Cover assembly, energy-storage cell, battery module, and method for filling an energy-storage cell

Abstract

The invention relates to a cover assembly (140) for a cell housing (110) of an energy-storage cell (100). In the installed state, the cover assembly (140) is designed to allow the cell housing (110) to be filled with an electrolyte (190). The cover assembly (140) has a terminating plate (120) with a securing assembly (200) which has an opening region (220). A first gas barrier (240) is designed to close the opening region (220) in a gas-tight manner prior to the process of filling the cell housing (110) and to be penetrated by a filling element, in order to fill the cell housing (110), such that an opening (221), through which the electrolyte (190) can be filled into the cell housing (110), is formed in the first gas barrier (240). Additionally, a second gas barrier (250) is designed to close the opening (221) in a gas-tight manner after the process of filling the cell housing (110).

Description

[0001] COVER ASSEMBLY, ENERGY STORAGE CELL, BATTERY MODULE AND METHOD FOR FILLING AN ENERGY STORAGE CELL

[0002] The present description relates to a cover assembly, an energy storage cell, a battery module and a method for filling an energy storage cell.

[0003] State of the art

[0004] Electrochemical storage cells such as lithium-ion cells often have to be transported over long distances after their production. For example, the transport of lithium-ion cells must be subject to international transport regulations, including the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR), the International Maritime Code (IMDG), the Regulations relating to the Transport of Dangerous Goods (DGR) of the International Air Transport Association (IATA), and the United Nations Manual of Tests and Criteria related to the Transport of Dangerous Goods. The transport regulations contain provisions for the labeling, packaging, documentation, handling, and storage of lithium-ion cells during transport to ensure their safety. Cells can sometimes be difficult to transport, especially if they have not yet received release approval (e.g., according to UN 38).3). On the other hand, additional built-in elements (such as temperature sensors) invalidate the approval and complicate transport by air or across national borders. Lithium-ion cells filled with electrolyte (development samples), in particular, can contain construction defects and are therefore considered potentially dangerous. As a result, such cells cannot always be transported cost-effectively, or at least not usually, and special packaging requirements are placed on them.

[0005] State-of-the-art electrochemical storage cells are usually filled with electrolyte immediately after assembly and then sealed. Dry cells must be protected from the ingress of air and moisture by complex transport packaging until they are filled. Figure 6 shows a cover assembly 140 from the prior art. The cover assembly 140 has a closure plate 120 with a groove 210 running around a longitudinal axis L. The end plate 120 further has a fastening assembly 200 with an opening 220 that is arranged substantially centrally with respect to the end plate 120. The fastening assembly 200 is arranged symmetrically to a longitudinal axis L. The fastening assembly 200 comprises a first support ring 201 arranged on one side of the end plate 120 and a second support ring 203 arranged on another side of the end plate 120, opposite the first side.The opening 220 is closed with a membrane 230.

[0006] The membrane 260 can be pierced using a filling tool, and then an electrolyte 190 can be filled into the cell housing 110. After filling and removing the filling tool from the cell housing 110 and the membrane 260, the membrane 260 essentially closes. This closure prevents large amounts of the electrolyte 190 from escaping from the cell housing 110. Particularly with electrolytes 190 whose boiling point is below room temperature, deposition can occur. However, the sealing of the membrane 260 is only sufficient for the filling process. During operation of the battery cell 100, a stable and permanent closure is required. Therefore, a cover is additionally provided, which is attached to the fastening arrangement 200 in a gas-tight manner.

[0007] A new cell design that protects the cell from air and moisture after assembly and allows for subsequent filling with electrolyte would need to be developed to simplify and improve storage and transportation processes. This could also significantly reduce the costs of packaging and transporting dry, non-electrolyte-filled cells and improve the efficiency and sustainability of the production of lithium-ion cells and similar electrochemical storage cells.

[0008] It is an object of the present description to provide a cover assembly, an energy storage cell, a battery module, and a method for filling an energy storage cell that simplify and improve the storage and transport processes of electrochemical energy storage cells.

[0009] These objects are achieved by a cover assembly, an energy storage cell, a battery module, and a method for filling an energy storage cell having the features of the independent and subordinate patent claims. Advantageous embodiments and further developments of the invention are set forth in the dependent claims. Summary

[0010] It is understood below that each feature described with respect to any embodiment may be used alone or in combination with other features described herein, and may be used in combination with one or more features of any other embodiment, or in any combination of any other embodiment, unless explicitly described as an alternative. Furthermore, equivalents and modifications not described below may be used without departing from the scope of the claimed subject matter.

