METHOD AND PLANT FOR THE PRODUCTION OF ELECTROCHEMICAL CELLS AND ELECTRODE FOR AN ELECTROCHEMICAL CELL

Description

[0001] The invention described below relates to a method and a plant for producing electrochemical cells capable of energy storage, as well as to an electrode for such an electrochemical cell.

[0002] Electrochemical cells capable of energy storage are able to convert stored chemical energy into electrical energy through a redox reaction. They typically comprise a positive and a negative electrode separated by a separator. During a discharge, electrons are released at the negative electrode through an oxidation process. This results in an electron current that can be tapped by an external electrical load, for which the electrochemical cell serves as an energy supplier. At the same time, an ion current corresponding to the electrode reaction occurs within the cell. This ion current passes through the separator and is enabled by an ion-conducting electrolyte.

[0003] If the discharge is reversible, meaning it is possible to reverse the conversion of chemical energy into electrical energy during the discharge and thus recharge the cell, it is called a secondary cell. The commonly used designation for secondary cells is the anode for the negative electrode and the cathode for the positive electrode, which refers to the discharge function of the electrochemical cell.

[0004] The widely used secondary lithium-ion cells are based on the use of lithium, which can migrate back and forth between the cell's electrodes in the form of ions. Lithium-ion cells are characterized by high energy density.

[0005] The negative and positive electrodes of a lithium-ion cell are typically so-called composite electrodes, which comprise not only electrochemically active components (especially components that can reversibly intercalate and deintercalate lithium ions) but also electrochemically inactive components (conductors, electrode binders, current collectors). During the manufacture of a lithium-ion cell, the composite electrodes are combined with one or more separators to form a composite body. The electrodes and separators are usually bonded together under pressure, possibly also by lamination or adhesive bonding.

[0006] In many embodiments, the composite body is flat, allowing multiple composite bodies to be stacked flat on top of one another. Very frequently, however, the composite body is formed in the form of a coil or processed into a coil. The composite body, regardless of whether it is coiled or not, typically comprises the sequence positive electrode / separator / negative electrode. Composite bodies are often manufactured as so-called bicells with the possible sequences negative electrode / separator / positive electrode / separator / negative electrode or positive electrode / separator / negative electrode / separator / positive electrode.

[0007] To produce composite electrodes, a flat layer of a paste-like electrode material containing an electrode binder and optionally a conductive agent as well as an electrochemically active component (often referred to as the active material) in particle form is typically applied to a suitable current collector and then dried. The electrode material is preferably applied to both sides of the current collector. In production terms, this is usually achieved by providing the current collectors as virtually endless strips, which then pass through a coating device in which, by intermittent coating, a stepped coating of the current collector is achieved, interrupted at defined intervals in the running direction. The current collector strip emerging from the coating device accordingly has coated and uncoated sections alternating in the running direction.

[0008] The current collector strip can then be separated by cutting the uncoated sections. If necessary, the current collector strip can be further cut into strips. This allows two or more individual electrodes to be produced from each of the coated sections.

[0009] After the resulting electrodes have been processed into composite bodies, they are transferred into a housing. The basic functionality of the cell can then be established by impregnating the composite body with an electrolyte. The resulting cell can then be subjected to functional and performance testing.

[0010] The defect-free nature of the electrodes produced is crucial to the quality of a cell. The use of defective electrodes usually means that cells built with them must be rejected as rejects.

[0011] It would be desirable to be able to detect any errors and tolerance deviations that may occur, at least for the most relevant components of an electrochemical cell, as early as possible, and ideally to be able to sort out components that are out of tolerance or defective as quickly as possible. This would require traceability of the components throughout the production chain and, of course, a corresponding means of unambiguous identification. Currently, individual components of electrochemical cells can at best be assigned to batches.

[0012] WO 2019 / 077943 A1 discloses providing current collectors with markings. The markings are not further specified.

[0013] From JP 2017-220356 A it is known to introduce markings in the form of holes into the edge area of ​​current collectors.

[0014] JP 2006-32223 A concerns lead-acid batteries that contain current collectors on which information about the respective electrode is stored. Among other things, the code serves to identify defective electrodes.

