Battery module and assembling method thereof, battery system, electric vehicle and shell

Abstract

The invention provides a battery module and an assembling method thereof, a battery system, an electric vehicle and a shell. A battery module includes a battery cell stack including a plurality of battery cells arranged in a stacking direction, and a case configured to accommodate the battery cell stack. The housing includes: a bottom; a top; two side portions arranged opposite to each other in the stacking direction and interconnecting the bottom portion and the top portion in the height direction; and a side opening through which the battery cell stack can be inserted into the case in an insertion direction, the insertion direction being orthogonal to the stacking direction and the height direction. The top portion includes an opening portion on the electrode terminals and the exhaust valves of the plurality of battery cells of the battery cell stack when the battery cell stack is accommodated in the case.

Description

TECHNICAL FIELD

[0001] Aspects of embodiments of the present disclosure relate to a battery module, a battery system comprising the battery module, and an electric vehicle comprising the battery module and / or the battery system. Further aspects of embodiments of the present disclosure relate to a method for assembling a battery module and a housing configured to house a stack of battery cells. BACKGROUND

[0002] Recently, vehicles using electric power as a power source (e.g., vehicles for transporting goods and people) have been developed. Electric vehicles are automobiles that are propelled permanently or temporarily by electric motors using energy stored in rechargeable (or secondary) batteries. Electric vehicles can be powered by batteries, such as in battery electric vehicles (BEVs), or can include a combination of electric motors and, for example, internal combustion engines, such as in plug-in hybrid electric vehicles (PHEVs). BEVs and PHEVs use high-capacity rechargeable batteries designed to provide power for propulsion over sustained periods of time.

[0003] Generally, a rechargeable (or secondary) battery cell includes an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. A solid or liquid electrolyte allows ions to move during charging and discharging of the battery cell. The electrode assembly is located in a case, and electrode terminals located outside of the case establish conductive connections to the positive electrode and the negative electrode, respectively. The shape of the case can be, for example, cylindrical or rectangular.

[0004] A battery master module is formed of a plurality of battery cells connected together in series and / or in parallel. For example, to achieve a high-power rechargeable battery and depending on the required or desired electric power, the battery master module is formed by interconnecting the electrode terminals of the plurality of battery cells.

[0005] The battery master module can be constructed in a block design or a modular design. In the block design, each battery cell is connected to a common current collector structure and a common battery management system, and its cells are arranged in a housing. In the modular design, a plurality of battery cells are connected together to form a (sub)module, and several (sub)modules are connected together to form the battery master module. In automotive applications, a battery system can consist of a plurality of battery (sub)modules and / or battery master modules connected to each other in series to provide a desired voltage.

[0006] Mechanical integration of the battery master module requires proper mechanical connections between the individual components (e.g., individual components of the battery module) and them with the support structure of the vehicle. These connections must remain functional and protected during the average service life of the battery system. Furthermore, installation space and interchangeability requirements must be met, particularly in mobile applications.

[0007] Mechanical integration of the battery module can be achieved by providing a carrier frame and by positioning the battery module thereon. Securing the battery cells or the battery module can be achieved by assembly recesses in the frame or by mechanical interconnections such as bolts or screws. Optionally, the battery module is restrained by fastening side plates to the lateral sides of the carrier frame. Furthermore, a cover plate can be secured on top and below the battery module.

[0008] The carrier frame of the battery master module is mounted to the load bearing structure of the vehicle. In some cases, the battery master module should be secured at the bottom of the vehicle and a mechanical connection can be established from the bottom side, for example, by bolts through the carrier frame of the battery master module. The frame can be made of aluminum or aluminum alloy to reduce the overall weight of the construction.

[0009] To reduce the manufacturing cost of the battery module, a conventional battery module includes a battery cell stack, a single frame having an open front surface and an open rear surface, and end plates for covering the open front surface and the open rear surface of the single frame. The battery module is horizontally assembled by inserting the battery cell stack into the open front surface or the open rear surface of the single frame and covering the open front surface and the open rear surface with the end plates.

[0010] However, despite the technical improvements, the manufacturing of the battery system is still cumbersome, cost-intensive, and the design of the battery module housing is limited due to the required or desired mechanical elastic properties to reduce the risk of the housing bending during the stacking or during the use of the battery system. During the operation of the battery system, the battery cells are heated and expanded due to the chemical reactions, thereby generating forces to the housing that bend the housing. The bending of the housing impairs the service life of at least the battery cells next to the bent housing and can further cause other unintended effects, which in turn can lead to a weakening of the entire battery system.

[0011] Accordingly, an aspect of the present disclosure can provide a simplified battery module with increased service life. SUMMARY

[0012] The present disclosure is defined by the appended claims and their equivalents. The following description is subject to such limitations. Any disclosure beyond the scope of the claims and their equivalents is intended for illustrative and comparative purposes.

[0013] According to one or more embodiments of the present disclosure, a battery module includes a battery cell stack having a plurality of battery cells arranged in a stacking direction, and a case configured to accommodate the battery cell stack. The case includes a bottom, a top, two sides arranged opposite to each other in the stacking direction and interconnecting the bottom and the top in a height direction, and a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction. The top has an opened section on electrode terminals of the plurality of battery cells of the battery cell stack and an exhaust valve.

[0014] According to one or more embodiments of the present disclosure, a battery system includes a plurality of battery modules arranged adjacent to each other.

