ELECTROCHEMICAL CELL FOR BATTERY PACK MODULE

Abstract

An electrochemical cell for a battery pack module comprising: - a housing extending along a longitudinal axis (X), said housing having a side wall comprising at least two longitudinally extending flat faces and covers at each end, - an electrochemical part housed within the housing, - two connection terminals disposed inside the housing and each connected to an electrode of the electrochemical part, each terminal being accessible through a window made in at least one different flat face, - each terminal being configured to receive a connection element to another cell. [Fig.1]

Description

Title of the invention: ELECTROCHEMICAL CELL FOR BATTERY PACK MODULE TECHNICAL FIELD AND PREVIOUS ART

[0001] The present invention relates to an electrochemical cell for a battery pack module, to a battery pack module, in particular for a motor vehicle, and to a motor vehicle comprising at least one such battery.

[0002] The strong demand for electric vehicles, particularly to reduce CO2 emissions, has resulted in significant development in the field of battery packs.

[0003] The batteries generally used are lithium-ion batteries comprising a plurality of electrochemical cells connected together in series or in parallel.

[0004] The cells traditionally include a flexible container, designated pouch, in which the electrodes and electrolyte are sealed.

[0005] Rigid cells extending axially have been developed, equipped at their ends with positive and negative terminals allowing interconnection with other cells.

[0006] A large number of cells are implemented, for example, a battery pack can comprise between 200 and 7000 cells, connected in series and parallel, depending on the capacity of the individual cell, the energy to be stored, or the application concerned.

[0007] To produce a battery pack providing the required voltage and current, the cells or cell modules are interconnected. The electrical interconnection of the terminals of the individual cells is achieved by means of cables or by bolting busbars or welding busbars to the positive and negative terminals of the cells. These cables or busbars are then connected to neighboring cells / modules, in series / parallel, to obtain the desired voltage and current for the complete battery pack.

[0008] The electrical connection technology, linking individual cells to form a series and / or parallel circuit, requires a complex and costly network of cables or metal grids. This necessitates space between the cells or modules for connection to the cell terminals or modules, and to allow cables to run along the battery to the battery management system (BMS) and the inverter. Busbars ensure the efficient flow of electrical current between the cells, thus guaranteeing optimal performance of the energy storage system.

[0009] The manufacture and implementation of bus bars used to connect the cells of electric vehicle batteries constitutes a complex process in the construction of the car battery pack. Indeed, the design of these bus bars takes into account various factors such as thermal management, electrical resistance, mechanical durability, and balanced distribution of electrical loads.

[0010] The manufacture of these components involves the use of advanced techniques.

[0011] All these elements have a significant impact on the cost price of a battery.

[0012] Furthermore, the complex network of high-voltage cables between 400V and 800V can present a danger of short circuit and electrocution throughout the handling phase by technicians when assembling the battery in the motor vehicle.

[0013] In addition, a large length of cabling is required, often several tens of meters, which increases the electrical resistance of the circuit, forcing manufacturers to adopt larger cross-section cables to reduce the resistance of the electric current and thus the heat generated by the latter.

[0014] In addition, bus bars, wiring and mesh bus bars are often made from expensive metals, including copper or copper-nickel alloy, also significantly impacting the total cost of the vehicle.

[0015] Implementing the interconnection requires significant space, which reduces the available space for the battery and represents a substantial mass to transport. Description of the invention

[0016] It is therefore one of the aims of the present application to provide an electrochemical cell for a battery pack module, making it possible to overcome the above disadvantages.

[0017] The stated objective is achieved by an electrochemical cell comprising a rigid, longitudinally extending housing with at least two flat lateral faces and two internal connection terminals. Each connection terminal is accessible through a window in the housing. The cell and the connection terminals are configured to ensure a connection between the cells by means of a connecting element penetrating the two cells to be connected.

[0018] Thanks to the invention, the connection network between the cells is then limited to small interconnection elements between two cells, the end cells being connected to the battery management system, which makes it possible to eliminate the long network of electrical connection cables linking the individual cells together to form battery packs.

[0019] It is no longer necessary to implement busbars bolted to each cell and / or a long cable network. Furthermore, the terminals do not protrude from the cells.

[0020] The risks of electrocution and short circuit are reduced.

[0021] In addition, the electrical assembly is significantly simplified.

[0022] Finally, the mass of the assembly can be reduced.

[0023] In a particularly advantageous way, the terminals

[0024] In other words, thanks to the invention, a network of interconnecting cables and busbars is replaced by interconnectors between each cell. The interconnection is carried out simultaneously with the assembly of the cells, which reduces the battery manufacturing time and simplifies production.

[0025] In a preferred embodiment, each cell has, at each of its longitudinal ends, a current collector / distributor ring forming an electrical terminal and intended to be connected to the electrochemical part of the cell. The ring is provided with a housing accessible through a window in the casing, the housing being configured to receive an interconnection element for another cell or a management system. The rings have the same internal geometric cross-section as the casing, thus acting as structural stiffeners for the casing, improving its torsional rigidity and limiting crushing.

