METHOD AND DEVICE FOR MANUFACTURING A VEHICLE BATTERY

Abstract

Battery module assembly comprising the following: a large number of battery cells stacked to form a module block; a multitude of modular blocks assembled together with a base connecting element extending between two end plates; and at least one upper connecting element extending between the two end plates on opposite sides of the module blocks from the base connecting element, wherein the upper connecting element and the base connecting element hold the module blocks pressed together and The end plates each have a frame section extending around an outer edge of the end plates and a middle section within the frame, the middle section being defined by a curved surface projecting inwards towards the other end plate to compress the battery cells between the middle sections of the end plates on opposite sides of the assembly.

Description

[0001] The present disclosure relates to a method for manufacturing a battery for a vehicle having an electrically operated drive motor, as well as components of the battery assembly.

[0002] High-voltage (HV) battery systems for vehicles are manufactured by assembling battery cells, electrical connections, and cooling devices to provide a dense pack with minimal unused space. For large-scale production HV battery systems, pouch cells can be used. Pouch cells are generally flat, layered ionic cells, such as lithium-ion cells, that can be inserted between structural and / or thermal conditioning layers. Many cells are stacked in one or more rows and held in a compressed arrangement. The frame or tray that holds the battery assembly should be robust to securely hold the battery cells in the vehicle. Additionally, the battery cells can be assembled as a sub-assembly off-site before being installed in the vehicle.Handling a large, horizontally oriented cell stack presents installation challenges because the stack can bend or shift during movement. The cell array may have wiring on one side and cooling components on the opposite side. Electrically connecting cells on one side of a cell stack is difficult when the stack is located near an adjacent one. Connecting the cell stack to a cooling system is also challenging when multiple batteries are stacked closely together. During charging and discharging, batteries expand and contract. Bagged cells can develop gas expansion inclusions during charging if they are not pressurized. These gas expansion inclusions reduce battery efficiency.

[0003] US Patent 2011 / 0 117 419 A1 describes a battery pack consisting of several module blocks, each of which in turn consists of several battery cells, held together by a frame with boundary walls. US Patent 2012 / 0 040 237 A1 also describes a battery pack. In this case, several module blocks, each consisting of a large number of battery cells, are mounted on a base plate and held together by frame elements between end plates.

[0004] The disclosed battery module assembly and the method for manufacturing a battery relate to the treatment of the above problems and other problems, as summarized below.

[0005] The disclosed embodiments relate to a modular battery assembly that provides a densely packed configuration and can be easily installed in a repeatable process. The method and the device also provide a simple, robust, and effective cell compression system.

[0006] According to a first and a second aspect of the present invention, battery module assemblies are provided having the features of claim 1 and having the features of claim 3.

[0007] In a battery module assembly, multiple cells are stacked to form a module block with end plates. Multiple modular blocks are assembled using a base connector that extends between two end plates. One or two connectors extend between the two end plates on the opposite side of the module blocks from the base connector. The base connector and one or more opposing connectors hold the module blocks pressed together and space the end plates apart by a predetermined distance. The connectors can be belts, rods, strips, or tubes suitable for joining the end plates. In the battery module assembly, each end plate has a frame section that extends around an outer edge of the end plate and a central section within the frame.The central section of each endplate projects inward toward the other endplate to compress the battery cells between the central sections of the endplates on opposite sides of the assembly. According to the first aspect, the central section can be defined by a partially cylindrical curved surface projecting inward toward the other endplate to compress the battery cells between the central sections of the endplates on opposite sides of the assembly. According to the second aspect, the central section can be defined by a partially spherical curved surface projecting inward toward the other endplate to compress the battery cells between the central sections of the endplates on opposite sides of the assembly.According to other aspects of the disclosure relating to the battery assembly, the connecting elements can have a first set of fastener receiving locations that are aligned with a second set of fastener receiving locations on the end plates. A fastener can be installed in the first and second fastener receiving locations to set the predetermined distance between the end plates.

