Battery equipment

Abstract

The present invention relates to a battery device. The battery device includes a housing, a core structure (10) arranged in the housing, a first interior space (14) in the housing configured for the flow of a coolant (22), a second interior space (16) in the housing, a phase change material (24), and at least one battery cell (18). The core structure (10) 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 triply periodic minimal curved surface. The phase change material (24) is arranged in the second interior space (16). At least one of the battery cells (18) is arranged in the first interior space (14) or the second interior space (16).

Description

[Technical field]

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

[0002] Batteries need to supply high currents for modern applications, for example as energy storage devices in electric cars or drones. However, this can cause very rapid heating of the respective battery cells. Batteries have an optimal operating temperature range, which is for example close to room temperature. In this temperature range the battery may be particularly powerful. On the contrary, at very high or very low temperatures the degradation of the battery accelerates. If the maximum temperature is exceeded, spontaneous combustion of the battery may occur, also called thermal runaway. The temperature is accordingly usually controlled by a temperature control system.

[0003] The temperature control system of the battery may be separated according to two operating principles. Active cooling allows to set the operating temperature of the battery, for example by an adjustable cooling fluid flow rate. However, active cooling requires energy, which can result in a decrease in system efficiency. It also does not prevent the cooling or heating of the battery by the environment during downtimes. In the case of passive cooling, there is no energy consumption, but the operating temperature cannot always be kept within the desired range. Generally, cooling the battery requires additional installation space and can be very heavy. Depending on the climate zone, heating of the battery may also be planned. Heating can occur either actively or passively.

[0004] US 2013 / 00844871 describes a battery using phase change materials. US 7,866,377 describes the use of minimal surfaces in heat exchangers. Summary of the Invention

[0005] A first aspect of the invention relates to a battery device. The battery device may be configured for example for a motor vehicle such as an electric car. The battery device may be configured as a battery store in a building, in particular used in a wall box for charging an electric car. The battery device may also be used for example for a drone or an electric bike. The battery device may be configured as an energy storage device for example for electric energy. The battery device may be configured for multiple charging and discharging.

[0006] The battery arrangement may have a housing. The housing may delimit a housing interior space. The housing may be manufactured, for example, from plastic or metal. The housing may have multiple wall elements or may be constructed as a unitarian one-piece element. The housing protects the other elements of the battery arrangement from environmental influences and allows, for example, fastening, in particular in a vehicle and / or in a building. The battery arrangement may have electrical contacts.

[0007] The battery device has a core structure arranged in the housing. The core structure may be configured to divide the housing interior space into at least two subspaces. The core structure may provide an additional protective function to protect the battery cells from mechanical influences. The core structure may form a load-bearing structure. The core structure may, for example, be permanently connected to the housing or may be configured as an integral one-piece element. As a result of the connection to the housing, the core structure may support and further reinforce the housing.

[0008] The battery arrangement has a first interior space in the housing. The first interior space is configured for the flow of the coolant. For this purpose, the first interior space has one or more access openings, and may in particular be configured as through openings in the housing. As a result, the coolant can flow through the first interior space. The battery arrangement may, for example, have a pump device for conveying the coolant through the first interior space, which pump device may be arranged inside or outside the housing. Also, a heat exchanger may be installed, in particular, outside the housing, for example, for cooling the coolant. Alternatively or additionally, the battery arrangement may have a heater, for example, for heating the coolant. The battery arrangement may therefore, in particular, have an active temperature control, or may at least be configured for cooling, in order to ensure that the operating temperature is maintained within a desired range. Alternatively or additionally, the battery arrangement may be heated by the coolant depending on the ambient temperature. The coolant may, for example, be air, water or a water-glycol mixture.

