Battery Sub-Module for Automotive Vehicles

Abstract

The present invention relates to a battery submodule (11) for an automotive vehicle comprising two pouch-type battery cells and a support frame (33), each battery cell comprising two electrodes (37, 38, 39, 40), each electrode (37, 38, 39, 40) protruding outside the support frame (33), a first electrode (37) of a first battery cell facing a first electrode (39) of a second battery cell outside the support frame (33) and connected to said first electrode (39) by a welded joint, and a second electrode (38) of the first battery cell facing a second electrode (40) of a second battery cell outside the support frame (33) and connected to said second electrode (40) by a welded joint. The present invention also relates to a battery module for an automotive vehicle comprising a plurality of battery submodules of the aforementioned type.

Description

[Technical field]

[0001] The present invention relates to a battery sub-module for an automotive vehicle, a battery module including the battery sub-module, a battery assembly including the battery module, an automotive vehicle including the battery assembly, a method for installing the battery sub-module, and a method for installing the battery module. [Background technology]

[0002] In the current state of the art, battery assemblies are already known which include several battery modules each containing pouch-type battery cells and are used, for example, in battery electric vehicles, also known as BEV, an acronym for the English "Battery Electric Vehicle".

[0003] However, due to their flexibility, the handling of the pouch-type battery cells during installation in the battery module is not easy, and the manufacturing and assembly of the battery module is somewhat cumbersome. In addition, the pouch-type battery cells are easily damaged during storage or handling before installation.

[0004] To address such inconveniences, it is known to fabricate battery submodules that include multiple pouch-type battery cells, as disclosed in WO 2020 / 111665 and U.S. Patent Application Publication No. 2021 / 0057692 A1, etc. However, assembling such battery submodules can be somewhat tricky, including with respect to retaining the pouch-type battery cells within the battery submodule. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 111665 [Patent Document 2] US Patent Application Publication No. 2021 / 0057692 Summary of the Invention [Problem to be solved by the invention]

[0006] Among other things, the present invention aims to simplify the assembly of battery sub-modules. [Means for solving the problem]

[0007] Therefore, the present invention provides a pouch-shaped first battery cell; a pouch-shaped second battery cell; a layer of compressible material sandwiched between a first battery cell and a second battery cell; A battery sub-module for an automotive vehicle comprising a cell stack including, stacked along a stacking axis E, the battery sub-module comprising a support frame made of a plastic material at least partially surrounding the first battery cell, the layer of compressible material, and the second battery cell; Each battery cell has two electrodes opposed to each other in a transverse direction relative to the stacking axis E; Each electrode protrudes outside the support frame; a first electrode of the first battery cell faces a first electrode of the second battery cell outside the support frame and is further connected to the first electrode of the second battery cell by a welding joint; a second electrode of the first battery cell faces a second electrode of the second battery cell outside the support frame and is further connected to the second electrode of the second battery cell by a welding joint; the support frame is partially disposed between the first electrode of the first battery cell and the first electrode of the second battery cell; the support frame is partially disposed between the second electrode of the first battery cell and the second electrode of the second battery cell; Preferably, the support frame supports the first battery cell, the layer of compressible material, and the second battery cell. This applies to battery sub-modules.

[0008] Thus, the support frame supports the cell stack only through the welded joints. More specifically, the pouch-type battery cells and the layer of compressible material sandwiched between the battery cells are held in place on the support frame through the welded joints. Therefore, no additional elements are required to fasten the stack elements to the support frame. Thus, the battery cells are easily held, and the assembly of the battery sub-modules is simplified. Moreover, such an assembly can be easily disassembled for reuse or recycling of its components.

[0009] A "pouch battery cell", in English "pouch cell battery", should be understood according to the usual meaning of this expression in the battery field as a pouch battery cell in which the electrolyte and the electrodes are accommodated in an internal space, and the internal space is enclosed by a pouch-shaped covering material. The covering material includes an outer barrier layer, a metal layer, and possibly an inner adhesive layer. The outer barrier layer prevents the penetration of external moisture and / or gas and is made of a polymer material or the like. The metal layer is capable of increasing the mechanical strength of the covering material. The metal layer is made of aluminum, for example. Alternatively, the metal layer is made of an alloy of iron, carbon, chromium and manganese, or of steel, or of nickel, or of a nickel alloy, or of aluminum. The electrodes extend protruding from the covering material in the form of tongue-shaped conductors, which, when the covering material is sealed around the tongue-shaped conductors, form the electrodes of the pouch battery cell when the pouch battery cell is assembled. The pouch battery cell is preferably rectangular in shape.

[0010] By "layer of compressible material" it is to be specifically understood that the layer of compressible material has a higher compressibility along the stacking axis E than the other elements of the cell stack, i.e. the first battery cell and the second battery cell.

[0011] Other optional features of the battery sub-module, taken alone or in combination, include:

[0012] The support frame properly supports two battery cells, namely a first battery cell and a second battery cell.

[0013] the support frame supports the cell stack only by weld joints connecting a first electrode of the first battery cell to a first electrode of the second battery cell and by weld joints connecting a second electrode of the first battery cell to a second electrode of the second battery cell.

