Method for associating a microcircuit with a battery cell

Abstract

The invention relates to a method for coupling a battery cell to a battery cell monitoring and control circuit, the method comprising the steps of: providing a battery cell (10) comprising a multilayer structure, the multilayer structure comprising two electrode layers (11, 12) separated by a separating layer (17), and two external conductive faces (13, 14) extending parallel to the layers of the multilayer structure; providing a microcircuit (MC) comprising two connection areas (21, 22) formed respectively on opposite faces of the microcircuit; arranging the microcircuit in a volume delimited by two planes respectively including the external conductive faces of the battery cell; forming a conductive connection (25, 26) between each connection area of ​​the microcircuit and a respective conductive face of the battery cell. Figure 1

Description

Title of the invention: Method for associating a microcircuit with a battery cell technical field

[0001] The present invention relates to multi-cell batteries connected in series and / or in series and parallel, and in particular the integration in each cell of the battery of a microcircuit for monitoring cell operating parameters. State of the art

[0002] For safety and lifespan reasons, certain types of multi-cell batteries require continuous or periodic monitoring of functional parameters during charge and discharge cycles. In particular, some batteries can spontaneously catch fire or explode, or produce violent outgassing. These include lithium-ion, sodium-ion, potassium-ion, magnesium-ion, or lithium / sodium metal sulfur batteries, with liquid electrolyte, solid polymer electrolyte (SPE), gel polymer electrolyte (GPE), or all-solid-state battery (ASSB).

[0003] The functional parameters to be controlled include, in particular, the temperature and pressure of each cell, the minimum discharge voltage and the maximum charge voltage of each cell. It is also desirable to monitor the electrical balance of all the cells, as well as the evolution of the battery voltage and current during charge and discharge cycles. Using these parameters makes it possible to control the output voltage and current of the charger, and also to manage functions such as balancing the battery's constituent blocks, as well as the battery's thermal protection. This controlled management makes it possible to determine the battery's State of Health (SOH), ensure a long service life, and anticipate the battery's Remaining Useful Life (RUL).

[0004] Generally, controlling the cells of a battery requires a multitude of wires and / or connections between the cells and a central unit called a "BMS" ("Battery Management System"). It is therefore understandable that in the case of a complex series / parallel cell assembly, this interconnection with the BMS proves complex, time-consuming, and industrially expensive, particularly when the number of interconnected cells is large, as in the case of batteries intended for mobility and operating at voltages exceeding 350 volts, i.e., a minimum of 100 blocks connected in series (depending on the electrochemical pair used). Thus, some batteries can contain several thousand cells. The resulting complexity of interconnection can represent a source of failure related to the battery's operating conditions. For example, batteries intended for mobility are subjected to vibrations and shocks, which can cause electrical disconnections, making reliable battery operation impossible, or even lead to short circuits or thermal runaways and compromise the integrity of the application due to their inherent danger, while also limiting battery sizing.

[0005] This interconnection complexity can be reduced by decreasing the number of measurement points. However, this measure requires significant safety margins on the detection thresholds to ensure the battery's operational safety. Indeed, battery cells generally age unevenly (primarily due to variations in internal resistance). This results in behaviors, particularly thermal behavior, that can vary from one cell to another within the same battery.

[0006] It is therefore desirable to be able to measure the functional parameters of each cell and transmit these measurements to a central BMS unit. To this end, it is desirable to be able to associate with each cell a microcircuit integrating sensors for these functional parameters and a transmission circuit with the central unit. The transmission circuit can use the cell connections to communicate with the central unit. It is desirable that the association method implemented be reliable, and in particular resistant to vibrations and shocks. It is also desirable that this association method be suitable for solid-state polymer matrix battery cells comprising a stack of layers including a layer forming an anode electrode, a layer forming a cathode electrode, and a separator layer between the anode and cathode layers. Summary

[0007] Embodiments relate to a method of coupling a battery cell to a battery cell monitoring and control circuit, the method comprising steps of: providing a battery cell comprising a multilayer structure, the multilayer structure comprising two electrode layers separated by a separation layer, and two external conductive faces extending parallel to the layers of the multilayer structure; providing a microcircuit ensuring battery cell control functions, the microcircuit comprising two connection areas formed respectively on opposite faces of the microcircuit, the microcircuit having a thickness in a direction perpendicular to the two connection areas, less than the thickness of the battery cell between the external conductive faces of the battery cell;arrange the microcircuit in a volume delimited by two planes including respectively the external conductive faces of the battery cell, the connection areas of the microcircuit being parallel to the; two planes; to form an electrically conductive link between each connection area of ​​the microcircuit and a respective conductive face of the battery cell.

