Energy storage device for a vehicle comprising a tank and an electrochemical battery

Abstract

Energy storage device for a vehicle comprising a tank and an electrochemical battery. Energy storage device (2) for a motor vehicle (1), comprising: - an electrochemical battery (4), the electrochemical battery comprising a set of electrochemical cells (21) and a casing (23) supporting all the electrochemical cells, and - a tank (3, 3') for storing an energy fluid, the tank being fixed to the casing (23) of the electrochemical battery. Figure for the abbreviation: Figure 2

Description

Title of the invention: Energy storage device for a vehicle comprising a tank and an electrochemical battery Technical field of the invention

[0001] The invention relates to an energy storage device for a vehicle comprising a tank for storing an energy fluid, in particular hydrogen, and an electrochemical battery. The invention also relates to a vehicle, in particular a motor vehicle, comprising such an energy storage device. Prior art

[0002] To make vehicle use less polluting, vehicles equipped with a hydrogen-powered fuel cell are known. These vehicles therefore carry a tank in which hydrogen is stored before being consumed by the fuel cell. The fuel cell provides electrical energy that can be used directly by an electric motor to propel the vehicle, or stored in an electrochemical battery on board the vehicle. The electrochemical battery can thus be recharged by means of the fuel cell. In addition, the electrochemical battery can also be configured to be recharged via an electricity distribution network. Such vehicles include two energy storage means: the hydrogen tank and the electrochemical battery.

[0003] The hydrogen pressure in the tank can be very high, for example, on the order of 700 bar. The tank must therefore be particularly resistant to the mechanical stresses exerted by pressurized hydrogen. Furthermore, hydrogen is a highly flammable gas that poses a fire hazard in the event of a leak. Hydrogen tanks must therefore also be impact-resistant to ensure passenger safety in the event of a vehicle accident. Prior art tanks generally take the form of one or more cylinders mounted on the vehicle. Such cylinders are particularly bulky and complex to integrate within the vehicle.

[0004] On the other hand, electrochemical batteries intended to power an electric motor are also dangerous energy storage devices. If damaged, they can catch fire and / or cause electric shocks or electrocution. An electrochemical battery typically comprises a set of electrochemical cells arranged in a casing that supports and protects the electrochemical cells from the external environment. The casing protects the other components. The vehicle is protected from any risk of contact with the electrical conductors of the electrochemical battery and prevents gas leaks in the event of an electrochemical cell malfunction. An electrochemical battery is also a very large and complex device to integrate into the vehicle. It typically extends along the vehicle floor.

[0005] Thus, vehicles known in the prior art that include both a tank for an energy fluid and an electrochemical battery to power an electric motor present a poor compromise between range, available space for passengers or for storing objects, and vehicle size. Presentation of the invention

[0006] The object of the invention is to provide an energy storage device for a vehicle that remedies the above disadvantages and improves upon known energy storage devices of the prior art.

[0007] More specifically, a first object of the invention is to provide a compact energy storage device comprising a reservoir and an electrochemical battery that offers optimal safety for vehicle users. Summary of the invention

[0008] The invention relates to an energy storage device for a motor vehicle, comprising: - an electrochemical battery, the electrochemical battery comprising a set of electrochemical cells and a casing supporting all the electrochemical cells, and - a reservoir intended for storing an energy-producing fluid, the reservoir being fixed to the casing of the electrochemical battery.

[0009] The housing may include a frame extending laterally around the electrochemical cells, and the reservoir may be attached to the frame.

[0010] The energy storage device may include at least one first fixing tab fixed, in particular screwed, on one side to the reservoir, and fixed, in particular screwed, on the other side to the casing of the electrochemical battery.

[0011] The energy storage device may include at least one second fixing bracket fixed, in particular screwed, on one side to the tank, and intended to be fixed, in particular intended to be screwed, on the other side to a chassis of the vehicle.

[0012] The reservoir can be positioned in a longitudinal extension of the battery, in particular at the rear of the electrochemical battery.

[0013] The reservoir may include a face in direct contact with the casing of the electrochemical battery.

[0014] The tank may include a rigid structure made of a composite material, and the tank may be attached to the electrochemical battery housing by fixing screws penetrating into the tank structure.

[0015] The tank may include at least a first pair of opposite walls connected to each other by a first set of connecting elements, passing through the tank and extending parallel to a first axis, the tank including at least one fixing interface arranged at one end of at least one connecting element, the tank being fixed to the housing of the electrochemical battery by means of at least one fixing interface.

[0016] The invention also relates to a vehicle, in particular a motor vehicle, comprising a chassis and an energy storage device as defined above, the electrochemical battery casing and the tank being fixed to the chassis.