[0014] The first battery cell, the second battery cell, and the layer of compressible material are held in place on the support frame through a weld joint connecting a first electrode of the first battery cell with a first electrode of the second battery cell and a weld joint connecting a second electrode of the first battery cell with a second electrode of the second battery cell.

[0015] The layer of compressible material is configured to absorb the expansion of the first battery cell and the second battery cell along the stacking axis E, and the layer of compressible material is configured to be thermally insulating, thereby thermally protecting the first battery cell and the second battery cell from each other. Therefore, the layer of compressible material can simultaneously and easily fulfill the function of absorbing the expansion of the battery cells and the function of thermally protecting the battery cells from each other.

[0016] The compressible material layer is selected from the group consisting of foam sheets and polymer-based tapes. Using foam sheets as the compressible material layer reduces the weight of the battery sub-module and is very economical. Alternatively, using polymer-based tapes as the compressible material layer makes it easier to apply the compressible material layer.

[0017] the layer of compressible material is flame-retardant, which should be understood as being able to withstand temperatures of, for example, more than 200° C., preferably complying with the UL94V0 standard, so that if either the first or the second battery cell catches fire, the other battery cell is protected;

[0018] The layer of compressible material is formed primarily from silicone.

[0019] The layer of compressible material has a Shore A hardness of 20 to 50. The Shore A hardness is measured, for example, according to the ASTM D-2240 standard.

[0020] -The layer of compressible material is 0.5-1.0g / cm 3 The density is measured, for example, according to the ASTM D-792 standard.

[0021] - The support frame is made of thermoplastic material, which makes it very simple and economical to manufacture.

[0022] - The support frame is manufactured by injection moulding, which makes it very simple and economical to manufacture.

[0023] The support frame, the first battery cell, and the second battery cell are rectangular. Therefore, the shape of the support frame corresponds to the shape of the battery cells, which limits the movement of the battery cells within the support frame. Also, the support frame limits the movement of the cell stack before welding joints are made, which facilitates assembly.

[0024] - the layer of compressible material is applied with adhesive on its two faces along the stacking axis E in order to keep it in contact with the first and second battery cells, thus facilitating assembly by providing a less rigid retention of the cell stack before the welded joints are made;

[0025] The battery submodule comprises a heat sink plate arranged at an end of the cell stack, and the heat sink plate and the support frame are fixed to each other via a fixing means.

[0026] The heat sink plate is L-shaped, such that the majority of the edges of the battery submodules that run parallel to the stacking axis E are formed by the heat sink plate. Thus, despite the use of a support frame made of plastic material, heat dissipation is improved by dissipating or cooling through the edges of the battery submodules that are mostly formed by the heat sink plate.

[0027] the edge of the battery submodule running parallel to the stacking axis E is preferably at least 75%, more preferably at least 90%, formed by the heat sink plate, so that heat dissipation is further improved;

[0028] -The heat sink plate is made of aluminum, which makes it lightweight, has excellent thermal conductivity, and is flame retardant.

[0029] The heat sink plate is coated with an adhesive on its inner surface to keep it in contact with the first or second battery cell, thus facilitating assembly by providing a rather weak retention of the cell stack on the heat sink plate and thus on the support frame before the welded joint is made.

[0030] The fastening means comprise fastening claws and / or clips and / or contours arranged on the support frame and / or the second battery cell and / or the heat sink plate, so that the fastening of the heat sink plate is very simple.

[0031] The heat sink plate is fixed to the support frame by fastening or latching, so that fixing of the heat sink plate is very simple.

[0032] The heat sink plate has latch tabs for latching to the support frame, so that fixing the heat sink plate to the support frame is extremely easy.

[0033] -The battery submodule includes a first busbar, and the first electrode of the first battery cell is directly welded to the first busbar, and the first electrode of the second battery cell is directly welded to the first busbar, so that the electrical connection between the first electrode and the first busbar is simple and reliable.

[0034] -The battery submodule includes a second busbar, and the second electrode of the first battery cell is directly welded to the second busbar, and the second electrode of the second battery cell is directly welded to the second busbar, so that the electrical connection between the second electrode and the second busbar is easily and reliably established.

[0035] The first bus bar is fixed to the support frame, which simplifies the installation of the first bus bar.

[0036] The first busbar is fastened or latched to the support frame, making the installation of the first busbar extremely simple.

[0037] The first busbar has claws which are fastened to the support frame.

[0038] The second busbar is fixed to the support frame, which makes the installation of the second busbar extremely simple.

[0039] The second busbar is fastened or latched to the support frame, making the installation of the second busbar extremely simple.

[0040] The second busbar is provided with claws, which are fastened to the support frame.

[0041] The distance between the first electrode of the first battery cell and the first electrode of the second battery cell outside the support frame is longer than the distance between the first electrode of the first battery cell and the first electrode of the second battery cell inside the support frame, which makes it easier to weld the first electrode to the first busbar during assembly.

[0042] The distance between the second electrode of the first battery cell and the second electrode of the second battery cell outside the support frame is longer than the distance between the second electrode of the first battery cell and the second electrode of the second battery cell inside the support frame, which makes it easier to weld the second electrode to the second busbar during assembly.

[0043] The first electrode of the first battery cell is directly welded to the first electrode of the second battery cell, which makes the electrical connection between the first electrodes extremely simple and reliable.

