Inner assembly of an electrochemical cell intended for battery production

Abstract

The present invention concerns an inner assembly of an electrochemical cell intended for battery production, said inner assembly comprising a conductor ribbon provided with a pattern readable by a sensor during the production of the inner assembly, said pattern being formed by reference elements having parameters detectable by said sensor and following one another substantially in a longitudinal direction of the conductor ribbon, wherein the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm, wherein said reference elements are grouped in groups of reference elements which follow one another substantially in the longitudinal direction of said conductor ribbon, said groups of reference elements being separated from each other by a free window of a predetermined length (F). The invention further concerns an electric battery comprising an electrochemical cell which in turn comprises such an inner assembly as well as a method and an apparatus for producing such an inner assembly.

Description

[0001] INNER ASSEMBLY OF AN ELECTROCHEMICAL CELL INTENDED FOR BATTERY PRODUCTION

[0002] The invention concerns an inner assembly of an electrochemical cell intended for battery production, comprising a predefined length of conductor ribbon; an electric battery comprising an electrochemical cell which in turn comprises such an inner assembly as well as a method and an apparatus for producing an inner assembly of an electrochemical cell intended for battery production.

[0003] The present invention finds application in the sector of the production of electrochemical cells intended for the production of electric batteries of the secondary type, also called rechargeable, which can be charged and discharged several times.

[0004] Such rechargeable batteries are commonly used for portable electronics, for electric vehicles, in industrial, military and aerospace applications.

[0005] Examples of such batteries are the rechargeable lithium-ion batteries, rechargeable nickel-cadmium batteries and rechargeable nickel-metal hydride batteries.

[0006] As known, the production of electrochemical cells involves, in wider terms: a step of packaging the electrochemical cell, in which an inner assembly of conductor elements (at least one for the anode and at least one for the cathode) and separator elements is made and in which said inner assembly is inserted in an outer protective casing, a step of filling the electrochemical cell with an electrolytic solution that is placed in contact with the inner assembly, and finally, a step of formation of the electrochemical cell that allows to make it suitable for delivering and / or storing electrical energy.

[0007] The packaging step, in particular, provides that the conductor elements and the separator elements are coupled according to a predefined structure, for example by superimposing them in alternating flat layers, as in the case of prismatic batteries, or by spirally winding alternating layers of conductor ribbons and separator ribbons to form a coil, as in the case of cylindrical batteries, or also by combining a separator ribbon with conductor elements in the form of foils that can be arranged between loops of the "Z"-folded ribbon, and coupled to it in a prismatic assembly.

[0008] In the present description as well as in the claims, certain terms and expressions are deemed to have, unless otherwise expressly indicated, the meaning expressed in the following definitions.

[0009] The term "ribbon" refers to any solid ribbon-shaped product which, within an industrial production apparatus, is in an elongated form, that is, with a longitudinal extension significantly greater than its transverse extension. The ribbon can be composed of homogeneous or heterogeneous material and can be formed by a single layer or by the superimposition of several layers.

[0010] The ribbon also has characteristics such as to allow a functional flexing during its advancing along a relative production apparatus.

[0011] The term "separator element" refers to a material that has the ability to isolate two further materials when it is interposed between them. More preferably, a separator element in this context is an electrically insulating material. The separator element can for example be in the form of a ribbon or a sheet.

[0012] The term "separator ribbon" generally refers to a "separator element" having a substantially ribbon-shaped form.

[0013] Thus, in this context, the term "separator ribbon" generally refers to a ribbonshaped element that has the ability to isolate two materials when it is interposed between them. More preferably, a separator ribbon in this context is a ribbonshaped element in electrically insulating material.

[0014] The term "conductor element" identifies a material that has the ability to conduct a current, e.g. electric current, without dispersing it significantly. The conductor element can for example be in the form of a ribbon or a foil.

[0015] The term "conductor ribbon" refers to a "conductor element" having a substantially ribbon-shaped shape.

[0016] The term "coupling" referred to a ribbon means combining the ribbon with a further ribbon or other element, or combining between them different portions of a same ribbon or of several ribbons (where said portions can be in the form of foils or sheets obtained from a transverse cut made on said ribbon(s) prior to coupling), in such a way as to obtain an overlapping layer structure of a different shape with respect to the ribbon, such as for example a coil or a prismatic assembly.

[0017] The term "winding" referred to a ribbon, indicates a preferred way of coupling the ribbon, with which it is coupled in a spiral structure by rotation around an axis, a flat surface or another structure. By winding, the ribbon will form one or more turns around the axis or the structure.

[0018] The term "coil" is intended to mean any spiral structure formed by winding at least one ribbon around an axis, a flat surface or other winding structure. Depending on the structure around which the ribbon is wound, the overall shape of the coil may be substantially cylindrical rather than crushed or otherwise shaped.

[0019] The term "inner assembly" refers to any solid product obtained by coupling a plurality of ribbons, or by coupling a ribbon with other elements, or again by coupling different portions of a same ribbon or of several ribbons (where said portions can be in the form of foils or sheets obtained by transversely cutting said ribbon(s)).

[0020] For example, the inner assembly can be formed by winding one or more ribbons, for example in the form of a coil, or by coupling a separator ribbon with conductor elements in the form of foils that can be arranged between loops of a "Z"-folded ribbon, and coupled to it in a prismatic-shaped assembly, as previously illustrated. Such foils can be obtained by transversely pre-cutting respective conductor ribbons.

[0021] Yet another example is represented by stacked solutions, in which separator elements in the form of individual sheets of insulating material and conductor elements in the form of individual foils of conductive material are superimposed in layers and coupled together in an alternating configuration. Also in this case, such conductor foils and such separator sheets can be obtained by transversely pre-cutting respective separator ribbons and respective conductor ribbons.

[0022] In particular, "inner assembly" of an electrochemical cell generically refers to the structure in which the conductor elements and the separator elements are combined within the electrochemical cell. Such a structure may be a substantially flat overlapping layer structure alternating on top of each other (achieved by means of stacking or Z-folding techniques) or it may be a coil structure formed by the spiral winding of conductor and separator ribbons alternating with each other.

[0023] With the term "overlapping layer structure" in reference to an inner assembly, it is intended to indicate a structure comprising a plurality of layers superimposed on each other that can be represented by the successive windings of a plurality of spiral-wound ribbons, or by the alternate layers formed by a "Z"-folded separator ribbon and by the conductor elements in the form of foils, or again by the conductor foils and separator sheets superimposed in layers that form the stacked solutions previously illustrated.

[0024] In the course of the present description and subsequent claims, with the term "distance" referred to two consecutive reference elements present in a ribbon, it is intended to indicate the distance measured along a longitudinal direction of the ribbon between two planes parallel to each other, perpendicular to the longitudinal direction of the ribbon and passing through two corresponding points of two reference elements adjacent to each other along the ribbon. These two corresponding points can for example be placed at the centre line of the respective reference elements.

[0025] The term "longitudinal" refers to a direction parallel to a direction of greater development of a ribbon.

[0026] The term "transverse" refers to a direction that is contained in a plane containing a longitudinal direction and is substantially perpendicular to the longitudinal direction. Considering a remarkably thin thickness of the ribbon, a transverse direction develops between two opposite and closer free edges of said ribbon.

[0027] The term "vertical" refers to a direction that is perpendicular to a plane that contains both a longitudinal direction and a transverse direction.

[0028] The term "length" is intended to indicate a quantity measured along a longitudinal direction.

[0029] The term "width" is intended to indicate a quantity measured along a transverse direction.

[0030] The term "tabs" referred to a ribbon is intended to indicate reference elements substantially in the form of a tongue or tooth made in correspondence of at least one longitudinal free edge of the ribbon. These reference elements thus shaped interrupt the continuity of the free edge in which they are made. In particular, this term refers to tabs that extend from a transversely outer longitudinal end to a transversely inner longitudinal end with the transversely outer end being aligned with the free edge of the ribbon and is a constituent part of said free edge or protrudes from the free edge. Furthermore, it is intended to indicate tabs extending between two longitudinally opposite transverse ends, where the transverse end of one tab may be in contact with the adjacent transverse end of the consecutive tab or may be spaced from the adjacent transverse end of the consecutive tab by a free space so as to form a serrated profile of the free edge of the ribbon. Each tab has three free edges formed by the longitudinal end aligned with the free edge of the ribbon or projecting from the free edge and two ends in the transverse direction which may or may not be parallel to each other and substantially perpendicular or incident with respect to the free edge. These tabs can be made by making transverse cuts or notches along the longitudinal edge of the ribbon so as to interrupt the continuity of the longitudinal edge or obtained in this way from a starting ribbon having a height greater than that of the design and subsequently removed to return the ribbon to the design height.

[0031] The term "holes" referred to a ribbon is intended to indicate through holes that completely pass through the ribbon over its entire thickness. The holes can have any shape. Furthermore, they can be completely contained inside the ribbon without touching the longitudinal free edges thereof or they can be made flush with one of the two longitudinal free edges so as to interrupt the continuity of said edge.

[0032] The term "notches" referred to a ribbon is intended to indicate surface recesses made on the ribbon over only part of its thickness.

[0033] The term "marks" referred to a ribbon is intended to indicate surface graphic elements made on the ribbon.

[0034] The term "protrusions" referred to a ribbon is intended to indicate surface projecting elements made on the ribbon. For example, the protrusions may be formed by deforming the ribbon or providing material.

[0035] The aforesaid marks, notches and protrusions may take any shape. Furthermore, they can be completely contained inside the ribbon without touching the longitudinal free edges thereof or they can be made flush with one of the two longitudinal free edges so as to interrupt the continuity of said edge.

[0036] The term "active electrode material" is intended to indicate an anodic or cathodic material which may comprise, in the case of anodic material, graphite or other carbonaceous materials or silicon-based materials and, in the case of cathodic material, lithium oxide, nickel, manganese, cobalt, aluminium or lithium and iron phosphate-based materials.

[0037] As part of the constant need to increase the performance and the efficiency of the production processes to create the inner assemblies described above, the Applicant has observed that these assemblies are produced in a production apparatus characterized by a high construction complexity. Moreover, the inner assemblies themselves generally exhibit high structural complexity.

[0038] The requirements in such a production apparatus are extremely complex. Increasingly higher production speeds and better product quality associated with minimum production costs are required. In addition, higher and higher levels of automation and control are required to verify that the apparatus is working correctly, according to established technical specifications.

[0039] In this context, the Applicant has perceived the need to monitor and possibly control the production process of inner assemblies in a reliable, precise and non- invasive manner.

[0040] The Applicant has noted that the aforementioned need can be met by means of a monitoring system that exploits characteristics of the ribbons used for the production of the inner assembly.

[0041] In the case of a conductor ribbon, the Applicant has observed that this type of ribbon may itself have surfaces with a naturally even appearance or may be provided, for structural or functional needs, with elements such as tabs or slots that alter the evenness of such surfaces. Although such elements may in some cases provide a pattern readable by a sensor, the reading of such a pattern may require the use of expensive and sophisticated detection devices or may not be suitable or sufficient to perform specific controls, required for the production process.

[0042] The Applicant has therefore found that the aforementioned type of automated monitoring can be achieved by equipping said conductor ribbon with a pattern readable by a sensor during the production of the inner assembly, wherein said pattern is formed by reference elements having parameters detectable by said sensor that allow monitoring one or more operating parameters of the conductor ribbon during the production of the inner assembly, wherein the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm, wherein the reference elements are grouped in groups separated from each other by a free window. The present invention therefore concerns, in a first aspect thereof, an inner assembly of an electrochemical cell intended for battery production.

