Battery device

Abstract

The invention relates to a battery device. The battery device has a housing, a core structure (10) arranged in the housing, a first interior space (14) in the housing configured for a cooling liquid (22) to flow through, a second interior space (16) in the housing, a phase change material (24) and at least one battery cell (18). The core structure (12) separates the first interior space (14) from the second interior space (16). The core structure (10) has a wall (12) configured substantially in the form of a triple periodic minimal curved surface. A phase change material (24) is arranged in the second interior space (16). At least one battery cell (18) is arranged in the first interior space (14) or the second interior space (16).

Description

Technical Field

[0001] The invention relates to a battery device. Background Art

[0002] In modern applications, batteries have to deliver large currents, for example as energy storage in electric cars or drones. However, this causes the individual battery cells to heat up rapidly. Batteries have an optimal operating temperature range, for example close to room temperature. Within this temperature range, the battery can be particularly powerful. In contrast, at temperatures that are too high or too low, the battery degrades faster. If the maximum temperature is exceeded, the battery may even ignite, which is also known as thermal runaway. The temperature is therefore usually controlled by a temperature control system.

[0003] Temperature control systems for batteries can be divided according to two operating principles. Active cooling allows the operating temperature of the battery to be set, for example by means of an adjustable coolant flow. However, active cooling requires energy, so the system efficiency is reduced. In addition, cooling or heating of the battery by the surroundings during shutdown cannot be avoided. In the case of passive cooling, no energy is consumed, but the operating temperature cannot always be kept within the desired range. Overall, battery cooling requires additional installation space and can be very heavy. Depending on the climate zone, the battery can also be heated intentionally. Heating can also take place actively or passively.

[0004] In US 2013 / 00844871 A1, a battery with a phase change material is described.

[0005] US Pat. No. 7,866,377 B2 describes the use of extremely small curved surfaces in heat exchangers. Summary of the invention

[0006] A first aspect of the invention relates to a battery device. The battery device can be configured, for example, for use in a motor vehicle, such as an electric vehicle. The battery device can be configured as a battery storage facility in a building, in particular in a wall box for charging electric vehicles. The battery device can also be used, for example, in drones, electric motorcycles, etc. The battery device can be configured as an energy storage for electrical energy. The battery device can be configured for multiple charging and discharging.

[0007] The battery device may have a housing. The housing may define a housing interior. The housing may be made, for example, of plastic or metal. The housing may have a plurality of wall elements or may also be configured as an integral, one-piece element. The housing may protect the respective other elements of the battery device from environmental influences and, for example, enable fastening, in particular in a vehicle and / or in a building. The battery device may have electrical contacts.

[0008] The battery device has a core structure arranged in the shell. The core structure can be configured to divide the inner space of the shell into at least two subspaces. The core structure can provide an additional protection function to protect the battery cell from mechanical influences. The core structure can form a load-bearing structure. The core structure can, for example, be permanently connected to the shell, or can be configured as an integral single-piece element. Due to the connection with the shell, the core structure can support the shell, thereby additionally playing the role of reinforcing the shell.

[0009] The battery device has a first interior space in the housing. The first interior space is configured for a coolant to flow through. To this end, the first interior space may have one or more inlet openings, in particular configured as through holes in the housing. Thus, the coolant can flow through the first interior space. The battery device may have, for example, a pump device for conveying the coolant through the first interior space, which pump device may be arranged inside or outside the housing. In addition, a heat exchanger may be provided, in particular outside the housing, for example for cooling the coolant. Alternatively or additionally, the battery device may have a heater, for example in order to heat the coolant. Therefore, the battery device may have an active temperature control function, in particular at least configured with a cooling function, in order to reliably keep the operating temperature within a desired range. Alternatively or additionally, depending on the ambient temperature, the battery device may also be heated by a coolant. The coolant may be, for example, air, water or a water-glycol mixture.

