Methods, application devices, and formulations for forming functional layers of electrochemical storage devices

Abstract

The present invention relates to a method for manufacturing a functional layer (110, 120, 130) of an electrochemical storage device, the method comprising: supplying a first formulation (P1) to a first reservoir (10) of an applicator (1), supplying a second formulation (P2) to a second reservoir (20) of the applicator (1), positioning the applicator (1) above a substrate (200) and moving the applicator (1) relative to the substrate (200) along a coating direction (C), and discharging the first formulation (P1) from the first reservoir (10) of the applicator (1) through the first slot (11) onto a coating surface (210) of the substrate (200), wherein the first slot (11) is oriented along a transverse axis ( and simultaneously discharging the second formulation (P2) from the second reservoir (20) of the applicator (1) through the second slot (21) onto the substrate (200), wherein the second slot (21) extends along the horizontal axis (L), wherein the first formulation (P1) and the second formulation (P3) form curtains (310, 320) between the applicator (1) and the substrate (200), and wherein a first functional layer (110) of the electrochemical storage device is formed on the application surface (210) from the first formulation (P1), and a second functional layer (120) of the electrochemical storage device is simultaneously formed on the first functional layer (110) from the second formulation (P2). The invention further relates to a coating device (1) and formulations (P1, P2, P3, P4) for producing functional layers (110, 120, 130) of electrochemical storage devices.

Description

[Technical Field]

[0001] The present invention relates to a method and application apparatus for forming a functional layer of an electrochemical storage device, and a formulation for forming a functional layer of an electrochemical storage device. [Background technology]

[0002] An electrochemical storage device within the meaning of this specification is a device capable of storing electrical energy due to its chemical composition. For example, such a device may be a battery, in particular a solid-state battery, such as a solid-state lithium-ion battery or a solid-state sodium-ion battery, or a capacitor, such as a supercapacitor. In such solid-state batteries, charged species (e.g., lithium ions or sodium ions) that migrate between the negative and positive electrodes of the battery during charging and discharging are embedded in a solid matrix (e.g., comprising an inorganic material, a polymer, or a mixture of inorganic materials and a polymer) that forms a solid electrolyte.

[0003] The electrochemical storage devices described above are often structured into functional layers that fulfill various functions in the electrochemical storage device. The functional layers may be electrochemically active layers (i.e., adapted to store or transport charged species such as ions or electrons), or they may be electrochemically passive layers (i.e., not adapted to store or transport charged species). A functional layer adapted for ion storage may be an intercalation host, such as an anode layer or a cathode layer. Furthermore, a functional layer configured for ion transport may be, for example, a solid electrolyte, and a functional layer adapted for electron transport may function, for example, as a current collector. A non-limiting example of an electrochemically passive layer is a protective layer (typically disposed as the outermost layer) adapted to protect the active layer, for example, from corrosion or degradation.

[0004] Solid-state electrolytes eliminate the use of organic, flammable liquid electrolytes by replacing the liquid with a solid that does not readily burn. This significantly reduces the risk of fire during use of devices powered by such solid-state electrochemical storage devices. Furthermore, some solid electrolytes are more stable electrochemically. Furthermore, solid-state electrolyte batteries do not require separators because the structural integrity of the solid electrolyte prevents internal short circuits between the negative and positive electrodes. For some combinations of active materials (i.e., involving the use of lithium metal), solid-state electrolyte batteries can achieve higher energy densities than state-of-the-art batteries that use liquid electrolytes.

[0005] Despite these advantages, the manufacturing costs and throughput of electrochemical storage devices with solid electrolytes are less than optimal using prior art methods, and as a result, solid electrolyte batteries are not currently economically competitive with batteries using liquid electrolytes. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a method (as well as an application apparatus and formulation) for producing a functional layer of an electrochemical storage device that can reduce production time and costs compared to prior art methods. [Means for solving the problem]

[0007] This object is achieved by the subject matter of the independent claims.Embodiments of the invention are defined in the dependent claims and are explained below. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a part of a coating device according to an embodiment of the present invention, taken along a plane parallel to the coating direction. [Figure 2] FIG. 2 is a schematic, partially cut-away perspective view of a portion of a coating apparatus according to an embodiment of the present invention, and of the curtain and functional layers formed during the practice of a method according to the present invention. [Figure 3] FIG. 3 is a schematic perspective view of a coating apparatus having a split manifold and associated pump inlets according to an embodiment of the invention. [Figure 4] FIG. 4 is a schematic perspective view of an application apparatus according to an embodiment of the invention and the curtain and functional layer formed in a first embodiment of the method according to the invention. [Figure 5] FIG. 5 is a cross-sectional view of a functional layer perpendicular to the application direction, the functional layer having been formed according to the embodiment of the method depicted in FIG. [Figure 6] FIG. 6 is a schematic perspective view of an application apparatus according to an embodiment of the invention and the curtain and functional layer formed in a second embodiment of the method according to the invention. [Figure 7] FIG. 7 is a cross-sectional view of a functional layer perpendicular to the application direction, the functional layer having been formed according to the embodiment of the method depicted in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] A first aspect of the invention relates to a method for manufacturing a functional layer of an electrochemical storage device, said method comprising: - providing a first formulation to a first reservoir of an application device; - providing a second formulation to a second reservoir of said applicator; - disposing the coating device above a substrate and moving the coating device relative to the substrate along a coating direction; - dispensing the first formulation from the first reservoir onto the coating surface of the substrate through a first slot of the applicator, the first slot extending along a transverse axis perpendicular to the coating direction and parallel to the coating surface, and simultaneously dispensing the second formulation from the second reservoir onto the substrate through a second slot of the applicator, the second slot extending along the transverse axis; - wherein the first formulation and the second formulation form a curtain between the coating device and the substrate; and - wherein a first functional layer of the electrochemical storage device is formed on the coating surface of the substrate from the first formulation, and a second functional layer of the electrochemical storage device is simultaneously formed on the first functional layer from the second formulation; Includes.

[0010] In certain embodiments, the first formulation and the second formulation collectively form a curtain between the coating device and the substrate.

[0011] In particular, the applicator may comprise a coating head or nozzle comprising at least a first slot and a second slot, and optionally a first and a second reservoir (alternatively, the first and second reservoirs may be arranged outside the coating head or nozzle and fluidly connected to the first or second slot). For example, the first and second reservoirs may be formed by a cavity in the coating head or nozzle or by a manifold insertable into the cavity of the coating head or nozzle. The first and second formulations may be supplied to the first and second reservoirs by a pump that transports the first and second formulations from separate storage reservoirs to the respective first and second reservoirs of the coating device, for example, via a tube or conduit. Of course, the coating device may also comprise one or more additional reservoirs and associated slots for depositing additional functional layers of the electrochemical storage device, in particular for depositing them simultaneously with the first and second functional layers.

[0012] The applicator is moved relative to the substrate, particularly by placing the substrate (e.g., in the form of a film or web) on a conveyor belt and driving the conveyor belt so that the substrate moves under the applicator's applicator head or nozzle, while the applicator remains stationary. Of course, it is also possible within the scope of the invention for the substrate to remain stationary while the applicator's applicator head or nozzle moves.

[0013] In particular, the coating device is arranged such that the first slot is located closer to the coating surface of the substrate than the second slot, thereby ensuring that the second functional layer is formed on top of the first functional layer.

[0014] In certain embodiments, the first and second formulations (and optionally the third and / or at least one further formulation) discharged from the first and second slots (and optionally the third and / or at least one further slot) of the coating device, in particular the coating die, form layers on top of each other on the discharge surface (also called "slide") of the coating device and flow down from the discharge surface onto the coating surface of the substrate in the form of a layer curtain. In other words, the first formulation and the second formulation (and optionally the third formulation and / or at least one further formulation) are discharged by slide curtain coating. In this way, functional layers can be produced simultaneously.

[0015] Alternatively, the first and second formulations can be discharged from slots at the bottom of a coating device (particularly a coating die), which are arranged adjacent to each other so that a layer curtain is formed from the first and second formulations at the slot outlet. Such coating devices do not include a particular discharge surface (slide). This method is also known as "slot curtain coating," and the corresponding coating die is called a "slot die." In contrast to slot coating, slide coating has the advantage that the number of slots, and therefore the number of layers produced, is not limited by geometric constraints.

