Electric energy storage module and corresponding battery housing

Abstract

The invention relates to an electric energy storage module (2) comprising two main extension walls (22) and side walls (23, 24, 25, 26) which are orthogonal to the main extension walls (22), means (28) for attachment to a housing (1) which is capable of accommodating such modules (2) stacked in a stacking direction (L), the module (2) being characterised in that the attachment means (28) comprise an attachment lug projecting from a main extension wall (22) or from one of the side walls (23, 24, 25, 26) in a direction (T, Z) orthogonal to the stacking direction (L), the attachment lug being capable of extending the module (2) towards a partition (10, 12, 18) of the housing (1), proximal to the main extension wall (22) or to the side wall (23, 24, 25, 26), in order to attach the module (2) to the partition (10, 12, 18).

Description

[0001] DESCRIPTION

[0002] Title of the invention: ELECTRICAL ENERGY STORAGE MODULE AND CORRESPONDING BATTERY BOX

[0003] The present invention relates to the fields of mechanics and electrical engineering and more specifically concerns the storage of electrical energy in electric accumulator batteries, capable of being installed in electric or hybrid electric vehicles.

[0004] The autonomy needs of electric or hybrid electric vehicles are pushing vehicle manufacturers to equip them with high-voltage batteries that store more and more energy. These batteries are called high-voltage batteries, as opposed to the service batteries of conventional vehicles, which are low-voltage, in the order of 12 to 48 V (volts). However, the more energy a battery of this type stores, the greater the number of modules present within a battery case and the greater its size. We are therefore looking to install increasingly bulky batteries on vehicles, and the safety constraints to be respected within the framework of these increasingly bulky batteries are at the same time increasingly important, including sufficient shock resistance.

[0005] This resistance requires in particular to provide a battery case that is sufficiently rigid so that it does not collapse and does not risk weakening the modules present inside the case, and to provide an assembly of the modules that ensures mechanical strength of these modules within the case of the high-voltage battery, so that they do not move in the case when it receives an impact. Some battery cases are thus equipped with stiffening crosspieces that extend from one wall of the case to the opposite wall, and the modules are fixed one by one on these stiffening crosspieces internal to these cases, these crosspieces ensuring good mechanical strength of the modules in the cases and good rigidity of the cases themselves.Although the presence of these crosspieces ensures good mechanical resistance, it should be noted that they take up a significant amount of space within the housing and that the space available for the modules is reduced, so that the energy storage performance of the battery is reduced.

[0006] The present invention aims to remedy at least in part the aforementioned drawbacks by providing an electrical energy storage module and a battery box integrating a set of such modules, which make it possible to dispense with the crosspieces of the battery box and thus ensure space savings for electrical storage members, such as electrical energy accumulator cells, without however affecting the rigidity necessary for the internal structure of the battery box.

[0007] To this end, the invention proposes an electrical energy storage module configured to house a plurality of storage members 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 housing capable of housing several modules identical to said module, the modules being capable of being stacked in a module stacking direction, in the battery housing, the module being characterized in that the fixing means comprise a fixing lug projecting from one of the main extension walls or one of the side walls in a direction orthogonal to the stacking direction, said fixing lug being capable of extending the module towards a partition of the battery housing, proximal to said main extension wall or to said side wall, for fixing the module to said partition.

[0008] The invention eliminates the need for crossbars extending between the energy storage modules to attach them to the battery housing, thereby saving space for storing more energy storage elements in each module. The energy storage elements take the form, for example, of cylindrical energy storage cells electrically connected in series with each other in each energy storage module.

[0009] As mentioned, the energy storage module according to the invention is equipped with a fixing lug extending the module towards a partition of the battery housing to fix the module to this partition. This fixing lug is for example arranged in a central portion of one of the walls of the module, and possibly extends over an entire dimension of this wall. In another exemplary embodiment, this fixing lug extends a side wall of the module to fix the latter to a side partition of the battery housing, i.e. separate from the bottom or the cover of this battery housing.

[0010] Since the walls of the energy storage module are generally made of synthetic organic material (i.e. plastic), the fixing lug extends the module to the partition to be screwed there for example, or serves as a support for another means of fixing such as a metal bracket which is fixed to the partition, and which makes it possible to mechanically reinforce the fixing of the module to the partition. The partition of the battery box is generally made of aluminum. Welding the bracket or the fixing lug, if it is metallic, to the partition of the battery box, is therefore possible instead of screwing these elements to the partition of the battery box.

