Filling device for filling a battery cell with an electrolyte and method for operating a filling device

Description

[0001] The invention relates to a filling device for filling a battery cell with an electrolyte and a method for operating a filling device.

[0002] Filling devices for filling battery cells are known in various designs from the prior art. These involve filling battery housings with a fluid, particularly an electrolyte.

[0003] In addition to the fluid, so-called jelly rolls or cell stacks can be arranged in the battery cells, into which the fluid, in particular the electrolyte, can be absorbed. This makes immediate filling of the battery housing more difficult, since the electrolyte saturates the jelly rolls or cell stacks with a time delay. In order to keep the active filling process by a filling device time-efficient and to achieve at least almost complete filling of the battery housing with fluid, it is known from the prior art to use so-called filling bodies, which are arranged funnel-like on the battery housings and in which the fluid to be supplied to the battery cell is arranged.

[0004] With known filling devices, it has proven to be disadvantageous that when filling a battery cell with electrolyte, it can never be completely ruled out that small gas bubbles remain in the jelly rolls or cell stacks, which reduces the filling level of the battery cell and the performance of the battery cell.

[0005] An object of an embodiment of the invention is to propose a filling device for filling a battery cell with an electrolyte and a method for operating such a filling device, in which the degree of filling of the battery cell can be increased and filling of a battery cell can be made more time-efficient. DE 1671748 B1 discloses an example of a filling device for filling a battery cell with an electrolyte.

[0006] This object is achieved by a filling device for filling a battery cell with an electrolyte, with at least one distributor unit, which has at least one receptacle, at least one flange section with which the distributor unit can be arranged in a planar manner on a contact surface of a battery cell comprising an opening, at least one continuous recess extending from the receptacle to the flange section, wherein the recess overlaps at least partially with the opening of the contact surface of the battery cell at least in the region of the flange section, and which comprises at least one fluid channel which opens with a channel opening on the flange section overlapping at least partially with the opening of the contact surface of the battery cell, with at least one filling unit,which can be fixed or is fixed in or on the receptacle of the distribution unit and through which an electrolyte can be supplied to the battery cell directly or indirectly via the recess of the distribution unit, and with at least one pressure adjustment unit to which at least one of the at least one fluid channel is functionally assigned and which comprises at least one pressure reducing means, in particular a vacuum pump, which can be brought into fluid communication with or is in fluid communication with at least one of the at least one fluid channel and by means of which a negative pressure can be generated at the channel opening of the fluid channel on the flange section.

[0007] Because the filling device comprises an adjustment unit that includes at least one pressure-reducing means capable of generating a negative pressure at the channel opening of the fluid channel on the flange portion, a negative pressure can be generated at the opening of the battery cell and within the battery cell when the filling device is in the arranged state. This reduces the risk of gas bubbles, particularly air bubbles, remaining in the battery cell when the filling unit fills the battery cell with electrolyte. Furthermore, by generating a negative pressure within the battery cell, filling the battery cell with electrolyte can be made faster.

[0008] A cavity in the battery cell is accessible through the opening in the contact surface of the battery cell. So-called jelly rolls or cell stacks can be arranged in the cavity of the battery cell. The jelly rolls or cell stacks consist of an anode layer, a separator layer, a cathode layer, and, if necessary, a further separator layer arranged on top of the anode layer. These layers can be rolled up or folded and, in the rolled up or folded state, can be arranged in the cavity of the battery cell.

[0009] The pressure reducing means can, in principle, be designed in any desired manner. In one embodiment of the filling device, the pressure reducing means comprises a vacuum pump.

[0010] In order to further improve the filling of the battery cell, it proves to be advantageous if the pressure adjustment unit comprises at least one pressure build-up means, in particular a pressure regulator, which can be brought into fluid connection with at least one of the at least one fluid channel and by means of which an overpressure can be generated at the channel opening of the fluid channel on the flange section.

