Electrical energy storage module and corresponding battery case

Abstract

Electrical Energy Storage Module and Corresponding Battery Housing. The invention relates to an electrical energy storage module (2) comprising two main extension walls (22) and side walls (23, 24, 25, 26) orthogonal to the main extension walls (22), and means (28) for attaching it to a housing (1) adapted to accommodate such modules (2) stacked along a stacking direction (L). The module (2) is characterized in that the attachment means (28) comprise a mounting tab projecting from one of the main extension walls (22) or from one of the side walls (23, 24, 25, 26) in a direction orthogonal (T, Z) to the stacking direction (L). This mounting tab is adapted to extend the module (2) towards a partition (10, 12, 18) of the housing (1), proximal to said main extension wall (22) or to said side wall. (23, 24, 25, 26), for fixing module (2) to said partition (10, 12, 18). (Figure 1)

Description

Title of the invention: Electrical energy storage module and corresponding battery case

[0001] The present invention relates to the fields of mechanics and electrotechnics and more specifically concerns the storage of electrical energy in electric accumulator batteries, suitable for use in electric or hybrid electric vehicles.

[0002] The need for greater range in electric and hybrid electric vehicles is driving manufacturers to equip them with high-voltage batteries that store increasing amounts of energy. These batteries are called high-voltage batteries, as opposed to the low-voltage auxiliary batteries in conventional vehicles, which are on the order of 12 to 48 V (volts). However, the more energy a battery of this type stores, the greater the number of modules within its casing and the larger its size. Consequently, there is a growing trend towards equipping vehicles with increasingly bulky batteries, and the safety requirements associated with these increasingly large batteries are also becoming more stringent, including sufficient shock resistance.

[0003] This resistance requires, in particular, a sufficiently rigid battery casing to prevent sagging and the risk of weakening the modules inside, and an assembly of the modules that ensures their mechanical stability within the high-voltage battery casing, preventing them from moving within the casing when it is subjected to an impact. Some battery casings are thus equipped with stiffening crossbars extending from one side of the casing to the opposite side, and the modules are individually fixed to these internal stiffening crossbars. These crossbars ensure good mechanical stability of the modules within the casings and good rigidity of the casings themselves.

[0004] While the presence of these cross members ensures good mechanical resistance, it should be noted that they take up a significant amount of space within the casing and that the space available for the modules is reduced, thus decreasing the energy storage performance of the battery.

[0005] The present invention aims to remedy, at least in part, the aforementioned drawbacks by providing an electrical energy storage module and a battery case integrating a set of such modules, which eliminates the need for battery case cross members and thus saves space for storage components electrical, such as electrical energy storage cells, without however affecting the rigidity required for the internal structure of the battery case.

[0006] To this end, the invention proposes an electrical energy storage module configured to house a plurality of storage elements between walls of the module, including two main extension walls and side walls orthogonal to the main extension walls, the module comprising means for fixing to a battery case capable of housing several identical modules to said module, the modules being capable of being stacked in a module stacking direction in the battery case, the module being characterized in that the fixing means comprise a fixing tab projecting from one of the main extension walls or from one of the side walls in a direction orthogonal to the stacking direction, said fixing tab being capable of extending the module towards a partition of the battery case, proximal to said main extension wall or to said side wall, for fixing the module to said partition.

[0007] Thanks to the invention, the crossbars extending between the energy storage modules to attach them to the battery casing are eliminated, thus saving space to store more energy storage elements in each module. The energy storage elements take, for example, the form of cylindrical energy storage cells, electrically connected in series with each other in each energy storage module.

[0008] As mentioned, the energy storage module according to the invention is equipped with a mounting bracket extending from the module to a partition of the battery case to secure the module to that partition. This mounting bracket is, for example, located in a central portion of one of the module's walls and may extend along an entire dimension of that wall. In another embodiment, this mounting bracket extends from a side wall of the module to secure it to a side partition of the battery case, that is, a partition separate from the bottom or lid of the battery case.

[0009] Since the walls of the energy storage module are generally made of synthetic organic material (i.e., plastic), the mounting bracket extends the module to the partition to be screwed in, for example, or serves as a support for another fastening method such as a metal bracket fixed to the partition, which mechanically reinforces the module's attachment to the partition. The battery case partition is generally made of aluminum. Therefore, welding the bracket or the mounting bracket, if it is metallic, to the battery case partition is a possible alternative to screwing these elements to the battery case partition.