[0043] Preferably, said inner assembly comprises a conductor ribbon.

[0044] Preferably, said conductor ribbon is provided with a pattern readable by a sensor during the production of the inner assembly.

[0045] Preferably, said pattern is formed by reference elements having parameters detectable by said sensor.

[0046] Preferably, said reference elements follow one another substantially in a longitudinal direction of the conductor ribbon.

[0047] Preferably, the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm.

[0048] Preferably, said reference elements are grouped in groups of reference elements which follow one another substantially in the longitudinal direction of said ribbon, said groups of reference elements being separated from each other by a free window of a predetermined length F.

[0049] Preferably, the parameters detectable by said sensor comprise the longitudinal dimension and / or the transverse dimension.

[0050] In one embodiment, the parameters detectable by said sensor comprise at least one of: structure, shape, material, colour, mutual distance and position. Regardless of the longitudinal dimension and / or the transverse dimension of the reference elements, these parameters can at least in part cooperate with each other to allow monitoring one or more operating parameters of the conductor ribbon during the production of the inner assembly.

[0051] Preferably, the parameters detectable by said sensor are collectively selected to allow monitoring one or more operating parameters of the conductor ribbon during the production of the inner assembly.

[0052] Preferably, the inner assembly comprises a predefined length of conductor ribbon.

[0053] In a second aspect thereof, the present invention concerns an electric battery comprising an electrochemical cell which in turn comprises an inner assembly according to the first aspect of the invention.

[0054] In a third aspect thereof, the present invention concerns a method for producing an inner assembly of an electrochemical cell intended for battery production.

[0055] Preferably, the method provides for transporting at least one conductor ribbon along a respective transport path to a coupling device.

[0056] Preferably, at the coupling device, the method provides for coupling said at least one conductor ribbon in an overlapping layer structure to create the inner assembly according to the first aspect of the invention.

[0057] In a fourth aspect thereof, the present invention concerns a method for producing an inner assembly of an electrochemical cell intended for battery production.

[0058] Preferably, the method provides for feeding one or more ribbons, at least one of which is a conductor ribbon requiring a pattern readable by a sensor during the production of the inner assembly.

[0059] Preferably, the method provides for forming said pattern by making on said at least one conductor ribbon reference elements following one another substantially in a longitudinal direction of the conductor ribbon.

[0060] Preferably, said reference elements have parameters detectable by said sensor.

[0061] Preferably, said parameters detectable by said sensor include at least one of: longitudinal dimension, transverse dimension, structure, shape, material, colour, mutual distance and position.

[0062] Preferably, the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm.

[0063] Preferably, said reference elements are grouped in groups of reference elements which follow one another substantially in the longitudinal direction of said conductor ribbon, said groups of reference elements being separated from each other by a free window of a predetermined length (F)

[0064] Preferably, the method provides for transporting said one or more ribbons along respective transport paths to a coupling device.

[0065] Preferably, at the coupling device, the method provides for coupling said one or more ribbons in an overlapping layer structure to create the inner assembly. In a further aspect, the present invention concerns an apparatus for producing an inner assembly for an electrochemical cell intended for battery production.

[0066] Preferably, the production apparatus comprises a transport system comprising transport devices configured to transport at least one ribbon along a respective transport path.

[0067] Preferably, the production apparatus comprises a coupling unit comprising at least one coupling device configured to couple said at least one ribbon fed by said transport system into an overlapping layer structure to create the inner assembly according to the first aspect of the invention.

[0068] According to the invention in its various aspects, the conductor ribbons used for the production of the inner assembly become objects provided with a pattern that lends itself to being read by a sensor and used to meet specific production process control needs. In particular, the sensor can make detections on individual reference elements, on groups of reference elements and / or on predetermined portions of ribbon that advances along the respective transport path. The conductor ribbon is therefore provided with characteristics that can be exploited by a monitoring system to monitor and, if necessary, control the production of an inner assembly.

[0069] In particular, the conductor ribbon is provided with reference elements having a longitudinal and / or transverse dimension comprised between 0.2 mm and 100 mm. These values allow, on the one hand, to read said pattern by identifying the individual reference elements (i.e. distinguishing them from one another) with commercially available low-cost sensors; i.e. without requiring the use of sophisticated and expensive detection devices, with high resolutions. On the other hand, they allow to form a pattern that lends itself to being used to carry out specific controls, required for the production process.

[0070] The present invention is particularly useful when the production process provides for using a conductor ribbon having surfaces with a generally even appearance (e.g., devoid of tabs or slots or other elements necessary to meet predetermined mechanical and / or electrical characteristics of the inner assembly) and, therefore, originally devoid of elements that could provide a pattern readable by a sensor and usable in an automated monitoring system of the production process.

[0071] Furthermore, the present invention lends itself to being used also in the case of a conductor ribbon already provided, for structural or functional needs, with elements such as tabs or slots that alter the evenness of said surfaces, to provide said conductor ribbon with a further pattern with respect to that provided by said elements. The latter solution can be advantageous if, for example, it is necessary to have an additional and different pattern that lends itself to being exploited by the monitoring system to make improved readings or in any case different from the readings that can be made with the pattern provided by the elements already present.

[0072] For example, thanks to detections carried out on the aforementioned reference elements in an inner assembly production apparatus, it is possible to monitor the advancement speed of the conductor ribbon at predetermined detection positions. Compared to a solution that monitors the advancement speed of the conductor ribbon by means of, for example, a linear encoder associated with a conveyor roller of the ribbon, which does not take into account any slippage of the conductor ribbon on the conveyor roller, the invention provides a reliable solution that allows detections to be carried out directly on the ribbon and thus be free of any problems of slippage of the ribbon on the conveyor roller. Moreover, thanks to the determinations carried out on a multitude of individually identified reference elements, the advancement speed can be monitored instant by instant in an extremely precise manner.

[0073] The invention also allows to monitor in real time, and in a precise and non- invasive way, the position of the conductor ribbon in the three directions (longitudinal, transverse and vertical) and / or the mutual position of several ribbons during the production of the inner assembly.

[0074] In addition, thanks to the monitoring of operating parameters relating to the conductor ribbon, the invention makes it possible to control operating parameters relating to the production of the inner assembly and, in particular, relating to the transport system, the coupling device, any ribbon cutting devices, any devices for forming reference elements, any devices for forming further reference elements (such as the tabs or slots mentioned above), any ribbon dispensing devices, any unwinding devices, any discard devices and / or any inspection devices suitable for identifying any defective inner assemblies to be discarded.

[0075] The present invention may have, in both aspects discussed above, at least one of the preferred features described below. Such features may be present individually or in combination with each other, unless expressly stated otherwise, in the apparatus of the present invention. Preferably, said pattern is readable by a sensor during the step for making the inner assembly, preferably in proximity to the coupling device and / or during the transport of the conductor ribbon along the respective transport path and / or during the feeding of the conductor ribbon by a dispensing device and / or during an operation of forming said reference elements and / or during an operation of forming further reference elements (such as the aforementioned tabs or slots) and / or during an operation of cutting the conductor ribbon.

[0076] Preferably, the reference elements are distributed, possibly in groups, substantially evenly in the longitudinal direction of the conductor ribbon.

[0077] Preferably, the reference elements follow one another in the longitudinal direction of the conductor ribbon over a large part of the entire length of the conductor ribbon.

[0078] Preferably, the reference elements follow one another in the longitudinal direction of the conductor ribbon substantially along the entire length of the conductor ribbon.

[0079] Preferably, the reference elements follow one another on one of the two major surfaces of the conductor ribbon (where "major surfaces" is intended to indicate the two surfaces that extend on the two faces of a plane on which the flattened conformation of the conductor ribbon develops and on which the longitudinal direction of the conductor ribbon extends).

[0080] The reference elements are greater than two in number. Preferably, the conductor ribbon is provided with tens, hundreds, thousands or tens of thousands of reference elements, depending on the length of the conductor ribbon and / or the density with which the reference elements are distributed.

[0081] Preferably, the conductor ribbon is provided with tens, hundreds or thousands of reference elements for each section of said conductor ribbon having a length corresponding to that predefined for said conductor ribbon in said inner assembly.

[0082] In one embodiment, the reference elements can be distributed along the longitudinal direction of the conductor ribbon over several rows parallel to each other.

[0083] The pattern can be superficial or passing-through. In other words, the reference elements can be superficial (i.e. they only affect one surface of the conductor ribbon or only partially cross its thickness) or passing-through (i.e. they completely cross the conductor ribbon over its entire thickness).

[0084] Preferably, said reference elements are selected from the group comprising the following types: tabs, holes, notches, marks and protrusions.

[0085] In one embodiment, said reference elements are intended to perform a mechanical and / or electrical function in the inner assembly.

[0086] In one embodiment, said parameters detectable by said sensor are collectively selected to preserve mechanical and / or electrical characteristics of the conductor ribbon.

[0087] Preferably, said sensor is selected from the group comprising: a photoelectric sensor, a magnetic sensor, an RGB sensor and an image acquisition device.

[0088] In a preferred embodiment, the image acquisition device is part of a vision system comprising a lighting device positioned so as to back-light the conductor ribbon with respect to the image acquisition device.

[0089] Preferably, the reference elements follow one another in proximity to one of the two free edges.

[0090] Preferably, said conductor ribbon has a height measured along a transverse direction thereof, has two opposite free edges extending along the longitudinal direction and which are spaced apart from each other by said height, and wherein the reference elements extend in a transverse direction from a transversely outer end to a transversely inner end.

[0091] Preferably, said conductor ribbon is devoid of a further pattern formed by further reference elements which follow one another substantially in a longitudinal direction of said conductor ribbon.

[0092] Preferably, said conductor ribbon is provided with at least one further pattern formed by further reference elements which follow one another substantially in a longitudinal direction of said conductor ribbon, said further pattern formed by said further reference elements being different from the pattern formed by said reference elements.

[0093] Preferably, said further reference elements are selected from the group comprising: tabs following one another substantially in a longitudinal direction of said conductor ribbon at at least one of the two free longitudinal edges and through slots following one another substantially in a longitudinal direction of said conductor ribbon.

[0094] Preferably, said conductor ribbon comprises a first longitudinal portion devoid of active battery electrode material and a second longitudinal portion having the active material, the reference elements being contained in said first longitudinal portion.

[0095] Preferably, said conductor ribbon comprises a first longitudinal portion devoid of active battery electrode material and a second longitudinal portion having the active material, the reference elements being contained in said second longitudinal portion.

[0096] Preferably, said first longitudinal portion extends transversely starting from one of the two free edges.

[0097] Preferably, the second longitudinal portion is transversely contiguous to the first longitudinal portion and extends transversely starting from the other of the two free edges.

[0098] Preferably, the reference elements are equally-distant from each other and spaced apart from each other, in the longitudinal direction of said conductor ribbon, by a predetermined distance D. In other words, the reference elements follow one another in the longitudinal direction with a pitch equal to said predetermined distance D.

[0099] Preferably, in order to avoid an overlap of the reference elements, the distance D between two consecutive reference elements is greater than or equal to the longitudinal dimension d of the reference elements.

[0100] Preferably, said distance D is at least 1 .5 times the longitudinal dimension of the reference elements, preferably at least twice the longitudinal dimension of the reference elements.

[0101] Preferably, said distance D is lower than one hundred times the longitudinal dimension of the reference elements, preferably lower than fifty times the longitudinal dimension of the reference elements, more preferably lower than ten times the longitudinal dimension of the reference elements.

