Vehicle-mounted battery pack and related road vehicle

Abstract

An in-vehicle battery pack (9) comprising: a plurality of battery modules (11) arranged adjacent to each other to form a battery pack (9) extending mainly along a longitudinal axis; a cooling system (16) comprising at least one inlet duct (17) for supplying a refrigerating fluid (F) and an outlet duct (18) for the refrigerating fluid (F); the cooling system (16) comprises a plurality of refrigeration panels (20) fluidly connected to each other and configured to be at least partially flowed through by at least a portion of a refrigeration fluid (F); wherein each battery module (11) comprises a corresponding refrigeration panel (20); wherein each battery module (11) comprises at least one hydraulic connection element (21) mounted on a respective panel and fluidly connecting a respective refrigeration panel (20) and at least one refrigeration panel (20) of an adjacent battery module (11).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the priority of Italian Patent Application No. 102023000024633 filed on November 21, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present invention relates to the field of energy storage systems for the automotive industry, in particular to an on-board battery pack with a modular cooling system and a road vehicle comprising the battery pack. Background Art

[0003] The vehicle can be equipped with a single electric motor or with multiple electric motors (in which case the drive is all-electric), or the vehicle can be equipped with one or more electric motors combined with a thermal engine (in which case the drive can be all-electric, all-thermal or hybrid).

[0004] The electric motor (or each electric motor) is mechanically connected to the drive wheels and electrically connected to an electrical energy storage system (also called a battery pack) through the interposition of an electronic power converter.

[0005] Electrical energy storage systems typically consist of two groups of electrochemical cells (also called modules) connected in series (to increase the total voltage) or in parallel.

[0006] Known electrical energy storage systems are usually large in size and heavy (particularly in the case of a fully electric drive, where the electrical energy storage system may weigh more than 500 kg).

[0007] In fact, in modern vehicles, the energy storage system has a flat and (relatively) thin structure so that it can be integrated in the floor of a road vehicle. In this arrangement, the energy storage system, once assembled, consists of a container having a lower wall (which constitutes the bottom of the vehicle facing the road), an upper wall and side walls perpendicular to and connecting the lower and upper walls to each other. Inside the container there are different modules, which are usually prismatic or "pouch" cells.

[0008] Battery modules commonly available on the market (not only in the automotive industry, but also in consumer electronics) usually consist of flat pouch cells whose thickness is more limited than other dimensions. They have two very large opposite faces (through which the heat is almost entirely dissipated) and four narrow rectangular sides, with the positive and negative terminals of the cells arranged on one side or on two opposite sides.

[0009] Specifically, the known electric vehicle energy storage system includes a battery pack, which is composed of a plurality of battery modules electrically connected to each other. Each battery module includes a large support structure (usually composed of six metal side walls closed to form a parallelepiped), which defines a plurality of electrochemical cells electrically connected to each other in series and / or parallel.

[0010] In general, in order to avoid the inconvenient phenomenon commonly known as "gassing", i.e. the formation of gas inside the individual cells, for example due to oxidation of the electrolyte or its chemical decomposition (which is often increased by phenomena such as overheating or overloading of the battery), the batteries are kept in a constant state of compression. According to the prior art, this compression is provided by the support structure (i.e. the side walls) of each battery module, which is configured to compress the battery perpendicularly to two large opposite faces. This compression is achieved, for example, by reinforcing the support structure and ensuring that at least two metal walls act as tie rods during the compression process. Therefore, each battery module is usually pre-assembled and then installed in the above-mentioned container.

[0011] Furthermore, lithium-ion batteries, commonly used in the automotive industry, are known to be very sensitive to temperature. The energy generated in the electrochemical process inevitably leads to an increase in the battery temperature, and it is also known that excessive temperatures can adversely affect the behavior and degradation of the battery to a great extent. In fact, when electrochemical cells overheat, they rapidly degrade, which can adversely affect the performance and safety of the battery pack. In these cases, in addition to malfunctions and breakages, there is also the risk of uncontrolled thermal events (thermal runaway).

[0012] Therefore, for optimal battery operation, it is very important to ensure adequate heat dissipation within the battery pack.

[0013] This dissipation is usually carried out by contacting the modules with a refrigeration panel. In other words, a refrigeration panel is mounted inside the container through which the refrigeration fluid flows and on which the modules, which are electrically connected to each other, are mounted. In this way, the refrigeration panel, which is in contact with one of the side walls of each module, dissipates the heat generated by the electrochemical cells and transferred to the side wall placed between them and the refrigeration panel.

