped cathode 108 having a ribbon-shaped cathode current collector 109 with a first longitudinal end 109a and a second longitudinal end parallel thereto. The cathode current collector 109 is preferably an aluminum foil. It comprises a strip-shaped main area on which a layer of positive electrode material 110 is carried, and a free end strip 109b extending along its first longitudinal end 109a, on which no electrode material 110 is carried but on which support material 133 is carried. Both electrodes are shown in an unwound state.

[0116] The anode 105 and cathode 108 are arranged offset from one another within the electrode-separator assembly 104, such that a first longitudinal end 106a of the anode current collector 106 protrudes from a first terminal end face 104a and a first longitudinal end 109a of the cathode current collector 109 protrudes from a second terminal end face 104b of the electrode-separator assembly 104. This offset arrangement can be seen in the bottom left image, which also shows two ribbon-shaped separators 156 and 157, which separate the electrodes 105 and 108 from one another in the winding.

[0117] In the bottom right diagram, the electrode-separator assembly 104 is shown in a rolled form, as may be used in an energy storage element according to Fig. 1. Electrode ends 106a and 109a protruding from end faces 104a and 104b are clearly visible. The roll shell 104c is preferably formed from a plastic film. [Explanation of symbols]

[0118] 100 Energy Storage Elements 101 Housing part 102 Housing lid 103 Electrical insulation seal 104 Electrode-separator assembly 104a End face 104b End face 104c Shell 105 Anode 106 Anode current collector 106a First longitudinal end 106b End area 106c Main area 106ba First strip-type subdivision 106bb Second strip-type subdivision 106bc Third strip-type subdivision 106bd First strip-type subdivision 106be Second strip-type subdivision 106bf First strip-type subdivision 106bg Second strip-type subdivision 107 Anode materials 108 Cathode 109 Current collector 109a End 109b End area 109ba sub-area 109bb small area 109bc sub-area 109c Main Area 110 Positive electrode materials 116 Separator 116a End 117 Contact sheet metal components 118 Contact sheet metal member 133 Supporting materials 156 Separator 157 Separator L1 protrusion L2 Length L3 Length L4 Length L5 Length

Claims

1. An electrochemical energy storage element (100) comprising an electrode-separator assembly (104), the electrochemical energy storage element (100) having the following features: a. said assembly (104) comprises at least one anode (105) and at least one cathode (108) as electrodes, and at least one separator (116) or at least one solid electrolyte in the order anode (105) / separator (116) or solid electrolyte / cathode (108); b. The anode (105) comprises an anode current collector (106), which is preferably a thin, electrically conductive substrate having a top side, a bottom side, and an end (106a); c. The cathode (108) comprises a cathode current collector (109), which is preferably a thin, electrically conductive substrate having a top side, a bottom side, and an end (109a); d. said anode current collector (106) comprises a main area (106c) on both sides of which a layer of negative electrode material (107) is carried, and end areas (106b) extending in strip form along said end portions (106a) and not carrying said negative electrode material (107); and / or said cathode current collector (109) comprises a main area (109c) on both sides of which a layer of positive electrode material (110) is carried, and end areas (109b) extending in strip form along said end areas (109a) and not carrying said positive electrode material (110); e. the assembly (104) has a side (104a or 104b) from which the end (106a) of the anode current collector (106) or the end (109a) of the cathode current collector (109) protrudes; f. the end section (106b or 109b) extending along the end (106a or 109b) protruding from the side (104a or 104b) is partially or completely coated with an electrically non-conductive layer of support material (133); g. the electrode, whose current collector includes the end (106a or 109a) protruding from the side (104a or 104b), has a first average thickness D1 in the main area (106c or 109c) of the current collector and a maximum thickness D2 in the end area (106b or 109b) coated with the layer of support material; h. D2≦D1 The electrochemical energy storage element (100).

2. Further features: a. the end section (106b or 109b) extending along the end protruding from the side surface (104a or 104b) is partially coated with the layer of support material (133); b. said end region (106b or 109b) extending along said end protruding from said side surface (104a or 104b) is further divided into a first strip-shaped subregion (106ba) that does not contain said support material (133), a second strip-shaped subregion (106bb) that is coated with said support material (133) on both sides, and a third strip-shaped subregion (106bc) that also does not contain said support material (133); c. the third strip-type subregion (106bc) is a terminal strip-type subregion, the first strip-type subregion (106ba) is immediately adjacent to the main region (106c) of the current collector, and the second subregion (106bb) separates the first strip-type subregion (106ba) from the second strip-type subregion (106bb); The electrochemical energy storage element (100) of claim 1, comprising at least one of:

3. Further features: a. the end section (106b or 109b) extending along the end protruding from the side surface (104a or 104b) is partially coated with the layer of support material (133); b. the end region (106b or 109b) extending along the edge protruding from the side surface (104a or 104b) is further divided into a first strip-shaped subregion (106bd) coated with the support material (133) on both sides and a second strip-shaped subregion (106be) that does not contain the support material; c. the second strip-shaped sub-region (106be) is a terminal strip-shaped sub-region, and the first strip-shaped sub-region (106bd) is immediately adjacent to the main region (106c) of the current collector and separates the main region (106c) from the second strip-shaped sub-region (106be); The electrochemical energy storage element (100) of claim 1, comprising at least one of:

4. Further features: a. the layer of the support material (133) is completely coated on the end section (106b or 109b) extending along the end protruding from the side surface (104a or 104b); b. The end section (106b or 109b) extending along the end protruding from the side surface (104a or 104b) is coated on both sides with the layer of the support material (133). The electrochemical energy storage element (100) of claim 1, comprising at least one of:

