The present invention relates to the field of the storage of electrical energy, more particularly that of electric batteries comprising a plurality of individual accumulators, in particular batteries for motor vehicles, and the subjects thereof are a battery module and a battery comprising at least one such module.
Many batteries, in particular with great autonomy and high power, in particular batteries on board combustion engine vehicles, hybrid vehicles and electric vehicles, are currently made up of a large number of individual battery elements (elementary accumulators), in particular of the Li-ion or Li-polymer type.
Each of these elements is, as standard, in the form of a sealed and electrically insulated cylinder provided with connection terminals at its opposite ends or at one end. In order to be kept fixed in the assembled state, they are connected together, generally by adhesive bonding or resin bonding, in blocks or packs, on one or more stage(s).
However, such an assembly held together with a binder material exhibits drawbacks.
Thus, when the number thereof is high, overheating (on account of a short-circuit or a malfunction) of an element may damage the entire battery by contamination and amplification caused by the confinement. Moreover, temperature control of the internal elements of such a pack by natural ventilation is problematic, if not impossible. Moreover, in the event of one element of a pack failing, the entire pack has to be changed. Lastly, the integrity over time of the material assembly under demanding climatic conditions and/or in a harsh vibratory environment is questionable and the quality of production of the assembly may be dubious and variable.
In order to try to overcome these drawbacks, means for mechanically joining the elements together, in a protective casing, have been proposed.
However, generally, these known solutions employ a large number of separate holding parts, requiring an outer shell that is strong and able to take up the internal stresses, involving tedious assembly operations, and/or are not designed for the purpose of effective thermal control of all of the elements, or for protecting the majority of the elements if just one of them fails.
Therefore, the problem addressed by the invention consists, first, in providing a simple battery embodiment in which the elements are held, individually, securely in place without a material connection or bonding between one another, and are advantageously protected if one of them fails, specifically with the aid of only mechanical means.
Moreover, the proposed embodiment should provide improved thermal control compared with the known solutions, without the design being more complex and without the need for forced ventilation.
Lastly, the proposed embodiment should be able to be easily adaptable to battery formats of variable size and power, and easy to manufacture, with identical base components and a similar assembly process, preferably in two successive aggregation phases, regardless of the final battery format.
At least the main problem above is solved by the invention by virtue of an electric battery module, in particular a motor vehicle battery module, comprising a plurality of individual accumulators in the form of battery elements or cells, of elongate, advantageously cylindrical, shape, preferably with a circular section, these battery elements being connected electrically together and to the connection terminals of the module and mounted in a container forming part of said module,
said battery module being characterized in that said container comprises:
The invention will be understood better by virtue of the following description, which relates to preferred embodiments that are given by way of nonlimiting examples and are explained by reference to the appended schematic drawings, in which:
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In accordance with the invention, said container 3 comprises:
Thus, by providing a profiled support body 4 with a comb-shaped section, the plurality of battery elements 2, although remaining grouped together (high power density), is stored in a manner segmented into rows Ri by compartmentalizing walls 5″ of the support body 4, the latter thus allowing them to be kept firmly in place, to be separated physically and electrically (mutual isolation of the rows Ri) and to be thermally controlled effectively (individualized arrangement and holding of the elements 2 with creation of air-circulation gaps).
The precise and individual holding of the battery elements 2 in the grooves 5 of the support body 4 provided by the first wedging means 6 allows the formation and maintenance of air-circulation gaps along the rows Ri, and around and possibly between the elements 2 of each row.
As shown in particular in
Thus, each pair of ladders 6 is shown in a profiled housing 5 in a layered manner (that is to say with their side members 6′ parallel to the longitudinal direction DL of the housing 5 in question) and provided with individual perforated recesses for receiving battery elements 2 in a wedged manner. Each ladder 6 may extend along the entire length of a housing 5 or preferably along only a whole fraction thereof.
The second wedging element(s) 7, preferably with surface extension, help to promote the interaction between the perforated components 6 (forming the first wedging elements 6 and framing, in pairs, the battery elements 2 between one another), for the one part, and the elements 2 that they sandwich between one another, for the other part. This/these second wedging element(s) 7 also complete(s) the locking of said elements 2 in position in the space by way of the first wedging element 6 and by acting on the latter.
In addition, this/these second wedging element(s) 7 also help, of course, on account of its/their shape and its/their position, to keep, in the support body 4, the ladders 6 and the battery elements 2, which the latter frame and confine, in the profiled housings 5.
The or each second wedging element 7 may either by fixed directly to the support body 4 or be held on and against the latter under pressure by a cover 23, or both.
In a similar way to the first wedging elements 6, the second wedging element(s) 7 advantageously also has/have a perforated shape allowing a free circulation of the air in the container 3. In addition, by urging the first wedging elements 6 toward the battery elements 2, the second wedging element(s) 7 keep said elements 2 and 6 away from the lateral walls 5″ (at least in the upper part, at the free edges of the walls 5″).
