Battery of an electric vehicle and method for producing a battery

Abstract

A battery of an electric vehicle, comprising a battery cell pack (20) with a plurality of battery cells (22), a battery housing (12) which delimits a housing interior (126), wherein the housing interior (126) is at least partially filled with a potting compound (V1, V2), wherein a separate partition wall element (30) is arranged in the housing interior (126), which is plate-like and has a transverse web (34) extending from the plate-like section, wherein a first space (40) is arranged on a first side of the partition wall element (30) and a second space (42) and a third space (44) are arranged on a second side of the partition wall element (30) opposite the first side, and wherein the second space (42) is separated from the third space by the transverse web (34), wherein between the transverse web (34) and a further battery component (261,262) a gap (46) connecting the second space (42) to the third space (44) is present, wherein a first potting compound (V1) is arranged in the first space and a potting compound (V2) is arranged in the second space (42), and wherein the separating element has at least one opening (501, 502) connecting the first space (40) and the second space (42), through which opening the first potting compound (V1) extends into the second space (42) and fills the second space (42) in the region of the opening (501, 502), wherein a section (521, 522) of the first potting compound (V1) extending into the second space (42) is arranged upstream of the gap (46) in the flow direction of the second potting compound (V2) during the filling process into the second space (42).

Description

[0001] The invention relates to a battery for an electric vehicle, comprising a battery cell pack with a plurality of battery cells and a battery housing defining a housing interior, wherein the housing interior is at least partially filled with a potting compound. Furthermore, the invention relates to a method for producing a battery.

[0002] Such batteries with a battery housing filled with a potting compound are generally known from the prior art. The potting compound is usually used to fix the battery cells in the battery housing, as a heat conductor for heat transfer between the battery cells and the battery housing and / or as a flame retardant to prevent a flame if hot gases escape from at least one of the battery cells in the event of thermal runaway of the battery cell. The battery housing can be filled with a potting compound completely or only in sections, i.e. predefined cavities. If the battery housing is only partially filled with the potting compound, there are also cavities which are left out of the potting compound, i.e. which are not filled with the potting compound. The cavities filled with the potting compound and those left out by the potting compound are usually delimited by the same battery components.In DE 10 2023 133 374 B3, for example, a battery with a partition wall element arranged on an end face of a battery cell stack is known, wherein the partition wall element separates at least one cavity to be filled with a fire protection foam and a cavity not to be filled with the fire protection foam.

[0003] Due to assembly and manufacturing tolerances and to ensure the simplest possible assembly, there are gaps between the battery components that delimit the cavities. This creates the risk that the liquid potting compound will flow into the cavity to be filled with the potting compound during the filling process, into the cavity that is specifically not intended to be filled with the potting compound.

[0004] The object of the invention is to provide a battery of an electric vehicle in which the different spaces, ie the cavities filled with the potting compound and those left open by the potting compound, can be separated from one another in a simple manner and an overflow of the potting compound into the space in which no potting compound is to be present can be avoided in a simple and reliable manner.

[0005] The problem is solved by the features of claim 1.

[0006] According to the invention, a separate partition wall element is arranged in the housing interior, separating three compartments from one another. A first compartment is arranged on a first side of the partition wall element, and a second compartment and a third compartment are arranged on a second side of the partition wall element opposite the first side. To separate the second compartment from the third compartment, the generally plate-shaped partition wall element has a transverse web oriented perpendicular to the base extension of the partition wall element, which extends over the entire length of the partition wall element and thereby separates the two compartments arranged on the second side of the partition wall element from one another.

[0007] A first casting compound is arranged in the first chamber. A second casting compound is arranged in the second chamber. The third chamber does not contain any casting compound, i.e., it is not filled with a casting compound. Thus, the partition wall element separates three chambers from each other, with two of the three chambers being filled with a casting compound.

[0008] Between the crosspiece and another battery component, which runs perpendicular to the crosspiece, there is a gap connecting the second chamber to the third chamber, for example due to assembly and manufacturing tolerances. This gap creates the risk that the second potting compound, which is in a liquid state during the filling process into the second chamber, could flow through the gap into the third chamber, which should be free of the potting compound.

[0009] In order to prevent the second potting compound from flowing into the third space, the partition wall element has at least one opening connecting the first space and the second space, through which opening the first potting compound extends into the second space and fills the second space in the region of the opening, wherein the first potting compound arranged in the second space is arranged upstream of the gap in the flow direction of the second potting compound during the filling process into the second space. The second potting compound is only filled into the second space when the first potting compound has already solidified, wherein the gap is sealed or separated when the second potting compound is filled into the second space by the section of the solidified first potting compound extending into the second space.

