Cell module and method for manufacturing a cell module, battery module and use of a battery module

Abstract

The invention relates to a cell module (100) for a high-voltage battery of an electrically powered vehicle, comprising a plurality of battery cells (12) connected in series and / or parallel and an evaporator device (40) thermally and mechanically connected to the battery cells (12), wherein the battery cells (12) are stacked in a longitudinal direction (14) and in a vertical direction (16) to form a cell stack (10). The spaces between the battery cells (12) are filled with a mechanically stabilizing and thermally insulating potting compound (18). The evaporator device (40) has a section (44) which, when the cell module (100) is installed in the high-voltage battery as intended, is thermally and mechanically connected to a cooling surface of the high-voltage battery. The invention further relates to a battery module (200) with a number of cell modules (100) as well as a method for manufacturing a cell module (100) and a use of a battery module (200).

Description

[0001] The invention relates to a cell module for a high-voltage battery of an electrically operated vehicle and to a battery module having a number of cell modules, a method for producing a cell module and a use of a battery module.

[0002] High-voltage batteries are typically divided into so-called battery modules. These battery modules contain the battery cells, possibly sensors, and provide a support structure for the battery cells. They also either contain the cooling system or provide the cooling connection for the battery cells. The cell stacks of the battery modules are often constructed from so-called pouch cells or hard-case cells.

[0003] DE 10 2008 034 699 B4 discloses a battery comprising a plurality of battery cells connected in parallel and / or series, and a cooling device thermally connected to the battery cells, including a cooling plate for controlling the temperature of the battery cells. The battery cells are thermally insulated from one another along their longitudinal axes by means of an insulation element.

[0004] DE 10 2021 124 581 A1 describes an electrical energy storage device with a battery module comprising a plurality of battery cells. An electrically insulating filler material formed by a cured potting compound is provided at least in one cavity between the battery cells and / or between a battery cell and a wall of the battery module. Hollow glass spheres or hollow mineral spheres are arranged in the potting compound.

[0005] DE 10 2022 102 336 A1 describes a drive battery with multiple battery cells. The drive battery has a sandwich structure, the upper force-absorbing cover layer and the lower force-absorbing cover layer of which, with respect to a vehicle vertical direction, are each operatively connected to vehicle side sills in which energy-absorbing deformation elements are provided. The cover layers of the drive battery are firmly connected to the end regions of the battery cells, so that the battery cells represent a structural core material of the sandwich structure of the drive battery. The battery cells are structurally permanently and shear-resistantly bonded to the cover layers and additionally operatively bonded to each other via an adhesive potting compound, for example, a resin with low density and low thermal conductivity.

[0006] DE 10 2022 000 147 A1 discloses an energy storage device with direct cooling, which has a coolant path through which a liquid, dielectric coolant can flow directly onto and around at least a respective partial area of ​​the storage cells to cool the storage cells, and a swelling seal held on the housing and directly delimiting at least part of the coolant path, which is formed from a material that swells upon contact with the coolant.

[0007] One object of the invention is to provide a scalable cell module for a high-voltage battery of an electrically operated vehicle.

[0008] Another task is to create a battery module with a number of such cell modules.

[0009] A further object is to provide a method for producing such a cell module.

[0010] A further task is to specify a use of a battery module with such cell modules.

[0011] The above-mentioned objects are solved by the features of the independent claims.

[0012] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

[0013] According to one aspect of the invention, a cell module for a high-voltage battery of an electrically operated vehicle is proposed, comprising a plurality of battery cells connected in series and / or in parallel and an evaporator device thermally and mechanically connected to the battery cells, wherein the battery cells are stacked in a longitudinal direction and in a vertical direction to form a cell stack.

[0014] The spaces between the battery cells are filled with a mechanically stabilizing and thermally insulating potting compound. The evaporator unit has a section that, when the cell module is properly installed in the high-voltage battery, is thermally and mechanically connected to a cooling surface of the high-voltage battery.

[0015] The proposed cell module can advantageously be constructed from standardized battery cells, for example, small-format round cells. Small-format battery cells, in particular, allow any installation space to be filled in a modular manner. By connecting the battery cells in parallel, a desired capacity can be achieved. By connecting them in series, a desired total voltage of the cell module can be achieved.

