A cylindrical battery cell for a battery module of a motor vehicle, a battery module, and a method

Abstract

A cylindrical battery cell 12 for a battery module (10, Figure 1) of a motor vehicle, comprising a cell housing 14 containing a plurality of layers 18 arranged adjacent to one another in an axial dire

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. Most specifically, the present invention relates to a cylindrical battery cell for a battery module of a motor vehicle. Furthermore, the present invention relates to a corresponding battery module for a motor vehicle and a method for manufacturing a corresponding cylindrical battery cell. BACKGROUND INFORMATION

[0002] In the state of the art, solid-state battery modules comprise several battery cells. However, solid-state battery technology may require high and uniform pressure to operate. The need for a pressure-applying device may be a challenge to apply solid-state battery technology in battery electric vehicles due to added weight and complexity. Furthermore, conventional designs of solid-state batteries using pouch or prismatic cells may require external features to apply and hold the required operational pressure. Another key issue with solid-state batteries or quasi solid-state batteries may deal with a difficulty in manufacturing large areas of electrode and solid electrolyte sheets to enable large scale battery cells. SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a cylindrical battery cell for a battery module of a motor vehicle, a battery module for a motor vehicle, as well as a method for manufacturing a cylindrical battery cell for a battery module of a motor vehicle, by which the battery module with the cylindrical cells can be manufactured with particularly improved effort.

[0004] This object is solved by a cylindrical battery cell for a battery module of a motor vehicle, a corresponding battery module for a motor vehicle, as well as a method for manufacturing a corresponding cylindrical battery cell for a battery module of a motor vehicle according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0005] One aspect of the present invention relates to a cylindrical battery cell for a battery module of a motor vehicle. Preferably, the motor vehicle is designed as a passenger car. Preferably, the motor vehicle is a battery electric vehicle (BEV) or a hybrid vehicle, in particular a plug-in hybrid vehicle (PHEV). The said solid-state battery cells may be understood as an electrical battery that uses a solid electrolyte for ionic conductions between electrolytes, for example instead of liquid or gel polymer electrolytes found in conventional batteries. The solid-state battery cell may be a cylindrical battery cell with a cylindrical shape.

[0006] The cylindrical battery cell comprises a cell housing, which at least partially defines a receiving space. In other words, the cell housing forms the said receiving space. Preferably, the receiving space extends within the said cell housing at least partially, in particular completely. The said receiving space may be referred to as housing space or storage space. Furthermore, the cylindrical battery cell comprises at least one, in particular pressurized, layered structure arranged in the receiving space. This means that the layered structure is located within the said cell housing. The said layered structure may be referred to as disc stack or disc stack design.

[0007] In particular, to manufacture the battery module with the cylindrical cells with particularly improved effort, for example to pressurize the said layered structure in a particularly effortless manner, the said layered structure comprises a plurality of layers arranged adjacent to one another in the axial direction of the battery cell. In other words, are the layers of the layered structure located adjacent to each other in axial direction of the cylindrical battery cell. This means that the layers are stacked in the said axial direction. The layers each comprise a respective cathode layer, a respective solid-state electrolyte layer and a further layer. The respective solid-state electrolyte layer is arranged in the axial direction of the cylindrical battery cell between the respective cathode layer and the respective further layer. In other words, the respective cathode layer is located on a first side of the respective solid-state electrolyte layer and the respective further layer is located on a second side of the respective solid-state electrolyte layer, wherein the said sides are different from each other, and are in particular facing away from each other. Preferably the said sides are facing away from each other.

[0008] In the present invention, it may be possible to circumvent the need of an external pressure applying device, whereby the present invention may allow the use a solid-state battery cell in cylindrical cell format. The present invention may allow the use of the same cylindrical pack architecture used in numerous conventional lithium-ion batteries and may simplify cell-to-pack-of-cell-to-chassis implementation in solid-state batteries. Pressures may be monitored on an individual cell level during manufacturing for better quality control, optimized pressure application depending on the thickness, design of electrodes and chemistries, as well as process tolerances. Furthermore, a difficulty known from the state of the art in manufacturing large areas of electrode and solid electrolyte sheets to enable large scale battery cells may be solved by the present invention, as pristine areas may be punched out for use, thus improving quality.