[0011] The following describes a cover assembly for a cell housing of an energy storage cell. According to one embodiment, the cover assembly, when installed, is configured to enable filling of the cell housing with an electrolyte. The cover assembly comprises a cover plate with a fastening assembly, which also has an opening region. Furthermore, the cover assembly comprises a first and a second gas barrier.

[0012] The first gas barrier is designed to seal the opening area in a gas-tight manner before filling the cell housing. A filling element penetrates the opening to fill the cell housing, creating an opening in the first gas barrier. The electrolyte can be poured into the cell housing through this opening. The second gas barrier is designed to seal the opening in a gas-tight manner after filling the cell housing.

[0013] The second gas barrier is designed, for example, to close a filling opening in the first gas barrier created by filling the cell housing. The cell housing can be filled through the first gas barrier and, for this purpose, can be pierced and / or penetrated, for example, by a filling element comprising a hollow needle. This forms a filling opening in the first gas barrier, which, due to material properties, can close at least partially, but possibly not completely. An optional septum can at least partially close the filling opening, so that leakage of electrolyte from the cell housing after the filling process is prevented or at least delayed. The cell housing can then be finally sealed by the second gas barrier, for example by (laser) welding, crimping, or other mechanical connections (e.g., screw connections).

[0014] An electrochemical storage cell refers below to an electrochemically based energy storage device, in particular a rechargeable energy storage device, which is suitable for storing electrical energy and delivering it to a consumer, for example, a consumer in a vehicle. The concept proposed here can be used for various storage cells, for example, lithium-ion batteries. In the following, the term "lithium-ion battery" is used synonymously for all terms commonly used in the art for lithium-containing galvanic elements and cells, such as lithium battery, lithium cell, lithium-ion cell, lithium-polymer cell, lithium-ion battery cell, and lithium-ion accumulator.

[0015] Sodium-ion batteries can also be used. The term “sodium-ion battery” is used synonymously for all terms commonly used in the prior art for sodium-containing galvanic elements and cells, such as sodium battery, sodium cell, sodium ion cell, sodium polymer cell, sodium ion battery cell, and sodium ion accumulator. The aspects presented in this description are not limited to specific types of galvanic elements and cells, but can be used for lithium, magnesium, and sodium-ion batteries, among others. For example, types that have SO2 as an electrolyte can be used. In particular, rechargeable batteries, so-called secondary batteries, are included. The terms “battery” and “electrochemical cell” are used synonymously with the terms “lithium-ion battery” and “lithium-ion cell,” respectively.“Sodium ion battery” and “sodium ion cell” are used.

[0016] The term "electrolyte" refers to a liquid or solid material through which ions can be conducted, enabling current to be transported between the electrodes of a battery, particularly between a cathode and an anode. Unlike electronic conductivity (through electrons) in the electrode materials, the electrolyte must be ionically conductive, i.e., conduct electrical current by transporting charged atoms or molecules (ions). The electrolyte is advantageously chemically stable over a wide temperature range and electrochemically stable against decomposition over the largest possible voltage range. Ideally, it is non-toxic and non-flammable, or at least has a high flash point and low heat of combustion. For example, the electrolyte is liquid under operating conditions, e.g., SO2 as an electrolyte.

[0017] The concept proposed here is based, among other things, on the considerations presented below. The disadvantages of the state of the art described above are based, on the one hand, on the fact that electrochemical storage cells are usually filled with electrolyte immediately after assembly and then sealed. The transport of such cells is generally complex and cost-intensive. Dry cells that are not yet filled with electrolyte can in principle be transported more easily, but until now they have had to be protected from the ingress of air and moisture by complex transport packaging until they are filled. Another aspect is that when dry cells are used to stock spare parts, they do not age because they have not been electrically activated. This also saves costs for air conditioning and recharging, and dry cells can be exposed to greater temperature fluctuations than activated cells.

[0018] One aspect proposes transporting assembled cells dry and equipping them with a special cell seal that prevents moisture from penetrating the cells during transport or storage. The new cell seal provides for cells to be filled with electrolyte, formed, and then sealed only at the location of their intended use or filling. A gas barrier is provided for this purpose, effectively and long-term protecting the cell casing from external influences (e.g., moisture). This allows the cell to be stored for almost any length of time and, when empty, can be easily transported and stored cost-effectively, as it does not have to be declared as hazardous material.

