Battery cell assembly and high-voltage storage with battery cell assembly
By using waveform connecting conductors and overload protection devices in high-voltage storage devices, combined with low thermal expansion materials, the problem of thermal event propagation in high-voltage storage devices is solved, achieving higher safety and service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BAYERISCHE MOTOREN WERKE AG
- Filing Date
- 2024-12-05
- Publication Date
- 2026-06-02
AI Technical Summary
Existing high-voltage storage devices are prone to secondary thermal events during thermal incidents, leading to damage to electrical insulation seals and short circuits. Existing fuses are complex and difficult to effectively prevent the propagation of thermal events.
A connecting conductor with a waveform section and overload protection device is used, which is fixed to the battery cell terminals and poles and supported by a carrier plate or cover to limit the expansion of the connecting conductor, reduce mechanical load and relative movement, and combine with bimetallic or low thermal expansion materials to suppress thermal expansion.
It effectively prevents the propagation of thermal events in the high-voltage storage device, reduces the relative movement and mechanical load between the battery cell terminals and the casing, and improves the service life and safety of the battery cell assembly.
Smart Images
Figure CN122139264A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a battery cell assembly having multiple battery cells in a high-voltage storage device, and a high-voltage storage device having such a battery cell assembly. Background Technology
[0002] Typically, a high-voltage storage device comprises multiple battery cells, which are combined into a battery cell assembly. Such high-voltage storage devices are used, for example, in motor vehicles, where typically four to six battery cells are combined in a parallel assembly. The battery cells are preferably vertically oriented circular cells, wherein the individual circular cells are interconnected through their terminals. The connection of the terminals is typically achieved via electrical connection conductors.
[0003] To ensure thermal safety, electrical conductors are typically equipped with fuses, especially overcurrent protection devices, to minimize the impact of thermal events. These fuses are specifically designed to prevent the propagation of thermal events. Detachable components, such as wirebonds, are often used for this purpose. However, such fuses are complex.
[0004] During thermal events, such as short circuits, battery cells generate heat and overvoltage occurs within them. The mechanical load resulting from this overvoltage can damage the electrical insulation seals located between the two poles of the battery cell in the terminal area. These electrical insulation seals are typically made of polymers such as epoxy molding compounds (EMC), polyphenylene sulfide (PPS), or perfluoroalkoxy (PFA).
[0005] Due to the heat generated within the battery cells, the connecting conductors expand and exert force on the battery cell terminals, which then transfer this force to the electrically insulating seals. Additional measures can be taken to prevent short circuits. A short circuit represents a second thermal event, in which temperatures in the range of 400°C to 500°C are released.
[0006] The safety devices known from the prior art function in the event of a second thermal event to prevent thermal runaway, so that the first or second thermal event does not spread to the surrounding battery cells. Summary of the Invention
[0007] The objective of this invention is to avoid the generation of a second thermal event within a high-voltage memory.
[0008] According to the present invention, this task is accomplished by a battery cell assembly of a high-voltage storage device. The battery cell assembly has a plurality of battery cells, each having a first electrode formed by a protruding battery cell terminal and a second electrode forming a battery cell housing. The battery cell assembly also includes a connecting conductor that electrically connects the battery cell terminal and / or the second electrode to each other. The connecting conductor is fixed to the battery cell terminal and / or electrode to be connected and, at least at an additional holding location, to an additional component. In other words, the connecting conductor is supported on the additional component, thereby restricting the expansion of the connecting conductor. Therefore, the mechanical load on the battery cell terminal is minimized and the relative movement between the battery cell terminal and the second electrode is reduced. In particular, the relative movement between the two electrodes is restricted to such an extent that short circuits or thermal events are prevented.
[0009] According to a preferred embodiment, the battery cell is a circular battery cell. Here, each of the circular battery cells has an opening in the battery cell housing through which a battery cell terminal extends. Therefore, the edge of the opening in the battery cell housing laterally surrounds the battery cell terminal. To electrically insulate the battery cell terminal from the battery cell housing, a battery cell seal is arranged between the battery cell terminal and the edge of the opening.
