Function-integrated separator, battery cell including the same, and method for manufacturing the same

Abstract

A separator (1) for spatially and electrically separating electrodes (2, 3) in a battery cell, the separator (1) comprising: a receptacle for at least one galvanic cell comprising an anode (2) and a cathode (3); a structure made of an electrically conductive material for electrically connecting the anode (2) and the cathode (3) to one another and for contacting the at least one galvanic cell from the outside; a channel system (5) for forming a cooling fluid flow in the separator (1); wherein at least the receptacle for the at least one galvanic cell and the channel system are integrally formed in the separator (1). In addition, a battery cell based on the separator according to the invention and a method for producing a separator and a battery cell are provided.

Description

Technical Field

[0001] The invention relates to a functionally integrated separator which, due to its advantageous mechanical and functional properties, can be used in particular for building traction batteries in electric vehicles. Background Art

[0002] With the increasing number of hybrid vehicles and especially electric vehicles, traction batteries play a very important role as energy storage, because the energy storage has a significant influence on the range of the vehicle. Batteries known in the prior art consist of individual cells (e.g. round cells, prismatic hard shell / pouch cells), which are combined into cell modules or directly into battery systems. These batteries consist of at least two individual cells. Cell modules are assembled into battery systems. These battery systems are ultimately installed in vehicles.

[0003] Known battery cells have a cathode and an anode which are spatially separated by a separator. The separator therefore assumes the main task of spatially and thereby simultaneously electrically separating the electrodes from one another and thus avoiding electrical short circuits. For example, the separator can be in the form of a separator foil between the anode and cathode electrodes. Alternatively, there can be a separator for all cells, for example in the case of a separator that is Z-folded for certain cell variants, or the separator can be made in one piece, for example in the case of round cells.

[0004] In the lithium-ion cells that are popular and widely used today, the separator is implemented as a porous foil made of one or more layers of plastic foil. In addition, the separator can be implemented by / with (additional) ceramic components. Summary of the invention

[0005] The object of the present invention is to provide a separator with which a compact and lightweight battery cell can be constructed.

[0006] This object is achieved by means of the method and apparatus described hereinafter. Further embodiments are also defined hereinafter.

[0007] According to the invention, a separator is provided for spatially and electrically separating electrodes in a battery cell. The separator has: a receptacle for at least one galvanic cell comprising an anode and a cathode; and a structure made of a conductive material for electrically connecting the anode and the cathode to each other and for contacting the at least one galvanic cell (galvanischen Zelle) from the outside. The separator also has a channel system for forming a cooling fluid flow in or through the separator. The separator according to the invention is characterized in that at least the receptacle for the at least one galvanic cell and the channel system are formed integrally in the separator.

[0008] The separator according to the present invention is a functionally integrated separator. In addition to the protective function of preventing electrical short circuits between (multiple) anodes and (multiple) cathodes, the functionally integrated separator also has new functions due to the spatial separation of anodes and cathodes, which will be discussed in more detail below.

[0009] The separator according to the invention can be manufactured by means of an additive manufacturing process (e.g. 3D printing). In this case, the separator can be manufactured separately from the at least one galvanic cell that is subsequently used. Preferably, during the manufacturing process of the corresponding battery cell, the separator can be manufactured around the correspondingly arranged cathodes and anodes, so that these cathodes and anodes are integrated / embedded in the separator during the manufacturing process.

[0010] According to different embodiments of the separator, a material or substance may be included in the separator, that is, in the separator structure or "separator frame", which allows the separator to reach its final strength in a delayed curing manner. The curing process can be induced over time or by heat. Therefore, for example, the separator is cured only when the corresponding battery cell is first operated and the heat emitted by the electrode is used. In particular, the curing process may be irreversible, thereby achieving mechanical strength in the final three-dimensional shape of the separator. For example, the delayed curing process can be carried out within a very short time range, which is selected so that the final strength can be reached very quickly, so that, for example, the next material layer can be directly applied in an additive manufacturing process to form a separator structure. However, the delayed curing process can also be carried out within a longer time range, which is selected so that the separator can be made and has an elasticity that is first sufficient to equip the separator with the electrodes of the at least one galvanic cell. Generally, the viscosity of the material used to form the separator can be adjusted so that the separator structure is not combined with the anode and cathode electrodes.