[0019] The proposed lid assembly makes it possible to transport electrochemical storage cells, lithium-ion cells, without having to meet strict hazardous goods requirements or provide complex packaging. This means that series cells and experimental cells can be transported easily by land, air or water. Furthermore, costly temperature control during transport, as is required for active cells to prevent aging at uncontrolled high temperatures, is no longer necessary. The low effort involved reduces transport costs. Know-how can also be secured if, for example, the electrolyte is not to be disclosed to the cell manufacturer. Furthermore, it can be useful to stock cells after the end of production (EoP) and only activate them when needed. The advantage here is that dry cells do not age and do not need to be temperature-controlled during storage.

[0020] According to one embodiment, a septum is arranged between the first and second gas barriers in the opening region. The septum is designed to be penetrated by the filling element for filling the cell housing. Furthermore, the septum is designed to close the opening region after the cell housing has been filled. For example, the septum is made of an elastic material. This ensures that no or only relatively little electrolyte or solvent escapes at the point where the filling element penetrates the septum.

[0021] According to one embodiment, the first gas barrier and the end plate are formed as a single piece. The end plate has a smaller thickness in the region of the first gas barrier. The smaller thickness is selected or configured to seal the opening area gas-tight before filling the cell housing and to be penetrated by the filling element for filling the cell housing in such a way that the (filling) opening is formed in the first gas barrier, through which the electrolyte can be filled into the cell housing.

[0022] According to one embodiment, the first gas barrier and the end plate are designed separately. The first gas barrier is inserted into the opening region of the end plate. For example, the end plate has a region into which the first gas barrier can be inserted and fixed. The first gas barrier is designed to seal the opening region in a gas-tight manner before filling the cell housing and to be penetrated by the filling element for filling the cell housing in such a way that the opening is formed in the first gas barrier through which the electrolyte can be filled into the cell housing.

[0023] According to one embodiment, the first gas barrier comprises a foil. The foil is arranged on a side of the septum facing the cell housing. A foil is preferably understood to be any thin, flat structure, for example made of plastic, rubber, metal or other materials or a combination of two or more different materials, which has a large flat area in relation to its thickness. This makes it possible to achieve, on the one hand, good sealing of the opening and, on the other hand, good penetrability of the first gas barrier. According to one embodiment, the first gas barrier comprises, for example, a metal and / or a metal foil. According to one embodiment, the end plate further comprises a circumferential groove. The circumferential groove is designed to enable the end plate to be broken open in the region of the groove.This happens, for example, when a certain overpressure has been reached or exceeded in the cell casing, allowing at least partial escape of the electrolyte through the broken area.

[0024] When the cover assembly is installed, if a certain pressure in the cell casing is reached or exceeded, the cover plate can break in the area of ​​the circumferential groove. This prevents the initial pressure in the cell casing from increasing further. This preferably achieves a controlled, directed, and therefore safe pressure relief. The cover assembly thus not only enables reliable and safe electrolyte filling under normal conditions, but also serves to relieve any excess pressure that may occur in the cell, for example, as a result of excessive heating caused by internal cell short circuits.

[0025] According to one embodiment, the end plate has a support ring in the region of the first gas barrier. The support ring is designed to receive and secure the second gas barrier. The support ring serves as the mechanical connection to the second gas barrier.

[0026] Furthermore, an energy storage cell is proposed. According to one embodiment, the energy storage cell comprises a cell housing and two electrodes arranged in the cell housing. Furthermore, the energy storage cell comprises a cover assembly according to one or more of the aspects discussed above. The cover assembly is attached to the cell housing, thus closing the cell housing.

[0027] Furthermore, a battery module is proposed. The battery module comprises a plurality of energy storage cells according to one or more of the aspects discussed above.

[0028] Furthermore, a motor vehicle with an electric drive or a hybrid drive and a battery module according to an aspect discussed above is proposed.

[0029] Furthermore, a method for producing an energy storage cell is proposed. According to one embodiment, a cell housing is first provided. A cover assembly is produced with a cover plate by structuring a workpiece with a fastening assembly having an opening region. A first gas barrier is provided and is configured to seal the opening region in a gas-tight manner before the cell housing is filled. It is further configured to be penetrated by a filling element for filling the cell housing such that an opening is formed in the first gas barrier, through which opening the electrolyte can be filled into the cell housing.

