Pouch battery cell and battery with such a

Abstract

The invention relates to a pouch battery cell (2). This comprises an electrode arrangement (AE) and a pouch bag (4) in which the electrode arrangement (8) is arranged. Furthermore, the pouch battery cell (2) has a film (22) which is arranged in a bag opening (20) of the pouch bag (4) and is joined to the pouch bag (4), wherein the film (22) forms a desired outlet point (26) for the escape of gas (G) from a cell interior (I). Furthermore, the invention relates to a battery (44) and an electrically powered motor vehicle having such a pouch battery cell (2).

Description

The invention relates to a pouch battery cell having a pouch in which an electrode arrangement is accommodated.An electrically driven motor vehicle typically has a traction battery (high voltage, HV battery) which supplies an electric motor with energy for driving the motor vehicle. An electrically driven motor vehicle is understood here to mean, in particular, an electric vehicle which stores the energy required for driving only in the traction battery (BEV), an electric vehicle having a range extended electric vehicle (REEV), a hybrid vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) and / or a fuel cell vehicle (FCEV), which temporarily stores the electrical energy generated by a fuel cell in the traction battery.Such a traction battery comprises a number of battery cells connected to one another, which are expediently designed as lithium-ion battery cells (Li-ion battery cells). For example, the battery cells are combined to form one or more battery modules. Several form variants of the lithium-ion battery cells are known, which are typically used for such a traction battery. Thus, the battery cells are designed as cylindrical cells (round cells), as pouch battery cells or as prismatic cells.In a conventional pouch battery cell, an electrode arrangement designed as an electrode stack or as a flat winding is accommodated in a casing, the so-called pouch bag. The pouch bag is produced, for example, from a single pouch film which is folded in the manner of book-following, or from two pouch films which each form a pouch bag half. The pouch film or at least one of the pouch films is formed in the shape of a trough (shell) during the production of the battery cell by means of a deep-drawing process, so that a receiving space for the electrode arrangement is formed. To form the pouch bag, the folded pouch film or pouch bags are joined in a circumferentially materially integral manner, for example by means of a heat sealing method.During operation of the battery cell, chemical reactions can take place which result in gas formation within the battery cell and, associated therewith, in an increase in the internal cell pressure. With a correspondingly high internal cell pressure, there is the risk that the pouch bag tears at a previously undefined location, in particular in the region of the sealing seam. Such uncontrolled degassing of the pouch cell can disadvantageously lead to damage or complete destruction of components in the installation space environment and / or represent a risk for a user.DE 10 2013 222 002 A1 discloses a battery having a plurality of battery cells which are arranged in a battery housing. At least one component of the battery housing has a passage via which a gas emerging from at least one of the battery cells can be discharged from the battery housing. Electrode assemblies of the battery cells are enclosed by frames that form a channel for the gas.DE 10 2020 216 452 A1 discloses a Poch cell. This comprises a pouch bag, wherein a degassing channel is provided which passes through the pouch bag and connects a pouch interior to an environment, wherein a closing element is seated in the degassing channel, and wherein the closing element is designed such that, when an overpressure occurs in the pouch interior, the closing element is pressed out of the degassing channel by the overpressure, and in the process releases the degassing channel.DE 10 2021 202 675 A1 relates to a battery cell having a housing. At least two housing parts of the housing are sealed in a gas-tight manner by a sealing seam. A first valve and a second valve switchably connect a volume enclosed by the housing to a surrounding area of the battery cell.The invention is based on the object of specifying a particularly suitable pouch battery cell. In particular, an escape of a gas formed in the battery cell at a predefined location at a correspondingly high internal cell pressure is to be made possible. Furthermore, a battery having such a pouch battery cell and an electrically driven motor vehicle having such a pouch battery cell should be specified.With regard to the pouch battery cell, the object is achieved according to the invention by the features of claim 1. with regard to the battery, the object is