Cell holders and methods for mounting a battery module

Abstract

The invention relates to a cell holder (1) comprising a partition (2) and two sliding guide elements (3) provided on opposite edges of the partition (2), which are arranged to be supported in a form-fitting manner on sliding guide rails (7) of the module frame (5) via sliding guide surfaces (6) when arranged in a packaging space (4) of a module frame (5), wherein at least two cell holders (1) can be stacked orthogonally to an extension plane (E) of the partition (2) to form a cell receptacle for a galvanic cell (8), wherein each cell holder (1) is movable in the stacked state relative to the module frame (5) and to each other in the stacking direction (SR).The cell holder according to the invention is characterized by at least one through-opening (9) extending in the stacking direction (SR) through a respective sliding guide element (3), the cross-sectional shape of which is adapted to the cross-sectional shape of a mounting rod (10) in order to enable the mounting rod (10) to pass through the through-opening (9) in the stacking direction (SR).

Description

[0001] The invention relates to a cell holder of the type defined in more detail in the preamble of claim 1 and to a method for assembling a battery module comprising such a cell holder.

[0002] 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.

[0003] 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.

[0004] German patent DE 10 2020 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.

[0005] 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.

[0006] The present invention aims to provide an improved cell holder that allows for particularly simple assembly of a battery module. A further objective of the present invention is to provide an improved method for assembling a battery module that can be carried out quickly, reliably, and with minimal effort.

[0007] According to the invention, these problems are solved by a cell holder with the features of claim 1 and a method for assembling a battery module with the features of claim 3. Advantageous embodiments and further developments are described in the dependent claims.

[0008] 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 can be stacked 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 by at least one through-opening extending in the stacking direction through each sliding guide element, the cross-sectional shape of which is adapted to the cross-sectional shape of a mounting rod in order to enable the mounting rod to pass through the through-opening in the stacking direction.

[0009] Several cell holders can be inserted into the packaging space of the module frame. Between each cell holder, a cell receptacle is formed for each individual electrolytic cell. The electrolytic cells can be electrically connected, for example, in parallel and / or series. This allows the desired voltage and capacity to be set for a corresponding battery module. The volume of the electrolytic cells changes between charging cycles and over their service life. Since the cell holders with their respective electrolytic cells are movable in the stacking direction, these volume changes can be accommodated without compressing the electrolytic cells against each other.

[0010] The electrical connection of the galvanic cells and the installation of sensor elements for monitoring the operating conditions of the corresponding battery module, such as temperature sensors or devices for monitoring internal resistances, voltages, current, and the like, are typically carried out before the assembly is inserted into the packaging space. Consequently, accessibility to relevant areas on the cell holder or the galvanic cell is typically comparatively poor after insertion into the packaging space. However, these relevant areas can be easily accessed before insertion.

[0011] During assembly, electrically conductive or signal-carrying components must be connected. Cables, which are prone to tearing, can be used for this purpose, complicating the assembly process. According to the invention, the individual cell holders, and thus the galvanic cells, are fixed in place, reducing the risk of cable breakage. For this purpose, at least one sliding guide element of each cell holder includes a through-opening for an assembly rod. Using this assembly rod, the arrangement of several cell holders and galvanic cells can be fixed relative to each other, except in the stacking direction, thus preventing unwanted relative movements during pre-assembly. This allows the battery module to be assembled quickly, safely, easily, and reliably. Furthermore, such an arrangement can be easily and safely inserted into the packaging space.The mounting rod can have an end stop, allowing, for example, the insertion of a clamping element at the opposite end of the mounting rod to secure it in the stacking direction after all cell holders have been threaded onto the rod. This clamping element must be removed before the assembly is placed in the packaging space.

[0012] An advantageous embodiment of the cell holder according to the invention provides that the through-opening has a circular cross-sectional shape. Generally, all possible cross-sectional shapes are suitable, such as a round, oval, or even any polygonal shape. For example, it could be a rectangular shape, square shape, star shape, or the like. With a polygonal cross-sectional shape, however, the mounting rod must be specifically oriented relative to the through-opening in order to be guided through it. With a circular shape, on the other hand, guiding the mounting rod through the through-opening is possible in any position, i.e., regardless of the mounting rod's rotation about its longitudinal axis.

[0013] The mounting rod can also be chamfered or have a conical tip at one or both of its ends. This facilitates threading the mounting rod into the through-hole. Alternatively, as already mentioned, the mounting rod can also be fitted with a stop plate or have a thickened section at one of its ends. This prevents cell holders threaded onto the mounting rod from slipping off.

[0014] A method for assembling a battery module, the battery module comprising at least two cell holders described above, at least one galvanic cell and a module frame, is further developed according to the invention by the following method steps: - Passing at least one first mounting rod through the through-opening of at least one sliding guide element of a first cell holder; - Arranging a galvanic cell on the first or a second cell holder; - Slide the second cell holder onto at least the first mounting rod, so that the first and second cell holders form the cell receptacle for the galvanic cell; - optional: appropriate arrangement of additional cell holders and galvanic cells; - Inserting the assembly consisting of at least the first cell holder, second cell holder, galvanic cell, and at least the first mounting rod into the packaging space of the module frame; and - Removal of all mounting rods from the module frame.

[0015] The mounting rod allows the assembly of cell holders and galvanic cells to be fixed in place, significantly simplifying its insertion into the packaging space. In particular, it prevents the tearing of electrical wiring, contacts, connections, and the like. After the assembly is inserted into the packaging space, the mounting rods can be easily pulled out of the corresponding through-holes in the opposite direction. Thanks to the support of the sliding guide elements via the sliding surfaces on the module frame's guide rails, the precise positioning of the assembly's components relative to each other is maintained.