[0016] At the cell level, standard cells can be used. These cells are highly available and can be supplied in similar designs by many cell manufacturers. Should this specific cell be discontinued, sufficient replacement suppliers are available.

[0017] In this way, the proposed cell module can serve as a spare cell block for batteries whose series production has been discontinued and whose battery cells, whose format is usually adapted to the installation space, are no longer in production. This advantageously ensures the procurement of spare parts even over longer periods.

[0018] With the proposed cell module, the battery cells, especially small-format round cells, can be freely stacked within a predefined installation space and, via the connection to the evaporator device, for example, in the manner of a heat pipe, can be thermally and mechanically connected to a cooling surface of the original series battery. This allows the series battery to continue operating with the existing cooling concept.

[0019] By incorporating the mechanically stabilizing and thermally insulating potting compound, thermal propagation can be advantageously prevented in the event of a thermal event in the cell module, preventing the thermal event from spreading to neighboring battery cells. In particular, small-format round cells generate relatively low amounts of energy in the event of a thermal event, allowing the battery cells to be thermally decoupled with close spacing. The battery cells can advantageously be arranged such that, in the event of a bursting element opening, they vent the hot gases toward the evaporator device, preventing neighboring battery cells from being directly exposed to the volume flow of hot gases. This allows for a high level of safety for the proposed cell module.

[0020] The proposed cell module solves the problem of integrating a cell module consisting of standard cells into the volume of a standard battery. The existing cooling concept can be retained. The cell module design described here enables optimal utilization of a cubic volume to realize the energy content of a standard battery.

[0021] According to an advantageous embodiment of the cell module, the cell stack can be thermally and mechanically connected to the evaporator device by means of a heat-conducting medium. This allows for a high heat transfer rate and thus efficient heat dissipation from the battery cells. Materials with a high thermal conductivity in the range greater than 3 W / mK can be advantageously used for this purpose.

[0022] According to an advantageous embodiment of the cell module, the potting compound can contain hollow bodies, in particular hollow glass spheres, as filler material. The potting compound serves both to mechanically stabilize the cell module and to provide thermal insulation, thus preventing thermal propagation. An epoxy resin, for example, can be used as the potting compound, which is well suited due to the small cell spacing. In principle, other thermally insulating materials such as polyurethane (PU) foams can also be used.

[0023] Spaces between the battery cells can be advantageously filled with a filler material using vacuum casting, which cures after the casting process. The filler material can advantageously consist of an epoxy casting resin in which hollow bodies, such as hollow glass spheres, are homogeneously distributed. The thermal conductivity of the hollow glass spheres is less than 0.1 W / mK.

[0024] The proportion of hollow glass spheres in the filler material can, for example, be between 60% and 75%. The nominal diameter of the hollow glass spheres can vary between 100 µm and 180 µm. Additionally, the hollow glass spheres can be designed with wall thicknesses less than 10% of the nominal diameter to enable the filler material to have the lowest possible thermal conductivity while maintaining high thermal resistance and a low weight.

[0025] The casting compound can be advantageously exposed to UV light to cure.

[0026] The composition of the filler material can be selected so that, in addition to high thermal resistance and thermal insulation between the individual battery cells, it improves the defined structural integrity of the cell module and enables the desired transmission of specified compressive, tensile and shear forces.

[0027] According to an advantageous embodiment of the cell module, cell poles of the battery cells can be electrically contacted by means of a printed circuit board, in particular by bonding, in particular by laser bonding, wherein the printed circuit board is glued to the cell stack. The cell poles can advantageously be electrically contacted to the printed circuit board by wire bonding. The printed circuit board can be mechanically and electrically insulated from the cell stack by means of an adhesive. A serial and / or parallel connection of the battery cells can be set via the printed circuit board. By connecting several individual round cells in parallel, a logical cell can be created which has the same energy content as the cell in the original cell block.

[0028] According to an advantageous embodiment of the cell module, the circuit board can have contact poles on at least one end face, by means of which the cell module can be electrically connected to other cell modules. Thus, a battery module can be created by interconnecting any number of cell modules.

