Method and station for removing electrolyte residue from cells

Abstract

The present invention relates to a method for removing external electrolyte residue from a partially treated electrochemical cell, comprising the steps of moving a plurality of suction units at least partially along a passage path of a partially treated electrochemical cell, wherein at least one temporary coupling of the suction unit with each cell or pack for transporting the cell is performed such that the suction unit is substantially integrated with the cell or pack along at least a portion of the passage path, and during such temporary coupling, electrolyte residue present on the outer surface of the head portion of the cell is aspirated.

Description

Technical Field

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[0001] The present invention relates to a method and a station for removing electrolyte residues present externally from partially processed cells (preferably electrochemical cells), and to a battery production method and a production line each including such a method and such a station.

[0002] The present invention is particularly suitable for the production of batteries (primary or secondary) of the electrochemical cylindrical (single or plural) cell type, such as lithium-ion batteries. However, the present invention is at least also suitable for the production of other electrolytic cells or electrochemical cells or other forms of cell packaging, such as prismatic cells or pouch cells.

[0003] For example, a battery production line (for single-cell batteries or multi-cell batteries) for producing lithium-ion batteries requires that at least some of the processing steps be carried out in a "dry room", i.e., in a sealed ultra-dry room, i.e., at a very low humidity level (typically about 1% by volume) and with a dew point that can be lower than -40°C. This occurs especially when the materials of the electrodes and / or electrolyte filled in the battery are sensitive to moisture, i.e., react with water.

[0004] [[ID=十七]]Typically, the step of filling an electrochemical cell during production involves filling a container with an electrode pre-inserted through a filling inlet disposed at the top or head of the cell with an electrolyte (typically in the form of a liquid or a gel).

[0005] Thereafter, in the drying room, there is also a step of sealing the battery so as to isolate the internal volume portion of the battery occupied by the electrolyte from the external environment. This sealing can be temporary and can be obtained by inserting a temporary plug or pin that is removed at a subsequent degassing station.

[0006] This conventional method for manufacturing batteries is not without its drawbacks, among which is the fact that electrolyte residue can accidentally accumulate around the filling inlet of the electrochemical cell during the filling step, and given the corrosive and flammable nature of the electrolyte, this could compromise the safety of the battery's hermetically sealed state, its operation, and / or its operation after sealing, whether temporary or permanent.

[0007] More specifically, corrosion can cause deterioration of the outer surface of the battery at the sealing plug, altering the shape of the inlet and allowing gases, and therefore air, to pass from the external environment into the internal volume of the battery and vice versa.

[0008] Furthermore, considering the toxicity of the electrolytes used in batteries, external residues could potentially cause injury to people handling batteries outside the production line, for example, if such electrolyte residues come into contact with the eyes and / or skin.

[0009] Furthermore, there is a risk that the electrochemical cell could ignite if the electrolytic residue comes into contact with the ambient humidity outside the drying room.

[0010] The aim of the present invention is to provide a method and production line for producing batteries, and in particular a method and station for removing external electrolyte residue from an electrochemical cell, which can improve upon the prior art in one or more of the embodiments described above.

[0011] Within the scope of this objective, the object of the present invention is to provide an electrochemical cell or battery filled with an electrolyte that is free of external electrolyte residue.

[0012] Another object of the present invention is to eliminate, or at least reduce, the health risks to people working on battery production lines where potentially harmful electrolytes are filled into batteries.

[0013] Another object of the present invention is to enable the removal of external electrolyte residue from an electrochemical cell while the electrochemical cell is moving in continuous motion along a production line.

[0014] Another object of the present invention is to enable the removal of external electrolyte residue without interfering with the temporary sealing plug that protrudes from the electrolyte filling inlet of the cell.

[0015] Furthermore, the present invention aims to overcome the shortcomings of the prior art in a way that replaces all existing solutions.

[0016] Another object of the present invention is to provide a reliable, easy-to-implement, and low-cost method and production line for producing batteries, and in particular a method and station for removing external electrolyte residue from electrochemical cells for said production method and production line.

[0017] This objective, as well as these and other objectives which will become more apparent below, are achieved by the method of claim 1, which optionally comprises one or more of the characteristics of the dependent claims.

[0018] The aim and objectives of the present invention are similarly achieved by the suction station according to claim 13, which optionally comprises one or more of the characteristics of the dependent claims.

[0019] The aim and objectives of the present invention are similarly achieved by the method according to claim 9 and the production line according to claim 24, which optionally comprises one or more of the characteristics of the dependent claims. [Brief explanation of the drawing]

[0020] Further characteristics and advantages of the present invention will become more apparent from the description of preferred but non-exclusive embodiments of the invention, which are shown in the accompanying drawings as non-limiting examples. [Figure 1] This is a block diagram of the battery production line according to the present invention. [Figure 2a]A block diagram of a machine on the production line of the previous figure in one embodiment according to the present invention. [Figure 2b] A block diagram of a machine on the production line of the previous figure in another embodiment according to the present invention. [Figure 2c] A block diagram of a machine on the production line of the previous figure in yet another embodiment according to the present invention. [Figure 3a] A schematic plan view of a filling station and a suction station according to the present invention. [Figure 3b] A detailed view of the passage route of the filling unit during the electrolyte filling cycle. [Figure 3c] A detailed view of the passage route of an electrochemical cell through the suction station of the previous figure. [Figure 4] A perspective view from above of a first suction unit used in a suction station according to the present invention. [Figure 5] A perspective view from below of a first suction unit used in a suction station according to the present invention. [Figure 6] An axial cross-sectional view of the suction unit of FIG. 4 or FIG. 5 coupled to an electrochemical cell inserted into a transport pack. [Figure 7] Same as the previous figure, but the first suction unit is in a position for sucking electrolyte. [Figure 8] An axial cross-sectional view of a modified example of the first suction unit according to the present invention. [Figure 9] Same as the previous figure, but the modified example of the first suction unit is in a position for sucking electrolyte. [Figure 10] An axial cross-sectional view of a second suction unit according to the present invention. [Figure 11] Same as the previous figure, but the second suction unit is in a position for sucking electrolyte. [Figure 12] A schematic axial cross-sectional view of a sealing unit that can be used in a sealing station upstream or downstream of a suction station according to the present invention.

