Method and line for filling electrochemical cell containers and battery production method

Abstract

1. A method for filling a container (C) of an electrochemical cell (302) with electrolyte, the method comprising the steps of filling a plurality of filling units (2) with electrolyte, coupling each filling unit (2) to a corresponding one of the containers (C) to form an integrated assembly (4), transferring the electrolyte from the filling units (2) to the container (C), and decoupling each filling unit (2) from the container (C), wherein the coupling and decoupling steps between the filling units (2) and the container (C) are performed inside a conditioned chamber (116, 116'), the conditioned chamber (116, 116') is bounded by a wall separating an environment therein from an environment therein outside, the pressure and / or humidity conditions of the internal environment being different from those of the external environment, and the step of transferring the electrolyte from the filling units (2) to the container (C) is performed at least partially in an environment external to the conditioned chamber (116, 116').

Description

[Technical Field]

[0001] The present invention relates to a method and line for filling an electrochemical cell container with an electrolyte, and to a battery production method.

[0002] The present invention is particularly adapted to the production of cylindrical cell type batteries (primary or secondary), such as lithium ion batteries, but the invention is in any case adapted to the production of other electrolytic or electrochemical cells or other forms of battery packaging, such as prismatic or pouch cells, which require a dry environment for their manufacture. [Background technology]

[0003] For example, battery production lines for producing lithium-ion batteries require that at least some of the processing steps be carried out in "dry rooms," i.e., sealed, ultra-dry rooms, where humidity is controlled at extremely low rates (typically on the order of 1% by volume) and the dew point can be below -40° C. This occurs especially when the electrode and / or electrolyte materials filling the battery are moisture sensitive, i.e., reactive with water.

[0004] The volume of the drying chambers housing the production lines is typically in the order of 10,000 to 20,000 cubic meters, requiring very high energy consumption (in the order of 500 kW or more) for the generation and recirculation of air flows and their cooling, drying and heating.

[0005] Furthermore, workers entering such dry environments must take certain precautions (essentially their clothing and the length of time they are allowed to remain) to prevent health problems, for example, related to their eyes and skin.

[0006] Another drawback of conventional battery production lines is that certain materials (e.g., zinc, copper, and / or nickel) cannot be used as the main material for the components of the machines that form the lines, because dust from these materials can interfere with the electrolyte or electrodes. Therefore, it is necessary to design or redesign the machines, especially those located inside the drying chamber, so that the corresponding components are made from materials other than those that cannot be used, i.e., materials that are compatible with the production of batteries.

[0007] Another minor problem relates to cleaning conventional drying chambers, which requires significant time and electricity expenditure to restore ultra-dry conditions. Summary of the Invention

[0008] It is an aim of the present invention to provide a battery production method and production line, and an associated electrolyte filling method and filling station, which can improve upon the known art in one or more of the above-mentioned aspects.

[0009] Within this aim, the object of the present invention is to reduce the energy consumption resulting from the use of drying chambers for the production of batteries.

[0010] Another object of the present invention is to eliminate or in any case reduce the risk to the health of workers working on battery production lines that require dry rooms.

[0011] Another object is to reduce the complexity associated with air recirculation systems and reduce the time required to restore an ultra-dry environment.

[0012] Another objective is to enable the use of components made from materials that are not normally allowed in machines primarily for battery production, such as zinc, copper and / or nickel.

[0013] Furthermore, another object of the present invention is to overcome the drawbacks of known techniques in an alternative manner to any existing solutions.

[0014] Another object of the present invention is to provide a battery production method and production line, and a filling method for a battery production line, that is reliable, easy to implement, and low cost.

[0015] This aim, as well as these and other objects that will become more apparent hereinafter, are achieved by a method for filling an electrolyte into a container of an electrochemical cell according to claim 1, optionally comprising one or more of the features of the dependent claims.

[0016] The aims and objects of the present invention are likewise achieved by a method for producing a battery as claimed in claim 14.

[0017] The aims and objects of the invention are likewise achieved by a filling line according to claim 15, optionally comprising one or more of the features of the dependent claims.

[0018] Further features and advantages of the present invention will become more apparent from the description of preferred, but non-exclusive, embodiments of the invention, shown by way of non-limiting example in the accompanying drawings, in which: [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram of a battery production line in accordance with the present invention. [Figure 2] FIG. 1 is a block diagram of the machinery of the production line of the previous figure. [Figure 3] 1 is a plan view of a filling device according to a first embodiment of the present invention; [Figure 4a] FIG. 10 shows the path of the container in the station of the previous figure. [Figure 4b] FIG. 10 shows the path of the filling unit in the station of the previous figure. [Figure 5]1 is a perspective view of a filling kit for use in a filling device according to the present invention; [Figure 6] FIG. 2 is an axial cross-sectional view of the kit of the previous figure. [Figure 7] FIG. 2 corresponds to the previous figure, but shows the filling unit while it is fixed to a pack containing containers. [Figure 8] FIG. 11 corresponds to the previous figure, but with the locking means actuated to form the integral assembly. [Figure 9] FIG. 2 is a plan view of a filling device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a P&ID diagram of the previous figure, which may also be applied to the first embodiment of the filling device. DETAILED DESCRIPTION OF THE INVENTION

[0020] Referring to the figure, a battery production line according to the present invention, generally designated by reference numeral 1, generally comprises an assembly 301 for manufacturing electrodes, an assembly 302 for assembling cells, and an optional assembly 303 for finishing cells, which may be separate from line 1.