[0017] The invention also relates to a method for designing an energy storage device as defined above, comprising: - the identification of an existing vehicle comprising an electrochemical battery equipped with a casing and a set of electrochemical cells supported by said casing, the casing being fixed to a vehicle chassis by a set of fastening means, then - the removal of some of the electrochemical cells from the electrochemical battery and the reduction of the volume of the electrochemical battery casing, then - the design of a tank intended to store an energy fluid, the tank comprising a geometric shape adapted so that the tank occupies the space freed up by the reduction in the volume of the crankcase, and so that the tank is fixed to the chassis of the vehicle by a part of said fixing means. Presentation of the figures

[0018] 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:

[0019] Fig. 1 is a schematic profile view of a motor vehicle equipped with an energy storage device according to an embodiment of the invention.

[0020] Fig. 2 is a perspective of a first embodiment of a reservoir of the energy storage device.

[0021] Fig. 3 is a partial and perspective view of the reservoir according to the first embodiment.

[0022] Fig. 4 is a partial and transparent view of the reservoir according to the first embodiment.

[0023] Fig. 5 is a cross-sectional view of a tank fixing interface according to the first embodiment.

[0024] Fig. 6 is a perspective view of a second embodiment of a reservoir of the energy storage device.

[0025] Fig. 7 is a perspective and bottom view of an energy storage device according to an embodiment of the invention.

[0026] Fig. 8 is a perspective and top view of the energy storage device of Fig. 7, an electrochemical battery of the energy storage device being shown without an electrochemical cell.

[0027] Fig. 9 is a longitudinal and vertical cross-sectional view of part of the energy storage device of Fig. 7. Detailed description

[0028] Figure 1 schematically illustrates a motor vehicle 1 according to an embodiment of the invention. The vehicle 1 may be, for example, a passenger car or a commercial vehicle. Alternatively, it could be a truck, a bus, a lifting machine, an agricultural machine, or even any other type of land vehicle. The invention can also be adapted to an aircraft or a boat.

[0029] In this document, the X-axis denotes the longitudinal axis of vehicle 1. When moving forward in a straight line, vehicle 1 progresses from rear to front in a direction parallel to its longitudinal axis. The X-axis is oriented from the front to the rear of the vehicle, that is, in the direction of reverse movement. The Y-axis denotes the transverse axis of the vehicle. The Y-axis is oriented from left to right, left and right being defined from the perspective of a driver of vehicle 1. The Z-axis denotes the axis perpendicular to the X-axis and the Y-axis. Vehicle 1 is assumed to be resting on a horizontal surface. The Z-axis is a vertical axis, oriented from bottom to top. The X, Y, and Z axes form an orthogonal coordinate system. This reference point defined in relation to vehicle 1 can be used to describe an energy storage device 2 of vehicle 1, even considered outside the vehicle, since the tank is intended to be integrated into the vehicle according to a particular orientation..

[0030] The vehicle 1 is equipped with an energy storage device 2 according to an embodiment of the invention. The energy storage device 2 comprises a tank 3, 3' and an electrochemical battery 4. The vehicle 1 also comprises a fuel cell 5 capable of converting hydrogen into an electric current, and an electric motor 6 powered by an electric current from the fuel cell 5. The electric motor 6 is configured to drive the drive wheels of the vehicle 1. The vehicle 1 further comprises a chassis 31 supporting, among other things, the energy storage device 2, the fuel cell 5, and the electric motor 6.

[0031] Figures 2 and 6 illustrate respectively a first embodiment of the reservoir 3 and a second embodiment of the reservoir 3'. Where possible, the same reference numerals are used to describe the same characteristics of the reservoir 3 and the reservoir 3'.

[0032] According to the illustrated embodiments, the tank 3, 3' is intended for storing hydrogen, or more precisely, dihydrogen. According to other variants, the tank 3, 3' could be configured to store other forms of energy gases, for example, liquefied petroleum gas or natural gas. The tank could even be intended for storing a liquid fuel such as gasoline, diesel fuel, or ethanol. In such a case, the vehicle could include a combustion engine capable of converting the energy of the energy fluid into electromotive force.

[0033] Generally speaking, the reservoir 3, 3' is intended to contain an energy fluid, that is to say, a fluid forming a fluid energy reserve, convertible into an electromotive force capable of moving the vehicle. The reservoir is therefore a component of the vehicle 1 that gives it a certain autonomy. The reservoir includes, in particular, an inlet opening for filling the reservoir with an energy fluid and an outlet opening for delivering and then consuming the energy fluid contained in the reservoir.

