Device for electrically contacting battery cells

Abstract

The invention relates to a device for electrically contacting battery cells (1), comprising battery cells (1) which are arranged next to each other transversely to the longitudinal axis (3) of the device in a main part (2) and which are contacted by an electrical conductor (5). The aim of the invention is to prevent damage to the conductor or the contacting of the conductor caused by operational changes in the size of individual battery cells in the event of vibration-related force factors and a sufficient tolerance compensation at the same time. The aim of the invention is to prevent damage to the conductor or the contacting of the conductor caused by operational changes in the size of individual battery cells in the event of vibration-related force factors and a sufficient tolerance compensation at the same time.

Description

[0001] Device for electrically contacting battery cells

[0002] Technical area

[0003] The invention relates to a device for electrically contacting battery cells with battery cells arranged next to one another in a base body transversely to their longitudinal axis, which battery cells are contacted by an electrical conductor.

[0004] State of the art

[0005] It is known from the prior art (US20210203029A1) to store battery cells arranged side by side in a base body, transverse to their longitudinal axis. To secure the individual battery cells, the base body has a support frame that encloses the cover-side battery cell end sections and thereby forms shell-side and cover-side stops for the battery cells. For electrical contact, an electrical conductor is provided that connects the battery cells to one another. This electrical conductor is supported on the side of the cover-side support frame opposite the battery cells, protrudes through openings in the area of ​​the cover-side stop, and is electrically connected to the battery cells.This arrangement prevents shear-induced forces from the battery cells acting on the electrical conductor, as the cover-side stop absorbs the shear forces, thus protecting the conductor against shear forces and the resulting damage to the contact. However, the disadvantage is that operational changes in the size of the battery cells, combined with vibrations particularly common in the automotive sector, can still lead to undesired loosening or, in the case of a material-to-material connection, damage to the contact. This is because the conductor is either held back by the support frame and thus cannot follow the movement of the battery cells, or is pulled through the opening and thus becomes undesirably deformed or damaged.To prevent such tensile force-related damage, the known device has a second support frame arranged on the bottom side on the side opposite the top-side support frame. This frame encloses the bottom-side battery cell end sections and thus forms stops for the battery cells on the shell and bottom sides. This restricts the movement of the battery cells in both directions along their longitudinal axis, which, however, can lead to damage to the device even more in the event of operationally induced size changes of the battery cells. Furthermore, this also limits the compensation of any manufacturing tolerances of the battery cells.

[0006] Description of the invention

[0007] The invention is therefore based on the object of proposing a device of the type described at the outset which avoids damage to the conductor or its contact caused by operational changes in the size of individual battery cells in the event of vibration-related force influences and at the same time provides sufficient tolerance compensation.

[0008] The invention achieves this objective by mounting the battery cells in the base body with play along their longitudinal axis, and by connecting a support plate, which is stationary relative to the electrical conductor, to each of the electrically contacted battery cells along their longitudinal axis in a shear- and tensile-resistant manner to mechanically relieve the electrical conductor. The features of the invention enable movement of the battery cells in the direction of their longitudinal axis relative to the base body, thus compensating for both operational and thermal expansion-related size changes and manufacturing-related size differences of the battery cells.However, relative movement between the battery cells, the carrier plate and the conductor is prevented within a tolerance range, as the carrier plate is connected to each of the electrically contacted battery cells along their longitudinal axis in a shear and tensile manner, and the conductor itself is fixedly connected to the carrier plate, in particular is fixed to the carrier plate. In this way, the carrier plate, together with the electrical conductor, can follow any movements of the battery cells along the longitudinal axis due to bending and / or twisting, whereby the electrical conductor is mechanically relieved and thus protected against forces acting in the tensile and shear directions. Preferably, the carrier plate is mounted in a floating manner relative to the base body. Floating means that the carrier plate is mounted in such a way that it can follow the vibration- and operational-related movement of the connected battery cells.This can be achieved by mounting the carrier plate with play along the longitudinal axis, particularly relative to the base body. In this way, the carrier plate can particularly effectively follow both the movements of the individual battery cells along their longitudinal direction and torsion-related offsets of a group of battery cells. For the purposes of the invention, a carrier plate is considered to be a component whose width and length are much greater than its thickness. The carrier plate, which is designed to be particularly insulating, can preferably be made of plastic. To increase performance, the device can comprise two or more base bodies arranged next to one another transversely to the longitudinal axis.

