Prismatic cell having two openings

Abstract

The invention relates to a prismatic cell consisting of a housing and at least one cover assembly having a base plate. The prismatic cell comprises at least one first opening and one second opening, which are located in the base plate. The first opening is designed to introduce an electrolyte into the prismatic cell. The second opening is designed to convey a residual gas out of the prismatic cell.

Description

[0001] Prismatic cell with two openings

[0002] Description

[0003] The invention relates to a prismatic cell and a method for filling a prismatic cell.

[0004] Currently, prismatic cells have a single filling opening. During the filling process, both the liquid electrolyte is poured in and the gas present in the cell is removed. Due to the layered structure of the cell stack or cell coil in prismatic battery cells, with fine-pored, highly compressed porous layers of the electrodes and separator, the introduction of the electrolyte into the pore structure is a slow process. The same applies to the removal of air from the pores. Due to the generally non-porous deflection plates in the layered structure, the fluid can only move parallel to the layers, which can lead to a countercurrent between gas and electrolyte, which can leave gas bubbles in the battery cell after the filling process. Furthermore, the removal of gas bubbles between the cell stack or cell coil and the inner wall of the housing is essential.

[0005] In current prismatic cells, the lid assembly consists of a metallic base plate. The fill port is located in this base plate. When the fill port is closed after filling and forming the cell, this fill port is welded with a metal closure piece. During this closing process, it cannot be completely ruled out that metal particles are released into the cell's interior. These metal particles cannot be detected by conventional quality control methods, but they can cause critical conditions (internal short circuits) during cell operation. The provision of multiple fill ports increases this risk.

[0006] The object of the invention is to provide an improved prismatic cell and an improved method for producing a prismatic cell that is simple and cost-effective to manufacture. This object is achieved by a prismatic cell having the features of claim 1 and claim 2, as well as by a method for producing the prismatic cell having the features of claim 11.

[0007] The subclaims show preferred developments of the invention.

[0008] The prismatic cell according to the invention comprises a housing and a first cover assembly with a first base plate. The first cover assembly is designed to close the housing. Furthermore, the prismatic cell comprises a first opening and a second opening arranged in the first base plate. The first opening is designed to introduce an electrolyte into the prismatic cell. The second opening is designed to vacuum the cell before the electrolyte is added and to expel any residual gas from the prismatic cell. Thus, an electrolyte can be introduced into the prismatic cell and any residual gas displaced by the electrolyte can be expelled from the prismatic cell at the same time, thereby increasing the filling rate of the prismatic cell.The removal of residual gas and the addition of electrolyte can also be designed in a pulsating manner, which allows the cell to be filled more quickly.

[0009] Variable adjustment of both the residual gas removal process (e.g., by varying the pressure) and the dosing process (pressure, flow rate, medium temperature) is also conceivable. By incorporating the first opening and the second opening into the first base plate, a simple construction of the prismatic cell with only one cover assembly is possible. The first cover assembly preferably includes terminal connections that enable electrical contact with the prismatic cell. The prismatic cell is preferably a prismatic accumulator cell.

[0010] The invention further relates to a prismatic cell comprising a housing, a first cover assembly with a first base plate, and a second cover assembly with a second base plate, wherein the first cover assembly and the second cover assembly are configured to close the housing. A first opening is arranged in the first base plate and a second opening in the second base plate. The first opening is configured to introduce an electrolyte into the prismatic cell. The second opening is configured to vacuum the cell before the electrolyte is metered in and / or to remove residual gas from the prismatic cell. The first cover assembly is preferably attached to the housing of the prismatic cell parallel to the second cover assembly. The housing can thus be a simple profile component.By creating the first opening on the first base plate and the second opening on the second base plate, a continuous filling process is enabled, which particularly shortens the filling process for elongated prismatic cells—so-called "blade" cells. The prismatic cell is preferably a prismatic accumulator cell.

[0011] The subject matter of the invention comprises, as the common inventive concept, a prismatic cell comprising a first opening and a second opening. The first opening is configured to introduce an electrolyte into the prismatic cell. The second opening is configured to expel residual gas from the prismatic cell. The filling openings are preferably made of plastic.