[0011] If the pressure adjustment unit comprises at least one pressure build-up means with which an overpressure can be generated at the channel opening of the fluid channel on the flange section, an overpressure can be generated in the cavity of the battery cell through the fluid connection via the opening to the cavity of the battery cell in an arranged arrangement of the filling device on the battery cell. This proves particularly advantageous if an electrolyte has been supplied to the battery cell via the filling unit. The applied overpressure can improve the saturation of, for example, a jelly roll arranged in the battery cell or a cell stack with electrolyte and reduce the required saturation time.

[0012] Furthermore, it proves to be advantageous if the pressure adjustment unit comprises at least one fluid supply means through which a fluid, in particular an inert gas such as argon or nitrogen, or a cleaning agent can be supplied to the channel opening of the fluid channel on the flange section.

[0013] Because the pressure control unit comprises at least one fluid supply means through which a fluid can be supplied to the channel opening, this fluid enters the interior of the battery cell via the opening when the filling device is arranged on the battery cell. This enables the battery cell to be flushed with a fluid designed as a cleaning agent. Furthermore, the fluid can also comprise an inert gas, such as argon or nitrogen, which improves the soaking or wetting of the jelly rolls or cell stacks when the fluid is subjected to an overpressure built up by the pressure buildup means.

[0014] Fluid supply means and pressure build-up means can work together functionally or form a common component.

[0015] In order to optimize the filling level of the battery cell, it proves to be advantageous if the negative pressure generated by the pressure reducing means is adjustable to less than 1 bar, in particular less than 500 mbar, in particular less than 200 mbar, in particular less than 20 mbar, and / or if the positive pressure generated by the pressure building means is adjustable to greater than 1 bar, in particular greater than 3 bar, in particular greater than 5 bar, in particular to a maximum of 6 bar.

[0016] In principle, it is conceivable that the negative pressure generated by the pressure reducing agent is in a range between 5 and 20 mbar or in a range between 150 and 200 mbar. For example, it is conceivable that the pressure reducing agent initially generates a negative pressure between 5 and 20 mbar in order to create at least a near-vacuum within the battery cell. This reduces the proportion of remaining air molecules or gas molecules within the battery cell. The pressure can then be increased to a level of 150 to 200 mbar for filling.

[0017] If the pressurizing agent generates a pressure of maximum 6 bar, the saturation of jelly rolls or cell stacks arranged in the battery cell can be improved.

[0018] Furthermore, embodiments of the filling device are conceivable in which the pressure build-up means, the fluid supply means and the pressure reduction means can be brought into fluid connection with the same fluid channel or in which the pressure build-up means can be brought into fluid connection with a pressure build-up fluid channel, the fluid supply means with a fluid supply channel and the pressure reduction means with a pressure reduction fluid channel.

[0019] If the pressure build-up means, fluid supply means, and pressure reduction means can be connected to the same fluid channel, the filling device can be designed simply. If the pressure build-up means can be fluidly connected to a pressure build-up fluid channel, the fluid supply means can be fluidly connected to a fluid supply channel, and the pressure reduction means can be fluidly connected to a pressure reduction fluid channel, the individual components of the adjustment unit are separated from one another.

[0020] Furthermore, embodiments are conceivable, in particular when the fluid supply means and the pressure build-up means form a common component, in which the pressure build-up fluid channel and the fluid supply channel comprise a common channel.

[0021] In a further development of the latter embodiment, it proves to be advantageous if the pressure build-up means, the fluid supply means and the pressure reduction means can be brought into fluid connection with the same fluid channel or if the pressure build-up means can be brought into fluid connection with a pressure build-up fluid channel, the fluid supply means with a fluid supply channel and the pressure reduction means with a pressure reduction fluid channel.

[0022] In such a case, it is conceivable that the individual fluid channels flow into a common channel that encompasses the channel opening.

