Prismatic battery cell with two openings

Abstract

The invention relates to a prismatic battery cell composed of a housing and at least one cover assembly with a base plate. The prismatic battery cell has a first opening and a second opening arranged in at least one of the base plates. Here, the first opening is configured to introduce an electrolyte into the prismatic battery cell. The second opening is configured to discharge residual gases from the prismatic battery cell.

Description

Technical Field

[0001] This invention relates to a prismatic battery cell and a method for injecting electrolyte into the prismatic battery cell. Background Technology

[0002] Currently, prismatic battery cells have only a single electrolyte filling port. This allows for the injection of liquid electrolyte while simultaneously removing gases present within the cell during the filling process. However, because the stacking or windings of prismatic battery cells employ a layered structure, with electrodes and separators forming microporous, highly compressed porous layers, introducing electrolyte into the porous structure is a slow process. Removing air from the pores is similarly slow; during this process, the presence of non-porous guide plates in the layered structure forces fluid to flow parallel to each layer, potentially leading to backflow between gas and electrolyte. This can result in residual air bubbles within the battery cell after the filling process. Furthermore, removing air bubbles between the cell stacks or windings and the inner wall of the casing is also crucial.

[0003] In current prismatic battery cells, the cover assembly is made of a metal substrate. The liquid injection port is located in the substrate. After the battery cell is filled and molded, the liquid injection port is sealed using a metal seal. During this sealing process, the possibility of metal particles being released into the battery cell's internal cavity cannot be completely ruled out. These metal particles cannot be detected through conventional quality control methods, but may trigger a critical state (internal short circuit) during the battery cell's operation. Attaching multiple liquid injection ports exacerbates this risk. Summary of the Invention

[0004] The purpose of this invention is to provide an improved prismatic battery cell and an improved method for manufacturing the prismatic battery cell, while ensuring simple manufacturing and low cost.

[0005] The solution of the present invention to achieve the above-mentioned objective is a prismatic battery cell having the features of claims 1 and 2 and a method for manufacturing a prismatic battery cell having the features of claim 11.

[0006] The dependent claims specify preferred improvements of the invention.

[0007] According to the present invention, the prismatic battery cell includes a housing and a first cover assembly having a first substrate. Here, the first cover assembly is configured to seal the housing. Furthermore, the prismatic battery cell includes a first opening and a second opening disposed in the first substrate. Here, the first opening is configured to introduce electrolyte into the prismatic battery cell. The second opening is configured to evacuate the battery cell before electrolyte dosing and to discharge residual gas from the prismatic battery cell. Thus, electrolyte can be introduced into the prismatic battery cell simultaneously, and residual gas displaced by the electrolyte can be discharged from the prismatic battery cell, thereby improving the filling speed of the prismatic battery cell. Here, residual gas removal and electrolyte dosing can also be performed in a pulsating manner, thereby enabling faster electrolyte injection into the battery cell.

[0008] It is also conceivable that the residual gas removal process (e.g., by changing the pressure) and the dosing process (pressure, flow rate; medium temperature) can be variably adjusted. By introducing a first opening and a second opening in the first substrate, a prismatic battery cell with only one cover assembly can be easily constructed. The first cover assembly preferably includes terminal posts, enabling electrical contact of the prismatic battery cell. The prismatic battery cell is preferably a prismatic rechargeable battery cell.

[0009] Furthermore, the present invention relates to a prismatic battery cell, comprising a housing, a first cover assembly having a first substrate, and a second cover assembly having a second substrate, wherein the first cover assembly and the second cover assembly are configured to enclose the housing. Here, a first opening is arranged in the first substrate, and a second opening is arranged in the second substrate. The first opening is configured to introduce electrolyte into the prismatic battery cell. The second opening is configured to evacuate the battery cell and / or expel residual gas from the prismatic battery cell before electrolyte dosing. Preferably, the first cover assembly is fastened to the housing of the prismatic battery cell in a manner parallel to the second cover assembly. Thus, the housing can be made of a simple profile component. By introducing the first opening in the first substrate and the second opening in the second substrate, a continuous electrolyte filling process can be achieved, which in particular shortens the electrolyte filling process for elongated prismatic battery cells (i.e., so-called "blade" battery cells). The prismatic battery cell is preferably a prismatic rechargeable battery cell.