[0026] In this embodiment, the housing can be equipped at each end with as many windows as there are flat faces on the housing, providing access to all faces of the internal current collector / distributor structural ring. Unused windows are sealed, allowing for considerable flexibility in cell assembly.

[0027] The invention also relates to a set of assembled cells, the cells being joined together for example by gluing the flat faces and interconnected by means of interconnecting elements between each pair of cells, and forming a rigid structure that can contribute to the rigidity of the vehicle to which it is attached.

[0028] The present invention then relates to an electrochemical cell for a battery pack module comprising:

[0029] a housing extending along a longitudinal axis (X), said housing comprising a side wall comprising at least two longitudinally extending flat faces and covers at each end, an electrochemical part housed in the housing,

[0030] two connection terminals arranged inside the housing and each connected to an electrode of the electrochemical part, each of the terminals being accessible to through at least one window made in at least one different flat face or in at least one of said covers,

[0031] each of the terminals being configured to receive a connection element to another cell.

[0032] Preferably, each of the terminals comprises an electrically conductive ring, inserted in the housing, each ring being connected to an electrode of the electrochemical part, and comprising at least one housing opposite the window and configured to house a part of the connecting element, the ring advantageously having a mechanical reinforcement function for the housing.

[0033] In one embodiment, at least one of the terminals is accessible through the cover and in which at least one housing is in an end face of the ring.

[0034] In another embodiment, the two terminals are accessible through the side wall of the housing and in which the housing of each terminal is in a side face of the ring.

[0035] For example, each window is located at one longitudinal end of the side wall of the housing and the covers closing the ends of the housing each fit into one longitudinal end of the housing, each of the covers having a side wall interposed between the housing and the ring, said side wall having a window opposite the housing of the ring and the window of a flat face of the housing.

[0036] The housing is advantageously made of electrically non-conductive material, for example of composite material comprising carbon or vegetable fibers.

[0037] The electrochemical cell may include thermal management means comprising a conduit for the flow of a heat transfer fluid, the conduit extending longitudinally and passing through the covers.

[0038] Preferably, the housing has a polygonal cross-section, advantageously triangular or hexagonal.

[0039] The present application also relates to a battery pack module comprising several electrochemical cells according to the invention, electrically connected to each other and in contact with each other by one or more of their flat faces, in which connecting elements connect adjacent cells in series or in parallel.

[0040] The connecting elements may have two blade-shaped ends, each intended to cooperate with a connection terminal of a cell, the connection terminals having brushes.

[0041] In an advantageous example, the module comprises two stiffened elements end elements covering the longitudinal ends of the cells. stiffeners may include means for supplying and collecting a heat transfer fluid connected to each duct of the cells, so as to ensure circulation of the heat transfer fluid in the duct, the supply and collection means advantageously including means for rapid hydraulic connection to an external hydraulic circuit.

[0042] According to an additional feature, the cells are joined together by gluing between at least two flat faces.

[0043] The present invention also relates to a battery pack module comprising several electrochemical cells according to the invention, electrically connected to each other by their longitudinal ends and a connector receiving at each of its ends, a longitudinal end of a housing and comprising conductive elements electrically connecting the two cells.

[0044] The present invention also relates to a motor vehicle comprising at least one module according to the invention, the management system of the electrochemical cell module, the cells being arranged relative to each other so as to extend substantially in a plane, a chassis equipped with a floor, the lower face of the floor being configured so as to fit into the upper face of the module, said module being secured to the floor and in contact with the lower face of the chassis, so that the module contributes to the rigidity of the chassis.

[0045] The vehicle includes, for example, a lower plate comprising a face configured to fit into the lower face of the module, and fixed to the floor, the module being locked between the floor and the lower plate. Brief description of the drawings

[0046] This application will be better understood with the aid of the following description and the attached drawings, in which: - [Fig. 1] is a schematic representation of an example of a module of interconnected electrochemical cells according to the invention, - [Fig.2] is a partially exploded view of an example of an electrochemical cell according to the invention that can be implemented in the module of [Fig.1], - [Fig.3] is a detailed view of [Fig.2], - [Fig.4] is a longitudinal cross-sectional view of the cell from [Fig.2] at one longitudinal end, - [Fig. 5] represents a module of electrochemical cells from [Fig. 2]. [Fig. 6] is a perspective view of another example of an electrochemical cell according to the invention. - [Fig.7A], - [Fig.7B], - [Fig.7C] are perspective representations of different examples of collector / distributor rings that can be implemented in the cells according to the invention, - [Fig.8] is a schematic representation of another example of an electrochemical cell, - [Fig.9] is a perspective view of a partially realized cell module including stiffeners, - [Fig. 10] is a detailed view of [Fig. 9], - [Fig.11] is an exploded view of an example of a motor vehicle according to the invention, - [Fig.12] is a detail view of [Fig.11], - [Fig. 13A] is a perspective view of an example embodiment of cells according to the invention and of a connector allowing longitudinal assembly, - [Fig.13B] is a perspective view of another example of an embodiment of a cell according to the invention allowing for longitudinal assembly, - [Fig. 14] is a top view of the complete module of [Fig. 9] including connectors, - [Fig.15] is a detailed view of [Fig.14], - [Fig. 16] is a perspective view of another example of integrating a battery pack according to the invention into a motor vehicle, - [Fig. 17] is an exploded view of [Fig. 16]. DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0047] Figure 1 shows a schematic representation of an example of an interconnected electrochemical cell module according to the invention.

