Electrochemical energy storage cell

Abstract

An electrochemical energy storage cell has the following features: it has a cylindrical housing which encloses an interior and has a top side and a bottom side and in between a circumferential housing jacket, the housing jacket has an inner housing side surface which delimits the interior to the outside, a wound composite formed in a hollow cylindrical manner is arranged in the interior and has a spiral structure which comprises at least two electrode strips wound in a spiral around a winding axis and at least one separator strip arranged between the electrode strips, the electrode strips each comprise a strip-shaped current collector with an active material coating on both sides, the wound composite formed in a hollow cylindrical manner comprises two end faces, a circumferential outer composite side surface and a circumferential inner composite side surface, the inner composite side surface defines an axially oriented cavity in the center of the wound composite, a winding core having a substantially cylindrical or hollow cylindrical shape is arranged in the axially oriented cavity.

Description

Technical Field

[0001] The present invention relates to an electrochemical energy storage battery having a cylindrical shell and a wound composite formed in a hollow cylindrical manner, and to a method for producing such an electrochemical energy storage battery. Background Technology

[0002] In the context of this application, an electrochemical energy storage battery is understood to mean an electrochemical battery comprising at least one positive electrode and at least one negative electrode, said at least one positive electrode and at least one negative electrode being separated from each other by a separator, and capable of absorbing, storing, and (if necessary) releasing electrical energy. When absorbing electrical energy (charging the battery) and releasing electrical energy (discharging the battery), an electrochemical reaction occurs in each case, and this electrochemical reaction consists of two partial reactions that are electrically coupled to each other but spatially separated. The partial reaction occurring at a relatively low redox potential occurs at the negative electrode, and the partial reaction at a relatively high redox potential occurs at the positive electrode. During discharge, electrons are released at the negative electrode by an oxidation process, causing electrons to flow to the positive electrode via an external load, which absorbs a corresponding number of electrons. Therefore, a reduction process occurs at the positive electrode. Simultaneously, for charge equalization purposes, an ionic current corresponding to the electrode reactions is generated inside the electrochemical battery. This ionic current passes through the separator and is ensured by an ion-conducting electrolyte.

[0003] In secondary (rechargeable) electrochemical energy storage batteries, the discharge reaction is reversible, meaning that it is possible to reverse the chemical energy generated during discharge into electrical energy.

[0004] When the terms "anode" and "cathode" are used together in the context of secondary electrochemical energy storage batteries, the electrodes are typically named according to their discharge capability. Therefore, the negative electrode in such a battery is the anode, and the positive electrode is the cathode.

[0005] Electrodes and separators in energy storage batteries are typically provided in the form of a composite. Such a composite can be a battery stack comprising multiple cells. However, the composite usually has a structure made of wound electrodes and separators (wound composite).

[0006] In the composite, the positive and negative electrodes are preferably in the form of flat strips coated on both sides, and the separator or separator strips are usually laid flat on each other. In this case, the electrodes and separators can be connected to each other, for example by means of lamination or adhesive bonding. The composite, whether or not they are wound, generally comprises the following sequence: positive electrode / separator / negative electrode. The composite is also often produced in the form of a so-called dual cell, which has the possible sequence: negative electrode / separator / positive electrode / separator / negative electrode, or positive electrode / separator / negative electrode / separator / positive electrode.

[0007] The strip-shaped electrodes usually each comprise an electrically conductive current collector and an electrochemically active component (also often referred to as active material) as well as an electrochemically inactive component. The current collectors are used to make electrical contact with the electrochemically active component over as large an area as possible. They usually comprise a strip-shaped flat metal substrate, for example made of a metal foil or a metal foam or a metal mesh or a metal grid or a metalized nonwoven fabric. Porous plastic films made of, for example, polyolefins or polyether ketones are particularly possible as separators for the wound composite.

[0008] In order to produce the electrodes for the wound composite, a paste in the form of a thin layer, comprising the electrochemically active component mentioned and an electrode binder as the electrochemically inactive component (and possibly an electrically conductive component), is usually applied to the current collector mentioned, dried and changed into the desired shape. These layers are usually rolled and pressed after drying.

[0009] In order to produce the wound composite, the strip-shaped positive and negative electrodes formed in this way are provided together with one or more strip-shaped separators to a winding device and, preferably, are wound spirally around a winding mandrel in the device. For this purpose, the electrodes and separators are usually wound onto a cylindrical or hollow-cylindrical winding core, which is located on a winding mandrel and remains in the wound composite after winding. In other configurations, it is also possible to produce the winding without a central winding core by forming the electrode assembly directly on the winding mandrel. The winding operation is discontinued after a usually predefined number of turns (in this case, for example, a turn is understood to mean each complete rotation of the electrode around the winding core or winding mandrel). This usually results in a wound composite having a hollow-cylindrical shape with an internally, axially oriented cavity.

[0010] Electrical contact to the electrodes of the wound composite can be made, for example, by means of an arrester lug protruding from an end face of the wound composite formed. The arrester lug can be welded to the current collector or can be part of the latter.

[0011] The cylindrical design is widespread in electrochemical energy storage batteries, in which case the electrodes are usually located in the interior of a cylindrical housing as part of a hollow-cylindrical wound composite. In particular, they can be cylindrical round batteries or button cells.

[0012] Such energy storage batteries are clear, for example, from DE 20 2015 004 285 U1. The basic structure of a button cell with a lithium-ion-based winding produced by spiral winding of strip-shaped electrodes and at least one strip-shaped separator is also known, for example, from WO 2010 / 146154 A2, WO 2012 / 048995 A1 and WO 2010 / 089152 A1.

[0013] The problem of such an energy storage cell with a wound complex having a spiral configuration lies in irregularities which locally occur in the spiral structure of the wound complex. Such irregularities preferably occur in regions in which one of the wound electrode strips ends and / or in which there is a sudden change in the thickness of one of the electrode strips. Each of the electrode strips of the winding has an inner end close to the winding core or to the axially oriented cavity and an outer end close to the winding outer side. The distance between the electrode strip and the winding axis continuously increases over the entire length of the electrode strip, starting from its inner end to its outer end. Irregularities are caused by locally occurring discontinuities with regard to the change in the distance between the electrode strip and the winding axis. A sudden change in the thickness and / or the end of the electrode strip can cause a sudden change in the direction of the turns of the adjacent electrode strip, which can locally lead to mechanical loads if the electrode strip is subject to volume changes during charging and discharging, since the occurring pressure in this case is not uniformly distributed. In particular, the problem here is that the volume of the anode or the anode coating expands when the energy storage cell is charged. As a result, the diameter of the entire wound complex generally increases, thus resulting in a pressure being exerted by the wound complex in the direction of the winding core arranged in the center of the wound complex and also in the direction of the housing surrounding the wound complex.

[0014] The occurring mechanical loads can have a very disadvantageous effect on the function of the energy storage cell. In addition to, for example, mechanical damage to the separator, which can be caused by collisions with the current collector, for example, ion exchange can be impeded, or in the case of lithium-ion batteries, even plating of lithium can occur. Plating of lithium is generally understood to mean the deposition and accumulation of metallic lithium on the anode. This can lead to the formation of dendrites, in which these dendrites pierce the separator and thus can cause a short circuit between the anode and the cathode. SUMMARY

[0015] In contrast, the present application is based on the object of providing an improved energy storage cell which solves the problems mentioned. In particular, it is intended to avoid an uneven pressure distribution occurring within the energy storage cell during charging and discharging, the result of which is that ion exchange is not impeded and plating is prevented.