[0010] The battery device has a second internal space in the housing. The second internal space can be separated from the first internal space fluid, for example. The battery device has a phase change material. The phase change material is arranged in the second internal space. Therefore, mixing with the coolant can be avoided. The phase change material can have a high melting enthalpy. The phase change material can be paraffin, for example. Another example of a phase change material is an aluminum silicon alloy. Other examples of phase change materials exist in the fields of, for example, salt hydrates, alcohols, fatty acids and salts. In addition, flame retardant additives can also be added to the phase change material. The phase change material can be selected so that it changes between two phases (particularly liquid and solid) within or close to the operating temperature range required for the battery device. The phase change material can have a higher effective thermal mass, thereby greatly increasing the thermal inertia of the battery device. Therefore, it can prevent or at least slow down the unexpected faster and / or higher temperature rise or temperature drop. Therefore, it is easier to maintain the desired operating temperature of the battery device. In addition, the size of the active cooling can be smaller because it no longer needs to absorb the corresponding thermal reaction of the battery separately. The phase change material can suppress load peaks and reduce the burden on active cooling and / or heaters. Furthermore, even during shutdown, that is to say, for example, when the battery device is switched off, the phase change material can maintain the temperature of the battery device better than without the phase change material or maintain the temperature of the battery device with less mass and volume. As a result, the service life of the battery device can be longer. Due to the phase change material, the battery device can be particularly light, since the dimensions of the corresponding active cooling components can be smaller. In addition, the efficiency of the system with such a battery device can be higher, since less energy may be required for active cooling. Since the battery device can be better kept within its optimal operating temperature range, the service life of the battery device can also be particularly long.

[0011] The battery device has at least one battery cell. The battery cell can be configured as a primary cell, for example. The battery cell can be an electrochemical energy storage and an energy converter. The battery cell can be, for example, a cylindrical battery cell, a prismatic battery cell or a pouch-shaped battery cell. The battery device can have a plurality of battery cells, which can be arranged in a housing in a specific packaging manner. For example, the battery cells can be evenly arranged at a specific distance from each other on a plane. All battery cells of the battery device can be configured identically. However, the battery device can also have two or more different battery cell types. In the following, for simplicity, reference will be made to battery cells, where applicable, this may also always refer to a plurality of or all battery cells.

[0012] The core structure separates the first interior space from the second interior space. The core structure can form a partition wall in the interior space of the shell. The partition can be fluid-tight, especially for phase change materials and coolants. The core structure has a wall constructed essentially in the form of a triple periodic minimum surface. The partition wall can partially or completely define at least one of the two interior spaces. The partition wall can also at least partially or completely define the two interior spaces. The triple periodic minimum surface can have an asymmetric crystal structure. The triple periodic minimum surface can have no interface. The details of the triple periodic minimum surface will be further explained below. The triple periodic minimum surface can form a particularly large surface area, so that heat can be particularly well and evenly transferred between the two interior spaces. The triple periodic minimum surface can form an associated recess for each battery cell, for example in the second interior space. The wall of the core structure can be formed by, for example, a metal material or a plastic. The triple periodic minimum surface can be combined with the shell to form two channels. Heat can be transferred particularly well between the coolant and the phase change material via the triple periodic minimal surfaces. Therefore, the combination of active cooling and thermal damping of the phase change material can be particularly effective. The phase change material can also prevent thermal runaway particularly well.

[0013] At least one battery cell is arranged in the first interior space or in the second interior space. Due to the arrangement of the battery cells in the second interior space, undesired rapid heating and cooling of the battery cells can be particularly well suppressed by the phase change material. As a result, each battery cell can be kept within the desired operating temperature range with only a particularly small amount of active temperature control. Due to the arrangement of the battery cells in the first interior space, the operating temperature of the battery cells can be set particularly accurately and reliably. However, the phase change material can suppress thermal load peaks.

[0014] In one embodiment of the battery device, the first interior space and / or the second interior space are bounded on one side by a covering layer. The covering layer can be formed by, for example, a part of the housing. On the opposite side, the first interior space and / or the second interior space can be bounded by another covering layer. The other covering layer can also be formed, for example, by a part of the housing. The covering layer can be connected to the core structure. Each covering layer can be non-conductive. Each covering layer can be formed as a plate, for example, made of an electrically insulating material. Each covering layer can also be formed, for example, by a composite material, and therefore has a particularly mechanical resistance. The covering layer can be locally adjacent to the core structure and / or form a sandwich structure with the core structure. Therefore, the battery device can be configured as a load-bearing structure. Therefore, for example, a reinforcement for mounting the battery device can be omitted in a vehicle. Therefore, the battery device can be configured as a load-bearing part of a chassis, for example. The covering layer can be located on the opposite side of a wall, for example, the wall is configured as a triple periodic minimal surface, and therefore defines or completely encloses the corresponding recess for the battery cell on the upper and lower sides. The covering layer can be connected to the core structure, for example, by a joining method (for example, welding, bonding or soldering). However, the two cover layers can also be connected to each other (for example by screwing) and clamp the core structure between them. The two cover layers can also be pressed against the core structure by the housing.

