FR3011129A1 - BATTERY MODULE FOR ELECTRIC OR HYBRID VEHICLE FOR COOLING CELLS, AND BATTERY THEREFOR - Google Patents

Abstract

The invention relates mainly to a battery module (1) for an electric or hybrid vehicle comprising at least two electrochemical cells (2) each comprising at least one positive terminal (3) and at least one negative terminal (4) projecting from the one of the faces of the cell (2). Said terminals (3, 4) of the cells (2) are electrically connected by means of at least one electrical connection device (5) arranged on the faces of the cells (2) from which said terminals (3, 4) project, each electrical connection device (5) comprises a first connecting means (7, 8) to a terminal (3, 4) of a cell (2) and a second connecting means (7, 8) to a terminal (3 , 4) of another cell (2), and each electrical connection device (5) comprises cooling means (12) able to cool said cells (2).

Description

Battery module for electric or hybrid vehicles for cooling the cells, and associated battery.

The invention mainly relates to a battery module for an electric or hybrid vehicle. The invention also relates to an associated battery comprising at least one such module. The technical field of the invention relates to energy sources with electrochemical storage comprising a plurality of electrochemical cells connected in series. These energy sources are used in particular electric batteries to ensure the traction of electric vehicles or hybrids. A battery comprises an assembly of modules which are arranged in a protective casing, these modules comprising an assembly of electrochemical cells. In the cells there are reversible electrochemical reactions to produce current when the battery is discharged, or to store energy when the battery is charging. Lithium-ion type batteries are particularly well known. The electrochemical cells may be cylindrical, prismatic or flexible. The invention relates to the field of prismatic cells which are in a rectangular shape, with a width of the order of one centimeter. Each cell includes a positive terminal and a negative terminal each of which is respectively electrically connected to an opposite negative or positive terminal of an adjacent cell. The charges and discharges of the battery cause heat generation at the cell terminals of the modules and in the electrodes of the cells supporting exothermic chemical reactions, which can lead to deterioration of these electrodes and associated cells, and reduction of their life. In order to solve this problem, the subject of the present invention is a battery module making it possible to dissipate the excess heat and to homogenize the temperature at the level of the electrodes via the terminals of the cells of the module.

For this purpose, the battery module for an electric or hybrid vehicle according to the invention comprises at least two electrochemical cells each comprising at least one positive terminal and at least one negative terminal projecting from one of the faces of the cell, characterized in that that said cell terminals are electrically connected by means of at least one electrical connection device disposed on the faces of the cells from which said terminals project, each electrical connection device comprises a first terminal connection means of a terminal cell and second connecting means to a terminal of another cell, and each electrical connecting device comprises cooling means adapted to cool said cells. In this way, the battery module according to the invention advantageously allows the batteries to be cooled at their terminals by means of an electrical connection device which also ensures the electrical connection between the cells. This cooling by the terminals is more effective than the end of the projecting terminals is the hottest part of the batteries. Preferably, each cooling means is disposed on the face of the electrical connection device opposite to that which is in contact with the cells on which the electrical connection device is arranged. Preferably, the electrical connection device provides the electrical connection of two adjacent cells. The cells of a battery module according to the invention are preferably stacked, two adjacent cells then being in contact at one of their faces. Preferably, each cooling means and at least a part of the body of the electrical connection device are thermally conductive. Advantageously, each cooling means is able to cool the batteries by being in contact with a flow of active air, such as a pulsed cold air flow, or of passive air, such as the circulating ambient air. in the associated battery. Preferably, the cell terminals of a battery module according to the invention project from the same face of said battery module. Preferably, the first connecting means is adapted to allow a connection to a positive or negative terminal of a cell and respectively the second connecting means is adapted to allow a connection to a terminal of opposite polarity of a cell.

