Device and method for discharging a battery cell

Abstract

The invention relates to a device (100) for discharging a battery cell (150), comprising: a carrier unit (110) on which the battery cell (150) can be arranged; the invention relates to a battery module (100) comprising a carrier unit (110), a battery cell (150) arranged on the carrier unit (110), and a discharge unit (120), which is provided for discharging the battery cell (150) arranged on the carrier unit (110), the carrier unit (110) and the discharge unit (120) being movable relative to one another, the carrier unit (110) having a first contact element (111), which is provided for electrically connecting to the battery cell (150) arranged on the carrier unit (110), the first contact element (111) being provided for electrically connecting to the battery cell (150) arranged on the carrier unit (110), and the discharge unit (120) being provided for discharging the battery cell (150) arranged on the carrier unit (110). The discharge unit (120) has a second contact element (121) which is designed to be electrically connected to the first contact element (111) of the carrier unit (110) in such a way that, when the carrier unit (110) and the discharge unit (120) are moved towards each other, a touch is generated between the first contact element (111) and the second contact element (121).

Description

Technical Field

[0001] The invention relates to a device and a method for discharging a battery cell. Background Art

[0002] Storage cells or batteries in (motor or electric) vehicles or in electric drive technology can be sent to a recycling process after their use at the end of their life. In addition, batteries that are marked as defective at the end of their production process and cannot be delivered for their intended purpose can also undergo recycling. Before recycling such batteries, it is useful to first discharge them as completely as possible in order to prevent fire risks during recycling and also to be able to use the residual energy of the battery. Summary of the invention

[0003] According to the invention, a device and a method for discharging a battery cell are proposed with the features of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the following description. Advantages and advantageous embodiments of the device according to the invention and of the method according to the invention are derived in a corresponding manner from this description.

[0004] The present invention proposes a (discharging) device which enables automated electrical contacting of battery cells for (high-current) discharging of the battery cells.

[0005] The device has a carrier unit and a discharge unit. The battery cell can be arranged on the carrier unit. The battery cell to be discharged can be automatically or manually mounted or fixed on the carrier unit, for example. The discharge unit is provided for discharging the battery cell arranged on the carrier unit. For this purpose, the discharge unit has in particular a device or can be connected to a corresponding device in order to extract electrical energy from the battery cell in a controlled and regulated manner until the battery cell is suitably completely discharged.

[0006] The carrier unit and the discharge unit are movable relative to one another. For this purpose, for example, both units or only one of the two units can be constructed so as to be movable. The carrier unit can, for example, be constructed so as to be movable or displaceable relative to the discharge unit. Alternatively or additionally, the discharge unit can, in turn, be constructed so as to be movable or displaceable relative to the carrier unit. The carrier unit can particularly suitably be moved toward the discharge unit until the carrier unit is at least partially arranged in or below the discharge unit. Correspondingly, the carrier unit can also be moved away from the discharge unit again or out of the discharge unit until the carrier unit is, in particular, completely arranged outside the discharge unit.

[0007] The carrier unit has a first contact element, which is provided for electrically connecting to a battery cell arranged on the carrier unit or to a contact or pole of the battery cell. In particular, a low-impedance, high-current-capable contact can be produced between the battery cell and the first contact element. For example, such a contact can be realized manually or automatically.

[0008] The discharge unit has a second contact element or a mating contact with the first contact element, which is provided for being electrically connected to the first contact element of the carrier unit in such a way that, when the carrier unit and the discharge unit are moved toward each other, a contact is produced between the first contact element and the second contact element or the contact elements come into contact, and thus an electrical contact can be established between the first contact element and the second contact element. In particular, the carrier unit and the discharge unit or the first contact element and the second contact element are aligned relative to each other in such a way that, when the carrier unit and the discharge unit are moved toward each other, at a specific position of the carrier unit relative to the discharge unit, the first contact element touches the second contact element and thus an electrical contact is established between the touching elements. As a result, a low-impedance, high-current-capable contact is also produced between the first contact element and the second contact element. In particular, this is a sliding contact.