[0015] In one embodiment of the battery device, at least one cover layer has at least one through hole for contacting a battery contact of a battery cell and / or for the flow of a coolant. Separate through holes can also be provided for the flow of coolant and electrical contact. For example, the through hole can be aligned with a recess of a battery cell. An associated through hole can be provided for each battery cell. The through hole can be provided only in one or two cover layers. One or more pipelines, such as power lines and / or fluid lines, can be guided through the through hole. The through hole can be additionally sealed. Thus, a fluid and / or an electric current can be introduced into and out of the first interior space and / or the second interior space.

[0016] In one embodiment of the battery device, at least one covering layer has a conductive path in contact with the battery cell, in particular wherein the conductive path is arranged on the outside of the covering layer. For example, the conductive path can be connected to the battery cell via a through hole. An associated conductive path can be provided for each battery cell. However, the conductive path can also be electrically connected to one or more battery cells, for example. The conductive path can be fixed on the covering layer. The conductive path can also be formed integrally with the covering layer, for example by etching or depositing on the covering layer. As a result of the conductive path, an electrical connection to the individual battery cells can be provided in a compact, robust and space-saving manner.

[0017] In one embodiment of the battery device, the core structure is manufactured by an additive method. For example, the core structure can be produced using metal 3D printing technology. Therefore, complex walls can be manufactured in a particularly simple way in the form of triple periodic minimal surfaces, especially in one step and / or as an integral single-piece element. For example, large undercuts can therefore also be manufactured in a simple way. Alternatively or additionally, the core structure can have been manufactured using a casting method. For example, two semi-finished products manufactured in a casting process can form the core structure. Therefore, a particularly large core structure can be manufactured cost-effectively. Alternatively or additionally, the core structure can also be manufactured using a machining method. For example, two semi-finished products manufactured using a milling method can form the core structure. Therefore, a particularly durable core structure can be provided. Alternatively or additionally, the core structure can be manufactured using a forming method. For example, two semi-finished products manufactured from a sheet material using a deep drawing process can form the core structure. Therefore, a particularly cost-effective large-scale production can be achieved.

[0018] In one embodiment of the battery device, the core structure is formed by two semi-finished products joined to each other. For example, the core structure can be formed by an upper shell and a lower shell, between which corresponding recesses for the battery cells are formed. Thus, the manufacture can be particularly simple, in particular because undercuts in the semi-finished products can be avoided. In addition, the battery cells can thus be inserted into the recesses in a particularly simple manner. The semi-finished products can be symmetrical to each other. For example, the core structure can also have three or more semi-finished products connected to each other. The semi-finished products can be connected to each other, for example, by a joining method (for example, welding, bonding or soldering).

[0019] In one embodiment of the battery device, the core structure further has a first grid structure arranged in the first inner space. The first grid structure can increase the load-bearing capacity of the battery device. For example, the first grid structure can support the core structure on the housing and / or the cover layer and connect them to each other. In addition, the first grid structure can increase thermal conductivity, in particular by increasing the surface area around which the coolant flows. Preferably, the first grid structure is a coarse grid structure with a large distance between the individual grid rods so as to maintain a low pressure loss when the coolant flows through the first inner space.

[0020] In one embodiment of the battery device, the core structure also has a second grid structure arranged in the second inner space. The second grid structure can serve as a substitute or supplement to the first grid structure. The second grid structure can increase the load-bearing capacity of the battery device. For example, the second grid structure can support the core structure on the housing and / or the covering layer and connect them to each other. The second grid structure can also increase the mechanical resistance of the core structure itself, for example, because different wall areas in the recesses for the battery cells are connected to each other via the second grid structure. The second grid structure can also, for example, retain the battery cells, in particular when the phase change material changes to its liquid state. In addition, the second grid structure can increase thermal conductivity, in particular by increasing the surface area contacted by the phase change material. Preferably, the second grid structure is a fine grid structure with a smaller distance between the individual grid bars in order to provide a particularly large surface area for heat transfer.

