FR3125360A1 - Electricity storage battery and corresponding manufacturing method - Google Patents

Abstract

Electricity storage battery and corresponding manufacturing method The electricity storage battery (3) comprises beams (33, 35) delimiting a plurality of compartments (37) for receiving electricity storage modules (5), a set (39) of resin elements, separate and independent of each other, being attached to the beams (33, 35), each resin element defining at least part of the internal surface of at least one of the compartments (37). Figure for abstract: 3

Description

Electricity storage battery and corresponding manufacturing method

The present invention generally relates to electricity storage batteries.

It is possible to provide that such an electricity storage battery includes:

- a plurality of modules, each module comprising a plurality of juxtaposed electricity storage cells in a transverse direction;

- An envelope internally delimiting a volume for receiving the modules;

- beams integral with the envelope and dividing the reception volume into a plurality of compartments, each module being received in one of the compartments.

The application filed in France under No. 2105349 proposes to overmold the cells of the same module using a layer of resin.

Such an approach offers the advantage that it is relatively easy to control the dimensions of the module in length, i.e. in the transverse direction, and in width, i.e. in the longitudinal direction. Indeed, the cumulative dimension tolerances of all the cells of the same module are relatively large, and this can be a problem for inserting the module in a compartment of determined length. With overmoulding, the length tolerance is that resulting from the resin layer molding operation. The individual dimension tolerances of each cell have virtually no impact.

Furthermore, the overmolded resin layer can advantageously be used to organize the circulation of a heat transfer fluid in contact with the cells, in particular in the case where the heat transfer fluid is a dielectric liquid circulating in direct contact with the cells.

Yet another advantage is that it is possible to replace a defective cell in a module, relatively easily.

However, the resin adheres very well to the cells, which makes its recycling relatively difficult. It is first necessary to rid the cells of the resin before treating them.

In addition, replacing the faulty cell in a module first requires cutting the resin layer. Then, after extracting the faulty cell and replacing it with a new cell, it is necessary to make a connection in the resin layer, which can be tricky.

In this context, the invention aims to provide an electricity storage battery in which the replacement of defective cells is facilitated, and which remains easy to manufacture.

To this end, the invention relates to an electricity storage battery, the battery comprising:
- a plurality of modules, each module comprising a plurality of juxtaposed electricity storage cells in a transverse direction;

- An envelope internally delimiting a volume for receiving the modules;

- beams integral with the envelope and dividing the reception volume into a plurality of compartments each delimited by an internal surface, each module being received in one of the compartments;

- a set of resin elements, separate and independent of each other, attached to the beams, each resin element defining at least part of the internal surface of at least one of the compartments.

Thus, the resin elements defining the internal surface of the compartments are attached to the beams.

By this we mean that these elements are manufactured during a stage preceding the installation on the beams. At the end of the manufacturing stage, and before installation on the beams, these elements already have their final shape.

Consequently, the layer of resin surrounding each module is no longer a layer integral with the module, which must be cut to replace one of the cells.

Replacement of cells is facilitated.

Furthermore, the resin elements are separate and independent of each other.

In other words, the compartments are dressed with a plurality of resin elements, this dressing being made up of several independent parts from each other.

By disjoint and independent, we mean here that the resin elements are not parts of the same part injected or formed directly in the envelope. These elements are not directly attached to each other. They are each mounted on one of the beams, and are held in position relative to each other by means of the beams and the battery casing.

These resin elements are therefore small parts, easy to produce, transport and mount on the beams of the battery.

Cell recycling is also facilitated because the resin does not adhere to the cells.

In addition, it is possible to remove the cells one by one, which was not possible in the application filed in France under No. 2105349.

The manufacture of the battery is faster than when the resin elements are overmolded in the envelope, as envisaged in the application filed under number FR2007331. The number and cost of machines needed for manufacturing are significantly reduced.

Resin elements can be used for tolerance management and cell respiration, regardless of cell geometry. This aspect is less well mastered in the application filed under number FR2007331.

The battery is much more compact than that of the application filed under the number FR2007331. Here, compactness means the ratio between the volume of the cells and the volume of the battery.

The battery may also have one or more of the characteristics below, considered individually or in all technically possible combinations:

• the beams include cross beams, the resin member assembly comprising a plurality of cross members each having an upstanding portion straddling one of the cross beams, the upstanding portion having two upstanding flanges spanning two opposite major faces of said cross beam;
• said transverse element comprises at least one side wing, extending one of the upright wings and defining the bottom of a compartment delimited by said transverse beam;
• the electricity storage cells of the same module have respective large faces facing each other, the transverse elements of the set of resin elements placed on the two transverse beams delimiting the same compartment having lateral flanges respectively delimiting a portion of the bottom of said compartment, said side wings being separated from each other by a distribution channel distributing a heat transfer fluid in cooling channels provided between the large faces of the electricity storage cells;
• the electricity storage cells of the same module each have three small faces placed opposite the bottom and transverse beams delimiting the reception compartment of said module, the transverse elements of the set of resin elements placed on said transverse beams delimiting, for each electricity storage cell, a circulation channel for a heat transfer fluid in contact with the three small faces;
• the transverse beams comprise end transverse beams having a large inner face delimiting one of the compartments and a large outer face facing the envelope, a stiffening element being fixed to the large outer face of each transverse beam end;
• the battery comprises bars for blocking the modules in the corresponding compartments, fixed to the transverse beams and projecting above the modules;
• the beams include longitudinal beams bounding each compartment at opposite transverse ends, the resin member assembly comprising a plurality of longitudinal members each having an upstanding portion straddling one of the longitudinal beams, the upstanding portion having a flange inner upright covering a large inner face of said longitudinal beam facing the interior of the compartment;
• the upright inner wing bears reliefs projecting towards the interior of the compartment, the module resting on the reliefs; And
• the battery comprises a cooling circuit for the electricity storage cells, filled with a heat transfer fluid, the cooling circuit comprises a heat transfer fluid distribution manifold and a heat transfer fluid evacuation manifold, at least one of the elements in resin having a raised part placed astride one of the beams, the raised part having an inner raised wing delimiting the internal surface of one of the compartments and an outer raised wing delimiting the distribution manifold and/or the evacuation manifold.