[0011] According to an optional feature of the invention, the module comprises connecting means configured to secure the module to another module, the fixing lug of the module at least partially forming the connecting means. In this context, the fixing lug has a dual function which makes it possible to reduce the number of parts to be provided in the battery box.

[0012] According to an optional characteristic of the invention, the fixing lug is integral with the wall of the module from which it protrudes.

[0013] According to an optional characteristic of the invention, the fixing lug is a part attached to the wall of the module from which it projects.

[0014] According to an optional characteristic of the invention, two first of the side walls of the energy storage module according to the invention are parallel to the stacking direction, and the two second of the side walls are orthogonal to the stacking direction, the fixing lug extending one of the second side walls.

[0015] According to an optional feature of the invention, each second side wall is extended by a fixing lug. This reinforces the mechanical strength of the modules within the battery housing. More particularly, each end of a second side wall or of each side wall can be extended by a fixing lug. In this embodiment, the second side wall of the module therefore serves as a crosspiece stiffening the battery housing, since the fixing lugs and this second side wall extend in continuity with each other by connecting one partition of the housing to another.

[0016] According to an optional feature of the invention, the second side wall(s) comprise 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 crosspieces of the prior art.

[0017] According to an optional feature of the invention, the fixing lug comprises a first part capable of extending the second side wall to the partition of the battery box, and a second part capable of being secured to the partition of the battery box by screwing or welding. This embodiment of the invention preferably uses a metal fixing lug having a right angle shape.

[0018] According to an optional characteristic of the invention, the fixing lug is made of electrically insulating material, for example synthetic organic material, and the fixing means further comprise a metal bracket, a first branch of which is fixed to the fixing lug and a second branch of which is capable of being fixed to the partition of the battery box.

[0019] According to an optional feature of the invention, the partition is a first partition of the battery housing, and the fixing means also comprise devices for securing the module to a second partition of the battery housing, orthogonal to the first partition of the battery housing. This feature makes it possible to further reinforce the mechanical strength of the modules in the battery housing, in particular in a direction orthogonal to the direction of extension of the module operated by the fixing lug.

[0020] In the embodiment where the fixing lug comprises a first part capable of extending the second side wall to the partition of the battery box, and a second part capable of being secured to the partition of the battery box, the first part constitutes for example a device for securing the module to the other partition of the battery box, by comprising a screw passage capable of receiving a screw orthogonal to the extension provided by the fixing lug.

[0021] According to an optional characteristic of the invention, the securing devices comprise:

[0022] - ears extending one of the side walls or main extension of the module, and capable of receiving screws orthogonally to the extension made by the fixing lug,

[0023] - 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 box to receive a fixing screw.

[0024] The ears allow the module to be fixed around its perimeter, for example directly on the bottom or the cover of the battery box, while the screw 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 box, before installing the energy storage devices in the module.

[0025] The ears may take the form of posts extending bosses on the bottom of the battery box and projecting inside the battery box, the bosses having screw passage holes cooperating with corresponding screw passage holes in the ears of the module. According to an optional feature of the invention, at least one of the securing devices comprises a vibration damping device. This is for example a damping pad compressed between a boss provided for the passage of screws in the bottom or the cover of the battery box, and the ear or the screw passage area in the main extension wall of the module.

[0026] The invention also relates to a battery box comprising a set of modules according to the invention, stacked in the stacking direction, and comprising means for connecting the modules to each other. These connecting means make it possible in particular to control the clearances between the different modules, these being able to be slightly deformed by thermal heating within the modules. They can also make it possible to fix one of the modules solely by means of a module according to the invention, which is itself fixed to the partition of the battery box.

[0027] According to an optional characteristic of the invention, the connecting means comprise, for example, the fixing lug of a first module of the set of modules, and the fixing lug of a second module of the set of modules, contiguous to the first module. These fixing lugs can, for example, take complementary shapes, capable of being screwed to each other without an intermediate element.

[0028] According to an optional feature of the invention, the connecting means further comprise a metal shim between the two fixing lugs, and through screws passing through the two fixing lugs and the metal shim. This shim makes it possible to maintain a predefined clearance between the two modules secured together by the connecting means.

