Assembly for relieving pressure in an outer insulation, and battery cell having pressure-relieved outer insulation

Abstract

The invention relates to an insulation assembly for a battery cell having an at least one-piece outer insulation, wherein: the outer insulation rests at least in regions on the outside of a cell housing and electrically insulates the cell housing; at least one depression or cavity is covered by the outer insulation; the outer insulation is supported and / or covered in or on the at least one cavity by at least one support element and / or is provided with a pressure compensation opening. The invention also relates to a battery cell.

Description

[0001] Cellforce Group GmbH MSP Ref: 48145 PT- WO CB / gro

[0002] ARRANGEMENT FOR PRESSURE RELIEF OF AN EXTERNAL INSULATION AND BATTERY CELL WITH PRESSURE-RELIEVED EXTERNAL INSULATION

[0003] The invention relates to an insulation arrangement for a battery cell with an outer insulation formed in at least one piece, wherein the outer insulation rests at least partially on the outside of a cell housing and electrically insulates the cell housing. The invention further relates to a battery cell with an insulation arrangement.

[0004] In the battery sector, so-called hard-case cells are known for storing electrical energy according to the electrochemical principle. Such cells can, for example, be designed as lithium-ion battery cells. Hard-case cells typically have a metal casing, which is cylindrical or prismatic in shape. Within the casing is a space to accommodate an electrode stack or coil consisting of anode layers, cathode layers, and separator layers. This space also contains an electrolyte.

[0005] In battery cells with two terminals insulated by the cell casing, a potential is present at the cell casing due to contact between the electrolyte and the inside of the casing. Battery cells with only one terminal, which is insulated from the cell casing, are also known. A second terminal is intentionally placed on the cell casing, resulting in an electrical voltage across the casing. To prevent unintentional short circuits, such battery cells must be provided with external insulation.

[0006] The external insulation typically consists of a thermoplastic film made of polyethylene terephthalate / Mylar (PET), polyethylene (PE) or polypropylene 48145 PT-WO CB / gro

[0007] (PP), which can be made in one or more parts. To ensure the electrical insulation of the entire cell housing, recesses and sealed openings in the cell housing are also covered by the outer insulation. Thus, a recessed or offset rupture membrane of the battery cell is also covered by the outer insulation. The opening behavior of the rupture membrane is only slightly altered by the outer insulation, as the thin film quickly yields to the gases escaping at high pressure and temperature during a thermal runaway of the battery cell.

[0008] Where the outer insulation does not lie flat against the outer surface of the cell casing, a gap or cavity forms between the outer insulation and the cell casing. The outer insulation in these cavities can be damaged by external pressure fluctuations or mechanical stress. This can impair the electrical insulation of the cell casing by the outer insulation during normal operation or during transport of the battery cell.

[0009] The present invention therefore aims to provide an insulation arrangement and a battery cell that enable the protection of the outer insulation in the cavity area. This objective is achieved by the features specified in claim 1. Further advantageous embodiments of the invention are part of the dependent claims.

[0010] According to one aspect of the invention, an insulation arrangement for a battery cell is provided, comprising at least a single-piece outer insulation. The arrangement, or insulation arrangement, serves to relieve pressure on the outer insulation in the area of ​​covered depressions, recesses, and / or openings through which the outer insulation can form cavities or voids.

[0011] The outer insulation rests, at least partially, on the outside of a cell housing and electrically insulates the cell housing. The cell housing can have at least one cell housing shell and at least one cell cover, which together form or enclose a receiving space. At least one electrode stack or at least one electrode coil can be positioned in this receiving space.

[0012] At least one recess and / or cavity in the cell housing is concealed or covered by the external insulation. This recess can be a notch, bulge, punch, milled area, or similar feature. For example, a recess can be formed by a rupture membrane located recessed within the cell housing or by a rupture membrane located on the inside of the cell housing. Furthermore, recesses can be provided in the area of ​​mechanical attachment points, external cooling fins or structures, filling openings, and the like. Such recesses are covered or coated by the external insulation, thus creating a cavity.

[0013] The outer insulation is supported in or on the at least one cavity by at least one support element and / or is covered by at least one support element and / or is provided with at least one pressure equalization opening. These measures allow the outer insulation, which is designed, for example, as an insulating film, to be relieved of external pressure in areas without direct contact with the cell casing. In particular, this prevents uncontrolled perforation of the outer insulation and ensures the electrical insulation of the battery cell casing.