[0015] According to one or more embodiments of the present disclosure, an electric vehicle includes a battery module and / or a battery system.

[0016] According to one or more embodiments of the present disclosure, a method for assembling a battery module includes arranging a plurality of battery cells in a stacking direction to form a battery cell stack, and inserting the battery cell stack into a case, wherein the case includes a bottom, a top, two sides arranged opposite to each other in the stacking direction and interconnecting the bottom and the top in a height direction, and a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction, wherein the top includes an opened section on electrode terminals of the plurality of battery cells of the battery cell stack and an exhaust valve.

[0017] One or more embodiments of the present disclosure include a case configured to accommodate a battery cell stack including a plurality of battery cells, the case including a bottom, a top, and two sides arranged opposite to each other in a stacking direction of the plurality of battery cells of the battery cell stack and interconnecting the bottom and the top in a height direction, and a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction, wherein the top includes an opened section on electrode terminals of the plurality of battery cells of the battery cell stack and an exhaust valve.

[0018] Further aspects of the present disclosure are set out in the claims and / or in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0019] Example embodiments will be described in greater detail by referring to the drawings, in which:

[0020] Figure 1is a schematic perspective view of a battery module in a first configuration according to one or more embodiments.

[0021] Figure 2 is a schematic perspective view of a battery module in a second configuration. Figure 1

[0022] Figure 3 Figure 2

[0023] Figure 4 is a schematic perspective view of a housing according to one or more embodiments.

[0024] Figure 5 is a schematic perspective view of a housing. Figure 4

[0025] Figure 6 is a schematic perspective view of a battery system including four Figure 1

[0026] Figure 7 is a schematic flowchart of a method for assembling a battery module according to one or more embodiments. Figure 1 DETAILED DESCRIPTION

[0027] Reference will now be made in detail to one or more embodiments, examples of which are illustrated in the accompanying drawings. Aspects and features of the embodiments and their implementation will be described in more detail with reference to the drawings, in which like reference numerals refer to like elements throughout. The present disclosure can be embodied in one or more of the different forms, and should not be construed as being limited only to the embodiments set forth herein. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the present disclosure to those skilled in the art.

[0028] Therefore, processes, elements, and techniques can not be described or can be described only briefly in order not to obscure aspects and features of the present disclosure that are considered to be essential to an understanding of the present disclosure by those of ordinary skill in the art. In the drawings, the relative sizes of the elements, layers, and regions can be exaggerated for the sake of clarity.

[0029] ​​​​​​It will be understood that when an element or layer is referred to as being "on" or "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers can be present. When an element or layer is referred to as being "directly on", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers present. For example, when a first element is described as "coupled" or "connected" to a second element, the first element can be directly coupled or connected to the second element or the first element can be indirectly coupled or connected to the second element via one or more intervening elements.

[0030] In the drawings, the size of various elements, layers, etc., can be exaggerated for clarity. Like reference numbers signify like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In addition, use of "may" when describing embodiments of the present disclosure relates to "one or more embodiments of the present disclosure." Expressions such as "at least one of," and "one or more of," when preceding a list of two or more items, cover the same examples as "one of" and "one but not more than one" or "one, two, three or four" of the items on the list. For example, "at least one of a, b, and c" covers the cases where a is the only item selected, b is the only item selected, c is the only item selected, a and b together are selected, a and c together are selected, b and c together are selected, and a, b, and c are all selected. As used herein, the terms "use," "using," and "used" can be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively. As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in a measurement or calculation that would be recognized by those of ordinary skill in the art.

[0031] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of example embodiments.

[0032] For ease of description, spatial relationship terms, such as "below", "under", "lower", "above", "upper", and the like, can be used herein for describing the orientation of one element or feature with respect to another element or feature, as illustrated in the drawings. It will be understood that the spatial relationship terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if a device is inverted, elements described as "below" or "under" other elements or features would then be oriented "above" the other elements or features. Thus, the terms "below" and "under" can encompass both orientations. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0033] The terminology used herein is for the purpose of describing embodiments of the present disclosure only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0034] A comparison of two objects being "the same" means "substantially the same". Thus, "the same" or "substantially the same" can include a deviation that is considered low in the art, for example, less than 5% deviation. In addition, uniformity of a parameter at a region can mean uniformity from an average perspective.

[0035] It will be further understood that when a film, region, or element is referred to as being "on" or "above" another film, region, or element, it can be directly on the other film, region, or element or one or more intervening films, regions, or elements can also be present.

[0036] Here, the terms "upper" or "top" and "lower" or "bottom" are defined according to the z-axis. For example, the upper cover is located at the upper portion of the z-axis, and the lower cover is located at the lower portion thereof. In the drawings, the size of elements can be exaggerated for clarity. For example, in the drawings, the size or thickness of each element can be arbitrarily shown for the purpose of illustration, and thus embodiments of the present disclosure should not be construed to be limited thereto.

[0037] In the following description of embodiments of the present disclosure, the singular form of the terms can include the plural form unless the context clearly indicates otherwise.