[0008] In this way, such a battery cell can be associated with a microcircuit, by a series of steps easily automated by implementing a robust assembly, particularly resistant to vibrations.

[0009] According to one embodiment, the method further comprises a step consisting of: forming an orifice in the battery cell through the multilayer structure, a first of the conductive bonds being formed by a first layer of conductive glue disposed in the orifice at the level of a first of the electrode layers, the microcircuit being disposed in the orifice, a first of the connection areas of the microcircuit being in contact with the first layer of conductive glue, a second of the conductive bonds being formed by a second layer of conductive glue disposed in the orifice on a second of the connection areas of the microcircuit, at the level of a second of the electrode layers.

[0010] Thus, the microcircuit is both connected to the terminals of the cell and completely protected and held rigidly in the orifice formed in the cell by the layers of conductive glue.

[0011] According to one embodiment, the first layer of conductive glue is crosslinked and / or polymerized after the insertion of the microcircuit into the orifice.

[0012] This arrangement ensures both good retention and good connection of the microcircuit to the cell.

[0013] According to one embodiment, the method further comprises a step of: forming an orifice in the battery cell through the multilayer structure, a first of the conductive links being formed by a first conductive layer fixed on one of the external conductive faces of the battery cell, so as to close an opening of the orifice, the microcircuit being disposed in the orifice, a first of the connection areas of the microcircuit being glued to the first conductive layer, a second of the conductive links being formed by a layer of conductive glue disposed in the orifice on a second of the connection areas of the microcircuit, at the level of a second of the electrode layers.

[0014] Thus, the microcircuit is both connected to the cell terminals and fully protected and rigidly held in the opening on one side by the conductive adhesive layer and on the other side by the first conductive layer to which it is bonded. Furthermore, only one layer of conductive adhesive is deposited in the opening, which reduces the number of steps required to assemble the microcircuit to the cell.

[0015] According to one embodiment, the first conductive layer has a self-adhesive side formed using a conductive adhesive, so as to attach to one of the external conductive faces of the battery cell and on the first connection area of ​​the microcircuit.

[0016] The use of a self-adhesive layer makes it possible to avoid an additional step of coating the first conductive layer with glue.

[0017] According to one embodiment, resin is inserted into the orifice around the microcircuit.

[0018] The resin allows the microcircuit and the cell electrodes to be isolated when the microcircuit is not encapsulated in an electrically insulating casing between the connection pads and the cell contains liquid electrolytes that can flow into the orifice. The resin also helps to reinforce the mechanical retention of the microcircuit within the cell.

[0019] According to one embodiment, resin in the orifice around the microcircuit is crosslinked and / or polymerized before the insertion of the conductive adhesive layer forming the second conductive bond. In this way, the conductive adhesive is prevented from mixing with the resin.

[0020] According to one embodiment, the resin in the orifice around the microcircuit and / or the conductive adhesive layer forming one or both of the conductive bonds is crosslinked and / or polymerized by heat treatment, and / or by an ultraviolet beam, and / or by an electron beam. The use of such an ultraviolet or electron beam reduces the crosslinking and / or polymerization operations required to a few seconds.

[0021] According to one embodiment, each of the conductive links is formed by an elongated conductive element fixed on one side to one of the connection areas of the microcircuit by gluing and / or ultrasonic welding and fixed on the other side to a respective conductive face of the cell, the microcircuit being arranged opposite a lateral face of the cell, the microcircuit being encapsulated in resin.

[0022] This assembly method allows the microcircuit to be connected to the cell without drilling into the cell, while ensuring good mechanical protection of the microcircuit.

[0023] According to one embodiment, the microcircuit is encapsulated in the resin.

[0024] According to one embodiment, the battery cell belongs to a group of cells Identical batteries are stacked in series, with each cell in the battery group having its own microcircuit. This assembly method allows for the formation of a battery with a large number of cells in series without significantly increasing the battery's weight and size.

