BATTERY COMPRISING A MODULE AND A HEAT EXCHANGE PLATE

Abstract

Electrical energy storage battery comprising: - a casing (1) having an inner face (Fi), - a module (2) comprising a heat exchange surface (S), and a fixing sleeve (3) of the module (2) to the inner face (Fi), - a heat exchange plate (4), inserted between this heat exchange surface (S) and the inner face (Fi), this plate (4) comprising a hollow part (Pc), and a solid part (PP) through which a hole (T) passes through its entire thickness, - a fixing means (5, 6), comprising on the one hand a protrusion (5) of the inner face (Fi) extending through the hole (T) and partly into the bore (A) of the sleeve (3), and on the other hand a clamping device (6) comprising a clamping head (7) extended by a threaded body (8) cooperating by screwing with the protrusion (5), this sleeve (3) comprising a first end (E1) bearing on the solid part (PP), and a second, opposite end (E2), receiving the support of the clamping head (7),the threaded body (8) penetrating the sleeve (3) through the second end (E2). Figure 1.

Description

Title of the invention: BATTERY COMPRISING A MODULE AND A HEAT EXCHANGE PLATE

[0001] The present invention relates to a battery, and more particularly to a battery of an electrically powered vehicle supplying an electric motor.

[0002] Throughout this document, the term "battery" shall be understood to mean an assembly comprising battery modules containing electrochemical energy storage cells. These modules include a casing that holds the cells stacked under compression against each other, and each has an outer casing comprising interfaces for mounting the module in a housing. This casing may include at least part of the casing. The battery may optionally include electrical or electronic means for managing the electrical energy of these modules. These modules are grouped in the housing or container and form a battery pack, often referred to as a "battery block." This housing generally contains a mounting interface and connection terminals.

[0003] Furthermore, the term "electrochemical energy storage cell" will be understood throughout the text of this document to mean cells that generate current by chemical reaction, for example, lithium-ion (or Li-ion), Ni-Mh, Ni-Cd or lead type.

[0004] In this field, it is known to cool or heat the battery modules by means of a plate through which a heat transfer fluid flows. This plate is in contact with the modules by thermal conduction through a heat exchange surface. This plate must also be positioned and fixed within the casing.

[0005] Generally, the module mounting interface and the cooling plate mountings are independent, which increases the number of mountings and the complexity of battery assembly. To solve this problem, common mountings have already been considered, but these create new problems, notably issues with the positioning of the modules and / or plates relative to the housing, or of the plate relative to the module, and consequently, uncontrolled play, particularly between the plate and the module.

[0006] The object of the invention is to remedy this problem. To this end, the invention relates to an electrical energy storage battery comprising: - a housing with an internal surface for supporting a module, - the electrical energy storage module, comprising a heat exchange surface, and a sleeve for fixing the module to the inner face, - a conduction heat exchange plate with the heat exchange surface, inserted between this heat exchange surface and the inner support face, this plate comprising in its thickness a hollow part intended to receive a heat transfer fluid, and a solid part through which a hole passes through its entire thickness, - a means of fixing the module to the inner face, comprising on the one hand a protrusion of the inner support face extending through the hole and partly into the bore of the sleeve, this protrusion comprising a first thread, and on the other hand a clamping device comprising a clamping head extended by a threaded body cooperating by screwing with the first thread, this sleeve comprising a first end bearing on the solid part, and a second, opposite end receiving the support of the clamping head, the threaded body penetrating the sleeve by the second end.

[0007] Thus, the protrusion allows the heat exchange plate to be centered relative to the housing by passing through the hole, and also allows the module to be centered relative to the housing by penetrating the mounting sleeve. Furthermore, the clamping head of the clamping device allows the mounting sleeve to be pressed against the housing, with the heat exchange plate sandwiched between the inner face and the first end of the mounting sleeve. This clamping device therefore clamps both the mounting sleeve and the solid portion of the heat exchange plate: thus, regardless of the clamping force, the heat exchange plate is not deformed.

[0008] According to one embodiment of the invention, the protrusion is a second sleeve whose bore includes the first thread. This second sleeve is, for example, a plain nut with a flange, this flange bearing against and / or welded to a face of the housing opposite the inner support face. The smooth portion of the nut is configured so as to center the exchange plate and the module relative to the housing.

[0009] According to one embodiment of the invention, the clamping device is a screw. Thus, the clamping head is the screw head, and the threaded body of this screw is screwed into the thread of the smooth flanged nut.

[0010] According to one embodiment of the invention, the protrusion is an added element fixed to the housing. For example, the added element is welded to the housing.