[0016] The first and second preparations are in particular liquids or slurries so that they can be dispensed from the respective slots of the applicator, where the term slurry refers to a composition comprising a liquid solvent or monomer and particles (in particular having a diameter of 1 nm to 500 μm) suspended in said liquid solvent or monomer.

[0017] The first and second formulations form a curtain while being dispensed onto the coating surface of the substrate from the respective slots of the coating device. Therefore, the above method can also be described as a curtain coating method. Within the scope of this specification, the term "curtain" refers to a continuous, free-falling sheet of liquid or slurry material. To achieve such a curtain, it is necessary to adjust the flow rate of the first or second formulation dispensed from the respective first or second slot, the coating speed at which the substrate moves relative to the coating device, and the rheological properties (e.g., viscosity) of the first and second formulations (e.g., shear-thinning behavior of the first or second formulation, i.e., a property in which the viscosity decreases with increasing shear rate).

[0018] Advantageously, curtain coating benefits from an effect called hydrodynamic assistance: the freely falling curtain creates a pressure field at the impact point on the coating surface of the substrate, which allows the formation of sufficiently thin layers (e.g., less than 30 μm, especially less than 5 μm) without any defects at very high coating speeds (e.g., from about 40 m / min to over 2500 m / min).

[0019] Furthermore, the inventors have found that curtain coating allows for the simultaneous application of multiple layers of material onto a substrate, so that separate layers no longer need to be processed (e.g., dry-pressed or hot-pressed) separately, significantly improving the manufacturing time of the resulting electrochemical storage device.

[0020] In certain embodiments, a third formulation is supplied to a third reservoir of the coating device, wherein the third formulation is ejected onto the substrate through a third slot of the coating device simultaneously with the first formulation and the second formulation, the third formulation forms a curtain between the coating device and the substrate, and a third functional layer of the electrochemical storage device is formed on the second functional layer from the third formulation.

[0021] In certain embodiments, the first formulation, the second formulation, and the third formulation collectively form a curtain between the coating device and the substrate.

[0022] In certain embodiments, at least one further formulation is supplied to a further reservoir of the coating device, wherein the further formulation is ejected onto the substrate through a further slot of the coating device simultaneously with the first formulation, the second formulation, and the third formulation, the further formulation forms a curtain between the coating device and the substrate, and a further functional layer of the electrochemical storage device is formed on the third functional layer from the further formulation.

[0023] In certain embodiments, the first formulation, the second formulation, the third formulation, and the at least one additional formulation collectively form a curtain between the coating device and the substrate.

[0024] In certain embodiments, the first and second preparations (and particularly also the third and at least one further preparation) exhibit shear thinning behavior, i.e., a decrease in viscosity upon increasing shear rate.

[0025] In certain embodiments, the first and second preparations (and in particular also the third and at least one further preparation) contain the same solvent or the same polymerizable monomer at the same concentration, so that diffusion does not occur at the interface between the first and second preparations (in particular any of the first, second, third and at least one further preparation), in particular in the resulting functional layer of the electrochemical storage device. In certain embodiments, the first and second preparations (and in particular also the third and at least one further preparation) contain the same salt composition at the same concentration, so that diffusion does not occur at the interface between the first and second preparations (in particular any of the first, second, third and at least one further preparation).

[0026] This reduces the diffusion gradient of the functional layer, particularly after deposition on the substrate, and, combined with the laminar flow during curtain coating, minimizes inter-layer mixing, improving the interfacial quality of the resulting functional layer and improving the quality of the electrochemical storage device.

[0027] In certain embodiments, the first functional layer, the second functional layer, the third functional layer, and / or the at least one additional functional layer form a solid electrolyte of the electrochemical storage device.

[0028] In certain embodiments, the solid electrolyte comprises an inorganic solid electrolyte, such as a ceramic or glass material, which may include lithium or sodium in its stoichiometric composition.

[0029] In certain embodiments, the inorganic solid electrolyte is LiPON, LiI, LiN, Li-β″-AlO, Li 3x La 2 / 3-x □ 1 / 3-2x TiO3 (LLTO, perovskite), Li3OCl (antiperovskite), Li 14 ZnGeO 16 (LiSICON),Li 1.3 Ti 1.7 Al 0.3 (PO4)3 (NaSICON type), Li7La3Zr2O 12 (garnet), thio-LiSICON, Li6PS5X (wherein X represents Cl, Br, or I), argyrodite, and Li 10 MP2S 12 (wherein M represents Ge or Sn).

[0030] In certain embodiments, the solid electrolyte comprises a polymer electrolyte, and particularly the solid electrolyte comprises a mixture of a polymer and a metal ion salt, more particularly a mixture of a lithium salt or a sodium salt.

[0031] In certain embodiments, the polymer electrolyte comprises a mixture of a polymer and a metal salt, a mixture of different polymers, a block copolymer, or a single-ion conducting polymer electrolyte, particularly a lithium polymer salt.

[0032] In certain embodiments, the polymer electrolyte comprises a polyether, in particular polyethylene oxide (PEO) or polypropylene oxide (PPO), a polysiloxane, a polycarbonate, a polyester, a polynitrile, a polyalcohol, a polyamine, or poly(bis-(methoxyethoxyethoxide)phosphazene (MEEP)).

[0033] In certain embodiments, the polymer electrolyte comprises a metal ion salt, particularly LiBF, LiClO, LiPF, LiAsF, LiCFSO (lithium trifluoromethanesulfonate (LiTf)), or LiN(CFSO) (lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)).

[0034] In certain embodiments, the polymer electrolyte comprises a metal ion salt, particularly NaBF, NaClO, NaPF, NaAsF, NaCFSO (sodium trifluoromethanesulfonate), or NaN(CFSO) (sodium bis(trifluoromethanesulfonyl)imide).

[0035] In certain embodiments, the polymer electrolyte comprises a mixture of a polymer and a metal salt, particularly a mixture of polyethylene oxide and LiBF, a mixture of polyethylene oxide and LiClO, a mixture of polyethylene oxide and LiPF, a mixture of polyethylene oxide and LiAsF, a mixture of polyethylene oxide and LiCFSO, a mixture of polyethylene oxide and LiN(CFSO), a mixture of polypropylene oxide and LiClO, a mixture of poly(bis-(methoxyethoxyethoxide)phosphazene and LiCFSO, or a mixture of polysilicone and LiN(CFSO).

[0036] In certain embodiments, the polymer electrolyte has a ratio of functional groups to charge carriers (e.g., ethylene oxide to lithium) of 5:1 to 50:1, i.e., there are 5 to 50 times as many functional groups on the polymer as there are metal ions in the salt that are charge carriers.

[0037] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or the at least one further preparation comprises a polymer, in particular polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), polyacrylic acid (PAA), carboxymethylcellulose (CMC), styrene butadiene rubber (SBR), poly(tetrafluoroethylene) (PTFE), polyethylene (PE), polystyrene (PS), polypropylene (PP), gelatin, starch, agar, alginate, amylose, gum arabic, carrageenan, casein, chitosan, (carbonyl-beta ) cyclodextrin, ethylene propylene diene monomer rubber (EPDM), gellan gum, guar gum, karaya gum, cellulose, pectin, PEDOT-PSS, poly(methyl acrylate) (PMA), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), polyacrylonitrile (PAN), polyisoprene (Plpr), polyaniline (PANi), polyimide (PI), polyurethane (PU), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), tara gum, tragacanth gum, TRD202A, or xanthan gum.

[0038] The addition of polymers to the respective formulations allows the provision of binders, the adjustment of the rheological properties of the formulation, and in particular the provision of solid ionic conductors for obtaining solid electrolyte layers.

[0039] In certain embodiments, the first functional layer, the second functional layer, the third functional layer, or at least one additional functional layer forms a positive or negative electrode of an electrochemical storage device.

[0040] In certain embodiments, the first functional layer, the second functional layer, the third functional layer, or at least one additional functional layer forms an electron transport medium, and in particular a current collector, of an electrochemical storage device.

[0041] In certain embodiments, the first functional layer, the second functional layer, the third functional layer, or at least one additional functional layer forms a protective layer of the electrochemical storage device. In certain embodiments, the protective layer is air- and / or water-impermeable, and in particular the protective layer is the top or bottom layer of a stack of functional layers (i.e., the protective layer is applied to the substrate as the first (bottom) or last (top) functional layer). This is advantageous in preventing malfunction and improving shelf life of the electrochemical storage device, since the other functional layers are protected from moisture and / or air.