[0009] The present invention may also enable a use of bipolar design of solid-state battery in a cylindrical cell format without the need to produce long lengths of solid-state electrodes or electrolytes as the actual dimensions are limited to the diameter of the cylindrical cell. A main advantage of the invention may be a simplification of a pressure application process for solid-state batteries. The proposed design of the cylindrical battery cell and / or a proposed method for manufacturing the cylindrical battery cell may enable the application of solid-state battery technology into cylindrical cells. Implication and the vision of the required pressures involved into individual cylindrical cell level may negate a need for a complex and heavy, in particular an external, pressure applying device. This may reduce overall battery weight in electric vehicles, thereby improving efficiency and making solid-state battery technology a more realistic technology to adapt in electric vehicle format.

[0010] According to an embodiment, the respective further layer is an anode layer. The said anode layer may be referred to as anode.

[0011] In another embodiment, the respective further layer is a facilitating layer, which is in particular made of silver carbon or silicon. As a result, the battery cell may be designed anode-less.

[0012] In another embodiment, the cylindrical battery cell comprises at least one lid, which at least partially defines the said receiving space in the axial direction of the cylindrical battery cell, wherein the layered structure is pressurized via the lid. In other words, the said receiving space is formed at least partially by the lid in axial direction of the cylindrical battery cell, wherein the lid is capable of pressurizing or pressurizes the layered structure arranged in the receiving space. This means that the layered structure is capable of being mechanically impacted or is mechanically impacted by the lid in order to generate the said pressure or pressurization, respectively. This may allow the layered structure to be pressurized with reduced effort.

[0013] In another embodiment, the cell housing comprises at least one wall defining the said receiving space in radial direction of the cylindrical battery cell and a cover element extending perpendicularly to the said wall, wherein the said cover element is arranged in the axial direction of the cylindrical battery cell on an outer side of the said lid. This means that the said receiving space is formed by the said wall in radial direction of the battery cell and the cover element is arranged, in particular, directly at the lid such that the lid is located between the layered structure and the cover element, wherein the cover element protrudes perpendicular to the wall. As a result, the layered structure may be pressurized via the cover element, which may impact the lid mechanically in order to impact the layered structure via the lid. This may allow the layered structure to be pressurized with reduced effort.

[0014] In another embodiment, the said cover element and the said wall are integrally formed as a single piece. This means that the cover element and the lid are formed in one piece, for example from a monobloc. This may enable the battery cell to be produced at particularly lower cost.

[0015] In another embodiment, the said cover element is made by flanging, in particular from the said wall. In other words, the cover element is manufactured or is produced by crimping. In particular, the wall can be treated by flanging in order to form the cover element from a part of the wall by flanging. This may enable the battery cell to be produced at particularly lower cost. In addition, the pressure for the layered structure can be generated with reduced effort.

[0016] In another embodiment, the said cover element and the said wall are formed separately from each other, and are in particular welded together. This means that the cover element and the lid may be joined together by welding. This may enable the battery cell to be produced at particularly lower cost.

[0017] Another aspect of the present invention relates to a battery module for a motor vehicle, comprising at least the cylindrical battery cell according to the first aspect of the invention. Preferably, the battery module comprises several ones of the cylindrical battery cells according to the first aspect of the invention. Advantageous embodiments of the solid-state battery module are to be regarded as advantageous embodiments of the battery module with one or more cylindrical battery cells.

[0018] Another aspect of the present invention relates to a method for manufacturing a cylindrical battery cell for a battery module of a motor vehicle according to the first aspect of the invention. Advantageous embodiments of the method are to be regarded as advantageous embodiments of the cylindrical battery cell and the battery module, which may be incorporated in a battery pack. The layers are arranged adjacent to one another in the axial direction of the battery cell in the receiving space, whereby the layer structures are formed. In other words, the receiving space is filled with the layers by stacking the layers on top of each other in the axial direction of the battery cell to form the said layered structure.

