End plate for battery cell arrangement

Abstract

The present disclosure relates to an end plate (8) for a battery cell arrangement (1) comprising a plurality of battery cells (2, 4), comprising a first surface (9) for contacting an outer surface (3) of an outermost battery cell of the battery cell arrangement, and a second surface (10) for at least partially receiving a compression force (F) for compressing the battery cell arrangement, the first surface is located on an opposite side of the second surface for distributing a compressive force (F) over the outer surface, the end plate having a first state (11) in which the second surface does not receive the compressive force and the first surface is in contact with a portion of the outer surface, and the end plate having a second state (12) in which the second surface is in contact with a portion of the outer surface. The end plate is configured to transition from a first state to a second state when the second surface receives a compressive force, the first surface being in contact with a larger portion of the outer surface in the second state than in the first state.

Description

Technical Field

[0001] The present disclosure relates to an end plate for a battery cell device, a battery cell device, and a method for manufacturing a battery cell device. Background Art

[0002] When manufacturing a battery cell device, the battery cells of the battery cell device should be compressed to optimize battery health and reduce the thickness of the overall size of the battery cell device, which may be particularly relevant in applications with limited installation space.

[0003] To withstand the applied compressive force, the outermost battery cells may be provided with a harder material than the internal battery cells between the outermost battery cells, such as extruded aluminum or die-cast aluminum. However, these materials are expensive and add additional weight to the battery cell device. Summary of the Invention

[0004] The object of handling compressive forces in an inexpensive and low-weight manner is at least partially solved by the subject matter of the independent claims of the present disclosure, where additional examples are incorporated in the dependent claims.

[0005] According to a first aspect of the present disclosure, there is provided an end plate for a battery cell device including a plurality of battery cells. The end plate includes a first surface and a second surface. The first surface is for contacting an outer surface of the outermost battery cells of the battery cell device, and the second surface is for at least partially receiving a compressive force for compressing the battery cell device. The first surface is located on the opposite side of the second surface and is for distributing the compressive force on the outer surface. The end plate has a first state in which the second surface does not receive the compressive force and the first surface contacts a part of the outer surface. Moreover, the end plate has a second state, and the end plate is configured to transition from the first state to the second state when the second surface receives the compressive force, and the first surface contacts a larger part of the outer surface in the second state than in the first state.

[0006] Therefore, the end plate of the present disclosure provides for receiving a compressive force based on which the end plate transitions from the first state to the second state. In the second state, the contact surface or contact area of the end plate with the outer surface of the outermost battery cells of the battery cell device increases, thereby providing a more uniform compressive force distribution throughout the battery cell device without having to use any expensive and / or heavy materials. Even without providing a hard and expensive material on the outermost battery cells, battery health can be improved and the battery size can be reduced.

[0007] The battery cell device can include any number of battery cells. All battery cells can be designed to be interchangeable with each other, for example, identical to each other. Specifically, the outermost battery cells can be designed to be interchangeable or identical to other battery cells (i.e., the inner battery cells located between the outermost battery cells), at least together with their housings or entirely. The battery cells can be arranged in rows and / or adjacent to each other. Two battery cells among the plurality of battery cells can be located at the opposite outermost sides of the battery cell device and are accordingly referred to as the outermost battery cells. The other battery cells can be located or placed between the two outermost battery cells and are referred to as the inner battery cells. The battery cell device can be, for example, a battery module or a battery pack having a number of battery cells as battery cores. Alternatively, for example, the battery cell device can be a battery pack having a number of battery modules as battery cells, where each of the battery modules can include a number of battery cores.