[0016] Preferably, at least one mounting rod is threaded through each sliding guide element. This allows the arrangement of cell holders and galvanic cells to be fixed not only on one side, but also on at least two sides of each cell holder. In a top view in the stacking direction, preferably two through-openings can be provided in each of the corresponding sliding guide elements, so that mounting rods can be guided through a left upper and lower through-opening as well as a right upper and lower through-opening.

[0017] The individual through-holes in the sliding guide elements are located in the same position from one sliding guide element to the next, so that when cell holders and galvanic cells are stacked, the respective through-holes align in the stacking direction. This allows corresponding mounting rods to be inserted through all cell holders or sliding guide elements in the stacking direction.

[0018] Preferably, at least one pre-assembly step is performed before the assembly is inserted into the packaging space. Fixing the cell holders and galvanic cells to each other not only facilitates the insertion of the assembly into the module frame's packaging space, but also allows, as already described, for the corresponding pre-assembly steps to be carried out due to the good accessibility of the relevant components.

[0019] The corresponding pre-assembly steps can be carried out once all the necessary cell holders and electrolytic cells for forming the assembly have been threaded onto the respective mounting rods. However, it is also possible to perform some or all of the pre-assembly steps gradually, i.e., to carry out one or more pre-assembly steps after each cell holder and / or electrolytic cell has been threaded onto the rods.

[0020] Preferably, at least one of the following pre-assembly steps is carried out: - Transporting the arrangement; - Welding of components, in particular welding of cell terminals of one or more galvanic cells; - Soldering of components; - Cabling of components; and / or - Performing a functional test of components.

[0021] The relevant components can include current-carrying components such as contact plates, wires, conductor tracks, conductors, plugs and the like, as well as sensors, measuring probes, valves, bursting elements and the like.

[0022] Various pre-assembly steps are possible, allowing the assembly to be almost completely completed before being inserted into the packaging space. The assembly then simply needs to be inserted into the packaging space and connected to other modules via connection elements, such as connectors, which extend from the packaging space at designated points. These modules include, for example, additional battery modules or power electronics such as a battery management system.

[0023] Further advantageous embodiments of the cell holder according to the invention and of the method according to the invention for mounting the battery module also result from the exemplary embodiments which are described in more detail below with reference to the figures.

[0024] This shows: Fig. 1 a schematic exploded view of a cell holder according to the invention; Fig. 2 a schematic representation of a battery module according to the invention; Fig. 3 a schematic detail representation of a sliding guide element of the cell holder; Fig. 4 a schematic detail representation of several cell holders fixed by means of a mounting rod; and Fig. 5 a schematic detail representation of cell holders fixed by means of several mounting rods.

[0025] Fig. Figure 1 shows a cell holder 1 according to the invention, comprising 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 for Fig. The two illustrated galvanic cells 8 are shown. In the illustrated embodiment, the galvanic cells 8 are pouch cells.

[0026] How Fig. As shown in Figure 2, the cell holders 1 and galvanic cells 8 stacked in this way can be inserted into the packaging space 4 of a module frame 5 to form a battery module 11.

[0027] The sliding guide elements 3 have sliding guide surfaces 6 which are positively engaged with sliding guide rails 7 of the module frame 5. This allows the cell holders 1 to be laterally fixed within the module frame 5, while each cell holder 1 remains movable relative to each other and relative to the module frame 5 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 connectors.

[0028] Fig. Figure 3 shows two of the sliding guide elements 3 in an enlarged view. Various components are visible, such as connectors 12, wiring 13 for the connectors 12, mounting points 14, and a screw 15 for attaching the sliding guide element 3 to the partition 2. A through-opening 9 in the stacking direction SR is also shown, through which a [missing information] can be inserted into the [missing information]. Fig. 4 and Fig. The mounting rod 10 shown in section 5 can be passed through it. Viewed in the stacking direction SR, the respective through-openings 9 of the sliding guide elements 3 are aligned, so that the individual cell holders 1 can be threaded onto said mounting rods 10.

[0029] Fig. Figure 4 shows a representation in which a corresponding mounting rod 10 is passed through several cell holders 1. The path of the through-opening 9 is indicated by two dashed lines. The cross-sectional shape of the through-opening 9 and the mounting rod 10 is particularly preferred as being circular. The individual cell holders 1 are fixed by threading them onto the mounting rod 10 transversely to the stacking direction SR, but remain movable relative to each other in the direction of the stacking direction SR.

[0030] It is also conceivable that a stopper element is threaded onto the mounting rod 10 to prevent the cell holders 1 from slipping in the stacking direction SR. Such a stopper element, not shown in detail, could, for example, be designed like a clamp. Alternatively, the mounting rod 10 could be threaded, allowing a nut to be screwed onto it.

[0031] It has at least one sliding guide element 3 for each cell holder 1, each with at least one through-opening 9. Particularly preferably, however, each sliding guide element 3 has two through-openings 9, so that the Fig. The advantageous embodiment of the arrangement shown in Figure 5 consists of cell holders 1 and galvanic cells 8. In a top view of the arrangement in the stacking direction SR, a mounting rod 10 is provided in each corner of the arrangement. This ensures that the respective cell holders 1 and galvanic cells 8 are fixed particularly reliably.

[0032] Particularly advantageous is the ability to perform further pre-assembly steps after arranging the cell holders 1 and galvanic cells 8 on the respective mounting rods 10. These steps include soldering, welding, or electrically contacting components such as cell terminals, connectors, and the like. The assembly is then inserted into the packaging space 4 of the module frame 5, and the mounting rods 10 are removed. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 003 892 B4

[0004]

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