[0011] According to one embodiment of the invention, the inner face rests on the cooling plate only on the solid part. This arrangement ensures that not only will the plate not be deformed during screwing, but also that the hollow part will not be in contact with the housing: this hollow part, the most fragile, will not be impacted by a shock causing deformation of the housing because a space will remain between this hollow part and the housing, allowing the shock to be absorbed without deforming the plate.

[0012] According to one embodiment of the invention, the inner face is a double bottom of the crankcase, or alternatively a bulge in the crankcase.

[0013] This double bottom is not necessarily over the entire surface of the bottom of the housing. This double bottom is, for example, located around the protrusion; in particular, this double bottom is a stiffening cross member of the internal support face, specifically a bottom cross member of the housing.

[0014] According to one embodiment of the invention, this battery comprises a thermally conductive means for filling a gap between the heat exchange surface and the heat exchange plate. This filling means is known to those skilled in the art and is, for example, in the form of a flexible mat or, more often, in the form of a thermally conductive paste, which is compressed during battery assembly when the module is positioned and then tightened into the casing. This paste, like the mat, absorbs geometric variations and thus ensures thermal contact between the plate and the module regardless of these variations.

[0015] According to one embodiment of the invention, the preserved space is created by a slight offset of the first end relative to the heat exchange surface. This offset ensures that the hollow part of the plate and the heat exchange surface of the module do not touch, thus providing a homogeneous distribution of the thermal paste.

[0016] According to one embodiment of the invention, the module comprises: - a first and second module end, - two sides joined together and connecting the two ends together, the heat exchange surface being an outer face on one side, the fixing sleeve being attached to an outer face on the other side.

[0017] This arrangement allows for a fixing sleeve to be placed on one side of the module, and in particular on each side of the module, i.e., on two opposite sides. The positioning of the fixing sleeves can therefore be chosen at any point along the length of the module, i.e., between its two ends.

[0018] This sleeve, for example, has an axis orthogonal to the exchange surface. This sleeve is, for example, coaxial with the protrusion. This sleeve is, for example, integral to the module by assembly, shrink fitting, or formed from the material on the module side.

[0019] Other features and advantages will become apparent from the following description of a particular, non-limiting embodiment of the invention, made with reference to the single [Fig. 1] in which:

[0020] [Fig.1]: represents a schematic cross-sectional view of an electrical energy storage battery according to an embodiment of the invention.

[0021] Figure 1 discloses an electrical energy storage battery comprising, according to the invention: - a casing 1 having an internal face Fi for supporting a module 2, - the electrical energy storage module 2, comprising a heat exchange surface S, and a fixing sleeve 3 for attaching the module 2 to the internal face Fi, - a heat exchange plate 4 by conduction with the heat exchange surface S, inserted between this heat exchange surface S and the internal support face Fi, this plate 4 comprising within its thickness a hollow part Pc intended to receive a heat transfer fluid, and a solid part PP through which a hole T passes through its entire thickness, - a means of fixing 5, 6 of the module 2 to the inner face Fi, comprising on the one hand a protrusion 5 of the inner face Fi of support extending through the hole T and partly into the bore A of the sleeve 3, this protrusion 5 comprising a first thread, and on the other hand a clamping device 6 comprising a clamping head 7 extended by a threaded body 8 cooperating by screwing with the first thread, this sleeve 3 comprising a first end El bearing on the solid part PP, and a second end E2, opposite, receiving the support of the clamping head 7, the threaded body 8 penetrating the sleeve 3 by the second end E2.

[0022] As not illustrated, this casing is closed by a cover to form a hermetically sealed internal space containing the modules. This cover may, for example, be formed by a section of the floor of a motor vehicle, but not necessarily. For example, this battery, that is, a battery as defined above, may be assembled outside the vehicle (casing, module, cover) and then, once assembled, attached to the motor vehicle, particularly under its floor. This vehicle may, for example, be electrically powered, with the battery powering an electric motor. For example, this vehicle may be a hybrid vehicle, or a fully electric vehicle. Applications are also possible outside the automotive sector, for example, for construction site power stations such as generators, or electrical energy storage facilities.

[0023] This battery may include electrical or electronic means for managing the electrical energy of these modules, for example, but not limited to: a charger, a current converter, a battery pack control unit, an inverter, charge and discharge control boards for each module and / or each cell, a junction box including electrical isolation contactors for the battery pack or for switching on and off external circuits connected to the battery pack. All these electrical or electronic means may be integrated at the level of each cell and / or each module.

[0024] The inner face Fi of the support for module 2 is, in this example, the bottom of the housing 1, this housing 1 forming a container closed by a lid not shown. [Fig. 1] illustrates a partial cross-sectional view of this bottom.