[0012] Prismatic cells can include electrical energy storage in the form of accumulators or supercapacitors.

[0013] Preferably, the first opening is arranged longitudinally of the first lid assembly adjacent to a first end of the first base plate, and the second opening is arranged longitudinally adjacent to a second end of the first base plate. This, preferably maximum, spacing of the first opening and the second opening on the first base plate promotes a continuous filling process, allowing the residual gas to escape from the prismatic cell as completely as possible.

[0014] Alternatively, the first opening is preferably arranged longitudinally adjacent to a first end of the first base plate, and the second opening is arranged longitudinally adjacent to a second end of the second base plate. Thus, during the filling process, the prismatic cell can be aligned such that the first opening is located at the lowest geodetic point possible and the second opening is located at the highest possible point, so that the residual gas can be displaced from the prismatic cell as completely as possible, and a continuous filling process can be realized.

[0015] Further preferably, the prismatic cell comprises a third opening, which is arranged in the first base plate and is configured to introduce an electrolyte into the prismatic cell. The additional third opening can accelerate the filling process and enable a uniform introduction of the electrolyte. Particularly preferably, the prismatic cell comprises a fourth opening, which is arranged in the second base plate and is configured to expel residual gas from the prismatic cell. The additional fourth opening can accelerate the filling process and enable a uniform expulsion of the residual gas.

[0016] Preferably, the first opening has a deflection device configured to deflect an electrolyte from an introduction direction oriented perpendicular to the first base plate and introduce it into the prismatic cell. The deflection device enables targeted introduction of the electrolyte into the prismatic cell, thus preventing air inclusions in the separator-electrode stack or at the interface between the stack and the inner cell housing wall.

[0017] More preferably, the second opening is arranged flush with the base plate, particularly on the inside of the base plate. This allows the residual gas to be optimally displaced by the electrolyte and escape through the second opening.

[0018] Particularly preferably, the prismatic cell has a polymer closure configured to close the openings with a material fit. The polymer closure is preferably glued or welded to the first or second base plate. Preferably, the polymer closure additionally closes the openings with a form-fitting connection. Thus, the polymer closure enables reliable sealing of the cell chemistry inside the prismatic cell from the environment.

[0019] The base plate is preferably made of plastic. This minimizes the risk of metallic or electrically conductive particles being released during the filling process or when closing the openings, thus minimizing the likelihood of cell failure due to such particles.

[0020] The first opening and / or the second opening are preferably designed as an insert in the base plate. This enables cost-effective and rapid production of the prismatic cell without extensive assembly effort.

[0021] The first opening and / or the second opening are further preferably integrated into the base plate, e.g. as openings in an injection-molded part.

[0022] The invention further describes a method for filling a previously described prismatic cell. For this purpose, a vacuum is created in the prismatic cell. A vacuum is understood to be a pressure which is lower than atmospheric pressure. In particular, the pressure in the prismatic cell is 100 - 200 mbar. This ensures that the electrolyte does not evaporate during filling. The prismatic cell is filled with an electrolyte through a first opening, with residual gas escaping through a second opening. The first opening and the second opening are then closed. Filling can take place continuously or in several steps, with filling and residual gas removal being able to take place alternately, for example. This can make it possible, for example, to generate pressure pulses during filling, which actively remove gas bubbles from the cell housing.Furthermore, all filling methods are conceivable, in which the parameters volume flow, pressure, and temperature are varied during electrolyte dosing, and the parameters pressure and volume flow are varied during residual gas extraction. In this context, it is conceivable to seal the filling device to the first opening, or the extraction device to the second opening. This can be achieved, for example, by means of a seal attached to the dosing system or to the base plate.

[0023] It is also conceivable to design the sizes (e.g. the diameter) of the first and second opening differently.

[0024] It is also conceivable to attach a sensor to the second opening that can detect when electrolyte escapes from the opening and thus the filling process is complete.

[0025] Further preferably, in the method, the prismatic cell is filled with the electrolyte through a third opening, with the residual gas escaping through a fourth opening.

[0026] The third and fourth openings are then also closed. This allows for faster and more targeted filling of the prismatic cell.