[0025] Embodiments may also relate to a battery cell comprising: a multilayer structure, the multilayer structure comprising two electrode layers separated by a separating layer, and two external faces conductive surfaces extending parallel to the layers of the multilayer structure; and a microcircuit providing battery cell control functions, the microcircuit comprising two connection areas formed respectively on opposite faces of the microcircuit, the microcircuit having a thickness in a direction perpendicular to the two connection areas, less than the thickness of the battery cell between the external conductive faces of the battery cell; and wherein: the microcircuit is disposed in a volume delimited by two planes including respectively the external conductive faces of the battery cell, the connection areas of the microcircuit being parallel to the two planes; a conductive link connects each connection area of ​​the microcircuit to a respective conductive face of the battery cell; and electrically insulating resin is disposed between the microcircuit and the battery cell.

[0026] According to one embodiment, the battery cell includes an orifice extending through the multilayer structure, a first of the conductive bonds being formed by a first layer of conductive glue disposed in the orifice at the level of a first of the electrode layers, the microcircuit being disposed in the orifice, a first of the connection areas of the microcircuit being in contact with the first layer of conductive glue, the resin surrounding the microcircuit in the orifice, a second of the conductive bonds being formed by a second layer of conductive glue disposed in the orifice on a second of the connection areas of the microcircuit, at the level of a second of the electrode layers.

[0027] According to one embodiment, the battery cell includes an orifice extending through the multilayer structure, a first of the conductive bonds being formed by a first conductive layer fixed on one of the external conductive faces of the battery cell, so as to close an opening of the orifice, the microcircuit being disposed in the orifice, a first of the connection pads of the microcircuit being glued to the first conductive layer, the resin being inserted in the orifice around the microcircuit, a second of the conductive bonds being formed by a layer of conductive glue disposed in the orifice on a second of the connection pads of the microcircuit, at the level of a second of the electrode layers.

[0028] According to one embodiment, the orifice around the microcircuit is filled with resin.

[0029] According to one embodiment, each of the conductive links comprises a elongated conductive element fixed on one side to a connection area of ​​the microcircuit by gluing and / or ultrasonic welding and fixed on the other side to a respective conductive face of the battery cell, the microcircuit being positioned opposite a lateral face of the cell and encapsulated in resin. Brief description of the figures

[0030] The present invention will be better understood with the aid of the following description of exemplary embodiments with reference to the accompanying figures, in which identical reference signs correspond to structurally and / or functionally identical or similar elements.

[0031] [Fig-1] Figure 1 is a schematic cross-sectional profile view along a plane of section AA' shown in figure 2, of a portion of a battery cell, according to one embodiment,

[0032] [Fig.2] Figure 2 is a schematic front view of the cell in a section plane BB' indicated on Figure 1, according to one embodiment;

[0033] [Fig.3] Figures 3A to 3F show in profile section a battery cell at different stages of a process of implanting a microcircuit in a battery cell, according to an embodiment;

[0034] [Fig.4] Figure 4 is a schematic cross-sectional profile view of a part of a battery cell, according to another embodiment;

[0035] [Fig.5] Figure 5 is a schematic cross-sectional profile view of a part of a battery cell, according to another embodiment;

[0036] [Fig.6] Figure 6 is a schematic cross-sectional profile view of a part of a battery cell, according to another embodiment;

[0037] [Fig.7] Figure 7 is a schematic cross-sectional profile view of a part of a battery cell, according to another embodiment;

[0038] [Fig.8] Figure 8 is a schematic cross-sectional profile view of a microcircuit that can be implanted in a cell, according to one embodiment;

[0039] [Fig.9] Figure 9 is a schematic cross-sectional profile view of a set of stacked cells, according to one embodiment;

[0040] [Fig. 10] Figure 10 schematically represents an electrical circuit in which several battery cells are connected in series and each associated with a microcircuit, according to one embodiment. Detailed description

[0041] Figures 1 and 2 represent a cell 10 having a planar, multilayer structure of small thickness relative to its length and / or width. The cell 10 comprises a first conductive electrode layer 11 forming an anode or cathode electrode, a conductive electrode layer 12 forming a cathode or anode electrode, and an intermediate separating layer 17, arranged between the electrode layers 11 and 12. In the example of Figure 1, the electrode layer 12 is in the lower position and the electrode layer 11 is in the upper position.

[0042] To couple the cell 10 to a microcircuit MC, an orifice 19 is formed through The layers 11, 12, 17 together constitute the cell 10. The orifice 19 has sufficient width to allow the insertion of the microcircuit MC. The orifice 19 may have a square, rectangular, or circular cross-section. In one embodiment, the microcircuit MC comprises connection areas 21, 22 formed on opposite faces of the microcircuit MC to contact, respectively, the electrode layers 11, 12 of the cell 10. The microcircuit MC may have a thickness in a direction perpendicular to the connection areas 21, 22 that is less than or equal to the thickness of the cell 10, including the electrode layers 11, 12, and the separation layer 17.

