Battery cell housing with a bursting groove and a predetermined breaking point, and battery cell

Abstract

The invention relates to a battery cell housing for a battery cell (12), comprising at least one housing wall (16) which at least partly delimits an inner volume (14) and primarily has a first material thickness (D1) and comprising overpressure relieving means (22) in the housing wall (16) for relieving an overpressure in the inner volume (14) in order to prevent an uncontrolled bursting of the battery cell housing (10). The overpressure relieving means (22) are integrally formed from the housing wall (16) and comprise a bursting groove (24), said bursting groove having a second material thickness (D2) which is smaller than the first material thickness (D1) and being spatially adjoined by at least one predetermined breaking point (26), said predetermined breaking point having a third material thickness (D3) which is smaller than the second material thickness (D2).

Description

[0001] BATTERY CELL HOUSING WITH A BURST SLOT AND SET BREAK POINT, AND BATTERY CELL

[0002] Description introduction

[0003] The invention relates to a battery cell housing according to the preamble of claim 1. The invention further relates to a battery cell.

[0004] German patent DE 102022 115428 B3 describes a battery cell with a battery cell housing enclosing an inner volume and with housing walls made of steel. A rectangular degassing opening for venting gases from the inner volume is provided on a narrower housing wall and is sealed with a foil.

[0005] The object of the present invention is to make the battery cell safer and more reliable. The influence of tolerances on the safety of the battery cell is to be reduced.

[0006] At least one of these problems is solved by a battery cell housing with the features according to claim 1. This allows the overpressure in the internal volume to be reduced more precisely and reliably. The battery cell housing can be manufactured more cost-effectively.

[0007] The battery cell casing can accommodate an electrode array for providing electrical energy to the battery cell. The battery cell can consist of at least the battery cell casing and the electrode array. The battery cell casing can be made of metal, in particular steel or aluminum, plastic, and / or a composite material. The battery cell casing can be made of sheet metal. The battery cell casing can be prismatic or cylindrical in shape.

[0008] The housing wall can be rectangular, for example, square. All other housing walls of the battery cell housing can be rectangular. The housing wall can be smaller than the largest housing wall of the battery cell housing. The battery cell housing can be manufactured by forming, deep drawing, and / or extrusion. The battery cell housing can be made in one piece or in multiple pieces. The battery cell housing can have at least one cover. At least one electrical contact for the electrical connection of the electrode assembly can be arranged on the cover. The housing wall can form the cover. Apart from the pressure relief devices, the housing wall can have only the first material thickness. The material thickness is a wall thickness.

[0009] The pressure relief devices prevent uncontrolled rupture of the battery cell casing in the event of thermal runaway. These devices are designed to release excessive internal pressure within the cell's volume through controlled rupture. This controlled rupture of the battery cell casing via the pressure relief devices prevents the pressure from spreading to potentially adjacent battery cells.

[0010] The pressure relief agents may have been introduced into the casing wall during the manufacturing of the battery cell housing.

[0011] The burst groove can define a burst contour in the event of a bursting of the housing wall. The burst contour can define the opening cross-section of the pressure relief means resulting from the bursting. The burst groove can follow a predetermined path on the housing wall. The path can be circular, arc-shaped, rectangular, wavy, oval, and / or straight, at least partially, and preferably primarily, entirely.

[0012] The burst groove can have a constant or variable cross-section along its length. The burst groove can have a rectangular or triangular cross-section, at least in sections, and especially predominantly.

[0013] The rupture groove can be located on the outside and / or inside of the battery cell casing. The rupture groove can be on one or both sides of the casing wall.

[0014] Bursting can involve tearing and deformation of the first housing wall in the area of ​​the pressure relief device. Bursting is irreversible.

[0015] Regarding the rupture of the battery cell casing, the predetermined breaking point can represent the weakest point in the pressure relief system, from which the cracking associated with the rupture originates. The rupture of the casing wall, and in particular of the entire battery cell casing, can begin at the predetermined breaking point.