The battery module according to the invention may also include the following optional characteristics considered in isolation or in any possible technical combination. the electrical connection device comprises an electrically conductive plate comprising at least two orifices capable of allowing respectively the passage of a terminal of a cell and a terminal of another cell, these two orifices defining the first and the second liaison medium; the establishment of the electrical connection device on the cells is thus advantageously facilitated, the simple insertion of the cell terminals in the orifices of the electrical connection device followed by a sliding movement allows to install the electrical connection device; the two orifices have a different diameter, which advantageously makes it possible to form polarizing means; the electrically conductive plate is preferably metallic; - The electrical connection device comprises at least two fixing means for securing the electrical connection device to said terminals of said cells, which ensures the maintenance of the electrical connection device on the cells; said fixing means are nuts in which said terminals engage; these nuts are preferably made of a conductive thermal material; at least one of the nuts comprises at least one lateral recess, this nut forming a cooling means; - The battery module comprises at least two electrical connection devices and said electrical connection devices are secured to each other by means of an insulating material; - The electrical connection devices are preferably all identical in particular to simplify and facilitate their manufacture, storage and installation; the shape and / or the number and / or the arrangement of the cooling means of an electrical connection device or of several separate electrical connection devices differ according to the position in the module of the cells on which the device (s) electrical connection is (are) disposed; this adaptation of the properties of the cooling means as a function of the position of the cells makes it possible to optimize the cooling, taking into account the parts of the battery module according to the invention that may be the hottest and / or the exposure to the air of the different parts of said module; said cooling means are arranged between the two connecting means of said associated electrical connection device; said cooling means are at least one rod and / or at least one fin; said cooling means are protuberances, fins or rods of different heights and / or diameters; said cooling means are preferably aligned along a plurality of lines disposed on either side of the longitudinal central axis of the electrical connection device; said cooling means are at least one protuberance and at least one fin or at least one central rod and at least one fin; the fins are preferably curved and arranged on either side of said protuberance or of said central rod; said cooling means each comprise a planar upper face; said cooling means comprising a planar upper face substantially have the shape, in a longitudinally-oriented transverse section, of an isosceles trapezium; the cells are stacked in such a way that the positive terminals and the negative terminals of all the cells of the same battery module according to the invention are respectively arranged on two opposite sides of the face of the battery module on which the device of electrical connection is arranged; the electrical connection devices thus extend substantially over the entire width of said module; The invention also relates to a battery for an electric or hybrid vehicle comprising at least one battery module of the aforementioned type. The invention also relates to a battery for electric or hybrid vehicle comprising at least one battery module of the aforesaid type disposed in a protective housing comprising a cover. The battery comprises at least one air inlet and at least one air outlet provided at the hood to form an airflow flow at the face of the battery module which comprises said cell terminals. the air inlet, the air outlet and said cooling means being arranged so that said air flow is directed towards the cooling means.

The battery according to the invention may also include the following optional features considered in isolation or in any possible technical combination: the battery cover comprises a first side wall comprising an air inlet and a second side wall opposite the first wall; side which comprises an air outlet, at least one pulsed air circulation flow is generated between the air inlet and the air outlet, said air flow stream being directed towards said air cooling means. battery modules according to the invention included in the battery; preferentially, in this case, the cells are stacked in such a way that the positive terminals and the negative terminals of all the cells of the same battery module according to the invention are respectively arranged on two opposite sides of the face of the battery module. on which the electrical connection device is arranged; the battery cover comprises a first side wall comprising at least two air inlets and a second side wall opposite to the first side wall which comprises at least two air outlets, at least two pulsed air circulation flows are generated between or by the two air inlets and the two air outlets, said air flow flows being directed towards the fixing means which can be said nuts forming cooling means; preferentially, these nuts comprise lateral recesses; the battery comprises at least one orientation partition of at least one airflow flow which extends substantially longitudinally over at least a portion of the internal face of at least one of the longitudinal walls of the hood of the battery, in the axial proximity of at least one airflow flow generated between at least one inlet and at least one associated air outlet.

