Solid electrolyte separator, battery cell with solid electrolyte separator, and method for producing a solid electrolyte separator

Abstract

A multilayer solid electrolyte separator (3) for a battery cell (1, 30) comprises at least two layers (3a-h), wherein the at least two layers (3a-h) are deposited layer by layer by means of aerosol deposition, and wherein one (3a) of the at least two layers (3a-h) comprises an ion conduction function and a separation function.

Description

[0001] Description

[0002] Solid electrolyte separator, battery cell with solid electrolyte separator and method for manufacturing a solid electrolyte separator

[0003] The invention relates to a solid electrolyte separator, a battery cell with a solid electrolyte separator and a method for manufacturing the solid electrolyte separator.

[0004] Solid electrolyte separators are components in solid-state batteries that help improve the safety and performance of modern energy storage systems. They replace the liquid electrolytes used in conventional batteries and also act as separators, physically isolating the electrodes to prevent short circuits. Unlike conventional lithium-ion batteries, which use liquid organic electrolytes and therefore pose an increased risk of ignition and explosion, solid electrolyte separators offer a non-flammable alternative. They reduce the hazards associated with volatile and flammable electrolytes while enabling higher energy density and improved electrochemical properties.

[0005] Solid electrolytes can be inorganic ceramics, solid polymers, and composite materials, and typically consist of a homogeneous layer produced by various manufacturing processes such as casting or sintering, with sintering requiring high temperatures exceeding 1000°C. Since the solid electrolyte separator is positioned between the two electrodes, a challenge lies in ensuring interface functionalization, which is typically achieved by adapting the electrode surface.

[0006] The object of the present invention is to provide an improved solid electrolyte separator that enables improved interface functionalization.

[0007] This problem is solved by the solid electrolyte separator according to claim 1, the battery cell according to claim 9, the method according to claim 10, and the aerosol deposition device according to claim 12. Further advantageous embodiments of the invention will become apparent from the dependent claims, the drawings, and the following description of preferred embodiments of the present invention.

[0008] A multilayer solid electrolyte separator according to the invention for a battery cell comprises at least two layers, wherein the at least two layers are deposited layer by layer by means of aerosol deposition, and wherein one of the at least two layers comprises an ion conduction function and a separation function.

[0009] The battery cell can be a solid-state battery cell, for example a “semi-solid state” battery cell, with a liquid electrolyte content of approximately 10 wt.% to 5 wt.%, or an “all-solid state” battery cell without liquid electrolyte.

[0010] The battery cell can be a thick-film battery cell. Alternatively, the battery cell can be a prismatic battery cell. A prismatic battery cell comprises a rigid casing in which a stack of electrodes is arranged. Alternatively, the battery cell can also be designed as a pouch cell with a flexible casing, or as a cylindrical cell or a round cell.

[0011] A battery cell can comprise electrodes, including or consisting of active material, and at least one anode and a cathode. A multilayer solid electrolyte separator is arranged between the electrodes. The separator prevents direct contact between the electrodes while simultaneously allowing ion flow within the cell.

[0012] The electrodes and separators can be arranged as a stack, with anodes, cathodes, and separators stacked alternately. This stack, also called an electrode stack, can be configured as a jellyroll or a jellystack. The electrode stack can then be sealed in a casing, such as a housing, which protects the battery cell from external influences and ensures its structural integrity. For example, the prismatic battery cell comprises over 100 layers of each electrode stack component.

[0013] The active material of the anode can be lithium metal or sodium metal. The anode can comprise a lithium alloy (e.g., lithium-silicon or lithium-tin), a silicon or silicon-carbon composite, metal sulfides and oxides (e.g., tin sulfide, nickel oxide), lithium titanate, phosphorus, hard carbon, or graphite. The battery cell anode can be designed as a zero-excess battery cell. Thus, the anode-side conductive foil can serve as the anode for depositing active material (e.g., lithium, sodium, etc.) during charging.

[0014] The cathode can have a layer thickness of 50 to 150 pm. A softer electrolyte (e.g., polymeric solid electrolyte, sulfide solid electrolyte (e.g., argodite, LPS-type (e.g., mixture of Li₂S and P₂S₅), LGPS-type (lithium-germanium-phosphorus-sulfur), etc.), halide (e.g., Li₂MX₄, Li₃MX₆, Li₂MX₄; M = Al, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X)) can be used in the cathode than in the solid electrolyte separator.

[0015] The solid electrolyte separator can include inorganic solid electrolyte, oxide-, sulfide-, and / or phosphate-based solid electrolyte, glassy solid electrolyte (e.g., lithium phosphorus oxynitrides (UPON)) and / or polymer-based solid electrolyte.

[0016] To ensure ion conductivity and separation (ion conduction layer), one of the at least two layers can be, for example, a lithium-conducting oxide (e.g., lithium lanthanum zirconium oxide (LLZO), lithium lanthanum titanium oxide (LLTO), etc.), or a lithium-conducting sulfide (e.g., argodite, lisicone, LPS-type (e.g., mixture of Li₂S and P₂S₅), LGPS-type, etc.), or a lithium-conducting halide (e.g., LiMX₄, U₃MX₆, Li₂MX₄; M = Al, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X), or a lithium-conducting phosphate (e.g., lithium aluminum germanium phosphate (LAGP), LATP (lithium aluminum titanium phosphate), etc.), or a sodium-conducting oxide or a sodium-conducting sulfide (e.g., Na3PS4), or a sodium conducting halide (e.g., LiMX4, Li3MX6, Li2MX4; M = AI, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X) or a sodium conducting phosphate.For example, the ion conduction layer can be a NASICON type (sodium superion conductor) (e.g., Nai. +x The ion conduction layer can consist of at least one of the materials listed above (Zr2SixP3-xOi2-type, 0 < x < 3, Na5RSi40i2-type, R = Y, Gd, Sm, etc.).

