Insulation unit and method for producing battery cells

Abstract

The invention relates to an insulation unit that is configured for installation in a cell cover assembly, having a base section with a receiving area, wherein the receiving area is configured to receive at least one arrester of at least one cell stack, in particular in at least partially curved form, wherein the receiving area is bounded at the edge along a height direction by at least one supporting element, which extends in the longitudinal direction from the base section, and wherein the receiving area can be bounded at least in certain areas along a depth direction by edge-side side sections, and wherein the base section has at least one opening and / or at least one recess, wherein the recess is configured to receive a collector plate at least in certain areas. The invention also relates to a cell cover assembly and a method for producing battery cells.

Description

[0001] INSULATION UNIT AND METHOD FOR MANUFACTURING BATTERY CELLS

[0002] The invention relates to an insulation unit configured for installation in a cell cover assembly and having a base section. Furthermore, the invention relates to a cell cover assembly and a method for manufacturing battery cells.

[0003] The production of so-called prismatic battery cells requires the interaction of a multitude of different components with different electrical charges. In addition to a multitude of electrodes (anodes and cathodes) separated from each other by microporous separators to form a cell stack, the respective electrodes are typically led out of the battery cells via cell caps and collector plates.

[0004] The respective internal collector plates are electrically connected to the external terminal plates to enable electrical connection to the battery cell. The external components of the battery cell in a hard-case design, particularly the cell lid and cell casing, are typically made of a metal such as aluminum. This creates the need to electrically insulate the respective collector plates, terminal plates, and conductor foils from the external components, such as the battery cell casing.

[0005] A problem with current battery cell manufacturing processes is that the respective electrode conductor foils are folded or bent when the cell housing is sealed with a cell lid. This can cause friction against the cell lid or cell housing in the folded or bent area. This can create an electrically conductive connection between the conductors and the external components of the battery cell, which prevents the cell housing from being potential-free and can increase the risk of a short circuit.

[0006] The present invention therefore has the object of creating an insulation unit, a cell cover assembly with such an insulation unit and a method for producing battery cells, which can reduce the risk of damage to arresters due to an assembly of battery cells.

[0007] This object is achieved by the features specified in claim 1. Further advantageous embodiments of the invention are part of the subclaims.

[0008] According to one aspect of the invention, an insulation unit is provided. The insulation unit is designed for installation in a cell lid arrangement and has a base section with a receiving area. The receiving area is designed to receive at least one conductor from at least one cell stack, in particular in a folded or bent form at least in some areas. The receiving area can be formed as a volume or a surface that adjoins the base section.

[0009] According to one embodiment, the receiving area can be delimited along a height direction by at least one support element extending longitudinally from the base section. Thus, the at least one support element can be positioned adjacent to the receiving area and, depending on the design, also delimit the receiving area at the edges.

[0010] The receiving area can be delimited at least partially by edge-side side sections, at least along a depth direction. By using side sections arranged at the edge, arresters that protrude into the receiving area and are folded or bent within the receiving area can be laterally protected and electrically insulated. According to the invention, installation of the insulation unit in a cell cover arrangement can be optimized if the base section has at least one opening and / or at least one recess. The recess is designed to accommodate a collector plate, at least partially. The at least one opening can connect the recess or the receiving area to an opposite side of the insulation unit. As a result, the collector plate can be coupled to a terminal plate or an external battery pole, for example via connecting pins or connecting elements.A rivet or screw connection can also be formed through the opening.

[0011] Advantageously, the insulation unit is formed in one or more parts from one or more electrically insulating materials. The insulation unit can be manufactured using 3D printing, injection molding, and the like.

[0012] The depth direction can be defined, for example, as a direction along a narrow or narrowest side of the insulation unit. The height direction extends perpendicular to the depth direction and corresponds to an elongated extension of the side sections or runs parallel to them. Thus, the base section can extend planarly essentially along the depth direction and the height direction. The length direction can be defined analogously to a surface normal of the base section. The side sections can protrude from the base section in a folded or solid form in the length direction and thus delimit or define a receiving section in the form of a volume.