[0023] In order to prevent fluid from flowing along an unintended flow direction, embodiments of the filling device are provided in which the pressure setting unit comprises at least one pressure build-up valve which is arranged between the pressure build-up means and the distributor unit on the fluid channel, in particular is fixed to the distributor unit, in which the pressure setting unit comprises at least one fluid supply valve which is arranged between the fluid supply means and the distributor unit on the fluid channel, in particular is fixed to the distributor unit, and / or in which the pressure setting unit comprises at least one pressure reduction valve which is arranged between the pressure reduction means and the distributor unit on the fluid channel, in particular is fixed to the distributor unit.

[0024] In such a case, a backflow to the respective agent is easily prevented.

[0025] The distributor unit can, in principle, be designed in any desired manner. It is advantageous if the distributor unit comprises a distributor body that forms a single, integral component with the flange portion, or if the distributor unit comprises a distributor body that includes a flange receptacle and a flange body that forms the flange portion, wherein the flange body is or can be secured to the flange receptacle of the distributor body.

[0026] If the distribution unit comprises a distributor body which forms a common, one-piece component with the flange section, the distribution unit can be designed with reduced components.

[0027] If the distributor unit comprises a distributor body comprising a flange receptacle and a flange body forming the flange portion, wherein the flange body is fixable or fixed to the flange receptacle of the distributor body, one and the same distributor body with different flange bodies can be used for different openings of battery cells.

[0028] In the case of a multi-part design of the distributor unit, in particular in the distributor body and flange body, the recess in the distributor body extends through the distributor body and flange body.

[0029] It proves to be advantageous if the at least one fluid channel and the recess comprise a common section at least in sections.

[0030] If the at least one fluid channel comprises the pressure build-up fluid channel, the fluid supply channel, and / or the pressure reduction fluid channel, these can jointly open into the recess; in particular, the recess can form the common section that opens into the channel opening on the flange section. In this case, the channel opening and the recess are formed jointly.

[0031] The at least one fluid channel can, in principle, be manufactured in any desired manner. It can be manufactured simply and cost-effectively if the at least one fluid channel comprises a bore extending transversely or obliquely to the recess of the distribution unit.

[0032] In such a case, the at least one fluid channel opens into the recess of the distributor unit, wherein the recess continues the fluid channel in the direction of the channel opening when the respective fluid channel opens into it.

[0033] In principle, it is conceivable for the filling unit to allow the electrolyte to flow directly through the recess of the distribution unit toward the battery cell. In a further development of the filling device, the filling unit comprises a metering valve arranged in the receptacle of the distribution unit and / or the filling unit comprises a metering needle arranged on the metering valve, which extends from the metering valve to the opening of the contact surface of the battery cell and through which electrolyte can be supplied to the battery cell.

[0034] The dosing needle can be immersed at least partially into the battery cell and, if so, can be designed to extend beyond the opening into the contact surface of the battery cell in the direction of the battery cell.

[0035] In this case, no electrolyte flows directly along a wall of the recess, but only via the dispensing needle.

[0036] This reduces the risk of electrolyte flowing through the at least one fluid channel, for example, in the direction of the pressure reducing agent.

[0037] The filling of a battery cell can be further simplified if the filling unit comprises at least one funnel-like filling body in which electrolyte can be arranged and through which electrolyte can be transported through the dosing valve and / or through the dosing needle towards the battery cell.

[0038] For example, electrolyte can be placed in the funnel-shaped filling body. The funnel-shaped filling body can, for example, include a level indicator to which the filling body can be filled with electrolyte. Electrolyte can then be transported via the dosing valve and the dosing needle toward the battery cell.

[0039] This makes it easy to equip the filling device with electrolyte without having to constantly supply electrolyte to the filling device.

[0040] In order to generate the negative pressure or the positive pressure, in particular within the battery cells, the filling device comprises at least one flange sealing means arranged on a side of the flange section, in particular of the flange body, facing the contact surface of the battery cell; on the flange section, in particular on the flange body, by at least one distributor unit sealing means arranged on a side of the distributor body facing the flange body between the distributor body and the flange body and / or by at least one metering valve sealing means arranged on a side of the distributor unit facing the metering valve between the distributor unit and the metering valve.