[0014] According to another aspect of the invention, a battery or battery cell is provided. The battery cell has at least one insulating arrangement according to the invention. Furthermore, the battery cell has a cell housing formed from a cell casing and at least one cell cover, which is enclosed at least partially by an outer insulation made of at least one piece. 48145 PT-WO CB / gro

[0015] The cell housing has a receiving space in which at least one electrode stack is arranged. At least one recess of the cell housing is covered by the outer insulation.

[0016] The external insulation can be a single piece or multiple pieces, with the respective pieces of the external insulation overlapping at least partially. For example, a first piece of external insulation can cover a cell lid. A second piece of external insulation can cover the cell casing and partially overlap the first piece of external insulation.

[0017] The outer insulation can consist of an electrically insulating material, such as PET. In particular, at least part of the outer insulation can be designed as a tube that shrinks when exposed to heat. At least part of the outer insulation can be designed as a film. The outer insulation can be connected to the cell housing by adhesive bonding, friction, and / or a form-fit connection. For example, the second part of the outer insulation can be designed as a tubular PET film that, after being slid over the cell housing, shrinks tightly when heated, with its initially protruding ends wrapping around the corners and edges of the at least one cell lid and overlapping another part of the outer insulation there.

[0018] In areas of depression, a gap or cavity forms between the outer insulation and the cell casing. This cavity subjects the freely suspended outer insulation to tensile stress under external pressure, potentially causing it to tear uncontrollably. The measures described above can effectively prevent this uncontrolled damage to the outer insulation.

[0019] By using at least one support element, the external insulation can be supported from the inside in the area of ​​the recess. This prevents local indentation of the external insulation in the cavity area. 48145 PT-WO CB / gro

[0020] Alternatively or additionally, an externally arranged support element can cover the cavity on the outside and protect the external insulation from being pushed in under pressure.

[0021] Alternatively, the outer insulation in the cavity area can be provided with at least one pressure equalization opening. This opening can be in the form of one or more small holes or penetrations through which the gas or venting gas, or the direct coolant, located in the cell housing's receiving chamber can pass, ensuring constant pressure equalization and preventing the outer insulation from being subjected to tensile stress and damage during pressure surges.

[0022] The measures mentioned above, individually or in any combination, enable the external insulation to be relieved of a tensile force in the area of ​​the cavity, which would result in a pressure load on the external insulation from the outside and would damage the external insulation laterally to the cavity.

[0023] The external insulation can be supported by at least one support element without requiring additional installation space if the support element is located within a cavity formed between a rupture membrane and the external insulation, with the support element resting at least partially on the rupture membrane. This allows the support element to be positioned directly on the rupture membrane to prevent tensile stress on the external insulation.

[0024] According to a further embodiment, the at least one support element is designed in the form of a support rib, which is formed by the rupture membrane or arranged on the rupture membrane. This allows for a particularly simple support element. The support element can be positioned in the cavity without additional fastenings and, for example, held in a predetermined position by a positive fit. Depending on the embodiment, the support element can be attached to the 48145 PT-WO CB / gro by gluing, welding, or brazing.

[0025] The rupture membrane and / or the cell casing must be connected to prevent its position from changing during operation or transport of the battery cell.

[0026] The optimal position of the support element can be ensured particularly easily from a technical standpoint if the cavity is completely or partially filled by at least one support element.

[0027] According to a further embodiment, the at least one support element rests at least partially on a step in the cell housing and / or at least partially on a reinforcing element arranged within the cell housing. The outer insulation can thus be supported on the step by the at least one support element. This prevents direct stress on the rupture membrane in the event of external pressure. The step can be subsequently attached to the cell housing or already incorporated into the cell housing during manufacturing.

[0028] The reinforcing element can, for example, be positioned inside the cell housing in the form of a strip and serve as a support for the rupture membrane. A projection can remain at the edge of the rupture membrane in the area of ​​an opening in the cell housing for positioning the membrane; this projection can serve as a step for supporting the reinforcing element. An opening in the cell housing intended for the rupture membrane can thus be enlarged by the dimension of this step. Advantageously, the rupture membrane with the reinforcing element closes the opening provided for this purpose in the cell housing.