According to a second aspect, the invention relates to a method for manufacturing an electricity storage battery having the above characteristics, and comprising the following steps:

- obtaining the plurality of modules;

- obtaining the envelope;

- obtaining the beams and fixing the beams to the envelope;

- obtaining the plurality of resin elements, disjoint and independent of each other;

- installation of the plurality of resin elements on the beams;

- inserting the modules into the compartments.

Other characteristics and advantages of the invention will emerge from the detailed description given below, by way of indication and in no way limiting, with reference to the appended figures, among which:

- there is a simplified schematic representation of a motor vehicle equipped with an electricity storage battery according to the invention;

- there is a perspective view of an electricity storage battery according to a first embodiment, part of the cover not being shown to show internal components of the battery;

- there is a perspective view of a compartment for the first embodiment of the battery, partially filled by the cells to reveal the circulation channels of the heat transfer fluid in contact with the large faces of the cells;

- there is a sectional view in a plane perpendicular to the transverse direction, showing two compartments for the first embodiment of the battery;

- there is a sectional view of an end cross beam of the battery of the , and the resin element arranged on this beam;

- there is a side view of a longitudinal beam of the compartment of the , and the resin element arranged on this beam;

- there is a side view of one end of the compartment of the , partially in section, for an alternative embodiment of the invention;

- there is a perspective view of the battery of the , the cover, the cells and the resin elements not being shown;

- there is a perspective view of the inserts delimiting the heat transfer fluid distribution and evacuation manifolds on the ;

- Figures 10 and 11 are perspective views of the end transverse beams and resin elements arranged on these beams, for a variant of the first embodiment of the battery;

- there is a perspective view of a compartment for a second embodiment of the battery;

- there is a perspective view of a resin element attached to a transverse beam of the compartment of the ;

- there is a sectional view in perpendicular to the transverse direction, showing two compartments for the second embodiment of the battery;

- there is a perspective view of a module locking bar mounted on a cross beam;

- there is a perspective view from below, of the blocking bar of the ; And

- there is a top view of the lower part of the battery according to the second embodiment, with a schematic representation of the cell cooling circuit.

The vehicle 1 represented on the is equipped with an electricity storage battery 3.

This vehicle is typically a motor vehicle, for example a car, a bus, a truck, etc.

This vehicle comprises, for example, an electric propulsion motor powered electrically by the electricity storage battery 3. The vehicle is propelled exclusively by the electric motor.

As a variant, the vehicle is of the hybrid type and thus comprises a heat engine and an electric motor powered electrically by the electric battery.

According to yet another variant, the vehicle is propelled by a combustion engine, the electric battery being provided to electrically supply other equipment of the vehicle, for example the starter, the lights, etc.

The electricity storage battery 3 comprises, as seen in Figures 2 and 17, a plurality of modules 5.

Each module 5 comprises a plurality of electricity storage cells 7 juxtaposed in a transverse direction T. The transverse direction T is materialized in certain figures.

The 7 electricity storage cells constitute an alignment.

Each electricity storage cell 7 has two large faces 9, perpendicular to the transverse direction T ( ).

Each electricity storage cell 7 also has an upper face 11, connecting two large faces 9 to each other. The upper face 11 carries electrical contacts 13.

Each electricity storage cell 7 also has three small faces, each connecting the two large faces 9 to each other ( ).

One of the small faces, hereinafter referred to as the lower face 15, is opposite the upper face 11.

Two of the small faces, referred to here as side faces 17, are opposite to each other.

Typically, the electricity storage cells 7 are of prismatic shapes. The side faces 17 are perpendicular to the large faces 9, to the upper face 11 and to the lower face 15. The upper face 11 and the lower face 15 are perpendicular to the large faces 9.

The upper face 11 and the lower face 15 are perpendicular to a direction of elevation E, materialized on certain figs.

The side faces 17 are perpendicular to a longitudinal direction L, materialized at least in certain figures.

The elevation direction E, the longitudinal direction L and the transverse direction T are perpendicular to each other.

The direction of elevation E is generally perpendicular to the rolling plane of the vehicle 1 when the battery 3 is mounted on board the latter.

In the present description, the top, the bottom, the top, the bottom, the upper and lower sides get along according to the direction of elevation E.

Two adjacent electricity storage cells 7 in alignment have large faces 9 facing each other.

The upper faces 11 of the electricity storage cells 7, carrying the electrical contacts 13, face the same side and are aligned in the transverse direction T.

The electrical contacts 13 of the different electricity storage cells 7 of the module 5 are connected to each other so as to place the electricity storage cells 7 in series and/or in parallel.

The connectors for connecting the electrical contacts 13 to each other are not shown.

The side faces 17 of the electricity storage cells 7 are aligned in the transverse direction T, and are substantially inscribed in two side planes parallel to each other, and perpendicular to the longitudinal direction L.

Similarly, the lower faces 15 are aligned in the transverse direction T and are substantially inscribed in the same lower plane perpendicular to the elevation direction E.

The electricity storage cells 7 of the same module 5 therefore together have the general shape of a parallelepipedic block, having an elongated shape in the transverse direction T.

The number of modules 5 provided in the battery 3 depends on the desired electricity storage capacity.

They are arranged in one or more rows, depending on the case.

In the embodiment of Figures 2 to 8, the battery 3 comprises nine modules 5, each module 5 comprising twenty electricity storage cells 7.

The modules 5 are arranged side by side in the longitudinal direction L, in a single row. They are all parallel to each other.

