Cooling and support device for an electrochemical module.

Abstract

Cooling and support device for an electrochemical module. Cooling device (6) for supporting at least one electrochemical module (4B) of a battery (3) of a motor vehicle (1), comprising a first plate (11), a second plate (12) extending parallel to the first plate, a hydraulic cooling circuit (13), and a honeycomb structure (14), the hydraulic cooling circuit being arranged between the first plate and the honeycomb structure, the honeycomb structure being arranged between the hydraulic cooling circuit and the second plate, the honeycomb structure comprising a face conforming to the shape of the cooling circuit. Figure for the abbreviation: Figure 5

Description

Title of the invention: Cooling and support device for an electrochemical module. Technical field of the invention

[0001] The invention relates to a cooling device for supporting at least one electrochemical module of a motor vehicle battery. The invention also relates to a battery comprising such a cooling device. The invention further relates to a motor vehicle comprising such a cooling device and / or such a battery. Finally, the invention relates to a method for manufacturing such a cooling device. Prior art

[0002] So-called "electric" motor vehicles comprise an electric motor capable of driving the vehicle's drive wheels and a battery capable of supplying electric current to the electric motor. The battery of such a vehicle generally comprises a plurality of electrochemical modules, also called electrochemical cells, in which energy is stored in chemical form. The electrochemical modules are generally held together by a metal frame and floor forming a rigid battery structure.

[0003] When they deliver an electric current, the electrochemical modules are likely to heat up. To maintain the electrochemical modules at a suitable temperature, the vehicles are also equipped with an electrochemical module cooling system. The cooling system includes a hydraulic cooling circuit through which a heat transfer fluid circulates to dissipate the heat generated by the electrochemical modules.

[0004] Vehicles are known in which the floor supporting the electrochemical modules is formed by extruded plates extending parallel to one another. Each plate includes an internal channel through which the heat transfer fluid circulates. These channels are connected so as to successively cool each of the electrochemical modules. However, such an architecture is heavy and bulky, and the cooling achieved is not sufficiently efficient.

[0005] Furthermore, motor vehicles known from the prior art offer insufficient safety in the event of a heat transfer fluid leak. Indeed, following an accident, the hydraulic circuit may be damaged and the heat transfer fluid may come into contact with electrical conductors carrying a high-intensity electric current. The heat transfer fluid can then conduct the electric current to the vehicle body. Presentation of the invention

[0006] The object of the invention is to provide a cooling device intended to support at least one electrochemical module of a motor vehicle battery, remedying the above disadvantages and improving upon the cooling devices known in the prior art.

[0007] More specifically, a first object of the invention is to provide a cooling device intended to support at least one electrochemical module of a battery which is relatively light and compact.

[0008] A second object of the invention is to provide a cooling device producing more efficient cooling of the electrochemical modules.

[0009] A third object of the invention is to provide a battery that improves the safety of vehicle users. Summary of the invention

[0010] The invention relates to a cooling device intended to support at least one electrochemical module of a motor vehicle battery, the cooling device comprising a first plate, a second plate extending parallel to the first plate, a hydraulic cooling circuit, and a honeycomb structure, the hydraulic cooling circuit being arranged between the first plate and the honeycomb structure, the honeycomb structure being arranged between the hydraulic cooling circuit and the second plate, the honeycomb structure comprising a face conforming to the shape of the cooling circuit.

[0011] The cooling device may include an intermediate plate extending between the first plate and the honeycomb structure, the intermediate plate comprising a set of reliefs, the hydraulic cooling circuit being formed by the assembly of the intermediate plate with the first plate.

[0012] The reliefs can be formed by stamping the intermediate plate.

[0013] The first plate can be an upper plate of the cooling device, and the second plate can be a lower plate of the cooling device.

[0014] The honeycomb structure can be made of aluminum, and / or the honeycomb structure can be attached to the cooling device by gluing.

[0015] The cooling device may be designed to support at least two separate electrochemical modules, and the hydraulic cooling circuit may include at least one bypass configured to cool the at least two electrochemical modules in parallel.

[0016] The invention also relates to a method for manufacturing a cooling device as defined above, the manufacturing method comprising: - the supply of a first plate, a second plate and an intermediate plate comprising a set of reliefs, then - the assembly of the first plate and the intermediate plate, notably by brazing, to form a hydraulic cooling circuit, - machining a honeycomb plate to form a honeycomb structure conforming to the shape of the cooling circuit, then - the assembly, in particular by gluing, of the hydraulic cooling circuit formed by the first plate and the intermediate plate, of the honeycomb structure and the second plate, the honeycomb structure being interposed between the intermediate plate and the second plate.

