Bagged electric battery cell and corresponding manufacturing process.

Abstract

This disclosure relates to a bag cell (100) for an electric battery module (1000), formed of a resealable bag (101) comprising at least one strip of electrodes (150, 152, 154) whose electrodes are capable, in operation, of electrochemically reacting an electrolyte, the electrochemical reaction of the electrolyte triggering the generation of a gas, the resealable bag (101) comprising a plurality of aligned housings (110, 120), each of said housings (110, 120) being formed in an internal surface of the resealable bag (101) and being capable of receiving the generated gas.

Description

Title of the invention: Bagged electric battery cell and corresponding manufacturing process. Technical field of the invention

[0001] This description relates to the field of energy storage. The present invention relates to a pouch cell for an electric battery, also known in English as a "pouch cell," in particular a pouch cell for an electric battery module. The invention also relates to a method for manufacturing such a pouch cell. State of the art

[0002] Pouch cells are formed by means of a stack of successive electrodes, separated by a porous electrical insulating film. The stack is placed in a flexible pouch, then an electrolyte is introduced into this pouch, which is sealed to make it airtight and form a cell. The electrolyte reacts with the active electrode materials, producing gases, which must be vented in a controlled manner.

[0003] In order to vent the gases, the bag includes at least one reservoir for storing said gases. These compartments are formed within the bag. The flexible bag has a first compartment in which the stack is arranged, and a second compartment for enclosing the stack by folding said bag around a folding axis. The first and second compartments together form a main compartment for the stack. The flexible bag has a first cavity and a second cavity, these cavities being separate from the first and second compartments, which together form a reservoir when the bag is folded around the folding axis. The reservoir is in fluidic communication with the main compartment to allow the gases generated in said main compartment to be vented to the reservoir.

[0004] Although these cells are satisfactory in several respects, they are not without drawbacks and thus remain improvable.

[0005] One drawback of these cells lies in the fact that the tanks may not perform their function optimally. Once the gas is trapped in the tank, the sealed cell is brought into an enclosure where the atmosphere is controlled, typically where the ambient pressure is lower than the pressure of the gas trapped in the tank. The tank is then punctured and the gas is vented into the enclosure. This involves aspirating the gas, which flows out of the tank. This aspiration can cause the tank to collapse and, consequently, some of the gas to escape. The gas remains trapped in the peripheral part of the tank, particularly in its corners, which is undesirable. Indeed, manufacturers want all the gas extracted from the tank while the cell remains inside the enclosure.

[0006] Consequently, there is a need to develop solutions to improve known bagged cells. In particular, the cell degassing reservoir must be improved. Object of the invention

[0007] In order to address this or these drawbacks, a bag cell for an electric battery module is proposed according to a first object of the present, the bag cell being formed of a resealable bag suitable for receiving an electrolyte, the resealable bag further comprising at least one strip of electrodes aligned along a first axis, the electrodes being suitable, in operation, for electrochemically reacting the electrolyte, the electrochemical reaction of the electrolyte triggering the generation of a gas, the resealable bag further comprising a plurality of housings aligned along a second axis substantially parallel to the first axis, each of said housings being formed in an internal surface of the resealable bag and being suitable for receiving the generated gas.

[0008] In the present, two axes are defined as "substantially parallel" when these two axes are parallel to within 5 degrees.

[0009] In the present, the electrolyte acts as a conductive medium allowing the flow of ions between the electrodes during the charging and discharging cycle of the cell.

[0010] This makes it possible to provide a pouch cell in which the risk of structural collapse of the resealable pouch is partially or totally reduced by creating separate compartments, thus preventing direct contact between the parts of the pouch during closure. By preventing contact between the pouch walls, this design strengthens its structure, thus preventing its collapse and preserving the integrity of the compartments intended to contain the gas released by the electrochemical reaction of the electrolyte.

[0011] According to one embodiment, at least one of the housings has a three-dimensional shape defined by a length "a", by a width "b" and by a height "c", the height "c" being less than or equal to the thickness of at least one strip of electrodes.

[0012] This makes it possible to provide a cell in a bag whose housings have a parallelepiped shape, this geometry being optimal for extracting these housings from the resealable bag when they contain the gas released by the electrochemical reaction of the electrolyte.

[0013] Moreover, it has also been surprisingly observed that this configuration allows for better management of space within the bag, thus maximizing the density of The system captures the released gas so that it can then be extracted. This improves cell performance while ensuring increased manufacturing efficiency, thanks to the simplification and standardization of the cell-in-bag formation steps. Furthermore, this structure reduces the risk of collapse of parts of the bag after gas capture and storage, thus providing greater structural stability to the cell.

