Battery for an electric vehicle and method for assembling a battery of an electric vehicle

Abstract

Battery of an electric vehicle, comprising at least one battery module (12, 14) which has a battery module housing (16) and at least one battery cell (20) arranged in a battery module housing (16), a cable housing (40) in which an electrical connecting element (36, 38) is arranged, wherein the battery module housing (16) has a through-opening (19) on a side facing the cable housing (40), through which a cable housing interior (46) of the cable housing (40) is connected to a housing interior (18) of the battery module housing (16), wherein the electrical connecting element (36, 38) and the battery cell (20) are electrically connected to each other via an electrical connecting device (30), wherein the electrical connecting device (30) is arranged at the through-opening (19) and is fixedly arranged with the battery module housing (16), wherein the cable housing (40) is attached to the electrical connecting device (30).

Description

[0001] The invention relates to a battery of an electric vehicle, comprising at least one battery module which has a battery module housing and at least one battery cell arranged in a battery module housing, a cable housing in which an electrical connecting element is arranged, wherein the battery module housing has a through-opening on a side facing the cable housing, through which a cable housing interior of the cable housing is connected to a housing interior of the battery module housing.

[0002] Such a battery is disclosed, for example, in DE 10 2021 122 075 A1, wherein the battery comprises several battery modules arranged side by side. Each battery module has a battery module housing and several battery cells arranged within the battery module housing. The individual battery modules or the battery cells of the battery modules are electrically interconnected with each other or with other components of the electric vehicle such that the battery module housings each have a through-opening on a common side, wherein a cable tray housing is arranged in the area of ​​the through-opening, through which one or more electrical connecting elements extend and which are electrically connected to the respective battery cells of the battery modules via the through-openings.At each of the through-openings, an annular element is arranged, completely enclosing the opening. This element is bonded to the corresponding battery module housing by a continuous material connection, in particular by welding. The housing seals against an annular sealing section of the annular element, which projects from an outer surface of the battery module housing, and is screwed to the annular element. For this purpose, the annular element has several threaded bores with an internal thread.

[0003] Similar battery designs are also disclosed in WO 2024 / 207 038 A1 and in DE 10 2021 116 328 A1.

[0004] A disadvantage of this type of battery design is that the ring-shaped elements must be connected to the battery module housing of each battery module in a separate step, in particular they must be welded to the battery module housing, which results in increased manufacturing and assembly costs during the production of the battery.

[0005] Typically, the battery modules are interconnected by electrical connection devices and electrical connecting elements running between these devices. Each battery module housing has a through-opening through which an electrical connection device is arranged. This device is electrically coupled to the battery cells on the inside and to the electrical connecting element on the outside. Such an electrical connection device, or a battery designed in this way, is disclosed, for example, in DE 10 2022 131 180 B3.

[0006] The object of the invention is to provide a battery in which the manufacturing and assembly costs can be reduced.

[0007] The problem is solved by the features of claim 1.

[0008] According to the invention, the electrical connecting element and the battery cell are electrically connected to each other via an electrical connecting device, wherein the electrical connecting device is arranged at the through-opening and is fixedly arranged with the battery module housing, wherein the cable housing is attached to the electrical connecting device.

[0009] With this battery design, the electrical connection device fulfills several functions, namely providing the electrical coupling and securing the housing. For this purpose, the electrical connection device is attached to the battery module housing, with the electrical connection device being arranged section by section inside and / or outside the battery module housing.

[0010] By attaching the cable tray housing to the electrical connection device, the manufacturing effort in the production of the battery can be reduced, with no additional components and additional assembly or manufacturing steps required to connect the cable tray housing and the battery module.

[0011] The cable tray housing is screwed to the electrical connection device. This allows the cable tray housing to be reliably and easily connected to the battery module or the electrical connection device. For example, if the battery module fails and needs to be replaced, the cable tray housing can be easily removed from the battery module. The electrical connection device has several threaded holes with internal threads for screwing the cable tray housing to the electrical connection device. For this purpose, the electrical connection device, which has a plastic housing or casing, can have insert sleeves embedded in the plastic housing or casing to create the internal threads. This ensures a particularly reliable screw connection.

[0012] In a preferred embodiment, the electrical connection device comprises a first connection part and a second connection part, which are connected to each other longitudinally such that one of the two connection parts rests against an outer surface of the battery module housing and the other connection part rests against an inner surface of the battery module housing, such that the battery module housing is clamped or braced longitudinally between the two connection parts, wherein the first connection part and / or the second connection part has a screw thread into which a screw for screwing the cable tray housing and the electrical connection device is screwed.This allows the electrical connection device to be attached to the battery module housing in a simple manner, wherein the electrical connection device bears against a circumferential surface of the through-hole with an outer circumferential surface, thereby fixing the electrical connection device radially with respect to a longitudinal axis of the electrical connection device, and bearing against the inside and outside of the battery module housing in the longitudinal direction of the electrical connection device, thereby fixing the electrical connection device axially with respect to the longitudinal axis to the battery module housing.Such a connection of the electrical connection device can be achieved by separating the two connecting parts in their disassembled state. One of the connecting parts is inserted through the through-hole, and the other connecting part is fixed to the inserted section of the first. For this purpose, the two connecting parts can be joined using a screw connection, where, for example, the inserted section of one connecting part has an external or internal thread, and the other connecting part has a mating thread. Alternatively, the two connecting parts could be snapped or clipped together.