[0048] The module M of [Fig.1] comprises several cells Cl assembled together and interconnected.

[0049] Each cell Cl comprises a rigid casing extending along a longitudinal axis X. In addition, it comprises an electrochemical part (not shown) housed in the casing.

[0050] The electrochemical part is, for example, of the jelly-roll type, comprising two conductive metal sheets laminated with active materials, wound around each other, between which is placed a separator made of polyethylene or polypropylene. The two metal sheets are connected to the terminals of the cell, through which the cell is connected to one or more other cells. Alternatively, the electrochemical part is in the solid state.

[0051] For example, electrochemical cells are of the lithium-ion type without this being limiting.

[0052] In the example shown and preferably, the housing 2 has a hexagonal cross-section and two flat end faces 6.

[0053] As schematically represented in [Fig.1], each cell has a positive terminal + at one of its longitudinal ends 2.1 and a negative terminal - at the other longitudinal end 2.2.

[0054] In [Fig.1], the cells Cl are connected to each other in series.

[0055] Figure 2 shows a partially exploded view of an example cell electrochemical according to the invention that can be implemented in the module of [Fig.1].

[0056] In [Fig.3], a detailed view of [Fig.2] can be seen, and in [Fig.4] a longitudinal cross-sectional view of the cell of [Fig.2] can be seen at a longitudinal end.

[0057] The housing 2 comprises a side casing 8, two end covers or bottoms 10 closing the longitudinal ends 8.1, 8.2 of the casing. In this example, the casing is composed of six flat walls.

[0058] The cell has at each end a current collector / distributor ring 10, one end forming the + terminal and the other the - terminal of the cell (Figures 2 to 4). In addition to its current collection and distribution function, the ring also advantageously has a structural mechanical function, improving the torsional rigidity of the housing and limiting crushing.

[0059] Only one of the collector / distributor rings, hereafter referred to as "rings" for simplicity, will be described in detail, the other ring having a similar structure and function. Ring 10 is made of electrically conductive material.

[0060] The ring 10 has an external shape with the same internal geometry as the housing; in the example shown, a hexagonal shape fitting into an open end 8.1 of the housing. The outer lateral surface has six flat faces. The ring is intended to be connected to one of the electrodes of the electrochemical section.

[0061] For example, each of the metal sheets has a tab protruding from one lateral end of the winding. One of the tabs protrudes from one longitudinal end and the other end protrudes from the other longitudinal end.

[0062] One of the tabs is for example welded to one of the rings and the other tab is welded to the other ring.

[0063] The ring 10 has a recess 12 configured to form a receptacle for an interconnection element IN which will be described in more detail below.

[0064] The recess 12 opens into a flat face of the outer lateral surface of the ring 10. The housing has a window 14 in one or more of its flat walls. The ring 10 is mounted in the housing so that the recess 12 and the window 14 are opposite each other.

[0065] The cover 13 also has a hexagonal shape and is hollow so as to receive the ring 10. In addition, the cover is provided with a window 16 in its side wall aligned with the window 14 and the receptacle 12.

[0066] In [Fig. 13A], another example of an embodiment can be seen in which the cell Cl' is configured to allow a connection with a cell via a side wall and a connection with a cell via an end wall.

[0067] In this example, seven cells are connected in parallel (the central cell not being shown) via their side walls and are connected in series with another set of cells (not shown) aligned along the longitudinal axis X. The connection between the two sets is achieved by means of a connector 70 which also provides the mechanical assembly. For this purpose, the cover 13' also provides the possibility of axially connecting two or more cells electrically and mechanically in a "cover-counter-cover" manner through dedicated windows 60 on the face of the cover 13, giving access to the side face of the ring 10 ([Fig. 13A]). The side face of the ring has slots 61 opposite the windows 60 of the cover 13', to accommodate raised male terminals 71 and insert into them. The male terminals can have different shapes or profiles

[0068] The male terminals made of electrically conductive material are carried by the connector 70 which has an intermediate plate 72 against which the covers 13 of the cells 10 rest once inserted into the connector 70. The male terminals protrude on either side of the intermediate plate.

[0069] The connector also includes a side wall 73 extending longitudinally on either side of the intermediate plate 72 and whose shape corresponds to the external shape of the cell assemblies. Thus, the longitudinal ends of the cell assemblies are received in the connector on either side of the intermediate plate 72.