[0014] Especially in high-performance vehicles such as sports cars, this involves considerable mass in relation to the limited space available for the storage system, i.e. the battery pack. Furthermore, the pre-assembly time of each battery module must be added to the normal installation of the battery module on the refrigeration panel.

[0015] However, the systems discussed above do not provide a complete solution to the heat dissipation problem.

[0016] Liquid cooling is usually the most effective solution to ensure stable thermal regulation of the battery, but - as mentioned earlier - it is a relatively complex, heavy and particularly cumbersome system (parameters that are particularly important for high-performance vehicles).

[0017] Finally, known cooling systems are usually designed in a specific way according to the model and size / capacity variations of the battery pack, with all the disadvantages that come with it in terms of component procurement and their construction and assembly.

[0018] For the reasons stated above, there is a need to improve the cooling of the battery so as to simplify and facilitate the assembly of the battery and reduce its weight. Summary of the invention

[0019] The object of the present invention is to provide an on-board battery pack and an associated road vehicle which at least partially avoid the above-mentioned disadvantages and which are simple and economical to manufacture.

[0020] According to the present invention, a vehicle-mounted battery pack and a related road vehicle are provided.

[0021] This disclosure describes preferred embodiments of the present invention and constitutes an integral part of this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention will now be described with reference to the accompanying drawings, which show some non-limiting embodiments of the invention, in which:

[0023] Figure 1 is a schematic plan view of an electric vehicle including a battery pack according to the present invention;

[0024] Figure 2 yes Figure 1 A schematic perspective view of a battery pack;

[0025] Figure 3 yes Figure 2 A schematic partially exploded perspective view of a battery pack in FIG. 1 , showing the positions of different modules of the battery pack before assembly;

[0026] Figure 4 and Figure 5 are respectively a schematic left perspective view and a right perspective view of the battery pack module in the aforementioned figure;

[0027] Figure 6 yes Figure 4 and Figure 5 A schematic partially exploded perspective view of a battery pack module;

[0028] Figure 7 yes Figure 3 a side view of

[0029] Figure 8 for Figure 2 Side view of. DETAILED DESCRIPTION

[0030] exist Figure 1 1 , numeral 1 denotes a road vehicle as a whole, which is provided with two front wheels 2 and two rear wheels 3 , at least one pair (or all) of the wheels receiving torque from a drivetrain 4 .

[0031] The road vehicle 1 is an at least partially electric vehicle (ie a hybrid vehicle or a fully electric vehicle). In other words, the drivetrain 4 may be a hybrid system (ie comprising an internal combustion heat engine and at least one electric motor) or an electric system (ie comprising only one or more electric motors).

[0032] In the drawings, the same numerals and the same reference letters denote the same elements or components having the same function.

[0033] For the purpose of the present invention, the term "second" component does not imply the existence of a "first" component. In fact, these terms are used only as labels to improve clarity and should not be interpreted in a limiting manner.

[0034] The elements and features included in the different preferred embodiments (including the drawings) described below may be combined with each other without thereby exceeding the protection scope of the present patent application.

[0035] The road vehicle 1 further comprises a body 5 defining a passenger compartment 6 configured to accommodate at least a driver and, if required, one or more passengers. The passenger compartment 6 defines at least one cockpit 7 for the driver.

[0036] Hereinafter, expressions such as “at the top”, “at the bottom”, “at the front”, “at the back” and the like are used with reference to the normal driving condition of the vehicle 1 along the normal driving direction D.

[0037] like Figure 1 As shown in the non-limiting example, it can be further defined:

[0038] - a longitudinal axis X integral with the vehicle 1 , which, in use, is horizontal and parallel to the normal direction of travel D of the vehicle 1 ;

[0039] - a transverse axis Y integral with the vehicle 1 , which, in use, is horizontal and orthogonal to the axis X; and

[0040] - A vertical axis Z integral with the vehicle 1 , which is vertical and orthogonal to the axes X, Y when in use.

[0041] The road vehicle 1 comprises a frame 8 which supports a vehicle body 5 .

[0042] Furthermore, the road vehicle 1 comprises an onboard battery pack 9 which is mounted on the vehicle frame 8 below the passenger compartment 6 , in particular in the region of a floor 10 of the road vehicle 1 , ie the vehicle bottom which delimits the road vehicle 1 at the lower side.