[0019] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0021] The drawings show in:

[0022] Fig 1 a schematic sectional view of an embodiment of a battery module;

[0023] Fig. 2 a schematic sectional view of an embodiment of a cylindrical battery cell; and

[0024] Fig. 3 several schematic sectional views of an embodiment of a cylindrical battery cell for illustrating an embodiment of a method for manufacturing the cylindrical battery cell.

[0025] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0026] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0027] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0028] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0029] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0030] Fig 1 shows a schematic sectional view according to an embodiment of a battery module 10 for a motor vehicle. Preferably, the motor vehicle comprises the battery module 10. The motor vehicle is preferably at least in part electrically operated or fully electrically operated. Therefore, the motor vehicle may comprise at least one electric motor. Preferably, the electric motor is supplied with energy by the battery module 10. The said battery module 10 comprises several cylindrical battery cells 12. A respective one of the said cylindrical battery cells 12 is shown in Fig. 2 in a schematic sectional view.

[0031] The cylindrical battery cell 12 comprises a cell housing 14, which at least partially defines a receiving space 16. The said cell housing 14 is shaped cylindrical at least partially, in particular completely. Furthermore, the said cylindrical battery cell 12 comprises a layered structure 20, which is arranged in the said receiving space 16. Preferably, the said layered structure 20 is pressurized. This means that the battery module 10, in particular the cylindrical battery cell 12, may comprise at least one pressure supply device, which is capable of pressurizing or pressurizes the said layered structure 20.

[0032] In order to produce the cylindrical battery cell 12, in particular the battery module 10, in a particularly improved manner, the layered structure 20 comprises a plurality of layers 18. In other words, the said layered structure 20 comprises several layers 18. In Fig. 2, four ones of the said layers 18 are shown as an example. The layers 18 are arranged adjacent to one another in an axial direction 24 of the cylindrical battery cell 12. In other words, the layers 18 are arranged next to one another in the axial direction 24 of the cylindrical battery cell 12. The layers 18 each comprise a respective cathode layer 26, a respective solid-state electrolyte layer 28 and a respective further layer 30. The respective cathode layer 26 may be referred to as cathode. The respective solid-state electrolyte layer 28 may be referred to as solid electrolyte. The respective solid-state electrolyte layer 28 is arranged in the axial direction 24 of the cylindrical battery cell 12 between the respective cathode layer 26 and the respective further layer 30. Preferably, the respective further layer 30 is a respective anode layer 32.

[0033] In the example shown in Fig. 2, the respective solid-state electrolyte layer 28 is arranged above the further layer 30 in upright direction of the battery module 10. And the respective cathode layer 26 is arranged above the respective solid-state electrolyte layer 28, in particular above the respective further layer 30, in the upright direction of the battery module 10. Alternatively, it is possible that the respective solid-state electrolyte layer 28 is arranged above the respective cathode layer 26 in upright direction of the battery module 10 and the respective further layer 30 is arranged above the respective solid-state electrolyte layer 28, and in particular above the respective cathode layer 26, in the upright direction of the battery module 10. Preferably, the said upright direction of the battery module 10 is parallel to a vehicle upright direction of the motor vehicle. It becomes clear that a disc stack design, in particular a final disc stack design of the layered structure 20, may be a cathode - solid electrolyte - anode or anode - solid electrolyte -cathode depending on the design.

[0034] As an alternative to the embodiment with the anode layer 32, the respective further layer 30 may be a facilitating layer, which is in particular made of silver carbon or silicon. This means that the anode can be replaced with a facilitating layer For example the facilitating layer may include Ag-C, silicon, or another comparable material if the design of the cylindrical battery cell 12 is to be an anode-less design.