[0029] The at least one support element can be designed in a particularly versatile manner, taking the form of a liquid and / or powdered and / or hardened and / or solid filling and / or an insert plate. Such a support element can be positioned within the cavity to support the external insulation from the inside. Specifically, the support element can be a loose filling with one or more granules or a liquid. A filling powder or liquid, for example, can function as a support element. Depending on its design, the support element can be a gel or a foam. The support element can also be formed by a hardened potting compound that remains liquid or hardens. Such a potting compound can consist, for example, of a hot melt adhesive, a resin without a hardener, or a resin with a hardener.

[0030] According to another embodiment, the insert plate is shaped as a hollow insert plate, a perforated insert plate, a grid-like insert plate, a slotted insert plate, or a solid insert plate. This allows the support element, designed as an insert plate, to be particularly versatile. By incorporating openings and holes into the insert, for example to create a grid-like or perforated insert plate, the mass of the battery cell can be optimized. An insert plate made of plastic or foam can also contribute to reducing the mass of the battery cell.

[0031] The external insulation can be easily protected against tensile stress if at least one support element is positioned on an outer surface of the insulation in the cavity area. For example, the support element can be designed as a pressure plate that is positioned on the outside of the insulation and covers the cavity. This allows the support element to directly absorb any pressure exerted on the insulation in the cavity area. Furthermore, an external placement of the support element protects the insulation in the cavity area from mechanical impacts such as scratches or shocks.

[0032] According to another embodiment, the at least one cavity is formed between a rupture membrane and the outer insulation, wherein the outer insulation is supported at least partially by the rupture membrane. This allows the rupture membrane itself to act as a support element and brace the outer insulation. The provision of an additional support element is therefore unnecessary. 48145 PT-WO CB / gro

[0033] The external insulation can be formed without a cavity in the area of ​​the rupture membrane and thus be protected against tensile stress if the external insulation is drawn so deeply in the cavity area that it rests at least partially on the rupture membrane. The external insulation, designed as a foil, can be drawn partially deep into the depression or recess so that the rupture membrane can support the external insulation from below or from the inside. This prevents any resulting tensile stress on the external insulation caused by external pressure surges.

[0034] According to a further embodiment, the outer insulation is deep-drawn in the cavity area, or the outer insulation has a recess in the cavity area. The recess in the outer insulation is closed by a deformed insulation section that projects into the cavity. Thus, the deformed insulation section, which is designed as part of the outer insulation, can be supported, at least partially, by the rupture membrane, a reinforcing plate, a support element, and the like. The deformed insulation section can be connected to the rest of the outer insulation, for example, by welding or bonding.

[0035] Supporting the outer insulation within the cavity can be particularly efficient if the rupture membrane is curved and / or deformed towards the outer insulation, at least in some areas of the cavity. This means the outer insulation is supported by the rupture membrane, at least in some areas, so that the membrane acts as a support element. If the rupture membrane is attached to the inside of the cell casing, it can be indented or deformed outwards so that the depression or recess in the cell casing is filled by the deformed rupture membrane, thus supporting the outer insulation from the inside.

[0036] In another embodiment, the rupture membrane is attached to a collar section designed to reduce or eliminate the gap between the rupture membrane and the outer insulation. Alternatively, or in addition to the deformed rupture membrane, the insertion of a collar section can reduce the cavity depth or eliminate the cavity entirely, allowing the outer insulation to rest locally on the rupture membrane. The collar section can serve as a support for the rupture membrane and may, for example, be formed on a reinforcing plate extending over the entire length of the cell. The collar section may, for example, project through a venting opening in the cell housing or at least into the venting opening. This allows the rupture membrane to be mounted flush with an adjacent wall of the cell housing.

[0037] Several embodiments of the invention are explained in more detail below with reference to the drawings. The drawings show:

[0038] Fig. 1 shows a sectional view of a cell casing with external insulation in the area of ​​a rupture membrane according to the prior art.

[0039] Fig. 2 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a support element designed as an insert plate,

[0040] Figs. 3, 4 show representations of an insulation arrangement according to an embodiment of the invention with a support element designed as a grid-shaped or perforated insert plate.