[0016] This object is achieved by means of an electrochemical energy storage cell having the features of claim 1. The claims dependent on claim 1 relate to preferred embodiments of the energy storage cell. The object is also achieved by means of a method for producing an electrochemical energy storage cell according to the method claims juxtaposed, in which case the advantageous configurations of the method occur according to the claims dependent on the said claims.

[0017] The electrochemical energy storage cell according to the application always has the following features:

[0018] a. The energy storage cell has a cylindrical casing, which encloses an interior and which has a top side and a bottom side and in between a circumferential casing sleeve.

[0019] b. The casing sleeve has an inner casing side surface, which delimits the interior to the outside.

[0020] c. A wound composite shaped in the manner of a hollow cylinder is arranged in the interior and which has a spiral structure comprising at least two electrode strips wound in a spiral around a winding axis and at least one separator strip arranged between the electrode strips.

[0021] d. The electrode strips each comprise a strip-like current collector with an active material coating on both sides.

[0022] e. The wound composite shaped in the manner of a hollow cylinder comprises two end faces, a circumferential outer composite side surface and a circumferential inner composite side surface.

[0023] f. The inner composite side surface defines an axially oriented cavity in the center of the wound composite.

[0024] g. A winding core having a substantially cylindrical or hollow cylindrical shape is arranged in the axially oriented cavity and has an outer circumferential surface lying on the inner composite side surface.

[0025] The energy storage cell according to the application is also characterized by the following features:

[0026] h. The winding core has a local deviation from the cylindrical or hollow cylindrical shape in at least one region of the outer circumferential surface.

[0027] In other words, the outer circumferential surface of the winding core has at least one adaptation or variation in its shape deviating from the cylindrical or hollow cylindrical shape. These adaptations or variations are used to compensate for irregularities of the spiral structure of the wound composite.

[0028] The expression "in at least one region of the outer circumferential surface" is used to mean that it is also entirely possible to provide a plurality of regions having a local deviation from the cylindrical or hollow cylindrical shape. This need not necessarily be the same deviation in different regions. Rather, it is possible to provide two or more regions in which different deviations from the cylindrical or hollow cylindrical shape of the winding core are provided. If reference is made below to a local deviation in a region of the outer circumferential surface, this means a deviation according to the above-mentioned feature h.

[0029] The above-mentioned feature h means that it is possible to compensate for locally occurring pressure peaks, in particular locally occurring pressure peaks in the region of irregularities of the spiral structure of the wound composite during charging or discharging of the wound composite. In particular, a pressure acting in a locally intensified manner in the central region of the wound composite, which can occur in particular during the charging process, can be compensated by the local deviations in the region of the outer circumferential surface of the wound composite provided according to the application. In particular, the above-mentioned risk of hindering ion exchange and - in the case of lithium-ion batteries - the risk of plating lithium is significantly reduced in these regions. Overall, it is thus possible to improve or prolong the reliability and service life of the energy storage battery.

[0030] The axially oriented cavity defined by the inner composite side surface and located in the center of the wound composite preferably has openings on both end faces. In a preferred embodiment, the cavity is thus partially filled by the winding core. If the winding core is not a hollow cylindrical winding core, but a solid winding core, the cavity is completely filled.

[0031] The end faces of the wound composite shaped in a hollow cylindrical manner are in particular end faces which are substantially circular, in which context the expression "substantially" relates to the fact that the mentioned irregularities which can occur in the spiral structure of the wound composite can result in deviations from the ideal circular shape in certain regions.

[0032] The substantially cylindrical or hollow cylindrical shape of the winding core according to the above-mentioned feature g relates to the fact that the winding core has a cylindrical or hollow cylindrical basic shape, but according to the above-mentioned feature h one deviation or possibly several deviations from the cylindrical or hollow cylindrical shape can be provided.

[0033] In a preferred embodiment, the electrochemical energy storage battery according to the application has at least one of the additional features a and b which follow:

[0034] a. the spiral structure of the winding comprises at least one local irregularity in at least one region in which one of the wound electrode strips ends and / or there is an abrupt change in the thickness of one of the electrode strips;

[0035] b. the at least one region of the outer circumferential surface of the winding core in which the local deviations from the cylindrical or hollow cylindrical shape occur is spatially assigned to a local irregularity of the wound composite.

[0036] The preceding features a and b are particularly preferably implemented in combination.

[0037] Local irregularities that can occur at different positions in the spiral structure can be equated to the irregularities in the spiral structure explained at the outset. In particular, regions occur in the central region and the outer region of the wound composite in which one of the wound electrode strips ends and / or the thickness of one of the electrode strips has a sudden change. In particular, in this case, the irregularity in the spiral shape of the wound composite is expressed as a locally occurring discontinuity in the change in the distance between the electrode strip and the winding axis. For example, in the case of an overlap of adjacent electrode strips with the end, a sudden change in the direction can occur in the region of the end of the electrode strip.

[0038] It is generally preferred that the outer turns of the wound composite are formed by separate separator strips and that the electrode strips can thus be insulated from the outside. The outer ends and the inner ends of the anode and the cathode are also generally not at the same position in the electrode assembly. In this case, each end of the anode and the cathode constitutes a defect in the winding structure and leads to irregularities in the winding structure.

[0039] It is also generally preferred that the current collectors of the electrodes are not coated with electrode material at the ends. For example, the inner turns of the wound composite can be formed solely by the anode current collector. A step or a sudden change in the thickness of the electrode strip occurs at the position at which the coating with active material begins and thus an additional defect occurs. Due to the production process, the maximum thickness of the coating often occurs at the beginning and the end of the coating with electrode material, with the result that irregularities can be further intensified in these regions.

[0040] In addition, a defect can occur if the coating on both sides of the cathode and / or the anode is not exactly opposite at their starting point, but is offset. The coating of the anode is particularly important, in particular because the active material of the anode often suffers particularly severe volume fluctuations during charging and discharging of the energy storage cell.

[0041] It is intended to compensate for the consequences caused by the defects by spatially assigning the local deviations in the region of the outer circumferential surface of the winding core to the local irregularities of the wound composite. For example, if there is a local pressure on the winding core due to a defect, this pressure is compensated by means of a winding core with a recess in which the wound composite can relax.

[0042] In particular, the spatial assignment can be achieved by means of local deviations that directly adjoin the defect or the local irregularity in space.

[0043] The spatial assignment can also relate to local deviations in the region of the outer circumferential surface, which are cut from a straight line that is guided through the winding axis and the local irregularity in the spiral structure.

[0044] The local deviations are particularly preferably spatially assigned to the local defects caused by the transition region in the active material coating of the anode.

[0045] In a further particularly preferred configuration of the electrochemical energy storage cell according to the application, the energy storage cell is distinguished by at least one of the following additional features a and b which follow:

[0046] a. The local deviation from the cylindrical or hollow-cylindrical shape relates to a stepwise or continuous reduction and / or enlargement of the outer diameter of the winding core.