[0034] The tank 3, 3' is intended to store the energy fluid under pressure, that is, at a pressure strictly greater than atmospheric pressure. In this case, the tank is intended to store the energy fluid, in particular hydrogen, at a pressure greater than or equal to 700 bar. Alternatively, the tank could be intended to store the energy fluid at a different pressure, for example, a pressure greater than or equal to 300 bar, or 500 bar, or 1000 bar, or any other value. The tank thus comprises a rigid structure capable of withstanding the forces exerted by the pressurized fluid it contains, that is, centrifugal forces acting from inside the tank that tend to cause it to burst.

[0035] Furthermore, the tank 3, 3' can have a capacity greater than or equal to 50 liters, preferably greater than or equal to 100 liters, or even greater than or equal to 150 liters. A 100-liter tank allows the storage of approximately 4 kg of hydrogen at 700 bar, which gives a motor vehicle a range of around 300 km.

[0036] The structure of the tank 3, 3' is also capable of withstanding significant impacts, particularly those occurring in the event of an accident involving vehicle 1, without generating any leakage of the energy fluid to the outside. Accident data and / or simulations and / or crash tests allow the structure to be dimensioned, including the required wall thicknesses, so that no leakage of energy fluid occurs, even in the most violent accidents.

[0037] Advantageously, the tank 3,3', whose high strength is necessary to withstand the high pressures of the energy fluid it contains and to ensure the safety of the vehicle's passengers in the event of an accident, can be used to stiffen the energy storage device 2, and more generally to stiffen the vehicle's structure. The tank is capable of supporting the weight exerted by other vehicle equipment and also provides a support for attaching this equipment.

[0038] The tank 3, 3' is capable of supporting loads of at least one hundred kilograms, and even several hundred kilograms. These loads can be static, such as those exerted by the weight of equipment like vehicle seats and / or the weight of vehicle passengers. They can also be dynamic, such as those that occur in specific situations like an impact with the vehicle. These various static or dynamic loads can exert compressive or shear forces on the tank. These forces are therefore oriented in a different direction from the centrifugal forces exerted by the pressurized energy fluid inside the tank.Advantageously, the resistance of the reservoir required to withstand the pressure exerted by the energy fluid it contains is therefore also used to support loads acting in different directions.

[0039] The tank 3, 3' may have a roughly parallelepiped shape. It may thus comprise three pairs of opposing walls. A first pair of opposing walls consists of a front wall 7A and a rear wall 7B. Walls 7A and 7B extend substantially parallel to the Y and Z axes. A second pair of opposing walls consists of a left side wall 8A and a right side wall 8B. Walls 8A and 8B extend substantially parallel to the X and Z axes. A third pair of opposing walls consists of an upper wall 9A and a lower wall 9B. Walls 9A and 9B extend substantially parallel to the X and Y axes. Alternatively, any other shape of the tank could be considered.

[0040] The tank 3, 3' is arranged in the rear part of the vehicle 1, in particular at the level of a rear portion of the vehicle's underbody. The tank 3, 3' extends, in particular, under a row of rear seats of the vehicle and / or under a trunk of the vehicle, or even as far as a rear bumper of the vehicle. The tank can thus be designed to support the load exerted by the rear seats and all the objects stored in the trunk of the vehicle.

[0041] The upper wall 9A may include recesses 10 for receiving the seat cushions of the vehicle, so that passengers seated on these seats are not positioned too high. Between the recesses 10, the upper wall 9A includes a central rib 11 protruding which allows to increase the volume of the tank without penalizing the comfort of passengers seated on the seats above the tank.

[0042] Advantageously, the tank 3, 3' also includes an anti-submarining device 12. Such a device forms a stop preventing the seats above the tank from sliding forward in the event of an accident. The anti-submarining device 12 is formed by a protrusion extending forward and upward in front of the recesses 10. The anti-submarining device 12 may have a streamlined shape along the Y-axis and / or extend across the entire width of the tank along the Y-axis. In addition to improving passenger safety, integrating the anti-submarining device 12 into the tank increases the tank's volume and thus its energy storage capacity.

[0043] The tank 3, 3' can be isolated from the passenger compartment by a simple protective element, for example made of plastic, which covers the tank. No structural element needs to be integrated between the tank 3, 3' and the vehicle seats above the tank, since the latter has sufficient strength to support the weight of the seats and the passengers seated on them.

[0044] The tank 3, 3' can also provide a support for attaching a safety device. The safety device is intended to protect the vehicle's occupants in the event of an accident. In particular, the safety device may include a seat belt and / or a device conforming to ISO 13216-1:1999, more commonly known as the "Isofix" system. These safety devices can be attached to the upper wall 9A of the tank.

