Manufacturing plant for producing a coated film web for a battery and method

Abstract

The invention relates to a production plant (10) for producing a coated film web (12), comprising a coating device which is designed to coat a film web (12) with a coating material (14), comprising a drying device (22) through which the coated film web (12) can be passed, whereby the coating material (14) is dried, comprising a roller-shaped deflection element (24) arranged behind the drying device (22) in the direction of movement (16), by means of which the dried, coated film web (12) can be deflected with regard to its direction of movement (16) by being applied to a circumferential surface of the deflection element (24), and comprising at least one stop (26) which is designed to limit buckling of the dried, coated film web (12) before it is applied to the circumferential surface of the deflection element (24).

Description

[0001] The invention relates to a manufacturing plant and a method for producing a coated film web.

[0002] WO 2013 / 079570 A1 discloses a method for producing electrodes for lithium-ion batteries, comprising a coating step, a calendering step, and a processing step. In the coating step, a strip-shaped current collector passes through a coating device in which one or more strips of an electrode material are applied to at least one side of the collector strip. The electrode material is applied to the collector strip in such a way that at least one region of the collector strip remains uncoated next to and / or between the strip(s). In the calendering step, the electrode material applied to the current collector is compacted in a calendering device. In the processing step, at least one of the uncoated regions is either directly stretched longitudinally or is stretched into a state in which it is more compliant with longitudinal stretching.

[0003] The object of the present invention is to provide a solution by means of which creases can be particularly effectively avoided when deflecting a coated film web.

[0004] This object is achieved according to the invention by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.

[0005] The invention relates to a manufacturing system for producing a coated film web, in particular for producing an electrode for a battery. The electrode can be configured, in particular, for use in a traction battery for a motor vehicle. The traction battery is configured to provide electrical energy for an electric drive train of the motor vehicle, whereby the motor vehicle can be electrically driven using the electrical energy from the traction battery.

[0006] The production plant comprises a coating device which is designed to coat a film web with a coating material. For example, the coating device can comprise at least one coating nozzle, in particular a slot nozzle, which is designed to apply the coating material to the film web. The production plant further comprises a drying device through which the coated film web can be passed. This dries the coating material. For example, the drying device can be a convection dryer. The production plant further comprises a roller-shaped deflection element which is reached by the coated film web downstream of the drying device in the direction of movement and by means of which the dried, coated film web can be deflected with respect to its direction of movement by being applied to a lateral surface of the deflection element.In particular, the deflection element is a deflection roller. The deflection element is particularly designed to be rotated about a rotational axis, wherein the rotational axis runs perpendicular to the direction of movement of the coated film web. Because the deflection element can be rotated about the rotational axis, the deflection element rolls along the film web when deflecting the coated film web, whereby friction between the film web and the deflection element can be kept particularly low. This allows the risk of damage to the coated film web during deflection by means of the deflection element to be kept particularly low.

[0007] Furthermore, the production system comprises at least one stop which is designed to limit the buckling of the dried, coated film web before it is applied to the outer surface of the deflection element. This stop is arranged in particular downstream of the drying device in the direction of movement, which means that the coated film web moves out of the drying device after drying by means of the drying device and then moves past the stop in the direction of movement. As the film web moves past the stop, the stop limits the buckling, in particular what is known as cupping, of the dried, coated film web. During cupping, the coated and dried film web can curve convexly or concavely after drying, for example by certain edges of the coated electrode web standing up and thus bending upwards.Drying of the coating material in the dryer device can cause the coating material to shrink and the coated film web to bulge as a result. In particular, the coated film web can bulge until its cross-section takes on the shape of a bowl. This phenomenon is a technical problem and is referred to as keying. At the point shortly before the first deflection of the dried film web with wrapping, the keying causes the film web to crease and fold up. In other words, areas of the coated film web can come to rest on top of one another as a result of the bulging and thus imprint wrinkles in the coated film web when deflected on the roller-shaped deflection element. By means of the at least one stop, this folding of the film web when it is placed on the outer surface of the deflection element can be particularly effectively prevented.As a result, the at least one stop makes it possible to prevent areas of the film web from folding onto one another when it is applied to the deflecting element or when it is deflected by means of the deflecting element. The problem of this curling could be avoided or limited by a targeted selection of process parameters for coating or drying the film web. However, this would lead to a severely restricted process window when selecting the process parameters, in particular the dryer parameters for drying the coated film web by means of the dryer device. The at least one stop makes it possible to not absolutely require such a targeted selection of process parameters for reducing or avoiding curling, since the curling can be limited, in particular avoided, by means of the at least one stop.