[0044] The second electrode of the first battery cell is directly welded to the second electrode of the second battery cell, which makes the electrical connection between the second electrodes extremely simple and reliable.

[0045] -The electrodes of each battery cell are different. Therefore, when assembling the battery sub-module, the difference provides an anti-mix-up effect for the electrodes, preventing the battery cells from being installed in reverse, thereby simplifying the assembly of the battery sub-module.

[0046] The total thickness of the support frame, measured along the stacking axis E, is less than the sum of the thicknesses of the cell stack and the heat sink plate, which facilitates compression of the battery cells when mounting the battery sub-modules within the battery module.

[0047] the support frame comprises anti-mix-up means formed by a convex element and a concave element having a shape complementary to the convex element, the convex element and the concave element being oriented on the same axis parallel to the stacking axis E, the convex element and the concave element being arranged in opposite orientations away from the center of the cell stack along the stacking axis E, whereby the anti-mix-up means can simplify the assembly of several battery sub-modules together, so that the assembly of a battery module comprising several identical battery sub-modules is easier and more reliable;

[0048] - The support frame has four asymmetrical and unequal edges. Therefore, when assembling the battery submodule, the unequal edges prevent the support frame from being installed incorrectly, which simplifies the assembly of the battery submodule.

[0049] The present invention also relates to a battery module for an automotive vehicle comprising a plurality of battery sub-modules as defined above, the battery sub-modules being stacked along a stacking axis E to form an array of battery sub-modules, the battery module comprising a fixing plate at each end of the array of battery sub-modules, the fixing plates being connected between each other along the stacking axis E by axial compression means, which axially compress the array of battery sub-modules.

[0050] Therefore, the battery module can be realized simply and very compactly.

[0051] Other optional features of the battery module, taken alone or in combination, include:

[0052] The battery sub-modules forming the battery sub-module array are all identical.

[0053] The battery sub-modules are electrically connected to each other.

[0054] - first electrodes of the array of battery sub-modules are electrically connected to each other by welding of the electrical connections, and second electrodes of the array of battery sub-modules are electrically connected to each other by welding of the electrical connections.

[0055] the axial compression means comprises at least one threaded rod, whereby the axial compression means is simple and economical to manufacture;

[0056] The fixing plate is made of reinforced plastic material, preferably fibre reinforced plastic material, or of metal, preferably aluminium.

[0057] - The convex elements of a battery sub-module are inserted into the concave elements of the adjacent battery sub-modules, which reliably prevents installation errors and prevents mix-ups during battery module assembly.

[0058] The battery modules are configured to transfer heat to a cooling plate, and each heat sink plate is in thermal communication with the cooling plate, for example by direct contact or by indirect contact using a thermally conductive paste.

[0059] The present invention also covers a battery assembly comprising a plurality of battery modules as defined above, preferably a battery assembly comprising a plurality of rows of battery modules as defined above.

[0060] The present invention is also directed to a motor vehicle, preferably a battery electric vehicle, comprising a battery assembly as defined above and preferably a cooling plate, each battery module of the battery assembly being configured to transfer heat to the cooling plate.

[0061] The present invention relates to a method for mounting a battery sub-module as defined above, comprising the steps of: - providing a support frame made of a plastic material; - producing a cell stack including a first pouch-shaped battery cell, a second pouch-shaped battery cell, and a layer of compressible material sandwiched between the first battery cell and the second battery cell, stacked along a stacking axis E, the cell stack being disposed in a support frame; - providing a welded joint between a first electrode of a first battery cell and a first electrode of a second battery cell; - providing a welded joint between a second electrode of the first battery cell and a second electrode of the second battery cell; The present invention also covers a method including the steps of:

[0062] Other optional features relating to the mounting method of the battery sub-modules, taken alone or in combination, include:

[0063] The method for assembling the battery sub-module may include the steps of: fixing a heat sink plate to one end of the cell stack such that the heat sink plate and the support plate are fixed to each other.

[0064] The method for mounting the battery sub-modules may include the steps of: fixing a first busbar to a support frame before performing a welding joint between a first electrode of a first battery cell and a first electrode of a second battery cell.

[0065] The method for mounting the battery sub-module includes the steps of: fixing a second busbar to a support frame before performing a welded joint between the second electrode of the first battery cell and the second electrode of the second battery cell.

[0066] The welded joint between the first electrode of the first battery cell and the first electrode of the second battery cell is achieved by welding between the first electrode of the first battery cell and the first busbar and between the first electrode of the second battery cell and the first busbar, preferably by laser welding.

[0067] The welded joint between the second electrode of the first battery cell and the second electrode of the second battery cell is achieved by welding between the second electrode of the first battery cell and the second busbar and by welding between the second electrode of the second battery cell and the second busbar, preferably by laser welding.

[0068] The method for mounting the battery sub-module includes the steps of: cutting off the free ends of the electrodes protruding from the first busbar or the second busbar after performing the welding joint.

