Cell holder, battery module, and vehicle

Abstract

The invention relates to a cell holder (1) comprising a separating wall (2) and two sliding guide elements (3) which are provided on opposite edges of the separating wall (2) and are configured so that when arranged in a packaging space of a module frame (6) each is supported via sliding guide surfaces (4) that positively fit sliding guide rails (5) on the module frame (6), wherein at least two cell holders (1) can be stacked orthogonally in relation to a plane of extension (E) of the separating wall (2) to form a cell receptacle (7) for a galvanic cell (8), wherein in their stacked condition cell holders (1) can be moved relative to the module frame (6) and relative to one another in the stacking direction (SR). The cell holder according to the invention is characterized in that each of the sliding guide elements (3) has an opening (9) through which cell surge protectors (10) of galvanic cells (8) can pass, and also has an electrically conductive clamping element (11) for clamping the cell surge protectors (10) in the opening (9); and each sliding guide element (3) comprises at least one connector (12) and a connection line (13) for the connector (12), the connector (12) being electrically connected via the connection line (13) to the clamping element (11) and / or to at least one sensor element located on the cell holder (1) in order to measure an operating parameter of the galvanic cell (8).

Description

[0001] Mercedes-Benz Group AG

[0002] Cell holder, battery module and vehicle

[0003] The invention relates to a cell holder of the type defined in more detail in the preamble of claim 1, as well as a battery module with such a cell holder and a vehicle with such a battery module.

[0004] Battery cells can change their volume over their lifespan. This is particularly true for battery cells with lithium anodes. During a charge or discharge cycle, the battery cells can expand and contract. This phenomenon is also known as "breathing" or "cell breathing." In addition, volume changes occur due to aging.

[0005] Typically, several battery cells are electrically connected to each other to achieve a desired cell voltage or capacity. The battery cells are arranged within a housing. Several battery cells can be connected together to form modules. Each battery module or battery must be designed so that changes in the volume of the individual battery cells do not adversely affect their operation. In particular, sufficient space should be provided to accommodate these volume changes. If the battery cells are restricted in their expansion, they will be compressed against each other and subjected to pressure. This can cause the materials from which the battery cells are made to wear down and accelerate the aging of the battery cells.

[0006] German patent application DE 102020 003 892 B4 discloses a cell holder for at least one battery cell and a cell module. The document describes a carrier for battery cells. The carrier consists of essentially rectangular walls that can be stacked in a stacking direction. Cavities are formed between the individual walls, which serve to hold the battery cells. The arrangement of battery cells and carrier is inserted into a module frame of a corresponding battery module. The respective carriers are supported on the module frame by corresponding guide structures. The carriers are not fixed relative to the module frame in the stacking direction, so that the carriers can move together with the battery cells in the stacking direction. This allows the aforementioned volume changes of the battery cells to be accommodated. The battery cells are preferably so-called pouch cells.

[0007] During operation, it is essential to monitor the battery cells to verify that the battery is functioning within its intended parameters. The mobility of the battery cells relative to one another complicates this monitoring. Furthermore, the demands placed on the electrical interconnection of relevant electronic components increase. Assembling a battery module is also challenging. Therefore, maintaining the safety of the individual battery components, particularly preventing short circuits, is a critical task under these demanding conditions.

[0008] Furthermore, DE 10 2013 021 553 A1 discloses a high-voltage battery with a temperature sensor whose signals can be read via signal lines. The temperature sensor and the signal lines are arranged on a component located between individual cells and are recessed within it.

[0009] Furthermore, US patent 2017 / 0309872 A1 discloses an electricity storage module. The electricity storage module comprises several galvanic cells with cell arresters. Each cell arrester has a projection which, together with a housing element, forms a connector.

[0010] Furthermore, US 2013 / 0029201 A1 discloses a cell module. The cell module comprises several individual cells laminated together via insulating parts. The insulating parts form an engagement element for an external connection.

[0011] Furthermore, US patent 2019 / 0067762 A1 discloses a mounting, a battery unit, and a battery module. The mounting forms a receptacle for a battery cell. The present invention aims to provide an improved cell holder that, when integrated into a battery module, allows for reliable and safe operation of the battery module.

[0012] According to the invention, this problem is solved by a cell holder having the features of claim 1. Advantageous embodiments and further developments, as well as a battery module with such a cell holder and a vehicle with such a battery module, are described in the dependent claims.

[0013] A cell holder of the generic type, comprising a partition and two sliding guide elements provided on opposite edges of the partition, which are configured to support themselves in a form-fitting manner on sliding guide rails of the module frame via sliding guide surfaces when arranged in a packaging space of a module frame, wherein at least two cell holders are stackable orthogonally to an extension plane of the partition to form a cell receptacle for a galvanic cell, wherein each cell holder is movable relative to the module frame and to each other in the stacking direction when stacked, is further developed according to the invention in that the sliding guide elements each have a recess for guiding cell terminals of galvanic cells through them and an electrically conductive clamping element for clamping the cell terminals in the recess;and at least one sliding guide element has more than one connector, wherein the connectors are each electrically connected via a connecting line to at least one sensor element arranged on the cell holder for detecting an operating characteristic of the galvanic cell.