[0017] The invention also relates to a battery for a motor vehicle comprising at least one electrochemical module, and a cooling device as defined above, the cooling device supporting the weight of at least one electrochemical module, the hydraulic cooling circuit of the cooling device being intended to cool at least one electrochemical module.

[0018] The battery may include a frame, a first stage of electrochemical modules fixed to the frame, the cooling device being fixed to the frame above at least a part of the first stage of electrochemical modules, the at least one electrochemical module supported by the cooling device forming a second stage of electrochemical modules.

[0019] The invention also relates to a motor vehicle comprising a cooling device as defined above, and / or a battery as defined above. Presentation of the figures

[0020] 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:

[0021] Fig. 1 is a schematic view of a motor vehicle equipped with a battery according to an embodiment of the invention.

[0022] Fig. 2 is a perspective view of a structural assembly of the battery.

[0023] Fig. 3 is a partial cross-sectional view of the battery, along an identified plane AA on [Fig.2]

[0024] Fig. 4 is a partial cross-sectional view of the battery, along a plane identified as BB on [Fig.2]

[0025] Figure 5 is an exploded view of a battery cooling device according to an embodiment of the invention.

[0026] Fig. 6 is a partial cross-sectional view of the cooling device. Detailed description

[0027] Figure 1 schematically illustrates a vehicle 1 according to an embodiment of the invention. The vehicle 1 can be, for example, a passenger car, a utility vehicle, a lifting machine, an agricultural machine, a truck or even a bus.

[0028] The vehicle 1 comprises an electric motor 2 and a battery 3 according to an embodiment of the invention. The electric motor 2 is capable of driving the drive wheels of the vehicle 1. The battery 3 is electrically connected to the electric motor 2 and is capable of supplying it with an electric current. The battery 3 is an energy reservoir giving the vehicle a certain autonomy. The battery 3 thus differs from the batteries conventionally installed in motor vehicles, whose nominal voltage is generally 12V, and which are used to power certain on-board equipment.

[0029] The battery 3 may have a voltage across its terminals of approximately 400V. The battery comprises a plurality of electrochemical modules 4A, 4B, also called electrochemical cells, in which energy is stored in chemical form. The electrochemical modules 4A, 4B may, for example, be of the lithium-ion type.

[0030] The electrochemical modules 4A, 4B are electrically connected to each other in series and / or in parallel. The battery 3 can, for example, comprise between one and twenty inclusive electrochemical modules. According to the embodiment presented, the battery 3 comprises twelve electrochemical modules 4 distributed over two stages. A first stage comprises ten electrochemical modules 4A (of which only eight electrochemical modules are visible in [Fig. 1]), and a second stage comprises two electrochemical modules 4B. The two electrochemical modules 4B of the second stage are positioned above two electrochemical modules of the first stage, which are not visible in [Fig. 1]. Alternatively, the number of electrochemical modules present in each stage could be arbitrary. In particular, the second stage can comprise any number of electrochemical cells greater than or equal to one.

[0031] Each electrochemical module 4A, 4B may include a shape that is at least roughly parallelepiped-shaped, and / or include a mass greater than or equal to 10kg, or even greater than or equal to 20kg, or even greater than or equal to 30kg.

[0032] The vehicle 1 further comprises a cooling system 5 for the battery 3. The cooling system 5 comprises a cooling device 6 according to an embodiment of the invention, a pump 7, and a heat exchanger 8. The cooling device 6 is connected by hydraulic lines to the pump 7 and the heat exchanger 8 in a closed circuit through which a fluid circulates heat transfer fluid. The cooling system 5 is configured so that the heat transfer fluid stores the heat generated by the electrochemical modules 4B at the level of the cooling device 6, then removes this heat through the heat exchanger 8. The pump 7 allows the heat transfer fluid to circulate in the cooling system.