[0043] The battery pack 9 comprises a plurality of battery modules 11, each of which comprises a support structure 12 (preferably in a box shape, as shown in the figure) and a group of electrochemical cells 13, such as Figure 6 As shown (of a known type, such as a pouch cell, which will not be described in detail). The electrochemical cell 13 is at least partially, in particular completely, bounded by the support structure 12. In other words, the support structure 12 accommodates the electrochemical cell 13.

[0044] Preferably (but not in a limiting manner), the box-like support structure 12 comprises a pair of opposing main walls 14, and two pairs of secondary walls 15 extend (particularly extend vertically) between the opposing main walls 14. In particular, the main walls 14 have a larger surface than the secondary walls.

[0045] Specifically, especially in the case of a soft-pack battery 13, one pair of secondary walls 15 also responds to the radial compression of the planar soft-pack battery 13 (this is a known practice and will not be described in detail below).

[0046] The battery modules 11 are preferably all identical and are arranged adjacent to one another to form a battery pack 9 which extends mainly along a longitudinal axis X.

[0047] Advantageously, the battery pack comprises a cooling system 16 comprising at least one inlet duct 17 for supplying a cooling fluid F and an outlet duct 18 for the cooling fluid F. By way of example, Figure 2 Some preferred but non-limiting paths of the refrigeration fluid F are shown in FIG.

[0048] In particular, the vehicle 1 also comprises a circulation system 19 for the refrigeration fluid F, which is configured to introduce said saturated fluid F into said at least one inlet pipe 17 and, when exhausted, to withdraw it from the outlet pipe 18 of the refrigeration fluid F. This circulation system is of a known type and will therefore not be described in detail below.

[0049] Specifically, the circulation system comprises two inlet ducts 17 and two outlet ducts 18, respectively arranged along the longitudinal axis on the same side of the battery pack 9. On the other hand, on the opposite side, the battery pack comprises only the inlet duct 17 and the outlet duct 18.

[0050] Advantageously, as shown in the embodiment of the figures, the cooling system 16 comprises a plurality of refrigeration panels 20 which are fluidically connected to one another and are configured to be at least partially traversed by at least a portion of the refrigeration fluid F.

[0051] In particular, each battery module 11 includes a corresponding cooling panel 20. This feature simplifies assembly by pre-assembling each individual module, thereby eliminating the need to share panels between multiple battery modules. In fact, in this case, multiple modules will be installed on the same panel, thereby reducing the scalability of the battery pack 9.

[0052] Furthermore, each battery module 11 includes at least one hydraulic connection element 21 , which is mounted on the corresponding panel 20 and fluidically connects the corresponding cooling panel 20 with at least one cooling panel 20 of an adjacent battery module 11 .

[0053] Specifically, Figures 4 to 6 As shown, each battery module 11 includes at least two hydraulic connection elements 21 between a respective refrigeration panel 20 and refrigeration panels of one or more adjacent battery modules 11 .

[0054] according to Figure 3-7 In the embodiment shown, in order to allow for a series arrangement, each battery module includes two hydraulic connection elements 21. The cooling fluid F flows into the panel 20 from one connection element and flows out of the panel from the other connection element (e.g. Figure 4 and 5 In other words, the first hydraulic connection element 21 is configured to introduce at least part of the refrigerant fluid F into the corresponding panel 20, while the second hydraulic connection element 21 is configured to extract at least part of the refrigerant fluid F from the corresponding panel 20.

[0055] Preferably (but not in a limiting manner), the first and second connection elements 21 are arranged parallel to each other and protrude from the same side of the refrigeration panel 20 .

[0056] Advantageously (but not in a limiting manner), each refrigeration panel 20 includes a pair of first openings 22, which connect the interior of the refrigeration panel 20 to the first and second connecting elements 21 of the battery module 11, respectively; and a pair of second openings 23, which connect the interior of the refrigeration panel 20 to the first and second connecting elements 21 of the adjacent battery module 11, respectively.

[0057] Specifically, the first opening 22 and the second opening 23 are both located on the same upper surface 24 of the cooling panel 20 , ie, the surface away from the battery 13 , so in the embodiment of the drawings, this surface faces the passenger compartment 6 .

[0058] Advantageously, but not in a limiting manner, the combination of the refrigeration panel 20 and the hydraulic connection element 21 defines a delivery line 25 and a return line 26 for the refrigeration fluid F. In particular, but not in a limiting manner, the return line 26 is surrounded by the delivery line 25 .