[0008] The production plant thus makes it possible to keep the risk of creases being formed in the film web when deflecting the coated, dried film web to a minimum, while process parameters for producing the film web can be selected with particular restrictions.

[0009] In a possible development of the invention, it is provided that the stop is arranged above a movement area through which the film web is guided before being applied to the deflection element, whereby the stop limits upward bulging of the film web. In particular, the at least one stop limits the upward bulging of the lateral edges of the film web. In this case, the at least one stop limits the bulging of the film web by the stop pressing the film web downwards or limiting the space in which the film web can bulge. In particular, the stop is arranged above the film web and is designed so that the underside of the film web rests against the stop. Furthermore, it can be provided that the deflection element is arranged below the film web so that the top of the film web rests on the deflection element for deflection.The stop thus limits the curvature of the film web away from the deflection element.

[0010] In a further possible embodiment of the invention, it is provided that the coating device is configured to coat a substrate film in the form of a film web with an electrode paste as the coating material. The electrode paste can in particular comprise an active material, for example in the form of a slurry. The substrate film can in particular be designed as a metallic conductor film. Thus, the production system is in particular configured to produce an electrode for a battery, in particular a vehicle battery. In particular, an electrode for a lithium-ion battery cell can be produced using the production system. The production system thus enables the electrode to be produced with particularly little waste, in that the folding and imprinting of folds in the electrode is particularly effectively avoided by means of the at least one stop.

[0011] In a further possible embodiment of the invention, the coating device is configured to coat the film web with at least two parallel, spaced-apart coating strips. This makes it possible for the film web coated with the at least two coating strips to be divided into respective film web strips after the coating strips have dried, with each film web strip each comprising a coating strip. This allows a particularly large number of electrodes to be produced simultaneously using the production system, as raw material for a particularly large number of electrodes is produced simultaneously by coating the film web with several coating strips.

[0012] The at least one stop is configured to limit the buckling of the film web for a film web with one coating strip, for a film web with two coating strips, or for a film web with more than two coating strips. This ensures that the risk of bending and creases can be kept particularly low, even for film webs with multiple coating strips.

[0013] In a further possible embodiment of the invention, it is provided that the at least one stop is provided by a roller which is designed to rotate about an axis of rotation running perpendicular to the direction of movement. In this case, the axis of rotation of the roller runs in particular parallel to the axis of rotation of the cylindrical deflection element, provided that the deflection element is a rotatable deflection element. By providing the stop by the roller, the roller can rotate about the at least one stop when guiding the film web along, as a result of which friction between the film web and the roller can be kept particularly low. As a result of the particularly low friction between the film web and the roller, there is particularly little adhesion between the film web and the roller, as a result of which the risk of damage to the film web as a result of adhesion to the roller can be kept particularly low.

[0014] In this context, it can be provided, in particular, that the roll is designed as a plastic roll, a rubber roll, or a roll with a rubber coating. In other words, the roll has a material on its outer surface that is, in particular, softer than the material of the film web, in particular than the substrate film. As a result, the risk of the film web being damaged as a result of contact with the roll can be kept particularly low.