[0009] Advantageously, the carrier plate and / or the conductor can overlap the adjacently arranged base bodies, thereby obtaining a compact device without preventing tolerance compensation.

[0010] In particular, the geometry of common round cells with grooves running along the periphery of the casing can be used particularly practically for a fixed connection to the carrier plate if the carrier plate has at least one locking element for each electrically contacted battery cell that engages a locking receptacle of the battery cell. In particular, if the locking receptacle extends in the region of the battery cell end section, thermal expansion-related force influences between the locking elements of the carrier plate and the conductor, which is fixedly arranged on the carrier plate and contacts the battery cell end section, can be reduced, since the heat- and operation-related change in size along the short battery cell section between the locking receptacle and the contacted end section, also known as cell breathing, is relatively small compared to the overall battery cell length.The locking receptacle of the battery cell can form a stop for the locking body in both directions along the longitudinal axis. Preferably, several locking bodies are provided, distributed circumferentially around the battery cell. In particular, three locking bodies can be provided, distributed circumferentially around the battery cell, which enables uniform force transmission from the battery cells to the carrier plate while still maintaining sufficient clearance between the locking bodies so that cell breathing does not result in excessive force. Furthermore, simple contacting and assembly conditions are achieved by arranging the locking bodies on the side of the carrier plate opposite the conductor.

[0011] A temperature control fluid can be contained within the base body. To prevent damage to the conductor and enable easy contact, the end sections of the battery cells can be located outside the base body, while the remaining section of the battery cells runs within the base body. The battery cells can be mounted via seals in the base body with clearance along their longitudinal axis, which not only prevents leaks but also improves tolerance compensation.

[0012] To achieve an advantageous and, in particular, easy-to-manufacture mounting of the carrier plate, it is proposed that the carrier plate have an opening for each electrically contacted battery cell. The openings can serve as receptacles for the battery cells, particularly their end sections, and allow, on the one hand, the dissipation of hot gas in the event of a thermal runaway and, on the other hand, easy access to the battery cell terminal facing the carrier plate for electrical contacting.

[0013] Advantageous contact conditions, especially an easily accessible voltage tap, are achieved when the conductor is arranged on the side of the carrier plate opposite the battery cells. If the conductor also has a conductor end section extending into each aperture, forming a fuse, damaged battery cells can be electrically decoupled from the remaining intact battery cells.

[0014] To ensure that in the event of damage to a battery cell, the surrounding battery cells are not only electrically separated from the damaged battery cell but are also protected from escaping hot gas, the openings on the side of the carrier plate opposite the battery cells can be surrounded at least in sections by a gas baffle. This can provide a directed flow path for the escaping hot gas away from the surrounding battery cells. At the same time, the conductor can be routed between the gas baffles, which preferably run along the contour of the openings, so that the gas baffles serve as receptacles for permanently securing the conductor to the carrier plate. Furthermore, the gas baffle can be interrupted in sections so that the conductor or its end sections are guided through the interruptions.

[0015] To ensure particularly stable securing of the battery cells along their longitudinal axis, it is proposed that the gas guide wall protrude beyond the aperture. In particular, the gas guide wall protrudes transversely to the longitudinal axis, opposite the aperture edge, toward the aperture center. This creates an axial stop for the battery cells, which further reinforces the shear- and tensile-resistant connection between the carrier plate and the electrically contacted battery cells. Furthermore, in the event of damage, the escape of hot gas in the contact area between the stop thus created and the battery cell end sections can be prevented and directed toward one of the designated interruptions in the gas guide wall.To ensure that both battery cell poles can be connected to the circuit without requiring a complex design that would compromise tolerance compensation and protection against operational vibrations, it is proposed that the locking elements be at least partially electrically conductive and connected to the conductor. This design is based on the idea that the peeled battery cell casing can be designed as a pole. In this way, the locking elements can be used to tap the voltage on the casing side. In particular, the locking elements can contact the casing-side pole of the battery cells, and the conductor end sections extending into the aperture can contact the battery cell end-section-side pole.

