Filling device for filling battery cells with an electrolyte liquid

Abstract

The invention relates to a filling device (1) for filling battery cells with an electrolyte liquid, having a metering cylinder, in which a specified quantity of electrolyte liquid can be received, and a metering piston (10), by means of which the electrolyte liquid quantity received in the metering cylinder can be discharged out of the metering cylinder and transferred into a battery cell. In order to allow a more reliable and precise filling process of the battery cells while minimizing the technical structural complexity, the invention proposes that both the metering cylinder as well as the metering piston (10) are arranged within a filling device (1) intermediate container (3) which is filled with electrolyte liquid.

Description

[0001] “Filling device for filling battery cells with a

[0002] electrolyte fluid"

[0003] The invention relates to a filling device for filling battery cells with an electrolyte liquid, with a dosing cylinder in which a predetermined amount of the electrolyte liquid can be accommodated, and a dosing piston by means of which the amount of the electrolyte liquid accommodated in the dosing cylinder can be expelled from the dosing cylinder and transferred into a battery cell.

[0004] Battery cells filled with electrolyte are assembled in large numbers to assemble batteries, particularly batteries for the drive systems of motor vehicles. Accordingly, these battery cells must be filled with electrolyte with comparatively little technical effort, and the filling process must be as precise and accurate as possible.

[0005] Based on the above-described prior art, the invention is based on the object of developing a filling device for filling battery cells with an electrolyte liquid of the type described at the outset in such a way that an exact and precisely predeterminable filling of the battery cells with electrolyte liquid is made possible without a noticeably increased technical-constructive

[0006] Effort for the design of the filling device results.

[0007] This object is achieved according to the invention in that both the dosing cylinder and the dosing piston are arranged within an intermediate container of the filling device which is filled with electrolyte liquid. 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 battery cells can be carried out precisely and quickly with the least possible effort. If, according to an advantageous embodiment of the filling device according to the invention, the dosing cylinder is arranged in a base part of the intermediate container, the forward and return stroke of the dosing piston movable in the dosing cylinder can be implemented in a simple manner, wherein the battery cell to be filled with electrolyte liquid can advantageously be arranged below the base part of the intermediate container.

[0008] 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 seal 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.

[0009] 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.

[0010] In order to ensure that the dosing cylinder is filled exactly with the desired filling volume during the return stroke of the dosing piston, it is advantageous if a 2 / 2-way valve or a check valve is arranged in a fluid connection between the dosing cylinder on the one hand and a battery cell to be filled with electrolyte liquid by means of the filling device on the other hand, by means of which the fluid connection can be released during the forward stroke of the dosing piston and blocked during the return stroke of the dosing piston.

[0011] Of course, it is possible to use the intermediate container of the

[0012] Filling device to be connected 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.

[0013] To ensure that unwanted air can escape from the intermediate container, it is advisable to provide a ventilation connection on the intermediate container through which the intermediate container can be vented. This ventilation connection can also advantageously be provided in the area of ​​the intermediate container cover.

[0014] 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 stroke and return stroke. Accordingly, the piston rod is attached to this receiving and guide member at its end section protruding through the cover, with a movement of the receiving and guide member in an up and down direction correspondingly resulting in a movement of the dosing piston within the dosing cylinder.

[0015] A linear drive has proven to be advantageous as the drive means for such a filling device, by means of which the dosing piston can be driven in the desired manner.

[0016] If the filling volume of the dosing cylinder is dimensioned so that it corresponds to the volume of the battery cell to be filled, a battery cell at a time can be filled with electrolyte fluid by means of a forward stroke movement of the dosing piston in the dosing cylinder, and this in exactly the intended quantity.

[0017] Accordingly, filling a battery cell with the respective intended quantity of electrolyte liquid is also possible if the filling volume of the dosing cylinder is dimensioned such that the volume of the 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.

[0018] For the linear drive, it is then advantageous to provide an end position metering.

[0019] 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 stop in any position within the dosing cylinder as soon as a battery cell is filled with the required amount of electrolyte fluid for that battery cell.

[0020] 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. A further advantageous embodiment of the filling device according to the invention is achieved if the filling device includes a vacuum chamber in which a battery cell designed as a pouch cell or with a hard wall can be accommodated, which is to be filled with electrolyte liquid in a metered manner by means of the filling device.

[0021] In the following, the invention is explained in more detail using an embodiment with reference to the drawing.

[0022] It shows :

[0023] Figure 1 is a perspective view of an embodiment of the filling device according to the invention;

[0024] Figure 2 is a perspective view of an intermediate container of the filling device according to the invention shown in Figure 1 with its cover and its base part;

[0025] Figure 3 is a plan view of the intermediate container shown in Figure 2;

[0026] Figure 4 shows the section B - B in Figure 3 ;

[0027] Figure 5 is a further plan view of the intermediate container shown in Figure 2; and

[0028] Figure 6 shows the section D - D in Figure 5 . An embodiment of a filling device 1 according to the invention, shown in a perspective view in Figure 1, serves to fill battery cells not shown in the figures with an electrolyte liquid. The filling of the battery cells not shown in the figures should be possible in a metered manner in vacuum, ambient pressure or overpressure. 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 battery cells of different designs. The filling device 1 according to the invention can also include a vacuum chamber in which a battery cell designed as a pouch cell or with a hard wall can be accommodated and is to be filled by means of the filling device 1.

[0029] The embodiment of the filling device 1 according to the invention shown in Figure 1 includes a frame part 2 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.

