Filling device for filling rigid-walled battery cells with an electrolyte liquid

Abstract

A filling device for filling rigid-walled battery cells (11) with an electrolyte liquid has a pumping device, by means of which the electrolyte liquid can be introduced under positive pressure, e.g. between 3 and 6 bar, into the rigid-walled battery cell (11). In order to ensure, under positive pressure, exact metering in the filling process and to minimize the technical design effort for the filling process, according to the invention the pumping device of the filling device (1) can be placed, by means of a short filling nozzle (13), directly and sealingly onto the filling opening (14) of the rigid-walled battery cell (11).

Description

[0001] "Filling device for filling rigid-walled battery cells with an electrolyte liquid"

[0002] The invention relates to a filling device for filling rigid-walled battery cells with an electrolyte liquid, with a pumping device by means of which the electrolyte liquid can be introduced into the rigid-walled battery cell under excess pressure, e.g. between 3 and 6 bar.

[0003] Rigid-walled battery cells filled with electrolyte are assembled in large numbers to form batteries, particularly batteries for the drive systems of motor vehicles. Accordingly, these rigid-walled battery cells must be filled with electrolyte with comparatively little technical effort, and the filling process parameters must be designed and maintained as precisely and accurately as possible.

[0004] Based on the prior art described above, the object of the invention is to further develop the generic filling device for filling rigid-walled battery cells with an electrolyte liquid in such a way that, with a comparatively low technical construction effort, it can be easily ensured that rigid-walled battery cells can be filled with electrolyte liquid in the shortest possible time, while adhering to even narrowly specified parameters for the quality of the filling.

[0005] This object is achieved according to the invention in that the pumping device of the filling device, with a short filling nozzle, can be placed directly and sealingly onto the filling opening of the rigid-walled battery cell. By means of a filling device designed in this way, it is possible to fill the rigid-walled battery cells with electrolyte liquid at a comparatively high overpressure, thereby reducing the time required for the filling process. If the rigid-walled battery cell is evacuated, e.g. by arranging it in a vacuum chamber, before the filling opening is brought into sealing contact with the short filling nozzle, evacuation of a dispensing needle of the filling device is superfluous since the evacuation of the rigid-walled battery cell is accomplished by means of the vacuum chamber.

[0006] Advantageously, the filling device according to the invention should be able to implement pressure change cycles with negative pressure and positive pressure with steep flanks and high frequency. This allows the filling process to be adapted to a wide variety of requirements.

[0007] If a support mold is provided to accommodate the rigid-walled battery cells to be filled, it is possible to accomplish the evacuation of the battery cells to be filled with comparatively little technical and structural effort by designing a vacuum chamber in the support mold.

[0008] According to an advantageous embodiment of the filling device according to the invention, its pumping device has a dosing piston and a dosing cylinder, wherein the pumping device includes a linear drive by means of which the dosing piston of the pumping device can be driven.

[0009] If the filling volume of the dosing cylinder is dimensioned in such a way that it corresponds to the volume of the rigid-walled battery cell to be filled, a rigid-walled battery cell can be filled with electrolyte fluid at a time by means of a feed movement of the dosing piston in the dosing cylinder, precisely in the intended quantity.

[0010] Accordingly, filling a rigid-walled battery cell with the respective intended quantity of electrolyte liquid is also feasible if the filling volume of the dosing cylinder is dimensioned such that the volume of the rigid-walled battery cell to be filled is an integer multiple of the filling volume of the dosing cylinder, whereby a corresponding number of pre-stroke movements of the dosing piston are then required.

[0011] For the linear drive, it is then advantageous to provide an end position metering.

[0012] According to an alternative embodiment of the filling device according to the invention, the filling volume of the dosing cylinder is arbitrary, in which case a controllable linear drive is provided. Accordingly, the dosing piston can be brought to a standstill in any position within the dosing cylinder as soon as a rigid-walled battery cell is filled with the required amount of electrolyte fluid for that rigid-walled battery cell.

