Battery module for a motor vehicle

Abstract

A battery module for a motor vehicle, comprising a battery module housing (30), at least one battery cell pack (40, 41) inserted into the battery module housing (30) in an assembly direction (M1, M2) and comprising at least two battery cells electrically connected in series, and two head plates (50) for closing the battery module housing (30), wherein the head plates (50) are arranged and designed to exert a prestressing force on the battery cell pack (40, 41) directly or indirectly in the assembly direction (M1, M2), and wherein the battery module (20) comprises at least one spring element (60) arranged between the head plates (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41), characterized in that the spring element (60) is made of fiber-reinforced plastic, and in that the battery module comprises at least one compensating element (70) designed as a foam pad,which is arranged for tolerance compensation between the head plates (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41).

Description

[0001] The invention relates to a battery module for a motor vehicle according to the preamble of claim 1 and to a method for assembling such a battery module according to the preamble of claim 8. The battery module can be a battery module of a motor vehicle battery, in particular a motor vehicle traction battery.

[0002] Battery modules are known from the prior art which comprise a battery module housing and a plurality of electrically interconnected battery cells which are arranged in the form of a battery cell pack within the battery module housing.

[0003] During operation of the battery cells (charging / discharging), an expansion of the battery cells can occur, known as swelling. This expansion of the battery cells can lead to a reduction in the service life of the battery cells. To prevent this reduction in service life, it is known from the prior art to pre-tension battery cells using metallic tensioning straps before they are inserted into the battery module housing. Furthermore, the document DE 10 2016 205 929 A1 discloses a battery pack for a motor vehicle with a frame provided with at least two cross members and at least two longitudinal members, and with a plurality of battery cells arranged between the cross members and the longitudinal members. The cross members are designed to fix the battery cells in the battery pack with a force fit. Furthermore, spring plates are arranged between the cross members and the battery cells, by means of which the compressive force exerted on the battery cells can be adjusted.DE 10 2014 215 611 A1 discloses a spring element used in a battery module for a motor vehicle, which is made of a fiber-reinforced plastic.

[0004] It is the object of the present invention to provide a battery module which has a simplified assembly and an increased service life.

[0005] The object is achieved by a battery module of the type mentioned at the outset having the features of the characterizing part of claim 1 and a generic method for assembling a battery module having the features of the characterizing part of claim 8.

[0006] The battery module according to the invention comprises a battery module housing, at least one battery cell pack inserted into the battery module housing in an assembly direction and comprising at least two battery cells electrically connected in series, and two head plates for closing the battery module housing. The head plates are arranged and designed to exert a prestressing force on the battery cell pack directly or indirectly in the assembly direction. The battery module comprises at least one spring element arranged between the head plates and the battery cell pack and / or between the battery cell packs. According to the invention, the spring element is made of fiber-reinforced plastic. According to the invention, the battery module further comprises at least one compensating element designed as a foam pad, which is arranged between the head plates and the battery cell pack and / or between the battery cell packs for tolerance compensation.

[0007] This design simplifies battery module assembly while simultaneously achieving a long battery module service life. The invention is particularly advantageous when used with load-bearing battery modules, since the battery module housing already meets the structural mechanical requirements (wall thickness, strength, etc.) for absorbing the expansion forces of the battery cells based on the crash requirements of the motor vehicle without any further modifications to the battery module housing.

[0008] In a preferred embodiment, the battery module comprises at least two battery cell packs which are arranged one behind the other in the assembly direction, wherein the head plates are arranged and designed to exert a prestressing force on the battery cell packs directly or indirectly in the assembly direction.

[0009] Preferably, a first battery cell pack of the at least two battery cell packs is inserted into the battery module housing along a first mounting direction and a second battery cell pack of the at least two battery cell packs is inserted into the battery module housing along a second mounting direction, wherein the second mounting direction runs opposite to the first mounting direction.

[0010] In a preferred embodiment, the battery module housing encloses the battery cell pack or the battery cell packs from four sides, wherein an opening is arranged on each of the remaining two sides of the battery module housing, through which opening the battery cell pack is inserted into the battery module housing in the assembly direction, preferably in the first assembly direction and / or in the second assembly direction, and which opening is closed by means of one of the head plates.