[0042] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or at least one further formulation comprises a solvent that evaporates, particularly after the formation of each functional layer, thereby increasing the solids content of the electrochemical storage device.

[0043] In certain embodiments, the solvent comprises or consists of water, acetonitrile, N-methyl-2-pyrrolidone, an alcohol, in particular ethanol or methanol, or tetrahydrofuran.

[0044] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises a polymerizable monomer, where polymerization of the monomer is particularly promoted or initiated by metal ions. Alternatively, polymerization of the monomer can be initiated by electromagnetic radiation of a specific wavelength (e.g., photopolymerization) or by the addition of radicals (radical polymerization). The polymerizable monomer may function as a solvent, particularly for suspending particles to form a slurry, or the monomer may be provided in addition to the solvent. Formulations comprising a polymerizable monomer have the advantage that a subsequent solvent evaporation step can be omitted and replaced by a polymerization step, which can significantly accelerate the production of electrochemical storage devices.

[0045] In certain embodiments, polymerization of the polymerizable monomer is initiated after forming the first functional layer, the second functional layer, the third functional layer, and / or at least one additional functional layer on the coating surface of the substrate.

[0046] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or at least one further formulation comprises a metal ion host, particularly a conversion material or an intercalation material. In particular, a functional layer comprising such a metal ion host can function as the negative or positive electrode of an electrochemical storage device.

[0047] In certain embodiments, the metal ion host is a cathode active material, particularly lithium nickel manganese cobalt oxide (Li-NMC, e.g., LiNi x Mn y Co z O2), lithium iron phosphate (LFP, LiFePO4), lithium nickel cobalt aluminum oxide (Li-NCA, e.g., Li a Ni x Co y Al z O z ), lithium cobalt oxide (LCO, LiCoO2), or lithium manganese oxide (LMO, LiMn2O4).

[0048] In certain embodiments, the metal ion host is a metal ion host that is compatible with the negative electrode active material, particularly graphite, silicon, lithium titanate (LTO, Li4Ti5O 12 ), or titanium dioxide (TiO2), or consists of it.

[0049] In certain embodiments, the first, second, third, and / or at least one further preparation comprises a precursor capable of forming a metal ion host, particularly a conversion or intercalation material. The metal ion host may be formed from the precursor by a chemical reaction that is initiated or occurs automatically after forming each functional layer of the electrochemical storage device by curtain coating. For example, the precursor may be a nitrate, carbonate, or hydroxide.

[0050] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or at least one further formulation comprises a solid ion conductor, in particular an inorganic material (e.g., a ceramic or glass material) or a polymer electrolyte.

[0051] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises a precursor capable of forming a solid ion conductor, in particular an inorganic material (e.g., a ceramic or a glassy / amorphous material) or a polymer electrolyte. The solid ion conductor may be formed from the precursor by a chemical reaction that is initiated or occurs spontaneously after forming each functional layer of the electrochemical storage device by curtain coating. In the case of a polymer electrolyte, this chemical reaction may be a polymerization reaction, and the precursor may be a monomer capable of forming a polymer by polymerization. Alternatively, in particular, the precursor may be a nitrate, carbonate, or hydroxide.

[0052] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or at least one further formulation comprises a solid electronic conductor, in particular a metal (e.g., aluminum or copper) or carbon (e.g., carbon black).

[0053] In a particular embodiment, the solid electronic conductor comprises conductive fibers, in particular carbon nanotubes, which simultaneously act as electronic conductors and improve the rheological properties (viscosity) of the formulation, thereby improving the stability of the curtain upon application.

[0054] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises a surfactant.

[0055] In certain embodiments, the first functional layer forms the positive or negative electrode of the electrochemical storage device, and the second functional layer forms the solid electrolyte.

[0056] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or the at least one further formulation have a low shear viscosity of from 1 mPas to 100,000 mPas, in particular from 100 mPas to 1,000 mPas.

[0057] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises lithium ions or sodium ions.

[0058] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises a liquid metal, particularly liquid lithium, liquid gallium, or a mixture of liquid lithium and liquid gallium (resulting in an alloy), or metal particles (resulting in a metal paste). Advantageously, lithium and gallium have relatively low melting temperatures, which facilitates manufacturing. The metal particularly forms an electronic conductor, such as a current collector, and a host for metal ions (e.g., ions form deposits on the metal layer). Forming a current collector by the method according to the present invention has the advantage, in contrast to prior art methods, of being able to form a very thin (e.g., 5 μm or less) current collector layer, thereby improving the quality of the electrochemical storage device. When the current collector is combined with a metal ion host, the thickness of the electrochemical storage device can be further reduced.

[0059] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one further preparation comprises a liquid metal, in particular liquid lithium, liquid gallium, or a mixture of liquid lithium and liquid gallium, wherein the preparation is heated before and / or during dispensing onto the application surface of the substrate.

[0060] In certain embodiments, the first preparation, the second preparation, the third preparation, and / or at least one additional preparation has a solubility of 1000 g mol -1 ~100,000 g mol -1 a first polymer having a molecular weight of 300,000 g mol -1~1200000g mol -1 and a second polymer having a molecular weight of 0.015. In particular, this bimodal size distribution allows for optimal rheological properties and simultaneously provides optimal conditions for the polymer electrolyte of solid-state electrochemical storage devices. It also results in a high solids content in the formulation, resulting in shorter drying times.

[0061] In certain embodiments, the application device, in particular the application head or nozzle, comprises a discharge surface configured to receive the first and second formulations (and optionally the third and / or at least one further formulation) discharged from the first and second slots (and optionally the third and / or at least one further slot) of the application device, in particular the first formulation and the second formulation (and optionally the third formulation and at least one further formulation) form layers on top of each other on the discharge surface, these layers forming a layered curtain between the application device and the application surface of the substrate.

[0062] In certain embodiments, the first reservoir and first slot, the second reservoir and second slot, the third reservoir and third slot, and / or at least one further reservoir and at least one further slot are separated along a horizontal axis into first and second portions, the first and second portions being physically separated to prevent flow of the respective formulation between the first and second portions, and in particular, the first portions form the terminal portions of the respective reservoirs along said horizontal axis.

[0063] In certain embodiments, the first reservoir and the first slot, the second reservoir and the second slot, the third reservoir and the third slot, and / or the at least one further reservoir and the at least one further slot further comprise a third portion physically separated from the first and second portions, in particular the second portion being disposed between the first and third portions, and the first and second portions forming opposite end portions of the respective reservoirs along the transverse axis.

[0064] For example, physical separation between the portions can be achieved by an integral wall in the application head or nozzle separating these portions of each reservoir, by placing separate manifolds in each portion of the application head or nozzle recess, or by inserting separators into each reservoir.

[0065] In certain embodiments, the first, second, third or at least one further formulation is supplied to the first portion of the respective reservoir at a first flow rate and the second formulation is supplied to the second portion of the respective reservoir at a second flow rate so that the functional layer formed by the respective formulation ejected from the first portion of the respective slot has a greater thickness in a direction perpendicular to the application surface than the functional layer formed by the respective formulation ejected from the second portion of the respective slot, in particular so that the first flow rate is greater than the second flow rate.

[0066] In a particular embodiment, the discharge surface comprises a recess whose width along the transverse axis corresponds to the width of the first portion of each reservoir and each slot, in particular extending from each slot along the entire discharge surface in the application direction, and in particular whose depth perpendicular to the discharge surface corresponds to the difference in thickness between the functional layer formed by the respective formulation discharged from the first portion and the functional layer formed by the respective formulation discharged from the second portion.

[0067] In certain embodiments, the first formulation, the second formulation, the third formulation, or at least one further formulation is supplied to the third portion of each reservoir at a third flow rate, such that the functional layer formed by each formulation ejected from the third portion of each slot has a greater thickness in a direction perpendicular to the application surface than the functional layer formed by each formulation ejected from the second portion of each slot, particularly when the third flow rate is equal to the first flow rate and the thickness of the functional layer formed by each formulation ejected from the third portion is equal to the thickness of the functional layer formed by each formulation ejected from the first portion.

[0068] In a particular embodiment, the ejection surface comprises recesses with a width along the transverse axis corresponding to the width of the third portion of each reservoir and each slot, in particular extending from each slot along the entire ejection surface in the application direction, and in particular having a depth perpendicular to the ejection surface that corresponds to the difference in thickness between the functional layer formed by the respective formulation ejected from the third portion and the functional layer formed by the respective formulation ejected from the second portion.