[0013] Preferably, a seal is arranged between the cable tray housing and the battery module housing, which seals the gap surrounding the through-opening between the cable tray housing and the battery module housing. The seal seals both the gap between the electrical connection device and the battery module housing, and the gap between the cable tray housing and the battery module housing, against the external environment. The seal can be a solid seal, for example made of an elastomer, in particular an O-ring. Alternatively, the seal can be a seal applied in a viscous state and cured.

[0014] In a preferred embodiment, a drainage channel is formed on an outer surface of the battery module housing, which is arranged on the side of the seal facing away from the through-opening. The drainage channel prevents water from accumulating at the seal and thus improves the sealing effect.

[0015] Preferably, several battery modules are provided, and the housing extends along the battery modules. Each battery module has a housing with a through-opening, and an electrical connection device, permanently attached to the housing, is arranged at each through-opening. The housing is then attached to these electrical connection devices. This allows for the simple and cost-effective production of a battery with multiple battery modules and a housing. The battery module housings and the electrical connection devices are identical, with the through-openings of the battery module housings aligned with each other, i.e., in a common line, along which the elongated housing is also arranged.

[0016] Preferably, the cable tray housing comprises a lower housing section and an upper housing section detachably connected to the lower housing section, with the lower housing section being attached to the electrical connection device. The lower housing section and the upper housing section are preferably made of sheet metal elements. Preferably, the sheet metal elements are screwed together or connected by another type of detachable connection. This allows the cable tray housing to be opened in the event of damage. Furthermore, this allows the cable tray housing to be easily screwed to the electrical connection device, whereby the lower housing section can first be screwed to the electrical connection device and then the upper housing section can be connected to the lower housing section.

[0017] The problem is further solved by a method for assembling a battery according to any one of the preceding claims 1 to 6. Here, a battery module housing having a through-opening, an electrical connection device, and a cable tray housing are first provided. The electrical connection device is then attached to the through-opening. Finally, the cable tray housing is attached to the electrical connection device by screwing it together. For the advantages, reference is made to the preceding claims.

[0018] An embodiment of the invention is explained in more detail with reference to the drawings. Fig. Figure 1 shows a perspective view of a battery, and Fig. Figure 2 shows a section of the battery. Fig. 1 in cross-section.

[0019] Fig. Figure 1 shows an embodiment of a battery 10 according to the invention, in particular a traction battery of an electric vehicle. The battery 10 comprises several battery modules 12, 14, which are arranged side by side. Fig. Figure 1 shows only two battery modules 12, 14 of the battery 10, where the battery 10 has more than two battery modules arranged next to each other or in series.

[0020] Each battery module 12, 14 comprises a battery module housing 16, in which several battery cells 20, in particular as a battery cell pack, are arranged. The battery module housing 16 is designed as an extruded profile and has two open end faces, which are sealed fluid-tight by a cover (not shown) after the battery cells 20 have been inserted into a housing interior 18. During assembly, the battery cells 20 or the battery cell packs are inserted into the battery module housing 16 from both sides, and the battery cells 20 inserted at the different end faces of the battery module housing 16 are electrically connected on their facing sides by an electrical connection device 30.

[0021] The electrical connection device 30 is arranged at a through-opening 19 formed in the battery module housing 16 and has two connection parts 32, 34, wherein a first connection part 32 forms an upper part and a second connection part 34 forms a lower part. The second connection part 34 is partially located inside the battery module housing 16 or within the housing interior 18 and projects outwards through the through-opening 19. The second connection part 34 has a collar 341 with which the second connection part 34 abuts an inner surface of the battery module housing 16 that bounds the housing interior 18. The first connection part 32 is located outside the housing interior 18 and is connected to the outwardly projecting section of the second connection part 34.The first connecting part 32 is designed in the form of a screw nut and is screwed onto the outwardly projecting section of the second connecting part 34. For this purpose, the first connecting part 32 has an internal thread and the second connecting part has an external thread. The first connecting part 32 is screwed onto the second connecting part 34 in such a way that the first connecting part 32 rests against an outer surface of the battery module housing 16. In this way, the battery module housing 16 is clamped between the two connecting parts 32, 34 of the electrical connection device 30. The second connecting part 34 comprises several electrical coupling elements (not shown) which are connected on the one hand to the battery cells 20 and on the other hand to electrical connecting elements 36, 38 located outside the battery module housing 16 and serving to connect the battery cells 20 and the battery modules 12, 14, respectively.The electrical connecting elements 36, 38 are arranged within a cable tray housing 40.

[0022] The cable tray housing 40 comprises a lower part 42 and an upper part 44, which are connected to each other, in particular by screws, and define an interior space 46. The electrical connecting elements 36, 38 are arranged in the interior space 46, with the electrical connecting device 30 engaging in the interior space 46 through an opening 48.