Other characteristics and advantages of the invention will emerge clearly from the description which is given below, by way of indication and in no way limitative, with reference to the appended figures in which: FIG. 1 is a schematic representation, according to a view of above, an embodiment of a battery module according to the invention which comprises a stack of cells according to a first embodiment, the polarity of the terminals of the cells arranged on the same side of the module being identical; FIG. 2 is a schematic representation, in a view from above, of an embodiment of a battery module according to the invention which comprises a stack of cells according to a second variant embodiment, the polarity of the terminals of the cells. arranged on the same side being alternated; Figure 3 is a sectional view of the battery module according to the invention along the section line III-III of Figure 1; Figure 4 is a schematic representation, in a view from above, of an electrical connection device according to a first particular embodiment; Figure 5 is a schematic representation, in a side view and along arrow V, of the electrical connection device of the first embodiment of Figure 4; Figure 6 is a schematic representation, in a view from above, of an electrical connection device according to a second particular embodiment; Figure 7 is a schematic representation, in a sectional view, of the electrical connection device of the second particular embodiment along section line VII-VII of Figure 6; Figure 8 is a schematic representation, in a view from above, of an electrical connection device according to a third particular embodiment; Figure 9 is a schematic representation, in a sectional view, of the electrical connection device of the third particular embodiment along section line IX-IX of Figure 8; FIG. 10 is a schematic representation, in a view from above, of the battery module according to the invention of the first variant embodiment of FIG. 1, on which is represented the pulsed air circulation flow ensuring the cooling of the terminals. cells ; Figure 11 is a schematic representation, in a side view, of a battery according to the invention in a first configuration; Figure 12 is a schematic representation, in a side view, of a battery according to the invention in a second configuration; and FIG. 13 is a diagrammatic representation in perspective of an embodiment of an attachment nut of an electrical connection device comprising cooling means, this nut being for example used in the battery of the second configuration illustrated on FIG. FIG. 12. With reference to FIGS. 1, 3, 6, 7 and 10, the battery module 1 according to a first variant comprises a stack of electrochemical cells 2. Each cell 2 comprises on one of its faces a terminal 10 positive 3 and a negative terminal 4, also called pods. These positive 3 and negative 4 terminals may take the form of smooth rod, or threaded rod. The stack illustrated in FIG. 1 is said to be "simple" because the positive terminals 3 and the negative terminals 4 of the cells 2 of the battery module 1 are all located on the same side. In a known manner, a positive or negative terminal 4 is electrically connected to an opposite positive and negative terminal 4 respectively of an adjacent cell 2. According to the invention, the electrical connection between two adjacent cells 2 is ensured by a electrical connection device 5. This electrical connection device 20 5 is for example an electrical connection piece formed for example made of a longitudinal metal plate 6. The electrical connection device 5 comprises at least two connecting means 7, 8 so to connect the electrical connection device 5 to the cells 2. These connecting means 7, 8 are, for example, orifices 7 and 8 adapted to receive a respective positive terminal 3 and negative terminal 25. It may be provided that the orifices intended to receive the positive terminals 3 are not of the same diameter as the receiving orifices of the negative terminals 4 so that these orifices 7, 8 form die means trompage. According to a particular embodiment, these orifices 7, 8 are located at each end of the electrical connection plate 6. As can be seen in FIG. 1, the battery module of the invention 1 comprises a succession of electrical connection devices 5 arranged obliquely on the upper face of the module 1 which comprises the faces of the cells 2 comprising the positive 3 and negative 4 terminals. 301 1 1 2 9 8 As shown in Figure 3, the positive terminals 3 and negative 4 of two adjacent cells 2 respectively pass through the associated orifices 7 and 8 of the electrical connection device 5. The terminals 3, 4 are secured to this electrical connection device 5 by a single nut 9, 10 when the rod of the 5 terminal 3, 4 is threaded, or by any other fastening means known to those skilled in the art when the rod of the terminal is not threaded. According to the invention, each electrical connection device 5 comprises cooling means 12. According to a particular embodiment, these cooling means 12 are arranged between the orifices 7, 8. However, according to another embodiment, these means 12 are located on all or part of the electrical connection device 5. According to one embodiment, these cooling means 12 extend substantially perpendicularly to this electrical connection device 5, on the face of the opposite electrical connection device 5 to that which is in contact with the cells 2 on which the electrical connection device 5 is arranged. These cooling means 12 are intended to be in contact with a pulsed air circulation flow 13 (FIG. 10), created in the battery and flowing at the face of the battery module 1 comprising the cooling means 12, such as it will be described later.