[0015] EP 1403943 A2 relates to cells in which a current collector sandwiches an electrode. A matrix code containing information about the respective electrode is applied to the current collector.

[0016] EP 825659 A2 describes the marking of electrodes using barcodes and other machine-readable markings as prior art. Within the scope of the described invention, it is then mentioned that codes can be applied to a current collector.

[0017] WO 2013 / 018254A1 describes cells in which the individual electrodes are provided with a code that allows for unique identification of the electrodes. The code is preferably applied directly to the current collector. The code can be a barcode, for example.

[0018] JP 2020-68050 A concerns cells in which the electrodes each have a unique marking, for example, in the form of a matrix code. The markings are made of an organic material.

[0019] To solve the above-mentioned difficulties, the method having the features of claim 1 as well as the system and electrode according to claims 5 and 6 are proposed. Further preferred embodiments of the method emerge from the dependent claims.

[0020] The invention relates to the production of electrochemical cells capable of energy storage, comprising a composite body formed from at least two electrodes and at least one separator. Particularly preferably, the cells to be produced comprise a housing enclosing an interior space, preferably composed of two or more housing parts, and the composite body arranged in the interior space and formed from the at least two electrodes and the at least one separator.

[0021] According to the invention, during the production of the electrochemical cells, a machine-readable code, in particular a barcode and / or a 2D code, is applied to the composite body or to at least one component of the composite body or, if appropriate, to at least one of the housing parts or another component of the cell to be produced, for example, a seal. This brings with it various advantages: The individual components of an electrochemical cell can be traced back to the individual components of the composite body, if necessary. Within a facility manufacturing electrochemical cells, the individual marking makes it possible to track at any time where, for example, a single electrode is located within a production process. When testing cells, possible correlations can be established between production parameters and the function or performance of the finished cells.

[0022] According to the invention, a machine-readable coding is understood to mean both a single machine-readable code, for example a single barcode or a single 2D code, and a plurality of machine-readable codes, for example several 2D codes in a row.

[0023] In the composite body, the electrodes are arranged in the sequence positive electrode / separator / negative electrode.

[0024] The electrochemical cells to be produced are preferably secondary lithium-ion cells with the aforementioned composite electrodes made of current collectors coated with electrode materials.

[0025] Basically, all electrochemically active components known for secondary lithium-ion cells can be used as active materials for the anode and cathode of the cells.

[0026] Carbon-based particles such as graphitic carbon or non-graphitic carbon materials capable of intercalating lithium, preferably also in particle form, can be used as active materials in the negative electrode. In addition, metallic and semi-metallic materials that can be alloyed with lithium can also be used. For example, the elements tin, aluminum, antimony and silicon are capable of forming intermetallic phases with lithium. Some compounds of silicon, aluminum, tin and / or antimony can also reversibly intercalate and release lithium. For example, in some preferred embodiments, the silicon can be present in oxide form in the negative electrode. Alternatively or additionally, lithium titanate (Li 4 Ti 5 O 12 ) or a derivative thereof can also be present in the negative electrode, preferably also in particle form.

[0027] Suitable active materials for the positive electrode include lithium metal oxide compounds and lithium metal phosphate compounds such as LiCoO 2 and LiFePO 4. Also particularly suitable are lithium nickel manganese cobalt oxide (NMC) with the molecular formula LiNi x Mn y Co z O 2 (where x + y + z is typically 1), lithium manganese spinel (LMO) with the molecular formula LiMn 2 O 4 , or lithium nickel cobalt aluminum oxide (NCA) with the molecular formula LiNi x Co y Al z O 2 (where x + y + z is typically 1). Derivatives thereof, for example lithium nickel manganese cobalt aluminum oxide (NMCA) with the molecular formula Li 1.11 (Ni 0.40 Mn 0.39 Co 0.16 Al 0.05 ) 0.89 O 2 or Li 1+x MO compounds and / or mixtures of the materials mentioned can also be used.