[0070] In one embodiment, the terminals 71 are integral with the intermediate plate 72, and the intermediate plate 72 is covered with an electrically insulating material such as ceramic or plastic. In another embodiment, the terminals 71 are inserted into the intermediate plate, which is made of an electrically insulating material. The side wall 72 of the connector 70 is also made of an electrically insulating material.

[0071] The connector 70 makes it possible to make long battery assemblies, useful for making structural building elements, such as shelters for motor vehicles.

[0072] It will be understood that the connector 70 can have different shapes depending on the number of cells Cl or configuration or structural properties required.

[0073] The connector 70 can be made for example by fusion, composite molding, or 3D printing.

[0074] In another embodiment shown in [Fig. 13B], the connector 80 allows two cells Cl to be axially connected (only one is shown). Similar to the connector 70, the connector 80 comprises an intermediate plate 82 and terminals 81 and receives, at each of its ends, a longitudinal end of a cell CL

[0075] In the example shown, the housing and the lid are made of metallic material. The ring 10 is electrically isolated from the casing and the lid 13 by means of an electrical insulating element 18 interposed between the ring 10, the lid 13, and the housing. In the example shown, the electrical insulating element 18 has a shape similar to that of the lid, its dimensions being such that it accommodates the ring and fits within the lid. Furthermore, it has a window 20 aligned with the windows 14 and 16 and the receptacle 12.

[0076] The various elements composing the cell housing are welded or glued depending on the materials used.

[0077] The cell also includes, at each terminal, a female electrical connector 22 comprising two contact brushes 24 held by an insert. The connector 22 fits into the receptacle of the ring and through the windows 14, 16 and 20.

[0078] In this example, a second electrical insulating element 28 is provided between the connector 22, the casing and the cover.

[0079] The female connector 22 is configured to house one end of a male connector 30.

[0080] The male connector 30 has two opposing connection ends, advantageously formed by blades 32. Each blade 32 is designed to be inserted between the contact brushes 24 of a female connector. The use of blades offers the advantage of providing some flexibility to facilitate the mechanical assembly, which will be described below.

[0081] It will be understood that neither the shape of the female connector nor that of the male connector is limiting.

[0082] Preferably, and as shown in Figures 3 and 4, positioning and locking means 33 for two cells are provided at the female connector. The means 33 comprise, for example, a frame-shaped piece that fits into the window 14 and surrounds the female connector 22. Furthermore, the piece 35 projects outwards from the housing so as to enter the window 14 of the other cell to be connected and to surround the female connector. The piece 33 also surrounds the male connector. Thus, after assembly, the two cells are locked relative to each other in translation along their direction. longitudinal by cooperation of the part and the windows 14. The implementation of this part requires a longitudinal positioning of the two cells relative to each other, thus mechanically protecting the connectors.

[0083] In a particularly advantageous example, the housing and / or the covers are made of an electrically insulating material, for example a composite material containing carbon fibers or ceramic, which makes it possible to avoid using electrically insulating elements.

[0084] In the example shown and also in a particularly advantageous manner, the cell includes thermal management means 34 internal to the cell comprising a tube 36 extending longitudinally and opening at the longitudinal ends of the cell.

[0085] The electrochemical part is advantageously wound around the tube 36 so that thermal management takes place at the heart of the cell. The tube then also serves as a support for the electrochemical part.

[0086] The tube 36 is intended to be connected to a heat transfer fluid supply and collection circuit so that the fluid circulates in the tube through the cell.

[0087] The heat transfer fluid primarily serves to extract the heat generated within the cell during its operation. Extracting heat from the core of the cell offers significantly greater efficiency than extracting heat from outside the cell, as is done in the prior art.

[0088] The longitudinal ends of the tube 36 pass through the covers and are connected to means for supplying and collecting heat transfer fluid, an example of which will be described below. The tube is welded or bonded to each of the covers.

[0089] It will be understood that an electrochemical cell without integrated thermal management means does not fall outside the scope of this application.

[0090] We will now describe the realization of the module of [Fig.1].

[0091] A first cell Cl is provided. One end of the male connector is inserted into the female connector of the + terminal. The assembly of [Fig.4] is obtained.

[0092] A second cell Cl is then brought close to cell Cl such that the negative terminal of the second cell Cl is opposite the first cell Cl and the flat faces of the two housings are facing each other. The other end of the male connector 30 is inserted into the female connector of the negative terminal of the second cell. When the male connector 30 is correctly positioned, the flat faces of the two cells are in contact with each other. This operation is repeated with other cells Cl until the desired voltage and current are reached.

[0093] The use of blades for the male connector 30 facilitates the electrical connection of the cells together by offering a certain degree of freedom during assembly.

[0094] In the example shown, and preferably, the + terminal and the - terminal are diametrically opposed, allowing for assembly in the form of a sheet as shown in [Fig. 5], which forms a cell module comprising a large number of cells according to the invention. It will be understood that several sheets or layers of cell modules, as shown in [Fig. 5], can be superimposed, depending on the need or application.