[0014] According to one embodiment, the ratio "a / b" of the length and width of at least one housing is greater than or equal to 1 and less than or equal to 6.

[0015] In this embodiment, if the resealable bag has a length "L", called the "side of the bag" and measurable along the direction defined by the second axis, and if the number of compartments of the resealable bag aligned in the same strip, i.e., along the second axis substantially parallel to the first axis, is defined by an integer "N", for example 2, 3, 4, 5, 6, 7, 8, 9 or 10 aligned compartments, then the ratio "a / b" can be defined as being within the interval [1; "L / N"]. Thus, the number "N" of compartments in the same strip can be chosen according to the length "L", and vice versa.

[0016] This allows the "a / b" ratio to be adjusted to define a given configuration of the bag and the compartments according to the desired dimensions. The cell design thus allows the stresses to be distributed uniformly along the direction of the second axis. The management of the electrode thickness is linked to the characteristics of the bag material.

[0017] Advantageously, the portion of the bag where the electrodes are inserted conforms to the maximum permissible tensile strength of the material forming the bag. If this thickness exceeds this limit, the bag risks being stretched further, increasing the risk of tearing or creasing. Adapting the number and arrangement of the housings along the direction of the second axis also helps to reduce the manufacturing costs of bags containing at least one housing. The risk of collapse of certain parts of the bag after gas capture is also reduced, ensuring better structural integrity.

[0018] According to one possible embodiment, the ratio "a / b" of the length and width of at least one housing unit is substantially equal to 4.

[0019] In the present, a ratio is defined as being substantially equal to a numerical value when that ratio is equal to that numerical value with a maximum possible deviation of 5%.

[0020] This optimizes the available space in the resealable bag, which contains multiple compartments regardless of their dimensions, while maximizing the efficiency of capturing the gas generated by the electrochemical reaction of the electrolyte. Surprisingly, tests have shown that this specific ratio of 4:1 promotes easy extraction of gas-filled compartments, while minimizing the risk of collapse of parts of the bag, maximizing the structural stability of the bag.

[0021] According to one embodiment, at least two of the consecutive housings are separated from each other by a portion of the internal surface of the resealable bag.

[0022] This allows for better separation of gases in each dwelling, minimizing the risk of mixing and facilitating the separate evacuation of each gas.

[0023] This also helps to strengthen the internal structure of the resealable bag, thus reducing the risks of deformation or deterioration of the bag during the electrochemical reaction of the electrolyte and the release of gas.

[0024] According to one embodiment, the plurality of dwellings comprises at least two series of several dwellings separated two by two, each of the two series of dwellings being aligned along the second axis.

[0025] In addition to improving the gas capture phenomenon during cell training due to the reaction of the electrolyte in the bag, this facilitates the manufacturing and extraction process of the housings when they have finished receiving the gas.

[0026] According to one possible embodiment, the respective axes of the housing series are substantially parallel to each other and, optionally, substantially parallel to the alignment of the electrode strip.

[0027] According to one embodiment, at least two consecutively aligned housings of the plurality of housings are further separated from each other by at least one stiffening element disposed in the internal surface of the resealable bag.

[0028] This strengthens the internal structure of the resealable bag by adding rigid elements between the compartments, thus providing greater resistance to deformation. Advantageously, the effects of bag swelling during the electrochemical reaction of the electrolyte and the release of gas are thus partially or totally compensated. Furthermore, the compartments are insulated to reduce interference between the gases generated in each compartment, thereby facilitating their individual evacuation.

[0029] According to another object of the present, a method for manufacturing a sachet cell is also proposed according to any one of the preceding embodiments, the manufacturing method comprising the steps of: a) supplying the resealable sachet suitable for receiving the electrolyte, the resealable sachet comprising at least one strip of electrodes, b) forming, in the internal surface of the resealable sachet supplied, the plurality of compartments such that said compartments are separated in pairs, c) closing the resealable sachet, implemented by folding the resealable sachet upon itself so as to seal each of the compartments separated in pairs with another respective compartment among the plurality of compartments separated in pairs, d) inserting the electrolyte in the closed resealable bag, e) electrochemical reaction of the electrolyte to trigger the generation of the gas, the generated gas being received in the plurality of sealed housings, and f) extraction from each of the housings which received the generated gas.

[0030] This optimizes the design of bagged cells by automating the sealing of the housings, thereby increasing reliability while reducing variability and potential failures due to imperfect seals. Furthermore, this significantly reduces scrap and manufacturing costs through improved yield, particularly when using molds and different materials to form the layers of the bagged cell. Precise sealing of the housings also reduces the risk of electrolyte waste and gas leaks within the cell.