[0008] The end plate has two states, namely the first state and the second state. The end plate can be switched between these two states by applying or not applying a compressive force from the compression unit thereto, and when the end plate is disposed at the outer surface of one of the outermost battery cells of the battery cell device (for example, when the first surface of the end plate contacts the outer surface of the outermost battery cell). The switching of the end plate can be based on the elastic deformation of the end plate, where the elastic deformation can cause the end plate to switch from a first shape (for example, a concave shape) in the first state (which can also be referred to as the unloaded state or the relaxed state of the end plate) to a second shape (especially a flat shape), in which the surface or area of the end plate contacting the outer surface increases. The second state can also be referred to as the loaded state or the tensioned state. By having a first shape and a smaller contact area with the outer surface of the outermost battery cell in the first state, the end plate can better adopt from its first shape to the second shape in the second state, thereby achieving a larger contact between the end plate and the outer surface of the outermost battery cell, especially substantially complete contact along the entire outer surface of the end plate and / or the outermost battery cell. In addition, the end plate can be made of a material that is much lighter and / or much softer than the material that may typically not have a state (especially a shape) conversion as described herein.

[0009] For example, the end plate can be configured as a solid plate. Being configured as a solid plate, the end plate can have a simple and easy-to-manufacture solid geometry in the form of a plate. In particular, the end plate can be a one-piece component, or in other words, the end plate is made of one piece.

[0010] In an example, the end plate may include a polymer material. In particular, the end plate may be made of a polymer material. This allows the end plate to be very light and cost-effective, while still allowing high compressive strength and a large contact area in the second state due to the first shape in the first state, when the end plate is transformed into the second state, the first shape is particularly transformed into a second shape with an increased contact area with the outer surface of the outermost battery cell.

[0011] In an example, the polymer material may be a fiber reinforced polymer material. Thus, the compressive strength of the end plate may be increased without adding any weight or high material costs.

[0012] In an example, the end plate may have a concave shape in a first state. Specifically, the concave shape may be concave relative to the outermost battery cell, and the concave shape may be arranged at the outer surface of the outermost battery cell. The concave shape may be provided by at least one bend of the end plate. Specifically, the end plate may be a pre-bent end plate. In the first state, the end plate may have a concave shape due to at least one bend. However, when it is converted to the second state, the shape may change, thereby overcoming at least one bend and providing a second shape, for example, in the form of a substantially flat shape. The concave shape may be formed so that the end plate, while being arranged at the outer surface of the outermost battery cell, also contacts a portion of the outer surface of the outermost battery cell, in particular a center or middle portion, and is otherwise spaced apart from the outer surface of the outermost battery cell. The portion of the end plate spaced apart from the outer surface of the outermost battery cell may form a concave portion of the end plate, and the center or middle portion of the end plate, which may be surrounded by the concave portion, may be substantially flat so as to contact the outer surface in the first state.

[0013] In an example, the end plate may have a substantially flat shape in the second state. Thus, a particularly large contact area between the end plate (particularly its first surface) and the outermost battery cell may be provided, thereby increasing the distribution of the compressive force over most or all of the outer surface of the outermost battery cell, and thereby improving the distribution of the compressive force throughout all battery cells.

[0014] In an example, the end plate can be configured to be in substantially full contact with the outer surface of the outermost battery cell in the second state. Thus, a maximum contact area between the end plate and the outermost battery cell can be provided, thereby increasing the distribution of the compressive force over the entire outer surface of the outermost battery cell and thereby improving the distribution of the compressive force throughout all battery cells.

[0015] In an example, the end plate may be configured for transition from a first state to a second state by elastic deformation. Thus, the end plate may provide elastic properties for elastic deformation from a first state (particularly a concave shape of the end plate) to a second state (particularly a substantially flat shape of the end plate).

[0016] According to a second aspect of the present disclosure, there is provided a battery cell device including a plurality of battery cells, two end plates according to the first aspect of the present disclosure, and at least one compression unit. The end plates are in a second state in which a first surface of the end plate contacts an outer surface of one of the outermost battery cells of the battery cell device, and a second surface receives a compression force from the at least one compression unit.

[0017] Thus, it can be provided that, for example, when the compression force is removed from the outermost battery cell by removing at least one compression unit from the end plate, the end plate can be converted from the second state to the first state, thereby returning to the concave shape. However, alternatively, it can be provided that additional fixing components and / or compression components, such as adhesives to be further described below, are provided, in which case the conversion from the second state to the first state can be prevented or restricted even if the compression force is partially or entirely removed. The two end plates can be arranged at the outermost battery cells located on opposite sides of each other and receive compression forces in opposite directions (or in other words, opposite orientations), for example, the directions of the compression forces are oriented towards each other. The battery cells of the battery cell device can be compressed against each other from different directions, thereby providing a more uniform pressure distribution throughout the battery cell device.

