Electric accumulator battery pack.

Abstract

Block (1) of electric vehicle accumulator batteries, said block (1) comprising N longitudinal solid electrochemical cells (25), each cell (25) having two positive and negative terminals;characterized in that it comprises a compartment (3) having an opposite front face and rear face and a row of N housings (15) ordered from 1 to N, each housing having two opposite openings leading respectively into said front and rear faces of said compartment (3), and in that the N cells (25) are respectively engaged in the N housings, so that the two terminals of each of the cells (25) extend respectively into said two opposite openings (17) of each of said housings (15) in order to be able, on the one hand, to connect electrically alternately two by two from the first housing the terminals extending into the openings (17) of the front face of said compartment (3), and on the other hand, to connect electrically alternately two by two from the second housing the terminals extending into the openings (17) of the rear face of said compartment (3) in order to connect said N cells in series. Figure from the summary: Figure 5;

Description

Title of the invention: Electric accumulator battery block.

[0001] The present invention relates to a battery pack of electric accumulators for an electric or hybrid motor vehicle.

[0002] Electric or hybrid motor vehicles include electric accumulator batteries or, more generally, electrical energy storage devices, comprising electrochemical cells for electrical energy storage. A battery pack generally comprises several battery modules, each having a plurality of electrochemical cells.

[0003] Conventionally, a prismatic electrochemical cell is a cell whose components are enclosed in a rigid and sealed casing. It is composed of one or more positive electrodes stacked alternately with one or more negative electrodes, as well as one or more separators to separate the positive and negative electrodes, the separator being soaked in electrolyte to allow ionic conduction between the electrodes.

[0004] A known type of battery module, shown in document WO2012096844, comprises a modular frame having walls that form housings. Each housing is adapted to receive a set of cells that are not fixed together and are held in a fixed position.

[0005] However, the arrangement of the batteries used requires several levels of hierarchy, including electrodes, cells, the module, the block, and finally the batteries. The assembly therefore requires a significant amount of space to obtain a battery with the desired voltage. The presence of these hierarchical levels also increases the complexity and duration of the assembly process.

[0006] Furthermore, the cells are also assembled in the module by welding or gluing. This assembly then results in a lack of rigidity in the whole.

[0007] There is therefore a need for a simplified and more rigid electrical accumulator battery pack.

[0008] To this end, a battery pack for electric vehicle accumulators is proposed, said pack comprising N solid electrolyte electrochemical cells, each cell having two opposite sides and two terminals, one positive and the other negative, extending respectively from said two sides. The pack comprises a compartment having an opposite front and rear face and a row of N slots ordered from 1 to N, each slot having two opposite openings leading respectively to said front and rear faces of said compartment, and the N cells are respectively engaged in the N slots, such that the two positive and negative terminals of each cell extend respectively from the two opposite openings of each of the said housings in such a way as to be able, on the one hand, to connect electrically alternately two by two from the first housing the terminals extending into the openings of the front face of the said locker, and on the other hand to connect electrically alternately two by two from the second housing the terminals extending into the openings of the rear face of the said locker in such a way as to connect the said N cells in series.

[0009] The structure of the block presented eliminates the need for a module, thus reducing the number of intermediaries and minimizing the block's volume, while also simplifying assembly. This structure also ensures the overall rigidity of the assembly.

[0010] Advantageously, the compartment is substantially rectangular in shape and has a double wall perpendicular to the housings comprising channels for the circulation of a heat transfer fluid.

[0011] The channels are directly integrated into the battery pack and are therefore close to the cells to be cooled. The proposed arrangement also makes it possible to limit thermal resistance by using several intermediaries.

[0012] Advantageously, the locker is obtained by extruding aluminium so as to form the housings.

[0013] Preferably, each cell of the plurality of cells comprises a plurality of active layers stacked one on top of the other, each comprising a positive electrode and a negative electrode separated by a solid electrolyte, and, said positive electrodes being connected to each other by the positive terminal and said negative electrodes being connected to each other by the negative terminal.

[0014] The cell used is a solid electrochemical cell which does not require a liquid electrolyte and therefore no airtight protection around it which would increase the volume of the cell.

[0015] Advantageously, each cell is surrounded by an insulating envelope made of polymer material. The cells are inserted into the housings of the tray formed from aluminum, which is a conductive material. Thus, the insulating envelope isolates the cells from the tray.

