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 are required to supply large currents in modern applications, such as energy storage devices in electric vehicles or drones. However, this can cause very rapid heating of each battery cell. Batteries have an optimal operating temperature range, which is, for example, close to room temperature. In this temperature range, batteries may be particularly powerful. Conversely, at very high or very low temperatures, battery degradation accelerates. If the maximum temperature is exceeded, spontaneous combustion of the battery may occur, also known as thermal runaway. Accordingly, the temperature is usually controlled by a temperature control system.

[0003] Battery temperature control systems may be separated according to two operating principles. Active cooling allows the operating temperature of the battery to be set, for example, by an adjustable cooling fluid flow rate. However, active cooling requires energy, which can result in reduced system efficiency. It also cannot prevent the battery from being cooled or heated by the environment during downtime. Passive cooling does not consume energy, but it cannot always maintain the operating temperature within the desired range. Generally, battery cooling requires additional installation space and can be very heavy. Depending on the climate zone, battery heating may also be planned. Heating can occur actively or passively.

[0004] US Patent Application Publication No. 2013 / 00844871 describes a battery using phase change materials. US Patent No. 7,866,377 describes the use of minimal surfaces in heat exchangers. Summary of the Invention

[0005] A first aspect of the present 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 for use in a wall box for charging an electric car. The battery device may also be used for example in a drone or an electric bike. The battery device may be configured as an energy storage device for example for electrical energy. The battery device may be configured for multiple charging and discharging.

[0006] The battery device may have a housing. The housing may delimit an interior space of the housing. The housing may be manufactured from, for example, 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 device from environmental influences and allows for fastening, for example, in particular in a vehicle and / or building. The battery device may have electrical contacts.

[0007] The battery device has a core structure disposed within the housing. The core structure may be configured to divide the housing interior space into at least two subspaces. The core structure may provide additional protection 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 configured as an integral, one-piece element. As a result of its connection to the housing, the core structure may support and further reinforce the housing.

[0008] The battery system has a first interior space within the housing. The first interior space is configured to allow a coolant to flow through it. For this purpose, the first interior space has one or more access openings, particularly through-openings in the housing. As a result, the coolant can flow through the first interior space. The battery system may, for example, have a pumping device for transporting the coolant through the first interior space, which may be arranged inside or outside the housing. A heat exchanger may also be installed, particularly outside the housing, for example, to cool the coolant. Alternatively or additionally, the battery system may have a heater, for example, to heat the coolant. Thus, the battery system may, in particular, have active temperature control, or may at least be configured for cooling, to ensure that the operating temperature is maintained within a desired range. Alternatively or additionally, the battery system may be heated by a 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 within the housing. The second internal space may be fluidly isolated from the first internal space, for example. The battery device includes a phase change material. The phase change material is disposed within 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 fields of salt hydrates, alcohols, fatty acids, and salts. Flame retardant additives may also be added to the phase change material. The phase change material may be selected to change between two phases, particularly between a liquid state and a solid state, within or near the desired operating temperature range of the battery device. Phase change materials have a high effective thermal mass, which can significantly increase the thermal inertia of the battery device. As a result, undesirably rapid and / or high temperature increases or decreases can be prevented or at least slowed. As a result, the desired operating temperature of the battery device is more easily maintained. Active cooling may also be more compact, since it no longer needs to absorb the respective thermal reactions of the batteries themselves. The phase change material can dampen load peaks to reduce the load on the active cooling and / or heater. 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 have a longer service life. As a result of the phase change material, the battery device may be significantly lighter, since each active cooling component is formed with smaller dimensions. Using such a battery device may also result in higher system efficiency, since less energy is required for active cooling. The service life of the battery device may also be significantly longer, since the battery device can be better maintained within its optimal operating temperature range.

[0010] A battery device includes 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 device may include multiple battery cells that may be arranged in a specific packing within a housing. For example, the battery cells may be uniformly arranged at a specific distance from each other in a plane. All battery cells of a battery device may be configured similarly. However, a battery device may also include two or more different battery cell types. In the following, for simplicity, reference will be made to a battery cell, but this may also relate to multiple or all battery cells, where applicable.