[0033] The battery 3 further comprises a structural assembly 9 supporting the electrochemical modules 4A, 4B. This structural assembly 9, clearly visible in [Fig. 2], can itself be fixed to the vehicle body. It can be arranged in a subframe of the vehicle, under the vehicle passenger compartment. The structural assembly 9 includes, in particular, a frame 10 to which the electrochemical modules 4A of the first stage are fixed. The frame 10 can be formed by a set of beams, for example, made of extruded aluminum. The beams can extend parallel to a longitudinal axis or parallel to a transverse axis of the vehicle. The beams can have a generally rectangular cross-section, with the longer side of the rectangle extending vertically.

[0034] The cooling device 6 is also a component of the structural assembly 9. The cooling device 6 is designed to support at least one electrochemical module 4B. In particular, according to the embodiment presented, the cooling device 6 supports two electrochemical modules 4B. The cooling device can thus support a mass greater than or equal to 20 kg, or even greater than or equal to 40 kg, or even greater than or equal to 60 kg.

[0035] As can be clearly seen in Figures 4 and 5, the cooling device 6 is attached to the frame 10 above two electrochemical modules 4A of the first stage. The cooling device 6 is in the form of a plate, in particular roughly rectangular or trapezoidal in shape. This plate rests on a portion of the frame 10. The cooling device 6, which could therefore be called a "cooling plate," thus forms a floor on which the electrochemical modules 4B of the second stage rest.

[0036] The cooling device 6 can extend substantially horizontally when the vehicle 1 is itself resting on a horizontal surface. The cooling device 6 can be supported by beams of the frame 10 that extend only beneath its perimeter. The cooling device 6 thus possesses sufficient rigidity to remain perfectly horizontal when the electrochemical modules it supports exert their weight.

[0037] As we will see later, the cooling device 6 has a very small thickness and can therefore be advantageously used in a battery comprising several stages of electrochemical modules. However, the cooling device 6 can also be used in a battery comprising a single stage of electrochemical cells. Furthermore, the cooling device 6 could also be suitable to support the first stage of 4A electrochemical modules of battery 3.

[0038] The cooling device 6 is now described in more detail with reference to Figures 5 and 6.

[0039] The cooling device 6 comprises a first plate 11 and a second plate 12 extending parallel to the first plate 11. The first plate 11 is an upper plate of the cooling device, and the second plate 12 is a lower plate of the cooling device. The first plate 11 is in particular in contact with the two electrochemical modules 4B supported by the cooling device 6.

[0040] The cooling device 6 further comprises a hydraulic cooling circuit 13 and a honeycomb structure 14. The hydraulic cooling circuit 13 is arranged between the first plate 11 and the honeycomb structure 14. The honeycomb structure 14 is arranged between the hydraulic cooling circuit 13 and the second plate 12. Therefore, the first plate 11, the hydraulic cooling circuit 13, the honeycomb structure 14, and the second plate 12 are superimposed in that order from top to bottom.

[0041] The hydraulic cooling circuit 13 comprises a set of pipes forming a serpentine shape. The path of the hydraulic cooling circuit 13 is designed to increase the heat exchange surface area with the first plate 11, which is itself in contact with the electrochemical modules 4B.

[0042] The heat generated by the electrochemical modules 4B supported by the cooling device 6 is dissipated by the hydraulic cooling circuit 13 through the first plate 11. Preferably, the first plate 11 is made of a material with excellent thermal conductivity. The first plate may be, for example, made of aluminum. It may have a thickness of between 1 mm and 5 mm inclusive, preferably between 1 mm and 3 mm inclusive, and in particular 2 mm. The arrangement of the hydraulic cooling circuit 13 under the first plate 11 allows the heat transfer fluid to circulate as close as possible to the electrochemical modules 4B to be cooled.

[0043] Advantageously, the hydraulic cooling circuit 13 is formed by assembling a raised intermediate plate 15 with the first flat plate 11. The intermediate plate 15 thus extends between the first plate 11 and the honeycomb structure 14. Preferably, the raised features of the intermediate plate are formed by stamping. These raised features are therefore obtained by deforming a flat plate of constant thickness. The intermediate plate can also be made of aluminum. It can have a thickness of between 0.5 mm and 3 mm inclusive. preferably between 0.5mm and 2mm inclusive, especially 1mm. The hydraulic cooling circuit is therefore particularly simple to manufacture.