[0025] It should be noted that in [Fig. 1], for simplicity, only the sections of module 2, fixing sleeve 3, and protrusion 5 are hatched, according to standard practice in industrial drawings. In particular, the hatching of module 2 is purely for the purpose of readability of the figure; it is clearly understood that this module 2 is not a solid block of material but, as previously described, contains, among other things, the cells.

[0026] The heat exchange surface S is here a bottom of the module 2, opposite the bottom of the housing 1 and therefore of the internal face Fi, but this arrangement is not mandatory: the internal face Fi can be for example not the bottom of the housing 1, but another part of the housing 1 such as the cover or any face of the housing 1 opposite the heat exchange surface S, thus the heat exchange surface S is not necessarily the bottom of the module 2 but can be a top or side Cl of the module 2, which is why the bottom, like the top of the module 2 is also called "side" (S) in this example.

[0027] The illustrated heat exchange plate 4 is a plate well known to those skilled in the art, and is made by joining two sheets one on top of the other. The first of the two sheets has a stamped indentation covered by the second sheet, thus forming a hollow portion Pc. This assembly is achieved, for example, by electric welding and / or bonding for a good seal. These sheets can be metallic or made of plastic. This hollow portion Pc forms, for example, a channel running along the heat exchange plate 4 along a surface corresponding to the heat exchange surface S. The heat transfer fluid is circulated in this channel by a circulation pump, which may or may not be integrated into the hermetically sealed internal space of the coil. The solid portion PP is formed by the junction between the first and second sheets.

[0028] Other cooling plate technologies 4 are known and applicable to this invention, for example, plates 4 produced by a casting or machining process with more or less complex assemblies, or by large plastic deformation of a single sheet by blow molding. The channel may be a narrow channel winding around the plate 4, or a blade-shaped channel passing through the cooling plate 4 in only one direction; this is not important for the invention presented. The hole T passes through the heat exchange plate 4 through its entire thickness, in the solid part PP, that is to say, through the first and second sheets in the area where they are in contact with each other.

[0029] The clamping device 6, by means of its clamping head 7, will clamp the sleeve 3 against the solid part PP of the heat exchange plate 4, and the heat exchange plate 4 against the inner face Fi. The clamping head 7 shown is only one example among others, and in [Fig. 1] is a wide-headed screw head, i.e., wider than the bore of the sleeve 3 and therefore covering the second end E2. The sleeve 3 and The solid PP part fully absorbs the clamping force of the clamping device 6, thus there is no deformation of the heat exchange plate 4.

[0030] The protrusion 5 is a second sleeve 5 whose bore includes the first thread. This second sleeve 5 is, for example, a bushing, just like the sleeve 3.

[0031] The clamping device 6 is illustrated as a wide-headed screw, but alternatively could be a smooth shouldered nut.

[0032] Figure 1 shows a significant clearance between sleeve 3 and the second sleeve 5. This clearance will be, for example, sliding if precise relative positioning between module 2, plate 4, and the inner face Fi is required. This clearance will be wider if there are several sleeves 3 for the same module 2 in order to absorb manufacturing variations. This clearance can be further increased, for example from 3 to 6 mm at the radius, for reasons of over-constraint. Similarly, a person skilled in the art will be able to adapt the shape of sleeve 3 and the second sleeve 5 according to the degrees of freedom to be immobilized.

[0033] the protrusion 5, and therefore the second sleeve 5, is an element added and fixed to the housing 1, like a shouldered bushing or a stamped bridge, but alternatively this protrusion 5 can be a deep boss on the inner face Fi including a threaded nut in its bottom to receive the clamping device 6.

[0034] For example, the added element 5 is welded to the housing 1 on its shoulder, or screwed, or glued.

[0035] Alternatively, the added element 5 is a stud, in particular a stud welded to the inner face Fi.

[0036] The inner face Fi is in contact with the cooling plate 4 only on the solid part PP.

[0037] The inner face Fi is a double bottom 9 of the housing 1, as illustrated in [Fig. 1], and alternatively a boss on the housing 1. In [Fig. 1], the double bottom is actually a sheet metal cross member in the shape of an inverted U, the ends of the U being welded to the bottom of the housing 1. This U then forms, with the bottom of the housing 1, a hollow body that is slightly recessed from the bottom of the housing, this U being located under the solid parts PP. The second sleeve 5 will, for example, be assembled onto this cross member before the cross member is welded to the bottom of the housing.

[0038] This battery includes a thermally conductive means 10 for filling a preserved space E between the heat exchange surface S and the heat exchange plate 4. This has been clearly explained in the general description.

[0039] This preserved space E is achieved by a dis-flush of the first end El with respect to the heat exchange surface S.