[0041] Furthermore, the object is achieved by a method for operating a filling device with at least one of the aforementioned features, comprising the steps: a. Arranging the filling device on a battery cell, wherein the recess of the filling device overlaps at least partially with an opening of a contact surface of the battery cell, at least in the region of the flange section; b. Generating a negative pressure at the channel opening of the fluid channel on the flange section by means of the pressure reducing means of the pressure setting unit until a specific filling pressure is reached; c. Filling the battery cell with electrolyte by means of the filling unit; d. Generating an overpressure at the channel opening of the fluid channel on the flange section by means of the pressure building means of the pressure setting unit until a specific wetting pressure is reached by filling in an inert gas.

[0042] Finally, it proves to be advantageous if the generation of a negative pressure at the channel opening of the fluid channel on the flange section by the pressure reduction means of the pressure setting unit until a certain filling pressure is reached, first a reduction of the pressure to 5 to 20 mbar and before the battery cell is filled with electrolyte by the filling unit an increase to a maximum of 500 mbar, in particular a maximum of 350 mbar, in particular a maximum of 200 mbar, and / or if the certain wetting pressure comprises a maximum of 6 bar, in particular a maximum of 5 bar, in particular a maximum of 4 bar.

[0043] If the pressure reduction device of the pressure adjustment unit initially lowers the pressure to 5 to 20 mbar at the fluid channel opening at the flange section until a certain filling pressure is reached, a cavity in the battery cell can be at least almost completely evacuated, creating a type of vacuum. This reduces the risk of gas molecules, especially air molecules, remaining when the battery cell is filled with electrolyte.

[0044] By increasing the pressure to a maximum of 500 mbar, filling the battery cell can be made easier.

[0045] Further features, details and advantages of the invention emerge from the appended patent claims, from the drawings and the following description of two preferred embodiments of the filling device and one embodiment of the method.

[0046] In the drawing shows: Figure 1: A schematic representation of a first embodiment of the filling device; Figure 2: A schematic representation of a second embodiment of the filling device; Figure 3: A schematic flow diagram of an embodiment of the method according to the invention.

[0047] The Figures 1 and 2each show exemplary embodiments of a filling device, designated overall by the reference numeral 2, for filling a battery cell 4 with an electrolyte. The filling device 2 of the two exemplary embodiments each comprises a distributor unit 6, the at least one receptacle 8, a flange section 10, with which the distributor unit 6 is arranged in planar contact with a contact surface 14 of the battery cell 4 comprising an opening 12, and at least one continuous recess 16 extending from the receptacle 8 to the flange section 10. The recess 16 overlaps, at least in the region of the flange section 10, at least in sections with the opening 12 of the contact surface 14 of the battery cell 4.

[0048] In addition, the distributor unit 6 comprises fluid channels 18, which open with a channel opening 20 on the flange section 10, at least in sections overlapping with the opening 12 of the contact surface 14 of the battery cell 4.

[0049] In addition, the filling device 2 comprises a filling unit 22 which is fixed in or on the receptacle 8 of the distribution unit 6 and through which electrolyte can be supplied to the battery cell 4.

[0050] Furthermore, the filling device 2 comprises a pressure adjustment unit 24, which is functionally assigned to at least one of the at least one fluid channel 18 and which comprises at least one pressure reducing means 26 fluidly connected to at least one of the at least one fluid channel 18. The pressure reducing means 26 can generate a negative pressure at the channel opening 20 of the fluid channel 18 on the flange portion 10.

[0051] In the exemplary embodiments shown in the figures, the pressure adjustment unit 24 additionally comprises a pressure build-up means 28, by which an overpressure can be generated at the channel opening 20 of the fluid channel 18 on the flange section 10. Furthermore, in the exemplary embodiments shown in the figures, the pressure build-up means 28 is configured such that it also comprises a fluid supply means 30. This allows fluid to be supplied to the channel opening 20 of the fluid channel 18 on the flange section 10.