[0047] b. The local deviation relates to at least one stepwise or continuous reduction and / or enlargement of the outer diameter of the winding core, wherein the at least one stepwise or continuous reduction and / or enlargement of the outer diameter preferably extends axially over the entire height of the winding core.

[0048] The immediately preceding features a and b are particularly preferably implemented in combination.

[0049] The stepwise or continuous reduction and / or enlargement of the winding core outer diameter can be a local reduction or a local enlargement of the outer diameter, depending on the viewing direction of the observer. In a particularly preferred manner, this reduction and / or enlargement of the outer diameter, and thus the local deviation, preferably extends axially over the entire height of the winding core. This is based on the fact that local defects, that is to say irregularities in the described winding composite, usually also extend over the entire height of the winding composite, as a result of which the deviation can compensate for defects extending axially in a particularly suitable manner by virtue of this configuration.

[0050] In particular, the stepwise reduction and / or enlargement of the winding core outer diameter makes it possible to compensate for sudden defects or other extreme defects in the spiral structure of the winding composite. It is also possible to provide a continuous reduction and / or enlargement in the outer circumferential surface. It is also possible to provide a combination of stepwise and continuous reduction / enlargement, wherein, for example, a continuous reduction of the outer diameter can be provided in one direction and then a stepwise enlargement of the outer diameter. This forms an axially oriented notch in the outer circumferential surface of the winding core, wherein a gentle slope is provided on one side and a steep slope is provided on the other side.

[0051] With regard to the configuration of the local deviation in the outer circumferential surface of the winding core, the electrochemical energy storage cell according to the application can also be distinguished by at least one of the following additional features a and b:

[0052] a. The local deviation in at least one region of the outer circumferential surface of the winding core relates to a recess in the outer circumferential surface of the winding core and / or a curvature of the outer circumferential surface of the winding core.

[0053] b. The local deviation in at least one region of the outer circumferential surface of the winding core relates to a recess in the outer circumferential surface of the winding core and / or a curvature of the outer circumferential surface of the winding core, wherein the recess and / or the curvature preferably extends axially over the entire height of the winding core.

[0054] The combination of the features a and b immediately preceding is particularly preferably implemented.

[0055] In particular, the recess in the outer circumferential surface of the winding core is to be understood as meaning a concave indentation in the outer circumferential surface. In particular, the curvature is to be understood as meaning a convex bulge of the outer circumferential surface.

[0056] In a preferred embodiment, the recess extends over the entire height of the winding core, for example in the form of a groove. The curvature can be in the form of a web, for example, which in a preferred embodiment extends over the entire height of the winding core. It can also be provided that the recess and the curvature are combined with one another in order to form a counterpart of the defect in the outer circumferential surface of the winding core in order to provide a receiving region for the over-extended region on the one hand and to provide a stop for avoiding displacement of the spiral structure on the other hand.

[0057] The use of the different possibilities for configuring the local deviations makes it possible to provide a winding core which is able to compensate one or more local defects in the wound composite in an optimum manner. Depending on the degree of manifestation of the defect, an appropriate deviation can be implemented in the region of the outer circumferential surface, which can compensate the uneven pressure distribution associated with the defect. For example, a recess can be used to compensate a locally increased extent of the wound composite. For example, if adjacent regions in the spiral structure are over-extended, a curvature in the outer circumferential surface of the winding core can be used to locally avoid displacement of the spiral structure. The combination of recesses and curvatures can thus be used in a particularly preferred manner.

[0058] In a particularly preferred manner, the winding core has local deviations from the cylindrical or hollow-cylindrical shape in two or more regions of the outer circumferential surface, which are each spatially assigned to a local defect. In this case, in particular, the number of local deviations depends on the number and position of the local defects in the respective wound composite which occur when producing the wound composite.

[0059] In a particularly preferred configuration of the electrochemical energy storage cell according to the application, the energy storage cell is characterized by at least one of the features a to c immediately following:

[0060] a. the winding core takes the form of a hollow cylinder and has an inner core side surface which delimits an axially oriented cavity inside the winding core.

[0061] b. the winding core has a recess in the outer circumferential surface and a corresponding curvature protruding into the axially oriented cavity as a local deviation.

[0062] c. the winding core has a curvature of the outer circumferential surface and a corresponding recess in the inner core side surface as a local deviation.

[0063] The features a and b, or a and c, or a to c immediately preceding are particularly preferably combined.

[0064] If the local deviations of the hollow cylindrical winding core have counterparts inside the winding core, this has the advantage that the local deviations can be precisely located for the winding process by means of suitable tools, for example by means of a winding mandrel which has a correspondingly exactly opposite design and is introduced into the winding core interior. In particular, the above-mentioned spatial allocation of the deviations of the local defects in the winding composite can thus be achieved in a particularly accurate and precise manner.

[0065] In this case, it is not absolutely necessary for the inner core side surface of the winding core to precisely simulate the outer circumferential surface with the deviation(s). Stepwise changes in the outer circumference can also be simulated, for example by means of continuous changes in the inner circumference.

[0066] The winding core according to the features a to c immediately preceding has a substantially uniform wall thickness in a particularly preferred manner.

[0067] In one particularly preferred embodiment of the energy storage battery, it is provided that the winding core has the mentioned axially oriented notch or another axial recess as a local deviation in the outer circumferential surface of the winding core, and it is provided that the end of one of the electrode strips or the end of one of the separator strips is to be arranged in the recess.

[0068] This is based on the fact that the inner end of the electrode strip forms an edge in the winding direction, over which the subsequent winding is placed during winding, which almost inevitably leads to a defect in the winding structure. If the end is placed in the notch or recess, this problem can be circumvented or at least reduced. Ideally, the occurrence of an edge over which winding has to be performed can be completely avoided.

[0069] In some embodiments, it is customary to weld the electrode assembly to the winding core at the starting point of the winding when the winding composite is produced. This welding usually leads to a local thickening, which disrupts the structure of the turns which follow immediately thereabove and possibly further abut. A disruptive edge can also be formed by the welding, for example.

[0070] When fastening the separator strip(s) in the notch or recess in the outer circumferential surface of the winding core, the occurrence of a thickening has no influence as long as the resulting edge does not protrude from the notch or recess.

[0071] In a further preferred configuration, the electrochemical energy storage battery according to the application is distinguished by the additional feature a immediately following:

[0072] a. The local deviations in at least one region of the outer circumferential surface of the winding core in the form of a hollow cylinder comprise hole diameters in the winding core wall, in particular slots in the wall.

[0073] In particular, the hole diameters in the wall can extend over the entire height of the winding core. Due to the slots or such gaps formed in this way, the local deviations can act as clamping elements. For example, a spacer strip can be clamped into the slots at the beginning of the winding process, as a result of which it is not necessary to weld the electrode assembly to the winding core.

[0074] In this case, it can be provided in a particularly advantageous manner that the ends of the wall of the winding core interrupted by the slots overlap, thus achieving clamping in a particularly advantageous manner. Alternatively, it can also be provided that the end surfaces of the wall of the hollow cylinder surrounding the slots directly strike against one another when pressed together.

[0075] It can also be provided that the electrochemical energy storage cell according to the application is characterized by one of the following features:

[0076] a. The outer circumferential surface of the winding core has one or more recesses for accommodating at least one sensor;

[0077] b. The outer circumferential surface of the winding core has one or more recesses for accommodating at least one sensor, wherein the recess(es) preferably extend axially over the entire height of the winding core.