MODE FOR CARRYING OUT THE INVENTION

[0021] Referring to the figure, the battery production line according to the present invention, generally shown as reference no. 1, comprises an electrode production unit 301, a cell assembly unit 302, and an optional cell finishing unit 303, although the optional cell finishing unit 303 can be separated from line 1.

[0022] Line 1 is preferably a production line that is at least partially continuous and is particularly suited for the production of cylindrical cell type batteries, such as lithium-ion batteries. However, the electrochemical cells that can be manufactured using Line 1 may also be prismatic cells, pouch cells, or button cells.

[0023] For simplicity, the following explanation will refer to the production of a single cylindrical cell.

[0024] Each unit 301, 302, and 303 comprises one or more processing stations, each processing station consisting of equipment adapted to perform one or more operations on one or more elements that will constitute the final cell, or on the final cell in the case of the cell finishing unit 303. A dehumidification unit 400 is associated with at least one of these processing stations.

[0025] In particular, the electrode production unit 301 is ● A mixing station 310 adapted to perform the step of mixing electrode raw materials (e.g., graphite-based material for the anode, and separately, lithium oxide-based material of metal for the cathode) with a conductive binder to form a mixture with a solvent. ●A covering station 311 is adapted to perform the step of covering the anode and cathode sheets, which function as current collectors, with a mixture obtained from station 310. ● Drying station 312 receives the coated sheet from station 311 and performs evaporation of the solvent in the mixture. ● Compression station 313 adapted to perform compression operations (e.g., calendering) on ​​dried sheets arriving from station 312. ●Optional cutting or "slitting" station 314 for cutting the electrode foil arriving from compression station 313 into thinner strips that will become the electrodes of the cell. It can be equipped with.

[0026] The cell assembly unit 302 is ● To obtain a stack (simply called a "stack") or roll ("jelly roll") in which a separator layer is inserted between the cathode layer and the anode layer, a stacking station (if the production line is for pouch cells) or a winding or bending station 320 (if the production line is for cylindrical or rectangular cells) is used to stack the cathode and anode strips arriving from the electrode production unit 301. ●For example, station 321 uses laser welding or ultrasonic welding to connect contact terminals or "tabs" to electrodes (laminated or wound) arriving from the previous station. ● Insertion station 322 for inserting (laminated or wound) electrodes into their respective casings (pouch-shaped, cylindrical, or rectangular, depending on the type of cell being produced). In the case of cylindrical cells, the casing is a substantially cylindrical can that opens at the insertion end. The casings can optionally be housed in their respective transport packs at station 322 and / or downstream stations, as described more below. ● A closing station 323 for closing a casing, wherein a cell casing (containing laminated or wound) electrodes arriving from station 322 is closed in the upper region with a lid, thus obtaining container C. However, to allow subsequent filling of container C with electrolyte without the need to remove the lid or to make a hole in the lid for filling purposes, the inlet 30 is preferably left in the closing lid. ● A filling station 324 for filling container C with an electrolyte, typically in liquid or gel form. This filling thus yields a filled container C', also referred to as a partially processed (electrochemical) cell C' in the following description. For example, in the case of a lithium-ion cell, the electrolyte may consist of a lithium salt dissolved in a non-aqueous organic solvent with an optional additive, or it may be another fluid or gel commonly used as an electrolyte in this type of battery. It can be equipped with.

[0027] According to one aspect of the present invention, the cell assembly unit 302 (inside or downstream of the filling station 324) or the finishing unit 303 may include at least one suction station 328a and / or 328b in which a step is performed to remove external electrolyte residue present around the inlet 30 (which may be temporarily blocked) of the partially processed electrochemical cell C' and / or on the crimping rim 40.

[0028] The finishing unit 303, which can be selectively partially separated from line 1, ● A sealing station 329 for a filled container C, adapted to seal the inlet 30 used to fill the container C with electrolyte and complete the cell (for example, using a temporary plug, or a plug that will be welded later after optional degassing), ●A chemical station 330 in which the steps of charging and discharging the cells are performed in particular according to predetermined voltage and current curves. ●Cells arriving from the chemical station are stored and monitored over a certain period of time in an aging station 331, for example, by periodically measuring the open-circuit voltage at arbitrarily selected different temperatures. ● End-of-Life ("EOL") Test Station 332 where cells stored in the aging station are further checked (for example, in relation to any loss) It can provide even more.

[0029] More specifically, in the illustrated embodiment, the sealing station 329 is positioned between two suction stations 328a and 328b, as shown in Figure 2a, and more specifically in Figure 3c, so that two suction units, as shown in Figures 4-7 (or Figures 8-9) and Figures 10 and 11, can similarly interact directly with the inlet 30 and crimping rim 40 of the partially treated electrochemical cell, respectively.

[0030] However, in two possible modifications of the illustrated embodiment, shown in Figures 2b and 2c, respectively, only one suction station 328a or 328b may be located upstream or downstream of the temporary sealing station, respectively, where the plug is temporarily inserted into the inlet 30 after filling and then removed downstream for an optional degassing operation in the chemical station 330, at which point the final sealing of the filling inlet 30 is performed.