In the embodiment of the , the battery 3 comprises sixteen modules 5, each module 5 comprising twelve electricity storage cells 7.

The 5 modules are arranged on a grid, in two rows of eight 5 modules.

In the same row, the modules 5 are juxtaposed in the longitudinal direction L.

Typically, each module 5 comprises between six and thirty electricity storage cells 7.

Electricity storage battery 3 further comprises an envelope 19, internally delimiting a volume 21 for receiving modules 5 ( ).

In the example shown, the envelope 19 has a bottom 23.

The bottom 23 is for example in the form of a substantially flat plate.

The bottom 23 carries the electricity storage cells 7.

It is substantially perpendicular to the elevation direction E.

The envelope 19 also includes a cover 25, visible at least on the .

The lid 25 has a concave shape towards the bottom 23. The lid 25, in the example shown, has an upper bottom 27 and a peripheral edge 29 surrounding the upper bottom 27. The peripheral edge 29 rises from the upper bottom 27 down 23.

The peripheral edge 29 is extended by an outgoing flange 31 resting against the bottom 23.

The electricity storage battery 3 further comprises a set of beams 33, 35 integral with the casing 19 and dividing the reception volume 21 into a plurality of compartments 37.

The beams 33, 35 are typically metal plates. They are rigidly fixed to the bottom 23.

As seen on the , the set of beams comprises beams 33 of transverse orientation.

The beams further comprise beams 35 of longitudinal orientation.

Each compartment 37 is delimited by two transverse beams 33 opposite to each other, and two longitudinal beams 35 opposite to each other.

The transverse beams 33 are all parallel to each other. They are part of planes parallel to each other, containing the transverse direction T and the elevation direction E.

The longitudinal beams 35 are also parallel to each other. They fit into planes containing the longitudinal direction L and the elevation direction E.

Certain transverse beams 33, referred to below as central transverse beams, separate two compartments 37 from each other.

Other transverse beams 33, called end transverse beams below, are located at the end of a row of modules 5 and only delimit a single compartment 37. In the example shown, the transverse end beams 33 are located opposite a portion of the peripheral edge 29.

In the example of Figures 2 to 8, the longitudinal beams 35 each delimit only one compartment. They are each located opposite a portion of the peripheral edge 29.

In the example of the , some longitudinal beams 35 separate two compartments 37 from each other, because there are several rows of compartments 37. These longitudinal beams 35 are referred to below as central longitudinal beams.

Other longitudinal beams 35, referred to below as longitudinal end beams, only delimit a single compartment 37. In the example shown, the longitudinal end beams 35 are located opposite a portion of the peripheral edge 29.

Each module 5 is received in one of the compartments 37. The modules 5 are oriented so that the side faces 17 of the electricity storage cells 7 are turned towards the transverse beams 33, and the lower face 15 towards the bottom 23. The upper face 11, carrying the electrical contacts 13, faces the upper bottom 27.

Advantageously, the electricity storage battery 3 comprises a set 39 of resin elements, visible in Figures 3 to 7, and 10 to 14 at least.

The resin elements are disjoint and independent of each other.

By this we mean that these elements are not part of the same piece made from material. They are not directly attached to each other, they are not joined by material bridges.

On the contrary, they can be placed in the battery or evacuated out of the battery individually, that is to say independently of each other, without having to cut or separate the resin elements from each other.

As visible in Figures 3 to 7, and 10 to 14, these resin elements are attached to the beams 33, 35.

Furthermore, each resin element defines at least a part of the internal surface of at least one of the compartments 37.

More specifically, the set of resin elements 39 comprises a plurality of central transverse elements 41 each having an upstanding part 43, placed astride one of the central transverse beams 33 (FIGS. 3, 4, 12 and 13).

The upright part 43 comprises two upright wings 45, covering the two large opposite faces of said central transverse beam 33.

The two upright flanges 45 are pressed against the opposite large faces of the central transverse beam 33. They brood substantially the entire surface of the large faces.

The upright part 43 includes an upper connecting portion 47, securing the two wings 45 to each other. Part 47 covers the upper edge of the central cross beam 33.

The central transverse element 41 further comprises two lateral wings 49, extending the upright wings 45.

The side wings 49 define the respective bottoms of the two compartments 37 separated by the central transverse beam 33.

The side wings 49 are pressed against the bottom 23 of the envelope 19, and each cover a zone of this bottom 23.

The side wings 49 are substantially perpendicular to the elevation direction E.

Thus, the central transverse element 41 has, considered in section perpendicular to the transverse direction T, the general shape of an inverted T.

The electricity storage battery 3 includes a central cross member 41 for each central cross beam 33.

The plurality of resin element 29 further comprises end transverse elements 51, each having an upstanding portion 53 placed astride one of the end transverse beams 33 ( ).

The upright portion 53 has an inner upright flange 55 covering the large inner face 57 of the end cross member 33. The large inner face 57 faces the interior of the compartment 37.

The inner upright wing 55 covers the entire large inner face 57 and is pressed against this large inner face 57.

The end transverse element 51 also comprises a lateral wing 59, extending the upright inner wing 55 and defining the bottom of the compartment 37.

The side wing 59 is pressed against the bottom 23 of the envelope 19.

The upright part 53 also has an outer upright flange 61 pressed against the large outer face 63 of the end transverse beam 33 ( ).

The outer upright wing 61 does not cover the whole of the large outer face 63. It only covers an upper band of the large outer face 63.

Upright portion 53 further includes a junction portion 65, connecting the inner upright flange 55 and the outer upright flange 61 to each other. The junction portion 65 covers the upper edge of the end cross beam 33 ( ).

Typically battery 3 includes one end cross member 51 for each end cross beam 33.

The plurality of resin elements 39 further comprises a plurality of longitudinal elements 67 visible in Figures 3, 6 and 7. Each longitudinal element 67 comprises an upright portion 69 placed astride one of the longitudinal beams 35.