[0017] This ionic conduction layer can be 1 to 50 pm thick, for example, 5 to 25 pm or 10 to 20 pm. The ionic conduction layer can have better ionic conduction properties than at least one, for example, several or all, of the other layers of the multilayer solid electrolyte separator. The ionic conduction layer can be the thickest layer of the multilayer solid electrolyte separator, which also ensures the separation function. The solid electrolyte separator can comprise more than two layers, for example, three, four, five, six, or more. Each layer of the multilayer solid electrolyte separator can be homogeneous within itself, for example, consisting of one material or a homogeneous composite material, but the layers can be heterogeneous with respect to each other, for example, having separate functionalities and / or different material compositions.

[0018] The solid electrolyte separator is deposited, for example layer by layer, using aerosol deposition (e.g., powder aerosol deposition). Thus, each layer of the multilayer solid electrolyte separator can be deposited as a separate layer, with the layers being deposited on top of each other to enable the multilayer structure of the solid electrolyte separator.

[0019] Aerosol deposition is a thin-film process that can be used in thick-film battery manufacturing and, unlike conventional thin-film processes with layer thicknesses in the nanometer range (e.g. 1-100 nm), enables layer thicknesses of 0.5 pm to 10 pm, for example 0.5 pm to 1 pm, per application.

[0020] Each layer of the multilayer solid electrolyte separator can be applied in one or more application layers of the same material. This allows the thickness of each layer to be varied, and thicker layers can be created, for example, by applying multiple application layers.

[0021] Aerosol deposition is a spray coating process for producing dense ceramic layers at room temperature. Unlike sintering at high temperatures (e.g., above 1000 °C), aerosol deposition can take place at room temperature. Furthermore, aerosol deposition enables optimal adhesion of the layer to the substrate. The ceramic layers can achieve a density of 90% to nearly 100% and can exhibit nanocrystalline structures.

[0022] For aerosol deposition, the material can initially be in loose powder form and then, by introducing a carrier gas through the powder, become a fluidized bed in which solid particles are brought into a quasi-liquid state by an upward flow of gas. The particles are thus kept in suspension, causing them to flow like a liquid. The resulting aerosol can then be sprayed onto a substrate as an aerosol jet using a nozzle. The particles in the aerosol jet collide with the substrate, causing them to break into fragments that recombine and form a ceramic layer.

[0023] Alternatively, the aerosol can also be generated using a Venturi nozzle, a brush generator, an atomizer, an ultrasonic nebulizer, a pressure nebulizer, or an electrostatic spray system, etc.

[0024] Each layer of the multilayer solid electrolyte separator can be applied in this way, for example, layer by layer. The substrate can be the anode, the cathode, or, in the case of a zero-excess anode, the anode-side discharge foil. Thus, the first layer can be applied to the anode, the cathode, or, in the case of a zero-excess anode, to the anode-side discharge foil, and the next layer can be applied to the first layer, and all further layers, if any, can be applied successively on top.

[0025] The multilayer solid electrolyte separator can be applied to both sides of the anode-side discharge foil.

[0026] Double-sided application is also possible if the multilayer solid electrolyte separator is applied to the anode or the cathode.

[0027] At least two, or for example all, layers of the multilayer solid electrolyte separator can have different material properties in order to ensure, for example, the different functionality of each layer.

[0028] Consequently, a double-sided, symmetrical application is possible in all three cases: the multilayer solid electrolyte separator is applied to both sides of the anode-side discharge foil (multilayer solid electrolyte separator, anode-side discharge foil, multilayer solid electrolyte separator); the multilayer solid electrolyte separator is applied to both sides of the anode and the anode-side discharge foil, with the anode also being applied to both sides accordingly (multilayer solid electrolyte separator, anode, anode-side discharge foil, anode, multilayer solid electrolyte separator); and the multilayer solid electrolyte separator is applied to both sides of the cathode and the cathode-side discharge foil, with the cathode also being applied to both sides (multilayer solid electrolyte separator, cathode, cathode-side discharge foil, cathode, multilayer solid electrolyte separator). solid electrolyte separator).In some embodiments, one of the at least two layers can serve as the anchor layer for the cathode. The anchor layer can therefore be more mechanically deformable than at least one, for example several or all, of the other layers of the multilayer solid electrolyte separator.

[0029] Consequently, the anchor layer can comprise a mechanically deformable sulfide electrolyte (e.g., argodite, LPS-type (e.g., a mixture of Li₂S and P₂S₅), LGPS-type), halide (e.g., UMX₄, Li₃MX₆, Li₂MX₄; M = Al, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X), polymer, and / or the solid electrolyte of the cathode (catholyte). The anchor layer can consist of at least one of the materials listed above.

[0030] The catholyte is typically softer than the solid electrolyte of a conventional separator. Therefore, depending on the design, the armature layer can be softer than the other layers of the multilayer solid electrolyte separator, for example, softer than the ion conduction layer. The armature layer can improve the interface with the cathode and generate a low interfacial resistance. For example, the armature layer can exhibit a lower interfacial resistance relative to the other layers of the multilayer solid electrolyte separator.

[0031] The armature layer can therefore be located on the cathode side relative to the ion conduction layer. The armature layer can have a thickness of 0.1 to 5 pm, for example, 1 to 3 pm. The armature layer can, for example, be configured with direct contact to the cathode. Thus, the armature layer can be the layer closest to the cathode in the multilayer solid electrolyte separator.

[0032] At least one of the at least two layers can be reduction-stable against an active material of the anode. For example, this reduction-stable layer can be reduction-stable against the active metal of the anode (e.g., lithium metal, sodium metal), which, for instance, can be deposited from the anode-side current collector foil in a zero-excess anode. The reduction-stable layer can be more reduction-stable than at least one, for example, several or all, of the other layers of the multilayer solid electrolyte separator.