[0011] The core structure separates the first internal space from the second internal space. The core structure can form a separation wall within the housing internal space. The separation can be fluid-tight, particularly with respect 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 can partially or completely define at least one of the two internal spaces. The separation wall can at least partially or completely define both internal spaces. The triple periodic minimum surface can have the symmetry of a crystal structure. The triple periodic minimum surface can have no interface. Details of the triple periodic minimum surface are described further below. The triple periodic minimum surface can form a very large surface area, thereby enabling very good and uniform heat transfer between the two internal spaces. The triple periodic minimum surface can form recesses corresponding to each battery cell, for example, in the second internal space. The wall of the core structure can be formed, for example, from a metal material or plastic. The triple periodic minimal curved surface can form two channels together with the housing. Heat can be transferred very well between the coolant and the phase change material through the triple periodic minimal curved 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 very well prevent thermal runaway.

[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 cell can be very well suppressed by the phase change material. Thus, each battery cell can be maintained within a desired operating temperature range, particularly with minimal active temperature control. As a result of the arrangement in the first internal space, the operating temperature of the battery cell 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 device, the first and / or second interior space is defined on one side by a covering layer. The covering layer may be formed, for example, by a portion of the housing. On the opposite side, the first and / or second interior space may be defined by an additional covering layer. This additional covering layer may also be formed, for example, by a portion of the housing. The covering layer may be connected to the core structure. Each covering layer may not be electrically conductive. Each covering layer may be formed, for example, as a plate made of an electrically insulating material. Each 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 with the core structure. As a result, the battery device may be configured as a load-bearing structure. As a result, for example, it is possible to omit reinforcement in the vehicle for installing the battery device. Therefore, the battery device may be configured, for example, as a load-bearing part of the chassis. The cover layers can be located on opposite sides of a wall configured as a triple periodic minimal curved surface, thereby defining or completely closing the recesses for the upper and lower battery cells. The cover layers can be connected to the core structure by a joining method such as 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 therebetween. The two cover layers can also be pressed against the core structure by a housing.

[0014] In one embodiment of the battery device, at least one of the cover layers is provided with 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 electrical contact. The through-openings may, for example, be aligned with the 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 cover layers. One or more wires, for example, power lines and / or fluid lines, may be routed through the through-openings. Otherwise, the through-openings may be sealed. As a result, fluids and / or electric currents can be routed to and from the first and / or second interior spaces.

[0015] In one embodiment of the battery device, at least one of the covering layers has a conducting path that contacts the battery cells, and in particular, the conducting path is provided to be 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 etching or depositing it on the covering layer. As a result of the conducting path, the electrical connection to each battery cell can be provided in a compact, robust, and space-saving manner.

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

[0017] In one embodiment of the battery device, 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. Manufacturing may therefore be very simple, in particular since undercuts in the semi-finished products may be avoided. Also, the battery cells may therefore be inserted into 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 includes a first lattice structure disposed within the first interior space. The first lattice structure can 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, particularly 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 individual lattice rods to maintain low pressure loss when the coolant flows through the first interior space.

[0019] In one embodiment of the battery device, the core structure further includes a second lattice structure disposed within the second interior space. The second lattice structure may alternatively or additionally be attached to 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 regions within 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, particularly when the phase-change material changes to its liquid state. The second lattice structure may also improve thermal conductivity, particularly 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 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, the core structure is provided as a double-walled structure having an additional wall. The additional wall may also be substantially in the form of a 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, both walls may have the same basic shape. 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 that of the phase change material in the second internal space to further stabilize the operating temperature. For example, one of the phase change materials may melt at the upper limit of a desired operating temperature range, and the other phase change material may melt at a desired lower limit of the desired operating temperature range. Alternatively, the intermediate space may be configured to allow a coolant to flow through. 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 the first interior space, for example, a constant cooling liquid flow may flow through the first interior space, and cooling liquid may flow only through the intermediate space as soon as the phase change material starts to melt.

[0022] In one 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, the core structure further includes a third lattice structure disposed within the intermediate space. The third lattice structure may secure 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 highly durable and can absorb high mechanical loads. Alternatively, however, the two walls may also be disposed 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 within the intermediate space.

[0024] One embodiment of the battery device provides 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 creating 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, and 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 accurately determined by solving the Weierstrass-Enneper equation.