[0043] The microcircuit MC is inserted into the orifice 19 onto a layer of conductive adhesive 26 such that one (22) of the connection areas 21, 22 is in contact with the adhesive layer 26 and with the electrode layer 12. The space in the orifice 19 around the microcircuit MC can then be filled with an electrically insulating encapsulating resin 23, without covering the upper connection area (21 in the example in Figure 1) of the microcircuit MC. The orifice 19 is then sealed by a layer of conductive adhesive 25 deposited in the orifice on the microcircuit MC, at the level of the upper electrode layer 11 of the cell 10. Thus, the microcircuit MC is both embedded in the cell 10 and rigidly fixed and connected to the electrodes 11, 12 of the latter.

[0044] The conductive adhesive layers 25, 26 are formed, for example, by a silver adhesive. The conductive adhesive layers 25, 26 and the resin 23 can be crosslinked and / or polymerized by low or high temperature thermal action (for example, by infrared radiation), or by an ultraviolet beam or an electron beam. These crosslinking and / or polymerization operations can be carried out simultaneously or successively, following the insertion of the microcircuit MC into the orifice 19 onto the first layer of conductive adhesive 25, then following the introduction of the resin into the orifice, and following the deposition of the second layer of adhesive 26. When the microcircuit MC is inserted into the orifice, the adhesive layer 26 may be only partially crosslinked and / or polymerized, which ensures good adhesion of the microcircuit.The crosslinking and / or polymerization of the adhesive layer 26 can be finalized following the placement of the microcircuit on the adhesive layer.

[0045] It should be noted that the resin 23 surrounding the microcircuit MC is designed to provide mechanical and / or chemical protection for the latter, particularly in cases where at least one of the cell's electrolytes is liquid. The resin 23 also prevents the cell or microcircuit from being short-circuited by the conductive adhesive 25, or by contact between the microcircuit and the cell if the edge of the microcircuit is not already covered with an insulating layer.

[0046] Furthermore, the thicknesses of the glue layers 25, 26 and the resin 23 in the orifice 19 are adjusted according to the relative thicknesses of cell 10 and microcircuit MC in order to avoid short-circuiting the cell.

[0047] After the formation of the orifice 19, a conductive pad 27 can be bonded to the underside of the cell 10 to support the adhesive layer 26. Similarly, after the application of the adhesive layer 25, a conductive pad 28 can be bonded to the upper side of the cell. The pads 27, 28 can be made of copper or aluminum and have a thickness of approximately 20 µm (plus or minus 10%). One or both of the pads 27, 28 can be replaced by an electrically conductive film covering the entire cell 10.

[0048] In the example of Figure 2, cell 10 has a rectangular shape in the section plane AA' of Figure 1. The orifice 19 is formed near a corner of cell 10 through layers 11, 12, 17.

[0049] Figures 3A to 3F represent the cell 10 at various successive stages S1 to S6 of a method for embedding a microcircuit MC, MC1-MC6 in a cell 10. Figure 3A illustrates the step S1 during which the mounting hole 19 is formed in the cell 10. The mounting hole 19 can be made by a laser cutting process or using a non-electrically conductive punch 30 or a punch coated with a non-electrically conductive coating. The cell 10 is then placed on a support ST, for example a table, below the tool 30. The hole 19 can be made at any location in the plane of the cell 10.

[0050] Figure 3B illustrates step S2 in which the cell 10 is glued using a conductive adhesive onto a conductive pad 28 previously placed on the support ST, with the orifice 19 centered on the pad. For this purpose, the pad 28 has, for example, a self-adhesive side, so that it can adhere to the cell 10 when the latter is pressed against the support on the pad.

[0051] Figure 3C illustrates step S3, during which a drop of conductive adhesive is poured into orifice 19. The conductive adhesive is fluid enough to form a conductive layer 26 at the bottom of orifice 19 on the pellet 28. The amount of adhesive deposited is such that the resulting layer 26 does not exceed the level of the cell's separation layer 17. The conductive adhesive is, for example, of the silver particle type.

[0052] Figure 3D illustrates step S4 during which the MC microcircuit is inserted into the orifice 19 in a position centered thereon. The adhesive layer 26 is then crosslinked and / or polymerized, for example in a few seconds using an ultraviolet beam or an electron beam.

