Battery cell housings, battery cell systems, and motor vehicles

Abstract

The present invention relates to a housing device (1) for a battery cell (2), comprising: a housing (10) configured to surround the battery cell (2); a first local weakened portion (11) configured to yield under a first pressure generated by the battery cell (2); and a second local weakened portion (12) arranged to at least partially cover the first local weakened portion (11) and configured to yield under a second pressure generated by the battery cell (2), wherein the second pressure is less than the first pressure.

Description

Technical Field

[0001] The invention relates to a housing arrangement for a battery cell and a motor vehicle having such a housing arrangement. Background Art

[0002] Battery cells are usually arranged in stacks and connected together to form a high-voltage battery. Due to malfunctions and / or malfunctions of individual battery cells, hot gases and particles can escape. These hot gases and particles can then also heat other battery cells, in particular those arranged next to them, thereby leading to a chain reaction, so-called heat propagation or thermal expansion. Summary of the invention

[0003] It is therefore an object of the present invention to specify an improved housing arrangement for a battery cell, a battery cell system consisting of a plurality of housing arrangements, and a motor vehicle having such a housing arrangement and / or such a battery cell system.

[0004] This object is achieved by the subject matter of the independent claim. Advantageous developments are given in the dependent claims.

[0005] According to a first aspect, a housing arrangement for a battery cell is specified.

[0006] Here, the housing device according to the present invention comprises: a housing, which is configured to surround a battery cell; a first local weakening portion, which is configured to yield / collapse under a first pressure generated by the battery cell; and a second local weakening portion, which is arranged to at least partially cover the first local weakening portion and is configured to yield under a second pressure generated by the battery cell, wherein the second pressure is less than the first pressure.

[0007] The housing device according to the invention is used in particular to reliably dissipate pressure generated by the battery cells from the interior of the housing out of the housing and conversely to prevent pressure acting on the housing from the outside from acting on the housing and thus on the battery cells. In particular, the housing device according to the invention is used to prevent or at least reduce heat propagation, i.e., heat diffusion, between a plurality of housing devices or battery cells.

[0008] In this case, the housing arrangement according to the invention firstly comprises a housing which is designed to surround a battery cell.

[0009] In this context, a battery cell is an electrical energy storage device based on electrochemical storage of energy. In particular, a battery cell is a rechargeable battery, so that the battery cell can be recharged. For example, a battery cell is based on lithium or a lithium compound, in particular a lithium-ion-based battery, and can also be referred to as a lithium-ion rechargeable battery. Typical examples of such lithium-ion rechargeable batteries are lithium-cobalt dioxide rechargeable batteries, lithium-manganese rechargeable batteries, lithium-nickel-manganese-cobalt rechargeable batteries, lithium-nickel-cobalt-aluminum rechargeable batteries and / or lithium iron phosphate rechargeable batteries.

[0010] In particular, the housing completely surrounds the battery cell, that is to say surrounds the battery cell on all sides, except for the first local weakening and the second local weakening described below. In this case, the housing can be designed in particular to be cuboid and have four side faces as well as a bottom face and a top face, in particular, these faces are all arranged substantially at right angles to each other.

[0011] The housing can consist in particular of a strong and / or hard material, such as metal, in particular aluminum. In particular, the housing consists of a material that does not yield, break and / or crack under either a first pressure or a second pressure (as will be described below) that occurs within the battery cell.

[0012] Here, the shell can have, in particular, a greater extension in the height and depth direction than in the width direction, thereby resulting in two larger, in particular equally large, for example rectangular or square side faces of the shell, and four smaller, in particular equally large, for example rectangular further faces, of which two further faces can, for example, be referred to as side faces and one further face can each be referred to as a top face and a bottom face.

[0013] The housing device also includes: a first local weakened portion, which is configured to yield under a first pressure generated by the battery cell housing; and a second local weakened portion, which is arranged to at least partially cover the first local weakened portion and is configured to yield under a second pressure generated by the battery cell housing, wherein the second pressure is less than the first pressure.

[0014] Here, a local weakening is a formation in the housing at which there is less material than outside or around the local weakening. Here, the local weakening can be formed by a thinner housing wall and / or a perforation or interruption of the material.