[0078] This embodiment is based on the fact that in many uses of energy storage cells, it is useful and / or necessary to monitor the operation of the energy storage cell. It is therefore known practice to integrate a sensor system in an electrochemical energy storage cell in order to be able, for example, to capture data relating to the temperature and / or pressure inside the cell. In addition, chemical sensors or voltage sensors are known, for example, in connection with energy storage cells. A sensor system in an energy storage cell can be used to monitor the state and / or to diagnose the energy storage cell.

[0079] Thus, in a preferred manner, the energy storage cell according to the application provides one or more recesses to be provided in the outer circumferential surface of the winding core as local deviations, which are used to accommodate one or more sensors. Depending on the intended position of the sensor in the energy storage cell, the recesses can extend more or less axially over the height of the winding core. It is also possible to provide a plurality of recesses at different positions on the outer circumferential surface of the winding core in order to accommodate a plurality of sensors. In particular, using such possible positions of one or more sensors in the energy storage cell, it is possible to capture the conditions in the center of the wound composite and thus in the interior of the energy storage cell.

[0080] Suitable sensors for such a configuration of an energy storage cell according to the application are, for example, a reference electrode for measuring the electrode potential of the cell, and / or a temperature sensor for monitoring the temperature, in particular for determining overheating, and / or a pressure sensor, which can be used to determine, for example, an excessive development of pressure, in particular an increase in the pressure inside the cell.

[0081] In the configuration of the outer circumferential surface of the winding core, for example, provision can also be made for electrically conductive bodies provided in the center of the winding complex and similar structural elements. Thus, one or more recesses can be provided in the outer circumferential surface of the winding core as local deviations, which provide space for these additional structural elements and / or the electrically conductive bodies.

[0082] In a particularly preferred manner, the electrochemical energy storage cell according to the application is characterized by the following additional feature a:

[0083] a. The winding core is formed from a plastic or a plastic composite material.

[0084] Plastic is a material that is widely used for the production of winding cores and can be easily processed for the purposes of the present application. For example, winding cores according to the application having local deviations from a cylindrical or hollow cylindrical shape can be produced as injection-molded parts. Another possibility is an extrusion process for producing the winding core. In a corresponding manner, plastic composite materials can be used to produce the winding core. Plastics and plastic composite materials also have the advantage of being lightweight and not substantially contributing to the weight of the resulting energy storage cell. Furthermore, they are electrically insulating and thus particularly suitable as a material for the winding core of an energy storage cell according to the application for this reason as well.

[0085] The energy storage cell according to the application has a preferably cylindrical housing. In this case, the cylindrical shape should not be understood in a strict geometrical sense. The housing can very well have deviations from a perfect cylinder, for example, in the region of the end where the housing is closed, or on the top side or the bottom side, which do not necessarily have to be completely flat. The housing sleeve or at least one section of the housing sleeve preferably has a mostly or completely constant outer radius and, in some embodiments, is very close to a perfect cylinder in terms of its shape.

[0086] In particular, the housing is a metal housing, which is preferably formed from metal housing parts of positive and negative polarity. The housing parts can consist of, for example, nickel-plated steel sheet, stainless steel, for example type 1.4303 or 1.4304, copper, nickel-plated copper or an alloy or non-alloy aluminum. The housing part that is electrically connected to the cathode can preferably consist of aluminum or an aluminum alloy, and the housing part that is electrically connected to the anode can preferably consist of copper or a copper alloy or nickel-plated copper.

[0087] The positive and negative polarity housing parts can for example take the form of a cup. They then each have a circular cup bottom, a circumferential cup wall, a cup edge with a terminal cut edge and a cup opening defined by the cup edge. The cup wall can preferably be described as an annular section of a hollow cylinder with a circular cross section. Their diameter preferably corresponds to or is larger than the diameter of the respective associated circular bottom. The cup wall is usually oriented orthogonally with respect to the associated bottom. In the assembled state, the cup bottom corresponds to the top and bottom side of the housing, while the cup wall forms an annular circumferential housing sleeve.

[0088] It is also possible for one of the housing parts (positive or negative) to take the form of a cup and to have a circular opening, while the housing part of the opposite polarity takes the form of a disc or comprises a disc with a closed opening.

[0089] An annular electrically insulating seal is preferably arranged between the housing parts.

[0090] With regard to the configuration of the housing sleeve, and in particular the configuration of the inner housing side surface, at least one of the following additional features a and b is provided in one particularly preferred embodiment of the electrochemical energy storage cell according to the invention:

[0091] a. The housing sleeve has a hollow cylindrical shape.

[0092] b. The housing sleeve has a local deviation from the hollow cylindrical shape in at least one region of its inner housing side surface.

[0093] The particularly preferred combination of the preceding features a and b is achieved.

[0094] This embodiment is based on the fact that the above-mentioned irregularities in the spiral structure of the wound composite can also occur in the outer region of the wound composite and can lead to inhomogeneous pressure loads in the outer region of the wound composite. Since the outer circumferential surface of the wound composite preferably adjoins the inner housing side surface in a two-dimensional manner, such irregularities in the spiral structure and their adverse effects on the function of the energy storage cell can be compensated by means of a deviation from the hollow cylindrical shape. In particular, irregularities in the outer region of the wound composite are expressed as a deviation from the ideal cylindrical shape or the hollow cylindrical shape in the outer circumference of the wound composite, which has a negative effect, in particular in the event of swelling and shrinking of the wound composite when charging and discharging the energy storage cell. To compensate for such irregularities, a deviation is preferably provided on the inner housing side surface in at least one region in a similar manner to the local deviation(s) explained above in at least one region of the outer circumferential surface of the winding core.

[0095] While the above-mentioned local deviations in the area of the outer circumferential surface of the winding core are used to compensate for defects in the area of the inner composite side surface, the deviations in at least one area of the inner housing side surface are primarily intended to compensate for defects in the area of the outer composite side surface of the wound composite. The component according to the application follows the principle that the shape of the inner housing side surface follows the progression of irregularities on the outer circumference of the wound composite, as a result of which the outer composite side surface can rest without interruption on the inner housing side surface.

[0096] In a particularly advantageous manner, the local deviations in at least one area of the outer circumferential surface can be combined with the local deviations in at least one area of the inner housing side surface, as a result of which all irregularities that can occur in the inner and outer areas of the wound composite can be compensated for.

[0097] However, it is also possible to provide deviations only on the outer circumferential surface of the winding core or only on the inner housing side surface. Thus, in principle, the embodiment in which the housing sleeve has a local deviation from the hollow cylindrical shape in at least one area of its inner housing side surface can also be realized independently of feature h of claim 1.

[0098] The energy storage battery according to the application is preferably distinguished by the additional feature a that follows:

[0099] a. At least one area of the inner housing side surface with deviations is spatially assigned to a local defect of the wound composite.

[0100] Since this local assignment can be configured in a similar manner to that described for the winding core, the energy storage battery according to the application allows for the compensation of a pressure that locally acts in the outer circumference of the wound composite, which is due to irregularities or defects in the outer area of the spiral structure of the wound composite. In particular, the end portions of the cathode electrode strips and the end portions of the anode electrode strips contribute to such defects in the outer area of the spiral structure of the wound composite. In the case of such wound composites, in particular, two defects typically occur in the outer circumference and are caused by the end portions of the respective electrode strips in the outer circumference of the wound composite. In particular, these two defects can be compensated for by means of a suitable local deviation of the housing sleeve from the hollow cylindrical shape.