[0016] In a preferred embodiment of the invention, it is advantageous if the predetermined breaking point is designed as an island. The predetermined breaking point can be locally limited. The predetermined breaking point can be implemented as a point. The predetermined breaking point can connect to the bursting groove on one side. The bursting groove can also connect to the predetermined breaking point at several offset transition points.

[0017] In a particular embodiment of the invention, it is advantageous if the burst groove is produced by at least one first machining process and the predetermined breaking point by at least one second machining process. The first machining process can be a forming and / or machining process. The first machining process can include embossing, broaching, deep drawing, upsetting, rolling, and / or punching. The first machining process can include milling, drilling, etching, and / or electrical discharge machining (EDM).

[0018] The second machining process can be a subtractive machining process. This second machining process can include milling, drilling, etching, and / or electrical discharge machining (EDM).

[0019] In a preferred embodiment of the invention, it is advantageous if the third material thickness is produced with higher accuracy by the second processing method than the second material thickness by the first processing method. The first processing method may have lower tolerances than the second processing method.

[0020] In a specific embodiment of the invention, it is advantageous if the overpressure relief means have at least one burst limit spatially adjacent to the burst groove, offset from the predetermined breaking point, with a fourth material thickness that is smaller than the second material thickness. The burst limit can follow a predetermined further path on the housing wall. This further path can be circular, arc-shaped, rectangular, wavy, oval, and / or straight, at least partially, and preferably primarily, entirely.

[0021] The fourth material thickness can be less than, the same as, or greater than the third material thickness.

[0022] The burst limit can also be spatially separated from the burst groove and / or the predetermined breaking point.

[0023] In a preferred embodiment of the invention, it is advantageous for the burst limiter to be arranged at the end of the burst groove. This allows the bursting to be spatially confined to the burst contour defined by the burst groove. The burst limiter can act as a crack limiter during bursting. The burst limiter can also enclose the burst groove at least partially, and in particular completely. In a preferred embodiment of the invention, the burst limiter forms a transition between the burst groove and the connection area of ​​the housing wall adjacent to the overpressure relief means, with the first material thickness. The burst limiter can spatially confine the bursting of the housing wall, particularly along the burst contour. The burst limiter prevents the bursting from spreading to the areas of the housing wall surrounding the overpressure relief means.

[0024] In a particular embodiment of the invention, it is advantageous if the predetermined breaking point is arranged centrally or at the end of the bursting groove with respect to a principal direction of extension. The predetermined breaking point can be arranged on the side of the bursting groove opposite the bursting limit with respect to the principal direction of extension.

[0025] In a particular embodiment of the invention, it is advantageous if the predetermined breaking point is arranged centrally or at the end of the burst groove with respect to an extension direction perpendicular to the main extension direction. The extension direction perpendicular to the main extension direction can be a further main extension direction.

[0026] Furthermore, within the scope of the invention, a battery cell with the features of claim 10 is proposed to solve at least one of the aforementioned problems. The battery cell can be arranged in a mobile device, for example, a vehicle or a stationary unit. The battery cell can be associated with a vehicle battery. The vehicle battery can provide electrical energy for propelling the vehicle.

[0027] Further advantages and advantageous embodiments of the invention will become apparent from the description of the figures and the illustrations.

[0028] Character description

[0029] The invention is described in detail below with reference to the illustrations. These show, in detail:

[0030] Figure 1: A spatial view of a battery cell housing in a special

[0031] embodiment of the invention.

[0032] Figure 2: A cross-section along AA from Figure 1. Figures 3, 5 and 7: A spatial view of a battery cell housing, each in a specific embodiment of the invention.

[0033] Figures 4, 6 and 8: A cross-section along AA from the corresponding previous figure.

