Easy-to-manufacture energy storage system and motor vehicle with it

Abstract

The present invention relates to an energy storage device (2) and a motor vehicle (1) equipped therewith. The energy storage device (2) comprises several individual battery cells (6) and a prefabricated, one-piece monolithic mounting block (4). The mounting block is made of an electrically insulating material and has several individual recesses (5). Exactly one of the battery cells (6) is inserted into each of these recesses (5) in a vertical direction (H), such that the material of the mounting block (4) completely surrounds each of the battery cells (6) perpendicular to the vertical direction (H).

Description

[0001] The present invention relates to an energy storage device, in particular a rechargeable battery for a motor vehicle. The invention further relates to a motor vehicle with such an energy storage device.

[0002] Batteries are already known in many different forms and are used in a wide variety of applications. Various challenges exist, such as achieving the highest possible performance, particularly low weight and resource requirements, good safety (e.g., through more efficient cooling), the greatest possible robustness, the simplest possible production, and / or other similar challenges.

[0003] As one approach, US 2012 / 0 021 260 A1 describes a battery module with multiple cells and a temperature regulator. The latter includes a heat transfer element through which the serially connected cells are isolated from each other in a liquid-tight manner.

[0004] As a further approach, EP 3 188 279 A1 describes a battery pack for an electric vehicle. The battery pack comprises several battery cells and a cooling loop, as well as a molded insert. The latter encloses the cells and the cooling loop, thus securing them relative to each other.

[0005] As a further approach, EP 3 748 764 A1 describes an energy source with multiple battery cells, a cooling plate, and a circular gate for circulating a coolant in a coolant channel of the cooling plate. The cooling plate has a structure that allows the coolant to flow in both longitudinal and lateral cooling channels.

[0006] Another conventional approach involves enclosing individual battery cells with a foam material to meet thermal and mechanical requirements. However, these current approaches also have drawbacks, so there is a need for further improvements.

[0007] The object of the present invention is to avoid the disadvantages of conventional energy storage devices, in particular foaming, gluing or casting battery cells in a multi-cell energy storage device.

[0008] This problem is solved by the subject matter of the main claim and the subsidiary claim or the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.

[0009] The energy storage device according to the invention has a plurality of individual rechargeable battery cells. The energy storage device according to the invention can therefore be a multi-cell battery or secondary battery. For example, the energy storage device according to the invention can be designed as a traction battery for an electric motor vehicle or the like. Furthermore, the energy storage device according to the invention has a prefabricated, one-piece, monolithic receiving block made of a dimensionally stable, electrically insulating material. This receiving block has a plurality of individual receptacles and can therefore also be referred to as a hollow block. Exactly one of the battery cells is inserted into each of these receptacles of the receiving block in a vertical direction, so that the material of the receiving block individually and completely, i.e. all the way around, each of the battery cells when viewed perpendicular to the vertical direction or in the circumferential direction around the vertical direction.

[0010] The size of the receptacles perpendicular to the vertical direction, for example their length and width or their diameter, can at least substantially correspond to the corresponding size or extent of one of the battery cells, for example except for tolerances or manufacturing requirements or additional space for a connecting layer or a layer of a leveling or thermally conductive compound or the like. The receptacle block can therefore form a solid matrix for the battery cells, which can be manufactured in advance and is dimensionally stable. The battery cells can then be inserted into this matrix during production of the energy storage device. The receptacle block can thus hold and fix the battery cells at least perpendicular to the vertical direction, for example relative to the receptacle block and thus also relative to one another.The fact that the mounting block can be manufactured as a standalone component independent of the battery cells enables particularly simple and cost-effective production and assembly.

[0011] In particular, the energy storage device according to the invention can be free of any foaming or encapsulation surrounding or securing the battery cells, i.e., a corresponding foam material. In conventional energy storage devices, the battery cells can be overmolded with such a foam material. While this can secure the battery cells, it can pose the challenge of preventing the battery cells from being moved or stuck together by the foam material when it is injected. Furthermore, with such foaming or encapsulation of the battery cells, individual battery cells cannot be replaced or can only be replaced with considerable effort. Likewise, the foaming can complicate the analysis or analyzability of faults in the energy storage device or individual battery cells of the energy storage device and ultimately cause a comparatively high consumption of resources.Also, typical foam materials must first dry or harden after being injected, which takes a considerable amount of time and can slow down, make more complex, or expensive the production of the energy storage device.