[0101] With regard to the configuration of this local deviation of the inner housing side surface, the energy storage battery according to the application is distinguished in particular by at least one of the additional features a to d that follow:

[0102] a. The local deviation relates to a stepped or continuous reduction and / or enlargement of the inner diameter of the housing sleeve.

[0103] b. The local deviation relates to a stepwise or continuous reduction and / or enlargement of the inner diameter of the housing sleeve, wherein the stepwise or continuous reduction and / or enlargement of the inner diameter preferably extends axially over the entire height of the housing.

[0104] c. The local deviation relates to a recess in the inner housing side surface and / or a curvature of the inner housing side surface.

[0105] d. The local deviation relates to a recess in the inner housing side surface and / or a curvature of the inner housing side surface, wherein the recess and / or the curvature preferably extend axially over the entire height of the housing.

[0106] A combination of recess and curvature, which can be provided together, is particularly suitable. Thus, an excessive local length during the charging / discharging process can be intercepted or picked up by means of the recess, wherein the spiral structure can be held and supported in its shape by means of the curvature.

[0107] In order to form the recess and the curvature, it can be provided that the housing sleeve is intentionally deformed. For example, a web made of plastic or another material can also be fixed to the inner housing side surface.

[0108] In order to realize a local deviation from the hollow cylindrical shape of the housing sleeve, the housing sleeve can also be reinforced by means of an annular insert placed on the inside of the housing sleeve. The height of the insert is preferably in the range of 50% to 100% of the height of the housing sleeve. The thickness of the insert can be of the order of magnitude of the thickness of the housing sleeve. The inner diameter of the housing sleeve can be locally reduced, for example, by using an annular insert which has an increased thickness in at least one section. The inner diameter of the housing sleeve can be locally enlarged, for example, by using an annular insert which has a reduced thickness in at least one section.

[0109] In order to locally enlarge the inner diameter of the housing sleeve, it is also possible to use a strip-shaped insert which rests on the inside of the housing sleeve over the entire length of the housing sleeve, but does not completely cover the inside since it is shorter than the inner circumference of the housing sleeve. The height of this insert is preferably also in the range of 50% to 100% of the height of the housing sleeve, and its thickness can be of the order of magnitude of the thickness of the housing sleeve.

[0110] In a particularly preferred manner, the energy storage cell according to the application is a secondary lithium-ion cell. Lithium-ion cells are generally distinguished by the fact that they comprise electrodes which can reversibly absorb lithium ions and can release them again. In addition, they contain an electrolyte which contains lithium ions. All materials which can absorb lithium ions and can release them again are possible as active materials for the electrodes of lithium-ion cells.

[0111] Carbon-based materials capable of intercalating lithium, such as graphitic or non-graphitic carbon materials, are particularly suitable for the negative electrode of a secondary lithium-ion battery. In addition, it is also possible to use metal and semimetal materials which can be alloyed with lithium. For example, the elements tin, antimony and silicon are capable of forming intermetallic phases with lithium. In particular, carbon-based active materials can also be combined with metal and / or semimetal materials. Alternatively or additionally, lithium titanate (Li4Ti5O12) or a derivative thereof can also be included in the negative electrode. 12 ) or a derivative thereof can also be included in the negative electrode.

[0112] Lithium metal oxide compounds and lithium metal phosphate compounds, such as LiCoO2and LiFePO4, are possible, for example, for the positive electrode of a lithium-ion battery and, in particular, for the positive electrode of a secondary lithium-ion battery. In particular, lithium nickel manganese cobalt oxides (NMC) of the empirical formula LiNi x Mn y Co z O2(wherein x+y+z is generally 1), lithium manganese spinels (LMO) of the empirical formula LiMn2O4, or lithium nickel cobalt aluminum oxides (NCA) of the empirical formula LiNi x Co y Al z O2(wherein x+y+z is generally 1) are also highly suitable. Mixtures of the materials can also be used.

[0113] Electrode binders and conductive members can be mentioned primarily as electrochemically inert components of a lithium-ion battery. Electrode binders ensure the mechanical stability of the electrode and ensure that the particles of the electrochemically active material are in contact with one another and with the current collector. Conventional electrode binders are based, for example, on polyvinylidene fluoride, polyacrylate or carboxymethyl cellulose. Conductive members such as carbon black are used to increase the electrical conductivity of the electrode.

[0114] In particular, porous plastic films made, for example, of polyolefins or of polyether ketones are possible as separators for lithium-ion batteries. Nonwovens and fabrics made of these materials can also be used.

[0115] As ion-conducting electrolyte, a lithium-ion battery can contain, for example, a mixture of organic carbonates in which a lithium salt is dissolved. Essentially any lithium salt known from the prior art for lithium-ion batteries is possible for this purpose. A prominent example thereof is lithium hexafluorophosphate (LiPF6). The electrodes and the separator of a lithium-ion battery are preferably impregnated with the electrolyte.

[0116] In a particularly preferred manner, the energy storage battery according to the application is distinguished by one of the following additional features:

[0117] a. the electrochemical energy storage battery is a cylindrical round cell, in particular a secondary lithium-ion battery in the form of a cylindrical round cell, or

[0118] b. The electrochemical energy storage cell is a coin cell, in particular a secondary lithium ion cell in the form of a coin cell.

[0119] Cylindrical round cells have a height which is greater than their diameter. In particular, they are suitable for applications in the automotive sector, for electric bicycles, or else for other applications with high energy requirements.

[0120] The lithium ion cell in the form of a round cell preferably has a height in the range of 15 mm to 150 mm. The diameter of the cylindrical round cell is preferably in the range of 10 mm to 60 mm. Within these ranges, a form factor of, for example, 18 x 65 (diameter times height in mm) or 21 x 70 (diameter times height in mm) is particularly preferred. Cylindrical round cells with these form factors are particularly suitable for powering electric drives of motor vehicles.

[0121] The nominal capacity of the lithium ion cell according to the application in the form of a cylindrical round cell is preferably up to 90,000 mAh. In the case of a form factor of 21 x 70, the cell as an embodiment of a lithium ion cell preferably has a nominal capacity in the range of 1500 mAh to 7000 mAh, particularly preferably in the range of 3000 to 5500 mAh. In the case of a form factor of 18 x 65, the cell as an embodiment of a lithium ion cell preferably has a nominal capacity in the range of 1000 mAh to 5000 mAh, particularly preferably in the range of 2000 to 4000 mAh.

[0122] In the European Union, manufacturer specifications regarding details relating to the nominal capacity of secondary energy storage cells are subject to strict regulation. For example, details relating to the nominal capacity of secondary nickel-cadmium energy storage cells must be based on measurements according to standards IEC / EN 61951-1 and IEC / EN 60622, details relating to the nominal capacity of secondary nickel-metal hydride energy storage cells must be based on measurements according to standard IEC / EN 61951-2, details relating to the nominal capacity of secondary lithium ion cells must be based on measurements according to standard IEC / EN 61960, and details relating to the nominal capacity of secondary lead-acid cells must be based on measurements according to standard IEC / EN 61056-1. Any details relating to the nominal capacity in the present application are preferably likewise based on these standards.