[0013] The use of side sections, which can be designed, for example, as side flaps or side walls, provides additional protection for the mechanically sensitive collector foils or arresters. Furthermore, the side sections provide additional electrical insulation of the arresters from the cell housing. The side sections can protect the arresters particularly effectively if they border the receiving area on one or both sides and protrude longitudinally from the base section.

[0014] The arresters can be in the form of arrester bundles, in the form of an arrester extension, in the form of groups of arresters and the like and can be folded or bent within the receiving area in order to minimize the space required in a cell housing between at least one cell stack and a cell cover.

[0015] According to a further embodiment, the side sections protrude from the base section along the depth direction or extend the base section along the depth direction. Advantageously, the side sections are foldably connected to the base section. This measure allows the entire insulation unit to be manufactured virtually flat, making it particularly easy to manufacture. In this embodiment, the receiving area is formed by bending or deforming the side sections, whereby the side sections can protrude from the base section in the longitudinal direction after bending or deformation.

[0016] Depending on the design, the side sections can be elastically connected to the base section. This allows the side sections, when inserted into a cell housing, to be pressed away from each other by spring force against the walls of the cell housing to maximize the receiving area for the arresters.

[0017] The side sections can be folded particularly precisely if they are foldably connected to the base section along a crease or perforation, for example in the form of a film hinge. Advantageously, the side sections are designed to be foldable along the crease or perforation at an angle between 1° and 180°. This allows the side sections to be manufactured particularly flexibly and integrally with the base section. According to a further embodiment, the receiving area is delimited at the edges along the height direction by at least one support element. Advantageously, the support elements can support the side sections in a folded state such that they cannot protrude into or fall into the receiving area. In an alternative embodiment, the side elements can pivot or be moved past the support elements so that there is no mutual interference.

[0018] The arresters arranged in the receiving area can be optimally protected even in the event of multiple folding or bending if the side sections are arranged at least on two opposite edges of the base section.

[0019] According to a further embodiment, the side sections, in the folded state, have an extension along the longitudinal direction that corresponds to or exceeds the extension of the at least one support element in the longitudinal direction. This measure can simplify the manufacture of the insulation unit or adapt it to the geometry of the available space in the cell housing.

[0020] According to a further aspect of the invention, a cell cover assembly is provided. The cell cover assembly has at least one terminal plate arranged on the outside, one collector plate arranged on the inside, a cell cover, and an insulation unit according to the invention. The terms "outside" and "inside" refer to a later installation position in a battery cell. If the cell cover assembly is installed as a component of the battery cell, the terminal plate can be positioned on the outside or outside an internal volume of the cell housing, and the collector plate can be positioned within the internal volume of the cell housing. Thus, the receiving section of the insulation unit is also arranged on the inside. The collector plate is positioned flat on a base section of the insulation unit. A side of the base section facing opposite the receiving section is arranged on the cell cover, in particular on the inside.On the outside, the terminal plate is mounted directly or indirectly on the cell cover. With an indirect arrangement, the terminal plate can be insulated from the cell cover or electrically insulated, allowing for a potential-free cell cover design.

[0021] The terms terminal plate and collector plate are not limited to a specific shape within the meaning of this description. In particular, the terminal plate and collector plate can be identical or differently shaped. They can also be made of different or identical materials.

[0022] Depending on the design, the terminal plate and collector plate can be plate-shaped, stepped, L-shaped, or have any two-dimensional or three-dimensional shape to suit the formation of the cell cover assembly. For example, the terminal plate and collector plate can have openings or recesses for inserting connecting elements, such as rivets, screw connections, connecting pins, and the like. The terminal plate and collector plate can have round or circular, oval, square, or any polygonal cross-sectional shape.

[0023] The terminal plate is advantageously electrically connected to the collector plate in the longitudinal direction through the cell cover and the base unit. This can be achieved, for example, with the aid of electrically conductive connecting means or directly if the terminal plate and the collector plate can touch each other at least partially after insertion into the cell cover assembly or are bent or punched towards each other in a process step.

[0024] According to a further aspect of the invention, a method for producing a battery cell with at least one cell cover assembly according to the invention is provided. In one step, at least one cell stack is provided with conductors projecting from the ends in the longitudinal direction. The conductors can project from the cell stack on one side or at least on two sides. For example, several conductors of one or more electrodes or poles can project from a common side of the cell stack or from opposite sides of the cell stack.