[0038] Electronic or electrical devices and / or any other related devices or components according to one or more embodiments of the present disclosure described herein can be implemented using any suitable hardware, firmware (e.g., dedicated integrated circuits), software, or combinations of software, firmware, and hardware. Moreover, various components of such devices can be implemented on flexible printed circuit films, tape carrier packages (TCPs), printed circuit boards (PCBs), or formed on a substrate. Electrical connections or interconnections described herein can be implemented by wires or conductive elements (e.g., wires or conductive elements on a PCB or another circuit carrier). The conductive elements can include metallization (e.g., surface metallization) and / or pins, and / or can include conductive polymers or ceramics. Moreover, electrical energy can be transmitted via wireless connections, e.g., using electromagnetic radiation and / or light.

[0039] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0040] According to one or more embodiments of the present disclosure, a battery module includes a battery cell stack and a case. The battery cell stack includes a plurality of battery cells arranged in a stacking direction. The case is configured to accommodate the battery cell stack.

[0041] The case includes a bottom, a top, and two sides. The two sides are arranged opposite to each other in the stacking direction and interconnect the bottom and the top in a height direction (e.g., the height direction is a direction of a height of the battery cells of the battery cell stack). One of the two sides interconnects a first end of the bottom and a first end of the top, and the other of the two sides interconnects a second end of the bottom and a second end of the top, the second end of the bottom being arranged opposite to the first end of the bottom in the stacking direction, and the second end of the top being arranged opposite to the first end of the top in the stacking direction. The bottom can correspond to a bottom of the case. The sides can include (e.g., can be formed as) side walls extending from the bottom to the top. The top can correspond to a top cover of the case.

[0042] The housing further comprises a side opening through which the battery cell stack is insertable into the housing in an insertion direction (or in a direction opposite to the insertion direction, which will not be repeated but is also considered in the following disclosure). The insertion direction is orthogonal to the stacking direction and orthogonal to the height direction. For example, the battery cell stack is inserted laterally into the housing through the side opening. In other words, the housing provides a structure around the inserted battery cell stack when viewed in the insertion direction. For example, the housing is a closed structure, such as a closed frame, with an insertion opening (the side opening) when viewed in the insertion direction. Due to this structure, a bending of the side portions in the stacking direction can be prevented or at least reduced, for example during assembly or operation of the battery module. On a side of the housing arranged opposite to the side opening in the insertion direction, the housing can be closed, for example by a wall extending in the height direction from the bottom to the top. Due to the closing of the side opposite to the side opening, this wall can act as a barrier when the battery cell stack is inserted into the housing. Thus, assembly thereof is facilitated and the robustness of the battery module can be increased. For example, the housing can comprise a further side opening at the side opposite to the side opening in the insertion direction, through which the battery cell stack is insertable into the housing in the insertion direction. Both side openings can be formed identically or almost identically. Thus, the battery cell stack is insertable into the housing from both sides (e.g. opposite sides), thereby facilitating assembly of the battery module. Furthermore, a smaller space along the insertion direction can be required or desired. In other words, the length of the battery cell stack with respect to the insertion direction can correspond to the length of the housing with respect to the insertion direction, such that the battery cell stack can be flush with the housing. Thus, a more compact battery module can be formed. The length of the housing in the insertion direction can be important such that the battery cell stack can be accommodated in the housing at least completely in the insertion direction.

[0043] The top comprises an opening portion which is located on the electrode terminals and the exhaust valves of the plurality of battery cells of the battery cell stack when the battery cell stack is accommodated in the housing (i.e. inserted into the housing). In other words, the opening portion is configured such that the electrode terminals and the exhaust valves of the plurality of battery cells of the accommodated battery cell stack are exposed when viewed from above (i.e. when viewed from the top of the housing). Due to the exposure of the functional areas (i.e. the electrode terminals and the exhaust valves) of the battery cells, the electrode terminals can be subsequently connected and the exhaust valves are not blocked by the housing in case of an exhaust event in which it is required or desired to exhaust the battery cells via the exhaust valves. The opening portion is surrounded by the top in the insertion direction, for example by the bars extending between the side portions in the stacking direction. In other words, although the opening portion provides access to the functional areas of the battery cells, the top increases the rigidity and the stiffness of the housing to resist potential bending of the side portions. Thus, a bending of the side portions of the housing can be prevented or at least reduced, thereby enabling an increased service life of the battery module.

[0044] According to one or more embodiments, the opening portion can include a slit-like opening extending through the top portion in the stacking direction and located on each of the electrode terminals and the exhaust valves of the plurality of battery cells of the battery cell stack when the battery cell stack is accommodated in the case. In other words, the slit-like opening has a size that allows all of the functional areas (i.e., the electrode terminals and the exhaust valves) of the battery cells of the battery cell stack to be exposed when viewed from above (i.e., from the top portion). Accordingly, at least one opening must be provided into the top portion to provide this functionality, thereby facilitating the manufacture of the battery module. Although reference is made to a slit-like opening, the shape of the opening is not limited thereto and can have different shapes, such as a circular shape, an elliptical shape, a diamond shape, and / or the like. Many battery cells have a rectangular shape, e.g., a square shape or a cuboid shape (prismatic cells), and are arranged in a row in the stacking direction such that straight rows of electrodes and exhaust valves are formed. Accordingly, the slit-like opening is effective for exposing the electrodes and the exhaust valves while providing the rigidity and stiffness of the case to resist potential bending of the side portions.