[0123] Like cylindrical round cells, also button cells are cylindrical. However, their height, preferably in the range of 4 mm to 15 mm, is equal or preferably smaller than their diameter, preferably in the range of 5 mm to 25 mm. In particular, they are suitable for supplying small electronic devices such as watches, hearing aids and wireless headsets with electrical energy.

[0124] The nominal capacity of the energy storage cell according to the invention in the form of a button cell in embodiments as lithium-ion cell is preferably up to 1500 mAh. More preferably, the nominal capacity is in the range of 100 mAh to 1000 mAh, particularly preferably in the range of 100-800 mAh.

[0125] Furthermore, the invention also comprises a method for producing an electrochemical energy storage cell, which is characterized by the following method steps:

[0126] a. Providing at least two electrode strips and at least one separator strip arranged between the electrode strips, each electrode strip having a strip-like current collector with an active material coating on both sides.

[0127] b. Providing a winding core having a substantially cylindrical or hollow cylindrical shape and having an outer circumferential surface, wherein the outer circumferential surface of the winding core has a deviation from the cylindrical or hollow cylindrical shape in at least one region.

[0128] c. For producing a wound composite, the electrode strips and the at least one separator strip are helically wound around the winding core in order to form a spiral structure, wherein the winding is performed in such a way that the deviation is spatially assigned to a local defect in the spiral structure.

[0129] d. Providing a cylindrical housing for the energy storage cell.

[0130] e. Introducing the wound composite into the housing,

[0131] f. Establishing an electrical contact with the wound composite and closing the housing.

[0132] The essence of the method is that a substantially cylindrical or hollow cylindrical winding core is used for producing the wound composite, wherein the outer circumferential surface of the winding core has a deviation from the cylindrical or hollow cylindrical shape in at least one region. This deviation or possible deviations can be used to compensate for irregularities in the spiral structure of the wound composite.

[0133] In the method, it is also provided that the deviation is spatially assigned to a local defect in the spiral structure of the wound composite, as a result of which the negative effects of the inhomogeneous pressure distribution caused by the structural irregularities can possibly be compensated in a particularly effective manner.

[0134] In a particularly preferred manner, the spatial allocation is achieved by using a correspondingly shaped winding mandrel onto which a winding core shaped in a hollow cylindrical manner can be pushed in order to achieve a suitable positioning of the electrode assembly to be wound onto the winding core. In this case, it is particularly advantageous if the inner wall of the winding core shaped in a hollow cylindrical manner directly or indirectly represents a deviation in the outer circumference of the winding core, as a result of which, for example, only one position of a winding mandrel having a correspondingly diametrically opposite shape within the winding core is possible. This makes it possible to ensure a correct positioning of the winding core with respect to the winding complex to be wound on the winding mandrel.

[0135] In particular, the energy storage cell that can be produced using the method is an energy storage cell having the features already explained above. Thus, with regard to further features of the energy storage cell, and in particular of the winding core, and thus also with regard to further features of the production method, reference is also made to the above description.

[0136] Finally, the present application comprises a winding tool that can be used to carry out the production method. In particular, the winding tool comprises a winding mandrel, or the winding tool is a winding mandrel, wherein the winding mandrel is shaped in accordance with a winding core formed in accordance with the present application. In particular, if the winding core is hollow cylindrical and the inner core side surface of the winding core simulates a deviation(s) on the outer circumferential surface of the winding core, such a winding mandrel preferably has a diametrically opposite shape in its outer circumferential surface that corresponds to the inner core side surface of the winding core. The winding tool, and in particular the winding mandrel, can be said to represent the inside of the winding core as negative. Corresponding to the inner circumference or the inner core side surface of the winding core, the winding mandrel can have a cam, for example, if the winding core exhibits a recess at this position.

[0137] Such a winding tool can be used in a particularly practical manner to produce a winding complex in which the winding start on the winding core can be positioned in a very precise manner and in which the spatial allocation of one or more deviations on the outer circumferential surface of the winding core to local defects in the winding complex can be achieved in a particularly precise manner.

[0138] Further features and advantages of the present application emerge from the claims and the following description of preferred exemplary embodiments of the present application in conjunction with the attached drawings. In this case, the individual features can be realized individually or in combination with one another. BRIEF DESCRIPTION OF DRAWINGS

[0139] In the drawings:

[0140] Figure 1 A cross section through a winding complex having an energy storage cell housing is shown for illustrating the problem on which the present application is based (prior art);

[0141] Figure 2 A, Figure 2 B shows a possible configuration of the hollow cylindrical winding core of the wound composite of the energy storage cell according to the invention;

[0142] Figure 3 A, Figure 3 B shows a further possible configuration of the hollow cylindrical winding core of the wound composite of the energy storage cell according to the invention;

[0143] Figure 4 A further possible configuration of the hollow cylindrical winding core of the wound composite of the energy storage cell according to the invention is shown;

[0144] Figure 5 A possible configuration of the housing of the energy storage cell according to the invention is shown;

[0145] Figure 6 A possible embodiment of the energy storage cell according to the invention is shown; and

[0146] Figure 7 A further possible configuration of the housing of the energy storage cell according to the invention is shown. DETAILED DESCRIPTION

[0147] Figure 1 The problem in a conventional energy storage cell with a wound composite shaped in a hollow cylindrical manner is illustrated. The illustration is based on an X-ray, which shows a cross section through a button cell. However, the illustrated case is also found in cylindrical round cells. The wound composite 1 is formed from spirally wound electrode strips and separator strips in between. The wound composite 1 is located in the interior of the energy storage cell, which is surrounded by a housing jacket 2 of the cylindrical housing. In this configuration, there is no winding core in the center 3 of such a conventional energy storage cell shown here or in the center of the wound composite 1. Electrical contact is made via a metal conductor 4 in the interior region of the wound composite 1 with one of the electrodes.

[0148] For example, the layer thickness of the separator strips can be in the range of approximately 20 pm. For example, the layer thickness of the cathode electrode strips can be in the range of approximately 150 pm. For example, the layer thickness of the anode electrode strips can be in the range of approximately 100 pm. For example, the thickness of the separator can also be approximately 12 pm or 16 pm, depending on the design. The coated electrode strips can also be in a thickness range of 110 pm ± 15 pm, depending on the design.

[0149] Local defects 5, 6, 7, 8 can be seen in the individual regions of the spiral structure of the wound composite 1, and they are formed by different transition regions and the end of the electrode strips when the wound composite 1 is produced.

[0150] If one looks from the inside outFigure 1 The spiral structure of the wound composite 1, the winding initially only begins with a few turns from the anode current collector to which the conductor 4 is welded. After a few turns, a transition is found at a location referred to as defect 5 to a section of the anode current collector which is coated with an active material coating on both sides. The inner end of the cathode electrode strip is found at a location referred to as defect 6. The end of the cathode electrode strip is located in the outer region of the wound composite 1 at a location referred to as defect 7. The outer end of the anode current collector is located at a location referred to as defect 8. These defects 5, 6, 7, 8 in the various regions of the spiral structure of the wound composite 1 result in irregularities in the approximately circular shape of the individual turns, which can also affect adjacent turns.