When the longitudinal beam 35 is a longitudinal end beam, it has a large inner face facing the interior of one of the compartments 37, and a large outer face facing away from the compartment 37.

The large outer face of the longitudinal end beam 35 extends opposite the peripheral edge 29 of the cover 25.

The upright part 69 then comprises an inner upright flange 71 covering the large inner face of the end longitudinal beam 35.

Upright portion 69 also includes an outer upstanding flange 73 spanning the large outer face of end longitudinal beam 35.

The inner upright flange 71 typically covers substantially all of the large inner face of the end longitudinal beam 35.

The outer upright flange 73 covers only a portion of the large outer face of the end longitudinal beam 35. Typically, it covers an upper band of the large outer face of the end longitudinal beam 35.

Upright portion 69 further includes junction portion 75, connecting inner upright flange 71 and outer upright flange 73 to each other. Junction portion 75 extends along the upper edge of the beam. longitudinal 35, and completely covers this upper edge.

The inner upright wing 71 advantageously carries reliefs 77 projecting towards the interior of the compartment 37.

Module 5 rests on reliefs 77.

In the example shown, the reliefs 77 are longitudinal ribs, extending longitudinally over the entire width of the inner upright wing 71. The reliefs 77 are regularly spaced from each other in the direction of elevation E. They are parallel to each other, and all identical.

In the example shown, each relief 77, considered in section perpendicular to the longitudinal direction L, has two inclined faces 79, converging towards a stop 81. The stop 81 is flat, and has for example a width of 0.5 mm. It is connected to the inclined faces 79 by parts in an arc of a circle, of radius substantially equal to 0.5 mm.

The reliefs 77 give additional flexibility to the areas of the internal surface of the compartment 37 which bear against the electricity storage cells 7. This is particularly advantageous for managing the manufacturing tolerances of the electricity storage cells 7.

For example, if the module 5 comprises a stack of twelve electricity storage cells 7 50 mm thick, the length of the module 5 along the transverse direction T can vary by a maximum of 1.6 mm, i.e. say more or less 0.8 mm compared to the nominal length.

Furthermore, the length tolerance of the compartment 37 in the transverse direction T, that is to say the tolerance on the position of the longitudinal beams 35 relative to each other in the transverse direction T, is about 0.2mm. The manufacturing tolerance on the height of the reliefs 77 is also approximately 0.2 mm.

The height of the reliefs 77 is chosen to manage all of these tolerances. For example, the height of the reliefs 77 is approximately 3.5 mm.

It is adjusted on a case-by-case basis, depending on the length tolerance of the module 5 in the transverse direction T, and variations in the length of this module 5 in the transverse direction t due to the breathing of the electricity storage cells 7 during the cycle (cycle of electric charge and discharge) or due to the aging of the electricity storage cells 7.

The geometry of the edge 81 can also be adapted to satisfy all the constraints.

In particular, the reliefs 77 must be flexible enough to bend when the module 5 is introduced into its housing 37.

When the longitudinal element 67 is attached to a central longitudinal beam 35, separating two compartments 37 from each other, then the upright part 69 comprises two inner upright flanges 71, of the type of the inner upright flange described below. above. The two inner upright flanges 71 cover the two large faces of the longitudinal beam 35. They both carry reliefs 77 of the type described above.

According to a variant embodiment shown in the , a plate 83 is interposed between the module 5 and the inner upright wing 71. The plate 83 is supported on one side against the reliefs 77. On the other side, the plate 83 is supported against the storage cell electricity 7 located at the end of the stack of cells. More precisely, it bears against the large face 9 of the electricity storage cell 7 facing the longitudinal beam 35.

The plate 83 is typically made of sheet steel or aluminum, or even made of rigid plastic such as, for example, polypropylene and polyamide. It makes it possible to distribute the force generated by the crushing of reliefs 77 over the entire large face 9 of the electricity storage cell 7 which is in contact with the plate 83.

Indeed, the electricity storage cell 7 comprises an outer casing which is typically made of aluminum. This envelope has a thickness of between 0.5 and 0.8 mm. If the compressive force applied by the reliefs 77 to the outer envelope becomes too great, this envelope may become deformed.

The use of a plate 83 makes it possible to avoid such deformation.

Furthermore, it is possible to vary the thickness of the plate 83. Thus, if the module 5 has tolerances in length along the transverse direction T which cannot be compensated only by the reliefs 77, it is possible to play on the thickness of plate 83.

Each resin element 41, 51, 67 is one piece. It came from matter. Typically it came by injection, as described below.

Each resin element 41, 51, 67 is in an elastic and flexible resin, having for example a hardness of approximately 70 Shore A.

The resin is preferably very resilient. By this we mean that the resin can deform under stress, but once the stress is gone, it returns to its initial state and geometry.

Typically, each resin element 41, 51, 67 is made of polyurethane, EPDM, or any other elastomer having the required mechanical characteristics.

The wings are thin sheets of material, each having a thickness between 1 and 4 mm, more precisely between 1.7 and 3 mm, and typically around 2 mm.

The battery 3 also includes bars 85 for blocking the modules 5 in the corresponding compartments 37 (FIGS. 15 and 16).

The bars 85 are provided to block the modules 5 in position relative to the beams 33, 35 in the elevation direction E. The bars 85 are fixed to the transverse beams 33 and project above the modules 5.

Typically, battery 1 has one locking bar 85 for each central cross beam 33.

As visible in Figures 15 and 16, each locking bar 85 comprises a central web 87, placed on the transverse beam 33, and tongues 89, extending longitudinally from the central web 87.

The central web 87 is elongated transversely and extends substantially over the entire length of the transverse beam 33.

The tongues 89 rest on the cells 7, and more precisely on the upper surfaces 11 of the electricity storage cells 7.