[0025] The respective arresters are each electrically connected directly or indirectly to at least one collector plate of at least one cell cover assembly. In the case of an indirect connection of the arresters, the arresters can be electrically coupled to the collector plates using arrester extensions or other auxiliary sections.

[0026] In a further step, before or after the cell stack is inserted into a cell housing, the arrester bundles are connected to a collector plate of at least one cell cover assembly. The at least one cell cover assembly is advantageously used to at least partially close at least one opening in the cell housing. When the opening in the cell housing is closed, the arresters connected to the collector plates are bent or folded. During the bending process, the arrester bundles are guided through at least one side section of the insulation unit and are spaced from the cell housing, at least in some areas.

[0027] The method allows battery cells, for example in the form of lithium-ion battery cells, to be produced that have a lower risk of damage to the arresters during assembly or production. This can be achieved in particular by the insulation unit and the side sections according to the invention.

[0028] In one embodiment, the cell cover and the insulation unit are mechanically pressed together by an electrically conductive connection between the terminal plate and the collector plate. This allows the entire cell cover assembly to be pressed together, for example, along the length direction, using the connection between the at least one terminal plate and collector plate, and formed into a coherent unit. This can technically simplify the further assembly of the cell cover assembly.

[0029] The collector plate can be arranged in a particularly space-saving manner if it is located in a receiving section and / or a recess in the base section of the insulation unit. This measure can reduce the length of the cell cover assembly.

[0030] According to a further embodiment, the collector plate is configured to electrically contact at least one flexible or bent arrester extension or at least one flexible or bent arrester bundle, wherein the arrester extension or the arrester bundle is arranged in a bent state within the receiving section of the insulation unit. Preferably, the arrester extension or the arrester bundle is designed or bent to be bendable along a bending region. This measure allows the at least one side section of the insulation unit to have a protective effect and to space the arresters, for example in the form of arrester bundles or arrester extensions and the like, from the cell housing, particularly in the bending region.

[0031] Rubbing or scratching of the arresters on the cell housing can be prevented if at least one side section of the insulation unit is designed to guide at least one bending area of ​​the arrester extension or the arrester bundle within the receiving section, at least at the edge.

[0032] Several embodiments of the invention are explained in more detail below with reference to the drawings. They show:

[0033] Fig. 1 is a perspective view of an insulation unit according to the invention with foldable side sections according to an embodiment of the invention, Fig. 2 is a perspective view of the insulation unit from Fig. 1 with folded side sections,

[0034] Fig. 3 is a sectional view of a battery cell to illustrate cell cover arrangements according to the invention according to an embodiment, and

[0035] Fig. 4 is a schematic flow diagram illustrating a method for producing battery cells according to an embodiment of the invention.

[0036] In the illustrations, identical reference numerals identify the same elements or structural components. The sizes and relative positions of the elements in the illustrations are not necessarily drawn to scale, and some of these elements are enlarged and positioned for clarity. Furthermore, the specific shapes of the elements shown are not intended to convey information about the actual shape of the individual elements, but were selected merely for ease of identification in the illustrations.

[0037] Figure 1 shows a perspective view of an insulation unit 10 according to the invention with foldable side sections 12 according to one embodiment of the invention. The insulation unit 10 is designed for installation in a cell lid assembly 20, which is shown in Figure 3.

[0038] The insulation unit 10 has a base section 11 with a receiving area A. The receiving area A is configured to receive at least one conductor 31 from at least one cell stack 30, in particular in a folded or bent form at least in some areas. The conductors 31 can be provided in the form of conductor foils.

[0039] The receiving area A can be designed as a volume or a surface which borders the base section 11 along a longitudinal direction L. In the illustrated embodiment, the receiving area A is delimited at the edges along a height direction H by a support element 13 which extends in the longitudinal direction L from the base section 11.

[0040] The support elements 13 can fulfill various functions and are provided optionally. For example, the support elements 13 can ensure a minimum distance in the longitudinal direction L relative to a cell stack 30.