Preferably, the support body 4 consists of a profiled component of comb-shaped cross section, comprising a plurality of parallel compartmentalizing walls 5″ that are regularly spaced apart from one another and form, with a common bottom wall 8, the elongate housings 5 (
The battery elements 2, which are arranged in simple alignments and each have a cylindrical shape, are consequently exposed over their entire lateral surface to the air flows that circulate and are controlled by the support body 4, in particular when said elements are kept at a small distance from one another by the first wedging elements 6 (for example by providing projections 9″ in the form of wedges with curved contact zones 9, 9′—see
In addition to locking the battery elements 2 in position in multiple directions (two axes and one half-axis), the support body 4 of comb-shaped section also forms, with its two exterior lateral walls and its bottom wall, a protective shell.
According to one feature of the invention, which can be seen in particular in
Advantageously, each crossmember 6″ has, along at least a part of its length, continuously or discontinuously, at least one pair of beveled, flat or curved, contact surfaces 9, 9′ that are intended to come into contact with two adjacent battery elements 2 of a row Ri.
The beveled surfaces 9, 9′ may for example be formed by the inclined surfaces of upper and lower projections 9″, which are in one piece with the crossmembers 6″ and form wedges or stop blocks that are tapered or the like, being positioned between two battery elements 2 in the joined-together state of the module 1.
According to one very favorable feature of the invention, illustrated in particular in
These blocks 10 form modular assemblies that are preassembled before they are fitted as a group in a housing 5 of the support body 4.
In these blocks 2″, which comprise for example 4 or 8 battery elements 2 each, the elements 2 can be oriented in an identical or non-identical manner (for example each half of the elements 2 may have its own orientation, which is the reverse of that of the other half).
Thus, each battery element 2 is held in two opposite frames that are each closed by two lateral crossmembers 6″ and two, upper and lower, side member portions 6′ of two first, opposite wedging elements 6 (
Each pair of mutually opposite first wedging components 6 thus forms a cage confining at least a part of the battery elements 2 of the row Ri received in the profiled housing 5 in question. The alignment of elements 2 in the row is thus segmented or subdivided by these pairs of opposite components 6 into modular structural and functional units, each enclosing several elements (4, 8 or 12 for example).
As is shown in
A pressure exerted on the second wedging element 7, of which there is preferably one for a given module 1, thus moves the two first wedging elements in question apart from one another and from the wall 5″ that separates them.
The side members 6′ advantageously have complementary sites 11 that cooperate with said projections 7′ so as likewise to effect fixing in the longitudinal direction DL of the elongate housings 5 between said first wedging elements 6 and second wedging element(s) 7 (and therefore likewise locking the battery elements 2 in position in said direction DL).
Advantageously, the or each second wedging element 7 consists of a meshwork plate having projections 7′ at the intersections of the mesh, these projections 7′ advantageously having a conical or frustoconical shape and the complementary sites 11 of the side members 6′ of the first wedging members 6 then consisting of partially circular cutouts that are preferably each situated facing a crossmember 6″ (
The perforated plate(s) forming the second wedging elements 7 may, furthermore, have second formations 7′″ in the form of pegs or spikes, which can serve as insertion stops for the first projections 7′ and/or as securing means involving interlocking in complementary sites and/or as positioning stops for the plates, strips or terminals forming the upper connection means 14′, which are complementary to the lower conductive strips 14.
In accordance with a design feature that is beneficial to the invention, reinforcing and stiffening the support body 4 and contributing to the wedging of the battery elements 2 in the housings 5, provision may be made for the bases of the lateral walls 5″ of the elongate housings 5, said bases being connected to the bottom wall 8 of the support body 4, to have, in cross section, a shape that flares in the direction of the common bottom wall 8, thereby forming a junction zone 12 with beveled surfaces 12′, i.e. surfaces that are inclined with respect to the bottoms 5′ of the housings 5, and for the lower side members 6′ of the first wedging elements 6 to come to bear, under the pressure of the projections 7′ of the second wedging element(s) 7, and if appropriate under the weight of the battery elements 2 that they confine or frame, against the beveled surfaces 12′, and thus to be urged toward said battery elements 2 (
The lower side members 6′ advantageously have an opposite bevel to that 12′ of the bottoms 5′ of the housings 5 (
Moreover, in order to simultaneously ensure secure locking in position, in spite of manufacturing tolerances, in particular in the direction of the longitudinal axes AL of the battery elements 2, in an isolated manner or in blocks 10, and at the same time to ensure the necessary electrical connection between these elements 2, the invention advantageously provides for the battery elements 2 to come to bear against the bottoms 5′ of the housings 5 that receive them via flexible strips 13 of elastically compressible material, which is a good heat conductor and preferably an electrical insulator, each flexible strip 13 extending over at least a part of the housing 5 in question. Moreover, electrically conductive lines or strips 14 that form part of the means 14′ for electrically connecting the battery elements 2 together are disposed between said battery elements 2 and said flexible strips 13, in a manner integrated or not integrated therewith (
The elastic compressibility of the material forming the flexible strips 13 makes it possible to ensure that all the battery elements 2 of a module 1 are immobilized in spite of any manufacturing and/or assembly discrepancies and to avoid hard impacts and the generation of noise in the event of vibrations.
