Energy storage device for motor vehicles

Abstract

Motor vehicle energy storage device. The energy storage device comprises a housing, at least one electrochemical module arranged within said housing, the housing comprising a bottom wall and an adhesive layer extending between the at least one electrochemical module and the bottom wall, the energy storage device further comprising a film extending between the adhesive layer and the bottom wall, and a traction means configured to exert a tensile force on said film. Figure for the abbreviation: 2

Description

Title of the invention: Energy storage device for motor vehicles. Technical field of the invention

[0001] The invention relates to an energy storage device for a motor vehicle. The invention also relates to a method for disassembling an energy storage device according to the invention. Prior art

[0002] Current legislation mandates the recycling of energy storage devices by automotive manufacturers. However, existing energy storage devices and the processes for disassembling them present drawbacks. In particular, the modules of energy storage devices are very difficult to separate from the battery casing, which complicates battery recycling. Disassembling energy storage devices is very often destructive, and the cost of recycling them is very high. Presentation of the invention

[0003] The object of the invention is to provide an energy storage device and a method for disassembling an energy storage device which remedies the above disadvantages and improves upon the devices and methods for disassembling known in the prior art. Summary of the invention

[0004] The invention relates to an energy storage device comprising a casing, at least one electrochemical module arranged inside said casing, the casing comprising a bottom wall and a layer of glue extending between the at least one electrochemical module and the bottom wall, the energy storage device further comprising a film extending between the layer of glue and the bottom wall, and a traction means configured to exert a tensile force on said film.

[0005] In one embodiment, the film comprises a lower surface in direct contact with the bottom wall, and an upper surface in direct contact with the glue layer.

[0006] In one embodiment, the film is made of a polymer material.

[0007] In one embodiment, the traction means comprises a winder connected pivot with the casing around a first axis, one edge of said film being fixed to said reel, the reel comprising a means for transmitting a torque configured to permit rotation of the reel around the first axis.

[0008] In one embodiment, the means for transmitting a torque includes a recess, in particular a hexagonal opening, intended to cooperate with a tool of complementary shape to the recess, the recess being accessible from outside the housing.

[0009] In one embodiment, the winder comprises two elements fixed to each other, in particular each element comprising a half-cylinder shape of revolution, in particular the two elements being fixed to each other by means of fixing screws, and the edge of the film is clamped between the two elements.

[0010] In one embodiment, the housing includes a side wall provided with a window, said window being positioned opposite said film.

[0011] In one embodiment, the device includes a shoe closing said window, an edge of the film being fixed to the shoe.

[0012] In one embodiment, the shoe includes at least one tapped opening positioned opposite a bearing surface formed on an outer surface of said side wall.

[0013] The invention further relates to a method for disassembling an energy storage device according to the invention, comprising a step of pulling on the film. Figures are shown.

[0014] These objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, given by way of non-limiting example, with reference to the accompanying figures, among which:

[0015] Fig. 1 is a first perspective view of an energy storage device according to a first embodiment of the invention.

[0016] Fig. 2 is a second perspective view of an energy storage device according to the first embodiment of the invention.

[0017] Fig. 3 is a first profile view of an energy storage device according to the first embodiment of the invention.

[0018] Fig. 4 is a perspective view of a tool suitable for collaborating with an energy storage device according to the first embodiment of the invention, for its disassembly.

[0019] Fig. 5 is a first perspective view of an energy storage device according to a second embodiment of the invention.

[0020] Fig. 6 is a second perspective view of an energy storage device according to a second embodiment of the invention.

[0021] Fig. 7 is a first profile view of an energy storage device according to the second embodiment of the invention.

[0022] Fig. 8 is a third perspective view of the energy storage device according to a second embodiment of the invention.

[0023] Figure 9 is a first illustration of the disassembly of a device energy storage according to the second embodiment of the invention.

[0024] Figure 10 is a second illustration of the disassembly of an energy storage device according to the second embodiment of the invention. Detailed description

[0025] Figure 1 schematically illustrates an embodiment of a motor vehicle 100 equipped with an energy storage device 1 according to the invention. The motor vehicle 100 can be any type of vehicle, in particular a passenger car or a commercial vehicle.