[0059] according to Figure 1 , Figure 2 and Figure 8 In the illustrated embodiment, a group of refrigeration panels 20 are arranged on the same first plane P. In other words, the refrigeration panels 20 are coplanar with each other.

[0060] Specifically, advantageously (but not in a restrictive manner), the hydraulic connection element 21 is arranged between adjacent refrigeration panels 20 on a second plane P' different from the first plane P (specifically, parallel to the first plane P, and preferably higher than the first plane P), that is, relative to the first plane P (that is, the plane where the refrigeration panel 20 is located), on the side opposite to the battery module 11.

[0061] Alternatively, the battery pack 9 may also be placed upside down by placing the cooling panel 20 and the connecting elements 21 at the bottom of the battery module 11 (towards the ground where the road vehicle 1 may rest).

[0062] Thus, generally speaking, the cooling panels 20 (together with the connecting elements 21, if necessary) define the outer wall of the battery pack 9, since they are arranged at the upper or lower end relative to a set of battery modules 11. In other words, the first plane P, i.e. a set of cooling panels 20, is not interposed between the battery modules 11.

[0063] Preferably, the hydraulic connection elements 21 form raised fluid bridges between adjacent refrigeration panels 20 .

[0064] Specifically, the hydraulic connection elements 21 are all arranged on the same side of the first plane P, ie they are always arranged on the outside. In this way, the space below or above the refrigeration panel 20 can be utilized to the maximum extent without having to obtain a channel for accommodating the connection elements 21 .

[0065] In the non-limiting embodiment of the figures, the battery modules 11 and thus the refrigeration panels 20 are mainly arranged along two parallel rows L. In other non-limiting embodiments not shown herein, the battery modules 11 and thus the refrigeration panels 20 are arranged along a single row or more than two rows.

[0066] In particular, advantageously (but not in a limiting manner), the hydraulic connection elements 21 are placed between adjacent refrigeration panels 20 in a direction parallel to the longitudinal axis X of the road vehicle, more particularly, all the hydraulic connection elements are parallel to each other.

[0067] like Figure 6As shown in the non-limiting embodiment of , each refrigeration panel 20 itself defines a wall of the support structure 12, in particular a main wall 14 of the support structure (i.e. with a greater extension), more specifically (not in a limiting way), a wall 14 arranged in the area of ​​the upper (or any external) face 24. Thus, in particular, the refrigeration panel 20 defines an upper closed portion of the box-like support structure 12, making it possible to dispense with one wall of the support structure 12, which, according to the prior art, has six different faces, one of which rests against the cooling system. In this way, the weight of the battery pack 9 can be reduced and its overall dimensions reduced. Thus, in particular, the refrigeration panel 20 defines one of the six walls of the box-like support structure. In this way, the size and weight of each module are limited, so that the active parts (electrodes, electrolyte, current collectors, etc.) are maximized.

[0068] Preferably (but not in a limiting manner), in each module 11, the refrigeration panel 20 is arranged transversely relative to the plurality of electrochemical cells 13. Specifically, the refrigeration panel 20 is arranged along a horizontal plane XY, while the electrochemical cells 13 may be arranged along a vertical plane, for example relative to the aforementioned axis YZ or XZ.

[0069] Preferably, but not in a limiting manner, the battery pack 9 comprises at least two extreme battery modules 27, which are arranged at the ends 28 of the battery pack along the longitudinal axis X of the battery pack 9. In particular, the extreme modules 27 are fluidically connected to the inlet duct 17 for supplying the cooling fluid F and to the outlet duct 18 for the cooling fluid F.

[0070] Preferably (but not in a limiting manner), in order to simplify assembly by reducing the number of components while ensuring the strength of the battery pack 9 , the cooling panel 20 is made of metal, particularly aluminum.

[0071] according to Figure 6 In a preferred but non-limiting embodiment, each refrigeration panel 20 comprises an inner element 29 and an outer element 30, which are coupled to each other and have a substantially planar shape. The inner element 29 and the outer element 30 are configured to form a chamber / box between them, in which the refrigeration fluid F flows. Specifically, the chamber / box extends in a planar manner between the elements 29, 30 along a first plane P.