[0013] If both the dosing cylinder and the dosing piston are arranged within an intermediate container of the filling device filled with electrolyte, the resulting direct fluid connection between the intermediate container on the one hand and the dosing cylinder on the other hand ensures that the filling process of rigid-walled battery cells can be carried out precisely and quickly with the least possible effort. The dosing cylinder can then be arranged in a base section of the intermediate container, whereby the forward and return stroke of the dosing piston movable in the dosing cylinder can be implemented in a simple manner and whereby the rigid-walled battery cell to be filled with electrolyte can advantageously be arranged below the base section of the intermediate container.

[0014] In order to keep the drive device for the forward and return stroke of the metering piston as simple as possible, it is advantageous if the piston rod of the metering piston projects through a cover of the intermediate container and is sealed by means of a gap seal or a scraper ring to cover the intermediate container. The forward and return stroke movement of the metering piston can then be realized by means of a drive means arranged externally with respect to the intermediate container while maintaining a tight seal in the interior of the intermediate container.A further advantageous embodiment of the filling device according to the invention is achieved if a fluid inlet is arranged between the intermediate container on the one hand and the dosing cylinder arranged in the intermediate container on the other hand, said fluid inlet containing a refill valve by means of which the fluid inlet between the intermediate container and the dosing cylinder can be blocked during a forward stroke of the dosing piston and the fluid inlet can be released during a return stroke of the dosing piston. This ensures that during the forward stroke of the dosing piston within the dosing cylinder all of the electrolyte fluid located within the dosing cylinder is transferred into the battery cell, wherein the dosing cylinder is again filled precisely during the return stroke of the dosing piston.

[0015] The dosing piston and / or the dosing cylinder can be conveniently made of a ceramic or stainless steel material. Depending on the design, the dosing piston can have a sealing element or a gap seal.

[0016] It is of course possible to connect the intermediate container of the filling device to an electrolyte storage container, wherein for this purpose the intermediate container, preferably in the region of its cover, has a fluid connection by means of which the intermediate container is connected to the electrolyte storage container.

[0017] To ensure that unwanted air in the intermediate container can escape from the intermediate container, it is expedient if a ventilation connection is formed on the intermediate container, by means of which the intermediate container can be vented. This ventilation connection can also advantageously be provided in the area of ​​the cover of the intermediate container. To ensure precise execution of the piston movement during the forward and return stroke of the dosing piston, it is advantageous if a receiving and guide member is provided above the cover of the intermediate container, by means of which the dosing piston is received at its piston rod protruding through the cover from the intermediate container and can be guided during the forward and return stroke.Accordingly, the piston rod is attached to this receiving and guiding member at its end section protruding through the cover, wherein a movement of the receiving and guiding member in an upward and downward direction results in a corresponding movement of the dosing piston within the dosing cylinder.

[0018] In order to enable venting of the dosing cylinder, it is advantageous if the dosing cylinder of the filling device according to the invention has a venting slot in the region of its upper end, through which the dosing cylinder can be vented if a conical tip of the dosing piston is arranged in the region of the upper end of the dosing cylinder.

[0019] In the following, the invention is explained in more detail using an embodiment with reference to the drawing.

[0020] It shows :

[0021] Figure 1 is a perspective view of an embodiment of the filling device according to the invention; and

[0022] Figure 2 is a schematic diagram of a rigid-walled battery cell arranged in a support form below the filling device according to the invention shown in Figure 1.

[0023] An embodiment of a filling device 1 according to the invention, shown in a perspective view in Figure 1, serves to fill rigid-walled battery cells 11 (not shown in Figure 1 but shown in Figure 2) with an electrolyte fluid. The filling of the rigid-walled battery cells 11 (not shown in Figure 1) should be possible in a metered manner under excess pressure. By means of suitable adapter parts etc., the filling device 1 according to the invention, described in more detail below, can be used to fill differently designed rigid-walled battery cells 11. The filling device 1 according to the invention can also include a vacuum chamber 22, shown in Figure 2, in which a rigid-walled battery cell to be filled by means of the filling device 1 can be accommodated.