[0031] Conveniently, one or more processing stations performing steps of a production process requiring an ultra-dry environment may be equipped with walls enclosing the space of the processing station to form each drying chamber 100, each drying chamber 100 preferably maintained at a pressure (slightly) higher than the external environment by injection of ultra-dry air from an optionally dedicated dehumidification unit 400 connected to that processing station.

[0032] The side walls of the drying chambers 100 of one or more processing stations are preferably fixed to the support frames, foundations, or tables of the devices that constitute or form part of the processing station.

[0033] Preferably, in a dedicated drying chamber 100 that forms a single block with each processing station, the volume of space to be dramatically reduced in humidity is thus minimized, for example, to less than 20 cubic meters (e.g., 5 to 15 cubic meters), and as a result, the electricity required to maintain an ultra-dry environment in such a drying chamber is greatly reduced. The operations required to clean and restore the ultra-dry environment are also considerably reduced and simplified by this reduction in volume.

[0034] The positive pressure continuously maintained within such a dedicated drying chamber 100 makes it possible to prevent contaminants and moisture from entering the drying chamber 100, even if at least one of the walls of the drying chamber 100 has one or more passage openings adapted to allow continuous or otherwise through entry and / or exit by products being processed in an ultra-dry environment at one or more processing stations.

[0035] By limiting the space where an ultra-dry environment is required, workers can work freely along the battery production line 1 without the special measures required by conventional drying rooms, and without the associated risks, as workers always work outside the stations equipped with each drying room while line 1 is in operation.

[0036] The equipment of a station equipped with a drying chamber 100 can optionally be designed to remain outside the drying chamber 100, while components primarily made from materials unsuitable for battery production or the processing performed by the equipment remain inside the equipment. For example, a motor with copper windings can be located outside the drying chamber 100 and connected via a gear drive to a movable part that operates or transports products inside the drying chamber 100.

[0037] The drying chamber 100 can be integrated with stations 324, 328a, 328b, and 329, which perform the filling of the container C with electrolyte, the aspiration of electrolyte residue present on the filled container C', and the sealing of the filled container C', respectively. In other words, the drying chamber 100 exclusively includes these stations 324, 328a, 328b, and 329, as in the embodiment of Figure 3a.

[0038] Preferably, the drying chamber 100 is defined by (moisture-proof) walls surrounding (the sides, top, and bottom) the operating parts of stations 324, 328a, 328b, and 329 so that a predetermined (slight) positive pressure ΔP1 relative to atmospheric pressure can be maintained within the drying chamber 100. This preset positive pressure is adapted to prevent contaminants and moisture from entering the drying chamber 100 and can be 10 to 20 Pascals, for example, 15 Pascals.

[0039] Stations 324, 328a, 328b, and 329, included in the drying chamber 100, are, as previously mentioned, preferably casings closed by lids and comprising a transport path for a series of containers C arriving from station 322 or 323, which include, for example, rolls or "jelly rolls" containing the electrodes of the battery. The containers C are transported, preferably in continuous motion, from an inlet 10 into the drying chamber 100 where the containers C to be filled enter, to an outlet 11 where the filled, cleaned, and preferably temporarily or finally sealed containers C (also indicated here as C') containing a predetermined amount of electrolyte inside exit.

[0040] The portion of the container transport path that passes through suction stations 328a and 328b and optionally through sealing station 329 will be referred to as the passage path T in the following description.

[0041] The inlet 10 and outlet 11 are preferably in the form of tunnels and preferably communicate with passage openings provided in the walls of the drying chamber 100, having an area of ​​the minimum dimensions necessary to allow the passage of containers C or C' and the passage of straight conveyors 10a and 11a for the containers (e.g., belts, chains, rollers, or screw feeder conveyors).

[0042] The inlet tunnel 10 and / or outlet tunnel 11 can also be kept at extremely low humidity levels because they are connected to other stations or other drying chambers within a group of stations for processing upstream and / or downstream of the drying chamber 100, for example. However, if container C arrives at the inlet 10 and / or filled container C' exits the outlet 11 while sealed with a (temporary) plug, there is no need to have tunnels at such inlet and / or outlet sections, nor is there a need to provide a drying environment on the straight conveyors 10a and / or 11a.

[0043] Considering that the internal volume of container C is largely occupied by electrodes in the form of, for example, "jelly rolls," the electrodes hinder the faster introduction of electrolyte into container C that would otherwise have been possible, and therefore it is preferable to use a solution involving the buffer station 110 described below.

[0044] Container C may have a cylindrical shape with a circular base, or a rectangular shape, a pouch shape, or a button shape, as shown in the drawing.

[0045] In a preferred embodiment of the present invention, each container C along the transport path is preferably housed in its own transport pack 3, the transport pack 3 being a beaker-shaped body that is open above its rim 31, allowing the container C to slide (automatically) through the rim 31 into the pack, leaving its upper opening 30 exposed, and to stabilize during various operations along the transport path and optionally along upstream and / or downstream paths of the drying chamber 100.

[0046] Pack 3 is preferably fitted to the outer surface of container C by a treadmill and / or shape-fit, so as to remain integral with container C along at least the entire path through the drying chamber 100, but preferably leaving at least one lateral gap 36 to allow for the creation of a vacuum inside container C before filling container C, and / or to allow for cleaning container C before and / or after filling container C with electrolyte. For example, pack 3 may have a substantially cylindrical shape. The height of pack 3 is such that the rim 31 is substantially flush with the head portion of container C (i.e., the top surface of the lid) when container C is inserted into pack 3.

[0047] Pack 3 may have a fixing surface on its side, in the illustrated embodiment, coaxial with the central axis of the pack and preferably annular, for example, in the form of at least one recess 32. The fixing surface 32 is preferably located close to the upper rim 31 of Pack 3.