[0029] According to a further aspect of the invention, a battery module with a number of cell modules is proposed, wherein the cell modules are arranged next to one another and are electrically connected via contact poles of the cell modules by means of busbars.

[0030] The proposed battery module can advantageously be constructed from cell modules with standardized battery cells, for example, small-format round cells. Small-format battery cells, in particular, allow any installation space to be filled in a modular manner. By connecting the battery cells in parallel, a desired capacity can be achieved. By connecting the cell cells in series, a desired total voltage of the cell module can be achieved, and by connecting the cell modules appropriately, a desired total voltage of the battery module can be achieved.

[0031] To achieve the same voltage level as in the original battery module, the cell modules are connected in series. The number of cell modules multiplied by the number of battery cells connected in series within the cell module must result in the same number of cells as in the original battery module.

[0032] To cool the battery cells, the evaporator units of the individual cell modules can be thermally connected to the original cooling surfaces, such as cooling plates, of the high-voltage battery via suitable heat-conducting media. This allows the original battery to continue operating with the original cooling concept.

[0033] In this way, the proposed battery module can serve as a spare parts module for batteries whose series production has been discontinued and whose battery cells, whose format is usually adapted to the installation space, are no longer in production. This advantageously ensures the procurement of spare parts even over longer periods.

[0034] The proposed battery module thus solves the problem of integrating a battery module consisting of standard cells into the production installation space. The existing cooling concept can be retained. The battery module design described here enables optimal utilization of a cubic installation space to realize the energy content of the production battery.

[0035] The battery module can be mechanically connected to the battery housing using the standard screw points and contact points. The battery module is screwed into the same locations as the original part. The electrical contact is also designed the same as the original part.

[0036] Due to the plug compatibility of the battery module, the replacement module can be controlled via the series electronics.

[0037] By selecting the appropriate round cell for the cell modules, no adjustments to the series software are required. The replacement module does not impair functionality when used in conjunction with the remaining series modules.

[0038] The availability of battery modules as spare parts is therefore not dependent on final stock levels or a manufacturer of battery cells for special formats.

[0039] At the cell level, standard cells can be used. These cells are highly available and can be supplied in similar designs by many cell manufacturers. Should this specific cell be discontinued, sufficient replacement suppliers are available.

[0040] After initial qualification, a replacement cell can be used for many high-voltage battery series. This significantly increases the production quantities of battery cells. Furthermore, in the event of further development of the battery cell, only one cell needs to be qualified, which is then used in all replacement parts.

[0041] The replacement parts are safer than the original cell blocks due to their ability to prevent thermal propagation.

[0042] The customer always receives replacement cell blocks with new cells. Overstocking is impossible.

[0043] The battery module concept can be scaled to other battery series.

[0044] According to an advantageous embodiment of the battery module, end plates can be arranged on the end faces of the cell modules. Contact plates can be arranged on the end plates, which are electrically coupled to the busbars and provide an electrical voltage of the battery module to the electrical module connections. In particular, the contact plates can be glued to the cell modules and / or the end plates. The high-voltage potential can be conducted to the outside via the contact plates. The battery module can thus advantageously provide electrical module connections similar to those found on the original series module.

[0045] According to an advantageous embodiment of the battery module, a common cover plate can be arranged on the cell modules, which overlaps the number of cell modules. In particular, the cover plate can be glued to the cell modules. The cover plate can advantageously hold the cell modules together mechanically. By attaching additional attachments, the battery module can be inserted and secured into the original series battery as a spare part, depending on the battery type and the series geometries and series holders.

[0046] According to a further aspect of the invention, a method for producing a cell module is proposed, at least comprising stacking a plurality of battery cells in a longitudinal direction and in a vertical direction to form a cell stack; filling gaps between the battery cells with a mechanically stabilizing and thermally insulating potting compound; thermally and mechanically connecting the cell stack to an evaporator device, in particular via a heat-conducting medium; arranging, in particular gluing, a printed circuit board to the cell stack; and serially and / or parallelly connecting the battery cells by means of the printed circuit board.

[0047] By means of the proposed method, the cell module described above can be manufactured in a simple and cost-effective manner.