[0045] Advantageously, the structure of the tank 3, 3' is made of composite material. Such a material is lighter than steel and even than any other metal for equivalent strength. Moreover, the manufacturing processes for composite material components allow for the creation of structures with a wide variety of geometric shapes. More complex structural shapes than those obtained with metal can thus be considered in order to utilize all available volume of the vehicle and thereby increase the tank's capacity. More complex tank shapes may be particularly advisable when the tanks are intended to store a pressurized gas rather than a liquid because, unlike a liquid, gas does not present a risk of retention within the tank.

[0046] The composite material may comprise a draped or preformed structure, and / or braided and resin-impregnated materials. The composite material may be made up of reinforcing elements and a matrix. The reinforcing elements may include carbon or glass fibers, which are lightweight materials, or Kevlar (registered trademark), which offers greater impact resistance. The matrix may be an organic matrix, for example, epoxy resin, phenolic resin or a modified polyester. The matrix can also be a metallic matrix.

[0047] Figures 3 and 4 illustrate in perspective view the structure of the tank 3 according to the first embodiment. The walls 7A and 7B are connected to each other by a first set of connecting elements 51 extending parallel to the X axis. Similarly, the walls 8A and 8B are connected to each other by a second set of connecting elements 52 extending parallel to the Y axis and the walls 9A and 9B are connected to each other by a third set of connecting elements 53 extending parallel to the Z axis.

[0048] According to one embodiment, the tank 3 could comprise only one set of connecting elements or only two sets of connecting elements from among the three sets of connecting elements 51, 52, 53. Alternatively, all or part of the sets of connecting elements 51, 52, 53 could extend in directions other than the X, Y, and Z axes, provided that the axis along which each set of connecting elements extends forms a non-zero angle with the axis along which the other sets of connecting elements extend. Advantageously, the three axes along which the three sets of connecting elements 51, 52, and 53 extend are perpendicular to each other so as to optimally stiffen the tank.

[0049] The connecting elements 51, 52, 53 pass completely through the tank 3 between two opposing walls. The connecting elements act as tie rods, reinforcing the strength of the tank: they are subjected to tensile stress when the energy fluid contained in the tank exerts pressure on the walls 7A, 7B, 8A, 8B, 9A, 9B. The connecting elements 51, 52, 53 are arranged inside the shell of the tank 3 and not on its periphery.

[0050] Preferably, each connecting element 51, 52, 53 is separate from the other connecting elements; that is, the connecting elements 51, 52, 53 are not in contact with each other and do not touch inside the tank. Thus, the tank 3 is not compartmentalized and the energy fluid can circulate easily within the tank 3.

[0051] The connecting elements 51, 52, 53 are hollow. In particular, the connecting elements, which could also be called "reinforcing wells," can be tubes when they have a circular cross-section. However, the cross-section of the connecting elements is not necessarily circular. For example, the cross-section of the connecting elements could also be square, rectangular, polygonal, or ovoid.

[0052] Figure 5 illustrates in more detail a connecting element 51, the other elements of The connecting elements are designed in a similar manner. Each connecting element 51, 52, 53 comprises a tubular shape having an external face 54 and an internal face 55. The external face 54 is turned towards the interior of the tank and is therefore intended to be in contact with the energy fluid, while the inner face 55 communicates with the outside of the tank and is therefore intended to be in contact with the ambient air.

[0053] The connecting elements 51, 52, 53 may be made of composite material or metal. They may also comprise both composite material and metal. In particular, they may comprise a metal tube arranged inside a composite material structure.

[0054] The inner face 55 may be made of a different material than that forming the structure of the tank. The inner face 55 may, in particular, be equipped with a metal tube extending along the entire length of the connecting element 51, 52, 53 or only at the ends of the connecting elements 51, 52, 53. The metal tube may optionally be corrugated around its outer circumference to ensure secure retention within the structure.

[0055] Each connecting element 51, 52, 53 comprises two opposing ends at the two opposite walls it connects. Due to the hollow nature of the connecting elements 51, 52, 53, the reservoir 3 includes, for each connecting element, an opening 56 passing through the reservoir completely. These openings 56 do not communicate with the energy fluid storage volume. Therefore, these openings 56 are not useful for delivering an energy fluid, in particular for delivering pressurized hydrogen to the fuel cell 5.

[0056] Conversely, the openings 56 can be used for the passage of electrical wires and / or hydraulic lines. This saves the space outside the tank intended for these electrical wires and / or hydraulic lines while also providing a means of securing them in place. The openings 56 can also be used to allow the drainage of a liquid from the vehicle, or even to provide ventilation for cooling or heating the passenger compartment. The openings 56 can also be used to attach various vehicle components.