[0021] The first grid structure may be different from the second grid structure. For example, the second grid structure may be finer than the first grid structure. Alternatively or additionally, the corresponding grid bars of the first grid structure may have a different thickness than the corresponding grid bars of the second grid structure. The grid structure may, for example, be formed by a plurality of intersecting grid bars.

[0022] In one embodiment of the battery device, the core structure is configured as a double-walled structure with another wall. The other wall can also be constructed in the form of a triple periodic minimal surface. In the case of a double-walled core structure, the two walls can be arranged substantially parallel to each other. For example, the basic shape of the two walls can be the same. The two walls can be offset relative to each other. One of the two walls can be smaller and, for example, arranged between the other wall and the second inner space. The intermediate space can be formed between the two walls of the core structure. The double-walled core structure may be particularly strong. Another phase change material can be arranged in another intermediate space. The phase change material can have a different melting point from the phase change material in the second inner space to further stabilize the operating temperature. For example, one of the phase change materials can melt at the upper limit of the desired operating temperature range, while the other phase change material can melt at the desired lower limit of the desired operating temperature range. Alternatively, the intermediate space can be configured for a coolant to flow through. Therefore, active cooling can be performed in a particularly variable manner, such as using different coolants in the intermediate space and the first inner space. For example, a constant coolant volume flow rate can flow through the first inner space, and once the phase change material starts to melt, the coolant only flows through the intermediate space.

[0023] In one embodiment of the battery device, the intermediate space is configured for a coolant to flow through, and / or for a phase change material to be arranged in the intermediate space.

[0024] In one embodiment of the battery device, the core structure also has a third grid structure arranged in the middle space. The third grid structure can fasten and support the two walls of the double-wall core structure to each other. The two walls of the core structure can be connected to each other by the third grid structure. Therefore, the core structure is particularly durable and can withstand higher mechanical loads. However, alternatively, the two walls can also be arranged adjacent to each other, for example, in a self-supporting manner. The third grid structure can improve the heat transfer between the two walls of the core structure and the heat transfer to the material in the middle space.

[0025] In one embodiment of the battery device, the walls of the core structure are formed as Schwarz-P surfaces. The Schwarz-P surface naturally forms a geometric shape that spans two independent spaces, thereby forming a recess for a cylindrical battery. For example, in a three-dimensional Cartesian coordinate system with coordinates x, y, and z, the Schwarz-P surface can be approximated by the formula cos(x)+cos(y)+cos(Z)=0. By inserting more parameters, the geometry can be compressed or stretched to adapt it to batteries of different shapes. The formula cos(a*x)+cos(b*y)+cos(c*z)=0 can be used as an approximation. However, the Schwarz-P surface can also be accurately determined by solving the Weierstrass-Enneper formula.

[0026] In one embodiment of the battery device, the walls of the core structure are determined in a manner suitable for the shape of the battery cell. For example, the walls of the core structure may have hexagonal symmetry. Thus, a suitable shape with a matching recess may be provided for a particular battery cell.

[0027] According to another aspect of the invention, a method for determining the shape of a wall of a core structure of a battery device, in particular a method for determining the shape of one of the walls of the core structure of a battery device, is provided. The method may comprise the step of selecting a cell shape of each cell of the battery device. The method may comprise the step of defining an arrangement of the cells in a desired package, in particular in a plane. The method may comprise the step of identifying a symmetry plane in a defined arrangement of the cells. The method may comprise the step of reducing the cell surface in the defined arrangement to a minimum symmetry cell. The method may comprise the step of selecting a contact surface of the cell with the wall. The method may comprise the step of defining a contact line on the selected contact surface. The method may comprise the step of defining the spatial position of the contact line. The method may comprise the step of determining the shape of the wall as a substantially triple periodic minimal surface as a function of the defined spatial position of the contact line and a function of the determined symmetry plane. Thus, a triple periodic minimal surface specific to the battery device may be determined in a simple manner. The step of determining the shape of the wall as a substantially triple periodic minimal surface may comprise converting the attachment surface formed by the defined contact line into a grid of prestressed spring elements and mass points in order to determine a spring-mass system. The step of determining the shape of the wall as a substantially triply periodic minimal surface may include a dynamic simulation of a spring-mass system until an equilibrium position is reached. For example, an extended finite element method solver such as ABAQUS / explicit is suitable for this purpose. The step of determining the shape of the wall as a substantially triply periodic minimal surface may include converting the equilibrium position into a geometric surface in order to determine the minimal surface. The step of determining the shape of the wall as a substantially triply periodic minimal surface may include mirroring the geometric surface on all identified symmetry planes in order to create cells of the triply periodic minimal surface. The step of determining the shape of the wall as a substantially triply periodic minimal surface may include periodically placing the generated batteries relative to each other according to the arrangement of the battery cells in the desired package in order to determine the shape of the wall of the core structure.