[0102] Preferably, the distance D between two reference elements has a value greater than 0.2 mm, more preferably greater than 0.4 mm, even more preferably greater than 1 mm.

[0103] Preferably, the distance D between two reference elements has a value lower than 5000 mm, more preferably lower than 1000 mm, even more preferably lower than 50 mm, even more preferably lower than 10 mm, even more preferably lower than 5 mm.

[0104] Preferably, the reference elements have a longitudinal dimension d with a value greater than 0.3 mm, more preferably greater than 0.5 mm, even more preferably greater than 1 mm, even more preferably greater than 2 mm. Preferably, the longitudinal dimension d of the reference elements has a value lower than 100 mm, more preferably lower than 10 mm, even more preferably lower than 5 mm, even more preferably lower than 3 mm.

[0105] Preferably, the reference elements have a transverse dimension with a value lower than or equal to a height of the ribbon measured along a transverse direction of the ribbon. More preferably, the reference elements have a transverse dimension with a value lower than or equal to one tenth of the height of the ribbon. More preferably, said transverse dimension has a value lower than or equal to one twentieth of the height of the ribbon.

[0106] Preferably, the reference elements have a transverse dimension with a value greater than 0.3 mm, more preferably greater than 0.5 mm, even more preferably greater than 1 mm, even more preferably greater than 2 mm. Preferably, the transverse dimension of the reference elements has a value lower than 100 mm, more preferably lower than 10 mm, even more preferably lower than 5 mm, even more preferably lower than 3 mm.

[0107] Preferably, the reference elements all have substantially the same longitudinal dimension d.

[0108] Preferably, the reference elements all have substantially the same transverse dimension.

[0109] In one embodiment, the reference elements are densely distributed in the longitudinal direction of the conductor ribbon. For example, the distance D between two consecutive elements is lower than, for example, ten times the longitudinal dimension of the reference elements. In one embodiment, the reference elements are loosely distributed in the longitudinal direction of the conductor ribbon. For example, the distance D between two consecutive elements is greater than, for example, ten or fifty times the longitudinal dimension of the reference elements.

[0110] Preferably, said predetermined length F of said free window is greater than said distance D between two consecutive reference elements.

[0111] Preferably, said predetermined length F of said free window has a value greater than 10mm, more preferably greater than 50mm, even more preferably greater than 100mm.

[0112] Preferably, said predetermined length F of said free window has a value lower than 1500mm, more preferably lower than 1000mm.

[0113] Preferably, the free windows separating two groups of consecutive reference elements all have the same length F.

[0114] Preferably, each group of reference elements has a same longitudinal extension corresponding to a predefined length for said conductor ribbon in said inner assembly.

[0115] Preferably, said length has a value greater than 500 mm, preferably greater than 1000 mm, even more preferably greater than 2000 mm. Preferably, said length has a value lower than 10,000mm, preferably lower than 8000mm.

[0116] Preferably, each group of reference elements comprises tens, hundreds or thousands of reference elements.

[0117] Preferably, the conductor ribbon is provided with tens, hundreds or thousands of reference elements for each section of said conductor ribbon having a length corresponding to that predefined for said conductor ribbon in said inner assembly.

[0118] Preferably, said reference elements follow one another in proximity to or at one of the two free edges.

[0119] Preferably, the reference elements each extend in a longitudinal direction between two transverse ends that are longitudinally opposite to each other.

[0120] In one embodiment, the transverse end of one reference element is in contact with the adjacent transverse end of the consecutive reference element. In another embodiment, the transverse end of one reference element is spaced from the adjacent transverse end of the consecutive reference element by a free space.

[0121] Preferably, said reference elements are all of the same type.

[0122] Preferably, the reference elements are equal to each other in shape and / or size.

[0123] Preferably, in the method of the invention, said at least one conductor ribbon requiring said pattern is selected from the group consisting of: a conductor ribbon having a generally even surface and a conductor ribbon provided with a further pattern formed by further elements following one another substantially in a longitudinal direction of said conductor ribbon, said further pattern formed by said further reference elements being different from the pattern formed by said reference elements.

[0124] Preferably, said further elements are selected from the group comprising: tabs following one another in a longitudinal direction of said conductor ribbon at at least one of said two free longitudinal edges and through slots following one another in a longitudinal direction of said conductor ribbon.

[0125] Preferably, in the method of the invention it is provided for also transporting at least one separator ribbon along a respective transport path to the coupling device.

[0126] Preferably, said at least one separator ribbon is provided with reference elements following one another substantially in a longitudinal direction of the separator ribbon. Preferably, said reference elements form on the separator ribbon a pattern readable by a sensor.

[0127] Preferably, in the method of the invention, before transporting said at least one separator ribbon and / or said at least one conductor ribbon along the respective transport path, said at least one ribbon is fed by a dispensing device.

[0128] In one embodiment, said at least one separator ribbon and / or said at least one conductor ribbon is stored in said dispensing device already provided with said reference elements.

[0129] In one embodiment, said at least one separator ribbon and / or said at least one conductor ribbon is stored in said dispensing device without said reference elements. In this embodiment, the method preferably comprises making said reference elements on said at least one separator ribbon and / or on said at least one conductor ribbon fed by the dispensing device. The reference elements may preferably be made by printing, drilling, thermoforming, cutting, compressing and / or notching.

[0130] Preferably, in correspondence of at least one respective predetermined detection position along the transport path of said at least one separator ribbon and / or said at least one conductor ribbon, in the method of the invention it is provided for taking measurements by means of said sensor on the respective reference elements passing at said detection position.

[0131] Preferably, it is provided for taking measurements adapted to individually identify at least a part of said reference elements passing at the respective detection position.

[0132] Preferably, on the basis of said detections, it is provided for individually identifying the reference elements of said at least a part of said reference elements.

[0133] Preferably, it is provided for monitoring operating parameters relating to said at least one separator ribbon and / or to said at least one conductor ribbon on the basis of said detections.

[0134] Preferably, it is provided for monitoring operating parameters relating to said at least one separator ribbon and / or to said at least one conductor ribbon on the basis of determinations made on a plurality of said individually identified reference elements.

[0135] Preferably, said plurality of individually identified reference elements comprises at least two reference elements, preferably tens of reference elements, more preferably hundreds of reference elements, even more preferably thousands of reference elements, even more preferably tens of thousands of reference elements.

[0136] Preferably, said determinations are carried out for each section of said at least one separator ribbon and / or said at least one conductor ribbon having a length corresponding to that predefined for said ribbon in said inner assembly.

[0137] Preferably, the operating parameters relating to said at least one separator ribbon and / or to said at least one conductor ribbon comprise at least one of: position of the ribbon in a direction of the respective transport path, position of the ribbon in a direction transverse to the direction of the respective transport path, position of the ribbon in a vertical direction with respect to the direction of the respective transport path and advancement speed of the ribbon along the respective transport path.

[0138] Preferably, the determinations made on said plurality of said reference elements are related to at least one of: presence or absence of the individual reference elements; distance D between two consecutive reference elements; dimensions of each reference element; shape of each reference element; position of each reference element; frequency of detection of the reference elements and advancement speed of the reference elements.

[0139] Preferably, it is provided for making the aforementioned determinations also in relation to the groups of reference elements.

[0140] Preferably, the determinations relating to the groups of reference elements comprising at least one detection between: longitudinal extension of each group of reference elements; presence of free window; length of each free window; frequency of detection of free windows; advancement speed of the free windows.

[0141] Preferably, for said at least one separator ribbon and / or for said at least one conductor ribbon provided with reference elements, said detections are carried out in correspondence of at least two respective predetermined detection positions along the transport path of said ribbon and the determinations made on said plurality of said reference elements on the basis of the detections carried out at said at least two respective detection positions are used to control different operating parameters relating to the production process.

[0142] Preferably, it is provided for controlling operating parameters of the production method on the basis of said detections.

[0143] In one embodiment, the operating parameters relating to the production process are at least one parameter relating to: coupling of said at least one separator ribbon and / or said at least one conductor ribbon; transport of said at least one separator ribbon and / or said at least one conductor ribbon; cutting of said at least one separator ribbon and / or said at least one conductor ribbon; dispensing of said at least one separator ribbon and / or said at least one conductor ribbon; formation of said reference elements in said at least one separator ribbon and / or said at least one conductor ribbon; formation of further reference elements in said at least one separator ribbon and / or said at least one conductor ribbon. Preferably, said detections are carried out near the coupling device and / or during the transport of said at least one conductor ribbon along the respective transport path and / or during a forming operation of said reference elements and / or during a forming operation of further reference elements and / or during a cutting operation of said at least one conductor ribbon.

[0144] Preferably, the production method comprises cutting said at least one separator ribbon and / or said at least one conductor ribbon in proximity to said coupling device, wherein said cutting is carried out taking into account said determinations made on said plurality of reference elements.

[0145] Preferably, said reference elements are grouped in groups of reference elements that follow one another in the longitudinal direction of said at least one separator ribbon and / or said at least one conductor ribbon and that are separated from each other by a free window of a predetermined length, said cutting being carried out at said free window.

[0146] Preferably, it is provided for verifying that the determinations made on the reference elements meet predetermined reference parameters.

[0147] Preferably, it is provided for implementing a predefined action in the event that the determinations made on the reference elements do not meet the predetermined reference parameters, said predefined action comprising the automatic issuing of a predetermined warning signal and / or a predetermined command signal for an automated control system of the inner assembly production.

[0148] In one embodiment of the method of the invention, it is provided for determining the advancement speed of said at least one separator ribbon and / or of said at least one conductor ribbon on the basis of said determinations made on the reference elements.

[0149] Preferably, it is provided for controlling operating parameters of the production method on the basis of the advancement speed determined.

[0150] In one embodiment of the method of the invention, it is provided for determining the position (in at least one of the three transverse, longitudinal and vertical dimensions) of said at least one separator ribbon and / or of said at least one conductor ribbon on the basis of said determinations made on the reference elements. Preferably, it is provided for controlling operating parameters of the production method on the basis of the determined position.

[0151] Preferably, in the production apparatus, at least one ribbon transported by the transport devices is a separator ribbon provided with reference elements that follow one another substantially in a longitudinal direction of the conductor ribbon. Preferably, said reference elements form on the separator ribbon a pattern readable by a sensor.

[0152] Preferably, the production apparatus comprises a monitoring system comprising at least one detection device associated with a respective separator ribbon and / or a respective conductor ribbon provided with reference elements at a respective detection position along the respective transport path.

[0153] Preferably, said at least one detection device is configured to carry out on the respective ribbon detections adapted to individually identify at least a part of said reference elements passing at the respective detection position.

[0154] Preferably, on the basis of said detections, the monitoring system is configured to individually identify the reference elements of said at least a part of said reference elements.

[0155] Preferably, the monitoring system is configured to monitor operating parameters relating to said ribbon on the basis of determinations made on a plurality of said individually identified reference elements.

[0156] Preferably, the monitoring system is configured to control operating parameters relating to the production apparatus on the basis of said determinations made on said plurality of said individually identified reference elements.

[0157] Preferably, the monitoring system is configured to verify that said determinations meet predetermined reference parameters.

[0158] Preferably, the monitoring system comprises a plurality of detection devices, each detection device being associated with a respective separator and / or conductor ribbon at a respective detection position along the respective transport path.

[0159] Preferably, the monitoring system comprises a plurality of detection devices associated with a same separator and / or conductor ribbon at respective detection positions along the respective transport path. Based on the detections carried out by said plurality of detection devices on the same ribbon, the monitoring system can be configured to control a same operating parameter at the various detection positions (for example mutual alignment of the ribbons in at least one of the three longitudinal, transverse and vertical sections) or different operating parameters (for example, mutual alignment of the ribbons, cutting of the ribbon and / or formation of further reference elements) at each detection position.