[0026] The motor vehicle 100 includes an energy storage device 1 comprising a housing 10, at least one electrochemical module 20 arranged inside said housing 10, the housing 10 comprising a bottom wall 11 and an adhesive layer 12 extending between the at least one electrochemical module 20 and the bottom wall 11. In addition, the energy storage device 1 further includes - a film 30 extending between the adhesive layer 12 and the bottom wall 11 of the housing 10, and - a traction means 40 configured to exert a traction force on said film 30.

[0027] In the remainder of the document, the energy storage device 1 is referred to as "battery pack 1", and an electrochemical module 20 is referred to as "module" or "battery module".

[0028] The battery pack 1 is described with reference to a direct orthonormal frame RI with center 01 and axes (XI, Yl, Zl), the frame RI being defined such that: - the bottom wall 11 of the casing 10 is contained within a plane containing the axes XI and Yl, - a wall 14, called the longitudinal wall of the casing 10, is contained in a plane containing the axes Yl and Zl, - a wall 13 called lateral of the casing 10 is included in a plane containing the axes XI and Zl.

[0029] The at least one module 20 arranged inside the housing 10 includes a face, called the lower face, parallel to the plane (XI, Y1); similarly, the layer of glue 12 extends along a first given plane between the at least one module 20 and the bottom wall 11, while being parallel to the plane (XI, Y1).

[0030] In addition, the film 30 extends along a second given plane, parallel to the plane (XI, Y1), the second given plane interposing itself between the plane (XI, Y1) and the first given plane.

[0031] Thus, the battery pack 1 according to the invention comprises the following elements, arranged in successive layers along the increasing ZI axis, - the bottom wall 11 of the housing 10, then - the film 30, then - the glue layer 12, then - the lower face of at least one module 20.

[0032] In other words, the film 30 comprises a lower surface in direct contact with the bottom wall 11, and an upper surface in direct contact with the glue layer 12.

[0033] In an alternative embodiment, an additional layer of glue 12 could be disposed between the bottom wall 11 of the housing 10 and the film 30. In addition or alternatively, the film 30 can be a self-adhesive film on the side facing the bottom wall 11, or even on both sides.

[0034] The film 30 fixes the modules 20 of the battery pack 1 to the casing 10.

[0035] The film 30 of the battery pack 1 according to the invention can be made of a material polymer, of the PPET type, in particular a Polyethylene type film with a thickness of approximately 200 pm.

[0036] Advantageously, the chemical bonds of the polymer have been engineered to make it highly extensible and / or stretchable. This property of the polymer allows a tensile force to be applied to the film 30, causing it to elongate while reducing its cross-section without breaking.

[0037] The stretchable property of film 30 is linked to its structure which exhibits low crystallinity.

[0038] The traction means 40 of the battery pack 1 is configured to exert a traction force on the film 30. In the described embodiments, the traction force exerted on the film 30 by the traction means 40 is exerted in a direction located in the plane along which the film 30 extends, i.e., in a direction substantially opposite to the Y1 axis. In one embodiment more specifically illustrated by Figures 3 and 8, the traction force may include a component along the Z1 axis (i.e., a component directed in a direction perpendicular to the bottom wall 11 of the housing 10 and directed towards the interior of the housing 10), the component along the Z1 axis being significantly smaller than the component in the direction opposite to the Y1 axis.

[0039] In the remainder of the document, two distinct embodiments of the traction means 40 are presented: - a first embodiment, illustrated by Figures 2 to 4, in which the traction means 40 comprises a winder 41 pivotally connected to the housing 10 around a first axis, an edge 31 of the film 30 being fixed to the winder 41, and - a second embodiment, illustrated by figures 5 to 10, in which the traction means 40 includes a shoe 42 closing a window 131 of the side wall 13 of the battery casing 10, the window 131 being arranged opposite the film 30, and an edge 31 of the film 30 being fixed to the shoe 42.

[0040] Advantageously, regardless of the embodiment of the traction means 40, the film 30 is fixed to the traction means 40 over its entire width measured along the axis XI.

[0041] With reference to figures 2 to 4, the first embodiment of the traction means 40 is described first.

[0042] In the first embodiment, the traction means 40 includes first of all a winder 41, that is to say a device in pivot connection with the casing 10 around a first axis (the first axis being parallel to the axis XI), the rotation of the device causing a winding of the film 30 on the device.