[0010] According to an optional feature of the invention, the module includes connecting means configured to secure the module to another module, the module's mounting tab forming at least partially the connecting means. In this context, the mounting tab has a dual function that reduces the number of parts required in the battery housing.

[0011] According to an optional feature of the invention, the fixing tab is one piece with the wall of the module on which it protrudes.

[0012] According to an optional feature of the invention, the fixing tab is a piece attached to the wall of the module on which it protrudes.

[0013] According to an optional feature of the invention, the first two of the side walls of the energy storage module according to the invention are parallel to the stacking direction, and the second two of the side walls are orthogonal to the stacking direction, the fixing tab extending from one of the second side walls.

[0014] According to an optional feature of the invention, each second side wall is extended by a mounting tab. This reinforces the mechanical stability of the modules within the battery housing. More specifically, each end of a second side wall or of each side wall can be extended by a mounting tab. In this embodiment, the second side wall of the module thus serves as a cross member stiffening the battery housing, since the mounting tabs and this second side wall extend continuously from one to another, connecting one partition of the housing to another.

[0015] According to an optional feature of the invention, the second side wall(s) have stiffening ribs. Thus, although these side walls are generally made of plastic, their stiffening, as well as the use of the two side walls orthogonal to the stacking direction of the modules, ensures sufficient rigidity to replace the crossbeams of the prior art.

[0016] According to an optional feature of the invention, the mounting bracket comprises a first part adapted to extend the second side wall to the battery housing partition, and a second part adapted to be secured to the battery housing partition by screwing or welding. This embodiment of the invention preferably uses a metal mounting bracket having a right-angle shape.

[0017] According to an optional feature of the invention, the fixing tab is made of electrically insulating material, for example of synthetic organic material, and the fixing means further comprise a metal bracket, a first arm of which is fixed to the fixing tab and a second arm is suitable for being fixed to the partition of the battery case.

[0018] According to an optional feature of the invention, the partition is a first partition of the battery case, and the fastening means also include devices for securing the module to a second partition of the battery case, orthogonal to the first partition of the battery case. This feature further strengthens the mechanical stability of the modules within the battery case, particularly in a direction orthogonal to the extension direction of the module created by the fastening tab.

[0019] In the embodiment where the fixing lug has a first part suitable for extending the second side wall to the battery box partition, and a second part suitable for being attached to the battery box partition, the first part constitutes, for example, a device for attaching the module to the other battery box partition, including a screw passage suitable for receiving a screw orthogonally to the extension made by the fixing lug.

[0020] According to an optional feature of the invention, the fastening devices comprise: - ears extending from one of the lateral or main extension walls of the module, and capable of receiving screws orthogonally to the extension created by the fixing tab, - and / or screw passage holes in at least one of the main extension walls, capable of cooperating with a screw passage hole in a bottom or cover of the battery case to receive a fixing screw.

[0021] The ears allow the module to be fixed around its perimeter, for example directly on the bottom or the cover of the battery case, while the screw passage holes are provided for example in a central portion of a main extension wall of the module, for screwing into the bottom of the battery case, before the energy storage components are placed in the module.

[0022] The ears may take the form of uprights extending from bosses on the bottom of the battery case and protruding into the battery case, the bosses having screw passage holes cooperating with corresponding screw passage holes in the ears of the module.

[0023] According to an optional feature of the invention, at least one of the fastening devices includes a vibration damping device. This is, for example, a damping pad compressed between a boss provided for screw passage in the bottom or cover of the battery case, and the lug or screw passage area in the main extension wall of the module.

[0024] The invention also relates to a battery case comprising a set of modules according to the invention, stacked along the stacking direction, and comprising means for connecting the modules to each other. These connecting means allow In particular, they allow for the control of play between the different modules, which can be slightly deformed by thermal heating within the modules. They can also allow one of the modules to be fixed solely by means of a module according to the invention, which is itself fixed to the battery housing partition.

[0025] According to an optional feature of the invention, the connecting means comprise, for example, the fixing tab of a first module of the module assembly, and the fixing tab of a second module of the module assembly, adjacent to the first module. These fixing tabs may, for example, have complementary shapes, suitable for being screwed together without an intermediate element.

[0026] According to an optional feature of the invention, the connecting means further comprise a metal spacer between the two mounting tabs, and through screws passing through both the mounting tabs and the metal spacer. This spacer maintains a predefined gap between the two modules joined together by the connecting means.