[0009] The discharge device is therefore particularly suitable for arranging the battery cell to be discharged on the carrier unit outside the discharge unit. The carrier unit can then be moved together with the mounted battery cell towards or into the discharge unit for discharging the battery cell, wherein electrical contact is automatically established between the discharge unit and the battery cell.

[0010] Within the scope of the method according to the invention for discharging a battery cell using the device according to the invention, the battery cell is first arranged on a carrier unit. The carrier unit is particularly expediently arranged outside the discharge unit at this point in time or at least so far away from the discharge unit that no electrical contact is established between the first contact element and the second contact element. The arrangement of the battery cell can be carried out, for example, as a manual working step or, for example, automatically.

[0011] The battery cell or its contact arranged on the carrier unit is thus electrically connected to the first contact element of the carrier unit. Since there is no contact between the first contact element and the second contact element at this point in time, the battery cell can be connected to the first contact element safely and without risk. For example, this electrical connection can also be realized as a manual working step. In addition, for example, it is also possible to realize an automatic electrical connection, for example, by a corresponding connecting mechanism of the carrier unit.

[0012] The carrier unit and the discharge unit are now moved toward each other, at least until a touch or contact is produced between the first contact element and the second contact element, and thus an electrical contact is established between the first contact element and the second contact element. After the battery cell to be discharged is arranged on the carrier unit outside the discharge unit and is electrically connected to the carrier unit, the carrier unit is expediently at least partially moved into the discharge unit until the first contact element and the second contact element mechanically touch and thus an electrical connection is established between the battery cell and the discharge unit.

[0013] The battery cell is then discharged by the discharge unit via the first contact element and the second contact element. For this purpose, a discharge current can be drawn from the discharge unit until the battery cell is, in particular, completely discharged. After the battery cell has been discharged, the battery cell can, for example, be fed to a recycling process.

[0014] The invention provides a flexible, easy and robust solution for discharging battery cells. The device can be easily expanded in particular, and the individual contact elements can also be adapted in particular to the current intensity of the discharge current. In addition, the device can be implemented in particular in a structurally and technically low-cost manner with low control technology and structural expenditure in terms of hardware, software, installation, wiring, etc. High reliability and fault tolerance can be achieved in particular by using a small number of components. The device can be handled in particular without the use of plug connections that are prone to wear and tear, and does not require drives and sensors for establishing such plug connections.

[0015] In order to discharge the battery cells in a conventional manner, a plug or a socket is often used, wherein one of the two elements is mechanically and electrically connected to the corresponding battery cell and then makes contact with the other of the two elements. Before contact, the two elements usually have to be aligned with each other. After this alignment, the elements are usually moved toward each other and into each other by means of a drive.

[0016] After discharge, the elements are moved away from each other again by means of a drive for decoupling. Due to the numerous plug-in processes of this kind, the contacts of the elements can easily wear out. Furthermore, complex and expensive positioning or alignment is often required, as well as separate drives for producing the plug connection and additional, costly sensor devices for monitoring the plug connection.

[0017] In contrast, the device according to the invention can be operated with little effort and is less susceptible to wear. In particular, a rough positioning between the carrier unit and the discharge unit is sufficient, since in particular it is not necessary to realize an exact plug connection, but rather only a simple contact of the first contact element and the second contact element is sufficient. Particularly expediently, a one-time alignment between the carrier unit and the discharge unit or between the first contact element and the second contact element is sufficient, so that these units or elements are then expediently always aligned with respect to one another with sufficient accuracy. Since in particular the alignment of these units and elements with respect to one another does not need to be changed during the discharge of the battery, their correct alignment is particularly maintained. Particularly expediently, it is not necessary to align the individual elements and units with one another individually before each discharge of the battery.