achieved by the features of claim 8 and with regard to the electrically driven motor vehicle, the object is achieved according to the invention by the features of claim 10. Advantageous embodiments and developments are the subject matter of the dependent claims. The explanations in connection with the pouch battery cell also apply here to the battery and / or to the electrically driven motor vehicle and vice versa.The pouch battery cell, also referred to below for short as a battery cell, a pouch cell or a cell, is in particular designed as a lithium-ion battery cell. In particular, the pouch battery cell is provided and configured for a battery, suitably for a traction battery of an electrically driven motor vehicle.The pouch battery cell comprises an electrode arrangement which is designed, for example, as an electrode stack or as an electrode winding, in particular as an electrode flat winding. Furthermore, the pouch battery cell comprises a pouch bag in which the electrode arrangement is arranged. In other words, the pouch bag forms a casing of the pouch battery cell.Furthermore, the pouch battery cell comprises a film which is arranged in a (first) pouch opening of the pouch pouch. The film is joined to the pouch bag. In particular, the film is joined to that section of the pouch bag which comprises the pouch opening, that is to say which delimits the pouch opening.The pouch bag thus comprises a cell interior in which the electrode arrangement is accommodated. In other words, the pouch encloses the cell interior, with the exception of the pouch opening.The foil forms a target outlet point for a gas formed in the pouch battery cell. In other words, the setpoint outlet point is provided for the purpose of gas formed within the pouch battery cell flowing out of the cell interior of the pouch battery cell through this setpoint outlet point at a correspondingly high internal cell pressure. The desired outlet point is therefore provided and configured such that the gas preferably passes through this outlet. Expediently, the target outlet point is designed in such a way that it opens at an internal cell pressure, in other words connects the cell interior to a surrounding area of the pouch battery cell in terms of flow, which surrounding area is smaller than a predefined or expected internal cell pressure, at which the pouch bag opens at a different point than at the target outlet point, in particular at a sealing seam. An uncontrolled escape of the gas in the region of the sealing seams or a burst or travel of the pouch at a previously unknown location is thus advantageously avoided. On the basis of the film, the gas is thus guided when it exits from the cell interior.The pouch bag thus comprises two (pouch bag sections) pouch sections between which the pouch opening is formed and between which the film is arranged. In particular, the two bag sections each form a pouch bag half (bag half), between which the electrode arrangement is arranged. For example, each of the pouch bag halves is formed on the basis of a respective pouch film; furthermore, for example and as an alternative, both pouch bag halves are formed on the basis of a single (common) pouch film which is folded in the manner of book following, the two pouch bag halves being formed on the basis of the film sections of the pouch film separated by the fold line.In particular, the two bag sections, in particular the two pouch bag halves, are joined to one another at their circumference, that is to say at their edge. A heat sealing process is expediently used for this purpose. In the region of the pouch opening, the two pouch sections are not joined to one another directly, but rather indirectly by means of the film, and / or are arranged at a distance from one another, such that a gas formed in the battery cell can flow out of the cell interior through the pouch opening (and through the setpoint outlet point of the film). Consequently, the electrode arrangement is not surrounded by the pouch bag in the region of the pouch opening.In particular, a plastic-aluminum composite film is used as pouch film for the pouch bag. The film forming the desired exit point is likewise a pouch film, for example.According to an expedient configuration of the pouch battery cell, the setpoint outlet point is formed by means of a slot in the film. In other words, the film has an elongated hole-like opening, i.e. an elongated opening which is continuous with respect to a direction from the electrode arrangement to the film and forms the desired outlet point.In this case, the slot is closed by a closure element, so that the slot and thus also the pouch battery cell is closed in a fluid-tight manner. The closure element is formed, for example, from wax or from resin or comprises wax or resin. Furthermore, for example, the closure element is formed on the basis of a (closure) film element