[0095] It will be understood that the relative arrangement of the + and - terminals can vary depending on the architecture of the assembly that one wishes to obtain.

[0096] In [Fig.6], we can see another example of an embodiment of cell C2 having a triangular cross-section.

[0097] The housing 202 comprises a housing with three flat faces. In this example, two windows 114 are made at each longitudinal end, making the cell suitable for either a series or parallel connection.

[0098] The collector / distributor rings 110 also have a triangular section and also have two windows 112 for mounting the female connector.

[0099] Unused windows are sealed.

[0100] Unused windows are advantageously sealed prior to assembly. Thus avoiding any accidental contact, or foreign objects becoming lodged there during handling.

[0101] As with cell Cl, covers are provided at each end as well as electrical insulating elements where appropriate.

[0102] Other cell shapes in which the housing has at least two flat longitudinal faces are conceivable. For example, the cell may have a square or rectangular cross-section. Still other shapes are conceivable, with two flat faces connected by curved faces. Furthermore, in the case of a cell with a hexagonal cross-section, the hexagon may not be regular. Nevertheless, a regular hexagonal cross-section and a regular triangular cross-section facilitate the production of the modules described below, which provide an additional rigidity function.

[0103] Figures 7A to 7C show examples of collector / distributor ring with different male connector shapes.

[0104] In [Fig. 7A], the ring 210 has a triangular external shape and the male connector 230 is similar to that described in relation to the CL cell

[0105] On [Fig.7B], the ring 310 has an external hexagonal shape and the male connector 330 has cross-shaped connection ends, the female connector has a corresponding shape.

[0106] On [Fig.7B], the ring 410 has a square outer shape and the male connector 430 has two cylindrical pin-shaped connection ends, the female connector has a corresponding shape.

[0107] It will be understood that the shape of the male connector of each of the figures 7A to 7C can be applied to each of the connectors of the other figures 7A to 7C.

[0108] The cell Cl advantageously includes thermal management means integrated into the cell allowing heat to be extracted from within the cell and also to be supplied with heat if needed.

[0109] These thermal management means can be applied to all cell shapes, for example those with triangular and square cross-sections.

[0110] Furthermore, a cell incorporating such means and not comprising at least two flat faces and a collector / distributor ring, nor a connector as described above, does not fall outside the scope of this application.

[0111] Fig. 8 represents a C3 cell with a circular cross-section integrating thermal management means and which is configured to be connected to other similar cells by cables and bus bars commonly used in batteries.

[0112] The thermal management means comprise a tube 36 aligned with the axis of the cell. Alternatively, the thermal management means comprise several tubes extending parallel to the longitudinal axis.

[0113] The assembled cells, for example in the form of a sheet as shown in [Fig.5], form a series of modules for a battery pack.

[0114] Preferably, the cells are joined together, preferably by bonding, most commonly with epoxy adhesive. Epoxy adhesive has the advantage of being heat-resistant and having good mechanical strength. In addition, epoxy adhesive provides thermal insulation between the cells, limiting the transfer of heat from one cell to another, particularly in the event of a malfunction of one of the cells.

[0115] In an advantageous embodiment, flame-inhibiting elements can be integrated into the glue to improve the safety of the battery pack.

[0116] Alternatively, the cells are welded to each other or mechanical means are provided between the cells.

[0117] Preferably, in order to stiffen the assembly of the cells of the module of [Fig.5] mechanical means are provided.

[0118] Figures 9 and 10 show an example of an assembly of Cl cells comprising such stiffening means, which also advantageously ensure the circulation of the heat transfer fluid within each of the cells.

[0119] The cells Cl are electrically connected to each other in series or in parallel and form a sheet such as that shown in [Fig.5]. The assembly is designated module M.

[0120] The assembly also includes two lateral stiffeners 38, each shaped to house the longitudinal ends of the cell sheet.

[0121] In this example and in a very advantageous way, the stiffeners include fluidic means for the circulation of the heat transfer fluid.

[0122] One of the stiffeners 38 provides the supply of heat transfer fluid and the other stiffener is used for collecting the heat transfer fluid.

[0123] In the example shown, each stiffener 38 has a fluid circuit supplying the cells in parallel. The circuit includes a main pipe 40 extending the length of the stiffener and secondary pipes 42 connected to the main pipe and supplying each of the cells. The main pipe has an end intended to be connected either to a heat transfer fluid source or to a heat transfer fluid collection tank, depending on the function of the circuit.

[0124] The main and secondary channels are preferably integrated into the stiffening body, for example by molding in a composite material directly into the stiffener. Alternatively, the main and secondary channels are stamped, machined, or formed from sheet metal and then bonded or welded into the stiffener.