[0014] By providing these connectors on the cell holder, a connection is made available for monitoring the safe operation of the corresponding battery module. This facilitates the acquisition and retrieval of relevant information, even when the galvanic cells are moving relative to one another. The connector can be configured as either a plug or a socket. A data processing module for evaluating the relevant information can be connected via the connector. Since at least one sliding guide element has more than one connector, it is possible to simultaneously read different operating parameters and / or electrically connect adjacent galvanic cells.

[0015] An advantageous further development of the cell holder according to the invention provides that the clamping element can be screwed or riveted to the respective cell connectors. This simplifies the manufacturing of the battery module. Corresponding galvanic cells can thus be arranged between the cell holder, and the respective cell connectors can be attached to the clamping element in the recess. By tightening the screws or riveting the cell connectors to the clamping element, the cell connectors and the clamping element are reliably fixed relative to each other. This ensures, in particular, the process reliability of an optional subsequent welding process. The cell connectors can then be welded to each other or to the clamping element using established welding methods.

[0016] The galvanic cell in question is, in particular, a pouch cell. It can be a lithium-ion cell. The cell terminations consist of a foil strip made of copper and an aluminum strip, forming the anode and cathode, respectively. Several adjacent galvanic cells can be directly connected electrically via interconnected cell terminations. However, it is also possible to connect adjacent galvanic cells using the aforementioned connectors. As already mentioned, the respective connectors can be electrically connected to the terminal element. By providing appropriate connecting leads, the connectors of two adjacent cell holders can be connected, thus enabling parallel or series connection of adjacent galvanic cells without the need to weld the individual cell terminations themselves.This simplifies the production of corresponding battery modules. In particular, the aforementioned cell holders can be pre-assembled with electrolytic cells during manufacturing. The anode on one side and the cathode on the other can be clamped to the respective holder and optionally welded. Several of these pre-assembled cell holders can then be stacked, and the electrical connections made via the connectors. It is also possible to connect measuring devices such as voltmeters to the connectors to monitor the electrical operating parameters of the individual electrolytic cells.

[0017] According to a further advantageous embodiment of the cell holders according to the invention, the connectors extend parallel to the plane of the partition, away from it. This facilitates the connection of corresponding mating connectors or connecting cables to the connectors. Particularly with a large number of stacked cell holders, accessibility perpendicular to the stacking direction is enabled. The machining steps required for assembly can then preferably be carried out on a single side or on two opposite sides of the battery module, which simplifies assembly.

[0018] According to a further advantageous embodiment of the cell holder according to the invention, it is further provided that at least two sensor elements, or at least one sensor element and the clamping element, are connected to the same connector. Such connectors can have a suitable number of pins or contacts. This allows the signals supplied by several sensor elements to be read simultaneously via the same connector, or enables electrical contacting of the respective galvanic cells. In particular, this simplifies manufacturing, as fewer connectors need to be connected to corresponding mating connectors.

[0019] A further advantageous embodiment of the cell holder according to the invention provides that the connecting cable is embedded at least partially in the structure of the partition and / or at least one of the sliding guide elements. The respective connecting cables are thus guided by the structure of the partition or...

[0020] The sliding guide elements are protected from damage. If the respective structures are electrically insulating, the protection against short circuits is also increased. Furthermore, space-efficient routing of the connecting cables is possible. In particular, the cell holders are pre-assembled with their respective connecting cables before the galvanic cells are installed.

[0021] According to a further advantageous embodiment of the cell holder according to the invention, the connecting cable runs at least partially along an edge of the partition. Thus, the connecting cable runs in the edge region of each galvanic cell, thereby avoiding mechanical contact between the connecting cable and the galvanic cell as far as possible. This prevents the connecting cable from being pressed into the structure of the galvanic cell when the cell expands, thus reducing the mechanical stress on the cell. Such connecting cables can carry electrical signals and therefore heat up during operation. By routing the connecting cables in the edge region, the transfer of this dissipation heat to the respective galvanic cells is prevented.

[0022] A further advantageous embodiment of the cell holder according to the invention provides that the partition and the sliding guide elements are made up of multiple parts. It would be possible to manufacture the two sliding guide elements and the partition monolithically. However, it is preferable to form the three components from individual parts. This increases the flexibility in the design of the corresponding battery modules. Different materials can be used to form the respective components, such as metals or metal alloys as well as plastics. For example, the partitions can be made of metal to increase the thermal mass and improve heat dissipation. The sliding guide elements can preferably be made of plastic to enable particularly low static friction between the sliding guide surfaces and the sliding guide rails. This also reduces the manufacturing costs of the sliding guide elements.Preferably, the corresponding components can be manufactured by casting, in particular injection molding.