[0151] In particular, with regard to the volume expansion and volume contraction during charging and discharging operation, a non-uniform pressure distribution is thereby caused, and this has an adverse effect on the function of the energy storage battery. In particular, the higher load on the separator at the irregularities, in particular at the beginning of the winding, that is to say in the centre of the wound composite 1, as a result of the pressure load and / or the adverse lithium plating, these can lead to soft short circuits and short circuits.

[0152] In order to avoid these problems in the wound composite, the present invention proposes a specific shape of the winding core located in the centre of the wound composite. In particular, this special shape of the winding core makes it possible to avoid problems occurring inside the wound composite.

[0153] Figure 2 Two possible examples of the shape of the winding core 10 are shown. In the outer circumferential surface of the winding core 10, shown here in cross section, the winding core 10 has a deviation 11 from the ideal hollow cylindrical shape of the winding core, wherein, in the viewing direction from left to right in the cross section shown here, a stepped enlargement of the outer diameter is achieved here (sub-plot A). According to the invention, the deviation 11 can be used to connect the electrode assembly to the winding core 10 at this location, for example by welding or adhesive bonding of the separator strip at this location. In this case, the special shape of the winding core 10 avoids edges or generally irregularities in the spiral structure being constructed, which would occur in the subsequent winding above the winding starting point at the location 11. Overall, this achieves a considerable increase in the uniformity of the winding in terms of its circularity, with the result that uniform tensile forces act during the charging and discharging operation of the energy storage battery, in particular in the case of volume increase and volume decrease. There is a point-like pressure load at the transition point, thus avoiding the risk of cracking. Excessive loading on the separator, in particular in the inner region of the spiral structure of the wound composite, is also avoided, with the result that, for example, lithium plating or other adverse effects of such irregularities are also avoided.

[0154] Figure 2The sub-diagram B of Figure 1 shows a further possible configuration of the winding core 10 with a deviation 11 in the outer circumference, wherein an adaptation 12 corresponding to the deviation 11 in the outer circumferential surface is made in the wall thickness in the inner core side surface of the hollow cylindrical winding core. The deviation 11 in the form of a stepped increase in the outer circumference is represented as an adaptation 12 on the inner circumference in a stable form. The adaptation 12 on the inner core side surface of the winding core 10 is thus shaped in a similar or corresponding manner to the deviation 11 on the outer circumferential surface of the winding core 10. This has the advantage that it is possible to align precisely with the winding starting point in a particularly simple manner when producing the wound composite.

[0155] Depending on the dimensioning of the energy storage cell, the dimensions of the winding core, which is preferably produced from plastic, can be adapted. For example, the outer diameter of the winding core of a button cell can be between 2 and 3 mm, for example 2.1 mm.

[0156] Figure 3 A further possibility of configuring the shape of the winding core 20 is shown. In this case, in the winding core 20 shaped in a hollow cylindrical manner there is a recess as a deviation 21 in sub-diagram A, which exhibits a continuous transition on the left-hand side to the wall thickness outside the local deviation 21 and exhibits a stepped or abrupt transition on the right-hand side to the wall thickness outside the deviation 21. In the local deviation 21 in the form of a recess in the outer circumference of the winding core 20, for example, the separator strip forming the end of the electrode assembly can be fastened to the winding core 20, for example by means of welding or adhesive bonding, with the result that no edge is formed or similar deformations occur.

[0157] Furthermore, the winding core 20 or generally the winding core according to the application can also comprise further local deviations in the outer circumference, which are able to compensate for further transition regions or irregularities in the spiral structure of the wound composite to be mounted thereon. In particular, at those defects where a particular thickness change occurs due to the electrode coating, a corresponding taper or recess can be provided in the outer circumferential surface of the winding core.

[0158] Figure 3 The sub-diagram B of Figure 1 shows a further possible configuration of the winding core 10 with a deviation 11 in the outer circumference, wherein an adaptation 12 corresponding to the deviation 11 in the outer circumferential surface is made in the wall thickness in the inner core side surface of the hollow cylindrical winding core. The deviation 11 in the form of a stepped increase in the outer circumference is represented as an adaptation 12 on the inner circumference in a stable form. The adaptation 12 on the inner core side surface of the winding core 10 is thus shaped in a similar or corresponding manner to the deviation 11 on the outer circumferential surface of the winding core 10. This has the advantage that it is possible to align precisely with the winding starting point in a particularly simple manner when producing the wound composite. Figure 2

[0159] Figure 4 ​Further possibilities for configuring the winding core 30 with a deviation 31 are shown, which is configured with an overlapping end of the wall in the case of a slot formed through the wall of the hollow cylindrical winding core 30. This provides a clamping location, which can be used to clamp the end of the separator strip on the winding core 30, for example, as a result of which any additional fastening, for example welding, is not required and a uniform spiral structure can be achieved simultaneously in the winding complex.

[0160] In a similar manner to the deviation in the outer circumferential surface of the winding core, the housing 50 around the winding complex can be configured with a deviation in the inner circumferential surface in order to compensate for irregularities or defects in the outer region of the winding complex. Figure 5 A deviation 51 in the inner housing side surface of the housing sleeve 50 is shown, in which a bend 52 in the direction of the winding complex to be arranged inside is combined with a recess 53, in which the wall thickness of the housing sleeve 50 is reduced. In this case, the recess 53 can compensate for local pressure peaks due to the non-uniform volume increase. The bend 52 can provide a support structure in order to additionally stabilize the spiral structure. For example, the configuration of the deviation 51 in the housing sleeve 50 can be used to compensate for defects according to Figure 1 position 8 in Fig. 8.

[0161] Figure 6 A schematic cross-sectional illustration through an electrochemical energy storage cell 100 according to the application is shown, which has a winding complex 60 located inside a housing 70. A winding core 10 is located in the center of the winding complex 60, which is distinguished by a deviation 11 in the form of a stepped enlargement of the outer diameter of the winding core. This winding core 10 corresponds to the configuration of the winding core of the application shown in subfigure A of Fig. 6. The end of the electrode strip can be placed against the step in the outer circumferential surface present in the region of the deviation 11. This makes it possible to prevent the formation of edges and thus irregularities in the resulting spiral structure. Figure 2

[0162] Overall, the energy storage cell according to the application is distinguished by a more uniform winding of the winding complex. This has a positive effect on the winding quality and minimizes faults, in particular those caused by the regularly occurring edges that are not present in the energy storage cell according to the application. In addition, the process of producing the energy storage cell and the winding process can also be optimized in the described manner. Furthermore, it is possible in principle to use more free volume in the energy storage cell in the energy storage cell according to the application, thus additionally giving rise to the potential for an increased capacity.

[0163] Figure 7 ​Further examples are shown of how a partial deviation 71 from the hollow cylindrical shape of the housing sleeve 70 can be implemented. For this purpose, the housing sleeve 70 can be reinforced by means of a strip-like insert 75, which rests on the inner side of the housing sleeve 70 over its entire length, but cannot completely cover the inner side, since it is shorter than the inner circumference of the housing sleeve 70. The inner diameter has been enlarged compared to all other sections in which the strip-like insert 75 does not cover the section 76 of the inner side.