[0034] Figure 1 shows a three-dimensional view of a battery cell housing in a specific embodiment of the invention. The battery cell housing 10 for a battery cell 12 has a prismatic shape and comprises a housing wall 16 that at least partially delimits an inner volume 14 and, adjoining it, at least two further housing walls 18 that connect to a housing wall 20 opposite the housing wall 16. The remaining housing walls, not shown here, for completely enclosing the inner volume 14 can, for example, be subsequently applied covers.

[0035] Within the internal volume 14, an electrode arrangement (not shown here) for generating electrical energy for the battery cell 12 can be arranged.

[0036] Overpressure relief devices 22 are arranged in the housing wall 16 to reduce overpressure in the internal volume 14 and prevent uncontrolled bursting of the battery cell housing 10. The overpressure relief devices 22 are integrally formed from the housing wall 16 and have a burst groove 24, to which a predetermined breaking point 26 is spatially connected at the end of the burst groove 24. The burst groove 24 follows a predetermined path 28, in this case a path that is at least partially circular. The burst groove 24 defines a burst contour in the event of a burst of the housing wall 16.

[0037] With regard to the bursting of the battery cell housing 10, the predetermined breaking point 26 forms the weakest point of the overpressure relief means 22, from which the cracking associated with the bursting originates. The predetermined breaking point 26 is preferably designed as an island, meaning it does not follow a continuous path but is locally delimited. The predetermined breaking point 26 is located centrally with respect to a main extension direction 30 of the bursting groove 24 and at the end of the bursting groove 24 with respect to an extension direction 32 perpendicular to the main extension direction 30.

[0038] The overpressure relief means 22 have a first burst limit 34 spatially adjacent to the burst groove 24 and offset from the predetermined breaking point 26, and a second burst limit 36 ​​spaced apart from it. The first and second burst limits 34, 36 each form a transition 38 between the burst groove 24 and the connection area 40 of the housing wall 16 adjacent to the overpressure relief means 22. This allows the bursting to be spatially limited to the burst contour defined by the burst groove 24, and finally by the burst limits 34, 36.

[0039] Figure 2 shows a cross-section along AA from Figure 1. The housing wall 16 has a first material thickness D1, the burst groove 24 a second material thickness D2 that is less than the first material thickness D1, the predetermined breaking point 26 a third material thickness D3 that is less than the second material thickness D2, and the first and second burst limits 34, 36 a fourth material thickness D4 that is less than the second material thickness D2. The third and fourth material thicknesses D3, D4 can be the same.

[0040] The burst groove 24 is preferably produced by at least one first machining process and the predetermined breaking point 26 by at least one second machining process.

[0041] Preferably, the third material thickness D3 is produced with higher accuracy using the second processing method than the second material thickness D2 using the first processing method. This allows the bursting process to start more accurately and in a more controlled manner.

[0042] Figures 3, 5, and 7 show a three-dimensional view of a battery cell housing, each in a specific embodiment of the invention. The battery cell housing 10 from Figure 3 is similar to that from Figure 1 except for the following differences. The path 28 of the burst groove 24 is elliptical.

[0043] Figures 4, 6, and 8 show a cross-section along AA from the previous figure. The housing wall 16 in Figure 4 has a first material thickness D1, the burst groove 24 has a second material thickness D2 that is less than the first material thickness D1, the predetermined breaking point 26 has a third material thickness D3 that is less than the second material thickness D2, and the first and second burst limits 34 and 36 have a fourth material thickness D4 that is less than the second material thickness D2. The third and fourth material thicknesses D3 and D4 can be the same.

[0044] The battery cell housing 10 from Figure 5 is identical to that from Figure 1 except for the following differences. The path 28 of the burst groove 24 is linear. The predetermined breaking point 26 is located centrally with respect to the burst groove 24. The first burst limit 34 is located at the end with respect to the burst groove 24 and opposite the second burst limit 36, which is also located at the end with respect to the burst groove 24.

[0045] The housing wall 16 in Figure 6 has a first material thickness D1, the burst groove 24 has a second material thickness D2 that is less than the first material thickness D1, the predetermined breaking point 26 has a third material thickness D3 that is less than the second material thickness D2, and the first and second burst limits 34, 36 have a fourth material thickness D4 that is less than the second material thickness D2. The third and fourth material thicknesses D3, D4 can be the same.