[0031] According to one possible embodiment, step d) of inserting the electrolyte is for example carried out by means of a needle, preferably adapted so as not to disturb the hermeticity of the sachet.

[0032] According to one possible embodiment, the folding of step c) of closing can be followed by heat sealing, in order to melt the edges or certain parts of the plastic of the bag during, making the whole airtight.

[0033] According to one embodiment, the formation step b) comprises a substep of separation b 1) of at least two housings of the plurality of housings by a part of the internal surface of the resealable bag and / or a substep b2) of stiffening at least two housings of the plurality of housings by at least one stiffening element in the internal surface of the resealable bag.

[0034] This makes it possible to create a sachet cell structure with high mechanical stability. In particular, substep bl) of separation ensures that each individual compartment is isolated from the others, reducing the risk of mixing or diffusion of gases between the compartments. More precise control of the gases emitted during the electrochemical reaction is also possible, while substep b2) of stiffening by the introduction of rigid elements reinforces the internal structure of the sachet during its manufacture, preventing the collapse or deformation of the compartments under the effect of internal stresses.

[0035] According to one embodiment, step b) of forming the plurality of housings includes a modulation of each housing so that each housing has a three-dimensional shape defined by a length "a", by a width "b" and by a height "c", the height "c" being less than or equal to the thickness of at least one strip of electrodes, the ratio "a / b" of the length and width of at least one housing being greater than or equal to 1, said ratio "a / b" of the length and width being less than or equal to 6.

[0036] According to one possible embodiment, the ratio "a / b" of the length and width is substantially equal to 4.

[0037] This provides flexibility in the design of each cell by adapting the "a / b" ratio according to the desired performance and the tools used during the design process. For example, an "a / b" ratio close to 1 leads to square housings, while a ratio close to 6 leads to elongated housings, which can improve gas evacuation and heat distribution within the cell depending on its dimensions. A ratio approximately equal to 4 has been observed to be the best compromise between gas capture efficiency in the housings and reducing the risk of bag collapse during manufacturing.

[0038] According to one embodiment, step b) of forming the plurality of housings is carried out by means of a mold and in which step f) of extracting each of the housings is carried out by means of a release agent.

[0039] This reduces the risk of structural damage to the cell or the housings during extraction, given the thinness of the materials involved. The use of a mold for forming the housings ensures high dimensional accuracy, while the application of a release agent during the extraction step minimizes the physical stresses that could compromise the integrity of the housings. Brief description of the figures

[0040] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0041] Fig. 1 is a top view of a bag cell developed with gas housings according to a first embodiment of the invention.

[0042] Fig. 2 is a perspective view of a sachet cell with gas holding compartments according to the first embodiment of the invention.

[0043] Fig. 3 is a side view of a sachet cell with gas holding compartments according to the first embodiment of the invention.

[0044] Fig. 4 is a top view of a bag cell developed with gas housings according to a second embodiment of the invention.

[0045] Fig. 5 is a perspective view of a sachet cell with gas holding compartments according to the second embodiment of the invention.

[0046] Fig. 6 is a top view of a bag cell developed with gas housings according to a third embodiment of the invention.

[0047] Fig. 7 is a perspective view of a sachet cell with gas holding compartments according to the third embodiment of the invention.

[0048] Fig. 8 is a schematic representation of an electric battery module comprising several cells in a bag.

[0049] Fig. 9 is a flowchart of steps of a manufacturing process according to embodiments of the invention.

[0050]

[0051] Unless otherwise indicated, common or similar elements in several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again for the sake of simplicity. Description of the implementation methods

[0052] Figures 1, 2 and 3 represent, respectively, a developed top view, a perspective view and a side view of a bag cell with gas holding chambers according to a first embodiment of the invention.

[0053] In particular, a sachet cell 100 for an electric battery module is illustrated, which is formed from a resealable sachet 101.

[0054] According to various possible embodiments, the film of the resealable bag 101 can be composed of several layers of materials to optimize the durability and safety of the cell. These materials often include combinations of polymers such as polypropylene or polyethylene and metallic or aluminum layers to ensure an effective barrier against moisture and oxygen, which is crucial for maintaining the chemical and electrical stability of the cell.

[0055] According to various possible embodiments, the electrodes of the electrode strip 150 can be formed from materials such as lithium nickel manganese cobalt and graphite.

[0056] The bag cell 100, and in particular the resealable bag 101, is suitable for receiving an electrolyte in the resealable bag 101. This electrolyte comprises various materials suitable for use of the bag cell 100 for an electric battery module, for example mixtures of liquid electrolytes containing lithium salts, organic solvents and various additives.