[0052] In the exemplary embodiments shown in the figures, the fluid channel 18 associated with the pressure reduction means 26 is designed as a pressure reduction fluid channel 32. Accordingly, the fluid channel 18 associated with the pressure build-up means 28 is designed as a pressure build-up fluid channel 34.

[0053] In the exemplary embodiments shown in the figures, the filling unit 22 comprises a metering valve 36, with which the filling unit 22 is secured in the receptacle 8 of the distributor unit 6. A metering needle 38 is arranged on the metering valve 36, which extends from the metering valve 36 in the direction of the opening 12 of the battery cell 4 and engages at least partially into the battery cell 4. The metering needle 38 extends through the recess 16 of the distributor unit 6. In order to prevent backflow through the fluid channels 18 in the direction of the pressure reducing means 26 or in the direction of the pressure building means 28, the pressure setting unit 24 comprises a pressure building valve 40, which is arranged on the distributor unit 6 between the pressure building means 28 and the distributor unit 6, and a pressure reducing valve 42, which is secured on the distributor unit 6 between the pressure reducing means 26 and the distributor unit 6.

[0054] Figure 1shows a first embodiment of the filling device 2, in which the metering valve 36 is connected to a fluid supply. Electrolyte is continuously dispensed toward the battery cell 4 via the metering valve 36 and the metering needle 38.

[0055] In the Figure 1 In the embodiment shown, the distributor unit 6 comprises a distributor body 44 which forms a common one-piece component with the flange section 10.

[0056] In addition, the embodiment according to Figure 1 a flange sealing means 46 which is arranged on a side of the flange section 10 facing the contact surface 14 of the battery cell 4.

[0057] Also in the embodiment according to Figure 2 such a flange sealant 46 is arranged on the side facing the contact surface 14 of the battery cell 4.

[0058] In contrast to the embodiment according to Figure 1is in the embodiment according to Figure 2 The distributor unit 6 is formed by a distributor body 44 and a flange body 48. The flange body 48 encompasses the flange portion 10 and is secured in a flange receptacle 50 of the distributor body 44. A distributor unit sealant 52 is arranged between the flange body 48 and the distributor body 44.

[0059] In the embodiment according to Figure 2 the distribution unit 6 additionally comprises a funnel-like filling body 54 in which electrolyte is arranged and through which electrolyte can be transported towards the battery cell 4 via the dosing valve 36 and the dosing needle 38.

[0060] Figure 3 shows a schematic flow diagram of an embodiment of a method according to the invention. With the aid of the representation of the filling device 2 in the Figures 1 and 2, the method is described below: In a first step 100, the filling device 2 is arranged on a battery cell 4, wherein the recess 16 of the filling device 2 overlaps at least partially with an opening 12 of a contact surface 14 of the battery cell 4, at least in the region of the flange section 10. As a result, the recess 16 and the opening 12 are in fluid communication.

[0061] In a subsequent step 101, the pressure reducing means 26 generates a negative pressure at the channel opening 20 of the fluid channel 18 on the flange portion 10 until a specific filling pressure is reached. In this case, the pressure can first be reduced to 5 to 20 mbar by the pressure reducing means 26 and then increased to the filling pressure, in particular to a maximum of 500 mbar.

[0062] As a result, the interior of the battery cell 4 is first evacuated and then, by establishing the specific filling pressure, the battery cell 4 is filled by the filling unit 22.

[0063] In a subsequent step 102, the battery cell 4 is filled with electrolyte by the filling unit 22.

[0064] In a subsequent step 103, the pressure build-up means 28 generates an overpressure until a specific wetting pressure is reached. A so-called inert gas can be used for this purpose. The specific wetting pressure can be a maximum of 6 bar.