[0160] The features and advantages of the invention will become clearer from the detailed description of an embodiment illustrated, by way of non-limiting example, with reference to the appended drawings wherein:

[0161] - figure 1 schematically shows a production apparatus according to an embodiment of the present invention;

[0162] - figure 2 shows a schematic front view of a ribbon without reference elements;

[0163] - figures 3 to 12 are front schematic views of possible alternative embodiments of a ribbon that can be used in an apparatus for producing an inner assembly according to the invention.

[0164] Figure 1 shows a production apparatus 100 for producing inner assemblies 1.

[0165] In the preferred example illustrated and described in detail herein, the production apparatus 100 is intended for the production of inner assemblies 1 to be used to create electrochemical cells.

[0166] The creation of the inner assembly 1 by means of the apparatus 100 of the present invention is carried out starting from at least one conductor ribbon.

[0167] In embodiments of the present invention not shown in the figures attached hereto, the inner assembly 1 can be composed (as discussed above) of a structure formed by a stack of conductor foils individually separated by a separator ribbon or, alternatively, by a multilayer structure of separator sheets alternated to conductor foils.

[0168] In the embodiment illustrated herein, the inner assembly 1 has a coil structure and the inner assembly 1 is packaged starting from a plurality of ribbons N1 , N2, N3, N4, specifically two conductor ribbons N1 , N3 and two separator ribbons N2, N4 arranged alternated. These ribbons N1 , N2, N3, N4 are suitably combined with each other to create an overlapping layer structure in which the anode, a first separator, the cathode and a second separator alternate. The order between anode and cathode is provided only by way of example and a sequence opposite to that previously indicated may also be provided.

[0169] In the embodiment illustrated in figure 1 , the apparatus 100 comprises a dispensing unit 110, a transport system 120 and a coupling unit 130.

[0170] In general, the apparatus 100 is configured to feed the ribbons N1 , N2, N3, N4, through the dispensing unit 110, transport them to the coupling unit 130 through the transport system 120 and couple them together, through the coupling unit 130, to create the inner assembly 1 .

[0171] In the illustrated example, the dispensing unit 110 comprises dispensing devices 111 of the ribbons N1 , N2, N3, N4 which may be large-sized coils in which the ribbons are collected so as to be unwound during operation of the apparatus 100. The dispensing devices 111 may be associated with respective actuators (not illustrated) adapted to rotate them about respective rotation axes.

[0172] The ribbons N1 , N2, N3, N4 unwound from the respective dispensing devices 111 are conveyed towards the coupling unit 130 through the transport system 120 (mainly placed between the dispensing unit 110 and the coupling unit 130).

[0173] The transport system 120 is configured to transport the ribbons N1 , N2, N3, N4 from the dispensing unit 110 to the coupling unit 130 along respective transport paths P1 , P2, P3, P4 different from one another that all converge at the coupling unit 130.

[0174] In the illustrated embodiment, in the coupling unit 130 the ribbons N1 , N2, N3, N4 are coupled by spiral winding, so as to obtain a coil structure.

[0175] In other embodiments, not illustrated in the figures, in the coupling unit 130 one or more separator ribbons can be folded in successive loops, with a substantially "Z" development and coupled, in an alternating manner, to anode elements and cathode elements in the form of foils. In this case, it can be provided for the presence of a special cutting station upstream of the coupling unit 130 adapted to obtain such foils from a cutting operation of one or more conductor ribbons transported by the transport system 120.

[0176] In further embodiments, also not illustrated in the figures, the coupling unit 130 may be configured to couple in an overlapping layer structure a plurality of conductor elements and a plurality of separator elements. In this case, it can be provided for the presence of a special cutting station upstream of the coupling unit 130 adapted to obtain said conductor elements and separator elements from a cutting operation of respective conductor and separator ribbons transported by the transport system 120.

[0177] The terms "upstream" and "downstream" refer herein to an advancement direction A of the ribbons N1 , N2, N3, N4 within the production apparatus 100, i.e. to a direction going from the dispensing devices 111 towards the coupling unit 130.

[0178] In the illustrated embodiment, the coupling unit 130 comprises at least one coupling device 131 , configured to couple the ribbons N1 , N2, N3, N4 so as to form the inner assembly 1 with overlapping layer structure.

[0179] For example, the coupling device 131 may be configured such that the ribbons N1 , N2, N3, N4 converge thereon and, preferably, are wound in a spiral shape.

[0180] The coupling device 131 may be configured to retain the ribbons N1 , N2, N3, N4 while they are coupled to form said inner assembly 1 .

[0181] To this end, in some embodiments it may be provided that the coupling device 131 comprises a gripping device (not shown).

[0182] Advantageously, the gripping device can be made by means of a rotating spindle divided into two portions capable of moving towards and away from each other. In this way a portion of the ribbons N1 , N2, N3, N4 can be interposed between the two portions of the rotating spindle when they are moved away from each other and then be retained between them when the two portions of the rotating spindle are approached against each other. In this way the ribbons N1 , N2, N3, N4 can be grasped to carry out the coupling operation.

[0183] Similarly, by moving both portions of the rotating spindle away, the inner assembly 1 can be unloaded once the coupling and any subsequent processing is finished.

[0184] The coupling device 131 is configured to spirally wind the ribbons N1 , N2, N3, N4 by rotation about a relative rotation axis X1 .

[0185] In preferred embodiments, the coupling unit 130 comprises more than one coupling device 131. In the embodiment illustrated in figure 1 , the coupling unit 130 comprises three coupling devices 131 supported on a support 132, for example in the form of a disc, which rotates about a second rotation axis X2, preferably parallel to the first rotation axis X1 , to alternate the operating position of the coupling devices 131 .

[0186] Preferably the coupling devices 131 are arranged around the rotation axis X2 angularly equally-distant.

[0187] In some embodiments, by rotating around the axis X2, the coupling devices 131 can be transferred from a station A in which the coupling of the ribbons N1 , N2, N3, N4 takes place, or at least begins, to a station B in which a finishing processing of the inner assembly 1 takes place after the coupling operation, to an unloading station C. More generally, however, the execution of the coupling operation and the execution of the finishing processing can also take place while the coupling devices 131 are rotating around the rotation axis X2.

[0188] The finishing processing may, for example, comprise applying at least one ribbon capable of blocking a flap or other portion of the inner assembly 1 in order to maintain the structure in the configuration obtained by winding or other type of coupling. A further example of a finishing operation can also be represented by marking operations, for example by laser, or by welding and / or gluing operations, or other operations suitable for applying inserts. Yet a further example of a finishing operation may comprise a step of folding two opposite axial ends of the conductor ribbons N1 , N3 as explained in more detail below with reference to figure 6.

[0189] In the unloading station C, an unloading device, not illustrated in the figure, picks up the inner assembly 1 after it has undergone finishing processing, to deliver it to a subsequent processing or storage station.

[0190] As approximately illustrated in figure 1 , the production apparatus 100 comprises a plurality of guide members (for example passive rollers 140, i.e. not motorized in rotation) configured to guide the ribbons N1 , N2, N3, N4 along the respective transport paths P1 , P2, P3, P4.

[0191] In use, the ribbons N1 , N2, N3, N4 are unwound continuously from the respective dispensing devices 111 and fed along the respective transport paths P1 , P2, P3, P4 up to the coupling device 131. The latter, once the ribbons N1 , N2, N3, N4 have been grasped, is rotated around its own axis X1 . In this process there may be the need to provide for specific interruptions of one or more of the ribbons N1 , N2, N3, N4 dispensed or to slow down or accelerate the advancement of one or more of the ribbons N1 , N2, N3, N4 due to operating needs linked to the specific processing being carried out.

[0192] For example, in the production of coils intended for the production of electrochemical cells, it may be provided that conductor ribbons N1 , N3 forming anode and cathode respectively are not present in the initial and / or terminal portion of the inner assembly 1 wound to form the coil. In other words, it can be provided that said inner assembly 1 has a terminal and / or initial flap in which only the two overlapping separator ribbons N2, N4 are present.

[0193] For the aforementioned reasons, in the transport system 120, along one or more of the transport paths P1 , P2, P3, P4, it may be provided for the presence of a specific accumulation device 121 (illustrated in figure 1 in a completely schematic way) configured in such a way as to temporarily accumulate a variable quantity of at least one of said plurality of ribbons N1 , N2, N3, N4. For example, in a manner known per se and not described or illustrated in detail, each accumulation device 121 may comprise fixed rollers and movable rollers (not illustrated). The movable rollers are configured to move toward or away with respect to the stationary rollers to vary the length of the accumulated ribbon. Such accumulation devices 121 advantageously allow a continuous unwinding of the respective ribbons N1 , N2, N3, N4 from the respective dispensing devices 131 despite the winding around the coupling devices 131 being intermittent since at the end of each coupling operation in a respective inner assembly 1 the ribbons N1 , N2, N3, N4 are temporarily blocked and cut and the support 132 driven in rotation to bring an empty coupling device 131 from the unloading station C to the coupling station A to start a new coupling cycle.

[0194] The transport system 120 may further comprise at least one unwinding device 122 (illustrated in figure 1 in a completely schematic way) along at least one of the paths P1 , P2, P3, P4 configured to grasp the respective ribbon and draw it towards the coupling unit 130 so as to reduce the load exerted on the coupling device 131 which should actively drag only the terminal part of the ribbon downstream of the unwinding device 122. For example, in a manner known per se and not described or illustrated in detail, each unwinding device 122 may comprise a driving roller operable in rotation to pull the respective ribbon and a passive counter-roller (i.e. not driven in rotation) arranged to press the respective ribbon on an outer lateral surface of the driving roller. The transport system 120 may further comprise at least one tensioning device 123 (illustrated in figure 1 in a completely schematic way) along at least one of the paths P1 , P2, P3, P4 configured to adjust the tension on the respective ribbon. For example, in a manner known per se and not described or illustrated in detail, each tensioning device 123 may comprise a dancer system with at least one tilting (or translating) dancer roller and at least one fixed roller cooperating with the dancer roller to support the respective ribbon.

[0195] The position of the accumulator device 121 , of the unwinding device 122 and of the long tensioning device 123 in transport paths P1 , P2, P3, P4 may be different from that illustrated in figure 1 which is entirely exemplary.

[0196] The production apparatus 100 also comprises cutting devices respectively associated with the ribbons N1 , N2, N3, N4 configured to cut the ribbons N1 , N2, N3, N4 in proximity to the station A where the coupling of the ribbons takes place.

[0197] In particular, in the illustrated embodiment, the case is considered in which the conductor ribbons N1 , N3 are not present in the initial and / or terminal portion of the inner assembly 1 wound to form the coil. In other words, it is provided that this inner assembly 1 has a terminal and / or initial flap in which only the two overlapping separator ribbons N2, N4 are present.

[0198] In this case, the production apparatus 100 comprises two cutting devices 133 configured to cut the conductor ribbons N1 and N3 upstream and in proximity to the coupling device 131 located in the station A for coupling the ribbons. The production apparatus 100 advantageously also comprises grippers (not illustrated) adapted to retain the conductor ribbons N1 , N3 after cutting.

[0199] Once the ribbons N1 , N3 have been cut, two free ends remain defined, one of which is wound on the coupling device 131 which then continues the winding with only the two separator ribbons N2, N4 to end the creation of the current inner assembly 1 . A second free end is instead retained by one of the aforementioned grippers waiting to be coupled to the coupling device 131 on which the winding of the subsequent inner assembly 1 will begin.