[0045] According to one or more embodiments, the opening portion can include three slit-like openings extending through the top portion in the stacking direction. Two of the three slit-like openings can be (e.g., formed to be) located on the electrode terminals, i.e., one slit-like opening on each row of electrode terminals, and the remaining slit-like opening of the three slit-like openings can be (e.g., formed to be) located on the exhaust valves of the plurality of battery cells of the battery cell stack when the battery cell stack is accommodated in the case. In other words, the top portion of the case can include one or more bars extending between the side portions in the stacking direction and arranged between the slit-like openings. The bars further increase the rigidity and stiffness of the case to resist potential bending of the side portions while still exposing the electrode terminals and the exhaust valves when viewed from above (i.e., from the top portion). The slit-like openings can be arranged parallel to each other. Although reference is made to slit-like openings, the shape of the openings is not limited thereto and can have different shapes, such as a circular shape, an elliptical shape, a diamond shape, and / or the like.

[0046] According to one or more embodiments, the opening portion can extend completely through the top portion in the stacking direction. In one or more embodiments, the opening portion can extend partially through the side portions. Accordingly, the manufacture of the case can be facilitated. In one or more embodiments, the horizontal exhaust passage (i.e., in the stacking direction) can extend partially through the side portions such that no additional space is needed or desired in the height direction to exhaust the exhaust gas from the battery module.

[0047] According to one or more embodiments, the battery cell stack can include a force distribution plate and a compressible elastic element arranged at each of the ends (e.g., opposite ends) of the battery cell stack in the stacking direction. In other words, both ends of the battery cell stack in the stacking direction are covered or surrounded by the force distribution plate. The force distribution plate can have a shape corresponding to the size of the battery cells of the battery cell stack when viewed in the stacking direction. Thus, the battery cell stack can be handled by contacting the force distribution plate without damaging the battery cell stack. The compressible elastic element can be on an outer surface of the force distribution plate with respect to the stacking direction. At least one of the compressible elastic elements can be a spring. When the battery cell stack is handled at the force distribution plate, the compressible elastic element can be compressed such that the length of the battery cell stack in the stacking direction is reversibly reduced until the battery cell stack is accommodated in the housing, where the compressible elastic element provides a restoring force or a counter force against the sides of the housing to ensure secure seating of the accommodated battery cell stack. Thus, assembly of the battery module is facilitated and its service life is improved.

[0048] The compressible elastic element can include a diminishing spring. At the beginning of compression, the diminishing spring is able to be compressed by applying a relatively small force, while the amount of force required for further compression of the spring increases during compression. Thus, when the battery cell stack is inserted into the housing to assemble the battery module, the length of the battery cell stack in the stacking direction can be relatively easily reduced. When the battery cell stack is accommodated in the housing, further compression of the diminishing spring requires or desires an increased amount of force to improve secure seating of the accommodated battery cell stack.

[0049] According to one or more embodiments, each side of the housing can include a recess for receiving the compressed compressible elastic element. The recess provides additional space for inserting the battery cell stack into the housing, thereby further facilitating assembly of the battery module. Each recess can have a depth that is greater than 5% and / or less than 30%, less than 20%, and / or less than 10% of the thickness of the side in the stacking direction. For example, the housing and the recess can be designed such that the compressible elastic element is compressed when the battery cell stack is accommodated in the housing. For example, the compressible elastic element can be compressed by at least 10% and / or at most 75%, at most 50%, or at most 25% with respect to the length of the compressible elastic element in a rest position (e.g., when the compressible elastic element is not compressed).

[0050] According to one or more embodiments, the housing can include a cooling plate arranged on the bottom portion. The cooling plate enhances heat dissipation. The cooling plate can be arranged on the inner side of the bottom portion. In other words, the cooling plate can be arranged between the bottom portion of the housing and the housed battery cell stack. Thus, due to this positioning, the transfer of heat (e.g., heat generated by the operation of the battery cells) in the battery module towards the outside of the battery module is further enhanced, thereby reducing the amount of swelling of the battery cells, and thus the amount of bending of the side portion of the housing.

[0051] According to one or more embodiments, the bottom portion, the top portion, and the side portion of the housing can be integrally formed. In other words, the housing can be integrally formed. For example, the housing can be extrusion formed, and optionally machined, e.g., to include an opening portion in the top portion. The integrally formed structure provides further rigidity and stiffness of the housing to resist potential bending of the side portion. In one or more embodiments, the bottom portion, the top portion, and the side portion of the housing can be connected to each other in a fabric-conclusive manner, where fabric-conclusive manner refers to a method of forming a fabric-like structure, where multiple components are connected similar to a way of weaving, resulting in a completely integral object. In other words, the bottom portion, the top portion, and the side portion can be separate parts, e.g., extrusion formed separate parts, which are connected to each other in a subsequent step, e.g., to form a woven fabric.

[0052] According to one or more embodiments, the housing can include (e.g., be made of) plastic or a hybrid combination including plastic. Due to the closed structure of the housing, its rigidity and stiffness are increased to such an extent that a material with less mechanical elasticity than other metals used in the art, such as aluminum, can be used. In contrast to metals, plastic is insulating, thereby reducing the risk of current leakage or short circuit.

