Energy storage cell having a wound electrode-separator assembly and method for making same

Abstract

An energy storage cell (1) is proposed that comprises an electrode-separator assembly (100) consisting of at least one positive electrode, at least one negative electrode, and at least one separator. The positive electrode is ribbon-shaped and comprises a ribbon-shaped cathode current collector (110) having a coating of a positive electrode material (111). The negative electrode is ribbon-shaped and comprises a ribbon-shaped anode current collector (120) having a coating of a negative electrode material (121). The electrode-separator assembly (100) is formed as a cylindrical winding with two terminal end faces and comprises the electrodes in a spirally wound form. The at least one separator comprises at least one separator ribbon (130, 140) that is arranged between the positive and negative electrodes and separates them from each other. The separator ribbon (130, 140) has a first planar surface and a second planar surface, each of which faces one of the electrodes, and the separator ribbon (130, 140) has a first longitudinal edge and a second longitudinal edge. The proposed energy storage cell is further characterized in that the separator ribbon (130, 140) has a coating of an inorganic non-conductor on at least some area on one of its planar surfaces, and at least one of the longitudinal edges (131, 141) of the separator ribbon (130, 140) is rolled in at least some portion.

Description

[Technical field]

[0001] The present invention relates to an energy storage cell having an electrode-separator assembly in the form of a cylindrical winding, and a method for making the same. [Background technology]

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

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

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

[0005] In principle, all materials capable of absorbing and releasing lithium ions can be used as electrochemically active components (active materials) for secondary lithium-ion cells. For example, carbon-based particles such as graphitic carbon are used for the negative electrode. The active material for the positive electrode 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 contain flat and / or ribbon-shaped current collectors, e.g., metal foils, which act as carriers for the respective active materials or corresponding electrode materials. The current collector for the negative electrode (anode current collector) can be made, for example, of copper or nickel, and the current collector for the positive electrode (cathode current collector) can be made, for example, of aluminum. Furthermore, the electrodes can contain, as electrochemically inactive components, an electrode binder (e.g., polyvinylidene fluoride (PVDF), or another polymer, e.g., carboxymethylcellulose), conductivity improving additives, and other additives. The electrode binder ensures the mechanical stability of the electrode and, in many cases, also the adhesion of the active material to the current collector.

[0007] Lithium-ion cells generally contain as an electrolyte a lithium salt solution, such as lithium hexafluorophosphate (LiPF6) in an organic solvent (e.g., carbonate ethers and esters).

[0008] During the production of lithium-ion cells, a composite electrode is typically combined with one or more separators to form an electrode-separator assembly. The electrodes and separators are often, but not necessarily, bonded together under pressure, optionally by lamination or bonding. The assembly can then be impregnated with an electrolyte to establish basic functionality of the cell.

[0009] In many embodiments, the electrode-separator assembly is formed in the form of a winding or processed into a winding. In the first case, for example, the ribbon-shaped positive electrode and the ribbon-shaped negative electrode, as well as at least one ribbon-shaped separator, are fed separately to a winding machine and spirally wound into a winding having a positive electrode / separator / negative electrode sequence. In the second case, the ribbon-shaped positive electrode and the ribbon-shaped negative electrode, as well as at least one ribbon-shaped separator, are first combined to form the electrode-separator assembly, for example by applying pressure as described above. Then, in a further step, the assembly is wound.

[0010] Applications in the automotive sector, for electric bicycles or other applications with high energy requirements, such as tools, require lithium-ion cells with the highest possible energy density, also capable of withstanding high currents during charging and discharging.

[0011] Cells for the aforementioned applications are often designed as cylindrical round cells, for example with a form factor of 21x70 (diameter x height, in mm). This type of cell generally comprises an electrode-separator assembly in the form of a winding. Modern lithium-ion cells of this form factor are already capable of achieving energy densities of up to 270Wh / kg.

[0012] WO 2017 / 215900 A1 describes an electrode-separator assembly and a cylindrical circular cell whose electrodes are ribbon-shaped and in the form of a winding. The electrodes each have a ribbon-shaped electrode provided with or coated with an electrode material. The electrodes with opposite polarity are arranged offset from each other in the electrode-separator assembly, so that the longitudinal edge of the current collector of the positive electrode protrudes from 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. To electrically contact the current collectors, the cell has a sheet metal part that rests flat on the end face of the winding and is assembled by welding to the longitudinal edge of the current collector. This makes it possible to electrically contact the current collector and therefore also the associated electrode over its entire length. A cell with a winding contacted in this way has a significantly reduced internal resistance. As a result, the large currents generated can be absorbed much better and also the heat can be dissipated better from the winding.

[0013] During the production of such cells, as well as during their operation, especially during charging and discharging, various particles, especially conductive particles, can penetrate into the electrode-separator assembly in the form of a winding. Here, the end faces of the windings are particularly critical areas, since there are some open areas. For example, soot particles or graphite or carbon black can be washed off the electrodes and deposited in the spaces between the electrodes. Furthermore, particles, for example metallic particles, can penetrate into the electrode-separator assembly during the production and assembly of the cell.

[0014] These particles can cause bridging between the polarities of the electrodes, which can lead to micro-short circuits. In extreme cases, this can lead to a short circuit, which can cause the cell to fail. Overall, this intrusion of various particles into the electrode-separator assembly poses a non-trivial safety risk for the cell. Summary of the Invention [Problem to be solved by the invention]

[0015] Against this background, the present invention sets itself the task of providing an improved energy storage cell which avoids or at least minimizes this safety risk due to particles penetrating the electrode-separator assembly, and moreover, the present invention sets itself the task of providing a method for manufacturing such an improved energy storage cell which is very easy to implement in practice. [Means for solving the problem]

[0016] This object is achieved by an energy storage cell and a method for manufacturing such an energy storage cell as specified in the independent claims. Preferred embodiments of the energy storage cell or the manufacturing method are also evident from the dependent claims.

[0017] The energy storage cell according to the invention has the following characteristics: a. the energy storage cell comprises an electrode-separator assembly consisting of at least one positive electrode, at least one negative electrode, and at least one separator; b. the positive electrode is ribbon-shaped and comprises a ribbon-shaped cathode current collector having a coating of positive electrode material; c. the negative electrode is ribbon-shaped and comprises a ribbon-shaped anode current collector having a coating of negative electrode material; d. the electrode-separator assembly is designed as a cylindrical winding having two terminal end faces and carrying the electrodes in a spirally wound form; e. at least one separator comprises at least one separator ribbon disposed between the positive electrode and the negative electrode separating the electrodes from each other; and f. at least one separator ribbon has a first planar side and a second planar side, each of the first planar side and the second planar side facing one of the electrodes, and the separator ribbon has a first longitudinal edge and a second longitudinal edge; It is characterized by:

[0018] According to the invention, the energy storage cell has the following additional features: g. the separator ribbon has a coating of an inorganic non-conductor on at least an area on one of the planar surfaces; and h. at least one of the longitudinal edges of the separator ribbon is at least partially rolled; It is characterized by:

[0019] The basic configuration of the electrode-separator assembly in the form of a winding of this energy storage cell according to the invention is comparable to the structure of the electrode-separator assembly of a conventional cell, as described, for example, in WO 2017 / 215900. A significant difference between the cell according to the invention and such a conventional cell is that at least one of the end faces or end faces of the electrode-separator assembly in the form of a winding is modified so that the longitudinal edge of the separator ribbon located on one or both end faces of the cylindrical winding is deformed, in particular at least partially rolled. This achieves a partial or complete closure of the end faces of the winding, so that the penetration of particles into the interior of the electrode-separator assembly is minimized or completely prevented. This reliably prevents micro-short circuits and / or short circuits caused by conductive particles that may penetrate into the electrode-separator assembly. In this respect, the safety level of the cell is significantly increased by the measures according to the invention.