[0015] Yielding here means, in particular, breaking, in particular chipping and / or splitting, folding open, opening and / or rupturing.

[0016] In particular, the first local weakening and the second local weakening are the only two weakenings of the shell, or the shell is weakest at the first local weakening and in particular at the second local weakening, or the shell yields most easily or first here.

[0017] Here, the first local weakening can also be referred to as a valve, a valve opening, a vent and / or a ventilation opening, whereas the second local weakening can be referred to as a protective cover which protects the ventilation opening from accidental opening, in particular due to external influences such as, for example, adjacent battery cells, as will be described below.

[0018] In this case, pressure in the housing can arise, for example, due to malfunctions and / or malfunctions of the battery cell, whereby an overpressure is generated in the interior of the battery cell or the housing relative to the normal pressure prevailing in the surroundings. For example, due to malfunctions of the battery cell, gases are generated which must escape from the housing. The escape of the gases occurs in a controlled manner first through the first local weakening and then through the second local weakening.

[0019] For this purpose, the first local weakening and the second local weakening are arranged in or on the housing at least partially, in particular mostly, and further in particular completely overlapping each other or one above the other. For example, the first local weakening and the second local weakening have a coverage of at least 50%, 60%, 70%, 80%, 90%, 95% or 100%.

[0020] In particular, the first local weakening and the second local weakening are arranged in particular in substantially direct contact with each other along the height and / or at a distance from each other of less than 5 mm, 4 mm, 3 mm, 2 mm or 1 mm.

[0021] Here, the first local weakening and the second local weakening can have similar or identical cross-sections, similar or identical shapes and / or similar or identical external dimensions, sizes and / or scales. For example, the first local weakening and the second local weakening are substantially configured as round, oval, elliptical or rectangular, in particular with or without rounded corners, as will be described below.

[0022] In this case, the first local weakness and the second local weakness are arranged and designed in particular relative to one another in such a way that the first local weakness yields first due to the pressure in the interior of the housing, for example due to the battery cells or generated there. For this purpose, the first local weakness is designed in such a way that it yields at a first predetermined pressure and releases the pressure, which in particular may also contain hot gases and / or particles from the battery cells, in particular mainly or exclusively to the second local weakness.

[0023] Subsequently, the second local weakening also yields, specifically already at a predetermined second pressure which is lower than the first pressure.

[0024] For example, the first pressure is an integer multiple greater than the second pressure, in particular at least 2, 5 or 10 times greater than the second pressure. For example, the first pressure is 2 bar, 3 bar, 5 bar, 7 bar, 9 bar, 10 bar or more, and / or the second pressure is 1 bar, 900 mbar, 700 mbar, 500 mbar, 300 mbar, 100 mbar or less.

[0025] In this case, in particular the first weakened portion and / or the second local weakened portion can be arranged in one of the smaller surfaces, in particular the top surface or the bottom surface. In other words, in particular the first local weakened portion and the second local weakened portion are arranged and configured in such a surface of the housing that has a smaller area than at least the other two side surfaces and in particular has the smallest extension dimension of the housing.

[0026] In particular, the first local weakening and the second local weakening are arranged on or along the underside of the housing or housing device, and also in particular on the side opposite to a possible connection of the housing device. The housing device is further arranged in particular in a motor vehicle such that the first local weakening and the second local weakening are arranged toward the underside and in particular toward the floor, such as, for example, an underbody protection device, and yield in particular in this direction, thereby also directing pressure and in particular a gas and / or particle flow in this direction.

[0027] In particular, according to the invention, the housing device can surround the battery cell as described above. In this case, the housing device can be used in particular as a housing device for a prismatic cell or can form such a prismatic cell together with the battery cell.

[0028] In particular, as will be described below, a battery cell housing system can be formed if a plurality of housings or housing arrangements are arranged adjacent to one another, in particular next to one another, and further in particular facing one another on one or two of the respective larger sides. In this case, the battery cell housing system can also comprise a plurality of battery cells and thus form a battery cell system.

[0029] The housing arrangement according to the invention makes it possible to reliably dissipate pressure from the interior of the housing, which is generated by the battery cells, out of the housing and conversely prevent pressure acting on the housing from the outside from acting on the housing and thus on the battery cells. In particular, the housing arrangement according to the invention serves to prevent or at least reduce heat propagation, i.e., heat diffusion, between a plurality of housing arrangements or battery cells.