[0021] Line 1 is preferably an at least partially continuous production line and is particularly adapted for the production of cylindrical cell type batteries, such as lithium-ion batteries, although the electrochemical cells that can be manufactured by line 1 can also be prismatic, pouch or button cells.

[0022] In the following description, for simplicity, reference will be made to the production of a single cylindrical battery.

[0023] Each assembly 301, 302, 303 comprises one or more processing stations, each consisting of equipment adapted to perform one or more operations on one or more elements that contribute to making up the final battery, or, in the case of assembly 303 for finishing a battery, on the final battery. Associated with at least one such processing station is a dehumidification unit 400.

[0024] In particular, the assembly 301 for manufacturing the electrodes comprises: a mixing station 310 adapted to perform the step of mixing the electrode raw materials (e.g., a graphite-based material for the anode and, separately, a lithium oxide of a metal-based material for the cathode) with a conductive binder to form a mixture with a solvent; a coating station 311 adapted to carry out the step of coating the anode and cathode sheets respectively with the mixture obtained from station 310, the function of which is to act as current collectors; a drying station 312 that receives the coated sheet from station 311 and performs evaporation of the solvent of the mixture; a compression station 313 adapted to perform a compression operation (for example by calendering) of the dried sheet arriving from station 312; an optional cutting or "slitting" station 314 for cutting the sheet of electrodes arriving from the compacting station 313 into thinner strips that become the electrodes of the battery; It can be equipped with:

[0025] The assembly 302 for assembling the battery includes: a lamination station (if the production line is for pouch batteries) or a winding station 320 (if the production line is for cylindrical or prismatic batteries) for laminating the cathode and anode strips arriving from the assembly for manufacturing electrodes 301 to obtain a stack (simply called a "stack") or a roll (called a "jelly roll") in which a separator layer is inserted between the cathode layer and the anode layer; a station 321 for connecting contact terminals or "tabs" to the electrodes (laminated or rolled) arriving from the previous station, for example using laser or ultrasonic welding; a station 322 for inserting the electrodes (laminated or rolled) into respective casings (pouch, cylindrical or prismatic, depending on the type of battery to be produced); In the case of cylindrical batteries, the casing is a generally cylindrical can open at the insertion end. The casing may optionally be housed in a corresponding shipping pack at station 322 and / or at a downstream station as better described below.

[0026] Station 323 for closing the casings, in which the cell casings containing the electrodes (laminated or rolled) arriving from station 322 are sealed with a cap, thus obtaining container C. However, it is preferable to leave an inlet on the closing cap to allow subsequent filling of container C with electrolyte.

[0027] Apparatus 100 or 100' for filling container C with electrolyte, typically in the form of a liquid or gel. For example, in the case of a lithium-ion battery, the electrolyte may consist of a lithium salt dissolved in a non-aqueous organic solvent, with optional additives, or may be another fluid or gel typically used as an electrolyte in this type of battery. The filling apparatus may include or be followed by an apparatus for sealing the filled container C', adapted to seal (e.g., with a plug) the inlet used to fill container C with the electrolyte, thereby completing the battery.

[0028] Finishing assembly 303, which may optionally be separate from line 1, includes: a forming station 330, in which the steps of charging and discharging the battery are carried out according to particular predetermined voltage and current curves; an aging station 331 where the batteries arriving from the formation station are stored and monitored for a period of time, for example by periodically measuring the open circuit voltage, optionally at different temperatures; an end-of-line or EOL testing station 332 where the batteries stored in the aging station are further checked (e.g., for any losses); It can be equipped with:

[0029] According to one aspect of the present invention, one or more of the processing stations performing steps of the production process requiring an ultra-dry environment, such as a station of a filling device, are provided with walls enclosing a space to form an environmentally regulated chamber, more specifically a drying chamber, which is suitably kept at a pressure higher than the external environment by injection of ultra-dry air originating from a dehumidification unit 400 connected to and optionally dedicated to that processing station.

[0030] The side walls of the conditioned chamber, or more particularly the drying chamber, are preferably fixed to a support frame, base or table of an apparatus that constitutes or forms part of the processing station, such as a support frame, base or table of a filling apparatus.

[0031] In a dedicated drying chamber, preferably forming a single block with each filling device, the volume of the space in which humidity must be dramatically reduced is thereby minimized, and may be, for example, less than 20 cubic meters (e.g., 5 to 15 cubic meters), resulting in significant savings in electricity for maintaining an ultra-dry environment in such a chamber. Operations for cleaning and restoring the ultra-dry environment are also significantly reduced and simplified by this reduced volume.

[0032] The higher pressure continuously maintained in such a dedicated drying chamber makes it possible to prevent the ingress of contaminants and moisture into the drying chamber, even if there are one or more passage openings on at least one of the walls of the drying chamber adapted for the continuous or otherwise passing in and out of the products to be processed in the ultra-dry environment at that processing station.

[0033] By limiting the space where an ultra-dry environment is required, workers can work freely along the battery production line 1 without the special equipment required by conventional drying chambers and without the associated risks, as workers always work outside the stations to which their respective drying chambers are attached while the line 1 is in operation.

[0034] The apparatus to which the drying chamber is attached may optionally be designed so that components made primarily of materials incompatible with battery production or the processes performed by the apparatus remain outside the drying chamber while remaining within the apparatus. For example, a motor with copper windings may be located outside the drying chamber and connected via gear transmission to moving parts that manipulate or transport product inside the drying chamber.