[0024] The embodiment of the filling device 1 according to the invention shown in Figure 1 includes a frame part by means of which the filling device 1 is held. The individual components of the filling device 1 described below are mounted on the frame part 2.

[0025] As can be seen from Figure 1, the filling device 1 includes an intermediate container 3, which is fastened to the frame part 2 of the filling device 1. The intermediate container 3 has a base part 4, a cover 5 and, in the illustrated embodiment of the intermediate container 3, a cylindrical glass wall, which together with the base part 4 and the cover 5 forms a container interior 7 of the intermediate container 3.

[0026] The base part 4 is firmly connected to the cover 5 of the intermediate container 3 by means of screw connections 8, wherein the screw connections 8 are arranged at the corners of the base part 4 and the cover 5.

[0027] The filling device 1 according to the invention shown in Figure 1 also includes a dosing cylinder 9, shown in principle in Figure 2. A quantity of electrolyte liquid that can be predetermined by the freely configurable volume of the dosing cylinder 9 can be accommodated in the dosing cylinder 9. The dosing cylinder 9 is arranged essentially within the base part 4 of the intermediate container 3. A dosing piston 10 of the filling device 1 can be moved up and down within the dosing cylinder 9 in Figure 2. During a return stroke movement, in which the dosing piston 10 moves from its lower position to its upper position, the dosing cylinder 9 is filled with electrolyte liquid from the container interior 7 of the intermediate container 3, which is filled with electrolyte liquid. For this purpose, a fluid inlet is formed in the base part 4 of the intermediate container 3, which is connected to the lower end section of the dosing cylinder 9 via a refill valve 12.During the return stroke of the dosing piston 10 into its upper position, the refill valve 12 releases the connection between the fluid inlet and the lower end region of the dosing cylinder 9.

[0028] During a forward stroke movement of the dosing piston 10, which is directed downwards in Figure 2, the refill valve 12 blocks the connection between the fluid inlet and the lower end section of the dosing cylinder 9. Accordingly, the electrolyte fluid located in the dosing cylinder 9 is conveyed by means of the dosing piston 10 through a dosing needle formed on the lower end section of the dosing cylinder 9 into the interior of the rigid-walled battery cell 11 shown in Figure 2 and connected to the filling device 1. The dosing needle 23 is provided with a shut-off valve 24. During a forward stroke movement of the dosing piston 10, the dosing needle 23 is released to the rigid-walled battery cell 11, while during the return stroke of the dosing piston 10 this dosing needle 23 is blocked by means of the shut-off valve 24.

[0029] The shut-off valve 24 is followed by a short filling nozzle 13, as shown in Figure 2, which can be placed directly and sealingly onto a filling opening 14 of the rigid-walled battery cell 11. In the open position of the shut-off valve 14, the rigid-walled battery cell 11 can thus be filled by a forward stroke of the dosing piston 10 under excess pressure.

[0030] The aforementioned vacuum chamber 22 is realized by a support form or a cell nest 16, which can be closed at its upper side by means of a cover 25, wherein a seal 30 is provided between the cover 25 on the one hand and the upper edge of the cell nest 16 on the other. A pressure connection 28 is provided in the wall of the cell nest 16, by means of which any desired vacuum conditions can be realized in the vacuum chamber 22. The dispensing needle 23, which penetrates the cover 25 of the cell nest 16, is sealed by means of a seal 29.