[0029] Furthermore, anti-vibration separating shims are optionally placed between the modules of the battery box according to the invention, to absorb vibrations from one module to another. According to an optional characteristic of the invention, an anti-vibration separating shim intended to be arranged between two neighboring modules is formed in one piece with a shim intended to be arranged between the two fixing lugs. Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several exemplary embodiments given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0030] [fig i] 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,

[0031] [fig 2] is a close-up view illustrating means for attaching modules to a side wall of the battery box,

[0032] [fig 3] is a perspective view of part of one of the modules visible in figure 2, with the part of the means of fixing to the side partition of the housing which are specific to it,

[0033] [fig 4] is a perspective view of a metal wedge intended to secure two fixing lugs of two separate modules according to the invention, in the embodiment of figures 1 and 2,

[0034] [fig 5] is a top view of a part of a module according to the invention in a battery case according to the invention, the module comprising means for connection to a bottom of the battery case, in an alternative embodiment of the invention, and

[0035] [fig 6] is a perspective view of a part of a module according to the invention in a battery case according to the invention, the module comprising means for connection to a bottom of the battery case, in another variant embodiment of the invention.

[0036] According to an embodiment of the invention shown in Figure 1, a battery housing 1 according to the invention houses several electrical energy storage modules 2, stacked in the battery housing 1 in a stacking direction L corresponding to a longitudinal dimension of the battery housing 1, i.e. corresponding to its largest dimension.

[0037] The battery housing 1 is, in this embodiment, made of aluminum. It comprises a partition 18 forming the bottom of the battery housing 1, extending in the stacking direction L and in a transverse direction T orthogonal to the stacking direction L. The bottom of the housing is bordered by lateral partitions, corresponding to two longitudinal partitions 10, 12 of the battery housing 1 and to two transverse partitions 14, 16 of the battery housing 1. The lateral partitions 10, 12, 14, 16 extend in a vertical direction Z oriented according to the thickness of the battery housing 1, smaller than the transverse dimension of the battery housing 1 extending in the transverse direction T. The vertical direction Z is therefore orthogonal to the transverse directions T and longitudinal L.

[0038] The cover of the battery housing 1 is not shown in Figure 1, revealing the upper walls of the modules 2. The upper walls of the modules 2 are main extension walls 22 of these modules 2, that is to say walls of larger dimensions than the side walls 23, 24, 25, 26 of these modules 2, which extend along the vertical dimension Z. Among the side walls of the module, two main side walls 23, 25 and two secondary side walls 24, 26 are defined so that the two main side walls, in opposition, are of larger dimensions than the two secondary side walls 24, 26. The two main side walls are parallel to the transverse direction T while the secondary side walls 24, 26 are parallel to the longitudinal direction L. The walls of the modules 2 are, in this embodiment of the invention, made of synthetic organic material, that is to say made of synthetic organic material. plastic.

[0039] The modules 2 house energy storage organs, which are here cylindrical cells 3 (referenced figure 5) accumulating energy, arranged parallel to each other, each presenting a mainly vertical orientation.

[0040] Each of the modules 2 in the battery housing 1 illustrated in FIG. 1 is a module according to the invention, with one or more fixing means 28 to the side partitions 10, 12 of the battery housing 1.

[0041] As visible in Figure 2, the fixing means 28 consist of fixing lugs 282 extending each of the side walls, here the main side walls 23, 25 of the modules 2, these fixing lugs 282 being fixed to the partitions 10, 12 of the battery box by means of metal brackets 284.

[0042] More precisely, a first branch of each of the metal brackets 284 is welded to one of the partitions 10, 12, while a second branch of each of the metal brackets 284, orthogonal to the first branch, is screwed to a fixing lug 282. Screw passage holes 286 are provided for this purpose in the second branches of the metal brackets.

[0043] The fixing lugs 282 are made of plastic material and extend the modules to the partitions 10, 12 in order to facilitate their fixing to these partitions. Of course, as a variant, the fixing lugs are attached to the modules 2, or are themselves in the form of a bracket and directly fixed by screwing or welding to the partitions 10, 12, without requiring an intermediate part for this.