[0027] Particularly preferred in this process is the active removal of residual gas. Filling with the electrolyte and removing the residual gas preferably occur simultaneously. This allows for increased filling speed and better control of the process. The residual gas can be actively removed, for example, by pumping.

[0028] Further details, advantages, and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings. It shows:

[0029] Fig. 1 A schematic perspective view of a prismatic cell according to a first embodiment,

[0030] Fig. 2 is a schematic perspective view of a prismatic cell according to a second embodiment,

[0031] Fig. 3 is a schematic sectional view of a prismatic cell according to a third embodiment,

[0032] Fig. 4 is a schematic perspective view of a prismatic cell according to a fourth embodiment, and

[0033] Fig. 5 shows a schematic detailed view of a first opening. A prismatic cell 1 and a method for producing the prismatic cell 1 according to a first embodiment are described in detail below with reference to Figure 1.

[0034] Figure 1 shows a perspective view of a prismatic cell, depicted as a prismatic accumulator cell. The prismatic cell 1 comprises a housing 2, which is closed by a first cover assembly 3. The housing 2 is preferably made of aluminum and is integrally connected to the first cover assembly 3.

[0035] The first cover assembly 3 has a first base plate 16. The first base plate 16 is an injection-molded plastic component into which further inserts 6 are integrated. Preferably, a metallic frame is connected to the first base plate 16 in a form-fitting, force-fitting, and / or material-fitting manner around the first base plate 16, so that the first cover assembly 3 can be welded to the housing 2 via the metallic frame.

[0036] In the longitudinal direction R1 of the first cover assembly 3, a bursting area 22 is arranged centrally, which enables the prismatic cell 1 to open in the event of a cell failure by pressure and / or temperature activation, so that the cell chemistry can leave the prismatic cell 1.

[0037] In a first end region and a second end region in the longitudinal direction R1, a terminal feedthrough 21 is integrated as an insert 6 into the first base plate 16 of the first cover assembly 3. The terminal feedthroughs 21 preferably have different polarities and enable electrical contact with the prismatic cell 1.

[0038] In the first base plate 16, a first opening 11 is arranged on one side of the bursting area 22 and a second opening 12 is arranged on an opposite side of the bursting area 22 in the longitudinal direction R1 between the bursting area 22 and the terminal feedthrough 21. The first opening 11 is configured to introduce an electrolyte 9 into the prismatic cell 1 in a filling step S2. The second opening 12 is configured to allow a residual gas 5 to escape from or be removed from the prismatic cell 1.

[0039] Thus, the prismatic cell 1 can be filled by creating a vacuum in the prismatic cell 1 in a step S1. In a further step S2, the prismatic cell 1 is filled with the electrolyte 9 through the first opening 11, whereby a residual gas 5 can escape from the second opening 12. The residual gas 5 can also be actively conveyed out of the prismatic cell 1 in a step S4. Finally, in a step S3, the first opening 11 and the second opening 12 are closed. Figure 1 shows the prismatic cell 1 filled with the electrolyte 9, in which the first opening 11 and the second opening 12 are each closed with a closure 15. The closure 15 is made of a plastic and welded to the first base plate 16. If the base plate 16, 17 and closure 15 are selected from the same materials, a particularly reliable weld can be achieved.

[0040] Figure 2 shows a prismatic cell 1 according to a second embodiment, which is designed as an elongated prismatic accumulator cell 1. The prismatic cell 1 has the first cover assembly 3 and a second cover assembly 4, which are arranged parallel to one another. The first cover assembly 3 is arranged at a first end in the filling direction R2, and the second cover assembly 4 is arranged at a second end in the filling direction R2. The filling direction R2 is oriented perpendicular to the surface of the first base plate 16.

[0041] The first cover assembly 3 comprises the first base plate 16 made of a plastic material, in which the terminal feedthrough 21 and the first opening 11 are arranged. The second cover assembly 4 is constructed similarly to the first cover assembly 3 and comprises a second base plate 17 made of a plastic material, in which another terminal feedthrough 21 and the second opening 12 are arranged.

[0042] The burst opening 22 of the prismatic cell 1 is integrated laterally into the housing 2.