[0010] In particular, the connecting conductor is mounted on the side where the first electrode of the corresponding battery cell is also located, and contacts the second electrode there. Therefore, one or more connecting conductors can be located on the same side of the battery cell and do not need to extend along the battery cell to the opposite side.
[0011] Preferably, the connecting conductor is fixed to the carrier plate and / or cover of the battery cell. Therefore, no additional components are needed to support or fix the connecting conductor, thereby preventing increased production costs. In particular, the carrier plate and cover are made of a material with a low coefficient of thermal expansion, so that the expansion of these components has little effect compared to the connecting conductor.
[0012] According to one embodiment, the retaining portion is formed by a void. Here, the void is designed to receive a protrusion of the additional component or a fixing member locked onto the additional component. Therefore, the connecting conductor is preferably fixed to the additional component by a form-locking connection. This enables reversible fixing, allowing replacement of the battery cell, connecting conductor, or battery cell seal, thereby improving the service life of the battery cell assembly.
[0013] According to an alternative embodiment, the retaining portion is formed by a protrusion, particularly a pin, on the connecting conductor. Here, the protrusion is designed to engage with a recess in the other component. Alternatively, the connecting conductor is riveted to the other component. Riveting also ensures that the fixation between the connecting conductor and the other component will not accidentally loosen.
[0014] Preferably, an overload protection device, particularly a fuse, is also provided on the connecting conductor. When a predetermined reference temperature is exceeded, the overload protection device can disconnect the connection between the connecting conductor and the battery cell contact system. Therefore, the overload protection device is used to prevent the propagation of thermal events.
[0015] Preferably, the overload protection device is configured as a narrowing section on the connecting conductor. Here, the narrowing section may be an elastically compressed section of the connecting conductor, which gives the connecting conductor a wavy structure in the side view.
[0016] According to one embodiment, the connecting conductors are each made of a metal sheet, wherein the metal sheet has at least one embossed portion. The metal sheet is, in particular, a conductive material, thereby ensuring a reliable electrical connection between the battery cell terminals and / or the second electrode. The embossed portion can be provided, in particular, on a narrowed portion that provides overload protection. Furthermore, the embossed portion serves to reinforce the connecting conductors, thereby minimizing the degree to which the connecting conductors expand due to heat and thus reducing the risk of short circuits.
[0017] The connecting conductor may have wavy sections in the top view, from which free-extending contact arms extend. These free-extending contact arms are fixed to the battery cell terminals and / or poles, with retaining portions disposed on the contact arms. In particular, when the retaining portions are disposed on the contact arms in such a way that they are supported on the battery cell housing, relative movement between the battery cell terminals and the battery cell housing is prevented. With the contact arms supported in this manner, expansion of the connecting conductor in the region of the battery cell terminals is minimized, thereby reducing the mechanical load on the battery cell terminals. Therefore, relative movement between the battery cell terminals and the opening edge is minimized.
[0018] Additionally, by supporting the retaining portion on the battery cell casing, outward bulging of the battery cell casing can be suppressed, thereby preventing further short circuits. Such outward bulging of the battery cell casing can occur due to increased internal pressure within the battery cell and can also cause short circuits at correspondingly high pressures.
[0019] The waveform segment is also optimized for the electrical connection of circular battery cells in two parallel, adjacent rows of battery cells, because the circular battery cells in adjacent rows are staggered and extend into the gaps between adjacent circular battery cells in adjacent rows. Therefore, the waveform can be used to connect one or more circular battery cells in one row to one or more circular battery cells in an adjacent row, or even to one or more circular battery cells in a more distant row. Furthermore, the waveform ensures flexibility.
[0020] Alternatively, the battery cell can also be a pouch-shaped battery cell or a prismatic battery cell. However, due to the geometry, a circular battery cell is preferred.