[0035] In a preferred embodiment of the invention, the conditioned chamber 116 (or, based on the embodiment shown in the figures, 116') is a dry chamber and is integrated into the station responsible for filling the container C with electrolyte. The conditioned chamber 116, 116' is defined or bounded by a (moisture-tight) wall that separates the environment inside the conditioned chamber from the environment outside the conditioned chamber. The pressure and / or humidity conditions of the environment inside the conditioned chamber (116, 116') are different from the outside environment.

[0036] The walls that bound the regulated chamber 116, 116′ enclose (laterally, upwardly, and downwardly) at least a portion of the operating parts of the filling device 100, 100′ (such as those that perform the filling and coupling and decoupling steps of the filling unit, as described below) so as to be able to maintain a predetermined pressure ΔP1 in the chamber 116, 116′ that is higher than the pressure outside the environment (i.e., a slight overpressure), in particular higher than atmospheric pressure. This predetermined higher pressure ΔP1 is adapted to prevent the ingress of contaminants and moisture into the chamber 116, 116′ and may be comprised between 10 Pa and 20 Pa, for example 15 Pa.

[0037] The filling device 100, 100' comprises a first path P1 for conveying a series of containers C to be filled, arriving from station 322 or 323 and which, as previously mentioned, are preferably casings closed by covers and contain battery electrodes, for example in the form of a roll or "jelly roll". The containers C are conveyed, preferably in continuous motion, from an inlet 10, 10', through which the containers C to be filled enter the device 100, 100', to an outlet 11, 11', through which the containers C filled with a predetermined amount of electrolyte (here the filled containers are also designated C') leave said station.

[0038] The inlets 10, 10' and outlets 11, 11' are preferably in the form of tunnels and communicate with passage openings which are present in the walls of the regulated chambers 116, 116' and preferably have an area S1 which is the minimum necessary to allow the passage of the container C or C' and the passage of the linear conveyors 10a, 10a' and 11a, 11a' for the containers (e.g. belt, chain, roller or screw feeder conveyors).

[0039] The inlet tunnel 10, 10' and / or the outlet tunnel 11, 11' may also be kept at extremely low humidity levels, for example because they are connected to other drying chambers in other stations or groups of stations for processing upstream and / or downstream of the filling device 100, 100'.

[0040] Considering that vessel C has most of its internal volume occupied by electrodes, e.g., in "jelly roll" form, these prevent what would otherwise be a faster introduction of electrolyte into vessel C, making it preferable to use a solution involving buffer stations 110, 110' described below.

[0041] The container C can have a cylindrical shape with a circular base, as in the case shown in the figure, or a prismatic, pouch or button shape.

[0042] In a preferred embodiment of the present invention, each container C along at least the first path P1 is suitably housed in a corresponding transport pack 3, which is a beaker-shaped body that is open at its upper rim 31 so as to allow the container C to (automatically) slide into the pack through the rim 31, leaving its upper inlet portion 30 exposed and stable during various operations along the entire first conveying path P1' and, optionally, along paths upstream and / or downstream of the filling device 100, 100'.

[0043] The pack 3 is preferably adapted to remain integral with the container C at least along the entire first path P1 by an interference-fit and / or form-fit connection with the outer surface of the container C, but preferably leaves at least one lateral gap 36 to allow for the creation of a vacuum in the container C before filling it and / or to allow for cleaning the container C before and / or after it has been filled with electrolyte. For example, the pack 3 can also have a generally cylindrical shape. The pack 3 can be, for example, a bucket or pail.

[0044] The pack 3 may have on its side a fastening surface, e.g. in the form of at least one recess 32, which in the illustrated embodiment is coaxial with the central axis of the pack and is preferably annular. The fastening surface 32 is preferably located adjacent to the upper rim 31 of the pack 3.

[0045] At the axially opposite end to the rim 31, the pack 3 has a base 33 suitable for giving internal support to the containers C and / or for providing an external resting surface used in any case for transporting the pack, and thus the containers C, at least along the first transport path P1 or some parts thereof. The base 33 may have at least one through-hole 34, for example in the center, for providing an optional inlet for cleaning the containers C after they have been filled, or for optional evacuation during insertion / removal of the containers C from the pack 3 and / or during the creation of a vacuum in the containers C before they are filled, as described below.

[0046] The sides of the packs 3 may have, in particular, enlarged radial portions 35 which essentially act as radial spacers when the packs are lined up on buffer stations 110, 110' (described below) associated with and preferably external to the filling apparatus 100, 100'.

[0047] The filling apparatus 100, 100' also includes a second path P2 for transporting a series of filling units 2. The filling units 2 are generally syringe-shaped units that can move along the second path P2, which is preferably a closed path. The second path P2 is at least partially overlapped on the first transport path P1, so that in the overlapped portion, the filling units 2 and the corresponding containers C are overlapped with each other in an axial direction, i.e., parallel to a direction that is generally perpendicular (vertical) to the floor on which the filling apparatus 100 or 100' is installed. The filling units 2 are transported along at least a portion of the second path P2, preferably in a continuous motion.

[0048] Each filling unit 2 essentially comprises a syringe-like unit with a reservoir 21 adapted to contain in its internal first chamber 21a a predetermined amount of electrolyte to be transferred to the respective container C. To this end, this reservoir 21 comprises a bottom opening 20 for the passage of the electrolyte, which may, but need not, have a diameter of the order of a few millimeters (e.g., 2-3 mm) and may suitably be connected to an upper inlet 30 of the respective container C, for example by forming an opening 20 with a spout 20a protruding outward from the reservoir 21.