[0057] The sachet cell 100 further comprises a strip of electrodes 150, said strip of electrodes preferably being provided at its ends with a cathode 152 and an anode 154 (the order being optionally reversed) and capable, in operation, of electrochemically reacting the electrolyte. The strip of electrodes 150 is aligned along a first axis OX1, preferably aligned along the same direction or orientation as one or more sides of the resealable sachet 101.

[0058] Optionally, the electrode strip 150 or its electrodes 152 and 154 are repeatedly stratified with a separating membrane (not shown) interposed between them.

[0059] After or during the injection of the electrolyte into the film of the sachet cell 101, a precharge is applied to the electrodes, for example, to electrically drive the sachet cell 100. After the application of this precharge, an electrochemical reaction of the electrolyte occurs, which triggers the generation of a gas. This gas can cause the sachet cell to swell. It is therefore advantageous to vent this gas to avoid structural stability problems in the cell.

[0060] The resealable bag 101 further includes the two housings 110 and 120, aligned along a second axis OX2 which is substantially parallel or parallel to the first axis OX1.

[0061] Each of the housings 110 and 120 is formed in an internal surface of the resealable bag 101 and is intended to be able to accommodate the gas generated by the electrochemical reaction of the electrolyte.

[0062] Although other shapes are possible, for example cylindrical housings, housings 110 and 120 each have a three-dimensional shape defined by a length "a", represented by 110a and 120a, and a width "b", represented by 110b and 120b. For identical housings, the lengths 110a and 120a are identical, and the widths 110b and 120b are also identical. When they are parallelepiped-shaped, each housing can also be defined by a height "c", for example 110c and 120c (not visible). By definition, the values ​​of "a", "b", and "c" are such that "a" is greater than or equal to "b" and "b" is greater than or equal to "c".

[0063] As shown, each of the housings 110 and 120 of the cell in the bag 100 generally does not include separators or stiffening elements, that is to say, they are each formed of a single entity, which preferably has the shape of a parallelepiped strip substantially parallel to the first axis defining the main direction of the electrode strip 150.

[0064] Preferably, the height "c" of each of the housings is less than or equal to the thickness of at least one strip of electrodes 150.

[0065] According to one possible embodiment, the resealable bag 101 of the cell 100 has a length that is less than or equal to 1000 millimeters, and preferably less than 600 millimeters. In the present embodiment, said length is measured along the direction defined by the first axis OX1.

[0066] Figures 4 and 5 represent, respectively, a developed top view and a perspective view of a sachet cell with gas holding compartments according to a second embodiment of the invention.

[0067] In particular, a sachet cell 200 for an electric battery module is illustrated which, as for the sachet cell 100, is formed of a resealable sachet 201 whose film may be similar to that of the film 101.

[0068] As with the previous embodiment, the sachet cell 200, and in particular the resealable sachet 201, is adapted to hold an electrolyte in the resealable sachet 101 and further comprises a strip of electrodes 250 aligned along a first axis OX1, also including a cathode 252 and an anode 254 (the order of which may optionally be reversed) intended to carry out the electrochemical reaction of the electrolyte. The first axis OX1 is preferably aligned along one side of the resealable sachet 101.

[0069] The resealable bag 201 further comprises two sets of six compartments, numbered 210, 211, 212, 213, 214, and 215 for the first set and numbered 220, 221, 222, 223, 224, and 225 for the second set. These two sets of compartments are aligned along a second axis OX2, which is substantially parallel to the first axis OX1. Each compartment is configured to accommodate the gas generated by the electrochemical reaction of the electrolyte.

[0070] As illustrated, the compartments of each of the series 210-215 and 220-225 are separated in pairs while being aligned along the second axis OX2. The separations between the compartments are preferably formed by the film itself of the resealable bag 201. In particular, these separations may be formed by a portion of the inner surface of the resealable bag 201 and / or its outer surface. It should be noted that the above is possible for all the embodiments described herein.

[0071] As shown, in a non-limiting manner, each of the dwellings has a three-dimensional shape defined by a length "a", represented by the lengths 210a-215a and 220a-225a, a width "b", represented by the widths 210a-215a and 220b-225b and a specific height "c" (not shown).

[0072] According to one possible embodiment, denoting by "L" the length of the side of the resealable bag 201 and by "N" the number of compartments formed along the same series, the following constraints arise from the geometries described above. First, for each compartment, its length "a" is greater than its width "b". Second, and when all compartments are defined by the same length, the number "N" of compartments in a series is less than the ratio "L / a". By combining constraints, a relationship is obtained that allows the number of compartments to be selected and optimized according to the dimensions of the bag cell.