[0012] These disadvantages can be avoided by the present invention. For example, by appropriately designing the receptacles, it can be ensured that the individual battery cells can be removed from the receptacle block particularly easily, and in particular non-destructively, for example in the vertical direction. This can, for example, make the battery cells easier to replace and thus improve the longevity or sustainability of the energy storage device as a whole. Because the receptacle block can be prefabricated separately, the energy storage device can then be easily assembled without any drying or curing time. This can be achieved with very few manual steps or manufacturing steps, since the receptacle block is manufactured as a single piece.In other words, the energy storage unit, for example, does not require a mounting or compartment structure for the battery cells to be assembled or constructed from multiple individual parts. This not only reduces manufacturing costs but also potentially reduces susceptibility to errors, improves robustness, and ensures particularly uniform thermal behavior of the mounting block and thus of the energy storage unit as a whole.

[0013] In one possible embodiment of the present invention, the receiving block is made of a plastic material. This allows the receiving block to be particularly lightweight and cost-effective and also function as electrical insulation between the battery cells. Because the receiving block is a separate component, requirements regarding the electrical insulation of adjacent battery cells can be met particularly easily and reliably by maintaining appropriate spacing between the individual receptacles. For example, incomplete filling of a space between the battery cells, or the formation of excessively large bubbles or the like, which is possible in a display material, can be easily avoided or circumvented.At the same time, by selecting a suitable plastic material from the multitude of plastic materials available today, individual adaptation to the specific requirements of a specific application can be achieved. This provides the appropriate flexibility of the energy storage device according to the invention and its properties.

[0014] In a possible further development of the present invention, the receiving block is designed as an injection-molded part. In other words, the receiving block can be manufactured or prefabricated using an injection molding process. This can enable particularly rapid and cost-effective production of the receiving block or a plurality of such receiving blocks for series or mass production of the energy storage device.

[0015] In a further possible embodiment of the present invention, the receptacles and the battery cells are cylindrically shaped. In particular, the receptacles can be arranged offset from one another perpendicular to the vertical direction. In other words, adjacent rows of receptacles can be offset from one another perpendicular to the vertical direction, for example by half the diameter of a receptacle, analogous to the arrangement with the closest sphere packing. Cylindrical battery cells can offer various advantages. In principle, however, arranging and securing cylindrical battery cells can be more difficult than, for example, securing or arranging at least substantially cuboid-shaped prismatic battery cells or the like. In the present case, however, this difficulty is solved in a particularly simple manner by the receptacle block.With the proposed use of cylindrical mounts and cylindrical battery cells, the vertical direction can correspond to a respective cylinder axis. The direction perpendicular to the vertical direction can therefore pass through a respective cylinder surface.

[0016] In a further possible embodiment of the present invention, the height of the receptacles in the vertical direction corresponds at least to a large part of the height of the battery cells in the vertical direction. In other words, the battery cells can be surrounded by the material of the receptacle block over a large part of their height. For example, the height of the receptacles, i.e. their extension in the vertical direction, can be at least 50% or at least 70% or at least 90% of the height or extension of the battery cells in the vertical direction. The battery cells can therefore be held and fixed particularly robustly and reliably by means of the receptacle block. For example, mechanical loads or forces can thus be distributed particularly evenly or over a particularly large area of ​​the battery cells.In addition, the mounting block can then provide a correspondingly large contact surface to the outer walls of the battery cells, so that particularly effective and even heat dissipation of the battery cells can be enabled.