[0030] According to a further development, the second local weakening has a desired breaking point.

[0031] The theoretical fracture site is a site, location and / or position in which, if fracture is to occur, fracture is expected to occur in or at the theoretical fracture site. In particular, the site or position of yielding is controlled, predefined or determined by the theoretical fracture site. The second local weakening portion may also be referred to as a theoretical fracture site as a whole. In particular, the second local weakening portion may also have a plurality of separate or mutually spaced theoretical fracture sites, which may form together an associated / continuous theoretical fracture site as the case may be.

[0032] Optionally, the first local weakening may also have one or more such theoretical breaking points.

[0033] In this case, the desired breaking point or points are produced, in particular, by punching out and / or perforating or by other material removal.

[0034] This development makes it possible to achieve a particularly rapid and effective discharge of gas from the interior of the housing.

[0035] According to a development, the second local weakening has a substantially rectangular shape, wherein at least one side of the rectangular shape is configured as a desired breaking point.

[0036] In particular, the second local weakening has a shape and / or proportion corresponding to the surface, in particular the bottom surface, on which it is located. For this purpose, for example, the longer side of the rectangle of the local weakening can be arranged along the longer side of the bottom surface of the rectangle or arranged parallel thereto, and the shorter side of the rectangle of the local weakening can be arranged along the shorter side of the bottom surface of the rectangle or arranged parallel thereto.

[0037] Here, the theoretical breaking point follows one of the sides of the rectangle or coincides with it. For example, at least one of the short sides and / or long sides of the rectangle of the local weakening can be configured as the theoretical breaking point and is turned outward or at least deformed when the pressure from the inside of the housing is released.

[0038] Alternatively or additionally, the rectangular second local weakening also has a desired breaking point extending parallel to one of the sides, which coincides, for example, with a perpendicular midline of one of the sides and thus provides a central or middle opening.

[0039] This development makes it possible to achieve a particularly rapid and effective discharge of gas from the interior of the housing.

[0040] According to a further development, at least two sides of the rectangular shape are designed as desired breaking points.

[0041] In this case, the two sides may in particular be opposite sides of the rectangular shape, and further in particular may be short sides of the rectangle.

[0042] In addition to the two sides of the rectangle of the second local weakening portion being constructed as theoretical breaking points, another third theoretical breaking point can also be provided, which extends parallel to one of the sides, in particular parallel to one or more long sides, and for example coincides with the perpendicular bisector of the short side, thereby providing a central or center opening.

[0043] Alternatively or additionally, another fourth theoretical breaking point can be provided, which extends parallel to one of the sides, in particular parallel to one or more short sides, and also coincides with the perpendicular bisector of the long side, thereby providing another central or center opening, which can be constructed together with the third theoretical breaking point to form a central cross-shaped theoretical breaking point.

[0044] This development makes it possible to achieve a particularly rapid and effective discharge of gas from the interior of the housing.

[0045] According to a further development, at least three sides of the rectangular shape are designed as desired breaking points.

[0046] In particular, according to this improvement, one of the long sides and two short sides of the rectangle are configured as theoretical breaking points. Alternatively, one of the short sides and two long sides of the rectangle are configured as theoretical breaking points.

[0047] This development makes it possible to achieve a particularly rapid and effective discharge of gas from the interior of the housing.

[0048] According to one development, all sides of the rectangle, ie all four sides, are designed as theoretical breaking points.

[0049] In addition to configuring all four sides of the rectangle of the second local weakening as theoretical breaking points, another fifth theoretical breaking point can also be provided, which extends parallel to one of the sides and, for example, coincides with the perpendicular bisector of one side, thereby providing a central or center opening.

[0050] This development makes it possible to achieve a particularly rapid and effective discharge of gas from the interior of the housing.

[0051] According to a development, the housing device further comprises a sealing element which extends over the second local weakening and seals the second local weakening.

[0052] In particular, the sealing element extends completely covering the entire second local weakening and / or all intended breaking points of the second local weakening.