[0028] The active materials are preferably embedded in a matrix made of an electrode binder, with neighboring particles in the matrix preferably being in direct contact with each other. Common electrode binders are based on, for example, polyvinylidene fluoride (PVDF), polyacrylate, or carboxymethylcellulose.

[0029] Furthermore, conductive agents can be added to the electrodes. Conductive agents serve to increase the electrical conductivity of the electrodes. Common conductive agents are carbon black and metal powder.

[0030] In the finished cell, the composite body is preferably impregnated with an electrolyte, preferably an electrolyte based on at least one lithium salt such as lithium hexafluorophosphate (LiPF 6 ), dissolved in an organic solvent (e.g., in a mixture of organic carbonates or a cyclic ether such as THF or a nitrile). Other suitable lithium salts include lithium tetrafluoroborate (LiBF 4 ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalato)borate (LiBOB).

[0031] The current collectors serve to electrically contact the electrochemically active components contained in the electrode material over as large an area as possible. The current collectors are preferably made of metal or are at least metallized on the surface. Suitable metals for the anode current collector include copper or nickel, or other electrically conductive materials, particularly copper and nickel alloys or nickel-coated metals. Stainless steel is also generally considered. Suitable metals for the cathode current collector include aluminum or other electrically conductive materials, particularly aluminum alloys.

[0032] Preferably, metal foils, for example with a thickness in the range of 4 µm to 30 µm, are used as the anode current collector and / or as the cathode current collector.

[0033] In addition to films, other substrates such as metallic or metallized nonwovens or open-pore foams or expanded metals can also be used as current collectors.

[0034] An electrically insulating plastic film, for example, can be used as a separator. To allow the electrolyte to penetrate it, it preferably has micropores. The film can be made of a polyolefin or a polyether ketone, for example. Nonwovens and fabrics made of these or similar plastic materials could also be used as separators.

[0035] The electrochemical cell to be produced, in particular the lithium-ion cell to be produced, can be a button cell. Button cells are cylindrical and have a height that is less than their diameter. The height of the button cell to be produced is preferably in the range of 4 mm to 15 mm. Furthermore, it is preferred that the button cell to be produced has a diameter in the range of 5 mm to 25 mm. Button cells are suitable, for example, for supplying small electronic devices such as watches, hearing aids, and wireless headphones with electrical energy.

[0036] The nominal capacity of a lithium-ion cell manufactured according to the method and designed as a button cell is generally up to 1500 mAh. The nominal capacity is preferably in the range of 100 mAh to 1000 mAh, particularly preferably in the range of 100 to 800 mAh.

[0037] Particularly preferably, the electrochemical cell to be produced, in particular the lithium-ion cell to be produced, is a cylindrical round cell. Cylindrical round cells have a height that is greater than their diameter. They are particularly suitable for applications in the automotive sector, for e-bikes, or for other applications with high energy requirements.

[0038] The height of cylindrical round cells to be manufactured is preferably in the range of 15 mm to 150 mm. The diameter of the cylindrical round cells is preferably in the range of 10 mm to 60 mm. Within these ranges, form factors of, for example, 18 x 65 (diameter times height in mm) or 21 x 70 (diameter times height in mm) are particularly preferred. Cylindrical round cells with these form factors are particularly suitable for powering electric motor vehicles.

[0039] The nominal capacity of a cylindrical, round lithium-ion cell produced according to the method is preferably up to 90,000 mAh. With a form factor of 21 x 70, the cell in one embodiment as a lithium-ion cell preferably has a nominal capacity in the range of 1,500 mAh to 7,000 mAh, particularly preferably in the range of 3,000 to 5,500 mAh. With a form factor of 18 x 65, the cell in one embodiment as a lithium-ion cell preferably has a nominal capacity in the range of 1,000 mAh to 5,000 mAh, particularly preferably in the range of 2,000 to 4,000 mAh.