[0016] Advantageously, it comprises, at the level of each slice of each cell, a first current-conducting plate in contact with the corresponding terminal.

[0017] Preferably, the first current-conducting plate has two fingers extending in the opposite direction to the cell and the block includes an insulating and sealing cover plate having two orifices, each finger extending respectively through the orifices.

[0018] The insulating and airtight cover plate protects the interior of the housings from dust, for example. Furthermore, the presence of the openings allows for conduction electric by the fingers of the first conductive plate while sealing the housings.

[0019] Advantageously, the block includes a second conductive plate attached to the fingers of the first conductive plate.

[0020] Preferably, the block comprises a plurality of current-conducting bridges attached to the second conductive plate so as to electrically connect the cells.

[0021] Another object of the invention is a motor vehicle comprising the battery pack described above.

[0022] Other features and advantages of the invention will become apparent from the following description of a particular embodiment of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

[0023] [Fig.1] is a schematic three-quarter perspective view of a battery block according to the invention.

[0024] [Fig.2] is a schematic three-quarter perspective view of an element of a block battery according to the invention.

[0025] [Fig.3] is a schematic three-quarter perspective view of another element of the battery pack according to the invention.

[0026] [Fig.4] is a schematic three-quarter perspective view of the assembly of the block of two battery elements according to the invention.

[0027] [Fig.5] is a schematic exploded three-quarter perspective view of the assembly of the block of several battery elements according to the invention.

[0028] [Fig.6] is a schematic three-quarter perspective view of the assembly of the block of several battery elements according to the invention.

[0029] Fig. 1 illustrates a block 1 of electric accumulator batteries for a motor vehicle.

[0030] This block 1 includes first of all a compartment 3 equipped with two lids 5 to protect the interior of the block 1.

[0031] Block 1 extends longitudinally and forms a substantially parallelepiped-shaped element.

[0032] Locker 3 also has a substantially rectangular parallelepiped shape. It extends longitudinally and has a front face 7 opposite a rear face 9. It also has a top wall 47 opposite a bottom wall 49 and side walls 51. Each face 7, 9 extends transversely and is covered respectively by a cover 5.

[0033] The compartment 3 is made of a metallic material commonly used in motor vehicles, such as aluminum, while the two lids 5 are made of an electrically insulating material commonly used in vehicles automotive materials such as acrylonitrile butadiene styrene, also known as ABS. Locker 3 is further obtained by extruding the metallic material.

[0034] The locker 3 can, in addition, be equipped with metal brackets 13 fixed to the side walls 51 which will allow, via a screw, for fixing them in the motor vehicle.

[0035] It can also involve simple drilling through the thickness of the side walls, without brackets. This solution is preferred to a gluing solution because the screwed assembly is more easily disassembled, which is an advantage for recycling by facilitating the separation of its components for processing.

[0036] The cover 5 of the front face 7 has two opposite openings allowing the passage of the two poles 11 of the battery: a positive pole and a negative pole in order to connect the battery to the electrical circuit of the motor vehicle.

[0037] As shown in [Fig.2], the compartment 3 defines a row of twenty housings 15 ordered from 1 to 20, each suitable for receiving a solid electrochemical cell which will be described in the description below.

[0038] However, the number of housings is not limited to twenty, it can be less or more, and depends on the voltage that one wishes to obtain for block 1.

[0039] For example, a cell can deliver a maximum voltage of 5V. In this case, with twenty cells, a maximum voltage of 100V is obtained.

[0040] Each housing has a first opening 17 leading into the front face (7) and a second opening (not shown in the figures) opposite the first opening 17 and leading into the rear face (9).

[0041] The lower wall 49 of the compartment 3 is a double wall 23 comprising circulation channels 21 of a heat transfer fluid such as glycol allowing the entire compartment 3 to be cooled or heated.

[0042] The upper wall 47 of the locker can also be a double wall alone or in combination with the double wall 23 of the lower wall 47.

[0043] Block 1 also includes twenty solid electrochemical cells 25 received in housings 15. As described previously, the number of cells is not limiting.

[0044] Figure 4 illustrates a solid electrolyte electrochemical cell 25. The cell 25 extends longitudinally and furthermore has two thinned edges forming slices 25a and 25b opposite to each other.

[0045] Fig. 3 illustrates the interior of cell 25 comprising a stack of active layers 26.

