CONTACTING BOARD

Description

[0001] The invention relates to a contacting board for an energy storage module, in particular for a lithium-ion rechargeable battery, comprising a flexible plastic substrate that provides first conductor tracks for electrically connecting a sensor board to terminals of the energy storage module. The invention further relates to an energy storage module, in particular a lithium-ion rechargeable battery, comprising a plurality of electrically interconnected lithium-ion cells, wherein the energy storage module is equipped with a contacting board.

[0002] According to DE 10 2015 010 925 A1, a cell connector unit and / or cell voltage tap unit is known from the prior art. This unit has a base body, which can also be referred to as a circuit board and made of plastic. This base body is equipped with a temperature control unit, which can be electrically connected, specifically in the form of a heating device. A meandering resistance wire can be provided as the heating device.

[0003] Furthermore, a battery module with multiple battery cells is known from the prior art according to US 2020 / 036064 A1, wherein the cell terminals of the battery cells are connected to each other via busbars. These busbars are covered by heating groups, each heating group having a heat-conducting pad. Each pad is in contact with a heat-conducting distribution plate, with heating elements attached to the heat-conducting distribution plates.

[0004] A contacting board of the type mentioned at the beginning, ie of the generic type, is known from EP 3 715 171 B1.

[0005] The contacting board known from EP 3 715 171 B1 has a flexible plastic substrate. This is designed, for example, like a foil.

[0006] The plastic substrate has first conductor tracks, which, in the final assembled state, serve to connect a sensor board to the connection terminals of the energy storage module. For this purpose, the contacting board has contact elements, which, in the final assembled state, are electrically connected to the connection terminals of the energy storage module. The plastic substrate has first conductor tracks, which, in the final assembled state, serve to connect a sensor board to the connection terminals of the energy storage module. For this purpose, the contacting board has contact elements, which, in the final assembled state, are electrically connected to the connection terminals of the energy storage module.

[0007] The first conductor tracks, which the plastic substrate has, are electrically connected at one end to the contacting elements that interact with the connection terminals of the energy storage module, and at the other end to a sensor board, thus forming an electrically conductive connection between the sensor board and the connection terminals of the energy storage module. The sensor board can be designed as a separate board or as a component of the contacting board.

[0008] The sensor board has an electronic circuit designed to evaluate voltage measurements.

[0009] The energy storage module has a plurality of electrically interconnected cells. Each cell has two terminals: a negative terminal and a positive terminal. For voltage measurement, the individual cells of the energy storage module are electrically connected to the sensor board, for which purpose the contacting board serves the purpose described above.

[0010] Voltage values ​​detected by the sensor board can be evaluated using the electronic circuitry provided by the sensor board. It is also possible to compare the voltage values ​​of individual cells of the energy storage module. This makes it possible to determine the state of charge, not only of the energy storage module itself, but also of the individual cells.

[0011] In the final assembly state, the contact board is placed on top of the energy storage module in the vertical direction. The position of the contact board is secured by connecting the contact elements of the contact board to the corresponding terminals of the energy storage module, e.g., soldered or welded. Furthermore, the contact board can also be glued or otherwise connected to the top side of the energy storage module or to the top side of the energy storage module's cells.

[0012] Although the contacting board known from EP 3 715 171 B1 has proven itself in everyday practical use, there is still room for improvement, particularly with regard to a broader range of applications. Task The invention is to further develop the design of a contacting board of the type mentioned at the outset in such a way that an expanded range of applications is achieved.

[0013] To Solution To achieve this object, the invention proposes a contacting board of the generic type, which is characterized in that the plastic substrate has a first large side and a second large side aligned parallel thereto, wherein one of the two large sides is equipped with a heating device, and wherein contacting elements are provided which interact with the connection poles of the energy storage module and are designed at a distance from the plastic substrate.

[0014] The plastic substrate, which is designed, for example, as a flexible plastic film, has two large sides that run parallel to each other. One of these two sides faces the energy storage module in the final assembly state. The other side of the plastic substrate, opposite this side, faces away from the storage module in the final assembly state.

[0015] According to the invention, the plastic substrate is provided with a heating device, specifically one of the two large sides is equipped with a heating device. It is preferred that the side of the plastic substrate facing the energy storage module in the final assembled state has the heating device.