[0041] For example, a support element 13 has an opening 14, which can be used to fill the battery cell 100 with an electrolyte. The base element 11 also has openings 15, which are explained in more detail in the description of Fig. 3.

[0042] The receiving area A can be delimited at least partially by edge-side side sections 12 along a depth direction T. By using edge-side side sections 12, arresters 31 that project into the receiving area A and are folded or bent within the receiving area A can be laterally protected and electrically insulated.

[0043] In the illustrated embodiment, the insulation unit 10 is made in one piece from an electrically insulating material.

[0044] The directional information depth direction T, length direction L and height direction H essentially refer to the battery cell 100 shown in Fig. 3 as a reference and suggest the installation position of the insulation unit 10 within the battery cell 100.

[0045] Preferably, the down conductors 31 of the cell stack 30 can be deformed along a bending axis or folding axis which runs parallel to the height direction H so that the side sections 12 can protect such bending regions B particularly optimally. Preferably, the side sections 12 are arranged on the base section 11 in such a way that they can support and / or guide one or more bending regions B of down conductors 31 over a large area. The side sections 12 are designed as bendable or foldable side tabs which initially or after production of the insulation unit 10 protrude from the base section 11 on both sides in the depth direction T or extend the base section 11 in the depth direction T. As a result of this measure, the entire insulation unit 10 can be manufactured almost flat and is therefore particularly simple from a technical perspective.In this embodiment, the receiving area can be formed by bending or deforming the side sections 12, wherein the side sections 12 protrude from the base section 11 in the longitudinal direction L after the bending or deformation.

[0046] The side sections 12 are foldably connected to the base section 11 along a fold or perforation 16. Thus, the side sections 12 can be bent, for example, at an angle of 90° along the perforation 16 to delimit the receiving area A on both sides along the depth direction T. Figure 1 shows the insulation unit 10 with side sections 12 that are not folded or bent.

[0047] Figure 2 shows a perspective view of the insulation unit 10 from Figure 1 with side sections 12 folded by 90°. In this form, the insulation unit 10 can be mounted in the battery cell 100, and in particular in a cell cover assembly 20, to protect the arresters 31.

[0048] Fig. 2 further illustrates that the side sections 12 are limited in their bending angle by the support elements 13, since the side sections 12 have an extension in the height direction H which exceeds a distance between the two support elements 13 in the height direction H. This distance between the support elements 13 also defines the extension of the receiving area A in the height direction H in the illustrated embodiment. Advantageously, the conductors 31 can also have an extension and position along the height direction H which corresponds to the dimensioning and arrangement of the receiving area A. Fig. 3 shows a sectional view of a battery cell 100 to illustrate cell cover assemblies 20 according to the invention according to one embodiment. The two ends or edge sections of the battery cell 100 along the length direction L are shown in detail.

[0049] The battery cell 100 has two cell stacks 20, which have conductors 31 projecting along the longitudinal direction L on two opposite sides 32, 33. A first side 32 has conductors 31 for forming a cathode or a positive battery pole. A second side 33 has conductors 31 for forming an anode or a negative battery pole. In the illustrated embodiment, the first side 32 and the second side 33 refer to the cell stacks 30 and the battery cell 100. By way of example, a cell cover arrangement 20 is provided on each of the two sides 32, 33.

[0050] Battery cells 100 with two battery poles arranged on one side 32, 33 can also have a cell cover arrangement 20 mounted thereon, which can electrically couple adjacently arranged conductors 31 of the respective electrodes.

[0051] The arresters 31 may be in the form of arrester bundles, in the form of an arrester extension, in the form of groups of arresters 31 and the like and may be folded or bent within the receiving area A in order to minimize space requirements in a cell housing 110 between the cell stacks 30 and a cell cover 21.

[0052] In the exemplary embodiment shown, two cell stacks 30 are provided, which are arranged next to one another along the height direction H. The respective conductors 31 are led to the cell cover arrangements 20 and electrically connected there.

[0053] The two cell cover assemblies 20 are, for example, identical in design, but may have different shapes or different components depending on the configuration. For the sake of simplicity, the following description will be made with reference to one cell cover assembly 20. The cell cover assembly 20 includes an externally arranged terminal plate 22, an internally arranged collector plate 23, a cell cover 21, and an insulation unit 10.