According to the variant embodiment shown in FIGS. 1, 3, 6, 7 and 10, the cooling means 12 comprise a central rod 15 and a plurality of fins 16, for example eight in number, distributed four by four, on either side of the central rod 15. According to a particular embodiment shown in FIG. 6, the concave side of each fin 16 is oriented towards the central rod 15, the fins 16 arranged on the same side of the central rod 15 having in this case a central axis coincident. According to the embodiment variant shown in FIGS. 4 and 5, the cooling means 12a comprise a plurality of rods 15a, for example ten in number, distributed over the surface of the electrical connection device 5. According to a particular embodiment , the rods 15a are distributed in equal number on two lines on either side of the longitudinal central axis of the electrical connection device 5a, the rods 15a of the same line being offset longitudinally relative to the rods 15a of the other line. More specifically, the rods 15a are distributed as follows: two rods of smaller height 15a1 are arranged in the central portion of the electrical connection device 5a, four rods of medium height 15a2 are arranged in pairs on both sides small rods 15a1 and four rods of greater height 15a3 are arranged in pairs on either side of the rods of medium height 15a2. However, all other arrangements and quantities of these rods 15a can be implemented. According to the alternative embodiment shown in Figures 8 and 9, the cooling means 12b comprise a plurality of flat fins 16b distributed in different rows 17b of several fins 16b. The cooling means 12, 12a, 12b subjected to the pulsed air circulation flow 13 make it possible to cool the terminals 3, 4 of the cells 2 as well as the electrodes of these cells 2, via the associated electrical connection devices 5, 5a, 5b.

To do this and with reference to FIG. 11, the battery module 1 comprising the electrical connection devices 5b as illustrated in FIGS. 8 and 9, is placed in a protective case 20, thus forming a battery. The battery comprises in particular a cover 21 which comprises an air inlet 22 at a first side wall and an air outlet 23 at the opposite side wall, the air inlet 22 and outlet 23 being merged according to the representation of Figure 11 due to their axial alignment. These inlet 22 and air outlet 23 make it possible to create a pulsed air flow 13 which circulates at the face 24 of the module 1 while being in contact with the cooling means 12b of the electrical connection device 5b, which it This results in the cooling of the positive 3 and negative 4 terminals of the cells 2. It is also possible to provide two orientation partitions 25 of the air flow 13 extending longitudinally on the inner face of the longitudinal main wall 26 of the cover 21. of the battery protection box 20. These orientation partitions 25 of the air flow 13 make it possible to direct and confine the flow of pulsed air 13 to the cooling means 12b in order to ensure optimum heat exchange between these cooling means 12b and the flow of air. air 13. The geometry of the cooling means 12, 12a, 12b in the form of rods, flat fins or not, is evaluated and chosen according to the cooling power required. Of course, the inhomogeneity of the cooling means 12, 12a, 12b, both in their shape and in their size, promotes cooling by contact with the air flow 13. It can be expected that all the connecting devices 5, 5a, 5b of the module 1 are identical, or that the electrical connection devices 5, 5a, 5b are different depending on the position of the associated cells 2 and their need more or less important to be cooled. It will also be possible for the electrical connection devices 5, 5a, 5b to be interconnected by means of an epoxy resin insulating material or by plastic overmolding, so that all the electrical connection devices 5, 5a, 5b are only one piece to be disposed on the face of the module 1 before the latter is placed in the protective housing 20. According to the alternative embodiment shown in Figure 12, the cooling means 12c may be nuts 9, 10 for fixing the electrical connection devices 5d with the positive and negative terminals of the cells not visible in this figure. These nuts 9, 10, after tightening, protrude from the associated electrical connection device 5d, on the side opposite to that of the electrical connection device 5d being in contact with the face of the battery module 1 on which the electrical connection device 5d is arranged. According to an alternative embodiment, the nut forming cooling means 12c comprises lateral recesses 28 for increasing the contact area between the pulsed air flow and the nut 12c. As shown in FIG. 12, in this configuration, a first side wall of the hood 21 comprises two air inlets 29a, 29b, and the opposite side wall comprises two pulsed air outlets 30a, 30b. The air inlets 29a, 29b and the air outlets 30a, 30b are located respectively substantially in the longitudinal axis of the rows of the nuts 9, 10 and are merged in FIG. 12 because of their axial alignment. These air inlets 29a, 29b and 30a, 30b generate two pulsed air flows 31a, 31b which when they circulate are in contact with the nuts 12c forming cooling means. An airflow orientation partition 32a, 32b extending longitudinally on the inner face of the longitudinal main wall 26 of the cover 21 of the battery protection housing 20, is formed near each air inlet 29a. , 29b so as to confine the resulting pulsed air flow 31 at the cooling means 12c.