[0009] The battery device has a second internal space in the housing. The second internal space may be, for example, fluidically isolated from the first internal space. The battery device has a phase change material. The phase change material is disposed in the second internal space. As a result, mixing with the coolant can be avoided. The phase change material may have a high enthalpy of melting. The phase change material may be, for example, paraffin wax. Additional examples of phase change materials include aluminum-silicon alloys. Additional examples of phase change materials exist in the field, for example, salt hydrates, alcohols, fatty acids, salts, etc. Also, flame retardant additives may be added to the phase change material. The phase change material may be selected to change between two phases, in particular between a liquid state and a solid state, within or near a desired operating temperature range of the battery device. The phase change material may have a high effective thermal mass, which may significantly increase the thermal inertia of the battery device. As a result, undesirably rapid and / or high temperature increases or decreases may be prevented or at least slowed down. As a result, the desired operating temperature of the battery device is more easily maintained. Also, active cooling may be more compact since it no longer has to absorb the respective thermal reactions of the battery itself. The phase change material can suppress load peaks to reduce the load on the active cooling and / or heater. Also, during downtime, i.e., when the battery device is turned off for example, the phase change material can maintain the temperature of the battery device better or with a lower mass and volume than without the phase change material. As a result, the battery device may be very light, since each active cooling component is formed with smaller dimensions, as a result of the phase change material. Also, using such a battery device, the system efficiency may be higher, since less energy is required for active cooling. The service life of the battery device may also be very long, since the battery device can be better maintained within its optimal operating temperature range.

[0010] The battery arrangement comprises at least one battery cell. The battery cell may be configured as, for example, a galvanic cell. The battery cell may be an electrochemical energy storage device and an energy converter. The battery cell may be, for example, a cylindrical battery cell, a prismatic battery cell or a pouch cell. The battery arrangement may comprise a plurality of battery cells that may be arranged in a certain packing in a housing. For example, the battery cells may be uniformly arranged at a certain distance from each other in a plane. All battery cells of the battery arrangement may be configured similarly. However, the battery arrangement may also comprise two or more different battery cell types. In the following, for simplicity, reference is made to a battery cell, which may also relate to a plurality or all battery cells, whenever applicable.

[0011] The core structure separates the first internal space from the second internal space. The core structure may form a separation wall in the housing internal space. The separation may be fluid-tight, particularly to the phase change material and the coolant. The core structure has a wall substantially configured in the form of a triple periodic minimum surface. The separation wall may partially or completely define at least one of the two internal spaces. The separation wall may at least partially or completely define both of the internal spaces. The triple periodic minimum surface may have the symmetry of a crystal structure. The triple periodic minimum surface may have no interface. Details of the triple periodic minimum surface are further described below. The triple periodic minimum surface may form a very large surface area, so that the heat can be transferred very well and uniformly between the two internal spaces. The triple periodic minimum surface may form recesses corresponding to each battery cell, for example, in the second internal space. The wall of the core structure may be formed, for example, from a metal material or a plastic. The triple periodic minimal surface can form two channels with the housing. Heat can be transferred very well between the cooling liquid and the phase change material through the triple periodic minimal surface. Therefore, the combination of active cooling and thermal damping by the phase change material can be very efficient. The phase change material can also prevent thermal runaway very well.

[0012] At least one battery cell is arranged in the first or second internal space. As a result of the arrangement in the second internal space, undesired rapid heating and cooling of the battery cells can be suppressed very well by the phase change material. Each battery cell can therefore be maintained within a desired operating temperature range, in particular with a minimum of active temperature control. As a result of the arrangement in the first internal space, the operating temperature of the battery cells can be set very accurately and reliably. However, thermal load peaks can be suppressed by the phase change material.

[0013] In one embodiment of the battery arrangement, it is provided that the first and / or second internal space is defined on one side by a covering layer. The covering layer may be formed, for example, by a part of the housing. On the opposite side, the first and / or second internal space may be defined by an additional covering layer. This additional covering layer may also be formed, for example, by a part of the housing. The covering layer may be connected to the core structure. The respective covering layer may not be electrically conductive. The respective covering layer may be formed, for example, as a plate made of an electrically insulating material. The respective covering layer may also be formed, for example, from a composite material, and therefore may be particularly mechanically resistant. The covering layer may locally abut the core structure and / or form a sandwich structure together with the core structure. As a result, the battery arrangement may be configured as a load-bearing structure. As a result, it is possible, for example, to omit reinforcements in the vehicle for installing the battery arrangement. The battery arrangement may therefore be configured, for example, as a load-bearing part of the chassis. The cover layers can, for example, be located on opposite sides of a wall configured as a triple periodic minimal surface, thereby defining or completely closing the respective recesses for the battery cells located above and below. The cover layers can be connected to the core structure by a joining method, for example by welding, adhesive bonding or soldering. However, the two cover layers can also be connected to each other, for example by a screw connection, sandwiching the core structure between them. The two cover layers can also be pressed against the core structure by a housing.