[0016] In order to be able to accommodate particularly extensive longitudinal axial offsets of the battery cells without having to resort to excessively flexible carrier plate material, it is proposed that the carrier plate comprise several carrier plate sections arranged in a carrier plate plane. In the area of ​​the transitions between two adjacent carrier plate sections, these can thus be displaced along the longitudinal axis when forces are applied within a predefined tolerance range. The tolerance range can be specified using connecting pieces that connect carrier plate sections to one another. A carrier film or a form-fitting connection, for example, can serve as a connecting piece. To ensure that different contact sections of the conductor that could cause a short circuit can be insulated from one another, the conductor can be embedded in a laminate.The conductor can also comprise several conductor pieces embedded together in a laminate. In a simple embodiment, the conductor pieces or the conductor itself can be sealed between two foils.

[0017] The base body of the device according to the invention preferably serves as a temperature control device for battery cells, which has pairs of opposite passages arranged along the longitudinal axis to circumferentially enclose the battery cells and a flow channel for a temperature control fluid running transversely to the longitudinal axis. Furthermore, seals for the battery cells can be provided in the passages. The base body preferably has supply connections for the temperature control fluid. The flow channel can be designed so that the temperature control fluid flows directly to the battery cells.

[0018] Brief description of the invention

[0019] The drawing shows an example of the subject matter of the invention.

[0020] Fig. 1 shows a section through a schematic side view of the device according to the invention for electrically contacting battery cells,

[0021] Fig. 2 is an oblique view from above of a partially exploded representation of the device according to the invention from Fig. 1 on an enlarged scale and Fig. 3 is an oblique view from below of the device according to the invention from Fig. 2.

[0022] Ways to implement the invention

[0023] A device according to the invention for electrically contacting battery cells 1 has, as can be seen from Fig. 1, a base body 2 in which the battery cells are mounted next to one another transversely to their longitudinal axis 3 and preferably excluding their battery cell end sections 4. The battery cells 1 are contacted with one another via an electrical conductor 5. According to the invention, the battery cells 1 are mounted with play along their longitudinal axis 3. This means that the battery cells can be moved within a predeterminable range along the longitudinal axis 3, whereby, for example, dimensional expansion of the battery cells 1 can be compensated. The required mounting with play along the longitudinal axis 3 can be achieved, for example, by mounting the battery cells 1 in the base body 2 via seals 6.To protect the contact during the movement of the battery cells caused by the play, the conductor 5 is fixedly arranged on a carrier plate 7, and the carrier plate 7 is connected to each of the electrically contacted battery cells 1 along the longitudinal axis 3 in a shear- and tensile-resistant manner to mechanically relieve the load on the electrical conductor 5. In this way, relative movement between the battery cells 1, the carrier plate 7, and the conductor 5 is prevented without limiting tolerance compensation, particularly when the carrier plate 7 is mounted in a floating manner relative to the base body 2. According to the features of the invention, the carrier plate 7 can overlap several base bodies 2 arranged next to one another. The same applies to the conductor 5.

[0024] The shear- and tensile-resistant connection can be achieved via locking bodies 8 of the carrier plate 7, which engage in a locking receptacle 9 of the battery cells 1, as best illustrated in Fig. 3. Preferably, three locking bodies are arranged circumferentially around the battery cell, which enables exact centering of the battery cells 1.

[0025] A simple assembly of the device is achieved in that the carrier plate 7 has openings 10 for the battery cells 1, so that these can be guided at least partially through the openings 10 (Figs. 2 and 3).

[0026] The conductor 5 can run between these openings 10, with its conductor end sections 11 forming fuses projecting into the openings 10. Preferably, the conductor 5 is arranged on the side of the carrier plate 7 opposite the battery cells 1, which allows easy accessibility for any contacting processes.