[0053] Figure 3E illustrates step S5 in which an electrically insulating resin 23 is poured into the orifice 19 around the microcircuit MC, without covering the latter. The resin 23 is then crosslinked and / or polymerized, for example in a few seconds using an ultraviolet beam or an electron beam. If necessary (to avoid short-circuiting the cell), the resin layer can extend above the level of the connection area 21 of the microcircuit by protecting the latter, for example, with a punch when inserting the resin in liquid form into the orifice 19.

[0054] Figure 3F illustrates step S6, during which a drop of conductive adhesive is poured into the orifice 19. The conductive adhesive is fluid enough to form a conductive layer 25 that completely seals the orifice 19. The adhesive layer 25 is then crosslinked and / or polymerized, for example, in a few seconds using an ultraviolet or electron beam. The amount of adhesive poured can be adjusted so that the upper surface of the adhesive layer 25 is substantially in the plane of the upper surface of the cell 10. However, this arrangement is not necessary, since the connection between the upper connection area 21 of the microcircuit 10 and the upper electrode 11 of the cell 10 is ensured by the lateral edges of the adhesive layer 25. Next, a conductive pad 27 is glued onto the cell 10 so as to cover the adhesive layer 25.For this purpose, the conductive pad 27 may have one face coated with a layer of conductive adhesive, making it self-adhesive. The adhesive layer 25 may not be fully cross-linked and / or polymerized at the time the pad 27 is applied. Thus, when the pad 27 is placed on the orifice 19, the pressure exerted on the pad for this purpose causes any excess adhesive to be removed. In this way, the adhesion of the pad 27 to the cell 10 is strengthened.

[0055] A final crosslinking and / or polymerization step by heat treatment or electron beam can be carried out to ensure that the glue layers 25, 26 and the resin layer 23 are perfectly solidified.

[0056] It should be noted that the glue layers 25 and 26 do not necessarily have the same thickness. Thus, one of the glue layers 25 and 26 may be thicker than the other glue layer. It is simply important that the glue layers 25 and 26 are positioned on either side of the level of the intermediate layer 14 of the cell 10.

[0057] It should also be noted that the pads 27, 28 can be omitted. For this purpose, the support ST on which the cell 10 is placed in step S2 can be non-stick, for example coated with a layer of Teflon. In this way, the conductive adhesive 26 poured into the orifice in step S3 does not adhere to the support ST or can be easily detached from it.

[0058] It should also be noted that the first layer of glue 26 can be omitted, the pad 28 then being retained. Thus, Figure 4 represents the cell 10 and the microcircuit MC inserted into the mounting hole 19 formed in the cell, according to a Another embodiment. The cell 10 is placed on the conductive pad 28, which is positioned over the orifice. The microcircuit MC is placed directly onto the pad 28 in the orifice. The microcircuit MC is thus held in place by the adhesive on the pad. The insulating resin 23 is then poured into the orifice around the microcircuit MC and subsequently crosslinked and / or polymerized. A layer of conductive adhesive 25' is then poured into the orifice 19 until it is completely filled, and subsequently crosslinked and / or polymerized. The conductive pad 27 can then be glued onto the cell 10, covering the orifice 19.

[0059] In the embodiments described above, the insertion of the MC microcircuit into the cell 10 can be carried out before the insertion of liquid electrolytes into the cell. This arrangement makes it possible, in particular, to avoid chemical attack of the microcircuit by such electrolytes, when the edge of the microcircuit is not covered with a protective insulating layer, and if the cell is of the liquid electrolyte type.

[0060] In the embodiments described above, when the edge of the microcircuit MC is covered with a protective insulating layer, the insertion of resin into the orifice 19 can be omitted. For this purpose, the orifice 19 can be made to the dimensions of the microcircuit, in order to minimize the free space between the microcircuit MC and the inner face of the orifice. The conductive adhesive deposited on the microcircuit MC to form the adhesive layer 25, 25' can be sufficiently viscous so as not to flow into the space left free in the orifice.

[0061] Figures 5 and 6 show the battery cell 10 in which the opening 19 is formed to the dimensions of the microcircuit, the microcircuit MC being inserted into the opening. The edge of the microcircuit MC is covered with a protective insulating layer 24. In Figure 5, the microcircuit MC is arranged between the layers of conductive adhesive 25, 26, the conductive pads 27, 28 being omitted. The layer 24 may be slightly elastic to facilitate the insertion of the microcircuit into the opening.

