A battery module for an electrical energy storage device of a motor vehicle, an electrical energy storage device and a method

Abstract

A battery module 10 for an electrical energy storage device 12 of a motor vehicle, comprising several storage elements 14, wherein an expandable intermediate material (e.g. foam) 16 is arranged betwee

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a battery module for an electrical energy storage device of a motor vehicle. Furthermore, the present invention relates to a corresponding energy storage device for a motor vehicle and a method for operating a corresponding battery module. BACKGROUND INFORMATION

[0002] In the state of the art, a battery module, which might be designed as a battery pack, comprises several battery cells. The said battery cells may expand and contract upon charge or discharge and may be integrated in the battery pack using some sort of mechanical mechanism to accommodate the volume change. At the same time, a relatively high stack pressure, for example between 50 kilopascal and 3 megapascal, may be applied as it usually may be beneficial for cell performance. In a thermal event, for example triggered by damage of a cell from the outside, this set-up known from the state of the art may not be beneficial because heat may travel easily from the battery cell with the thermal event to the next battery cell. SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a battery module for an electrical energy storage device of a motor vehicle, a corresponding electrical energy storage device for a motor vehicle, as well as a method for operating a battery module for an electrical energy storage device of a motor vehicle, by which safety of the battery module can be particularly increased.

[0004] This object is solved by a battery module for an electrical energy storage device of a motor vehicle, a corresponding electrical energy storage device for a motor vehicle, as well as a method for operating a battery module for an electrical energy storage device of a motor vehicle according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0005] One aspect of the present invention relates to a battery module for an electrical energy storage device of a motor vehicle. Preferably, the motor vehicle is designed as a passenger car. Preferably, the motor vehicle is a battery electric vehicle (BEV) or a hybrid vehicle, in particular a plug-in hybrid vehicle (PHEV). The energy storage device may be understood as an accumulator or a battery respectively, which may be referred to as storage battery.

[0006] The battery module comprises several storage elements, which are preferably designed as storage cells. The said storage cells may be referred to as battery cells. Therefore, the battery module may be referred to as cell module or cell pack. Preferably, the battery module is designed as a cell array.

[0007] A respective distance is provided between two respective adjacent storage elements. In other words, the storage elements are spaced apart at least partially. Therefore, there is a respective space between two respective storage elements. The said respective distance may be referred to as spacing, gap or clearance. A respective intermediate material is arranged in the said respective distance. This means that the respective intermediate material is arranged between two respective storage elements, in particular two adjacent respective battery cells. In other words, the respective intermediate distance is at least partially filled by the respective intermediate material. The respective intermediate material may be understood as a respective intermediate element, which may be formed of the respective intermediate material.

[0008] In particular, to increase safety of the battery module, in particular safety against the thermal event, the battery module comprises at least one activation device. This means that the respective expandable material is arranged in the respective distance, in particular between the storage elements. Furthermore, the said respective intermediate material is a respective expandable material effected, in particular initiated by heat, by the activation device so that the respective distance between the storage elements is capable of being increased during a thermal event. The activation device is capable of applying heat to the respective intermediate material or the respective expandable material, respectively, in order to effect, in particular to initiate, the respective increase in volume of the respective intermediate material or the respective expandable material, respectively. Therefore, the respective distance between the storage elements is capable of being increased or is increased respectively. In other words, the respective distance in a first state of the battery module comprises a first value and in a second state of the battery module comprises a second value, that is larger than the first value, wherein the activation device is capable of changing between the states, in particular changing from the first state or normal position to the second state or safety position by increasing the respective volume of the respective expandable material caused by the heat applied to the respective expandable material. Therefore, the respective distance between the storage elements may be increased. The respective expandable material may be understood as a material, which is capable of increasing its volume, in particular on purpose, as a function of its temperature. The said respective expandable material may be referred to as expandable chemical or chemical. Preferably, the said volume increase is significant, for example, it is a volume increase of at least 50, 100 or 200 %. For example, the said respective expandable material is a high-pressure intumescent material. An intumescent material may be understood as safelincs that usually may be used for fire protection (to close gaps or crush pipes). The intumescent material may contain a char-forming agent like polyhydric alcohol and / or chemicals like ammonium phosphate, in particular ammonium polyphosphate (APP), to create an insulating flame retardant layer with higher volume than before. The materials known in the fire protection industry likely need hundreds of degree Celsius temperature, but a range from 150 degree Celsius or higher may be preferred. Ideally, a trigger temperature may start at 100 degree Celsius.