[0043] Figure 2 illustrates an embodiment of the pivot joint between the housing 10 and the winder 41. In this embodiment, two battery modules 20 are distributed along the direction XI in the battery pack 1, with a first film 30 being arranged under a first module and a second film 30 being arranged under a second module. The first and second films 30 are attached to the same winder 4L.

[0044] In the embodiment illustrated by [Fig.2], the winder 41 rests on three lower half-bearings 416 fixed to the bottom wall 11 of the housing 10 and distributed uniformly along the XL direction. Three upper half-bearings 417 collaborate with the lower half-bearings to fix the winder 41 to the bottom wall 11 of the housing 10 while forming a rotational guide surface for the winder 41 around the first axis.

[0045] The traction means 40 according to the first embodiment further includes a first fastening means for attaching an edge 31 of the film 30 to the reel 4L. The first fastening means is illustrated by Figures 2 and 3. The reel 41 comprises two elements 413, 414 fixed to each other, an edge 31 of the film 30 being placed between the two elements 413, 414. In particular, the reel 41 comprises two semi-cylinders of revolution 413, 414 of the same volume, each semi-cylinder 413, 414 having a semicircle as its base. The edge 31 of the film 30 is positioned between the two half-cylinders 413, 414, so that it is clamped between the two flat surfaces of the half-cylinders 413, 414. The joining of the two half-cylinders 413, 414 defines a cylinder with a circular cross-section, around which the film 30 can be wound during the removal of the battery pack 1. In other words, the first fastening method is implemented by the winder 4L

[0046] Advantageously, the two half-cylinders 413, 414 are fixed to each other by at least one fixing screw 415 passing through the winder 41 in a direction perpendicular to the axis XL

[0047] Preferably, at least one fixing screw 415 is directed perpendicularly to the flat surfaces of the two half-cylinders 413, 414. At least one fixing screw 415 thus forms part of the first fixing means because it passes through the film 30.

[0048] Furthermore, the winder 41 includes a torque transmission means 412 configured to allow rotation of the winder 41 about the first axis. An embodiment of the transmission means 412 is illustrated by [Fig. 4], which represents a so-called disassembly chuck. The chuck has a hexagonal end 4122 adapted to engage with a hexagonal hole 4121 formed at one end of the winder 41, also called the drive recess 4121. When the hexagonal end of the chuck is inserted into the hexagonal hole of the winder 41, the assembly formed by the chuck and the winder 41 allows an operator to apply a rotational movement to the winder 41, the rotational movement of the first axis generating a tensile force in a direction opposite to the axis Y1. Since the reel 41 is fixed to the bottom wall 11 of the housing 10 by a pivot joint, the tensile force causes a displacement and / or stretching of the film 30 towards the reel 4L

[0049] Advantageously, the drive footprint 4121 is accessible to an operator from outside the housing 10.

[0050] With reference to figures 5 to 10, the second embodiment of the traction means 40 is then described. In this embodiment, the housing 10 includes a side wall 13 provided with a window 131, the window 131 being positioned opposite the film 30. The window 131 thus allows access to the film 30 and therefore to exert a traction force on the film 30 (possibly by any means).

[0051] In other words, opposite each battery module 20, an opening, in particular rectangular, is made in a lower area of ​​the side face 13 of the housing 10. In addition, each opening is intended to receive a shoe 42, the shoe 42 closing the window 131, an edge 31 of the film 30 being fixed to the shoe 42.

[0052] In the remainder of the document, the term "shoe 42" is used to designate an assembly of parts that fit into an opening in the side face 13 of the housing 10 so as to close the opening, an edge 31 of the film 30 being fixed to the shoe 42, the assembly of parts further comprising a means for translating the shoe 42 relative to the housing 10 in a direction opposite to the axis YL. In other words, a shoe 42 can be defined as a drawer whose first function is to close an opening in the side face 13 of the housing 10, and a second function is to be fixed to the film 30 and to open, by a translational movement in a direction opposite to the axis Yl, to exert a tensile force on the film 30.

[0053] To this end, the shoe 42 includes a traction means 40 according to the second embodiment. Figure 6 illustrates a battery pack 1 comprising two modules 20, each module 20 being arranged on a film 30, and one end of each film 30 being connected to a traction means 40 according to the second embodiment.

[0054] Figures 7 to 10 illustrate more precisely a traction means 40 according to the second embodiment.