[0043] The first opening 11 is arranged adjacent to a lower end in the direction R1. The second opening 12 is arranged adjacent to an upper end in the direction R1. Thus, the prismatic cell 1 can be filled with the electrolyte 9 through the first opening 11 in a lower region, whereby the residual gas 5 present in the prismatic cell 1 can escape or be transported out through the second opening 12 arranged above.

[0044] Figure 3 shows a sectional view of a prismatic cell 1 according to a third embodiment. The prismatic cell 1 in Figure 3 is similar to the accumulator cell 1 in the first embodiment, with the first opening 11 being arranged adjacent to a first end in the longitudinal direction R1, and the second opening being arranged adjacent to a second end in the longitudinal direction R1. A first terminal feedthrough 21a is arranged between the first opening 11 and the bursting region 22, and a second terminal feedthrough 21b is arranged between the bursting region 22 and the second opening 12.

[0045] The first terminal feedthrough 21a is connected to a negative electrode 7 inside the prismatic cell 1, thus forming an anode. The second terminal feedthrough 21b is connected to a positive electrode 8 inside the prismatic cell 1, thus forming a cathode. The negative electrode 7 and the positive electrode 8 are arranged parallel to one another and separated from each other by the electrolyte 9.

[0046] The first base plate 16 of the first cover assembly 3 is integrally connected to the housing 2 via a welded joint 27. The first opening 11 and the second opening 12 are designed as inserts 6. The first opening 11 has a dovetail-shaped connection with the first base plate 16. The second opening 12 has an undercut connection with the first base plate 16.

[0047] The first opening 11 has a deflection device 18, which deflects the electrolyte 9 from the introduction direction R2 and introduces it laterally into the prismatic cell 1 in the direction of the housing 2. Thus, the electrolyte 9 can be introduced into the prismatic cell 1 in a targeted manner, reducing the risk of gas inclusions.

[0048] The second opening 12 is arranged flush with the first base plate 16, both on the inside and outside of the prismatic cell 1. Thus, the residual gas 5 can escape or be transported out of the prismatic cell 1 as completely as possible when the second opening 12 is oriented upwards.

[0049] Figure 4 shows a prismatic cell 1 according to a fourth embodiment. The prismatic cell 1 is depicted as a prismatic accumulator cell 1 and is similar to the prismatic cell 1 according to the second embodiment.

[0050] Compared to the prismatic cell 1 in the second embodiment, the prismatic cell 1 in Figure 4 has an additional third opening 13 in the first cover assembly 3 and a fourth opening 14 in the second cover assembly 4. The prismatic cell 1 can be filled with an electrolyte 9 through the first opening 11 and the third opening 13. The second opening 12 and the fourth opening 14 allow a residual gas 5 to escape from the prismatic cell 1 or to be transported out of the prismatic cell 1.

[0051] The terminal feedthrough 21 is arranged in the first cover assembly 3 and the second cover assembly 4 centrally in the first and second base plates 16, 17 in the direction R1. In the direction R1, the first opening 11 and the third opening 13 are arranged laterally next to the terminal feedthrough 21 in the first base plate, and the second opening 12 and the fourth opening 14 are arranged in the second base plate.

[0052] During the filling process S2, the prismatic cell 1 is preferably oriented vertically, so that the second lid assembly 4 is arranged above the first lid assembly 3 and the electrolyte 9 fills the prismatic cell 1 from bottom to top. Figure 5 shows a detailed view of a prismatic cell 1 according to a fifth exemplary embodiment. The detailed view shows a sectional view of the first opening 11, which is closed by the closure 15. The shape of the first opening 11 and the associated closure 15 can also be combined with the other exemplary embodiments of the invention.

[0053] The closure 15 has a material-locking region 15a and a form-locking region 15b. The material-locking region 15a has a flat-cylindrical shape. The form-locking region 15b adjoining the material-locking region 15a has a conical shape with a recess 15c at the lower end in the filling direction R2.

[0054] The inner contour of the first opening 11 is adapted to the outer contour of the closure 15, so that the closure 15 lies flush with the first opening 11. The upper side of the closure 15 at the material connection area 15a is also arranged flush with the outer side of the first base plate 16.