[0009] In the present invention, the respective intermediate material arranged between the storage elements is capable of being, in particular mechanically, expanded and potentially in addition capable of becoming thermally more resistive. Preferably, the said respective intermediate material may expand and in addition may change its thermal conductivity properties when triggered by a high temperature. Therefore, it may be possible to actively create the respective spacing, in particular to increase the respective spacing, between the storage elements due to the heat provided by the activation device or the expandable material, respectively. This may be effected by a method, which depends on the volume increase of the respective expandable material. This may be triggered by a high temperature condition detected by an electronic computing device or automatically triggered by an independent mechanism. The electronic computing device may be designed as a battery management system. For example, the battery management system may detect a battery condition that may indicate a thermal event such as a thermal runaway event. The battery management system may utilize artificial intelligence and / or other processes to determine a thermal event such as a high temperature after detecting an abnormal pressure or another battery condition. The invention is based in particular on the recognition that the material between cells does not need to be a thermal barrier, which may require more space and may lead to inferior thermal properties during normal operation. Only in the event of a problem, for example, the said thermal event, the battery cells may be put in a thermally much more separated configuration, in particular in the said second state for the safety position. Due to the increase of the distance between the storage elements, heat transfer between the storage elements may be reduced, for example, in case of the thermal event. Therefore, an unsafe chain reaction between the storage elements may be avoided securely. In other words, thermal propagation between the storage elements may be avoided securely. Furthermore, the inventive solution may afford another improvement; for example from a control perspective, the battery module may be capable of adjusting to a state of more safety without any software involved.

[0010] It is therefore intended that with the present invention in case of a safety problem that the storage elements may be placed in a beneficial state in terms of thermal propagation. This could apply for any battery assembly even with cylindrical cells, prismatic or pouch cells with various setup configurations within the battery module. The expanding material may be utilized to separate battery cells. With the present invention for the on-event battery cell spacing with the expanding material that maintains a pressure, the storage elements may normally be packed denser but moved to a less dense packaging in case of emergency.

[0011] In another embodiment, the battery module comprises at least one pressure supply device, by which the storage elements are capable of being pressurized or pressurized.

[0012] In another embodiment, the storage elements are capable of being pressurized or pressurized by the pressure supply device during the increase in volume of the respective expandable material, and in particular during the increase of the respective distance.

[0013] In another embodiment, during initiation of the volume increase of the respective expandable material, reduction of the pressurization of the storage elements by the pressure supply device is omitted.

[0014] In another embodiment, the storage elements are arranged between two end plates, wherein the storage elements are capable of being pressurized or are pressurized by the pressure supply device via at least one of the end plates.

[0015] In another embodiment, the respective expandable material is foam.

[0016] In another embodiment, the foam is arranged in a respective pouch, which is arranged in the respective distance or between the storage elements, respectively.

[0017] In another embodiment, the battery module comprises at least one temperature sensor and an electronic computing device by which the activation device is capable of being controlled as a function of a temperature detected by the temperature sensor in order to effect the volume increase by the activation device, in particular by the heat applied by the activation device.

[0018] Another aspect of the present invention relates to an electrical energy storage device for a motor vehicle, comprising at least the battery module according to the first aspect of the invention. Advantageous embodiments of the electrical energy storage device are to be regarded as advantageous embodiments of the battery module and vice versa.

[0019] Another aspect of the present invention relates to a method for operating a battery module, in particular according to the first aspect of the invention, for an electrical energy storage device, in particular according to the second aspect of the invention, of a motor vehicle. Advantageous embodiments of the method are to be regarded as advantageous embodiments of the battery module and the electrical energy storage device and vice versa.

[0020] A still further aspect of the present invention relates to a computer program product comprising program code means for performing a method according to the preceding aspect.

[0021] Furthermore, the present invention relates to a non-transitory computer-readable storage medium comprising at least the computer program product according to the preceding aspect.

