Cylindrical battery cell housing with intrinsic pressure relief means

Abstract

The present invention relates to a cylindrical battery cell housing (7) of a battery cell with a battery cell housing jacket (8) with a cross section which is cylindrical at least in some regions having a first material of an aluminium alloy. The problem of providing a battery cell housing (7) which has a more simple structure and greater battery capacity while having the same installation size of the battery cell, and simultaneously providing high reliability against the destruction of the battery cell housing jacket (8) and thus against thermal runaway is solved in that the battery cell housing jacket (8) is connected in a frictional and / or integral manner to a battery cell housing cover (9) having a second material of an aluminium alloy, wherein the battery cell housing cover (9) is designed as a sheet metal blank which, due to its mechanical properties is designed as a pressure relief means of the battery cell housing (7), wherein in the event that a permitted inner pressure of the battery cell housing is exceeded, the battery cell housing (9) ensures pressure relief of the battery cell in the axial direction.

Description

[0001] May 22, 2024 Cylindrical Battery Cell Housing with Intrinsic Pressure Relief Means The present invention relates to a cylindrical battery cell housing of a battery cell with a battery cell housing shell with an at least partially cylindrical cross-section comprising a first material made of an aluminum alloy. Battery cells are used in a variety of technical applications to supply an electrical consumer with electrical energy. In particular, lithium-ion (Li) secondary battery cells, hereinafter referred to as battery cells, are used, for example, in electromobility, especially in electric cars, electric bicycles, and electric scooters; in consumer electronics, in laptop computers, tablet computers, mobile phones, digital cameras, and video cameras; or in energy technology, especially in battery storage systems, to name just a few.Often, several battery cells are connected in series or parallel to form a battery module or battery system. A widely used format for battery cell casings is cylindrical, which, as the name suggests, have a cylindrical shape and are available in various diameters and sizes. Generally, in applications with high charging capacity, there is a tendency to increase the volume of the battery cells in order to increase the energy density of battery modules through the higher energy storage capacity of the individual battery cells. The dominant battery cell format with cylindrical battery cell casings corresponds to the 18650 type with a diameter of 18 mm. These are being replaced in various applications by the 21700 type with a diameter of 21 mm.However, a substitution of type 21700 battery cells with 46 mm diameter 46800 battery cells is also expected, for example in the field of electromobility. The growing cell formats place demands on the dissipation of heat generated inside the battery cell and thus on the electrical and thermal conductivity of the battery cell housing. The predominantly used lithium-containing electrolyte is typically highly reactive. Therefore, in the event of malfunctions, faulty control, mechanical damage, or improper use, chemical reactions can release gases inside the battery, which can unduly increase the internal pressure in the battery cell housing. If suitable safety mechanisms are not provided, this can result in a massive temperature increase and, in the worst case, thermal runaway of the individual cell.If the pressure increase combined with a temperature increase due to exothermic reactions inside the battery cell leads to damage to the battery cell casing, resulting in the escape of hot or burning gases through the casing surface of the battery cell. For example, in battery cell modules containing multiple battery cells and whose casings are arranged very closely together, this can result in the destruction of the entire battery module. The thermal runaway spreads from the individual cell to other cells, the affected module, or the entire battery, which usually leads to a fire in the battery. Fires in lithium-ion batteries cannot be extinguished using conventional means. Thermal runaway must therefore be prevented at all costs.For this purpose, cylindrical battery cell housings have a complex battery cell housing cover as a safety device, which, in addition to the electrical battery contact, can in particular have an electrically conductive current interruption device, for example in the form of a punched or embossed metallic disc, which on the one hand interrupts the current when a specific pressure load from the interior of the battery cell is applied. I / ZI 230389WOMay 22, 2024 can cause a change in shape and / or burst at even higher internal pressure, releasing the gases within the battery via the battery contact in the axial direction of the battery cell housing. Destruction of the battery cell housing shell and thus of other battery cells can thus be avoided. Fig. 1 shows such a structure of a battery cell housing cover in a schematic sectional view. As can be seen from the example in Fig. 1, the current interruption disc can be crimped to the electrical contact of the battery cell. The crimped combination of current interruption disc and electrical contact of the battery cell is in turn crimped to the battery cell housing shell. Optionally, further safety devices, such as a PTC (positive thermal coefficient) switch, can be crimped to the battery cell housing shell or to the electrical contact and the current interruption disc.This double crimp connection of the battery cell housing cover is complex and error-prone. At the same time, the complex battery cell housing cover with its safety devices takes up a relatively large volume of the battery cell. A prismatic battery cell with a safety valve for pressure equalization in the battery cell housing cover is known from Chinese utility model CN ​​205564827 U. Japanese patent application JP 200393059 A solves the problem of potential deformation of the battery cell housing due to increased internal pressure by providing a multilayer composite material that provides both high strength and good weldability for the batteries. A pressure relief device is not disclosed. US patent application US 2019 / 0368008 A1 discloses an aluminum alloy for a "battery part," where the "battery part" refers to a "net" as a current collector. ist. Z I / ZI 230389WOMay 22, 2024The object of the present invention is therefore to provide a battery cell housing which, on the one hand, enables a simpler structure and a larger battery capacity with the same size of the battery cell and, at the same time, offers a high level of security against destruction of the battery cell housing shell and thus against the spread of "thermal runaway" to other battery cells.According to a first teaching of the present invention, the stated object is achieved in that the battery cell housing shell is non-positively and / or materially connected to at least one battery cell housing cover comprising a second material made of an aluminum alloy, wherein the at least one battery cell housing cover is designed as a sheet metal blank, and the sheet metal blank, due to its mechanical properties, is designed as a pressure relief means of the battery cell housing, wherein, when a permissible internal pressure of the battery cell is exceeded, preferably exclusively, the at least one battery cell housing cover ensures pressure relief of the battery cell in the axial direction. The sheet metal blank of the battery cell housing cover is preferably circular.Simulations have shown that by appropriately selecting the materials for the battery cell housing shell and the battery cell housing cover, both of which are aluminum alloys, the battery cell housing cover can intrinsically serve as a pressure relief device due to its mechanical properties. The mechanical properties of the sheet metal blank result from the composition of the aluminum alloy and the tempering state of the sheet metal blank. It was shown that, under these conditions, the battery cell housing cover in the form of a sheet metal blank reliably relieves pressure in the battery cell in the axial direction as a pressure relief device without damaging the battery cell housing shell. Since the battery cell housing cover ensures pressure relief, a complex design of the battery cell housing cover, in particular a bursting disc inside the Z. I / ZI 230389WOMay 22, 2024 Battery cell can be dispensed with and at the same time a high level of safety against thermal runaway can be achieved. The simplified design of the battery cell housing cover as a sheet metal blank allows the volume of the battery cell housing available for storing electrical energy to be increased and a larger battery capacity to be achieved. According to a first embodiment, the material of the battery cell housing shell differs from the material of the at least one battery housing cover in the tempered state of the aluminum alloy and / or in the alloy composition. In this way, different mechanical properties of the battery cell housing shell and the battery housing cover can be provided, so that pressure relief in the event of an accident occurs exclusively via the battery housing cover.According to a further embodiment, the at least one battery cell housing cover is preferably integrally connected to the battery cell housing shell via a weld seam, preferably a laser weld seam. This provides a highly sealed connection between the battery cell housing cover and the battery cell housing shell, which reliably protects the interior of the battery cell from external influences and can simultaneously be manufactured in a highly automated manner. Laser weld seams are characterized by particularly high precision and very little influence on the joining partners, so that the material properties are not or only slightly impaired even in the area of ​​the weld seam.In order to determine suitable materials for the battery cell casing shell and the battery cell casing cover, so that only the battery cell casing cover provides pressure relief in the axial direction of the battery cell in the event of an inadmissibly high internal pressure within the battery cell, it was initially assumed that the specific strain energy of the battery cell casing cover necessary for failure of the battery cell casing cover must be smaller, e.g. I / ZI 230389WO May 22, 2024 as the specific strain energy for the failure of the battery cell casing material. The specific strain energy up to uniform strain ^^g is approximated over a trapezoidal area in the stress-strain diagram as follows: where ^^( ^^p) is the technical stress and ^^p is the technical plastic strain in the uniaxial tensile test, and ^^(0) = ^^p0.2 is the yield strength and ^^( ^^g) =^^ mthe tensile strength. The following condition to be fulfilled for the material of the battery cell housing cover D and the material of the battery cell housing shell M is hereby formulated: This inequality states that the specific strain energy required to plastically deform the respective material to uniform elongation should have a smaller value for the lid than for the shell. It should therefore be easier to cause the lid to plastic failure than the shell. With a further condition to be fulfilled, materials for the battery cell housing lid are excluded in this embodiment that satisfy equation (2) but essentially deform elastically, so that despite condition (3), plastic deformation of the battery cell housing shell can occur. With the further condition ( ^^ ) to be fulfilled p0,2 ) D < ( ^^ p0,2 ) M (3) Z I / ZI 230389WOMay 22, 2024, plastic deformation of the battery cell housing shell is excluded. Equation (2) can now be solved for ( ^^p0,2)D and summarized with equation (3). As a result, the yield strength of the material of the at least one battery cell housing cover ( ^^p0,2)D of this embodiment of the invention satisfies the following condition: ( ^^ p0,2 ) D < ( ^^ p0,2 ) D,zul (4a) with the maximum permissible yield strength for the cover and ( ^^ p0,2 ) M : Yield strength of the battery cell casing, ( ^^ g ) M : Uniform expansion of the battery cell casing, ( ^^ g ) D : Uniform expansion of the battery cell housing cover, ∙ ^^ g ) M : Product of tensile strength and uniform elongation of the battery cell casing shell,∙ ^^ g ) D: Product of tensile strength and uniform elongation of the battery cell housing cover. In this embodiment, an upper limit is set for the yield strength of the battery cell housing cover material ( ^^p0.2)D depending on the material properties of the uniform elongation ^^g, the tensile strength ^^m of the battery cell housing cover and the battery cell housing shell, and the yield strength of the battery cell housing shell ( ^^p0.2)M. The resulting material combinations enable the provision of a I / ZI 230389WOMay 22, 2024 Battery cell housing cover, which ensures exclusive pressure relief in the event of excessive internal pressure. Internal pressures can be specified for battery cells, at which exceeding these limits, destruction of the battery cell is to be prevented by targeted pressure relief in the axial direction, preventing the occurrence of a "thermal runaway." In the further consideration, the cylindrical battery cell housing is approximated by an enclosed tube. The tube body corresponds to the battery cell housing shell with a wall thickness of ^^M and an inner radius of ^^i. The tube ends correspond to battery housing covers with a wall thickness of ^^D. The integral connection of the battery cell housing cover with the battery cell housing shell is mechanically considered as a fixed clamping of the battery cell housing cover, so that the stress components listed in Table 1 for such a tube body can be defined: Tabelle 1 Component σ ^^ σ ^^ σ ^^ σV,TD eckel 3 ^^ 2∙^^ ∙ ( i ^^) 0.225 ∙ ^^ ∙ ( i 2 )− ^^ σ ^^ − σ ^ ≈ σ(at the edge) 4 ^^D ^^ ^ ^^ D Mantel ^^ ∙ ^^ − ^^ i ^^ ∙ ^^i σ − σ ≈ σ ^^M 2 ∙ ^^ ^^ ^^ ^^ M In Table 1, σ ^^ is the stress in the radial direction, σ ^^ is the stress in the circumferential direction, σ ^^ is the stress in the axial direction and σV,T is the equivalent stress according to Tresca (cf. “Dubbel Taschenbuch für den Maschinenbau”, Volume 1, Part II Mechanics, 26th edition, Springer-Verlag, 2020). For given permissible internal pressures ^^zul, advantageous wall thicknesses for the battery cell housing cover can now be determined by specifying the wall thicknesses and the material of the I / ZI 230389WO May 22, 2024 battery cell casing shell. For this purpose, it is initially assumed that initiation of flow in the battery cell casing cover