[0027] Furthermore, anti-vibration separation shims are optionally placed between the modules of the battery housing according to the invention, to absorb vibrations from one module to another. According to an optional feature of the invention, an anti-vibration separation shim intended to be placed between two adjacent modules is formed in one piece with a shim intended to be placed between the two mounting tabs.

[0028] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0029] [Fig. 1] is a top view of a battery case according to the invention, the cover of which has been removed, in one embodiment of the invention,

[0030] [Fig.2] is a close-up view illustrating means of attaching modules to a side panel of the battery case,

[0031] [Fig.3] is a perspective view of part of one of the modules visible on the [Fig.2], with the part of the means for attaching it to the side panel of the case which is specific to it,

[0032] [Fig.4] is a perspective view of a metal wedge intended to secure two mounting brackets for two separate modules according to the invention, in the embodiment shown in Figures 1 and 2,

[0033] [Fig.5] is a top view of part of a module according to the invention in a battery case according to the invention, the module comprising means for connection to a base of the battery case, in one embodiment of the invention, and

[0034] [Fig.6] is a perspective view of part of a module according to the invention in a battery case according to the invention, the module comprising means for connecting to a bottom of the battery case, in another embodiment of the invention.

[0035] According to an embodiment of the invention represented in [Fig.1], a battery case 1 according to the invention houses several electrical energy storage modules 2, stacked in the battery case 1 in a stacking direction L corresponding to a longitudinal dimension of the battery case 1, i.e. corresponding to its largest dimension.

[0036] In this embodiment, the battery case 1 is made of aluminum. It comprises a partition 18 forming the bottom of the battery case 1, extending along the stacking direction L and along a transverse direction T orthogonal to the stacking direction L. The bottom of the case is bordered by lateral partitions, corresponding to two longitudinal partitions 10, 12 of the battery case 1 and two transverse partitions 14, 16 of the battery case 1. The lateral partitions 10, 12, 14, 16 extend along a vertical direction Z oriented along the thickness of the battery case 1, which is smaller than the transverse dimension of the battery case 1 extending along the transverse direction T. The vertical direction Z is therefore orthogonal to the transverse direction T and the longitudinal direction L.

[0037] The cover of the battery case 1 is not shown in [Fig. 1], revealing the upper walls of the modules 2. The upper walls of the modules 2 are the main extension walls 22 of these modules 2, that is, walls with larger dimensions than the lateral walls 23, 24, 25, 26 of these modules 2, which extend along the vertical dimension Z. Among the lateral walls of the module, two main lateral walls 23, 25 and two secondary lateral walls 24, 26 are defined such that the two main lateral walls, in contrast, are larger than the two secondary lateral walls 24, 26. The two main lateral walls are parallel to the transverse direction T while the secondary lateral walls 24, 26 are parallel to the longitudinal direction L.In this embodiment of the invention, the walls of modules 2 are made of synthetic organic material, i.e., plastic.

[0038] The modules 2 house energy storage organs, which here are cylindrical cells 3 (referenced [Fig.5]) energy accumulators, arranged parallel to each other, each with a predominantly vertical orientation.

[0039] Each of the modules 2 in the battery case 1 illustrated in [Fig.1] is a module according to the invention, with one or more means of attachment 28 to the side partitions 10, 12 of the battery case 1.

[0040] As can be seen in [Fig.2], the fastening means 28 consist of fastening tabs 282 extending from each of the side walls, here the side walls main 23, 25 of the modules 2, these fixing tabs 282 being fixed to the partitions 10, 12 of the battery box by means of metal brackets 284.

[0041] More specifically, a first arm of each of the metal brackets 284 is welded to one of the partitions 10, 12, while a second arm of each of the metal brackets 284, orthogonal to the first arm, is screwed to a fixing tab 282. Screw passage holes 286 are provided for this purpose in the second arms of the metal brackets.

[0042] The fixing brackets 282, which are made of the same material as the side walls 23, 25, are made of plastic and extend the modules to the partitions 10, 12 to facilitate their attachment to these partitions. Alternatively, the fixing brackets are attached to the modules 2, or are themselves L-shaped and directly fixed by screwing or welding to the partitions 10, 12, without requiring an intermediate part.