[0010] This provides a simple and cost-effective way for the first casting compound to overflow into the second chamber, preventing the second casting compound from flowing from the second chamber into the third chamber. No additional sealing elements or similar devices are required.

[0011] In order to limit the area in the second chamber filled with the first potting compound during the filling process, a tool, for example a formwork element, is inserted in the region of the second opening of the second chamber. This allows the section of the first potting compound protruding into the second chamber to be easily formed. The formwork element can be removed after the first potting compound has solidified, or it can remain in the battery. Removing the formwork element can reduce the weight of the battery. If the formwork element is not removed, the assembly effort for the battery can be reduced by eliminating the step of removing the formwork element.

[0012] The partition wall element is preferably arranged on an end face of the battery cell pack, the first space being delimited at least by the battery cells and the partition wall element. The first space is also delimited by further battery components. In particular, the first space is delimited, in addition to the partition wall element, by two plate-like insertion aid elements used to install the battery cell pack in the battery housing, by the battery housing and / or by a battery cell carrier. The insertion aid elements are arranged on the two outermost battery cells of the battery cell pack and project beyond the battery cell pack and the partition wall element transversely to the stacking direction. The second and third spaces are also delimited, in addition to the partition wall element, by the two insertion aid elements, i.e. by the sections of the insertion aid elements projecting beyond the battery cell pack, by the battery housing and / or by the battery cell carrier.

[0013] The battery housing comprises, in particular, a base body constructed as an extruded profile with two open sides and two covers that close the open sides of the base body. During the assembly process, the battery cell pack is inserted into the battery housing through one of the open sides, and the open sides are then closed with a cover.

[0014] In a preferred embodiment, a frame-like battery cell carrier is arranged on the battery cell pack, on which the partition element is arranged. The battery cell carrier is preferably arranged on both sides of the battery cell pack and serves in particular to hold the battery cell pack together. Additionally, an electrical connection unit is arranged on the battery cell carrier in the region of the second space. In a preferred embodiment, the partition element is locked to the battery cell carrier, which can simplify the assembly of the partition element.To lock the partition element to the battery cell carrier, the partition element preferably has a plurality of locking elements and at least one support element. During assembly of the partition element to the battery cell carrier, the partition element is moved translationally in the direction of the battery cell carrier until the support element rests against the battery cell carrier. Upon the support element resting against the battery cell carrier, the locking elements engage in the openings of the battery cell carrier. Alternatively, the partition element can also be connected to the battery cell carrier using other connection techniques, such as screwing or gluing.

[0015] Preferably, the partition element is made in one piece. In a preferred embodiment, the partition element is made of plastic. In particular, the partition element is made of a thermoplastic material and is manufactured by injection molding. This allows the partition element to be manufactured in a simple and cost-effective manner.

[0016] Preferably, each of the encapsulants is a flame-retardant material. This can reduce the risk of ignition of a gas escaping from one of the battery cells due to thermal runaway, thus preventing a fire in the battery. Furthermore, the encapsulant can reduce the risk of contaminating other battery cells in the battery pack by preventing the hot gases from overflowing to the other battery cells through the first encapsulant.

[0017] Preferably, the first and second casting compounds are identical. Alternatively, the casting compounds can differ from each other, allowing the use of casting compounds with different material properties, thus allowing the casting compounds to be optimally tailored to the application.

[0018] Preferably, a gap connecting the second chamber to the third chamber is present at each of two opposite ends of the transverse web, wherein the partition wall element has two openings arranged such that the sections of the first casting compound extending into the second chamber are located upstream of the gaps in the flow direction of the second casting compound during the filling process into the second chamber. Such a configuration can prevent the second casting compound from flowing from the second chamber into the third chamber, despite the presence of gaps on both sides.

[0019] The invention is further achieved by a method for producing a battery according to one of claims 1 to 10. In this process, a first potting compound is first filled into the first space, wherein the first potting compound flows into the second space via the at least one opening. After the first potting compound has solidified, the second potting compound is filled into the second space. By means of such a two-stage filling process of the potting compounds, the first space can first be filled with the first potting compound and the section projecting over the opening into the second space for sealing the gap can be manufactured or cast. Subsequently, ieWhen the first casting compound, and in particular the portion of the first casting compound projecting into the second space, has solidified, the second casting compound is filled into the second space, wherein the portion of the first casting compound arranged in the second space reliably prevents leakage of the second casting compound from the second space into the third space.