According to another aspect of the invention, relating to the problem of temperature control, at least the common bottom wall 8 defining the bottoms 5′, of the different elongate housings 5 of the support body 4 and preferably also their lateral walls 5″, is (are) made of a material that is a good heat conductor, each elongate housing 5 having, at its bottom 5′, a formation 15 that defines a profiled protruding surface that serves as a support base for the battery elements 2 received in the housing 5 in question, advantageously via compressible strips 13, 14 that are electrically insulating or conductive, respectively, and thermally conductive.
Preferably, the profiled support body 4 is made entirely and in one piece from a material that is a good heat conductor, advantageously a metal material, preferably aluminum or an alloy thereof, for example in the form of an extruded component. Advantageously, the first wedging elements 6 and second wedging element(s) 7 consist of components injection molded from plastics material.
The temperature control of the support body 4 and of the battery elements 2 by a suitable means can be realized in different ways, for example by the Peltier effect, by exposure of a temperature-controlled forced air flow or the like.
However, according to one embodiment which is effective, economical and easily structurally integrable, provision is advantageously made for the bottoms 5′ of the different elongate housings 5 of the support body 4, which, where appropriate, form a common bottom wall 15, to be subjected to the action of a thermal control means 16, for example of the type involving the circulation of a heat-transfer fluid 16′, this thermal control means 16 either being attached to the support body 4 of the module 1, in that it belongs to one module 1 or is shared between two modules 1, or being associated with said module 1 by being in contact therewith, being secured thereto or cooperating therewith, in that it belongs to a set of thermal control means common to several modules 1.
Such a thermal control means 16 may also be easily connected to the fluid circulation circuits of a vehicle, in the case of an onboard battery.
In order to promote and optimize the transmission of the effects of the thermal control between the walls 5″ and the air circulating by natural (or forced) convection, provision may also be made for the lateral walls 5″ of the elongate housings 5 to have, on their two opposite faces, a non-flat surface structure 17, for example a pattern of ribs/grooves or profiled undulations.
The different technical provisions mentioned above make it possible to arrive at optimized thermal control in the case of battery elements 2 that exhibit much higher thermal conduction (by a factor of at least 5, or preferably at least by a factor of 10) along their longitudinal axis AL than in their radial direction, this being associated with a circular cylindrical or at least elliptical shape.
Specifically, the bearing of the battery elements 2 on the strips 13, 14 (the strips 13 being made for example of filled silicone and the strips or lines 14 being metallic) and on the bottom wall 8, these all being thermally conductive, allows good heat transfer by conduction at the bottoms 5′ of the housings 5.
In addition, on account of their cylindrical outer shape, the battery elements 2 have an outer lateral surface that is entirely exposed to the circulation of natural air internal to the module 1, even when the adjacent elements 2 of a block 10 or of a row Ri are in contact (maximum occupation density). However, the fixing of a free interval, even a narrow slot (for example at most equal to 1 mm in width), between two adjacent elements 2 can contribute favorably to a circulation of air around said elements 2 and therefore to the thermal control thereof by natural volumetric air circulation, without compromising the energy storage density of the module 1.
Furthermore, a perforated structure, for the one part, of the crossmembers 6″ of the first wedging elements 6 in the form of ladders or of frames with cross pieces and, for the other part, of the plate forming the second wedging element 7, and also a height of the compartmentalizing walls 5″ less than that of the blocks 10 also promotes the circulation of air by natural convection in a battery 22 containing one or more battery modules 1.
In addition, through the subdivision into several levels of the group of battery elements 2 forming the module 1, the effects of temperature control are felt at the very heart of the collection of battery elements 2, by exposing them individually to the temperature control action of the conductive lateral and bottom walls 5″ and 8—control transposed directly to the interior of the group of battery elements 2 forming the module 1.
Said strips or lines 14 are advantageously part of a device for electrically interconnecting the different elements 2 in the form of a set of lower 14 and upper 14′ bars that connect together adjacent elements 2 in order to connect them in parallel, these groups of elements 2 in parallel of one and the same row Ri being themselves connected in series or in parallel/series (see arrangement and interconnection of the elements 2 in
More specifically, the electrical connection of the battery elements 2 of a module 1 may, for example, be organized advantageously on three different levels, depending in particular on the desired voltage/current ratio for a design of a given module 1 (total number of elements 2, length and number of housings 5 of the support body 4).