[0200] The cutting devices 133 may comprise a knife or other cutting system such as a laser ablation system or ultrasonic or a hot-wire system.

[0201] The production apparatus 100 comprises a further cutting device 134 configured to cut, once the winding operation on the coupling device 131 is ended, also the ribbons N2, N4 remained after the ribbons N1 , N3 have been cut by the cutting devices 133.

[0202] For example, the cutting device 134 can be configured in such a way as to cut the ribbons N2, N4 in a cutting zone defined in an intermediate position between the coupling station A and the finishing station B.

[0203] Once the ribbons N2, N4 have been cut, two free ends remain defined, one of which is wound on the coupling device 131 which is brought at the finishing station B, thus ending the creation of the current inner assembly 1 . A second free end, on the other hand, is wound on the coupling device 131 arranged at the coupling station A, so as to start the winding of the next inner assembly.

[0204] The cutting device 134 may comprise a knife or other cutting system such as a laser ablation system or ultrasonic or hot-wire.

[0205] According to the invention, at least one of the conductor ribbons N1 , N3 is provided with reference elements 17 which follow one another substantially in a longitudinal direction L of the respective ribbons so as to form a pattern T readable by a sensor during the production of the inner assembly 1 . Preferably, both conductor ribbons N1 , N3 are provided with reference elements 17.

[0206] In the illustrated embodiment, all the ribbons N1 , N2, N3, N4, both the separator ribbons N2, N4, and the conductor ribbons N1 , N3, are provided with reference elements 17 following one another in a longitudinal direction L of the respective ribbons N1 , N2, N3, N4.

[0207] The invention however also applies to cases where the reference elements 17 are present on only one or only part of the ribbons N1 , N2, N3, N4.

[0208] The ribbons N1 , N2, N3, N4 can be, in whole or in part, stored in the respective dispensing devices 111 devoid of the respective reference elements 17.

[0209] In this case, the production apparatus 100 preferably comprises forming devices 112 configured for forming said reference elements 17 on all or part of the ribbons N1 , N2, N3, N4.

[0210] In the illustrated embodiment, the production apparatus 100 comprises forming devices 112 for forming said reference elements 17 on all the ribbons N1 , N2, N3, N4. The forming devices 112 are arranged along the paths P1 , P2, P3, P4 immediately downstream of the dispensing devices 111 of the respective ribbons N1 , N2, N3, N4.

[0211] For example, the forming devices 112 may comprise suitable devices adapted, in a manner known per se and not described or illustrated in detail, to carry out a printing (e.g. ink), drilling, thermoforming, cutting, compressing or notching operation, for example by laser ablation.

[0212] In an alternative embodiment (not illustrated), the ribbons N1 , N2, N3, N4 can be, in whole or in part, stored in the respective dispensing devices 111 already provided with the respective reference elements 17. In this case, the forming devices 112 may be omitted for such ribbons. Each ribbon N1 , N2, N3, N4 stored in the respective dispensing device 111 may have hundreds or thousands or tens of thousands of reference elements 17, depending on the length (e.g. tens or hundreds of metres) of the ribbon stored in the respective dispensing device 111 and / or the density required for the reference elements 17.

[0213] As illustrated in figures 2-8, each ribbon N1 , N2, N3, N4 has a height H measured along a transverse direction of the ribbon. In addition, each ribbon N1 , N2, N3, N4 has two opposite free edges 12a, 12b extending along the longitudinal direction L of the ribbon and being spaced from each other by said height H.

[0214] The height H is typically selected as a function of the height of the inner assembly 1 to be made.

[0215] According to the invention, the reference elements 17 act as references readable by a sensor. In particular, the reference elements 17 have parameters detectable by said sensor including at least one of longitudinal dimension, transverse dimension, structure, shape, material, colour, mutual distance and position that are collectively selected to allow monitoring one or more operating parameters of the conductor ribbon during the production of the inner assembly 1 .

[0216] Figure 2 shows an example of ribbon N1 , N2, N3, N4 that can be stored in the respective dispensing device 111 devoid of the respective reference elements 17. This ribbon has both major surfaces with a "neutral" appearance, generally even. In other words, such surfaces are devoid of elements that could provide a pattern T readable by a sensor during production of the inner assembly 1 within the production apparatus 100. This "neutral" appearance is typical of a separator ribbon N2, N4 which by its nature has surfaces with a generally even appearance. According to the invention, said separator ribbon N2, N4 is equipped with the reference elements 17 so as to provide a pattern T readable by a sensor during the production of the inner assembly 1 inside the production apparatus 100. As explained in more detail below, this "neutral" aspect can also concern a conductor ribbon N1 , N3.

[0217] Figures 3-9 show examples of ribbons N1 , N2, N3, N4 provided with respective reference elements 17.

[0218] In the cases illustrated in figures 3-9, the reference elements 17 follow one another with a constant pitch. In other words, the reference elements 17 are equally-distant from each other and spaced apart from each other, along the longitudinal direction L of the ribbon N1 , N2, N3, N4, by a predetermined distance D.

[0219] For example, in the embodiments illustrated in figures 3-5, 7 and 8, the reference elements 17 are densely distributed and the distance D may have a value comprised between 0.2 mm and 5 mm.

[0220] In the embodiments illustrated in figures 6 and 9, on the other hand, the reference elements 17 are more loosely distributed and the distance D can have a value comprised between 5 mm and 100 mm.

[0221] In the cases illustrated in figures 3-5, the reference elements 17 are made on one of the two major surfaces of the ribbon N1 , N2, N3, N4, in particular on the upper surface with respect to the respective transport path P1 , P2, P3, P4 within the production apparatus 100.

[0222] In the cases illustrated in figures 6-9, the reference elements 17 are made at the free edge 12a of the ribbon N1 , N2, N3, N4.

[0223] In the cases illustrated in figures 3-9, the reference elements 17 are distributed evenly in the longitudinal direction L and follow one another in said longitudinal direction L substantially over the entire length of the respective transport path P1 , P2, P3, P4 or over a large part of such length. Typically, in this length of the respective transport path P1 , P2, P3, P4, each ribbon N1 , N2, N3, N4 is provided with tens, hundreds or thousands of reference elements 17, depending on the extension of this length and the desired distribution density for the reference elements 17 In particular, in the embodiments illustrated by way of example in figures 3-9, the reference elements 17 are grouped in groups of reference elements 17 following one another along the longitudinal direction L of the ribbon N1 , N2, N3, N4 and said groups of reference elements 17 are separated from one another by a free window 10 of a predetermined length F. For example, in the embodiments illustrated, the length F can have a value comprised between 100mm and 1000mm.

[0224] Preferably, for each ribbon N1 , N2, N3, N4, the groups of reference elements 17 all have a same longitudinal extension corresponding to a desired length for the respective ribbon N1 , N2, N3, N4 in the final inner assembly 1. This length is typically different from ribbon to ribbon. For example, this length can be comprised between 1500 mm and 8000 mm.

[0225] Preferably, each group comprises tens or hundreds or thousands of reference elements 17.

[0226] The reference elements 17 may be tabs, holes, notches, marks (in particular graphic marks), protrusions and the like.

[0227] In some embodiments, the reference elements 17 have structure, shape, material, colour, position, and / or dimensions which make them mechanically and electrically substantially neutral. This ensures that their presence does not require redesigning the inner assembly 1.

[0228] The reference elements 17 can follow one another in proximity to or at one of the two free edges 12a, 12b of the ribbon N1 , N2, N3, N4 (for example, of the free edge 12a in the case of figures 4-8) or in a central zone of the ribbon N1 , N2, N3, N4 (see figure 3).

[0229] Preferably, the reference elements 17 all have the same longitudinal dimension d and the same transverse dimension.

[0230] In the embodiments illustrated by way of example in figures 3-9, the reference elements 17 of each ribbon N1 , N2, N3, N4 are all of the same type and equal to each other. In particular, they all have the same dimension and shape. In addition, they are aligned with each other along the same line parallel to the longitudinal direction L.

[0231] The reference elements 17 could in any case be different from ribbon to ribbon. For example, it could be provided that the reference elements 17 are equal to each other for each pair of separator ribbons N2, N4 and for each pair of conductor ribbons N1 , N3 but that they are different for the two pairs.

[0232] As illustrated in figures 3-9, the reference elements 17 extend transversely between two longitudinal ends 17a, 17b which are transversely opposite to them. Furthermore, the reference elements 17 extend in the longitudinal direction between two transverse (or lateral) ends 19 that are longitudinally opposite to each other. The longitudinal direction d extends between the two transverse ends 19 while the transverse direction extends between the two longitudinal ends 17a, 17b.

[0233] In the embodiment of figure 3, the reference elements 17 are in the form of a circle. These circles may be small through holes (for example with a diameter comprised between 0.2 and 0.5 mm) or may be surface markings printed, notched or protruding on one of the two major surfaces of the respective ribbon N1 , N2, N3, N4 with a notch depth or height of the protrusion that substantially does not alter the surface of the ribbon. Furthermore, the reference elements 17 are located in a central position, spaced from the two opposite free edges 12a, 12b. In particular, the two longitudinal ends 17a, 17b and the two transverse ends 19 are contained inside the free edges 12a, 12b; in particular, said ends 17a, 17b and 19 are spaced apart and separated from the free edges 12a, 12b. In this case, the reference elements 17 guarantee the continuity of both the two free edges 12a, 12b.

[0234] In the embodiment of figure 4, the reference elements 17 are in the form of squares. Such squares may be notched or protruding on one of the two major surfaces of the respective ribbon N1 , N2, N3, N4 with a notch depth or height of the protrusion that substantially does not alter the surface of the ribbon. Alternatively, such squares may be drawn or printed in dark colour on one of the two major surfaces. Furthermore, the reference elements 17 are located in proximity to the free edge 12a with the two longitudinal ends 17a, 17b and the two transverse ends 19 contained inside the free edges 12a, 12b. In particular, said ends 17a, 17b and 19 are spaced apart and separated from the free edges 12a, 12b. Also in this case, therefore, the reference elements 17 guarantee the continuity of both the two free edges 12a, 12b.

[0235] In the embodiment of figure 5, the reference elements 17 are in the form of butterflies that could be printed, notched or protruding on one of the two major surfaces of the respective ribbon N1 , N2, N3, N4 with a notch depth or height of the protrusion that substantially does not alter the surface of the ribbon. Furthermore, the reference elements 17 are located in proximity to the free edge 12a with the two longitudinal ends 17a, 17b and the two transverse ends 19 contained inside the free edges 12a, 12b. In particular, said ends 17a, 17b and 19 are spaced apart and separated from the free edges 12a, 12b. Also in this case, therefore, the reference elements 17 guarantee the continuity of both the two free edges 12a, 12b.

[0236] In other embodiments (not illustrated), the reference elements 17 may have different shapes and positions with respect to those shown by way of example only in figures 3-5. For example, they could be tangent to or aligned with one of the two free edges 12a, 12b.

[0237] In the embodiments of figures 6-7, the reference elements 17 are recesses made in a transverse direction starting from the free edge 12a of the ribbon N1 , N2, N3, N4.

[0238] It is noted that although in figures 6-7, the recesses are made in a direction perpendicular to the free edge 12a so as to form reference elements 17 of substantially rectangular or square shape, such recesses could be made in an incident direction (i.e. inclined by an angle other than 90°) with respect to the free edge 12a so as to form reference elements 17 having different shapes, for example fishbone.