[0062] In Figure 6, the battery cell 10 is placed on the self-adhesive conductive pad 28, with the microcircuit MC positioned between the pad 28 and the conductive adhesive layer 25'. The conductive adhesive layer 25' can be covered by the conductive pad 27 glued to the upper face 13 of the battery cell.

[0063] Figure 7 shows an edge of the cell 10 and the microcircuit MC associated with the cell, according to another embodiment. To connect the microcircuit MC to the cell 10, a first elongated conductive element 27' is fixed to the connection area 21 of the microcircuit and to the upper face of the upper electrode layer 11 of the cell, and a second elongated conductive element 28' is fixed to the connection area 22 of the microcircuit and to the lower face of the lower electrode layer 12 of the cell 10, the microcircuit being positioned opposite a lateral face (slice) of the cell. The MC microcircuit is then encapsulated in a resin envelope 23'. The elongated elements 27', 28' can be in the form of wires or strips having the same structure as the pads 27, 28.

[0064] According to one embodiment, each of the elongated elements 27', 28' has the shape of a strip which is glued to a connection area 21, 22 of the microcircuit and to one of the external faces 13, 14 of the electrode layers 11, 12. For this purpose, a conductive adhesive may be used. According to another embodiment, each of the strips 27', 28' may have a face coated with a layer of conductive adhesive, so as to be self-adhesive for sticking to a connection area of ​​the microcircuit and to one of the external faces 13, 14 of the electrode layers 11, 12.

[0065] According to one embodiment, the elongated elements 27', 28' are fixed to the connection pads 21, 22 of the microcircuit by welding, for example by ultrasonic welding. Each of the elongated elements 27', 28' can then be bonded to one of the outer faces of the electrode layers 11, 12, by a layer of conductive adhesive.

[0066] According to one embodiment, the elongated elements 27', 28' (strips or wires) are both glued and soldered to the connection areas 21, 22 of the MC microcircuit. The elongated elements 27', 28' can also be ultrasonically welded to the outer faces 13, 14 of the electrode layers 11, 12, when the outer faces 13, 14 are formed by metallic layers.

[0067] According to one embodiment, the elongated elements 27', 28' (strips or wires) are fixed to the connection areas 21, 22 of the MC microcircuit during the manufacture of the latter.

[0068] According to one embodiment, the resin envelope 23' is formed around the microcircuit MC so as to ensure the fixation of the latter on the lateral face of the cell 10.

[0069] The assembly methods described above can be applied, in particular, to any type of planar solid or semi-solid cell. Thus, these methods can be applied to a planar cell comprising opposing external conductive faces formed by an anode collector film and a cathode collector film. These methods can also be applied to a cell comprising an anode layer (11 or 12), a cathode layer (12 or 11), and a separator layer (17) between the anode and cathode layers. The anode layer comprises an anode current collector film and an anode reservoir layer between the collector film and the intermediate layer 17. Similarly, the cathode layer of the cell 10 also comprises a cathode current collector film and a cathode reservoir layer between the collector film and the intermediate layer 17.The anode current collector film is coated or impregnated with a mixture in a pasty or semi-liquid state solidified by crosslinking and / or polymerization, forming the reservoir layer and containing at least . An anode active material dispersed in a first liquid electrolyte. Similarly, the cathode current-collecting film is coated or impregnated with a mixture in a paste-like or semi-liquid state, solidified by crosslinking and / or polymerization, forming the reservoir layer and containing at least one cathode active material dispersed in a second liquid electrolyte. The intermediate layer comprises an electrically insulating and porous film impregnated with a third electrolyte solidified by crosslinking and / or polymerization. The entire assembly may be crosslinked and / or polymerized by an electron beam. The paste-like or semi-liquid mixtures and the third electrolyte may comprise a monomer or prepolymer mixture that can include crosslinking and / or polymerizing functions selected from acrylate, methacrylate, vinyl, styrene, isocyanate, acrylamide, and methacrylamide functionalities.Pasty or semi-liquid mixtures include electron-conducting fillers such as carbon black, carbon nanofibers, titanium nitride-coated carbon nanofibers, carbon nanotubes, graphene powders, graphene oxide powders, metallic fibers, or metallic powders such as carbon fluoride powders, aluminum powders, or nickel powders, conductive metal oxides, conductive polymers, or conductive ceramic powders. The first and second electrolytes may include a lithium or sodium salt dissolved in a liquid solvent.