[0057] To this end, the reservoir 3 may include a set of fastening interfaces 57, each arranged at one end of at least one connecting element 51, 52, 53, in particular arranged in one end of an opening 56. As illustrated in [Fig. 5], all or part of the fastening interfaces 57 may include an insert for cooperating with a fastening screw 58, for example, an M8 or M10 type fastening screw. The insert may be formed in the metal tube fitting the inner face 55 of the connecting elements or be an additional element fitted against the inner face 55 of the connecting elements, for example, a plastic dowel. The insert may, for example, have a length between 20 mm and 60 mm inclusive. The insert may be threaded or unthreaded. The insert thus provides a fastening means extending deep into the volume of the tank. Such a fastening method is particularly robust and allows for the securing of heavy loads.

[0058] Each mounting interface 57 allows vehicle equipment to be attached to a wall of the tank 3. A mounting interface 57 can be arranged at the end of the opening 56 located on the side of the wall against which the equipment is attached. Alternatively, a mounting interface 57 could also be arranged at the end of the opening 56 located on the opposite side of the wall against which the equipment is attached. In this case, a shaft or cable connecting the mounting interface 57 to the equipment could extend inside the opening 56 along its length. Such an arrangement would, for example, allow mounting interfaces to be provided at the lower wall 9B for attaching equipment to the upper wall 9A, thus facilitating vehicle assembly or maintenance operations.

[0059] Advantageously, such fastening interfaces 57 can be provided at the ends of each opening 56 of the tank 3. Each connecting element 51, 52, 53 can thus support two fastening interfaces 57 arranged on two opposite faces of the tank. The tank can therefore be provided with a multitude of fastening interfaces 57 allowing various equipment to be fixed in a wide variety of positions.

[0060] The same equipment can even be attached to the tank 3 using two or more mounting interfaces, so as to ensure a secure attachment. The same equipment can also easily be attached in different positions on the tank without requiring modification.

[0061] The same tank 3 can also be easily reused for different vehicle models because the multitude of mounting interfaces provides many possibilities for attaching equipment.

[0062] Openings 56 that are not intended for attaching vehicle equipment may be plugged with a sealing means to prevent the accumulation of mud, sand, soil, pebbles, or any other particles. In particular, unused openings 56 may be plugged with individual caps or with a film surrounding the entire tank or any other protective device. Unused openings 56 may eventually be used during the vehicle's service life, for example, to attach new equipment or an accessory.

[0063] Advantageously, the connecting elements 51, 52, 53 are distributed at regular intervals, for example, between 5 cm and 30 cm inclusive, particularly between 10 cm and 20 cm inclusive. Consequently, the mounting interfaces 57 are distributed on the walls of the tank at regular intervals. The mounting interfaces 57 are thus arranged in a grid pattern on the surface of the tank 3. This further facilitates the reuse of the same tank and the same equipment for different vehicle models, as the same equipment can be mounted in several locations on the tank. without requiring any adapter parts. The tank thus forms a modular structure onto which numerous components can be attached. The invention therefore allows for greater design freedom in motor vehicles while achieving economies of scale.

[0064] According to the second embodiment, the tank 3' is devoid of connecting elements as described above. The strength of the tank 3' can then be provided by the thickness of its walls, and possibly by the addition of other reinforcing inserts.

[0065] Generally speaking, and as can be seen in Figures 7 and 8, the reservoir 3, 3' is positioned in the longitudinal extension of the electrochemical battery 4, at the rear of the electrochemical battery 4. The front wall 7A of the reservoir faces a rear wall of the electrochemical battery 4, or is even in direct contact with a rear wall of the electrochemical battery 4. The energy storage device 2 is thus particularly compact.

[0066] The electrochemical battery 4 can be configured to deliver a direct current with a voltage of approximately 400V, or possibly 800V. The electrochemical battery 4 can be recharged by an electric current from the fuel cell 5 and / or by connection to an electricity distribution network. The electric motor 6 can thus be powered by an electric current from the electrochemical battery 4. The tank 3, 3' associated with the fuel cell 5 can therefore act as a range extender for the vehicle when the electrochemical battery 4 is discharged.

[0067] The electrochemical battery 4 comprises a set of electrochemical cells 21, for example, of the lithium-ion type. The electrochemical cells 21 are electrically connected to each other, for example, in series and / or in parallel. The electrochemical cells 21 can be grouped into electrochemical modules. Each electrochemical module thus comprises several electrochemical cells 21. The electrochemical battery 4 can comprise, for example, between two and twenty electrochemical modules. The electrochemical modules are preferably distributed on the same level. The electrochemical battery 4 thus has a relatively low height along the Z-axis, which allows the electrochemical battery 4 to be integrated into the vehicle's underbody. The electrochemical modules can be separated from each other by partitions 22. The electrochemical battery 4 also includes a cooling device.The cooling device may include a cooling plate, which extends under the electrochemical modules to cool them. Finally, the electrochemical battery 4 may also include an electronic controller and electrical conductors, notably to connect the electrochemical battery 4 to the electric motor 6.