[0048] At the axially opposite end of the rim 31, the pack 3 has a base 33 which is suitable for providing internal support to the container C and / or at least providing an outward mounting surface used for transporting the pack, and therefore the container C, along at least a portion of the transport path or some portion thereof, through the drying chamber 100. The base 33 may have, for example, at least one through hole 34 in the center, for providing an optional inlet for washing the container C after it has been filled, or for optional evacuation during insertion / removal of the container C into / from the pack 3, and / or during the creation of a vacuum inside the container C before it is filled, as described below.

[0049] The sides of pack 3 may have an extended radial portion 35 that, in particular, is associated with the drying chamber 100 and preferably functions substantially as a radial spacer when the packs are lined up in a buffer station 110 (described below) located outside the drying chamber 100.

[0050] The filling station 324 comprises a filling unit R (which is configured as a substantially independent syringe body that is recirculated within the filling station 324, but is not shown in detail) containing a preset amount of electrolyte (contained in the filling unit R), which is adapted to temporarily engage with the battery container C (for example, using a grapple that engages with a recess 32 in the pack 3) to flow a preset amount of electrolyte (contained in the filling unit R) by gravity or by direct injection into the container C through the inlet 30 of the closing lid of the container C.

[0051] Referring to Figures 4 to 11, according to one aspect of the present invention, suction stations 328a and 328b each comprise a plurality of suction units 2a and 2b that can move in continuous motion toward / away from a portion of a passage path T in order to temporarily bind to each partially processed electrochemical cell C' or each pack containing thereof that has been prefilled at a filling station 324.

[0052] The suction units 2a and 2b are circulated in continuous motion along their respective closed circular orbits S1 and S2 by their respective means of transport. The circular orbits S1 and S2 overlap with the aforementioned portion of the passage path T of the partially processed cell C'.

[0053] Suction stations 328a and 328b each comprise two carousels 150a and 150b, with a temporary sealing carousel 152 interposed between the two carousels 150a and 150b. These carousels are preferably adapted to transport partially processed cells C' arriving along the portion of the passage path T where the aforementioned circular orbits S1 and S2 overlap, by, for example, individually picking up cells C' (or packs 3 containing cells C') with grippers positioned at a constant pitch around the central rotation axes of carousels 150a, 150b, and 152, and holding them over the entire portion of the passage path T mentioned above.

[0054] As an alternative to carousels 150a and 150b, two transport star wheels (not shown) may be used, which also rotate in continuous motion around a central axis of rotation and are adapted to transport partially processed cells C' (or packs 3 containing cells C') along the portion of the aforementioned passage path T where the aforementioned circular orbits S1 and S2 overlap, while keeping these cells or packs spaced apart at a constant pitch around the axis of rotation of the star wheels. In this case, the transport star wheels may have recesses in their respective peripheral regions, which are adapted to receive the sides of the respective cells C' or packs 3 and transport them along the portion of the passage path T passing around the axis of rotation of the star wheels.

[0055] The suction units 2a and 2b are integral to the rotation of their respective carousels 150a or 150b (or similar transfer star wheels not shown) and are positioned at the constant pitch mentioned above around the rotation axis of each carousel 150a or 150b (or transfer star wheel not shown) so as to overlap with the electrochemical cell C' or pack 3 that is transported or carried by their respective carousels 150a or 150b (or by the transfer star wheels), i.e., so as to overlap with the grip clamps of their respective carousels 150a or 150b (or the recesses of their respective transfer star wheels).

[0056] Referring to the first suction station 328a and Figures 4-7, each first suction unit 2a comprises a body 5 adapted to engage with the head portion 38 of a filled container C' (or, in an alternative embodiment, the rim 31 of the corresponding pack 3). The body 5 may have a substantially bell-shaped geometric structure, with the open surface of the bell facing the passage path T (i.e., downward) and configured to engage with the head portion 38 (i.e., the top surface) (or the rim 31 of the pack 3) of the container C' (or the pack 3 containing the container C') to center a single suction unit 2 on each container C' (or pack 3 containing the container C').

[0057] More specifically, the open surface of the bell is defined by a circumferential outer shape 6 that is optionally toothed and slopes inward, thereby defining a roughly frustoconical inner surface and facilitating the centering of the main unit 5 onto the container C'.

[0058] A suction plunger 7, which is functionally in communication (particularly fluid communication) with a suction means (e.g., a vacuum pump coupled to a demister or a pressurized line coupled to a venturi ejector) and can slide relative to the body 5 along a direction substantially coaxial with the body, is coupled to the body 5, thereby allowing the body 5 to be coupled to a filled container C' or a pack 3 of container C', the corresponding suction plunger 7 to move perpendicular to the inlet 30 and centrally between a position far from the inlet 30 and a position closer to the inlet 30 or in contact with the inlet 30. These two positions can be defined by two corresponding stroke limiting stoppers projecting radially from the suction plunger 7.

[0059] The connection between the suction plunger 7 and the body 5 is preferably a shape-fit connection (square or sleeve connection) that allows only sliding. However, the shape-fit connection can be adapted to also allow rotation of the suction plunger 7 about its own central axis, and for this purpose, the suction plunger may have a substantially cylindrical shape with a circular cross-section, as shown in the drawing, for example. This relative rotation between the plunger 7 and the body 5 optionally allows for cleaning by friction around the inlet 30 and the inlet itself when the plunger is in contact.

[0060] In this embodiment, in accordance with the fact that the first suction step is performed before the sealing step (as shown in Figures 2a and 2b), and therefore the container C' containing the electrolyte is open at the inlet 30 at the time of the suction step, the suction plunger 7 preferably comprises a head 8 having a blind central portion 9 (to close or reduce the opening of the inlet 30 when positioned in contact), and a plurality of lateral suction channels 70 that emerge into the outer peripheral region of the inlet 30. The lateral channels communicate with an internal duct within the suction plunger 7 that emerges into an internal chamber of the body 5 connected to the suction means.