[0069] The welded joint between the first electrode of the first battery cell and the first electrode of the second battery cell is performed, preferably by laser welding, by directly joining the first electrode of the first battery cell and the first electrode of the second battery cell. Fingers of a tool are inserted between the first electrode of the first battery cell and the first electrode of the second battery cell outside the support frame so that the welding can be performed without damaging the support frame. The first electrode of the first battery cell is folded back over the fingers so as to come into contact with the first electrode of the second battery cell, and the welding between the first electrode of the first battery cell and the first electrode of the second battery cell is performed. Alternatively, the first electrode of the second battery cell is folded back over the fingers so as to come into contact with the first electrode of the first battery cell, and the welding between the first electrode of the first battery cell and the first electrode of the second battery cell is performed.

[0070] The welded joint between the second electrode of the first battery cell and the second electrode of the second battery cell is performed by directly welding the second electrode of the first battery cell and the second electrode of the second battery cell, preferably by laser welding. Fingers are inserted between the second electrode of the first battery cell and the second electrode of the second battery cell outside the support frame so that the welding can be performed without damaging the support frame. The second electrode of the first battery cell is folded back over the fingers so as to come into contact with the second electrode of the second battery cell, and the welding between the second electrode of the first battery cell and the second electrode of the second battery cell is performed. Alternatively, the second electrode of the second battery cell is folded back over the fingers so as to come into contact with the second electrode of the first battery cell, and the welding between the second electrode of the first battery cell and the second electrode of the second battery cell is performed.

[0071] The present invention relates to a method for mounting a battery module as defined above, comprising the steps of: - stacking a plurality of battery sub-modules as previously defined in an array of battery sub-modules along a stacking axis E; - providing a fixing plate at each end of the row of battery sub-modules; - axially compressing the array of battery sub-modules by attaching axial compression means along the stacking axis E, thereby connecting the fixing plates to each other; The present invention also covers a method including the steps of:

[0072] Other optional features relating to the mounting method of the battery module, taken alone or in combination, include:

[0073] The method for mounting the battery modules comprises, after the step of mounting the axial compression means, the step of electrically connecting the battery sub-modules together by welding via the respective first electrodes and / or the respective first busbars and / or by welding via the respective second electrodes and / or the respective second busbars.

[0074] The invention will be better understood from reading the following description, given by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0075] [Figure 1] FIG. 1 is a schematic diagram of a motor vehicle including a battery assembly including a plurality of battery modules. [Diagram 2] FIG. 1 is a perspective view of a battery module including multiple battery sub-modules according to a first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of a cell stack forming part of a battery submodule according to a first embodiment. [Figure 4] FIG. 2 is a perspective view of a battery submodule according to the first embodiment. [Diagram 5] FIG. 5 is an exploded perspective view of a detail of the battery submodule shown in FIG. 4. [Figure 6]FIG. 5 is a perspective view of a support frame forming part of the battery submodule shown in FIG. 4. [Figure 7] FIG. 13 is an exploded perspective view of a detail of a battery submodule according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0076] Like numbers refer to like elements throughout all drawings.

[0077] In this detailed description, the implementations listed below are examples. Although the description is given with respect to one or more embodiments, it does not mean that each feature relates to only one embodiment. Individual features of different embodiments may be combined and / or substituted with each other to produce other implementations.

[0078] 1 shows diagrammatically a motor vehicle 1 comprising a battery assembly 3 and a cooling plate 5. In this example, the motor vehicle 1 is a battery electric vehicle and as such comprises an electric motor 7 arranged to drive the movement of the motor vehicle 1.

[0079] The battery assembly 3 includes a plurality of battery modules 9. More specifically, in this example, the battery assembly 3 includes a plurality of rows of battery modules 9, preferably two rows of four battery modules 9, as shown in Figure 1. Each battery module 9 of the battery assembly 3 is configured to transfer heat to the cooling plate 5.

[0080] As particularly shown in Fig. 2, the battery module 9 includes a plurality of battery submodules 11. The battery submodules 11 are stacked along a stacking axis E to form a row of battery submodules 11. In this example, the battery module 9 includes eight battery submodules 11, and all of the battery submodules 11 forming the row of battery submodules 11 are identical. The battery module 9 includes fixing plates 13a, 13b at each end of the row of battery submodules 11.

[0081] The fixing plates 13a, 13b are made of reinforced plastics material, preferably fibre reinforced plastics material, or of metal, preferably aluminium.

[0082] The fixing plates 13a, 13b are connected to each other along the stacking axis E by an axial compression means 15, which axially compresses the row of battery submodules 11. The axial compression means 15 includes at least one threaded rod 17. More specifically, in this example, as shown in FIG. 2, the axial compression means 15 includes four threaded rods 17.

[0083] Each threaded rod 17 extends along the stacking axis E and has a threaded end 19 for connection with one of the two fixed plates 13a, 13b and an abutment head 21 for the other of the two fixed plates 13a, 13b so as to obtain axial compression along the stacking axis E. One of the two fixed plates 13a, 13b has a through hole 23 through which the threaded rod 17 passes, while the other has a connection hole 25 which engages with the threaded end 19. The abutment head 21 bears around the through hole 23.