[0010] The various subjects of this invention share a common inventive concept: a prismatic battery cell comprising a first opening and a second opening. Here, the first opening is configured to introduce electrolyte into the prismatic battery cell. The second opening is configured to exhaust residual gas from the prismatic battery cell. Preferably, the openings are made of plastic.

[0011] Prismatic battery cells may include energy storage devices in the form of batteries or supercapacitors.

[0012] Preferably, the first opening is arranged longitudinally adjacent to a first end of the first substrate in the first cover assembly, and the second opening is arranged longitudinally adjacent to a second end of the first substrate. By arranging the first and second openings in the first substrate with the maximum spacing in this way, a continuous liquid injection process is facilitated, allowing residual gas to escape from the prismatic battery cell as completely as possible.

[0013] Optionally, the first opening is preferably arranged longitudinally adjacent to the first end of the first substrate, and the second opening is arranged longitudinally adjacent to the second end of the second substrate. Thus, during the liquid injection process, the prismatic battery cell can be oriented such that the first opening is arranged in the region with the lowest possible position in the direction of gravity, and the second opening is arranged in the region with the highest possible position in the direction of gravity, so that residual gas can be discharged from the prismatic battery cell as completely as possible, and a continuous liquid injection process can be achieved.

[0014] More preferably, the prismatic battery cell further includes a third opening, which is disposed in the first substrate and configured to introduce electrolyte into the prismatic battery cell. The additional third opening accelerates the electrolyte injection process and enables uniform introduction of electrolyte. Particularly preferably, the prismatic battery cell includes a fourth opening, which is disposed in the second substrate and configured to allow residual gas to escape from the prismatic battery cell. The additional fourth opening accelerates the electrolyte injection process and enables uniform venting of residual gas.

[0015] Preferably, the first opening has a deflection device configured to deflect the electrolyte from an introduction direction perpendicular to the first substrate and introduce it into the prismatic battery cell. The deflection device enables targeted introduction of the electrolyte into the prismatic battery cell, thereby preventing cavitation in the separator electrode stack or at the boundary layer between the stack and the inner wall of the battery cell casing.

[0016] More preferably, the second opening is flush with the substrate, especially on the inner side of the substrate. This allows residual gas to be replaced by the electrolyte as completely as possible and escape through the second opening.

[0017] Particularly preferably, the prismatic battery cell has a polymer seal configured to close the opening in a material-fitting manner. The polymer seal is preferably bonded or welded to a first substrate or a second substrate.

[0018] Preferably, the polymer closure further closes the opening in a form-fitting manner. Thus, the polymer closure enables reliable sealing of the battery chemistry inside the prismatic battery cell relative to the external environment.

[0019] The substrate is preferably made of plastic. Therefore, the risk of metal or conductive particles being released during the liquid injection or opening sealing process is extremely low, thereby minimizing the probability of cell failure due to such particles.

[0020] The first opening and / or the second opening are preferably disposed as inserts in the substrate. This enables the low-cost and rapid manufacture of prismatic battery cells without requiring extensive assembly work.

[0021] Furthermore, the first opening and / or the second opening are preferably integrated into the substrate, for example, as openings in an injection molded part.

[0022] The present invention also describes a method for injecting electrolyte into the aforementioned prismatic battery cell. For this purpose, a vacuum is created within the prismatic battery cell. "Vacuum" refers to a pressure below atmospheric pressure. The pressure within the prismatic battery cell is particularly between 100 and 200 millibars. This ensures that the electrolyte does not evaporate during injection. Electrolyte is injected into the prismatic battery cell through a first opening, while residual gas escapes from a second opening. Subsequently, the first and second openings are sealed. Here, injection can be performed continuously or in multiple steps, for example, injection and residual gas removal can be performed alternately. This allows, for example, the generation of pressure pulses during injection, thereby actively removing air bubbles from the battery cell casing. Various injection methods are also conceivable, in which parameters such as volumetric flow rate, pressure, and temperature are changed during electrolyte dosing, and parameters such as pressure and volumetric flow rate are changed during residual gas extraction.

[0023] In this regard, it is also conceivable that the injection device is sealed to the first opening, or the aspiration device is sealed to the second opening. This can be accomplished, for example, by attaching a seal to the dispensing system or the substrate.

[0024] It is also conceivable that the first and second openings have different dimensions (e.g., diameters).

[0025] It is also conceivable that a sensor be attached to the second opening, which can detect when the electrolyte flows out of the opening, thereby determining whether the electrolyte injection process has been completed.