[0015] In a further possible embodiment of the invention, it is provided that the at least one stop has a width in a width direction running perpendicular to the direction of movement, which width corresponds at least to the extension width of the coated film web running perpendicular to the direction of movement, wherein the film web has this extension width in a length region along the direction of movement in which the film web bears against the stop. In other words, the width of the stop is selected to be so wide that the stop covers the film web over the entire width of the film web, upwards or downwards, at least in the length region of the film web in which the film web is in contact with the stop.In other words, the film web has a length with respect to the direction of movement which, in terms of its shape, corresponds to a strip of the film web, wherein the strip extends with its longitudinal direction in a transverse direction or the width direction of the film web. The transverse direction of the film web runs perpendicular to the direction of movement of the film web. In this length region, the film web rests against the stop at least in a section along the transverse direction. The width of the stop is designed such that the stop covers the film web in this length region over the entire transverse width of the film web, upwards or downwards, depending on whether the stop is arranged above or below the film web. If the stop is arranged above the film web, then the stop covers the film web upwards over its entire width.If the stop is positioned below the film web, it covers the entire width of the film web downwards. Because the stop is designed at least wide enough to completely cover the film web upwards in the transverse direction, the stop can reliably limit the buckling of the film web. This minimizes the risk of lateral edges of the film web buckling past the stop.

[0016] The invention further relates to a method for producing a coated film web, in particular an electrode for a battery, in particular a traction battery of a motor vehicle. In the method, the film web is coated with a coating material by means of a coating device. Furthermore, the method provides that the coated film web is passed through a drying device, whereby the coating material is dried. The method further provides that buckling of the dried, coated film web is limited by means of at least one stop after drying and before it is applied to a lateral surface of a deflection element, which is in particular roller-shaped.The method further provides for the film web to be applied to the outer surface of the roller-shaped deflection element reached by the film web downstream of the dryer device, thereby deflecting the film web. In particular, the method can be implemented using the production system as already described in connection with the production system according to the invention.

[0017] Further features of the invention may emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0018] The drawing shows: Fig. 1 a schematic side view of a section of a production plant for coating a film web; Fig. 2 a schematic plan view of the coated film web; and Fig. 3 a schematic sectional view of the coated film web.

[0019] In the figures, identical and functionally identical elements are provided with the same reference symbols.

[0020] In Fig. 1 shows a section of a production plant 10 for producing a coated film web 12, in particular for producing an electrode for a battery, in particular a vehicle battery. The production plant 10 comprises a Fig. 1, which is configured to coat a film web 12, 20 with a coating material 14. The production system 10 is configured, in particular, to coat a substrate film 20 as film web 12 with an electrode paste as coating material 14. In the present case, a copper substrate film is coated with the coating material 14 as the substrate film 20. The coating device can apply the coating material 14 in the form of a single strip or in the form of several coating strips 18 arranged parallel to one another and laterally spaced from one another. Fig. 2 and Fig. Figure 3 shows the film web 12 coated with the coating material 14. In the present case, the coating material 14 is coated with two coating strips 18 arranged parallel to one another with respect to a direction of movement 16 and spaced laterally apart.

[0021] The production plant 10 further comprises a drying device 22 through which the coated film web 12 can be guided in the direction of movement 16. After drying in the drying device 22, the coated, dried film web 12 is moved out of the drying device 22 in the direction of movement 16. The production plant 10 further comprises a roller-shaped deflection element 24 and at least one stop 26. In the present case, the production plant 10 comprises two stops 26. As in Fig. 1, the coated film web 12, after leaving the dryer device 22, is moved in the direction of movement 16 towards the deflection element 24, is applied to the outer surface of the deflection element 24 and is folded around the deflection element 24, whereby the film web 12 is deflected. In order to keep friction between the deflection element 24 and the coated film web 12 particularly low, it can be provided that when deflecting the film web 12, the deflection element 24 rotates about a first axis of rotation 28, which runs perpendicular to the direction of movement 16 of the film web 12. As in Fig. 1, the film web 12 is placed with its uncoated side against the outer surface of the deflecting element 24 and the direction of movement 16 of the film web 12 is changed by guiding it over the outer surface of the deflecting element 24.