[0049] The reservoir 21 is associated with a plunger 22 which can move axially relative to the reservoir 21 by means of a guide body 24 which, as in the illustrated embodiment, is fixed to the reservoir 21 by means of a flange joint, for example. In particular, the guide body 24 of the plunger 22 is provided with a tubular guide 242 which is coaxial with but external to the reservoir 21 and which is associated with the plunger 22 so that it can slide therein.

[0050] The plunger 22 is provided with a piston 23, fixed to or integral with the plunger 22 and capable of sliding with an airtight seal along the internal side wall of the reservoir 21, dividing the internal space of the reservoir into a first chamber 21a for containing the electrolyte to be transferred to the container C and a second chamber 21b for containing a pressurized gas (e.g., air) suitable for expanding the volume of the second chamber 21b of the reservoir 21 and simultaneously moving the piston 23 in a direction decreasing the volume of the first chamber 21a, thereby forcing the electrolyte to flow out of the opening 20. For this purpose, the plunger 22 is provided at its other axial end with an internal coaxial channel 25 connected to the second chamber 21b and closed by a one-way valve 28 that can be mechanically opened only to introduce or discharge the gas in the second chamber 21b of the reservoir 21.

[0051] The kit formed by the filling unit 2 and by the respective packs 3 also comprises temporary fastening means 27 which connect the filling unit 2 and the container C to one another and temporarily integrate them together, more particularly the filling unit 2 and the packs 3, if any, to one another, thereby being suitable for forming an integrated assembly 4, for example as shown in Figure 8.

[0052] Temporary fastening means 27 are preferably associated with each filling unit 2, but may alternatively be provided on the packs 3, if present.

[0053] The temporary fixing means 27 may be provided with one or more claws 271, for example a grapple formed by a plurality of said claws 271 which can move towards / away from each other around the central axis of the filling unit 2.

[0054] In other embodiments not shown, the temporary fixing means may use other snap action connecting means to achieve temporary fixing either by interference fit or friction fit (e.g. using a threaded connection).

[0055] The axial movement of the drive slider 274 and the guide body 24 towards and away from each other results in the disengagement and fixation of the filling unit 2 and the pack 3, respectively, i.e., the movement of the hooks 272 of the claws 271 towards and away from each other along corresponding axial planes, respectively.

[0056] In both embodiments, the filling apparatus 100, 100' comprises a filling station 13 (such as a filling carousel 130, 130') configured to fill the filling units 2 with electrolyte, and a docking station 14 (such as a docking carousel 140, 140') configured to couple each filling unit 2 to a corresponding one of the containers C to form an integrated assembly 4 for transferring the electrolyte from the filling unit 2 to the container C coupled to the filling unit 2.

[0057] The coupling of each filling unit 2 to a corresponding container C at the coupling station 14 includes a first sub-step of alignment between the filling unit 2 and the container C, in which the filling unit 2 and the container C are aligned and approach each other, and a second sub-step of sealing connection, in which a liquid-tight connection is created therebetween. Prior to transferring the electrolyte, a vacuum may be created in the container C.

[0058] The filling apparatus 100, 100′ also comprises a separation station 12 adapted to separate each (empty) filling unit 2 from the corresponding (filled) container C with which it forms an integral assembly 4. The separation station 12 is preferably a separation carousel 120, 120′ configured to axially separate the emptied filling unit 2 from the corresponding container C filled with a predetermined amount of electrolyte.

[0059] The filling station 13, the combining station 14, and the separation station 12 are arranged inside the conditioned chamber 116, 116'. The first transport path P1 of the container C extends along a first portion located inside the conditioned chamber 116, 116' (passing along the path from the filling station 13 to the combining station 14) and along a second portion located at least partially outside the conditioned chamber 116, 116', passing from the combining station 14 to the separation station 12; thus, the transfer of electrolyte from the filling unit 2 to the container C coupled to the filling unit 2 can occur at least partially in an environment outside the conditioned chamber 116, 116'.

[0060] Furthermore, the filling device 100' may include a sealing carousel 150' adapted to block the inlet portion 30 of the container C used to fill the container C with electrolyte, as in the second embodiment.

[0061] Each of the above-mentioned carousels is rotatable, preferably in a continuous motion, about a respective central axis of rotation which is preferably vertical for all of the carousels.

[0062] Each carousel 120, 120', 130, 130', 140, 140' and 150' is preferably provided with a plurality of gripping means evenly arranged around its circumference and adapted to hold at least a corresponding one of the filling units 2 and / or a corresponding container C or a corresponding pack 3 containing the container C during rotation of the corresponding carousel.

[0063] Preferably, transfer starwheels are also provided upstream and downstream of each of the carousels 120, 120', 130, 130', 140, 140' and 150' to transfer the objects to be conveyed (filling units 2, containers C-C', integrated assemblies 4) from one carousel to the other, or from one carousel to the linear conveyor, or vice versa.

[0064] The first and second transport paths P1 and P2 ideally comprise arcs described by the gripping means of the carousels and transfer starwheels as they rotate about their respective central axes of rotation. The arcs of the first and second paths P1 and P2 ideally overlap along the circumferences described by the gripping means of the separating carousels 120, 120' and the combining carousels 140, 140'.