[0048] The cell module can advantageously be constructed from standardized battery cells, such as small-format round cells. Small-format battery cells, in particular, allow any installation space to be filled in a modular manner. By connecting the battery cells in parallel, a desired capacity can be achieved. By connecting them in series, a desired total voltage of the cell module can be achieved.

[0049] With the cell module, the battery cells, especially small-format round cells, can be freely stacked within a predefined installation space and, via the connection to the evaporator device, for example, in the manner of a heat pipe, can be thermally and mechanically connected to a cooling surface of a series battery. This allows the series battery to continue operating with the existing cooling concept.

[0050] By incorporating the mechanically stabilizing and thermally insulating potting compound, thermal propagation can be advantageously prevented in the event of a thermal event in the cell module, preventing the thermal event from spreading to neighboring battery cells. In particular, small-format round cells generate relatively low amounts of energy in the event of a thermal event, allowing the battery cells to be thermally decoupled with close spacing. The battery cells can advantageously be arranged such that, in the event of a bursting element opening, they vent the hot gases toward the evaporator device, preventing neighboring battery cells from being directly exposed to the volume flow of hot gases. This allows for a high level of safety for the proposed cell module.

[0051] According to a further aspect of the invention, the use of a battery module as a replacement module in a high-voltage battery of an electrically operated vehicle is proposed, wherein the battery module has electrical, mechanical and thermal interfaces of an original battery module of the high-voltage battery, and wherein sections of evaporator devices of the battery module are thermally and mechanically connected to a cooling surface of the high-voltage battery, in particular via a heat-conducting medium.

[0052] At the cell level, the battery module can utilize standard cells. These cells are widely available and can be supplied in similar designs by many cell manufacturers. Should this specific cell be discontinued, sufficient replacement suppliers are available.

[0053] In this way, the cell module can serve as a spare cell block for batteries whose series production has been discontinued and whose battery cells, whose format is usually adapted to the installation space, are no longer in production. This advantageously ensures the availability of spare parts even over longer periods.

[0054] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0055] Showing: Fig. 1 is a schematic exploded view of a cell module according to an embodiment of the invention; Fig. 2 a schematic exploded view of a battery module according to an embodiment of the invention; and Fig. 3 a flowchart of a method for producing a cell module according to an embodiment of the invention.

[0056] In the figures, identical or similar components are numbered with the same reference numerals. The figures show only examples and are not to be understood as limiting.

[0057] Fig. 1 shows a schematic exploded view of a cell module 100 according to an embodiment of the invention.

[0058] The cell module 100 for a high-voltage battery of an electrically powered vehicle has a plurality of battery cells 12 connected in series and / or parallel. For this purpose, the battery cells 12 are stacked in a longitudinal direction 14 and a vertical direction 16 to form a cell stack 10. Gaps between the battery cells 12 are filled with a mechanically stabilizing and thermally insulating potting compound 18 (shown schematically). The potting compound 18 can advantageously comprise hollow bodies, in particular hollow glass spheres, as filler material. The potting compound 18 serves, on the one hand, for mechanical stabilization and, on the other hand, for thermal insulation, so that thermal propagation can advantageously be prevented in the event of a thermal event in a battery cell 12. An epoxy, for example, can be used as the potting compound 18.

[0059] The proportion of hollow glass spheres in the filler material can, for example, be between 60% and 75%. The nominal diameter of the hollow glass spheres can vary between 100 µm and 180 µm. Additionally, the hollow glass spheres can be designed with wall thicknesses less than 10% of the nominal diameter to enable the filler material to have the lowest possible thermal conductivity while maintaining high thermal resistance and a low weight.

[0060] The potting compound 18 can advantageously be exposed to UV light for curing.

[0061] The filling material can be selected with regard to its composition such that, in addition to the high thermal resistance and the thermal insulation between the individual battery cells 12, it improves the defined structural integrity of the cell module 100 and enables a desired transmission of predetermined compressive, tensile and shear forces.

[0062] The cell module 100 further comprises an evaporator device 40 thermally and mechanically connected to the battery cells 12. Section 42 of the evaporator device 40 is in thermal contact with the end surfaces of the battery cells 12, thereby dissipating heat from the battery cells 12.