[0016] The contacting board according to the invention ultimately provides two functionalities. Firstly, first conductor tracks are provided in a conventional manner, which, in accordance with the prior art, serve to electrically connect a sensor board to the connection terminals of the energy storage module. Secondly, the contacting board is equipped with a heating device that, if necessary, enables the energy storage module or the cells of the energy storage module to be subjected to heat. In order to enable the most direct heat transfer possible from the heating device to the energy storage module or to the cells provided by the energy storage module, the heating device is preferably arranged on the side of the plastic substrate that faces the energy storage module in the final assembled state.The heating device can alternatively be arranged on the side of the plastic substrate which faces away from the energy storage module in the finally assembled state. In this case, the plastic substrate of the contacting board does have a disadvantageous heat-insulating effect, but due to the very thin design of the plastic substrate, e.g. as a flexible plastic film, there is only a slight deterioration in heat transfer when used as intended. The advantage of arranging the heating device on the large side of the plastic substrate which faces away from the energy storage module in the finally assembled state is that the intended and correct alignment of the heating device in relation to the individual cells provided by the energy storage module is possible directly during assembly and / or maintenance, i.e. without further aids by visual inspection.

[0017] Due to technological limitations, charging at low temperatures is not possible for all energy storage modules, particularly lithium-ion batteries. The contacting board according to the invention provides a remedy here, since a predeterminable temperature for the individual cells of the energy storage module can be achieved through demand-based and selective operation of the heating device provided by the contacting board, which enables optimized charging of the cells. This advantageously eliminates the need for separate heating foils known from the prior art. In its inventive design, the contacting board, which is already provided, serves as a heating foil replacement, since it also provides the additional functionality of the heating device.The contacting board according to the invention thus has an expanded range of applications, since it not only serves to electrically connect a sensor board to the connection poles of the energy storage module, but also offers the possibility of heating the energy storage module or the cells provided by it if necessary.

[0018] The inventive integration of a heating device into a contacting board is advantageously particularly cost-effective, since it eliminates the need for an additional heating device, for example, in the form of a heating foil, and further additional components are also unnecessary. The finished design of an energy storage module using a contacting board according to the invention therefore proves to be simpler and thus more cost-effective in both production and assembly compared to the prior art.

[0019] The inventive arrangement of the heating device on the contacting board also provides the advantage that the heating device can be easily electrically connected to the energy storage module, so that during normal operation, the heating device is powered by the total voltage of the energy storage module. Alternatively, an external power supply for the heating device can, of course, also be provided. However, the electrical connection of the heating device to the energy storage module is advantageous, as this does not require any additional components and / or assembly steps during production.

[0020] Overall, the contacting board according to the invention provides a board that is multifunctional in that, on the one hand, it ensures a proper electrical connection between a sensor board and the connection poles of the energy storage device when used as intended, but on the other hand it also provides a heating device that, if necessary, enables the energy storage module to be heated to a temperature that supports or ensures an optimized charging process.

[0021] According to the invention, contacting elements are also provided that interact with the connection terminals of the energy storage device and are spaced apart from the plastic substrate. The contacting elements are therefore not provided by the flexible plastic substrate of the contacting board. In contrast to the prior art, this results in a much less delicate structure for the contacting board, which is particularly advantageous with regard to assembly of the contacting board, especially because an automated arrangement of the contacting board on an energy storage module is much easier to implement.

[0022] The contacting elements—also called cell taps—are preferably formed with the associated conductor tracks in a single manufacturing step. A separate design of the contacting elements from the conductor tracks is also conceivable, of course. The only decisive factor, however, is that the contacting elements are not supported by the plastic substrate of the contacting board. Rather, the contacting elements are formed at a distance from the plastic substrate, thus being adjacent to the plastic substrate in the fully assembled state. Connecting sections are used to electrically connect the contacting elements with the associated conductor tracks of the plastic substrate, as will be explained in more detail below.

[0023] According to the prior art according to EP 3 715 171 B1 already cited above, the flexible plastic substrate of the contacting board provides a main branch on the one hand and strip-shaped secondary branches on the other. The strip-shaped secondary branches, with their end region opposite the main branch, each provide contact areas which carry the contacting elements which interact with the connection poles of the energy storage device. In contrast to this embodiment, the embodiment according to the invention dispenses with strip-shaped secondary branches. Instead, the contacting elements are spaced apart from the plastic substrate, i.e. formed outside thereof, and are electrically connected directly to the first conductor track of the contacting board via a corresponding electrical connection.The ladder-shaped design of the plastic substrate, which is preferred due to the heating device provided according to the invention, can therefore advantageously remain unchanged.