5. Further features: a. the end section (106b or 109b) extending along the end protruding from the side surface (104a or 104b) is partially coated with the layer of support material (133); b. the end region (106b or 109b) extending along the end protruding from the side surface (104a or 104b) is further divided into a first strip-shaped subregion (106bf) coated with the support material (133) on both sides and a second strip-shaped subregion (106bg) that does not include the support material (133); c. the second strip-shaped sub-region (106bg) is a terminal strip-shaped sub-region and the first strip-shaped sub-region (106bf) is immediately adjacent to the main region (106c) of the current collector and separates the main region (106c) from the second strip-shaped sub-region (106bg); d. The main area (106c) is partially or completely coated with the electrically non-conductive layer of the support material (133). The electrochemical energy storage element (100) of claim 1, comprising at least one of:

6. Further features: a. the electrode-separator assembly (104) is a wound body, each comprising the anode (105) and the cathode (108), and the at least one separator (116) or at least one layer of the solid electrolyte, each spirally wound in ribbon form; b. A wound electrode-separator assembly (104) includes first and second end faces (104a, 104b) and a wound body shell (104c) disposed therebetween; c. said anode current collector (106) is ribbon-shaped and comprises its main section (106c) and said end sections (106b) parallel to each other, said main section (106c) being strip-shaped like said end sections (106b); d. said cathode current collector (109) is ribbon-shaped and comprises its main section (109c) and said end sections (109b) parallel to each other, said main section (109c) being strip-shaped like said end sections (109b); e. the end (106a) of the anode current collector (106) protrudes from one of the end faces (104a), and the end (109a) of the cathode current collector (109) protrudes from the other end face (104b); f. a contact sheet metal member (117, 118) is secured to the first and / or second end faces (104a, 104b); g. The contact sheet metal member (117) or the contact sheet metal members (117, 118) are welded to the end portion (106a, 106b) protruding from each end face (104a, 104b) or to the end portions protruding from each end face (106a, 106b). The electrochemical energy storage element (100) according to any one of claims 1 to 5, comprising at least one of

7. Further features: a. the electrode-separator assembly (104) comprises a plurality of anodes (105) and a plurality of cathodes (108) in a stack form, adjacent electrodes of opposite polarity in the stack being separated by the at least one separator (116) or at least one layer of solid electrolyte; b. each of said anode current collectors (106) of said anodes (105) comprises said main area (106c) on both sides of which a layer of said negative electrode material (107) is carried, and said end areas extending in strip form along said ends (106a) and not carrying said negative electrode material (107); c. each of the cathode current collectors (109) of the cathodes (108) includes a main region (109c) on both sides of which a layer of the positive electrode material (110) is disposed, and an end region (109b) extending in a strip along the end (109a) and not carrying the positive electrode material (110); d. the stack is prismatic and has a first side from which the end (106a) of the anode current collector (106) protrudes and a second side from which the end (109a) of the cathode current collector (109) protrudes; e. a contact sheet metal member (117, 118) is secured to said first and / or second side; f. The contact sheet metal member (117, 118) or members are welded to the ends (106a, 109a) protruding from each side. The electrochemical energy storage element (100) of any one of claims 1 to 5, comprising at least one of:

8. Further features: a. the support material (133) is a ceramic material; b. the support material (133) comprises ceramic particles and a binder; c. The ceramic material or ceramic particles are boehmite (AlO(OH) or γ-AlOOH). The electrochemical energy storage element (100) of any one of claims 1 to 7, comprising at least one of:

9. Further features: a. the energy storage element (100) comprises an air-tight and liquid-tight housing in which the electrode-separator assembly (104) is disposed; b. The electrode-separator assembly (104) is electrically connected to a portion of the housing or to an electrode passing through the housing via the contact sheet metal members (117, 118). The electrochemical energy storage element (100) of any one of claims 1 to 8, comprising at least one of:

10. A method for producing an electrochemical energy storage element according to any one of claims 1 to 9, comprising the steps of: a. applying a layer of electrode material (107, 110) within a major area (106c, 109c) of a current collector (106, 109) having a top side, a bottom side, and an end; b. applying a layer of support material in an end area of ​​said current collector extending in a strip along said edge (106a) and not carrying said electrode material; c. if necessary, calendering said current collector coated with said layer of electrode material and said layer of support material; The method comprises the steps of: d. the layers of electrode material (107, 110) and of support material (133) are selected and applied such that the electrode produced has a first average thickness D1 in the main regions (106c, 109c) and a maximum thickness D2 in the edge regions (106b, 109b), where D2≦D1; method.

11. Further features: a. applying said layer of support material (133) using a suspension comprising said support material (133) in particulate and / or dissolved form and a suspending agent; b. the suspending agent comprises at least one member from the group consisting of water, N-methyl-pyrrolidone (NMP) and ethanol; c. the suspension comprises a binder; d. the suspension comprises the particulate support material (133) having a d50 value in the range of 0.2 μm to 0.5 μm; e. the suspension does not contain particles having a size >2 μm; f. the suspension contains additives that affect its processing properties; g. The suspension comprises the following components in the following proportions: Suspension agent: 40-90% by weight Particulate support material 10-60% by weight Binder: 1 to 5% by weight Additives 0-5% by weight (The above components total 100% by weight) The method of claim 10, comprising at least one of:

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