[0068] The electrochemical battery 4 also includes a housing 23 that supports and holds the electrochemical cells 21. The housing 23 is attached to the vehicle chassis 31. The chassis 31 is part of the vehicle body, that is, a rigid structure, preferably made of steel, that supports all the vehicle's components, including the fuel cell 5, the electric motor 6, as well as a passenger compartment, bodywork, or running gear. In particular, the chassis includes two longitudinal members 32 extending parallel to the longitudinal axis X on the right and left sides of the vehicle. The housing 23 is attached to the two longitudinal members 32.

[0069] More specifically, the housing 23 comprises a frame 24 extending laterally around the electrochemical cells 21. The frame 24 thus forms a belt that surrounds the electrochemical cells 21 at the front, at the rear, and along their right and left sides. The separating partitions 22 extend between the right and left sides of the frame 24.

[0070] The casing 23 is fixed to the chassis 31 via the frame 24. For example, fixing screws can pass through holes provided in the longitudinal members 32 and in the frame 24 or through fixing tabs fixed to the frame 24.

[0071] The housing 23 also includes a lower plate 25 attached to the frame 24. The lower plate 25 supports all the electrochemical cells 21. The lower plate 25 extends substantially horizontally beneath the electrochemical cells 21 and is preferably made of metal, for example, aluminum. The cooling plate described above preferably extends between the lower plate 25 and the electrochemical cells 21. The lower plate 25 protects the electrochemical cells from impacts and / or upward projections. It also protects the electrical conductors of the electrochemical battery from any unwanted contact.

[0072] The housing 23 also includes a top plate 26 attached to the frame 24. The top plate 26 extends substantially horizontally above the electrochemical cells 21 and is preferably made of metal, for example, aluminum. The top plate 26 protects the electrochemical cells 21 from downward-directed projections, in particular from runoff water, and also protects the electrical conductors of the electrochemical battery from any unwanted contact.

[0073] Advantageously, the frame 24 is formed by a series of profiled elements 27 fixed one after the other. Each profiled element 27 is straight and extends horizontally. Each profiled element 27 has a constant cross-section along the direction in which it extends. This cross-section preferably has a rectangular shape with a shorter horizontal side and a longer vertical side. The profiled elements are preferably made of aluminum, which offers a very good compromise between lightness and rigidity. The various profiled elements 27 are preferably welded together. one after the other. Thus, the junction between the profiled elements 27 is watertight. The frame 24 roughly comprises a rectangular shape. We can thus distinguish a front profiled element 27f, a rear profiled element 27r, a right profiled element 27d, and a left profiled element 27g.

[0074] The lower plate 25 is fixed, for example screwed, against an underside of the profiled elements 27. Similarly, the upper plate 26 is fixed, for example screwed, against an upper side of the profiled elements 27. The lower plate 25, the upper plate 26, and the profiled elements 27 thus form a sealed enclosure around the electrochemical cells 21.

[0075] The housing 23 extends along the transverse axis Y across the width of the vehicle 1 and is therefore exposed to potential side impacts against the vehicle. The housing 23 may include shock absorbers capable of absorbing the energy of an impact in the event of a collision of the vehicle with an obstacle. The shock absorbers may, in particular, be positioned along the left and right sides of the housing 23. The shock absorbers may extend parallel to the longitudinal axis X. The shock absorbers may be attached, in particular by screwing or welding, to the profiled elements 27g and 27d.

[0076] According to the invention, the reservoir 3, 3' is attached to the casing 23 of the electrochemical battery 4. The reservoir 3, 3' is not attached via a structural element such as a component of the vehicle chassis. Rather, the reservoir 3, 3' is attached directly or indirectly to the casing 23 via a fastening means such as a mounting bracket. The rigidity of the battery casing is thus used to provide at least one support point for the reservoir. Conversely, the rigidity of the reservoir is used to provide at least one support point for the electrochemical battery. This results in a particularly compact energy storage device compared to an arrangement where the electrochemical battery and the reservoir are attached independently to the vehicle chassis. The structure of the reservoir and the casing 23 of the electrochemical battery reinforce each other.

[0077] In particular, the tank 3, 3' is fixed to the frame 24 which forms a particularly strong crankcase structure. More specifically, the tank 3, 3' is fixed to the rear profiled element 27r.