[0018] In particular, no additional sensor means are required to monitor the positioning and alignment of the carrier unit and the discharge unit and the first and second contact elements. For example, the correct positioning of these elements relative to one another can be easily inferred by monitoring the contact voltage between the first and / or second contact elements.

[0019] Furthermore, in particular no plug connections are required for establishing an electrical connection in the discharge device. Since easy mechanical contacting, in particular easy touching, of the first and second contact elements is sufficient to establish the electrical contact, there is in particular no risk of contact wear due to a mechanical plugging process.

[0020] The invention makes it possible in particular to realize a reliable discharge process and to react reliably even in hazardous situations. In the event of a fire during the discharge of the battery, for example, the carrier unit can be immediately removed from the discharge unit. In particular, no additional effort is required for this. For example, it is not necessary to separate the mechanical connection and it is not necessary to decouple the plug connection. In addition, the electrical device mounted on the carrier unit can be protected, for example, by means of a covering element such as a cover plate, so that the electrical device is not damaged in the event of a fire and when extinguishing a fire. In addition, in particular, no open wiring structures are provided in the discharge unit, or the wiring structures can be protected by means of a covering element such as a cover plate, so that the electrical device is not damaged in the event of a fire and when extinguishing a fire.

[0021] It goes without saying that a plurality of battery cells can also be arranged on the carrier unit, and the first contact element can be connected to these battery cells. For this purpose, for example, the individual battery cells can be electrically connected to each other by series connection or parallel connection or a combination thereof, and the first contact element can be connected to these connected battery cells. It also goes without saying that the discharge device can also have a plurality of carrier units and a plurality of discharge cells, wherein the carrier units are appropriately assigned to the discharge cells, respectively.

[0022] Advantageously, the second contact element of the discharge cell can be electrically connected to a discharge circuit of the device, which is provided for discharging the battery cell when the battery cell is arranged on the carrier unit and electrically connected to the first contact element of the carrier unit and when the first contact element is connected to the second contact element. The discharge circuit can have, for example, electrical or electronic components in order to be able to draw a discharge current from the battery cell in a controlled and regulated manner. The battery cell can be discharged in particular completely or at least as far as possible by means of the discharge circuit in order to be able to utilize the residual energy present in the battery and, for example, feed it into the power grid.

[0023] Advantageously, the first contact element can be electrically connected to the battery cells arranged on the carrier unit via flexible line connections of the device. These flexible, non-rigid line connections can particularly suitably enable the first contact element to be flexibly connected to battery cells of different types and sizes. In addition, the corresponding battery cells can be flexibly arranged on the carrier unit and do not have to be mounted in precisely defined positions.

[0024] The first contact element is preferably connected to the carrier unit in a fixed or immovable manner. Since the first contact element can be connected to the battery cell expediently via a flexible line connection, the first contact element can be mounted particularly rigidly. Since the position of the first contact element relative to the carrier unit cannot be changed in this way, it is particularly expedient to maintain the correct alignment of the first contact element relative to the second contact element even after multiple replacements of the battery cells.

[0025] According to a particularly preferred design, the second contact element comprises elastically supported electrodes. These electrodes are therefore supported in a manner that allows them to move relative to the discharge unit, in particular in a direction of movement perpendicular to the direction of movement, along which the carrier unit and the discharge unit can move toward each other or the carrier unit can move toward the discharge unit. Particularly expediently, the second contact element is configured as a collector with a compression spring. If the elastically supported electrodes of the first contact element, which is particularly fixedly connected to the carrier unit, and the second contact element move toward each other and eventually touch, the second contact element can be lifted against the spring force, so that no damage to the individual elements occurs. Therefore, in particular, precise positioning and movement control of the individual units is not required, so that contact of the contact elements can be reliably produced by roughly aligned movements.

[0026] Preferably, the second contact elements each comprise a graphite electrode, in particular a resiliently mounted graphite electrode. Electrodes made of graphite can achieve particularly advantageous properties for current transmission. The first contact element can be made of copper, for example, in order to achieve electrochemically advantageous properties in combination with graphite, such as low wear, good contact connection and low contact resistance.