[0020] As will be explained in more detail in connection with the preferred manufacturing process for the energy storage cell according to the invention below, such a roll-forming at the longitudinal edges of the separator ribbons is achieved in particular by a heat treatment, in which the separator ribbons are provided with an at least partially inorganic non-conductor coating, which may for example be a ceramic coating. It is particularly preferred if this ceramic coating is located on only one of the flat faces of the respective separator ribbon, at least in the region of the longitudinal edges of the separator ribbon. During the heat treatment, this one-sided coating causes the longitudinal edges of the separator ribbons to roll in a predictable and defined manner, resulting in a regularly formed structure in the end face region of the winding, which closes the end faces of the winding. The measures according to the invention thus achieve a targeted and controlled complete or partial closure of the windings.

[0021] Preferably, at least one of the longitudinal edges of the separator ribbon is rolled such that it comprises at least one complete winding, preferably two or more windings, and particularly preferably, it comprises an area in which, as a result of being rolled, the separator ribbon is present in at least two layers.

[0022] The coating with an inorganic non-conductor and the rolling of the longitudinal edges of the separator ribbon, in addition to the primarily mechanical function of sealing the end faces of the windings, also have an electrical insulating function. Furthermore, the coating and the rolling of the longitudinal edges can also provide a mechanical stabilizing function for the electrode-separator assembly.

[0023] The energy storage cell according to the invention is particularly preferably a lithium-ion cell.

[0024] For the electrodes of the lithium-ion cell according to the invention, in principle all electrode materials known for secondary lithium-ion cells can be used.

[0025] Carbon-based particles such as graphite carbon, or preferably also in particulate form, non-graphite carbon materials capable of intercalating lithium can be used as the active material in the negative electrode. Alternatively or in addition, lithium titanate (Li4Ti5O 12 ) or derivatives thereof can also preferably be included in the negative electrode, also in particulate form. Furthermore, the negative electrode can contain, as the active material, at least one material from the group comprising silicon, aluminum, tin, antimony, or compounds or alloys of these materials, which can reversibly store or release lithium, for example silicon oxide (specifically, SiO x , 0 < x < 2), optionally in combination with a carbon-based active material. Tin, aluminum, antimony, and silicon can form intermetallic phases with lithium. The capacity to accommodate lithium, especially in the case of silicon, far exceeds that of graphite or equivalent materials. Mixtures of silicon and carbon-based storage materials are often used. Thin anodes made of metallic lithium are also suitable.

[0026] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds, such as LiCoO2 and LiFePO4. Lithium nickel manganese cobalt oxide (NMC) having the chemical formula LiNi x Mn y Co z O2 (where x + y + z is typically 1), lithium manganese spinel (LMO) having the chemical formula LiMn2O4, or lithium nickel cobalt aluminum oxide (NCA) having the chemical formula LiNi x Co y Al z O2 (where x + y + z is typically 1) are also particularly suitable. Derivatives thereof, for example, lithium nickel manganese cobalt aluminum oxide (NMCA) having the chemical formula Li 1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 O2, or Li 1+xMixtures of MO compounds and / or materials mentioned above can also be used. The cathode active material is also preferably used in particulate form.

[0027] Alternatively, the energy storage cell according to the invention can be a sodium-ion cell, a potassium-ion cell, a calcium-ion cell, a magnesium-ion cell or an aluminum-ion cell. Among these variants, energy storage cells having a sodium-ion cell chemistry are particularly preferred according to the invention.

[0028] The negative electrode material of the sodium ion-based energy storage element according to the invention is, for example, one of the following materials: Carbon, in particular hard carbon (pure or doped with nitrogen and / or phosphorus) or soft carbon, or graphene-based materials, carbon nanotubes, graphite - Phosphorus or Sulfur - Polyanions, e.g. Na2Ti3O7, Na3Ti2(PO4)3, TiP2O7, TiNb2O7, Na-Ti-(PO4)3, Na-V-(PO4)3 - Transition metal oxides, e.g. V2O5, MnO2, TiO2, Nb2O5, Fe2O3, Na2Ti3O7, NaCrTiO4, Na4Ti5O 12 Alternatively, a Na metal anode can be used on the anode side.

[0029] The positive electrode material of the sodium ion-based energy storage element according to the invention is, for example, one of the following materials: - Polyanions: NaFePO4 (triplyte type), Na2Fe(P2O7), Na4Fe3(PO4)2(P2O7), Na2FePO4F, Na / Na2[Fe 1 / 2 Mn 1 / 2 ]PO4F, Na3V2(PO4)2F3, Na3V2(PO4)3, NaCoPO4, Na2CoPO4F - Silicates: Na2MnSiO4, Na2FeSiO4 - Layered oxides: NaCoO2, NaFeO2, NaNiO2, NaCrO2, NaVO2, NaTiO2, Na(FeCo)O2, Na(NiFeCo)3O2, Na(NiFeMn)O2, and Na(NiFeCoMn)O2, Na(NiMnCo)O2

[0030] Regardless of whether the electrode is based on sodium-ion or lithium-ion cell chemistry, the electrode preferably includes an electrode binder and / or additives to improve electrical conductivity. The active material is preferably embedded in the matrix of the electrode binder, and adjacent particles in the matrix are preferably in direct contact with each other. The conductive agent has the function of increasing the electrical conductivity of the electrode. Common electrode binders are, for example, based on polyvinylidene fluoride (PVDF), (Li-) polyacrylate, styrene butadiene rubber, or carboxymethyl cellulose, or a mixture of different binders. Common conductive agents are carbon black, fine graphite, carbon fibers, carbon nanotubes, and metal powders.

[0031] The energy storage cell according to the invention preferably comprises an electrolyte, in the case of a lithium-ion cell in particular an electrolyte based on at least one lithium salt present dissolved in an organic solvent (for example in a mixture of an organic carbonate or a cyclic ether, such as THF or a nitrile), for example lithium hexafluorophosphate (LiPF6). Other usable lithium salts are for example lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(oxalato)borate (LiBOB).