[0033] The reduction-stable layer can therefore be arranged anode-side relative to the ion conduction layer. The reduction-stable layer can have a thickness of 0.1 to 5 pm, for example, 1 to 3 pm. The reduction-stable layer can comprise aluminum oxide (Al₂O₃), TiCh, lithium phosphoroxynitride (LiPON), stable binary and quasi-binary lithium salts, e.g., LiX, X=F, CI, Br, Li₃N, LiH, U₂CO₃, etc., or lithium lanthanum zirconium oxide (LLZO), or at least consist of one of these materials.

[0034] At least one of the at least two layers can be oxidation-stable against an active material of the cathode. For example, this oxidation-stable layer can be oxidation-stable with respect to the cathode. The oxidation-stable layer can be more oxidation-stable than at least one, for example, several or all, of the other layers of the multilayer solid electrolyte separator.

[0035] The oxidation-stable layer can therefore be arranged on the cathode side relative to the ion conduction layer. The reduction-stable layer can have a thickness of 0.1 to 5 pm, for example 1 to 3 pm.

[0036] The anchor layer can also serve as an oxidation-stable layer, i.e., one layer of the multilayer solid electrolyte separator can have multiple functionalities.

[0037] The oxidation-stable layer may include LLZO, NASICON or lithium aluminum titanium phosphate (LATP), LLTO (lithium titanate), halide (e.g., UMX4, U3MX6, Ü2MX4; M = AI, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X), or at least consist of one of these materials.

[0038] In some embodiments, at least one of the at least two layers can improve the wettability, for example with lithium or sodium. Improved wettability can be expressed by a contact angle, for example with lithium / sodium metal, of less than 100°, for example less than 90°.

[0039] Consequently, at least one of the at least two layers can have a contact angle of less than 100°, for example less than 90°, with respect to a metal anode (e.g., lithium metal anode or sodium metal anode).

[0040] A contact angle of less than 100° for a layer can mean that, when measuring the contact angle of the layer with the material of the adjacent substrate, for example, lithium or sodium (which may be present as a molten droplet at elevated temperature), the contact angle of the molten droplet to the layer would be less than 100°. Therefore, the contact angle of this layer with a contact angle of less than 100° relative to the adjacent substrate, for example, the anode or the anode-side conductive foil, can be optimized to enable improved wetting properties, for example, for the active metal (e.g., lithium metal, sodium metal). This layer can thus exhibit better wetting properties than at least one, for example, several or all, of the other layers of the multilayer solid electrolyte separator.

[0041] This layer with improved wetting properties can therefore be positioned on the anode side relative to the ion conduction layer. The layer can have a thickness of 0.1 to 5 pm, for example, 1 to 3 pm.

[0042] This layer with improved wetting properties can be an inert ceramic, or aluminum oxide (Al2O3), TiCh, or lithium phosphorus oxynitride (LiPoN), alloying metals (e.g., layers comprising tin (Sn), antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P) or zinc (Zn)), or at least consist of one of these materials.

[0043] The reduction-stable layer can also be designed as a layer with improved wetting properties. Thus, a single layer of the multilayer solid electrolyte separator can exhibit multiple functionalities.

[0044] In some embodiments, at least one of the at least two layers may comprise, or at least consist of, tin (Sn), antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P) or zinc (Zn).

[0045] This position can therefore support the nucleation of the active material, for example, the active material of the anode. Nucleation in the active material of an anode (e.g., lithium metal anode or sodium metal anode) refers to the initial process in which ions (e.g., lithium ions or sodium ions) are reduced during the charging cycle of the battery cell (e.g., to elemental lithium or elemental sodium) and begin to deposit on the anode surface. This nucleation process is crucial because it influences how, for example, the lithium metal or sodium metal grows on the anode.

[0046] If nucleation occurs uniformly across the anode surface, it results in a smooth and homogeneous deposit, increasing the efficiency of the battery cell and extending its lifespan. Uneven nucleation, however, can lead to dendritic growth. Dendrites are needle-like structures that, as they grow, can penetrate the separator and cause short circuits, posing a significant safety risk.

[0047] At least one layer of the solid electrolyte separator can therefore be designed to support or improve nucleation and / or reduce dendrite growth. Thus, this nucleation-supporting layer can be more conducive to nucleation on the anode than at least one, for example several or all, of the other layers of the multilayer solid electrolyte separator.

[0048] This nucleation-supporting layer can comprise metallic, alloying, or non-alloying particles, for example, in a proportionate amount. These metallic, alloying, or non-alloying particles can optimize the electronic connection of the anode to the current collector foil.

[0049] This layer with improved nucleation properties can therefore be positioned anode-side relative to the ion conduction layer. The layer can have a thickness of 0.1 to 5 pm, for example, 1 to 3 pm.

[0050] A layer can be designed as a layer with improved nucleation properties and / or as a reduction-stable layer and / or as a layer with improved wetting properties. Thus, a layer of the multilayer solid electrolyte separator can exhibit several functionalities, for example, three functionalities.

[0051] A layer of the multilayer solid electrolyte separator can exhibit any of the aforementioned functionalities. Thus, any combination of functionalities is possible for a single layer. Furthermore, the multilayer solid electrolyte separator can include an ion conduction layer and any other combination of layers (e.g., an anchor layer, or an anchor layer and a reduction-stable layer, or an anchor layer and an oxidation-stable layer, or a layer that is both an anchor layer and reduction-stable, etc.).

[0052] The different layers of the multilayer solid electrolyte separator can consist of or comprise material from the same material class with different chemical compositions. For example, a material from the same material class, such as LLZO, with different dopants and / or different morphologies (e.g., particle morphologies) can be present in the different layers of the multilayer solid electrolyte separator. The difference in chemical composition can lead to a difference in the functionality of the layer.

[0053] At least two adjacent layers of the multilayer solid electrolyte separator can be configured as gradients. This allows for optimization of the resistance.