[0084] As particularly shown in FIG. 3, the battery submodule 11 is a stack of cells stacked along a stacking axis E, a pouch-shaped first battery cell 27; a pouch-shaped second battery cell 29; a layer 31 of compressible material sandwiched between the first battery cell 27 and the second battery cell 29; The cell stack includes:

[0085] The battery submodule 11 further comprises a support frame 33 made of a plastic material, as particularly shown in Fig. 3 and Fig. 5. As shown in Fig. 4, the support frame 33 at least partially surrounds the first battery cell 27, the layer of compressible material 31 and the second battery cell 29. More specifically, the support frame 33 supports the first battery cell 27, the layer of compressible material 31 and the second battery cell 29. Thus, in this example, the support frame 33 certainly supports two battery cells, namely the first battery cell 27 and the second battery cell 29. In this example, the support frame 33, the first battery cell 27 and the second battery cell 29 are rectangular. The support frame 33 is made of a thermoplastic material and is manufactured by injection molding.

[0086] The battery submodule 11 also includes heat sink plates 35 disposed at the ends of the cell stack.

[0087] 4, the first battery cell 27 includes two electrodes 37, 38 that are opposed to each other in a transverse direction relative to the stacking axis E, and the second battery cell 29 includes two electrodes 39, 40 that are opposed to each other in a transverse direction relative to the stacking axis E. Each of the electrodes 37, 38, 39, 40 is, for example, a tongue formed of a metal sheet, preferably an aluminum sheet.

[0088] Each of the electrodes 37, 38, 39, 40 protrudes from the support frame 33. The first electrode 37 of the first battery cell 27 faces the first electrode 39 of the second battery cell 29 outside the support frame 33 and is connected to the first electrode 39 of the second battery cell 29 by a welded joint. The second electrode 38 of the first battery cell 27 faces the second electrode 40 of the second battery cell 29 outside the support frame and is connected to the second electrode 40 of the second battery cell 29 by a welded joint. Thus, the support frame 33 supports the cell stack only by the welded joint that connects the first electrode 37 of the first battery cell 27 to the first electrode 39 of the second battery cell 29 and the welded joint that connects the second electrode 38 of the first battery cell 27 to the second electrode 40 of the second battery cell 29. In other words, the first battery cell 27, the second battery cell 29 and the layer of compressible material 31 are held in place on the support frame through weld joints connecting the first electrode 37 of the first battery cell 27 to the first electrode 39 of the second battery cell 29 and weld joints connecting the second electrode 38 of the first battery cell 27 to the second electrode 40 of the second battery cell 29.

[0089] The support frame 33 is disposed partially between a first electrode 37 of the first battery cell 27 and a first electrode 39 of the second battery cell 29, and the support frame 33 is disposed partially between a second electrode 38 of the first battery cell 27 and a second electrode 40 of the second battery cell. The total thickness of the support frame 33, as measured along the stacking axis E, is less than the sum of the thicknesses of the cell stack and the heat sink plate 35, thereby facilitating compression of the battery cells 27, 29 during installation of the battery sub-module 11 within the battery module 9.

[0090] In this example, the electrodes 37, 38, 39, 40 each pass through a cut in the support frame 33, and the portions of the support frame 33 that are thinned along the stacking axis E due to the cuts protrude outward in the form of ears on either side of the support frame 33 in a direction transverse to the stacking axis E.

[0091] In this example, the electrodes 37, 38, 39, 40 of each battery cell 27, 29 are different from each other. Thus, as shown in particular in Fig. 5, the marking on the first electrode 37 of the first battery cell 27 distinguishes it from the second electrode of the first battery cell 27. Similarly, the marking on the first electrode 39 of the second battery cell 29 distinguishes it from the second electrode 40 of the second battery cell 29. In this example, the marking consists of a hyphen "-". In a variant not shown, the support frame 33 has four asymmetrically different edges.

[0092] 3, the layer of compressible material 31 sandwiched between the first battery cell 27 and the second battery cell 29 is configured to absorb expansion of the first battery cell 27 and the second battery cell 29 along a stacking axis E. Furthermore, the layer of compressible material 31 is configured to have thermal insulation properties, thereby thermally protecting the first battery cell 27 and the second battery cell 29 from each other, and the layer of compressible material 31 is flame retardant.

[0093] In this example, the layer of compressible material 31 is selected from the group consisting of foam sheets and tapes mainly made of polymeric materials. Preferably, the layer of compressible material 31 is made mainly of silicone, has a Shore A hardness of 20-50 and a compressibility of 0.5-1.0 g / cm 3 In this example, the layer of compressible material 31 is coated with an adhesive on both sides thereof along the stacking axis E to maintain contact between the layer of compressible material 31 and the first and second battery cells 27 and 29.

[0094] In this example, the heat sink plate 35 is made of aluminum, and the inner surface of the heat sink plate 35 is in contact with the outer surface of the second battery cell 29 .

[0095] Moreover, the heat sink plate 35 is L-shaped, such that the majority of the edge of the battery submodule 11 extending parallel to the stacking direction X is formed by the heat sink plate 35. In Figs. 2, 3, 4 and 6, said edge of the battery submodule 11 is the upper edge. More specifically, in this example, this edge of the battery submodule 11 extending parallel to the stacking axis E is preferably formed by at least 75%, more preferably at least 90%, of the heat sink plate 35, as shown in particular in Fig. 4. This edge of the battery submodule 11 is configured to transfer heat to the cooling plate 5.