[0023] According to a further advantageous embodiment of the cell holder according to the invention, it is further provided that a temperature value, a voltage value, a current value, a strain value, and / or a pressure value can be read via at least one connector. For reading the voltage and current values, said connector is preferably electrically connected to the clamping element. This enables a corresponding data processing module to read electrical parameters of the galvanic cell. Dedicated sensor elements, such as a temperature sensor, strain gauges, pressure sensor, and the like, can also be provided on the cell holder. The respective sensor elements can be arranged on the partition wall as well as on the respective sliding guide elements. Thus, comprehensive monitoring of a corresponding battery module is possible.The individual sensor elements can be arranged so that they come into contact with the galvanic cells when the cells are mounted on their respective cell holders. For example, temperature sensors, strain gauges, or pressure sensors can be attached to the surface of a galvanic cell, such as a pouch cell. This allows the temperature of the galvanic cell to be monitored, as well as its expansion during cell breathing. A corresponding pressure sensor could, for example, be a force sensor.

[0024] The individual cell holders are movable relative to each other in the stacking direction. However, depending on the available installation space, the number of installed galvanic cells, and the size of the individual galvanic cells, it is possible that during operation a cell holder might reach a stop, causing at least some of the galvanic cells to be compressed together. Such an event can be detected by installing suitable pressure sensors. This can then be used to activate an emergency mode for the corresponding battery module. For example, the battery module could be deactivated, or at least the affected galvanic cells could be disconnected from the rest of the battery module.

[0025] A battery module according to the invention, comprising a module frame and at least one galvanic cell, is characterized by at least two cell holders as described above. One or more such battery modules can be electrically interconnected to form a battery. Such a battery can be used as a traction battery for a vehicle.

[0026] A vehicle according to the invention is characterized by an at least partially electrified powertrain, wherein a traction battery provided for supplying the powertrain comprises at least one battery module as described above. The vehicle can be any road vehicle such as a car, truck, van, bus, or the like. In general, it could also be a rail vehicle, watercraft, or aircraft. Further advantageous embodiments of the cell holder and battery module according to the invention are also described in more detail below with reference to the figures.

[0027] This shows:

[0028] Fig. 1 shows a schematic perspective view of an arrangement consisting of a cell holder according to the invention and two galvanic cells;

[0029] Fig. 2 shows a schematic detail of the cell holder;

[0030] Fig. 3 shows a schematic representation of a battery module according to the invention;

[0031] Fig. 4 shows a schematic detail of a connector of the cell holder; and

[0032] Fig. 5 shows another schematic detail view of several connectors.

[0033] Figure 1 shows a cell unit consisting of a cell holder 1 according to the invention and two galvanic cells 8 arranged thereon. The assembly is shown connected in the upper left of the figure and in an exploded view in the lower right. Figure 2 shows the cell holder 1 in greater detail.

[0034] The cell holder 1 comprises a partition 2 and two sliding guide elements 3 arranged on opposite edges of the partition 2. The partition 2 extends in a plane E, and several cell holders 1 can be stacked relative to each other in a stacking direction SR orthogonal to the plane E. Two adjacent partitions 2 each form a cell receptacle 7 for the galvanic cells 8.

[0035] As shown in Figure 3, the cell holders 1 and galvanic cells 8 stacked in this manner can be inserted into the packaging space of a module frame 6 to form a battery module 14.

[0036] The sliding guide elements 3 have sliding guide surfaces 4 which are positively engaged with sliding guide rails 5 of the module frame 6. This allows the cell holders 1 to be laterally fixed within the module frame 6, while each cell holder 1 remains movable relative to each other and relative to the module frame 6 in the stacking direction SR. Thus, the cell holders 1 and galvanic cells 8 can move in the stacking direction SR as the volume of the galvanic cells 8 increases or decreases. The resulting volume changes of the galvanic cells 8 can therefore be compensated, thereby minimizing the mechanical stress on the galvanic cells 8. The galvanic cells 8 can be electrically connected via cell terminals 10, which are of sufficient length.

[0037] According to the invention, the sliding guide elements 3 each comprise recesses 9 for guiding the cell arresters 10 of the galvanic cells 8 through them. A clamping element 11 is provided for each sliding guide element 3 to fix said cell arrester 10, or the cell arresters 10 of two adjacent galvanic cells 8, in the recess 9. A recess 9 can thus serve to accommodate a single cell arrester 10 or several cell arresters 10. In particular, the clamping element 11 and the respective cell arrester 10 can be screwed or riveted together. Subsequently, a cell arrester 10 and a clamping element 11 can be welded together. The cell arresters 10 of two adjacent galvanic cells 8 provided on the same side can also be welded together.