is to be allowed so that it deforms plastically. The equivalent stress according to Tresca desThe battery cell housing cover may therefore reach a maximum yield strength of ( ^^p0,2)D of the battery cell housing cover. Accordingly, the following applies:(σ V,T ) D ≤ ( ^^ p0,2 ) D . (5)At the same time, the battery cell casing must not deform plastically. The equivalent stress according to Tresca (σ V,T ) M of the battery cell casing shell must therefore be smaller than the yield strength ( ^^p0,2)M of the battery cell casing cover:(σ V,T ) M < ( ^^ p0,2 ) M (6) Finally, it should be ensured that the battery cell casing remains undamaged. This results in the following condition for the reference stresses according to Tresca and (σV,T)M of battery cell housing cover and shell:(σ V,T ) D > (σ V,T ) M . (7)From inequality (5) by multiplication with ( ^^p0,2)M and applying inequality (6) the following estimate can be made:(σ V,T )D ∙ (σ V,T ) M < (σ V,T ) D ∙ ( ^^ p0,2 ) M ≤ ( ^^ p0,2 ) D ∙ ( ^^ p0,2 ) M (8)From this, the following condition for the pressure ^^ can be derived using the stress components from Table 1:Z I / ZI 230389WO May 22, 2024 Analogously, the inequality (7) multiplied by (σV,T)D yields the following estimate using inequality (6):( ^^ 2 2 p 0,2 ) D ≥ (σ V,T ) D > (σ V,T ) M ∙ (σ V,T ) D (10) By inserting the stress components from Table 1, the pressure is ^^: Inequalities (9) and (11) must be satisfied simultaneously. This leads to the following estimate for the maximum permissible internal pressure ^^zul:^^ < ^^ zul (12a) According to inequality (5), it was assumed that the battery cell housing cover is loaded until the beginning of yield. In reality, however, the battery cell housing cover is loaded until failure in order to relieve pressure. The tensile strength ^^m is characterized by the onset of necking in the uniaxial tensile test and is suitable as the load limit for the battery cell housing cover. The true tensile strength ^^m is calculated from ^^m as folgt: Z I / ZI 230389WO May 22, 2024 with ^^ m : tensile strength,^^g : uniform elongation.By replacing ( ^^p0,2)D with ( ^^m)D, the permissible pressure ^^zul follows from equation (12b): ^^zul From equation (14) an advantageous specification for the wall thickness ^^ can now be derived for a further embodiment of the battery cell housing. D des Battery cell housing cover. The wall thickness ^^D of the battery cell housing cover depends on the mechanical properties ( ^^p0,2 ) M and ( ^^ m ∙ (1 + ^^ g )) D and the wall thickness of the battery cell casing shell^^ at a given ∗ ∗M em internal pressure ^^ = ^^zul, where ^^ is the internal pressure in the battery cell casing at which the cover fails as intended: mit ^^ M : Wall thickness of battery cell casing, ^^ D : Wall thickness of battery cell housing cover,^^∗ : Specified internal pressure in the battery cell housing at the time of cover failure,^^ m : Tensile strength,^^g : Uniform elongation,D : Index battery cell housing cover,Z I / ZI 230389WO May 22, 2024 M : Index battery cell casing shell. With these wall thicknesses ^^M, plastic deformation of the battery cell casing shell can be excluded. To take into account the anisotropy of the plastic properties of the sheet materials, mean values ​​( ^^p0.2)avg, ( ^^m)avg and ( ^^g) are preferably used. für dieYield strength ^^p0.2, the tensile strength ^^m or the uniform elongation ^^g over the three directions 0°, 45° and 90° to the rolling direction according to the relationship known from sheet metal forming ^^ 1 avg = ∙ ( ^^0° + 2 ^^45° + ^^90°) is taken into account in equations (4a), (4b) as well as (14) and (15), whereby the value at 45° must be taken into account twice in the averaging process and “ ^^” is a placeholder for one of the quantities ^^p0.2, ^^m or ^^g. According to a further embodiment of the battery cell housing, the battery cell housing cover provided for pressure relief triggers pressure relief of the battery cell housing at an internal pressure of 0.5 MPa (5 bar) to 2.5 MPa (25 bar), preferably 0.7 MPa to 2.0 MPa (7 to 20 bar), particularly preferably 0.7 MPa to 1.5 MPa (7 to 15 bar). This prevents major damage to a battery module, for example due to explosive pressure relief, since the pressure relief is safely triggered in the axial direction even at moderate internal pressures.A sufficiently stable battery cell housing shell can be provided according to a further embodiment of the battery cell housing in that the battery cell housing shell has a yield strength ^^p0.2 of more than 100 MPa, preferably more than 150 MPa, particularly preferably more than 180 MPa. It has been shown, especially with the preferred values ​​for the yield strength, that the selection of the material for the battery cell housing cover increases. I / ZI 230389WOMay 22, 2024. According to a next embodiment of the battery cell housing, the battery cell housing shell comprises a wrought aluminum alloy, preferably a wrought aluminum alloy of type AA3xxx. To provide maximum strength, a wrought aluminum alloy of type AA5xxx can also be used for the battery cell housing shell. Due to their microstructure, wrought aluminum alloys exhibit preferred properties with regard to impermeability and ductility compared to cast aluminum materials. The aluminum alloy of type AA3xxx is characterized by high strength, good welding, and corrosion properties. The aluminum alloy types AA3004, AA3104, AA3005, or AA3105, for example, are characterized by particularly high recycling friendliness, with possible recycling contents of more than 70%, preferably more than 90%.A particularly high recycling potential with recycled metal contents of more than 90% while simultaneously achieving the other necessary properties such as good formability, high yield strengths, good weldability and good corrosion properties can be achieved by the battery cell casing shell having an aluminum alloy with the following alloying components in wt.%: 0.1% ≤ Si ≤ 0.5%, preferably 0.2% ≤ Si ≤ 0.4%, 0.20% ≤ Fe ≤ 0.8%, preferably 0.40% ≤ Fe ≤ 0.6%, Cu ≤ 0.6%, preferably 0.10% ≤ Cu ≤ 0.30%, 0.3% ≤ Mn ≤ 1.4%, preferably 0.50% ≤ Mn ≤ 1.1%, 0.01% ≤ Mg ≤ 1.5% %, preferably 0.05% ≤ Mg ≤ 1.30% or preferably 0.30% ≤ Mg ≤. 1,20 %, Cr ≤ 0.25%, preferably Cr ≤ 0.1%, Zn ≤ 0.4%, Ti ≤ 0.2%, preferably 0.005 wt% ≤ Ti ≤ 0.1 wt% or preferably 0.005 wt% ≤ Ti ≤ 0.05 wt%, balance Al and unavoidable impurities, individually maximum 0.05%, in total maximum 0.15%.Z I / ZI 230389WOMay 22, 2024 The silicon content of the aluminum alloy is preferably in the range 0.1 wt.% ≤ Si ≤ 0.5 wt.%. In one embodiment of the battery cell housing, the silicon content of the aluminum alloy is in the range 0.2 wt.% ≤ Si ≤ 0.4 wt.%. The silicon content of 0.1 wt.% ≤ Si ≤ 0.5 wt.%, in combination with the iron and manganese contents in the specified amounts, leads in particular to relatively uniformly distributed, compact particles of the quaternary α-Al(Fe,Mn)Si phase. These precipitated particles increase both the strength of the aluminum alloy and its electrical and thermal conductivity, since they remove iron and manganese from the solid solution, but without negatively affecting other properties such as corrosion behavior or formability. Silicon contents of less than 0.1 wt.-% lead to reduced precipitation of α-Al(Fe,Mn)Si phases, which can impair electrical and thermal conductivity due to dissolved manganese. Furthermore, the absence of α-Al(Fe,Mn)Si phases negatively affects tool wear. Silicon contents of more than 0.5 wt.% in combination with magnesium can lead to the formation of Mg2Si phases, which negatively affects the solid solution strengthening of the magnesium. The silicon content corridor of the preferred embodiment of 0.2 wt.% ≤ Si ≤ 0.4 wt.% represents an ideal compromise between high strength and high electrical and thermal conductivity. The iron content of the aluminum alloy is preferably in the range 0.2 wt.% ≤ Fe ≤ 0.8 wt.%. In a preferred embodiment of the battery cell housing, the iron content of the aluminum alloy is in the range 0.4 wt.% ≤ Fe ≤ 0.6 wt.%. The iron content of 0.2 wt.% ≤ Fe ≤ 0.8 wt.%-%, in combination with the manganese content in the specified amount, leads to the formation of Al6(Mn,Fe) phases and, as already explained above, in combination with the silicon and manganese contents in the specified amounts, to the precipitation of particles of the quaternary α-Al(Fe,Mn)Si phase. Iron contributes to reducing the solubility of manganese in aluminum, whereby more manganese is bound in intermetallic phases, which has a positive effect on electrical and thermal conductivity. In addition, the intermetallic phases influence recovery Z. I / ZI 230389WOMay 22, 2024 and recrystallization processes and improve the thermal stability of the mechanical properties. Iron contents of more than 0.8 wt.% favor the formation of coarse intermetallic phases, which can impair formability in the deep drawing process. Iron contents that are too low, less than 0.2 wt.%, on the other hand, severely restrict the aluminum alloy's tolerance for ferrous scrap, as common scrap grades generally contain a significant amount of iron. Therefore, excessively restricting the iron content can hinder the realization of high recycling rates. The preferred range of the iron content of the embodiment of 0.4 wt.% ≤ Fe ≤ 0.6 wt.%, therefore represents an ideal combination of recyclability, i.e. the use of high recycled material contents, thermal stability, electrical and thermal conductivity, and formability. The copper content of the aluminum alloy is preferably in the range Cu ≤ 0.6 wt.%.In a preferred embodiment of the battery cell housing, the copper content of the aluminum alloy is in the range 0.1 wt.% ≤ Cu ≤ 0.3 wt.%. By permitting a copper content of up to 0.6 wt.%, an increased tolerance of the aluminum alloy for copper-containing aluminum alloy scrap is achieved, which favors the realization of high recycled material proportions in the production of the battery housing. However, since excessive copper contents can have a negative impact on the corrosion properties, the copper content is limited according to the invention to a maximum of 0.6 wt.% to achieve sufficiently high electrolyte resistance. For improved electrolyte resistance and sufficiently high electrical and thermal conductivity, the copper content is limited to 0.3 wt.% in the aforementioned embodiment.However, the presence of copper also simultaneously increases the strength of the aluminum alloy through solid solution strengthening, which, however, only becomes clearly apparent at a content of 0.1 wt.%. A preferred range of 0.1 wt.% ≤ Cu ≤ 0.3 wt.% thus represents a compromise between high strength, sufficiently high Z. I / ZI 230389WOMay 22, 2024 electrical and thermal conductivity and further improved electrolyte resistance with sufficient recycling tolerance. The manganese content of the aluminum alloy is preferably in the range 0.3 wt.% ≤ Mn ≤ 1.4 wt.%. In one embodiment of the battery cell housing according to the invention, the manganese content of the aluminum alloy is in the range 0.5 wt.% ≤ Mn ≤ 1.1 wt.%. The manganese content of 0.3 wt.% ≤ Mn ≤ 1.4 wt.%, or 0.5 wt.% ≤ Mn ≤ 1.1 wt.%, in combination with the silicon and iron contents in the specified amounts, leads, as already explained above, to the precipitation of particles of the quaternary α-Al(Fe,Mn)Si phase and the Al6(Mn,Fe) phase. The intermetallic phases inhibit recovery and recrystallization curtains, thus improving the thermal stability of the mechanical properties. Manganese contents of less than 0.3 wt.% already reduce the strength increase through dispersoid and solid solution strengthening.Manganese contents of less than 0.3 wt.% lead to insufficient strength enhancement through dispersoid and solid solution hardening, while manganese contents of more than 1.1 wt.%, especially more than 1.4 wt.%, promote the formation of coarse intermetallic phases, which adversely affect the forming properties in the deep drawing process. Furthermore, manganese contents of more than 1.1 wt.%, especially more than 1.4 wt.%, reduce the electrical and thermal conductivity of the battery cell casing to such an extent that thermal management becomes inefficient. The magnesium content of the aluminum alloy is preferably in the range 0.01 wt.% ≤ Mg ≤ 1.5 wt.%. In one embodiment of the battery cell housing according to the invention, the magnesium content of the aluminum alloy is in the range 0.05 wt.% ≤ Mg ≤ 1.3 wt.%, preferably 0.3 wt.% ≤ Mg ≤ 1.2 wt.%. Because a magnesium content of up to 1.5 wt.-% is permitted, an increased tolerance of the aluminum alloy for magnesium-containing aluminum alloy scrap such as UBC scrap (UBC: Used Beverage Can) is achieved, which enables the realization of high recycling rates in the production of the Z. I / ZI 230389WOMay 22, 2024 battery cell housings. In addition, the presence of magnesium at a content of 0.05 wt.% and above leads to efficient solid solution strengthening, which contributes to increased work hardening and thus increases strength. However, since excessive magnesium contents have a negative effect on electrical and thermal conductivity, the magnesium content is limited to a maximum of 1.5 wt.%. To achieve improved mechanical properties, the magnesium content in the aforementioned embodiment is preferably increased to at least 0.05 wt.%, in particular to at least 0.3 wt.%. The preferred range of 0.3% ≤ Mg ≤ 1.2%, in combination with work hardening, enables sufficiently high strength to prevent cracking of the battery cell housing shell. The chromium content of the aluminum alloy is preferably in the range Cr ≤ 0.25 wt.%.In one embodiment of the battery cell housing, the chromium content of the aluminum alloy is in the range Cr ≤ 0.1 wt.%. By permitting a chromium content of up to 0.25 wt.%, an increased tolerance of the aluminum alloy for chromium-containing aluminum alloy scrap is achieved, which promotes the realization of high recycling rates in the production of the battery cell housing. In addition, chromium also increases strength and forms dispersoids that increase thermal stability and inhibit recrystallization- or recovery-related softening. However, since excessive chromium contents can negatively impact the electrical conductivity of the aluminum alloy, the chromium content is limited to a maximum of 0.25 wt.%. For improved conductivity while still maintaining sufficient recycling tolerance and strength, the chromium content is limited to 0.1 wt.% in a preferred embodiment.The zinc content of the aluminum alloy is preferably in the range Zn ≤ 0.4 wt.%. By permitting a zinc content of up to 0.4 wt.