Thus, a first electrical connection level can be realized between the battery elements 2 of an alignment of elements 2 of a block 10: it can be of the parallel, parallel/series or series type depending on the desired characteristics.
A second electrical connection level can be realized between blocks 10, which are adjacent or non-adjacent, of a row Ri of elements 2 mounted in an aligned and wedged manner in an elongate housing 5 of the support body 4.
Lastly, the third electrical connection level can consist in linking the different rows Ri together and to a common connector 1′ for interfacing with and connecting to the outside that belongs to the module 1 in question.
These electrical connections between elements 2 of a block 10, between blocks 10 that make up a row Ri and between rows Ri of a module 1 are realized by combination of the lower conductive strips or lines 14 and the upper conductive strips 14′, together forming a structured electrical connection network linked to the lower and upper terminals of the elements 2, as can be seen in particular from the appended figures.
In accordance with a preferred design variant of the invention, which is both compact and effective and illustrated in particular in
Advantageously, the internal volume of the double bottom 19 comprises one or more path(s) for the heat transfer fluid 16′ to circulate between an inlet port 20 and an outlet port 20′, this/these path(s) being formed either only by formations 18′ integrated into the attached wall 18 of the double bottom 19 or by cooperation of mutually complementary formations present respectively on the common bottom wall 8 and on the attached wall 18.
The circulation paths may in particular comprise main circulation ducts 20″ formed laterally in the continuation of the ports 20 and 20′; and optionally transverse secondary circulation paths or routes (not shown specifically), fluid likewise being able to circulate through the entire volume of the double bottom 19, which may or may not be transversely compartmentalized.
In order to allow easy and strong assembly, provision may be made for the profiled support body 4 to have, along the lateral sides of the common bottom wall 8, outwardly protruding lips 21, and for the attached wall 18, which forms the double bottom 19 with the common bottom wall 8, to be secured to said support body 4 at said lips 21, for example by clip-fastening means 21′, by screw means or by similar mechanical assembly means.
The invention also relates, as shown in
As can be seen from the abovementioned figures, the battery 22 may be adapted to a large number of formats (size, power) depending on the envisioned use (slave battery, main energy source, backup battery, etc.) and on the power and/or energy that is/are required.
According to a first embodiment of the invention, which can be seen in
The cover 23 may in particular be fixed to reinforced lips or protruding end flanges 4′ of the outer lateral walls of the support body 4.
This cover 23 may be made in one piece or be formed of a plurality of constituent parts that are joined together.
This cover 23, which is fixed by being screwed or clip-fastened for example at lateral flanges or upper lips of the support body 4, may be involved in locking the second wedging element 7 in position on the blocks 10, for example by way of deformed or indented zones 23′ that engage by cooperating with projections 7′ at their recessed ends opposite to their conical ends that provide the beveled surfaces 7″.
According to a second embodiment of the invention, which can be seen in
Lastly, according to a third embodiment of the invention, which is illustrated partially in
The thermal control means integrated in the tray 24 and, if appropriate, in the cover 24′ of the casing may, for example, correspond to the control means described and shown in more detail in the French patent applications 1853129, 1853131 et 1856167 in the name of the applicant.
The invention also relates to a method for producing a battery module 1 as described above, characterized in that it consists essentially in forming battery sub-modules 10 by confining a plurality of battery elements 2 between two first wedging elements 6 in the form of frames provided with transverse crossmembers 6″, in fitting these sub-modules 10 in the different elongate housings 5 of a profiled support body 4 having a comb-shaped section, advantageously with elastically compressible and conductive strips 13, 14 being interposed at the bottoms 5′ of the housings 5, in fitting complementary means for electrically connecting the different battery elements 2, in attaching at least one second wedging element 7 above the elongate housings 5, this engaging with the first wedging elements 6 and locking the sub-modules 10 in position in the housings 5, preferably with pressurization, on account of said second wedging element 7 being fixed to the support body 4 and/or of the bearing of a cover 23 at least partially covering said support body 4.
Lastly, the invention also relates to a method for manufacturing a battery 22 as described above.
This method is characterized in that it consists in producing one or more battery module(s) (1), advantageously by implementing the method for producing a battery module, and then, depending on the desired type of resultant battery 22, in carrying out one of the three following sets of consecutive operations a), b) or c):
Of course, the invention is not limited to the embodiments described and shown in the appended drawings. Modifications remain possible, in particular as regards the makeup of various elements or by substitution of equivalent techniques, without otherwise departing from the scope of protection of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1874281 | Dec 2018 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/086906 | 12/23/2019 | WO | 00 |