[0069] In certain embodiments, the second formulation is supplied to the first portion at a first flow rate and the second formulation is supplied to the second portion at a second flow rate, such that the second functional layer formed by the second formulation discharged from the first portion of the second slot has a greater thickness in a direction perpendicular to the application surface than the second functional layer formed by the second formulation discharged from the second portion of the second slot. In particular, the first slot has a width extending along the horizontal axis equal to the width of the second portion of the second slot, in particular, such that the first functional layer formed by the first formulation is embedded in the second functional layer formed by the second formulation.

[0070] In certain embodiments, the second formulation is supplied to the third portion of the second reservoir at a third flow rate, such that the functional layer formed by the second formulation ejected from the third portion of the second slot has a greater thickness in a direction perpendicular to the application surface than the functional layer formed by the second formulation ejected from the second portion of the second slot, particularly such that the third flow rate is equal to the first flow rate and the thickness of the functional layer formed by the second formulation ejected from the third portion is equal to the thickness of the functional layer formed by the second formulation ejected from the first portion.

[0071] As mentioned above, supplying different portions of each reservoir with different flow rates of the formulation can be used to laterally embed adjacent functional layers applied through separate slots or to form interconnections between functional layers, especially if this slot has a width equal to that of the second (middle) portion. The flow rate required to achieve a given thickness depends on the width of the slot along the transverse axis. Optional recesses in the ejection surface corresponding to the width of the first and / or third portion allow the underlying functional layer to be embedded by the underlying functional layer while maintaining a flat surface of the underlying layer, which is advantageous for depositing additional layers on the underlying layer.

[0072] In certain embodiments, the first or second formulation is dispensed from a first portion and the further formulation is dispensed from a second portion such that the first or second formulation and the further formulation are arranged in a predetermined pattern on the application surface of the substrate to jointly form a first or second functional layer of the electrochemical storage device.

[0073] For example, the solid electrolyte of a solid electrolyte battery can be applied to be laterally embedded, for example, by a layer of active material (anode or cathode) or a protective layer, or to form interconnections between layers in a single manufacturing step.

[0074] Of course, the reservoirs and associated slots can be divided into additional sections (other than the first, second, and third sections) to obtain specific patterns of functional layers and to allow interconnections between layers.

[0075] In certain embodiments, the functional layer is chemically, thermally, optically, or mechanically excited to change the composition and / or structure of the functional layer.

[0076] In certain embodiments, the first formulation, the second formulation, the third formulation, and / or at least one further formulation comprises a solvent, which is evaporated after forming a functional layer on the application surface of the substrate.

[0077] In certain embodiments, the functional layer is dried after forming the functional layer on the application surface of the substrate.

[0078] In certain embodiments, the functional layer is exposed to an electric and / or magnetic field while drying, which, among other things, results in the formation of a morphologically and directionally defined conductive network (e.g., the formation of lithium ion channels) in the solid electrolyte functional layer, thereby improving the quality of the electrochemical storage device.

[0079] In certain embodiments, at least two adjacent functional layers are crosslinked after forming the functional layers on the application surface of the substrate, i.e., the interfaces of adjacent layers are linked by chemical reactions between the chemical groups of the layers, resulting in improved mechanical stability, particularly reduced subsequent chemical reactions between the layers, and / or improved ionic conductivity through the layer interfaces.

[0080] In certain embodiments, pressure and / or heat are applied to the functional layer after it is formed on the application surface of the substrate.

[0081] In certain embodiments, the functional layer is calendered after forming the functional layer on the coating surface of the substrate. Calendering can be performed by passing the stack of functional layers between two rollers separated by a small gap, with or without additional heating, resulting in compaction of the layers.

[0082] In certain embodiments, after forming the functional layers on the application surface of the substrate, a chemical reaction occurs in at least one of the functional layers, and in particular, this chemical reaction causes polymerization of a monomer, formation of a metal ion host from a precursor, formation of a solid ionic conductor from a precursor, or formation of a solid electronic conductor from a precursor.

[0083] In certain embodiments, the functional layer is sintered after forming the functional layer on the coated surface of the substrate, in particular by applying heat, radiation (e.g., infrared radiation, light, e.g., laser light or microwaves).

[0084] In certain embodiments, the substrate is removed from the functional layer after forming the functional layer on the application surface of the substrate. In other words, the substrate is used as a sacrificial layer, and is peeled off or removed after curtain application of the functional layer of the electrochemical storage device. This has the advantage of reducing the overall weight of the electrochemical storage device. Furthermore, removing the rigid substrate makes it possible to adapt the shape of the functional layer stack of the electrochemical storage device, or even to realize a flexible electrochemical storage device depending on the components used in the functional layer, for example, to integrate the electrochemical storage device into a textile or wearable device.

[0085] In certain embodiments, the first formulation, the second formulation, the third formulation, or at least one additional formulation comprises a polymer, and the first formulation and / or the second formulation are dispensed onto the application surface of the substrate at a temperature above the melting point of the polymer. In particular, the first formulation, the second formulation, the third formulation, and / or at least one additional formulation do not contain a solvent. The use of such solvent-free formulations allows for the formation of functional layers with high solid content by cooling (resulting in solidification of the polymer) instead of evaporating the solvent, thereby improving the speed of the manufacturing method.

[0086] A second aspect of the present invention is - a first reservoir for receiving a first preparation, - a first slot for dispensing the first formulation from the first reservoir onto a coating surface of a substrate so as to form a curtain between the coating device and the substrate during dispensing of the first formulation onto the coating surface; - a second reservoir for receiving a second preparation, - a second slot extending parallel to the first slot for dispensing the second formulation from the second reservoir onto the application surface simultaneously with the first formulation, such that a curtain of the second formulation forms between the applicator device and the application surface during dispensing of the second formulation onto the application surface; Including, - wherein the coating device is disposed above the substrate and moves relative to the substrate along a coating direction; Including, The present invention relates to a coating device for producing functional layers of electrochemical storage devices.

[0087] In certain embodiments, the first slot and the second slot are configured and arranged such that a first functional layer of the electrochemical storage device can be formed on the application surface from a first formulation, and a second functional layer of the electrochemical storage device can be simultaneously formed on (and with) the first functional layer from a second formulation.

[0088] In certain embodiments, the coating device comprises a third reservoir for receiving a third formulation and a third slot for discharging the third formulation from the third reservoir onto the coating surface of the substrate, thereby causing the third formulation to form a curtain between the coating device and the substrate while discharging the third formulation onto the coating surface, and in particular, the third slot is configured and arranged so that a third functional layer of the electrochemical storage device can be formed on the second functional layer simultaneously with the first and second functional layers.

[0089] In certain embodiments, the coating device comprises at least one further reservoir for receiving a further formulation and at least one further slot for discharging the further formulation from the further reservoir onto the coating surface of the substrate, thereby causing a curtain of the further formulation to form between the coating device and the substrate while the further formulation is being discharged onto the coating surface, and in particular wherein the at least one further slot is configured and arranged so that a further functional layer of the electrochemical storage device can be formed simultaneously with the first, second (and optionally third) functional layer, more particularly on the third functional layer.

[0090] In certain embodiments, the applicator, in particular the applicator head or nozzle, has a discharge surface configured to receive the first and second formulations (and optionally the third and / or at least one further formulation) discharged from the first and second slots (and optionally the third and / or at least one further slot) of the applicator, and the discharge surfaces can be arranged in particular so that the first and second formulations (and optionally the third and / or at least one further formulation) form layers on top of each other on the discharge surface, and these layers form a layered curtain between the applicator and the application surface of the substrate. In this way, functional layers can be produced simultaneously.

[0091] In particular, the application device can include an application head or nozzle that includes at least a first slot, a second slot, a third slot, and / or at least one additional slot, and optionally also a first reservoir, a second reservoir, a third reservoir, and / or at least one additional reservoir (alternatively, the first, second, third, and / or at least one additional reservoir may be arranged outside the application head or nozzle and in fluid connection with the respective first, second, third, or additional slot). For example, the first, second, third, and / or at least one additional reservoir may be formed by a cavity in the application head or nozzle or by a manifold that is insertable into a cavity in the application head or nozzle. The first formulation, second formulation, third formulation, and / or fourth formulation may be provided in the first, second, third or further reservoirs, respectively, by a pump that transports each formulation from a separate storage reservoir to the respective reservoir of the application device, for example via a tube or conduit.