[0063] The evaporator device 40 has a section 44, which, when the cell module 100 is properly installed in the high-voltage battery, is thermally and mechanically connected to a cooling surface of the high-voltage battery. To achieve better thermal contact, a heat-conducting medium 32 can be arranged between the section 44 and the cooling surface of the battery. The cell stack 10 is thermally and mechanically connected to the evaporator device 40 by means of a heat-conducting medium 30. For this purpose, the heat-conducting medium 30 can expediently have a high thermal conductivity in the range greater than 3 W / mK.

[0064] The evaporator device 40 can, for example, be designed to function as a heat pipe. Heat from the battery cells 12 is absorbed in section 42 of the evaporator device 40 and causes a cooling medium contained in the evaporator device 40 to evaporate. The evaporated cooling medium is transported to section 44, where it transfers the heat to the cooling surface of the battery, and thereby condenses. The condensed liquid is returned to section 42, thus restarting the cycle.

[0065] Cell poles of the battery cells 12 are electrically contacted by means of a printed circuit board 20, in particular by bonding, in particular by laser bonding. The printed circuit board 20 can expediently be bonded to the cell stack 10 by means of an adhesive 26 or adhesive strips (shown schematically).

[0066] The circuit board 20 allows the serial and parallel connection of the battery cells 12 to be configured. By connecting several individual round cells 12 in parallel, a logic cell can be created that has the same energy content as the logic cell in the original cell block.

[0067] The circuit board 20 has contact poles 22 on at least one end face 24, by means of which the cell module 100 can be electrically connected to other cell modules 100.

[0068] Fig. 2 shows a schematic exploded view of a battery module 200 according to an embodiment of the invention

[0069] The battery module 200 has a number of cell modules 100 as shown in Fig. 1. The cell modules 100 are arranged next to one another in the transverse direction 17 and are electrically connected via contact poles 22 of the printed circuit boards 20 of the cell modules 100 by means of short busbars 54.

[0070] End plates 70 are arranged on the end faces 62 of the cell modules 100 for mechanical stabilization.

[0071] Contact plates 60 are arranged on the end plates 70. The contact plates 60 are electrically coupled to the busbars 54. Electrical module connections 64 on the contact plates 60 provide an electrical voltage to the battery module 200.

[0072] The contact plates 60 can be glued to the cell modules 100 and / or the end plates 70, in particular via adhesive strips.

[0073] Thus, the battery module 200 can provide the same external geometry and electrical connections 64 as the original battery module as a replacement part and can be conveniently installed into the original battery as a replacement part. The battery module 200 can perform the same electrical functions as the original battery module.

[0074] A common cover plate 50 is arranged on the cell modules 100, which overlaps the number of cell modules 100 and thus contributes to the mechanical stabilization of the battery module 200. The cover plate 50 can be glued to the cell modules 100, for example, using adhesive strips 52.

[0075] Additional attachments, not shown, can be used to create series geometries and series holders and are battery-specific. The battery module 200 can then be inserted into the battery and secured using the series screw points.

[0076] The described battery module 200 can thus advantageously be used as a replacement module in a high-voltage battery of an electrically powered vehicle. For this purpose, the battery module 200 has electrical, mechanical, and thermal interfaces of an original battery module of the high-voltage battery. Sections 44 of evaporator devices 40 of the battery module 200 are thermally and mechanically connected to a cooling surface of the high-voltage battery, in particular via a heat-conducting medium 32, for cooling the battery cells 12.

[0077] In Fig. 3 is a flowchart of a method for manufacturing a cell module 100 according to an embodiment of the invention.

[0078] According to the proposed method, in a first step S100, a plurality of battery cells 12 are stacked in a longitudinal direction 14 and in a vertical direction 16 to form a cell stack 10.

[0079] In a next step S102, spaces between the battery cells 12 are filled with a mechanically stabilizing and thermally insulating potting compound 18.

[0080] Thereafter, in step S104, the cell stack 10 can be thermally and mechanically connected to an evaporator device 40, in particular via a heat-conducting medium 30.