[0032] For sodium-ion cells, the cell preferably contains an electrolyte comprising at least one of the following solvents and at least one of the following conductive salts: Organic carbonates, ethers, nitriles and mixtures thereof are particularly suitable as solvents. - Preferred conductive salts are NaPF6, sodium difluoro(oxalato)borate (NaBOB), NaBF4, sodium bis(fluorosulfonyl)imide (NaFSI), sodium 2-trifluoromethyl-4,5-dicyanoimidazole (NaTDI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), NaAsF6, NaBF4, NaClO4, NaB(C2O4)2, NaP(C6H4O2)3, NaCF3SO3, sodium triflate (NaTf), and Et4NBF4. In a preferred embodiment, additives may be added to the electrolyte.

[0033] The nominal capacity of the lithium-ion based energy storage element according to the invention designed as a cylindrical round cell is preferably up to 15000 mAh. In the case of a 21×70 form factor, the energy storage element in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1500 mAh to 7000 mAh, particularly preferably in the range of 3000 to 5500 mAh. In the case of a 18×65 form factor, the cell in one embodiment as a lithium-ion cell has a nominal capacity preferably in the range of 1000 mAh to 5000 mAh, particularly preferably in the range of 2000 to 4000 mAh.

[0034] In the European Union, manufacturer information on the nominal capacity of secondary batteries is highly regulated. For example, information on the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to the IEC / EN 61951-1 and IEC / EN 60622 standards, information on the nominal capacity of secondary nickel-hydrogen hybrid batteries must be based on measurements according to the IEC / EN 61951-2 standard, information on the nominal capacity of secondary lithium batteries must be based on measurements according to the IEC / EN 61960 standard, and information on the nominal capacity of secondary lead-acid batteries must be based on measurements according to the IEC / EN 61056-1 standard. Any information on nominal capacity in this application is preferably based on these standards.

[0035] The current collector of the energy storage cell according to the invention has the function of electrically contacting the electrochemically active components contained in the respective electrode materials over as large an area as possible, in particular the ribbon-shaped metal foil, which consists of a metal foil or at least has a metallized surface.

[0036] In the lithium-ion cell according to the invention, suitable metals for the anode current collector include copper or nickel, or other conductive materials, in particular copper and nickel alloys, or nickel-coated metals. In particular, materials of the type EN CW-004A or EN CW-008A with a copper content of at least 99.9% can be used as copper alloys. Alloys of the type NiFe, NiCu, CuNi, NiCr and NiCrFe are particularly suitable as nickel alloys. Stainless steels, such as type 1.4303 or 1.4404 or type SUS304, can also be considered.

[0037] Aluminum, or other conductive materials including aluminum alloys, are particularly suitable as metals for the cathode current collector for the lithium-ion cells according to the present invention.

[0038] Suitable aluminum alloys for the cathode current collector include, for example, Al alloys of types 1235, 1050, 1060, 1070, 3003, 5052, Mg3, Mg212 (3000 series), and GM55. Also suitable are AlSi, AlCuTi, AlMgSi, AlSiMg, AlSiCu, AlCuTiMg, and AlMg. The aluminum content of these alloys is preferably greater than 99.5%.

[0039] The energy storage cell according to the invention may have a metallic housing, which is per se customary for such cells. The housing for a cell according to the invention in the form of a cylindrical circular cell advantageously comprises a housing cup, which serves to accommodate the wound electrode-separator assembly, and a lid component, which closes the opening of the housing cup. The housing cup may be, for example, a deep-drawn component made of nickel-plated steel or stainless steel and with a wall thickness in the range of 0.1 mm to 2 mm. Advantageously, a seal is arranged between the lid component and the housing cup, which, on the one hand, serves to seal the cell housing, but on the other hand also has the function of electrically insulating the lid component and the housing cup from each other. The seal is, for example, mounted on the edge of the lid component. To close the circular cell, the opening edge of the housing cup can be bent radially inwards over the edge of the lid component surrounded (crimped) by the seal, so that the lid component, including the seal, is securely fixed in the opening of the housing cup.

[0040] To assemble the cell, the electrode-separator assembly is generally produced first, after which, in a separate operation, the electrode-separator assembly is inserted into a cylindrical metallic housing and then sealed.

[0041] The electrode coil itself may first be produced, specifically on a winding machine, then transported to a separate assembly line and inserted into a half-cup made, for example, of nickel-plated steel or stainless steel.

[0042] In other embodiments, the housing may be produced, for example, by wrapping a metal foil multiple times.

[0043] In a preferred embodiment of the energy storage cell according to the invention, the cell has the following additional features: a. the anode current collector and the cathode current collector each have a first longitudinal edge and a second longitudinal edge; b. an anode current collector having a strip-shaped main area provided with a layer of negative electrode material and a free edge strip extending along a first longitudinal edge and free of electrode material; c. a cathode current collector having a strip-shaped main area provided with a layer of positive electrode material and a free edge strip extending along a first longitudinal edge and free of electrode material; d. the negative and positive electrodes are formed and / or positioned relative to one another within the electrode-separator assembly such that a free edge strip of the anode current collector forms one of the terminal end faces of the cylindrical winding and / or a free edge strip of the cathode current collector forms the other of the terminal end faces; Preferably, the above-mentioned features a. to c. and particularly preferably features a. to d. are realized in combination with one another.

[0044] According to the above mentioned feature d., it is particularly preferred that a free edge strip of the anode current collector on one terminal end face of the cylindrical winding and a free edge strip of the cathode current collector on the other terminal end face form the respective end faces. A particular advantage here is that the respective electrodes can be contacted via these free edge strips of the current collectors. This contact can be made, for example, via sheet metal parts or contact components resting on one or both end faces of the winding and connected, for example by welding, to the longitudinal edges of the current collectors. Such a cell design is associated with a significantly reduced internal resistance, so that high currents can be absorbed very well and heat can be dissipated well from the winding. In a particularly preferred further development of these embodiments of the energy storage cell according to the invention, the cell has the following additional features: a. the electrode-separator assembly designed as a cylindrical winding has an end face formed by the longitudinal edge of the anode current collector, in particular of the free edge strip of the anode current collector, or by the longitudinal edge of the cathode current collector, in particular of the free edge strip of the cathode current collector; b. the longitudinal edge of the anode current collector, in particular of the free edge strip of the anode current collector, and / or the longitudinal edge of the cathode current collector, in particular of the free edge strip of the cathode current collector, encloses a gap having a spiral shape; c. the rolled longitudinal edge of the separator strip is disposed within the gap having a spiral shape, thus closing the end surface formed by the longitudinal edge of the anode current collector or the cathode current collector, respectively; In a particularly preferred embodiment, the above-mentioned features a., b. and c. are realized in combination with one another.

[0045] In this case, the rolled longitudinal edge of the separator ribbon may be located only on one end face of the winding-shaped electrode-separator assembly. In a particularly preferred embodiment, the rolled longitudinal edges of the separator ribbon are located on both end faces of the winding-shaped electrode-separator assembly. This may preferably be the rolled longitudinal edges of two separator ribbons. It is also possible that the two longitudinal edges of the separator strip are rolled on the two end faces of the winding.

[0046] In an embodiment having rolled longitudinal edges of one or more separator ribbons on both end faces of the electrode-separator assembly in the form of a winding, intrusion of particles on both end faces of the winding is reliably prevented, so that in this particular embodiment micro-short circuits and / or short circuits due to intruding particles are particularly reliably prevented or at least significantly minimized.