bonded to the film. At most, the closure element is expediently designed in such a way that it releases the slit in a predetermined pressure range and / or in a predetermined temperature range, in particular in such a way that the closure element dissolves and / or releases from the film, in such a way that the gas can flow out.According to an alternative embodiment, the desired exit point is formed as a desired tear point of the film. The intended tear point is formed by a film section with reduced film thickness. In the case of an increased internal cell pressure owing to gas formation, opening of the battery cell at this desired tear point is particularly likely on account of the reduced film thickness.The opening of the pouch battery cell at the setpoint outlet point is in particular irreversible.According to an advantageous embodiment, the bag opening is formed between the first bag section and the second bag section of the pouch bag. In this case, the first pouch section forms a gas pocket which is open towards the electrode arrangement. For this purpose, the end of the first bag section facing away from the electrode arrangement is folded over in a suitable manner toward the electrode arrangement, in other words the free end of the first bag section is bent over toward the inside of the bag.The turned-over part of the first bag section thus delimits the bag opening. This part of the first bag section is also referred to as the inner wall of the gas pocket.Expediently, the film forming the desired outlet point is joined to the inner wall of the gas pocket.In a suitable manner, the second bag section forms a second gas pocket which is open towards the electrode arrangement in an analogous manner to this. In particular, the film forming the desired outlet point is joined to an (inner) wall of the second gas pocket delimiting the bag opening. The bag opening is thus formed on the basis of the first and the second gas pockets and is bounded by the first and the second gas pockets.The gas pocket advantageously forms a receiving space for gas formed in the battery cell. The gas pockets thus form a predefined region for gas accumulating, which is formed in particular during an aging process of the battery cell.Particularly preferably, the section of the pouch film forming the gas pocket is one-piece, i.e. contiguous with that section of the pouch film which covers the electrode arrangement, in particular comprises the latter.According to an advantageous configuration of the pouch battery cell, the wall of the first gas pocket facing away from the pouch opening, i.e. the outer wall of the first gas pocket and / or the (outer) wall of the second gas pocket facing away from the pouch opening, has a wavy or zigzag shape, in particular a wavy or zigzag-shaped cross section. Thus, the respective outer wall is shaped, in particular bent, in a wave- or zigzag-shaped manner towards gas pocket inside and gas pocket outside. In other words, the outer wall has depressions which project alternately toward the inside of the gas pocket and elevations which project toward the outside of the gas pocket. In this way, a deformability, i.e. a flexibility, of the respective outer wall is advantageously increased when the gas formed in the battery cell is received in the respective gas pocket and the associated deformation of the outer wall is increased.According to a suitable configuration of the pouch battery cell, the film forming the setpoint outlet point is joined to the end of the first of the gas pocket which faces the electrode arrangement. In other words, the film is joined to the end of the inner wall of the first gas pocket facing the cell interior, in particular glued to the latter or welded to the latter. Furthermore, in an analogous manner to this, the film forming the desired outlet point is joined to the end of the second of the gas pocket which faces the electrode arrangement. The two gas pockets expediently project beyond the film forming the desired outlet point in a direction from the electrode arrangement to this film. The ends of the first gas pocket and the second gas pocket facing away from the electrode arrangement bear against one another and are expediently held in contact with one another; for example, these two ends are clamped to one another, in particular in a releasable manner, for this purpose. Alternatively or additionally, the first gas pocket and the second gas pocket are joined to one another, in particular in a fluid-tight manner, at their ends facing away from the electrode arrangement, for example glued and / or welded to one another, in particular by means of a heat-sealing method.The two gas pockets thus cover the bag opening, in particular the two gas pockets close the bag opening, the film forming the desired outlet point being arranged between the two gas pockets. If the two gas pockets are