[0043] In order to maintain good mechanical strength and, in particular, good rigidity of the modules 2, the side walls of the modules 2, extended by the fixing tabs 282 (here, the main side walls 23, 25), are stiffened by ribs 252, visible [Fig. 3]. These stiffening ribs 252 occupy the entire thickness of the side walls 23„, that is, here, their entire longitudinal dimension 25, over a median portion of these side walls 23, 25, and take the form of crossbars, the side walls being perforated between the arms of these crossbars. These crossbars allow for a material saving relative to the function performed.

[0044] The proximal fixing tabs 282 of two contiguous modules, in the stacking direction L, are secured together by through screws 281, here schematically represented on [Fig.2], which allow both this securing and their attachment to the metal brackets 284.

[0045] It is understood that these through screws pass through:

[0046] - the screw passage holes 286 visible in [Fig.2] and provided in the second arm of a first metal bracket 284, welded by its first arm to the partition 12,

[0047] - corresponding screw passage holes 283 visible in [Fig.3] and provided in the first of the two proximal fixing tabs 282 between the two contiguous modules 2,

[0048] - corresponding screw passage holes 42 provided in a metal spacer 4 represented [Fig.4] and inserted between the first of the two proximal fixing lugs 282 and the second of the two proximal fixing lugs 282,

[0049] - corresponding screw passage holes 283 provided in the second of the two 282 proximal attachment lugs between each other, and

[0050] - the screw passage holes 286 provided in the second arm of a second metal bracket 284, welded by its first arm to partition 12.

[0051] As shown in [Fig. 4], the metal spacer 4 has a T-shaped form with a main arm 41, designed to be clamped between the adjacent mounting tabs 282 and within which the screw holes 42 are formed, and a head 43 allowing the metal spacer 4 to be held by gravity on the mounting tabs 282 on the side of the partition 12 during the assembly of the modules 2 in the battery case 1. This metal spacer 4 contributes to the rigidity of the modules 2 and their vibration resistance in the battery case 1. For reference, the gap maintained between the mounting tabs 282 by the thickness of the metal spacer 4 is approximately 5 mm (millimeters). Alternatively, the metal wedge 4 extends between the two modules 2 to between the two opposite fixing tabs 282 which are fixed to the opposite side partition 10, so that the wedge also acts as a spacer between the two adjacent modules.Of course, the attachment of these two opposing mounting tabs 282 is symmetrical to that of the mounting tabs 282 shown in figures 2 to 4 in relation to the side partition 12 of the battery case 1.

[0052] In an embodiment of the invention, the metal wedge 4 is not used, the fixing tabs then having complementary shapes allowing them to be joined together while ensuring the presence of a gap between the two modules 2 to which they belong.

[0053] Figure 5 now illustrates an alternative embodiment of the invention, in which the elements identical to those of the main embodiment of the invention bear the same reference numerals. In the variant illustrated in Figure 5, the means 28 for attaching the modules 2 to the partitions 10, 12 are not shown, in order to better distinguish them from the devices 20 for securing the modules 2 to the partition 18 forming the bottom of the battery case 1.

[0054] These fastening devices 20 are tabs or eyelets, arranged on the side walls, here the secondary side walls 24, 26, of the modules 2, proximal to the bottom of the battery case 1. Each has a screw hole opposite a screw hole in a boss on the bottom of the battery case 1, this boss projecting into the battery case 1. These screw holes accommodate a fixing screw for attaching the tab 20 to the corresponding boss. Damping pads, for example made of rubber, are inserted between the bosses and the tabs 20 and ensure good vibration damping of the modules 2 within the battery case 1.

[0055] Figure 6 illustrates another embodiment of the invention, in which the elements identical to those of the main embodiment of the invention bear the same reference numerals. In this other embodiment, the modules 2 have ears 21 on the side walls, here the main side walls 23, 25, of the modules 2, these ears 21 being proximal to the partition 18 forming the bottom of the battery case 1, for the fixing of the modules 2 to this partition 18.

[0056] In this other embodiment of the invention, the side walls 23, 25 comprise three distinct portions formed from material, namely two thick, parallelepiped-shaped longitudinal end portions connected by a thinner portion that is corrugated in the longitudinal direction L, so as to maintain good rigidity of these side walls 23, 25 while saving material. This thinner portion therefore plays the same role as the stiffening ribs 252 of the principal embodiment of the invention.

[0057] Furthermore, in this other embodiment of the invention, the ears 21 are arranged in hollows of the undulation formed by the thinner portion of the side wall 25. These ears 21 take the form of uprights starting vertically at the level of this thinner portion, and extending until reaching a boss 11 protruding from the bottom of the battery case 1.