[0073] According to one possible embodiment, when the housings have identical lengths, widths and / or heights, their length "a" is preferably greater than or equal to 20 millimeters and preferably less than or equal to to 200 millimeters. This optimizes the operation and manufacturing of the bag cell when the resealable bag has a length "L" less than or equal to 600 millimeters.

[0074] These technical advantages do not preclude obtaining similar results for other dimensions, since it is always possible to choose the number of housings based on predetermined values ​​of "L" and "a". The widths "b" of the housings can also be adapted in a similar way to select the number of housing sets in the resealable bag.

[0075] Without limitation, the aforementioned dimensions of the dwellings are also applicable to the other embodiments described herein.

[0076] The dimensions of the housings can be predetermined for the manufacture of the bagged cells. In particular, the ratio "a / b" of the length "a" and the width "b" of each housing in the same series, or even of all the housings, is greater than or equal to 1 and less than or equal to 6. The ratio "a / b" of the length and width of at least one housing is greater than or equal to 1 and less than or equal to 6. This makes it possible to maximize the use of the available space inside the bag while adapting the ratio of the surface area covered by the housings to that left free by the partitions.

[0077] Without limitation, the aforementioned values ​​of the ratio “a / b” are also applicable to the other embodiments described herein.

[0078] As a first example, and to illustrate different possible manufacturing choices, it is possible to design a cell in a bag 200 whose film 201 has a length "L" equal to 500 millimeters. In this case, each of the two sets of compartments can comprise four compartments of length "a" equal to 100 millimeters and separated from each other by 20 millimeters (as well as from the edges of the bag with a separation of 20 millimeters) along the direction of the first axis OX1 and / or the second axis OX2. The width "b" of the compartments can here be chosen to be equal to 25 millimeters, thus defining a ratio "a / b" equal to 4.

[0079] Although other configurations are possible in this embodiment, more than two sets of housings on the same side of the electrode strip 250 can be provided in the film of the bag 201 of the cell in the bag 200. For example, three, four, or five sets if the respective dimensions of the housings and the cell in the bag 200 allow it. A single set of housings can also be provided.

[0080] As a second example, it is possible to design a cell in a bag 200 whose film 201 has a length "L" equal to 600 millimeters. In this case, it is possible to form, in particular, three aligned series of four compartments each, each of the compartments having a length "a" equal to 50 millimeters and separated from each other by 80 millimeters (as well as from the edges of the bag with a separation of 80 millimeters). The width "b" of the housings can be chosen to be equal to 40 millimeters, thus defining a ratio "a / b" equal to 2. Alternatively, the width "b" of the housings can be chosen to be equal to 80 millimeters, thus defining a ratio "a / b" equal to 1, or respectively equal to 1.

[0081] As shown, the compartments 210 to 215 and 220 to 225 of the cell in the bag 200 are generally not rigidly separated, for example by means of stiffening elements. Preferably, the height "c" of each of the compartments is also less than or equal to the thickness of at least one strip of electrodes 250.

[0082] Figures 6 and 7 represent, respectively, a developed top view and a perspective view of a sachet cell with gas holding chambers according to a third embodiment of the invention.

[0083] In particular, a sachet cell 300 for an electric battery module is illustrated which, as for sachet cells 100 and 200, is formed from a resealable sachet 301, and whose film can be of similar composition and dimensions to that of film 101 and film 201.

[0084] As with the previous embodiments, the sachet cell 300, and in particular the resealable sachet 301, is adapted to hold an electrolyte in the resealable sachet 301 and further comprises a strip of electrodes 350 aligned along a first axis OX1, also including a cathode 352 and an anode 354 (the order of which may optionally be reversed) intended to carry out the electrochemical reaction of the electrolyte. The first axis OX1 is preferably aligned with the same direction as one side of the resealable sachet 301.

[0085] Since the number of compartments is not limited, a resealable bag 301 is illustrated here, comprising two sets of five compartments, numbered 310, 311, 312, 313, and 314 for the first set and numbered 320, 321, 322, 323, and 324 for the second set. These sets of compartments are aligned along a second axis OX2, which is substantially parallel to the first axis OX1. As with the previous embodiments, each compartment is configured to accommodate the gas generated by the electrochemical reaction of the electrolyte.

[0086] As illustrated, the housings of each of the 310-315 and 320-325 series are connected to each other by stiffening elements, which can be called "stiffeners", which further define a separation distance between each pair of housings, these stiffening elements being able to be aligned along the second axis OX2.