[0040] In the European Union, manufacturers' specifications regarding the nominal capacities of secondary batteries are strictly regulated. For example, specifications regarding the nominal capacity of secondary nickel-cadmium batteries must be based on measurements according to the standards IEC / EN 61951-1 and IEC / EN 60622; specifications regarding the nominal capacity of secondary nickel-metal hydride batteries must be based on measurements according to the standard IEC / EN 61951-2; specifications regarding the nominal capacity of secondary lithium batteries must be based on measurements according to the standard IEC / EN 61960; and specifications regarding the nominal capacity of secondary lead-acid batteries must be based on measurements according to the standard IEC / EN 61056-1. Any specifications regarding nominal capacities in this application are preferably also based on these standards.

[0041] In all embodiments in which the cell to be produced is a button cell or a cylindrical round cell, the composite body arranged in the interior is preferably cylindrical, in particular as a cylindrical coil comprising spirally wound electrode and separator layers. Accordingly, it preferably has two terminal, essentially circular end faces and a circumferential casing.

[0042] The current collectors and separators required to produce such a composite body are preferably band-shaped and preferably have the following dimensions: A length in the range of 0.3 m to 25 m A width in the range of 30 mm to 145 mm

[0043] In the case of a cylindrical round cell with the form factor 18 x 65, for example, the current collectors preferably have a width of 56 mm to 62 mm, preferably 60 mm, and a length of not more than 1.5 m on.

[0044] In the case of a cylindrical round cell with the form factor 21 x 70, for example, the current collectors preferably have a width of 56 mm to 68 mm, preferably 65 mm, and a length of not more than 2.5 m on.

[0045] The housing of the button cell and the round cells is preferably substantially cylindrical. In a preferred embodiment, the housing comprises, for example, a cup-shaped first housing part with a base and a circumferential side wall and an opening, and a second housing part that closes the opening. In many other preferred embodiments, the housing parts are electrically insulated from one another by a plastic seal.

[0046] In principle, the composite bodies to be produced within the scope of the inventive method can also be arranged in a prismatic housing, in particular in the stacked form mentioned above. In these embodiments, the housing is not enclosed by an electrochemical cell. Rather, it preferably encloses a plurality of connecting bodies.

[0047] If the housing is prismatic, the housing generally comprises a plurality of rectangular side walls as well as a polygonal, in particular rectangular, upper part and a polygonal, in particular rectangular, lower part. It is preferably composed of a first and a second housing part, wherein the first housing part preferably comprises the side walls and the polygonal lower part, while the second housing part preferably corresponds to the polygonal upper part.

[0048] The method according to the invention is preferably characterized by at least one of the following features a. to e.: a. The composite body is cylindrical and has two terminal, essentially circular end faces and a circumferential jacket. b. The machine-readable code is applied to the jacket. c. The outer side of the jacket is formed at least partially, preferably completely, by a separator winding and / or by an adhesive film. d. The machine-readable coding comprises or is a barcode. e. The bars of the code are circular bars that encircle the jacket.

[0049] Particularly preferably, the immediately above features a., b., d. and e. are implemented in combination.

[0050] The circumferentially applied coding enables automated readability during processing of the composite body from all sides.

[0051] A barcode that can be used according to the invention may in particular be a code defined in one of the following international standards: ISO / IEC 15420 (commercial bar codes EAN, UPC, IAN, JAN) ISO / IEC 16390 (2 / 5 family code) ISO / IEC 16388 (Code 39) ISO / IEC 15417 (Code 128)

[0052] In some embodiments, it is preferable to apply a code other than a barcode, for example, a 2D code, to the composite body or another component of the cell to be manufactured. 2D codes can be, for example, codes defined in one of the following international standards: ISO / IEC 18004 (QR code) ISO / IEC 16022 (DataMatrix code) ISO / IEC JTC1 SC31 (Han-Xin code) ISO / IEC 15417

[0053] In some embodiments, the machine-readable code may also be a composite code, i.e. a code composed of a linear barcode and a 2D code.

[0054] In further embodiments, the code may also be an encoding comprising alphanumeric characters, for example, a encoding consisting of numbers, a encoding consisting of letters, or a mixed encoding comprising numbers and letters and, if appropriate, special characters (for example, punctuation marks such as periods and commas, plus and minus signs, parentheses, or letters with diacritics). Of course, the encoding may also include characters from non-European languages, for example, Chinese, Japanese, Korean, or Cyrillic characters.