[0053] According to one or more embodiments, the top portion can include a convex shape. In other words, the middle section of the top portion in the stacking direction can have a thickness that is greater than the thickness of the end portions of the top portion (e.g., the end portions of the top portion). Due to the convex shape, the risk of bending of the side portion can be further reduced. The top portion can include a single convex shape arranged at one surface (e.g., the inner surface or the outer surface), or a double convex shape arranged on both surfaces (e.g., opposite surfaces), i.e., the inner surface and the outer surface, thereof. The convex shape can be formed such that the middle section of the top portion in the stacking direction can have a thickness that is at least 5% or at least 10% greater than the thickness of the end portions of the top portion and / or less than 100%, less than 75%, less than 50%, or less than 25%.

[0054] The present disclosure also includes a battery system comprising a plurality of battery modules according to one or more embodiments of the present disclosure arranged adjacent to each other. For example, the battery system can be a traction battery. The plurality of battery modules can be arranged adjacent to each other in a modular manner, for example in a grid-like manner. In other words, the battery modules can be arranged adjacent to each other in a stacking direction and / or in an insertion direction. Thus, a cost-effective and space-saving battery system with a high service life can be provided.

[0055] The present disclosure also includes an electric vehicle comprising a battery module according to one or more embodiments of the present disclosure and / or a battery system according to one or more embodiments of the present disclosure.

[0056] Furthermore, the present disclosure relates to a method for assembling a battery module, i.e. the above-mentioned battery module.

[0057] According to a step of the method, a stack of battery cells is formed by arranging a plurality of battery cells in a stacking direction.

[0058] According to a further step of the method, a housing configured to accommodate the stack of battery cells is provided. The housing comprises a bottom, a top, two side portions arranged opposite to each other in the stacking direction and interconnecting the bottom and the top in a height direction, and a side opening through which the stack of battery cells can be inserted into the housing in an insertion direction, which is orthogonal to the stacking direction and orthogonal to the height direction. The top comprises an opening portion which is located on the electrode terminals and the exhaust valves of the plurality of battery cells of the stack of battery cells when the stack of battery cells is accommodated in the housing.

[0059] According to a further step of the method, the stack of battery cells is inserted into the housing in the insertion direction through the side opening.

[0060] According to a step of the method, the electrode terminals of each row of the plurality of battery cells of the accommodated stack of battery cells can be interconnected. In one or more embodiments, the electrode terminals of the battery cells of the stack of battery cells can be interconnected before being inserted into the housing. In other words, the electrode terminals of the provided stack of battery cells can already be interconnected.

[0061] According to a further step of the method, inserting the stack of battery cells can comprise the steps of compressing the compressible elastic elements of the stack of battery cells, for example with a pincer device, and placing the compressed stack of battery cells into the housing.

[0062] The present disclosure also includes a case configured to accommodate a battery cell stack. The case includes a bottom, a top, two sides arranged opposite to each other in a stacking direction of battery cells of the battery cell stack and interconnecting the bottom and the top in a height direction, and a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction. The top includes an opening portion located on electrode terminals and exhaust valves of the battery cells of the battery cell stack when the battery cell stack is accommodated in the case.

[0063] Specific embodiments

[0064] Figure 1 is a schematic perspective view of a battery module 100 in a first configuration according to one or more embodiments. Figure 2 is a schematic perspective view of the battery module 100 in a second configuration. Figure 1 is a schematic perspective view of the battery module 100 in a second configuration.

[0065] The battery module 100 includes a battery cell stack 10 and a case 30 configured to accommodate the battery cell stack 10. In a first configuration, the battery cell stack 10 and the case 30 are separated from each other. In a second configuration, the battery cell stack 10 is accommodated in the case 30.

[0066] The battery cell stack 10 includes a plurality of battery cells 12 arranged in a stacking direction S. As Figure 1 illustrated, the battery cells 12 can include prismatic cells, i.e. cells whose chemical substances are enclosed in a rigid housing, but are not limited thereto. The battery cells 12 can have a rectangular shape, which allows the battery cells 12 to be efficiently stacked in the stacking direction S. For example, the shortest side of each battery cell 12 is arranged in a direction parallel to the stacking direction S. On a top surface, each battery cell 12 includes a pair of electrode terminals 14 arranged on opposite ends of the battery cell 12 in a direction orthogonal to the stacking direction S, e.g. an insertion direction I, which will be explained in more detail with respect to the case 30 later. Each battery cell 12 also includes an exhaust valve 16 between the pair of electrode terminals 14. Due to the stacking structure, the electrode terminals 14 and the exhaust valves 16 are arranged in respective rows extending along the stacking direction S.

[0067] The battery cell stack 10 further comprises a force distribution plate 18 and a compressible elastic element 20, each of which is arranged at each of the ends (e.g. opposite ends) of the battery cell stack 10 in the stacking direction S. The force distribution plate 18 is formed and arranged such that the surface of the respective outer battery cell 12 of the battery cell stack 10 in the stacking direction S is substantially covered (e.g. completely covered) by the force distribution plate 18. Thus, the battery cell stack 10 can be handled by contacting the force distribution plate 18 without damaging the battery cell stack 10. The compressible elastic element 20 can be a decompression spring which is on the outer surface of the respective force distribution plate 18 in the stacking direction S. The compressible elastic element 20 can be compressed during handling of the battery cell stack 10 at the force distribution plate 18 (e.g. handling with a pliers device) such that the length of the battery cell stack 10 in the stacking direction S is reversibly reduced until the battery cell stack 10 can be accommodated in the housing 30 as described later in more detail with respect to Figure 3 The present disclosure is not limited thereto, however, and the force distribution plate 18 and the compressible elastic element 20 can also not be provided.