[0011] Preferably, the head plates are connected to the battery module housing in a form-fitting and / or force-fitting and / or material-fitting manner, preferably screwed or welded.

[0012] The spring element can be used to preload the battery cell packs and to compensate for the expansion of the battery cells.

[0013] Preferably, the at least one spring element is designed as a leaf or disc spring.

[0014] In a preferred embodiment, the spring element is made of glass fiber reinforced plastic.

[0015] Preferably, the spring element is designed to exert a substantially constant force on the battery cell pack and / or the head plate over its spring travel. This can further improve the service life of the battery cells.

[0016] The invention further relates to a method for assembling a battery module, comprising the following method steps: - Providing a battery module housing, at least one battery cell pack comprising at least two battery cells electrically connected in series and two head plates; - Inserting the at least one battery cell pack into the battery module housing in an assembly direction; and - closing the battery module housing and directly or indirectly pre-tensioning the at least one battery cell pack in the assembly direction by the head plates, wherein, according to the invention, at least one spring element made of fiber-reinforced plastic is arranged between the head plate and the battery cell pack and / or between the battery cell packs, and wherein at least one compensating element designed as a foam pad is arranged between the head plate and the battery cell pack and / or between the battery cell packs, wherein tolerances between the head plates and the battery cell pack and / or between the battery cell packs are compensated by means of the compensating element.

[0017] In a preferred embodiment, at least two battery cell packs are arranged one behind the other in the assembly direction in the battery module housing, wherein the at least two battery cell packs are prestressed in the assembly direction by means of the head plates.

[0018] Preferably, a first battery cell pack of the at least two battery cell packs is inserted into the battery module housing along a first mounting direction and a second battery cell pack of the at least two battery cell packs is inserted into the battery module housing along a second mounting direction, wherein the second mounting direction runs opposite to the first mounting direction.

[0019] In a preferred embodiment, the battery module housing encloses the battery cell pack or the battery cell packs from four sides, wherein an opening is arranged on each of the remaining two sides of the battery module housing, characterized in that the battery cell pack is pushed into the battery module housing through one of the openings in the assembly direction.

[0020] Preferably, in order to close the battery module housing and to directly or indirectly prestress the at least one battery cell pack in the assembly direction, the head plates are connected to the battery module housing in a form-fitting and / or force-fitting and / or material-fitting manner, preferably by screwing or welding.

[0021] In a preferred embodiment, a substantially constant force is exerted on the battery cell pack and / or the head plate by means of the spring element over its spring travel.

[0022] Details and further advantages of the battery module according to the invention and the method according to the invention for assembling a battery module are explained using the exemplary embodiment described below. The following illustrate: Fig. 1 and Fig. 2: a perspective view of a battery module according to the application according to the embodiment.

[0023] The application relates to a battery module 20 for a motor vehicle. The battery module 20 comprises a battery module housing 30, at least one battery cell pack 40, 41 inserted into the battery module housing 30 in an assembly direction M1, M2 and comprising at least two battery cells electrically connected in series, and two head plates 50 for closing the battery module housing 30. The head plates 50 are arranged and designed to exert a preload force on the battery cell pack 40, 41 directly or indirectly in the assembly direction M1, M2. Fig. 2 shows the battery module 20 according to the embodiment in an assembled state.

[0024] The battery module can comprise at least two battery cell packs 40, 41 arranged one behind the other in the assembly direction M1, M2. The head plates 50 can be arranged and configured to exert a preload force on the battery cell packs 40, 41 directly or indirectly in the assembly direction M1, M2.

[0025] The battery cell packs 40, 41 can comprise a support structure 42 on the side of the end of the battery cell pack 40, 41 that is first inserted into the battery module housing 30. This is particularly evident from Fig. 1. The battery cell packs 40, 41 prestressed by the head plates 50 can support each other in the center of the battery module housing 30, in particular by means of their support structure 42. Alternatively, the battery cell packs 40, 41 can support each other in the center of the battery module housing 30 on the battery module housing 30 itself, in particular on a welded-in sleeve of the battery module housing 30. The support structure 42 can be made of plastic. The batteries of the battery cells 40, 41 can be designed as pouch cells or prismatic cells. The battery module housing 30 can be designed in one piece or in multiple pieces.