[0055] In some particularly preferred embodiments, it is also possible for the machine-readable coding to comprise a barcode or a 2D code or a composite code in combination with one or more alphanumeric characters or a sequence of alphanumeric characters.

[0056] Further components of the cell to be produced, which according to the invention are preferably provided with the machine-readable coding, are the housing parts and, if appropriate, the mentioned seal, which can be arranged between the housing parts.

[0057] In many cases, it is preferable to apply the machine-readable coding directly to the composite body, to at least one component of the composite body, to at least one of the housing parts, or to one of the other components of the cell to be produced. However, it may also be preferable to apply the coding to at least one label, which is then applied to the composite body, to at least one of its components, or to another component of the cell, in particular by gluing.

[0058] In a particularly preferred variant of the method according to the invention, at least one of the electrodes of the composite body is provided with a machine-readable code. In particular, both the positive and negative electrodes are provided with a machine-readable code.

[0059] According to the invention, for the production of the electrodes of the electrochemical cells a. at least one layer of an electrode material is applied to a strip-shaped current collector passing through a coating device, wherein b. the application of the layer takes place intermittently, so that after passing through the coating device the current collector can be divided longitudinally into sections coated with electrode material and uncoated sections lying in between, and c. the strip-shaped current collector coated with electrode material passes through at least one separating device in which the coated and uncoated sections are severed longitudinally and the uncoated sections are severed transversely, so that successive sections coated with electrode material are separated from one another and each of the coated sections is severed longitudinally into at least two sub-sections. In this case d.each of the coated sections is assigned a machine-readable code that identifies the respective section, and e. the code is applied to the strip-shaped current collector and / or the electrode material applied thereto in such a way that it can be retrieved from each of the partial sections after passing through the at least one separating device and enables the partial sections to be assigned to the coded section.

[0060] According to the invention, the following applies: f. The coding comprises lines or consists of lines that are applied perpendicularly or obliquely to the main direction of extension of the strip-shaped current collector to the strip-shaped current collector and / or the electrode material applied thereto.

[0061] The separated sections correspond to the electrodes of the cells to be produced and can be processed further immediately if necessary.

[0062] This method makes it possible to assign electrodes after the cutting process to a current collector strip, a section on the current collector strip and, if appropriate, a track within the section at any stage of the method according to the invention.

[0063] Particularly preferably, the band-shaped current collector is coated on both sides with a layer of the respective electrode material.

[0064] In a further development of the particularly preferred variant, the method according to the invention is characterized by the following feature a.: a. The machine-readable coding includes or is a barcode.

[0065] The use of a barcode offers particular advantages in the particularly preferred variant. For example, the lines of the barcode can be divided by a corresponding longitudinal cut in the main extension direction of the strip-shaped current collector without any loss of information. A barcode can thus identify all subsections of a coated section after passing through at least one separating device.

[0066] It would be simpler to apply the barcode lines in the main direction of the strip-shaped current collector. However, the advantages described above outweigh the difficulties that arise when applying vertically or diagonally aligned lines.

[0067] If the lines of the barcode are oriented obliquely, they preferably form an angle of 89.9° to 1°, particularly preferably of 89.9° to 25°, in particular of 89.9° to 45°, with a longitudinal edge of the band-shaped current collector.

[0068] The layer of electrode material is usually applied to the current collector in the form of a rectangular or strip-shaped area. The coated sections thus preferably have a rectangular or strip-shaped geometry. In the particularly preferred variant, the lines of the barcode preferably have a length that corresponds to or exceeds the width of the coated area.

[0069] In a further development, the procedure is further characterized by the following additional feature a.: a. The coding assigned to a coated section is applied to the current collector in at least one of the uncoated sections immediately adjacent to that section.

[0070] It is preferred to apply the coding to the current collector after the electrode material has been applied. However, it is also entirely possible to apply the coding to the current collector before it passes through the coating device. This can even be particularly advantageous, as in this embodiment, the coding can also serve as a marker for a section to be coated and thus help control the intermittent coating of the current collector. In this embodiment, a device for recognizing the applied code can be assigned to the coating device.