joined to one another at their end facing away from the electrode arrangement, the joining connection is designed in such a way that a force necessary for releasing this joining and / or a cell internal pressure necessary for this purpose is less than a predetermined or expected cell internal pressure at which the pouch bag opens at a different point than at the joined gas pockets, in particular at the sealing seam. For example, the two gas pockets are joined to one another by a sealing method, in particular heat sealing, wherein a width of the sealing seam is between 0.25 times and 0.75 times the width of the sealing seam at the circumference of the bag halves. In summary, the joint connection between the two gas pockets forms a desired rice location at their ends facing away from the electrode arrangement because of their comparatively weak formation.According to a suitable development, the pouch bag has a further (second) bag opening. This is expediently formed in a manner analogous to the (first) bag opening between the first and the second bag section of the pouch bag. A further film is arranged in the further bag opening and joined to the pouch bag, wherein the further film analogously forms a further desired outlet point.Preferably, the first and the second bag opening are arranged spaced apart from one another on a common end face of the pouch bag. In particular, the first and the second bag section are joined directly to one another in the region between the two bag openings.A further aspect of the invention relates to a battery. In particular, the battery is provided and configured for an electrically driven motor vehicle. The battery is suitably a traction battery for a motor vehicle, preferably a high-voltage battery, which provides electrical energy for a traction drive and / or for a high-voltage on-board electrical system, for example with an electrical voltage between 60 V and 1500 VAt most, the battery comprises a pouch battery cell in one of the variants illustrated above. The battery expediently comprises a plurality of such pouch battery cells, which are expediently electrically connected in series and / or in parallel with one another. For example, the pouch battery cells are combined to form a cell module and / or accommodated in a module frame or in a module housing.Optionally, the battery further comprises a cover. This is expediently of strip- or plate-shaped design. The cover is arranged on that end face of the pouch battery cell on which the foil is arranged. The cover comprises a continuous, in particular hole-like, recess. This is aligned with the film forming the desired exit point. Thus, the desired outlet point thus opens into the recess. The recess thus forms a gas channel.If present, the first and / or the second gas pocket, which delimit the setpoint outlet point, project into the recess of the cover. Thus, a defined receiving region for the respective gas pocket is formed on the basis of the cutout. In addition, the respective gas pocket prevents an undefined outflow of the gas along the side of the cover facing the pouch battery cell. The gas pockets thus guide the gas emerging through the desired outlet point into the cutout.If the pouch battery cell has more than one desired outlet point, a separate cutout is expediently provided in the cover for each of these.According to a preferred embodiment, the cover rests on this end face of the poking cell and / or is held on it and / or is pressed against it. In particular, the cover lies against and / or is pressed against the pouch battery cell in the region next to the pouch opening, that is to say next to the film forming the desired outlet point. The region of the target outlet point is therefore not covered by the cover, but the target outlet point opens into the recess of the cover. In the region in which the cover abuts the pouch battery cell, the cover prevents deformation of the pouch battery cell, in particular during the formation of the gas, such that undesired opening of the pouch battery cell in this region is prevented or at least a risk thereof is. The cover thus exerts a counter pressure on the pouch battery cell there.A further aspect of the invention relates to an electrically driven motor vehicle. This comprises a pouch battery cell in one of the variants illustrated above. In particular, its traction battery comprises such a pouch battery cell. Additionally or alternatively, the electrically driven motor vehicle comprises a battery which is designed according to one of the variants illustrated above.Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Shown therein are: FIG. 1 aschematically shows, in a side view, a pouch battery cell having a pouch with an electrode arrangement accommodated therein, FIG. 1 bschematically shows, in a plan view, the pouch battery cell, wherein a film forming a setpoint outlet point is arranged in a pouch opening of the pouch pouch, FIG. 1 cshows schematically in a sectional view the pouch battery cell with the sectional plane A according to FIG. 1 b, FIG. 1d is a schematic enlarged detail of the region B of FIG. 1c, FIG. 2a is a schematic sectional view of the bag opening with the film arranged therein, wherein the film has a slit sealed with a resin, FIG. 2 bschematically illustrates an alternative embodiment of the pouch battery cell in a sectional view, wherein the slot of the foil is closed by an adhesively bonded foil element, FIG. 2 cschematically illustrates an alternative embodiment of the pouch battery cell in a sectional view, wherein the target outlet point is formed as a target rice point with reduced film thickness, FIG. 2 dschematically illustrates an alternative embodiment of the pouch battery cell in a sectional view, wherein the film is arranged between gas pockets flanking the pouch opening, and wherein the gas pockets are arranged on one another on the free end side, FIG. 3 schematically shows two pouch battery cells according to an alternative embodiment, wherein the respective pouch opening has only one gas pocket on one side, and wherein a cell intermediate pad is arranged between the two pouch battery cells, FIG. 4 aschematically illustrates a battery with an alternative configuration of the pouch battery cell, wherein the pouch battery cell has a plurality of pouch openings on a common end face, in each of which a film forming a setpoint outlet point is arranged, and wherein a cover with recesses is arranged on the end face, FIG. 4 bschematically illustrates the battery in a sectional view with the sectional plane C according to FIG. 4 a, and FIG. 5 schematically shows an alternative embodiment of the battery, wherein a plurality of pouch battery cells are arranged next to one another, each of which has a plurality of pouch openings on its end face, wherein the pouch openings open into recesses of a common cover.Parts and sizes corresponding to one another are always provided with the same reference numerals in all figures.FIGS. 1 ato 1 dschematically illustrate a pouch battery cell 2, in particular configured as a lithium-ion battery cell. The pouch battery cell 2 (battery cell 2, cell 2) comprises a pouch bag 4 as a casing. Pouch bag 4 thus comprises a cell interior 6, in which an electrode arrangement 8, for example, embodied as an electrode stack or as an electrode flat coil, is accommodated. The cathodes (not shown in detail) of the electrode arrangement 8 are in this case electrically connected to a conductor 10 and the anodes (not shown in detail) of the electrode arrangement 8 are electrically connected to a further conductor 10, the two conductors being led outwards. In other words, the two diverters 10 pass through the pouch bag 4. The direction from one of these end faces 12 to the other is denoted by "X" in the adjacent direction diagram.The pouch bag 4 has two deep-drawn pouch bag halves (pouch halves) as pouch sections 14 and 16. According to the example shown here, the two bag sections 14, 16 are formed by a single (common) pouch film which is folded in the manner of book-following, wherein the two bag sections 14, 16 are formed by the film sections of the pouch film separated by the fold line. The electrode arrangement 8 is thus arranged between the two pouch sections 14 and 16 and projects beyond them.The arresters 10 are arranged between the two pouch sections 14 and 16 and are led out of the cell interior 6 to the outside of the cell. At those end sides 12 at which the arresters 10 protrude, the bag sections 14 and 16 are joined to one another in a fluid-tight manner along their edge, in particular by heat sealing.According to an alternative, not shown in any more detail, the two bag sections 14 and 16 are formed by means of a respective pouch film.The pouch bag 4 is preferably open at one of the end sides 18 of the pouch battery cell 2, through which the arresters do not pass, in other words a pouch opening 20 of the pouch bag is arranged at this end side 12. The bag sections 14, 16 are therefore not joined to one another, at least not directly, to form the bag opening 20. Preferably, the two bag sections 14, 16 are spaced apart from one another in the region of the bag opening 20. The direction from the electrode arrangement to the end face 18 with the bag opening 20 is denoted by "Z" in the adjacent spatial diagram.The direction oriented perpendicular to the X direction X and to the Z direction, i.e. the direction from one of the bag halves to the other, is designated by "Y".In the bag opening 20, thus between the bag sections 14, 16, a film 22, which is expediently an aluminum composite film, is arranged. This film 22 is joined to the pouch bag 4, in particular to the two bag sections 14, 16. For example, the film 22 is bonded or welded to