[0020] An embodiment of the invention is explained in more detail with reference to the drawing. Fig. 1 shows a section of a battery in perspective view, Fig. 2 shows a section of the battery from Fig. 1, Fig. 3a shows the battery from Fig. 1 and Fig. 2 during a filling process of a first casting compound into a first space, and Fig. 3b shows the battery from Fig. 1 and Fig. 2 during a filling process of a second casting compound into a second space.

[0021] Fig. Figure 1 shows a battery 10, in particular a traction battery of an electric vehicle. The battery 10 can also be merely a part of a traction battery of the electric vehicle, i.e., a battery module that, together with other battery modules, forms the traction battery.

[0022] The battery 10 has a battery housing 12 which is in the Fig. 1 is indicated by dashed lines, so that the arranged in the battery housing 12

[0023] Battery components are visible. The battery housing 12 has, for example, a base body designed as an extruded profile with two side walls 122, 125, a cover 124, and a base 123. The two open sides of the base body are each closed by a cover 126. The battery housing 12 defines a housing interior 121.

[0024] A battery cell pack 20 with a plurality of battery cells 22 stacked in the stacking direction is arranged in the housing interior 121. The battery cell pack 20 is held together by a frame-like battery cell carrier 24, which is permeable to fluids. An insertion aid element 261, 262 is arranged on each of the two outermost battery cells 22 of the battery cell pack 20. These insertion aid elements serve to simplify the insertion of the battery cell pack 20 through one of the two open sides of the main body of the battery housing 12 into the housing interior 121. An electrical connection element 28 is also arranged on the battery cell carrier 24 to electrically couple the battery 10 to another component, wherein all battery cells 22 are interconnected and electrically connected to the electrical connection element 28.

[0025] A partition element 30 is arranged on a side of the battery cell carrier 24 facing away from the battery cells 22. The partition element 30 is plate-shaped and connected to the battery cell carrier 24 via several snap-in connections. The partition element 30 is made of plastic and manufactured by injection molding.

[0026] The partition wall element 30 is designed such that several spaces 40, 42, 44 of the housing interior 121 are separated from one another, wherein a first space 40 is arranged on a side facing the battery cell pack 20 and is delimited by the partition wall element 30, the battery cell pack 20, the two insertion aid elements 261, 262, and the battery housing 12. The partition wall element 30 has several predetermined failure regions 32. A second space 42 and a third space 44 are arranged on a side of the partition wall element 30 facing away from the battery cell pack 20, wherein the third space 44 is separated from the second space 42 by a transverse web 34. The cover 126 rests against the free end of the transverse web 34 facing away from the battery cell pack 20 and, together with the separating element 30, the insertion aid elements 261, 262 and the battery housing 12, delimits the second space 42 and the third space 44.The transverse web 34, with its two ends aligned in the stacking direction of the battery cell pack 20, adjoins an insertion aid element 261, 262, wherein, due to inevitable manufacturing and assembly tolerances, a gap 46 is present between the insertion elements 261, 262 and the transverse web 34 of the separating element 30. In . Fig. 2, the gap 46 with a gap width S is shown in an enlarged view.

[0027] In a fully assembled state of the battery 10, the first chamber 40 and the second chamber 42 are each filled with a potting compound V1, V2. The potting compounds V1, V2 are identical and made of a flame-retardant material, in particular a foam. Alternatively, the potting compounds V1, V2 can be designed differently from one another. The potting compounds V1, V2 serve to ensure that, in the event of a thermal runaway of one of the battery cells 22 and the resulting escape of hot, electrically conductive gases, other battery cells 22 of the battery cell pack 20 are not connected, and a short circuit on electrically conductive, exposed components, in particular on the electrical connection element 28, is prevented.

[0028] During the manufacture of the battery 10 or during the assembly of the battery 10, the two potting compounds V1, V2 are successively filled into the spaces 40, 42, whereby first the first space 40 is filled with the first potting compound V1 and then the second space 42 is filled with the second potting compound V2. Fig. 3a, the arrows indicate the filling of the first casting compound V1 into the first chamber. Fig. In Figure 3b, the arrows indicate the filling of the second casting compound V2 into the second chamber 42. The casting compounds V1 and V2 are poured into the chambers 40 and 42 in a liquid state and then solidify.