[0054] The terminal plate 22 can be electrically contacted on the outside of the battery cell 100. The collector plate 23 installed on the inside is designed to electrically contact the arresters 31 within the cell housing 110.

[0055] The collector plate 23 is positioned flat in a recess or depression 17 of the base section 11 of the insulation unit 10. A side of the base section 11 facing the receiving section A is arranged on the inside of the cell cover 21. The terminal plate 22 is arranged on the outside of the cell cover 21.

[0056] The terminal plate 22 is separated from the cell cover by an insulator 24

[0057] 21 electrically insulated, which is located between the cell cover 21 and the terminal plate

[0058] 22 is arranged.

[0059] The terminal plate 22 is electrically connected to the collector plate 23 in the longitudinal direction L through the cell cover 21 and the base unit 11. The electrical connection is made by means of connecting means 40, which protrude through the openings 15 in the base unit 11 of the insulation unit 10.

[0060] The connecting means 40 are designed, for example, as riveted connections welded to the collector plates 23. The corresponding welding points are indicated schematically. The design of the connecting means 40 secures all components of the cell cover assembly 20 to one another in a fixed position. The insulator 24, the cell cover 21, and the insulation unit 10 are connected to one another between the collector plate 23 and the terminal plate 22. Preferably, a fluid-tight compression joint is used to form the cell cover assembly 20. Fig. 3 further illustrates different possibilities for protecting the arresters 31 from contact with the cell housing 110 by the side sections 12 of the insulation unit 10.

[0061] On the first side 32, the conductors 31 are bent into an L-shape and welded or soldered to the collector plate 23 at the ends. The conductors 31 of the respective cell stacks 30 can be guided along the longitudinal direction L along the side sections 12 toward the base section 11. At a bending area B, the conductors 31 are bent so that they can rest parallel on the collector plate 23.

[0062] Analogous to the first side 32, on the second side 33, arresters 31 are also electrically connected to the collector plate 23. In contrast, here the arresters 31 are folded or bent in an S-shape along bending regions B in order to be placed within the receiving region A. During assembly of the cell cover assembly 20, the respective arresters 31 would be elastically pressed toward the cell housing 110 at the bending regions B. This interaction of the arresters 31 with the cell housing 110 has a potential for damage.

[0063] The use of the insulation unit 10 with the side sections 12 enables the arresters 31 to be spaced apart from the cell housing 110. Relative movement and / or friction occurs exclusively between the side sections 12 of the insulation unit 10 and the cell housing 110 during the manufacture of the battery cell 100. Friction and thus damage to the arresters 31 of the cell stack 30 can thus be effectively prevented.

[0064] Figure 4 shows a schematic flow diagram illustrating a method 50 for producing battery cells 100 according to one embodiment of the invention. Reference is made to the battery cell 100 shown in Figure 3 by way of example.

[0065] In a step 51, at least one cell stack 30 is provided with conductors 31 projecting at the ends in the length direction L. The conductors 31 can project from the cell stack 30 on one or both sides. For example, several conductors 31 of one or more electrodes or poles can project from a common side 32, 33 of the cell stack 30 or from the cell stack 30 on opposite sides 32, 33 of the cell stack 30.

[0066] In a further step 52, the respective arresters 31 are each electrically connected directly or indirectly to at least one collector plate 23 of at least one cell cover assembly 20. In the case of an indirect connection of the arresters 31, the arresters 31 can be electrically coupled to the collector plates 23 using arrester extensions (not shown) or other auxiliary sections.

[0067] In a further step, before or after the cell stack 30 is inserted into a cell housing 110, the arrester bundles are connected to a collector plate 23 of at least one cell cover arrangement.

[0068] The at least one cell cover assembly 20 is used to at least partially close at least one opening of the cell housing 110. When the opening of the cell housing 110 is closed 53, the conductors 31 connected to the collector plates 23 are bent or folded. In a step 54 of the method 50, the conductors 31 are guided through at least one side section 12 of the insulation unit 10 during bending and are spaced at least partially from the cell housing 110.