[0054] For example, one layer can comprise (or consist of) a material containing at least two components homogeneously distributed at a predefined concentration. The adjacent layer can comprise (or consist of) the same material with the same components, but at a different concentration. This creates a gradient in the chemical composition of the material across at least two layers of the multilayer solid electrolyte separator. The gradient can be generated by a gradual change in the chemical composition with each application step of the aerosol deposition.

[0055] The multilayer solid electrolyte separator, for example, allows the combination of different materials that together fulfill several functionalities, e.g., electrochemical stability, strength, etc.

[0056] Similarly, the multilayer solid electrolyte separator can exhibit different mechanical properties; for example, soft layers (e.g., catholyte, polymer solid electrolyte, sulfide solid electrolyte (e.g., argodite, LPS-type, LGPS-type, etc.), halide (e.g., UMX4, Ü3MX6, U2MX4; M = Al, Ga, Zr, In, Sc, Y; X = F, CI, Br, I; mixtures of M and mixtures of X) and hard layers (e.g., oxide and / or phosphate (e.g., NASICON-type (e.g., Nai)) can be used. + xZr2Si x P3-xOi2-typ, 0 < x < 3, Na5RSi40i2-typ, R = Y, Gd, Sm, etc.), LAGP, LATP, etc.) are combined in the multilayer solid electrolyte separator, making the multilayer solid electrolyte separator particularly stable against vibrations and other mechanical disturbances.

[0057] In some embodiments, a battery cell may comprise the multilayer solid electrolyte separator. The battery cell may include any feature described in this specification relating to a battery cell.

[0058] For example, the battery cell, such as in the case of a zero-excess anode, can comprise an anode-side leakage foil, a cathode and a cathode-side leakage foil, wherein the multilayer solid electrolyte separator can be deposited on the anode-side leakage foil by means of aerosol deposition.

[0059] Some embodiments may relate to a method for manufacturing the multilayer solid electrolyte separator by aerosol deposition. The method may include any feature described in this specification relating to the manufacture of the solid electrolyte separator or the battery cell, for example, relating to aerosol deposition.

[0060] For example, the process can include the steps of providing the anode-side current collector foil and layer-by-layer deposition of the multilayer solid electrolysis preform onto the anode-side current collector foil using aerosol deposition. The deposition can, for example, be performed on both sides.

[0061] The multilayer solid electrolysis separator can be manufactured in a continuous process, whereby different layers with different functions can be produced successively.

[0062] After depositing the multilayer solid electrolyte separator onto the anode-side current collector foil, the cathode can be applied directly to the multilayer solid electrolyte separator. The cathode can be manufactured directly onto the multilayer solid electrolyte separator using conventional methods, such as casting or dry coating. An anchor layer as a cathode-side layer is advantageous for the direct application of the cathode, i.e., layering the cathode directly onto the solid electrolyte separator.

[0063] If the multilayer solid electrolyte separator is deposited on both sides, a cathode can also be applied to both sides. This allows for the production of an initial thin electrode stack. In this case of direct application of the cathode material to the multilayer solid electrolyte separator to produce the cathode, a cathode-side leakage foil can be applied to the cathode. For example, the cathode-side leakage foil can be applied by alternating stacking, such as in the following sequence: cathode-side leakage foil, electrode stack (e.g., comprising cathode, multilayer solid electrolyte separator, (anode), anode-side leakage foil, (anode), multilayer solid electrolyte separator, cathode), cathode-side leakage foil, electrode stack, cathode-side leakage foil, etc.In contrast to directly stacking the cathode onto the solid electrolyte separator to produce the cathode, the cathode can alternatively be produced separately. This allows for stacking together with a separately produced cathode.

[0064] For example, the cathode is first manufactured separately from the multilayer solid electrolyte separator, for instance by applying cathode material directly to the cathode-side discharge foil. The cathode with the cathode-side discharge foil and the anode (or anode-side discharge foil) with the multilayer solid electrolyte separator can then be stacked to form an electrode stack.

[0065] Some embodiments may include an aerosol deposition device for producing the multilayer solid electrolyte separator, comprising multiple nozzles for ejecting an aerosol jet, and multiple separate aerosol chambers for generating the aerosol from a powder. The aerosol deposition device may include any feature relating to the aerosol deposition and / or the aerosol deposition device described in this specification.

[0066] For example, at least two of the multiple nozzles can be operated from one aerosol chamber. This allows the nozzles for each material to be arranged on separate aerosol chambers, enabling the cyclical reuse of uncollected material without contamination. The aerosol stream is, for example, an aerosol jet.

[0067] Different materials can be applied through different nozzles in a nozzle array using aerosol deposition. Thus, the multiple nozzles can be configured as a nozzle array. For example, several nozzle arrays can also be provided.

[0068] For example, multiple nozzles can be used for each material, such as for each layer. The number of nozzles can be based on the belt speed, the coating rate of the material, and / or the target layer thickness.

[0069] Exemplary embodiments of the invention are now described by way of example and with reference to the accompanying drawing, in which:

[0070] Fig. 1 schematically shows an embodiment of a solid electrolyte battery cell; Fig. 2a schematically shows the production of a multilayer solid electrolyte separator by aerosol deposition according to an embodiment;

[0071] Fig. 2b schematically shows the production of a multilayer solid electrolyte separator by means of aerosol deposition according to an exemplary embodiment;

[0072] Fig. 2c schematically shows the production of a multilayer solid electrolyte separator by means of aerosol deposition according to an exemplary embodiment;

[0073] Fig. 2d schematically shows an embodiment of a solid electrolyte battery cell with a multilayer solid electrolyte separator produced by means of aerosol deposition;

[0074] Fig. 2e schematically shows the production of a multilayer solid electrolyte separator by means of aerosol deposition according to an exemplary embodiment;

[0075] Fig. 2f schematically shows an embodiment of a solid electrolyte battery cell with a multilayer solid electrolyte separator produced by means of aerosol deposition;