301 1 1 2 9 11 The electrical connection device 5d shown in Figure 12 comprises as a single cooling means 12c the nuts 9,10 for fixing positive terminals 3 and negative 4 to the electrical connection devices 5d. But it can be advantageously provided that the electrical connection devices 5 5 further comprise cooling means 12, 12a, 12b such as those described with reference to FIGS. 4 to 9. In this case, pulsed air inlets and outlets. will be provided accordingly to generate air flow streams in contact with all the cooling means 12, 12a, 12b, 12c. The use of the nuts 9, 10 comprising lateral recesses 28 to form cooling means 12c is particularly advantageous when the stack of the cells 2 is such that the positive 3 and negative 4 terminals of the cells 2 of the stack are alternately arranged on one side and the other of the module 1 (Figure 2). As shown in this FIG. 2, in this configuration, the electrical connection devices 5d connecting a positive or negative terminal 4 to the opposite negative 4 or positive 3 terminal of the adjacent cell 2 are of short length and are not do not extend over the width of the module unlike the electrical connection devices 5, 5a, 5b designed for single stacking (Figure 1).

The presence of the nuts forming cooling means 12c thus makes it possible to have cooling means available when the cells 2 are stacked in such a way that the positive 3 and negative 4 terminals on the same side are alternated. The electrical connection device 5, 5a, 5b, 5d of the invention from which the cooling means 12, 12a, 12b, 12c extend, that they are directly secured to the electrical connection device 5, 5a 5b, as is the case for the configurations of FIGS. 4 to 9, or that they are nuts for fixing the electrical connection device 5d with the positive 3 and negative 4 terminals of the cells 2, makes it possible to perform a dual function electrical connection and cooling, the latter function being implemented by the circulation of the pulsed air stream (s) in the battery.

Claims (16)