[0055] The traction means 40 according to the second embodiment comprises - a drawer front 424 arranged parallel to the lateral face 13 of the housing 10 of the battery pack 1, - a first half-cylinder 425 fixed at its ends to the drawer front by two axes arranged perpendicular to the front, a flat face of the first half-cylinder being arranged parallel to the bottom wall 11 of the housing 10 and oriented towards an upper face of the housing 10, - a second half-cylinder 426 fixed to the first half-cylinder by fixing screws 415, a flat face of the second half-cylinder being arranged opposite the flat face of the first half-cylinder 425, the film 30 being clamped between the two flat faces and through which the fixing screws 415 pass.

[0056] Furthermore, - Initial 421 threads are made on each drawer front; in particular, four 421 threads of a first diameter are made near the corners of each drawer front, and - Second tapped holes 133, of a second diameter, are made on the lateral face 13 of the housing 10 opposite each first tapped hole 421, the second diameter being strictly smaller than the first diameter.

[0057] In one embodiment, the first diameter is equal to 6 millimeters and the second diameter is equal to 4 millimeters.

[0058] When the shoe 42 is used to close the side face of the housing 10, screws 422—called fixing screws—of a second diameter are inserted into the threaded holes 421 of the shoe 42. Since the diameter of the fixing screws 422 is strictly smaller than the diameter of the threaded holes 421, the fixing screws 422 pass freely through the holes in the front face of the shoe 42. The fixing screws 422 are then fixed to the second threaded holes made in the side face 13 of the housing 10; the fixing screws 422 thus hold the shoe 42 in the position of closing the side face 13 of the housing 10.

[0059] When the shoe 42 is used to exert a tensile force on the film 30, screws 423—called removal screws—of a first diameter are inserted into the first threaded holes 421 of the shoe 42, the first threaded holes 421 of the shoe 42 also being of a first diameter. Since the thread size of the removal screws 423 is adapted to the size of the first threaded holes 421, the removal screws 423 are screwed into the first threaded holes 421 until they have passed through the front of the shoe 42. The removal screws 423 then reach the second threaded holes 133 made on the side wall 13 of the housing 10, the diameter of the second threads 133 being less than the diameter of the removal screws 423. The removal screws 423 are then in contact with an outer surface 132 of the lateral face 13 of the housing 10, so that continuing to screw the removal screws 423 causes a movement of the shoe 42 in the opposite direction to the direction Yl.

[0060] In other words, screwing a threaded element into the tapped opening 421 of the shoe 42 results in a force tending to move the shoe 42 away from the side wall 13, by reaction of the end of the threaded element against the bearing surface (i.e., against an external face of the side wall of the housing). This exerts a tensile force on the film 30. In practice, the bearing surface of the removal screws corresponds to the edges of the tapped holes 133 of a second diameter, the size of which is smaller than the diameter of the removal screws 423. In an alternative embodiment, the bearing surface could be a solid surface and not the edges of the tapped holes made on the housing 10.

[0061] Thus, the shoe 42 then exerts a tensile force on the film 30.

[0062] Furthermore, regardless of the embodiment of the traction means 40 of the film 30, when due to the displacement of the film 30, at least one module 20 of the battery pack 1 remains stationary relative to the housing 10, due to a reaction force exerted by the side wall 13 of the housing 10 on at least one module 20.

[0063] Thus, the displacement and / or stretching of the film 30 relative to the at least one module 20 eventually induces a separation between the glue layer 12 and the film 30 and / or a separation between the housing 10 and the film 30.

[0064] In other words, the traction exerted on the film 30 makes it possible to shear the glue 12 and to destroy the chemical bonds between the film 30 and the battery module 20 and / or between the housing 10 and the film 30.

[0065] Depending on the characteristics of the material constituting the film 30, in particular depending on the ability of the material to stretch without breaking, the deformation of the film 30 can promote the separation between the film 30 and a battery module 20.

[0066] Optionally, a second layer of glue could be arranged between the bottom wall 11 of the housing 10 and the film 30. In addition or alternatively, the film 30 could be a self-adhesive film on the side facing the bottom wall 11, or even on both sides.

[0067] Advantageously, the presence of the film 30 between the glue layer 12 and the bottom wall 11 of the housing 10 does not modify the mechanical characteristics of the attachment of the modules 20 to the housing 10.