[0044] 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 lugs 282, here the main side walls 23, 25, are stiffened by ribs 252, visible in Figure 3. These stiffening ribs 252 occupy the entire thickness of the side walls 23, i.e. here their entire longitudinal dimension 25, on a median portion of these side walls 23, 25, and take the form of crosspieces, the side walls being perforated between the branches of these crosspieces. These crosspieces allow a saving of material compared to the function performed.

[0045] The proximal fixing lugs 282 of two contiguous modules, in the stacking direction L, are secured to each other by through screws 281, shown schematically here in FIG. 2, which allow both this securing and their fixing to the metal brackets 284.

[0046] We understand that these through screws pass through:

[0047] - the screw passage holes 286 visible in Figure 2 and provided in the second branch of a first metal bracket 284, welded by its first branch to the partition 12, - corresponding screw passage holes 283 visible in Figure 3 and provided in a first of the two proximal fixing lugs 282 of the two contiguous modules 2,

[0048] - corresponding screw passage holes 42 provided in a metal wedge 4 shown in figure 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 proximal fixing lugs 282 between them, and

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

[0051] As visible in Figure 4, the metal shim 4 has a T shape with a main branch 41, intended to be clamped between the contiguous fixing lugs 282 and within which the screw passage holes 42 are made, and a head 43 allowing the metal shim 4 to be held by gravity on the fixing lugs 282 on the side of the lateral partition 12 during the assembly of the modules 2 in the battery housing 1. This metal shim 4 contributes to the rigidity of the modules 2 and to their vibration resistance in the battery housing 1. As an indication, the clearance maintained between the fixing lugs 282 by the thickness of the metal shim 4 is of the order of 5mm (millimeters). Alternatively, the metal wedge 4 extends between the two modules 2 to between the two opposite fixing lugs 282 which are fixed to the opposite side partition 10, so that the wedge also acts as a spacer between the two neighboring modules.Of course, the fixing of these two opposite fixing lugs 282 is symmetrical to that of the fixing lugs 282 shown in Figures 2 to 4 in relation to the side partition 12 of the battery housing 1.

[0052] In an alternative embodiment of the invention, the metal shim 4 is not used, the fixing lugs then having complementary shapes allowing them to be secured to each other while ensuring the presence of a clearance between the two modules 2 to which they belong. 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 references. In the variant illustrated in Figure 5, the means 28 for fixing the modules 2 to the partitions 10, 12 are not illustrated, to better distinguish devices 20 for securing the modules 2 to the partition 18 forming the bottom of the battery housing 1.

[0053] These securing devices 20 are ears or eyelets, arranged on the side walls, here the secondary side walls 24, 26, of the modules 2, proximally to the bottom of the battery housing 1. They each comprise a screw passage hole arranged opposite a screw passage hole arranged in a boss of the bottom of the battery housing 1, this boss projecting inside the battery housing 1. These screw passage holes receive a fixing screw to fix the ear 20 to the corresponding boss. Damping pads, for example made of rubber, are inserted between the bosses and the ears 20 and allow good vibration resistance of the modules 2 in the battery housing 1.

[0054] Figure 6 illustrates another alternative embodiment of the invention, in which the elements identical to those of the main embodiment of the invention bear the same references. In this other variant, the modules 2 comprise 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 housing 1, for fixing the modules 2 to this partition 18.

[0055] In this other embodiment of the invention, the side walls 23, 25 comprise three separate portions made of one material, namely two thick, parallelepipedal longitudinal end portions, connected by a less thick portion but corrugated in the longitudinal direction L, so as to maintain good rigidity of these side walls 23, 25 while saving material. This less thick portion therefore plays the same role as the stiffening ribs 252 of the main embodiment of the invention. In addition, in this other embodiment of the invention, the ears 21 are arranged in hollows of the corrugation formed by the less thick portion of the side wall 25. These ears 21 take the form of uprights starting vertically at this less thick portion, and extending until they reach a boss 11 projecting from the bottom of the battery housing 1.

[0056] 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 housing 1.

[0057] Identical ears 21 are also arranged in the same way on the side wall 23 to fix the latter to the bottom of the battery housing 1, these ears 21 cooperating with corresponding bosses 11 of the bottom of the battery housing 1.