[0030] As can be seen from a combination of Figures 1 and 2, 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 6 which, together with the base part 4 and the cover 5, forms an interior space 7 of the intermediate container 3. The base part 4 is firmly connected to the cover 5 of the intermediate container 3 by means of screw connections 8, the screw connections 8 being arranged at the corners of the base part 4 and the cover 5. The filling device 1 according to the invention shown in Figure 1 also includes a dosing cylinder 9. In the dosing cylinder 9, a quantity of the electrolyte liquid which can be predetermined by the freely configurable volume of the dosing cylinder 9 can be absorbed.The dosing cylinder 9 is essentially arranged 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 the direction shown in Figures 1, 2, 4 and 6. In its upper position shown in Figures 4 and 6, the dosing piston 10 has just performed a return stroke movement. During this return stroke movement, in which the dosing piston 10 has moved from its lower position (not shown in the figures) to the upper position shown in Figures 4 and 6, 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, as can be seen from Figure 6, a fluid inlet 11 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 into its upper position shown in Figures 4 and 6, the refill valve 12 releases the connection between the fluid inlet 11 and the lower end region of the dosing cylinder.

[0031] During a forward stroke movement of the dosing piston 10, which is directed downwards in Figures 1, 2, 4 and 6, the refill valve 12 blocks the connection between the fluid inlet 11 and the lower end section of the dosing cylinder 9. Accordingly, the electrolyte liquid in the dosing cylinder 9 is conveyed by means of the dosing piston 10 through a fluid connection 13 formed at the lower end section of the dosing cylinder 9 into the interior of the battery cell (not shown in the figures) connected to the filling device 1. A 2 / 2-way valve or a check valve is arranged in the fluid connection 13. During the forward stroke movement of the dosing piston 10, the fluid connection 13 to the battery cell is opened, whereas during the return stroke of the dosing piston 10 this fluid connection 13 is blocked.

[0032] At the upper end section of the dosing cylinder 9 there is a venting slot through which the dosing cylinder 9 can be vented.

[0033] 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 16 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 16, a scraper ring or a similar sealing means can also be provided.

[0034] 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 14 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.

[0035] 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 container interior 7 of the intermediate container 3 can be vented.

[0036] To carry out the forward and return stroke movement of the dosing piston 10, a linear drive 19 is arranged on the frame part 2 of the filling device 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 Figure 1. By means of the linear drive 19, 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. To ensure a precise 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.

[0037] The linear drive 19 can be designed in an end-position dosing, in which case the filling volume of the dosing cylinder 9 can correspond to the volume of the battery cell to be filled or the volume of the battery cell to be filled is an integer multiple of the filling volume of the dosing cylinder 9.

[0038] The linear drive 19 can also be designed as a freely adjustable linear drive. The filling volume of the dosing cylinder 9 can then be configured as desired without impairing the filling of battery cells.

Claims

PATENT CLAIMS 1. Filling device for filling battery cells with an electrolyte liquid, with a dosing cylinder (9) in which a predetermined amount of the electrolyte liquid can be received, and a dosing piston (10) by means of which the amount of electrolyte liquid received in the dosing cylinder (9) can be expelled from the dosing cylinder (9) and transferred into a battery cell, characterized in that both the dosing cylinder (9) and the dosing piston (10) are arranged within an intermediate container (3) of the filling device (1) filled with electrolyte liquid.

2. Filling device according to claim 1, wherein the dosing cylinder (9) is arranged in a base part (4) of the intermediate container (3).

3. Filling device according to claim 1 or 2, the dosing piston (10) with its piston rod (15) projects 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 (16) or a scraper ring.

4. Filling device according to one of claims 1 to 3, in which a fluid inlet (11) 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 (11) 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 (11) can be released by a return stroke of the dosing piston (10).

5. Filling device according to one of claims 1 to 4, wherein the dosing piston (10) and / or the dosing cylinder (9) is / are made of a ceramic or a stainless steel material.

6. Filling device according to one of claims 1 to 5, wherein the dosing piston (10) is made of a stainless steel material and has a sealing element.

7. Filling device according to one of claims 1 to 5, wherein the dosing piston (10) is made of a ceramic material and is sealed by means of a gap seal.

8. Filling device according to one of claims 1 to 7, in which a 2 / 2-way valve or a check valve is arranged in a fluid connection (13) between the dosing cylinder (9) on the one hand and a battery cell to be filled with electrolyte liquid by means of the filling device (1) on the other hand, by means of which the fluid connection (13) can be released during the forward stroke of the dosing piston (10) and can be blocked during the return stroke of the dosing piston (10).

9. Filling device according to one of claims 1 to 8, 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.

10. Filling device according to one of claims 1 to 9, in which a ventilation connection (18) is provided on the intermediate container (3). is formed, by means of which the intermediate container (3) can be vented.

11. Filling device according to one of claims 3 to 10, 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 on 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.

12. Filling device according to one of claims 1 to 11, which has a linear drive (19) by means of which the dosing piston (10) can be driven.

13. Filling device according to one of claims 1 to 12, wherein the filling volume of the dosing cylinder (9) is dimensioned such that it corresponds to the volume of the battery cell to be filled.

14. Filling device according to one of claims 1 to 13, wherein the filling volume of the dosing cylinder (9) is dimensioned such that the volume of the battery cell to be filled is an integer multiple of the filling volume.

15. Filling device according to claim 13 or 14, wherein a linear drive (19) with end position dosing is provided.

16. Filling device according to one of claims 1 to 11, in which the filling volume of the dosing cylinder (9) is arbitrary and a controllable linear drive (19) is provided.

17. Filling device according to one of claims 1 to 16, the dosing cylinder (9) of which has a venting slot (14) in the region of its upper end, 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).

18. Filling device according to one of claims 1 to 17, with a vacuum chamber in which a battery cell designed as a pouch cell or hard-walled can be accommodated, which is to be filled with electrolyte liquid in a metered manner by means of the filling device (1).

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