%, the aluminum alloy achieves increased tolerance for zinc-containing aluminum alloy scrap, which further promotes the realization of high recycling rates. Zinc also increases strength. If excessively high zinc content is detected, the aluminum alloy can be used for the production of zinc-containing scrap. I / ZI 230389WOMay 22, 2024 Since zinc contents impair the weldability, electrical and thermal conductivity, and corrosion resistance of the aluminum alloy, the zinc content is limited according to the invention to a maximum of 0.4 wt.%. The titanium content of the aluminum alloy is preferably in the range Ti ≤ 0.2 wt.%. In one embodiment of the battery cell housing, the titanium content of the aluminum alloy is in the range 0.005 wt.% ≤ Ti ≤ 0.1 wt.%, preferably 0.005 wt.% ≤ Ti ≤ 0.05 wt.%. By permitting a titanium content of up to 0.2 wt.%, an increased tolerance of the aluminum alloy for titanium-containing aluminum alloy scrap is achieved, which favors the realization of high recycling rates in the production of battery cell housings.However, excessive titanium contents can negatively impact the forming properties of the aluminum alloy and significantly reduce its electrical and thermal conductivity, so that the titanium content is limited according to the invention to a maximum of 0.2 wt.%. In addition to the alloy components mentioned above, the aluminum alloy according to this exemplary embodiment of the battery cell housing contains aluminum and unavoidable impurities as the remainder. Unavoidable impurities are alloy components that are not intentionally added to the alloy, but are inevitably present in the aluminum alloy due to the manufacturing process. The content of a single unavoidable impurity is limited to 0.05 wt.%, and the total content of all unavoidable impurities is limited to 0.15 wt.%.This ensures that the unavoidable impurities have no, or no significant, negative effects on the properties of the aluminum alloy, for example, through undesirable phase formation. If maximum strength of the battery cell casing shell is desired, the use of a wrought alloy of type AA5xxx is advantageous. High strength combined with sufficient weldability for sealing the Z. I / ZI 230389WOMay 22, 2024 The connection of the battery cell casing shell with the battery cell casing cover can be achieved by using an aluminum alloy with the following alloying components in wt.%: Si < 0.3%, Fe < 0.4%, Cu < 0.2%, Mn < 0.8%, 2.5% < Mg < 6.0%, preferably 3% < Mg < 6.0%, Cr < 0.2%, Zn < 0.25%, Ti ≤ 0.15%, preferably 0.001% ≤ Ti ≤ 0.1%, the remainder being Al and unavoidable impurities, individually a maximum of 0.05% and in total a maximum of 0.15%. Due to the high achievable strengths, battery cell casing shells made of AA5xxx alloys can meet demanding load requirements and can therefore be considered, for example, as structural components in vehicles. The magnesium content of more than 2.5 wt.%, preferably more than 3.0 wt.%.At these magnesium contents, the maximum hot cracking tendency of the aluminum alloy during welding is already exceeded, so that magnesium contents of more than 2.5 wt.%, preferably more than 3.0 wt.%, enable an efficient welding process. At at least 6.0 wt.%, processing of the aluminum alloy by cold rolling becomes increasingly difficult, as hardening increases sharply during cold rolling and the susceptibility to intergranular corrosion increases significantly. Silicon contents of less than 0.3 wt.% are preferable to minimize hot cracking during the welding process and to avoid the formation of Mg2Si phases, which extract magnesium from the solid solution and thus reduce solid solution hardening. Iron is an impurity in Z. I / ZI 230389WOMay 22, 2024 industrial primary metal and recycling. Iron contents of less than 0.4 wt.%, in combination with manganese contents of less than 0.8 wt.%, lead to the formation of AlMnFe phases, which, as dispersoids, contribute to the efficient control of recrystallization and recovery, thus allowing for optimization of the grain structure. Higher iron contents can lead to the formation of coarse intermetallic phases, while manganese contents above 0.8 wt.% undesirably reduce thermal and electrical conductivity. Chromium, as a dispersoid former, contributes to microstructure control during recovery and recrystallization processes, as well as to microstructure stabilization under thermal stress. However, chromium impairs electrical and thermal conductivity, so the chromium content is limited to less than 0.2 wt.%. Zinc impairs corrosion resistance and is therefore limited to less than 0.25 wt.%.Titanium is used to refine the grain or to optimize the cast structure during the casting process. However, titanium reduces the electrical and thermal conductivity comparatively significantly, so that the titanium content is preferably limited to a maximum of 0.15 wt.%, more preferably 0.001 wt.% ≤ Ti ≤ 0.1 wt.%. If, according to a further embodiment of the battery cell housing, the at least one battery cell housing cover comprises a wrought aluminum alloy of the type AA1xxx, AA8xxx, or AA3xxx, preferred mechanical properties of the battery cell housing cover can be achieved with conventional alloys. The material of the battery cell housing cover preferably has the temper state H24, H14, H18, or H19. In these hard-rolled states, the work-strength capacity of the aluminum alloy of the material is limited, so that precisely adjustable axial pressure relief is achieved through failure of these materials.Preferably, the battery cell housing cover comprises an aluminum alloy with the following alloy components in wt.%: 0.1% ≤ Si ≤ 0.5%, Z. I / ZI 230389WOMay 22, 2024 Fe ≤ 0.8%, preferably 0.20% ≤ Fe ≤ 0.8%, Cu ≤ 0.3%, Mn ≤ 1.4%, 0.005% ≤ Mg ≤ 0.8%, preferably 0.01% ≤ Mg ≤ 0.5%, more preferably 0.01% ≤ Mg ≤ 0.3%, Cr ≤ 0.25%, Zn ≤ 0.4%, Ti ≤ 0.2%, preferably 0.005 wt% ≤ Ti ≤ 0.1 wt%, or preferably 0.005 wt% ≤ Ti ≤ 0.05 wt%, balance Al and unavoidable impurities, individually maximum 0.05%, in total maximum 0.15 %. The silicon content of the aluminum alloy is preferably in the range 0.1 wt.% ≤ Si ≤ 0.5 wt.%. In one embodiment of the battery cell housing cover, the silicon content of the aluminum alloy is in the range 0.2 wt.% ≤ Si ≤ 0.4 wt.%. The silicon content of 0.1 wt.% ≤ Si ≤ 0.5 wt.%, in combination with the iron and manganese contents in the specified amounts, leads in particular to relatively uniformly distributed, compact particles of the quaternary α-Al(Fe,Mn)Si phase.These precipitated particles increase both the strength of the aluminum alloy and its electrical and thermal conductivity, as they remove iron and manganese from the solid solution, without negatively affecting other properties such as corrosion behavior or formability. Silicon contents of less than 0.1 wt.% lead to reduced precipitation of α-Al(Fe,Mn)Si phases, which can impair electrical and thermal conductivity due to dissolved manganese. Furthermore, the absence of α-Al(Fe,Mn)Si phases has a negative effect on tool wear. Silicon contents of more than 0.5 wt.% in combination with magnesium can lead to the formation of Mg2Si phases, which negatively affects the solid solution strengthening of the magnesium. The silicon content corridor of the aforementioned embodiment of 0.2 wt.% ≤ Si ≤ 0.4 wt.% Z. I / ZI 230389WOMay 22, 2024 represents an ideal compromise between high strength and high electrical and thermal conductivity. The iron content of the aluminum alloy is preferably in the range 0.2 wt.% ≤ Fe ≤ 0.8 wt.%. In one embodiment of the battery cell housing cover, the iron content of the aluminum alloy is in the range 0.4 wt.% ≤ Fe ≤ 0.6 wt.%. The iron content of 0.2 wt.% ≤ Fe ≤ 0.8 wt.%, in combination with the manganese content in the specified amount, leads to the formation of Al6(Mn,Fe) phases and, as already explained above, in combination with the silicon and manganese contents in the specified amounts, to the precipitation of particles of the quaternary α-Al(Fe,Mn)Si phase. Iron contributes to reducing the solubility of manganese in aluminum, whereby more manganese is bound in intermetallic phases, which has a positive effect on electrical and thermal conductivity.In addition, the intermetallic phases influence recovery and recrystallization processes and improve the thermal stability of the mechanical properties. Iron contents of more than 0.8 wt.% promote the formation of coarse intermetallic phases, which can impair formability in the deep-drawing process. Iron contents of less than 0.2 wt.%, on the other hand, severely restrict the tolerance of the aluminum alloy for ferrous scrap, since common scrap grades generally have a significant iron content. Therefore, excessively limiting the iron content can hinder the realization of high recycling rates. The iron content range of the aforementioned embodiment, 0.4 wt.% ≤ Fe ≤ 0.6 wt.%, therefore represents an ideal combination of recyclability, use of high recycled material content, thermal stability, electrical and thermal conductivity, and formability.According to the invention, the copper content of the aluminum alloy is in the range of Cu ≤ 0.3 wt.%. By permitting a copper content of up to 0.3 wt.%, the aluminum alloy achieves sufficient tolerance for copper-containing aluminum alloy scrap, which facilitates the realization of high recycled material content in the production of the battery housing cover. I / ZI 230389WOMay 22, 2024 However, the presence of copper also simultaneously increases the strength of the aluminum alloy through solid solution strengthening, which, however, must be limited for the battery cell housing cover material. A maximum Cu content of Cu ≤ 0.3 wt.% ensures sufficiently low strain hardening. The manganese content of the aluminum alloy is preferably in the range Mn ≤ 1.4 wt.%. As already explained above, the manganese content of Mn ≤ 1.4 wt.%, in combination with the silicon and iron contents in the specified amounts, leads to the precipitation of particles of the quaternary α-Al(Fe,Mn)Si phase and the Al6(Mn,Fe) phase. The intermetallic phases hinder recovery and recrystallization curtains and thus improve the thermal stability of the mechanical properties. Manganese contents of more than 1.4 wt.% promote the formation of coarse intermetallic phases, which can have an adverse effect on the forming properties.The magnesium content of the aluminum alloy is preferably in the range of 0.005% ≤ Mg ≤ 0.8%. In one embodiment of the battery cell housing cover, the magnesium content of the aluminum alloy is preferably in the range of 0.01% ≤ Mg ≤ 0.5%, more preferably 0.01% ≤ Mg ≤ 0.3%. By permitting a magnesium content of up to 0.8 wt.%, an increased tolerance of the aluminum alloy for magnesium-containing aluminum alloy scrap, such as UBC scrap, is achieved, which further promotes the realization of high recycling rates in the production of the battery cell housing covers. In addition, the presence of magnesium at a content of 0.01 wt.% and above leads to efficient solid solution strengthening, which contributes to enhanced work hardening and thus increases strength.In the present case, excessive work hardening of the battery cell housing cover material is detrimental to pressure relief, so that the magnesium content ≤ 0.8%, preferably ≤ 0.5%, more preferably ≤ 0.3% is suitable in order to avoid excessive work hardening. I / ZI 230389WOMay 22, 2024 The chromium content of the aluminum alloy is preferably in the range Cr ≤ 0.25 wt.%. In one embodiment of the battery cell housing cover, the chromium content of the aluminum alloy is in the range Cr ≤ 0.1 wt.%. By permitting a chromium content of up to 0.25 wt.%, an increased tolerance of the aluminum alloy for chromium-containing aluminum alloy scrap is achieved, which promotes the realization of high recycling rates in the production of the battery cell housings. In addition, chromium also increases strength and forms dispersoids that increase thermal stability and inhibit recrystallization- or recovery-related softening. However, since excessive chromium contents can have a negative impact on the electrical conductivity of the aluminum alloy, the chromium content is limited to a maximum of 0.25 wt.% according to the invention.For improved conductivity while still maintaining sufficient recycling tolerance and strength, the chromium content in the above-mentioned embodiment is limited to 0.1 wt.%. The zinc content of the aluminum alloy is preferably in the range Zn ≤ 0.4 wt.%. By permitting a zinc content of up to 0.4 wt.%, an increased tolerance of the aluminum alloy for zinc-containing aluminum alloy scrap is achieved, which further promotes the realization of high recycling rates. Zinc also has a strength-enhancing effect. However, since excessive zinc contents impair the weldability, electrical and thermal conductivity, and corrosion resistance of the aluminum alloy, the zinc content is preferably limited to a maximum of 0.4 wt.%. The titanium content of the aluminum alloy is preferably in the range Ti ≤ 0.2 wt.%. In one embodiment of the battery cell housing cover, the titanium content of the aluminum alloy is in the range 0.005 wt.% ≤ Ti ≤ 0.1 wt.-%, preferably 0.005 wt.% ≤ Ti ≤ 0.05 wt.%. By permitting a titanium content of up to 0.2 wt.%, an increased tolerance of the aluminum alloy for titanium-containing aluminum alloy scrap is achieved, which favors the realization of high recycling rates in the production of battery cell housing covers. However, excessively high titanium contents can negatively affect the forming properties of the aluminum alloy. I / ZI 230389WOMay 22, 2024 significantly influence and reduce the electrical and thermal conductivity, so that the titanium content is limited to a maximum of 0.2 wt.%. In addition to the alloying components mentioned above, the aluminum alloy of the battery cell housing cover contains aluminum and unavoidable impurities as the remainder. Unavoidable impurities are alloying components that are not intentionally added to the alloy, but are inevitably present in the aluminum alloy due to the manufacturing process. The content of a single unavoidable impurity is preferably limited to 0.05 wt.%, and the total content of all unavoidable impurities is limited to 0.15 wt.