[0018] In an example, the housing of the battery cell can include two end plates and side plates. The side plates can be two or more (e.g., four), and can cover the battery cell from the sides where the end plates do not cover the battery cell. The side plates can extend along all the battery cells, while the end plates can be arranged only at one corresponding outermost battery cell, or in other words, the end battery cells are arranged at one end or the outermost side of the battery cell device.

[0019] In an example, each of the end plates can distribute the compression force substantially uniformly on the outer surface of the outermost battery cell. In other words, for example, the end plate transfers the compression force from the at least one compression unit substantially uniformly onto the entire outer surface of the outermost battery cell. This can be facilitated when the end plate is in substantially full contact with the outer surface of the outermost battery cell and when the compression force is also evenly distributed on the end plate. Thus, the pressure distribution throughout the battery cell device can be provided as uniformly as possible to improve the health of the battery cell device.

[0020] In an example, the battery cells can be arranged adjacent to each other, particularly with their surfaces facing each other and / or parallel to each other. The battery cell device can further include battery pads between adjacent battery cells. The battery pads can further contribute to the uniform pressure distribution between the battery cells.

[0021] In an example, the battery pad may include a compressible material. For example, the compressible material may be a foam material. For example, the foam material may be a foamed plastic material. Thus, the assistance of the battery pad in providing a uniform pressure distribution between the battery cells can be further increased. Alternatively or additionally, the battery pad may be configured to thermally isolate adjacent battery cells from each other. Thus, the battery pad provides another function in addition to the uniform pressure distribution, reducing the risk of thermal problems in the battery cell device, particularly the risk of thermal runaway.

[0022] In an example, at least one compression unit may be a compression band for compressing the battery cells. For example, an alternative term for the compression band is a compression strip. The compression band may be made of an elastic material, which can be stretched by being tightened. Such a compression band can be tightened, for example, by having an inner dimension or diameter smaller than the outer dimension or diameter of the battery cell device and pulling the compression band onto the battery cell device, thereby providing a compressive force on one or both opposite end plates (particularly their second surfaces) of the battery cell device.

[0023] In an example, at least one compression unit may be adhered to the outermost surface of the outermost battery cell through an adhesive bonding joint. In addition to the compression unit, such an adhesive bonding joint can also be provided by using an adhesive. For example, the compression unit may be at least partially attached to one or both end plates of the battery cell device through the adhesive, thereby providing an adhesive bonding joint in addition to the force bonding between the end plates provided by the applied compressive force. This has the advantage that even if the compression unit relaxes over time and the compressive force decreases over time, the compression applied to the battery cell device is particularly persistent, for example, for a period of ten years or longer.

[0024] According to a third aspect of the present disclosure, there is provided a method for manufacturing a battery cell device according to the second aspect of the present disclosure, wherein the method includes:

[0025] Arranging a plurality of battery cells between two end plates, and

[0026] Arranging at least one compression unit at the second surfaces of the two end plates such that the second surfaces receive a compressive force from the at least one compression unit, thereby compressing the plurality of battery cells.

[0027] Of course, the method may include additional steps corresponding to the features described above with respect to the end plates and the battery cell device. For example, the method may further include arranging a battery pad between adjacent battery cells and / or adhering at least one compression unit to the outermost surface of the outermost battery cell through an adhesive bonding joint.

[0028] Note that the above examples can be combined with each other regardless of the aspects involved. In addition, any feature mentioned with respect to either the end plate or the battery cell arrangement can also be applied to the method, and vice versa.

[0029] With reference to the examples described below, these and other aspects of the present disclosure will become apparent and be elucidated. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Examples of the present disclosure will be described below with reference to the following drawings.