[0024] According to a further feature of the invention, a first conductor track opens into a connection path to which a contacting element is electrically connected. The connection path therefore serves as an electrical bridge between a first conductor track and a contacting element. In this case, more than just one contacting element can preferably be connected to a connection path. The connection path therefore offers the advantage of being able to electrically connect one or more contacting elements to a first conductor track in a simple manner. The use of two contacting elements connected in parallel offers the particular advantage of increasing the reliability of cell voltage measurement. Furthermore, due to the design of a connection path, a welded connection can be dispensed with, which simplifies production.During assembly, it is then only necessary to electrically connect the contact elements to the cell poles, which is preferably done by welding.

[0025] According to a further feature of the invention, a preferably S-shaped connecting section is provided for electrically connecting a contacting element to a connection path. A contacting element is thus electrically connected to a connection path via the interposition of a connecting section. Such a connecting section advantageously offers the possibility of positioning the cooperating contacting element relative to the plastic substrate. This supports precise alignment of the contacting elements for electrical connection to an associated connection pole of the energy storage module. To increase positional variability, the connecting section is preferably S-shaped. This allows both lengthening and bending relative to the plastic substrate.Any inaccuracies in the fit between the position of the contact board on the electrical storage module and the position of the energy storage module's terminals can thus be advantageously compensated. This also makes it possible to compensate for any manufacturing tolerances.

[0026] According to a further feature of the invention, the connecting section and the associated contacting element are formed integrally, preferably from nickel, and soldered to the connection path. According to this embodiment, the contacting element is formed by a so-called nickel pad, which can be soldered directly to the associated connection path of the contacting board via the connecting section provided integrally therefrom. This further supports simple and cost-effective production.

[0027] According to a further feature of the invention, it is provided that the heating device has a second conductor track made of copper applied, preferably printed, to the plastic substrate.

[0028] The heating device is designed as a heating coil, consisting of a conductor track applied to the plastic substrate. The conductor track is preferably made of copper and is, for example, printed onto the plastic substrate. The result is a contacting board that has a plastic substrate as the carrier material, which is equipped with first conductor tracks on a first side and second conductor tracks on a second side. The first conductor tracks serve, as described above, to electrically connect a sensor board to connection terminals of the energy storage module, whereas the second conductor tracks form the heating device according to the invention as a heating coil. The design of the heating device proves to be particularly simple and cost-effective.In particular, this embodiment allows a contacting board to be formed in one work step, the functionality of which also provides that of the heating device.

[0029] According to a further feature of the invention, the second conductor track is designed to have a meandering shape, at least in sections. This creates compact heating resistors which, thanks to their arrangement on the plastic substrate of the contacting board, are securely positioned directly above a corresponding cell of the energy storage module in the final assembled state. This creates an overall compact heating device, which also advantageously enables precise positioning of the individual cells of the energy storage module.

[0030] In this context, according to a further feature of the invention, it is proposed that the plastic substrate have a geometric configuration that corresponds to the cell arrangement within the energy storage module. For example, a ladder-shaped configuration of the plastic substrate can be provided, wherein the plastic substrate has strip sections that, in the final assembled state, lie directly above a cell of the energy storage module. These strip sections have, on their underside facing the respective cell, the meandering second conductor tracks of the heating device according to the invention. This ensures a direct, precisely positioned assignment between the second conductor tracks of the heating device and the respective cell of the energy storage module.

[0031] According to a further feature of the invention, the second conductor track is designed to be electrically connectable to the energy storage module. This advantageously makes it possible to supply the heating device from the total voltage of the energy storage module. This can be implemented structurally, for example, by the second conductor tracks terminating in contacts, which in turn are electrically connected to the terminals of the energy storage module during their intended use.

[0032] According to a further feature of the invention, the contacting board carries temperature sensors. These are coupled to the sensor board by means of corresponding conductor tracks, so that the cell temperature measurements provided by the temperature sensors during intended use can be evaluated by the sensor board's electronic circuitry. An evaluation of the recorded cell temperatures can serve not only to monitor the cell temperature but also to regulate the heating device. In particular, the recorded temperature values ​​can be used to determine at the start of a charging process whether or not the heating device should be switched on for an optimized charging process. Furthermore, an automated shutdown of the heating device is naturally also possible when the cell temperature required for an optimized charging process is reached.