[0046] An active layer 26 comprises a positive electrode 27, a negative electrode 29 and a solid electrolyte 31.

[0047] The solid electrolyte 31 is a solid separator that acts as a separator between each electrode with its electrical insulating properties but also the role of electrolyte through which the ions move. The solid electrolyte 31, can be, for example, ceramic or polymer.

[0048] In some cases, the solid electrolyte 31 may be contained in the positive electrode 27.

[0049] The positive electrode 27, also called the cathode, has a positive current collector 27a adapted to conduct a flow of electrons between the active material of the electrode and a terminal of the cell.

[0050] Generally, the material of the positive current collector is chosen according to the electrochemical couple used for the cell. The most commonly used couple is notably aluminum and copper.

[0051] Thus, the positive current collector 27a can be made of aluminium. However, it can also be made up, for example, of lithium iron phosphate, lithium nickel manganese cobalt oxide, or lithium manganese oxide.

[0052] The positive current collector 27a is located at one end of the positive electrode 27.

[0053] The stacking of active layers is then carried out so that the positive current collectors 27a of each active layer are on the same side and are therefore stacked on top of each other.

[0054] The negative electrode 29, also called the anode, is a longitudinally extending plate of a certain thickness. It is made of solid metallic lithium.

[0055] The negative electrode 29 has a negative current collector 29a which can extend longitudinally through the thickness of the lithium plate. It also extends outwards from one end of the negative electrode 29.

[0056] The negative current collector 29a is made of a conductive metallic material such as copper.

[0057] The stacking of active layers is then carried out so that the negative current collectors 29a of each active layer are on the same side and are therefore stacked on top of each other.

[0058] The negative current collectors 29a extend and stack opposite the stacking of the positive current collectors 27a.

[0059] The negative electrodes 29 of a cell 25 are connected to each other at the negative current collector 29a by a negative terminal 35. The connection is made by ultrasonic or laser welding.

[0060] The positive electrodes 27 of a cell 25 are also connected to each other at the level of the positive current collector 27a by a positive terminal 33. The connection is made by ultrasonic or laser welding.

[0061] The positive terminal 33 extends from the slice 25a of the cell 25 while the negative terminal 35 extends from the slice 25b of the cell 25. They extend respectively from the two slices 25a, 25b opposite each other.

[0062] The two positive and negative terminals 33, 35 can be substantially flat as shown in [Fig.3] but they can also have a Z-shaped form as shown in [Fig.4]. They are therefore not limited by their shape, which can be adapted according to the defined assembly.

[0063] Figure 4 shows a cell 25 before its insertion into a housing 15.

[0064] The cell 25 is then surrounded by an insulating envelope 37 so as to electrically isolate it from the aluminum compartment 3 having the housings 15 in which it is engaged. The insulating envelope 37 may in particular be made of an insulating polymer material.

[0065] The insulating envelope 37 is notably installed around the cell 25 against its external faces.

[0066] On either side of the cell 25, the two slices 25a and 25b are covered respectively by a sealing assembly 39 comprising a retaining frame 39a, a first current-conducting plate 39b and an insulating and waterproof plate 39c.

[0067] The retaining frame 39a secures the assembly to the edge 25a or 25b. It is installed, in particular, by interlocking it with the insulating casing or by welding. The frame 39a is made of an electrically insulating material, which may be acrylonitrile butadiene styrene, or ABS.

[0068] The first current-conducting plate 39b is installed so as to be in contact with the two positive and negative terminals 33, 35 for current flow. The two positive and negative terminals 33, 35 are also welded to the first current-conducting plate 39b by ultrasound or laser. The plate is made of a conductive material such as metal or a metal alloy.

[0069] The first conductive plate 39b also has two fingers 39d oriented towards the insulating plate 39c. The two fingers 39d will allow the cells to be connected to each other as will be explained later in the description.

[0070] The insulating and waterproof plate 39c seals the cell 25 to prevent liquid or solid impurities from entering the cell. It also provides electrical insulation so that current flows only at the two positive and negative terminals 33, 35 and the first conductive plate 39b.

[0071] The insulating plate 39c also has two orifices 39e into which the fingers 39d will be inserted so as to protrude from the orifices 39e.