[0044] The intermediate plate 15 thus comprises a set of channels 16 through which the heat transfer fluid can circulate. More specifically, the intermediate plate 15 comprises first horizontal surfaces 17, in contact with an underside of the first plate 11, and second surfaces 18, located away from the underside of the first plate 11 and forming the circulation channels for the heat transfer fluid. The intermediate plate 15 can be attached to the first plate 11 by brazing the first surfaces 17 to the underside of the first plate. The first surfaces extend around the perimeter of the intermediate plate and between the channels 16. The assembly of the intermediate plate to the first plate is a leak-proof assembly.As a side note, as can be seen in figures 3 and 4, the 4A electrochemical modules of the first stage can also benefit from a hydraulic cooling circuit designed according to the same principle, namely the assembly of a flat top plate with a raised plate forming the channels of the hydraulic cooling circuit.

[0045] The honeycomb structure 14 comprises an upper face in contact with the hydraulic cooling circuit 13 and conforming to the shape of the cooling circuit. The upper face of the honeycomb structure is a raised face, i.e., not flat. In particular, the upper face of the honeycomb structure 14 conforms to the hollows and bumps of the intermediate plate 15 corresponding to the first surfaces 17 and the second surfaces 18. The lower face of the honeycomb structure 14 may be flat and bear against the upper face of the second plate 12, which is also flat.

[0046] The honeycomb structure 14 allows the support forces exerted by the electrochemical modules 4B on the first plate 11 to be transferred to the second plate 12. Thus, the honeycomb structure, together with the second plate 12, contributes to increasing the rigidity of the cooling device 6. Thanks to the integration of the honeycomb structure, the thickness of the first plate 11 can be reduced because it is supported by the honeycomb structure 14 and by the second plate 12. A reduced thickness of the first plate 11 allows for better transfer of the heat produced by the electrochemical modules 4B to the hydraulic cooling circuit 13 and makes the first plate 11 lighter.

[0047] The honeycomb structure 14 comprises a set of cells delimited by walls extending perpendicularly to the first plate 11 and the second plate 12, i.e., vertical walls. The cross-section of each cell may be hexagonal, square, rectangular, triangular, or any other shape suitable for tiling the plane. The honeycomb structure 14 may also comprising cells of different shapes. Advantageously, the honeycomb structure 14 can also be made of aluminum. The upper face of the honeycomb structure can be machined from a plate of constant thickness to form the reliefs conforming to the shape of the intermediate plate 15. The honeycomb structure 14 can have a thickness from 3 mm to 20 mm inclusive, in particular from 5 mm to 10 mm inclusive, for example, a thickness of 8 mm opposite the first surfaces. It can be attached to the intermediate plate 15 and to the second plate 12 by bonding, in particular using polyurethane adhesive. The honeycomb structure 14 has high compressive strength for a very low weight. In addition, a honeycomb plate is easily machinable to the desired shape.

[0048] Finally, the second plate 12 can also be made of aluminium. It can have a thickness of between 0.5mm and 3mm inclusive, preferably between 0.5mm and 2mm inclusive, in particular 1mm.

[0049] Thus, the total thickness of the cooling device 6, that is to say its dimension along the vertical axis when extended horizontally, can be between 5 mm and 30 mm inclusive, preferably between 10 mm and 15 mm inclusive. The cooling device 6 is therefore particularly compact.

[0050] Furthermore, the cooling device 6 may include various components. In particular, it may include a hydraulic inlet 19 and a hydraulic outlet 20 connected to two ends of the hydraulic cooling circuit 13. The hydraulic inlet 19 and the hydraulic outlet 20 may, for example, include hydraulic fittings extending vertically. Alternatively, these hydraulic fittings could extend horizontally from a section of the cooling device 6.

[0051] The formation of the hydraulic cooling circuit 13 by combining the intermediate plate 15 with the first plate 11 allows for considerable design flexibility in the routing of the hydraulic lines that comprise it. Advantageously, the hydraulic cooling circuit 13 can include a branch configured to cool the two electrochemical modules 4B in parallel. This results in more uniform cooling of the two electrochemical modules compared to an architecture where the electrochemical modules are arranged in series on the hydraulic cooling circuit. Indeed, in such architectures, the heat transfer fluid is already partially heated by the time it reaches the last electrochemical modules, and these are therefore less effectively cooled.

[0052] The cooling device may also include protective walls 21 extending over a peripheral edge of the cooling device, between The first plate 11 and the second plate 12, opposite the honeycomb structure 14. These protective walls 21 can be made of resin, for example. They protect the more fragile honeycomb structure.