[0026] More preferably, in the method, electrolyte is injected into the prismatic battery cell through the third opening, wherein residual gas escapes from the fourth opening.

[0027] Subsequently, the third and fourth openings were also sealed. This allows for faster and more targeted liquid injection into the prismatic battery cells.

[0028] Particularly preferably, in the method, residual gas is actively removed. Preferably, electrolyte is injected and residual gas is vented simultaneously. This increases the filling speed and improves control over the injection process. Residual gas can be actively removed, for example, using a pump. Attached Figure Description

[0029] For further details, advantages, and features of the present invention, please refer to the accompanying drawings and specific embodiments below. In the figures: Figure 1 A schematic perspective view of a prismatic battery cell according to a first embodiment is shown; Figure 2 A schematic perspective view of a prismatic battery cell according to a second embodiment is shown; Figure 3 A schematic cross-sectional view of a prismatic battery cell according to a third embodiment is shown; Figure 4 A schematic perspective view of a prismatic battery cell according to a fourth embodiment is shown; and Figure 5 A schematic detail view of the first opening is shown. Detailed Implementation

[0030] The following reference Figure 1 The prismatic battery cell 1 according to the first embodiment and the method for manufacturing the prismatic battery cell 1 will be described in detail below.

[0031] Figure 1 A perspective view of a prismatic battery cell is shown, illustrating a prismatic rechargeable battery cell. The prismatic battery cell 1 includes a housing 2 enclosed by a first cover assembly 3. The housing 2 is preferably made of aluminum and is connected to the first cover assembly 3 in a material-fit manner.

[0032] The first cover assembly 3 has a first substrate 16. The first substrate 16 is an injection-molded part made of plastic, in which additional inserts 6 are integrated. Preferably, a metal frame is connected to the first substrate 16 in a form-fit, force-fit, and / or material-fit manner, so that the first cover assembly 3 can be welded to the housing 2 via the metal frame.

[0033] A burst zone 22 is centrally arranged on the longitudinal direction R1 of the first cover assembly 3. In the event of battery cell failure, the burst zone 22 can be opened by pressure activation and / or temperature activation to allow battery chemicals to leave the prismatic battery cell 1.

[0034] In the first end region and the second end region, feedthrough terminals 21 are integrated as inserts 6 into the first substrate 16 of the first cover assembly 3 along the longitudinal direction R1. The feedthrough terminals 21 preferably have different polarities and are capable of achieving electrical contact between the prism-shaped battery cells 1.

[0035] In the first substrate 16, a first opening 11 is arranged on one side of the burst zone 22 and the feedthrough electrode 21 along the longitudinal direction R1 between the burst zone 22 and the feedthrough electrode 21, and a second opening 12 is arranged on the opposite side of the burst zone 22. The first opening 11 is configured to introduce electrolyte 9 into the prismatic battery cell 1 in the electrolyte injection step S2. The second opening 12 is configured to allow residual gas 5 to escape or be discharged from the prismatic battery cell 1.

[0036] Therefore, the prismatic battery cell 1 can be filled with electrolyte as follows: Step S1, a vacuum is created in the prismatic battery cell 1. Step S2, electrolyte 9 is injected into the prismatic battery cell 1 through the first opening 11, wherein residual gas 5 can escape from the second opening 12. Step S4, residual gas 5 can also be actively discharged from the prismatic battery cell 1. Finally, step S3, the first opening 11 and the second opening 12 are closed.

[0037] Figure 1 The diagram shows a prismatic battery cell 1 filled with electrolyte 9, wherein both the first opening 11 and the second opening 12 are closed by a closure 15. The closure 15 is made of plastic and is welded to a first substrate 16. Particularly reliable welding can be achieved if the substrates 16, 17 and the closure 15 are made of the same material.

[0038] Figure 2 A prismatic battery cell 1 according to a second embodiment is shown, the prismatic battery cell being designed as an elongated prismatic rechargeable battery 1. The prismatic battery cell 1 has a first cover assembly 3 and a second cover assembly 4 arranged parallel to each other. Here, the first cover assembly 3 is arranged at a first end in the liquid injection direction R2, while the second cover assembly 4 is arranged at a second end in the liquid injection direction R2. Here, the liquid injection direction R2 is perpendicular to the surface orientation of the first substrate 16.