[0029] When pouring the second casting compound V2 into the second chamber 42, the problem arises that the liquid second casting compound V2 would flow through the gap 46 into the third chamber 44, in which no casting compound should be present. To prevent the second casting compound V2 from overflowing into the third chamber 44, the partition wall element 30 has two openings 501, 502 that fluidically connect the first chamber 40 to the second chamber 42. The openings 501, 502 are arranged directly in front of the two gaps 46. During the filling process of the casting compound V1, which is filled before the second casting compound V2, the first casting compound V1 flows via the openings 501, 502 into the second space 42, wherein in the region of the openings 501, 502 a formwork element 541, 542 is arranged, which are designed such that the entire cross section of the second space 42 in the region of the openings 501, 502 is filled with the first casting compound V1 when the first casting compound V1 is filled. The cured first potting compound V1 forms a projection 521, 522 extending into the second space 42, by which the regions in which the gaps 46 are arranged are separated from the remaining space 42 in such a way that when the second potting compound V2 is filled into the second space 42, the second potting compound V2 can only flow up to the two projections 521, 522 of the first potting compound V1.The formwork elements 541, 542 can either be removed after the first potting compound V1 has solidified and before the second potting compound V2 is filled, or they can remain in the battery 10. Alternatively, the projections 521, 522 can also be formed by a filling tool mold, wherein the filling tool mold is removed after the first potting compound V1 has solidified.

[0030] In this way, the overflow of the liquid second casting compound V2 into the third space 44 can be reliably prevented in a simple manner.

Claims

[1] Battery of an electric vehicle, with a battery cell pack (20) with several battery cells (22), a battery housing (12) which delimits a housing interior (126), wherein the housing interior (126) is at least partially filled with a potting compound (V1, V2), characterized by , that a separate partition wall element (30) is arranged in the housing interior (126), which is designed in the form of a plate and has a transverse web (34), wherein a first space (40) is arranged on a first side of the partition wall element (30) and a second space (42) and a third space (44) are arranged on a second side of the partition wall element (30) opposite the first side, and wherein the second space (42) is separated from the third space by the transverse web (34), wherein a gap (46) connecting the second space (42) to the third space (44) is present between the transverse web (34) and a further battery component (261, 262) running transversely to the transverse web, wherein a first potting compound (V1) is arranged in the first space and a second potting compound (V2) is arranged in the second space (42), and wherein the partition wall element (30) has at least one opening (501, 502) connecting the first space (40) and the second space (42) to one another, through which opening the first potting compound (V1) extends into the second space (42) and fills the second space (42) in the region of the opening (501, 502), wherein a section (521, 522) of the first potting compound (V1) extending into the second space (42) is arranged upstream of the gap (46) in the flow direction of the second potting compound (V2) during the filling process into the second space (42). [2] Battery according to claim 1, characterized bythat the first space is filled with the casting compound (V1, V2) before the second space and the gap (46) is sealed when the second casting compound (V2) is filled into the second space (42) by the section (521, 522) of the solidified first casting compound (V1) extending into the second space (42). [3] Battery according to claim 1 or 2, characterized by that the partition wall element (30) is arranged on an end face (201) of the battery cell pack (20), wherein the first space (40) is delimited at least by the battery cells (22) and the partition wall element (30). [4] Battery according to one of the preceding claims, characterized by that a frame-like battery cell carrier (24) is arranged on the battery cell pack (20), on which the partition wall element (30) is arranged. [5] Battery according to claim 4, characterized by that the partition element (30) is locked to the battery cell carrier (24). [6] Battery according to one of the preceding claims, characterized by that the partition wall element (30) is made in one piece. [7] Battery according to one of the preceding claims, characterized by that the partition element (30) is made of plastic. [8] Battery according to one of the preceding claims, characterized by that the casting compounds (V1, V2) are each flame-retardant substances. [9] Battery according to one of the preceding claims, characterized by that the first casting compound (V1) and the second casting compound (V2) are the same or different from each other. [10] Battery according to one of the preceding claims, characterized bythat at two mutually opposite ends of the transverse web (34) there is in each case a gap (46) connecting the second space (42) to the third space (44), wherein the partition wall element (30) has two openings (501, 502) which are arranged such that the sections (521, 522) of the first casting compound (V1) extending into the second space (42) are arranged in front of the gaps (46) in the flow direction of the second casting compound (V2) during the filling process into the second space (42). [11] A method for producing a battery according to any one of claims 1 to 10, comprising the following steps: Filling a first casting compound (V1) into the first space (40), wherein the first casting compound (V1) flows into the second space (42) via the at least one opening (501, 502), Solidification of the first casting compound (V1), Fill the second casting compound (V2) into the second chamber (42). [12] Method according to claim 11, characterized bythat before the first casting compound (V1) is filled into the first space (40), a formwork element (541, 542) is arranged in the second space (42) in the region of the opening (501, 502). [13] Method according to claim 12, characterized by that the formwork element (541, 542) is removed after the first casting compound (V1) has solidified.

Images