[0061] The blind section 9 can optionally be provided in the form of a flow control element that protrudes axially from the head 8 and is adapted to completely block the inlet 30 when the suction plunger 7 is in contact.

[0062] In all illustrated embodiments, the head 8 of the suction plunger 7 is preferably shaped to be partially housed around the inlet 30 within a recess 37 provided in the closing lid of the container C', and its function is to collect and contain electrolyte residue dripped from each filling unit of the filling station 324.

[0063] Referring to Figures 8 and 9, an embodiment 2a', which is a modified version of unit 2a, can be provided as an alternative to the first suction unit 2a.

[0064] Embodiment 2a' of the first suction unit includes, for example, a first suction body 44 that is functionally in communication with the suction means (in particular, in fluid communication), has a substantially cylindrical shape with a circular cross-section, and is hollow inside, as shown in the drawing.

[0065] In the illustrated embodiment, in accordance with the fact that the first suction step is performed before the sealing step (as shown in Figures 2a and 2b), and therefore the container C' containing the electrolyte is open at the inlet 30 at the time of the suction step, the first suction body 44 preferably comprises a head 45 having a blind central portion 46 (to close or reduce the opening of the inlet 30 when positioned in contact) surrounded by a plurality of lateral suction channels 47 that emerge into the outer peripheral region of the inlet 30. The lateral channels 47 communicate with an internal duct within the first suction body 44 that emerges into an internal chamber connected to the suction means. The suction means (not shown) can be implemented using a venturi ejector, in which (dry) air from an external pump or pressurizing line is injected into a nozzle inside the ejector, which first narrows and then widens to generate a negative pressure that allows for the suction of electrolyte residue through a lateral port of the ejector connected to the internal chamber of the first suction body 44. In this way, electrolyte residue is discharged from an outlet port inside the ejector, which is approximately coaxial with the nozzle inside the ejector, and this residue can be collected in a container.

[0066] The blind portion 46 of the head 45 may optionally be provided in the form of a flow control element 48 that protrudes axially from the head 45 and is adapted to completely block the inlet 30 when the first suction body 44 is in contact.

[0067] The head 45 of the first suction body 44 is preferably shaped to be partially housed in a recess 37 provided in the closing lid of the container C' around the inlet 30, and its function is to collect and contain electrolyte residue dripped from each filling unit of the filling station 324.

[0068] Structurally, the first suction body 44 can be cantilevered to a first vertical sliding rod 49 that is rotatably integrated with the carousel 150a, so that the first suction body 44 can be superimposed on the passage path T and descend directly onto the cell C' below, which is transported by the suction carousel.

[0069] More specifically, the first suction body 44 can be moved by the action of the first elastic means 50, together with the first sliding rod 49, so as to be loaded toward its position in contact with cell C' (Figure 9).

[0070] Preferably, the first sliding rod 49 is connected to a cam driveer that rests on a fixed cam to move the first suction body 44 vertically during the rotation of each carousel.

[0071] Referring to the second suction station 328b and Figures 10 and 11, each second suction unit 2b comprises a second suction body 41 having a hollow, substantially toroidal shape and functionally communicating with (in particular, fluidly communicating with) the suction means, positioned on the rim 40 (which can be crimped) of the cell's top cover (or head) and adapted to pass through without interference by a sealing plug or pin 20 protruding from the cell.

[0072] Structurally, the second suction body 41 can be cantilevered to a second vertical sliding rod 42 that rotates integrally with the carousel 150b, so that the second suction body 41 can be superimposed on the passage path T and descend directly onto the cell C' below, which is transported by the suction carousel 150b.

[0073] The second suction body 41 comprises one or more peripheral suction channels 43 connected to the suction means by an annular cavity inside the second suction body 41. The peripheral suction channels 43 are directed downward, i.e., toward the grip clamp or support surface of the pack 3 or cell C', so as to face the cell or pack at the (crimping) rim 40 of cell C'.

[0074] The second suction body 41 can be moved by the action of the second elastic means 51, together with the second sliding rod 42, so as to be loaded toward its position in contact with cell C'.

[0075] Preferably, the second sliding rod 42 is also connected to a cam driveer that rests on a fixed cam so as to move the second suction body 41 during the rotation of each carousel.

[0076] The suction means of the suction units 2a, 2a', and 2b described above may be equipped with a Venturi ejector (or Venturi meter) for each suction body 5, 44, 41, where (preferably dry) air from an external pump or pressurizing line is injected into a nozzle (inside the ejector), and the cross-section of the nozzle narrows along the longitudinal axis of the ejector and then widens, generating a negative pressure that allows for the suction of electrolyte residue through a side port of the ejector (by the Venturi effect). This side port is connected to the internal chamber of the plunger 7, or the first suction body 44, or the second suction body 41, depending on the suction units 2a, 2a', and 2b in question. In this way, the electrolyte residue can be discharged from the outlet port of the ejector (which is substantially coaxial with the inlet nozzle of the ejector) and collected in a container.

[0077] Referring to Figure 12, the sealing station 329 may comprise a plurality of compressed air-driven syringes 12 adapted to take each sealing plug 20 from a magazine feeder and insert it into the inlet 30 of a filled container C'. These syringes 12 may be positioned coaxially above means for gripping the container C', which are provided on the carousel 152 at equidistant positions from each other around the rotation axis of the carousel 152. In this way, the syringes 12 of the sealing carousel 152 can take individual plugs 20 that are continuously supplied to the carousel 152, for example by a star conveyor 151 for loading plugs, during the continuous rotation of the carousel.