[0096] To maintain contact between the heat sink plate 35 and the second battery cell 29, an adhesive is also applied to the inside surface of the heat sink plate 35.

[0097] The heat sink plate 35 and the support frame 33 are secured to each other by fastening means 41. Thus, the heat sink plate 35 is secured to the support frame 33 by fastening or latching.

[0098] As shown in particular in Fig. 3, the fastening means 41 comprise fastening claws 43 and / or clips and / or contours arranged on the support frame 33 and / or the second battery cell 29 and / or the heat sink plate 35. More specifically, in this example, the heat sink plate 35 is fastened to the support frame 33 by fastening, and the fastening means 41 comprise fastening claws 43 arranged on the heat sink plate 35, which fastening claws 43 are inserted into the support frame 33 by elastic deformation and hold the heat sink plate 35 and the support frame 33 fixed to each other. Alternatively, according to a variant not shown, the heat sink plate 35 is fastened to the support frame 33 by latching, and the heat sink plate 35 comprises latching claws that are latched to the support frame 33.

[0099] To this end, the battery modules 9 are configured to transfer heat to the cooling plate 5, and each heat sink plate 35 is in thermal communication with the cooling plate 5. The heat transfer can be achieved, for example, by direct contact or indirect contact using a thermally conductive paste.

[0100] The battery submodule 11 further includes a first busbar 47, where the first electrode 37 of the first battery cell 27 is directly welded to the first busbar 47, and the first electrode 39 of the second battery cell 29 is directly welded to the first busbar 47.

[0101] The battery submodule 11 also includes a second busbar 49, with the second electrode 38 of the first battery cell 27 directly welded to the second busbar 49 and the second electrode 40 of the second battery cell 29 directly welded to the second busbar 49.

[0102] The first busbar 47 is secured to the support frame 33 by fastening or latching. In this example, the first busbar 47 includes tabs 50 that are fastened to the support frame 33. More specifically, the first busbar 47 has a shape complementary to a portion of the support frame 33 that extends between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29. This portion of the support frame 33 is thinned along the stack axis E and protrudes outwardly in a direction transverse to the stack axis E in the form of ears.

[0103] In this example, the second busbar 49 is identical to the first busbar 47. As such, the second busbar 49 is secured to the support frame 33 by fastening or latching, and the second busbar 49 is provided with tabs 50 that are clamped against the support frame 33. More specifically, the second busbar 49 has a shape complementary to the portion of the support frame 33 that extends between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29. This portion of the support frame 33 is thinned along the stacking axis E and protrudes outward in the form of ears transverse to the stacking axis E.

[0104] The first bus bar 47 and the second bus bar 49 are electrically conductive and are made, for example, of copper or aluminum.

[0105] The distance between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29 outside the support frame 33 is longer than the distance between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29 inside the support frame 33. That is, as shown in FIG. 5, before the battery submodule 11 is assembled, the width Lb of the first bus bar 47 is larger than the distance Dc between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell. Similarly, the distance between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29 outside the support frame 33 is longer than the distance between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29 inside the support frame 33. That is, before the battery submodule 11 is assembled, the width of the second busbar 49 is greater than the distance between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell.

[0106] 6, the support frame 33 further comprises a mix-up prevention means 51 formed of a convex element 53 and a concave element 55 having a shape complementary to the convex element 53, the convex element 53 and the concave element 55 being oriented on the same axis parallel to the stacking axis E, the convex element 53 and the concave element 55 being arranged in opposite orientation away from the center of the cell stack along the stacking axis E. In this example, the convex element 53 is male and the concave element 55 is female.

[0107] In the battery module 9, the convex element 53 of the battery submodule 11 is inserted into the concave element 55 of the adjacent battery submodule 11.

[0108] On the other hand, in the battery module 9, the battery submodules 11 are electrically connected to each other. For example, the first electrodes 37, 39 of the row of battery submodules 11 are electrically connected to each other by welding of the electrical connection parts, and the second electrodes 38, 40 of the row of battery submodules 11 are electrically connected to each other by welding of the electrical connection parts. The electrical connection parts are welded, for example, by overlapping and bending the first electrodes 37, 39 and the second electrodes 38, 40, respectively, and then laser welding them. Alternatively, the first electrical connection rod is brought into contact with the first bus bar 47 and laser welded to the first bus bar 47, and the second electrical connection rod is brought into contact with the second bus bar 49 and laser welded to the second bus bar 49.

[0109] FIG. 7 shows a detail of a battery submodule 11' according to a second embodiment. To make the structure of the battery submodule 11' easier to understand, FIG. 7 shows only the first battery cell 27 and the second battery cell 29. This battery submodule 11' according to the second embodiment differs from the battery submodule 11 according to the first embodiment described above in that no busbars are included. Indeed, in this second embodiment, the first electrode 37 of the first battery cell 27 is directly welded to the first electrode 39 of the second battery cell 29. Similarly, although not shown, the second electrode 38 of the first battery cell 27 is directly welded to the second electrode 40 of the second battery cell 29.