[0008] According to another aspect of the disclosure, a battery assembly is provided for a vehicle that includes an electrically powered drive motor. The assembly includes a battery container that is installed in the vehicle. A first modular arrangement of battery cells is arranged in a row, with a first and a second endplate installed at opposite ends of the row of battery cells. A first plurality of connecting elements holds the first and second endplates together. A first set of electrical connections to each of the battery cells is provided on one side of the first modular arrangement. A second modular arrangement of battery cells is also arranged in a row, with a third and a fourth endplate installed at opposite ends of the battery row. A second plurality of connecting elements holds the third and fourth endplates together.A second set of electrical connections for each of the battery cells is provided on one side of the second modular assembly. The first and second modular assemblies are installed in the battery container with the first and second sets of electrical connections facing each other.

[0009] According to other aspects of the disclosure relating to the battery assembly for a vehicle, a cooling system for the battery cells can be provided, which is attached to the first and second modular arrangements on the sides of the modular arrangements facing away from the side containing the electrical connections. The cooling system can further comprise at least one cooling tube that is mechanically attached to the battery cells to enable the transfer of thermal energy between the cooling system and the battery cells. The cooling system is in fluid flow communication with the cooling tube on one side of the modular arrangement.

[0010] The battery assembly may also include a first plurality of connecting elements attached to a flange formed at the end plates, extending in the same plane as the connecting elements and at the same height as the end plates. The second plurality of connecting elements may have a stepped flange connected to the connecting element via an intermediate section. The intermediate section is perpendicular to both the connecting element and the stepped flange. A plurality of stiffening ribs may be formed at a corner defined by the intermediate section and the stepped flange. The stepped flanges are attached to the flange formed at the end plate, which extends in the same plane as the stepped flange, and are positioned lower than the connecting elements.

[0011] According to another aspect of the disclosure, a method for manufacturing a battery for a vehicle is disclosed. The method comprises stacking a plurality of pouch cells in a module. A pair of end plates is assembled with at least one base connector. A plurality of modules is stacked on the at least one base connector to fill the space between the end plates. At least one top connector is placed between the end plates to keep the two end plates apart by a predetermined distance. The pouch cells are electrically connected to each other at a first set of the plurality of modules. At least some of the pouch cells are connected to a cooling system interface on the second side of the plurality of modules of the first side, opposite the first side.After installing the modules between the pair of end plates, stacking the modules on the base connecting element, attaching the upper connecting element between the end plates, electrically connecting the cells to each other, and connecting the bag cells to the cooling system interface, a large number of modules are placed into a battery holder in the vehicle.

[0012] Other aspects of the process include the modules having tabs that define slots, and during the insertion step, a tool is provided that includes hooks extending from the tool and oriented to engage in the slots defined by the tabs in the modules. The process further includes lifting the modules, supported by the tool, from above.

[0013] The battery holder can be a trough comprising a multitude of weld studs. The end plates define slots that are elongated in the direction in which the connecting elements between the end plates extend. In the process, the step of inserting the multitude of modules onto the battery holder can further include aligning the slots of the end plates with the weld studs on the trough to secure the modules to the trough.