[0058] Each boss 11 and each ear 21 are provided with a screw passage hole allowing the insertion in the vertical direction Z of a screw into these holes, to fix the module 2 to the bottom of the battery case 1.

[0059] Identical ears 21 are also arranged in the same way on the side wall 23 to fix it to the bottom of the battery case 1, these ears 21 cooperating with corresponding bosses 11 on the bottom of the battery case 1.

[0060] Although not shown in this [Fig. 6], bosses 11 are also provided under the modules 2, with screw holes in the lower walls of the modules 2 (i.e., in their main extension walls proximal to the bottom of the battery case 1) cooperating with corresponding screw holes in these bosses 11 for inserting fixing screws. These screw holes are therefore located directly under cylindrical cells 3 or between cylindrical cells 3.

[0061] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the characteristics of the different embodiments of the invention envisaged in this application can be combined to carry out the invention, provided that these embodiments are not incompatible with each other.

Claims

Demands

1. Electrical energy storage module (2) configured to house a plurality of storage components (3) between walls of the module (2), including two main extension walls (22) and side walls (23, 24, 25, 26) orthogonal to the main extension walls (22), the module (2) comprising means for attaching (28) to a battery case (1) capable of housing several identical modules (2) to said module (2), the modules (2) being capable of being stacked in a stacking direction (L) of the modules (2) in the battery case (1), the module (2) being characterized in that the attachment means (28) comprise a mounting tab (282) projecting from one of the main extension walls (22) or from one of the side walls (23, 24, 25, 26) in a direction orthogonal (T, Z) to the stacking direction (L), said mounting bracket (282) being suitable for extending the module (2) towards a partition (10, 12, 18) of the battery housing (1),proximal to said main extension wall (22) or to said side wall (23, 24, 25, 26), for fixing the module (2) to said partition (10, 12, 18), and in that the module comprises connecting means configured to secure the module (2) to another module (2), the fixing tab (282) of the module (2) forming at least partially the connecting means, and in which the fixing tab (282) is made of electrically insulating material, and the fixing means (28) further comprise a metal bracket (284) of which a first arm is fixed to the fixing tab (282) and a second arm is suitable for being fixed to the partition (10, 12) of the battery housing (1).

2. Electrical energy storage module (2) according to claim 1, wherein the fixing tab (282) is integral with the wall of the module (2) on which it protrudes, or is an added part on the wall of the module (2) on which it protrudes.

3. Electrical energy storage module (2) according to any one of claims 1 to 2, wherein the first two of the side walls (24, 26) are parallel to the stacking direction (L), and the second two of the side walls (23, 25) are orthogonal to the stacking direction (L), the fixing tab (282) extending one of the second side walls (23, 25).

4. Electrical energy storage module (2) according to claim 3, wherein each second side wall (23, 25) is extended by a fixing tab (282).

5. Electrical energy storage module (2) according to claim 3 or 4, wherein the second side wall(s) (23, 25) have stiffening ribs (252).

6. Electrical energy storage module (2) according to any one of claims 1 to 5, wherein the partition (10, 12) is a first partition of the battery case (1), and the fastening means (28) also include devices for securing the module (2) configured to be secured to a second partition (18) of the battery case (1), orthogonal to the first partition (10, 12) of the battery case (1).

7. Electrical energy storage module (2) according to claim 6, wherein the fastening devices comprise: - lugs (20, 21) extending from one of the side walls (23, 24, 25, 26) or main extension walls (22) of the module (2), and adapted to receive screws orthogonally to the extension made by the fixing tab (282), - and / or screw passage holes in at least one of the main extension walls (22), adapted to cooperate with a screw passage hole in a bottom (18) or a cover of the battery housing (1) to receive a fixing screw.

8. Electrical energy storage module (2) according to claim 7, wherein at least one of the fastening devices includes a vibration damping device.

9. Battery housing (1) comprising a set of modules (2) according to any one of claims 1 to 8, stacked along the stacking direction (L), and comprising means for connecting the modules (2) to each other.

10. Battery housing (1) according to claim 9, in which the connecting means comprise the fixing tab (282) of a first module (2) of the module assembly (2), and the fixing tab (282) of a second module (2) of the module assembly (2), contiguous to the first module (2). 12

11. Battery housing (1) according to claim 10, wherein the connecting means further comprise a metal wedge (4) between the two fixing tabs (282), and through screws passing through the two fixing tabs (282) and the metal wedge (4).

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