[0065] The features of the invention disclosed in the above description, in the claims and in the drawings can be essential both individually and in any combination in the realization of the invention in its various embodiments within the scope of the following claims. List of reference symbols

[0066] 2Befüllvorrichtung 4Batteriezelle 6Verteilereinheit 8Aufnahme 10Flanschabschnitt 12Öffnung 14Anlagefläche 16Aussparung 18Fluidkanal 20Kanalöffnung 22Befülleinheit 24Druckeinstelleinheit 26Druckreuktionsmittel 28Druckaufbaumittel 30Fluidzuführmittel 32Druckreuktions-Fluidkanal 34Druckaufbau-Fluidkanal 36Dosierventil 38Dosiernadel 40Druckaufbauventil 42Druckreuktionsventil 44Verteilerkörper 46Flanschdichtmittel 48Flanschkörper 50Flat-head seal 52Transparency-sealing agent 54Filling body 100-103Transport speed

Claims

1. Filling device (2) for filling a battery cell (4) with an electrolyte, with at least one distributor unit (6), with at least one receptacle (8), which has at least one flange section (10), with which the distributor unit (6) can be arranged so as to lie flat against a contact surface (14) of a battery cell (4) comprising an opening (12), with at least one continuous cut-out (16) extending from the receptacle (8) to the flange section (10), wherein the cut-out (16) overlaps at least in the region of the flange section (10) at least in sections with the opening (12) of the contact surface (14) of the battery cell (4), and which comprises at least one fluid channel (18), which opens with a channel opening (20) on the flange section (10) at least overlapping in sections with the opening (12) of the contact surface (14) of the battery cell (4), with at least one filling unit (22) which can be fixed or secured in or on the receptacle (8) of the distributor unit (6) and through which an electrolyte can be supplied to the battery cell (4) directly, or indirectly via the cut-out (16) of the distributor unit (6), and with at least one pressure adjustment unit (24), to which at least one of the at least one fluid channel (18) is functionally assigned and which comprises at least one pressure reduction means (26), in particular a vacuum pump, which can be brought into fluid connection with at least one of the at least one fluid channel (18) and by means of which a negative pressure can be generated at the channel opening (20) of the fluid channel (18) on the flange section (10).

2. Filling device (2) according to claim 1, characterised in that the pressure adjustment unit (24) comprises at least one pressure build-up means (28), in particular a pressure regulator, which can be brought into fluid connection with at least one of the at least one fluid channel (18) and by means of which an overpressure can be generated at the channel opening (20) of the fluid channel (18) on the flange section (10).

3. Filling device (2) according to claim 1 or 2, characterised in that the pressure adjustment unit (24) comprises at least one fluid supply means (30), through which a fluid, in particular an inert gas, such as argon or nitrogen, is injected into the channel opening (20) of the fluid channel (18) on the flange section (10).

4. Filling device (2) according to one of the preceding claims, characterised in that the negative pressure generated by the pressure reduction means (26) can be set at less than 1 bar, in particular less than 500 mbar, in particular less than 200 mbar, in particular less than 20 mbar, and / or that the overpressure generated by the pressure build-up means (28) is set at greater than 1 bar, in particular greater than 3 bar, in particular greater than 5 bar, in particular at a maximum of 6 bar.

5. Filling device (2) according to one of the preceding claims, characterised in that the pressure build-up means (28), the fluid supply means (30) and the pressure reduction means (26) can be brought into fluid connection with the same fluid channel (18) or that the pressure build-up means (28) can be brought into fluid connection with a pressure build-up fluid channel (34), the fluid supply means (30) can be brought into fluid connection with a fluid supply channel and the pressure reduction means (26) can be brought into fluid connection with a pressure reduction fluid channel (32).

6. Filling device (2) according to claim 5, characterised in that the pressure build-up fluid channel (34), the fluid supply channel and the pressure reduction fluid channel (32) can be separated from one another and spaced from one another at least on the side opposite the channel opening (20) on the flange section (10) and / or the pressure build-up fluid channel (34), fluid supply channel and pressure reduction fluid channel (32) open together into the channel opening (20) on the flange section (10).