[0014] The above aspects of the disclosure and other aspects will become more understandable in light of the accompanying drawings and the detailed description below of the embodiments shown. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] They show: Fig. 1 a perspective view of a battery module assembly comprising a plurality of module blocks fitted between a pair of end plates connected by a plurality of connecting elements; Fig. 2 a fragmentary rear elevation view of an end plate having an outwardly extending flange connected to a connecting element via a fastening element; Fig. 3 a schematic perspective view of an end plate and a battery cell in a stretched perspective view; Fig. 4 a cross-sectional view along line 4-4 from Fig. 3; Fig. 5 a cross-sectional view of an alternative embodiment of an end plate similar to Fig. 4; Fig. 6 a perspective view of a battery tray or holder comprising two different types of end plates connected to each other via two different types of connecting elements; Fig. 7 a fragmentary rear elevation view of an end plate having an inwardly extending flange connected to a connecting element via a fastening element; Fig. 8 a fragmentary perspective view, partly in cross-section, showing an alternative embodiment of an end plate having an outwardly oriented flange connected to a connecting element having a stepped flange with stiffening ribs; Fig. 8A and Fig. 8B Cross-sections of one of the upper connecting elements along lines 8A-8A and 8B-8B from Fig. 8 seen; Fig. 9 a perspective view of a tool that can be used to raise the arrangement of a variety of modular battery blocks for installation in a battery holder or tray; Fig. 10 A schematic perspective view of a battery module assembly without the end frames and with the terminal plate pulled away from the front of the module; and Fig. 11 A schematic perspective view of a plurality of battery modules assembled without the end frames, with the terminal plates attached to the front part of the modules and the terminal plates connected to each other and to control wires by high voltage wires. DETAILED DESCRIPTION

[0016] A detailed description of the illustrated embodiments of the present invention is provided below. The disclosed embodiments are examples of the invention, which can be implemented in various and alternative forms. The figures are not necessarily to scale. Some features may be enlarged or reduced to show details of certain components. The specific structural and functional details disclosed in this application are not to be considered limiting but merely as a representative basis to teach the person skilled in the art the practical implementation of the invention.

[0017] With reference to Fig. 1 A battery module assembly 10 is provided to support and compress a plurality of battery modules 12. The battery modules 12 comprise a plurality of battery cells 16. The battery cells are ionic “bag-like” cells that are stacked horizontally within the modules 12. The battery cells can be lithium-ion or other electrochemical battery cells. The modules 12 are held between a pair of end plates 18, which exert a compressive force, as indicated by the arrows in Fig. The forces specified in Figure 1 are exerted on the sides of the modules 12 and, in turn, on the sides of the battery cells 16. A lower connecting element 20 connects the lower sections of the end plates 18 to each other. A pair of upper connecting elements 26 is attached to the top of the end plates 18. The end plates 18 include a lower flange 28 that extends outwards from the end plates 18. An upper flange 30 is also provided on each of the end plates and can either extend outwards, as shown in Figure 1. Fig. 1 is shown on the left, or can extend inwards, as shown by the end plate in Fig. Figure 1 on the right shows cooling tubes 34 extending along the outer sides of the battery module assembly 10. With reference to Fig. Figure 2 shows the left flange 30 of the end plate 18 as it is connected to the upper connecting elements 26 via a fastening element 32. The fastening element 32 can be a conventional fastener with nut and bolt, a bolt with a weld nut, or the like. With reference to Fig. 1. The distance between the end plates 18 is adjusted by the length of the connecting elements 26 and 20, which are attached by the fasteners 32 that define the distance between the end plates 18. The fasteners can be a combination of nuts, bolts, special studs, or weld nuts. During installation of the battery module assembly, the end plates can be arranged in an assembly fixture that exerts a compressive force on the plurality of modules 12. The fasteners 32 hold the modules 12 compressed together when they are assembled with the end plate 18.

[0018] With reference to Fig. Figure 3 shows an end plate 18 with a battery cell 16 in a stretched perspective view. The end plate comprises a frame section 46 that extends around the perimeter of a central section 48. The central section 48 may comprise a partially spherical surface 50, as indicated by the transparent lines in Fig. 3 is specified. The spherical surface 50 can have a parabolic shape or another concave surface that can exert a pressure force on the battery cells between the end plates 18 in the central section 48. The spherical surface 50 is provided to resist the expansion of gases within the cells 16 when the cells are charged.

[0019] With reference to Fig. Figure 4 shows a cross-section through the end plate 18 to illustrate the curvature of the surface 50. It is understood that the surface 50 could also be a partially cylindrical surface. In any case, the curvature could appear as if it has the same arc-shaped form as seen in Fig. Figure 4 shows that the curvature of the cylindrical surface can be generated either around a horizontal or a vertical axis.