[0030] According to one embodiment, a second gas barrier is provided which is designed to close the opening in a gas-tight manner after filling the cell housing.

[0031] Furthermore, a method for transporting an energy storage cell is proposed. According to one embodiment, an energy storage cell is first manufactured according to one or more of the above-mentioned aspects. The manufactured energy storage cell is then transported from the production site to a site of further use of the energy storage cell. The transport can take place without electrolyte having already been filled into the energy storage cell.

[0032] Furthermore, a method for filling an energy storage cell is proposed. The energy storage cell can be manufactured and / or transported according to the method described above. According to one embodiment, the first gas barrier is penetrated by a filling element, wherein an opening is formed in the first gas barrier by the filling element. Furthermore, the cell housing is filled with electrolyte, and for this purpose, the filling element is guided through the opening. Finally, the opening is sealed gas-tight by means of a second gas barrier.

[0033] In the following, exemplary embodiments of the invention are described with reference to the accompanying drawings. Further details, preferred embodiments, and further developments emerge from them. Identical or similarly functioning components are provided with the same reference numerals in the figures. The illustrated components and their relative sizes are not to be considered to scale. To the extent that components and parts in the various figures have the same function, their description is not necessarily repeated for each of the following figures.

[0034] Brief description of the drawings Showing in detail:

[0035] Figure 1 shows an embodiment of a battery cell,

[0036] Figure 2A, 2B an embodiment of a cover assembly,

[0037] Figures 3A - 3D show an embodiment of a method for producing a cover assembly,

[0038] Figures 4A - 4C show an embodiment of a method for filling an energy storage cell,

[0039] Figures 5A, 5B show another embodiment of a cover assembly, and

[0040] Figure 6 shows an embodiment of a cover assembly from the prior art.

[0041] Detailed description

[0042] Figure 1 schematically illustrates a battery cell 100 according to one embodiment. The battery cell 100 has a hollow cylindrical cell housing 110 (round cell) with a longitudinal axis L. The cell housing 110 can also be cuboid-shaped. The cell housing 110 has, for example, an electrically conductive material for contacting. However, it is also conceivable for the cell housing 110 to have an electrically insulating material. The cell housing 110 is closed on one side by a base plate 130. On a side opposite the base plate 130, the cell housing 110 is closed by a cover assembly 140. The cover assembly 140 has a cover plate 120. The area shown in dashed lines in the figure is described in more detail in the following figures.

[0043] The end plate 120 is arranged in a circumferential groove of the cell housing 110, with an electrically insulating element 150 arranged between the end plate 120 and the groove, which electrically insulates the end plate 120 from the cell housing 110. In addition, the electrically insulating element 150 acts gas-tight, so that the cell housing 110 can be sealed gas-tight with the cover assembly 140. The opening of the groove points in the direction of the longitudinal axis L.

[0044] However, it is also conceivable that no electrically insulating element 150 is arranged between the closure plate 120 and the groove. This can be useful if the cell housing 110 comprises an electrically insulating material. Furthermore, it is conceivable that an electrode of one polarity is passed through the base plate 130 of the cell housing 110, wherein the feedthrough is electrically insulated from the cell housing 110 and is also integrated into the base plate 130. In this case, too, the cover can be directly connected to the cell housing 110, in particular crimped or welded.

[0045] An electrode winding 160 (also called an electrode coil or "jelly roll") is arranged in the cell housing 110. The electrode coil 160 has electrodes with a first, positive polarity 170 and electrodes with a second, negative polarity 175. However, the electrode coil 160 can also be designed such that the first polarity is negative and the second polarity is positive. The electrode coil 160 is arranged in the cell housing 110 such that electrodes with a positive polarity 170 and electrodes with a negative polarity 175 are arranged alternately in the radial direction. A separator 180 is arranged between each of the electrodes with a positive polarity 170 and the electrodes with a negative polarity 175, so that the electrodes with different polarities 170, 175 are electrically insulated from one another, wherein the separator 180 comprises an electrically insulating material. Furthermore, an electrolyte 190 with a certain fill level is schematically shown in the cell housing 110.The electrolyte 190 is filled into the cell housing 110 through the lid assembly 140 (indicated as a dashed area).