Claims

CLAIMS 1. Insulation unit (10) which is designed for installation in a cell lid arrangement (20), comprising a base section (11) with a receiving area (A), wherein the receiving area (A) is designed to receive at least one conductor (31) from at least one cell stack (30), in particular in an at least partially folded or bent form, wherein the receiving area (A) can be delimited at least along one spatial direction at least partially by edge-side side sections (12), characterized in that the base section (11) has at least one opening (15) and / or at least one recess (17), wherein the recess (17) is designed to receive at least partially a collector plate (23).

2. Insulation unit according to claim 1, wherein the side sections (12) delimit the receiving area (A) on one side or on both sides and protrude from the base section (11) along the length direction (L).

3. Insulation unit according to claim 1 or 2, wherein the side sections (12) protrude from the base section (11) along the depth direction (T) or extend the base section (11) along the depth direction (T), wherein the side sections (12) are movably connected to the base section (11).

4. Insulation unit according to claim 3, wherein the side sections (12) are foldably connected to the base section (11) along a fold or perforation (16), wherein the side sections (12) are foldable along the fold or perforation (16) at an angle between 1° and 180°.

5. Insulation unit according to one of claims 1 to 4, wherein the receiving area (A) is defined along the height direction (H) at the edge by at least one Support element (13) which extends in the longitudinal direction (L) from the base section (11).

6. Insulation unit according to one of claims 1 to 5, wherein the side sections (12) are arranged at least on two opposite edges of the base section (11).

7. Insulation unit according to claim 5, wherein the side sections (12) in the folded state have an extension along the length direction (L) which corresponds to or exceeds an extension of the at least one support element (13) in the length direction (L).

8. Cell cover arrangement (20), comprising at least one terminal plate (22) arranged on the outside, one collector plate (23) arranged on the inside, a cell cover (21) and an insulation unit (10) according to one of the preceding claims, wherein the collector plate (23) is positioned flat on a base section (11) of the insulation unit (10), wherein a side of the base section (11) facing away from the receiving section (A) is arranged, in particular on the inside, on the cell cover (21), wherein the terminal plate (22) is arranged directly or indirectly on the outside of the cell cover (21), wherein the terminal plate (22) is electrically conductively connected to the collector plate (23) in the longitudinal direction (L) through the cell cover (21) and the base unit (11).

9. Cell cover arrangement according to claim 8, wherein the cell cover (21) and the insulation unit (10) are mechanically pressed together by an electrically conductive connection (40) between the terminal plate (22) and the collector plate (23).

10. Cell cover assembly according to claim 8 or 9, wherein the collector plate (23) is arranged in a receiving section (A) and / or a recess (17) of the base section (11) of the insulation unit (10), wherein the Collector plate (23) is configured to electrically contact at least one bendable or bent arrester extension or at least one bendable or bent arrester bundle, wherein the arrester extension or the arrester bundle is arranged in a bent state within the receiving section (A) of the insulation unit (10), wherein the arrester extension or the arrester bundle is designed or bent to be bendable along a bending region (B).

11. Cell lid arrangement according to claim 10, wherein at least one side section (12) of the insulation unit (10) is designed to guide at least one bending region (B) of the arrester extension or the arrester bundle within the receiving section (A) at least at the edge.

12. A method (50) for producing a battery cell (100) with at least one cell cover arrangement (20) according to one of claims 8 to 11, wherein at least one cell stack (30) is provided with conductors (31) projecting at its ends in the longitudinal direction (L), wherein the respective conductors (31) are each directly or indirectly electrically connected to at least one collector plate (23) of at least one cell cover arrangement (20), wherein the conductors (31) are connected to a collector plate (23) of at least one cell cover arrangement (20) before or after the cell stack (30) is introduced into a cell housing (110), wherein the at least one cell cover arrangement (20) is used to close at least one opening of the cell housing (110), wherein when the opening of the cell housing (110) is closed, the conductors (31) connected to the collector plates (23) are bent,wherein the conductors (31) are guided through at least one side section (12) of the insulation unit (10) during bending and are spaced from the cell housing (110) at least in some areas.

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