[0053] The sealing element has two functions: On the one hand, the sealing element should ensure, in particular in the region of the intended breaking point, that external influences, for example those of adjacent battery cells, cannot act on the interior of the housing or housing arrangement and thereby damage the battery cells located therein.

[0054] On the other hand, the yielding element of the second local weakening should be fixed to the housing or housing device, for example in a rectangular shape, so that although the second local weakening can be opened, for example by folding open, the yielding element still remains fixed to the housing and is thus prevented from being lost.

[0055] In this case, the sealing element is arranged in particular between the first local weakening and the second local weakening and / or on the inner side or the upper side of the second local weakening.

[0056] Here, the sealing element can be configured in a variety of ways. For example, the sealing element can be configured as a film that extends over the second local weakening portion and / or its theoretical breaking point and holds it together.

[0057] Alternatively or additionally, the sealing element can be configured as a local material accumulation formed by incomplete material removal. In particular, the material of the second local weakening portion can be a thermoplastic material, such as plastic, wherein the sealing element can be produced by heating after the punching or material removal of the theoretical fracture site.

[0058] In particular, the material of the second local weakening can be a fiber composite material, in particular with a plastic matrix. In this case, an endless fiber reinforcement can be optionally achieved. The second local weakening can be produced, for example, in an injection molding process or a pressing method.

[0059] In this case, the sealing element can be designed in particular to seal the housing or the housing arrangement and in particular the interior of the battery cell in an air-tight and / or gas-tight manner.

[0060] For example, the proposed breaking point initially becomes gas-permeable due to the material removal, while the sealing element re-establishes the gas-tightness of the housing or the housing arrangement.

[0061] This development makes it possible to achieve particularly reliable discharge of gas from the interior of the housing and to prevent the ingress of gas from other battery cells.

[0062] According to a further development, the second local weakening portion is offset relative to the remaining portion / other portions of the housing in the direction of the first local weakening portion.

[0063] In particular, the second local weakening is offset inwardly toward the outer contour of the housing and / or toward the first local weakening. This offset can also be referred to as setback.

[0064] By means of this development, the ingress of gas from other battery cells is particularly effectively prevented, since the second local weakness can bear against the first local weakness when subjected to pressure from below and can yield only under opposing pressure from the inside.

[0065] According to a further development, the first local weakening is made of a material different from that of the second local weakening.

[0066] For this purpose, the first local weakening comprises a material different from that of the second local weakening, in particular, the first material has a melting point different from that of the second material.

[0067] Here, as described above, the second local weakening can be made of a thermoplastic material, while the first local weakening can be made of a metal, in particular aluminum. In particular, the first local weakening can be made of the same material as the housing and / or in particular thus be configured as one piece with the housing, while the second local weakening is configured as different from or separate from the housing.

[0068] In particular, the first local weakening is made of the same material as the housing, and the second local weakening is made of another second material.

[0069] By means of this development, the ingress of gas into other battery cells is prevented particularly effectively, since the second local weakness has different material properties than the first local weakness and therefore responds differently to thermal stresses.

[0070] According to a further aspect, a battery cell system is specified, which comprises at least two housing devices according to any of the above-described embodiments, which are arranged next to each other, in particular along large sides, wherein each housing device can enclose a battery cell.

[0071] According to yet another aspect, a motor vehicle is provided, which comprises a housing device and / or a battery cell system according to any of the above-described embodiments. For example, the battery cell system is used as an energy storage device for a motor vehicle, which can be designed in particular as a purely electric and / or hybrid motor vehicle.

[0072] The motor vehicle according to the invention is preferably designed as a car, in particular a passenger car or a commercial vehicle, or as a bus or a motorcycle.

[0073] With regard to embodiments of the motor vehicle and of the battery cell system and the advantages associated therewith, reference is made to the embodiments of the housing arrangement described above and the advantages associated therewith.

[0074] The present invention also includes combinations of features of the embodiments described. Therefore, the present invention also includes implementations which each have a combination of features of a plurality of the embodiments described, as long as these embodiments are not described as mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The following describes an embodiment of the present invention.

[0076] Figure 1 A schematic perspective view of an embodiment of a housing device is shown;

[0077] Figure 2 Shows Figure 1 A schematic side sectional view of an embodiment of the housing device in;

[0078] Figure 3 Shows Figure 2 A schematic perspective view of an embodiment of the second local weakened portion in FIG.