[0011] According to various embodiments of the separator, the separator may have a porosity that allows ion transport. In application, ie in the case of forming a separator structure, the porosity may already be present as a property of the material used to manufacture the separator.

[0012] According to various embodiments of the separator, an evaporable solvent may be contained in the separator. Porosity in the separator structure may also be subsequently produced by evaporating the solvent (eg by means of heat treatment or UV radiation). This applies to both liquid-based electrolytes and solid-state electrolytes.

[0013] According to another embodiment of the separator, the channel system formed in the separator can be formed by a hollow mold arranged in the separator. Here, the hollow mold can be inserted during the manufacture of the separator structure. After the separator structure is solidified, these hollow molds can be dissolved with a solvent to produce the shaped cooling channel / system.

[0014] In the case of a separator with porosity, the hollow mold can, for example, have two layers. The inner layer can be dissolved with a solvent. The outer layer remains and thus produces tightness. Alternatively, after the single-layer hollow mold has been dissolved by a solvent, a sealant can be introduced, which seals the porous openings in the separator at the interface with the dissolved hollow mold. In general, a channel system for a cooling system can be formed in the separator, which has a small number of subcomponents with fewer interfaces, and thus fewer potential leak points.

[0015] When using the separator according to the invention to construct a corresponding battery cell, the separator can mechanically fix other components (such as anode electrodes / anode stacks, busbars, etc.) to ensure mechanical stability in the event of vibrations and impacts in the vehicle. In this case, the separator according to the invention can withstand tension, compression and torsion in all directions due to its one-piece design. However, the material of the separator can preferably have sufficient elasticity in order to be able to compensate for tolerance fluctuations, aging effects or material stresses caused by temperature differences, for example.

[0016] The separator according to the invention may also have reinforcing elements embedded therein (eg metal profiles and / or glass fibers), which are introduced therein during manufacture of the separator in order to achieve a predetermined mechanical strength in the final form or to further increase the predetermined mechanical strength.

[0017] In various embodiments, a battery cell is provided, which has at least one galvanic cell including an anode and a cathode, wherein the at least one galvanic cell is embedded or arranged in the separator according to the present invention described above, so that the at least one galvanic cell can be contacted from the outside by means of a structure made of a conductive material, and the anode and cathode of the at least one galvanic cell are electrically connected to each other, and a cooling circuit can be realized by means of a channel system. In order to form a cooling circuit, the channel system can be coupled to a coolant reservoir and a pump. In general, the battery cell formed in this way can have all the aforementioned spatial structural characteristics of the separator according to the present invention. In a battery cell constructed based on the separator according to the present invention, the separator can surround or contain at least two electrode stacks, which are composed of an anode and a cathode as corresponding galvanic cells. Particularly preferably, the separator can be an integrally associated component for the entire battery system and surrounds all galvanic cells. An integrally associated component can be understood as a component that does not have any conventional joints (at these conventional joints, individual components are joined together by means of gluing, welding, riveting, etc.), but is made integrally during the manufacturing process, for example, by additive manufacturing (for example, by a 3D printing process).

[0018] The battery cells constructed based on the functionally integrated separator according to the invention can be single-electrolyzer cells that are used directly in traction batteries. Existing battery subcomponents known from the prior art, such as cell housings, cell module frames, etc., can be omitted because their functions are taken over by the separator. By using the functionally integrated separator according to the invention, batteries that are smaller, lighter and have lower manufacturing costs than existing batteries can be manufactured. In this case, the existing properties of conventional separators - electrically and spatially separating the electrodes of the primary cell - are not adversely affected by the functional expansion of the separator according to the invention described here. Other components of the conventionally constructed battery (such as electronic devices for monitoring the individual electrode stacks) can also be used as before and can advantageously be directly embedded in the separator and thus mechanically fixed by the separator.

[0019] The busbars that were individually insulated in previously known batteries can also be integrated / embedded in the separator. As a result, less installation space and material are required, making the corresponding battery lighter overall.

[0020] According to the present invention, a method for manufacturing a separator is also provided, the method comprising the step of forming a separator structure by means of an additive process. The step of forming the separator structure comprises: forming a plurality of cavities as a receptacle for at least one galvanic cell comprising an anode and a cathode; forming a structure made of a conductive material for electrically connecting the anode and the cathode to each other and for contacting the at least one galvanic cell from the outside; and forming a channel system for forming a cooling fluid flow in or through the separator. Here, at least the receptacle for at least one galvanic cell and the channel system are integrally formed in the separator. The provided separator may in particular be the separator already described above.