[0047] In a particularly preferred embodiment, at least one longitudinal edge of at least one separator ribbon is rolled over its entire length, which therefore means that the entire respective end face along which the longitudinal edge of the separator ribbon extends in a spiral is in principle completely closed by the rolled longitudinal edge of the separator ribbon, so that particles can no longer penetrate into the interior of the electrode-separator assembly.

[0048] In a further preferred embodiment, at least one longitudinal edge of at least one separator ribbon is rolled over at least 30%, preferably at least 50%, in particular at least 70% of its length.

[0049] When manufacturing an energy storage cell according to the invention, it is particularly advantageous in the present context if this closing of the end faces of the windings occurs relatively early in the manufacturing process, in particular immediately after the windings have been formed, the advantage here being that the windings are protected from the early stages of the manufacturing process.

[0050] In a preferred embodiment of the energy storage cell according to the invention, the cell has the following additional features: a. at least one separator comprises a separator ribbon having at least a portion of a longitudinal edge that is rolled as a first separator ribbon; b. the at least one separator comprises a second separator ribbon disposed between the positive and negative electrodes to separate the electrodes from one another; c. a second separator ribbon having a first planar surface and a second planar surface, each of the first planar surface and the second planar surface facing one of the electrodes, and the second separator ribbon having a first longitudinal edge and a second longitudinal edge; and d. the second separator strip also has a coating of an inorganic non-conductor on at least an area on one of the planar surfaces; e. at least one of the longitudinal edges of the second separator ribbon is at least partially rolled; Preferably, the above-mentioned features a. to e. are realized in combination with each other.

[0051] This embodiment of the energy storage cell according to the invention is therefore particularly characterized by the fact that the electrode-separator assembly is provided with at least two separator ribbons, which separate the positive and negative electrodes from each other. The sequence in the electrode-separator assembly in the form of a winding may in particular be formed as follows: separator ribbon / positive electrode / separator ribbon / negative electrode or alternatively: separator ribbon / negative electrode / separator ribbon / positive electrode.

[0052] Both the first and the second separator ribbons are characterized by the fact that only the area on at least one of their planar faces is provided with a coating with an inorganic nonconductor. Preferably, at least one or both longitudinal edges of each separator ribbon are coated on one face, then in each case the complete surface coating of the separator ribbon can be provided on one face. The rolled longitudinal edges of the first and second separator strips can be located on one or both end faces of the electrode-separator assembly in the form of a winding.

[0053] In a particularly preferred embodiment of the energy storage cell having a winding with at least two separator ribbons, the cell has the following additional features: a. the cathode current collector and the anode current collector each have a first longitudinal edge and a second longitudinal edge; b. a cathode current collector having a strip-shaped main area provided with a layer of positive electrode material and a free edge strip extending along a first longitudinal edge and free of electrode material; c. the anode current collector having a strip-shaped main area provided with a layer of negative electrode material and a free edge strip extending along a first longitudinal edge and free of electrode material; d. the negative and positive electrodes are formed and / or positioned relative to one another within the electrode-separator assembly such that a free edge strip of the anode current collector of the electrode-separator assembly projects from one of the terminal end faces and a free edge strip of the cathode current collector of the electrode-separator assembly projects from the other of the terminal end faces; e. the free edge strip of the cathode current collector encircles the first gap having a spiral shape; f. the rolled longitudinal edge of the first separator strip is disposed within the first gap having a spiral shape, thus closing an end face of the electrode-separator assembly formed by the edge strip of the cathode current collector; g. the free edge strip of the anode current collector encircles a second gap having a spiral shape; h. the rolled longitudinal edge of the second separator strip is disposed within the second gap having a spiral shape, thus closing an end face of the electrode-separator assembly formed by the edge strip of the anode current collector; In a particularly preferred embodiment, the above-mentioned features a to h are realized in combination with one another.

[0054] In this embodiment, the edge strip of the anode current collector, free of electrode material, protrudes from one end face of the winding-shaped electrode-separator assembly, and the edge strip of the anode current collector, free of electrode material, protrudes from the opposite end face, which means that the respective end face is formed by this free edge strip. The free edge strip of the current collector is therefore in principle available for contacting the respective electrode over its entire length. The two separator strips are arranged in the electrode-separator assembly such that the rolled longitudinal edge of one separator strip closes the end face of one side of the winding and the rolled longitudinal edge of the second, i.e. the other, separator strip closes the opposite end face of the electrode-separator assembly.

[0055] With regard to coating the separator ribbons with an inorganic non-conductor, the energy storage cell according to the invention may, in a preferred embodiment, have the following additional features: a. at least one separator ribbon has a coating of an inorganic non-conductor on only one of the flat surfaces of the separator ribbon; b. at least one separator ribbon has a coating of an inorganic non-conductor along only one of the separator ribbon's longitudinal edges; c. at least one separator ribbon has only one flat surface completely coated with an inorganic nonconductor; In a preferred embodiment, the above-mentioned features a. and b. or the above-mentioned features a. and c. are realized in combination with each other.

[0056] The above mentioned feature a., that only one of the flat faces of the separator ribbon is coated with the inorganic non-conductor, is particularly advantageous: due to such coating on one side, when an electrode-separator assembly in the form of a winding is provided, the rolling of the longitudinal edges of the separator ribbon is achieved in a particularly controlled and reproducible manner only by heat treatment of the or each end face of the winding.

[0057] Exclusive coating of one region of the separator ribbon's longitudinal edges according to feature b. above is in principle sufficient for rolling each longitudinal edge in the course of manufacturing a cell according to the invention. However, complete surface coating of each side of the separator ribbon according to feature c. above may be preferred. This provides advantages to the coating process, since the coating can be performed with less effort.

[0058] If desired, the separator ribbon can be coated with the inorganic non-conductor only along a portion of its length, however, coating the entire length of the separator ribbon is particularly preferred, where only the longitudinal edge regions of the separator ribbon are coated, if desired, and then the entire length of the separator ribbon is coated.

[0059] In a further preferred embodiment of the energy storage cell according to the invention, the cell has the following additional features: a. the inorganic non-conductor coating is located on a flat surface of the separator strip facing the positive electrode; b. the inorganic non-conductor coating is located on a flat surface of the separator strip that faces the negative electrode; c. the longitudinal edges of the separator ribbon are rolled so that the inorganic non-conductive coating faces outward; is characterized by at least one of the following:

[0060] For example, when two separator ribbons are provided in an electrode-separator assembly, one separator ribbon may have a single-sided coating facing the positive electrode and the other separator ribbon may have a single-sided coating facing the negative electrode, or vice versa. It is also possible for the single-sided coatings of the two separator ribbons to face either the positive or negative electrode. In either case, it is particularly preferred if the coating on one side of the separator ribbon faces the positive electrode.