[0035] In the present example, the cylindrical battery cell 12 comprises a lid 34, which at least partially defines the said receiving space 16 in the axial direction 24. Preferably, the said lid 34 is formed separately from the cell housing 14. As can be seen in Fig. 2, the said lid 34 is arranged on top of the layered structure 20. Preferably, the layered structure 20 is pressurized via the lid 34, in particular by the lid 34. This means that the said pressurization of the layered structure 20 is at least partially generated by the lid 34. Thus, the said pressure supply device may be formed at least partially by the said lid 34. In other words, the pressure supply device may comprise the said lid 34 or may use the said lid 34, in order to generate the afore-mentioned pressurization. The lid 34 may also be referred to as cylindrical can lid.

[0036] In the example shown in Fig. 2, the cell housing 14 comprises a wall 36 defining the said receiving space 16 in the radial direction 38 of the cylindrical battery cell 12. For example, the cell housing 14 comprises a floor element 40, which is connected with the said wall 36. Furthermore, the cell housing 14 comprises a cover element 42 extending perpendicularly to the wall 36. The cover element 42 is arranged in the axial direction 24 on an outer side 44 of the lid 34. This means that the lid 34 is arranged between the layered structure 20 and the cover element 42. Preferably, the lid 34 is pressurized via the said cover element 42, in particular by the said cover element 42, in order to generate the said pressurization of the layered structure 20. Thus, the said pressure supply device may be formed at least partially by the said lid 34 and the said cover element 42. In other words, the pressure supply device may comprise the lid 34 and the cover element 42 or the pressure supply device may use the lid 34 and the cover element 42, in order to generate the aforementioned pressurization.

[0037] According to an embodiment, the cover element 42 and the wall 36 are integrally formed as a single piece, wherein the cover element 42 is preferably made by flanging. The said flanging may also be referred to as crimping.

[0038] According to another embodiment, the cover element 42 and the wall 36 are formed separately from each other, and are for example welded together.

[0039] It becomes clear that the lid 34 can be fixed using the crimping method and / or another comparable method, and there may be a welding of an additional lid to hold the overall disc stack in the required dimension, in particular under pressure. The cylindrical cell housing 14 and / or the crimping fixture and / or the welded lid design may be such as to accommodate the changes in pressure as a direction response to charge and discharge of the cylindrical battery cell 12.

[0040] Based on measured characteristics, for example thickness, porosity, electro density, etc., a compression of stacked components of the cylindrical battery cell 12, in particular the layered structure 20, may be tuned within a given tolerance, to help maintain optimum pressure ranges despite potential deviation in the characteristics. For example, an optimum pressure range generated by the pressure supply device is for example in a range from 0 MPa to 30 MPa. The cover element 42 and or the lid 34 may be a part of the said pressure supply device.

[0041] For example, additional structural support may be provided via the use of at least one, in particular external, module frame of the battery module 10 to further provide robustness with respect to pressure. The said module frame may be designed as a, in particular external, bus bar 46. The said module frame may also be referred to as external pack frame. Preferably, the battery cells 12 are connected electrically to each other via the said bus bar 46. In the example shown in Fig. 1, the battery module 10 comprises two bus bars 46, 48, wherein a first one of the said bus bars 46 is arranged on an upper side of the battery module 10 and the second one of the bus bars 48 is arranged on a lower side of the battery module 10. Thus, the battery cells 12 can be fixed onto at least one of the bus bars 46, 48, for example in addition with a pack-module frame, to provide further support to maintain optimum pressure. The respective bus bar 46, 48 may be referred to as conductor rail.

[0042] In the example shown in Fig. 1, the battery module 10 comprises a bottom pressure plate 50 and a top pressure plate 52, wherein the said pressure plates 50, 52 are connected to each other via side fixture plates 54. The pressure plates 50, 52 are arranged on different sides of the battery cells 12 in the axial direction 24 of the battery cells 12. Preferably, the said pressure plates 50, 52, 54 are capable of pressurizing or pressurize the respective layered structure 20 of the respective battery cell 12 via the respective cover element 42 and the respective lid 34. This means that the said pressure plates 50, 52, 54 may be a part of the said pressure supply device. In other words, the pressure supply device may comprise the pressure plates 50, 52, 54.