[0021] According to one embodiment, the connecting conductors are implemented in a multi-layered manner, wherein the connecting conductors particularly include interconnected plates. Here, the material of one plate has OK properties. -1 The first layer has a small or negative coefficient of thermal expansion, while the other layer is made of a conductive material. In other words, the connecting conductor is preferably made of bimetal, wherein two layers are rolled together. Here, the first layer is used to establish electrical contact between the individual battery cells by contacting the battery cell terminals and / or second electrodes of adjacent battery cells. Conversely, the second layer is designed to reinforce the connecting conductor and suppress the expansion of the first layer. Therefore, the second layer has a small or negative coefficient of thermal expansion, but preferably 0K. -1 The coefficient of thermal expansion. The second layer can be, for example, an iron-nickel alloy. By reinforcing the connecting conductors, only a small expansion of the connecting conductors occurs even when the battery cell heats up, thereby preventing mechanical contact between the battery cell terminals and the battery cell casing.
[0022] As an alternative to bimetallic materials, the connecting conductor may also have a rolled plate in the contact area between the connecting conductor and the battery cell terminal, or between the connecting conductor and the second electrode.
[0023] The aforementioned task is also addressed according to the present invention by a high-voltage storage device having a battery cell assembly and a housing as described above. The battery cell is received within the housing, as with a carrier plate in the electrode region. Here, connecting conductors are fixed to the carrier plate, particularly at the holding locations. By additionally fixing the carrier plate within the housing, various types of movement are minimized, thereby significantly reducing the risk of thermal events. Attached Figure Description
[0024] Other advantages and features of the invention will become apparent from the following description and the accompanying drawings. In the drawings:
[0025] Figure 1 A schematic diagram of a battery cell assembly according to the present invention is shown in top view;
[0026] Figure 2a As shown in Figure 1 A schematic diagram of the connecting conductors used;
[0027] Figure 2b A schematic diagram of the corresponding other components is shown;
[0028] Figure 3a A schematic diagram illustrating another embodiment of the connecting conductor;
[0029] Figure 3b A schematic diagram of the corresponding other components is shown;
[0030] Figure 4 Show Figure 1 A schematic diagram of the battery cell contact connection system in the battery cell assembly.
[0031] Figure 5 A schematic diagram of the carrier plate shown in Figure 3 is presented;
[0032] Figure 6 A schematic diagram of the connecting conductor according to the second embodiment is shown;
[0033] Figure 7 A schematic diagram of the connecting conductor according to the third embodiment is shown;
[0034] Figure 8 A schematic diagram of a high-voltage memory according to the present invention is shown. Detailed Implementation
[0035] exist Figure 1 The diagram shows a battery cell assembly 10 of a high-voltage storage device 12. Here, the battery cell assembly 10 includes a plurality of battery cells 14 and connecting conductors 16 (e.g., four connecting conductors 16 in this case), which are part of a battery cell contact connection system 18. The battery cell contact connection system 18 will be described in more detail below.
[0036] The topmost connecting conductor 16 connects eight battery cells 14 to each other to form a parallel assembly 20. The second and third connecting conductors from the top connect ten battery cells 14 to each other, and the bottom connecting conductor connects five battery cells 14 to each other. The parallel assemblies 20 are also connected in series with each other.
[0037] The battery cell 14 is preferably a circular battery cell, especially a circular battery cell corresponding to a 4.2-volt storage battery. Therefore, conventional battery cells 14 can be used in the high-voltage storage device 12, thereby reducing costs.
[0038] The battery cells 14 are arranged in rows, with each row of the sequentially positioned battery cells 14 staggered from the others. Thus, the electrically insulating seal 22 can be positioned between the rows of battery cells 14.
[0039] Furthermore, each battery cell 14 can extend into the gap between adjacent circular battery cells in adjacent rows for reference. Figure 1 It is constructed compactly in the vertical direction.
[0040] exist Figure 2a In the diagram, the connecting conductor 16 can be seen in detail. The connecting conductor 16 has a wave-shaped section 24 from which a freely extending contact arm 26 extends in the opposite direction. Here, the contact arm 26 is part of the battery cell contact connection system 18 and is used to establish an electrical connection between the individual battery cells 14.
[0041] The waveform segment 24 is a wavy structure connecting conductor 16, which is located in the plate plane of the plate-shaped connecting conductor 16.