[0022] A computing unit / electronic computing device may in particular be understood as a data processing device, which comprises processing circuitry. The computing unit can therefore in particular process data to perform computing operations. This may also include operations to perform indexed accesses to a data structure, for example a look-up table, LUT.

[0023] In particular, the computing unit may include one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits, ASIC, one or more field-programmable gate arrays, FPGA, and / or one or more systems on a chip, SoC. The computing unit may also include one or more processors, for example one or more microprocessors, one or more central processing units, CPU, one or more graphics processing units, GPU, and / or one or more signal processors, in particular one or more digital signal processors, DSP. The computing unit may also include a physical or a virtual cluster of computers or other of said units.

[0024] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0025] A memory unit may be implemented as a volatile data memory, for example a dynamic random access memory, DRAM, or a static random access memory, SRAM, or as a non-volatile data memory, for example a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, a flash memory or flash EEPROM, a ferroelectric random access memory, FRAM, a magnetoresistive random access memory, MRAM, or a phase-change random access memory, PCRAM.

[0026] The battery module comprises several storage elements. A respective distance is provided between two respective adjacent storage elements and a respective intermediate material is arranged in the respective distance.

[0027] In order to increase safety of the battery module, in particular against a thermal event, the respective intermediate material is a respective expandable material, and the battery module comprises at least one activation device which provides or applies heat to the respective expandable material, whereby the respective distance between the storage elements is increased by an increase of volume of the respective expandable material effected by the provided or applied heat, in particular by the heat supplied by the activation device. In other words, a respective volume increase of the respective expandable material is effected by heat, which is supplied by the activation device and is provided or applied to the respective expandable material, whereby the respective distance between the storage elements is, in particular selectively, increased. For example, the provided heat is caused by overheating of the battery. This means that the provided heat may be heat resulting from the overheated battery.

[0028] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0030] The drawings show in:

[0031] Fig. 1 a schematic side view of an embodiment of a battery module; and

[0032] Fig. 2 a schematic side view of an embodiment of a battery module with increased distance between storage elements.

[0033] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0034] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0035] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0036] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0037] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0038] Fig. 1 shows a schematic side view according to an embodiment of a battery module 10 for an electrical energy storage device 12 of a motor vehicle. The said side view in Fig. 1 may be a sectional view. The motor vehicle is preferably at least in part electrically operated or full electrically operated. Therefore, the motor vehicle may comprise at least one electric motor. Preferably, the electric motor is supplied with energy by the electrical energy storage device 12, in particular by the battery module 10. For example, the electrical energy storage device 12 is designed as a battery, in particular, a low voltage or high voltage battery. A high voltage battery may be 60V to 1500V. The battery module 10 comprises several storage elements 14. Preferably, the storage elements 14 are cells, which may be referred to as battery cells. The battery module 10 is capable of executing a method for operating the battery module 10.

[0039] As shown in Fig. 1, a respective distance is provided between two respective adjacent storage elements 14 and a respective intermediate material 16 is arranged in the respective distance. This means that the said distance is filled by the said respective intermediate material 16 at least partially. The said intermediate material 16 may be understood as inter-cell material.

[0040] The energy storage device 12, in particular the battery module 10, comprises at least one activation device 18, which is capable of providing or applying heat to the respective intermediate material 16. This means that the activation device 18 may provide heat, whereby the respective intermediate material 16 may be applied by the said heat. Furthermore, the respective intermediate material 16 is a respective expandable material 20, by whose increase in volume, effected by the said heat provided by the activation device 18, the respective distance between the storage elements 14 is capable of being increased. In other words, the respective expandable material 20 is capable of being expanded by heat provided by the activation device 18 to effect the respective increase in volume. Therefore, for example in case of a thermal event, the respective distance between the storage elements 14 may be increased by the volume increase of the respective expandable material 20 caused, in particular initiated, by the activation device 18 or the heat supplied by the activation device 18, respectively. As a result, heat transfer between the storage elements 14 may be reduced. As shown in Fig. 1, the storage elements 14 and the intermediate material 16 such as the expandable material 20, , are constructed separately from each other. The expandable material 20 may be understood as a chemical that is able to expand, in particular due to a change in temperature. In other words, the respective expandable material 20 is a chemical that may increase its volume dramatically when heated over a threshold and pressure generated from the expandable material 20 remains after the thermal event ends.