[0070] Figure 8 shows the structure of the MC microcircuit. The microcircuit is formed in an active layer AL on a semiconductor substrate SB. The active layer AL is covered by an electrically insulating layer IL2 and the electrically conductive layer 22. A through-conductive via CV2 connects a conductive area of ​​the active layer AL to the conductive layer 22. Another through-conductive via CV1 connects a conductive area of ​​the active layer AL to the conductive layer 21 deposited on the back side of the substrate SB. The back side of the substrate SB and the conductive layer 21 can be insulated from each other by an insulating layer IL1. The edge of the substrate SB can be insulated by an insulating layer IL3.

[0071] The MC microcircuit formed in the AL active layer includes a power supply circuit to supply the microcircuit from the voltage supplied by the cell to which it is associated, a processing unit for example of the microcontroller type, analog / digital converters, in particular for reading the temperature and for measuring voltage, a reference voltage source, a stage for reading the voltage across the cell terminals coupled to one of the analog / digital converters, a temperature sensor coupled to one of the analog / digital converters, a communication circuit for communicating with a battery central unit, and a circuit ensuring a balancing function of the associated cell.

[0072] Figure 9 shows several cells 10, labeled CL1, CL2, ... CL6, stacked so that they are connected in series. Each cell has a respective microcircuit MC, labeled MCI, MC2, ... MC6, embedded in the cell and connected to the cell electrodes. In this stack, the microcircuits MC1-MC6 are separated by conductive elements 31 comprising conductive layers 25, 26, and optionally, pads 27, 28. The lower connection area of ​​the microcircuit MCI in the lower cell CL1 is connected to the latter by a conductive element 33 comprising the conductive layer 26 and optionally the pad 28. The upper connection area of ​​the microcircuit MC6 in the upper cell CL6 is connected to the latter by a conductive element 32 comprising the conductive layer 25 and optionally the pad 27.

[0073] The electrode layers 11,12 may have a pasty appearance so that the conductive pellets 27, 28 can be pressed into these layers before or after the assembly of the cell with other cells as illustrated in Figure 9.

[0074] It should be noted that it is not necessary to align the orifices 19 formed in the stacked cells CL1, CL2, ... CL6. If the conductive pads 27, 28 are used, it may be preferable for them not to be superimposed, particularly to limit the formation of excess thickness. To this end, the orifices 19 made in the cells CL1-CL6 can be formed by respecting a grid pattern on the surface of the cells, with meshes larger than the pads 27, 28.

[0075] The assembly described with reference to Figure 9 makes it possible to obtain the electrical circuit shown in Figure 10. Figure 10 represents the CL4-CL6 cells connected in series, each cell being associated with a respective MC1-MC6 microcircuit connected in parallel to the cell electrodes.

Claims

Claims

1. 1. A method of coupling a battery cell to a battery cell monitoring and control circuit, the method comprising steps of: providing a battery cell (10) comprising a multi-layer structure, the multi-layer structure comprising two electrode layers (11, 12) separated by a separation layer (17), and two conductive outer faces (13, 14) extending parallel to the layers of the multi-layer structure; providing a microcircuit (MC) providing battery cell control functions, the microcircuit comprising two connection pads (21, 22) formed respectively on opposite faces of the microcircuit, the microcircuit having a thickness in a direction perpendicular to the two connection pads, less than the thickness of the battery cell between the conductive outer faces of the battery cell;arranging the microcircuit in a volume delimited by two planes respectively including the conductive external faces of the battery cell, the connection pads of the microcircuit being parallel to the two planes; and forming an electrically conductive connection (25, 26, 25', 26') between each connection pad of the microcircuit and a respective conductive face of the battery cell; and;

2. 2. The method of claim 1, further comprising a step of: forming an orifice (19) in the battery cell (10) through the multilayer structure, a first of the conductive bonds being formed by a first layer of conductive glue (26) disposed in the orifice at a first (12) of the electrode layers (11, 12), the microcircuit (MC) being disposed in the orifice, a first (22) of the connection pads (21, 22) of the microcircuit being in contact with the first layer of conductive glue, a second of the conductive bonds being formed by a second layer of conductive glue (25) disposed in the orifice on a second (21) of the connection pads of the microcircuit, at a second (11) of the electrode layers.

3. 3. The method of claim 2, wherein the first layer of conductive glue (26) is crosslinked and / or polymerized after insertion of the microcircuit (MC) into the orifice (19).