[0065] Another overlapping portion between the first path P1 and the second path P2 is along the buffer stations 110, 110′ and along the supply conveyors 107, 107′ and discharge conveyors 108, 108′ for the integrated assemblies 4 to / from the buffer stations 110, 110′. Preferably, such supply and discharge conveyors pass for a part thereof through tunnels 109, 109′ connected to the outer wall of the conditioned chambers 116, 116′ and pass through this wall at passage openings, each or all of which preferably have a predetermined cross section S2 minimized so as to be able to maintain a pressure corrected with respect to atmospheric pressure inside the conditioned chambers 116, 116′ and optionally inside the tunnels 109, 109′.

[0066] Prior to the uncoupling operation, the integrated assembly 4 is transported along a portion of a transport path that exits the conditioned chamber 116, 116′, travels a certain portion outside the conditioned or drying chamber 116, 116′, and then re-enters such chamber 116, 116′ (P1 and P2 are superimposed). Such portion of the transport path is preferably located in a buffer station 110, 110′.

[0067] The buffer stations 110, 110' are arranged along overlapping portions of the paths P1 and P2 leading from the connecting carousels 140, 140' to the separating carousels 120, 120' and are associated with the supply conveyors 107, 107' and discharge conveyors 108, 108' of the integrated assemblies 4, which supply and discharge the integrated assemblies 4 from the buffer stations 110, 110', respectively, at the production rate of the filling devices 100, 100'.

[0068] The buffer stations 110, 110' are preferably external to the conditioned chambers 116, 116'.

[0069] The buffer station 110, 110' is a FIFO (first in, first out) type accumulator and may be an accumulator table or an assembly of accumulator conveyors, preferably located outside the filling device 100, 100' and outside the conditioned chamber 116, 116', for example, next to or above the filling device 100, 100'. The FIFO accumulator may have one or more moving pads, conveyor belts, motorized roller conveyors or sliding surfaces optionally arranged to form a serpentine route, and in any case a route suitable for accumulating a (large number of) integrated assemblies 4, by distributing the integrated assemblies 4 over a wide surface or by making them travel a winding and / or long path, in order to keep the integrated assemblies 4 (in particular N*t integrated assemblies, where N is the production rate of the filling device 100 or 100' converted into containers C' per minute and t is the time in minutes for filling each container C with a predetermined amount of electrolyte) in the buffer station 110, 110' for the time required for the containers C to be filled with their respective predetermined amounts of electrolyte.

[0070] The integrated assemblies 4 arrive at the buffer stations 110, 110' preferably consecutively, aligned and optionally spaced apart from one another at the same pitch as the pitch between the gripping means of the carousels of the filling devices 100, 100' and between the receptacles of the transfer starwheels.

[0071] The buffer stations 110, 110' are suitable for advancing the integrated assemblies 4 arriving from the feeder conveyors 107, 107' towards the output conveyors 108, 108' at a speed and path length determined by the time (t) required to fill each individual container C with a predetermined amount of electrolyte. Each such input integrated assembly 4 comprises a filling unit 2 filled with a predetermined amount of electrolyte and a container C which has not yet been filled with such amount.

[0072] The pressure exerted by the gas inside the second chamber 21b' slowly transfers the amount of electrolyte to the container C of the integrated assembly 4, allowing the integrated assembly 4 to remain in the buffer station 110, 110' for the time required to complete the transfer of the amount of electrolyte from the filling unit 2 of the integrated assembly 4 to the container C.

[0073] Thanks to the buffer stations 110, 110′, the filling apparatus 100, 100′ can operate at a high production rate N (e.g., between 100 and 600 containers C per minute) by rapidly filling the filling units 2 using carousels 130, 130′ having a limited number of gripping means and filling nozzles (e.g., several times as many as 10, e.g., between 30 and 60). In the buffer stations 110, 110′, each filling unit 2 autonomously fills the corresponding container C of the integrated assembly 4 over a (longer) time t required by the internal characteristics of the container C and / or the nature of the electrolyte by transferring a predetermined amount of electrolyte, which the filling unit 2 then receives from the filling carousel 130, 130′ in a much shorter time (e.g., 5 seconds), to the container C in time t (e.g., 10 minutes). Therefore, the filling carousel 130, 130′ can have a relatively small number of filling nozzles and taps (e.g., between 30 and 60).

[0074] The chambers 116, 116' are connected via delivery pipes 117, 117' to a dehumidification unit 400, which is adapted to generate and inject into the chambers 116, 116' an ultra-dry air flow, i.e., an air flow having a controlled humidity percentage of the order of a few volume percent, for example less than 3 volume %, more preferably less than 2 volume % or 1 volume %, and is adapted to maintain a very low dew point, for example a value of about -40°C or less (e.g., -60°C).

[0075] Dehumidification unit models that provide these performance levels are known, and in the present invention, they allow for energy consumption that is significantly lower than the energy used in conventional drying chambers with volumes of tens of thousands of cubic meters. For example, the power required by dehumidification unit 400 for a drying chamber with a volume of approximately 10 cubic meters may be on the order of 30 to 40 kW.

[0076] The dehumidification unit 400 may comprise a drying or adsorption rotor (typically having a very large surface) impregnated with a hygroscopic material that absorbs moisture from the air, and the hygroscopic material is regenerated with a hot air stream to remove moisture that has accumulated on the rotor.

[0077] The flow rate of ultra-dry air injected into the regulated chambers 116, 116' through the delivery pipes 117, 117' is determined based on the value of the higher pressure ΔP1 desired to have in the chambers 116, 116' relative to atmospheric pressure, as well as by the extents S1 and S2 of the openings on the walls of the regulated chambers 116, 116' for the passage of the container C and the integrated assembly 4, respectively.