[0076] Fig. 3a schematically shows an embodiment of a two-layer solid electrolyte separator produced by aerosol deposition;

[0077] Fig. 3b schematically shows an embodiment of a two-layer solid electrolyte separator produced by aerosol deposition;

[0078] Fig. 3c schematically shows an embodiment of a three-layer solid electrolyte separator produced by aerosol deposition;

[0079] Fig. 3d schematically shows an embodiment of a three-layer solid electrolyte separator produced by aerosol deposition;

[0080] Fig. 3e schematically shows an embodiment of a three-layer solid electrolyte separator produced by aerosol deposition;

[0081] Fig. 3f schematically shows an embodiment of a four-layer solid electrolyte separator produced by aerosol deposition;

[0082] Fig. 3g schematically shows an embodiment of a four-layer solid electrolyte separator produced by aerosol deposition;

[0083] Fig. 3h schematically shows an embodiment of a five-layer solid electrolyte separator produced by aerosol deposition;

[0084] Fig. 3i schematically shows an embodiment of a four-layer solid electrolyte separator produced by aerosol deposition;

[0085] Fig. 3j schematically shows an embodiment of a five-layer solid electrolyte separator produced by aerosol deposition;

[0086] Fig. 3k schematically shows an embodiment of a six-layer solid electrolyte separator produced by aerosol deposition;

[0087] Fig. 31 schematically shows an embodiment of two layers of a solid electrolyte separator; Fig. 4 schematically shows an aerosol deposition device for producing a multilayer solid electrolyte separator of this embodiment;

[0088] Fig. 5 schematically shows an aerosol generation device of an aerosol deposition device for producing a multilayer solid electrolyte separator of a specific design;

[0089] Fig. 6a schematically shows a diagram of a method for producing a multilayer solid electrolyte separator by aerosol deposition according to an embodiment; Fig. 6b schematically shows a diagram of a method for producing a battery cell with a multilayer solid electrolyte separator according to an embodiment;

[0090] Fig. 6c schematically shows a diagram of a method for manufacturing a battery cell with a multilayer solid electrolyte separator according to an exemplary embodiment;

[0091] Fig. 7a schematically shows a side view of a battery cell with a solid electrolyte separator of this design; and

[0092] Fig. 7b schematically shows a perspective view of a battery cell with a solid electrolyte separator according to an exemplary embodiment.

[0093] Fig. 1 schematically shows an embodiment of a solid electrolyte battery cell 1. The battery cell comprises an anode 2, a multilayer solid electrolyte separator 3, a cathode 4, and current collectors 6a, 6b. A negative terminal 5a and a positive terminal 5b of an external circuit are attached to each of the current collectors 6a, 6b. The current collector 6a is located on the cathode side, which is shown on the left in the figure, and the current collector 6b is located on the anode side, which is shown on the right in the figure.

[0094] Figures 2a to 2d together schematically show the production of a multilayer solid electrolyte separator 3 by means of aerosol deposition according to an exemplary embodiment.

[0095] Fig. 2a shows that a first layer 3a is applied to the current collector foil 6a by means of aerosol deposition (not visible). This represents the structure of a zero-excess anode, for example made of lithium metal. Therefore, the anode is deposited directly onto the current collector foil 6a, and during operation of the battery cell, the anode 2 is built up from the current collector foil 6a.

[0096] In Fig. 2b, the second layer 3b of the solid electrolyte separator 3 is applied to the first layer 3a. Consequently, a multilayer solid electrolyte separator 3 is formed, as shown in Fig. 2c.

[0097] Subsequently, using a conventional method, for example a casting process, the cathode 4 and the cathode-side discharge foil 6b are applied to the solid electrolyte separator 3, as shown in Fig. 2d. This results in a battery cell 1 (e.g., 1, Fig. 1) with the discharge foil 6a, the zero-excess anode 2, the multilayer solid electrolyte separator 3, the cathode 4 and the cathode-side discharge foil 6b.

[0098] Fig. 2e shows an alternative embodiment in which a multilayer solid electrolyte separator 3 is deposited on both sides of the current collector foil 6a. First, the first layer 3a is applied to both sides of the current collector foil 6a by aerosol deposition. Subsequently, the second layer 3b is applied over the first layer 3a on both sides of the current collector foil 6a.

[0099] Subsequently, a cathode (e.g., 4, Fig. 2f) and a cathode-side discharge foil (e.g., 6b, Fig. 2f) can be arranged on both sides, as shown for a two-layer cell in Fig. 2f. For a multi-layer cell, for example, with more than two layers, the cathode-side discharge foil (e.g., 6b, Fig. 2f) can be stacked alternately.

[0100] Fig. 2f shows a battery cell 1 designed as a cell stack with a two-layer cell structure. The battery cell 1 of Fig. 2f comprises the double-sided multilayer solid electrolyte separator 3 of Fig. 2e, which is deposited on a conductive foil 6a, as well as double-sided cathodes 4 and conductive foils 6b, with each cathode 4 with conductive foil 6b being arranged on one of the two multilayer solid electrolyte separators 3. This can be achieved either by directly depositing the cathode 4 onto the two solid electrolyte separators 3 using a conventional method (e.g., casting) and subsequently inserting the conductive foils 6b into the electrode stack. Alternatively, the cathode 4 with conductive foil 6b can be manufactured separately and then assembled with the conductive foil 6a and solid electrolyte separators 3 of Fig. 2e.

[0101] In a multilayer cell, for example with more than two layers, the cathode-side current collector foil (e.g., 6b, Fig. 2f) can be stacked alternately. In the cell stack of Fig. 2f, the cathode 4 is symmetrically attached to the current collector foil 6b on both sides in this case.