4. 4. The method of claim 1, further comprising a step of: forming an orifice (19) in the battery cell (10) through the multilayer structure, a first of the conductive connections being formed by a first conductive layer (28) attached to one of the conductive outer faces (14) of the battery cell, so as to close an opening of the orifice, the microcircuit (MC) being arranged in the orifice, a first of the connection pads (22) of the microcircuit being bonded to the first conductive layer, a second of the conductive connections being formed by a layer of conductive glue (25') arranged in the orifice on a second (21) of the connection pads of the microcircuit, at a second (11) of the electrode layers.

5. 5. Method according to claim 4, in which the first conductive layer (28) has a self-adhesive face formed using a conductive glue, so as to be fixed on one of the external conductive faces (14) of the battery cell and on the first connection pad of the microcircuit (MC).

6. 6. Method according to one of claims 2 to 5, wherein: resin (23) is inserted into the orifice (19) around the microcircuit (MC), and / or resin (23) in the orifice (19) around the microcircuit (MC) is crosslinked and / or polymerized before the insertion of the conductive adhesive layer (25, 25') forming the second conductive bond, and / or resin (23) in the orifice (19) around the microcircuit (MC) and / or the conductive adhesive layer (26, 25, 25') forming one and / or the other of the conductive bonds is crosslinked and / or polymerized by heat treatment, and / or ultraviolet beam and / or electron beam.

7. 7. Method according to claim 1, in which each of the conductive connections (27', 28') is formed by an elongated conductive element (27', 28') fixed on one side to one of the connection pads (21, 22) of the microcircuit (MC) by gluing and / or ultrasonic welding and fixed on the other side to a respective conductive face (13, 14) of the cell (10), the microcircuit being arranged opposite a lateral face of the cell, the microcircuit being encapsulated in resin (23').

8. 8. Method according to claim 7, in which the microcircuit (MC) is encapsulated in resin (23').

9. 9. Method according to one of claims 1 to 8, in which the battery cell (10) belongs to a group of identical battery cells (CL1-CL6), stacked so that they are connected in series, a respective microcircuit (MC1-MC6) being coupled to each battery cell of the group of battery cells.

10. 10. A battery cell comprising: a multilayer structure, the multilayer structure comprising two electrode layers (11, 12) separated by a separation layer (17), and two conductive outer faces (13, 14) extending parallel to the layers of the multilayer structure; and a microcircuit (MC) providing battery cell control functions, the microcircuit comprising two connection pads (21, 22) formed respectively on opposite faces of the microcircuit, the microcircuit having a thickness in a direction perpendicular to the two connection pads, less than the thickness of the battery cell between the conductive outer faces of the battery cell; and wherein: the microcircuit is arranged in a volume delimited by two planes respectively including the conductive outer faces of the battery cell, the connection pads of the microcircuit being parallel to the two planes;a conductive connection (25, 26, 25', 26') connects each connection pad of the microcircuit to a respective conductive face of the battery cell. electrically insulating resin (23) is arranged between the microcircuit and the battery cell.;

11. 11. Battery cell according to claim 10, comprising an orifice (19) extending through the multilayer structure, a first of the conductive connections being formed by a first layer of conductive glue (26) arranged in the orifice at a first (12) of the electrode layers (11, 12), the microcircuit (MC) being arranged in the orifice, a first (22) of the connection pads (21, 22) of the microcircuit being in contact with the first layer of conductive glue, a second of the conductive connections being formed by a second layer of conductive glue (25) arranged in the orifice on a second (21) of the connection pads of the microcircuit, at a second (11) of the electrode layers.

12. 12. Battery cell according to claim 10, comprising an orifice (19) extending through the multilayer structure, a first of the conductive connections being formed by a first conductive layer (28) fixed on one of the external conductive faces (14) of the battery cell (10), so as to close an opening of the orifice, the microcircuit (MC) being arranged in the orifice, a first (22) of the connection pads (21, 22) of the microcircuit being glued to the first conductive layer, a second of the conductive connections being formed by a layer of conductive glue (25) arranged in the orifice on a second (21) of the connection pads of the microcircuit, at a second (11) of the electrode layers.

13. 13. Battery cell according to one of claims 10 to 12, in which the orifice (19) around the microcircuit (MC) is filled with resin (23).

14. 14. Battery cell according to claim 10, in which each of the conductive connections comprises an elongated conductive element (25', 26') fixed on one side to a connection pad (21, 22) of the microcircuit (MC) by gluing and / or ultrasonic welding and fixed on the other side to a respective conductive face (13, 14) of the battery cell (10), the microcircuit being arranged opposite a lateral face of the cell and encapsulated in resin (23').

Images