[0028] In one embodiment of the battery device, the shape of the walls of the core structure, in particular the shape of the walls separating the two inner spaces from each other, matches the shape of the battery cell. As a result, the battery device can be particularly compact. For example, the corresponding recess in the second inner space can be adapted to the shape of the battery cell. In particular, the cross section of the recess can correspond to the cross section of the battery cell. For example, the shape of the walls of the core structure can match the cylindrical or prismatic shape of the battery cell, or match the battery cell configured as a pouch-shaped cell.

[0029] In one embodiment of the battery device, the battery device has a pump device, which is configured to convey a cooling liquid through the first inner space. For example, the pump device can be connected to the first inner space via one or more through holes in at least one cover layer. If the core structure is configured as a double wall, the pump device can also be configured to convey a cooling liquid through the intermediate space. The pump device can, for example, have a pump. The battery device can also have a cooling liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A first exemplary embodiment of a core structure of a battery arrangement is shown in a schematic perspective view.

[0031] Figure 2 A schematic perspective view shows how a cooling fluid flows around a first exemplary embodiment of a core structure of a battery arrangement.

[0032] Figure 3 A schematic cross-sectional view shows how a first embodiment of a core structure of a battery device accommodates corresponding battery cells and phase change materials.

[0033] Figure 4 Another schematic cross-sectional view shows how a first embodiment of the core structure of a battery device accommodates corresponding battery cells and phase change materials.

[0034] Figure 5 A first exemplary embodiment of how a core structure can be produced by a deep drawing method is shown in a schematic perspective view.

[0035] Figure 6 A second exemplary embodiment of a core structure of a battery arrangement with an additional grid structure is shown in a schematic perspective view.

[0036] Figure 7 A schematic sectional view shows a grid structure of a second exemplary embodiment of a core structure of a battery arrangement.

[0037] Figure 8 A third exemplary embodiment of a core structure of a battery device configured as a double wall is shown in a schematic perspective view.

[0038] Fig. 9 The intermediate space formed by the double-walled core structure is shown in a schematic sectional view.

[0039] Fig.10 A method for determining the shape of a triply periodic minimal surface of a core structure is schematically illustrated.

[0040] Fig.11 Different views show the use of Fig.10 The shape of the core structure with hexagonal symmetry was determined by the method. DETAILED DESCRIPTION

[0041] Figure 1 A first embodiment of a core structure 10 of a battery device is shown in a schematic perspective view. The core structure 10 has a wall 12 which is configured in the form of a triply periodic minimal surface. In the example shown, the wall 12 of the core structure 10 is configured as a Schwarz-P surface.

[0042] The battery device has a housing (not shown), which is configured here, for example, in a rectangular manner and completely accommodates the core structure 10. The core structure 10 adjoins the housing in the outer area and is held by the housing. On the upper side and the lower side, the housing forms a covering layer, which adjoins the wall 12 and is connected to the wall 12 of the core structure 10. Therefore, a durable sandwich structure is formed with the core structure. The housing interior space is divided into a first interior space 14 and a second interior space 16 by the core structure 10, so that there is no fluid transmission between the two interior spaces 14, 16.

[0043] The battery device has a plurality of battery cells 18 which are uniformly arranged in a package and which are configured as cylindrical battery cells 18 in the example shown and are arranged in a cylindrical shape. Figures 2 to 4 In Figures 2 to 4 , it can be seen that the core structure 10 forms a separate recess 20 in the second inner space 16, which recess 20 corresponds to the shape of the battery cell 18. The associated battery cell 18 is arranged in each recess 20. In the example shown, the battery device has only one level of battery cells 18. However, the battery device can also have multiple levels of battery cells 18 arranged one above the other and can therefore extend in the vertical direction. To this end, multiple core structures 10 can be stacked one above the other, or the core structure 10 can extend in the vertical direction, wherein additional recesses 20 are formed for additional battery cell layers.