[0039] The first cover assembly 3 includes a first substrate 16 made of plastic, in which a feed post 21 and a first opening 11 are arranged. The second cover assembly 4 has a similar configuration to the first cover assembly 3 and includes a second substrate 17 made of plastic, in which another feed post 21 and a second opening 12 are arranged.

[0040] The burst zone 22 of the prismatic battery cell 1 is laterally integrated into the housing 2.

[0041] The first opening 11 is arranged near the lower end in direction R1. The second opening 12 is arranged near the upper end in direction R1. Thus, electrolyte 9 can be injected into the lower region of the prismatic battery cell 1 through the first opening 11, while residual gas 5 present in the prismatic battery cell 1 can escape or be discharged from the second opening 12 located above.

[0042] Figure 3 A cross-sectional view of a prismatic battery cell 1 according to a third embodiment is shown. Figure 3 The prismatic battery cell 1 in this embodiment is the same as the battery cell 1 in the first embodiment, wherein the first opening 11 is arranged adjacent to the first end in the longitudinal direction R1, and the second opening is arranged adjacent to the second end in the longitudinal direction R1. A first feed post 21a is arranged between the first opening 11 and the explosion zone 22, and a second feed post 21b is arranged between the explosion zone 22 and the second opening 12.

[0043] The first feed post 21a is connected to the negative electrode 7 inside the prismatic cell 1, thus forming the anode. The second feed post 21b is connected to the positive electrode 8 inside the prismatic cell 1, thus forming the cathode. The negative electrode 7 and the positive electrode 8 are arranged in parallel layers and separated from each other by the electrolyte 9.

[0044] The first substrate 16 of the first cover assembly 3 is connected to the housing 2 via a welding connection 27 in a material-fitting manner. The first opening 11 and the second opening 12 are provided in the form of inserts 6. Here, the first opening 11 is connected to the first substrate 16 in a dovetail shape. The second opening 12 is connected to the first substrate 16 in an inverted snap-fit ​​manner.

[0045] The first opening 11 has a deflection device 18 that deflects the electrolyte 9 from the introduction direction R2 and laterally introduces it into the prismatic battery cell 1 towards the housing 2. This allows the electrolyte 9 to be introduced into the prismatic battery cell 1 in a targeted manner, reducing the risk of cavitation.

[0046] The second opening 12 is flush with the first substrate 16, whether it is inside or outside the prismatic battery cell 1. Therefore, when the second opening 12 is oriented upward, the residual gas 5 can escape or be discharged from the prismatic battery cell 1 as completely as possible.

[0047] Figure 4 A prismatic battery cell 1 according to a fourth embodiment is shown. The prismatic battery cell 1 is illustrated as a prismatic rechargeable battery cell 1 and is identical to the prismatic battery cell 1 of the second embodiment.

[0048] Compared to the prismatic battery cell 1 in the second embodiment, Figure 4 The prismatic battery cell 1 has an additional third opening 13 in the first cover assembly 3 and an additional fourth opening 14 in the second cover assembly 4. Electrolyte 9 can be injected into the prismatic battery cell 1 through the first opening 11 and the third opening 13. The second opening 12 and the fourth opening 14 allow residual gas 5 to escape from or be discharged from the prismatic battery cell 1.

[0049] In the first cover assembly 3 and the second cover assembly 4, the feed post 21 is centrally arranged in the first substrate 16 and the second substrate 17 in the direction R1. In the direction R1, a first opening 11 and a third opening 13 are arranged in the first substrate on the side of the feed post 21, and a second opening 12 and a fourth opening 14 are arranged in the second substrate.

[0050] In the electrolyte injection process S2, the prismatic battery cell 1 is preferably vertically oriented so that the second cover assembly 4 is arranged above the first cover assembly 3, and the electrolyte 9 is filled into the prismatic battery cell 1 from bottom to top.

[0051] Figure 5 A detailed view of the prismatic battery cell 1 according to a fifth embodiment is shown. This detailed view shows a cross-sectional view of the first opening 11, which is closed by a closure 15. The shapes of the first opening 11 and the associated closure 15 can also be combined with other embodiments of the invention.

[0052] The closure 15 has a material-fitting region 15a and a shape-fitting region 15b. The material-fitting region 15a is cylindrical. The shape-fitting region 15b adjacent to the material-fitting region 15a is conical and has a recess 15c at its lower end in the injection direction R2.