[0068] Now referring to the housing 30, it will be described with respect to Figure 2 The housing 30 comprises a bottom 32, a top 34, a first side 36 and a second side 38. The bottom 32 and the top 34 are arranged opposite to each other in a height direction H (see Figure 1 ). The height direction H refers to the direction of the height of the battery cells 12 of the battery cell stack 10. Thus, the height direction H is orthogonal to the stacking direction S. The first side 36 and the second side 38 are arranged opposite to each other in the stacking direction S and interconnect the bottom 32 and the top 34 in the height direction H.

[0069] The housing 30 further has a side opening 40 through which the battery cell stack 10 can be inserted into the housing 30 in an insertion direction I. As Figure 1 shown, the insertion direction I is orthogonal to the stacking direction S and orthogonal to the height direction H. In other words, when viewed in the insertion direction I (see Figure 2 ), the housing 30 provides a structure around the inserted or accommodated battery cell stack 10. For example, when viewed in the insertion direction I, the housing 30 is a closed structure, e.g. a closed frame, having an insertion opening (the side opening 40). Due to this structure, bending of the sides 36, 38 in the stacking direction S can be prevented or at least reduced, e.g. during assembly or operation of the battery module 100.

[0070] On the side opposite to the side opening 40 in the insertion direction I, the housing 30 can be closed, for example by a wall extending in the height direction H from the bottom 32 to the top 34. Due to the closure of the side opposite to the side opening 40, this wall can serve as a barrier when the battery cell stack 10 is inserted into the housing 30. Thus, its assembly is facilitated and the robustness of the battery module 100 can be improved.

[0071] In one or more embodiments and as shown in Figure 1 and Figure 2 The housing 30 comprises a further side opening at the side opposite to the side opening 40 in the insertion direction I, through which the battery cell stack 10 can also be inserted into the housing 30 in the insertion direction I. The two side openings can be formed identically or almost identically. Thus, if necessary or desired, the battery cell stack 10 can be inserted into the housing 30 from both sides (e.g. opposite sides), thereby facilitating the assembly of the battery module 100. Furthermore, less space is required or desired in the insertion direction I. In other words, the length of the battery cell stack 10 in the insertion direction I can correspond to the length of the housing 30 in the insertion direction I, so that the battery cell stack 10 can be arranged flush with the housing 30 (or less than flush with the housing 30, i.e. the housing 30 protrudes from the battery cell stack 10). Thus, a compact battery module 100 can be provided. The length of the housing 30 in the insertion direction I can be important, so that the battery cell stack 10 can be accommodated in the housing 30 at least with respect to the insertion direction I (e.g. completely in the housing 30), as shown in Figure 2

[0072] As further shown in Figure 1 and Figure 2 The top 34 of the housing 30 has an opening portion 42, which is located on the electrode terminals 14 and the exhaust valve 16 of the plurality of battery cells 12 of the battery cell stack 10 when the battery cell stack 10 is accommodated in the housing 30 (see Figure 2 ​). In other words, the opening portion 42 is configured so that when viewed from above (i.e., when viewed from the top 34 of the housing 30), the electrode terminals 14 and the vent valves 16 of the plurality of battery cells 12 of the accommodated battery cell stack 10 are exposed. Due to the exposure of the electrode terminals 14 and the vent valves 16 (which can be considered as the functional areas of the battery cell 12), the electrode terminals 14 can be subsequently connected more easily, and in the event of a venting event in which it is necessary or desired to vent the battery cell 12 via the vent valve 16, the vent valve 16 is not blocked by the housing 30. The opening portion 42 is surrounded by the top 34 in the insertion direction I, for example, by one or more rods extending between the side portions 36, 38 in the stacking direction S. In other words, although the opening portion 42 provides access to the functional areas of the battery cell 12, the top 34 increases the rigidity and stiffness of the housing 30 to resist potential bending of the sides 36, 38. Therefore, bending of the sides 36, 38 of the housing 30 can be prevented or at least reduced, thereby increasing the service life of the battery module 100. The opening portion 42 can facilitate inserting the battery cell stack 10 into the case 30 or removing the battery cell stack 10 from the case 30 .

[0073] like Figure 1 and Figure 2 As shown, the opening portion 42 may include three slit-shaped openings 44 extending through (e.g., completely extending through) the top portion 34 in the stacking direction S. Two of the three slit-shaped openings 44 are formed to be located on the corresponding rows of electrode terminals 14, i.e., there is one slit-shaped opening 44 for each row of electrode terminals 14, and the remaining of the three slit-shaped openings 44 are formed to be located on the vent valves 16 of the plurality of battery cells 12 in the battery cell stack 10 when the battery cell stack 10 is accommodated in the case 30. In other words, the top portion 34 of the case 30 includes two outer rods and two inner rods extending from one of the side portions 36, 38 to the other of the side portions 36, 38 in the stacking direction S, such that each slit-shaped opening 44 is formed between two adjacent rods. Providing more connections to the top 34 in the stacking direction S, such as using additional rods to provide three slit-like openings 44, provides greater rigidity and stiffness to the housing 30 to resist potential bending of the sides 36, 38, while still ensuring that the electrode terminals 14 and the exhaust valve 16 are exposed when viewed from above (i.e., from the top 34). The slit-like openings 44 are arranged parallel to each other.