[0078] For example, if the volume of the regulated chamber 116' is approximately 6 cubic meters and the higher pressure ΔP1 is maintained at +15 Pa relative to atmospheric pressure, the flow rate of the delivery air may be approximately 1150 cubic meters, taking into account the passage openings that will necessarily be present in one or more walls of the regulated chamber to allow the continuous passage of the products processed by the filling device 100, 100'.

[0079] A second higher pressure ΔP2 relative to atmospheric pressure is also optionally maintained inside the entrance tunnel 10, 10′, preferably higher than the higher pressure ΔP1 maintained in the regulated chamber 116, 116′, to suppress the flow of air out of the chamber itself, which might otherwise disturb the operator. A difference of a few Pascals between the two higher pressures ΔP2 and ΔP1 (e.g., ΔP2-ΔP1=5 Pa) may be sufficient.

[0080] Preferably, a pressure lower than that present in the environment outside the conditioned chamber is maintained within tunnels 11, 11' and / or 109, 109' is maintained. In particular, a slightly negative pressure relative to atmospheric pressure, on the order of a few Pascals (e.g., a negative pressure ΔP3 of about -5 Pa relative to atmospheric pressure), is instead maintained so as to create a kind of air barrier that further prevents external contaminants from entering conditioned chamber 116, 116' while still allowing air flow from the outside toward tunnels 11, 11' and / or 109, 109'. Tunnels 11, 11' and 109, 109' can be connected to tubes or channels 118, 118', 119, 119' for air to exit toward suction device 115'.

[0081] The operation of the present invention is apparent from the foregoing description.

[0082] Below, features and possible combinations of features of embodiments of the present disclosure are described as a list of clauses.

[0083] Item 1. A battery manufacturing method including an electrode fabrication step (301) and a battery assembly step (302), wherein each of the electrode fabrication step and the battery assembly step includes a plurality of processing steps for one or more elements that constitute the manufactured battery, each of the processing steps being performed by a respective processing station (310-314, 320-323, 100, 100'), and at least one of the processing steps being performed in a drying chamber (116, 116') of the corresponding processing station that performs that processing step.

[0084] Item 2. The method according to Item 2, wherein the drying chamber is maintained at a higher pressure than the outside of the drying chamber.

[0085] Item 3. The method according to item 3, wherein the drying chamber is formed by a wall having at least one opening for the passage of elements from and / or to the outside of the element processed in the processing station comprising the drying chamber.

[0086] Item 4. The method according to one or more of items 1 to 3, wherein a moisture content of less than 3 vol.%, preferably less than 2 vol.% or 1 vol.%, and optionally a dew point of -40°C or less, is maintained in the drying chamber.

[0087] Item 5. The method according to one or more of items 1 to 4, wherein the drying chamber (116, 116') is formed by a wall fixed to the frame, base or table of a processing device of a processing station comprising the drying chamber.

[0088] Item 6. The method according to one or more of Items 1 to 5, wherein the processing step carried out in the dry chamber is a step of filling an electrolyte into containers (C) each containing an electrode of a battery.

[0089] Item 7. The method according to item 6, wherein a plurality of filling units (2), each adapted to contain a predetermined amount of electrolyte, are recirculated along a closed path (P2), and along a portion of the closed path (P2), the plurality of filling units (2) are temporarily integrated with the corresponding containers (C) and transported to separate buffer stations (110, 110') for autonomously filling the containers (C).

[0090] Item 8. A battery production line (1) comprising a group of electrode fabrication stations (301) and a group of battery assembly stations (302), each of the groups (301, 302) comprising a plurality of processing stations (310-314, 320-323, 100, 100') that perform respective processes on one or more elements that make up the manufactured battery, and at least one of the processing stations comprising a drying chamber (116, 116') in which the respective process is performed.

[0091] Item 9. The line according to item 8, wherein the processing station comprises a wall surrounding a station space defining the drying chamber, and the drying chamber is connected to a dehumidification unit (400).

[0092] Item 10. The line according to item 9, wherein the dehumidification unit (400) is adapted to maintain moisture in the drying chamber at less than 3% by volume, preferably less than 2% by volume or 1% by volume, and a dew point of -40°C or less.

[0093] Item 11. The line according to one or more of items 8 to 10, wherein the drying chamber (116, 116') is kept at an overpressure relative to the outside of the drying chamber.

[0094] Item 12. The line according to one or more of items 8 to 11, wherein at least one of the walls of the drying chamber has at least one opening for the passage of elements processed in the processing station comprising the drying chamber from the drying chamber (116, 116') and / or to the outside of the drying chamber (116, 116').

[0095] Item 13. The line according to one or more of items 8 to 12, wherein the drying chamber wall is fixed to a frame, foundation or table of a processing device of a processing station including the drying chamber.

[0096] Item 14. The line according to one or more of items 8 to 13, wherein the at least one processing station equipped with the drying chamber is an apparatus or station (100, 100') for filling an electrolyte into a container (C) containing an electrode of a battery.

[0097] Item 15. The line according to item 14, wherein the filling device or filling station (100, 100') comprises a plurality of filling units (2), each adapted to contain a predetermined amount of electrolyte, and means for recirculating the filling units (2) along a closed path (P2), along which the filling units are temporarily integrated with the corresponding containers (C) and transported to a buffer station (110, 110') separate from the filling device or filling station (100, 100') for autonomously filling the containers with the predetermined amount of electrolyte.