[0043] Fig. 3 illustrates a method for manufacturing the respective cylindrical battery cell 12 of the battery module 10. Preferably, at the beginning the cell housing 14 or the receiving space 16, respectively, is empty. The layers 18 are arranged adjacent to one another in the axial direction 24 of the battery cell 12 in the receiving space 16 or the cell housing 14, respectively. The lid 34 may be arranged on top of the layered structure 20 arranged in the receiving space 16. After that, the layered structure 20 arranged in the receiving space 16 may be pressurized via the lid 34. This is illustrated by an arrow 56. For this purpose, is the lid 34 for example impacted by an object 58. The cover element 42 may be formed by flanging or crimping, respectively. Alternatively, the cover element 42 is welded together with the walls 36 of the cell housing 14. Preferably, the cover element 42 comprises an opening 60. The said object 58 can be passed through the opening 60 in order to pressurize the layered structure 20 via the cover element 42.

[0044] It becomes clear that the present invention may provide a solid-state cylindrical cell design and a process, in order to manufacture the said solid-state cylindrical cell design. Signs battery module cylindrical battery cell cell housing receiving space layer layered structure axial direction cathode layer solid-state electrolyte layer further layer anode layer lid wall radial direction floor element cover element outer side first bus bar second bus bar bottom pressure plate top pressure plate side pressure plate arrow object opening

Claims

1. A cylindrical battery cell (12) for a battery module (10) of a motor vehicle, comprising a cell housing (14) which at least partially defines a receiving space (16), and a layered structure (20) arranged in the receiving space (16), characterized in thatthe layered structure (20) comprises a plurality of layers (18) arranged adjacent to one another in the axial direction (24) of the cylindrical battery cell (12), wherein the layers (18) each comprise a respective cathode layer (26), a respective solid-state electrolyte layer (28), and a respective further layer (30), and wherein the respective solid-state electrolyte layer (28) is arranged in the axial direction (24) of the cylindrical battery cell (12) between the respective cathode layer (26) and the respective further layer (30).

2. The cylindrical battery cell (12) according to claim 1, characterized in thatthe respective further layer (30) is an anode layer (32).

3. The cylindrical battery cell (12) according to claim 1, characterized in thatthe respective further layer (30) is a facilitating layer, which is in particular made of silver-carbon or silicon.

4. The cylindrical battery cell (12) according to any one of claims 1 to 3, characterized in thatthe cylindrical battery cell (12) comprises a lid (34), which at least partially definesthe receiving space (16) in the axial direction (24), wherein the layered structure(20) is pressurized via the lid (34).

5. The cylindrical battery cell (12) according to claim 4, characterized in thatthe cell housing (14) comprises a wall (36) defining the receiving space (16) in the radial direction (38) of the cylindrical battery cell (12) and a cover element (42) extending perpendicularly to the wall (36), wherein the cover element (42) is arranged in the axial direction (24) on an outer side (44) of the lid (34).

6. The cylindrical battery cell (12) according to any one of claims 1 to 5, characterized in thatthe cover element (42) and the wall (36) are integrally formed in one piece.

7. The cylindrical battery cell (12) according to any one of claims 1 to 6, characterized in thatthe cover element (42) is made by flanging.

8. The cylindrical battery cell (12) according to any one of claims 1 to 5, characterized in thatthe cover element (42) and the wall (36) are formed separately from each other, and are in particular welded together.

9. A battery module (10) for a motor vehicle, comprising at least the cylindrical battery cell (12) according to any one of claims 1 to 8.

10. A method for manufacturing a cylindrical battery cell (12) for a battery module (10) of a motor vehicle according to any one of claims 1 to 8, wherein the layers (18) are arranged adjacent to one another in the axial direction (24) of the battery cell (12) in the receiving space (16), whereby the layered structure (20) is formed.

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