[0087] Preferably, the separation distance between two housings joined by a given stiffening element, and therefore the corresponding length of said stiffening element, is greater than or equal to 1 millimeter and less than or equal to 500 millimeters, for example 20 millimeters. Preferably, the length of each stiffening element is less than or equal to 200 millimeters, and less than or equal to the length of each housing.

[0088] According to one possible embodiment, the separations between the compartments can be formed both by stiffening elements and by the film itself of the resealable bag 301, as was the case for the bag cell described in the second embodiment. For example, these separations can be formed by a portion of the surface of the resealable bag 301 and further comprise a reinforced plastic element, a heat-sealable strip, or an adhesive strip acting as a stiffening element between two given compartments.

[0089] As shown, and without limitation, each of the dwellings has a three-dimensional shape defined by a length "a", represented by the lengths 310a-314a and 320a-324a.

[0090] In addition, the housing 310 is separated from the housing 311 of the same aligned series by the housing 330, the latter having a proper length 330a which defines the separation distance between 310 and 311. The housing 311 is separated from the housing 312 by the stiffening element 331 of length 331a, the housing 312 is separated from the housing 313 by the stiffening element 332 of length 332a and the housing 313 is separated from the housing 314 by the stiffening element 333 of length 333a. Similarly, housing 321 is separated from housing 322 by stiffening element 341 of length 341a, housing 322 is separated from housing 323 by stiffening element 342 of length 342a and housing 323 is separated from housing 324 by stiffening element 343 of length 343a.

[0091] According to one possible embodiment, the respective width of each stiffening element, for example the width 330b (not shown, as are the widths 331b-314b and the widths 340b-341b) of the separator 330, is equal to, less than, or greater than the width of at least one of the two housings that this stiffening element separates. Preferably, the width of each stiffening element is less than or equal to the width of the narrower of the two housings, for reasons of economy and space.

[0092] According to possible examples, various types of adhesive strips can be used as stiffening elements, these being adapted to adhere to the film of the resealable bag 301. These strips then serve as a connecting seal between the two compartments separated by the stiffening element and provide additional rigidity at the junction point. The choice of these stiffening elements or adhesive strips can be made according to their resistance to humidity, their durability, and their ability to maintain a strong bond even under stress.

[0093] As described previously, denoting by "L" the length of the side of the resealable bag 301 and by "N" the number of housings formed along the same series, The length "a" of each dwelling is optionally greater than its width "b". If all dwellings are defined by the same length, the number "N" of dwellings in a series is less than the ratio "L / a".

[0094] By way of example, and to illustrate different possible manufacturing choices, it is possible to design a cell in a bag 300 whose film 301 has a length "L" equal to 460 millimeters, and comprising two sets of housings on one side of the electrode strip 350. In this case, each of the two sets of housings can comprise five housings of length "a" equal to 60 millimeters and separated from each other in pairs by a stiffening element of length equal to 10 millimeters (as well as the edges of the bag with a separation of 10 millimeters) along the direction of the first axis OX1 and / or the second axis OX2. The width "b" of the housings can here be chosen to be equal to 30 millimeters or to 15 millimeters, thus defining a ratio "a / b" equal to 2 or to 4.

[0095] Fig. 8 schematically represents the formation of an electric battery module with several cells in a bag.

[0096] In particular, an electric battery module 1000 is illustrated comprising a fold, in the shape of a "Z", of two or more bagged cells 101a, 101b and 101c, which may also be one or more bagged cells according to the first embodiment, the second embodiment or the third embodiment.

[0097] As described, a sachet cell comprises different layers of polymer materials with specific properties defining its mechanical strength, moisture and oxygen barrier, and electrical insulation. An outer layer composing this sachet cell can be a high-strength polymer such as nylon, robust and capable of withstanding significant mechanical stresses.

[0098] The intermediate layers of such a bagged cell generally include various lamination films and barrier layers made of aluminum or similar materials, which provide protection against external elements and contribute to the overall shape and rigidity of the cell and its components

[0099] As shown, the at least two sachet cells 101a, 101b, 101c, ... are superimposed and folded successively one on top of the other to form a "Z"-shaped structure. This structure is obtained by arranging the electrodes and accordion-style separators to form a stack of electrodes of the sachet cell.

[0100] In order to manufacture relatively lightweight batteries in various shapes required for the uses presented herein, and unlike the winding methods used for prismatic or cylindrical modules and batteries, the internal components of the bagged modules and batteries are densely stacked in several layers, which also improves space efficiency and increases capacity energy-efficient. Furthermore, the exterior of pouch-type batteries is not rigid, allowing them to be designed in various sizes and shapes. They are foldable and flexible, making them highly functional.