[0055] The closure 15 is made of the same material as the first base plate 16, in particular plastic, so that the material connection area 15a can form a welded connection 27 with the base plate 16 at its circumference.

[0056] The conical shape of the form-fitting region 15b can be elastically deformed during the closing process S3 and inserted into the first opening 11. After the closure 15 is inserted into the first opening 11, the form-fitting region 15b expands and, in addition to the material connection, forms a form-fitting connection with the first base plate 16.

[0057] In addition to the above written description of the invention, reference is hereby explicitly made to the graphic representation of the invention in the figures for its supplementary disclosure.

Claims

Patent claims 1. Prismatic cell (1), comprising . a housing (2), . a first cover assembly (3) with a first base plate (16), wherein the first cover assembly (3) is arranged to close the housing (2), and . a first opening (11) and a second opening (12) arranged in the first base plate (16), . wherein the first opening (11) is arranged to introduce an electrolyte (9) into the prismatic cell (1), and . wherein the second opening (12) is arranged to convey a residual gas (5) out of the prismatic cell (1).

2. Prismatic cell (1), comprising . a housing (2), . a first cover assembly (3) with a first base plate (16), . a second cover assembly (4) with a second base plate (17), wherein the first cover assembly (3) and the second cover assembly (4) are arranged to close the housing (2), . a first opening (11) arranged in the first base plate (16), and . a second opening (12) arranged in the second base plate (17), . wherein the first opening (11) is arranged to introduce an electrolyte (9) into the prismatic cell (1), and . wherein the second opening (13) is arranged to convey a residual gas (5) out of the prismatic cell (1).

3. Prismatic cell (1) according to claim 1, wherein the first opening (11) in the longitudinal direction (R1) of the first lid assembly (3) is arranged adjacent to a first end of the first base plate (16), and wherein the second opening (12) in the longitudinal direction (R1) is arranged adjacent to a second end of the first base plate (16).

4. Prismatic cell (1) according to claim 2, wherein the first opening (11) is arranged in the longitudinal direction (R1) adjacent to a first end of the first base plate (16) and wherein the second opening (12) is arranged in the longitudinal direction (R1) adjacent to a second end of the second base plate (17).

5. Prismatic cell (1) according to claim 2 or 4, comprising a third opening (13) which is arranged in the first base plate (16) and is designed to introduce an electrolyte into the prismatic cell (1), and / or comprising a fourth opening (14) which is arranged in the second base plate (17) and is designed to convey a residual gas (5) out of the prismatic cell (1).

6. Prismatic cell (1) according to one of the preceding claims, wherein the first opening (11) has a deflection device (18) which is designed to deflect an electrolyte (9) from an introduction direction (R2) which is oriented perpendicular to the first base plate (16) and to introduce it into the prismatic cell (1).

7. Prismatic cell (1) according to one of the preceding claims, wherein the second opening (12) is arranged flush with the base plate (5).

8. Prismatic cell (1) according to one of the preceding claims, wherein the prismatic cell (1) has a polymeric closure (15) which is designed to close the openings (11, 12, 13, 14) in a materially bonded manner.

9. Prismatic cell (1) according to one of the preceding claims, wherein the base plate (16, 17) is made of a plastic.

10. Prismatic cell (1) according to one of the preceding claims, wherein the first opening (11) and / or the second opening (12) are designed as an insert (6) in the base plate (16).

11. A method for filling a prismatic cell (1) according to one of the preceding claims, comprising the steps: - generating (S1) a vacuum in the prismatic cell (1), - filling (S2) the prismatic cell (1) with an electrolyte (9) through a first opening (11), whereby a residual gas (5) escapes from a second opening (12), and - Closing (S3) the first opening (11) and the second opening (12) 12. The method according to claim 11, comprising the step: - filling (S2) the prismatic cell (1) with the electrolyte (9) through a third opening (13), the residual gas (5) escaping from a fourth opening (14), and - Closing (S3) the third opening (13) and the fourth opening (14).

13. The method according to claim 11 or 12, comprising the step: - active removal (S4) of the residual gas (5) from the prismatic cell (1).

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