[0031] The sealing connection between the filling opening 14 of the rigid-walled battery cell 11, on the one hand, and the filling nozzle 13, which is arranged below the shut-off valve 24 of the dispensing needle 23, is achieved by means of a delivery device 26, shown only in principle in Figure 2, by means of which the rigid-walled battery cell 11 and thus its individual opening 14 can be sealingly delivered against the lower edge of the filling nozzle 13. The delivery device 26 is sealed by means of a seal 27 with respect to the wall of the cell nest 16 through which it penetrates.

[0032] The dosing unit formed from the dosing cylinder 9 and the dosing piston 10 is located during the filling process with the filling nozzle 13 immediately or directly on the rigid-walled battery cell 11 or its filling opening 14, with only the shut-off valve 24 being interposed.

[0033] For the filling process, the rigid-walled battery cell 11 is first introduced into the vacuum chamber 22 formed in the cell nest 16. This can be accomplished by a slide or similar device. After the rigid-walled battery cell 11 has been introduced into the vacuum chamber 22 and the cell nest 16 has been closed by creating a sealing connection between the cell nest 16 and its cover 25, the rigid-walled battery cell 11 is evacuated by generating negative pressure in the vacuum chamber 22 by means of the pressure connection 28. After the rigid-walled battery cell 11 has been evacuated, the rigid-walled battery cell 11 is pressed against the short filling nozzle 13 of the dosing unit via the feed device 26. The shut-off valve 24 is then opened and the rigid-walled battery cell 11 is filled with electrolyte fluid by means of the dosing unit through the dosing needle 23.After the filling process is completed, the rigid-walled battery cell 11 is lowered by means of the feed device 26 and then removed from the cell nest 16. Emptying the dispensing needle 23 is not necessary since the rigid-walled battery cell 11 is evacuated, as described above, not by means of the dispensing needle 23, but by means of the vacuum chamber 22.

[0034] At the upper end section of the dosing cylinder 9 there is a venting slot through which the dosing cylinder 9 can be vented.

[0035] The drive movement for the forward and return stroke of the dosing piston 10 is transmitted to the latter by means of a piston rod 15, to which the dosing piston 10 is attached and which protrudes through the cover 5 of the intermediate container 3. A suitable gap seal is provided to seal between the outer surface of the piston rod 15, which is movable relative to the cover 5 of the intermediate container 3, and the cover 5. Instead of the gap seal, a scraper ring or a similar sealing means can also be provided.

[0036] In the illustrated embodiment, the dosing piston 10 is cylindrical, with its external dimensions corresponding to the internal dimensions of the dosing cylinder 9. At its lower end portion facing the lower end portion of the dosing cylinder 9, the dosing piston 10 has a conical tip. Due to the design of the lower end of the dosing piston 10 as a conical tip, the venting slot formed in the dosing cylinder 9 at its upper end portion is released relatively early during the return stroke movement of the dosing piston 10.

[0037] In the illustrated embodiment, the intermediate container 3 has a fluid connection 17 on its cover 5, through which the intermediate container 3 of the filling device 1 can be filled with electrolyte fluid from an electrolyte reservoir not shown in the figures. Furthermore, a ventilation connection 18 is provided on the cover 5 of the intermediate container 3, through which the interior of the intermediate container 3 can be vented.

[0038] 1. The linear drive 19 is connected to a receiving and guide member 21 via a drive member 20, which is only indicated in the drawing in FIG. 1. The receiving and guide member 21, to which the upper end of the piston rod 15 projecting upwards through the cover 5 of the intermediate container 3 is fastened, and thus the piston rod 15 and the dosing piston 10, can be moved up and down in the figures by means of the linear drive 19. In order to ensure an exact mechanical connection between the linear drive 19 on the one hand and the piston rod 15 on the other, the receiving and guide member 21 is guided and held in a suitable manner on the frame part 2.

[0039] The linear drive 19 can be designed with end-position dosing, in which case the filling volume of the dosing cylinder 9 can correspond to the volume of the rigid-walled battery cell 11 to be filled, or the volume of the rigid-walled battery cell 11 to be filled can be an integer multiple of the filling volume of the dosing cylinder 9. The linear drive 19 can also be designed as a freely controllable linear drive. The filling volume of the dosing cylinder 9 can then be designed as desired without any impairments when filling rigid-walled battery cells 11.