[0071] Particularly preferably, the coding is placed on the current collector, in particular in the uncoated section, in such a way that it is not damaged when the uncoated section is severed in the transverse direction.

[0072] In a simple case, the coding of a section includes a number that allows the section to be uniquely identified. Sections are preferably numbered consecutively.

[0073] It is further preferred that the particularly preferred variant of the method is characterized by at least one of the immediately following additional features a. and b.: a. The coding shall include, where applicable, in addition to the section's identification, the result of at least one test to which the section was subjected. b. The coding shall include, where applicable, in addition to the section's identification, information on the length and / or width of the section.

[0074] The test may, for example, involve checking the thickness of the electrode coating.

[0075] An electrode produced according to the particularly preferred variant of the process according to the invention is characterized by the following feature a.: a. It comprises a machine-readable code containing information that enables the electrode to be assigned to a section of a strip-shaped current collector coated with electrode material from which the electrode was manufactured.

[0076] Regarding preferred embodiments of the electrode, its individual components, the code and its positioning, reference is made to the above statements to avoid repetition.

[0077] Furthermore, the electrode is characterized by the following features a. and b.: a. The electrode is strip-shaped. b. The coding, in particular the barcode, comprises lines or consists of lines that are aligned perpendicularly or obliquely to the main direction of extension of the electrode.

[0078] A plant suitable for carrying out the method according to the invention, in particular a plant suitable for carrying out the particularly preferred variant of the method according to the invention, is characterized in particular by a combination of the following features: a. It comprises a coating device in which a layer of an electrode material is intermittently applied to a strip-shaped current collector passing through the coating device. b. It comprises at least one cutting device designed to cut through the strip-shaped current collector coated with electrode material in the longitudinal and transverse directions. c. It comprises a device for applying a machine-readable code to the strip-shaped current collector and / or the electrode material applied thereto, which code is designed to apply lines perpendicular or oblique to the main direction of extension of the strip-shaped current collector to the strip-shaped current collector and / or the electrode material applied thereto.

[0079] The coating device can, for example, comprise a nozzle as described in EP 2 775 771 B1. The separating device can comprise mechanical means, such as a knife, and / or a laser for separating the current collector. The device for applying the machine-readable coding can, for example, be a printer.

[0080] Furthermore, it is possible to apply the coding in the form of a label, particularly by gluing it on. The device for applying the machine-readable coding can therefore also be a labeling device.

[0081] In some preferred embodiments, the label may also be an RFID tag containing the machine-readable coding. In this case, the coding can be read wirelessly.

[0082] Further features of the invention and advantages resulting from the invention will become apparent from the drawings and the following description of the drawings. The embodiments described below serve merely to illustrate and facilitate a better understanding of the invention and are not to be construed as limiting in any way.

[0083] The drawings show schematically Fig. 1 an embodiment of a current collector provided with a barcode and coated with a layer of an electrode material according to the particularly preferred variant of the method according to the invention, Fig. 2 a further embodiment of a current collector provided with a barcode and coated with a layer of an electrode material according to the particularly preferred variant of the method according to the invention, Fig. 3 a current collector provided with several individual codes and coated with a layer of an electrode material (not according to the invention), Fig. 4 a current collector provided with several individual codes and coated with a layer of an electrode material (not according to the invention), Fig. 5 an embodiment of a cylindrical composite body on whose shell a machine-readable code is applied (not according to the invention). Fig. 6 a further embodiment of a cylindrical composite body on whose shell a machine-readable code is applied (not according to the invention).

[0084] The Fig. 1 The current collector 100 shown comprises sections 101 and 103 coated with electrode material, as well as uncoated sections 102, in alternating sequence. The current collector 100 is a strip-shaped metal foil. The electrode material is applied to the current collector 100 in the form of a thin layer. The uncoated section 102 separates the two coated sections 101 and 103. In the uncoated section 102, a barcode 104 is applied directly to the current collector 100. The barcode 104 consists of lines aligned perpendicular to the main extension direction H of the current collector 101. The barcode 104 is assigned to the section 103 and identifies it. It conveys a number assigned to the section 103.