[0033] According to a further feature of the invention, the plastic substrate is equipped on one of its two large sides with a third conductor track providing a balancing resistor. According to this embodiment, the contacting board has a third conductor track. This provides at least one balancing resistor. Preferably, several such balancing resistors are provided, one resistor per parallel connection. The conductor track is formed on one of the two large sides of the plastic substrate. In this context, however, it is preferred that the large side of the plastic substrate is equipped with the third conductor track, which faces away from the energy storage module in the final assembled state. Accordingly, the heating device is provided by a first large side of the plastic substrate, whereas the third conductor track is formed on the other of the two large sides of the plastic substrate.Alternatively, both the third conductor track and the heating device can be provided on one and the same large side of the plastic substrate. However, particularly for space reasons, it is preferable to use both large sides of the plastic substrate equally to accommodate the individual conductor tracks. Therefore, for reasons of simplified manufacturing, it is desirable to accommodate the heating device on one of the two large sides of the plastic substrate and both the first and third conductor tracks on the other of the two large sides.

[0034] Passive balancing is used to charge all of the energy storage module's cells equally when charging. Passive balancing only works near the end of charge, i.e., when the energy storage module's cells are almost fully charged. A balancing resistor is connected in parallel with each cell that has already reached the end-of-charge voltage, limiting the voltage to the end-of-charge voltage. This cell is then only slightly charged or even slightly discharged, while the other cells that have not yet reached the end-of-charge voltage continue to receive the full supply of charging current. The power of the parallel resistor is adapted to the charging current, as the excess energy is dissipated in the form of heat at the resistor. A particular advantage of this balancing method is that it is cost-effective and technically simple to implement.

[0035] According to the current state of the art, the balancing resistors for passive balancing are housed on a dedicated circuit board of a battery management system. The disadvantage of this prior art arrangement is that thermal management only allows for low balancing currents. Furthermore, the different voltage levels of the cell chemistries NMC (lithium nickel manganese cobalt), LFP (lithium iron phosphate), and LTO (lithium titanium oxide) pose a major disadvantage when designing resistors in a modular battery management system.

[0036] The proposed placement of the balancing resistors on a flexible contact board, rather than on a battery management system board, overcomes these disadvantages. The high thermal capacity of the energy storage module's cells ensures good heat dissipation, enabling significantly larger balancing currents. Furthermore, the arrangement of the balancing resistors on the flexible contact board allows the resistors to be tailored to the cell voltage levels. This results in a significant increase in the performance of passive balancing.

[0037] In this context, the invention proposes a contacting board for an energy storage module, in particular a lithium-ion accumulator, with a flexible plastic substrate which provides first conductor tracks for an electrical connection of a sensor board to connection poles of the energy storage module, wherein the plastic substrate has a first large side and a second large side aligned parallel thereto, wherein one of the two large sides is equipped with a heating device, and wherein the plastic substrate is equipped on its side facing away from the energy storage module in the finally assembled state with a third conductor track providing a balancing resistor.

[0038] The invention proposes a contacting board that is capable of being protected in its own right, comprising a heating device and a balancing resistor. Preferably, the heating device is arranged on one side of the plastic substrate of the contacting board, while the balancing resistor is located on the other side of the plastic substrate. With regard to the heating device and the balancing resistor used in combination with it, the previously explained advantages of the heating device and the balancing resistor are combined.

[0039] According to a further feature of the invention, the third conductor track is electrically connected to the first conductor tracks. This provides a direct electrical coupling of the first conductor tracks to the third conductor track, which provides a balancing resistor. This results in a simple design of the contacting board, which also allows all the conductor tracks to be easily applied by printing onto the flexible plastic substrate of the contacting board.

[0040] As already stated above, according to a further feature of the invention, it is preferred that the side of the plastic substrate facing away from the energy storage module in the final assembled state be equipped with the third conductor track and / or the first conductor tracks. Accordingly, the heating device or the second conductor track provided by the heating device is arranged on the side of the plastic substrate facing the energy storage module in the final assembled state.