[0046] Figures 2A and 2B show an embodiment of a cover assembly. The cover assembly 140 has a cover plate 120. The cover plate 120 has a groove 210 running circumferentially with respect to the longitudinal axis L of the cell housing 110 (see Figure 1). The groove 210 has a triangular cross-section. The cross-section can also have a semicircle, a rectangle, or another shape. The cover plate 120 has a smaller thickness in the region of the groove 210 than the thickness of the cover plate 120 during its manufacture and can therefore be broken open more easily in these areas. The cover plate 120 has a fastening assembly 200 with an opening region 220 arranged substantially centrally with respect to the cover plate 120. The fastening assembly 200 is arranged symmetrically to the longitudinal axis L (see Figure 1).

[0047] The fastening arrangement 200 comprises an opening region 220. In the opening region 220, the end plate 120 has a first gas barrier 240. In this exemplary embodiment, the gas barrier 240 and the end plate 120 are integral and made of the same material. The first gas barrier 240 is designed as a region of the end plate 120 that has a smaller thickness than the thickness outside the opening region 220. The end plate 120 is, in a sense, thinned out in the opening region 220. The smaller thickness is selected such that a filling element 300 can penetrate or pierce it to fill the cell housing 110.

[0048] The end plate 120 also has a recess 202 in the opening region 220. The recess 202 in the end plate 140 is configured to receive a septum 230. The septum 230 is configured to be penetrated by the filling element 300 for filling the cell housing 110 and to close the opening region 220 after the cell housing 110 has been filled. For example, the septum 230 comprises an elastic material into which the filling element 300 can be injected. The septum 230 closes automatically after the filling element 300 is withdrawn. The fastening arrangement 200 further comprises a support ring 201 arranged on an upper side of the end plate 120. The septum 230 is arranged in the support ring 201 and is fixed thereby. In contrast to the first gas barrier 240, the septum 230 is not completely gas-tight.

[0049] The battery cell 100 can be configured for storage and transport in a first state (see Figure 2A). In this state, the cell is assembled but not filled with electrolyte. The cover assembly 140 shown in Figure 2A can be mounted on the cell housing 110 and seals it. In the first state, the first gas barrier 240 is intact, i.e., not penetrated or punctured by a filling element, and seals the cell in a gas-tight manner. Optionally, the septum 230 is arranged in the support ring 201 or the recess 202 and additionally seals the cell.

[0050] During operation of the battery cell 100, a stable and permanent closure is required. Therefore, in a second state (or operating state), the battery cell 100 can additionally be supplemented with a second gas barrier 250 (for example, a lid), which can be made of metal (see Figure 2B). The septum 230 is arranged between the first and second gas barriers 240, 250 in the opening region 220. The septum 230 may not be completely gas-tight, so that gas and / or electrolyte 190 could escape during operation of the battery cell 100. The second gas barrier 250 enables a gas-tight closure of the cell housing 110, so that gas cannot escape via the septum 230. The attachment of the second gas barrier 250 to the support ring 201 is preferably formed with a material fit and is carried out, for example, by welding, such as laser or ultrasonic welding.

[0051] In an alternative embodiment, the first gas barrier 240 can be implemented separately from the end plate 120. For example, the first gas barrier 240 is implemented in an opening of the end plate 120 in the opening region 220 or connected thereto. Alternatively, the first gas barrier 240 can also be implemented on a surface of the septum 230, for example, as a foil. Preferably, the first gas barrier in the various embodiments is made of metal, a metal alloy, or a metal composite.

[0052] Figures 3A to 3D schematically show exemplary manufacturing states of a cover assembly.

[0053] In a first step, an unmachined workpiece is provided (see Figure 3A). The workpiece 121 forms the base for the end plate 120 with a longitudinal axis L, shown in a side view. In the side view of the end plate 120, the longitudinal axis L runs substantially perpendicular to the end plate 120 (not shown).

[0054] In a next step, the workpiece is structured to form the end plate 120 (see Figure 3B). For this purpose, the opening region 220 is introduced into the workpiece, for example by milling notches and shapes. For example, the recess 202 is provided to accommodate the septum 230. In particular, the end plate 120 is structured substantially centrally such that the first gas barrier 240 is formed. For this purpose, the substantially central region of the end plate 120 is designed such that it has a smaller thickness than the thickness outside the opening region. The end plate 120 is, in a sense, thinned out in the opening region 220. The smaller thickness is selected such that a filling element 300 can penetrate or pierce it to fill the cell housing 110.The end plate 120 can be used as a cover of a battery cell and can permanently protect the cell interior against external influences, whereby the first gas barrier 240 seals the cell 100 in a gas-tight manner.