[0085] In two longitudinal sections through the current collector 100 along lines 105 and 106, which are aligned parallel to the main extension direction H, the coated sections 101 and 103 are each divided into three subsections. Each of the subsections resulting from section 103 is also identified after the longitudinal section by the barcode 104, which is also severed during the longitudinal sections.

[0086] A cross-section through an area of ​​section 102 not provided with the barcode 104 along the line 107 separates sections 101 and 103 from each other.

[0087] The Fig. 2 The current collector 100 shown comprises sections 101 and 103 coated with electrode material, as well as uncoated sections 102, in alternating sequence. The current collector 100 is a strip-shaped metal foil. The electrode material is applied to the current collector 100 in the form of a thin layer. The uncoated section 102 separates the two coated sections 101 and 103. In the coated section 101, a barcode 104 is applied directly to the electrode material. The barcode 104 consists of lines aligned perpendicular to the main extension direction H of the current collector 101. The barcode 104 is assigned to the section 101 and identifies it. It conveys a number assigned to the section 101.

[0088] In two longitudinal sections through the current collector 100 along lines 105 and 106, which are aligned parallel to the main extension direction H, the coated sections 101 and 103 are each divided into three subsections. Each of the subsections resulting from section 101 is also identified after the longitudinal section by the barcode 104, which is also severed during the longitudinal sections.

[0089] The resulting sections cannot be distinguished from one another solely by the barcode. Therefore, it may be provided to apply numbers or symbols to the current collector in addition to the barcode, which allow the sections to be distinguished. Examples of the sections resulting from the longitudinal sections are shown in Fig. 2 each numbered, see reference number 111. Here, the number before the hyphen could, for example, be a number corresponding to section 101. Such additional marking would, of course, also be required for the Fig. 1 shown embodiment is conceivable.

[0090] A cross-section through section 102 along line 107 separates sections 101 and 103.

[0091] The Fig. 3 The current collector 100 shown comprises sections 101 and 103 coated with electrode material, as well as uncoated sections 102, in alternating sequence. The current collector 100 is a strip-shaped metal foil. The electrode material is applied to the current collector 100 in the form of a thin layer. The uncoated section 102 separates the two coated sections 101 and 103. In the uncoated section 102, several individual codes 104 are applied directly to the current collector 100. The individual codes 104 are each QR codes. They are assigned to the section 101 and identify it. Each of the individual codes 104 carries a number assigned to this section 101. In addition, each of the individual codes 104 carries another individual number that distinguishes it from all other individual codes 104 assigned to the section 101.

[0092] In four longitudinal sections through the current collector 100 along lines 105, 106, 108, and 109, which are aligned parallel to the main extension direction H of the current collector 101, the coated sections 101 and 103 are each divided into five subsections. Each of the subsections resulting from section 101 is also identified by one of the individual codes 104 after the longitudinal sections and can be distinguished from other subsections by the additional individual number.

[0093] A cross-section through section 102 along line 107 separates sections 101 and 103.

[0094] The Fig. 4 The current collector 100 shown comprises sections 101 and 103 coated with electrode material, as well as uncoated sections 102, in alternating sequence. The current collector 100 is a strip-shaped metal foil. The electrode material is applied to the current collector 100 in the form of a thin layer. The uncoated section 102 separates the two coated sections 101 and 103. In the coated section 101, several individual codes 104 are applied directly to the electrode material. Each of the individual codes 104 is a QR code. They are assigned to the section 101 and identify it. Each of the individual codes 104 carries a number assigned to this section 101. In addition, each of the individual codes 104 carries a further individual number that distinguishes it from all other individual codes 104 assigned to the section 101.

[0095] In three longitudinal sections through the current collector 100 along lines 105, 106, and 108, which are aligned parallel to the main extension direction, the coated sections 101 and 103 are each divided into four subsections. Each of the subsections resulting from section 101 is also identified by one of the individual codes 104 after the longitudinal sections and can be distinguished from other subsections by the additional individual number.