[0072] In particular (but not in a limiting manner), the inner element 29 comprises a flow guide element 31 for guiding the refrigerant fluid F into and out of the openings 22 and 23. More specifically, the flow guide element 31 is V-shaped so as to have one of the openings 22 or 23 in a recess. Preferably, the flow guide element 31 is a raised portion extending from the bottom of the chamber / box (preferably housed by the inner element 29).

[0073] Preferably (but not in a limiting manner), in order to simplify assembly by reducing the number of components while ensuring the strength of the battery pack 9 , the hydraulic connection element 21 is made of metal, in particular aluminum.

[0074] In some preferred non-limiting cases, the hydraulic connection element 21 is configured to inject and extract the refrigeration fluid F inside the corresponding refrigeration panel 20 along a direction transverse to the longitudinal axis X of the battery pack 9, in particular a vertical direction (ie, along the Z axis).

[0075] Preferably, but not in a limiting manner, a set of cooling panels 20 constitutes a planar cooling body 32 configured to be arranged towards the vehicle passenger compartment 6 relative to the rest of the battery pack 9. In this way, in addition to making it possible to simplify the assembly operations by placing the modules 11 sequentially on the floor 10 of the road vehicle 1, it is also possible to exploit the properties of the air: by cooling in contact with the planar body 32, the air tends to descend, making the cooling of the electrochemical cells 13 inside the battery pack 9 more efficient.

[0076] Thus, as described above, the modules 11 are configured to be connected in a series arrangement to form the cooling system 16 .

[0077] Specifically, the battery pack 9 is suitable for connection to the powertrain 4 of the at least partially electric vehicle 1 and is designed to store electrical energy generated by an electric motor (not shown here). The battery pack 9 is connected to the electric motor through a built-in power converter (commonly referred to as an inverter), which converts the direct current generated by the battery pack 9 into alternating current for supplying the electric motor, and vice versa, according to the different needs of the electric motor and the battery pack 9.

[0078] The battery pack 9 comprises at least one section for accommodating a battery management system (BMS) which is designed to control the operating parameters of the electrochemical cells 13 , measuring a number of parameters such as current intensity, voltage and temperature.

[0079] Although the above invention specifically relates to some precise embodiments, it should not be considered as being limited to these embodiments, because its scope of protection also includes all variations, changes or simplifications covered by the technical solution of the present disclosure, such as different shapes, different positions, different material types, etc. of the battery pack.

[0080] The present invention has many advantages.

[0081] First, it removes the walls of the electrochemical cell's metal container (ie, support structure) which would result in an undesirable increase in weight and size.

[0082] Furthermore, due to the improved space utilization, a larger sized battery can be inserted within the same volume.

[0083] Another advantage of the present invention is that the assembly of the battery pack can be simplified by eliminating all plastic and rubber components that are typically part of the cooling system and its connection to the modules.

[0084] Furthermore, as the model of the road vehicle changes (for example as the floorpan size changes), the number of intermediate modules can also be varied as required by varying the capacity and size of the battery pack.

[0085] Furthermore, by integrating the cooling system into a single module, it can be more easily positioned on the upper portion of the battery pack.

[0086] Finally, the invention enables standardization of the hydraulic components, which is already the case with the electrical components, thereby enabling the battery modules to be connected to one another in a simple and repetitive operation.

[0087] List of reference numerals:

[0088] 1 Vehicle

[0089] 2 Front wheels

[0090] 3 Rear wheels

[0091] 4 Powertrain

[0092] 5 Body

[0093] 6 Passenger compartment

[0094] 7 Cockpit

[0095] 8 Frame

[0096] 9 Battery Pack

[0097] 10. Bottom Plate

[0098] 11 Modules

[0099] 12 Support structure

[0100] 13. Cell

[0101] 14 Main wall

[0102] 15th wall

[0103] 16 Cooling System

[0104] 17 Inlet pipe

[0105] 18 Export pipeline

[0106] 19 Circulatory system

[0107] 20 Refrigeration Panel

[0108] 21 Hydraulic connection elements

[0109] 22 First Opening

[0110] 23 Second Opening

[0111] 24 upper surface

[0112] 25 Transmission Lines

[0113] 26 Return Line

[0114] 27 Extreme Battery Module

[0115] 28 end

[0116] 29 Internal components

[0117] 30 External components

[0118] 31. Flow guide element

[0119] 32 Plane cooling body

[0120] D Driving direction

[0121] F Refrigeration fluid

[0122] L Parallel rows

[0123] P First plane

[0124] P' Second plane

[0125] X longitudinal axis

[0126] Y Horizontal axis

[0127] Z vertical axis

Claims

1. A vehicle-mounted battery pack (9), comprising: - a plurality of battery modules (11), each of the plurality of battery modules (11) comprising a support structure (12) and a group of electrochemical cells (13), the electrochemical battery group being at least partially, in particular completely, delimited by the support structure (12); the battery modules (11) being arranged adjacent to one another to form the battery group (9), the battery group extending mainly along a longitudinal axis (X); - a cooling system (16) comprising at least one inlet duct (17) for a refrigerating fluid (F) and an outlet duct (18) for said refrigerating fluid (F); The cooling system (16) comprises a plurality of fluidly connected refrigeration panels (20) configured to be at least partially traversed by at least a portion of the refrigeration fluid (F); Wherein, each battery module (11) comprises a corresponding cooling panel (20); Each battery module (11) comprises at least one hydraulic connection element (21), which is mounted on a corresponding panel and fluidically connects the corresponding refrigeration panel (20) and at least one refrigeration panel (20) of an adjacent battery module (11).

2. The battery pack (9) according to claim 1, wherein each battery module (11) comprises at least two hydraulic connection elements (21) between the corresponding refrigeration panel (20) and the refrigeration panels of one or more adjacent battery modules (11), wherein the first hydraulic connection element (21) is configured to introduce at least part of the refrigeration fluid (F) into the corresponding panel (20), and the second hydraulic connection element (21) is configured to extract at least part of the refrigeration fluid (F) from the corresponding panel (20).

3. The battery pack (9) according to any one of the preceding claims, wherein the combination of the refrigeration panel (20) and the hydraulic connection element (21) defines a delivery line (25) and a return line (26) of the refrigeration fluid (F).

4. The battery pack (9) according to any one of the preceding claims, wherein the assemblies of the refrigeration panels (20) are arranged on a same first plane (P).

5. Battery pack (9) according to claim 4, wherein the hydraulic connection element (21) is inserted between adjacent refrigeration panels (20) on a second plane (P') different from the first plane (P), in particular by forming a raised fluid bridge between adjacent refrigeration panels (20).

6. The battery pack (9) according to any of the preceding claims, wherein each respective refrigeration panel (20) itself defines a wall of the support structure (12), in particular a wall of a pair of main walls (14) of the support structure (12).

7. The battery pack (9) according to claim 6, wherein in each module (11), the cooling panel (20) is arranged transversely with respect to the plurality of electrochemical cells (13).

8. The battery pack (9) according to any of the preceding claims, comprising at least two extreme battery modules (27) which are arranged at the ends of the battery pack (9) along the longitudinal axis (X) of the battery pack (9) itself; wherein The extreme cell module (27) is fluidically connected to an inlet pipe (17) of the cooling fluid (F) and an outlet pipe (18) of the cooling fluid (F).

9. A battery pack (9) according to any one of the preceding claims, wherein: The hydraulic connecting element (21) is made of metal, in particular aluminum.

10. The battery pack (9) according to any one of the preceding claims, wherein: The refrigeration panel (20) is made of metal, in particular aluminum.

11. The battery pack (9) according to any one of the preceding claims, wherein: The hydraulic connection element (21) is configured to inject and extract the refrigeration fluid (F) inside the corresponding refrigeration panel (20) along a direction transverse to the longitudinal axis (X) of the battery pack (9), in particular a vertical direction.

12. The battery pack (9) according to any of the preceding claims, wherein a group of the cooling panels (20) constitutes a planar cooling body, which is configured to be arranged towards the vehicle passenger compartment (6) relative to the rest of the battery pack (9).

13. The battery pack (9) according to any one of the preceding claims, wherein the battery modules (11) are configured to be connected in series to form the cooling system (16).

14. A road vehicle (1) comprising: - four wheels, wherein at least two of the four wheels are drive wheels; - a passenger compartment (6) configured to accommodate at least one driver; - a powertrain that is at least partially electrically powered and configured to transmit drive torque to at least two drive wheels; The road vehicle (1) is characterized in that it also includes: - a battery pack (9) according to any of the preceding claims, which is mounted below the passenger compartment (6), in particular on the floor (10) of the road vehicle (1); - a system (19) for circulating the refrigerant fluid (F), configured to introduce the fluid in a saturated state into at least one of the inlet pipes (17) and to extract it from the outlet pipe (18) of the refrigerant fluid (F).

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