[0110] An example of a method for mounting the battery sub-modules 11, 11' defined above will be described below. The mounting method is as follows: - providing a support frame 33 made of plastic material; - producing a cell stack comprising, stacked along a stacking axis E, a pouch-shaped first battery cell 27, a pouch-shaped second battery cell 29 and a layer 31 of compressible material sandwiched between the first battery cell 27 and the second battery cell 29, the cell stack being arranged in a support frame 33; - making a welded joint between a first electrode 37 of the first battery cell 27 and a first electrode 39 of the second battery cell 29; - making a welded joint between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29; Includes.

[0111] The method of mounting the battery sub-modules 11, 11' further includes the step of fixing a heat sink plate 35 to the end of the cell stack so that the heat sink plate 35 and the support frame 33 are fixed to each other.

[0112] The mounting method of the battery submodule 11 according to the first embodiment further comprises a step of fixing the first busbar 47 to the support frame 33 before the step of performing a welded joint between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29. The welded joint between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29 is performed by welding between the first electrode 37 of the first battery cell 27 and the first busbar 47 and between the first electrode 39 of the second battery cell 29 and the first busbar 47, preferably by laser welding.

[0113] The mounting method of the battery submodule 11 according to the first embodiment further comprises a step of fixing the second busbar 49 to the support frame 33 before the step of performing a welded joint between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29. The welded joint between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29 is performed by welding between the second electrode 38 of the first battery cell 27 and the second busbar 49 and between the second electrode 40 of the second battery cell 29 and the second busbar 49, preferably by laser welding.

[0114] According to a variant not shown, the mounting method of the battery submodule 11 according to the first embodiment further comprises, after performing the welding joint, a step of cutting off the free ends of the electrodes 37, 38, 39, 40 protruding outside the first busbar 47 or the second busbar 49.

[0115] The mounting method of the battery submodule 11′ according to the second embodiment is further characterized in that the welded joint between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29 is achieved by performing direct welding between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29, preferably by laser welding.

[0116] In order to be able to perform the welding without damaging the support frame 33, fingers are inserted outside the support frame 33 between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29. The first electrode 37 of the first battery cell 27 is folded back over the fingers so as to come into contact with the first electrode 39 of the second battery cell 29, and welding is performed between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29. Alternatively, according to a variant not shown, the first electrode 39 of the second battery cell 29 is folded back over the fingers so as to come into contact with the first electrode 37 of the first battery cell 27, and welding is performed between the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29.

[0117] Similarly, although not shown, the mounting method of the battery submodule 11' according to the second embodiment is further characterized in that the welded joint between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29 is performed by directly welding the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29, preferably by laser welding.

[0118] To allow welding to occur without damaging the support frame, fingers are inserted outside the support frame 33 between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29. The second electrode 38 of the first battery cell 27 is folded back over the fingers to contact the second electrode 40 of the second battery cell 29, and welding is performed between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29.

[0119] Alternatively, according to a variant not shown, the second electrode 40 of the second battery cell 29 is folded back over the fingers so as to contact the second electrode 38 of the first battery cell 27, and welding is performed between the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29.

[0120] An example of a method for mounting the battery module 9 defined above will be described below. The mounting method is as follows: - stacking a plurality of battery sub-modules 11, 11' as previously defined along a stacking axis E in the form of an array of battery sub-modules 11, 11'; - arranging fixing plates 13a, 13b at each end of the row of battery sub-modules 11, 11'; - axially compressing the array of battery sub-modules 11, 11' by attaching axial compression means 15 along the stacking axis E, thereby connecting the fixing plates 13a, 13b to each other; Includes.

[0121] The battery sub-module installation method further includes, after the installation step of the axial compression means 15, a step of electrically connecting the battery sub-modules 11, 11' to each other by welding via their respective first electrodes 37, 39 and / or their respective first busbars 47 and / or by welding via their respective second electrodes 38, 40 and / or their respective second busbars 49.

[0122] The invention is not limited to the described embodiment, and other embodiments will be apparent to those skilled in the art.

[0123] In particular, it is possible to combine the first and second embodiments such that the battery sub-module comprises a first bus bar 47 connecting the first electrode 37 of the first battery cell 27 and the first electrode 39 of the second battery cell 29, and the second electrode 38 of the first battery cell 27 is directly welded to the second electrode 40 of the second battery cell 29, or the battery sub-module comprises a second bus bar 49 connecting the second electrode 38 of the first battery cell 27 and the second electrode 40 of the second battery cell 29, and the first electrode 37 of the first battery cell 27 is directly welded to the first electrode 39 of the second battery cell 29. [Explanation of symbols]

[0124] 1 Motor vehicles 3 Battery Assembly 5 Cooling plate 7 Electric Motor 9 Battery Module 11, 11' Battery Submodule 13a, 13b Fixing plate 15 Axial compression means 17 Threaded Rod 19 Threaded End 21 Contact head 23 Through hole 25 Connection hole 27 First Battery Cell 29 Second Battery Cell 31 Layer of compressible material 33 Support frame 35 Heat sink plate 37, 38, 39, 40 electrodes 41 Fixing means 43 Fastening claw 47 First busbar 49 Second busbar 50 Claws 51 Measures to prevent mix-ups 52 Convex element 53 Concave element E Lamination axis Lb Width Dc Distance