[0042] The contact arm 26 is divided into contacts for the first electrode 28 and the second electrode 30, wherein the first electrode 28 is typically the positive electrode and the second electrode 30 is the negative electrode. The contact area of the first electrode 28 is formed by a circular plate 32, while the contact area of the second electrode 30 is formed by a free end 36 with a recess 34 connected to the conductor 16. Thus, the recesses 34 surround the first electrode 30 of the corresponding circular battery cell at a distance.
[0043] exist Figure 2a In the illustrated embodiment, the connecting conductor 16 further includes a plurality of recesses 38. The recesses 38 are designed to receive protrusions 40 or fixing members 42, thereby allowing the connecting conductor 16 to be secured to another component. The other component is... Figure 2b As shown in the figure. Therefore, the empty portion 38 forms a holding portion 60 for connecting the conductor 16.
[0044] Alternatively, connecting conductor 16 is also as in Figure 3a As can be seen, it may have a protrusion 44, which can engage with the recess 46 of the other component, as in Figure 3b As shown, so as to fix the connecting conductor 16.
[0045] Therefore, the connection between the connecting conductor 16 and the other component is established by a form-locking connection.
[0046] Therefore, this connection is preferably a reversible connection, so that each battery cell 14 can be replaced if needed.
[0047] Another alternative, not shown, specifies that the connecting conductor 16 is riveted to the other component.
[0048] Figure 4 The battery cell contact connection system 18 of the battery cell 14 of the battery cell assembly 10 is shown. The battery cell 14 includes a battery cell terminal 50 formed by a protrusion 48, which forms a first pole 28.
[0049] A battery cell terminal 50 extends through an opening 52 in a battery cell housing 54 forming the second electrode 30. An electrically insulating battery cell seal 56 is arranged between the battery cell terminal 50 and the edge of the opening 52 in the battery cell housing 54.
[0050] Furthermore, the battery cell contact connection system 18 includes a connecting conductor 16, and in particular a contact arm connecting the connecting conductor 16, the contact arm being in Figure 4 The conductor 16 is attached to the battery cell terminal 50. An overload protection device 58, particularly a fuse, is installed at the contact point between the conductor 16 and the battery cell terminal 50, i.e., the circular plate 32.
[0051] The overload protection device 58 is used to disconnect the connection between the battery cell terminal 50 and the connecting conductor 16 that is in contact with another battery cell 14 when a predetermined reference temperature is exceeded. Therefore, the overload protection device 58 is used to prevent the propagation of thermal events.
[0052] As in Figure 2a As can be seen, the overload protection device 58 can be formed by a narrowing portion on the connecting conductor 16. Alternatively, the overload protection device 58 can also have two contacts, such as, for example, in... Figure 7 As can be seen from the text.
[0053] exist Figure 7 The overload protection device 58 shown in the side view has a wavy structure, wherein the overload protection device 58 extends from the plane of the connecting conductor 16 and forms an elastically compressed section that acts in the direction between the holding parts 60.
[0054] In addition to the battery cell contact connection system 18 and the overload protection device 58, Figure 4 and Figure 7 The image also shows a retaining portion 60. The retaining portion 60 secures the connecting conductor 16 to another component, in this case, a carrier plate 62. Figure 5 One embodiment of the carrier plate 62 can be seen here. In this embodiment, the connecting conductor 16 is integrated into the carrier plate 62 and is therefore fixed on the carrier plate.
[0055] Alternatively or additionally, the connecting element 16 may be secured to the cover 64 of the battery cell assembly 10 via an additional retaining portion 60 (see [link]). Figure 8).
[0056] exist Figure 6 The second embodiment of the connecting conductor 16 can be seen in the diagram. According to this embodiment, the connecting conductor 16 is multi-layered and includes two interconnected plates 66. In principle, the connecting conductor 16 may also be composed of more than two plates 66, 67; however, the connecting conductor 16 is preferably bimetallic.
[0057] The first plate 66 is made of a conductive material and is designed to establish electrical contacts between the individual battery cells 14. Therefore, the first plate 66 corresponds to the connecting conductor 16 already described above.