[0068] The invention further relates to a method for disassembling an energy storage device 1 according to the invention, the method comprising a step of pulling on the film 30 of the energy storage device 1 according to the invention.

[0069] If the battery pack 1 includes a traction means 40 according to the first embodiment of the invention, the traction step on the film 30 comprises an operator inserting a hexagonal end of a mandrel into a hexagonal hole made at one end of the winder 41 of the traction means 40. The operator then applies a torque to the winder 41 via the mandrel. The winder 41 then exerts a traction force on the end of the film 30. In an alternative embodiment, the traction step can be performed automatically.

[0070] If the battery pack 1 includes a traction means 40 according to the second embodiment of the invention, the traction step on the film 30 includes - firstly, the fixing screws that secure a shoe 42 of the traction means 40, - then the removal screws are screwed into the threaded holes of the shoe 42 of the traction means 40, - then screwing the removal screws against the side wall 13 of the housing 10 so as to move the shoe 42 in a direction opposite to the direction Yl.

[0071] Regardless of the embodiment of the traction means 40, the traction force causes a deformation of the film 30, which in turn causes a disassembly of the battery module 20 by shearing or destruction of the chemical bonds between the film 30 and the battery module 20 and / or between the casing 10 and the film 30.

[0072] Finally, the energy storage device according to the invention has multiple advantages.

[0073] First, the invention is simple to implement during the assembly and disassembly phases of the battery pack. In particular, the invention does not require any specific tool for assembling or disassembling the battery pack.

[0074] Furthermore, the battery pack components are not damaged during disassembly. In particular, a layer of adhesive is placed between the film and a battery module, preventing the film from adhering to the battery module, thus facilitating the disassembly and recycling of the battery modules.

[0075] Furthermore, due to its very low thickness, the film does not alter, or only very slightly alters, the transfer of calories from the modules to the battery pack casing.

Claims

Demands

1. Energy storage device (1) comprising a housing (10), at least one electrochemical module (20) arranged inside said housing, the housing comprising a bottom wall (11) and an adhesive layer (12) extending between the at least one electrochemical module (20) and the bottom wall (11), characterized in that the energy storage device (1) further comprises a film (30) extending between the adhesive layer (12) and the bottom wall (11), and a traction means (40) configured to exert a traction force on said film (30).

2. Energy storage device (1) according to the preceding claim, characterized in that the film (30) comprises a lower surface in direct contact with the bottom wall (11), and an upper surface in direct contact with the glue layer (12).

3. Energy storage device (1) according to any one of the preceding claims, characterized in that the film (30) is made of a polymer material.

4. Energy storage device (1) according to any one of the preceding claims, characterized in that the traction means (40) comprises a winder (41) pivotally connected with the housing (10) about a first axis, an edge (31) of said film (30) being fixed to said winder (41), the winder (41) comprising a torque transmission means (412) configured to permit rotation of the winder (41) about the first axis.

5. Energy storage device (1) according to the preceding claim, characterized in that the torque transmission means (412) comprises a recess (4121), in particular a hexagonal opening (4121), intended to cooperate with a tool of complementary shape to the recess (4121), the recess (4121) being accessible from outside the housing (10).

6. Energy storage device (1) according to any one of claims 4 or 5, characterized in that the winder (41) comprises two elements (413, 414) fixed to each other, in particular each element (413, 414) comprising a half-cylinder shape of revolution, in particular the two elements (413, 414) being fixed to each other by means of fixing screws (415), and in that the edge (31) of the film (30) is clamped between the two elements (413, 414).

7. Energy storage device (1) according to any one of claims 1 to 3, characterized in that the casing (10) comprises a side wall (13) provided with a window (131), said window (131) being positioned opposite said film (30).

8. Energy storage device (1) according to the preceding claim, characterized in that it comprises a shoe (42) closing said window (131), an edge (31) of the film (30) being fixed to the shoe (42).

9. Energy storage device (1) according to the preceding claim, characterized in that the shoe (42) comprises at least one threaded opening (421) positioned opposite a bearing surface formed on an outer surface (132) of said side wall (13).

10. Method for disassembling an energy storage device (1) according to any one of the preceding claims, characterized in that it comprises a step of pulling on the film (30).

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