%. This ensures that the unavoidable impurities have no, or no significant, negative effects on the properties of the aluminum alloy, for example, through undesired phase formation.The increased Si and Fe contents of the preferred aluminum alloy for the battery cell housing cover contribute to good recycling potential. This also applies to the claimed Cu, Mn, and Mg contents. At the same time, the preferred mechanical properties, such as a moderate to high yield strength with low uniform elongation ^^g, can be achieved in the preferred tempering states H24, H14, H18, or H19. The battery cell housing can be used for any cylindrical battery format. However, particular advantages are achieved with battery cell housings with an inner radius of at least 7 mm, preferably at least 10 mm according to a preferred embodiment. In particular, the increase in the volume provided for the active material has a particularly significant effect on the storage capacity for larger formats, since the volume increases quadratically with increasing radius. I / ZI 230389WOMay 22, 2024 The aforementioned advantages apply to battery cell housing designs that have a cup-shaped, cylindrical battery cell housing shell with a battery cell housing base and a battery cell housing cover, or a tubular, cylindrical battery cell housing shell with two battery cell housing covers. While cup-shaped battery cell housings require only one joining step to provide a closed battery cell housing, but must be drawn into a cup shape for this purpose, a tubular battery cell housing shell requires at least two joining operations at both ends to provide a closed battery cell housing. Preferably, the battery cell housing shell does not have a longitudinal weld seam, but rather comprises a seamless tube.Seamless tubes can be produced, for example, by extrusion and / or tube drawing and have homogeneous properties in the circumferential direction and thus no potential "weak point" such as a weld seam. When using longitudinally welded tubes, at least three joining operations are required to create the battery cell housing, but the material selection is greater due to the manufacturing process of the longitudinally welded tube. For longitudinally welded tubes, almost all weldable aluminum alloys can be considered as materials in any temper state. Optionally, in addition to the battery cell housing cover designed as a pressure relief device, at least one further pressure relief device, preferably at least one further bursting element for axial pressure relief of the battery cell housing, can be provided.This can further increase the safety of the battery cell housing against thermal runaway, as an additional pressure relief device is provided. For example, such an additional pressure relief device can be implemented in the battery cell housing base of the cup-shaped battery cell housing shell, for example, by means of an embossing that locally reduces the wall thickness. An embossing can also be provided in the battery cell housing cover as an additional pressure relief device. I / ZI 230389WOMay 22, 2024. The embossing is preferably provided on the opposite side of the battery cell housing. According to a next embodiment, a particularly easy-to-manufacture battery cell housing is provided in that the battery cell housing has a battery cell housing cover or a battery cell housing base with an opening for passing through an electrical pole, preferably the anode of the battery cell, wherein the passed-through electrical pole is electrically insulated from the battery cell housing base and / or cover. The opening for passing through the one electrical pole can be introduced into the cup-shaped battery cell housing or into the sheet metal blank of the battery cell housing cover using simple punching steps. The sheet metal blank can preferably be coated on one side with an electrically insulating layer in order to easily provide electrical insulation from the pole to be passed through inside the battery cell housing.The same can also be done for the battery cell housing shell in order to electrically insulate it from the active material in a simple manner. The electrical insulation can, for example, already be applied during aluminum strip production. In order to make particularly good use of the available battery cell volume and provide maximum battery cell capacity, according to one embodiment, the wall thicknesses of the material of the battery cell housing shell are between 0.20 mm and 1.5 mm, preferably 0.3 mm to 1.2 mm, and / or the wall thicknesses of the material of the battery cell housing cover are between 0.3 mm and 2.0 mm, preferably between 0.4 mm and 1.5 mm. The invention will be explained in more detail below using exemplary embodiments in conjunction with the drawing. In the drawing, Fig. 1 shows a schematic sectional view of the structure of conventional battery cell housings. I / ZI 230389WO22 May 2024Fig. 2 shows a schematic sectional view of a first embodiment of a battery cell housing according to the invention,Fig. 3 shows an enlargement of the pole area of ​​the battery cell housing from Fig. 2 Fig. 4 shows a schematic sectional view of a second embodiment of a battery cell housing according to the invention, Fig. 5 shows an enlargement of the pole area of ​​the battery cell housing from Fig. 4.As previously explained, Fig. 1 shows a schematic sectional view of a conventional battery cell housing 1. The electrical contact 2 of the battery cell housing is visible, which is connected to the battery electrode foil 5 via a PTC switch 3 and a current interruption disc 4, which also serves as a rupture disc for pressure relief. Not only is the assembly of this structure complex due to the double crimping and thus also prone to errors, but a relatively large volume of the battery cell housing 1 is also used for the safety devices. The battery cell housing shell 6 of the conventional battery cell housing 1 is usually made of steel. Fig.Fig. 2 also shows, in a schematic sectional view, an embodiment of a battery cell housing 7 according to the invention, with a battery cell housing shell 8 comprising a first material made of an aluminum alloy and a battery cell housing cover 9 comprising a second material made of an aluminum alloy. Z is located in the battery cell housing cover 9. I / ZI 230389WOMay 22, 2024, an electrical contact 10 is provided for contacting the battery cell, which contacts the battery electrode foil (not shown) through an opening in the battery cell housing cover 9. An internal pressure p prevails inside the battery cell housing 7. Unlike a conventional battery cell housing 1, the battery cell housing cover 9 in the battery cell housing 7 according to the invention is designed as a circular sheet metal blank and, in this exemplary embodiment, has an opening for the passage of the electrical contact 10. Furthermore, due to its mechanical properties, the battery cell housing cover 9 is designed as a pressure relief means for the battery cell housing 7, so that if a permissible internal pressure of the battery cell is exceeded, only the battery cell housing cover 9 ensures pressure relief of the battery cell in the axial direction.This preferably takes place at the edge of the battery cell housing cover 9 attached to the battery cell housing shell 8, since this is where the greatest mechanical stress is present. The direction of pressure relief in the event of failure of the battery cell housing cover 9 is shown in Fig. 3, which shows an enlarged view of the battery cell housing cover 9 of the battery cell housing 7. For particularly high safety requirements, additional safety mechanisms such as burst beads or embossing in the battery cell housing cover 9 or in the battery cell housing base 11 of the battery cell housing 7 can be provided. The preferably exclusive pressure relief via the battery cell housing cover 9 is achieved in that the material of the battery cell housing shell 8 differs from the material of the at least one battery housing cover 9 in the tempered state of the aluminum alloy and / or in the alloy composition.Although force-locking connections between the battery cell housing cover 9 and the battery cell housing shell 8 are also conceivable, theZ. I / ZI 230389WOMay 22, 2024 at least one battery cell housing cover 9 is connected to the battery cell housing shell 8, preferably via a weld seam, preferably via a laser weld seam. The internal pressure ^^ at which the pressure relief through the battery cell housing cover 9 is to begin is preferably 0.5 MPa to 2.5 MPa (5 bar to 25 bar), preferably 0.7 MPa to 2.0 MPa (7 bar to 20 bar), particularly preferably 0.7 MPa to 1.5 MPa (7 bar to 15 bar). Since the battery cell housing shell 8 is to remain intact at these internal pressures, the battery cell housing shell 8 preferably has a yield strength ^^p0.2 of more than 100 MPa, preferably more than 150 MPa, particularly preferably more than 180 MPa. The preferred materials for the battery cell casing are wrought aluminum alloys, preferably an AA3xxx or AA5xxx aluminum alloy. However, other wrought aluminum alloys with high mechanical yield strengths are also possible.A preferred aluminum alloy of the battery cell housing shell 8 has the following alloy components by weight: 0.1% ≤ Si ≤ 0.5%, preferably 0.2% ≤ Si ≤ 0.4%, 0.20% ≤ Fe ≤ 0.8%, preferably 0.40% ≤ Fe ≤ 0.6%, Cu ≤ 0.6%, preferably 0.10% ≤ Cu ≤ 0.30%, 0.3% ≤ Mn ≤ 1.4%, preferably 0.50% ≤ Mn ≤ 1.1%, 0.01% ≤ Mg ≤ 1.5%, preferably 0.05% ≤ Mg ≤ 1.30% or preferably 0.30% ≤ Mg ≤. 1,20 %, Cr ≤ 0.25%, preferably Cr ≤ 0.1%, Zn ≤ 0.4%, Ti ≤ 0.2%, preferably 0.005 wt% ≤ Ti ≤ 0.1 wt% or preferably 0.005 wt% ≤ Ti ≤ 0.05 wt%, balance Al and unavoidable impurities, individually maximum 0.05%, in total maximum 0.15%.Z I / ZI 230389WOMay 22, 2024 The aluminum alloy of the battery cell casing shell 8 has a high recycling potential and provides high strength and, at the same time, good forming behavior with high corrosion resistance and good weldability. Another preferred aluminum alloy for the highest strength requirements of the battery cell casing shell 8 has the following alloy components by weight: Si < 0.3%, Fe < 0.4%, Cu < 0.2%, Mn < 0.8%, 2.5% < Mg < 6.0%, preferably 3% < Mg < 6.0%, Cr < 0.2%, Zn < 0.25%, Ti ≤ 0.1%, preferably 0.001% ≤ Ti ≤ 0.1%, balance Al and unavoidable impurities, individually a maximum of 0.05% and in total a maximum of 0.15%. It enables a further increase in the strength of the battery cell housing shell, which can then also assume the functions of a structural component. The embodiment shown in Fig. 2 has a battery cell housing cover 9 with an opening for the passage of an electrical terminal 10 of the battery cell. The embodiment shown in Fig.4, on the other hand, has a battery cell housing base 11, which provides the opening for the electrical contact 10. In the embodiment shown in Fig. 4, the battery cell housing cover 9 is arranged opposite the electrical contact, so that the pressure relief through the battery cell housing cover 9 occurs in the opposite direction to the electrical contact 10. In both variants, however, the pressure relief takes place exclusively via the battery cell housing cover 9, so that it occurs in the axial direction of the battery cell housing 7, thus preventing "thermal runaway." I / ZI 230389WOMay 22, 2024 The wall thicknesses of the material of the battery cell housing shell 8 in the present embodiments of Figs. 2 and 4 are between 0.2 mm and 1.5 mm, preferably 0.3 mm to 1.2 mm, and / or the wall thicknesses of the material of the battery cell housing cover 9 are between 0.3 mm and 2.0 mm, preferably between 0.4 mm and 1.5 mm. This achieves sufficient internal pressure stability of the battery cell housing 7. For a cylindrical battery cell housing 7, various alloys were investigated using mechanical properties to determine material combinations for the battery cell housing shell 8 and the battery cell housing cover 9 that ensure pressure relief exclusively via the battery cell housing cover 9. As soon as the condition from equations (4a, b) was met, the material combination was designated as suitable.In order to take into account the anisotropy of the plastic properties of the sheet materials in the simplest possible way, mean values ​​( ^^p0,2)avg,( ^^m)avg and. for the yield strength ^^p0.2, the tensile strength ^^m or the uniform elongation ^^g over the three directions 0°, 45° and 90° to the rolling direction according to the relationship known from sheet metal forming ^^ 1 avg = ∙(^^0° + 2^^45° +^^90°) are taken into account, whereby the value at 45° must be considered twice in the averaging process and “^^” is a placeholder for one of the quantities ^^p0.2, ^^m or ^^g. All mechanical properties are specified or measured according to DIN EN ISO6892-1. Table 2 shows the compatibility of various aluminum alloys with a battery cell casing 8 comprising an aluminum alloy of type AA 3104 in the temper H19. As can be seen from Table 2, the materials made of an aluminum alloy of type AA3003 in the temper H24, in the temper H14Z I / ZI 230389WOMay 22, 2024 or an aluminum alloy AA1050-H19 for a pressure-relieving battery cell housing cover 9 in combination with the aluminum alloy type 3104 in temper H19 for the battery cell housing shell 8, since these material combinations fulfill the condition in equation (4a,b). Regardless of this result, for a battery cell housing type 4680 with an inner radius Ri of 23 mm, all materials in combination with the aluminum alloy AA3104-H19 for the battery cell housing shell 8 ensure sufficient internal pressure stability of at least 8 bar, as shown in Table 3. The values ​​for the permissible internal pressure pzul were determined using equation (14) using the specified wall thicknesses sD = 0.8 mm and sM = 0.75 mm. If other alloys are used as material for the battery cell housing shell 8, different material combinations result which are suitable for effecting pressure relief exclusively via the battery cell housing cover.Combinations of the materials listed in Table 2 are considered, from which the values ​​for the permissible internal pressure ^^zul for various materials of the battery cell casing shell 8 calculated in Tables 3a and 3b using equation (14) were calculated using the wall thicknesses specified in Tables 3a and 3b. In all cases, ^^zul > 0.5 ^^ ^^ ^^ (5 bar) is guaranteed. A minimum of 0.7 MPa (7 bar) is not achieved by every material combination. Tables 4 and 5 summarize the respective differences ( ^^p0,2,avg)D,zul − ( ^^p0,2,avg)D with ( ^^p0,2,avg)D,zul calculated for the combinations of the materials listed in Table 2 using equation (4b). Only material combinations that have a difference value greater than zero are considered suitable. I / ZI 230389WOMay 22, 2024 Table 2 Alloy Directional mean values ​​Maximum permissible Rp0.2 difference Pressure relief exclusively via battery cell case cover Condition Rp0.2,avg [MPa] Rm,avg [MPa] Ag,avg [%] (Rp0.2,avg)zul [MPa] (Rp0.2,avg)zul - Rp0.2,avg [MPa] 3104 H19 279.3 301.2 2.93 279.3 0.00 Sheath material 3003 H24 146.4 158.0 2.81 279.3 132.9 Ja1050 H19 167.5 177.8 1.83 279.3 111.8 Ja3003 H14 171.0 177.8 0.93 279.3 108.3 Yes3005 H14 182.9 192.8 1.48 279.3 96.4 Yes5005 H22 122.8 144.5 7.83 72.9 -50.0 No 1050 O 46.1 84.8 31.03 -30.0 -76.1 No3003 O 50.0 118.7 24.52 -49.2 -99.2 No5182 H48 389.5 415.4 1.67 279.3 -110.2 No3104 H24 236.2 270.7 5.48 39.9 -196.3 No5182-G O 148.1 287.3 22.42 -211.3 -359.4 NoZ I / ZI 230389WO May 22, 2024