[0041] Fig. 5 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a support element designed as a hollow insert plate,

[0042] Fig. 6 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a potting compound as a support element, 48145 PT-WO CB / gro

[0043] Fig. 7 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a support element resting on a step of the cell housing,

[0044] Figs. 8, 9 Representations of an insulation arrangement according to an embodiment of the invention with a support element resting on a step of a reinforcing element,

[0045] Fig. 10 shows a sectional view of an insulation arrangement according to an embodiment of the invention with an outer insulation deep-drawn in the area of ​​a cavity,

[0046] Figs. 11, 12 show representations of an insulation arrangement according to an embodiment of the invention with an insulation section deformed in the area of ​​a cavity.

[0047] Fig. 13 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a pressure equalization opening,

[0048] Figs. 14, 15 show representations of an insulation arrangement according to an embodiment of the invention with at least one support element designed as a support rib, which rests on a bursting membrane.

[0049] Fig. 16 shows a sectional view of an insulation arrangement according to an embodiment of the invention with a support element covering a cavity on the outside,

[0050] Figs. 17, 18 Representations of an insulation arrangement according to an embodiment of the invention with a deformed rupture membrane as a support element,

[0051] Figs. 19, 20 show illustrations of an insulation arrangement according to an embodiment of the invention with a bursting membrane arranged on a collar section as a support element, and 48145 PT-WO CB / gro

[0052] Figs. 21, 22 show representations of a battery cell according to an embodiment of the invention with an insulation arrangement.

[0053] In the illustrations, identical reference numbers denote the same elements or structural components. The sizes and relative positions of the elements in the illustrations are not necessarily drawn to scale, and some of these elements are shown enlarged and repositioned for clarity. Furthermore, the distinctive shapes of the drawn elements are not intended to convey information about the actual shape of the individual elements but were chosen solely for easier identification in the illustrations.

[0054] Fig. 1 shows a sectional view of a cell housing 200 with external insulation 210 in the area of ​​a rupture membrane 220 according to the prior art. The cell housing 200 is designed as a cell housing 200 of a battery cell not described in detail and has the external insulation 210 as external electrical protection. The external insulation 210 covers all recesses of the cell housing 200.

[0055] The burst membrane 220 is welded to an inner side of the cell housing 200, so that a void or cavity 230 with a depth corresponding to the material thickness of the cell housing 200 is created between the foil-like outer insulation 210 and the burst membrane 220.

[0056] In the event of an external pressure increase or external pressure load D, the outer insulation 210 is forced into the cavity 230. This load causes a tensile force Z on the outer insulation 210 around the cavity 230. This can cause the outer insulation 210, which serves as electrical insulation, to tear uncontrollably.

[0057] Fig. 2 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention with a support element 21 designed as an insert plate 20. The insulation arrangement 10 is designed to be used in a battery cell 100 (see Figs. 21, 22) and has an outer insulation 11 formed in at least one part.

[0058] The arrangement or insulation arrangement 10 serves to relieve pressure on the outer insulation 11 in the area of ​​covered depressions, recesses and / or openings through which the outer insulation 11 forms cavities 12 or hollow spaces. In the illustrated embodiment, the cavity 12 is arranged in a bottom area or in a base B of the cell housing 31.

[0059] The outer insulation 11 rests, at least partially, on the outside of a cell housing 31 and electrically insulates the cell housing 31. This causes a depression 14 formed in the area of ​​a rupture membrane 13 to be covered by the outer insulation 11, thus forming the cavity 12.

[0060] The outer insulation 11, for example, is made of a PET film, which can be flat or tubular depending on the design.

[0061] In the illustrated embodiment, the formed recess 14 is a vent opening which is closed on the inside, or from one direction of a receiving chamber A of the cell housing 31, by the rupture membrane 13. Alternatively, the at least one recess 14 of the cell housing 31 can be designed as a cutout, bulge, punching, milling, or the like.

