Filling device for battery cells

Abstract

In order to create a filling device (1) for battery cells (2) by means of which the time needed to fill the battery cells (2) with battery fluid can be minimised, the invention proposes that the filling device (1) has a cell nest (3) in which the battery cell (2) can be received and in which the outer wall (4) of the battery cell (2) can be supported.

Description

[0001] Filling device for battery cells

[0002] The invention relates to a filling device for battery cells, e.g. Li-ion battery cells. When producing battery assemblies made up of such battery cells, it has been found that the time required to fill the battery cells with battery fluid is high. The stack or winding density of the electrodes or separators provided in the battery cells must be taken into account here. The higher the winding density, the longer the time required to fill the battery cells with battery fluid. The negative pressure that is applied in the battery cell before it is filled must also be taken into account as a factor that influences this time. Negative pressures of 4 to 6 mbar are generally usual in this case. Furthermore, the time required to fill the battery cells with battery fluid can be reduced by the filling orinfluence the dosing pressure with which the battery fluid is filled into the battery cell.

[0003] The invention is based on the object of providing a filling device for battery cells by means of which it can be ensured that the time required for filling the battery cells with battery fluid can be minimized without any risks of bursting or damage to the outer wall of the battery cells occurring.

[0004] This object is achieved according to the invention in that the filling device has a cell nest in which the battery cell can be accommodated and the outer wall of the battery cell can be supported. Due to the support of the outer wall of the battery cell, the filling process can be carried out with a significantly higher dosing or filling pressure compared to the prior art, so that the time required for the time-critical filling of the battery cells with battery fluid can be significantly reduced.

[0005] In order to ensure that the battery cell is supported on all sides during the filling process, it is advisable for the cell nest to be open on one side and to be closable by means of a closing wall, which then also makes it considerably easier to insert the battery cell into the filling device.

[0006] According to an advantageous development of the filling device according to the invention, the cell nest is open at its top and can be covered by a lid. In order to fill the battery cell with battery fluid with the least possible technical and structural effort, it is advantageous if the battery cell located in the cell nest can be filled through a filling nozzle or a dispensing needle that extends through the closure wall or through the lid.

[0007] To simplify the insertion of the battery cell into the filling device according to the invention, in an advantageous development of the filling device according to the invention, the closing wall or the lid or the cell nest can be moved away from the cell nest or the closing wall or the lid for inserting the battery cell into the cell nest and, after the battery cell has been inserted into the cell nest, can be moved towards the cell nest or the closing wall or the lid. In an expedient embodiment of the filling device according to the invention, the inner contour of the cell nest corresponds to the outer contour of the battery cell, so that the battery cell can be received in a form-fitting manner in the cell nest or in the filling device, whereby inadmissible stresses on the outer wall of the battery cell can be reliably excluded.

[0008] Alternatively, it is possible to design a cell nest receiving chamber that accommodates the battery cell so that it can be pressurized. This pressurization can be used to support the outer wall of the battery cell during the filling process. Depending on the specifications for the pressurization of the cell nest receiving chamber, a correspondingly increased filling or dosing pressure can then be achieved.

[0009] In order to allow the highest possible pressure to be applied to the receiving space of the cell nest, it is advantageous if a seal is arranged between the closing wall or the lid on the one hand and the cell nest on the other.

[0010] Advantageously, the inner contour of the receiving space of the cell nest serving to accommodate the battery cell is not adapted to the contour of the outer wall of the battery cell to be filled with battery fluid in the filling device. As long as it is guaranteed in this embodiment that a gap remains between the inner contour or the inner wall of the receiving space of the cell nest serving to accommodate the battery cell, on the one hand, and the outer wall of the battery cell to be filled with battery fluid in the filling device, on the other hand, a planned filling process of the battery cell can be reliably ensured under virtually any adjustable pressure. This means that battery cells with differently contours can be filled within one and the same filling device.

[0011] When using the filling device described above or when carrying out a filling process for battery cells based on it, the outer wall of the battery cells is supported during the filling process. For support, the battery cell is either positively received in a cell nest of the filling device during the filling process, or the outer wall of the battery cell is subjected to pressure within the cell nest during the filling process.

[0012] In the following, the invention is explained in more detail using embodiments with reference to the drawing.

[0013] It shows :

[0014] Figure 1 is a schematic sectional view of a first embodiment of the filling device for battery cells according to the invention; and

[0015] Figure 2 is a schematic sectional view of a second embodiment of the filling device for battery cells according to the invention.

[0016] An embodiment of a filling device 1 according to the invention, shown in a basic sectional view in Figure 1, by means of which a battery cell, preferably a Li-ion battery cell 2 is to be filled with battery fluid, has a cell nest 3, the opening surface of which is formed on its upper outer surface in the embodiment of the filling device 1 shown in Figure 1. In the case of the embodiment of the filling device 1 shown in Figure 1, the inner contour of the cell nest 3 corresponds to the outer contour of an outer wall 4 of the battery cell 2. At its upper side, which has the opening surface, the cell nest 3 can be closed by means of a closing wall, e.g. the cover 5 shown in Figure 1, so that the battery cell 2 can be accommodated within the cell nest 3, enclosed on all sides.