[0002] Table 3a COVER MATERIAL 3104-H19 3003-H24 1050-H19 3003-H14 3005-H14 5005A-H22 1050-O 3003-O 5182-H48 3104-H24 5182-O 3104-H19 21.3 11.8 13.1 13.0 14.2 11.3 8.1 10.7 24.9 20.5 22.7 3003-H24 15.5 11.2 11.8 11.8 12.3 11.0 8.1 10.7 18.0 14.8 16.5 F 1050-H19 16.5 11.8 12.6 12.6 13.1 11.3 8.1 10.7 19.3 15.9 17.6 FOT 3003-H14 16.7 11.8 12.8 12.7 13.3 11.3 8.1 10.7 19.5 16.0 17.8 SK 3005-H14 17.3 11.8 13.1 13.0 13.7 11.3 8.1 10.7 20.2 16.6 18.4 R E W 5005A-H22 14.2 10.2 10.8 10.8 11.2 10.0 8.1 9.8 16.5 13.6 15.1 - L E T 1050-O 8.7 6.3 6.6 6.6 6.9 6.1 5.2 6.0 10.1 8.3 9.2 N A 3003-O 9.0 6.5 6.9 6.9 7.2 6.4 5.4 6.2 10.5 8.7 9.6 M 5182-H48 22.5 11.8 13.1 13.0 14.2 11.3 8.1 10.7 29.4 20.7 25.5 3104-H24 19.6 11.8 13.1 13.0 14.2 11.3 8.1 10.7 22.9 18.8 20.9 5182-O 15.5 11.2 11.9 11.8 12.3 11.0 8.1 10.7 18.1 14.9 16.6Calculated permissible pressure ^^zul [bar] for the following geometric parameters of the battery cell: ^^i = 23 mm, ^^D = 0.8 mm, ^^M = 0.75 mmZI / ZI 230389WO 22. Mai 2024