The locking bar 85 comprises several pairs of tongues 89, regularly distributed along the transverse direction T along the central core 87. Each pair of tongues 89 comprises a first tongue 89 extending longitudinally from one side of the core central 87 and a second tongue 89 extending longitudinally on the other side of the central core 87. The first tongue 89 makes it possible to block electricity storage cells 7 housed in the compartment 37 located on one side of the transverse beam 33, and the second tongue 89 makes it possible to block electricity storage cells 7 housed in the compartment 37 located on the other side of the transverse beam 33.

The two languages 89 of the same pair extend from the same zone 90 of the central soul 87.

Each tongue 89 bears on two electricity storage cells 7 neighboring the row of cells.

It bears at the level of the contact plane between the large faces 9 of the two electricity storage cells 7. It extends between the respective electrical contacts 13 of these two electricity storage cells 7.

To allow the fixing of the locking bar 85 to the transverse beam 33, the locking bar 85 has oblong holes 91.

The transverse beam 33 has tongues 93 engaged in the oblong orifices 91.

The oblong orifices 91 are elongated in the transverse direction T. They are regularly spaced in the transverse direction T.

They are arranged in the central soul 87, and more precisely in areas 90 from which extend the languages 89.

Tabs 93 project upward from the top edge of cross beam 33.

Each tongue 93 comprises a central part made in one piece with the transverse beam 33, and two foldable lugs integral with the central part.

The ears and the central part are initially in the plane of the transverse beam 33, as illustrated in particular in Figures 3 and 15. To achieve the fixing of the locking bar 85 to the transverse beam 33, the locking bar 85 is d first placed on the transverse beam 33, the tongues 93 each engaging in an oblong orifice 91.

Then, the lugs of each tongue 93 are bent, so that each lug is inclined with respect to the transverse direction T. The ends of the lugs are then arranged in line with a solid part of the blocking bar 85, blocking this locking bar 85 in position relative to the transverse beam 33 in the direction of elevation E.

Advantageously, the blocking bar 85 is entirely covered with a layer of resin 95. This resin is elastic and flexible. It is electrically non-conductive. It is typically of the same type as the resin constituting the elements 41, 51 and 67.

The battery 3 comprises a circuit 97 for cooling the electricity storage cells 7, filled with a heat transfer fluid.

The cooling circuit 97 is configured so that the heat transfer fluid circulates in contact with the electricity storage cells 7.

Typically, the heat transfer fluid is a dielectric liquid, for example an oil. Alternatively, the heat transfer fluid is a gas.

Two embodiments of the invention will now be described.

They differ in the organization of the circulation of the heat transfer fluid inside the battery.

The first embodiment is shown in Figures 2 to 9.

In this first embodiment, the cooling circuit 97 includes cooling channels 99 provided between the large faces 9 of the electricity storage cells 7 (see the ).

Thus, in this first embodiment, it is the large faces 9 of the electricity storage cells 7 which are in contact with the heat transfer fluid.

For example, two neighboring electricity storage cells 7 of the same module 5 are separated from each other by a gap 101 ( ). A plate 103 is placed in the gap 101, parallel to the large faces 9 of the electricity storage cells 7 which surround it. A resin layer 105 is deposited on each large face of the plate 103. This resin layer 105 delimits the cooling channels 99.

There is thus a cooling channel 99 at least on each side of the plate 103, so as to cool the two large faces 9 delimiting the gap 101 in which the plate 103 is placed.

The cooling channels 99 have a fluid inlet to the bottom 23 and a fluid outlet to the upper bottom 27.

As described above, the two central transverse beams 33 delimiting the same compartment 37 each carry a central transverse element 41. These two central transverse elements 41 each have a lateral wing 49 delimiting a portion of the bottom of said compartment 37.

As visible in Figures 3 and 4, the two side wings 49 are separated from each other by a distribution channel 107 distributing the heat transfer fluid in the cooling channels 99 formed between the large faces 9 of the storage cells of electricity 7.

In other words, the side wings 49 sets do not completely cover the bottom of the compartment 37.

The distribution channel 107 extends over the entire length of the compartment 37, taken along the transverse direction T, from one longitudinal beam 35 to the other.

One of the two longitudinal beams 35 comprises, at its lower edge, a notch 109, constituting an inlet of the distribution channel 107. On the other hand, the distribution channel 107 is closed at its end opposite to the notch 109.

In the example shown in Figures 2 to 9, the casing 19 has a heat transfer fluid inlet 111 in the casing 19, and a heat transfer fluid outlet 113 outside the casing 19.

The cooling circuit 97 further comprises a heat transfer fluid distribution manifold 115, connected directly to the heat transfer fluid inlet 111, and a heat transfer fluid evacuation manifold 117, connected directly to the heat transfer fluid outlet 113. These manifolds 115, 117 are visible more particularly in Figures 8 and 9.

The distribution manifold 115 is arranged between the cover 25 on the one hand and the end transverse beams 33 and the end longitudinal beams 35 on the other.

Similarly, the evacuation manifold 117 is arranged between the cover 25 on the one hand and the end transverse beams 33 and the end longitudinal beams 35 on the other.

More precisely, the distribution manifold 115 and the evacuation manifold 117 are partially delimited by inserts 119, 121, 123, 125 (see FIGS. 2, 8 and 9).

These inserts 119, 121, 123, 125 are housed between the cover 25 on the one hand and the longitudinal end beams 33 and the transverse end beams 35 on the other.

The insert 119 extends transversely. The insert 119 is pressed against the large external face of the end transverse beam(s) 33 located on one side of the battery 3. A groove 131 is cut in the external face of the insert 119, which is pressed against the peripheral edge 29 of the cover. The heat transfer fluid inlet 111 opens into the groove 131. The groove 131 extends from the inlet 111 to a transverse end of the insert 119.