[0031] Figure 1 A cross-sectional view of a battery cell device is shown, where one end plate is in a first state; and

[0032] Figure 2 A cross-sectional view of a battery cell device is shown, where two end plates are in a second state. DETAILED DESCRIPTION

[0033] The drawings are only schematic representations and are only used to illustrate examples of the present disclosure. Identical or equivalent elements are in principle provided with the same reference numerals.

[0034] Figure 1 A cross-sectional view of a battery cell device 1 including a plurality of battery cells 2, 4 is shown. Only four exemplary battery cells 2, 4 are shown herein. However, the number of battery cells 2, 4 can be more or less than Figure 1 and Figure 2 that shown. In this example, the battery cells 2, 4 are prismatic, for example having a prismatic housing. Alternatively, the battery cells 2, 4 can be of a cylindrical design, a pouch design, or any other design.

[0035] For example, the battery cell device 1 can be a battery module or a battery pack. In a battery module, the battery cells 2, 4 can be individual battery cells, which can be electrically connected to each other, for example in series, to form a battery module. In a battery pack, the battery cells 2, 4 can be individual battery modules, which can include individual battery cells and can be electrically connected to each other, for example in series or in parallel.

[0036] The battery cell device 1 can include other components not shown herein. Such other components can be, for example, bus bars for electrically connecting the battery pack cells 2, 4 to each other, one or more control units or logic boards configured to control the charging and / or discharging of the battery pack cells 2, 4, a temperature control unit for controlling the temperature of the battery pack cells 2, 4, and / or the like.

[0037] The battery cells 2, 4 of this example are arranged parallel to and / or adjacent to each other. Specifically, the battery cells 2, 4 face each other with their respective largest outer surfaces 3. Between each pair of adjacent battery cells 2, 4, the battery cell device 1 includes a battery pad 5. The battery pad 5 may have at least partial thermal insulation properties, at least partially thermally isolating the adjacent battery cells 2, 4 from each other. For this purpose, the battery pad 5 may be made of a material having a low thermal conductivity, for example. The battery pad 5 may comprise a compressible material or be made of a compressible material, such as a foam material. By having a compressible material, the battery pads 5 may include compression properties such that they can be compressed. In this way, the compression force applied to the battery cells 2, 4 to compress the battery cell device 1 can be distributed between the battery cells 2, 4 in a particularly uniform manner.

[0038] The battery cell device 1 further includes side plates 7 arranged at the bottom and top of the battery cells 2, 4. Specifically, the side plates 7 may extend along all the battery cells 2, 4. The side plates 7 may face the circumferential surfaces of the battery cells 2, 4.

[0039] In addition, the battery cell device 1 includes two end plates 8, as Figure 2 shown. In Figure 1 only one end plate 8 is shown by way of example. Apart from the number of end plates 8, Figure 1 and Figure 2 the further difference between Figure 1 is that the end plate 8 in Figure 2 is in the first state 11, while the end plate 8 in

[0040] is in the second state 12. The end plates 8 of the battery cell device 1 may face the ends or fronts of the outermost battery cells 2, particularly the outer surfaces 3, for example, be oriented or face the outside of the battery cell device 1. The ends or fronts may be oriented perpendicular to the circumferential surfaces.

[0041] Figure 1 The end plates 8 of Figure 1 are configured to be arranged at the outer surfaces 3 of the outermost battery cells 2 of the battery cells 2, 4 of the battery cell device 1. Thus, the battery end plates 8 are shown in

[0042] as being arranged at the outer surface 3 of the leftmost outermost battery cell 2, particularly directly arranged such that its first surface 9 faces the outer surface 3 of the leftmost outermost battery cell 2, i.e., with no other parts therebetween. Thus, the first surface 9 may touch the outer surface 3 of the outermost battery cell 2.

[0042] In addition, Figure 1 the end plates 8 are configured to receive the compression force F from the compression unit 13 to compress the battery cell device 1. This is shown in Figure 2 where the compression force F provided by the compression unit 13 is applied to and received by the end plate 8 and, in turn, compresses the battery cell device 1. In particular, compared withFigure 1 The end plate 8 shown, relative to and together with Figure 2 The other end plate 8 in compresses the battery cells 2, 4 from the opposite side of the battery cell device 1 through the same compression unit 13, where the other end plate 8 is arranged at the right outermost battery cell 2. Thus, the end plate 8 distributes the compression force F from the compression unit 13 substantially uniformly over the outer surface 3 of the outermost battery cell 2 to all the battery cells 2, 4.