[0102] The embodiments shown in Figures 2a-c and 2e illustrate the fabrication of a two-layer solid electrolyte separator 3, wherein the deposition of each layer begins at the anode side. Alternatively, more than two layers can be deposited, e.g., as shown in Figures 3c to 3k, with each layer being deposited separately, as shown in Figures 2a and 2b or 2e. The composition of the layers of the solid electrolyte separator 3 (e.g., Figures 3a to 3k) determines the sequence of the layers to be deposited, with deposition beginning at the anode side, as shown in Figures 2a and 2e.

[0103] Alternatively, deposition can also take place on the cathode side at cathode 4, resulting in a reversed deposition sequence.

[0104] Figures 3a to 3k show various embodiments of a multilayer solid electrolyte separator 3, which is deposited by means of aerosol deposition.

[0105] Fig. 3a schematically shows an embodiment of a two-layer solid electrolyte separator 3 produced by aerosol deposition. Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3b is arranged on the cathode side of layer 3a and includes an anchor function for the cathode, thereby ensuring good contact between the solid electrolyte separator 3 and the cathode. This structure enables efficient ion conduction and a stable connection to the cathode.

[0106] Fig. 3b schematically shows another embodiment of a two-layer solid electrolyte separator 3 produced by aerosol deposition. Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3c is arranged on the anode side of layer 3a and is reduction-stable with respect to the anode. This structure offers both good ion conductivity and a stable interface with the anode, thereby ensuring the electrochemical stability of the solid electrolyte separator 3.

[0107] Fig. 3c schematically shows an embodiment of a three-layer solid electrolyte separator 3 produced by aerosol deposition. Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3b is arranged on the cathode side of layer 3a and provides an anchoring function for the cathode, thus ensuring good contact between the solid electrolyte separator 3 and the cathode. Layer 3c is arranged on the anode side of layer 3a and is reduction-stable with respect to the anode. This three-layer structure enables optimized functionality of the solid electrolyte separator 3 by providing both good ion conductivity and a stable interface with respect to the anode and cathode. Fig. 3d schematically shows another embodiment of a three-layer solid electrolyte separator 3 produced by aerosol deposition.Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3d is arranged on the cathode side of layer 3a and is oxidation-stable with respect to the cathode. Additionally, a further layer 3b is arranged on the cathode side of the second layer 3d, which provides an anchoring function for the cathode.

[0108] Alternatively, layer 3b can fulfill both functions, i.e., be both oxidation-stable and serve as an anchor layer for the cathode (see embodiment in Fig. 3a).

[0109] Fig. 3e schematically shows another embodiment of a three-layer solid electrolyte separator 3 produced by aerosol deposition. Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3c is arranged on the anode side of layer 3a and is reduction-stable with respect to the anode. Additionally, a further layer 3e made of tin (Sn) (alternatively antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) is arranged on the anode side of layer 3c, which promotes nucleation. In battery technology, homogeneous nucleation of the anode is desired, and dendrite growth, which can impair the performance and safety of the battery cell, must be prevented. Layer 3e supports homogeneous nucleation and thus ensures a uniform and stable deposition of the active material.

[0110] Alternatively, layer 3e contains metallic, alloying or non-alloying particles that provide improved electronic connectivity between the anode and the current collector.

[0111] Fig. 3f schematically shows an embodiment of a four-layer solid electrolyte separator 3 produced by aerosol deposition. The layers 3c, 3a, 3d, and 3b are arranged in this order from the anode side to the cathode side. Layer 3a is ion-conducting and fulfills the separation function between the anode (e.g., 2, Fig. 1, 2a-f) and the cathode (e.g., 4, Fig. 1, 2a-f). Layer 3d is arranged on the cathode side of layer 3a and is oxidation-stable with respect to the cathode. Layer 3c is arranged on the anode side of layer 3a and is reduction-stable with respect to the anode. Layer 3b is arranged on the cathode side of layer 3d and comprises an anchor function for the cathode.

[0112] Fig. 3g schematically shows another embodiment of a four-layer solid electrolyte separator 3 produced by aerosol deposition. The layers 3e, 3c, 3a, and 3b are arranged in this order from the anode side to the cathode side. Layer 3e consists of tin (Sn) (alternatively antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) and promotes nucleation, as explained with respect to Fig. 3e. Layer 3c is reduction-stable with respect to the anode. Layer 3a is ion-conducting and fulfills the separation function, while layer 3b is arranged on the cathode side of layer 3a and provides an anchoring function for the cathode.

[0113] Fig. 3h schematically shows an embodiment of a five-layer solid electrolyte separator 3 produced by aerosol deposition. The layers 3e, 3c, 3a, 3d, and 3b are arranged in this order from the anode side to the cathode side. Layer 3e consists of tin (Sn) (alternatively antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) and promotes nucleation. Layer 3c is reduction-stable with respect to the anode. Layer 3a is ion-conducting and performs the separation function. Layer 3b is arranged on the cathode side adjacent to layer 3d and acts as an anchor for the cathode. Layer 3d is arranged on the cathode side adjacent to layer 3a and is oxidation-stable with respect to the cathode.

[0114] Fig. 3i schematically shows another embodiment of a four-layer solid electrolyte separator 3 produced by aerosol deposition. Layers 3f, 3e, 3c, and 3a are arranged in this order from the anode side to the cathode side. Layer 3f exhibits wetting behavior with lithium or sodium metal, characterized by contact angles of less than 90°, which gives it good wetting properties. Layer 3e consists of tin (Sn) (alternatively antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) and promotes nucleation. Layer 3c is reduction-stable with respect to the anode. Layer 3a is ion-conducting and performs the separation function.

[0115] Fig. 3j schematically shows another embodiment of a five-layer solid electrolyte separator 3 produced by aerosol deposition. Layers 3f, 3e, 3c, 3a, and 3b are arranged in this order from the anode side to the cathode side. Layer 3f exhibits wetting behavior with lithium or sodium metal, characterized by contact angles of less than 90°, which gives it good wetting properties. Layer 3e consists of tin (Sn) (alternatively antimony (Sb), silver (Ag)), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) and promotes nucleation. Layer 3c is reduction-stable with respect to the anode. Layer 3a is ion-conducting and fulfills the separation function. Layer 3b is arranged on the cathode side of layer 3a and provides an anchoring function for the cathode.