[0079] Figure 4 Shows Figure 3 Schematic side sectional view of the second local weakening portion in FIG. DETAILED DESCRIPTION

[0080] The embodiments described below are preferred embodiments of the present invention. In the embodiments, the components described in the embodiments are respectively individual features of the present invention that can be regarded as independent of each other, and these features also improve the present invention independently of each other. Therefore, the present disclosure should also include feature combinations that are different from the feature combinations shown in the embodiments. In addition, the described embodiments can also be supplemented by other features in the features already described in the present invention.

[0081] In the figures, the same reference numerals respectively denote elements with the same function.

[0082] Figure 1 A schematic perspective view of an embodiment of a housing arrangement 1 is shown.

[0083] The housing device 1 forms a housing for a battery cell 2 arranged in the interior of the housing device 1 and comprises a housing 10 configured to surround the battery cell 2 and comprises a first local weakening 11 and a second local weakening 12, both of which are arranged in Figure 1 On the underside which is not shown in detail.

[0084] The housing 10 has a substantially cuboid shape and has an extension in height H and depth T which is greater than the extension in width B.

[0085] The housing device also has two connecting elements, of which only one connecting element 3 is provided with a reference numeral for the sake of clarity. The connecting element is arranged on the side of the housing opposite the first local weakening 11 and the second local weakening 12.

[0086] Figure 2 Shows Figure 1 Schematic side sectional view of an embodiment of the housing device 1 in FIG.

[0087] The arrangement of the first local weakening 11 and the second local weakening 12 is shown in detail here. Both the first local weakening 11 and the second local weakening 12 are located on the lower side of the shell device, opposite the underbody protection device, which forms the floor or lower enclosure of the motor vehicle.

[0088] Here, the first local weakening portion 11 and the second local weakening portion 12 are arranged one above the other along the height H of the housing device 1 and have substantially the same shape and extension size. Here, the first local weakening portion 11 and the second local weakening portion 12 are designed to overlap and cover each other along the width B and depth T.

[0089] In this case, the first local weakening 11 is designed to yield at a first pressure P generated by the battery cell 2 , and the second local weakening 12 is designed to yield at a second pressure generated by the battery cell 2 , wherein the second pressure is lower than the first pressure.

[0090] Here, the second local weakening 12 is at least partially offset inwardly relative to the rest of the housing 10 toward the first local weakening 11. For this purpose, the second local weakening 12 has an offset. Here, the second local weakening 12 is held or fastened at the housing 10 by means of a holding element 14.

[0091] The pressure P generated by the battery cells 2 in the interior of the housing 10 and the hot gases and particles associated therewith are therefore discharged in the direction of the underbody protection device 4 first by yielding of the first local weakness 11 and then by yielding of the second local weakness 12. There, the gases and particles are cooled, and when they are reflected by the underbody protection device 4 and strike against the further housing device according to the invention and in particular against the second local weakness arranged on the further housing device, the second local weakness effectively prevents the gases and particles from penetrating into the interior of the housing and thus prevents thermal expansion of the second battery cell.

[0092] Figure 3 Shows Figure 2 A schematic three-dimensional view of an implementation of the second local weakening portion in FIG.

[0093] Here, in Figure 31 and 2 show different embodiments of the second local weakening 12. The second local weakening 12 has one or more theoretical breaking points, which are shown by dashed lines in the figure. Here, the local weakening 12 is shown essentially as a rectangle.

[0094] Here, a first embodiment of the second local weakening portion 12-1 has a total of four theoretical breaking locations, two of which coincide with the short sides of the second local weakening portion 12-1, and the other two theoretical breaking locations coincide with the perpendicular bisectors of the long sides and the short sides of the second local weakening portion 12-1 and thus form a cross.

[0095] Here, the second embodiment of the second local weakened portion 12-2 has a total of three theoretical breaking locations, two of which coincide with the short sides of the second local weakened portion 12-2, respectively, and the other theoretical breaking portion coincides with the perpendicular bisector of the short side, and the perpendicular bisector of the short side extends parallel to the long side of the second local weakened portion 12-1.