[0061] Originally, ceramic coatings were used on the separator to stabilize it as a whole against thermal stresses. In this case, however, the coating made of inorganic nonconductors has the effect, among other things, of deforming small areas of the separator under thermal stresses. The coating made of inorganic nonconductors stabilizes only the surface to which it is applied. In contrast, the other surface shrinks slightly at high temperatures and the edges of the separator roll.

[0062] Regarding the material for the coating of the separator ribbon, the energy storage cell according to the invention preferably has the following additional features: a. the inorganic non-conductor coating comprises a material selected from the group consisting of ceramic materials, glass-ceramic materials, glass, lithium ion conductive ceramic materials, oxide materials, metal oxide materials, aluminum oxide, titanium oxide, titanium nitride, titanium aluminum nitride, silicon oxide, silicon dioxide, titanium carbonitride, or a combination of these materials; It is characterized by:

[0063] One of these materials can be used for the coating, or two or more, if desired.

[0064] Ceramic materials are particularly preferred, which are to be understood in particular as carbides, nitrides, oxides, silicides or mixtures and derivatives of these compounds.

[0065] In particular, for example, glass-ceramic materials can be used that contain crystalline particles embedded in an amorphous glass phase. The term glass basically means any inorganic glass that is thermally stable and preferably chemically stable towards the electrolyte present in the cell according to the invention.

[0066] For example, aluminum oxide, titanium oxide and silicon dioxide are particularly suitable as coating materials for the separator strips, since these materials are characterized by particularly favorable thermoplastic properties.

[0067] Particularly preferably, the coating is formed on the at least one separator ribbon from an inorganic non-conductor by deposition from the gas phase, in particular by a PVD method (PVD=Physical Vapor Deposition), for example SALD (Spatial Atomic Layer Deposition) being particularly suitable.

[0068] In an alternative preferred embodiment, the coating of the inorganic nonconductor can also be formed by a coating composition, which in addition to the inorganic nonconductor further comprises a binder for fixing the inorganic nonconductor to at least one separator ribbon. For example, a plastic-based binder from the group including PVA (polyvinyl alcohol), PVDF (polyvinylidene fluoride) and SBR (styrene butadiene rubber) is preferably suitable as the binder.

[0069] In a particularly preferred embodiment of the energy storage cell according to the invention, the cell has the following additional features: a. the energy storage cell comprises at least one contact component laid flat on one end surface of an electrode-separator assembly formed as a cylindrical winding; It is characterized by:

[0070] In particular, the contact components may rest on the free edge strips of the anode current collector forming the respective end faces of the windings, or on the free edge strips of the cathode current collector forming the respective end faces, and may be used to contact the respective electrodes.

[0071] Such contact elements, for example flat sheet metal parts in the form of a disk or similar, can be provided on one or possibly both end faces of the winding. In particular, both the positive and negative electrodes can be directly or indirectly contacted to the housing using such contact elements. However, it is also possible that contacting with such contact elements is used only on one side of the winding or for only one of the electrodes, the other electrode contacting the housing, for example via a metallic contact strip (internal arrester) or similar.

[0072] In a particularly preferred embodiment, such an internal arrester is not necessary and the electrodes are contacted via the longitudinal edges of the current collector strips on the end faces of the windings via the above-mentioned contact components, whereby the end faces of the windings can be electrically connected via contact components which are connected to the housing by means of corresponding arresters or by means of contact components which are directly connected to the housing.

[0073] The present invention further includes a method of manufacturing an energy storage cell as described above, the method comprising the steps of: a. providing at least one ribbon-shaped positive electrode and at least one ribbon-shaped negative electrode, the ribbon-shaped positive electrode comprising a ribbon-shaped cathode current collector having a coating of a positive electrode material, and the ribbon-shaped negative electrode comprising a ribbon-shaped anode current collector having a coating of a negative electrode material; b. providing at least one separator ribbon having a first planar surface and a second planar surface, the separator ribbon having a coating of an inorganic non-conductor on at least an area on one of its planar surfaces; c. forming an electrode-separator assembly formed as a cylindrical winding from the electrode strips, at least one separator strip being disposed between the positive and negative electrodes to separate the electrodes from one another; d. inserting the electrode-separator assembly into a cylindrical housing, the electrode-separator assembly being axially disposed within the housing; Includes.

[0074] According to the invention, the method comprises the steps of: e. subjecting the electrode-separator assembly to a heat treatment such that at least one longitudinal edge of at least one separator strip is rolled in at least a portion; It is characterized by:

[0075] An important aspect of the method according to the invention is feature e. mentioned above, according to which the electrode-separator assembly in the form of a winding is subjected to a heat treatment such that at least one longitudinal edge of at least one separator ribbon is rolled, at least in part.

[0076] Such a rolling of the longitudinal edges of the separator ribbon can be applied to one or both end faces of the electrode-separator assembly in the form of a spiral, so that either one or both end faces of the electrode-separator assembly in the form of a spiral are subjected to the heat treatment. It is important that the longitudinal edges of the separator ribbon are coated with an inorganic non-conductor. Ceramic materials are particularly preferred here. It is particularly advantageous if this coating is only on one side of the separator ribbon, i.e. if it is a one-sided coating. This coating is preferably located at least in the region of the respective longitudinal edges of the separator ribbon, but it can also cover the entire surface of the flat side of the separator ribbon. This coating, in particular this one-sided coating of the separator ribbon, achieves a targeted and controlled rolling of the respective longitudinal edges by the heat treatment. This one-sided coating means that the longitudinal edges of the separator ribbon having a spiral shape are preferably rolled completely and regularly in one direction over their entire length, so that all rolled side edge portions have the same orientation in the cross-sectional view of the spiral.

[0077] The inorganic material for the coating of the separator ribbon is in particular a thermoplastic material, which when heated undergoes thermal deformation, which causes the separator ribbon to roll due to the prevailing tensile forces, thus closing the open areas on the end faces of the electrode-separator assembly.

[0078] The separator ribbon itself is preferably temperature stable. Only the coating on the separator ribbon is a thermoplastic resin.

[0079] The separator ribbon itself is an electrically insulating flat structure, for example a film, fabric or fleece, made for example from plastic, which has a thickness in the range of 5 μm to 50 μm, preferably in the range of 10 μm to 30 μm, depending on the dimensions of the energy storage cell according to the invention. If the separator ribbon is formed by a plastic film, this film may be made, for example, of polyolefins or polyetherketones.

[0080] The coating thickness of the separator ribbon with the inorganic non-conductor is, for example, in the range of 0.5 μm to 5 μm.

[0081] Preferably, the anode current collector and / or the cathode current collector are each a ribbon-shaped metal foil having a thickness in the range of 4 μm to 30 μm.

[0082] The anode current collector ribbons, cathode current collector ribbons, and separator ribbons of the cells according to the invention preferably have the following dimensions: - Length ranging from 0.5m~25m, - Widths ranging from 40mm to 145mm.

[0083] When manufacturing an electrode-separator assembly in a wound configuration, it is preferred that the separator ribbon has the same width as the electrode ribbon or current collector ribbon before heat treatment. Due to heat treatment of the end faces of the electrode-separator assembly after winding, the longitudinal edges of the separator ribbon are rolled such that the rolled portions of the separator ribbon are located between the outer ends of the respective current collectors and the main areas of the electrode ribbon that are coated with electrode material.