[0092] In certain embodiments, the applicator includes edge guides configured to prevent necking of the curtain between the applicator and the coating surface of the substrate, where "necking" refers to the thinning of the curtain along a lateral axis due to surface tension. In particular, the edge guides may include or consist of tabs or plates extending perpendicularly from both side edges of the discharge surface toward the coating surface.

[0093] In certain embodiments, the application device comprises a conveyor mechanism, e.g., a conveyor belt, configured to move the substrate (e.g., in the form of a film or web) against the application direction relative to the application device, particularly relative to the application head or nozzle, while the application device, particularly the application head or nozzle, remains stationary. In particular, if the substrate is a web, film, or foil, the substrate can move by itself without an additional conveyor belt.

[0094] In certain embodiments, the coating device includes an actuator configured to move the coating head or nozzle relative to the substrate along a coating direction.

[0095] In certain embodiments, the first reservoir, the second reservoir, the third reservoir, and / or the further reservoirs comprise respective pump inlets for connecting the respective reservoirs to a pump such that the formulation is delivered into the respective reservoirs by the pump. The pump inlets of the first, second, third, and / or further reservoirs may be connected to the same pump or to separate pumps.

[0096] In certain embodiments, the applicator device comprises at least one pump connected to a pump inlet of the first reservoir, the second reservoir, the third reservoir, and / or the further reservoir.

[0097] In certain embodiments, the first reservoir (and also the first slot), the second reservoir (and also the second slot), the third reservoir (and also the third slot), and / or the further reservoir (and also the further slot) are divided into a first portion and a second portion (respectively) along the horizontal axis, wherein the first portion and the second portion are physically separated. In particular, the first reservoir, the second reservoir, the third reservoir, and / or at least one further reservoir comprises a first pump inlet connected to the first portion and a second pump inlet connected to the second portion, wherein the first pump inlet and the second pump inlet are configured to be connected to respective pumps to supply the respective formulations to the first portion and the second portion. In particular, the first portion forms a first end portion of the first, second, third, or further reservoir along the horizontal axis. In other words, the first portion is defined by a wall that forms an end of the respective first, second, third or further reservoir along the transverse axis.

[0098] In certain embodiments, the first reservoir, the second reservoir, the third reservoir, and / or the additional reservoir comprises a third portion, wherein the second portion is disposed between the first portion and the third portion along the transverse axis. In particular, the third portion forms a second end portion of the respective reservoir opposite the first end portion. In particular, each reservoir comprises a third pump inlet connected to the third portion.

[0099] In certain embodiments, the first and / or third portions of the second slot extend beyond the first slot along the transverse axis such that the second functional layer can be formed laterally relative to the first functional layer, in particular thereby embedding the first functional layer, i.e., the second slot is wider than the first slot.

[0100] In certain embodiments, the applicator comprises a first pump connected to a first pump inlet connected to a first portion of the first, second, third, and / or at least one additional reservoir, and a second pump connected to a second pump inlet connected to a second portion of the first, second, third, and / or at least one additional reservoir, particularly a third pump connected to a third pump inlet connected to a third portion of the first, second, third, and / or at least one additional reservoir.

[0101] Using this setup, different formulations can be dispensed into these parts of the reservoir and ejected from the associated slot parts to obtain functional layers that constitute a predetermined pattern of material, e.g. embedding a particular layer or forming interconnections between layers.

[0102] In certain embodiments, the application device comprises a pump controller configured to set a first flow rate of the first pump and a second flow rate of the second pump so that the functional layer formed by each formulation, particularly the formulation ejected from the first portion of each slot, has a greater thickness in a direction perpendicular to the application surface than the functional layer formed by the formulation, particularly the second formulation, ejected from the second portion of each slot.

[0103] In certain embodiments, the ejection surface comprises recesses with a width along the transverse axis corresponding to the width of each reservoir and the first portion of each slot, in particular said recesses extending from each slot along the entire ejection surface in the application direction. If the depth of the recess corresponds to the difference in thickness between the functional layer ejected from the first portion of each slot and the functional layer ejected from the second portion of each slot, this makes it possible to obtain an upper functional layer that embeds the lower functional layer while maintaining a flat surface of the upper functional layer.

[0104] In certain embodiments, the application device further comprises a third pump connected to a third pump inlet connected to a third portion of the first, second, third, and / or at least one additional reservoir, wherein the pump controller is configured to set a third flow rate of the third pump, in particular so that the functional layer formed by each formulation dispensed from the third portion of each slot has a greater thickness perpendicular to the application surface than the functional layer formed by the formulation dispensed from the second portion of each slot, in particular so that the third flow rate is equal to the first flow rate. Alternatively, in certain embodiments, the first pump is further connected (in addition to the first pump inlet connected to the first portion) to a third pump inlet connected to the third portion of the first, second, third, or at least one additional reservoir, in particular so that the functional layers formed by the formulations dispensed from the first and third portions have the same thickness.

[0105] In certain embodiments, the ejection surface comprises recesses with a width along the transverse axis corresponding to the width of each reservoir and the third portion of each slot, in particular said recesses extending from each slot along the entire ejection surface in the application direction. If the depth of the recesses corresponds to the difference in thickness between the functional layer ejected from the third portion of each slot and the functional layer ejected from the second portion of each slot, this makes it possible to obtain an upper functional layer that embeds the lower functional layer while maintaining a flat surface of the upper functional layer.

[0106] In certain embodiments, the application device comprises a first pump connected to a first pump inlet connected to a first portion of the second reservoir, and a second pump connected to a second pump inlet connected to a second portion of the second reservoir, wherein the application device comprises a pump controller configured to set a first flow rate of the first pump and a second flow rate of the second pump, so that the functional layer formed by the second formulation ejected from the first portion of each slot has a greater thickness in a direction perpendicular to the application surface than the functional layer formed by the second formulation ejected from the second portion, wherein in particular the first slot has a width extending along a horizontal axis equal to the width of the second portion of the second slot, so that in particular the first functional layer formed by the first formulation is embedded in the second functional layer formed by the second formulation.

[0107] The above-described embodiments with divided reservoirs (and slots) allow for the application of different formulations in a predetermined pattern in one functional layer of an electrochemical storage device. For example, this can be applied to laterally embed the solid electrolyte of a solid electrolyte battery with a layer of active material (anode or cathode) or a protective layer, or to form an interconnect between two layers separated by an additional layer in a single manufacturing step. Alternatively, formulations from different portions can be applied at different flow rates. For example, a higher flow rate can be applied to the outer (first and / or third) portions than to the central (second) portion. This can be used to laterally embed a previous functional layer applied via a separate slot, especially if this slot has a width equal to the width of the second (middle) portion.

[0108] A third aspect of the present invention relates to a formulation (ie the first, second, third or at least one further formulation described above) for forming a functional layer of an electrochemical storage device.

[0109] In certain embodiments, the preparations exhibit shear thinning behavior, i.e., a decrease in viscosity upon increasing shear rate.

[0110] In certain embodiments, the preparation is a liquid or a slurry.

[0111] In certain embodiments, the preparation comprises a solvent.

[0112] In certain embodiments, the preparation comprises a polymerizable monomer, and in particular the polymerization of the monomer is initiated or promoted by metal ions, more particularly lithium ions. Alternatively, the polymerization of the monomer can be initiated by electromagnetic radiation of certain wavelengths (e.g., photopolymerization) or by the addition of radicals (radical polymerization).

[0113] In certain embodiments, the formulation includes a metal ion host or a precursor capable of forming a metal ion host, including, inter alia, a conversion material or an intercalation material.

[0114] In certain embodiments, the formulation comprises a solid ion conductor or a precursor capable of forming a solid ion conductor, particularly comprising an inorganic material containing metal ions, more particularly lithium ions or sodium ions.

[0115] In certain embodiments, the formulation comprises a solid electronic conductor, or a precursor capable of forming a solid electronic conductor, particularly comprising a metal or carbon.

[0116] In certain embodiments, the formulation has a low shear viscosity of 1 mPas to 100,000 mPas, in particular 100 mPas to 1,000 mPas, such that the formulation can form a curtain between the applicator and the application surface of the substrate when it is dispensed from the slot of the applicator onto the application surface.