[0078] In a preferred embodiment, stations 324, 328a, 328b, and 329 include a plurality of carousels 120, 130, 140, 150a, 150b, and 152 configured to define transport paths that allow empty containers C to enter the drying chamber 100, filled containers C' to exit the drying chamber 100, and exchange of unit assemblies 4 with the buffer station 110.

[0079] More specifically, the transport path may consist of overlapping sections designed to minimize the overall bulk of the transport path.

[0080] Referring to Figures 3a, 3b, or 3c, for example, there can be a first and a second transport path, ideally including the arcs of the circumferences drawn by the gripping means of the carousel and the transport star wheel around their respective central axis of rotation. The arcs of the first and second transport paths are preferably superimposed along the circumferences drawn by the gripping means of the separating carousel 120 and the joining carousel 140.

[0081] Other overlapping sections between the first and second transport paths are along the buffer station 110 and along the supply conveyor 107 and discharge conveyor 108 for the unit assemblies 4 to and from the buffer station 110. Preferably, such supply and discharge conveyors pass through a tunnel 109 connected to the side wall of the drying chamber 100 with respect to a portion thereof, passing through this wall at through openings, each or all of which preferably have a preset cross-section minimized to maintain a pressure modified with respect to atmospheric pressure inside the drying chamber 100 and optionally inside the tunnel 109.

[0082] In the embodiment, ●A separation carousel 120 adapted to separate the empty filling unit R' from each container C' which is filled with a predetermined amount of electrolyte, ● A filling carousel 130 for filling electrolytes into the filling unit R, ●A coupling carousel 140 is fitted to temporarily secure the filled filling units R to each container C to be filled, so as to form a unit assembly 4, ● At least one of two suction carousels 150a and 150b, which are adapted to remove trace amounts of electrolytes from a filled container C'. It is possible for it to exist.

[0083] Any star wheel or carousel 151 or 152 located between the two suction carousels 150a and 150b can be used to apply the sealing plug 20 to the inlet 30 of the filled container C'.

[0084] Each of the carousels mentioned above can preferably rotate in a continuous motion around its respective central axis of rotation, which is preferably perpendicular to all of the carousels.

[0085] Each carousel 120, 130, 140, 150a, 150b, and 152 preferably comprises a plurality of gripping means, which are evenly arranged along the peripheral region of each carousel and are adapted to hold or support at least each of the filling units and / or each container C / C' or each pack 3 containing the container C / C' during the rotation of each carousel.

[0086] Preferably, transfer star wheels are also present upstream and downstream of each of the carousels 120, 130, 140, 150a, and 150b to transfer the objects to be transported (filling units R / R', suction units 2a / 2a' / 2b, syringes 12, containers C / C', or unit assemblies 4) from one carousel to another, or from one carousel to a linear conveyor, or vice versa.

[0087] The buffer station 110 is positioned along the overlapping portion of the path from the combined carousel 140 to the separated carousel 120 and is associated with the supply conveyor (107) and discharge conveyor (108) of the unit assembly 4, which supply the unit assembly 4 to the buffer station 110 and discharge the unit assembly 4 from the buffer station 110 at the production speeds of stations 324, 328a, 328b, and 329, respectively.

[0088] The buffer station 110 is a FIFO (first-in, first-out) type buffer and can preferably be an accumulation table or accumulation conveyor assembly located outside the drying chamber 100, for example, next to or above the drying chamber 100. The FIFO buffer may have one or more moving pads, conveyor belts, electric roller conveyors, or sliding surfaces, optionally arranged to form a meandering route and a route suitable for accumulating at least (a large number of) unit assemblies 4 (in particular, N*t unit assemblies, where N is the production rate of stations 324, 328a, 328b, and 329 converted to containers C' per minute, and t is the time in minutes required to fill each container C with a predetermined amount of electrolyte) by distributing the unit assemblies 4 over a wide surface or by moving them along a winding path and / or a long path, so that the unit assemblies 4 remain in the buffer station 110 for a length of time required to fill each container C with a predetermined amount of electrolyte.

[0089] The unit assemblies 4 arrive at the buffer station 110 preferably in a continuous, aligned, and optionally spaced apart from one another at the same pitch as the pitch between the carousel gripping means of stations 324, 328a, 328b, and 329, and between the receptacles of the transfer star wheels.

[0090] The buffer station 110 is configured to advance the unit assemblies 4 arriving from the feeder conveyor 107 toward the discharge conveyor 108 at a speed and path length determined by the time (t) required to fill each container C with a predetermined amount of electrolyte. Each such arriving unit assembly 4 comprises a filling unit R filled with a predetermined amount of electrolyte and a container C that does not yet contain such an amount.

[0091] While the unit assembly 4 is placed inside the buffer station 110, the electrolyte is slowly transferred from the filling unit R to the container C.

[0092] Complete transfer is ensured by the fact that each unit assembly 4 can be left undisturbed for the entire amount of time required to complete the transfer of a predetermined amount of electrolyte from the filling unit R of the unit assembly 4 to the container C.

[0093] The drying chamber 100 is connected via a discharge pipe 117 to a dehumidification unit 400 suitable for injecting into the drying chamber 100 an ultra-dry airflow, i.e., an airflow having a controlled humidity percentage of several volume percent, for example less than 3 volume percent, more preferably 2 volume percent or less than 1 volume percent, and suitable for maintaining a very low dew point, for example a value of about -40°C or lower (e.g., -60°C).

[0094] The operation of the present invention is clear from the above description.

[0095] In particular, referring to Figures 3a, 4-7, and 10-11, the partially treated electrochemical cells C' (each partially treated electrochemical cell C' is preferably located in its own pack 3) arrive at the suction stations 328a and 328b from the separation carousel 120 and the sealing station 329 (particularly the sealing carousel 152), respectively.