[0098] Item 16. The line according to one or more of items 8 to 15, wherein the processing station comprising a drying chamber is selected from one or more of a mixing station (310), a coating station (311), a drying station (312), a compression station (313), a slitting station (314), a laminating or rolling station (320), a terminal connection station (321), a station for inserting electrodes into respective casings (322), a station for closing the casings (323), a filling device or station (100, 100'), a forming station (330), an aging station (331), an end-of-line testing station (332).

[0099] Item 17. A method for filling an electrolyte into a container (C) containing electrodes for the manufacture of a respective battery, characterized in that the filling is carried out in a dedicated drying chamber (116, 116') provided in a filling device or station (100, 100') that carries out the filling.

[0100] Item 18. The method according to item 17, wherein the drying chamber is maintained at an overpressure relative to the exterior of the drying chamber.

[0101] Item 19. The method according to item 17, wherein the drying chamber is formed by a wall having at least one opening for the passage of a container (C) to be filled with the electrolyte and / or already filled with the electrolyte from and / or to the outside of the filling device or station.

[0102] Item 20. The method according to one or more of items 17 to 19, wherein the moisture content in the drying chamber is less than 3% by volume, preferably less than 2% by volume or 1% by volume, and a dew point of -40°C or less.

[0103] Item 21. The method according to one or more of items 17 to 20, wherein the drying chamber (116, 116') is formed by a wall fixed to a frame, base, or table of a filling device constituting a filling device including the drying chamber.

[0104] Item 22. The method according to one or more of items 17 to 21, wherein a plurality of filling units (2), each adapted to contain a predetermined amount of electrolyte, are recirculated along a closed path (P2), and along a portion of the closed path (P2), the filling units (2) are temporarily integrated with the corresponding containers (C) and transported to separate buffer stations (110, 110') for autonomously filling the containers (C).

[0105] Item 23. A station for filling electrolyte into containers (C) for batteries, comprising an inlet (10, 10') for empty containers (C), an outlet (11, 11') for containers (C) filled with electrolyte, and a first path (P1) for transporting the containers between the inlet (10, 10') and the outlet (11, 11'), characterized in that the filling device or filling station comprises a drying chamber (116, 116') in which the respective processes are carried out.

[0106] Item 24. A filling device or filling station according to item 23, comprising a wall surrounding the space of the station forming the drying chamber, connected to a dehumidifying unit (400).

[0107] Item 25. The filling device or filling station according to item 24, wherein the dehumidifying unit (400) is adapted to maintain moisture in the drying chamber at less than 3% by volume, preferably less than 2% by volume or 1% by volume, and a dew point of -40°C or less.

[0108] Item 26. A filling device or filling station according to one or more of items 23 to 25, wherein the drying chamber (116, 116') is kept at an overpressure relative to the outside of the drying chamber.

[0109] Item 27. A filling device or filling station according to one or more of items 23 to 26, wherein at least one of the drying chamber walls comprises at least the inlet section (10, 10') and the outlet section (11, 11').

[0110] Item 28. A filling device or filling station according to one or more of Items 23 to 27, wherein the drying chamber wall is fixed to a frame, base or table of a processing device constituting the filling device.

[0111] Item 29. A second path (P2) for conveying a series of filling units (2), wherein the first path (P1) and the second path (P2) at least partially overlap each other; a separation carousel (120, 120'), a filling carousel (130, 130') of the filling unit (2), and a connecting carousel (140, 140'); Furthermore, the first path (P1) from the combining carousel to the separating carousel traverses a buffer station (110), which is preferably external to the drying chamber; the filling carousel (130) is adapted to introduce into each of the filling units (2) a predetermined amount of electrolyte to be injected into the container (C); the docking carousel (14) is adapted to temporarily secure a corresponding one of the filling units (2) arriving from the filling carousel (130) to each of the containers (C) so as to form an integrated assembly (4) in which the filling unit (2) and the corresponding container (C) are in fluid communication; each of said filling units is adapted to autonomously transfer said predetermined amount of electrolyte to said container of a respective integrated assembly (4); the separation carousel (120, 120') is adapted to disassemble the integrated assemblies (4) exiting the buffer station (110, 110') and separate the emptied filling unit (2) of each integrated assembly (4) from the corresponding filled container (C); Item 29. A filling device or filling station according to one or more of items 23 to 28.

[0112] Indeed, it has been found that the invention fully achieves its intended aims and objectives.

[0113] The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other technically equivalent elements.

[0114] In practice, the materials used can be any, depending on the requirements and the state of the art, as long as they fit the specific application, as well as the required dimensions and shape.

[0115] The disclosure of Italian Patent Application No. 102022000021240, from which this application claims priority, is incorporated herein by reference.

[0116] Where a technical feature described in any claim is followed by a reference sign, such reference sign is inserted solely for the purpose of enhancing the comprehension of the claim, and therefore such reference sign does not have any limiting effect on the interpretation of each element identified by such reference sign as an example.