[0117] In certain embodiments, the preparation comprises 1000 g mol -1 ~100,000 g mol -1 a first polymer having a molecular weight of 300,000 g mol-1 ~1200000g mol -1 and a second polymer having a molecular weight of 0.015. In particular, this bimodal size distribution allows for optimal rheological properties and simultaneously provides optimal conditions for the polymer electrolyte of solid-state electrochemical storage devices. It also increases the solid content of the formulation, thereby shortening drying times.

[0118] In certain embodiments, the preparation comprises a polymer, in particular polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), polyacrylic acid (PAA), carboxymethylcellulose (CMC), styrene butadiene rubber (SBR), poly(tetrafluoroethylene) (PTFE), polyethylene (PE), polystyrene (PS), polypropylene (PP), gelatin, starch, agar, alginate, amylose, gum arabic, carrageenan, casein, chitosan, (carbonyl-β) cyclodextrin, ethylene propylene glycol, propylene glycol stearate ... Examples of suitable acrylic resins include polyvinyl alcohol (EPDM), gellan gum, guar gum, karaya gum, cellulose, pectin, PEDOT-PSS, poly(methyl acrylate) (PMA), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), polyacrylonitrile (PAN), polyisoprene (Plpr), polyaniline (PANi), polyimide (PI), polyurethane (PU), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), tara gum, tragacanth gum, TRD202A, or xanthan gum.

[0119] The addition of polymers to the formulation makes it possible to provide a binder, to adjust the rheological properties of the formulation, and also to provide a solid ion conductor, in particular for obtaining a solid electrolyte layer.

[0120] In certain embodiments, the formulation includes a solvent that evaporates, particularly after the formation of each functional layer, thereby increasing the solids content of the electrochemical storage device. In certain embodiments, the solvent comprises or consists of water, acetonitrile, N-methyl-2-pyrrolidone, alcohol, particularly ethanol or methanol, or tetrahydrofuran.

[0121] In certain embodiments, the formulation comprises a polymerizable monomer, particularly where the polymerization of the monomer is promoted or initiated by metal ions. The polymerizable monomer may function as a solvent, particularly for suspending the particles to form a slurry, or the monomer may be provided in addition to a solvent. Formulations comprising a polymerizable monomer have the advantage that a subsequent solvent evaporation step can be omitted and replaced by a polymerization step, which can significantly accelerate the fabrication of electrochemical storage devices.

[0122] In certain embodiments, the formulation includes a metal ion host, particularly a conversion or intercalation material. In particular, functional layers including such metal ion hosts can function as the negative or positive electrodes of electrochemical storage devices.

[0123] In certain embodiments, the metal ion host comprises or consists of a positive electrode active material, particularly lithium nickel manganese cobalt oxide (Li-NMC, e.g., Li a Ni x Mn y Co z O2), lithium iron phosphate (LFP, LiFePO4), nickel cobalt aluminum oxide (Li-NCA, e.g., Li a Ni x Co y Al z O2), lithium cobalt oxide (LCO, LiCoO2), or lithium manganese oxide (LMO, LiMn2O4).

[0124] In certain embodiments, the metal ion host is a metal ion host that is compatible with the negative electrode active material, particularly graphite, silicon, lithium titanate (LTO, Li4Ti5O 12 ) or titanium dioxide (TiO2), or consists of it.

[0125] In certain embodiments, the formulation includes a precursor capable of forming a metal ion host, particularly a conversion material or intercalation material. The metal ion host may be formed from the precursor by a chemical reaction that is initiated or occurs spontaneously after forming each functional layer of the electrochemical storage device by curtain coating. For example, the precursor may be a nitrate, carbonate, or hydroxide.

[0126] In certain embodiments, the formulation comprises a solid ionic conductor, in particular an inorganic material (e.g., a ceramic or glass material) or a polymer electrolyte.

[0127] In certain embodiments, the formulation comprises a precursor capable of forming a solid ion conductor, including, in particular, an inorganic material (e.g., a ceramic or glass material) or a polymer electrolyte. The solid ion conductor may be formed from the precursor by a chemical reaction that is initiated or occurs spontaneously after forming each functional layer of the electrochemical storage device by curtain coating. In the case of a polymer electrolyte, this chemical reaction may be a polymerization reaction, and the precursor may be a monomer capable of forming a polymer by polymerization. Alternatively, in particular, the precursor may be a nitrate, carbonate, or hydroxide.

[0128] In certain embodiments, the formulation comprises a solid electronic conductor, in particular a metal (e.g., aluminum or copper) or carbon (e.g., carbon black). In certain embodiments, the solid electronic conductor comprises conductive fibers, in particular carbon nanotubes. These conductive fibers simultaneously act as electronic conductors and improve the rheological properties (viscosity) of the formulation, resulting in improved curtain stability during application.

[0129] In certain embodiments, the preparation comprises a surfactant.

[0130] In certain embodiments, the preparation comprises lithium ions or sodium ions.

[0131] In certain embodiments, the preparation comprises a liquid metal, in particular liquid lithium, liquid gallium, or a mixture of liquid lithium and liquid gallium, or metal particles (leading in particular to a metal paste). The metal in particular forms an electronic conductor, such as a current collector. Forming a current collector by the method according to the invention has the advantage, in contrast to prior art methods, that it is possible to form a very thin current collector layer (e.g., 30 μm or less, in particular 5 μm or less), which results in improved quality of the electrochemical storage device.

[0132] Where alternative forms of a single separable feature are described herein as "embodiments," it is to be understood that such alternative forms can be freely combined to form separate embodiments of the invention disclosed herein.

[0133] The present invention is further illustrated by the following examples and figures, from which further embodiments and advantages can be derived, which are intended to illustrate the invention without limiting its scope.

[0134] FIG. 1 is a cross-sectional view of a coating head 4 of a coating device 1 according to an embodiment of the present invention, taken along a plane parallel to the coating direction C, and FIG. 2 is a corresponding perspective view of the coating head 4. As shown in FIGS. 1 and 2, the coating head 4 comprises a first reservoir 10, a second reservoir 20, and a third reservoir 30 for receiving a first formulation P1, a second formulation P2, and a third formulation P3, respectively. In the depicted example, the reservoirs 10, 20, and 30 are formed by cylindrical cavities in the body of the coating head 4, which extend along a transverse axis L that should be aligned perpendicular to the coating direction C when performing the method according to the present invention. The reservoirs 10, 20, and 30 each branch into associated slots 11, 21, and 31 in the discharge face 2 or slide of the coating head 4. The discharge face 2 comprises a convex curvature 2a on which a lip 3 is arranged, which forms the bottom end of the coating head 4 in the arrangement shown in FIGS. 1 and 2.

[0135] According to one embodiment of the curtain coating method according to the invention, a first formulation P1 is fed into the first reservoir 10, a second formulation P2 is fed into the second reservoir 20 and a third formulation P3 is fed into the third reservoir 30 via respective pump inlets (not shown in Figure 1, see e.g. Figure 3) in the reservoirs 10, 20, 30 which are connected to respective pumps (not shown). By generating flows of the respective formulations P1, P2, P3, the formulations P1, P2, P3 are discharged from the slots 11, 21, 31 and, due to the inclined arrangement of the coating head 4, flow downwards on the discharge surface 2 towards the curved portion 2a and the lip 3.

[0136] At the position of the first slot 11, the second preparation P2 forms a layer on the first preparation P1 discharged from the first slot 11. Similarly, at the position of the second slot 21, the third preparation P3 forms a layer on the second preparation P2 discharged from the second slot 21. Provided that the compositions and rheological properties of the first preparation P1, the second preparation P2, and the third preparation P3 are appropriately set and laminar flow occurs, these layers formed on the discharge surface 2 do not mix but form a layered curtain consisting of a first portion 310 of the first preparation P1, a second portion 320 of the second preparation P2, and a third portion 330 of the third preparation P3, and this curtain flows down from the lip 3 of the coating head 4 onto the coating surface 210 of the substrate 200.

[0137] The substrate 200 is moved by, for example, a conveyor mechanism relative to the coating head 4 in the coating direction C. As a result, the functional layers 110, 120, and 130 are formed on the coating surface 210, overlapping one another.