[0026] Preferably, a first battery cell pack 40 of the at least two battery cell packs 40, 41 is inserted into the battery module housing 30 along a first mounting direction M1 and a second battery cell pack 41 of the at least two battery cell packs 40, 41 is inserted along a second mounting direction M2, wherein the second mounting direction M2 runs opposite to the first mounting direction M1.

[0027] The battery module housing 30 can enclose the battery cell pack 40, 41 or the battery cell packs 40, 41 from four sides, as in particular Fig. 1. On each of the remaining two sides of the battery module housing 30, an opening 32 can be arranged through which the battery cell pack 40, 41 is inserted into the battery module housing 30 in the assembly direction M1, M2 and which is closed by means of one of the head plates 50.

[0028] The head plates 50 can be connected to the battery module housing 30 in a form-fitting and / or force-fitting and / or material-fitting manner, preferably by screwing or welding.

[0029] The battery module 20 comprises at least one spring element 60, which is arranged between the head plates 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41. The spring element 60 can be designed to indirectly exert the preload force on the battery cell packs 40, 41. The head plates 50 exert the preload force on the spring elements 60, which then transmit the preload force to the battery cell packs 40, 41.

[0030] The at least one spring element 60 can be designed as a leaf or disc spring. The spring element 60 is made of fiber-reinforced plastic, in particular glass-fiber-reinforced plastic.

[0031] The spring element 60 can be designed to exert a substantially constant force over a spring travel on the battery cell pack 40, 41 and / or the head plate 50.

[0032] The battery module 20 comprises at least one compensating element 70, which is arranged between the head plate 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41 for tolerance compensation. The compensating element 70 is designed as a foam pad.

[0033] The application further relates to a method for assembling a battery module 20 according to the application. The method comprises the following method steps: - Providing a battery module housing 30, at least one battery cell pack 40, 41 comprising at least two battery cells electrically connected in series and two head plates 50; - Inserting in an assembly direction M1, M2 the at least one battery cell pack 40, 41 into the battery module housing 30; and - Closing the battery module housing 30 and directly or indirectly pre-tensioning the at least one battery cell pack 40, 41 in the assembly direction M1, M2 by the head plates 50, wherein at least one spring element 60 made of fiber-reinforced plastic is arranged between the head plate 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41 and wherein at least one compensating element 70 designed as a foam pad is arranged between the head plate 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41, wherein tolerances between the head plates 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41 are compensated by means of the compensating element 70.

[0034] Fig.2 shows a battery module 20 which is assembled using the method according to the application.

[0035] At least two battery cell packs 40, 41 can be arranged one behind the other in the battery module housing 30 in the assembly direction M1, M2. The at least two battery cell packs 40, 41 can be preloaded in the assembly direction M1, M2 by means of the head plates 50. In this case, a first battery cell pack 40 of the battery cell packs 40, 41 can first be inserted into the battery module housing 30 along a first assembly direction M1, and then a second battery cell pack 41 of the battery cell packs 40, 41 can be inserted into the battery module housing 30 along a second assembly direction M2.

[0036] The battery module housing 30 can enclose the battery cell pack 40, 41 or the battery cell packs 40, 41 on four sides. An opening 32 can be arranged on each of the remaining two sides of the battery module housing 30. The battery cell pack 40, 41 can be inserted into the battery module housing 30 through one of the openings 32 in the assembly direction M1, M2.

[0037] In order to close the battery module housing 30 and to directly or indirectly prestress the at least one battery cell pack 40, 41 in the assembly direction M1, M2, the head plates 50 can be connected to the battery module housing 30 in a form-fitting and / or force-fitting and / or material-fitting manner, preferably by screwing or welding.

[0038] At least one spring element 60 is arranged between the head plate 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41. By means of the spring element 60, a substantially constant force can be exerted on the battery cell pack 40, 41 and / or the head plate 50 over its spring travel.

[0039] At least one compensating element 70, designed as a foam pad, is arranged between the head plate 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41. Tolerances between the head plates 50 and the battery cell pack 40, 41 and / or between the battery cell packs 40, 41 can be compensated by means of the compensating element 70.