[0023] According to the invention, the cable tray housing 40 is screwed to the electrical connection device 30 by several screw connections 50, 52. For this purpose, the lower part of the cable tray housing 42 has a bore 501, 521, and the second connecting part 34, in particular the collar 341, has two threaded bores 502, 522, wherein a screw 503, 523 (schematically illustrated) is inserted from the interior of the cable tray housing 46 through the bore 501, 521 and through a local recess 161, 162 of the battery module housing 16 and is screwed into the threaded bore 502, 522. This presses the lower part of the cable tray housing 42 against the outer surface of the battery module housing 16. The local recesses 161, 162 can each be formed by a groove-like recess on a circumferential surface of the passage opening 19 or by a separate bore.

[0024] To seal a gap between the outside of the lower part of the cable tray housing 42 and the outer surface of the battery module housing 16, a circumferential seal 54 is arranged in the gap, which is designed to be elastically deformable and is elastically deformed when the cable tray housing 40 is screwed to the electrical connection device 30.

[0025] To prevent water from accumulating at the gap or seal 54, a drainage channel 56 is provided on the outer surface of the battery module housing 16.

[0026] During the assembly of the battery 10, the battery module housings 16, the electrical connection devices 30, and a cable tray housing 40 are first provided. The battery cells 20 are then inserted into the battery module housing 16, and the electrical connection devices 30 are mounted on the battery module housing 16 such that the second connection part 34 is inserted into the through-opening 19 from the interior of the housing 18, and the first connection part 32 is attached to the second connection part 34. Additionally, the battery cells 20 are electrically connected to the second connection part 34. The lower part of the cable tray housing 42, with a pre-mounted seal 54, is then placed onto the battery module housing 16, and the lower part of the cable tray housing 42 is screwed to the second connection part 34 such that the screws 503 and 523 are inserted into the bores 501 and 521 and screwed into the threaded bores 502 and 522.The electrical connecting elements 36, 38 are then arranged in the interior of the cable tray housing 46 and electrically connected to the electrical connecting device 30, i.e., to the second connecting part 34. Finally, the upper part 44 of the cable tray housing is mounted by screwing it to the lower part 42 of the cable tray housing.

Claims

[1] Battery of an electric vehicle, with at least one battery module (12, 14) comprising a battery module housing (16) and at least one battery cell (20) arranged in a battery module housing (16), a cable tray housing (40) in which an electrical connecting element (36, 38) is arranged, wherein the battery module housing (16) has a through-opening (19) on a side facing the cable tray housing (40), through which a cable tray housing interior (46) of the cable tray housing (40) is connected to a housing interior (18) of the battery module housing (16), characterized by , that the electrical connecting element (36, 38) and the battery cell (20) are electrically connected to each other via an electrical connecting device (30), wherein the electrical connecting device (30) is arranged at the through-opening (19) and is fixedly arranged with the battery module housing (16), wherein the cable tray housing (40) is attached to the electrical connecting device (30) in such a way that the cable tray housing (40) is screwed to the electrical connecting device (30). [2] Battery according to claim 1, characterized by, that the electrical connection device (30) has a first connection part (32) and a second connection part (34) which are connected to each other longitudinally such that one of the two connection parts (32, 34) abuts an outer surface of the battery module housing (16) and the other connection part (32, 34) abuts an inner surface of the battery module housing (16) such that the battery module housing (16) is clamped longitudinally between the two connection parts (32, 34), wherein the first connection part (32) and / or the second connection part (34) has a screw thread (502, 522) into which a screw (503, 523) is screwed for screwing the cable tray housing (40) and the electrical connection device (30). [3] Battery according to any one of the preceding claims, characterized by, that a seal (54) is arranged between the cable housing (40) and the battery module housing (16), which seals a gap surrounding the through-opening (19) between the cable housing (40) and the battery module housing (16) all around. [4] Battery according to claim 3, characterized by , that a drainage channel (56) is formed on an outer surface of the battery module housing (16), which is arranged on one side of the seal (54) facing away from the through-opening (19). [5] Battery according to any one of the preceding claims, characterized by, that several battery modules (12, 14) are provided and the cable tray housing (40) extends along the battery modules (12, 14), each battery module (12, 14) having a battery module housing (16) with a through-opening (19), wherein an electrical connection device (30) firmly connected to the battery module housing (16) is arranged at each of the through-openings (19) of the battery module housings (16), and wherein the cable tray housing (40) is attached to the electrical connection devices (30). [6] Battery according to any one of the preceding claims, characterized by , that the cable tray housing (40) has a cable tray housing lower part (42) and a cable tray housing upper part (44) detachably connected to the cable tray housing lower part (42), wherein the cable tray housing lower part (42) is attached to the electrical connection device (30). [7] Method for assembling a battery (10) according to any one of the preceding claims 1 to 6, comprising the following steps: Providing a battery module housing (16) which has a through-opening (19), Providing an electrical connection device (30), providing a cable tray housing (40), Attaching the electrical connection device (30) to the through-hole (19), and Attaching the cable tray housing (40) to the electrical connection device (30), wherein the cable tray housing (40) is screwed to the electrical connection device (30).

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