[0138] In particular, the first formulation P1, the second formulation P2, and the third formulation P3 are slurries with suitable rheological properties (i.e., suitable viscosity, preferably shear thinning behavior) for use in curtain coating. In order to obtain a stable curtain, it is necessary to appropriately set the flow rates of the formulations P1, P2, and P3, as well as the coating speed at which the substrate 200 moves relative to the coating head 4 and opposite to the coating direction C.

[0139] In particular, the application head 4 is provided with edge guides (not shown) formed by tabs extending vertically from both side edges of the lip 3 towards the application surface 210 to guide the edges of the curtains 310, 320, 330 and prevent necking.

[0140] The functional layers 110, 120, 130 of the electrochemical storage device can be, for example, the positive electrode 110, solid electrolyte 120, and negative electrode 130 of a solid-state metal-ion battery (e.g., a solid-state lithium-ion battery or a solid-state sodium-ion battery). According to this example, the first formulation P1 contains a metal ion host (conversion material or intercalation material) suitable for forming a positive electrode of a solid-state ion battery, such as NMC, LFP, NCA, LCO, or LMO. The second formulation P2 contains a solid ion conductor, such as an inorganic matrix containing metal ions, a polymer electrolyte such as a mixture of a polymer and a metal ion salt, or a mixture of an inorganic matrix containing a metal salt and a polymer electrolyte. The third formulation P3 contains a metal ion host suitable for forming a negative electrode of a solid-state ion battery, such as graphite, silicon, LTO, or TiO.

[0141] Alternatively, the dispensed formulation may include, for example, metal or carbon black to form a solid electronic conductor, such as a current collecting layer.

[0142] In order to adjust the rheological properties of the first preparation P1, the second preparation P2 and the third preparation P3, these preparations can contain a polymer, in particular a mixture of two polymers of different molecular weights.

[0143] Furthermore, the preparations P1, P2, P3 may contain a solvent or a polymerizable monomer and, optionally, a surfactant.

[0144] The described curtain coating method has the advantage that multiple very thin layers (e.g., less than 30 μm) of electrochemical storage devices can be formed simultaneously at high coating speeds (e.g., 40 m / min to 2500 m / min), which can significantly improve the manufacturing time of electrochemical storage devices such as solid-state ion batteries.

[0145] An exemplary procedure for making a slurry formulation according to the present invention for forming a solid electrolyte layer is as follows: 2.67 g of PEO (M v Dissolve LLZO powder (d 600000) in 77 g of acetonitrile. Add 1.67 g of LiTFSI and stir with a spatula. mean 12 g of 400 nm (12 g of EO:Li) is added and stirred again with a spatula. These mass ratios are specifically chosen to result in approximately equal volume ratios of ceramic and polymer in the dried film. The molar ratio of EO:Li is 10.4:1. The total solids content in the slurry is 17.5 wt %, and (m PEO +m LiTFSI +m LLZO ) / m total The low shear steady viscosity is about 130 mPas.

[0146] Further, an exemplary procedure for preparing a slurry formulation according to the present invention for forming a positive electrode layer is as follows: 6 g acetonitrile, 0.25 g PEO(M v 35000), 0.167g PEO(M v 600000), 0.27g LiTFSI, 1.1g LFP (host) (d mean 1 micron), 0.1375 carbon black (60 nm).

[0147] After curtain coating, the stack of functional layers can be subjected to several post-processing steps, in particular: 1) Evaporation of solvent 2) Drying 3) Cross-linking treatment 4) Hot press processing 5) Calendar processing 6) Initiation of chemical reactions between the components of the functional layer 7) Sintering process 8) Initiation of further chemical reactions between the components of the functional layer 9) The compression treatment

[0148] 3 to 7 show further embodiments of a coating device 1 and a curtain coating method according to the invention that can be advantageously used to produce structured functional layers 110, 120, 130 of electrochemical storage devices.

[0149] 3 is a semi-transparent perspective view of the application head 4, depicting only one reservoir 10 and associated slot 11 for simplicity (however, this arrangement can be used in application heads including three or more reservoirs and slots). In the embodiment according to FIG. 3, the reservoir 10 is formed by three physically separated manifolds, resulting in a first portion 10a, a second portion 10b, and a third portion 10c, which are arranged along a transverse axis L, with the second portion 10b forming the middle portion and the first portion 10a and the third portion 10c forming the opposite end portions. The first portion 10a includes a first pump inlet 13a, the second portion 10b includes a second pump inlet 13b, and the third portion 10c includes a third pump inlet 13c, each configured to be connected to a pump so that the respective portions 10a, 10b, and 10c of the reservoir 10 can be supplied with the respective formulations P1, P2, P3, and P4.

[0150] In Figure 4, the application head 4 is depicted, with the first reservoir 10 divided into a first portion 10a (extending along the horizontal axis L across a width X1), a second portion 10b (extending along the horizontal axis L across a width X2), and a third portion 10c (extending along the horizontal axis L across a width X3), similar to Figure 3.

[0151] A first preparation P1 is dispensed from the first portion 10a and the third portion 10c of the first slot 11, and a further preparation P4 is simultaneously dispensed from the second portion 10b of the first slot 11. Furthermore, at the same time, the first preparation P1 is dispensed from the second slot 21 over the entire width X1+X2+X3 of the second slot 21.

[0152] 5, the curtain coating process depicted in FIG. 4 results in a structured first functional layer 110 in which the first formulation P1 laterally embeds the further formulation P4, and a uniform second functional layer 120 formed from the first formulation. For example, the first formulation P1 may form the active material of an electrochemical storage device, and the further formulation P4 may form a solid electrolyte that is protected from moisture and air ingress by the active material.

[0153] 6 shows a further embodiment of an applicator 1 in which the second reservoir 20 and corresponding second slot 21 are divided into a first portion 20a having a width X1 along the horizontal axis L, a second portion 20b having a width X2 along the horizontal axis L, and a third portion 20c having a width X3 along the horizontal axis L. This can be achieved, for example, by separate manifolds as shown in FIG. 3. Each of the portions 20a, 20b, and 20c has an associated pump inlet 13a, 13b, and 13c (not shown in FIG. 6) branching off from the side of the second reservoir 20 opposite the slot 21, similar to the embodiment shown in FIG. 3.

[0154] The discharge surface 2 of the applicator 1 comprises a recess 2b that is aligned with the first portion 20a of the second slot 21 and has a width along the transverse axis L that corresponds to the width X1 of the first portion 20a of the second slot 21, where the recess 2b extends from the second slot 21 along the entire discharge surface 2 in the application direction C. Furthermore, the discharge surface 2 comprises a further recess (not shown) that is aligned with the third portion 20c and has a width along the transverse axis L that corresponds to the width X3 of the third portion 20c.

[0155] The second formulation P2 is supplied at a first flow rate to the first portion 20a and the third portion 20c by pump(s) connected to the first pump inlet 13a and the third pump inlet 13c (see FIG. 3), and the second formulation P2 is supplied at a second flow rate to the second portion 20b by a pump connected to the second pump inlet 13b (see FIG. 3), so that a thicker layer of the second formulation P2 is deposited on the substrate 200 along the widths X1 and X3 than along the width X2. Simultaneously, the first formulation P1 is discharged from the first slot 11 connected to the first reservoir 10, where the first slot 11 has a width w equal to the width X2 of the second reservoir 20 and the second portion 20b of the second slot 21.

[0156] The resulting pattern of material deposited on the substrate 200 by the curtain coating method depicted in FIG. 6 is shown in FIG. 7. Similar to the result shown in FIG. 5, the first functional layer 110 consists of a core of the first formulation P1 along width X2 laterally sandwiched between two portions of the second formulation P2 deposited thereon (along widths X1 and X3). The second functional layer 120 is a uniform layer of the second formulation P2 across the entire width X1+X2+X3. The uniform top surface of the second functional layer 120 is due to the recess 2b in the ejection surface 2, the depth of which (perpendicular to the ejection surface 2) is, in this case, equal to the thickness of the first functional layer 110, compensating for the additional volume of the second formulation P2 ejected from the first and third portions 20a and 20c of the second slot 21. Similar to the results shown in FIG. 5 above, the first formulation P1 can form the active material of the electrochemical storage device, and the second formulation P2 can form a solid electrolyte that is protected from moisture and air ingress by the active material.