[0096] Next, these cells C' are transported along the passage path T to the exit section 11 (by the suction carousels 150a and 150b, and the sealing carousel 152, if present).

[0097] At the first suction station 328a, as a cell C' is picked up by the continuously rotating first suction carousel 150a, the rotation of the carousel 150a causes the first suction unit 2a to move downward through the area where the cell C' arrives. The body 5 approaches each cell C', and in this way the body 5 engages with each cell C' (or each pack 3) so as to keep the first suction unit 2a substantially integrated with the cell C' (or each pack 3) across the arc of the rotational circumference of the carousel 150a.

[0098] During this temporary connection, the plunger 7 is lowered by sliding toward the cell C', and the suction means is activated to remove electrolyte residue present on the outer surface of the head portion 38 of the container C', particularly around the inlet 30.

[0099] Referring to embodiments in Figures 8 and 9, as an alternative to the embodiments in Figures 4 to 7, when cell C' is picked up by the continuously rotating first suction carousel 150a, the rotation of the carousel 150a causes the first suction body 44 of the first suction unit 2a' to move downward as it passes through the area where cell C' arrives.

[0100] The approach of the first suction body 44 to each cell C' causes the first suction body 44 to engage with each cell C' (or each pack 3) in such a way that the first suction unit 2a' is substantially integrated with the cell C' across the arc of the circumference of rotation of the carousel 150a.

[0101] During this temporary coupling, the suction means is activated to remove electrolyte residue present on the central surface of the head portion 38 of container C', particularly in the recess 37.

[0102] Meanwhile, the flow control element 48 that closes the opening 30 prevents the suction means from sucking out the electrolyte contained in container C' and prevents the electrolyte from splashing out of container C' due to the movement of container C'.

[0103] Subsequently, container C' is passed from the star conveyor 151 to a sealing carousel 152 equipped with a syringe 12 that has previously picked up the sealing plug 20.

[0104] Next, these plugs are inserted into the inlet 30 of container C' by pressure.

[0105] At the second suction station 328b, as a cell C' is picked up by the continuously rotating second suction carousel 150b, the rotation of the carousel 150b causes the suction body 41a of the second suction unit 2b to move downward through the area where the cell C' arrives. The approach of the second suction body 41 to each cell C' causes the second suction body 41 to engage with each cell C' (or each pack 3) in such a way that the second suction unit 2b is substantially integrated with the cell C' across the arc of the rotational circumference of the carousel 150b.

[0106] During this temporary coupling, the suction means is activated to remove electrolyte residue present on the outer surface of the head portion 38 of container C', particularly around the crimping rim 40.

[0107] In fact, the present invention has been shown to fully achieve its intended aims and objectives. In particular, the present invention makes it possible to remove electrolyte residue without relying on actions such as blowing, which involve moving or diffusing the electrolyte residue onto the outer surface of the electrochemical cell. The use of cleaning cloths that require frequent replacement, as well as other hazardous cleaning techniques such as thermal ablation, is also avoided.

[0108] The present invention, thus conceived, is subject to numerous modifications and variations, all of which fall within the scope of the appended claims. Furthermore, all details may be replaced by other technically equivalent elements.

[0109] In fact, the materials used may be arbitrary, depending on the requirements and the latest technology, as long as they are suitable for the specific application and the specified dimensions and shape.

[0110] The disclosures of Italian Patent Application No. 102023000013746, to which this application claims priority, are incorporated herein by reference.

[0111] Where reference numerals follow technical features mentioned in any claim, such reference numerals are inserted solely for the purpose of enhancing the understanding of the claim, and therefore do not have any limiting effect on the interpretation of each element identified by such reference numerals.

Claims

1. A method for removing external electrolyte residue from partially processed cells resulting from a station for filling electrolytes for a battery production line, The method includes the step of transporting the cell along a passage path (T), Each of the cells comprises a container (C') having a head portion (38) with an inlet (30) for accessing the internal volume of the container (C'), The internal volume contains a predetermined amount of the electrolyte. In the method, The method includes the step of moving a plurality of suction units (2a, 2a', 2b) at least partially along the passage path, The above method, during the moving step, The steps include temporarily connecting the suction units (2a, 2a', 2b) to the cell or the pack so that at least one of the suction units (2a, 2a', 2b) is substantially integrated with each cell or the pack for transporting each cell along at least a portion of the passage path, During the temporary bonding step, the step of aspirating any residual electrolyte present on the outer surface of the head portion of the container (C') is performed. A method characterized by including the following.

2. The aforementioned suction unit, A first suction unit (2a, 2a') configured for the step of aspirating any residual electrolyte that may be present in the center of the head portion of the container (C'), A second suction unit (2b) configured for the step of aspirating any residual electrolyte that may be present at the periphery of the head portion of the container (C') and The method according to claim 1, comprising one or both of the above.

3. The first suction unit (2a) The main unit (5) and A suction plunger (7) is slidably coupled to the main body and functionally communicates with the suction means. Equipped with, The aforementioned step of temporarily connecting, The steps of bringing the main body and the cell closer together, The steps include engaging the main body with the head portion of the container (C') or the pack, The steps include sliding the suction plunger against the main body (5) and toward the outer surface of the head portion of the container (C'), The method according to claim 2, including the method described in claim 2.

4. The main body (5) has a substantially bell shape and an open base configured to engage with the head portion or the pack so as to center the first suction unit (2a) relative to the container (C'), The method according to claim 3, wherein the suction plunger (7) can slide within the body (5) along a direction substantially coaxial with the body (5).

5. The first suction unit (2a') comprises a first suction body (44) that is functionally in communication with the suction means, The aforementioned step of temporarily connecting, The steps include bringing the first suction body and the container (C') closer together, The steps include engaging the first suction body (44) with the central surface (37) of the head portion of the container (C') and The method according to claim 2, including the method described in claim 2.