[0014] In one embodiment of the battery arrangement, it is provided that at least one of the covering layers has at least one through-opening for accessing the battery contacts of the battery cells and / or for the flow of coolant. Separate through-openings may also be provided for the flow of coolant and for electrical contact. The through-openings may, for example, be aligned with recesses for the battery cells. A corresponding through-opening may be provided for each battery cell. Through-openings may be provided only in one or both covering layers. One or more lines, for example power lines and / or fluid lines, may be led through the through-openings. Otherwise, the through-openings may be sealed. As a result, fluids and / or electric currents can be led to and from the first and / or second internal space.

[0015] In one embodiment of the battery arrangement, it is provided that at least one of the covering layers has a conducting path in contact with the battery cells, in particular that the conducting path is arranged on the outside of the covering layer. For example, the conducting path may be connected to the battery cells through a through opening. A corresponding conducting path may be provided for each battery cell. However, the conducting path may also be, for example, electrically connected to one or more battery cells. The conducting path may be fixed to the covering layer. The conducting path may also be formed integrally with the covering layer, for example by being etched or deposited in the covering layer. As a result of the conducting path, the electrical connection to each battery cell can be provided compact, robust and space-saving.

[0016] In one embodiment of the battery device, it is provided that the core structure is manufactured by an additive method. For example, the core structure may be manufactured by metal 3D printing. As a result, the composite wall can be manufactured in a very simple manner in the form of a triply periodic minimal surface, in particular in one step and / or as an integral one-piece element. Thus, for example, large undercuts may also be manufactured in a simple manner. Alternatively or additionally, the core structure may be manufactured by a casting method. For example, two semi-finished products manufactured in a casting process may form the core structure. As a result, very large core structures can be manufactured cost-effectively. Alternatively or additionally, the core structure may be manufactured by a machining method. For example, two semi-finished products manufactured by a milling method may form the core structure. As a result, a very durable core structure can be provided. Alternatively or additionally, the core structure may be manufactured by a moulding method. For example, two semi-finished products manufactured by deep drawing from a sheet may form the core structure. This allows for very cost-effective mass production.

[0017] In one embodiment of the battery arrangement, it is provided that the core structure is formed from two semi-finished products joined together. For example, the core structure may be formed from an upper shell and a lower shell between which respective recesses for the battery cells are formed. The manufacturing may therefore be very simple, in particular because undercuts in the semi-finished products may be avoided. Also, the battery cells may therefore be inserted in the recesses in a very simple manner. The semi-finished products may be symmetrical to one another. For example, the core structure may also have three or more semi-finished products joined together. The semi-finished products may be connected to one another by a joining method, such as welding, adhesive bonding or soldering.

[0018] In one embodiment of the battery device, the core structure further comprises a first lattice structure arranged in the first interior space. The first lattice structure may improve the load-bearing capacity of the battery device. For example, the first lattice structure may support and connect the core structure to the housing and / or the covering layer. The first lattice structure may also improve thermal conductivity, in particular by increasing the surface area around which the coolant flows. Preferably, the first lattice structure is a coarse lattice structure with a large distance between the individual lattice rods to maintain low pressure losses when the coolant flows through the first interior space.

[0019] In one embodiment of the battery device, the core structure further comprises a second lattice structure arranged in the second internal space. The second lattice structure may alternatively or additionally be placed on the first lattice structure. The second lattice structure may improve the load-bearing capacity of the battery device. For example, the second lattice structure may support and connect the core structure to the housing and / or the covering layer. The second lattice structure may also improve the mechanical resistance of the core structure itself, for example in that different wall areas in the recesses for the battery cells are connected to each other via the second lattice structure. The second lattice structure may, for example, hold the battery cells, especially when the phase change material changes to its liquid state. The second lattice structure may also improve the thermal conductivity, especially by increasing the surface area in contact with the phase change material. Preferably, the second lattice structure is a fine lattice structure with a small distance between the individual lattice rods to provide a very large surface area for heat transfer.