[0027] The first contact elements are preferably each designed as a busbar or as a planar sliding contact or sliding track. The first contact elements are therefore particularly expediently designed as planar, elongated current-carrying conductors made of rigid material and in particular serve as current supply lines for the second contact elements.

[0028] The second contact elements are preferably each configured as a current collector. The second contact elements thus serve in particular to transmit electrical energy from the first contact elements configured as busbars. Particularly expediently, the second contact elements serve as current collectors for transmitting energy from the first contact elements as current-carrying conductors to the discharge circuit.

[0029] Particularly expediently, the first contact element and the second contact element form a system for transmitting current, which consists of a rigid busbar and a resiliently supported current collector. Such a system can also be used, for example, in electric motor applications in order to supply power to a rotating armature there, or, for example, to supply energy to an electrically driven rail vehicle or a lifting device. Corresponding variants of such a system offer enormous technical and commercial advantages for the discharge of (vehicle) battery cells. In this way, the first contact element and the second contact element can be electrically connected flexibly, with low wear and particularly easily by easy contact, without the need for precise alignment and positioning, without the need for plug-in connections or mechanical plug-in processes, and with fewer components to be installed.

[0030] According to an advantageous embodiment, the carrier unit can be moved toward and away from the discharge unit by means of a movement device of the device, such as, for example, a conveyor belt or a transport belt or a conveyor system. In this way, a particularly easy, automated contacting of the contact elements can be achieved. In addition, such a movement device also enables a particularly rapid reaction in the event of a hazard, such as a fire, and immediate removal of the carrier unit from the discharge unit.

[0031] Preferably, the first contact element is beveled at the front and / or rear end, respectively, as viewed in the (movement) direction in which the carrier unit and the discharge unit can move relative to one another. In particular, a reliable and easy contact with the second contact element can be achieved by such a bevel. If the first contact element is beveled, for example, at its front end, as viewed in the movement direction, the second contact element can be lifted against the spring force at this bevel. Furthermore, the rear end can also be beveled in order to allow a two-sided application.

[0032] Advantageously, after the battery cell has been discharged, the carrier unit and the discharge unit are moved away from each other again, at least until the first contact element and the second contact element no longer touch and the electrical contact between the first contact element and the second contact element is severed. The battery cell or its contact part or parts are advantageously separated from the first contact element of the carrier unit and the battery cell is advantageously removed from the carrier unit. The separation and removal of the battery cell can each be carried out, for example, as a manual working step or, for example, automatically. After the battery cell has been completely discharged, in particular, the carrier unit is advantageously moved out of the discharge unit again and the discharged battery cell can be removed in a reliable manner outside the discharge unit and replaced by another battery cell to be discharged.

[0033] The present invention is suitable for a large number of different battery cells, in particular lithium battery cells or lithium battery modules. The present invention is particularly suitable for battery cells from the field of (motor or electric) vehicles or electric drive technology. The individual battery cells can be, for example, so-called battery cells, the smallest battery cell installed in the vehicle can be understood as a battery cell, which can have a cell voltage between 2.5V and 4.4V, for example. In addition, the individual battery cells can also be configured as battery modules, for example, a series circuit of a plurality of such battery cells can be understood in particular as a battery module, which can have a rated voltage of up to 60V, for example. The individual battery cells can also be, for example, a battery pack, a series circuit composed of a large number of such battery modules is called a battery pack, which can have a rated voltage of 200V to 1000V, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further advantages and embodiments of the invention are apparent from the description and the accompanying drawings.

[0035] It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention.

[0036] The present invention is schematically shown in the drawings based on exemplary embodiments and will be described in detail below with reference to the drawings.