[0044] The first inner space 14 is configured to allow the coolant 22 to flow through. Figures 2 to 4 , it can be seen that the first interior space 14 is completely filled with a coolant 22. The coolant 22 is, for example, a water-glycol mixture. The battery arrangement has a pump device, which is connected to the first interior space 14 via an inlet and an outlet, in order to convey the coolant 22 through the first interior space 14. Thus, the temperature of the battery arrangement can be actively controlled, for example for cooling and heating. On the upper side and / or the lower side, the battery cells 18 are not in contact with the coolant 22. There, the battery cells 18 are electrically connected in order to be able to supply current to a load and be charged.

[0045] For this purpose, the cover layer has associated through-holes aligned with the battery cells 18 and the recesses 20. The cover layer is formed, for example, from an electrically insulating material in a sandwich structure, wherein the respective conductive paths are deposited or etched on the side facing away from the first interior space 14.

[0046] The second internal space 16 fluidly connects the recesses 20 to each other. A phase change material 24 (e.g., paraffin) is arranged in the second internal space 16 and surrounds the battery cell 18. The phase change material 24 forms a thermal buffer and significantly increases the thermal inertia of the battery device within the expected operating temperature range of the battery device. The core structure 10 is formed of, for example, a metal material so as to enable rapid heat transfer between the first internal space 14 and the second internal space 16, thereby achieving rapid heat transfer between the coolant 22 and the phase change material 24.

[0047] In another embodiment, the phase change material 24 is arranged in the first interior space 14 and the coolant 22 is arranged in the second interior space 16. In this case, a pump device is connected to the second interior space 16 via an inlet and an outlet to convey the coolant 22 therethrough.

[0048] The core structure 10 can be produced, for example, by means of an additive method, so that complex geometries of the core structure 10 can be produced in a particularly simple manner. Figure 5 The forming method for manufacturing the core structure 10 is shown in different schematic diagrams. A deep drawing tool 30 is shown, which forms the negative shape of a part of the wall 12. A metal plate 32 having a through hole 34 corresponding to the recess 20 is placed on the deep drawing tool 30. By pressing with another deep drawing tool (not shown), a semi-finished product 36 is formed from the metal plate 32, the shape of which corresponds to the upper half or the lower half of the core structure 10. Two such semi-finished products 36 are joined to each other, for example by bonding, soldering or welding, so as to form a semi-finished product 36 such as a core structure 10. Figure 5 The wall 12 of the core structure 10 is shown. Thus, cost-effective large-scale production can be achieved.

[0049] The shape of the covering layer corresponds, for example, to Figure 5 The shape of the metal sheet 32 ​​is shown, from which the semi-finished product 36 is deep-drawn.

[0050] Figure 6 A second exemplary embodiment of a core structure 10 of a battery device is shown in a schematic perspective view. Figure 7 A second embodiment of a core structure 10 of a battery device is shown in a schematic cross-sectional view. Since the basic structure and basic operation mode are the same as the first embodiment, only the differences from the first embodiment will be described.

[0051] The second embodiment of the core structure 10 has a first grid structure 50, which is arranged in the first interior space 14. The first grid structure 50 is formed by uniformly arranged metal grid bars 52, which intersect and connect with the wall 12. In addition, the grid bars can also be connected to the shell, especially the cover layer, in order to structurally strengthen the shell. The first grid structure 50 improves the heat transfer between the wall 12 and the coolant 22 by increasing the contact surface area.

[0052] The second embodiment of the core structure 10 has a second grid structure 54, which is arranged in the second interior space 16. The second grid structure 54 is formed by uniformly arranged metal grid rods 56, which intersect and connect with the wall 12. Therefore, the second grid structure 54 can reinforce the wall 12. The second grid structure 54 improves the heat transfer between the wall 12 and the phase change material 24 and the battery cell 18 by increasing the contact surface area. The grid rods 56 of the second grid structure 54 can be in contact with the battery cell 18 to provide additional support for the phase change material 24 during the liquid state. However, the grid rods 56 of the second grid structure 54 can also be spaced apart from the battery cell 18.