[0020] The first lattice structure may be different from the second lattice structure. For example, the second lattice structure may be finer than the first lattice structure. Alternatively or additionally, each lattice rod of the first lattice structure may have a thickness different from the thickness of each lattice rod of the second lattice structure. The lattice structure may be formed, for example, from a plurality of intersecting lattice rods.

[0021] In one embodiment of the battery device, it is provided that the core structure is configured as a double wall with an additional wall. The additional wall may also be configured in the form of a substantially triply periodic minimal surface. In the case of a double-walled core structure, the two walls may be arranged substantially parallel to each other. For example, the basic shape of both walls may be the same. The two walls may be offset from each other. One of the two walls may be smaller and may be arranged, for example, between the other wall and the second internal space. An intermediate space may be formed between the two walls of the core structure. The double-walled core structure may be very robust. An additional phase change material may be arranged in the additional intermediate space. This phase change material may have a melting point different from the melting point of the phase change material in the second internal space in order to further stabilize the operating temperature. For example, one of the phase change materials may melt at the upper limit of the desired operating temperature range and the other phase change material may melt at the desired lower limit of the desired operating temperature range. Alternatively, the intermediate space may be configured to allow a coolant to flow. As a result, active cooling can be performed in a very variable manner, for example by using different cooling liquids in the intermediate space and in the first internal space, for example a constant cooling liquid flow may flow through the first internal space and the cooling liquid may flow only through the intermediate space as soon as the phase change material starts to melt.

[0022] In an embodiment of the battery arrangement, it is provided that the intermediate space is configured such that a coolant flows through the intermediate space and / or a phase change material is arranged within the intermediate space.

[0023] In one embodiment of the battery device, it is provided that the core structure further comprises a third lattice structure arranged in the intermediate space. The third lattice structure may fix and support the two walls of the double-walled core structure to each other. The two walls of the core structure may be connected to each other via the third lattice structure. As a result, the core structure is very durable and can absorb high mechanical loads. Alternatively, however, the two walls may also be arranged adjacent to each other, for example in a self-supporting manner. The third lattice structure may improve heat transfer between the two walls of the core structure and to the material in the intermediate space.

[0024] In one embodiment of the battery device, it is provided that each wall of the core structure is configured as a Schwarz-P-surface. The Schwarz-P-surface naturally forms a shape that spans two separate spaces, thereby forming a recess for a cylindrical battery. The Schwarz-P-surface can be approximated, for example, by the equation cos()+cos()+cos()=0 in a three-dimensional Cartesian coordinate system with coordinates x, y, z. By inserting additional parameters, the shape can be scaled to fit batteries of various shapes. The equation cos(*)+cos(*)+cos(*)=0 can be used as an approximation. However, the Schwarz-P-surface can also be determined exactly by solving the Weierstrass-Enneper equation.

[0025] In one embodiment of the battery device, it is provided that the walls of the core structure are determined in a manner that matches the shape of the battery cell. For example, the walls of the core structure may have a hexagonal symmetry. As a result, a suitable shape that matches the recess can be provided for a particular battery cell.