[0041] The invention further proposes an energy storage module, in particular a lithium-ion accumulator, which has a plurality of lithium-ion cells electrically interconnected with one another, characterized by a contacting board of the type described above, i.e. of the type according to the invention. Such an energy storage module has the advantages already explained above with reference to the contacting board according to the invention.

[0042] According to a further feature of the invention, the contacting board is electrically connected to terminal connections provided by the energy storage module, with the large side of the plastic substrate facing the energy storage module containing the heating device. An energy storage module equipped in this way has the advantages already explained above with reference to the contacting board.

[0043] Further features and advantages of the invention will become apparent from the following description with reference to the figures. Figure 1 shows a schematic top view of the side of a contacting board according to the invention facing an energy storage module in the final assembled state; Figure 2 shows a schematic detail view of a heating device provided by the side of the contacting board facing the energy storage module; and Figure 3 shows a schematic detailed view of the side of the contacting board facing away from the energy storage module in the final assembled state, which side is equipped with first and third conductor tracks.

[0044] A contacting board 1 according to the invention is shown schematically in Figure 1 shown.

[0045] The contacting board 1 has a flexible plastic substrate 2, which is designed, for example, as a flexible plastic film. In the illustrated embodiment, the plastic substrate 2 is designed like a conductor and has longitudinal sections 15 on one side and transverse sections 16 on the other.

[0046] Fig. 1 shows the side 4 of the contacting board 1 facing an energy storage module in the final assembled state, which can also be referred to as the large side 17. This side 4 of the plastic board 1 facing the energy storage module in the final assembled state is equipped according to the invention with a heating device 5. The heating device 5 has a conductor track 6 applied to the plastic substrate, preferably printed thereon. This factual connection is particularly evident from the detailed view according to Figure 2 .

[0047] The conductor track 6 of the heating device 5 is formed at least in sections in a meandering manner, as can also be seen in particular from the illustration according to Fig. 2 results.

[0048] The meandering course of the conductor tracks 6 creates quasi heating resistors which, when energized, heat the cells of the energy storage module that interact with them.

[0049] As can be seen from the illustration Fig. 1 The conductor track 6 is designed to run in a meandering manner in the region of the transverse sections 16 of the plastic substrate 2. These transverse sections 16 are located directly above the respective cells of the energy storage module in the final assembled state of the contacting board 1. This ensures direct heat transfer from the heating device 15 to the corresponding cells of the energy storage module.

[0050] As can be seen from a summary of the Figures 1 and 2Furthermore, the contacting board 1 also has temperature sensors 13. These interact with the associated cells of the energy storage module in the final assembled state of the contacting board and enable cell temperature detection. By means of an electronic circuit, the heating device 5 is switched on or off, preferably depending on the cell temperatures detected by the temperature sensors 13.

[0051] The heating device 5 is preferably powered by the total voltage of the energy storage module, for which purpose the conductor track 6 of the heating device 5 leads into corresponding contacts. These contacts establish an electrical connection between the heating device 5 and the energy storage module during intended use.

[0052] The flexible plastic substrate 2 further provides first conductor tracks 3 for electrically connecting a sensor board to terminals of the energy storage module. The first conductor tracks 3 are formed on the side 8 facing away from the energy storage module in the final assembled state, ie, the large side 18 of the plastic substrate 2, as shown in the detailed illustration according to Fig. 3 For electrical contacting of the first conductor tracks 3 with one or more sensor boards not specifically shown in the figures, corresponding contacts 7 are provided, as can be seen in particular from the illustration according to Fig. 1 results.

[0053] On the connection pole side, the contacting board 1 provides contacting elements 10. These are electrically connected to a first conductor track 3. For this purpose, a connection path 11 is provided, which is provided by the plastic substrate 2 and into which the first conductor track 3 electrically opens. An S-shaped connecting section 12 is provided for electrically connecting a contacting element 10 to the connection path 11. The contacting element 10 and the associated connecting section 11 are preferably formed as a single piece. Nickel is the preferred material for the contacting element 10 and the connecting section 12. Soldering can preferably be provided for connecting a connecting section 12 to a connection path 11.

[0054] The preferably S-shaped design of the connecting section 12 provides the advantage that the position of the contacting element 10, which is not supported by the plastic substrate 2, can be adjusted relative to the plastic substrate 2. This allows any manufacturing or positioning tolerances to be compensated, ensuring proper contact between a contacting element 10 and a terminal of the energy storage module in every case. The S-shaped design of the connecting section 12 also serves to compensate for relative movements between the contacting board 1 and the energy storage module in the event of dynamic loading.