[0020] Fig. Figure 5 is a cross-sectional view similar to the cross-section from Fig. 4, to illustrate another embodiment in which the central section 48 is provided as a flat surface 56 which applies a compressive force uniformly over the entire surface of the Fig. exerts 16 on the 3 battery cells shown.

[0021] With reference to Fig. Figure 6 shows a battery trough 38 with two alternative designs of end plates 60, 68 and upper connecting elements 26, 26'. A pair of full-height end plates 60, which have inwardly extending flanges 62, is shown in the foreground. Fig. 6 shown. The end plates 60 can include stiffening ribs 64, which reinforce the end plate 60 as required. As shown in Fig. 6 and Fig. As shown in Figure 7, a weld stud 66 can be inserted in a reversed orientation to fasten the upper flange 30 of the end plate 60 to an upper connecting element 26.

[0022] With reference to Fig. 6 and Fig. 8 will be a pair of low-profile end plates 68 in the background area of Fig. Figure 6 shows that the low-profile end plates 68 are connected to the upper connecting element 26', which includes an intermediate section 71 extending downwards from the upper connecting element 26' to a stepped flange 70. Stiffening ribs 72 are provided to stiffen the stepped flanges 70 and the intermediate section 71. A weld stud 74 and nut 76, or the like, can be used to fasten the stepped flanges 70 of the upper connecting elements 26 to the upper flange 30 of the end plate 68. With reference to Fig. 8A and Fig. 8B refers to cross-sections of one of the upper connecting elements 26 along lines 8A-8A and 8B-8B in Fig. 8. In Fig. 8A The connecting element 26 does not have a stiffening rib 77. In Fig. 8B The connecting element 26 includes a reinforcing rib 77. The reinforcing rib 77 is provided to stiffen the connecting element 26.

[0023] With reference to Fig. Figure 9 shows a tool that can be used to transport the battery module assembly 10 from a sub-assembly location to place it as a unit onto the battery tray 38. The battery module assemblies 10 are assembled such that all cable connections are made with the contact tabs 52 (in Fig. (4 shown) can be completed at a subassembly site so that the battery cells 16 are conductively connected before being assembled with the battery tray. High-voltage busbar connections and electrical sensor wiring can also be assembled at a subassembly site. The main high-voltage connections need not be made at the subassembly site if they are accessible in the finished battery assembly to avoid handling high-voltage connectors and cables for a heavy module arrangement. The sides of the battery cells 16 that are wired together are assembled with the battery tray 38 in an opposite orientation, with the battery cell wiring located in the central area of ​​the battery tray 38.

[0024] According to the method for manufacturing a battery for a vehicle, a plurality of pouch battery cells 16 are stacked to form a module 12. A pair of end plates 18 is attached to at least one lower connecting element 20, and then a plurality of the modules 12 are installed on the lower connecting element 20 between the end plates 18. After all the modules 12 have been installed on the lower connecting element 20 between the end plates 18, at least one upper connecting element 26 is attached between the end plates 18 to hold the two end plates 18 at a predetermined distance. The upper connecting elements 26 are typically attached to the assembly when the end plates 18 are subjected to compression pressure by an assembly fixture. The battery cells 16 can then be electrically connected to one another on a first side of a plurality of modules 12.At least some of the battery cells 16 can be attached to a cooling system interface or to cooling tubes 34 on a second side of the plurality of modules 12, opposite the first side. After installing the modules 12 between the pair of end plates 18, stacking the modules 12 on the lower connecting element 20, attaching the upper connecting element 26 between the end plates 18, electrically connecting the battery cells 16, and connecting the battery cells 16 to the cooling system interface 34, the plurality of modules 12 can be placed in a battery holder 38 or tray in the vehicle.