[0062] The support element 21, designed as an insert plate 20, is inserted into cavity 12. The insert plate 20 is solid, for example made of plastic, and completely fills the recess 14 and cavity 12. The use of the insert plate 20 prevents the outer insulation 11 in the area of ​​the filled cavity 12 from being compressed, thus preventing the uncontrolled development of tensile forces Z. 48145 PT-WO CB / gro

[0063] Figures 3 and 4 show representations of an insulation arrangement 10 according to an embodiment of the invention with a support element 21 designed as a grid-shaped or perforated insert plate 20. In contrast to the one in Figure 3,

[0064] In the embodiment shown in Figure 2, the insert plate 20 is perforated or grid-shaped to reduce weight and to facilitate the opening of the rupture membrane 13 under the influence of internal cell pressure.

[0065] Figure 3 shows a three-dimensional exploded view of the insulation assembly 10 without the outer insulation 11, to illustrate the recess 14 in the area of ​​the rupture membrane 13. The perforated insert plate 20 shown serves as a support element 21 and is placed into the recess 14. The outer insulation 11 can then be pulled over the cell housing 31. In the area of ​​the recess 14, the support element 21 supports the outer insulation 11 and effectively prevents damage from external pressure fluctuations.

[0066] Figure 3 further illustrates an exemplary structure of the cell housing 31. The cell housing 31 is shaped for use in a prismatic hardcase battery cell and has a tubular cell housing shell 30. A cell cover 32 is arranged on each of two opposite narrow sides of the cell housing 31. The cell housing shell 30 is closed by the cell covers 32, thus creating the inner receiving space A.

[0067] The venting opening, positioned on the underside or base B of the cell casing 30, is closed by the rupture membrane 13, for example by welding, on an inner side of the cell casing 30. The rupture membrane 13 is thereby recessed or recessed relative to an outer contour of the cell casing 31, resulting in the recess 14.

[0068] Fig. 4 shows a sectional view of the insulation arrangement 10 to illustrate the support function of the perforated or grid-shaped insert plate 20 in the cavity 12. The outer insulation 11 can be supported or protected by the insert plate 20 against indentations directed towards the rupture membrane 13. 48145 PT-WO CB / gro

[0069] Figure 5 shows a further sectional view of an insulation arrangement 10 according to an embodiment of the invention. In contrast to the embodiments already described, a hollow insert plate 20 is arranged in the cavity 12 to support the outer insulation 11.

[0070] The support element 21, designed as a hollow insert plate 20, is hollow in the direction of the rupture membrane 13 and can be supported at the edge of the rupture membrane 13, for example, outside of notches or perforations 13' of the rupture membrane 13. This does not affect the immediate opening behavior of the rupture membrane 13, since a gap 20' exists between the rupture membrane 13 and the hollow insert plate 20.

[0071] Figure 6 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention, with a potting compound 22 serving as a support element 21. The recess 14 in the area of ​​the rupture membrane 13 is filled, for example, with a curing resin or a foam, such as polyurethane foam. The outer insulation 11 can then be applied to the cell housing 31, with the potting compound 22 preventing or at least minimizing indentation of the outer insulation 11 in the area of ​​the recess 14. The use of a foam-like potting compound 22 can minimize any influence on the opening pressure and the opening behavior of the rupture membrane 13.

[0072] Depending on the design, the potting compound 22 can be in liquid or powder form and enclosed in the cavity 12 by the outer insulation 11.

[0073] Fig. 7 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention with a support element 21 resting on a step 32 of the cell housing 31. The support element 21 is exemplary designed as a plate which does not completely fill the cavity 12. 48145 PT-WO CB / gro

[0074] Analogous to the embodiment shown in Fig. 5, a gap 20' is formed between the bursting membrane 13 and the support element 21 by the step 32. The support element 21, which rests on the step 32, prevents the outer insulation 11 from being indented in the area of ​​the cavity 12.

[0075] The step 32 can be formed completely around the entire surface or in sections and allows the support element 21 to be spaced away from the bursting membrane 13. In addition, the support element 21 resting on the at least one step 32 can decouple the bursting membrane 13 from external pressure fluctuations.

[0076] Figures 8 and 9 show sectional views of an insulation arrangement 10 according to an embodiment of the invention, with a support element 21 resting on a step 42 of a reinforcing element 41. Analogous to the embodiment shown in Figure 7, a step 42 is introduced into the venting opening 14 by an additional reinforcing element 41.