7. Filling device (2) according to one of the preceding claims, characterised in that the pressure adjustment unit (24) comprises at least one pressure build-up valve (40), arranged between a pressure build-up means (28) and the distributor unit (6) on the fluid channel (18), in particular fixed on the distributor unit (6), that the pressure adjustment unit (24) comprises at least one fluid supply valve, arranged between the fluid supply means (30) and the distributor unit (6) on the fluid channel (18), in particular is fixed to the distributor unit (6), and / or that the pressure adjustment unit (24) comprises at least one pressure reduction valve (42), arranged between the pressure reduction means (26) and the distributor unit (6) on the fluid channel (18), in particular fixed on the distributor unit (6).

8. Filling device (2) according to one of the preceding claims, characterised in that the distributor unit (6) comprises a distributor body (44) that forms a common, one-piece component with the flange section (10) or that the distributor unit (6) comprises a distributor body (44) that comprises a flange receptacle (50) and a flange body (48) that forms the flange section (10), wherein the flange body (48) can be fixed or is fixed to the flange receptacle (50) of the distributor body (44).

9. Filling device (2) according to one of the preceding claims, characterised in that the at least one fluid channel (18) and the cut-out (16) comprise a common section, at least in some sections.

10. Filling device (2) according to one of the preceding claims, characterised in that the at least one fluid channel (18) comprises a bore extending transversely or obliquely to the cut-out (16) of the distributor unit (6).

11. Filling device (2) according to one of the preceding claims, characterised in that the filling unit (22) comprises a dosing valve (36) that is arranged in the receptacle (8) of the distributor unit (6) and / or that the filling unit (22) comprises a dosing needle (38) that is arranged on the dosing valve (36), which extends from the dosing valve (36) to the opening (12) on the contact surface (14) of the battery cell (4) and through which electrolyte can be supplied to the battery cell (4).

12. Filling device (2) according to one of the preceding claims, characterised in that the filling unit (22) comprises at least one funnel-shaped filling body (54), in which electrolyte can be arranged and through which electrolyte can be transported through the dosing valve (36) and / or through the dosing needle (38) in the direction of the battery cell (4).

13. Filling device (2) according to one of the preceding claims, characterised by at least one flange sealing means (46) that is arranged on a side of the flange section (10) facing the contact surface (14) of the battery cell (4), in particular of the flange body (48); on the flange section (10), in particular on the flange body (48), by at least one distributor unit sealing means (52) that is arranged on the side of the distributor body (44) facing the flange body (48) between the distributor body (44) and the flange body (48) and / or by at least one dosing valve sealing means that is arranged on the side to the distributor unit (6) facing the dosing valve (36) between the distributor unit (6) and the dosing valve (36).

14. Method for operating a filling device (2), according to one of claims 1 to 13, comprising the steps: a. Arrangement of the filling device (2) on a battery cell (4), wherein the cut-out (16) on the filling device (2) overlaps at least in the area of the flange section (10), at least in sections, with the opening (12) of a contact surface (14) of the battery cell (4); b. Generation of negative pressure on the channel opening (20) of the fluid channel (18) on the flange section (10) by the pressure reduction means (26) of the pressure adjustment unit (24) until a certain filling pressure is achieved; c. Filling of the battery cell (4) with electrolyte by the filling unit (22); d. Generation of overpressure on the channel opening (20) of the fluid channel (18) on the flange section (10) by the pressure build-up means (28) of the pressure adjustment unit (24) until a certain wetting pressure is achieved by adding an inert gas;15. Method according to claim 14, characterised in that the generation of a negative pressure at the channel opening (20) of the fluid channel (18) on the flange section (10) by the pressure reduction means (26) of the pressure adjustment unit (24) until a specific filling pressure is achieved, initially a reduction of the pressure to 5 to 20 mbar and, before the battery cell (4) is filled with electrolyte by the filling unit (22), an increase to a maximum of 500 mbar, in particular a maximum of 350 mbar, in particular a maximum of 200 mbar takes place, and / or that the determined wetting pressure comprises a maximum of 6 bar, in particular a maximum of 5 bar, in particular a maximum of 4 bar.