[0043] As Figure 1 shown, the end plate 8 (actually Figure 1 the two end plates 8) has a first state 11, in which the end plate 8 does not receive the compression force F from the compression unit 13. In other words, as Figure 1 shown, the end plate 8 is in a relaxed or unloaded state. In this state, the end plate 8 has a concave shape. The concave shape enables the end plate 8 to contact a part of the outer surface 3 of the corresponding outermost battery cell 2 while being arranged at the outer surface 3 of the outermost battery cell 2. In particular, the concave shape extends outwardly to the outer surface 3 or the outermost battery cell 2, thereby contacting a part thereof.

[0044] As Figure 2 shown, the end plate 8 also has a second state 12, and the end plate 8 is configured to transition from the first state 11 to the second state 12 when the end plate 8 receives the compression force F while being arranged at the outer surface 3 of the outermost battery cell 2. The end plate 8 contacts a larger portion of the outer surface 3 of the outermost battery cell 2 in the second state 12 than in the first state 11. In particular, the end plate 8 is in substantially full surface contact with the outer surface 3 of the outermost battery cell 2 in the second state 12, thereby distributing the compression force F evenly (or in other words uniformly) over the entire outer surface 3 of the outermost battery cell 2. Thus, the compression force F is transmitted to the other battery cells 4, or in other words, the internal battery cells 4, in a uniform manner via the battery pad 5. Thereby, a particularly uniform compression throughout the battery cell device 1 is achieved.

[0045] The transition of the end plate 8 from the first state 11 to the second state 12 can be based on the elastic deformation of the end plate 8. For the transition, the end plate 8 can be deformed or reformed from a concave shape (e.g., as Figure 1 shown) to a substantially flat shape (e.g., as Figure 2 shown).

[0046] As Figure 1As shown, the end plate 8 can have an intermediate section 14, which can include the part of the first surface 9 of the end plate 8 that contacts the outer surface 3 of the outermost battery cell 2, or in other words, the part that touches the outer surface 3. The end plate 8 can also have a peripheral section 15 that surrounds the intermediate section 14 and is curved relative to the intermediate section 14, especially away from the outermost battery cell 2 that the end plate 8 is configured to be arranged thereon. Thereby, a concave shape can be provided.

[0047] As further seen in Figure 1 and Figure 2 the end plate 8 is configured as a solid plate. In particular, the end plate 8 can be made as a single plate or a monolithic plate. The end plate 8 can include a polymer material or be made of a polymer material. The polymer material can be a fiber-reinforced polymer material. The fiber-reinforced polymer material can be, for example, a glass fiber-reinforced polymer material.

[0048] The compression unit 13 can be, for example, a compression strap. As Figure 2 shown, for example, the compression strap can compress the battery cell arrangement 1 from opposite sides of the battery cell arrangement 1, and the outermost battery cells 2 are located on the opposite sides. Thus, the two outermost battery cells 2 receive a compression force F from the compression unit 13.

[0049] The compression unit 16 can be joined to the outermost battery cell 2 by an adhesive bonding joint. Thus, in addition to the applied compression force F, an adhesive can also be used to provide this joining. This has the advantage that even if the compression unit 13 and / or the adhesive bonding joint slacken or weaken over time and the compression force F decreases over time, the compression applied to the battery cell arrangement 1 is particularly durable, for example, for a period of ten years or longer.

[0050] As used herein, the phrase "at least one" with respect to a list of one or more entities shall be understood to mean at least one entity selected from any one or more of the entities in the list of entities, but not necessarily including at least one of each entity specifically listed within the list of entities, and not excluding any combination of the entities in the list of entities. This definition also allows that entities other than those specifically identified within the list of entities referred to by the phrase "at least one" may optionally exist, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently, "at least one of A and / or B") may, in one example, refer to at least one A, optionally including more than one A, without B (and optionally including entities other than B); in another example, refer to at least one B, optionally including more than one B, without A (and optionally including entities other than A); in yet another example, refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other entities). In other words, the phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" may represent A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and optionally any combination of any of the foregoing with at least one other entity.