the first and second bag portions 14, 16. The corresponding adhesive or the corresponding weld seam is schematically indicated in the figures and is provided with the reference sign 24. The film 22 is thus arranged within the bag opening 20. In FIG. 1 a, the film 22 is covered by the pouch 4 and is therefore shown in dashed lines.As is shown in more detail further below in connection with FIGS. 2 ato 2 d, the film 22 forms a setpoint outlet point 26 for an outlet of gas, which was formed within the pouch battery cell, in particular on the electrode arrangement 8, from the cell interior 6.As can be seen in particular in the sectional representations of FIGS. 1 cto 3, the pouch battery cell 2 comprises a first gas pocket 28 open toward the electrode arrangement 8 and a second gas pocket 30 open toward the electrode arrangement 8, each serving for receiving gas formed within the pouch battery cell 2.For this purpose, the first bag section 14, in particular its free end, is folded over towards the inside of the bag, i.e. bent, forming the first gas pocket 28. The film 22 is joined to the first gas pocket, namely to its turned-over free end. The turned-over portion of the first gas pocket 28 which encloses and bounds the pocket opening forms the inner wall 32 of the first gas pocket.In an analogous manner to this, the second bag section 16, in particular its free end, is folded over towards the inside of the bag, i.e. towards the first gas bag 28, forming the second gas bag 30. The film 22 is joined to the second gas pocket 30, namely to its turned-over free end. In summary, the film 22 is arranged in the bag opening 20 between the two gas pockets 28, 30 and joined to the two gas pockets 28, 30. The folded-over portion of the second gas pocket 30, which encloses and delimits the pocket opening 20, forms the inner wall 32 of the second gas pocket 30.As can be seen in FIGS. 2 a, 2 band 2 d, the setpoint exit point 26 is formed on the basis of a slot in the film 22. This is thus a slot-like, continuous opening in the film 22, the slot being expediently closed in a fluid-tight manner by means of a closure element 34. According to the exemplary embodiment of FIG. 2 a, the closure element 34 is formed as a resin or as a wax. According to the exemplary embodiment of FIG. 2 b, the closure element 34 is an adhesively bonded film element.In the embodiment of the pouch battery cell 2 according to FIG. 2 d, the two gas pockets 28 and 30 project beyond the film 22 in the Z direction, that is to say in the direction from the electrode arrangement 8 to this film 22. For example, the film is glued or welded to this end. Similarly, in an analogous manner to this, the film 22 is joined to the end of the second gas pocket 30 which faces the electrode arrangement 8, i.e. the cell interior 6. In summary, the film 22 is arranged between the two gas pockets 28, 30, in particular with respect to the Y direction between the end thereof facing the electrode arrangement, the inner wall 32 thereof. The ends 36 of the first gas pocket 28 and of the second gas pocket 30 facing away from the electrode arrangement 8 are therefore not joined to the film 22 and are thus free. These ends 36 abut each other and are joined to each other, in particular in a fluid-tight manner.The two gas pockets 28 and 30 thus cover the bag opening 20 and close it. The film 22 is thus arranged within the space enclosed by the pouch bag 4.The joint connection between the gas pockets 28 and 30 is designed in such a way that a force necessary for releasing this joint and / or a cell internal pressure necessary for this purpose is less than a cell internal pressure which is predetermined or expected, at which the pouch bag opens at a different point than at the joined gas pockets, in particular at the sealing seam.In the variant of the pouch battery cell 2 according to FIG. 2 c, the setpoint outlet point 26 is designed as a setpoint rice point. The desired rice location is formed here by a film section 38 with reduced, i.e. reduced thickness. In other words, the film 22 comprises a region (film section 38), the thickness of which, that is to say the extent thereof in a direction perpendicular to the surface spanned by the film, is smaller than in the remaining region thereof.The two gas pockets 28, 30 are each formed on the basis of the inner wall 32 delimiting the bag opening 20 and an outer wall 40 opposite one another with respect to the Y direction. Thus, the outer wall 40 is the wall of the respective gas pocket facing away from the bag opening 20. The respective outer wall 40 has a wave or zigzag shape. In particular, its cross section is wave-shaped or zigzag-shaped. Thus, the respective outer wall 40 is bent in a wave- or zigzag-shaped manner alternately towards the gas pocket inside and the gas pocket outside.In the variants of the pouch battery cell 2 according to FIGS. 