[0022] In order to prevent areas of the film web 12 from folding over when applied to the outer surface of the deflection element 24 as a result of the film web 12 buckling after drying, and consequently wrinkles from being imprinted in the coated film web 12 when the film web 12 is deflected, at least one stop 26 is provided. In the present case, the production system 10 comprises two stops 26, each provided by a roller 30. The respective rollers 30 are each rotatable about a second axis of rotation 32. The second axis of rotation 32 runs parallel to the first axis of rotation 28 and perpendicular to the direction of movement 16 of the film web 12 in a region in which the film web 12 rests against the respective rollers 30. In the present case, the rollers 30 are each designed as plastic rollers or as rubber rollers or with a rubber coating. In the present case, the rollers 30 are arranged in a line with respect to the respective second axes of rotation 32.This means that the rollers 30 are arranged such that the second axes of rotation 32 lie on top of one another and are thus arranged concentrically to one another.

[0023] In the present case, each of the rollers 30 covers an associated lateral edge of the coated film web 12 upwards, as in Fig. 2 can be recognized particularly well. In Fig. 3 it can be seen that the rollers 30 overlap the respectively assigned edge of the film web 12 upwards, whereby the edge of the film web 12, which bulges upwards as a result of the drying of the coated film web 12, can come into contact with the respectively assigned roller 30. By selecting a height of the respective rollers 30 with regard to their arrangement above the film web 12, it can be adjusted how far the respective edges of the film web 12 can bulge before they strike the respectively assigned rollers 30. By this striking of the bulging edges of the film web 12, the bulging of the film web 12 can be limited. In other words, the rollers 30 are designed to limit the bulging of the dried, coated film web 12, in particular the bulging of its edges, before the film web 12 is applied to the lateral surface of the deflection element 24.As an alternative to providing two rollers 30, one of which is each assigned to an edge of the film web 12, the production system 10 can have only a single stop 26. This can be provided, for example, by a single roller. In particular, this stop 26 provided by the single roller has a width in a width direction running perpendicular to the direction of movement 16, which width corresponds at least to the extension width of the coated film web 12, which the film web 12 has in the length region 34 with respect to the direction of movement 16, in which the film web 12 rests against this stop 26. In this case, the extension width of the coated film web 12 runs along a transverse direction, which runs perpendicular to the direction of movement 16 from one side edge of the film web 12 to the other side edge of the film web 12.

[0024] To be among the Fig. 2 and Fig.In order to prevent the film web 12 from bulging in an uncoated central region in the embodiments of the coated film web 12 shown in Figure 3 with the two coating strips 18 arranged parallel to one another and spaced from one another, a further roller (not shown in the figures) can be provided, which also provides a stop 26 and which is arranged in the longitudinal region 34 so as to overlap the film web 12 in the central, uncoated region. As a result, bulging of the uncoated region of the film web 12 between the two coating strips 18 can be particularly effectively limited by means of this further roller.

[0025] The respective rollers 30 serve as a stop 26 to reduce the curling or standing up of the edge of the coated film web 12 in order to prevent the film web 12 from folding over during subsequent winding onto a winding element or during deflection around the deflection element 24.

[0026] There is a technical need to minimize the cupping of an electrode web, in this case the coated film web 12, in the coating process for electrodes for lithium-ion cells in the manufacturing plant 10. In the coating process for electrodes for lithium-ion cells, the electrode paste with active material is applied in the form of a slurry to a metallic conductor foil. This can be done in a roll-to-roll process. During the drying process, when only one side of the substrate foil 20 is coated, the drying of the paste from the active material and thus of the coating material 14 can cause the coating to contract and the film web 12 to bulge until it takes on the shape of a bowl in cross-section. This cupping can lead to the film web 12 forming a crease and folding up shortly before the first deflection by means of the deflection element 24 with wrap.