[0084] The coating of the separator ribbon is preferably carried out before the actual winding of the electrode-separator assembly. Such winding of the electrode ribbon and of the separator ribbon itself is preferably carried out in a winding machine in a manner known per se, the winding machine being supplied with the corresponding electrode and separator ribbons. In other embodiments, the assembly of electrode and separator ribbons can be first produced and then fed to the winding machine.

[0085] After or during the insertion of the electrode-separator assembly into the cylindrical housing, the electrodes are contacted to the housing in a manner known per se, for example by means of one or two of the contact elements already described, which may be attached to one or, if necessary, both end faces of the cylindrical winding. The introduction of the electrolyte and the closing of the housing may also be carried out in a manner known per se.

[0086] The housing may be a conventional metallic housing, which essentially comprises a housing cup and a lid, in other embodiments the housing may also be formed in other ways, for example by winding of a metal foil or otherwise.

[0087] Particularly preferred embodiments of the method according to the invention have the following additional features: a. A temperature in the range of 200°C to 700°C is used for the heat treatment; b. the heat treatment is carried out using hot air and / or infrared radiation and / or a laser beam; At least one of the following is provided:

[0088] Depending on the material and type of coating and depending on the material and thickness of the separator ribbon, the heat treatment can be adapted, in particular with regard to temperature and duration of the heat treatment.

[0089] Regarding the process technology, for example, a hot air blower, an infrared lamp or a laser beam can be used to heat treat the end faces of the electrode-separator assembly. This treatment of the electrode-separator assembly in the form of a winding is preferably carried out immediately after the winding is formed, for example while it is still in the winding machine. This has the advantage that the winding is protected from any penetrating particles at an early stage.

[0090] In a particularly preferred embodiment of the method according to the invention, the method comprises the following additional features: a. the cathode current collector of the positive electrode and / or the anode current collector of the negative electrode have a free edge strip along one of their longitudinal edges that is not coated with electrode material; b. after the electrode-separator assembly is formed, the free edge strip of the cathode current collector and / or the free edge strip of the anode current collector forms one of the end faces of the cylindrical winding; c. a contact component is placed flat on and secured to the free edge strips of the cathode current collector and / or the anode current collector to electrically contact the positive and / or negative electrodes; d. the fastening is performed by welding, in particular by laser welding; Preferably, the above-mentioned features a. to d. are realized in combination with each other.

[0091] As already mentioned above in connection with the features of the energy storage cell, such contact elements can be provided on one or possibly both end faces of the winding-shaped electrode-separator assembly, which can then be connected to the housing element via an additional arrester or, if necessary, directly.

[0092] Securing the contact components to the end faces of the windings preferably occurs some time before the electrode-separator assembly is transported from the winding machine to a separate assembly line for assembling the housing.

[0093] It is particularly preferred to fasten the contact components by means of welding, in particular laser welding. With such a contact method, the free edge areas of the current collectors, which form the spiral-shaped end faces in the winding, can be very precisely contacted and locally limited to the respective contact components by establishing a defined material connection. This makes it possible to maintain very small distances between the point contact areas over the entire spiral electrode length, in the sense of a so-called multi-pin contact, and thus achieve a quasi-continuous contact. In principle, a continuous contact is even possible over the entire length of the spiral of the electrode ribbon.

[0094] In a particularly preferred embodiment, the method according to the invention further comprises the following additional features: a. the heat treatment is performed by transferring heat through contacting components; b. the heat treatment occurs in the course of contacting at least one electrode; At least one of the following is provided: Preferably, the above mentioned features a. and b. are realised in combination with each other.

[0095] The heat treatment according to the concept according to the invention by coupling heat via the contact elements is particularly advantageous since such heat coupling occurs very evenly. Only the contact elements, which have the shape of a plate and are metallic elements, need to be heated. Due to the uniform coupling of heat to the end faces of the windings, the longitudinal edges are rolled in a particularly regular and reproducible manner. It is particularly advantageous if the contact elements completely cover the respective end faces of the windings.

[0096] Particularly advantageously, the heat treatment can be carried out in the course of contacting at least one electrode ribbon. In this embodiment, both the electrical connection of the respective electrode and the sealing of the respective end face are achieved in a single work step. This is due to the fact that when the contact components are welded onto the end faces, as is preferably used for contacting the electrodes, sufficient heat is usually generated to achieve the desired effect of rolling the spiral longitudinal edge of the separator ribbon. Therefore, in this embodiment, it is not essential to carry out the heat treatment for roll formation in a separate step.

[0097] With regard to further features of the method according to the invention, reference is also made to the above description of the features of the energy storage cell according to the invention.

[0098] Finally, the invention includes an energy storage cell that can be produced according to the described method. In this energy storage cell according to the invention, the electrode-separator assembly in the form of a winding is characterized in that one or both of the end face areas of the winding are rolled by thermally deforming the respective longitudinal edges of the separator ribbon. The end faces closed thereby or the end faces of the electrode-separator assembly in the form of a winding closed thereby protect the electrode-separator assembly from penetrating particles that could possibly cause micro-short circuits or short circuits of the cell. For further characteristics of this energy storage cell, reference is also made to the above description.

[0099] Further features and advantages of the present invention will become apparent from the following preferred embodiments in conjunction with the drawings. The individual features can be realized separately or in combination with one another. [Brief description of the drawings]

[0100] [Figure 1] FIG. 1 is a schematic diagram of a longitudinal section through a lithium ion energy storage cell according to the present invention. [Diagram 2] 1 is an X-ray representation of a portion of the end face area of ​​a winding-shaped electrode-separator assembly according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0101] 1 shows a schematic view of a longitudinal section through a lithium-ion energy storage cell 1 according to the invention in the form of a cylindrical round cell. The energy storage cell 1 comprises a metallic housing formed of a housing cup 10 and a housing lid 11. Between the housing cup 10 and the lid 11 a seal 12 is provided, for example in the form of a circumferential sealing ring.

[0102] Within the central interior space of the energy storage cell 1 is an electrode-separator assembly 100 formed as a cylindrical winding with terminal end faces at upper and lower regions of the cell. The winding shaped electrode-separator assembly 100 is formed with a ribbon shaped positive electrode and a ribbon shaped negative electrode, the electrodes being separated from each other by separator ribbons 130 and 140. The positive electrode comprises a ribbon shaped current collector 110 coated on both sides with a positive electrode material 111. The negative electrode comprises an anode current collector 120 coated on both sides with a negative electrode material 121.

[0103] In this exemplary embodiment, the electrodes are formed such that each current collector 110, 120 has a strip-shaped main area and has a layer of the respective electrode material 111, 121 on both sides of the main area. In addition, the cathode current collector 110 has a free edge strip 112 that runs along the longitudinal edge of the cathode current collector and is not coated with electrode material. The anode current collector 120 also has a free edge strip 122 along one of its longitudinal edges that is not coated with electrode material. In this embodiment, the free edge strip 112 of the cathode current collector is located in the region of the top end face of the winding-shaped electrode-separator assembly 100, and the free edge strip 122 of the anode current collector is located in the region of the opposite end face of the electrode-separator assembly 100. In this exemplary embodiment, the electrical contact of the electrodes occurs via these free edge strips 112 and 122 of the current collectors.