[0026] A further aspect relates to a method for determining the shape of a wall of a core structure of a battery arrangement, in particular one of the walls of the core structure of a battery arrangement according to the invention. The method may comprise the step of selecting a battery cell shape for each battery cell of the battery arrangement. The method may comprise the step of defining a desired packing, in particular an arrangement of the battery cells in a plane. The method may comprise the step of identifying a symmetry plane in the defined arrangement of the battery cells. The method may comprise the step of reducing the battery cell surfaces in the defined arrangement to the smallest symmetrical unit. The method may comprise the step of selecting a contact surface between the battery cell and 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 a spatial position of the contact line. The method may comprise the step of determining the shape of the wall substantially as a triply periodic minimal surface depending on the defined spatial position of the contact line and the identified symmetry plane. As a result, a specific triply periodic minimal surface of the battery arrangement can be determined by a simple method. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include converting the attachment surface formed from the defined contact lines into a mesh of prestressed spring elements and mass points in order to determine the spring-mass system. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include performing a dynamic simulation of the spring-mass system until an equilibrium position is reached. Extended finite element method solvers such as ABAQUS / explicit are, for example, suitable for this purpose. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include converting the equilibrium position into a shape surface in order to determine the minimal surface. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include mirroring the shape surface on all identified symmetry surfaces in order to generate cells of the triply periodic minimal surface. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include arranging the generated cells periodically with respect to each other according to the arrangement of the battery cells in the desired packing in order to determine the shape of the walls of the core structure.

[0027] In one embodiment of the battery arrangement, it is provided that the shape of each wall of the core structure, in particular separating the two internal spaces from each other, is adapted to the shape of a battery cell. As a result, the battery arrangement may be very compact. For example, each recess in the second internal space may be adapted to the shape of a battery cell. In particular, the cross-section of the recess may correspond to the cross-section of the battery cell. For example, the shape of the wall of the core structure may be adapted to the cylindrical or rectangular shape of a battery cell, or to a battery cell configured as a pouch cell.

[0028] In one embodiment of the battery arrangement, it is provided to have a pump device configured to convey the cooling liquid through the first interior space. For example, the pump device may be connected to the first interior space via one or more through openings in at least one covering layer. The pump device may also be configured to convey the cooling liquid through the intermediate space when the core structure is configured as a double wall. The pump device may, for example, comprise a pump. The battery arrangement may also comprise a cooling liquid. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic perspective view showing a first embodiment of a core structure of a battery pack. [Diagram 2] FIG. 1 is a schematic perspective view showing how the coolant flows around a first embodiment of the core structure of a battery pack. [Diagram 3] A schematic cross-sectional view showing how a first embodiment of a core structure of a battery device houses each battery cell and phase change material. [Figure 4] FIG. 2 is another schematic cross-sectional view showing how the first embodiment of the core structure of the battery device houses each battery cell and phase change material. [Diagram 5] FIG. 2 is a schematic perspective view showing how a first embodiment of a core structure is manufactured by a deep drawing method. [Figure 6]A schematic perspective view showing a second embodiment of a core structure of a battery device having an additional lattice structure. [Figure 7] FIG. 11 is a schematic cross-sectional view showing a lattice structure of a second embodiment of the core structure of a battery device. [Figure 8] FIG. 11 is a schematic perspective view showing a third embodiment of the core structure of a battery pack configured as a double wall. [Figure 9] FIG. 1 is a schematic cross-sectional view showing an intermediate space formed by a double-walled core structure. [Figure 10] 1 illustrates a schematic diagram of a method for determining the shape of a triply periodic minimal surface of a core structure. [Figure 11] 11A to 11C show different views of the shape of a core structure with hexagonal symmetry determined by the method according to FIG. 10 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] 1 is a schematic perspective view of a first embodiment of a core structure 10 of a battery arrangement. The core structure 10 has walls 12 configured in the form of triply periodic minimal surfaces. In the example shown, the walls 12 of the core structure 10 are configured as Schwarzian P surfaces.

[0031] The battery device here has a housing (not shown), for example rectangular in configuration, configured to completely house the core structure 10. The core structure 10 locally abuts on the outside and is held by the housing. On the upper and lower sides, the housing abuts, respectively, on the walls 12 and forms a covering layer joined to the walls 12 of the core structure 10. As a result, together with the core structure, a durable sandwich structure is formed. The interior space of the housing is separated by the core structure 10 into a first interior space 14 and a second interior space 16, such that no fluid communication is possible between the two interior spaces 14, 16.

[0032] The battery arrangement is uniformly arranged in the packing and comprises a plurality of battery cells 18, which in the example shown are configured as cylindrical battery cells 18 and are shown in figures 2 to 4. It can be seen in figures 3 and 4 that the core structure 10 forms individual recesses 20 in the second internal space 16, which recesses are adapted to the shape of the battery cells 18. A corresponding battery cell 18 is arranged in each recess 20.