The insert 121 extends longitudinally. It is pressed against the longitudinal end beams 35 juxtaposed on one side of the battery 3 and against the peripheral edge 29 of the cover. It only extends over part of the height of the longitudinal end beams 35, so that a channel 133 is formed between a lower edge 134 of the insert 121 and the bottom 23 of the casing. The channel 133, at one longitudinal end, communicates with the groove 131 of the insert 119. The channel 133 is closed at its opposite longitudinal end. Notches 109 open into channel 133.

Insert 123 extends longitudinally. It is pressed against the longitudinal end beams 35 juxtaposed on one side of the battery 3 opposite the insert 121.

The insert 123 extends only over part of the height of the longitudinal beams 35. Thus, an evacuation channel 135 for the heat transfer fluid is delimited between the lower edge 137 of the insert 123 and the bottom 31 of the 'envelope.

The insert 123, along its upper edge, has a collection groove 139. This groove 139 is formed in the large outer face of the insert 123, which is pressed against the peripheral edge 29 of the cover.

A passage 141 is made at the longitudinal end of the insert 123 located opposite the insert 119, through which the collection groove 139 communicates with the evacuation channel 135.

The evacuation channel 135 therefore communicates at one longitudinal end with the passage 141, and at another longitudinal end with a groove 143 formed in the insert 119.

The groove 143 is dug in the large outer face of the insert 119, pressed against the peripheral edge 29 of the cover. It extends transversely from the transverse end of the insert 119 which adjoins the insert 123, as far as the heat transfer fluid outlet 113. The groove 143 communicates with the evacuation channel 135.

Insert 125 extends transversely. It is pressed against the end transverse beam(s) 33 located opposite the insert 119.

The heat transfer fluid inlet 111 and the heat transfer fluid outlet 113 are designed to be connected to a cooling circuit on board the vehicle 1, typically comprising a heat transfer fluid circulation member and a heat exchanger. The heat exchanger is provided to evacuate the heat generated by the electricity storage battery 3. The circulation member sets the heat transfer fluid in motion. Its delivery is fluidically connected to the coolant fluid inlet 111 and its suction to the coolant fluid outlet 113.

As a variant, the heat exchanger and the circulation member are integrated into the electricity storage battery 3. In this case, the evacuation collector is fluidically connected to an inlet of the heat exchanger, the collector upstream being fluidly connected to the discharge of the circulation member. The suction of the circulator is connected to the outlet of the heat exchanger.

The circulation of the heat transfer fluid will now be detailed for the first embodiment.

The heat transfer fluid enters the battery 3 through the heat transfer fluid inlet 111 and flows into the groove 131. It follows the groove 131, then flows into the channel 133 which distributes the heat transfer fluid in the distribution channels 107 From the distribution channels 107, the heat transfer fluid is distributed in the cooling channels 99, and flows in contact with the large faces 9 of the electricity storage cells 7 of the various modules 5. It comes out of the cooling channels 99 from the top, and then flows transversely above the upper faces 11 of the electricity storage cells 7. The heat transfer fluid is collected in the collection groove 139, flows to the passage 141, and circulates then in the evacuation channel 135 and the groove 143 until the heat transfer fluid outlet 113.

According to an advantageous variant of the invention, the upright outer wing 61 of at least one transverse end element 51 delimits the distribution manifold 115 and/or the evacuation manifold 117.

Typically, the outer upright flange 61 of one of the end transverse elements 51 forms the insert 119 ( ), and the outer upright flange 61 of another end cross member forms the insert 125 ( ).

When the battery 3 comprises several rows of compartments 37, the insert 119 and the insert 125 are formed by the outer upright flanges 61 of all the transverse end elements 51 located on the same side of the battery 3.

According to a variant of the invention, not shown, the longitudinal elements 67 placed on the longitudinal end beams 35 advantageously have outer upright flanges 73 which together delimit the distribution manifold 115 and/or the evacuation manifold 117.

More specifically, the outer upright wings 73 of the longitudinal elements 67 placed on one side of the battery 3 together form the insert 121.

These outer upright flanges 73 are juxtaposed longitudinally without being fixed to each other.

In the same way, the longitudinal elements 67 placed on the longitudinal beams 35 located on the other side of the battery 3 have outer upright flanges 73 which together form the insert 123.

The outer upright flanges 73 are juxtaposed longitudinally without being fixed to each other.

It should be noted that, in the first embodiment, the free surface of the transverse resin elements is flat, in the sense that it does not include any relief defining fluid circulation channels, as in the second embodiment.

A second embodiment of the invention will now be described, with reference to Figures 12 to 17.

As indicated above, each compartment 37 is delimited by two transverse beams 33.

The transverse elements 41, 51 placed on the transverse beams 33 delimit, for each electricity storage cell 7 of the module 5 housed in the compartment 37, a channel 145 for the circulation of the heat transfer fluid in contact with the three small faces 15, 17 of the electricity storage cell 7.

When the compartment 37 is located at the end of a row, the circulation channels 145 are delimited by a central transverse element 41 and an end transverse element 51. When the compartment 37 is located in the middle of a row, the circulation channels 145 are delimited by two central transverse elements 41.

The side wings 49 of the cross members 41, 51 together cover the entire bottom of the compartment 37. In other words, the edges of the side wings 49 touch each other, so that there is no gap or channel. between the edges of the side wings 49.

The circulation channels 145 each have a U-shape.

Each circulation channel 145 thus comprises two lateral portions 147, connected to one another by a central portion 149.

Each side portion 147 is delimited between the upright wing 45, 55 of one of the transverse elements 41, 51 and one of the side faces 17 of the electricity storage cell 7. The central portion 149 is delimited between the wings sides 49 and the underside 15 of the electricity storage cell 7.

The central portion 149 thus comprises two sections, each delimited by one of the two side wings 49 together defining the bottom of the compartment 37. These two sections are placed longitudinally in the extension of one another.