[0041] Fig. 1 shows the battery module 10 in a first state, in particular, before the said volume increase or the increase of the respective distance between the storage elements 14, respectively. Fig. 2 shows the battery module 10 in a schematic side view, in particular in a sectional view, wherein in Fig. 2 the battery module 10 is in a second state, in which the said volume increase or the increase of the distance between the storage elements 14, respectively, has already taken place. So, the said volume increase or the said increase of the distance, respectively, is illustrated in Fig. 2.

[0042] In the embodiment shown in Fig. 1 and 2, the battery module comprises at least one pressure supply device 30, by which the storage elements 14, and in particular the intermediate material 16, are capable of being pressurized or are pressurized. In other words, the said pressure supply device 30 is capable of applying a force in order to effect the said pressurization of the storage elements 14 or the intermediate material 16, respectively. Preferably, the storage elements 14, and in particular the intermediate material 16, are capable of being pressurized or pressurized by the pressure supply device 30 during the increase in volume of the respective expandable material 20, and in particular during the increase of the respective distance. In other words, the said pressure stays on at least during the initiation of the said volume increase, in particular during a complete process of the said volume increase. This means that the pressure applied or supplied by the pressure supply device 30, respectively, remains during the said increase of distance. For example, during initiation of the volume increase of the respective expandable material 20, in particular during the complete process of the volume increase of the respective expandable material 20, reduction of the pressurization of the storage elements 14, in particular the pressurization of the respective expandable material 20, by the pressure supply device 30 is omitted. In other words, the pressure supplied or applied by the pressure supply device 30, respectively, remains undiminished at least during the said initiation of the volume increase of the respective expandable material 20.

[0043] In the embodiment shown in Fig. 1 and Fig. 2, the storage elements 14 are arranged between two end plates 22, 24. The storage elements 14 are capable of being pressurized or pressurized by the pressure supply device 30 via at least one of the end plates 22, 24. This means that the storage elements 14, and in particular the intermediate material 16, are force-loaded, in particular pressure-loaded, by the pressure supply device 30 via at least one of the said end plates 22, 24. This is illustrated in Fig. 1 and Fig. 2 by respective pressure 26, 28 arrows. In other words, the said pressure supply device 30 is capable of applying a force to at least one of the end plates 22, 24, in order to generate the said pressure. In the example in Fig. 1 and Fig. 2, a first one of the end plates 22 is designed as a mechanical support, and the second one of the end plates 24 is force loaded by the pressure supply device 30. The pressure supply device 30 may be referred to as pressure generating device or stack pressure generating device.

[0044] Preferably, the respective expandable material 20 is a foam 32. In the present embodiment, the foam 32 is capable of being expanded by the heat supplied by the activation device 18 in order to effect the said respective increase in volume, to apply a pressure between the storage elements 14, and to maintain the pressure after the thermal event. This means that the expansion of the foam 32 arranged between the storage elements 14 may be activated by the said heat. For example, the foam 32 is arranged in a respective pouch 33 or in pouches 33, respectively. The said respective pouch 33 is arranged between the storage elements 14, in particular at the said respective distances.

[0045] Preferably, the volume expansion of the foam 32 generates more pressure applied to the storage elements 14 than the pressure supply device 30. Preferably, the pressure supplied by the expansion of the foam 32 leads to a movement of the storage elements 14 away from each other, and the pressure supplied by the pressure supply device 30 leads to a movement of the storage elements 14 towards each other. In other words, the foam 32 generates more pressure than the stack pressure, and in consequence the storage elements 14 are separated, whereby the said distance between the storage elements 14 is increased. For example, the volume increase of the expandable material 20 is accompanied by a movement of the second end plate 24 relative to the first end plate 22. Preferably, the said movement is caused by the volume increase of the expandable material 20.

[0046] Preferably, the energy storage device 12, in particular the battery module 10, comprises at least one temperature sensor 34 and an electronic computing device 36, by which the activation device 18 is capable of being controlled as a function of a temperature detected by the temperature sensor 34 in order to effect the said volume increase by the activation device 18. So, the temperature sensor 34 may detect the said temperature and the said electronic computing device 36 may control the activation device 18 as a function of the detected temperature in order to effect the said volume increase.