[0033] In the example shown, the battery arrangement has only one level of battery cells 18. However, the battery arrangement may also have multiple levels of battery cells 18 arranged one above the other, thereby allowing for a vertical extension. For this purpose, multiple core structures 10 can be stacked one above the other, or the core structure 10 can be extended vertically, with additional recesses 20 formed for the additional battery cell levels.

[0034] The first interior space 14 is configured for the coolant 22 to flow through it. In figures 2-4 it can be seen that the first interior space 14 is completely filled with the coolant 22. The coolant 22 is, for example, a water-glycol mixture. The battery arrangement has a pump device connected to the first interior space 14 via an inlet and an outlet configured to convey the coolant 22 through the first interior space 14. The temperature of the battery arrangement can thus be actively controlled, for example for cooling and heating. On the upper and / or 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 and charge a load.

[0035] For this purpose, the covering layers respectively correspond to through-openings aligned with the battery cells 18 and the recesses 20. The covering layers are, for example, formed from an electrically insulating material in a sandwich structure, with the respective conductive paths being deposited or etched on the side remote from the first internal space 14.

[0036] The second internal space 16 fluidly connects the recesses 20 to each other. A phase change material 24, e.g., paraffin wax, is disposed in the second internal space 16 and surrounds the battery cells 18. The phase change material 24 forms a thermal buffer and significantly increases the thermal inertia of the battery device in the desired operating temperature range of the battery device. The core structure 10 is formed, for example, from a metallic material to enable rapid heat transfer between the first internal space 14 and the second internal space 16, and thus between the coolant 22 and the phase change material 24.

[0037] In another embodiment, the phase change material 24 is arranged in the first interior space 14 and the cooling liquid 22 is arranged in the second interior space 16. In this case, a pumping device is connected to the second interior space 16 via an inlet and an outlet for conveying the cooling liquid 22 therethrough.

[0038] The core structure 10 can be produced, for example, by additive processes, so that the complex shape of the core structure 10 can be produced in a very simple manner. Figure 5 shows a different schematic diagram of a forming method for producing the core structure 10. A deep-drawing tool 30 is shown, which forms the negative shape of a portion of the wall 12. A sheet metal plate 32 with a through opening 34 corresponding to the recess 20 is placed in the deep-drawing tool 30. By pressing with an additional deep-drawing tool (not shown), a semi-finished product 36 is formed from the sheet metal plate 32, the shape of which corresponds to the upper or lower half of the core structure 10. As shown in Figure 5, two such semi-finished products 36 are joined to each other, for example by adhesive bonding, soldering or welding, to form the wall 12 of the core structure 10. As a result, cost-effective mass production is possible.

[0039] The shape of the coating layer corresponds, for example, to the shape of the sheet metal plate 32 shown in FIG. 5, from which the semi-finished product 36 is to be deep-drawn.

[0040] Fig. 6 is a schematic perspective view showing a second embodiment of the core structure 10 of a battery pack, and Fig. 7 is a schematic cross-sectional view showing the second embodiment of the core structure 10 of a battery pack. Since the basic structure and basic operation mode are the same as those of the first embodiment, only the differences from the first embodiment will be described.

[0041] The second embodiment of the core structure 10 has a first lattice structure 50 arranged in the first interior space 14. The first lattice structure 50 is formed from uniformly arranged metal lattice rods 52 crosswise connected to the wall 12. The lattice rods may also be connected to the housing, in particular to the covering layer, in order to structurally reinforce the housing. The first lattice structure 50 improves the heat transfer between the wall 12 and the coolant 22 due to the increased contact surface area.

[0042] The second embodiment of the core structure 10 has a second lattice structure 54 disposed within the second interior space 16. The second lattice structure 54 is formed from uniformly spaced metal lattice rods 56 that are crosswise connected to the walls 12.