[0157] In particular, the flow rate f is adjusted to ensure that the second preparation P2 is deposited along the widths X1 and X3 with a thickness equal to the sum of the layer thicknesses of the first preparation P1 and the second preparation along the width X2 in the direction perpendicular to the horizontal axis L. P1,X2 , f P2,X1 , f P2,X2 , and f P2,X3 can be set according to the following formula:

number

[0158] [Table 1]

Claims

1. A method for manufacturing a functional layer (110, 120, 130) of an electrochemical storage device, comprising: a. providing a first formulation (P1) in a first reservoir (10) of an application device (1); b. providing a second formulation (P2) in a second reservoir (20) of said application device (1); c. disposing the coating device (1) above the substrate (200) and moving the coating device (1) relative to the substrate (200) along a coating direction (C); d) dispensing the first formulation (P1) from the first reservoir (10) of the applicator (1) through a first slot (11) onto the application surface (210) of the substrate (200), the first slot (11) extending along a transverse axis (L) perpendicular to the application direction (C) and parallel to the application surface (210), and simultaneously dispensing the second formulation (P2) from the second reservoir (20) of the applicator (1) through a second slot (21) onto the substrate (200), the second slot (21) extending along the transverse axis (L); e. wherein the first preparation (P1) and the second preparation (P3) form a curtain (310, 320) between the application device (1) and the substrate (200), wherein in particular the first preparation (P1) and the second preparation (P2) exhibit shear thinning behavior; and f. wherein a first functional layer (110) of the electrochemical storage device is formed on the application surface (210) from the first formulation (P1), and a second functional layer (120) of the electrochemical storage device is simultaneously formed on the first functional layer (110) from a second formulation (P2); Including, Said first preparation (P1) and / or said second preparation (P2) comprise the following components: i. a solvent and / or polymerizable monomers; ii. a metal ion host or a precursor capable of forming a metal ion host; iii. A solid ionic conductor or a precursor capable of forming a solid ionic conductor; iv. a solid electronic conductor; at least one of: The method.

2. The method of claim 1 , wherein the first functional layer (110) and / or the second functional layer (210) form a solid electrolyte of the electrochemical storage device.

3. The solid electrolyte is a. an inorganic solid electrolyte, and / or b. Polymer electrolytes, especially those comprising a mixture of a polymer and a metal ion salt; The method of claim 2 , comprising:

4. The first functional layer (110) and / or the second functional layer (210) of the electrochemical storage device a. Positive or negative electrode; b. an electron transport medium, particularly a current collector, and / or c. protective layer, The method of any one of claims 1 to 3, wherein

5. 5. The method according to claim 1, wherein the first preparation (P1) and the second preparation (P2) comprise the same solvent and / or the same polymerizable monomer and / or the same salt concentration in the same concentration, so that no diffusion occurs at the interface between the first preparation (P1) and the second preparation (P2).

6. The first preparation (P1) and / or the second preparation (P2) may have a concentration of 1000 g mol －１ ~100000g mol －１ a first polymer having a molecular weight of 300,000 g mol －１ ~1200000g mol －１ and a second polymer having a molecular weight of

7. 7. The method according to any one of claims 1 to 6, wherein the first reservoir (10) and the first slot (11) or the second reservoir (20) and the second slot (21) are divided along a transverse axis (L) into a first portion (10a, 20a) and a second portion (10b, 20b), the first portion (10a, 20a) and the second portion (10b, 20b) being physically separated from each other, in particular the first portion (10a, 20a) forming an end portion of the first or second reservoir (10, 20) along the transverse axis (L).

8. The second preparation (P2) is supplied to the first portion (10a, 20a) at a first flow rate, and the second preparation (P2) is supplied to the second portion (10b, 20b) at a second flow rate, wherein the first flow rate and the second flow rate are set so that the second functional layer (120) formed by the second preparation (P2) discharged from the first portion (20a) has a thickness perpendicular to the application surface (210) that is greater than the second functional layer (120) formed by the second preparation (P2) discharged from the second portion (20b), and in particular, the first functional layer (110) formed by the first preparation (P1) is embedded by the second functional layer (120) formed by the second preparation (P2).

8. The method according to claim 7, wherein the first slot (11) has a width (w) extending along a transverse axis (L) equal to the width (w) of the second portion (20b), and more particularly, the application device (1) comprises a discharge surface (2) configured to receive the first formulation (P1) discharged from the first slot (11) and the second formulation (P2) discharged from the second slot (21), and in particular, the discharge surface (2) comprises recesses (2a) having a width along the transverse axis (L) corresponding to the width of the first portion (10a, 20a) of each of the reservoirs (10, 20) and each of the slots (11, 21), and even more particularly, the recesses (2a) extend from each of the slots (11, 21) along the entire discharge surface (2) in the application direction (C).

9. 8. The method of claim 7, wherein the first or second preparation (P1, P2) is provided in the first portion (10a, 20a) of the first or second reservoir (10, 20) and the further preparation (P4) is provided in the second portion (10b, 20b) of the first or second reservoir (10, 20) such that the first or second preparation (P1, P2) and the further preparation (P4) are arranged in a given pattern on the application surface (210) of the substrate (200) to jointly form the first or second functional layer (110, 120).

10. A coating device (1) for producing a functional layer (110, 120, 130) of an electrochemical storage device, comprising: a. a first reservoir (10) for receiving a first preparation (P1); b. a first slot (11) for dispensing the first formulation (P1) from the first reservoir (10) onto the application surface (210) of the substrate (200) so that the first formulation (P1) forms a curtain (310) between the application device (1) and the application surface (210); c. a second reservoir (20) for receiving a second preparation (P2); d. a second slot (21) for dispensing the second formulation (P2) from the second reservoir (20) onto the application surface (210) simultaneously with the first formulation (P1), so that the second formulation (P2) forms a curtain (320) between the application device (1) and the application surface (210); Equipped with e. wherein the coating device (1) is configured to be positioned above the substrate (200) and move relative to the substrate (200) along a coating direction (C); Including, the first slot (11) and the second slot (21) are configured and arranged so that a first functional layer (110) of the electrochemical storage device can be formed on the application surface (210) from the first formulation (P1) and a second functional layer (120) of the electrochemical storage device can be simultaneously formed on the first functional layer (110) from the second formulation (P2); and The first reservoir (10) or the second reservoir (20) is divided along a horizontal axis (L) into a first portion (10a, 20a) and a second portion (10b, 20b), wherein the first portion (10a, 20a) and the second portion (10b, 20b) are physically separated, and the first or second reservoir (10, 20) is connected to a first pump inlet (13a) connected to the first portion (10a, 20a) and a second pump inlet (13b) connected to the second portion (10b, 20b). a second pump inlet (13b) connected to the first portion (10a, 20a) and the second portion (10b, 20b), the first pump inlet (13a) and the second pump inlet (13b) being configured to be connected to respective pumps for supplying the respective preparations to the first portion (10a, 20a) and the second portion (10b, 20b), in particular the first portion (10a, 20a) forming a terminal portion of the first reservoir (10) along the transverse axis (L); The coating device (1) is characterized by:

11. 11. The application device (1) according to claim 10, characterized in that the application device (1) comprises a discharge surface (2) configured to receive the first formulation (P1) discharged from the first slot (11) and the second formulation (P2) discharged from the second slot (21), in particular the discharge surface (2) comprises recesses (2a) having a width along a transverse axis (L) corresponding to the width of the first portion (10a, 20a) of each of the reservoirs (10, 20) and each of the slots (11, 21), more in particular the recesses (2a) extending from each of the slots (11, 21) along the entire discharge surface (2) in the application direction (C).

12. Ingredients: i. a solvent and / or polymerizable monomers; ii. a metal ion host or a precursor capable of forming a metal ion host; iii. A solid ionic conductor or a precursor capable of forming a solid ionic conductor; iv. a solid electronic conductor or a precursor capable of forming a solid electronic conductor; at least one of: A formulation (P1, P2, P3, P4) for forming a functional layer (110, 120, 130) of an electrochemical storage device, comprising: In particular, the preparations (P1, P2, P3, P4) exhibit shear thinning behavior and are capable of forming curtains (310, 320, 330) between the coating device (1) and the coating surface (210) of the substrate (200) when the preparations (P1, P2, P3, P4) are ejected from the slots (11, 21, 31) of the coating device (1) onto the coating surface (210).

13. The preparations (P1, P2, P3, P4) were prepared at 1000 g mol －１ ~100000g mol －１ a first polymer having a molecular weight of 300,000 g mol －１ ~1200000g mol －１ and a second polymer having a molecular weight of 0.01 to 0.01.

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