[0239] In the embodiments of figures 8-9, the reference elements 17 are tab-shaped where the transversely outer longitudinal end 17a protrudes from the free edge 12a of the ribbon and the two opposite transverse ends 19 extend in a transverse direction starting from the free edge 12a towards the inside of the ribbon. In particular, each tab has a substantially rectangular or square shape defined by three free edges formed by the two transverse ends 19 (extending in the transverse direction) and the transversely outer longitudinal end 17a (extending in the longitudinal direction L). The transversely inner end 17b is aligned with the free edge 12a. These tabs can be made by making transverse cuts or holes along a free edge 12a’ of a starting ribbon having a height H’ greater than the height H as per design for the ribbon. After their use as a pattern T readable by a sensor by the monitoring system 150 described below, these tabs can be removed upstream or downstream of the coupling device 131 to return the ribbon N1 , N2, N3, N4 to the design height H before the coupling of the ribbons N1 , N2, N3, N4 for the formation of the inner assembly 1 , or they can be folded.

[0240] It is noted that although in figures 8-9, the two transverse ends 19 of each tab extend in the transverse direction, such transverse ends 19 could extend in an incident direction with respect to the free edge 12a and, possibly, in two different directions from one another.

[0241] Preferably, in order to avoid an overlap of the reference elements 17, the distance D between two consecutive reference elements is greater than or equal to the longitudinal dimension d of the reference elements.

[0242] For example, in figure 7, the distance D between two consecutive reference elements is substantially twice the longitudinal dimension d of the reference elements 17.

[0243] In the embodiments illustrated in figures 3-9, the reference elements have a longitudinal dimension d with a value comprised between 1 and 5 mm, preferably between 2 and 3 mm.

[0244] In addition, they have a transverse dimension with a value comprised between 1 and 5 mm, preferably between 2 and 3 mm.

[0245] Thanks to these dimensions, the configurations illustrated in figures 3-9 advantageously provide a pattern T with reference elements 17 that can be easily distinguished from one another by a commercially available low-cost sensor, without requiring particularly high resolutions. The identification of the individual reference elements 17 can, for example, be carried out with a photoelectric sensor adapted to provide an output signal of the on-off or 1 -0 type or an image acquisition device with adequate resolution, possibly associated with an illumination device adapted to back-light the ribbon with respect to the image acquisition device. Thanks to the dimensions of the reference elements, it is possible to use a commercially available low-cost sensor, with a medium-low resolution.

[0246] The reference elements 17 described with reference to figure 7 form tabs 20 that lend themselves to being used in particular for the conductor ribbons N1 , N3 as these tabs 20 can constitute functional elements thereof, adapted to facilitate a step of defining the electrical pole of an electrochemical cell as well as to improve the evenness of electrical contact between the electrical pole and the conductor ribbon of the electrochemical cell. In fact, once the electrochemical cell is completed, the conductor ribbons N1 , N3, act as electrodes in particular as an anode and cathode for the electrochemical cell.

[0247] As schematically illustrated in figure 7, usually the conductor ribbon N1 , N3 comprises a first longitudinal portion 15 devoid of active electrode material 14 and a second longitudinal portion 16 having the active material 14. In this case, the reference elements 17 are preferably contained in the first longitudinal portion 15 free of active electrode material 14.

[0248] The first longitudinal portion 15 extends transversely starting from the longitudinal free edge 12a towards the other free edge 12b without however reaching said other free edge 12b. The extension in the transverse direction of the first portion 15 is lower than the transverse extension of the second longitudinal portion 16.

[0249] The second longitudinal portion 16 is transversely contiguous to the first longitudinal portion 15 and extends transversely starting from the other longitudinal free edge 12b.

[0250] The active electrode material 14 may be an anodic or cathodic material and may comprise, in the case of anodic material, graphite or other carbonaceous materials or silicon-based materials and, in the case of cathodic material, lithium oxide, nickel, manganese, cobalt, aluminium or lithium and iron phosphate-based materials.

[0251] The conductor ribbons N1 , N3 are typically wound in such a way that, at a first end of the electrochemical cell, a first conductor ribbon N1 protrudes beyond the separator ribbon N2, N4 (to define an electrical pole of the electrochemical cell) and in such a way that the separator ribbon N2, N4 protrudes beyond the second conductor ribbon N3 (to avoid short circuits between the two electrodes). Similarly, at the second end of the electrochemical cell the second conductor ribbon N3 protrudes beyond the separator ribbon N2, N4 and the separator ribbon N2, N4 protrudes beyond the first conductor ribbon N1 .

[0252] Typically, each part of conductor ribbon N1 , N3 projecting from the separator ribbon N2, N4 is not coated with active electrode material 14 and is used to define an electrical pole of the electrochemical cell. In particular, in order to improve the evenness of electrical contact between electrical pole and conductor ribbon of the electrochemical cell, the part of each conductor ribbon N1 , N3 projecting with respect to the separator ribbon N2, N4 is usually folded towards a central axis of the electrochemical cell to define a (more or less regular) electrical pole surface of the electrochemical cell to which an electrical pole plate can be connected or which can be connected to a battery pole. This folding step can be facilitated thanks to the tabs 20 described with reference to figure 7 made in the conductor ribbons N1 , N3.

[0253] The aforesaid folding step can, for example, be carried out in the finishing station B or another station.

[0254] It is noted that while for the separator ribbons N2, N4 the reference elements 17 are elements added ad hoc on surfaces which by themselves have a generally even appearance this is not necessarily true for the conductor ribbons N1 , N3.

[0255] For the conductor ribbons N1 , N3, in fact, there may be cases in which the production process provides for using conductor ribbons having surfaces with a generally even appearance (for example, devoid of tabs or slots or other elements necessary to meet predetermined mechanical and / or electrical characteristics of the inner assembly) and, therefore, originally devoid of elements that could provide a pattern readable by a sensor and usable during the production process of the inner assembly 1 . In these cases, similarly to what is done for the separator ribbons N2, N4, it can be envisaged to equip such ribbons with the reference elements 17.

[0256] On the other hand, there may be cases in which the production process provides for using conductor ribbons N1 , N3 already provided, for mechanical and / or electrical needs, with elements such as the tabs 20 described with reference to figure 7 that alter the evenness of such surfaces.

[0257] In these cases, it may be provided for exploiting the pattern already provided by such tabs 20 or by the recesses 17 forming such tabs 20 to carry out the controls required during the production process of the assembly 1 in the production apparatus 100. Alternatively or in addition, in the event that the pattern already provided by these elements is not sufficient or in any case is not adequate to implement the required controls, it can be envisaged (as schematically illustrated in figures 10-12 below) to add the reference elements 17 of the type described above in such a way as to form a further and different pattern T that lends itself to being exploited by the monitoring system 150 described below to carry out improved readings or in any case different from the readings that can be carried out with the pattern T’ provided by the elements already present. By way of example, figure 10 shows a case in which the production process provides for using conductor ribbons N1 , N3 already provided, for mechanical and / or electrical needs, with tabs 20 formed by recesses 17’ that form a pattern T’ to which, for production process control needs, auxiliary reference elements 17 of the type described above are added that are such as to form a further and different pattern T that lends itself to being exploited by the monitoring system 150 to carry out improved readings or in any case different from the readings that can be carried out with the pattern T’ provided by the tabs 20 already present. In the example illustrated in figure 10, the reference elements 17 are in the shape of butterflies as in the embodiment of figure 5 and are positioned in proximity to the free edge 12b which is opposite to that in which the pattern T’ formed by the tabs 20 is present. Compared to the pattern T’, the pattern T is formed by reference elements 17 which, having a larger longitudinal dimension d than the recesses 17’, can be more easily distinguished from each other using a commercially available low-cost sensor.

[0258] As a further example, figure 11 shows a case in which the production process provides for using conductor ribbons N1 , N3 already provided, for mechanical and / or electrical needs, with tabs 20 that form a pattern T’ to which, for production process control needs, auxiliary reference elements 17 of the type described above are added that are such as to form a further and different pattern T that lends itself to being exploited by the monitoring system 150 to carry out improved readings or in any case different from the readings that can be carried out with the pattern T’ provided by the tabs 20 already present. In the example illustrated in figure 11 , the auxiliary reference elements 17 are in the form of circles as in the embodiment of figure 3 and are positioned in proximity to the same free edge 12a in which the pattern T’ formed by the tabs 20 is already present. Furthermore, in the example illustrated in figure 11 , the auxiliary reference elements 17 are distributed evenly in the longitudinal direction L of the ribbon N1 , N3, without free windows. Compared to the pattern T’ which is discontinuous due to the presence of the free windows 10, the even distribution of the pattern T can improve the accuracy and reliability of some detections carried out on the reference elements 17, for example, to determine the advancement speed thereof and their actual position.

[0259] As a further example, figure 12 shows a case in which the production process provides for using conductor ribbons N1 , N3 provided with tabs 20 adapted to facilitate - as described above - the step of defining the electrical pole as well as to improve the evenness of electrical contact between the electrical pole and the conductor ribbon of the electrochemical cell. In this case, it may be provided for the presence of auxiliary reference elements 17 of the type described above that are such as to form a pattern T that lends itself to being exploited by the forming devices 112 described above to facilitate the forming step of such tabs 20. This pattern T can in fact be exploited to indicate to the forming devices 112 the exact positions in which to carry out the recesses 17’ suitable for defining the tabs 20. This pattern T can then be used again along the transport path P1 , P3 of the conductor ribbon N1 , N3 to monitor the ribbon at one or more detection positions R1 , R2, R3, as described in more detail below.

[0260] In the example illustrated in figure 12, the auxiliary reference elements 17 are dots positioned in proximity to the same free edge 12a in which the pattern T’ formed by the recesses 17’ is to be formed.

[0261] In the case of figure 12, it can be provided that the conductor ribbons N1 , N3 are stored in the respective dispensing devices 111 already provided with the reference elements 17 and that the forming devices 112 are adapted to form the tabs 20 on these ribbons with the aid of the pattern T provided by the reference elements 17.

[0262] Alternatively, it can be provided that the conductor ribbons N1 , N3 are stored in the respective dispensing devices 111 without both the reference elements 17 and the tabs 20 and that the forming devices 112 are adapted to form the reference elements 17 first; thereafter the tabs 20 can be made with the aid of the pattern T provided by the reference elements 17.

[0263] It is noted that although the configurations of figures 10-12 have been described with reference to conductor ribbons N1 , N3, it is not excluded that they can be used to make two different patterns T, T’ in the separator ribbons N2, N4.

[0264] It is also noted that figures 3-12 represent the ribbons N1 , N2, N3, N4 and the reference elements 17 in a completely indicative and schematic way (in other words, they are not to scale so it is not possible to derive precise values for the dimensions of the various elements depicted).

[0265] According to the invention, the apparatus 100 also comprises a monitoring system 150 comprising a plurality of detection devices 151 associated with each ribbon N1 , N2, N3, N4 at respective detection positions R1 , R2, R3 along the respective transport path P1 , P2, P3, P4. Each detection device 151 is configured to make detections on the reference elements 17 passing at the respective detection position R1 , R2, R3.

[0266] To this end, each detection device 151 may comprise, for example, a photoelectric type sensor; a magnetic sensor; an image acquisition device and / or an RGB sensor. In the case of a magnetic sensor, the reference elements 17 may comprise ferromagnetic material adapted to be intercepted by said sensor.