As visible in Figures 12 and 13, the circulation channels 145 are formed by recessed reliefs provided on the free surface of the transverse elements 41, 51.

The circulation channels 145 are separated from each other by blocks 151 formed in the transverse elements 41, 51, these blocks 151 preventing leakage of heat transfer fluid from one circulation channel 145 to another.

The circulation of the heat transfer fluid in battery 1 is organized as illustrated in the .

The distribution circuit 97, as before, comprises a heat transfer fluid distribution manifold 115, connected directly to the heat transfer fluid inlet 111, and a heat transfer fluid evacuation manifold 117 connected directly to the heat transfer fluid outlet 113.

The distribution manifold 115 is longitudinal and is for example arranged between the longitudinal beams 35 and the cover 25.

The cooling circuit 97 further comprises a plurality of heat transfer fluid distribution sub-manifolds 153 extending in parallel from the distribution manifold 115. Each distribution sub-manifold 153 extends transversely and serves a module 5 or more modules 5 placed in the extension transversely to each other.

In the example shown in the , each distribution sub-collector 153 serves two modules 5, aligned transversely.

The cooling circuit 97 further comprises evacuation sub-collectors 155, connected in parallel to the evacuation collector 117.

Each evacuation sub-collector 155 extends transversely, and serves a module 5 or several modules 5 aligned transversely.

In the example shown in the , each evacuation sub-manifold 155 serves two modules 5.

As visible in FIGS. 14 and 17, the distribution 153 and evacuation 155 sub-collectors are arranged between the upper faces 11 of the electricity storage cells 7 and a cover 157, placed above the module 5. A bump 159 is formed in cover 157, its top resting against the upper faces 11 of electricity storage cells 7. Bump 159 extends transversely over the entire length of cover 157. It separates the sub-collector from distribution 153 of the evacuation sub-manifold 155, as visible on the .

Each electricity storage cell 7 has an electrical contact 13 engaged in the distribution sub-manifold 153 and the other electrical contact 13 engaged in the evacuation sub-manifold 155.

The U-shaped circulation channels 145 are each connected on the upstream side to the distribution sub-manifold 153 and on the downstream side to the evacuation sub-manifold 155. In other words, one of the lateral portions 147, at its upper end, communicates with the distribution sub-manifold 153, and the other side portion 147, at its upper end, communicates with the evacuation sub-manifold 155.

To do this, as seen in Figures 15 and 16, the locking bars 85 are shaped to allow the passage of heat transfer fluid.

As described above, each blocking bar 85 has zones 90 from which the tongues 89 originate. Between the zones 90, the blocking bar 85 has convex zones 159, offset upwards with respect to the zones 90. Thus, the convex zones 159 are not in contact with the upper edge of the transverse beam 33, nor with the upper faces 11 of the electricity storage cells 7.

As seen on the , a passage 161 for the heat transfer fluid is thus created between the convex zone 159 and the upper face 11 of the electricity storage cell 7 facing each other, the heat transfer fluid being able to flow from the circulation channel 145 into the distribution 153 or evacuation 155 sub-manifold through this passage 161.

A rib 163 of transverse orientation is formed under the convex zone 159 ( ). This rib 163 bears against the upper edge of the transverse beam 33. It connects the two zones 90 arranged on either side of the convex zone 159. Thus, the heat transfer fluid circulating in a compartment 37 cannot pass into the adjacent compartment 37 between the convex zone 159 and the transverse beam 33.

The circulation of the heat transfer fluid in the second embodiment will now be explained.

The heat transfer fluid enters the battery through the heat transfer fluid inlet 111. It circulates in the distribution manifold 115, from which it is distributed in the distribution sub-manifolds 153. From a distribution sub-manifold 153, it is distributed in the U-shaped circulation channels 145, through the passages 161 provided under the blocking bar 85. It circulates in the U-shaped circulation channels 145 in contact with the three small faces 15, 17 of the cell of corresponding electricity storage 7, up to the corresponding evacuation sub-collector 155 .

It passes from the U-shaped circulation channel 145 to the evacuation sub-manifold 155 through the passages 161 located under the blocking bar 85 opposite.

The heat transfer fluid then follows each exhaust sub-manifold 155 to the exhaust manifold 117, then to the heat transfer fluid outlet 113.

According to an advantageous aspect applicable to all the embodiments and all the variants described above, stiffening elements 165 are fixed to the end transverse beams 33 (FIGS. 10 and 11).

For example, at least one stiffening element 165 is fixed on a large outer face of each end transverse beam 33, that is to say on the large face facing outwards of the compartment 37 delimited by the transverse beam end 33.

The stiffening element 165 is for example a U-shaped metal profile, of transverse orientation, extending over the entire length of the end transverse beam 33 and welded to the end transverse beam 33.

The stiffening elements 165 make it possible to prevent the transverse beams 33 from buckling. The block formed by the beams 33, 35 and the modules 5 then becomes quite rigid, due to the absence of play between the beams 33, 35 and the modules 5, and the fact that the stiffening elements 165 prevent the transverse beams 33 from buckling.

The stiffening elements 165 in particular give this block good resistance in the event of transverse force, for example following a side impact on the vehicle 1. The transverse beams 33 and the blocking bars 85 do not in fact themselves present high mechanical resistance, because they do not have ribs that could increase their resistance to buckling.

Similarly, in the event of significant acceleration in the longitudinal direction L, for example in the event of a longitudinal impact, the stiffening elements 165 will withstand the pressure force applied by the electricity storage cells 7 on the transverse beams 33 .

The electricity storage battery 3 described above has multiple advantages.

It is advantageously cooled by a heat transfer fluid which circulates in contact with the cells. This makes it possible to cool the cells in an extremely efficient manner.

The fact of using resin elements which have parts placed astride the transverse beams makes it possible to conveniently cover the two large faces of these transverse beams.