[0077] The venting opening 14 is illustrated in a three-dimensional representation in Fig. 8, where for the sake of clarity only the cell casing shell 30 of the cell casing 31 and the reinforcing plate 41 with the burst membrane 13 are shown.

[0078] On the underside B of the cell casing 30, a reinforcing element 41 extending over the entire cell length is positioned internally and welded to the cell casing 30. The reinforcing element 41 has a perforation 43 corresponding to the venting opening 14, which is closed by the rupture membrane 13.

[0079] The opening 43 in the reinforcing element 41 is progressively smaller than the opening or venting opening 14 in the cell casing 30. The resulting step 42 allows the support element 21, designed as an insert plate, to rest against it, thus preventing the rupture membrane 13 from being subjected to external pressure. 48145 PT-WO CB / gro

[0080] The immediate opening behavior of the rupture membrane 13 is not impaired by the gap 20' formed between the rupture membrane 13 and the support element 21. In the illustrated embodiment, the gap 20' has a depth corresponding to the material thickness of the reinforcing element 41. The gap 20' and the internal arrangement of the reinforcing element 41 in the receiving chamber A of the cell housing 31 are illustrated particularly clearly in Fig. 9.

[0081] Fig. 10 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention with an outer insulation 11 deep-drawn in the area of ​​a cavity 12 .

[0082] The outer insulation 11, designed as an insulating film, is drawn by deep drawing or thermoforming in the area of ​​the venting opening 14 towards the receiving chamber A of the cell housing 31, thus preventing the formation of a cavity 12. The outer insulation 11 therefore rests directly on the rupture membrane 13 and can be supported directly by the rupture membrane in the event of external overpressure.

[0083] Figures 11 and 12 show representations of an insulation arrangement 10 according to an embodiment of the invention with an insulation section 1 T deformed in the area of ​​a cavity 12.

[0084] The outer insulation 11 has a recess 11" in the area of ​​the cavity 12 or the rupture membrane 13. A pre-formed insulation section 1T is inserted into this recess 11". The insulation section 1T projects into the recess 14 and prevents the formation of the cavity 12. In particular, the insulation section 1T can bear against the rupture membrane 13.

[0085] The insulation section 11' can be formed as a deep-drawn foil piece and connected to the outer insulation 11 by heat sealing. Fig. 11 shows a three-dimensional exploded view of the insulation section 1 T ge- 48145 PT-WO CB / gro. Fig. 12 illustrates the insulation section 11' connected to the outer insulation 11 in a sectional view.

[0086] Figure 13 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention with a pressure equalization opening 15. The outer insulation 11 is provided with a hole or pressure equalization opening 15 in the area of ​​the venting opening 14, through which gases and liquids can pass unhindered. This allows pressure equalization to occur between the open cavity 12 and an external environment, so that the outer insulation 11 is not subjected to tensile stress and destroyed by external pressure surges.

[0087] Figures 14 and 15 show illustrations of an insulation arrangement 10 according to an embodiment of the invention with at least one support element 21 designed as a support rib 23, which rests on the rupture membrane 13. Two elongated support ribs 23 are shown by way of example, which are fixed to the rupture membrane 13.

[0088] The support ribs 23 are, for example, made of a plastic and serve as support for the outer insulation 11 under external pressure. The support ribs 23 are preferably not positioned in the area of ​​the perforations 13' or predetermined breaking points of the rupture membrane 13, so that the opening behavior of the rupture membrane is not altered.

[0089] The exact arrangement of the support ribs 23 on the rupture membrane 13 is illustrated in a perspective view shown in Fig. 14. Fig. 15 shows a cross-sectional view of the outer insulation 11 resting on the support elements 23 in the area of ​​the cavity 12.

[0090] Fig. 16 shows a sectional view of an insulation arrangement 10 according to an embodiment of the invention with a support element 21 covering a cavity 12 on the outside. Such a support element 21 can be designed as a cover plate or pressure plate and rest on the outside of the outer insulation 11 48145 PT-WO CB / gro to prevent deformation of the outer insulation 11 due to pressure in the area of ​​the cavity 12. The support element 21 preferably covers the cavity 12 at its edge.

[0091] In the illustrated embodiment, the support element 21 is made of a thermoplastic material and is connected to the outer insulation 11 by heat sealing. Thus, the outer insulation 11 is structurally reinforced in the cavity area by the support element 21 to counteract deformation of the outer insulation 11.