[0037] FIG. 1 schematically shows a preferred embodiment of the device according to the invention. DETAILED DESCRIPTION

[0038] exist Figure 1a and Figure 1b A preferred embodiment of the device according to the invention for discharging (vehicle) battery cells is shown schematically in a top view in FIG. 1 and is denoted by reference numeral 100 .

[0039] like Figure 1aAs shown in FIG. 1 , the device 100 includes a carrier unit 110 and a discharge unit 120. Figure 1a In the example of FIG. 1 , two carrier units 110 and two discharge cells 120 are provided, wherein one of the carrier units 110 is respectively assigned to one of the discharge cells 120. The device 100 can also have other pairs of carrier units 110 and discharge cells 120 or, for example, only one carrier unit 110 and only one discharge cell 120.

[0040] Each of the carrier units 110 has a carrier or workpiece carrier 113, on which a battery cell 150 or a plurality of battery cells can be arranged, for example, manually or automatically. Each carrier unit 110 also has two first contact elements 111, which can be fixedly connected to the corresponding carrier unit 110 or fixedly connected to the carrier 113. These first contact elements 111 can be made of copper, for example, and are configured as busbars. The battery cells 150 arranged on the carrier unit 110 or on the carrier 113 can be automatically or manually electrically connected to the first contact elements 111. For this purpose, the contact portion or pole 151 of the battery cell 150 can be connected to one of the contact elements 111 respectively via a flexible line connection portion 112. The flexible line connection portion 112 can be clamped to the contact portion or pole 151 of the battery cell 150, for example.

[0041] The carrier units 110 are each mounted so as to be movable relative to the respectively associated discharge unit 120, which is indicated by reference numeral 130. The individual carrier units 110 can be arranged, for example, on a conveyor belt or transport belt and can be moved toward and away from the respective discharge unit 120 by means of such a conveyor belt as a movement device. The individual carrier units 110 can thus, for example, be partially or completely moved to a discharge position 124 of the respective discharge unit 120 and moved out of the discharge position again.

[0042] The discharge units 120 are each provided for discharging a battery cell 150 arranged on a corresponding associated carrier unit 110. Each discharge unit 120 has two second contact elements 121. Each of these contact elements 121 has an electrode 122, for example a resiliently supported graphite electrode 122, which is elastically supported by a spring element 123. The electrodes are shown in three dimensions in the figures, wherein, however, their direction of movement preferably extends perpendicularly to the direction of movement of the carrier unit (that is, in the figures, they therefore extend out of the drawing plane).

[0043] Furthermore, the device has a discharge circuit 140, wherein each of the discharge cells 120 is connected to the discharge circuit 140. For example, a separate discharge circuit can also be provided for each discharge cell 120. The discharge circuit 140 has, for example, electrical or electronic components in order to extract a discharge current from the battery cell to be discharged in a controlled and regulated manner and to feed the extracted energy into the grid.

[0044] In order to discharge the battery cells arranged on the carrier unit 110 in this way, an electrical / mechanical contact is established between the first contact element 111 of the carrier unit 110 and the second contact element 121 of the corresponding discharge unit 120. For this purpose, the corresponding carrier unit 110 is moved toward the corresponding discharge unit 120 by a corresponding conveyor belt 130 until a contact is established between the corresponding first contact element 111 and the corresponding second contact element 121.

[0045] exist Figure 1b . There, the left-hand carrier unit 110 is completely moved to the discharge position 124 of the left-hand discharge unit 120. The first contact element 111 of the carrier unit 110 and the second contact element 121 of the left-hand discharge unit touch each other, so that an electrical contact is established between these contact elements. The first contact element 111 acts as a busbar or a planar sliding contact or sliding track, and the second contact element 121 acts as a current collector. The elastically supported graphite electrode 122 is therefore pressed from above onto the contact element 111 in the plane of the drawing and is therefore used to transfer energy from the busbar or the first contact element 111 to the discharge circuit 140.