[0055] Optionally, the end plate 120 can be structured with a groove 210 extending circumferentially relative to the longitudinal axis L of the cell housing 110 (see Figure 1). The groove 210 has, for example, a triangular cross-section. The cross-section can also have a semicircle, a rectangle, or another shape. The end plate 120 has a smaller thickness in the area of ​​the groove 210 than the thickness of the original workpiece 121 and can therefore break open more easily in these areas.

[0056] In the next step, the septum 230 is inserted into the recess 202 (see Figure 3C). The septum 230 protects the battery cell 100 after filling with electrolyte 190 against the ingress of air and moisture and prevents the evaporation of the electrolyte solvent.

[0057] In a next step, a first support ring 201 is attached to one side of the opening area 220 (see Figure 3D). The attachment is preferably carried out by a material bond, for example, by welding, such as laser or ultrasonic welding. The first support ring 201 is arranged axially symmetrically to the longitudinal axis L. The circumferential groove 210 is arranged radially further outward with respect to the longitudinal axis L than the first support ring 201. The arrangement shown in Figure 3D corresponds to the arrangement in Figure 2A.

[0058] Alternatively or additionally, it is conceivable that, instead of the support ring 203, the fastening assembly 200 is formed in one piece and forms a circumferential groove. The groove is open at one section so that the septum 230 can be arranged in the groove.

[0059] In a further step (see Figure 4C), the opening region 220 is closed by the second gas barrier 250, which rests on the first support ring 201 in the opening region 220. This step only occurs after the energy storage cell 100 has been filled with electrolyte 190. This can occur, for example, after the energy storage cell 100 has been transported from a manufacturing site to a site of first use.

[0060] Figures 4A to 4C schematically show an embodiment of a method for filling an energy storage cell 100. In a first step (see Figure 4A), the first gas barrier 240 (and, if present, the septum 230) is penetrated by a filling element 300, for example, by a hollow needle. The insertion of the needle pierces the gas barrier 240. This creates an opening (filling opening 221) in the end plate 120, through which the electrolyte 190 can be filled into the cell housing 110.

[0061] In a next step, the cell is first evacuated and then filled with the electrolyte 190 (see Figure 4B).

[0062] In a further step (see Figure 4C), the cell 100 is sealed gas-tight. For this purpose, the second gas barrier 250 is arranged on the support ring 201 and welded to it, e.g., using a laser or ultrasound, or mechanically connected in some other way. Alternatively, the second gas barrier 250 can have a screw thread and be screwed to the support ring 201. This allows for subsequent refilling of electrolyte 190 and / or solvent, e.g., to extend the service life of the cell.

[0063] Figures 5A and 5B schematically show an operation of the fastening assembly 200.

[0064] During normal operation (see Figure 5A), the end plate 120 is connected to the cell casing 110 of the battery cell 100 and forms a gas-tight seal around the cell 110. In the event of a safety incident, the end plate 120 can break open in the area of ​​the groove 210, breaking out a portion of the end plate 120. This allows gases to escape the cell 100, reducing excess pressure and / or critical temperatures.

[0065] Although the above description has been illustrated and described in detail using exemplary embodiments, it is not limited by the exemplary embodiments. Rather, other variations of the description may be derived therefrom by those skilled in the art without departing from the scope of protection defined by the claims.