[0047] The electronic computing device may be understood as a data processing device, which comprises processing circuitry. Therefore, the electronic computing device may be referred to as a computing unit. The electronic computing device may, in particular, process data to perform computing operations. This may also include operations to perform indexed accesses to a data structure.

[0048] In particular, the electronic computing device may include one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits, ASIC, one or more field-programmable gate arrays, FPGA, and / or one or more systems on a chip, SoC. The electronic computing device may also include one or more processors, for example one or more microprocessors, one or more central processing units, CPU, one or more graphics processing units, GPU, and / or one or more signal processors, in particular one or more digital signal processors, DSP. The electronic computing device may also include a physical or a virtual cluster of computers or other of said units.

[0049] In various embodiments, the electronic computing device includes one or more hardware and / or software interfaces and / or one or more memory units. A memory unit may be implemented as a volatile data memory, for example a dynamic random access memory, DRAM, or a static random access memory, SRAM, or as a non-volatile data memory, for example a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, a flash memory or flash EEPROM, a ferroelectric random access memory, FRAM, a magnetoresistive random access memory, MRAM, or a phase-change random access memory, PCRAM.

[0050] Overall, it may be recognized that an on-event battery cell spacing with an expanding chemical where the pressure remains may be provided, in particular by the said expandable material 20. reference signs battery module energy storage device storage element intermediate material activation device expandable material first end plate second end plate pressure pressure pressure supply device foam pouch temperature sensor computing device

Claims

1. A battery module (10) for an electrical energy storage device (12) of a motor vehicle, comprising several storage elements (14), wherein a respective distance is provided between two respective adjacent storage elements (14) and a respective intermediate material (16) is arranged in the respective distance, characterized in thatthe battery module (10) comprises at least one activation device (18) and the respective intermediate material (16) is a respective expandable material (20), by whose increase in volume, effected by heat provided by the activation device (18), the respective distance between the storage elements (14) is capable of being increased.

2. The battery module (10) according to claim 1, characterized in thatthe battery module comprises a pressure supply device (30), by which the storage elements (14) are capable of being pressurized or are pressurized.

3. The battery module (10) according to claim 1 or 2,characterized in thatthe storage elements (14) are capable of being pressurized or pressurized by the pressure supply device (30) during the increase in volume of the respective expandable material (20).

4. The battery module (10) according to claim 3,characterized in thatduring initiation of the volume increase of the respective expandable material (20), reduction of the pressurization of the storage elements (14) by the pressure supply device (30) is omitted.

5. The battery module (10) according to any one of claims 1 to 4, characterized in thatthe storage elements (14) are arranged between two end plates (22, 24), wherein the storage elements (14) are capable of being pressurized by the pressure supply device via at least one of the end plates (22, 24).

6. The battery module (10) according to any one of claims 1 to 5, characterized in thatthe expandable material (20) is foam (32).

7. The battery module (10) according to claim 6, characterized in thatthe foam (32) is arranged in a respective pouch (33), which is arranged in the respective distance.

8. The battery module (10) according to any one of claims 1 to 7, characterized in thatthe battery module (10) comprises at least one temperature sensor (34) and an electronic computing device (36) by which the activation device (18) is capable of being controlled as a function of a temperature detected by the temperature sensor (34) in order to effect the volume increase by the activation device (18).

9. An electrical energy storage device (12) for a motor vehicle, comprising at least the battery module (10) according to any one of claims 1 to 8.

10. A method for operating a battery module (10) for an electrical energy storage device (12) of a motor vehicle, wherein the battery module (10) comprises several storage elements (14) and a respective distance is provided between two respective adjacent storage elements (14) and a respective intermediate material (16) is arranged at the respective distance, characterized in thatthe respective intermediate material (16) is a respective expandable material (20) and the battery module (10) comprises at least one activation device (18) which provides heat to the respective expandable material (20), whereby the respective distance between the storage elements (14) is increased by an increase of volume of the respective expandable material (20) effected by the provided heat.

Images