[0017] In a further possible embodiment of the present invention, the receptacles or the receptacle block are flatter in the vertical direction than the battery cells, so that the battery cells protrude from the receptacle block at one end or both ends in the vertical direction, i.e. at their top and / or their bottom. For example, a respective contact or cell housing cover or cell housing base of the battery cells can protrude completely or partially from the respective receptacle. If the battery cells protrude from the receptacle block, for example at their top or with their cover, this can enable particularly simple and reliable electrical contacting of the battery cells. This can then, for example, prevent an installation space conflict or a cell contacting system from colliding with the receptacle block. If the battery cells protrude at their bottom orwith its base protruding from the receiving block, a particularly simple and reliable thermal connection on the corresponding underside of the battery cells to a cooling plate or the like can be enabled or ensured.

[0018] In a further possible embodiment of the present invention, a thermally conductive leveling compound, in particular an electrically insulating or non-electrically conductive one, is arranged between an outer side of one of the battery cells and an inner side of the corresponding receptacle facing said cell. Such a thermally conductive leveling compound can be soft or malleable, in particular flowable or spreadable, permanently or at least during assembly, i.e., the manufacture of the energy storage device. The leveling compound can thus compensate for tolerances and unevenness or fill unevenness or gaps. The leveling compound can, for example, be a thermally conductive paste or a thermally conductive adhesive or the like.This allows for a particularly good, uniform, and full-surface thermal connection of the battery cells to the material of the mounting block, while simultaneously facilitating particularly simple production of the energy storage device. The latter is possible because the mountings can then be slightly larger than the battery cells perpendicular to the vertical direction, allowing the battery cells to be inserted into the mountings with minimal resistance and eliminating the need to press them into the mountings.

[0019] Although, particularly in conventional cylindrical battery cells, a primary heat transfer device can run vertically, the embodiment of the present invention proposed here also allows the support block to be used to dissipate heat from the battery cells. Because the battery cells are surrounded by the support block material on all sides and thermally bonded to it over a correspondingly large area by means of the thermally conductive compensating compound, particularly effective and uniform heat dissipation and temperature control of the battery cells is possible.

[0020] In a further possible embodiment of the present invention, the receiving block has at least one cooling channel, which is arranged or formed in the material of the receiving block between the receptacles and is elongated, i.e. runs, perpendicular to the vertical direction. In other words, a flow direction of a cooling medium flowing through the at least one cooling channel can be or run at least substantially perpendicular to the vertical direction. Because the receiving block is prefabricated here as an independent, dimensionally stable component, it can also be used to guide a cooling medium or coolant, or to provide or accommodate the at least one cooling channel or a corresponding coolant line. This means that a separate coolant line, which in a conventional energy storage device would also have to be individually fixed and foamed in, can be dispensed with, or such a coolant line can be realized or implemented particularly easily.be arranged in the energy storage device. The receiving block can therefore also serve as a matrix for forming or accommodating at least one cooling channel or a corresponding coolant line. Thus, the receiving block can be multifunctional and serve not only to hold, fix, and protect the battery cells, but also to cool or temper them.

[0021] In a further possible embodiment of the present invention, the energy storage device has an outer housing in which the receiving block is arranged. During production of the energy storage device, for example, the receiving block can first be inserted into the outer housing. The battery cells can then be inserted into the receiving block. Likewise, the battery cells can be inserted into the receiving block outside the outer housing and then the assembly or combination of the receiving block and the battery cells inserted therein can be inserted into the outer housing. Further components, such as a cell contact system for electrically contacting the battery cells or a battery management system or sensors, for example for monitoring voltage, state of charge or temperature and / or the like, can be arranged in the outer housing.By arranging the mounting block in such an outer housing, the mounting block can be designed in a particularly minimalist manner and specifically optimized for its actual functionality as a matrix for the battery cells. For example, the mounting block does not have to completely surround the battery cells in all directions to ensure their protection and electrical insulation, etc. This can also benefit the energy storage device's particularly simple production and the particularly easy replacement of individual battery cells.

[0022] The present invention also relates to a motor vehicle equipped with the energy storage device according to the invention. The energy storage device according to the invention can serve or be configured, in particular, as a traction battery of the motor vehicle.