[0066] 100 battery cells

[0067] 110 cell casings

[0068] 120 end plate

[0069] 121 Workpiece

[0070] 122 Part of the end plate

[0071] 130 base plate

[0072] 140 cover assembly,

[0073] 150 Insulating element

[0074] 160 electrode coils

[0075] 170 electrodes with positive polarity

[0076] 175 electrodes with negative polarity

[0077] 180 Separator

[0078] 190 Electrolyte

[0079] 200 mounting arrangement

[0080] 201 first support ring

[0081] 202 recess

[0082] 203 second support ring

[0083] 210 groove

[0084] 220 opening area, opening

[0085] 221 Filling opening

[0086] 230 Septum

[0087] 231 Filling opening

[0088] 240 first gas barrier

[0089] 250 second gas barrier

[0090] 260 membrane

[0091] 300 filling element

Claims

1. A cover assembly (140) for a cell housing (110) of an energy storage cell (100), wherein the cover assembly (140) is configured in the installed state to enable filling of the cell housing (110) with an electrolyte (190), wherein the cover assembly (140) comprises: - an end plate (120) with a fastening assembly (200) having an opening area (220); - a first gas barrier (240) which is designed to close the opening region (220) in a gas-tight manner before filling the cell housing (110) and to be penetrated by a filling element (300) for filling the cell housing (110) in such a way that an opening (221) is formed in the first gas barrier (240), through which the electrolyte (190) can be filled into the cell housing (110); and - a second gas barrier (250) which is designed to close the opening (221) in a gas-tight manner after the cell housing (110) has been filled.

2. The cover assembly according to claim 1, wherein - a septum (230) is arranged between the first and second gas barriers (240, 250) in the opening region (220), and - the septum (230) is designed to be penetrated by the filling element (300) for filling the cell housing (110) and is designed to close the opening region (220) after filling the cell housing (110).

3. The cover assembly according to any one of the preceding claims, wherein - the first gas barrier (240) and the end plate (120) are made in one piece and - the end plate (120) has a smaller thickness in the region of the first gas barrier (240), which is designed to close the opening region (220) in a gas-tight manner before the cell housing (110) is filled and to be penetrated by the filling element (300) for filling the cell housing (110) in such a way that the opening (221) is formed in the first gas barrier (240), through which opening the electrolyte (190) can be filled into the cell housing (110).

4. The cover assembly according to any one of the preceding claims, wherein - the first gas barrier (240) and the end plate (120) are designed separately from each other and - the first gas barrier (240) is inserted into the opening area (220) of the end plate (120).

5. The lid assembly according to any one of the preceding claims, wherein the first gas barrier (240) comprises a foil and the foil is arranged on a side of the septum (230) facing the cell housing (110).

6. The lid assembly according to any one of the preceding claims, wherein the first gas barrier (240) comprises a metal and / or a metal foil.

7. The cover assembly (140) according to any one of the preceding claims, wherein - the end plate (120) further comprises a circumferential groove (210), and - the circumferential groove (210) is designed to enable the end plate (120) to be broken open in the region of the groove (210) when a certain overpressure has been reached or exceeded in the cell housing (110), so that at least partial escape of the electrolyte (190) through the broken open region is made possible.

8. The lid assembly (140) according to any one of the preceding claims, wherein the end plate (120) has a support ring (201) in the region of the first closure element (230), and the support ring (201) is configured to receive and fix the second gas barrier (250).

9. An energy storage cell (100) comprising: - a cell housing (110); - two electrodes (170, 175) arranged in the cell housing (110); - a lid assembly (140) according to any one of the preceding claims, wherein the lid assembly (140) is attached to the cell housing (110) so that the cell housing (110) is closed.

10. A battery module with a plurality of energy storage cells (100) according to claim 9.

11. A method for manufacturing an energy storage cell (100), comprising the steps of: - providing a cell housing (110), - producing a cover assembly (140) with a cover plate (120) by - a workpiece is structured with a fastening assembly (200) having an opening area (220), and - a first gas barrier (240) will precede it, which is designed to close the opening region (220) in a gas-tight manner before the cell housing (110) is filled and to be penetrated by a filling element (300) for filling the cell housing (110) in such a way that an opening (221) is formed in the first gas barrier (240), through which opening the electrolyte (190) can be filled into the cell housing (110).

12. The method according to claim 11, wherein a second gas barrier (250) is provided which is configured to close the opening (221) in a gas-tight manner after filling the cell housing (110).

13. A method for transporting an energy storage cell (100), comprising the steps of: - producing the energy storage cell (100) according to claim 11, and - Transporting the energy storage cell (100) from the place of manufacture to a place of further use of the energy storage cell (100).

14. A method for filling an energy storage cell (100) manufactured according to claim 11 and / or transported according to claim 13; the method comprising the steps: - penetration of the first gas barrier (240) by a filling element (300), wherein the filling element (300) forms an opening (221) in the first gas barrier (240), - filling the cell housing (110) with electrolyte (190) by means of the filling element (300) through the opening (221), and - gas-tight closure of the opening (221) by means of a second gas barrier (250).

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