[0027] In the production plant 10, the film web 12 is deflected after exiting a dryer section of the dryer device 22 by means of the deflection element 24, which is here designed as a deflection roller, in order to guide the film web 12 to a winder. At the exact point shortly before a first deflection of the film web 12 with wrapping, a curl causes the film web 12 to crease and fold. To reduce curling, a stop 26 is located after exiting the dryer section at a distance of approximately 100 millimeters from the deflection roller above respective edge regions of the film web 12, which are raised due to curling. Positioning the respective stop 26 above the raised edges of the film web 12 during curling makes it possible to provide a limit for the curling of the edges of the film web 12.In this way, sagging can be limited and folding of the edge of the film web 12 before deflection by means of the deflection roller can be particularly effectively prevented. The stop 26 for limiting the erecting of the edges of the film web 12 and folding over as the web continues is represented by at least one roller or, in this case, at least one roller 30, which is located above the respective associated edge of the film web 12. In particular, the respective roller 30 has at least a certain minimum width which is sufficient to prevent further erecting of the film web 12. A position and height of the arrangement of the respective rollers 30 above the film web 12 are selected such that folding of the film web 12 is prevented at the deflection roller next after the dryer outlet. List of reference symbols 10 Manufacturing facility 12 film strips 14 Coating material 16 Direction of movement 18 coating strips 20 substrate film 22 Drying device 24 Deflection element 26 stop 28 first axis of rotation 30 rolls 32 second axis of rotation 34 length range QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2013 / 079570 A1

[0002]

Claims

[1] A manufacturing plant (10) for producing a coated film web (12), comprising a coating device configured to coat a film web (12) with a coating material (14), a drying device (22) through which the coated film web (12) can be passed, whereby the coating material (14) is dried, a roller-shaped deflection element (24) arranged downstream of the drying device (22) in the direction of movement (16), by means of which the dried, coated film web (12) can be deflected with respect to its direction of movement (16) by being applied to a lateral surface of the deflection element (24), and at least one stop (26) configured to limit bulging of the dried, coated film web (12) before being applied to the lateral surface of the deflection element (24). [2] Manufacturing plant (10) according to claim 1, characterized bythat the stop (26) is arranged above a movement area through which the film web (12) is guided before being applied to the deflection element (24), whereby the stop (26) limits an upward bulging of the film web (12). [3] Manufacturing plant (10) according to claim 1 or 2, characterized by that the coating device is designed to coat a substrate film (20) as a film web (12) with an electrode paste as a coating material (14). [4] Manufacturing plant (10) according to one of the preceding claims, characterized by that the coating device is designed to coat the film web (12) with at least two coating strips (18) running parallel to one another and arranged at a distance from one another. [5] Manufacturing plant (10) according to one of the preceding claims, characterized bythat the stop (26) is provided by a roller (30) which is designed to rotate about an axis of rotation (32) running perpendicular to the direction of movement (16). [6] Manufacturing plant (10) according to claim 5, characterized by that the roller (30) is designed as a plastic roller or as a rubber roller or with a rubber coating. [7] Manufacturing plant (10) according to one of the preceding claims, characterized by in that the stop (26) has a width in a width direction running perpendicular to the direction of movement (16), which width corresponds at least to the extension width of the coated film web (12) running perpendicular to the direction of movement (16), wherein the film web (12) has this extension width in a length region (34) along the direction of movement (16) in which the film web (12) rests against the stop (26). [8] Method for producing a coated film web (12), in which - a film web (12) is coated with a coating material (14) by means of a coating device, - the coated film web (12) is passed through a drying device (22), whereby the film web (12) is dried, - a buckling of the dried, coated film web (12) after drying and before being applied to a lateral surface of a deflecting element (24) is limited by means of at least one stop (26), and - the film web (12) is applied to the outer surface of the roller-shaped deflection element (24) arranged behind the drying device (22) in the direction of movement (16), whereby the film web (12) is deflected.

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