[0092] The support element 21 rests here on the cell housing 31, which frames the cavity 12.

[0093] Figures 17 and 18 show representations of an insulation arrangement 10 according to an embodiment of the invention with a deformed rupture membrane 13 as a support element 21. Figure 17 shows a perspective view of the bottom section B of the cell casing 30 with the venting opening 14 and the deformed rupture membrane 13, which is inserted into the venting opening 14.

[0094] In the illustrated embodiment, the rupture membrane 13 is positioned on the inside of the cell housing 31. The rupture membrane 13 is convex outwards, i.e., towards the outer insulation 11, by deep drawing or embossing. This allows the rupture membrane 13 to project through the venting opening 14 to an outer contour of the cell housing shell 30 and to be flush with the cell housing shell 30. This ensures that the venting opening 14 is completely filled by the rupture membrane 13, so that no cavity 12 is formed in the area of ​​the rupture membrane 13 after the outer insulation 11 is attached. Advantageously, any external pressure applied to the outer insulation 11 can be absorbed by the rupture membrane 13.

[0095] Fig. 18 illustrates in a cross-sectional view the outwardly deformed rupture membrane 13 and the flush termination with the cell casing 30. 48145 PT-WO CB / gro

[0096] Figures 19 and 20 show illustrations of an insulation arrangement 10 according to an embodiment of the invention, with a rupture membrane 13 arranged on a collar section 44 as a support element 21. Analogous to the embodiment shown in Figure 8, a reinforcing element 41 is used here in the receiving space A of the cell housing 31, which supports the rupture membrane 13. For example, the rupture membrane 13 can be welded to the reinforcing element 41. For this purpose, the reinforcing element 41 has an opening 43, which is limited by the collar section 44.

[0097] The rupture membrane 13 is welded to the collar section 44 and closes the opening 43 of the reinforcing element 41. The collar section 44 is dimensioned such that it, together with the rupture membrane 13, projects through the venting opening 14. The rupture membrane 13 is positioned flush with the outer contour of the cell casing shell 30 by the collar section 44 in order to support the outer insulation 11.

[0098] In the illustrated embodiment, the reinforcing element 41 is connected to the cell housing shell 30 on the inside, or in the receiving space A, of the cell housing 31. Fig. 20 illustrates in a sectional view the reinforcing element 41 arranged in the receiving space A and the positioning of the rupture membrane 13 by the collar section 44 relative to the outer insulation 11.

[0099] Figures 21 and 22 show illustrations of a battery cell 100 according to an embodiment of the invention with an insulation arrangement 10. In contrast to the embodiments already shown, the battery cell 100 uses an insulation arrangement 10 with a cell housing 31, which has a cup-shaped cell housing shell 30 and a cell cover 32 for closing the cell housing shell 30. The cup-shaped cell housing shell 30 is closed at the bottom and has a rectangular cross-section. 48145 PT-WO CB / gro

[0100] The battery cell 100 is shaped as a hardcase battery cell and has two battery poles B1, B2 arranged in the cell lid 32.

[0101] The rupture membrane 13 closes a venting opening 14 which is incorporated into the cell lid 32. The rupture membrane 13 is recessed relative to an outer contour of the cell lid 32.

[0102] The outer insulation 11 of the battery cell 100 is designed in two parts. The cell cover 32 is electrically insulated by a first part 16 of the outer insulation 11. The first part 16 of the outer insulation 11 is designed as a film adapted to the cell cover 32. The outer insulation 11 can, for example, be made of PET.

[0103] The cell casing, shaped like a cup, is insulated by a second part 17 of the outer insulation 11. This second part 17 of the outer insulation 11 is a PET film deep-drawn in a cup shape, which, after being placed over the cell casing, is shrunk tightly onto the cell casing 30 by heating. An initially protruding edge of the second part 17 of the outer insulation 11 can, due to the heat, fold around the corners to the cell lid 32 and overlap the first part 16 of the outer insulation 11 there.

[0104] A cavity 12 formed by the first part 16 of the outer insulation 11 between the outer insulation 11 and the rupture membrane 13 is filled by a support element 21 designed as an insert plate to support the outer insulation 11 under external pressure. The respective externally visible components of the battery cell 100 and the insulation assembly 10 are illustrated in the exploded view shown in Fig. 21.