[0116] Fig. 3k schematically shows another embodiment of a six-layer solid electrolyte separator 3 produced by aerosol deposition. The layers 3f, 3e, 3c, 3a, 3d, and 3b are arranged in this order from the anode side to the cathode side. Layer 3f exhibits wetting behavior with lithium or sodium metal, characterized by contact angles of less than 90°, which gives it good wetting properties. Layer 3e consists of tin (Sn) (alternatively antimony (Sb), silver (Ag)), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn)) and promotes nucleation. Layer 3c is reduction-stable with respect to the anode. Layer 3a is ion-conducting and fulfills the separation function. Layer 3d is arranged on the cathode side of layer 3a and is designed to be oxidation-stable with respect to the cathode.Layer 3b is located on the cathode side of layer 3d and includes an anchor function for the cathode.

[0117] As explained in the embodiments shown in Figs. 3a to 3k, the different layers of the solid electrolyte separator 3 fulfill different functions.

[0118] Layer 3a is always present because it ensures the basic function of the separator by being ion-conducting and fulfilling the separation function between the anode and cathode.

[0119] Layer 3b is arranged on the cathode side and includes an anchoring function for the cathode.

[0120] Layer 3c is arranged on the anode side and is reduction-stable relative to the anode.

[0121] Layer 3d is located on the cathode side and is oxidation-stable relative to the cathode.

[0122] Layer 3e consists of tin (Sn), antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn) and promotes nucleation. Alternatively, it may contain metallic, alloying, or non-alloying particles that improve the electronic connection between the anode and the current collector. Layer 3e may also comprise tin (Sn), or antimony (Sb), silver (Ag), indium (In), aluminum (Al), silicon (Si), nickel (Ni), iron (Fe), phosphorus (P), or zinc (Zn). Layer 3f has a contact angle of less than 90°, which gives it good wetting properties.

[0123] Any combination of multiple layers is possible, with layer 3a always being present to ensure the basic separation and ion conduction function.

[0124] A single layer can possess multiple properties. For example, layer 3b can have both an anchoring function and the oxidation-stable properties of layer 3d. Similarly, the anode-side layer 3c can be reduction-stable and / or exhibit the improved nucleation properties and / or the good wetting properties of layers 3e and 3f. Any combination of multiple functionalities within a single layer is possible. The order of the layers can also be reversed; for instance, layer 3d can be directly adjacent to layer 3a. Likewise, on the anode side, layer 3e or 3f can be directly adjacent to layer 3a. Consequently, any sequence of layers 3f, 3e, and 3c is possible on the anode side. The same applies to layers 3b and 3d on the cathode side.

[0125] Fig. 31 schematically shows an embodiment of a solid electrolyte separator 3 comprising two adjacent layers 3g and 3h configured as gradients. The two layers 3g and 3h can represent any two adjacent layers 3a to 3f from Figs. 3a to 3k.

[0126] Each layer, 3g and 3h, is homogeneous and comprises the two materials 8a and 8b. The two layers, 3g and 3h, are arranged as gradients, with material 8a present in a higher concentration in layer 3g than in layer 3h. Furthermore, material 8b is present in a lower concentration in layer 3g than in layer 3h. Therefore, a gradient exists for both material 8a and material 8b. This gradient structure allows for optimized adjustment of the material properties of the solid electrolyte separator 3, thereby improving the electrochemical stability and functionality of the separator.

[0127] Fig. 4 schematically shows an aerosol deposition device 10 for producing a multilayer solid electrolyte separator 3 of a specific embodiment.

[0128] Aerosol deposition for the production of dense ceramic layers (e.g., 3a to 3h, Fig. 3a-l) of the solid electrolyte separator (e.g., 3, Fig. 1-31) takes place at room temperature. The aerosol deposition device 10 comprises a vacuum pump 11, a deposition chamber 12 in which a substrate 20 is arranged, and an aerosol generation device (e.g., 21, Fig. 5) comprising a nozzle device 13 and an aerosol chamber 14.

[0129] The aerosol chamber 14 contains the material 18a in the form of loose powder, from which the aerosol is formed. The material 18a is picked up by the gas stream of the carrier gas 16 and transported to the nozzle assembly 13.

[0130] In the present embodiment, the aerosol chamber 14 rests on a vibrating unit 15. The vibrating unit 15 causes the aerosol chamber 14 and the powder 18a contained therein to vibrate. To generate the aerosol from the powder 18a, the carrier gas 16 from the carrier gas chamber 16a is passed through the powder 18a in the vibrating aerosol chamber 14, thereby producing aerosolized particles. A valve 17, for example a mass flow controller, is arranged between the carrier gas chamber 16a and the aerosol chamber 14 to regulate the amount of carrier gas 16. This enables precise control of the gas flow and thus uniform aerosol generation.

[0131] However, aerosol generation can also be achieved in any other known way, for example by means of a brush generator.

[0132] The deposition chamber 12 is connected to the vacuum pump 11, which creates a vacuum. Driven by the pressure difference, the aerosolized particles from the aerosol chamber 14 are transported through a nozzle of the nozzle assembly 13 to the evacuated deposition chamber 12. The aerosol is accelerated and forms an aerosol jet 18 at the nozzle outlet. The particles in the aerosol jet 18 collide with the substrate 20, causing them to break into fragments that recombine and form a ceramic film (e.g., layers 3a to 3h, Fig. 1-31).