6. The method according to claim 5, wherein the first suction body (44) comprises a head (45) having a blind central portion (46) adapted to temporarily block the inlet (30) during the suction step.

7. The second suction unit (2b) comprises a second suction body (41) that is functionally in communication with the suction means, The aforementioned step of temporarily connecting, The steps include bringing the second suction body and the container (C') closer together, The steps include engaging the second suction body (41) with the peripheral region of the head portion of the container (C') and The method according to any one of claims 2 to 6, including the method described in any one of claims 2 to 6.

8. The method according to claim 7, wherein the second suction body (41) is passed by a sealing plug (20) protruding from the inlet (30) and has a substantially toroidal shape adapted to position the second suction body (41) itself on the rim of the head portion (38) of the container (C').

9. A method for manufacturing a battery, comprising an electrode production step (301), a cell assembly step (302), and a step for finishing the cell (303), The cell assembly step includes filling the container with the electrolyte at a filling station. In the method, A method characterized by including, after the filling step, a method for removing residue according to any one of claims 1 to 8.

10. The cell assembly step, A step of sealing the container (C) performed after the first suction step performed by the first suction unit (2a, 2a') and / or before the second suction step performed by the second suction unit (2b). The method according to claim 9, including the method described in claim 9.

11. The method according to any one of claims 1 to 10, wherein the method for removing residue is performed inside a drying chamber (100).

12. Multiple suction units (2a, 2a', 2b) The method according to any one of claims 9 to 11, wherein the temporarily coupling step and the suction step are performed and the material is recirculated along a closed track (S1, S2) that overlaps the portion of the passage path (T).

13. A suction station (328a, 328b) for removing external electrolyte residue from a partially processed cell after the cell has been filled with electrolyte, A passage for the cell, or a passage for a pack adapted to include at least one of the cells, To temporarily attach at least one suction unit (2a, 2a', 2b) itself to each cell or each pack being transported along the aforementioned passage path, the at least one suction unit (2a, 2a', 2b) is capable of moving along a portion of the passage path and toward / away from the passage path, A suction station (328a, 328b) characterized by being equipped with the following features.

14. The suction station (328a, 328b) according to claim 13, comprising means for moving the suction units (2a, 2a', 2b) in continuous motion along a closed circular orbit (S1, S2) that overlaps with a portion of the passage path (T) of the cell.

15. A carousel or star wheel (150a, 150b) capable of rotating in continuous motion around a rotation axis, comprising a carousel or star wheel (150a, 150b) adapted to transport or carry the cells or packs along a portion of a passage path while keeping them spaced apart at a constant pitch around the rotation axis, The suction station (328a, 328b) according to claim 13 or 14, wherein the suction units (2a, 2a', 2b) are arranged on the carousel or star wheel at a constant pitch around the axis of rotation so as to overlap the cell or the pack.

16. The at least one suction unit, A suction station (328a) according to any one of claims 13 to 15, comprising a first suction unit (2a) having a main body (5) and a suction plunger (7) slidably coupled to the main body and functionally communicating with a suction means.

17. The main body (5) has a substantially bell shape and an open base configured to engage with the head portion of the cell or a pack for cell transport so as to center the first suction unit (2a) with respect to the cell. The suction station (328a) according to claim 16, wherein the suction plunger (7) can slide within the main body (5) along a direction substantially coaxial with the main body (5).

18. The suction plunger (7) When the suction plunger is positioned closer to the part of the passage path, a central blind portion (9) for blocking the filling inlet (30) of the cell, One or more side suction channels (70) that communicate with the suction means and open at a position adjacent to the central part (9) of the blind, A suction station (328a) according to claim 16 or 17, comprising a head (8) having a head (8).

19. The suction plunger (7) A suction station (328a) according to any one of claims 16 to 18, coupled to the main body (5) by a shape-fit coupling adapted to allow the suction plunger to slide and, optionally, rotate in the axial direction relative to the main body.

20. The at least one suction unit, A suction station (328a) according to any one of claims 13 to 15, comprising a first suction unit (2a') having a first suction body (44) having a substantially cylindrical shape with a cross section functionally in communication with a suction means and adapted to be coupled to the head portion (38) of the cell (C').

21. The first suction body (44) The suction station (328a) according to claim 20, comprising one or more suction channels (47) that communicate with the suction means and exit below and in the center of the first suction body so that the residue can be suctioned in an area adjacent to the inlet (30).

22. The at least one suction unit, The system includes a second suction unit (2b) which has a second suction body (41) functionally in communication with the suction means, The second suction body (41) A suction station (328b) according to any one of claims 13 to 21, having a substantially toroidal shape that is passed through a sealing plug (20) protruding from the cell and adapted to position the second suction body (41) itself on the rim (40) of the head portion (38) of the cell.

23. The second suction body (41) The suction station (328b) according to claim 22, comprising one or more peripheral suction channels (43) that communicate with the suction means and extend downward so as to face the rim (40) of the head portion (38) of each cell during passage.

24. Battery production line (1), A group of electrode production stations (301), A group of cell assembly stations (302), Cell finishing unit (303) and Equipped with, Each of the above groups (301, 302, 303) is The battery comprises a plurality of processing stations (310-314, 320-324, 328a, 328b, 329) which perform a respective process on one or more elements constituting the manufactured battery. At least one of the processing stations is The cell comprises a station (324) for filling the container (C) containing the electrodes with an electrolyte. In battery production line (1), A battery production line (1) characterized in that at least one of the processing stations downstream of the filling station is a suction station (328a, 328b) according to any one of claims 13 to 23.

25. The aforementioned suction stations (328a, 328b) The battery production line (1) according to claim 24, preferably comprising a drying chamber (100) shared with the station for filling.

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