Claims

[1] Battery module for a motor vehicle, comprising a battery module housing (30), at least one battery cell pack (40, 41) inserted into the battery module housing (30) in an assembly direction (M1, M2) and comprising at least two battery cells electrically connected in series, and two head plates (50) for closing the battery module housing (30), wherein the head plates (50) are arranged and designed to exert a prestressing force on the battery cell pack (40, 41) directly or indirectly in the assembly direction (M1, M2), and wherein the battery module (20) comprises at least one spring element (60) arranged between the head plates (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41), characterized bythat the spring element (60) is made of fiber-reinforced plastic and that the battery module comprises at least one compensating element (70) designed as a foam pad, which is arranged for tolerance compensation between the head plates (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41). [2] Battery module according to claim 1, characterized by at least two battery cell packs (40, 41) which are arranged one behind the other in the assembly direction (M1, M2), wherein the head plates (50) are arranged and designed to exert a prestressing force on the battery cell packs (40, 41) directly or indirectly in the assembly direction (M1, M2). [3] Battery module according to one of claims 1 or 2, characterized byin that the battery module housing (30) encloses the battery cell pack (40, 41) or the battery cell packs (40, 41) from four sides, wherein an opening (32) is arranged on each of the remaining two sides of the battery module housing (30), through which opening the battery cell pack (40, 41) is inserted into the battery module housing (30) in the assembly direction (M1, M2) and which is closed by means of one of the head plates (50). [4] Battery module according to one of claims 1 to 3, characterized by that the head plates (50) are connected to the battery module housing (30) in a form-fitting and / or force-fitting and / or material-fitting manner, preferably by screwing or welding. [5] Battery module according to one of claims 1 to 4, characterized by that the at least one spring element (60) is designed as a leaf or disc spring. [6] Battery module according to one of claims 1 to 5, characterized bythat the spring element (60) is made of glass fiber reinforced plastic. [7] Battery module according to one of claims 1 to 6, characterized by that the spring element (60) is designed to exert a substantially constant force over its spring travel on the battery cell pack (40, 41) and / or the head plate (50). [8] Method for assembling a battery module (20), comprising the following method steps: - Providing a battery module housing (30), at least one battery cell pack (40, 41) comprising at least two battery cells electrically connected in series, and two head plates (50); - Inserting the at least one battery cell pack (40, 41) into the battery module housing (30) in an assembly direction (M1, M2); and - closing the battery module housing (30) and directly or indirectly pre-tensioning the at least one battery cell pack (40, 41) in the assembly direction (M1, M2) by the head plates (50), characterized by that at least one spring element (60) made of fiber-reinforced plastic is arranged between the head plate (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41), and that at least one compensating element (70) designed as a foam pad is arranged between the head plate (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41), wherein tolerances between the head plates (50) and the battery cell pack (40, 41) and / or between the battery cell packs (40, 41) are compensated by means of the compensating element (70). [9] Method of assembly according to claim 8, characterized bythat at least two battery cell packs (40, 41) are arranged one behind the other in the assembly direction (M1, M2) in the battery module housing (30), wherein the at least two battery cell packs (40, 41) are prestressed in the assembly direction (M1, M2) by means of the head plates (50). [10] Method for assembly according to one of claims 8 or 9, wherein the battery module housing (30) encloses the battery cell pack (40, 41) or the battery cell packs (40, 41) from four sides, wherein an opening (32) is arranged on each of the remaining two sides of the battery module housing (30), characterized by that the battery cell pack (40, 41) is inserted through one of the openings (32) in the assembly direction (M1, M2) into the battery module housing (30). [11] Method of assembly according to one of claims 8 to 10, characterized byin that, in order to close the battery module housing (30) and to directly or indirectly prestress the at least one battery cell pack (40, 41) in the assembly direction (M1, M2), the head plates (50) are connected to the battery module housing (30) in a form-fitting and / or force-fitting and / or material-fitting manner, preferably by screwing or welding. [12] Method of assembly according to one of claims 8 to 11, characterized by that by means of the spring element (60) a substantially constant force is exerted on the battery cell pack (40, 41) and / or the head plate (50) over its spring travel.

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