[0025] In one embodiment of the battery device, the walls of the core structure are defined in a manner that matches the shape of the battery cell. For example, the walls of the core structure may have hexagonal symmetry. As a result, an appropriate 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 device, in particular one of the walls of the core structure of a battery device according to the present invention. The method may include selecting a battery cell shape for each battery cell of the battery device. The method may include defining a desired packing, in particular an arrangement of the battery cells in a plane. The method may include identifying a plane of symmetry within the defined arrangement of the battery cells. The method may include reducing the battery cell surfaces within the defined arrangement to the smallest symmetric unit. The method may include selecting a contact surface between the battery cell and the wall. The method may include defining a contact line at the selected contact surface. The method may include defining a spatial position of the contact line. The method may include determining the shape of the wall substantially as a triply periodic minimal surface according to the defined spatial position of the contact line and the identified plane of symmetry. As a result, a specific triply periodic minimal surface of the battery device can be determined by a simple method. 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 to determine a spring-mass system. 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. An extended finite element method solver, such as ABAQUS / explicit, is suitable for this purpose, for example. Determining the shape of the wall substantially as a triply periodic minimal surface may include converting the equilibrium position into a shape surface to determine the minimal surface. Determining the shape of the wall substantially as a triply periodic minimal surface may include mirroring the shape surface to all identified symmetry planes to generate cells of the triply periodic minimal surface. Determining the shape of the wall substantially as a triply periodic minimal surface may include periodically arranging the generated cells relative to one another according to the arrangement of the battery cells in the desired packing to determine the shape of the walls of the core structure.

[0027] In one embodiment of the battery device, it is provided that the shape of each wall of the core structure separating the two internal spaces from each other is adapted to the shape of the battery cells. As a result, the battery device 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 a cylindrical or rectangular shape of the battery cell, or to a battery cell configured as a pouch cell.

[0028] In one embodiment of the battery device, it is provided that the battery device has a pump device configured to transport the coolant 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 transport the coolant 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 device may also comprise a coolant. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic perspective view showing a first embodiment of a core structure of a battery pack. FIG. [Figure 2] FIG. 1 is a schematic perspective view showing how the coolant flows around a first embodiment of the core structure of the battery pack. [Figure 3] 1 is a schematic cross-sectional view showing how a first embodiment of the core structure of a battery device houses each battery cell and phase change material. FIG. [Figure 4] FIG. 10 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. [Figure 5] 1 is a schematic perspective view showing how a first embodiment of a core structure is manufactured by a deep drawing method; FIG. [Figure 6]10 is a schematic perspective view showing a second embodiment of the core structure of a battery device having an additional lattice structure. FIG. [Figure 7] FIG. 10 is a schematic cross-sectional view showing a lattice structure of a second embodiment of the core structure of the battery device. [Figure 8] FIG. 10 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] 10 shows 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 INVENTION

[0030] 1 is a schematic perspective view showing a first embodiment of a core structure 10 of a battery device. 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 herein has a housing (not shown), which is configured, for example, rectangularly and is configured to completely house the core structure 10. The core structure 10 locally abuts the housing on the outside and is held by the housing. On the upper and lower sides, the housing abuts against the walls 12, respectively, forming covering layers bonded 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, thereby preventing fluid communication 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 interior space 16, which recesses are adapted to the shape of the battery cells 18. A corresponding battery cell 18 is placed in each recess 20.

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

[0034] The first interior space 14 is configured to allow the flow of a coolant 22. In Figures 2 to 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 device has a pump device connected to the first interior space 14 via an inlet and an outlet configured to transport the coolant 22 through the first interior space 14. Thus, the temperature of the battery device can be actively controlled, for example, for cooling and heating. On the upper and / or lower sides, the battery cells 18 are not in contact with the coolant 22. There, the battery cells 18 are electrically connected to supply current to a load and to be able to charge the load.

[0035] For this purpose, the covering layers each 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 each conductive path being deposited or etched on the side remote from the first interior 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 within 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 within 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 therefore between the coolant 22 and the phase change material 24.

[0037] In another embodiment, the phase change material 24 is disposed in the first interior space 14 and the coolant 22 is disposed 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 coolant 22 therethrough.