[0021] The structure formed of the conductive material may be manufactured by directly depositing the conductive material during the manufacture of the separator according to the invention or by placing / inserting prefabricated conductive elements at appropriate locations within the separator structure during the manufacture of the separator structure.

[0022] According to a further embodiment of the method, the channel system can be formed by inserting a hollow mold into the separator structure. The hollow mold can be designed in one or two layers and placed in place in the separator structure "under fabrication" during the additive manufacturing process.

[0023] According to a further embodiment of the method, the material of the separator or the separator structure may comprise a material which is cured over a delayed period of time to allow the separator to reach its final strength. This aspect has already been discussed in detail in connection with the properties of the separator according to the invention.

[0024] According to a further embodiment of the method, an evaporable solvent may be included in the material of the separator structure.As mentioned before, in the case of a non-porous separator structure, the porosity may be formed by evaporation of the solvent in the separator structure.

[0025] According to the present invention, a method for manufacturing a battery cell is also provided, which comprises: implementing the method for manufacturing a separator according to the present invention in such a way that when the separator structure is formed by means of an additive process, material is deposited around the anode and cathode of the at least one galvanic cell to replace the cavity. In the same way as the separator structure is formed around the electrodes of the at least one galvanic cell, the above-mentioned other components can be placed in the separator at an appropriate time during the manufacture of the separator according to the present invention and thus embedded in the separator. Therefore, this method for manufacturing a battery cell involves a situation in which the functional elements of the separator (such as electrodes, busbars and pole connections) and the hollow body for forming the channel system are inserted into the separator structure during the manufacture of the separator.

[0026] In general, the present invention discloses the following technical solutions 1, 6, 7 and 11, and the following 2-5 and 8-10 are preferred technical solutions:

[0027] 1. A separator (1) for spatially and electrically separating electrodes (2, 3) in a battery cell, wherein the separator (1) comprises:

[0028] A receiving portion for at least one galvanic cell including an anode (2) and a cathode (3);

[0029] a structure made of an electrically conductive material for electrically connecting the anode (2) and the cathode (3) to one another and for contacting the at least one galvanic cell from the outside;

[0030] a channel system (5) for forming a cooling fluid flow in the separator (1);

[0031] At least the receptacle for the at least one galvanic cell and the channel system are formed integrally in the separator (1).

[0032] 2. The separator (1) according to 1 above,

[0033] The separator comprises a material which is cured over a delayed period of time to allow the separator (1) to reach its final strength.

[0034] 3. The separator (1) according to 1 or 2 above,

[0035] The separator (1) has a porosity to allow ion transmission.

[0036] 4. The separator (1) according to 1 or 2 above,

[0037] The separator (1) contains an evaporable solvent.

[0038] 5. The separator (1) according to any one of 1 to 4 above,

[0039] The channel system (5) is formed by a hollow mold arranged in the separator (1).

[0040] 6. A battery cell having:

[0041] at least one galvanic cell comprising an anode (2) and a cathode (3);

[0042] The at least one galvanic cell is embedded in a separator (1) according to any one of items 1 to 5 above, so that the at least one galvanic cell can be contacted from the outside by means of a structure made of a conductive material, and the anode (2) and cathode (3) of the at least one galvanic cell are electrically connected to each other, and a cooling circuit can be realized by means of the channel system (5).

[0043] 7. A method for manufacturing a separator (1), comprising:

[0044] The separator structure is formed by means of additive manufacturing, including:

[0045] forming a plurality of cavities as a receiving portion for at least one galvanic cell including an anode (2) and a cathode (3);

[0046] forming a structure made of an electrically conductive material for electrically connecting the anode and the cathode to each other and for externally contacting the at least one galvanic cell;

[0047] forming a channel system (5) for forming a cooling fluid flow in the separator (1);

[0048] At least the receptacle for the at least one galvanic cell and the channel system (5) are formed integrally in the separator.

[0049] 8. The method according to item 7 above,

[0050] The channel system (5) is formed by inserting a hollow mould into the separator structure.

[0051] 9. The method according to 7 or 8 above,

[0052] The material of the separator structure comprises a delayed curing material to enable the separator (1) to reach its final strength.

[0053] 10. The method according to any one of 7 to 9 above,

[0054] The material of the separator structure contains an evaporable solvent.