[0096] The third embodiment of the second local weakening 12-3 has a total of five theoretical breaking locations, wherein three theoretical breaking locations coincide with the sides of the second local weakening 12-3, i.e., two theoretical breaking locations coincide with the short sides and one theoretical breaking location coincides with the long side. The other two theoretical breaking locations extend at least partially along the second long side of the second local weakening 12-3.

[0097] The fourth embodiment of the second local weakening portion 12-4 has a total of four theoretical breaking locations, wherein all four theoretical breaking locations respectively coincide with one side of the second local weakening portion 12-3, that is, two theoretical breaking locations coincide with the short sides and two theoretical breaking locations coincide with the long sides.

[0098] The fifth embodiment of the second local weakening 12-5 has a total of five theoretical breaking locations, wherein four theoretical breaking locations coincide with all sides of the second local weakening 12-3, i.e., two theoretical breaking locations coincide with the short sides and two theoretical breaking locations coincide with the long sides. Here, the fifth theoretical breaking location extends along the perpendicular midline of the short side, and the perpendicular midline of the short side extends parallel to the long side of the second local weakening 12-3.

[0099] In this case, the second local weakness 12 is covered by a sealing element 13 , which is shown here by way of example as a film and seals the second local weakness or the intended breaking point inwardly.

[0100] It is understandable that the same or different second theoretical breaking points 12 may be provided for a plurality of housing devices arranged side by side or arranged successively in the direction of the width B.

[0101] Combined with the following Figure 4How the second local weakening 12 yields when loaded with a pressure force P is explained.

[0102] Figure 4 Shows Figure 3 Schematic side sectional view of the second local weakening portion in FIG.

[0103] Here, the first embodiment of the second local weakening 12 - 1 is folded downwards from both sides opposite to the height H.

[0104] The second embodiment of the second local weakening 12 - 2 is also folded downward from both sides opposite to the height H.

[0105] The third embodiment of the second local weakening 12 - 3 is folded downwards opposite to the height H only on one side.

[0106] A fourth embodiment of the second local weakening 12-4 falls off from all sides and is pushed away in the opposite direction of the height H, wherein Figure 3 The film shown in FIG. 1 catches the detached components.

[0107] A fifth embodiment of the second local weakening 12 - 5 falls off from all sides and in two pieces and is pushed away in the opposite direction of the height H, wherein Figure 3 The film shown in FIG. 1 catches the detached components.

[0108] Overall, the example shows how exhaust gas openings in a high-voltage cell stack can be effectively protected from thermal expansion in the event of a malfunction.

Claims

1. A housing device (1) for a battery cell (2), the housing device comprising: - a housing (10) which is designed to surround the battery cell (2); - a first local weakening (11) configured to yield under a first pressure generated by the battery cell (2); and A second local weakening (12) is arranged to at least partially cover the first local weakening (11) and is configured to yield under a second pressure generated by the battery cell (2), wherein the second pressure is lower than the first pressure.

2. The housing device (1) according to claim 1, wherein: The second local weakening portion (12) has a theoretical breaking point.

3. The housing device (1) according to claim 1 or 2, wherein: The second local weakening (12) has a substantially rectangular shape, at least one side of which is configured as a theoretical breaking point.

4. The housing device (1) according to claim 3, wherein: At least three sides of the rectangular shape are configured as theoretical breaking points.

5. The housing device (1) according to claim 3 or 4, wherein: All sides of the rectangular shape are designed as desired breaking points.

6. The housing device (1) according to any one of the preceding claims, further comprising a sealing element (13) which extends over the second local weakened portion (12) and seals the second local weakened portion.

7. The housing device (1) according to any one of the preceding claims, wherein: The second local weakened portion (12) is offset relative to the remaining portion of the housing (10) in the direction of the first local weakened portion (11).

8. The housing device (1) according to any one of the preceding claims, wherein the first local weakened portion (11) is made of a material different from that of the second local weakened portion (12).

9. A battery cell system (100), comprising at least two housing devices (1) according to any one of the preceding claims, which are arranged side by side, wherein: In particular, each housing device (1) encloses a battery cell (2).

10. A motor vehicle comprising a housing device (1) according to any one of claims 1 to 8 and / or a battery cell system (100) according to claim 9.

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