REVENDICATIONS1. Battery module (1) for an electric or hybrid vehicle comprising at least two electrochemical cells (2) each comprising at least one positive terminal (3) and at least one negative terminal (4) projecting from one of the faces of the cell (2), characterized in that said terminals (3, 4) of the cells (2) are electrically connected by means of at least one electrical connection device (5, 5a, 5b, 5d) arranged on the faces of the cells ( 2) from which said terminals (3, 4) protrude, each electrical connection device (5, 5a, 5b, 5d) comprises a first connection means (7, 8) to a terminal (3, 4) of a cell (2) and a second connecting means (7, 8) to a terminal (3, 4) of another cell (2), and each electrical connection device (5, 5a, 5b, 5d) comprises means cooling system (12, 12a, 12b, 12c) suitable for cooling said cells (2). 2. Battery module (1) according to claim 1, characterized in that each cooling means (12, 12a, 12b, 12c) is disposed on the face of the electrical connection device (5, 5a, 5b, 5d) opposite to that in contact with the cells (2) on which the electrical connection device (5, 5a, 5b, 5d) is arranged. 3. Battery module (1) according to one of claims 1 and 2, characterized in that the electrical connection device (5, 5a, 5b, 5d) provides the electrical connection of two adjacent cells (2). 4. Battery module (1) according to any one of claims 1 to 3, characterized in that the electrical connection device (5, 5a, 5b, 5d) comprises an electrically conductive plate (6) comprising at least two orifices (7, 8) adapted respectively to allow the passage of a terminal (3, 4) of a cell (2) and a terminal (3, 4) of another cell (2), these two orifices ( 7, 8) defining the first and the second connecting means (7, 8). 5. Battery module (1) according to claim 4, characterized in that the two orifices (7, 8) have a different diameter. 6. Battery module (1) according to any one of the preceding claims, characterized in that the electrical connection device (5, 5a, 5b, 5d) comprises at least two fastening means (9, 10) for securing the electrical connection device (5, 5a, 5b, 5d) at said terminals of said cells (2). 7. Battery module (1) according to claim 6, characterized in that said fixing means (9, 10) are nuts in which said terminals engage. 8. Battery module (1) according to claim 7, characterized in that at least one of the nuts (9, 10) comprises at least one lateral recess (28), this nut (9, 10) forming a cooling means (12). Battery module (1) according to any one of the preceding claims, characterized in that the battery module (1) comprises at least two electrical connection devices (5, 5a, 5b, 5d) and said connection devices electrical (5, 5a, 5b, 5d) are secured to each other by means of an insulating material. 10. Battery module (1) according to any one of the preceding claims, characterized in that the shape and / or the number and / or the arrangement of the cooling means (12, 12a, 12b, 12c) of a device electrical connection (5, 5a, 5b, 5d) or a plurality of separate electrical connection devices (5, 5a, 5b, 5d) differ depending on the position in the module (1) of the cells (2) on which the device or device (s) electrical connection (5, 5a, 5b, 5d) is (are) arranged (s). 11. Battery module (1) according to any one of the preceding claims, characterized in that said cooling means (12, 12a, 12b) are arranged between the two connecting means (7, 8) of said electrical connection device. associated (5, 5a, 5b). 12. Battery module (1) according to any one of the preceding claims, characterized in that said cooling means (12, 12a, 12b) are at least one rod and / or at least one fin. 13. Battery module (1) according to any one of the preceding claims, characterized in that said cooling means (12a) are protuberances, fins or rods (15a1, 15a2, 15a3) of different heights and / or diameters. 14. Battery module (1) according to any one of the preceding claims, characterized in that the cooling means (12) are at least one protuberance and at least one fin (16) or at least one central rod (15) and at least one fin (16). 15 15. Battery for electric or hybrid vehicle comprising at least one battery module (1) according to any one of the preceding claims. 16. Battery for electric or hybrid vehicle comprising at least one battery module (1) according to any one of claims 1 to 14 disposed in a protective housing (20) comprising a cover (21), characterized in that it comprises at least one air inlet (22; 29a, 29b) and at least one air outlet (23; 30a, 30b) provided at the hood (21) to form an air flow ( 13; 31a, 31b) at the face of the battery module (1) which comprises said terminals (3,4) of the cells (2), the air inlet (22; 29a, 29b), the exit of air (23; 30a, 30b) and said cooling means (12, 12a, 12b, 12c) being arranged in such a way that said air flow (13; 31a, 31b) is directed towards the cooling means (12, 12a, 12b, 12c). 10 30