[0038] The core structure 10 can be manufactured, for example, by additive processes, so that the complex shape of the core structure 10 can be produced in a very simple manner. FIG. 5 is a schematic diagram illustrating a different forming method for manufacturing the core structure 10. A deep-drawing tool 30 is shown forming the negative shape of a portion of the wall 12. A sheet metal plate 32 having 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 blank 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 FIG. 5, two such blanks 36 are joined together, 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 the battery device, and Fig. 7 is a schematic cross-sectional view showing the second embodiment of the core structure 10 of the battery device. 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 includes a first lattice structure 50 disposed within the first interior space 14. The first lattice structure 50 is formed from uniformly spaced metal lattice rods 52 that crosswise connect to the wall 12. The lattice rods may also be connected to the housing, particularly the coating layer, to structurally reinforce the housing. The first lattice structure 50 improves 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 undesirably high flow resistance of the coolant 22 in the first internal space 14 can be avoided. As a result of the fine second lattice structure 54, very good heat transfer between the phase change material 24 and other regions can be achieved, resulting in very good thermal attenuation.

[0045] Fig. 8 is a schematic perspective view showing a third embodiment of the core structure 10 of the battery device, and Fig. 9 is a schematic cross-sectional view showing the third embodiment of the core structure 10 of the battery device. 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 structure with an additional wall 70. The additional wall 70 is arranged parallel to the wall 12 and has the shape of a triply periodic minimal surface, shown in this example as a Schwarz P surface. The core structure defines an intermediate space 74 between the two walls 12, 70. The two walls 12, 70 do not need to be fixed to each other because they are connected to the covering layer. However, in the example shown, the two walls 12, 70 are arranged within the intermediate space 74 and connected to each other by an optional third lattice structure 76, each having lattice rods 78. The third lattice structure 76 improves heat transfer between the two walls 12, 70 and the material arranged within 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, the first lattice structure 50 and / or the second lattice structure 54 may also be provided in addition to the third lattice structure 76. The intermediate space 70 may be configured to allow a coolant to flow therethrough and may be fluidly connected to a pumping device for this purpose. Alternatively, a phase change material may be disposed in the intermediate space 70.

[0048] FIG. 10 schematically illustrates 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 a battery device. Cross sections of typical battery cell shapes, namely, cylindrical battery cells, prismatic battery cells, and pouch cells, are shown. In step 102, an arrangement of the battery cells 18 in a desired packing in a plane is defined. Cylindrical battery cells 18 are, for example, uniformly arranged concentrically around each other. Prismatic battery cells 18 are, for example, uniformly arranged in a row. In step 104, a symmetry plane 106 within the defined arrangement of the battery cells 18 is identified. In step 110, the battery cell surfaces within the defined arrangement are reduced to the smallest symmetry unit, indicated by 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 symmetry unit 108. A contact line is defined on the selected contact surface. The spatial position of the contact line is then defined. The shape of the wall 10 is determined substantially as a triply periodic minimal surface according to the defined spatial positions of the contact lines and the identified symmetry planes. The step of determining the shape of the wall substantially as a triply periodic minimal surface may include converting the mounting surface formed from the defined contact lines into a mesh of prestressed spring elements and mass points to determine a 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. As a result, a specific triply periodic minimal surface of the battery device 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 equilibrium position into a shape surface 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 onto all identified symmetry planes to generate cells of the triply periodic minimal surface. Determining the wall shape substantially as a triply periodic minimal surface may include periodically arranging the generated cells relative to one another according to the 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. In this case, the core structure 10 has a wall 12 with hexagonal symmetry. Also shown at the top of Figure 11 are the individual cells of the wall 12 determined according to the method described above. The cells are periodically arranged relative to one another to generate the 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 plates 34 Through opening 36 Semi-finished products 50 1st lattice structure 52 Lattice rod of first lattice structure 54 Second lattice structure 56 Lattice rod of second lattice structure 70 Additional Walls 74 Intermediate Space 76 Third lattice structure 78 Third lattice structure lattice rod 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 automobile vehicle or a building, comprising: a housing; a core structure (10) disposed within the housing; a first interior space (14) within the housing configured to allow a coolant (22) to flow; 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 battery cell (18) is disposed in the first interior space (14) or the second interior 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 locally abutting 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. The battery device 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. the core structure (10) is 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 3, in particular, wherein the first lattice structure (50) is different from the second lattice structure (54).

6. 4. The battery device according to claim 1, wherein the core structure (10) is configured as a double wall having 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 coolant 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); 7. A battery arrangement according to claim 6, in particular, wherein 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 Schwarz P surface, or A battery arrangement according to any one of claims 1 to 3, wherein each wall (12) of the core structure (10) has hexagonal symmetry.

9. 4. The battery device according to claim 1, 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 claims 1 to 3, further comprising a pump arrangement configured to transport the cooling liquid (22) through the first interior space (14).

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