[0074] like Figure 1 and Figure 2As further illustrated, the housing 30 comprises a cooling plate 48 on the bottom portion 32. The cooling plate 48 enhances heat dissipation. The cooling plate 48 is on the inner side of the bottom portion 32, i.e. the surface of the bottom portion 32 facing the accommodated battery cell stack 10. In other words, the cooling plate 48 is between the bottom portion 32 of the housing 30 and the accommodated battery cell stack 10. Thus, due to the provision of the cooling plate 48, the transfer of heat, e.g. heat generated by the operation of the battery cells 12, in the battery module 100 towards the outside is further enhanced, thereby reducing the amount of swelling of the battery cells 12 and, thus, the amount of bending of the side portions 36, 38 of the housing 30. However, the present disclosure is not limited thereto and can not provide the cooling plate 48.

[0075] Referring to Figure 3 Fig. 3, which is a schematic enlarged view of the region III shown in Figure 2 Fig. 2, an enlarged cross-section of one of the end portions of the battery module 100 in the stacking direction S shows that each of the side portions 36, 38 of the housing 30 comprises a recess 46 for receiving a respective compressed compressible elastic element 20 when the battery cell stack 10 is accommodated in the housing 30. The compressible elastic element 20 is compressed during handling of the battery cell stack 10 at the force distribution plate 18, e.g. with a pincer device, such that the length of the battery cell stack 10 in the stacking direction S is reversibly reduced until the battery cell stack 10 is accommodated in the housing 30. The compressible elastic element 20 provides a restoring force or counter force to the side portions 36, 38 of the housing 30 to ensure a firm seating of the accommodated battery cell stack 10. Thus, the assembly of the battery module 100 is facilitated and its service life is improved.

[0076] The recess 46 is configured to provide further space in the stacking direction S for inserting the battery cell stack 10 into the housing 30, thereby further facilitating the assembly of the battery module 100. Each recess 46 has a depth of more than 5% and less than 20% of the thickness of the respective side portion 36, 38 in the stacking direction S. For example, the housing 30 and the recess 46 are designed such that the compressible elastic element 20 is compressed by at least 10% and at most 50% with respect to the length of the compressible elastic element 20 in the rest position, e.g. when the compressible elastic element 20 is not compressed, when the battery cell stack 10 is accommodated in the housing 30. However, the present disclosure is not limited thereto and can not provide the recess 46.

[0077] Figure 4 is a schematic perspective view of the housing 30 according to one or more embodiments, Figure 5 is a schematic cross-section of the housing 30 as shown in Figure 4 Fig. 2, and Figure 4 and Figure 5As shown, the top portion 34 can have a convex shape. In other words, the middle section of the top portion 34 in the stacking direction S has a greater thickness than the thickness of the end portions (e.g., opposite end portions) of the top portion 34 in the stacking direction S (see Figure 5 ). At least one (or each) of the bars extending between the side portions 36, 38 comprises a convex shape (see Figure 4 ). Due to the convex shape, the risk of bending of the side portions 36, 38 can be further reduced. The top portion 34 comprises a single convex shape arranged at one surface (e.g., an outer surface as shown in Figure 4 and Figure 5 ). The convex shape is formed such that the middle section of the top portion 34 in the stacking direction S has a thickness that is at least 5% and less than 25% greater than the thickness of the end portions of the top portion 34 in the stacking direction S. However, the present disclosure is not limited thereto, and the convex shape can not be provided. For example, the bars can also be flat.

[0078] The housing 30 can comprise (or be made of) plastic or a hybrid combination comprising plastic. Due to the closed structure of the housing 30, its rigidity and stiffness increase to such an extent that a material with less mechanical elasticity than other metals used in the art, such as aluminum, can be used. In contrast to metals, plastic is insulating, thereby reducing the risk of current leakage or short circuit. The mechanical properties of plastic and aluminum are shown in Table 1 below.

[0079]

[0080] Table 1: Mechanical properties of plastic and aluminum

[0081] Figure 6 is a schematic perspective view of a battery system 1000 comprising four Figure 1 battery modules 100 as shown. The plurality of battery modules 100 can be arranged adjacent to each other in a modular manner, e.g., in a grid-like arrangement. In other words, the battery modules 100 can be adjacent to each other in the stacking direction S and in the insertion direction I. As shown in Figure 6As shown, the battery modules 100 can be arranged in a 2x2 grid-like fashion. Thus, a cost-effective and space-saving battery system 1000 with a high service life can be provided in a modular fashion. For example, the exhaust gas channels provided by the slit-like openings 44 on the exhaust valves 16 of each battery module 100 can be fluidically connected with the respective exhaust gas channels of adjacent battery modules in the stacking direction S, so that the exhaust gas channels can be more easily implemented by the battery system 1000 and do not require any additional space in the height direction H. Furthermore, the electrode terminals 14 of the respective rows of adjacent battery modules in the stacking direction S can also be more easily interconnected, if required or desired. However, the battery system 1000 is not limited to the shown number of battery modules 100 and can comprise any number of battery modules 100 in any arrangement, as required or desired for a particular case.

[0082] Figure 7 a method for assembling a battery module 100 according to one or more embodiments is shown. Figure 1 a schematic flowchart of a method for assembling a battery module 100 according to one or more embodiments is shown.

[0083] According to a first step 50, a plurality of battery cells is arranged in a stacking direction S to form a battery cell stack 10 as described above.