[0003] Tabelle 3b DECKEL-WERKSTOFF 3104-H19 3003-H24 1050-H19 3003-H14 3005-H14 5005A-H22 1050-O 3003-O 5182-H48 3104-H24 5182-O 3104-H19 26,6 14,7 16,4 16,2 17,7 14,1 10,0 13,4 31,0 25,5 28,3 3003-H24 19,2 13,9 14,7 14,6 15,3 13,6 10,0 13,3 22,5 18,5 20,5 F 1050-H19 20,6 14,7 15,7 15,7 16,4 14,1 10,0 13,4 24,0 19,8 21,9 F O T 3003-H14 20,8 14,7 15,9 15,8 16,5 14,1 10,0 13,4 24,3 20,0 22,2 S K 3005-H14 21,5 14,7 16,4 16,2 17,1 14,1 10,0 13,4 25,1 20,6 22,9 R E W 5005A-H22 17,6 12,8 13,5 13,4 14,0 12,5 10,0 12,2 20,6 16,9 18,8 - L E T 1050-O 10,8 7,8 8,3 8,2 8,6 7,7 6,5 7,5 12,6 10,4 11,5 N A3003-O 11.2 8.1 8.6 8.6 8.9 8.0 6.7 7.8 13.1 10.8 12.0 M 5182-H48 28.0 14.7 16.4 16.2 17.7 14.1 10.0 13.4 36.6 25.8 31.8 3104-H24 24.4 14.7 16.4 16.2 17.7 14.1 10.0 13.4 28.5 23.5 26.0 5182-O 19.4 14.0 14.8 14.7 15.4 13.7 10.0 13.4 22.6 18.6 20.6Calculated permissible pressure ^^zul [bar] for the following geometric parameters of the battery cell: ^^i = 10.5 mm, ^^D = 0.45 mm, ^^M = 0.35 mmZ I / ZI 230389WO May 22, 2024