1 ato 2 dand FIGS. 4 ato 5, both the first and the second gas pockets 28, 30 are formed. The bag opening 20 is thus bounded on both sides with respect to the Y direction by the gas pockets 28, 30. FIG. 3 shows an alternative embodiment according to which, in contrast, only the first gas pocket 28 or only the second gas pocket 30 is formed. The film 22 is joined to the inner wall of this gas pocket 28 or 30. In addition, the film 22 is arranged with the respective other pouch section 16 or 16 on its inner side, that is to say on its side facing the electrode arrangement 8, and joined to the latter.As can also be seen in FIG. 3, a cell intermediate pad 42 is arranged between two such pouch battery cell 2. In this case, the gas pockets 28, 30 are formed on the basis of the respective bag section 14 or 16 facing away from the cell intermediate pad 42. Thus, the cell intermediate pad 42 abuts those bag portions 16 and 14 that do not form a gas pocket.The cell intermediate pad 42 is in particular configured such that the pouch battery cells 2 abutting thereon are thermally protected and / or at least slightly compensate swelling of one of the pouch battery cells 2.For example, the space area formed between the gas pockets 28, 30 serves as a common gas channel.In a manner not shown in more detail, a battery, in particular a high-voltage battery for a high-voltage on-board electrical system of an electrically driven motor vehicle, comprises at least one pouch battery cell 2 in one of the variants shown above.FIG. 4 ashows a further embodiment of a battery 44. This comprises a pouch battery cell 2, in which more than one pouch opening 20 is present on the end face 18. By way of example, the pouch bag has four bag openings 20 arranged on this end face 18. In each of the bag openings 20, a film 22 is arranged which forms a desired outlet point 26 in a similar manner to the embodiments of FIGS. 1 ato 3 and is joined to the pouch bag 4. The bag openings 20 are arranged spaced apart from one another on the end face 18.Furthermore, the battery 44 comprises a cover 46, which is shown transparently for the purpose of better visibility of the pouch battery cell 2 arranged behind it in the illustration according to FIG. 4 a. The cover 46, which is formed for example from plastic, has a rectangular or strip-shaped base body which is arranged on the end face 18 having the bag openings 20. Recesses 48 continuous through the base body in the Z direction are aligned with the foils 22 of the pouch battery cell 2, so that the setpoint outlet point 26 of the foils 22 opens into the respective recess 48. The recess 48 thus forms a gas channel for any gas flowing out through the film 22.As can be seen in particular in the sectional view of FIG. 4 b, with the sectional plane C of FIG. 4 a, through one of the films 22 and perpendicular to the Y direction, the first and the second gas pockets 28 and 30 of the respective bag opening 20 project into the associated recess 48. By way of example, the closure element 34 of FIG. 4 bis designed as an adhesively bonded film element, but any of the variants of FIGS. 2 ato 2 dmay be used for the battery 44.In the region with respect to the Y direction between two of the bag openings (provided with the reference sign "D" in FIG. 4 a), the pouch bag 4, in particular its sealed seam, is reinforced. For example, an adhesive tape is provided which joins the two bag halves to one another in this region D (in particular in addition to a joining connection of the two bag halves by heat sealing). Alternatively or additionally, the width of the sealing seam is increased here. Alternatively or additionally thereto, the bag sections 14, 16 joined to one another are bent over in this region D, in particular by 90°, so that these sections, and in particular the sealing seam, are oriented perpendicular to the Z direction there.The cover 46 abuts the pouch battery cell 2, in particular the end face 18 thereof, at the region adjacent to the pouch opening 20 or adjacent to the pouch openings 20. Thus, the cover 46 lies in the regions D on the end face 18. Preferably, the cover 46 is pressed against the pouch battery cell 2, in other words, the cover exerts a pressure on the pouch battery cell 2. In this way, and particularly if the bag sections 14, 16 joined to one another are bent over in this region D, so that they are oriented perpendicular to the Z direction, opening of the pouch bag 4 in this region is prevented by means of the cover 46 or a risk thereof is at least reduced.FIG. 5 shows a further embodiment of the battery 44. In this case, a common plate-shaped cover 46 is provided for a plurality of pouch battery cells 2 arranged next to one another in the Y direction. This cover comprises recesses 48 for all pouch battery cells 2, wherein the setpoint outlet points 26 open into the respective recess.In a manner not