Claims

1. Electrochemical energy storage battery (100), which has the following characteristics: a. The energy storage battery (100) has a cylindrical housing that encloses the interior and has a top side, a bottom side and a circumferential housing sleeve (50; 70) in the middle. b. The housing sleeve (50; 70) has an inner housing side surface that defines the boundary from the inside to the outside. c. A wound composite (60) formed in a hollow cylindrical shape is arranged inside and has a helical structure comprising at least two electrode strips helically wound around a winding axis and at least one spacer strip arranged between the electrode strips, wherein there is no direct electrical contact between the two electrode strips. d. Each electrode strip comprises a strip-shaped current collector with an active material coating on both sides. e. A wound composite (60) formed in a hollow cylindrical manner includes two end faces, an outer circumferential composite side surface, and an inner circumferential composite side surface. f. The inner composite side surface defines an axially oriented cavity at the center of the wound composite (60), and g. A winding core (10; 20; 30) having a generally cylindrical or hollow cylindrical shape is arranged in an axially oriented cavity and has an outer circumferential surface lying flat on the side surface of the inner composite. and characterization features: h. The winding core (10; 20; 30) has a local deviation from the cylindrical or hollow cylindrical shape (11; 21; 31) in at least one region of the outer circumferential surface. i. The helical structure of the winding includes at least one local irregularity in at least one region, where one of the wound electrode strips terminates and / or the thickness of one of the electrode strips changes abruptly. j. At least one region of the outer circumferential surface of the winding core (10; 20; 30) that exhibits a local deviation from the cylindrical or hollow cylindrical shape (11; 21; 31) is spatially assigned to the local irregularity of the winding composite (60).

2. The electrochemical energy storage battery (100) according to the preceding claims, having at least one of the following additional features: a. Local deviations from the cylindrical or hollow cylindrical shape (11; 21) involve a step-like or continuous decrease and / or increase in the outer diameter of the winding core; b. The local deviation (11; 21) involves at least one step-like or continuous decrease and / or increase in the outer diameter of the winding core, wherein, At least one step or continuous decrease and / or increase in the outer diameter extends axially on the winding core.

3. The electrochemical energy storage battery (100) according to any one of the preceding claims, having at least one of the following additional features: a. A local deviation (21) in at least one region of the outer circumferential surface of the winding core (20) involves a depression in the outer circumferential surface of the winding core and / or a bend in the outer circumferential surface of the winding core; b. A local deviation (21) in at least one region of the outer circumferential surface of the winding core (20) involves a depression in the outer circumferential surface of the winding core and / or a bend in the outer circumferential surface of the winding core, wherein, The dents and / or bends extend axially on the winding core.

4. The electrochemical energy storage battery (100) according to any one of claims 1-2, having at least one of the following additional features: a. The winding core (10; 20) is in the form of a hollow cylinder and has an inner core side surface that defines the boundary of an axially oriented cavity inside the winding core; b. Winding core (10; 20) It has a depression in the outer circumferential surface as a local deviation and a corresponding bend protruding into the axially oriented cavity; c. Winding core (10; 20) It has a bend in the outer circumferential surface as a local deviation and a corresponding depression in the inner core side surface.

5. The electrochemical energy storage battery (100) according to any one of claims 1-2, has the following additional features: a. Local deviations (31) in at least one region of the outer circumferential surface of a winding core (30) in the form of a hollow cylinder include the aperture in the wall of the winding core, and in particular the slot in the wall.

6. The electrochemical energy storage battery (100) according to any one of claims 1-2, having at least one of the following additional features: a. The outer circumferential surface of the winding core (10; 20; 30) has one or more recesses for accommodating at least one sensor; b. The outer circumferential surface of the winding core (10; 20; 30) has one or more recesses for accommodating at least one sensor, wherein, (One or more) recesses extend axially on the winding core.

7. The electrochemical energy storage battery (100) according to any one of claims 1-2, having at least one of the following additional features: a. The shell has a hollow cylindrical shape; b. The shell has a local deviation from the shape of the hollow cylinder in at least one region of its inner shell side surface (51).

8. The electrochemical energy storage battery (100) according to claim 7, having the following additional features: a. At least one region of the inner shell side surface with local deviation (51) is spatially assigned to a local defect in the winding composite (60).

9. The electrochemical energy storage battery (100) according to claim 7, having at least one of the following additional features: a. Local deviations (51) involve a step-like or continuous decrease and / or increase in the inner diameter of the housing sleeve; b. Local deviations (51) involve a stepped or continuous decrease and / or increase in the inner diameter of the housing sleeve, wherein, The inner diameter decreases or increases in a stepped or continuous manner and / or increases axially on the shell; c. Local deviations (51) involve depressions (53) in the inner shell side surface and / or bending (52) of the inner shell side surface. d. Local deviations (51) involve recesses (53) and / or bends (52) in the inner shell side surface, wherein the recesses and / or bends extend axially on the shell.

10. The electrochemical energy storage battery (100) according to any one of claims 1-2, having one of the following additional features: a. Electrochemical energy storage batteries are cylindrical or spherical batteries, or b. Electrochemical energy storage batteries are button batteries.

11. The electrochemical energy storage battery (100) according to claim 2, wherein at least one of the outer diameters decreases or increases axially over the entire height of the winding core in a stepped or continuous manner.

12. The electrochemical energy storage battery (100) according to claim 3, wherein the indentation and / or bending extends axially over the entire height of the winding core.

13. The electrochemical energy storage battery (100) according to claim 6, wherein (one or more) recesses extend axially over the entire height of the winding core.

14. The electrochemical energy storage battery (100) according to claim 9, wherein the stepwise or continuous decrease and / or increase in the inner diameter extends axially over the entire height of the casing.

15. The electrochemical energy storage battery (100) according to claim 9, wherein the indentation and / or bending extends axially over the entire height of the housing.

16. A method for producing an electrochemical energy storage battery, comprising the following steps: a. Provide at least two electrode strips and at least one partition strip disposed between the electrode strips, each electrode strip having a strip-shaped current collector coated with an active material on both sides, wherein there is no direct electrical contact between the two electrode strips; b. Providing a winding core (10; 20; 30) having a generally cylindrical or hollow cylindrical shape, wherein the winding core has an outer circumferential surface, The outer circumferential surface of the winding core has a deviation from the cylindrical or hollow cylindrical shape in at least one region (11; 21; 31). c. In order to produce the wound composite (60), the electrode strip and at least one septum strip are spirally wound around the winding core (10; 20; 30) to form a spiral structure, wherein the winding is performed in such a way that deviations (11; 21; 31) are spatially distributed to local defects in the spiral structure; d. Provide a cylindrical housing (70) for the energy storage battery; e. Introduce the wound composite (60) into the housing (70), f. It makes electrical contact with the wound composite (60) and encloses the housing (70). The spiral structure of the winding includes at least one local irregularity in at least one region, where one of the wound electrode strips terminates and / or the thickness of one of the electrode strips changes abruptly. At least one region of the outer circumferential surface of the winding core (10; 20; 30) that exhibits a local deviation from the cylindrical or hollow cylindrical shape (11; 21; 31) is spatially assigned to the local irregularity of the winding composite (60).

17. The method according to claim 16, characterized in that, The energy storage battery (100) produced using the method may have at least one of the features described in claims 1 to 15.

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