[0267] Each detection device 151 is preferably configured (e.g., in terms of resolution, illumination, and / or optics) to make detections that allow the reference elements 17 to be individually identified (i.e., one by one). For example, in a preferred embodiment, the image acquisition device is part of a vision system comprising a lighting device (not illustrated) positioned so as to back-light the ribbon with respect to the image acquisition device.

[0268] The photoelectric type sensor may comprise, for example, a laser photocell, a photo-barrier sensor, a fibre optic sensor, and / or a reflection sensor.

[0269] For example, when the reference elements 17 are formed by notches, graphic marks or protrusions it may be useful to use a magnetic sensor, an image acquisition device (possibly associated with a backlight as discussed above) and / or an RGB sensor.

[0270] On the other hand, when the reference elements 17 are formed by holes or tabs having a longitudinal dimension d of a certain width as in the embodiments illustrated, it may be useful to use a photoelectric sensor. In this case, this sensor can provide in output an on-off (or 1-0) type signal.

[0271] Although the embodiment illustrated in figure 1 comprises a same plurality of detection devices 151 for each ribbon N1 , N2, N3, N4, the invention also applies to the case of only one detection device for each ribbon N1 , N2, N3, N4 or to the case of a different number of detection devices 151 for each ribbon N1 , N2, N3, N4, including the case of absence of detection devices for one of the ribbons N1 , N2, N3, N4 or a part thereof.

[0272] Based on the detections carried out on the reference elements 17 by the detection devices 151 , the monitoring system 150 is preferably configured (for example in terms of hardware and / or software) to identify the individual reference elements 17, distinguishing them from one another. In particular, the monitoring system 150 is preferably configured to process the detections carried out on the reference elements 17 so as to determine the presence or absence of the individual reference elements 17; the distance D between two consecutive reference elements 17; the position of the reference elements 17; the dimensions of each reference element 17; the shape of each reference element 17; the frequency of detection of the reference elements 17 and / or the advancement speed of the reference elements 17.

[0273] Furthermore, the monitoring system 150 may be configured to determine the longitudinal extension of each group of reference elements 17; the presence or absence of the free window 10; the length of each free window 10; the frequency of detection of the free windows 10 and / or the advancement speed of the free windows 10.

[0274] The monitoring system 150 is preferably configured to monitor operating parameters relating to at least one of said ribbons N1 , N2, N3, N4 (for example position and / or advancement speed) by processing the detections made on a plurality (for example tens, hundreds or thousands) of individually identified reference elements 17.

[0275] The monitoring system 150 is preferably configured to separately and / or jointly process the detections carried out on the reference elements 17 of each ribbon N1 , N2, N3, N4 at each detection position R1 , R2, R3.

[0276] The monitoring system 150 is preferably configured to separately and / or jointly process the detections carried out on the reference elements 17 of the various ribbons N1 , N2, N3, N4 at the respective detection positions R1 , R2, R3.

[0277] The aforementioned processing may be implemented at least in part at a central level by a central processing unit 152 operatively associated with the various detection devices 151 and / or at least in part locally by each detection device 151.

[0278] The monitoring system 150 can be configured to exploit the detections carried out on the reference elements 17 of the various ribbons N1 , N2, N3, N4 only for the purpose of collecting data on the operation of the production apparatus 100 or it can exploit these detections to carry out not only a monitoring but also a control of the production of the inner assembly. That is, the data collected can be used to intervene on the production process.

[0279] For example, the monitoring system 150 is configured to verify that the detections carried out on the reference elements 17 and / or groups of reference elements 17 meet predetermined reference parameters.

[0280] Furthermore, the monitoring system 150 is configured to implement a predefined action on the basis of the detections carried out on the reference elements 17 and / or groups of reference elements 17, for example in the event that the detections carried out by one or more of the detection devices 151 do not meet said predetermined reference parameters.

[0281] Such implementation of said predefined action may be implemented at least in part at a central level by the central processing unit 152 and / or at least in part locally by each detection device 151 .

[0282] Said action may comprise the automatic issuing of a predetermined warning signal and / or a predetermined command signal for an automated control system (not shown) of the production apparatus 100.

[0283] The warning signal can be of the visual and / or audible type and be adapted to warn an operator on the non-conformities found with respect to the predetermined reference parameters.

[0284] In addition or alternatively, the monitoring system 150 can be configured to automatically stop the production apparatus 100 and / or define, by means of appropriate decision-making algorithms, a corrective action to be taken to remedy the non-conformities identified between the detections made on the reference elements 17 and the predetermined reference parameters; signal the corrective action to be taken; indicate (for example by means of a display, not illustrated) a sequence of step-by-step instructions to guide an operator in implementing the corrective action.

[0285] The corrective action may, for example, result in one or more inner assemblies 1 being discarded during production in the apparatus 100. In this case, the assembly to be discarded can be delivered from the unloading station C to a special station adapted to collect the assemblies 1 to be discarded. The decision to discard could derive from the detection of parameters that do not meet the design specifications for the inner assembly 1 which may, for example, be relating to the same reference elements 17, to the mutual alignment of the various ribbons N1 , N2, N3, N4, to their tensioning, to their length in the inner assembly 1 etc.

[0286] In addition or alternatively, the corrective action may concern one or more of the devices present in the production apparatus 100 such as the dispensing devices 111 , the forming devices 112, the accumulator devices 121 , the unwinding devices 122, the tensioning devices 123, the winding devices 131 and the cutting devices 133, 134.

[0287] For example, in the case of defective reference elements 17 the corrective action may concern the forming devices 112.

[0288] In the case of reference elements 17 advancing at a higher or lower speed than that as per design, the corrective action may, for example, concern the dispensing devices 111 and / or the accumulator devices 121 and / or the unwinding devices 122 and / or the tensioning devices 123.

[0289] In case a mutual misalignment is detected between the ribbons N1 , N2, N3, N4 in the transverse, longitudinal and / or vertical direction, the corrective action may, for example, concern the dispensing devices 111 and / or the accumulator devices 121 and / or the unwinding devices 122 and / or the tensioning devices 123 and / or any alignment devices of the ribbons N1 , N2, N3, N4 (not illustrated) of the production apparatus 100.

[0290] The corrective action can be implemented by the aforementioned automated control system of the production apparatus 100 with the aid of actuators (not illustrated) operatively associated with one or more of the devices present in the production apparatus 100 such as the dispensing devices 111 , the forming devices 112, the accumulator devices 121 , the unwinding devices 122, the tensioning devices 123, the winding devices 131 , the cutting devices 133, 134.

[0291] In this case, the detection devices 151 and / or the central unit 152 will be adapted to send appropriate command signals to the actuators so that they can implement the respective corrective action to be taken.

[0292] With an appropriate feedback system, the detection devices 151 and / or the central unit 152 will then be able to check that the corrective actions taken are effectively effective in returning the detections carried out on the reference elements 17 in compliance with the respective predetermined reference parameters.

[0293] Thanks to the detections carried out on the reference elements 17 and on the groups of reference elements 17, it is therefore possible to monitor operating parameters relating to the ribbons N1 , N2, N3, N4 and to control the production process of the inner assembly 1 .

[0294] For example, it is possible to verify in real time, and in a non-invasive way, for each ribbon N1 , N2, N3, N4 the amount of material that is fed instant by instant and, in particular, the advancement speed at the respective detection positions R1 , R2, R3 and identify the presence of any deviations from a quantity / speed as per designed. This check is extremely important to make sure that the inner assembly 1 produced by the production apparatus 100 has the right amount of material of the four ribbons N1 , N2, N3, N4 and that they are wound with the desired winding tension (i.e. that they are not wound looser or tighter than the design specifications).

[0295] Compared to a solution that monitors the feeding of the ribbons N1 , N2, N3, N4 by means of, for example, a linear encoder associated with one of the guide rollers 140, which does not take into account any slippage of the ribbon N1 , N2, N3, N4 on the guide roller 140, the invention provides a reliable solution that allows the detections to be carried out directly on the ribbon N1 , N2, N3, N4 and thus be free from any slippage problems of the ribbon N1 , N2, N3, N4 on the guide roller 140.

[0296] In addition or alternatively, by taking measurements on the reference elements 17, the present invention allows to verify the presence of any forming defects of the reference elements 17 that could lead to the formation of defective products in cases where said reference elements 17 constitute functional elements useful to create the inner assembly 1 (for example, in the case of a use of the tabs 20 during the definition of the electrical pole of the electrochemical cell as described above with reference to figure 7).

[0297] In addition or alternatively, as described above with reference to figure 12, the detections on the reference elements 17 can be exploited by the forming devices 112 to accurately determine the positions on which to carry out the tabs 20.

[0298] In addition or alternatively, the detections carried out by the detection devices 151 that are positioned at the detection position R3 that is in proximity to the cutting devices 133, 134 can be advantageously used to control the cutting of the ribbons N1 , N2, N3, N4 on the basis of the detections carried out on the reference elements 17.

[0299] In particular, the cutting devices 133, 134 are preferably configured to cut the ribbons N1 , N2, N3, N4 at the free windows 10 between one group of reference elements 17 and the other. Considering that, thanks to the detections on the reference elements 17, it is possible to know instant by instant the amount of ribbon N1 , N2, N3, N4 that is actually fed and, in particular, the speed with which it is actually fed at the detection position R3, the cutting devices 133, 134 can advantageously exploit this information to carry out a real-time control of the cutting of the ribbons N1 , N2, N3, N4. In particular, after cutting at a free window 10, the cutting devices 133, 134 are able to determine in a predictive and precise way at which time instant to make the next cut, once they know the distance between two consecutive free windows 10 and the actual current advancement speed of the ribbon N1 , N2, N3, N4 at the detection position R3.

[0300] In addition or alternatively, with a suitable vision system, the aforementioned detections can be exploited to determine in real time the mutual position of the various ribbons N1 , N2, N3, N4 and / or the position of each ribbon N1 , N2, N3, N4 along the direction of the respective transport path P1 , P2, P3, P4 and / or in a direction transverse to the direction of the respective transport path. The positions thus determined can, for example, be compared with references to verify the presence of any deviations from design specifications.

[0301] In addition or alternatively, the aforementioned detections can be exploited to measure displacements and / or vibrations of the ribbon N1 , N2, N3, N4 in a vertical direction (which is perpendicular to the two transverse and longitudinal directions) and the frequency of vibration of the ribbon in said vertical direction.

[0302] The reference elements 17 thus provide a pattern T readable by a sensor during the production of the inner assembly 1. In particular, the sensor can make detections on individual reference elements 17, on groups of reference elements 17 and / or on predetermined portions of ribbon N1 , N2, N3, N4 that advances along the respective transport path P1 , P2, P3, P4 that can be exploited by the monitoring system 150 to monitor operating parameters of the ribbons N1 , N2, N3, N4 and control operating parameters relating to the production of the inner assembly 1 .

[0303] Thanks to the determinations made on a multitude of individually identified reference elements, the invention makes it possible to monitor these operating parameters of the ribbons N1 , N2, N3, N4 in real time and in a precise and non- invasive way.

[0304] In configurations of ribbons N1 , N2, N3, N4 similar to those shown in figures 10- 12, the monitoring system 150 may exploit both patterns T and T’ to perform the above-described monitoring and controls.

[0305] As described above, in the case of the separator ribbons N2, N4, which by their nature have surfaces with an even appearance, these reference elements 17 are accessory elements with respect to the mechanical and / or electrical characteristics of the inner assembly 1 and are added ad hoc for the sole purpose of providing a pattern readable by a sensor that can be used by the monitoring system 150 during the production process of the inner assembly 1.