shown in more detail, an electrically driven motor vehicle has the pouch battery cell 2 in one of the variants of FIGS. 1 ato 4 band / or a battery 44 having such a pouch battery cell 2.The invention is not limited to the above-described embodiments. Rather, within the scope of the claims, other variants of the invention can also be derived from this by the person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments and / or in the claims can also be combined with one another in another manner without departing from the subject matter of the invention.List of reference characters2 Pouch battery cell 4 Pouch pouch pouch pouch 6 Cell inner region 8 Electrode arrangement 10 Arrester 12 End face 14 First pouch section 16 Second pouch section 18 End face 20 Pouch opening 22 Film 24 Adhesive / weld seam 26 Setpoint outlet point 28 First gas pouch 30 Second gas pouch 32 Inner wall 34 Closure element 36 End of the gas pouch 38 Film section 40 Outer wall 42 Cell interposer 44 Battery 46 Cover 48 Cutout X X-direction Y Y-direction Z Z-directionReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2013 222 002 A1

[0006] DE 10 2020 216 452 A1

[0007] DE 10 2021 202 675 A1

[0008]

Claims

Pouch battery cell (2), in particular for a traction battery (TB) of an electrically driven motor vehicle, having - an electrode arrangement (8), - a pouch bag (4) in which the electrode arrangement (8) is arranged, and - a film (22) which is arranged in a pouch opening (20) of the pouch bag (4) and is joined to the pouch bag (4), wherein the film (22) forms a setpoint outlet point (26) for an escape of gas (G) from a cell interior (6).Pouch battery cell (2) according to Claim 1, characterized - in that the pouch opening (20) is formed between a first pouch section (14) and a second pouch section (16) of the pouch pouch (4), - wherein the first pouch section (14) forms a first gas pocket (28) which is open towards the electrode arrangement (8), wherein the film (22) is joined to an inner wall (32) of the first gas pocket (28) which delimits the pouch opening (20), and / or - wherein the second pouch section (16) forms a second gas pocket (30) which is open towards the electrode arrangement (8), wherein the film (22) is joined to an inner wall (32) of the second gas pocket (30) which delimits the pouch opening (20).Pouch battery cell (2) according to Claim 1 or 2, characterized - in that the setpoint outlet point (26) is formed by means of a slot in the film (22), and - in that the slot is closed by a closure element (34).Pouch battery cell (2) according to one of Claims 1 to 3, characterized in that the setpoint outlet point (26) is formed by a film section (38) having a reduced film thickness.Pouch battery cell (2) according to one of Claims 2 to 4, characterized - in that the film (22) is joined to the end of the first and second gas pockets (28, 30) facing the electrode arrangement (8), - wherein the first gas pocket (28) and the second gas pocket (30) bear against one another with their ends (36) facing away from the electrode arrangement (8), and / or - wherein the first gas pocket (28) and the second gas pocket (30) are joined to one another, in particular in a fluid-tight manner, at their ends (36) facing away from the electrode arrangement (8).Pouch battery cell (2) according to one of Claims 2 to 5, characterized in that the outer wall (40) of the first gas pocket (28) facing away from the pouch opening (20) and / or the outer wall (40) of the second gas pocket (30) facing away from the pouch opening (20) has a corrugated shape or a zigzag shape.Pouch battery cell (2) according to one of Claims 1 to 6, characterized in that the pouch has a further pouch opening (20), wherein a further film (22) is arranged in the further pouch opening (20) and joined to the pouch pouch (4), and / or wherein the pouch opening (20) and the further pouch opening (20) are arranged at a distance from one another on a common end side (18) of the pouch (4).Battery (44), in particular traction battery for an electrically driven motor vehicle, having - a pouch battery cell (2) according to one of Claims 1 to 7, and / or - a cover (46), which is arranged on that end face (18) of the pouch battery cell (2) on which the pouch opening (20) is arranged, and has a cutout (48) as a gas channel, - wherein the setpoint outlet point (26) opens into the cutout (48), and / or - wherein the first gas pocket (28) and / or the second gas pocket (30) project into the cutout (48).Battery (44) according to claim 8, characterised in that the cover (46) abuts, in particular presses against, the pouch battery cell (2) in the region next to the pouch opening (20).Electrically driven motor vehicle having a pouch battery cell (2) according to one of Claims 1 to 7, and / or having a battery (44) according to Claim 8 or 9.

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