[0078] According to one embodiment, the energy storage device 2 comprises at least one first mounting lug 41a, 41b, 41c fixed, in particular screwed, on one side to the reservoir 3, 3', and fixed, in particular screwed, on the other side to the casing 23 of the electrochemical battery 4. The number of first mounting lugs may be arbitrary. According to the embodiment presented, the energy storage device comprises three first mounting lugs 41a, 41b, 41c.

[0079] The first mounting tabs 41a, 41b, 41c are preferably made of metal, for example steel or aluminum. The first mounting tabs 41a, 41b, 41c They can be manufactured from a sheet of metal folded and cut to a given shape. The first mounting lugs 41a, 41b, 41c may include first mounting holes cooperating with first mounting screws and with the battery housing 23, in particular with the rear profiled element 27r. The first mounting lugs 41a, 41b, 41c may also include second mounting holes cooperating with second mounting screws penetrating the tank structure 3' 3'. Advantageously, the second mounting screws cooperate with mounting interfaces 57 as described previously. The second mounting screws may, in particular, cooperate with threaded inserts integrated into the tank structure.

[0080] With reference to Figures 2, 6 and 8, the first mounting bracket 41a is L-shaped. It includes a horizontal portion fixed to an upper face (or alternatively to a lower face) of the rear profiled element 27r. The first mounting bracket 41a includes a vertical portion fixed to the front wall 7A of the tank.

[0081] With reference to Figures 2, 6, and 7, the first mounting bracket 41b also has an L-shape. It includes a transverse portion fixed to a rear face of the rear profiled element 27r. The first mounting bracket 41b includes a longitudinal portion fixed to the side wall 8A of the tank. The first mounting bracket 41c can be designed symmetrically to the first mounting bracket 41b. The first mounting bracket 41c includes a longitudinal portion fixed to the side wall 8B of the tank.

[0082] Furthermore, the energy storage device 2 also includes at least one second mounting bracket 42a, 42b, 42c fixed, in particular screwed, on one side to the reservoir 3, 3', and fixed, in particular screwed, on the other side to the chassis 31. The number of second mounting brackets can be arbitrary. According to the embodiment presented, the energy storage device includes four second mounting brackets 42a, 42b, 42c, of which only three are visible in Figures 2, 6 and 7.

[0083] As with the first mounting brackets 41a, 41b, 41c, the second mounting brackets 42a, 42b, 42c are preferably made of metal, for example, steel or aluminum. The second mounting brackets 42a, 42b, 42c can be made from a sheet of metal folded and cut to a given shape. The second mounting brackets 42a, 42b, 42c may include first mounting holes cooperating with first mounting screws and with the vehicle chassis 31. The second mounting brackets 42a, 42b, 42c may also include second mounting holes cooperating with second mounting screws penetrating the structure of the tank 3' 3'. Advantageously, the second mounting screws cooperate with mounting interfaces 57 as described previously. The Secondary fixing screws can, in particular, cooperate with threaded inserts integrated into the tank structure. Secondary fixing lugs 42a, 42b, 42c can, in particular, be fixed against the rear wall 7B and / or against the side walls 8A, 8B of the tank. Secondary fixing lugs 42a, 42b, 42c can also be L-shaped.

[0084] The number of first mounting lugs 41a, 41b, 41c and second mounting lugs 42a, 42b, 42c can be arbitrary. In one embodiment, the first and second mounting lugs could form a single flange or collar. This flange could at least partially surround the tank. The flange is thus configured to fix the tank 3, 3' to the housing 23 on the one hand and to the chassis on the other.

[0085] According to one embodiment, illustrated in [Fig. 2], at least one first mounting lug 41a, 41b, 41c and at least one second mounting lug 42a, 42b, 42c are attached to the structure of the tank 3. Advantageously, at least one first mounting lug and at least one second mounting lug are then attached to the tank 3 using mounting interfaces 57 as described previously. According to this embodiment, at least one first mounting lug and at least one second mounting lug thus extend completely outside the structure of the tank 3.

[0086] According to a second embodiment, illustrated in [Fig. 6], at least one first mounting lug 41a, 41b, 41c and at least one second mounting lug 42a, 42b, 42c are anchored in the composite material forming the rigid structure of the tank 3'. Each of the at least one first mounting lug and the at least one second mounting lug includes a portion embedded within the tank structure. Thus, the at least one first mounting lug and the at least one second mounting lug are integrated into the tank during the manufacture of the tank's composite structure. As a note, anchoring the at least one first mounting lug and / or the at least one second mounting lug in the rigid structure of the tank would also be possible with the tank 3 according to the first embodiment.