[0046] The battery cell housing 10 from Figure 7 is similar to that from Figure 5 except for the following differences. The burst limit 41 follows an oval path 42 that completely surrounds the burst groove 24.

[0047] The housing wall 16 in Figure 8 has a first material thickness D1, the burst groove 24 has a second material thickness D2 that is less than the first material thickness D1, the predetermined breaking point 26 has a third material thickness D3 that is less than the second material thickness D2, and the first and second burst limits 34, 36 have a fourth material thickness D4 that is less than the second material thickness D2. The third material thickness D3 is less than the fourth material thickness D4. The burst limit is designed in cross-section as a notch 44.

[0048] Reference symbol list

[0049] 10 battery cell housings

[0050] 12 battery cells

[0051] 14 internal volume

[0052] 16 Housing wall

[0053] 18 more case walls

[0054] 20 opposite case wall

[0055] 22 Overpressure relief agents

[0056] 24 Burstnut

[0057] 26 Breakaway point

[0058] 28 Route description

[0059] 30 Main direction of extension

[0060] 32 Direction of extension

[0061] 34 first burst limit

[0062] 36 second burst limit

[0063] 38 Transition

[0064] 40 Connection area

[0065] 41 Burst limit

[0066] 42 further route

[0067] 44 notch

[0068] D1 first material thickness

[0069] D2 second material thickness

[0070] D3 third material thickness

[0071] D4 fourth material thickness

Claims

Patent claims 1. Battery cell housing for a battery cell (12), comprising at least one housing wall (16) which at least partially delimits an internal volume (14) and has a first material thickness (D1), in the housing wall (16) overpressure relief means (22) for reducing overpressure in the internal volume (14) to prevent uncontrolled bursting of the battery cell housing (10), characterized in that the overpressure relief means (22) are formed in one piece from the housing wall (16) and comprise a burst groove (24) having a second material thickness (D2) that is less than the first material thickness (D1), to which at least one predetermined breaking point (26) having a third material thickness (D3) that is less than the second material thickness (D2) is spatially connected.

2. Battery cell housing according to claim 1, characterized in that the predetermined breaking point (26) is designed in an island-like manner.

3. Battery cell housing according to claim 1 or 2, characterized in that the burst groove (24) is produced by at least a first machining process and the predetermined breaking point (26) is produced by at least a second machining process.

4. Battery cell housing according to claim 3, characterized in that the third material thickness (D3) is produced by the second processing method with a higher accuracy than the second material thickness (D2) by the first processing method.

5. Battery cell housing according to one of the preceding claims, characterized in that the overpressure relief means (22) have at least one burst limit (34, 36, 41) spatially adjoining the burst groove (24) offset from the predetermined breaking point (26) and with a fourth material thickness (D4) that is less than the second material thickness (D2).

6. Battery cell housing according to claim 5, characterized in that the burst limit (34, 36, 41) is arranged at the end of the burst groove (24).

7. Battery cell housing according to claim 4 or 6, characterized in that the burst limit (34, 36, 41) forms a transition (38) between the burst groove (24) and the connection area (40) of the housing wall (16) with the first material thickness (D1) adjacent to the overpressure relief means (22).

8. Battery cell housing according to one of the preceding claims, characterized in that the predetermined breaking point (26) is arranged centrally or at the end of the bursting groove (24) with respect to a main extension direction (30) of the bursting groove (24).

9. Battery cell housing according to claim 8, characterized in that the predetermined breaking point (26) is arranged centrally or at the end of the burst groove (24) with respect to an extension direction (32) perpendicular to the main extension direction (30).

10. Battery cell (12) comprising a battery cell housing (10) according to one of the preceding claims and at least one electrode arrangement contained in the internal volume (14) of the battery cell housing (10) and providing electrical energy.

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