[0055] 11. A method for manufacturing a battery cell, comprising:

[0056] The method for manufacturing a separator (1) according to any one of the above 7 to 10 is implemented in such a way that when the separator structure is formed by means of an additive process, material is deposited around the anode and cathode of the at least one galvanic cell to replace the cavity.

[0057] It goes without saying that the features mentioned above and the features still to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Further advantages and embodiments of the invention are apparent from the entirety of the description and the drawings.

[0059] Figure 1 A cross-sectional view of an embodiment of a functionally integrated separator is shown. DETAILED DESCRIPTION

[0060] Figure 1 A cross-sectional view of an embodiment of a functionally integrated separator 1 is shown. Only a partial area of ​​the separator 1 is shown here, wherein in addition to the separator 1, two electrodes 2, 3 of a galvanic cell are shown, namely an anode 2 and a cathode 3. The figure illustrates the basic principle according to which a corresponding battery cell can be constructed on the basis of the separator 1 according to the invention. The two electrodes are embedded in the separator 1. The curing of the substance / material 4 contained in the separator material is irreversible, so that the separator 1 reaches its mechanical strength in its final three-dimensional final shape after a predetermined time.

[0061] Furthermore, lines 5 for liquid cooling of the electrodes 2, 3 are provided in the separator 1. As already described, these lines can be formed by inserting corresponding one or two-layer hollow profiles into the structure of the separator during the manufacture of the separator. Furthermore, busbars 6 embedded in the separator 1 are shown. Depending on the desired design, the same poles of the galvanic cells within the battery cell are connected in series or in parallel with each other by means of busbars 6, which, due to their properties, are able to transmit greater currents.

Claims

1. A separator (1) for spatially and electrically separating electrodes (2, 3) in a battery cell, wherein the separator (1) comprises: A receiving portion for at least one galvanic cell including an anode (2) and a cathode (3); a structure made of an electrically conductive material for electrically connecting the anode (2) and the cathode (3) to one another and for contacting the at least one galvanic cell from the outside; a channel system (5) embedded in the separator and used to form a cooling fluid flow in the separator (1); wherein at least the receptacle for the at least one galvanic cell and the channel system are integrally formed in the separator (1); wherein the separator further comprises a bus bar embedded in the separator and formed integrally with the separator; and The one-piece structure of the separator is formed by means of an additive process.

2. The separator (1) according to claim 1, The separator comprises a material which is cured over a delayed period of time to allow the separator (1) to reach its final strength.

3. The separator (1) according to claim 1 or 2, The separator (1) has a porosity to allow ion transmission.

4. The separator (1) according to claim 1 or 2, The separator (1) contains an evaporable solvent.

5. The separator (1) according to claim 1 or 2, The channel system (5) is formed by a hollow mold arranged in the separator (1).

6. A battery cell having: at least one galvanic cell comprising an anode (2) and a cathode (3); The at least one galvanic cell is embedded in a separator (1) according to any one of claims 1 to 5, so that the at least one galvanic cell can be contacted from the outside by means of a structure made of a conductive material, and the anode (2) and cathode (3) of the at least one galvanic cell are electrically connected to each other, and a cooling circuit can be realized by means of the channel system (5).

7. A method for manufacturing a separator (1), comprising: The separator is formed into an integrated structure by means of additive manufacturing, including: forming a plurality of cavities as a receiving portion for at least one galvanic cell including an anode (2) and a cathode (3); forming a structure made of an electrically conductive material for electrically connecting the anode and the cathode to each other and for externally contacting the at least one galvanic cell; forming a channel system (5) embedded in the separator and used to form a cooling fluid flow in the separator (1); wherein at least the receptacle for the at least one galvanic cell and the channel system (5) are integrally formed in the separator; and A busbar is formed which is embedded in the separator and formed integrally with the separator.

8. The method according to claim 7, The channel system (5) is formed by inserting a hollow mould into the separator structure.

9. The method according to claim 7 or 8, The material of the separator structure comprises a delayed curing material to enable the separator (1) to reach its final strength.

10. The method according to claim 7 or 8, The material of the separator structure contains an evaporable solvent.

11. A method for manufacturing a battery cell, comprising: The method for manufacturing a separator (1) according to any one of claims 7 to 10 is implemented in such a way that when the separator structure is formed by means of an additive process, material is deposited around the anode and cathode of the at least one galvanic cell to replace the cavity.

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