[0038] As shown in Figures 4 and 5, according to the invention, at least two connectors 12 are provided for each sliding guide element 3, each of which is connected via a connecting cable 13 to the clamping element 11 and / or a sensor (not shown) for detecting an operating characteristic of one of the respective galvanic cells 8. In the embodiment shown, the connectors 12 are each designed as sockets. However, a design as plugs is also possible. The connecting cable 13 preferably runs at least partially within a structure of the partition 2 and / or the sliding guide element 3. The connecting cable 13 preferably runs in the region of an edge of the partition 2. Routing the connecting cable 13 in such a recess of the structure is quick and easy due to the good accessibility. Furthermore, the structure protects the connecting cable 13 from mechanical damage and short circuits.

[0039] A data processing module can be connected to the respective sensors (not shown) or the terminal elements 11, and thus to the cell current collectors 10, via the respective connectors 12. This allows, for example, the cell voltage, the current, or even temperatures, strain values, pressure values, and the like to be recorded and processed. This enables the correct operation of the higher-level battery module 14 to be monitored. Furthermore, adjacent galvanic cells 8 can be electrically interconnected via the connectors 12. This allows for simple assembly and monitoring of the operating parameters despite the ability of the cell holders 1 and the galvanic cells 8 to move relative to each other in the stacking direction SR.

[0040] As shown in Figure 5, connectors 12 of different designs can also be provided. One or more sensor elements can be connected to the respective connectors 12. In particular, different versions of the connectors 12 are provided on opposing sliding guide elements 3, as shown in Figure 5. This allows the cell holders 1 to be arranged alternately rotated about the vertical axis in the stacking direction SR, so that the respective cathodes and anodes of the galvanic cells 8 can be connected alternately.

[0041] The cell holder 1 and the battery module 14 according to the invention are characterized by a simple design, a long service life, and secure cable routing. Translational movement of the cell holder 1 and galvanic cells 8 in the stacking direction SR is possible. Simple and secure connection of respective sensors or electrical contacts to a data processing module for processing corresponding information is possible. The connectors 12 allow for a simple and secure signal connection while reducing the risk of short circuits.

Claims

Mercedes-Benz Group AG Patent claims 1. Cell holder (1), comprising a partition (2) and two sliding guide elements (3) provided on opposite edges of the partition (2), which are configured to be positively supported on sliding guide rails (5) of the module frame (6) via sliding guide surfaces (4) when arranged in a packaging space of a module frame (6), wherein at least two cell holders (1) are stackable orthogonally to an extension plane (E) of the partition (2) to form a cell receptacle (7) for a galvanic cell (8), wherein each cell holder (1) is movable relative to the module frame (6) and to each other in the stacking direction (SR) when stacked, characterized in that the sliding guide elements (3) each have a recess (9) for passing cell terminals (10) of galvanic cells (8);and at least one sliding guide element (3) has more than one connector (12), wherein the connectors (12) are each electrically connected via a connecting line (13) to at least one sensor element arranged on the cell holder (1) for detecting an operating characteristic of the galvanic cell (8).

2. Cell holder (1) according to claim 1, characterized in that the sliding guide elements (3) each have an electrically conductive clamping element (11) for clamping the cell arresters (10) in the recess (9); and one of the connectors (12) is electrically connected to the clamping element (11) via the connecting line (13).

3. Cell holder (1) according to claim 2, characterized in that the clamping element (11) is designed to be screwed or riveted to the respective cell conductors (10).

4. Cell holder (1) according to one of claims 1 to 3, characterized in that the connectors (12) extend parallel to the extension plane (E) of the partition (2) away from it.

5. Cell holder (1) according to one of claims 2 to 4, characterized in that at least two sensor elements or at least one sensor element and the clamping element (11) are connected to the same connector (12).

6. Cell holder (1) according to one of claims 1 to 5, characterized in that the connecting line (13) is embedded at least partially in the structure of the partition (2) and / or at least one of the sliding guide elements (3).

7. Cell holder (1) according to one of claims 1 to 6, characterized in that the connecting line (13) runs at least sectionally along an edge of the partition wall (2).

8. Cell holder (1) according to one of claims 1 to 7, characterized in that the partition (2) and the sliding guide elements (3) are designed in multiple parts relative to each other.

9. Cell holder (1) according to one of claims 1 to 8, characterized in that a temperature value, a voltage value, a current value, a strain value and / or a pressure value can be read out via at least one connector (12).

10. Battery module (14) comprising a module frame (6) and at least one galvanic cell (8), characterized by at least two cell holders (1) according to one of claims 1 to 9.

11. Vehicle characterized by an at least partially electrified powertrain, wherein a traction battery provided for supplying the powertrain comprises at least one battery module (14) according to claim 10.

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