[0306] In the case of the conductor ribbons N1 , N3, these reference elements 17 may be elements necessary to meet predetermined structural and / or electrical characteristics of the inner assembly 1 (as, for example, in the case of the tabs 20 of the conductor ribbons N1 , N3 described with reference to figure 7). Alternatively, such reference elements 17 may be accessory elements with respect to mechanical and / or electrical characteristics of the inner assembly 1 and be added ad hoc for the sole purpose of providing a further pattern readable by a sensor and usable by the monitoring system 150 during the production process of the inner assembly 1 . This can be particularly useful in the case where the production process provides for using a conductor ribbon having surfaces with a generally even appearance or in the case of a conductor ribbon N1 , N3 already provided, for mechanical and / or electrical needs (as shown, for example, with reference to figures 10-12), with elements such as tabs 20 or slots that alter the evenness of said surfaces, to provide said conductor ribbon N1 , N3 with a further pattern with respect to that provided by said elements.

[0307] The production apparatus 100 described above advantageously allows to produce a high number of inner assemblies per minute (for example 10, 20, 30 or 40 per minute) and to guarantee high advancement speeds of the ribbons N1 , N2, N3, N4, for example of the order of 1 -5 m / s.

[0308] In the embodiment illustrated in figure 1 , the production apparatus 100 comprises a fixed frame 101 , a movable support 135 and a movement device (not illustrated) configured to move the movable support 135 with respect to the fixed frame 101.

[0309] In this embodiment, the coupling unit 130 is preferably mounted on the movable support 135 so as to be moved integrally with the movable support 135. In this case, the coupling devices 131 and the support 132 are, on the one hand, movable in rotation around the respective axes X1 , X2 with respect to the movable support 135 and, on the other hand, are mounted on the movable support 135 so as to be moved integrally therewith.

[0310] The movement device is configured to move the movable support 135 according to an alternating translation motion along a translation direction Tr.

[0311] In this embodiment, the cutting devices 133, 134 and the detection devices 152 for supporting the cutting at the detection position R3 are preferably mounted on the movable support 135 so as to be moved integrally with the movable support 135.

[0312] In the illustrated embodiment, some guide rollers 140 are mounted on the movable support 135 while other guide rollers 140 are mounted integral to the fixed frame 101.

[0313] Furthermore, the detection devices 151 at the detection positions R1 , R2, the dispensing devices 111 , the forming devices 112, the accumulator devices 121 , the unwinding devices 122 and the tensioning devices 123 are mounted integral to the fixed frame 101 .

[0314] Preferably the movable body 135 may be in the form of a movable carriage oscillating back and forth in the translation direction Tr.

[0315] The movement along the translation direction Tr of the coupling devices 131 realized by means of the movable body 135 advantageously has the effect of varying the length of the paths P1 , P2, P3, P4 of the ribbons N1 , N2, N3, N4.

[0316] This can make it possible to obtain an accumulation effect and, by coordinating the movement in the translation direction with the coupling operation, it is possible to form the inner assembly 1 in association with the movement of the coupling device 131 along the direction T. This can entail a series of advantages, in particular the possibility of producing the inner assembly 1 according to a continuous process without the need to stop or slow down the ribbons N1 , N2, N3, N4 during the various coupling, finishing and unloading steps, to increase the speed of creation of the inner assembly 1 and to avoid or contain the onset of tension states on the ribbons N1 , N2, N3, N4 during processing.

[0317] The present invention applies in any case also to the case in which all the devices of the production apparatus 100 are mounted on one or more fixed frames, without the presence of the movable body 135.

Claims

1. CLAIMS1 . Inner assembly of an electrochemical cell intended for battery production, said inner assembly comprising a conductor ribbon provided with a pattern readable by a sensor during the production of the inner assembly, said pattern being formed by reference elements having parameters detectable by said sensor and following one another substantially in a longitudinal direction of the conductor ribbon, wherein the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm, wherein said reference elements are grouped in groups of reference elements which follow one another substantially in the longitudinal direction of said conductor ribbon, said groups of reference elements being separated from each other by a free window of a predetermined length (F).

2. Inner assembly according to claim 1 , wherein said reference elements all have the same longitudinal dimension.

3. Inner assembly according to claim 1 or 2, wherein the longitudinal dimension of said reference elements is at least equal to 0.5 mm and lower than or equal to 10 mm.

4. Inner assembly according to any one of the preceding claims, wherein the reference elements are equally-distant from each other and spaced apart from each other, in the longitudinal direction of said conductor ribbon, by a predetermined distance (D).

5. Inner assembly according to claim 4, wherein said predetermined distance (D) is greater than the longitudinal dimension of the reference elements.

6. Inner assembly according to claim 5, wherein said predetermined distance (D) is at least 1.5 times the longitudinal dimension of the reference elements, preferably at least twice the longitudinal dimension of the reference elements.

7. Inner assembly according to claim 5 or 6, wherein said predetermined distance (D) is lower than one hundred times the longitudinal dimension of the reference elements, preferably lower than fifty times the longitudinal dimension of the reference elements, more preferably lower than ten times the longitudinal dimension of the reference elements.

8. Inner assembly according to any one of claims 4 to 7, wherein saidpredetermined distance (D) is between 1 mm and 5000 mm.

9. Inner assembly according to claim 8, wherein said predetermined distance (D) is lower than 1000 mm, preferably lower than 50 mm, more preferably lower than 10 mm.

10. Inner assembly according to any one of the preceding claims, wherein said reference elements are selected from the group comprising the following types: tabs, holes, notches, marks and protrusions.

11. Inner assembly according to any one of the preceding claims, wherein said reference elements are intended to perform a mechanical and / or electrical function in the inner assembly.

12. Inner assembly according to any one of the preceding claims, wherein said parameters detectable by said sensor are collectively selected to preserve mechanical and / or electrical characteristics of the conductor ribbon.

13. Inner assembly according to any one of the preceding claims, wherein said sensor is selected from the group consisting of: a photoelectric sensor, a magnetic sensor, an RGB sensor and an image acquisition device.

14. Inner assembly according to any one of the preceding claims, wherein the reference elements follow one after the other in said longitudinal direction substantially evenly over a large part of the length of the ribbon.

15. Inner assembly according to any one of the preceding claims, wherein said ribbon is devoid of a further pattern formed by further reference elements following one another substantially in a longitudinal direction of said conductor ribbon.

16. Inner assembly according to any one of the preceding claims 1 to 14, wherein said ribbon is provided with at least one further pattern formed by further reference elements following one another substantially in a longitudinal direction of said conductor ribbon, said further pattern formed by said further reference elements being different from the pattern formed by said reference elements.

17. Inner assembly according to any one of the preceding claims, comprising a first longitudinal portion free of active battery electrode material and a second longitudinal portion having the active material, the reference elements being contained in said first longitudinal portion.

18. Inner assembly according to any one of the claims 1 to 16, comprising a first longitudinal portion free of active battery electrode material and a second longitudinal portion having the active material, the reference elements being contained in said second longitudinal portion.

19. Inner assembly according to claim 18, wherein said predetermined length (F) of said free window is greater than said distance (D) between two consecutive reference elements.

20. Inner assembly according to claim 18 or 19, wherein said predetermined length (F) of said free window has a value greater than 10 mm, more preferably greater than 50 mm, even more preferably greater than 100 mm.

21. Inner assembly according to any one of claims 18 to 20, wherein said predetermined length (F) of said free window has a value lower than 1500 mm, more preferably lower than 1000 mm.

22. Inner assembly according to any one of claims 18 to 21 , wherein the free windows separating two groups of consecutive reference elements all have the same length (F).

23. Inner assembly according to any one of the preceding claims, wherein said reference elements are all of the same type.

24. Inner assembly according to any one of the preceding claims, wherein the reference elements are equal to each other in shape and / or size.

25. Inner assembly according to any one of the preceding claims 18 to 24, wherein each group of reference elements has a same longitudinal extension corresponding to a predefined length for said conductor ribbon in said inner assembly.

26. Inner assembly according to any one of the preceding claims, wherein the conductor ribbon is provided with tens, hundreds or thousands of reference elements for each section of said conductor ribbon having a length corresponding to that predefined for said conductor ribbon in said inner assembly.

27. Electric battery comprising an electrochemical cell which in turn comprises an inner assembly according to any one of claims 1 to 26.

28. Method for producing an inner assembly for an electrochemical cell intendedfor battery production, the method comprising:- transporting at least one conductor ribbon along a respective transport path to a coupling device;- coupling, at the coupling device, said at least one conductor ribbon in an overlapping layer structure to create an inner assembly according to any one of claims 1 to 26.

29. Method according to claim 28, wherein said at least one conductor ribbon is fed by a dispensing device wherein said at least one conductor ribbon is stored already provided with said reference elements.

30. Method according to claim 28, wherein said at least one conductor ribbon is fed by a dispensing device wherein said at least one conductor ribbon is stored without said reference elements, and the method comprises:- making said reference elements on said at least one conductor ribbon fed by the dispensing device.

31. Method according to claim 30, wherein the reference elements are produced by printing, drilling, thermoforming, cutting, compressing or notching.

32. Method according to any one of claims 28 to 31 , further comprising:- monitoring, in correspondence of at least one respective predetermined detection position along the transport path of said at least one conductor ribbon, said at least one conductor ribbon by taking measurements by means of said sensor on the respective reference elements passing at said detection position.

33. Method according to claim 32, further comprising: monitoring operating parameters relating to said at least one conductor ribbon on the basis of said detections.

34. Method according to claim 32 or 33, also comprising: checking operating parameters of the production method on the basis of said detections.

35. Method according to any one of claims 32 to 34, wherein said detections are carried out near the coupling device and / or during the transport of said at least one conductor ribbon along the respective transport path and / or during a forming operation of said reference elements and / or during a forming operation of furtherreference elements and / or during a cutting operation of said at least one conductor ribbon.

36. Method according to any one of claims 32 to 35, comprising: implementing a predefined action in the event that the detections taken on the reference elements do not meet the predetermined reference parameters, said predefined action comprising the automatic issuing of a predetermined warning signal and / or a predetermined command signal for an automated control system of the inner assembly production.

37. Method for producing an inner assembly for an electrochemical cell intended for battery production, the method comprising:- feeding one or more ribbons, at least one of which is a conductor ribbon requiring a pattern readable by a sensor during the production of the inner assembly;- forming said pattern by making on said at least one conductor ribbon reference elements following one another substantially in a longitudinal direction of the conductor ribbon, wherein said reference elements have parameters detectable by said sensor and wherein the longitudinal and / or transverse dimension of said reference elements is at least equal to 0.2 mm and lower than or equal to 100 mm, and wherein said reference elements are grouped in groups of reference elements which follow one another substantially in the longitudinal direction of said conductor ribbon, said groups of reference elements being separated from each other by a free window of a predetermined length (F);- transporting said one or more ribbons along respective transport paths to a coupling device;- coupling, at the coupling device, said one or more ribbons in an overlapping layer structure to create the inner assembly.

38. Method according to claim 37, wherein said at least one conductor ribbon requiring said pattern is selected from the group consisting of: a conductor ribbon having a generally even surface and a conductor ribbon provided with a further pattern formed by further elements following one another substantially in a longitudinal direction of said conductor ribbon, said further pattern formed by said further reference elements being different from the pattern formed by saidreference elements.

39. Apparatus for producing an inner assembly for an electrochemical cell intended for battery production, comprising:- a transport system comprising transport devices configured to transport at least one ribbon along a respective transport path;- a coupling unit comprising at least one coupling device configured to couple said at least one ribbon fed by said transport system into an overlapping layer structure for creating an inner assembly according to any one of claims 1 to 26.

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