[0017] A dispensing needle 6 extends through the cover 5 and can be used to fill the battery cell 2, which is provided with a connecting element 7 for this purpose. The battery fluid is filled through the dispensing needle 6 under excess pressure in order to keep the time required for the filling process as short as possible. Since the outer wall 4 of the battery cell 2 is supported by the inner contour of the cell nest 3 or the underside of the cover 5 when the cell nest 3 is closed by the cover 5, the filling process can be carried out with a high dispensing pressure, since damage to the outer wall 4 of the battery cell 2 is reliably avoided due to the support of this outer wall 4 in the cell nest 3. In the case of rigid-walled battery cells, a filling nozzle can be provided instead of the dispensing needle 6.

[0018] In order to insert the battery cell 2 into the cell nest 3 of the filling device 1, the cell nest 3 can be opened away from the cover 5 and fed towards the cover 5, as shown in principle in Figure 1. A corresponding feeding device 8 is only shown in principle in Figure 1. Alternatively, it is possible to design the cover 5 to be opened and closed instead of the cell nest 3. Due to the positive support of the outer wall 4 of the battery cell 2 during the filling process, the battery fluid can be filled into the battery cell 2 with a dosing pressure which is considerably higher than in the prior art, so that the filling process takes comparatively little time.

[0019] The further embodiment of the filling device 1 according to the invention, shown in a basic sectional view in Figure 2, differs from the embodiment of the filling device 1 shown in Figure 1 in that the inner contour of a receiving space 9 of the cell nest 3 serving to receive the battery cell 2 is not adapted to the contour of the outer wall 4 of the battery cell 2 to be filled with battery fluid in the filling device 1. In the case of the embodiment of the filling device 1 shown in Figure 2, the receiving space 9 of the cell nest 3 is connected to a pressurized fluid source (not shown in Figure 2) by a fluid connection 10 penetrating the wall of the cell nest 3. Accordingly, an overpressure can be realized in the receiving space 9 of the cell nest 3, by means of which overpressure the outer wall 4 of the battery cell 2 located in the receiving space 9 and to be filled with battery fluid can be supported.The higher the pressurization of the receiving space 9, the higher the dosing pressure can be by means of which the battery cell 2 is filled with battery fluid. Accordingly, in the case of the filling device 1 described above, the time required for filling the battery cell 2 with battery fluid can be significantly reduced. Battery cells 2 with different contours can be filled in one and the same receiving space 9, as long as it is ensured that a gap always remains between the inner contour of the receiving space 9 and the outer surface of the battery cell 2 to be filled during the filling process.

[0020] In the case of the embodiment of the filling device 1 shown in Figure 2, a seal 11 is provided between the lower surface of the lid 5 facing the cell nest 3 and the upper edge of the cell nest 3, which seal enables high pressures within the receiving space 9.

Claims

PATENT CLAIMS 1. Filling device for battery cells (2), characterized in that the filling device (1) has a cell nest (3) in which the battery cell (2) can be received and the outer wall (4) of the battery cell (2) can be supported.

2. Filling device according to claim 1, the cell nest (3) of which is open on one side and can be closed by means of a closing wall (5).

3. Filling device according to claim 2, the cell nest (3) of which is open at its top and can be covered by a lid (5).

4. Filling device according to claim 2 or 3, wherein the battery cell (2) located in the cell nest (3) can be filled through a filling nozzle or a dosing needle (6) which extends through the closure wall or the lid (5).

5. Filling device according to one of claims 2 to 4, in which the closure wall or the lid (5) or the cell nest (3) can be moved away from the cell nest (3) or the closure wall or the lid (5) for inserting the battery cell (2) into the cell nest (3) and can be moved towards the cell nest (3) or the closure wall or the lid (5) after inserting the battery cell (2) into the cell nest (3).

6. Filling device according to one of claims 1 to 5, wherein the inner contour of the cell nest (3) corresponds to the outer contour of the battery cell (2), so that the battery cell (2) can be received in a form-fitting manner in the cell nest (3) or in the filling device (1).

7. Filling device according to one of claims 1 to 5, in which a receiving space (9) of the cell nest (3) serving to receive the battery cell (2) can be pressurized and the outer wall (4) of the battery cell (2) can be supported during the filling process by means of pressurization.

8. Filling device according to claim 7, with a seal (11) which is arranged between the closing wall or the lid (5) and the cell nest (3).

9. Filling device according to claim 7 or 8, wherein the inner contour of the receiving space (9) of the cell nest (3) serving to receive the battery cell (2) is not adapted to the contour of the outer wall (4) of the battery cell (2) to be filled with battery fluid in the filling device (1).

10. Filling method for battery cells (2), characterized in that the outer wall (4) of the battery cells (2) is supported during the filling process.

11. Filling method according to claim 10, wherein the battery cells (2) are positively received in a cell nest (3) during the filling process.

12. Filling method according to claim 10, wherein the outer wall (4) of the battery cells (2) is pressurized in a cell nest (3) during the filling process.

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