[0051] By studying the drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed examples when practicing the claimed disclosure. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the claims.

[0052] List of reference signs

[0053] 1 Battery cell device

[0054] 2 Outermost battery cell

[0055] 3 Outer surface

[0056] 4 Inner battery cell

[0057] 5 Battery pad

[0058] 6 Housing

[0059] 7 Side plate

[0060] 8 End plate

[0061] 9 First surface

[0062] 10 Second surface

[0063] 11 First state

[0064] 12 Second state

[0065] 13 Compression unit

[0066] 14 Intermediate section

[0067] 15 Peripheral section

Claims

1. An end plate (8) for a battery cell device (1) comprising a plurality of battery cells (2, 4), the end plate (8) comprising a first surface (9) and a second surface (10), the first surface (9) being used to contact an outer surface (3) of an outermost battery cell (2) of the battery cell device (1), the second surface (10) being used to at least partially receive a compressive force (F) for compressing the battery cell device (1), the first surface (9) being located on an opposite side of the second surface (10) for distributing the compressive force (F) on the outer surface (3), The end plate (8) has a first state (11), in which the second surface (10) does not receive the compressive force (F) and the first surface (9) is in contact with a portion of the outer surface (3), and The end plate (8) has a second state (12), and the end plate (8) is configured to switch from the first state (11) to the second state (12) when the second surface (10) receives the compressive force (F), and the first surface (9) is in contact with a larger part of the outer surface (3) in the second state (12) than in the first state (11).

2. The end plate (8) according to claim 1, comprising a polymer material.

3. The end plate (8) according to claim 2, the polymer material being a fiber reinforced polymer material.

4. The end plate (8) according to claim 1, the end plate (8) having a concave shape in the first state (11).

5. The end plate (8) according to claim 1, wherein the end plate (8) has a flat shape in the second state (12).

6. The end plate (8) according to claim 1, wherein the first surface (9) is in full contact with the outer surface (3) in the second state (12).

7. The end plate (8) according to claim 1, wherein the end plate (8) is configured to be transformed from the first state (11) to the second state (12) by elastic deformation.

8. A battery cell device (1), comprising a plurality of battery cells (2, 4), two end plates (8) according to any one of the preceding claims, and at least one compression unit (13), wherein the end plate (8) is in the second state (12), in which the first surface (9) of the end plate (8) contacts the outer surface (3) of one of the outermost battery cells (2) of the battery cell device (1), and the second surface (10) receives the compression force (F) from the at least one compression unit (13).

9. The battery cell device (1) according to claim 8, comprising a housing (9) of the battery cell (2, 4), wherein the housing (9) comprises the two end plates (8) and the side plate (7).

10. The battery cell device (1) according to claim 8 or 9, each of the end plates (8) evenly distributes the compression force (F) on the outer surface (3) of the outermost battery cell (2).

11. The battery cell arrangement (1) according to claim 8, the battery cells (2, 4) being arranged adjacent to each other, and the battery cell arrangement (1) comprising battery pads (5) between adjacent battery cells (2, 4).

12. The battery cell device (1) according to claim 8, wherein the battery pad (5) comprises a compressible material.

13. The battery cell device (1) according to claim 8, wherein the compression unit (13) is a compression band for compressing the battery cells (2, 4).

14. The battery cell arrangement (1) according to claim 8, the at least one compression unit (13) being adhered to the outermost surface (3) of the outermost battery cell (2) by an adhesive bonding joint.

15. A method for producing a battery cell device (1) according to any one of claims 8 to 14, wherein: The method comprises: The plurality of battery cells (2, 4) are arranged between the two end plates (8), and The at least one compression unit (13) is arranged at the second surface (10) of the two end plates (8) so that the second surface (10) receives the compression force (F) from the at least one compression unit (13), thereby compressing the plurality of battery cells (2, 4).

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