[0101] For example, the superposition is implemented so that the respective electrode strips of the folded sachet cells, and thus the succession of cathodes and anodes 154a-152a of the sachet cell 101a, the succession 154b-152b of the sachet cell 101b and the succession 154c-152c of the sachet cell 101c, are aligned to be arranged next to each other.

[0102] This "Z" folding thus provides a successive stacking of the cells in the bag and a stacking of separators in a uniform and zigzag manner, which minimizes the stresses applied to cells 101a, 101b, 101c and following, which prevents contact between the anodes and the cathodes.

[0103] The inner layer of the film in the bag cell also plays an important role in the chemical containment and insulation of the battery. This layer ensures that the bag can safely contain the active electrochemical components of the battery, such as the electrolyte and the electrodes, and contributes in particular to the dissipation of heat generated during battery operation.

[0104] Fig. 9 is a flowchart which specifies the different stages of a process for manufacturing a cell in a sachet according to one or more embodiments of the invention.

[0105] As illustrated, the manufacturing process begins with a first step a) denoted E10, corresponding to the acronym "FRN", which involves providing a resealable bag such as that of the 100, 200, and 300 bagged cells discussed in previous embodiments. In particular, this resealable bag, 101, 201, or 301, includes a film adapted to receive the electrolyte as well as the integrated electrode strip.

[0106] The first step a) denoted E10 is followed by a second step b) denoted E20, corresponding to the acronym "FORM", which includes the formation of a plurality of separate housings in the resealable bag previously provided.

[0107] By way of non-limitation, the formation of housings can be implemented based on the "Z" folding described above. For example, it is possible to use a mold to shape the bagged cell according to the required specifications, such as dimensions, the "a / b" ratio, or the presence of means or stiffening elements.

[0108] During this second step b) denoted E20, one or two additional substeps, bl) denoted E22 and / or b2), denoted E24, may be implemented.

[0109] In particular, step b) denoted E20 of housing formation includes a substep bl) denoted E22, corresponding to the acronym "SEP", and providing for separating the housings from the bag cell so that each of them is isolated.

[0110] For this manufacture of separate housings, in one example, a downward force is applied by a mold to the stack of layers of material in the bagged cell. This force is preferably applied uniformly to avoid deformations and ensure the accuracy of the forming.

[0111] To form housings of precise dimensions, it is preferable to use a mold that is not heated. If heat is applied to the mold, it may undergo deformations that will affect the shape of the housings. It is therefore advantageous to use a mold that is not preheated and, subsequently, a release agent.

[0112] During this second step b) denoted E20, a reversal of the mold movement can be implemented to shape the lower part of the bag formed by the cell, thus ensuring symmetry between the two halves of the bag cell, before releasing it without damaging its structure or its layers.

[0113] Optionally, and in addition to, following, or during substep bl) of separation, step b) denoted E20 may further include a substep b2) denoted E24, corresponding to the acronym "RIG", which provides for placing one or more stiffening elements between at least two formed compartments in order to separate and isolate them. Possible examples of stiffening elements have been described above in the context of the third embodiment, intended to be placed between different compartments in order to reinforce the overall structure of the bag cell for the purpose of extracting the compartments containing the gas formed thereafter.

[0114] Then, in a third step c) denoted E30 and corresponding to the acronym "FERM", the film of the bagged cell is sealed by sealing it upon itself, thus partitioning the compartments. This step ensures the airtightness of the bagged cell, preventing electrolyte leaks. This sealing can be carried out by various techniques, for example by heat sealing.

[0115] The third step c), denoted E30, is followed by a fourth step d), denoted E40, corresponding to the acronym "ELY". The fourth step d) comprises the introduction of the electrolyte into the sachet cell, for example into the compartments or inside the sealed film of the sachet cell, subsequently leading to the activation of the electrochemical reactions when an electrical charge is applied to the electrodes of the sachet cell.

[0116] In particular, applying an electrical charge to the electrodes of the sachet cell triggers a fifth step e), denoted E50, following the fourth step d) and corresponding to the acronym "GAS". It is during this fifth step e) that gas generation occurs in the sachet cell, due to electrochemical reactions taking place between the electrolyte and the electrodes. These gases are then received and retained within the formed compartments.

[0117] At the end of the process, a sixth step f), denoted E60, and corresponding to the acronym "EXT", follows the fifth step e) and comprises the extraction (E60) of the housings that contained the generated gas. A bagged cell is obtained, suitable for use within a corresponding electric battery module.