[0023] Further features of the invention may emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0024] The drawing shows: Fig. 1 a partial schematic representation of a motor vehicle with an improved energy storage device; and Fig. 2 a partial schematic side view of the energy storage device.

[0025] In the figures, identical and functionally equivalent elements are provided with the same reference numerals. For the sake of clarity, only a representative selection of identical or similar elements may be explicitly identified in the figures.

[0026] Fig. 1 shows a partial schematic representation of a motor vehicle 1 with an energy storage device 2, which here can in particular be a traction battery of the motor vehicle 1. The energy storage device 2 can therefore be designed in particular as a high-voltage battery or high-voltage storage device (HVS). The energy storage device 2 has an outer housing 3 in which a receiving block 4 is arranged. The receiving block 4 can in particular be made of a plastic material. The receiving block 4 has a plurality of recesses or receptacles 5. In each of these receptacles 5, one of a plurality of battery cells 6 of the energy storage device 2 is inserted.

[0027] The battery cells 6 are thus held or fixed relative to one another by the support block 4. Compared to conventional traction batteries, in which the individual battery cells 6 are foamed or encased, i.e., surrounded by foam, this foam can be omitted in the energy storage device 2 shown here and effectively or functionally replaced by the support block 4.

[0028] For further illustration, Fig.2 shows a partial schematic side or cross-sectional view of the energy storage device 2. Here, it can be seen that the battery cells 6 can protrude beyond the receiving block 4 at their ends in a schematically illustrated vertical direction H. It can also be seen here that cooling channels 8 can be arranged or formed in intermediate regions 7 between adjacent battery cells 6 in the receiving block 4. By way of example, the energy storage device 2 here has two cooling channels 8 arranged one above the other in the vertical direction H. For example, a coolant or cooling medium can flow in opposite directions through these cooling channels 8 arranged one above the other, so that one of the cooling channels 8 can function as an inlet and the other as a return. However, other configurations of cooling channels 8 and / or flow patterns are also possible.

[0029] Overall, the described examples show how a hollow block with integrated cooling can be realized and used as a matrix for cells in an electrical energy module instead of a foam matrix. List of reference symbols 1 motor vehicle 2 energy storage units 3 outer casings 4 Recording block 5 recordings 6 battery cells 7 intermediate areas 8 cooling channel H Vertical direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2012 / 0 021 260 A1

[0003] EP 3 188 279 A1

[0004] EP 3 748 764 A1

[0005]

Claims

[1] Energy storage device, comprising a plurality of individual battery cells and a prefabricated one-piece monolithic receiving block, which is made of a dimensionally stable electrically insulating material and has a plurality of individual receptacles, into each of which exactly one of the battery cells is inserted in a vertical direction, so that the material of the receiving block completely surrounds each of the battery cells perpendicular to the vertical direction. [2] Energy storage device according to claim 1, characterized by that the receiving block is made of a plastic material. [3] Energy storage device according to claim 2, characterized by that the mounting block is an injection-molded part. [4] Energy storage device according to one of the preceding claims, characterized by that the receptacles and the battery cells are cylindrically shaped, in particular with an arrangement offset from one another perpendicular to the vertical direction. [5] Energy storage device according to one of the preceding claims, characterized by that the height of the mounts in the vertical direction corresponds at least to a large part of the height of the battery cells in the vertical direction. [6] Energy storage device according to one of the preceding claims, characterized by that the receptacles are flatter in the vertical direction than the battery cells, so that the battery cells protrude from the receptacle block at their top and / or bottom. [7] Energy storage device according to one of the preceding claims, characterized by that a thermally conductive compensating mass is arranged between the outer sides of the battery cells and the inner sides of the receptacles facing them for the thermal connection of the battery cells to the receptacle block. [8] Energy storage device according to one of the preceding claims, characterized by that the receiving block has at least one cooling channel which is arranged in the material of the receiving block between the receptacles and is elongated perpendicular to the vertical direction. [9] Energy storage device according to one of the preceding claims, characterized by that the energy storage device has an outer housing in which the receiving block is arranged. [10] Motor vehicle, comprising an energy storage device according to one of the preceding claims, in particular as a traction battery.

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