[0025] The in Fig. The tool shown in Figure 9 comprises a rod 78 attached to a plurality of upper hooks 80 and a plurality of end hooks 82. The rod 78 may be provided with eyelets 84 which can be used to lift the rod 78 and the battery module assembly 10 from the subassembly location for installation on the battery tray 38 or other holder provided in the vehicle. A latch 86 may be provided to lock the battery module assembly 10 in engagement with the upper hooks 80 and the end hooks 82.

[0026] With reference to Fig. Figure 10 shows a single module in which the end plates are 18 (in Fig. (1 shown) are taken from the plurality of battery cells 16. The battery cells each have contact tabs that are electrically connected to provide the desired voltage between the positive module terminal 92 and the negative module terminal 94. A plurality of control terminals 96 are provided on the terminal plate 90 and are used to connect the module 12 to a controller, which is used to sample and monitor the operation of the module 12. Tubular sections of the cooling system 34 are shown on the opposite side of the module with respect to the terminal plate 90.

[0027] With reference to Fig. Figure 11 provides a simplified view of an arrangement of modules 12, each comprising a plurality of battery cells 16 that form a battery module assembly 10. The positive terminals 92 and the negative terminals 94 are connected between the modules 12 via high-voltage busbars. The control connectors 102 are shown as they are connected to the terminal plates 90. Fig. Figure 11 shows only two connectors 102, but any number could be provided depending on the number of sensors and the control conditions. For example, in Fig.Figure 10 shows six control terminals 96, which would require six control connectors 102. The outermost positive terminals 92 and negative terminals 94 are connected to high-voltage wires 106 that supply power to the vehicle. The high-voltage wires 106, the high-voltage busbars, and the control wires 104 can be attached before the battery assembly is installed in the vehicle to provide easy access. However, the high-voltage wires can also be connected after installation in a vehicle if the connection points are accessible in the completed system. Handling high-voltage wires 106 after they have been attached to the assembly of modules 12 increases the weight, and handling the entire assembly with the high-voltage wires can be avoided if they are attached after installation.

[0028] Although exemplary embodiments have been described previously, it is not intended that these embodiments describe all possible forms of the invention. Instead, the words used in the description are descriptive rather than limiting, and it is understood that various modifications can be made without departing from the spirit and scope of the invention. Furthermore, the features of various implementing embodiments can be combined to form further embodiments of the invention.

Claims

[1] Battery module assembly comprising: a large number of battery cells stacked to form a module block; a multitude of modular blocks assembled together with a base connecting element extending between two end plates; and at least one upper connecting element extending between the two end plates on opposite sides of the module blocks from the base connecting element, wherein the upper connecting element and the base connecting element hold the module blocks pressed together and The end plates each have a frame section extending around an outer edge of the end plates and a middle section within the frame, the middle section being defined by a curved surface projecting inwards towards the other end plate to compress the battery cells between the middle sections of the end plates on opposite sides of the assembly. [2] Battery module assembly according to claim 1, wherein the curved surface exerts a non-linear reaction force when it holds the module blocks pressed together. [3] Battery assembly comprising the following: a large number of battery cells stacked to form a module block; a multitude of modular blocks assembled together with a base connecting element extending between two end plates; and at least one upper connecting element extending between the two end plates on opposite sides of the module blocks from the base connecting element, wherein the upper connecting element and the base connecting element hold the module blocks pressed together and The end plates each have a frame section extending around an outer edge of the end plates and a middle section within the frame, the middle section being defined by a partially spherical curved surface projecting inwards towards the other end plate. to compress the battery cells between the middle sections of the end plates on opposite sides of the assembly. [4] Battery assembly according to one of the preceding claims, wherein the upper connecting elements have a first set of attachment points aligned with a second set of attachment points on the end plates, wherein the upper connecting elements are attached to the end plates at the first and second attachment points to establish a predetermined distance between the end plates. [5] Battery assembly according to claim 4, wherein the predetermined distance is selected to exert a pressure force on the plurality of module blocks.

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