Claims

Demands

1. Bag cell (100; 200; 300) for an electric battery module (1000), the bag cell (100; 200; 300) being formed of a resealable bag (101; 201; 301) adapted to hold an electrolyte, the resealable bag (101; 201; 301) further comprising at least one strip of electrodes (150, 152, 154; 250, 252, 254; 350, 352, 354) aligned along a first axis (OX1), the electrodes being adapted, in operation, to cause the electrolyte to react electrochemically, the electrochemical reaction of the electrolyte triggering the generation of a gas, the resealable bag (101; 201; 301) further comprising a plurality of housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) aligned along a second axis (OX2) substantially parallel to the first axis (OX1), each of said housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) being formed in an internal surface of the resealable bag (101;201; 301) and being capable of receiving the generated gas.;

2. Bag cell (100; 200; 300) according to claim 1, wherein at least one of the housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) has a three-dimensional shape defined by a length "a" (110a, 120a; 210a, 211a, 212a, 213a, 214a, 220a, 221a, 222a, 223a, 224a; 310a, 311a, 312a, 313a, 314a, 320a, 321a, 322a, 323a, 324a), by a width "b" and by a height "c", the height "c" being less than or equal to the thickness of at least one strip of electrodes (150, 152, 154; 250, 252, 254; 350, 352, 354).

3. Bag cell (100; 200; 300) according to claim 2, wherein the ratio "a / b" of the length and width of at least one housing is greater than or equal to 1 and less than or equal to 6.

4. Bag cell (200; 300) according to any one of the preceding claims, wherein at least two of the consecutive housings (210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225) are separated from each other by a portion of the internal surface of the resealable bag (201).

5. Bag cell (200; 300) according to any one of the preceding claims, wherein the plurality of dwellings (210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225) comprises at least two series of several separate dwellings in pairs, each of the two series of dwellings being aligned along the second axis (0X2).

6. Bag cell (300) according to any one of the preceding claims, wherein at least two consecutively aligned housings of the plurality of housings (310, 311, 312, 313, 314, 320, 321, 322, 323, 324) are further separated from each other by at least one stiffening element (330, 331, 332, 333, 340, 341, 342, 343) disposed in the internal surface of the resealable bag (301).

7. A method for manufacturing a sachet cell (100; 200; 300) according to any one of claims 1 to 6, the manufacturing method comprising the steps of: a) supplying (E10) the resealable sachet (101; 201; 301) suitable for holding the electrolyte, the resealable sachet (101; 201; 301) comprising at least one strip of electrodes (150, 152, 154; 250, 252, 254; 350, 352, 354), b) forming (E20), in the inner surface of the supplied resealable sachet (101; 201; 301), the plurality of housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) so that said housings are separated in pairs, c) closure (E30) of the resealable bag (101; 201; 301), implemented by folding the resealable bag (101; 201;301) on itself so as to seal each of the two-by-two separate housings with another respective housing from among the plurality of two-by-two separate housings, d) insertion (E40) of the electrolyte into the closed resealable bag (101; 201; 301), e) electrochemical reaction (E50) of the electrolyte to trigger the generation of the gas, the generated gas being received into the plurality of sealed housings, and f) extraction (E60) from each of the housings which received the generated gas.;

8. A manufacturing method according to claim 7, wherein step b) of formation (E20) comprises substep b) of separation (E22) of at least two of the plurality of housings (210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225) by a portion of the inner surface of the resealable bag (201) and / or substep b2) of stiffening at least two of the plurality of housings (310, 311, 312, 313, 314, 320, 321, 322, 323, 324) by at least one stiffening element (330, 331, 332, 333, 340, 341, 342, 343) in the internal surface of the resealable bag (301).

9. A manufacturing method according to claim 7 or 8, wherein step b) of forming (E20) the plurality of housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) comprises modulating each housing so that each housing has a three-dimensional shape defined by a length "a" (110a, 120a; 210a, 211a, 212a, 213a, 214a, 220a, 221a, 222a, 223a, 224a; 310a, 311a, 312a, 313a, 314a, 320a, 321a, 322a, 323a, 324a), by a width "b" and by a height "c", the height "c" being less than or equal to the thickness of at least one electrode strip (150, 152, 154; 250, 252, 254; 350, 352, 354), the ratio "a / b" of the length and width of at least one housing being greater than or equal to 1, said ratio "a / b" of the length and width being less than or equal to 6.

10. A manufacturing method according to any one of claims 7 to 10, wherein step b) of forming (E20) the plurality of housings (110, 120; 210, 211, 212, 213, 214, 215, 221, 222, 223, 224, 225; 310, 320) is carried out by means of a mold and wherein step f) of extracting (360) each of the housings is carried out by means of a release agent.

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