[0046] The discharge device 100 thus enables the respective battery cell 150 to be discharged to be arranged outside the discharge unit 120 on the respective carrier unit 110 and connected there to the respective first contact element 111 via the flexible line connection 112. Subsequently, the respective carrier unit 110 together with the installed battery cell 150 can be moved into the respective discharge unit 120 for discharging the battery cell, wherein the electrical contact between the respective first and second contact elements 111, 121 is automatically established.

[0047] After complete or sufficient discharge, the carrier unit 110 can be moved out of the discharge unit 120 again, wherein the electrical contact between the corresponding first and second contact elements 111, 121 is automatically disconnected. Outside the discharge unit 120, the discharged battery cell 150 can then be replaced by another battery cell to be discharged.

Claims

1. A device (100) for discharging a battery cell (150), the device comprising: a carrier unit (110) on which the battery unit (150) can be arranged; and a discharge unit (120) configured to discharge a battery unit (150) arranged on the carrier unit (110), in, The carrier unit (110) and the discharge unit (120) are capable of moving relative to each other. The carrier unit (110) has a first contact element (111), which is configured to be electrically connected to a battery unit (150) arranged on the carrier unit (110). The discharge unit (120) has a second contact element (121), which is configured to be electrically connected to a first contact element (111) of the carrier unit (110) in the following manner: when the carrier unit (110) and the discharge unit (120) move toward each other, the first contact element (111) and the second contact element (121) are brought into contact.

2. The device (100) according to claim 1, comprising a discharge circuit (140), wherein: The second contact element (121) of the discharge unit (120) can be electrically connected to the discharge circuit (140), and the discharge circuit is configured to discharge the battery cell (150) when the battery cell (150) is arranged on the carrier unit (110) and is electrically connected to the first contact element (111) of the carrier unit (110) and when the first contact element (111) is electrically connected to the second contact element (121).

3. The device (100) according to claim 1 or 2, comprising a flexible line connection (112), wherein: The first contact element (111) can be electrically connected to a battery unit (150) arranged on the carrier unit (110) via the flexible circuit connection portion (112).

4. The device (100) according to any one of the preceding claims, wherein: The first contact element (111) is fixedly connected to the carrier unit (110).

5. The device (100) according to any one of the preceding claims, wherein: The second contact elements (121) each comprise a resiliently supported electrode (122, 123).

6. The device (100) according to any one of the preceding claims, wherein: The second contact elements (121) each include a graphite electrode (122).

7. The device (100) according to any one of the preceding claims, wherein: The first contact elements (111) are each designed as a busbar.

8. The device (100) according to any one of the preceding claims, and wherein: The second contact elements (121) are each designed as a current collector.

9. The device (100) according to any one of the preceding claims, comprising a movement device (130) which is provided for moving the carrier unit (110) towards the discharge unit (120) and away from the discharge unit.

10. The device (100) according to any one of the preceding claims, wherein When viewed along the direction along which the carrier unit (110) and the discharge unit (120) are movable relative to each other, the first contact element (111) is chamfered at the front and / or rear end.

11. A method for discharging a battery cell (150) using a device (100) according to any one of the preceding claims, the method comprising the steps of: Arranging the battery unit (150) on the carrier unit (110); electrically connecting the battery unit (150) to a first contact element (111) of the carrier unit (110); Moving the carrier unit (110) and the discharge unit (120) relative to each other, at least until the first contact element (111) and the second contact element (121) touch each other and electrical contact is established between the first contact element (111) and the second contact element (121); The battery cell (150) is discharged by the discharge unit (120) via the first contact element (111) and the second contact element (121).

12. The method according to claim 11, further comprising, after discharging the battery cell (150): Moving the carrier unit (110) and the discharge unit (120) away from each other, at least until the first contact element (111) and the second contact element (121) no longer touch each other and separating the electrical contact between the first contact element (111) and the second contact element (121); separating the battery unit (150) from the first contact element (111) of the carrier unit (110); The battery unit (150) is removed from the carrier unit (110).

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