[0004] Table 4 COVER MATERIAL 3104-H19 3003-H24 1050-H19 3003-H14 3005-H14 5005A-H22 1050-O 3003-O 5182-H48 3104-H24 5182-O 3104-H19 0.0 132.9 111.8 108.3 96.4 -50.0 -76.0 -99.2 -110.2 -196.3 -359.4 3003-H24 -289.1 0.0 -21.1 -24.6 -36.5 -158.2 -103.4 -133.8 -292.0 -350.9 -397.2 F F 1050-H19 -364.7 -79.0 0.0 -3.5 -15.4 -186.5 -110.5 -142.8 -425.1 -391.4 -407.1 OT S3003-H14 -469.5 -188.5 -167.7 0.0 -155.1 -225.8 -120.4 -155.4 -609.6 -447.5 -420.8 KR 3005-H14 -391.6 -107.1 -42.9 11.9 0.0 -196.6 -113.1 -146.1 -472.4 -405.8 -410.6 EW 5005A-H22 -156.5 -23.6 -44.7 -48.2 -60.1 0.0 -63.4 -83.3 -266.7 -124.9 -341.9 - L E 1050-O -233.3 -100.3 -121.4 -124.9 -136.8 -76.8 0.0 -3.9 -343.4 -190.1 -254.1 TN 3003-O -229.3 -96.4 -117.5 -121.0 -132.9 -72.8 2.3 0.0 -339.5 -186.2 -250.9 AM 5182-H48 -123.2 173.3 222.0 218.5 206.6 -96.1 -87.7 -113.9 0.0 -262.2 -375.5 3104-H24 -43.2 89.8 68.7 65.2 53.3 87.4 -41.4 -55.3 -153.3 0.0 -311.4 5182-O -131.3 1.7 -19.4 -22.9 -34.8 25.2 102.0 98.1 -241.4 -88.1 0.0The numerical values ​​correspond to the difference ( ^^p0.2,avg)D,zul − ( ^^p0.2,avg)D [MPa] of the respective material combination.Z I / ZI 230389WO May 22, 2024