[0087] To design the energy storage device 2 described above, the following design process can be adopted. First, an existing vehicle is identified that includes an electrochemical battery. The electrochemical battery comprises a casing and a set of electrochemical cells supported by said casing. The battery is attached to a vehicle chassis by a set of fastening means. The existing motor vehicle may, for example, be a mass-produced vehicle or one intended for mass production. The casing of the existing energy storage device includes, in particular, a frame, a bottom plate, and a top plate. Next, some of the electrochemical cells are removed from the electrochemical cell assembly, and the battery casing is reduced accordingly. The casing can be truncated so that it only extends around the remaining electrochemical cells. The shapes of the frame, bottom plate, and top plate can be adapted accordingly to form a sealed enclosure around the remaining electrochemical cells. This results in a new electrochemical battery that is smaller than the original electrochemical battery. Reducing the volume of the electrochemical battery frees up space around it. Then, a reservoir for storing an energy fluid is designed with a geometric shape adapted to occupy the space freed up by the reduction in the volume of the electrochemical battery.The reservoir can potentially occupy a larger volume than the volume occupied by the portion of the original electrochemical battery that was removed. Advantageously, the reservoir thus designed is attached on one side to the new electrochemical battery and on the other side to the chassis using the fastening means provided for attaching the original electrochemical battery. The energy storage device 2 can therefore be designed and manufactured without modifying, or with minimal modification to, a chassis initially intended to support only an electrochemical battery 4. This design process can be implemented virtually on a computer, for example, using computer-aided design (CAD) software.

[0088] Finally, thanks to the invention, a vehicle equipped with an energy storage device comprising an electrochemical battery and a reservoir for an energy fluid is provided. The energy storage device is particularly compact, thus preserving a large volume for passengers and / or for transporting objects within the vehicle. The energy storage device is simple to install since it can be installed in place of a pre-existing electrochemical battery. The electrochemical battery and the reservoir can also be easily removed, for example, for maintenance operations.

Claims

Demands

1. Energy storage device (2) for a motor vehicle (1), comprising: - an electrochemical battery (4), the electrochemical battery comprising a set of electrochemical cells (21) and a casing (23) supporting the set of electrochemical cells, and - a tank (3, 3') for storing an energy fluid, the tank being fixed to the casing (23) of the electrochemical battery, the tank (3, 3') comprising a rigid structure made of a composite material, and the tank being fixed to the casing (23) of the electrochemical battery (4) by fixing screws penetrating into the structure of the tank.

2. Energy storage device (2) according to the preceding claim, characterized in that the casing (23) comprises a frame (24) extending laterally around the electrochemical cells, and in that the reservoir (3, 3') is fixed to the frame.

3. Energy storage device (2) according to any one of the preceding claims, characterized in that it comprises at least one first fixing lug (1) fixed, in particular screwed, on the one hand to the reservoir (3, 3'), and fixed, in particular screwed, on the other hand to the casing (23) of the electrochemical battery (4).

4. Energy storage device (2) according to any one of the preceding claims, characterized in that it comprises at least one second fixing lug fixed, in particular screwed, on the one hand to the tank (3, 3'), and intended to be fixed, in particular intended to be screwed, on the other hand to a chassis of the vehicle.

5. Energy storage device (2) according to any one of the preceding claims, characterized in that the reservoir is positioned in a longitudinal extension of the battery, in particular at the rear of the electrochemical battery (4).

6. Energy storage device (2) according to any one of the preceding claims, characterized in that the reservoir (3, 3') comprises a face in direct contact against the casing (23) of the electrochemical battery (4).

7. Energy storage device (2) according to any one of the preceding claims, characterized in that the reservoir (3, 3') comprises at least a first pair of opposing walls (7A, 7B) connected to each other the other by a first set of connecting elements (51), passing through the tank and extending parallel to a first axis (X), the tank comprising at least one fixing interface (57) arranged at one end of at least one connecting element (51, 52, 53), the tank being fixed to the casing (23) of the electrochemical battery (4) by means of at least one fixing interface.

8. Vehicle (1), in particular motor vehicle, characterized in that it comprises a chassis (31) and an energy storage device (2) according to any one of the preceding claims, the casing (23) of the electrochemical battery (4) and the tank (3, 3') being fixed to the chassis.

9. A method for designing an energy storage device (2) according to any one of claims 1 to 7, comprising: - identifying an existing vehicle comprising an electrochemical battery (4) provided with a casing and a set of electrochemical cells supported by said casing, the casing being fixed to a chassis of the vehicle by a set of fastening means, then - removing a portion of the electrochemical cells of the electrochemical battery and reducing the volume of the casing of the electrochemical battery, then - designing a tank for storing an energy fluid, the tank comprising a geometric shape adapted so that the tank occupies the space freed up by the reduction in the volume of the casing, and so that the tank is fixed to the chassis of the vehicle by a portion of said fastening means.

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