[0125] Preferably, the open end of the main pipe is equipped with a quick-connect hydraulic fitting 46 allowing for quick removal and installation of the battery pack. The fitting allows the pipe 40 to be connected to the hydraulic circuit of the motor vehicle, which includes a heat transfer fluid-air heat exchanger located on the front of the vehicle, behind an opening, to take advantage of the airflow when the vehicle is moving.

[0126] The stiffeners 38, forming stiffening / consolidation structures, serve to link and reinforce a basic structure. The stiffeners provide greater strength to the entire cell assembly. The battery pack is thus structurally sound, mechanically linking the cells together. The stiffeners can be manufactured, for example, from cast, machined, or printed aluminum, or from stamped steel sheet, or from composite materials such as carbon or plant fibers in an epoxy resin matrix by autoclave molding.

[0127] It will be understood that stiffeners having only a mechanical function do not fall outside the scope of the present invention.

[0128] Furthermore, a module comprising cells integrating thermal management means and in which the supply and collection of the heat transfer fluid are ensured by a network of pipes connecting to each of the tubes 36 without being integrated into the stiffeners does not fall outside the scope of this application.

[0129] In a particularly advantageous way, the battery pack according to the invention is integrated into the motor vehicle so that it plays a structural role in addition to its function of supplying and storing electrical energy.

[0130] Indeed, in current motor vehicles whose energy is supplied at least in part by electrochemical cells, the electrochemical cells are "dead weight". Their only function is to supply energy to the vehicle's electric motor, and to store energy during recharging.

[0131] In addition, additional elements are to be provided to maintain the cells, organize them into modules, protect them and integrate them into the vehicle chassis.

[0132] Figures 11 and 12 show a particularly advantageous example of the integration of electrochemical cells into a motor vehicle.

[0133] In [Fig. 11], an exploded view can be seen of part of a motor vehicle comprising a monocoque chassis 48 integrating both the chassis and the body made in one piece.

[0134] The chassis 48 has in its lower part a floor 50. The lower face 51 of the floor is shaped so that the cell module M fits into the lower face of the floor.

[0135] In the example shown, the assembly of cells with hexagonal cross-section M forms a honeycomb network whose lower and upper faces have hollow and protruding parts, the lower face of the floor has corresponding protruding and hollow parts.

[0136] Furthermore, the vehicle includes a lower plate 52 or lower subframe intended to be fixed to the floor, the module being clamped between the floor and the lower plate 52. The upper face 54 of the lower plate 52 is also shaped to fit into the lower face of the module. The lower subframe is, for example, bolted to the chassis to clamp the module against the chassis.

[0137] The lower plate 52 also forms a protective cover, eliminating the need for a dedicated cover.

[0138] The lower plate is mounted between the two stiffeners 38 and does not cover it.

[0139] The assembly formed by cooperation of the floor, the module and the lower plate It utilizes the intrinsic rigidity of each cell and its complete network formed by the module, which is then locked between the lower base plate and the lower part of the monocoque. The mass of the entire simplified assembly is considerably reduced compared to current structures.

[0140] In addition, the location of the battery pack under the vehicle makes it possible to lower its center of gravity and improve its stability.

[0141] The invention avoids having to resort to a heavy and bulky structure to protect the cells.

[0142] Thanks to this achievement the cells are no longer a “dead weight” but contribute to the rigidity of the vehicle.

[0143] In the example shown, the cells are arranged perpendicular to the longitudinal axis of the vehicle. Alternatively, they are oriented parallel to it.

[0144] In other words, in a preferred example the cell envelopes form polygonal cross-section tubes glued or welded together forming a network or lattice whose upper face forms a three-dimensional surface mechanically locking into a correspondingly shaped structure forming part of the chassis and interlocking with it.

[0145] The module forms a stiffening subframe by its ability to be mechanically locked by the base of the monocoque, in its lower part.

[0146] The mechanical function ensured by the cooperation of the cell module and the chassis is further improved when the cells are joined together by gluing, welding or any other mechanical means, and preferably by the addition of stiffeners. A self-supporting sub-assembly is thus created.

[0147] This "self-supporting" assembly utilizes the intrinsic rigidity of each cell and its complete network, formed by the pack of cells bonded together, which is then locked between the lower plate and the lower part of the chassis. The mass of the assembly, thus simplified, is considerably reduced.

[0148] By way of example, the length of the polygonal section tubes forming the subframe is between 100 mm and 2000 mm, and their section is between 20 mm and 200 mm, for example 30 mm.

[0149] The lower face of the chassis is for example made directly by stamping, or by gluing or welding extruded, semi-hexagonal sections onto the flat sheet of the lower part of the monocoque.

[0150] The lower plate is for example made by welding hexagonal half-tubes onto a plate or sheet, by extrusion, or by additive manufacturing of the 3-D printing type.

[0151] The cell module formed by a set of triangular cells has hollow and raised areas on both faces which also contributes to the rigidity of the chassis.

[0152] Any assembly of electrochemical cells allowing a certain level of interlocking between the cells and with the chassis falls within the scope of the present invention.