Claims

1. providing a plurality of filling units (2), each adapted to contain a predetermined amount of electrolyte; Filling each filling unit (2) with said electrolyte, followed by coupling each filling unit (2) to a corresponding one of a plurality of containers (C), thereby forming an integrated assembly (4) for transferring the electrolyte from the filling unit (2) to the container (C) coupled thereto; followed by transferring the electrolyte from the filling unit (2) to the container (C) connected thereto, followed by Separating each filling unit (2) from the respective container (C) with which it formed the integral assembly (4); A method for filling electrolyte into a plurality of containers (C) of an electrochemical cell (302), comprising:

10. The method of claim 9, wherein the coupling and decoupling steps are performed inside a conditioned chamber (116, 116'), the conditioned chamber (116, 116') being bounded by a wall separating an environment inside the conditioned chamber (116, 116') from an environment outside the conditioned chamber (116, 116'), the pressure and / or humidity conditions of the environment inside the conditioned chamber (116, 116') being different from the outside environment, and the step of transferring the electrolyte from the filling unit (2) to the container (C) coupled thereto is performed at least partially in the environment outside the conditioned chamber (116, 116').

2. 2. The method of claim 1, wherein after the coupling step, the integrated assembly (4) is transported along a conveying path that exits the conditioned chamber (116, 116'), travels outside the conditioned chamber (116, 116'), and then re-enters the conditioned chamber (116, 116') before the decoupling step.

3. 3. The method according to claim 1 or 2, wherein during the step of transferring the electrolyte from the filling unit (2) to the container (C) coupled thereto, the integrated assembly (4) is transported to a buffer station (110, 110′) outside the conditioned chamber (116, 116′).

4. 4. The method according to claim 1, wherein the wall of the regulated chamber (116, 116') is provided with an inlet and an outlet, the inlet and the outlet being configured and dimensioned to allow the entrance of the plurality of containers (C) to be filled and the exit of the plurality of containers (C) filled with electrolyte, respectively.

5. 5. The method according to any one of claims 1 to 4, wherein the containers (C) to be filled enter the regulated chamber (116, 116') by passing through an inlet tunnel (10, 10') maintained at a pressure higher than the pressure maintained in the regulated chamber (116, 116').

6. The method of any one of claims 1 to 5, wherein the conditioned chamber (116, 116') is maintained at a pressure higher than the external environment.

7. The method according to any one of claims 1 to 6, wherein a relative humidity of less than 3%, preferably less than 2%, more preferably less than 1% is maintained inside the conditioned chamber (116, 116').

8. The method according to any one of claims 1 to 7, wherein a dew point of -40°C or less is maintained inside the conditioned chamber (116, 116').

9. 9. The method according to claim 1, wherein the step of coupling each filling unit (2) to a corresponding one of the plurality of containers (C) comprises a first sub-step of aligning the filling unit (2) with the container (C) in which the filling unit (2) and the container (C) are aligned with each other, and a second sub-step of sealing and connecting in which a liquid-tight connection is created therebetween, wherein a vacuum is created in the container (C) after the first sub-step of aligning and before the second sub-step of sealing and connecting, and wherein the vacuum is further created before the step of transferring the electrolyte.

10. 10. The method according to any one of claims 1 to 9, wherein, upon leaving the regulated chamber (116, 116'), the filled containers (C) pass through an outlet tunnel (11, 11') maintained at a pressure lower than the pressure present in the environment outside the regulated chamber (116, 116').

11. The method according to any one of claims 1 to 10, wherein the step of filling each filling unit (2) with the electrolyte is accomplished inside the regulated chamber (116, 116').

12. 12. The method according to any one of claims 1 to 11, wherein each filling unit (2) comprises a syringe-like unit having a reservoir (21, 21') with an opening (20) for the passage of the electrolyte, the opening (20) being connectable to an inlet (30) of the container (C), and a piston (23, 23') movable within the reservoir (21, 21') configured to transfer the electrolyte from the reservoir (21, 21') to the container (C).

13. The method according to any one of claims 1 to 12, further comprising the step of housing each of the plurality of containers (C) in a corresponding transport pack (3) before the step of coupling each filling unit (2) to each container (C).

14. A method for producing a battery, comprising a step (301) of manufacturing an electrode and a step (302) of assembling a battery, wherein said step (302) of assembling a battery comprises a plurality of processing steps, characterized in that one of said plurality of processing steps comprises the filling method according to any one of claims 1 to 13.

15. a conveying path (P1) for the plurality of containers (C); a filling station (13) configured to fill the filling unit (2) with said electrolyte; a docking station (14) configured to couple each filling unit (2) to a corresponding one of the plurality of containers (C) to thereby form an integrated assembly (4) for transferring the electrolyte from the filling unit (2) to the container (C) coupled thereto; a separation station (12) configured to separate each filling unit (2) from its corresponding container (C) after transferring electrolyte to said container (C); In a line for filling an electrolyte into a container (C) of an electrochemical cell (302), the line comprising: the line further comprises a conditioned chamber (116, 116'), the conditioned chamber (116, 116') being bounded by a wall separating an environment inside the conditioned chamber (116, 116') from an environment outside the conditioned chamber (116, 116'), the pressure and / or humidity conditions of the environment inside the conditioned chamber (116, 116') being different from the outside environment, the filling station (13), the combining station (14), and the separation station (12) being located inside the conditioned chamber (116, 116'); and a filling line, characterized in that the transport path (P1) of the plurality of containers (C) extends along a first portion located inside the conditioned chambers (116, 116'), passes from the filling station (13) to the combining station (14), extends along a second portion located at least partially outside the conditioned chambers (116, 116'), and passes from the combining station (14) to the separation station (12), so that the transfer of the electrolyte from the filling unit (2) to the containers (C) coupled thereto can take place at least partially in the environment outside the conditioned chambers (116, 116').

16. 16. The filling line of claim 15, further comprising a buffer station (110) arranged outside the conditioned chamber (116, 116') and through which the second portion of the conveying path (P1) of the plurality of containers (C) passes.

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