[0053] The distance between the grid bars 52 of the first grid structure 50 is greater than the distance between the grid bars 56 of the second grid structure 54. The first grid structure 50 is thicker than the second grid structure 54. Since the first grid structure 50 is thicker, it is possible to avoid excessive flow resistance of the coolant 22 in the first internal space 14. Since the second grid structure 54 is thinner, it is possible to achieve particularly good heat transfer between the phase change material 24 and other areas, thereby achieving a particularly good thermal damping effect.

[0054] Figure 8 A third exemplary embodiment of a core structure 10 of a battery device is shown in a schematic perspective view. Fig. 9 A third embodiment of a core structure 10 of a battery device is shown in a schematic cross-sectional view. Since the basic structure and basic operation mode are the same as the first embodiment, only the differences from the first embodiment will be described.

[0055] The core structure 10 according to the third embodiment is configured as a double wall with another wall 70. The other wall 70 is arranged parallel to the wall 12 and also has the shape of a triple periodic minimal surface, which is shown as a Schwarz-P surface in the example shown. The core structure forms an intermediate space 74 between the two walls 12, 70. The two walls 12, 70 are connected to the cover layer respectively and therefore do not have to be fastened to each other. However, in the example shown, the two walls 12, 70 are connected to each other by an optional third grid structure 76, which is arranged in the intermediate space 74 and has corresponding grid rods 78. The third grid structure 76 improves the heat transfer between the two walls 12, 70 and the heat transfer to the material arranged in the intermediate space 74. In addition, the third grid structure 76 can make the core structure 10 more robust with respect to mechanical loads.

[0056] like Fig. 9 As shown, the core structure 10 according to the third embodiment may not have the first grid structure 50 and the second grid structure 54. However, in another embodiment, the first grid structure 50 and / or the second grid structure 54 may be provided in addition to the third grid structure 76. The intermediate space 74 may be configured for a coolant to flow through and be fluidly connected to a pump device for this purpose. Alternatively, a phase change material may be arranged in the intermediate space 74.

[0057] Fig.10A method for determining the shape of a triple periodic minimal surface of a core structure 10 is schematically shown. In step 100, the cell shapes of individual cells 18 of a battery device are selected. Cross-sections of typical cell shapes, namely cylindrical cells, prismatic cells and pouch cells, are shown. In step 102, the arrangement of the cells 18 in a desired package in a plane is defined. The cylindrical cells 18 are arranged uniformly, for example, in concentric circles around each other. The prismatic cells 18 are arranged uniformly, for example, in rows. In step 104, a symmetry plane 106 in the defined arrangement of the cells 18 is identified. In step 110, the cell surface in the defined arrangement is reduced to a minimum symmetry cell, as shown in box 108. In step 112, the contact surface of the cell 18 with the wall 12 of the core structure 10 is selected in the minimum symmetry cell 108. A contact line is defined on the selected contact surface. Subsequently, the spatial position of the contact line is defined. The shape of the wall 10 is determined as a substantially three-fold periodic minimal surface as a function of the defined spatial position of the contact line and as a function of the identified symmetry planes. The step of determining the shape of the wall as a substantially three-fold periodic minimal surface may comprise converting the attachment surface formed by the defined contact line into a grid of prestressed spring elements and mass points in order to determine the spring mass system. The step of determining the shape of the wall as a substantially three-fold periodic minimal surface may comprise a dynamic simulation of the spring mass system until an equilibrium position is reached. Thus, a triple periodic minimal surface specific to the battery device can be determined in a simple manner. The step of determining the shape of the wall as a substantially three-fold periodic minimal surface may comprise converting the equilibrium position into a geometric surface in order to determine the minimal surface. The step of determining the shape of the wall as a substantially three-fold periodic minimal surface may comprise mirroring the geometric surface on all identified symmetry planes in order to create cells of the three-fold periodic minimal surface. The step of determining the shape of the wall as a substantially three-fold periodic minimal surface may comprise periodically placing the resulting batteries relative to each other according to the arrangement of the battery cells in the desired package in order to determine the shape of the wall of the core structure.