[0081] In the next step S106, a circuit board 20 is arranged, in particular glued, on the cell stack 10.

[0082] In step S108, the battery cells 12 are connected in series and / or parallel by means of the circuit board 20, in particular by wire bonding.

[0083] This allows a cell module 100 to be manufactured in a simple and cost-effective manner for use in a battery module 200 as a replacement module for a high-voltage battery. List of reference symbols 10 cell stacks 12 battery cells 14 Longitudinal direction 16 Vertical direction 17 Transverse direction 18 Potting compound 20 circuit board 22 contact pole 24 front side 26 Adhesive 30 Heat-conducting medium 32 Heat-conducting medium 40 Evaporator device Section 42 Section 44 50 cover plate 52 adhesive strips 54 Busbar 60 contact plate 62 front side 64 module connection 70 End plate 100 cell modules 200 battery modules 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] DE 10 2008 034 699 B4

[0003] DE 10 2021 124 581 A1

[0004] DE 10 2022 102 336 A1

[0005] DE 10 2022 000 147 A1

[0006]

Claims

[1] Cell module (100) for a high-voltage battery of an electrically operated vehicle, with a plurality of battery cells (12) connected in series and / or in parallel and an evaporator device (40) thermally and mechanically connected to the battery cells (12), wherein the battery cells (12) are stacked in a longitudinal direction (14) and in a vertical direction (16) to form a cell stack (10), wherein spaces between the battery cells (12) are filled with a mechanically stabilizing and thermally insulating potting compound (18), wherein the evaporator device (40) has a section (44) which, when the cell module (100) is installed as intended in the high-voltage battery, is thermally and mechanically connected to a cooling surface of the high-voltage battery. [2] Cell module according to claim 1, wherein the cell stack (10) is thermally and mechanically connected to the evaporator device (40) by means of a heat-conducting medium (30). [3] Cell module according to claim 1 or 2, wherein the potting compound (18) comprises hollow bodies, in particular hollow glass spheres, as filling material. [4] Cell module according to one of the preceding claims, wherein cell poles of the battery cells (12) are electrically contacted by means of a printed circuit board (20), in particular by bonding, in particular by laser bonding, wherein the printed circuit board (20) is glued to the cell stack (10). [5] Cell module according to one of the preceding claims, wherein the printed circuit board (20) has contact poles (22) on at least one end face (24), by means of which the cell module (100) can be electrically connected to other cell modules (100). [6] Battery module (200) with a number of cell modules (100) according to one of the preceding claims, wherein the cell modules (100) are arranged next to one another and are electrically connected via contact poles (22) of the cell modules (100) by means of busbars (54). [7] Battery module according to claim 6, wherein end plates (70) are arranged on end faces (62) of the cell modules (100), wherein contact plates (60) are arranged on the end plates (70), which are electrically coupled to the busbars (54) and provide an electrical voltage of the battery module (200) at electrical module terminals (64), in particular wherein the contact plates (60) are glued to the cell modules (100) and / or the end plates (70). [8] Battery module according to claim 6 or 7, wherein a common cover plate (50) is arranged on the cell modules (100), which overlaps the number of cell modules (100), in particular wherein the cover plate (50) is glued to the cell modules (100). [9] Method for producing a cell module (100) according to one of the preceding claims, at least comprising Stacking a plurality of battery cells (12) in a longitudinal direction (14) and in a vertical direction (16) to form a cell stack (10); Filling spaces between the battery cells (12) with a mechanically stabilizing and thermally insulating potting compound (18); Thermally and mechanically connecting the cell stack (10) to an evaporator device (40), in particular via a heat-conducting medium (30); Arranging, in particular gluing, a printed circuit board (20) to the cell stack (10); Serial and / or parallel connection of the battery cells (12) by means of the circuit board (20). [10] Use of a battery module (200) according to one of claims 6 to 8 as a replacement module in a high-voltage battery of an electrically operated vehicle, wherein the battery module (200) has electrical, mechanical and thermal interfaces of an original battery module of the high-voltage battery, wherein sections (44) of evaporator devices (40) of the battery module (200) are thermally and mechanically connected to a cooling surface of the high-voltage battery, in particular via a heat-conducting medium (32).

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