[0153] Alternatively, a lower plate is not implemented and the cell module is directly fixed to the chassis, for example by means of bolts.

[0154] The design of Figures 10 and 11 simplifies and streamlines manufacturing during integration into the vehicle, reducing assembly time and cost. Furthermore, the mass and size are significantly reduced.

[0155] In the example shown the chassis is a monocoque chassis, but the invention also applies to a chassis not incorporating the bodywork, as will be described below.

[0156] In a preferred mode, the cell module comprises polygonal cross-section cells such as those in [Fig.1] locked together by gluing and stiffeners.

[0157] The cell housing is, for example, produced by extrusion, molding, or 3D printing. The housing is, for example, made of aluminum or composite material.

[0158] The electrical connection of the module to the power management system is made directly when the module(s) are placed against the chassis. For this purpose, suitable connectors E1+ and El-, visible in Figures 14 and 15, are provided. The E1+ and El- connectors are preferably positioned perpendicular to the upper plane of the battery pack and connect to the terminals of one of the end cells Cl of the battery pack M, with a male element E2, which is inserted through a window made in the stiffener 38 opposite the window 14 of the cell Cl housing, to make contact with the ring 10.

[0159] An E1+ connector is located at one end of the pack M in one of the stiffeners 38 and an El- connector is located at the opposite end of the pack M in the other stiffener 38.

[0160] The battery pack according to the invention is particularly suitable for rapid replacement, for example in a battery exchange station, designated "battery-swap station" in Anglo-Saxon terminology, ensuring the replacement of a discharged battery pack with a charged battery pack.

[0161] Indeed, the battery pack can be easily exchanged by removing the lower plate or the battery pack itself and disconnecting the hydraulic system, if present, by manipulating the quick-connect fittings. The battery pack can be removed by lowering it; another battery pack is then installed by bringing it close to the chassis, connecting the hydraulic circuit to the vehicle's circuit, and replacing the lower plate, or by directly attaching the battery pack to the chassis.

[0162] All of these operations can be carried out automatically by a dedicated robot in a suitable station.

[0163] The replacement is particularly safe because the battery pack offers great robustness both mechanically, electrically and hydraulically.

[0164] It will be understood that a battery pack contributing to the rigidity of the chassis may not include integrated thermal management means. Furthermore, the electrical connection between the batteries may differ from that described in relation to the cell. Connection via cables and busbars also applies.

[0165] The present invention is also particularly suited to the integration of sensors within cells or a module.

[0166] Figures 16 and 17 show another example of integrating the battery pack according to the invention into a "skate" type platform, in which the battery pack M forms a linking bridge between the front TAV and rear TAR running gear in a single module, independent of the bodywork.

[0167] The rolling platform or PR chassis comprises the electric suspension / motor / running gear assemblies and a central structural box housing the battery pack. In this example, the vehicle body serves a simple "cladding" role, unlike the previously described example, in which the body is an integral part of the load-bearing monocoque to which the aforementioned mechanical components, suspension / motor / running gear, are directly bolted.

[0168] In this configuration the M battery pack acts as an intermediate link structure between the front and rear axles, thanks to its rigidity and positioning.

[0169] The housing 57 of the platform receiving the battery pack forms an inverted "cradle" 57, into which the battery pack is placed from below. The inner face of the housing is shaped to fit into the outer face of the battery pack.

[0170] On the one hand, the housing includes an upper plate 55 whose lower profile fits and is perfectly embedded in the upper hollows and reliefs of the battery pack M. On the other hand, the housing includes at its longitudinal ends plates S connecting the plate 55 to the front axle TAV and the rear axle TAR and shaped to fit the external shape of the end cells of the battery pack.

[0171] Very advantageously, additional stiffeners 56 are attached to the lateral edges of the plate 55 and fit into the stiffeners 38 of the battery block.

[0172] The additional stiffeners 56 are shaped so that when assembled to the plate 55, their face located inside the cradle is in a plane offset from the inner face of the plate 55 so as to fit into the upper reliefs of the stiffeners 38.

[0173] The cradle 57 formed by the plate 55, the stiffeners 56 and the plates S forms the linking bridge between the structures of the front TAV and rear TAR running gear.

[0174] For example, the platform is made by welding, bolting or bonding the front / rear axles TAV, TAR to the intermediate plate 55 held between the two additional stiffeners 56. The intermediate plate 55 and the stiffeners Additional 56 can be stamped from a single piece of sheet steel, or aluminum, welded together, or molded from composite materials.

[0175] The cradle 57 is composed of the plate 55, welded or glued, depending on the materials used, to the plate stiffeners 56, and completed at the ends by the connecting plates S.

[0176] For example, the S connecting plates are obtained by extrusion or pressure molding of aluminium, or of stamped steel sheet, or of composite materials.

[0177] The complete cradle 57 is then riveted and glued, welded or bolted, depending on the materials used, to the front TAV and rear TAR axles.