[0058] Conversely, the second plate 67 is designed to reinforce the connecting conductor 16 and is preferably made of a material with a small coefficient of thermal expansion. Preferably, this material has an OK temperature range. -1 The coefficient of thermal expansion is positive or negative. Therefore, the second plate 67 suppresses the expansion of the connecting conductor 16, thereby minimizing the total expansion. The material used for the second plate 67 can be, for example, an iron-nickel alloy.
[0059] exist Figure 7 The third embodiment of the connecting conductor 16 can be seen here. The connecting conductor 16 shown here is preferably made of a metal sheet having at least one embossed portion 68. The embossed portion 68 is used to reinforce the connecting conductor 16 and thus minimize its expansion.
[0060] exist Figure 7 The connecting conductor 16 shown here is connected to the circular plate 32 and the recess 34, and has an overload protection device 58. Here, the overload protection device 58 can be seen not only in the single-connector version but also in the double-connector variant.
[0061] Figure 8 A high-voltage storage device 12 is shown, which includes a battery cell assembly 10 and a housing 70. The individual battery cells 14 of the battery cell assembly 10 are received in the housing 70, which can be closed by a cover 64.
[0062] In addition to the battery cell 14, a carrier plate 62 is also received in the housing 70, wherein the carrier plate 62 is arranged in the region of the poles 28, 30 of the battery cell 14. Here, the connecting conductor 16 is fixed to the carrier plate 62 by a retaining part 60.
Claims
1. A battery cell assembly (10) of a high-voltage storage device (12), the battery cell assembly having: a plurality of battery cells (14), each battery cell (14) having a battery cell terminal (50) formed by a protrusion (48) of a first pole (28) and a second pole (30) forming a battery cell housing (54); and a connecting conductor (16) electrically connecting the battery cell terminal (50) and / or the second pole (30) to each other, wherein, The connecting conductor (16) is fixed to the battery cell terminal (50) and / or the second pole (30) to be connected and is fixed to an additional component at least at the additional holding part (60).
2. The battery cell assembly (10) according to claim 1, characterized in that, The additional components on which the connecting conductor (16) is fixed are the carrier plate (62) and / or cover (64) of the battery cell (14).
3. The battery cell assembly (10) according to claim 1 or 2, characterized in that, The holding part (60) is formed by a gap (38) designed to receive a protrusion (40) of the other component or to receive a fixing part (42) locked onto the other component.
4. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, The retaining part (60) is formed by a protrusion (44) on the connecting conductor (16), in particular a pin, which is designed to be fitted into a vacancy (46) in the other component, and / or the connecting conductor (16) is riveted to the other component.
5. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, An overload protection device (58), particularly a fuse, is provided on the connecting conductor (16). When the temperature exceeds a predetermined reference temperature, the overload protection device can disconnect the connection between the connecting conductor (16) and the battery cell contact connection system.
6. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, The connecting conductors (16) are each made of metal plates having at least one embossed portion (68).
7. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, The retaining part (60) is located between the adjacent battery cell terminal (50) and / or the second pole (30) fixed by the connecting conductor, and / or at the free end (36) of the connecting conductor (16).
8. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, The connecting conductor (16) has a waveform segment (24), from which a freely extending contact arm (26) extends. The contact arm is fixed to the battery cell terminal (50) and / or the second pole (30), and a retaining part (60) is provided on the contact arm (26).
9. The battery cell assembly (10) according to any one of the preceding claims, characterized in that, The connecting conductor (16) is implemented as a multilayer structure and includes interconnected plates (66, 67), wherein the first plate (66) is made of a conductive material, and the material of the second plate (67) has 0K -1 The coefficient of expansion is positive or negative.
10. A high-voltage storage device (12) having a battery cell assembly (10) according to any one of the preceding claims and an outer casing (70) in which the battery cell (14) is received, and a carrier plate (62) in the region of the poles (28, 30), wherein the connecting conductor (16) is fixed to the carrier plate, particularly at the holding portion (60).