[0058] Fig.11 Shown in perspective Fig.10 The result of the method shown in . In this case, the core structure 10 has hexagonally symmetrical walls 12. Fig.11 In FIG. 1 , a single unit cell of the wall 12 determined according to the above method is also shown at the top. The units are periodically placed relative to each other so that a triply periodic minimal surface shape of the wall 12 is generated from the units.

[0059] Reference Symbols

[0060] 10 Core Structure

[0061] 12 walls

[0062] 14First Interior Space

[0063] 16 Second Internal Space

[0064] 18 battery cells

[0065] 20 recesses

[0066] 22 Coolant

[0067] 24Phase change materials

[0068] 30 Deep Stamping Tools

[0069] 32 Metal Plate

[0070] 34 through holes

[0071] 36 Semi-finished products

[0072] 50 first grid structure 52 grid rods of the first grid structure

[0073] 54 second grid structure 56 grid rods of the second grid structure

[0074] 70 Another Wall

[0075] 74 The Space Between

[0076] 76 Third grid structure 78 Grid rods of the third grid structure

[0077] 100 Step / Selection of battery cell shape 102 Step / Definition of battery cell arrangement 104 Step / Identification of symmetry plane

[0078] 106 Symmetry plane

[0079] 108 boxes / minimum symmetric unit

[0080] 110 Steps / Reduction of the battery cell surface 112 Steps / Selection of contact surfaces

Claims

1. A battery device, in particular for a battery storage facility in a motor vehicle or a building, wherein the battery device comprises a housing, a core structure (10) arranged in the housing, a first interior space (14) in the housing configured for a coolant (22) to flow through, a second interior space (16) in the housing, a phase change material (24) and at least one battery cell (18), wherein: The core structure (10) separates the first internal space (14) from the second internal space (16), The core structure (10) has walls (12) arranged substantially in the form of a triply periodic minimal surface, The phase change material (24) is arranged in the second inner space (16), and The at least one battery cell (18) is arranged in the first interior space (14) or the second interior space (16).

2. The battery device according to claim 1, wherein: The first interior space (14) and / or the second interior space (16) is bounded on one side by a covering layer and on the opposite side by another covering layer, in particular wherein the covering layer regionally adjoins the core structure (10) and / or forms a sandwich structure with the core structure (10).

3. The battery device according to claim 2, wherein: At least one of the cover layers has at least one through-hole, which is used for contacting a battery contact of the battery cell (18) and / or for the coolant (22) to flow through. and / or, At least one of the cover layers has an electrically conductive path in contact with the battery cell (18), in particular wherein the electrically conductive path is arranged on the outside of the cover layer.

4. The battery device according to claim 1, wherein: The core structure (10) is manufactured by additive manufacturing, casting, machining and / or forming. In particular, the core structure (10) is formed from two semi-finished products (36) which are connected to each other.

5. The battery device according to claim 1, wherein: The core structure (10) further comprises a first grid structure (50) arranged in the first inner space (14), and / or, The core structure (10) further comprises a second grid structure (54) arranged in the second inner space (16), In particular, the first grid structure (50) is different from the second grid structure (54).

6. The battery device according to claim 1, wherein: The core structure (10) is configured as a double wall with another wall (70), wherein the other wall (70) is also configured in the form of a substantially triply periodic minimal surface and an intermediate space (74) is formed between the two walls (12, 70) of the core structure (10).

7. The battery device according to claim 6, wherein: The intermediate space (74) is configured to allow a coolant to flow through, and / or for a phase change material to be arranged in the intermediate space (74), and / or, The core structure (10) further comprises a third grid structure (76) arranged in the intermediate space (74), In particular, the two walls (12, 70) of the core structure (10) are connected to one another via the third grid structure (76).

8. The battery device according to claim 1, wherein: The walls (12, 70) of the core structure (10) are configured as Schwarz-P surfaces, or, The walls (12) of the core structure (10) have hexagonal symmetry.

9. The battery device according to claim 1, wherein: The shape of the walls (12, 70) of the core structure (10) is matched to the shape of the battery cell (18), in particular to the cylindrical or prismatic shape of the battery cell or to a battery cell (18) configured as a pouch cell.

10. The battery device according to claim 1, wherein: The battery device has a pump device, which is configured to convey the cooling liquid (22) through the first interior space (14).

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