[0178] A base plate 52 may be provided under the battery pack 52 in a manner similar to the example described above.

[0179] In the case of a battery pack M interchangeable by automated rapid replacement stations, the pack M, together with its base / protection plate 52, is bolted against the cradle 57, perfectly embedded and locked ensuring its structural function.

[0180] In the case of a fixed battery pack M, i.e. not intended to be replaced in quick replacement stations, the pack M can be bolted, or glued and riveted to the cradle 57 in a definitive and permanent manner.

[0181] The module can be implemented in any motor vehicle, whether rolling, flying or floating.

[0182] Furthermore, it will be understood that electrochemical cells and in particular modules can be implemented in any type of system and not necessarily in a motor vehicle.

[0183] The present invention applies to any other energy storage element implemented in mobile systems, for example, and without limitation, in ships, aircraft and industrial machines.

[0184] Alternatively, the invention can be implemented in fixed systems to supply electrical power to any industrial, construction site activity and / or public energy supply to individuals.

[0185] Furthermore, the present invention, in particular the examples in Figures 13A and 13B, can advantageously be implemented in structural building elements such as columns, structural works for buildings, decorative panels for facades, car shelters or carports.

Claims

Demands

1. Electrochemical cell for battery pack module comprising: a housing (2) extending along a longitudinal axis (X), said housing (2) having a side wall comprising at least two longitudinally extending planar faces and covers (13) at each end, an electrochemical part housed in the housing (2), two connection terminals disposed inside the housing and each connected to an electrode of the electrochemical part, each of the terminals being accessible through at least one window (14) made in at least one different planar face or in at least one of said covers, each of the terminals being configured to receive a connection element to another cell.

2. Electrochemical cell according to claim 1, in which each of the terminals comprises an electrically conductive ring (10) inserted in the housing (2), each ring (10) being connected to an electrode of the electrochemical part, and comprising at least one housing (12) opposite the window (14) and configured to house a part of the connecting element, the ring (10) advantageously having a mechanical reinforcement function of the housing.

3. Electrochemical cell according to claim 1 or 2, wherein at least one of the terminals is accessible through the cover (13) and wherein at least one housing (12) is in an end face of the ring (10).

4. Electrochemical cell according to claim 1 or 2, wherein the two terminals are accessible through the side wall of the housing and wherein the housing of each terminal is in a side face of the ring (10).

5. Electrochemical cell according to claim 4, wherein each window (14) is located at a longitudinal end of the side wall of the housing (2) and wherein the covers (13) closing the ends of the housing (2) are each inserted into a longitudinal end of the housing (2), each of the covers (13) having a side wall interposed between the housing (2) and the ring (10), said side wall having a window (16) opposite the housing of the ring (10) and the window (14) of a flat face of the housing (2).

6. Electrochemical cell according to any one of claims 1 to 5, wherein the housing (2) is made of electrically non-conductive material, for example of composite material comprising carbon or plant fibers.

7. Electrochemical cell according to any one of the preceding claims, comprising thermal management means including a conduit for the flow of a heat transfer fluid, the conduit extending longitudinally and passing through the covers.

8. Electrochemical cell according to any one of the preceding claims, wherein the housing (2) has a polygonal cross-section, advantageously triangular or hexagonal.

9. Battery pack module comprising several electrochemical cells (Cl) according to claim 4 or 5, electrically connected to each other and in contact with each other by one or more of their flat faces, in which connecting elements connect adjacent cells in series or in parallel.

10. Module according to the preceding claim, wherein the connecting elements (30) have two blade-shaped ends, each intended to cooperate with a connection terminal of a cell (Cl), the connection terminals having brushes.

11. Module according to claim 9 or 10, comprising two end stiffening elements (38) covering the longitudinal ends of the cells (Cl).

12. Module according to the preceding claim in combination with claim 7, wherein the stiffening elements (38) comprise means for supplying and collecting a heat transfer fluid connected to each duct of the cells, so as to ensure circulation of the heat transfer fluid in the duct, the supplying and collecting means advantageously comprising means for rapid hydraulic connection to an external hydraulic circuit.

13. Module according to any one of claims 9 to 12, wherein the cells (Cl) are joined together by gluing between at least two flat faces.

14. Battery pack module comprising several electrochemical cells according to claim 3, electrically connected to each other by their longitudinal ends and a connector (70, 80) receiving at each of its ends, a longitudinal end of a housing and comprising conductive elements (81) electrically connecting the two cells.

15. Motor vehicle comprising at least one module according to any one of claims 9 to 14, the management system of the electrochemical cell module, the cells being arranged relative to each other so as to extend substantially in a plane, a chassis having a floor, the lower face of the floor being configured so as to fit into the upper face of the module, said module being secured to the floor and in contact with the lower face of the chassis, so that the module participates in the rigidity of the chassis.

16. Vehicle according to the preceding claim, comprising a lower plate including a face configured to fit into the lower face of the module, and fixed to the floor, the module being locked between the floor and the lower plate.

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