The fact that these same resin elements also have side wings, extending the central wings and defining the bottom of the compartments, makes it possible to conveniently coat the bottom of the compartments with a layer of resin.

The transverse resin elements can be used to create a channel passing under the lower faces of the cells, and distributing the heat transfer fluid in the cooling channels provided between the large faces of the cells. This makes it possible to intelligently organize the circulation of the heat transfer fluid and easily create a fluid distribution manifold in the cooling channels.

The transverse resin elements can also be used to create circulation channels for the heat transfer fluid in contact with the small side and bottom faces of the cells. This makes it possible to organize the circulation of the heat transfer fluid in contact with the cells in an economical and efficient manner.

The transverse resin elements are advantageously used to delimit the heat transfer fluid distribution and evacuation manifolds.

Placing a stiffening element at each end transverse beam stiffens the structure and absorbs the forces resulting from transverse or longitudinal shocks.

A method of manufacturing a battery having the above characteristics will now be described.

This method is particularly suitable for manufacturing the battery 3 above. Conversely, battery 3 above is specially designed to be manufactured by the process below.

The process includes the following steps:

- obtaining the plurality of modules 5;

- obtaining envelope 19;

- Obtaining the beams 33, 35 and fixing the beams 33, 35 to the casing 19;

- Obtaining the plurality of resin elements 41, 51, 67, disjoint and independent of each other;

- Installation of the plurality of resin elements 41, 51, 67 on the beams 33, 35;

- insertion of 5 modules in 37 compartments.

The resin elements 41, 51, 67 are typically made in molds, for example by injection.

The step of obtaining the plurality of resin elements 41, 51, 67 is carried out before the step of positioning on the beams 33, 35.

Claims (11)

Electricity storage battery, the battery (3) comprising:
- a plurality of modules (5), each module (5) comprising a plurality of electricity storage cells (7) juxtaposed in a transverse direction (T);
- an envelope (19) internally delimiting a volume (21) for receiving the modules (5);
- beams (33, 35) integral with the casing (19) and dividing the reception volume (21) into a plurality of compartments (37) each delimited by an internal surface, each module (5) being received in one of the compartments (37);
- a set (39) of resin elements, separate and independent of each other, attached to the beams (33, 35), each resin element defining at least part of the internal surface of at least one of the compartments (37). A battery according to claim 1, wherein the beams comprise cross beams (33), the resin element assembly (39) comprising a plurality of cross elements (41, 51) each having an upstanding portion (43, 53 ) placed astride one of the transverse beams (33), the upright part (43, 53) having two upright flanges (45, 55) covering two large opposite faces of said transverse beam (33). Battery according to Claim 2, in which the said transverse element (41, 51) comprises at least one lateral wing (49, 59), extending one of the upright wings (45, 55) and defining the bottom of a compartment (37 ) delimited by said transverse beam (33). Battery according to Claim 3, in which the electricity storage cells (7) of the same module (5) have respective large faces (9) facing each other, the transverse elements (41) of the assembly (39) of resin elements placed on the two transverse beams (33) delimiting the same compartment (37) having respective side wings (49, 59) each delimiting a portion of the bottom of said compartment (37), said side wings (49, 59) being separated from each other by a distribution channel (107) distributing a heat transfer fluid in cooling channels (99) formed between the large faces (9) of the electricity storage cells ( 7). Battery according to Claim 3, in which the electricity storage cells (7) of the same module (5) each have three small faces (15, 17) placed opposite the bottom and the transverse beams ( 33) delimiting the reception compartment (37) of said module (5), the transverse elements (41, 51) of the set (39) of resin elements placed on said transverse beams (33) delimiting, for each cell of electricity storage (7), a channel (145) for the circulation of a heat transfer fluid in contact with the three small faces (15, 17). Battery according to any one of Claims 2 to 5, in which the transverse beams (33) comprise end transverse beams having a large internal face delimiting one of the compartments (37) and a large external face facing of the casing (19), a stiffening element (165) being fixed to the large outer face of each end transverse beam (33). Battery according to any one of Claims 2 to 6, in which the battery (1) comprises bars (85) for blocking the modules (5) in the corresponding compartments (37), fixed to the transverse beams (33) and projecting above the modules (5). A battery according to any one of claims 1 to 7, wherein the beams comprise longitudinal beams (35) delimiting each compartment (37) at opposite transverse ends, the set (39) of resin elements comprising a plurality of longitudinal elements (67) each having an upright part (69) placed astride one of the longitudinal beams (35), the upright part (69) having an inner upright flange (71) covering a large inner face of said longitudinal beam ( 35) facing the interior of the compartment (37). Battery according to Claim 8, in which the inner upright wing (71) carries reliefs (77) projecting towards the interior of the compartment (37), the module (5) resting on the reliefs (77). Battery according to any one of Claims 2 to 10, in which the battery (3) comprises a circuit (97) for cooling the electricity storage cells (7), filled with a heat transfer fluid, the cooling circuit ( 97) comprises a heat transfer fluid distribution manifold (115) and a heat transfer fluid discharge manifold (117), at least one of the resin elements (51, 67) having an upright portion (53, 69) placed astride on one of the beams (33, 35), the upright part (53, 69) having an inner upright flange (55, 71) delimiting the internal surface of one of the compartments (37) and an outer upright flange (57, 73) delimiting the distribution manifold (115) and/or the evacuation manifold (117). A method of manufacturing a battery according to any one of claims 1 to 11, the method comprising the following steps:
- obtaining the plurality of modules (5);
- obtaining the envelope (19);
- obtaining the beams (33, 35) and fixing the beams (33, 35) on the casing (19);
- obtaining the plurality of resin elements (41, 51, 67), disjoint and independent of each other;
- placing the plurality of resin elements (41, 51, 67) on the beams (33, 35);
- inserting the modules (5) into the compartments (37).