[0072] The cells 25 are inserted into the housings 15 of the compartment 3. The cells 25 are inserted into the housings so that in one housing out of two, the positive terminal 33 extends from the openings 17 leading into the front face 7 while in the remaining housings, the negative terminal 35 extends from the openings 17 leading into the front face 9.

[0073] The positive terminals 33 and negative terminals 35 are therefore distributed alternately at the front face 7 and the rear face 9.

[0074] Both faces are then covered with insulating and sealing cover plates 41 so as to completely close the housings 15. The insulating plates 41 are welded to the compartment 3 at the level of their edges 41a by laser welding in particular.

[0075] The insulating plates 41 further have two orifices 41b so as to receive the fingers 39d.

[0076] As illustrated in [Fig. 6], a second set of conductive plates 43 is further installed and attached to the insulating plates 4L. These plates also have openings 43a to receive the fingers 39d for the flow of current. The plates 43 are welded to the fingers 39d at the openings 43a.

[0077] To achieve a series connection, at the front face 7, the second conductive plates 43 are alternately electrically connected and welded in pairs from the first housing, while the opposing second conductive plates 43 at the rear face 9 are alternately electrically connected in pairs from the second housing. Furthermore, a second conductive plate cannot be electrically connected to more than one other second plate.

[0078] However, according to the invention, a completely different assembly is possible. For example, the block would have an electrical architecture with two cells in parallel and the groups of two parallel cells would be mounted five times in series, i.e. ten cells in total.

[0079] Each connection is made by welding two second plates 43 to a current-conducting bridge 45 which connects them two by two.

Claims

Demands

1. A block (1) of electric vehicle accumulator batteries, said block (1) comprising N solid electrolyte electrochemical cells (25), each cell (25) having two opposite slices (25a, 25b) and two terminals, one positive and the other negative (33, 35), extending respectively from said two slices (25a, 25b); characterized in that it comprises a compartment (3) having an opposite front face (7) and a rear face (9) and a row of N slots (15) ordered from 1 to N, each slot (15) having two opposite openings (17) leading respectively to said front face (7) and rear face (9) of said compartment (3), and in that the N cells (25) are respectively engaged in the N slots (15), such that the two positive and negative terminals (33,35) of each of the cells (25) extend respectively from said two opposite openings (17) of each of said housings (15) in such a way as to be able, on the one hand, to connect electrically alternately two by two from the first housing the terminals extending into the openings (17) of the front face (7) of said compartment (3), and on the other hand, to connect electrically alternately two by two from the second housing the terminals extending into the openings (17) of the rear face (9) of said compartment (3) so as to connect said N cells in series.

2. Battery block (1) according to claim 1, characterized in that the compartment (3) is substantially rectangular parallelepiped and in that it has a double wall (23) perpendicular to the housings (15) comprising circulation channels (21) for a heat transfer fluid.

3. Battery block (1) according to claim 1 or 2, characterized in that the compartment (3) is obtained by extruding aluminum.

4. Battery block (1) according to any one of claims 1 to 3, characterized in that each cell of the plurality of cells (25) comprises a plurality of active layers (26) stacked one on top of the other, each comprising a positive electrode (27) and a negative electrode (29) separated by a solid electrolyte (31); and, said positive electrodes (27) being connected to each other by the positive terminal (33) and said negative electrodes (29) being connected to each other by the negative terminal (35).

5. Battery block (1) according to any one of claims 1 to 4, characterized in that each cell (25) is surrounded by an insulating casing (37) made of polymer material.

6. Battery block (1) according to any one of claims 1 to 5, characterized in that it comprises, at the level of each slice (25a, 25b) of each cell (25), a first current-conducting plate (39b) in contact with the corresponding terminal (33, 35).

7. Battery block (1) according to claim 6, characterized in that the first current-conducting plate (39b) has two fingers (39d) extending in the opposite direction to the cell (25) and in that the block comprises an insulating and sealing cover plate (41) having two orifices (41b), each finger (39d) extending respectively through the orifices (41b).

8. Battery block (1) according to claim 7, characterized in that it comprises a second conductive plate (43) integral with the fingers (39d) of the first conductive plate (39).

9. Battery block (1) according to claim 8, characterized in that it comprises a plurality of current-conducting bridges (45) attached to the second conductive plates (43) so as to electrically connect the cells (25).

10. Motor vehicle characterized in that it comprises the battery pack (1) according to any one of the preceding claims.

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