[0053] The cooling device 6 also includes openings 22 passing through the cooling device perpendicularly to the first and second plates for the passage of electrical conductors, in particular for the passage of bus bars. In the embodiment illustrated in Figures 1 and 2, the cooling device 6 includes four openings 22. In the embodiment illustrated in [Fig. 5], the cooling device 6 includes two openings 22. Alternatively, the number of openings could be any number.

[0054] The cooling device 6 also includes inserts 23 passing through the cooling device perpendicularly to the first and second plates for attaching the cooling device. These inserts may be smooth or threaded. They may be designed to cooperate with any type of fastener such as screws, rivets, or pins. These inserts 23 may be used to attach the cooling device to the frame 10.

[0055] In addition, the cooling device 6 also includes mounting flanges 24 for retaining each of the electrochemical modules 4B. The mounting flanges 24 can be attached to the cooling device by means of inserts 23 provided for this purpose.

[0056] The cooling device 6 can be manufactured as follows. First, the first plate 11, the second plate 12, and the intermediate plate 15 are provided. The intermediate plate 15 may have been previously stamped to the desired shape. The plates 11, 12, and 15 may be provided with openings 22 and holes into which the inserts 23 will be inserted. Next, the first plate 11 and the intermediate plate 15 are assembled, notably by brazing, to form the hydraulic cooling circuit 13. Then, or in parallel with the previous steps, a honeycomb plate is machined to form the honeycomb structure conforming to the shape of the cooling circuit 13. Finally, the hydraulic cooling circuit 13, the honeycomb structure 14, and the second plate 15 are assembled, notably by bonding.Next, the cooling device 6 can be equipped with protective walls 21, inserts 23 and fixing flanges 24.

[0057] Once manufactured, the cooling device 6 can be assembled to the frame 10. Then, the electrochemical modules 4B can be attached to the cooling device 6 via the fixing flanges 24. This provides a particularly light and compact device to support the electrochemical modules 4B.

[0058] During operation of the vehicle 1, a heat transfer fluid circulates in the hydraulic cooling circuit 13 and efficiently cools the electrochemical modules 4B. Furthermore, the vehicle's operational safety is also improved. In the event of a leak in the hydraulic cooling circuit 13, the honeycomb structure 14 provides an additional barrier preventing the heat transfer fluid from spreading throughout the vehicle. This limits the risk of electric shock or electrocution to vehicle users.

Claims

Demands

1. Battery (3) for a motor vehicle (1), characterized in that it comprises a frame (10), a first stage of electrochemical modules (4A) fixed to the frame, a cooling device (6) fixed to the frame above at least a portion of the first stage of electrochemical modules, and at least one electrochemical module (4B) forming a second stage of electrochemical modules, the at least one electrochemical module (4B) being supported by the cooling device (6), the cooling device (6) comprising a first plate (11), a second plate (12) extending parallel to the first plate, a hydraulic cooling circuit (13) for cooling the at least one electrochemical module (4B), and a honeycomb structure (14), the hydraulic cooling circuit being arranged between the first plate and the honeycomb structure,The honeycomb structure being arranged between the hydraulic cooling circuit and the second plate, the honeycomb structure comprising a face conforming to the shape of the cooling circuit, the cooling device (6) also comprising inserts (23) passing through the cooling device perpendicularly to the first plate and the second plate for fixing the cooling device.

2. Battery (3) according to the preceding claim, characterized in that the cooling device (6) comprises an intermediate plate (15) extending between the first plate (11) and the honeycomb structure (14), the intermediate plate comprising a set of reliefs, the hydraulic cooling circuit (13) being formed by the assembly of the intermediate plate with the first plate.

3. Battery (3) according to the preceding claim, characterized in that the reliefs are formed by stamping the intermediate plate (15).

4. Battery (3) according to any one of the preceding claims, characterized in that the first plate (11) is an upper plate of the cooling device, and the second plate (12) is a lower plate of the cooling device.

5. Battery (3) according to any one of claims 2 to 4, characterized in that the honeycomb structure (14) is made of aluminium, and / or in that the honeycomb structure (14) is attached to the cooling device by gluing.

6. Battery (3) according to any one of the preceding claims, characterized in that the cooling device (6) supports at least two separate electrochemical modules (4B), and in that the hydraulic cooling circuit (13) includes at least one bypass configured to cool the at least two electrochemical modules in parallel.

7. Motor vehicle (1), characterized in that it comprises u a battery (3) according to any one of the preceding claims.

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