[0104] The free edge strip 122 of the anode current collector is electrically connected to the bottom of the housing cup 10. The free edge strip 112 of the cathode current collector is electrically connected to a contact element 13, whereby this contact element 13, for example in the form of a metallic disk or plate, rests on a corresponding end face of the electrode-separator assembly 100. The contact element 13 is connected to the housing lid 11 via an arrester 14. Furthermore, an electrical insulator 15 is provided between the contact element 13 and the surrounding housing cup 10.

[0105] The winding-shaped electrode-separator assembly 100 is designed so that separator ribbons 130, 140 are located between the positive and negative electrode ribbons, which insulate the electrodes from each other.

[0106] The essence of the invention is that the separator ribbons 130 and 140 protruding at the end faces of the cylindrical electrode-separator assembly 100 are rolled in their longitudinal regions 131 and 141 to form a regular structure. This deformation of the longitudinal edges of the separator ribbons 130, 140 results in a large or even complete closure of the open areas of the electrode-separator assembly 100 in the form of a convolution at each end face of the electrode-separator assembly 100, which is shown here in a schematic manner. This deformation of the longitudinal regions of the separator ribbons 130, 140 ensures that conductive particles cannot penetrate into the interior of the electrode-separator assembly 100. Such particles may cause bridges between the polarities of the electrodes, leading to micro-short circuits or short circuits. This is avoided by the measures according to the invention.

[0107] The configuration of the separator ribbon's longitudinal edges 131, 140 is specifically achieved by thermally deforming these regions of the separator ribbon. Targeted and reproducible deformation of the separator ribbon's longitudinal edges is specifically achieved by coating one side of the separator ribbon with an inorganic non-conductor, specifically a thermoplastic ceramic material. For clarity, this single-sided coating is not shown in FIG. 1.

[0108] During the heat treatment to form these structures, the coating on the separator ribbon thermally deforms and shrinks, causing the longitudinal edges of the separator ribbon to roll.

[0109] The coating, preferably on one side of the separator ribbon, may be limited to a longitudinal region of the separator ribbon. In a preferred embodiment, the separator ribbon is coated with an inorganic non-conductor over the entire surface, in any case on one side.

[0110] 1, the rolled longitudinal edge 131 of the separator ribbon 130 in the region of the top end face of the electrode-separator assembly, and the rolled longitudinal edge 141 of the other separator ribbon 140 on the opposite end face, protrude beyond the main area of ​​the electrode ribbon that is coated with electrode material. In this way, closure of the electrode-separator assembly 100 on both end faces of the resulting winding is achieved by rolling up the respective protruding longitudinal edges 131, 141.

[0111] The longitudinal edges of the current collectors 112, 122 available for contacting the electrodes protrude between the rolled-up longitudinal edges 131, 141 of the separator ribbon at the end faces of the winding.

[0112] During the manufacturing process of the energy storage cell 1 according to the invention, the end faces of the winding are advantageously subjected to a heat treatment (heat treatment) more or less immediately after the production of the wound electrode-separator assembly 100, so that the longitudinal edges 131, 141 of the separator ribbon are rolled up accordingly, closing the winding and thus protecting it.

[0113] It is particularly preferred if the heat treatment according to the invention is carried out by coupling heat via the contact element 13 by heating this disk-shaped metallic element and thus uniformly transferring the heat to the end face of the winding.

[0114] In a particularly preferred embodiment, this relates to the contacting process of the electrodes, in which the current collectors are electrically connected via laser welding to the contacting components 13 or, if applicable, to the bottom of the housing 10. Generally, the heat generated during laser welding is sufficient to cause the longitudinal edges of the separator ribbon according to the invention to roll.

[0115] Regardless of the coating of the separator ribbon, the current collectors may also be provided with a coating that improves their stability during the manufacturing process, particularly during welding of the corresponding contact components.

[0116] 2 shows an X-ray longitudinal section of a portion of an end face region of an electrode-separator assembly 100 in the form of a winding of an energy storage cell according to the invention. The regularly rolled longitudinal edge 131 of the separator ribbon 130 is clearly visible. By coating one side of the separator ribbon 130, a uniform and defined deformation of the spiral longitudinal edge 131 is achieved, which closes the open area of ​​the electrode-separator assembly 100 in this end face region.

[0117] In addition, in this cross-sectional view, one can see the protruding free edge of the current collector 112, e.g., the cathode current collector, which protrudes beyond the rolled area 131 and is available for electrical contact of the electrode.

Claims

1. An energy storage cell (1) having the following features: a. the energy storage cell comprises an electrode-separator assembly (100) consisting of at least one positive electrode, at least one negative electrode, and at least one separator; b. the positive electrode is ribbon-shaped and comprises a ribbon-shaped cathode current collector (110) having a coating of positive electrode material (111); c. the negative electrode is ribbon-shaped and comprises a ribbon-shaped anode current collector (120) having a coating of negative electrode material (121); d. The electrode-separator assembly (100) is designed as a cylindrical winding having two terminal end faces and carries the electrodes in a spirally wound form; e. the at least one separator comprises at least one separator ribbon (130, 140) disposed between the positive electrode and the negative electrode, separating the positive electrode and the negative electrode from each other; f. the separator ribbon (130, 140) has a first planar surface and a second planar surface, each of the first planar surface and the second planar surface facing one of the electrodes, and the separator ribbon (130, 140) has a first longitudinal edge and a second longitudinal edge; having Thereby, the energy storage cell has the following additional features: g. said separator ribbon (130, 140) having a coating of an inorganic non-conductor on at least an area on one of said planar surfaces; and h. the longitudinal edges (131, 141) of said separator ribbons (130, 140); at least one of the first and second electrodes is rolled at least in part; An energy storage cell (1) characterized by:

2. Additional features include: a. the anode current collector (120) and the cathode current collector (110) each have a first longitudinal edge and a second longitudinal edge; b. said anode current collector (120) comprising a strip-shaped main area provided with a layer of said negative electrode material (121) and a free edge strip (122) extending along said first longitudinal edge and free of said electrode material; c) said cathode current collector (110) comprising a strip-shaped main area provided with a layer of said positive electrode material (111) and a free edge strip (112) extending along said first longitudinal edge and free of said electrode material; d. the negative electrode and the positive electrode are formed and / or positioned relative to one another within the electrode-separator assembly (100) such that the free edge strip (122) of the anode current collector (120) forms one of the terminal end faces of the cylindrical winding and / or the free edge strip (112) of the cathode current collector (110) forms the other of the terminal end faces; 10. The energy storage cell of claim 1, comprising at least one of:

3. Additional features include: a. the electrode-separator assembly (100) designed as a cylindrical winding has an end face formed by the longitudinal edge of the anode current collector (120), in particular of the free edge strip (122) of the anode current collector, or by the longitudinal edge of the cathode current collector (110), in particular of the free edge strip (112) of the cathode current collector; b) the longitudinal edge of the anode current collector (120), in particular the free edge strip (122) of the anode current collector, and / or the longitudinal edge of the cathode current collector (110), in particular the free edge strip (112) of the cathode current collector, encloses a gap having a spiral shape; c. the rolled longitudinal edges (131, 141) of the separator ribbons (130, 140) are disposed within the gap having the spiral shape, thus closing the end faces formed by the longitudinal edges of the anode current collector (120) or the cathode current collector (110), respectively; 3. The energy storage cell of claim 2, comprising at least one of:

4. Additional features include: a. the longitudinal edges (131, 141) of the separator ribbon are rolled along their entire length; The energy storage cell according to any one of claims 1 to 3, having

5. Additional features include: a. the at least one separator comprises a separator ribbon having at least a portion of the longitudinal edge (131) that is rolled as a first separator ribbon (130); b. the at least one separator comprises a second separator ribbon (140) disposed between the positive electrode and the negative electrode to separate the electrodes from one another; c. the second separator ribbon (140) has a first planar surface and a second planar surface, each of the first planar surface and the second planar surface facing one of the electrodes, and the second separator ribbon (140) has a first longitudinal edge and a second longitudinal edge; d. said second separator ribbon (140) also having a coating of an inorganic non-conductive material on at least an area on one of said planar surfaces; e. at least one of said longitudinal edges (141) of said second separator ribbon is at least partially rolled; The energy storage cell according to any one of claims 1 to 4, comprising at least one of:

6. Additional features include: a. the cathode current collector (110) and the anode current collector (120) each have a first longitudinal edge and a second longitudinal edge; b) said cathode current collector (110) comprising a strip-shaped main area provided with a layer of said positive electrode material (111) and a free edge strip (112) extending along said first longitudinal edge and free of said electrode material; c) said anode current collector (120) comprising a strip-shaped main area provided with a layer of said negative electrode material (121) and a free edge strip (122) extending along said first longitudinal edge and free of said electrode material; d. the negative electrode and the positive electrode are formed and / or positioned relative to one another within the electrode-separator assembly (100) such that the free edge strip (122) of the anode current collector protrudes from one of the terminal end faces of the electrode-separator assembly and the free edge strip (112) of the cathode current collector protrudes from the other of the terminal end faces; e. the free edge strip (112) of the cathode current collector encircles a gap having a spiral shape; f. the rolled longitudinal edge (131) of the first separator ribbon is disposed within the gap having the spiral shape, thus closing the end face of the electrode-separator assembly formed by the edge strip (112) of the cathode current collector; g. the free edge strip (122) of the anode current collector includes a second gap having a spiral shape; h. the rolled longitudinal edge (141) of the second separator ribbon is disposed within the second gap having the spiral shape, thus closing the end face of the electrode-separator assembly formed by the edge strip (122) of the anode current collector; 6. The energy storage cell of claim 5, comprising at least one of:

7. Additional features include: a. the at least one separator ribbon (130, 140) having the coating of the inorganic non-conductor on only one of its planar surfaces; b. said at least one separator ribbon (130, 140) having said coating of said inorganic non-conductor along only one of said separator ribbon's longitudinal edges (131, 141); c. the at least one separator ribbon (130, 140), wherein only one of the flat faces of the separator ribbon is coated with the inorganic non-conductor over its entire surface; The energy storage cell according to any one of claims 1 to 6, comprising at least one of:

8. Additional features include: a. the coating of the inorganic non-conductor is located on a planar surface of the separator ribbon (130, 140) that faces the positive electrode; b. the coating of the inorganic non-conductor is located on a planar surface of the separator ribbon (130, 140) that faces the negative electrode; c. the longitudinal edges of the separator ribbon (131, 141) are rolled so that the coating of the inorganic nonconductor faces outward; The energy storage cell according to any one of claims 1 to 7, comprising at least one of:

9. Additional features include: a. the coating of the inorganic nonconductor comprises a material selected from the group consisting of ceramic materials, glass-ceramic materials, glass, lithium ion conducting ceramic materials, oxide materials, metal oxide materials, aluminum oxide, titanium oxide, titanium nitride, titanium aluminum nitride, silicon oxide, silicon dioxide, titanium carbonitride, or a combination of these materials; The energy storage cell according to any one of claims 1 to 8, having

10. Additional features include: a. the energy storage cell (1) comprises at least one contact component (13) laid flat on one end face of the electrode-separator assembly (100) formed as a cylindrical winding; The energy storage cell according to any one of claims 1 to 9, having

11. A method for manufacturing an energy storage cell (1) according to any one of claims 1 to 10, said method comprising the steps of: a. providing at least one ribbon-shaped positive electrode and at least one ribbon-shaped negative electrode, said ribbon-shaped positive electrode comprising a ribbon-shaped cathode current collector (110) having a coating of a positive electrode material (111) and said ribbon-shaped negative electrode comprising a ribbon-shaped anode current collector (120) having a coating of a negative electrode material (121); b. providing at least one separator ribbon (130, 140) having a first planar surface and a second planar surface, said separator ribbon (130, 140) having a coating of an inorganic non-conductor on at least an area on one of its planar surfaces; c. forming an electrode-separator assembly (100) formed as a cylindrical winding from electrode ribbons, said at least one separator ribbon (130, 140) being disposed between said positive and negative electrodes to separate said electrodes from one another; d. Inserting the electrode-separator assembly (100) into a cylindrical housing (10, 11), the electrode-separator assembly (100) being axially disposed within the housing; e) the electrode-separator assembly (100) is subjected to a heat treatment such that at least one longitudinal edge (131, 141) of the at least one separator ribbon (130, 140) is rolled at least in part.

12. Additional features include: a. a temperature in the range of 200°C to 700°C is used for the heat treatment; b. the heat treatment is carried out using hot air and / or infrared radiation and / or a laser beam; The method of claim 11 , comprising at least one of:

13. Additional features include: a. the cathode current collector (110) of the positive electrode and / or the anode current collector (120) of the negative electrode have a free edge strip (112, 122) along one of their longitudinal edges that is not coated with the electrode material; b. after the electrode-separator assembly (100) is formed, the free edge strip (112) of the cathode current collector and / or the free edge strip (122) of the anode current collector form one of the end faces of the electrode-separator assembly (100) formed as a cylindrical winding; c) a contact element (13) is placed flat on and fixed to the free edge strips of the cathode current collector (112) and / or the anode current collector (122) for electrically contacting the positive and / or negative electrodes; d. The fixing is performed by welding, specifically by laser welding; The method according to claim 11 or 12, comprising at least one of the following:

14. Additional features include: a. the heat treatment is carried out by transferring heat through said contact element (13); b. the heat treatment occurs during contact with the at least one electrode; The method according to any one of claims 11 to 13, comprising at least one of the following:

15. An energy storage cell (1) producible by the method according to any one of claims 10 to 14.

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