[0055] As can be seen from the illustration Fig. 3Furthermore, the plastic substrate 2 is equipped, on its side 8 facing away from the energy storage module in the final assembled state, with a third conductor track 9 providing a balancing resistor 14. The third conductor track 9 is electrically connected to the first conductor track 3 and thus also to the contacting elements 10.

[0056] The contacting board according to the invention provides a multifunctional contacting board 1. This is because the contacting board 1 according to the invention not only accommodates first conductor tracks for electrically connecting a sensor board to connection poles of the energy storage module. Balancing resistors 14 and a heating device 5 are also integrated into the contacting board 1. The heating device 15 is located on one side of the plastic substrate 2, namely on the side 4 facing the energy storage module in the final assembled state. The other conductor tracks, i.e., the first conductor tracks 3 and the third conductor tracks 9, are arranged on the other side of the plastic substrate 2, namely on the side 8 facing away from the energy storage module in the final assembled state. Reference symbol

[0057] 1Contacting board 2Plastic substrate 3First conductor track 4Energy storage module facing side 5Heating device 6Second conductor track 7Contacts 8Energy storage module facing away from side 9Third conductor track 10Contacting elements 11Connection path 12Connection section 13Temperature sensors 14Balancing resistors 15Longitudinal section 16Cross section 17First large side 18Second large side

Claims

1. Contacting board for an energy storage module, in particular a lithium-ion accumulator, comprising a flexible plastic substrate (2) which provides first conductor tracks (3) for an electrical connection of a sensor board with connection poles of the energy storage module, wherein the plastic substrate (2) has a first large side (17) and a second large side (18) aligned parallel to this, wherein one of the larges sides (17, 18) is equipped with a heating device (5) and wherein contacting elements (10) interacting with the connection poles of the energy storage module are provided which are formed at a distance from the plastic substrate (2).

2. Contacting board according to claim 1, characterized in that a first conductor track (3) leads into a connection path (11) to which a contacting element (10) is electrically connected.

3. Contacting board according to claim 1 or 2, characterized by a preferably s-shaped connecting section (12) with the interposition of which a contacting element (10) is electrically connected to a connection path (11).

4. Contacting board according to claim 3, characterized in that the connecting section (12) and the contacting element (10) are integrally formed preferably from nickel and are soldered to the connection path (11).

5. Contacting board according to any one of the preceding claims, characterized in that the heating device (5) comprises a second conductor track (6) made of copper applied to, preferably imprinted on the plastic substrate (2).

6. Contacting board according to claim 5, characterized in that the second conductor track (6) is designed meandering at least in sections.

7. Contacting board according to claim 5 or 6, characterized in that the second conductor track (6) is designed to be electrically connected to the energy storage module.

8. Contacting board according to any one of the preceding claims, characterized in that the plastic substrate (2) is equipped on its side facing away from the energy storage module in the final assembled state with a third conductor track (9) which provides a balancing resistor (14).

9. Contacting board according to claim 8, characterized in that the third conductor track (9) is electrically connected to the first conductor track (3).

10. Contacting board according to claim 8 or 9, characterized in that the first (17) of the two large sides (17, 18) is equipped with the heating device (5) and the second (18) of the two large sides (17, 18) is equipped with the third conductor track (9) and preferably also with the first conductor track (3).

11. Contacting board according to any one of the preceding claims, characterized in that the large side (17) aligned with the heating device (5) is the side (4) of the plastic substrate (2) facing the energy storage module in the final assembled state.

12. Contacting board according to any one of the preceding claims, characterized in that the large side (18) equipped with third conductor track (9) and / or the first conductor track (3) is the side (8) of the plastic substrate (2) facing away from the energy storage module in the final assembled state.

13. Energy storage module, in particular lithium-ion accumulator, comprising a plurality of electrically interconnected lithium-ion cells, characterized by a contacting board according to any one of the preceding claims 1 to 12.

14. Energy storage module according to claim 13, characterized in that the contacting board is electrically connected at pole terminals provided by the energy storage module, wherein the large side (17) of the plastic substrate (2) facing the energy storage module has the heating device (5).