[0043] Thus, the second lattice structure 54 can reinforce the wall 12. The second lattice structure 54 improves heat transfer between the wall 12, the phase change material 24, and the battery cells 18 due to an increased contact surface area. The lattice rods 56 of the second lattice structure 54 can contact the battery cells 18 to further support the battery cells 18 while the phase change material 24 changes to a liquid state. However, the lattice rods 56 of the second lattice structure 54 may be spaced apart from the battery cells 18.

[0044] The distance between the lattice rods 52 of the first lattice structure 50 is greater than the distance between the lattice rods 56 of the second lattice structure 54. The first lattice structure 50 is coarser than the second lattice structure 54. As a result of the coarse first lattice structure 50, an undesirable high flow resistance of the cooling liquid 22 in the first interior space 14 can be avoided. As a result of the fine second lattice structure 54, a very good heat transfer between the phase change material 24 and other areas can be achieved, which results in a very good thermal damping.

[0045] Fig. 8 is a schematic perspective view showing a third embodiment of the core structure 10 of a battery pack, and Fig. 9 is a schematic cross-sectional view showing the third embodiment of the core structure 10 of a battery pack. Since the basic structure and basic operation mode are the same as those of the first embodiment, only the differences from the first embodiment will be described.

[0046] The core structure 10 according to the third embodiment is configured as a double wall with an additional wall 70. The additional wall 70 is arranged parallel to the wall 12 and further has the shape of a triply periodic minimal surface, shown in this example as a Schwarzian P surface. The core structure forms an intermediate space 74 between the two walls 12, 70. The two walls 12, 70 do not need to be fixed to each other, since they are each connected to a coating layer. However, in the example shown, the two walls 12, 70 are arranged in the intermediate space 74 and connected to each other by an optional third lattice structure 76, each having a lattice rod 78. The third lattice structure 76 improves the heat transfer between the two walls 12, 70 and the material arranged in the intermediate space 74. The third lattice structure 76 can also make the core structure 10 more robust against mechanical loads.

[0047] The core structure 10 according to the third embodiment may not include the first lattice structure 50 and the second lattice structure 54, as shown in Fig. 9. However, in another embodiment, in addition to the third lattice structure 76, the first lattice structure 50 and / or the second lattice structure 54 may also be provided. The intermediate space 70 may be configured to allow the cooling liquid to flow and may be configured to be fluidly connected to a pump device for this purpose. Alternatively, a phase change material may be arranged in the intermediate space 70.

[0048] FIG. 10 shows a schematic diagram of a method for determining the shape of the triply periodic minimal surface of the core structure 10. In step 100, a battery cell shape is selected for each battery cell 18 of the battery device. Cross sections of typical battery cell shapes are shown, namely cylindrical battery cells, prismatic battery cells and pouch cells. In step 102, an arrangement of the battery cells 18 is defined in a desired packing in a plane. The cylindrical battery cells 18 are arranged uniformly, for example, in concentric circles around each other. The prismatic battery cells 18 are arranged uniformly, for example, in rows. In step 104, a symmetry plane 106 in the defined arrangement of the battery cells 18 is identified. In step 110, the battery cell surfaces in the defined arrangement are reduced to the smallest symmetrical unit, shown as a box 108. In step 112, a contact surface between the battery cell 18 and the wall 12 of the core structure 10 is selected within the smallest symmetrical unit 108. A contact line is defined on the selected contact surface. The spatial position of the contact line is then defined. Depending on the defined spatial positions of the contact lines and the identified symmetry planes, the shape of the wall 10 is determined substantially as a triply periodic minimal surface. The step of determining the shape of the wall substantially as a triply periodic minimal surface may comprise converting the attachment surface formed from the defined contact lines into a mesh of prestressed spring elements and mass points in order to determine the spring-mass system. The step of determining the shape of the wall substantially as a triply periodic minimal surface may comprise performing a dynamic simulation of the spring-mass system until an equilibrium position is reached. As a result, a specific triply periodic minimal surface of the battery arrangement can be determined by a simple method. The step of determining the shape of the wall substantially as a triply periodic minimal surface may comprise converting the equilibrium position into a shape surface in order to determine the minimal surface. The step of determining the shape of the wall substantially as a triply periodic minimal surface may comprise mirroring the shape surface onto all identified symmetry planes in order to generate cells of the triply periodic minimal surface. Determining the wall shape substantially as a triply periodic minimal surface may include arranging the generated cells periodically relative to one another according to an arrangement of the battery cells in a desired packing to determine the wall shape of the core structure.