[0058] Although not shown in this figure 6, bosses 11 are also provided under the modules 2, screw passage holes in the lower walls of the modules 2 (therefore in their main extension walls proximal to the bottom of the battery housing 1) cooperating with corresponding screw passage holes in these bosses 11 to insert fixing screws therein. These screw passage holes are therefore located directly under cylindrical cells 3 or between cylindrical cells 3.

[0059] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the characteristics of the different variant embodiments of the invention envisaged in this application can be combined to achieve the invention, insofar as these variants are not incompatible with each other.

Claims

CLAIMS 1- Electrical energy storage module (2) configured to house a plurality of storage members (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 (28) for fixing to a battery housing (1) capable of housing several modules (2) identical to said module (2), the modules (2) being capable of being stacked in a stacking direction (L) of the modules (2), in the battery housing (1), the module (2) being characterized in that the fixing means (28) comprise a fixing lug (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 fixing lug (282) being capable of 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) on said partition (10, 12, 18) so as to act as a crossbar support forming a crosspiece., 2- Module (2) for storing electrical energy according to claim 1, comprising connecting means configured to secure the module (2) to another module (2) according to claim 1, the fixing lug (282) of the module (2) at least partially forming the connecting means. 3- Module (2) for storing electrical energy according to claim 1 or 2, in which the fixing lug (282) is in one piece with the wall of the module (2) on which it projects, or is a part added to the wall of the module (2) on which it projects. 4- Electrical energy storage module (2) according to any one of claims 1 to 3, in which two first of the side walls (24, 26) are parallel to the stacking direction (L), and the two second of the side walls (23, 25) are orthogonal to the stacking direction (L), the fixing lug (282) extending one of the second side walls (23, 25)- 5- Module (2) for storing electrical energy according to claim 4, in which each second side wall (23, 25) is extended by a fixing lug (282). 6- Electrical energy storage module (2) according to any one of claims 3 to 5, in which the fixing lug (282) comprises a first part capable of extending the second side wall (23, 25) to the partition (12, 10) of the battery housing (1), and a second part capable of being secured to the partition (12, 10) of the battery housing (1) by screwing or welding. 7- Electrical energy storage module (2) according to any one of claims 4 to 6, in which the fixing lug (282) is made of electrically insulating material, and the fixing means (28) further comprise a metal bracket (284) of which a first branch is fixed to the fixing lug (282) and a second branch is capable of being fixed to the partition (10, 12) of the battery housing (1). 8- Electrical energy storage module (2) according to any one of claims 1 to 7, in which the partition (10, 12) is a first partition of the battery housing (1), and the fixing means (28) also comprise devices for securing the module (2) to a second partition (18) of the battery housing (1), orthogonal to the first partition (10, 12) of the battery housing (1). 9- Module (2) for storing electrical energy according to claim 8, in which the securing devices comprise: - ears (20, 21) extending one of the side walls (23, 24, 25, 26) or main extension (22) of the module (2), and capable of receiving screws orthogonally to the extension provided by the fixing lug (282), - and / or screw passage holes in at least one of the main extension walls (22), capable of cooperating with a screw passage hole in a bottom (18) or a cover of the battery housing (1) to receive a fixing screw. io- Electrical energy storage module (2) according to claim 9, in which at least one of the securing devices comprises a vibration damping device. 11- Battery case (1) comprising a set of modules (2) according to any one of claims 1 to 10, stacked in the stacking direction (L), and comprising means for connecting the modules (2) to each other. 12- Battery case (1) according to claim 11, in which the connecting means comprise the fixing lug (282) of a first module (2) of the set of modules (2), and the fixing lug (282) of a second module (2) of the set of modules (2), contiguous to the first module (2). 13- Battery housing (1) according to claim 12, in which the connecting means further comprise a metal wedge (4) between the two fixing lugs (282), and through screws passing through the two fixing lugs (282) and the metal wedge (4). 14- Battery box (1) according to any one of claims 11 to 13, in which the means for fixing the modules extend at least one side wall (23, 25) of said modules at its two ends so as to be fixed on two opposite partitions of the box (1) so as to play the role of a transverse support bar forming a crosspiece. 15- Battery housing (1) according to the preceding claim, which does not comprise a cross support bar forming a crosspiece independent of the modules, in particular a metal one.

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