[0040] This module 2 includes: - a first and second module end, - a stack of electrochemical cells compressed between the two ends of the module, - two contiguous sides S, Cl together and connecting the two ends together, the heat exchange surface S being an outer face of one side S, the fixing sleeve 3 being integral with an outer face of the other side Cl.

[0041] These first and second ends are, for example, part of a band holding the stacked cells in compression against each other, and sides S, Cl may be part of the band but also independent of it, that is, not participating in maintaining the compression of the cells. In all cases, these sides, for example, four in number to form a rectangular parallelepiped with the two ends, form an outer casing of module 2 comprising interfaces for fixing this module 2 in the housing 1, this casing therefore being able to include a part of the band. Thus, side Cl carrying the fixing sleeve 3 is, for example, made of a metallic material, in particular aluminum, a tab made of this material or added on, extending orthogonally to side Cl, and this tab comprising the fixing sleeve 3. For example, this tab and the fixing sleeve 3 form a single piece.For example, this side Cl, the lug, and the fixing sleeve 3 form a single piece. For example, this jaw 3 is either press-fitted or press-fitted into the lug. Of course, this lug is not essential; the fixing sleeve 3 can, for example, be attached to side Cl.

[0042] This same side 1 may also include several fixing sleeves 3, aligned and extending along the length of side 1. The battery pack containing several modules, a first module 2 next to a second module 2 may for example have the fixing sleeves 3 staggered with respect to each other.

[0043] The axis of the fixing sleeve 3 is for example parallel to the side Cl and orthogonal to the cooling plate 4 and to the inner face Fi, the protrusion 5 being concentric to the fixing sleeve 3.

[0044] Electrochemical cells are for example parallelepiped-shaped, or prismatic and whose chemistry is enclosed in a rigid envelope.

[0045] Alternatively, the cells are in the form of pockets.

[0046] These cells are cylindrical in variant form, but in this case, those skilled in the art know that they do not need to be compressed together because the rigid cylinder, by its very shape, prevents the cells from swelling. The strapping then no longer serves to compress the cells but to position them. However, there will be an envelope containing all these cells, forming a module. This envelope is also parallelepiped-shaped and has two ends and four sides, these sides being equivalent to sides S, Cl of the present description, and the fixing sleeve 3 being integral with one outer face of the other side CL.

[0047] For example, these cells are of the lithium-ion (or Li-ion) type.

Claims

Demands

1. An electrical energy storage battery comprising: - a housing (1) having an inner face (Fi) for supporting a module (2), - the electrical energy storage module (2), comprising a heat exchange surface (S), and a sleeve (3) for attaching the module (2) to the inner face (Fi), - a heat exchange plate (4) for conduction with the heat exchange surface (S), inserted between this heat exchange surface (S) and the inner face (Fi) of the support, this plate (4) comprising within its thickness a hollow portion (Pc) for receiving a heat transfer fluid, and a solid portion (PP) through which a hole (T) passes through its entire thickness, - a means (5, 6) for attaching the module (2) to the inner face (Fi), comprising on the one hand a protrusion (5) of the inner face (Fi) of the support extending through the hole (T) and partly into the bore (A) of the sleeve (3), this protrusion (5) comprising a first thread,and on the other hand a clamping device (6) comprising a clamping head (7) extended by a threaded body (8) cooperating by screwing with the first thread, this sleeve (3) comprising a first end (E1) bearing on the solid part (PP), and a second, opposite end (E2) receiving the support of the clamping head (7), the threaded body (8) penetrating the sleeve (3) by the second end (E2).

2. Battery according to claim 1, the protrusion (5) being a second sleeve (5) whose bore includes the first thread.

3. Battery according to any one of the preceding claims, the clamping device (6) being a screw.

4. Battery according to any one of the preceding claims, the protrusion (5) being an element added and fixed to the casing (1).

5. Battery according to claim 4, the added element (5) being welded to the casing (1).

6. Battery according to any one of the preceding claims, the inner face (Fi) being in contact with the cooling plate (4) only on the solid part (PP).

7. Battery according to claim 6, the inner face (Fi) being a double bottom (9) of the casing (1), or a boss of the casing (1).

8. Battery according to any one of the preceding claims, comprising a thermally conductive means (10) for filling a preserved space (E) between the heat exchange surface (S) and the heat exchange plate (4).

9. Battery according to claim 8, the preserved space (E) being achieved by a dis-flush of the first end (El) with respect to the heat exchange surface (S).

10. Battery according to any one of the preceding claims, the module (2) comprising: - a first and second module end, - two adjoining sides (S, Cl) connecting the two ends together, the heat exchange surface (S) being an outer face of one side (S), the fixing sleeve (3) being integral with an outer face of the other side (Cl).

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