Claims

1. A pouch-shaped first battery cell (27); a pouch-shaped second battery cell (29); a layer of compressible material (31) sandwiched between the first battery cell (27) and the second battery cell (29); A battery submodule (11, 11') for an automotive vehicle (1) comprising a cell stack including, stacked along a stacking axis E, the battery sub-module (11, 11') comprises a support frame (33) made of a plastic material at least partially surrounding the first battery cell (27), the layer of compressible material (31) and the second battery cell (29); the support frame (33) supports the first battery cell (27), the layer of compressible material (31) and the second battery cell (29), each battery cell (27, 29) having two opposing electrodes (37, 38, 39, 40) transversely opposed to the stacking axis E; a first electrode (37) of the first battery cell (27) faces a first electrode (39) of the second battery cell (29) outside the support frame (33) and is further connected to the first electrode (39) of the second battery cell (29) by a welded joint; and a second electrode (38) of the first battery cell (27) faces a second electrode (40) of the second battery cell (29) outside the support frame (33) and is further connected to the second electrode (40) of the second battery cell (29) by a welded joint. the support frame (33) being partially disposed between the first electrode (37) of the first battery cell (27) and the first electrode (39) of the second battery cell (29); and the support frame (33) being partially disposed between the second electrode (38) of the first battery cell (27) and the second electrode (40) of the second battery cell (29); The battery sub-module (11, 11') is characterized by:

2. 2. The battery submodule (11, 11') according to claim 1, wherein the layer of compressible material (31) is configured to absorb expansion of the first battery cell (27) and the second battery cell (29) along the stacking axis E, the layer of compressible material (31) is configured to be thermally insulating, whereby the first battery cell (27) and the second battery cell (29) are thermally protected from each other, and the layer of compressible material (31) is selected from the group consisting of foam sheets and tapes mainly made of polymeric materials.

3. A heat sink plate (35) is provided at an end of the cell stack, The heat sink plate (35) and the support frame (33) are fixed to each other via a fixing means (41); The battery submodule (11, 11') according to claim 1 or 2, wherein the heat sink plate (35) is L-shaped such that a majority of the edge of the battery submodule extending parallel to the stacking axis E is formed by the heat sink plate (35).

4. 4. The battery submodule (11) according to claim 1, further comprising a first busbar (47), the first electrode (37) of the first battery cell (27) being directly welded to the first busbar (47), and the first electrode (39) of the second battery cell (29) being directly welded to the first busbar (47).

5. The battery submodule (11) of claim 4, wherein the first busbar (47) is fixed to the support frame (33).

6. 6. The battery submodule (11) according to any one of claims 1 to 5, wherein a distance between the first electrode (37) of the first battery cell (27) and the first electrode (39) of the second battery cell (29) outside the support frame (33) is longer than a distance between the first electrode (37) of the first battery cell (27) and the first electrode (39) of the second battery cell (29) within the support frame (33).

7. 7. The battery submodule (11') according to any one of claims 1 to 6, wherein the second electrode (38) of the first battery cell (27) is directly welded to the second electrode (40) of the second battery cell (29).

8. 8. A battery submodule (11, 11') according to any one of claims 1 to 7, wherein the total thickness of the support frame (33), when measured along the stacking axis E, is less than the sum of the thicknesses of the cell stack and the heat sink plate (35).

9. 9. The battery submodule (11, 11') according to any one of claims 1 to 8, wherein the support frame (33) comprises an anti-mix-up means (51) formed by a convex element (53) and a concave element (55) having a shape complementary to the convex element (53), the convex element (53) and the concave element (55) being oriented along the same axis parallel to the stacking axis E, and the convex element (53) and the concave element (55) being arranged in opposite directions away from the center of the cell stack along the stacking axis E.

10. The battery submodule (11, 11') according to any one of claims 1 to 9, wherein the support frame (33) supports exactly two battery cells, namely the first battery cell (27) and the second battery cell (29).

11. The support frame (33) the weld joint connecting the first electrode (37) of the first battery cell (27) to the first electrode (39) of the second battery cell (29); the weld joint connecting the second electrode (38) of the first battery cell (27) to the second electrode (40) of the second battery cell (29); The battery submodule (11, 11') according to any one of claims 1 to 10, wherein the cell stack is supported only by a spring.

12. the first battery cell (27), the second battery cell (29), and the layer of compressible material (31); the weld joint connecting the first electrode (37) of the first battery cell (27) to the first electrode (39) of the second battery cell (29); the weld joint connecting the second electrode (38) of the first battery cell (27) to the second electrode (40) of the second battery cell (29); The battery sub-module (11, 11') according to any one of claims 1 to 11, wherein the battery sub-module (11, 11') is held in position on the support frame (33) through a

13. 13. A battery module (9) for an automotive vehicle comprising a plurality of battery submodules (11, 11') according to any one of claims 1 to 12, wherein the battery submodules (11, 11') are stacked along the stacking axis E to form an array of the battery submodules (11, 11'), and the battery module (9) comprises fixing plates (13a, 13b) at each end of the array of battery submodules (11, 11'), the fixing plates (13a, 13b) being connected to each other along the stacking axis E by axial compression means (15), the axial compression means (15) axially compressing the array of battery submodules (11, 11').

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