[0027] From Fig. 2 it can be seen that the openings 10 on the side of the carrier plate 7 opposite the battery cells 1 are surrounded by a gas guide wall 12, which can in particular follow the contour of the opening 10. The gas guide wall 12 can specify a flow direction away from the intact battery cells 1 for any hot gas flowing out of the battery cells 1. The gas guide walls 12 can be separated by interruptions 13 through which the conductor end sections 11 are guided or which function as gas outlet openings. Advantageously, the gas guide walls 12 simultaneously serve as positive and / or non-positive receptacles for the electrical conductor 5, which can thereby be guided between the gas guide walls 12 and thus fixedly connected to the carrier plate 7. In an embodiment forming an axial stop for the battery cells 1, the gas guide wall 12 can partially protrude beyond the opening 10.

[0028] In one embodiment, the carrier plate 7 can comprise a plurality of carrier plate sections 14 arranged in a carrier plate plane, which together form a connecting piece forming a positive connection via springs 15 and spring receptacles 16.

[0029] Fig. 1 illustrates that the base body 2 can form a temperature control device that has pairs of opposite passage openings 17 for circumferentially enclosing the battery cells 1 with respect to the longitudinal axis 3, which are sealed by circumferential seals 6. For temperature control, in particular for direct flow, of the battery cells 1, the base body 2 has a flow channel 18 for a temperature control fluid running transversely to the longitudinal axis 3. The base body 2 can have supply connections 19 for the inlet and outlet of the temperature control fluid.

[0030] Figs. 1 and in particular 2 illustrate that the conductor 5 can not only contact the outwardly directed poles of the battery cell end sections 4 via its conductor end sections 11, which preferably protrude from the conductor plane in the direction of the battery cells 1, but also the electrically opposite poles of the battery cells 1 can be contacted on the jacket side via conductor tongues 20.

[0031] Although not shown in Fig. 2 for reasons of clarity, the conductor tabs 20 and conductor end sections 11 relating to a battery cell 1 are assigned to two different, mutually insulated sections of the conductor 5, so that the battery cells 1 can be contacted not only in parallel but also in series. Fig. 1 discloses that the conductor 5 can be embedded in an insulating laminate 21 for this purpose. As an alternative to the conductor tabs 20, the locking bodies 8 can be electrically conductive and connected to the conductor 5.

Claims

Patent claims 1. Device for electrically contacting battery cells (1) with battery cells (1) arranged next to one another in a base body (2) transversely to their longitudinal axis (3), which battery cells are contacted by an electrical conductor (5), characterized in that the battery cells (1) are mounted in the base body (2) with play along the longitudinal axis (3) and that a carrier plate (7) which is stationary relative to the electrical conductor (5) is connected in a shear- and tensile-resistant manner to each of the electrically contacted battery cells (1) along the longitudinal axis (3) for mechanically relieving the load on the electrical conductor (5).

2. Device according to claim 1, characterized in that the carrier plate (7) has at least one locking body (8) engaging in a locking receptacle (9) of the battery cell (1) for each electrically contacted battery cell (1).

3. Device according to claim 1 or 2, characterized in that the battery cells (1) are mounted via seals (6) in the base body (2) with play along the longitudinal axis (3).

4. Device according to one of claims 1 to 3, characterized in that the carrier plate (7) has an opening (10) for each electrically contacted battery cell (1).

5. Device according to claim 4, characterized in that the conductor (5) is arranged on the side of the carrier plate (7) opposite the battery cells (1) and has a conductor end section (11) for each opening (10) forming a fuse and projecting into the opening (10).

6. Device according to claim 4 or 5, characterized in that the openings (10) on the side of the battery cells (1) opposite Support plate (7) is at least partially surrounded by a gas guide wall (12).

7. Device according to claim 6, characterized in that the gas guide wall (12) protrudes beyond the opening (10).

8. Device according to one of claims 1 to 7, characterized in that the locking bodies (8) are at least partially electrically conductive and are connected to the conductor (5).

9. Device according to one of claims 1 to 8, characterized in that the carrier plate (7) comprises a plurality of carrier plate sections (14) arranged in a carrier plate plane.

10. Device according to one of claims 1 to 9, characterized in that the base body (2) forms a temperature control device which has pairs of opposite passage openings (17) for circumferentially enclosing the battery cells (1) with respect to the longitudinal axis (3) and has a flow channel (18) for a temperature control fluid running transversely to the longitudinal axis (3).

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