[0105] An electrode stack 110 is arranged in the receiving chamber A of the cell housing 31. The electrode stack 110 has unnumbered anode layers, cathode layers, and separator layers. The anode layers and the cathode layers are electrically connected to the battery terminals B1 and B2, respectively. Furthermore, the receiving chamber A is filled with an electrolyte. Fig. 22 shows a sectional view, which also illustrates the internal structure of the battery cell 100.

Claims

48145 PT-WO CB / gro REQUIREMENTS 1. Insulation arrangement (10) for a battery cell (100) with an outer insulation (11) comprising at least one part, wherein the outer insulation (11) rests at least partially on the outside of a cell housing (31) and the cell housing (31) is electrically insulated, wherein at least one recess (14) or cavity (12) is covered by the outer insulation (11), wherein the outer insulation (11) is supported and / or covered in the at least one recess (14) or on the at least one cavity (12) by at least one support element (21) and / or is provided with a pressure equalization opening (15).

2. Insulation arrangement according to claim 1, wherein the at least one support element (21) is arranged within a cavity (12) formed between a bursting membrane (13) and the outer insulation (11), wherein the at least one support element (21) rests at least partially on the bursting membrane (13).

3. Insulation arrangement according to claim 1 or 2, wherein the at least one support element (21) is designed in the form of a support rib (23) which is formed by the bursting membrane (13) or arranged on the bursting membrane (13).

4. Insulation arrangement according to one of claims 1 to 3, wherein the cavity (12) is completely or partially filled by the at least one support element (21).

5. Insulation arrangement according to one of claims 1 to 4, wherein the at least one support element (21 ) rests at least partially on a step (32) of the cell housing (31 ) and / or at least partially on a step (42) of a reinforcement element (41 ) arranged in the cell housing (31 ). - 22 / 25 - 48145 PT-WO CB / gro 6. Insulation arrangement according to one of claims 1 to 5, wherein the support element (21) is formed in the form of a liquid or hardened potting compound (22) and / or in the form of an insert plate (20).

7. Insulation arrangement according to claim 6, wherein the insert plate (20) is shaped as a hollow insert plate, as a perforated insert plate, as a grid-shaped insert plate, as a slotted insert plate or as a solid insert plate.

8. Insulation arrangement according to one of claims 1 to 7, wherein the at least one support element (21 ) is arranged on an outer surface of the outer insulation (11 ) in the area of ​​the cavity (12).

9. Insulation arrangement according to one of claims 1 to 8, wherein the at least one cavity (12) is formed between a burst membrane (13) and the outer insulation (11), wherein the outer insulation (11) is supported at least partially by the burst membrane (13).

10. Insulation arrangement according to claim 9, wherein the outer insulation (11) in the area of ​​the cavity (12) is drawn so deep that it rests at least partially on the burst membrane (13).

11. Insulation arrangement according to claim 10, wherein the outer insulation (11) is deep-drawn in the region of the cavity (12), or wherein the outer insulation (11) has a recess in the region of the cavity (12), wherein the recess of the outer insulation (11) is closed by a deformed insulation section (11') which projects into the recess (14).

12. Insulation arrangement according to one of claims 9 to 11, wherein the bursting membrane (13) in the region of the cavity (12) is at least partially curved and / or deformed towards the outer insulation (11), wherein the outer insulation (11) 48145 PT-WO CB / gro solierung (11 ) is supported at least in certain areas by the burst membrane (13).

13. Insulation arrangement according to any one of claims 9 to 12, wherein the burst membrane (13) is attached to a collar section (44) which is configured to reduce or eliminate a gap between the burst membrane (13) and the outer insulation (11).

14. Battery cell (100), comprising at least one insulating arrangement (10) according to one of the preceding claims, and comprising a Cell housing (31) formed by a cell casing shell (30) and at least one cell cover (32), wherein the cell housing (31) is enclosed at least partially by an outer insulation (11) made up of at least one part, wherein the cell housing (31) has a receiving space (A) in which at least one electrode stack (110) is arranged, wherein the cell housing (31) has at least one recess (14) and / or cavity (12) which is covered by the outer insulation (11).

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