[0053] The inner profile of the first opening 11 matches the outer profile of the closure 15 so that the closure 15 is flush with the first opening 11. The upper side of the closure 15 at the material mating area 15a is also flush with the outer side of the first substrate 16.

[0054] The closure 15 and the first substrate 16 are made of the same material, especially plastic, so that the material mating area 15a can form a welded connection 27 with the substrate 16 along its circumference.

[0055] During the closing process S3, the conical shape of the form-fitting region 15b can undergo elastic deformation and be inserted into the first opening 11. After the closing member 15 is introduced into the first opening 11, the form-fitting region 15b will expand and, in addition to the material fit connection, will also form a form fit connection with the first substrate 16.

[0056] In addition to the foregoing textual description of the invention, reference is made here to the accompanying drawings for further explanation.

Claims

1. A prismatic battery cell (1), the prismatic battery cell (1) comprising: •Shell (2); • A first cover assembly (3) having a first substrate (16), wherein the first cover assembly (3) is configured to close the housing (2); and • A first opening (11) and a second opening (12) arranged in the first substrate (16). • Wherein, the first opening (11) is configured to introduce electrolyte (9) into the prismatic battery cell (1), and •The second opening (12) is configured to discharge residual gas (5) from the prismatic battery cell (1).

2. A prismatic battery cell (1), the prismatic battery cell (1) comprising: •Shell (2); • First cover assembly (3) with first substrate (16); • A second cover assembly (4) with a second substrate (17), wherein the first cover assembly (3) and the second cover assembly (4) are configured to close the housing (2). • A first opening (11) disposed in the first substrate (16); and • A second opening (12) is arranged in the second substrate (17). • Wherein, the first opening (11) is configured to introduce electrolyte (9) into the prismatic battery cell (1), and •The second opening (12) is configured to discharge residual gas (5) from the prismatic battery cell (1).

3. The prismatic battery cell (1) according to claim 1, wherein, The first opening (11) is arranged in the longitudinal direction (R1) of the first cover assembly (3) adjacent to the first end of the first substrate (16), and the second opening (12) is arranged in the longitudinal direction (R1) adjacent to the second end of the first substrate (16).

4. The prismatic battery cell (1) according to claim 2, wherein, The first opening (11) is arranged in the longitudinal direction (R1) adjacent to the first end of the first substrate (16), and the second opening (12) is arranged in the longitudinal direction (R1) adjacent to the second end of the second substrate (17).

5. The prismatic battery cell (1) according to claim 2 or 4, comprising: A third opening (13) is disposed in the first substrate (16) and configured to introduce electrolyte into the prismatic battery cell (1); and / or includes a fourth opening (14) disposed in the second substrate (17) and configured to discharge residual gas (5) from the prismatic battery cell (1).

6. The prismatic battery cell (1) according to any one of the preceding claims, wherein, The first opening (11) has a deflection device (18) configured to deflect the electrolyte (9) from an introduction direction (R2) perpendicular to the first substrate (16) and introduce it into the prismatic battery cell (1).

7. The prismatic battery cell (1) according to any one of the preceding claims, wherein, The second opening (12) is arranged to be flush with the substrate (16).

8. The prismatic battery cell (1) according to any one of the preceding claims, wherein, The prismatic battery cell (1) has a polymer closure (15) configured to close the opening (11, 12, 13, 14) in a material-fit manner.

9. The prismatic battery cell (1) according to any one of the preceding claims, wherein, The substrates (16, 17) are made of plastic.

10. The prismatic battery cell (1) according to any one of the preceding claims, wherein, The first opening (11) and / or the second opening (12) are disposed in the substrate (16) as inserts (6).

11. A method for injecting electrolyte into a prismatic battery cell (1) according to any one of the preceding claims, the method comprising the following steps: - A vacuum (S1) is generated in the prismatic battery cell (1); - Electrolyte (9) is injected (S2) into the prismatic battery cell (1) through the first opening (11), wherein residual gas (5) escapes from the second opening (12); as well as - Close (S3) the first opening (11) and the second opening (12).

12. The method according to claim 11, wherein the method comprises the following steps: - Electrolyte (9) is injected (S2) into the prismatic battery cell (1) through the third opening (13), wherein the residual gas (5) escapes from the fourth opening (14); as well as - Close (S3) the third opening (13) and the fourth opening (14).

13. The method according to claim 11 or 12, wherein the method comprises the following steps: - The residual gas (5) is actively discharged (S4) from the prismatic battery cell (1).

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