[0049] Figure 11 is a perspective view showing the result of this method shown in Figure 10. The core structure 10 in this case has a wall 12 with hexagonal symmetry. In Figure 11, the individual cells of the wall 12 determined according to the method described above are also shown at the top. The cells are arranged periodically with respect to each other in order to generate a triply periodic minimal surface shape of the wall 12 from the cells. [Explanation of symbols]

[0050] 10 Core Structure 12. Wall 14 1st interior space 16 Second interior space 18 Battery Cells 20 Recess 22 Coolant 24 Phase change materials 30 Deep drawing tools 32 Sheet Metal Plate 34 Through opening 36 Semi-finished products 50 1st lattice structure 52 Lattice rod of the first lattice structure 54 Second lattice structure 56 Lattice rod of the second lattice structure 70 Additional Walls 74 Intermediate Space 76 Third lattice structure 78 Lattice rod of the third lattice structure 100 steps / battery cell shape selection 102 steps / definition of battery cell placement 104 Step / Symmetry Plane Identification 106 Symmetry Plane 108 boxes / smallest symmetrical unit 110 steps / reduction of battery cell surface 112 Step / contact surface selection

Claims

1. A battery device, particularly for use in a battery store in an automotive vehicle or building, comprising: a housing; a core structure (10) disposed within the housing; a first interior space (14) within the housing configured for the flow of a coolant (22); a second interior space (16) within the housing; a phase change material (24); and at least one battery cell (18); The core structure (10) 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 triply periodic minimal surface, The phase change material (24) is disposed within the second interior space (16); At least one of the battery cells (18) is disposed in the first internal space (14) or the second internal space (16).

2. 2. The battery device according to claim 1, wherein the first internal space (14) and / or the second internal space (16) are defined on one side by a covering layer and on the opposite side by an additional covering layer, in particular the covering layer abutting locally against the core structure (10) and / or forming a sandwich structure together with the core structure (10).

3. At least one of the cover layers has at least one through opening for accessing the battery contacts of the battery cells (18) and / or for the flow of the cooling liquid (22); and / or 3. A battery arrangement according to claim 2, wherein at least one of the covering layers has a conductive path in contact with the battery cell (18), in particular the conductive path being arranged on the outside of the covering layer.

4. said core structure (10) being manufactured by additive, casting, machining and / or molding processes; A battery arrangement according to any one of claims 1 to 3, in particular, wherein the core structure (10) is formed from two semi-finished products (36) joined together.

5. the core structure (10) further comprises a first lattice structure (50) disposed within the first interior space (14); and / or The core structure (10) further comprises a second lattice structure (54) disposed within the second interior space (16); A battery arrangement according to any one of claims 1 to 4, in particular wherein the first lattice structure (50) is different from the second lattice structure (54).

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

7. The intermediate space (74) is configured such that a cooling fluid flows through the intermediate space (74) and / or a phase change material is disposed within the intermediate space (74); and / or The core structure (10) further comprises a third lattice structure (76) disposed within the intermediate space (74); A battery arrangement according to claim 6, in particular, in which the two walls (12, 70) of the core structure (10) are connected to each other via the third lattice structure (76).

8. Each wall (12, 70) of the core structure (10) is configured as a Schwartz P surface, or A battery arrangement according to any one of the preceding claims, wherein each wall (12) of the core structure (10) has hexagonal symmetry.

9. A battery device according to any one of claims 1 to 8, wherein the shape of each wall (12, 70) of the core structure (10) is adapted to the shape of the battery cell (18), in particular to a cylindrical or rectangular shape of the battery cell, or to a battery cell (18) configured as a pouch cell.

10. The battery arrangement according to any one of the preceding claims, comprising a pump arrangement configured to convey the cooling liquid (22) through the first interior space (14).

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