[0096] A cross-section through section 102 along line 107 separates sections 101 and 103.

[0097] The Fig. 5 The cylindrical composite body 110 shown, formed from electrodes and separators by spiral winding, is identified by a QR code 104. The QR code 104 is applied to the outer side of the casing of the composite body 110.

[0098] The outer side of the casing can be formed by an outer winding of one of the separators of the composite body 110 or by an adhesive film. The QR code 104 (or another machine-readable code) can be applied directly to the outer side, i.e., in particular, to the winding of the separator or the adhesive film, for example, by means of a printing process. Alternatively, the QR code 104 (or another machine-readable code) can also be located on a label that has been affixed to the outer side.

[0099] It is also possible for the QR code 104 (or another machine-readable code) to be applied to an adhesive strip that is glued to the outer side of the casing of the composite body 110 to secure an outer turn of the composite body 110 formed by winding, for example, a turn of a separator tape. In other words, an adhesive label with a QR code applied to it can be used to secure the winding.

[0100] The Fig. 6 The cylindrical composite body 110 shown is identified by a barcode 104. The barcode 104 is applied to the shell of the composite body 110. The bars of the code are circular lines that encircle the shell.

Claims

1. Method for producing electrochemical cells capable of energy storage and comprising - a housing which encloses an interior, and - an assembly disposed in the interior and formed of at least two electrodes and at least one separator, where, for the production of the electrodes, a. at least one layer of an electrode material is applied to a tapelike current collector passing through a coating apparatus, b. the layer is applied intermittently, so that the current collector after passing through the coating apparatus is subdivisible in longitudinal direction into sections coated with electrode material and uncoated sections between them, and c. the tapelike current collector coated with electrode material passes through at least one parting apparatus, in which - in longitudinal direction the coated and the uncoated sections and - in transverse direction the uncoated sections are severed, so that successive sections coated with electrode material are dissociated from one another and each of the coated sections is separated in longitudinal direction into at least two subsections, wherein d. each of the coated sections is assigned a machine-readable coding which identifies the respective section, and e. the coding is applied to the tapelike current collector and / or to the electrode material applied thereon, in such a way that after passing through the at least one parting apparatus, the coding is retrievable on each of the subsections and enables assignability of the subsections to the coded section, characterized in that f. the coding comprises lines or consists of lines which are applied perpendicularly or obliquely to the principal extent direction of the tapelike current collector to the tapelike current collector and / or to the electrode material applied thereon.

2. Method according to Claim 1, having the following additional feature: a. the machine-readable coding comprises a barcode or is a barcode.

3. Method according to one of the preceding claims, having the following additional feature: a. the coding assigned to a coated section is applied to the current collector in at least one of the uncoated sections immediately bordering that section.

4. Method according to one of the preceding claims, having the following additional feature: a. The coding includes, optionally as well as the identification of the section, the result of at least one test to which the section has been subjected. b. The coding includes, optionally as well as the identification of the section and / or the result of the at least one test, information on the length and / or on the width of the section.

5. Electrode produced by a method according to any one of the preceding claims, having the following features: a. It comprises a machine-readable code which includes information which enables assignability of the electrode to a section, coated with electrode material, of a tapelike current collector from which the electrode has been fabricated. b. The electrode is of tapelike design. c. The coding, more particularly the barcode, comprises lines or consists of lines which are oriented perpendicularly or obliquely to the principal extent direction of the electrode.

6. System for producing electrochemical cells capable of energy storage, having the following features: a. It comprises a coating apparatus in which a layer of an electrode material is applied intermittently to a tapelike current collector passing through the coating apparatus. b. It comprises at least one parting apparatus which is designed to sever the tapelike current collector, coated with electrode material, in longitudinal direction and in transverse direction. c. It comprises an apparatus for applying a machine-readable coding to the tapelike current collector and / or to the electrode material applied thereon, said apparatus being designed to apply - lines perpendicularly or obliquely to the principal extent direction of the tapelike current collector to the tapelike current collector and / or to the electrode material applied thereon.