[0005] Table 5 LID MATERIAL 3104-H19 3003-H24 1050-H19 3003-H14 3005-H14 5005A-H22 1050-O 3003-O 5182-H48 3104-H24 5182-O 3104-H19 n.io. inventive inventive inventive inventive according to according to according to n.io. n.io. n.io. n.io. n.io. n.io. n.io. 3003-H24 n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. 1050-H19 n.io. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. 3003-H14 n.io. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. F F O3005-H14 n.io. n.io. n.io. according to the invention n.io. n.io. n.io. n.io. n.io. n.io. n.io.T S ß KR E W 5005A-H22 not ok n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. n.i.o. - L E T N A1050-O n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. n.io. M 3003-O n.io. n.io. n.io. n.io. n.io. n.io. according to the invention n.io. n.io. n.io. n.io.5182-H48 n.io. according to the invention ... n.io.3104-H24 n.io. inventive device according to the invention according to the invention according to the invention according to n.io. n.io. n.io. n.io. n.io. n.io. n.io.5182-O n.io. inventive device according to the invention according to n.io. n.io. n.io. according to n.io. n.io. n.io.Z I / ZI 230389WO May 22, 2024

Claims

May 22, 2024 Patent Claims 1. Cylindrical battery cell housing (7) of a battery cell with a battery cell housing shell (8) with at least partially cylindrical cross-section comprising a first material made of an aluminum alloy, characterized in that the battery cell housing shell (8) is non-positively and / or materially connected to at least one battery cell housing cover (9) comprising a second material made of an aluminum alloy, wherein the at least one battery cell housing cover (9) is designed as a sheet metal blank, and the sheet metal blank, due to its mechanical properties, is designed as a pressure relief means of the battery cell housing (7), so that when a permissible internal pressure (p) of the battery cell is exceeded, the at least one battery cell housing cover (9) ensures pressure relief of the battery cell in the axial direction. 2.Battery cell housing according to claim 1, characterized in that the material of the battery cell housing shell (8) differs from the material of the at least one battery housing cover (9) in the tempered state of the aluminum alloy and / or in the alloy composition.

3. Battery cell housing according to claim 1 or 2, characterized in that the at least one battery cell housing cover (9) is integrally connected to the battery cell housing shell (8) via a weld seam, preferably via a laser weld seam. - 2 -4. Battery cell housing according to one of claims 1 to 3, characterized in that the yield strength ( ^^p0,2)D of the material of the at least one battery cell housing cover (9) satisfies the condition with ( ^^ p0,2 ) M: Yield strength of the battery cell casing shell, : Uniform elongation of the battery cell casing shell, : Uniform elongation of the battery cell casing cover, Product of tensile strength and uniform elongation of the battery cell casing shell,∙ ^^ g ) D : Product of tensile strength and uniform elongation of the battery cell housing cover, erfüllt.

5. Battery cell housing according to one of claims 1 to 4, characterized in that the wall thickness ^^D of the battery cell housing cover (9) is: with ^^ M : Wall thickness of battery cell casing, ^^ D : Wall thickness of battery cell housing cover, ^^ ∗ : Specified internal pressure in the battery cell casing at the time of Z I / ZI 230389WO May 22, 2024 - 3 - Failure of the cover, D: Index battery cell housing cover M: Index battery cell housing shell.

6. Battery cell housing according to one of claims 1 to 5, characterized in that the battery cell housing cover (9) provided for pressure relief triggers pressure relief of the battery cell housing (7) at an internal pressure of 0.5 MPa to 2.5 MPa, preferably 0.7 MPa to 2.0 MPa, particularly preferably 0.7 MPa to 1.5 MPa.

7. Battery cell housing according to one of claims 1 to 6, characterized in that the battery cell housing shell (8) has a yield strength ^^p0.2 of more than 100 MPa, preferably more than 150 MPa, particularly preferably more than 180 MPa. aufweist.

8. Battery cell housing according to one of claims 1 to 7, characterized in that the battery cell housing shell (8) comprises a wrought aluminum alloy, preferably a wrought aluminum alloy of type AA3xxx or type AA5xxx.

9. Battery cell housing according to one of claims 1 to 8, characterized in that the battery cell housing shell (8) comprises an aluminum alloy with the following alloying constituents by weight: 0.1% ≤ Si ≤ 0.5%, preferably 0.2% ≤ Si ≤ 0.4%, 0.20% ≤ Fe ≤ 0.8%, preferably 0.40% ≤ Fe ≤ 0.6%, Cu ≤ 0.6%, preferably 0.10% ≤ Cu ≤ 0.30%, 0.3% ≤ Mn ≤ 1.4%, preferably 0.50% ≤ Mn ≤ 1.1%, 0.01% ≤ Mg ≤ 1.5%, preferably 0.05% ≤ Mg ≤ 1.30% or preferably 0.30% ≤ Mg ≤ 1.20%, Z I / ZI 230389WO May 22, 2024 - 4 - Cr ≤ 0.25%, preferably Cr ≤ 0.1%, Zn ≤ 0.4%, Ti ≤ 0.2%, preferably 0.005 wt.% ≤ Ti ≤ 0.1 wt.% or preferably 0.005 wt.% ≤ Ti ≤ 0.05 wt.%.

10. Battery cell housing according to one of claims 1 to 9, characterized in that the battery cell housing shell (8) comprises an aluminum alloy with the following alloying constituents in wt.%:S i < 0,3 %,Fe < 0.4%, Cu < 0.2%, Mn < 0.8%, 2.5% < Mg < 6.0%, preferably 3% < Mg < 6.0%, Cr < 0.2%, Zn < 0.25%, Ti ≤ 0.15%, preferably 0.001% ≤ Ti ≤ 0.1%, remainder Al and unavoidable impurities, individually a maximum of 0.05%, in total a maximum of 0.15%.

11. Battery cell housing according to one of claims 1 to 10, characterized in that the at least one battery cell housing cover (9) comprises a wrought aluminum alloy of the type AA1xxx, AA8xxx or AA3xxx, wherein the material of the battery cell housing cover (9) preferably has the temper state H24, H14, H18 or H19.

12. Battery cell housing according to one of claims 1 to 11, characterized in that the battery cell housing cover (9) comprises an aluminum alloy with the following alloying components in wt.%:Z I / ZI 230389WO May 22, 2024 - 5 - 0.1% ≤ Si ≤ 0.5%, Fe ≤ 0.8%, preferably 0.20% ≤ Fe ≤ 0.8%, Cu ≤ 0.3%, Mn ≤ 1.4%, 0.005% ≤ Mg ≤ 0.8%, preferably 0.01% ≤ Mg ≤ 0.5%, more preferably 0.01% ≤ Mg ≤ 0.3%, Cr ≤ 0.25%, Zn ≤ 0.4%, T i ≤ 0,2 %, Rest Al and unavoidable impurities, individually maximum 0.05%, inS umme maximal 0,15 %.

13. Battery cell housing according to one of claims 1 to 12, characterized in that the battery cell housing (7) has an inner radius of at least 15 mm, preferably at least 18 mm.

14. Battery cell housing according to one of claims 1 to 13, characterized in that the battery cell housing (7) has a cup-shaped, cylindrical battery cell housing shell (8) with a battery cell housing base (11) and a battery cell housing cover (9) or has a tubular, cylindrical battery cell housing shell with two battery cell housing covers (9), wherein optionally, in addition to the battery cell housing cover (9) designed as a pressure relief means, at least one further pressure relief means, preferably at least one further bursting element for axial pressure relief of the battery cell housing (7) is provided.Battery cell housing according to one of claims 1 to 14, characterized in that the battery cell housing (7) has a battery cell housing cover (9) or aZ. I / ZI 230389WO May 22, 2024 - 6 - Battery cell housing base (11) with an opening for the passage of an electrical pole of the battery cell, wherein the passed electrical pole is electrically insulated from the battery cell housing base (11) and / or cover (9).

16. Battery cell housing according to one of claims 1 to 15, characterized in that the wall thickness of the material of the battery cell housing shell (8) is between 0.2 mm and 1.5 mm, preferably 0.3 mm to 1.2 mm, and / or the wall thickness of the material of the battery cell housing cover (9) is between 0.3 mm and 2.0 mm, preferably between 0.4 mm and 1.5 mm. I / ZI 230389WO May 22, 2024

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