Claims

PATENT CLAIMS 1. Filling device for filling rigid-walled battery cells (11) with an electrolyte liquid, with a pumping device by means of which the electrolyte liquid can be introduced into the rigid-walled battery cell (11) under excess pressure, e.g. between 3 and 6 bar, characterized in that the pumping device of the filling device (1) can be placed directly and sealingly onto the filling opening (14) of the rigid-walled battery cell (11) with a short filling nozzle (13).

2. Filling device according to claim 1, by means of which pressure change cycles with negative pressure and positive pressure with steep flanks and high frequency can be realized.

3. Filling device according to claim 1 or 2, with a support mold (16) for receiving the rigid-walled battery cells (11) to be filled.

4. Filling device according to one of claims 1 to 3, the pumping device having a dosing piston (10) and a dosing cylinder (9), and which includes a linear drive (19) by means of which the dosing piston (10) of the pumping device can be driven.

5. Filling device according to claim 4, wherein the filling volume of the dosing cylinder (9) is dimensioned such that it corresponds to the volume of the rigid-walled battery cell to be filled.

6. Filling device according to claim 4, wherein the filling volume of the dosing cylinder (9) is dimensioned such that the volume of the rigid-walled battery cell (1) to be filled is an integer multiple of the filling volume.

7. Filling device according to claim 5 or 6, wherein a linear drive (19) with end position dosing is provided.

8. Filling device according to claim 4, wherein the filling volume of the dosing cylinder (9) is arbitrary and a controllable linear drive (19) is provided.

9. Filling device according to one of claims 1 to 8, whose pumping device is arranged in an intermediate container (3) of the filling device (1) filled with electrolyte liquid.

10. Filling device according to claim 9, the dosing piston (10) with its piston rod (15) protrudes through a cover (5) of the intermediate container (3) and is sealed to the cover (5) of the intermediate container (3) by means of a gap seal or a scraper ring.

11. Filling device according to claim 9 or 10, in which a fluid inlet is arranged between the intermediate container (3) on the one hand and the dosing cylinder (9) arranged in the intermediate container (3) on the other hand, in which a refill valve (12) is located, by means of which the fluid inlet between the intermediate container (3) and the dosing cylinder (9) can be blocked during a forward stroke of the dosing piston (10) and the fluid inlet can be released during a return stroke of the dosing piston (10).

12. Filling device according to one of claims 4 to 11, wherein the dosing piston (10) and / or the dosing cylinder (9) is / are made of a ceramic or a stainless steel material.

13. Filling device according to one of claims 4 to 12, wherein the dosing piston (10) is made of a stainless steel material and has a sealing element.

14. Filling device according to one of claims 4 to 12, wherein the dosing piston (10) is made of a ceramic material and is sealed by means of a gap seal.

15. Filling device according to one of claims 9 to 14, which includes a fluid connection (17) by means of which the intermediate container (3) of the filling device (1) can be connected to an electrolyte storage container.

16. Filling device according to one of claims 9 to 15, in which a ventilation connection (18) is formed on the intermediate container (3), by means of which the intermediate container (3) can be vented.

17. Filling device according to one of claims 9 to 16, which has a receiving and guiding member (21) above the cover (5) of the intermediate container (3), by means of which the dosing piston (10) can be received from its piston rod (15) projecting through the cover (5) from the intermediate container (3) and can be guided during the forward stroke and return stroke.

18. Filling device according to one of claims 4 to 17, the dosing cylinder (9) in the region of its upper end has a Has a venting slot through which the dosing cylinder (9) can be vented when a conical tip of the dosing piston (10) is arranged in the region of the upper end of the dosing cylinder (9).

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