[0084] According to a second step 52 of the method, a housing 30 is provided which is configured to accommodate the battery cell stack 10. The housing 30 refers to the housing 30 as described above. The housing 30 comprises a bottom 32, a top 34, two side portions 36, 38 which are arranged opposite to each other with respect to the stacking direction S and which interconnect the bottom 32 and the top 34 in a height direction H, and a side opening 40 through which the battery cell stack 10 can be inserted into or removed from the housing 30 in an insertion direction I. The insertion direction I is orthogonal to the stacking direction S and orthogonal to the height direction H. The top 34 comprises an opening portion 42 to be located on the electrode terminals 14 and the exhaust valves 16 of the plurality of battery cells 12 of the battery cell stack 10 when the battery cell stack 10 is accommodated in the housing 30, for example as shown in Figure 2 .

[0085] According to a third step 54 of the method, the battery cell stack 10 is inserted into the housing 30 in the insertion direction I through the side opening 40, for example as shown in Figure 1 .

[0086] Aspects and features of the present disclosure are not limited to those described above, and other aspects and features which are not mentioned herein can be clearly understood by a person skilled in the art from the description of the present disclosure and the appended claims.

[0087] Although embodiments have been disclosed herein, and specific terms have been employed, they are used and intended only in a generic and descriptive sense, and not for purposes of limitation. Thus, equivalent substitutions and modifications will be apparent to one of ordinary skill in the art and can be made without departing from the spirit and scope of the disclosure as set forth in the following claims and their equivalents.

[0088] Reference numerals

[0089] 10 cell stack

[0090] 12 battery cell

[0091] 14 electrode terminal

[0092] 16 exhaust valve

[0093] 18 force distribution plate

[0094] 20 compressible elastic element

[0095] 30 housing

[0096] 32 bottom

[0097] 34 top

[0098] 36 first side

[0099] 38 second side

[0100] 40 side opening

[0101] 42 opening portion

[0102] 44 slit-like opening

[0103] 46 recess

[0104] 48 cooling plate

[0105] 50 first step

[0106] 52 second step

[0107] 54 third step

[0108] 100 battery module

[0109] 1000 battery system

[0110] S stacking direction

[0111] I insertion direction

[0112] H height direction

Claims

1. A battery module, comprising: a stack of battery cells comprising a plurality of battery cells arranged in a stacking direction; and a housing configured to accommodate the stack of battery cells, wherein the housing comprises: a bottom; a top; two side portions arranged opposite to each other in the stacking direction and interconnecting the bottom and the top in a height direction; and a side opening through which the stack of battery cells is insertable into the housing in an insertion direction, the insertion direction being orthogonal to the stacking direction and orthogonal to the height direction, and wherein the top has an opening portion located on electrode terminals of the plurality of battery cells of the stack of battery cells and on a gas exhaust valve.

2. The battery module according to claim 1, wherein the opening portion comprises a slit-like opening extending through the top in the stacking direction.

3. The battery module according to claim 2, wherein the slit-like opening comprises three slit-like openings, wherein at least two of the three slit-like openings are located on the electrode terminals and at least one of the three slit-like openings is located on the gas exhaust valve of the plurality of battery cells of the stack of battery cells.

4. The battery module according to claim 1, wherein the opening portion extends through the top in the stacking direction.

5. The battery module according to claim 1, wherein the stack of battery cells further comprises a force distribution plate and a compressible elastic element, the force distribution plate and the compressible elastic element each being arranged at opposite end portions of the stack of battery cells in the stacking direction.

6. The battery module according to claim 5, wherein the compressible elastic element comprises a progressive spring.

7. The battery module according to claim 5, wherein each of the side portions of the housing comprises a recess configured to receive the compressible elastic element.

8. The battery module according to claim 1, wherein the housing further comprises a cooling plate on the bottom.

9. The battery module according to claim 1, wherein the bottom, the top and the side portions of the housing are integrally connected to each other in a fabric final manner.

10. The battery module according to claim 1, wherein the housing comprises a plastic or a hybrid combination comprising a plastic.

11. The battery module according to claim 1, wherein the top comprises a convex shape.

12. A battery system comprising a plurality of battery modules according to any one of claims 1 to 11.

13. An electric vehicle comprising a battery module according to any one of claims 1 to 11 and / or a battery system according to claim 12.

14. A method for assembling a battery module, the method comprising: arranging a plurality of battery cells in a stacking direction to form a stack of battery cells; and inserting the stack of battery cells into a housing, wherein the housing comprises: a bottom; a top; two side portions arranged opposite to each other in the stacking direction and interconnecting the bottom and the top in a height direction; and ​ a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction, wherein the top portion includes an opening portion located on an electrode terminal and an exhaust valve of the plurality of battery cells of the battery cell stack.

15. A case configured to accommodate a battery cell stack including a plurality of battery cells, the case comprising: a bottom portion; a top portion; two side portions arranged opposite to each other in a stacking direction of the plurality of battery cells of the battery cell stack, interconnecting the bottom portion and the top portion in a height direction; and a side opening through which the battery cell stack is insertable into the case in an insertion direction orthogonal to the stacking direction and orthogonal to the height direction, wherein the top portion includes an opening portion located on an electrode terminal and an exhaust valve of the plurality of battery cells of the battery cell stack.

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