[0133] The substrate 20 is initially the separator foil (e.g., 6a, Fig. 1, 2a-f) on which the ceramic film is deposited, or a previously deposited layer (e.g., 3a to 3g, Fig. 3a-3I) of the solid electrolyte separator that has already been deposited (see Fig. 2a, b, e). The substrate 20 is designed as a movable belt and is arranged on a substrate guide 19. The substrate guide 19 is designed for a continuous process, so that the substrate 20 is moved into the chamber from the left and out of the chamber from the right. The device 10 can include a nozzle assembly 13 with several nozzles and also several aerosol chambers 14, as shown in Fig. 5.

[0134] Fig. 5 schematically shows an embodiment of an aerosol generation device 21 of the aerosol deposition device 10 of Fig. 4 for producing a multilayer solid electrolyte separator of the corresponding design.

[0135] The aerosol generation device 21 comprises a nozzle unit 13 with five nozzles 13a, 13b, 13c, 13d, and 13e arranged in a row. It further comprises three aerosol chambers 14a, 14b, and 14c, each designated for a separate layer of the solid electrolyte separator (e.g., 3, Figs. 1 to 3I). The first three nozzles in the row, 13a, 13b, and 13c, are designated for the first layer. This layer (e.g., 3a, 3g, 3h, Figs. 2a-3l) is thicker than the second (e.g., 3b-h, Figs. 2a-3l) and third layers (e.g., 3b-h, Figs. 2a-3l); therefore, three nozzles are used to ensure uniform and efficient coating. The fourth nozzle, 13d, is intended for the second layer, and the fifth nozzle, 13e, is intended for the third layer. The first three nozzles, 13a, 13b, and 13c, are connected to the first aerosol chamber, 14a. The fourth nozzle, 13d, and the fifth nozzle, 13e, each have their own aerosol chamber.Nozzle 13d is connected to aerosol chamber 14b, while nozzle 13e is connected to aerosol chamber 14c.

[0136] This configuration enables precise control of the deposition of each layer of the solid electrolyte separator by applying different materials from various aerosol chambers 14a, 14b, and 14c to the substrate (e.g., 20, Fig. 4) through the corresponding nozzles 13a to 13e. The substrate guide 19 of Fig. 4 moves the movable substrate to change its position relative to the nozzles, thus ensuring uniform coating in the layer sequence. Consequently, the substrate is initially positioned over the first three nozzles 13a, 13b, and 13c. After the first layer is deposited from these three nozzles, the substrate moves over the next nozzle 13d to deposit the next layer. Subsequently, the substrate moves over the next nozzle 13e to deposit the next layer.

[0137] Materials are therefore applied through different nozzles in the nozzle array by means of aerosol deposition. Several nozzles are used for the material of the first layer, the number of nozzles being determined by the belt speed, the coating rate of the material, and the target layer thickness. Alternatively, the other layers can also be applied using multiple nozzles. Furthermore, more nozzles can be provided for more than three layers (e.g., Fig. 3h-3k).

[0138] Furthermore, the nozzles for each material are located in a separate aerosol chamber in order to be able to cyclically reuse non-separated material without contamination.

[0139] Fig. 6a schematically shows a diagram of a method 40 for producing a multilayer solid electrolyte separator by aerosol deposition according to an exemplary embodiment. The method comprises steps 41 and 42. In step 41, an anode-side current collector foil (e.g., 6a, Fig. 1, 2a-f) is provided. In step 42, the solid electrolyte separator (e.g., 3, Fig. 1-3I) is applied layer by layer to the current collector foil by aerosol deposition. The method 40 corresponds to the process steps as shown in Fig. 2a-c. Alternatively, the method comprises the steps as shown in Fig. 2e.

[0140] Fig. 6b schematically shows a diagram of a method 40a for manufacturing a battery cell (e.g., 1, Figs. 1-2e or 30, Figs. 6a, 6b) with a multilayer solid electrolyte separator, according to an embodiment. The method comprises steps 41 and 42 from Fig. 7a. Furthermore, the method comprises steps 43 and 44. In step 43, a cathode (e.g., 4, Figs. 1, 2d, 2f) is applied to the multilayer solid electrolyte separator. In step 44, a cathode-side conductive foil (e.g., 6b, Figs. 1, 2d, 2f) is applied to the cathode.

[0141] Fig. 6c schematically shows a diagram of a method 40b for manufacturing a battery cell (e.g., 1, Figs. 1-2e or 30, Figs. 6a, 6b) with a multilayer solid electrolyte separator, according to an embodiment. The method comprises steps 41 and 42 from Fig. 7a. Furthermore, the method comprises steps 43a and 44a. In step 43a, a cathode (e.g., 4, Figs. 1, 2d, 2f) is applied to a cathode-side conductive foil (e.g., 6b, Figs. 1, 2d, 2f).

[0142] In step 44a, the anode-side leakage foil with solid electrolyte separator from step 42 and the cathode with cathode-side leakage foil from step 43a are assembled to form a battery cell (e.g., 1 , Fig. 1 , 2d or 2e).

[0143] Fig. 7a shows a schematic side view and Fig. 7b shows a schematic perspective view of a battery cell 30 comprising a solid electrolyte separator of this embodiment (e.g., 3, Fig. 1-41). Battery cell 30 (e.g., 1, Fig. 1, 2d, 2f) is a prismatic battery cell and comprises a housing 31 in which an electrode stack is arranged. The electrode stack comprises anodes (e.g., 2, Fig. 1-2f), cathodes (e.g., 4, Fig. 1, 2d, 2f), and multilayer solid electrolyte separators (e.g., 3, Fig. 1-31). For example, the prismatic battery cell comprises over 100 layers of each electrode stack component. The housing 31 is closed on both sides (x-direction) by covers 32. The housing 31 also contains a pressure relief valve 34 through which gas can escape from the battery cell 30. Each of the two covers 32 of the battery cell 30 has a connection 33.

[0144] Reference symbol list Battery cell Anode Solid electrolyte separator a Layer b Layer c Layer d Layer e Layer f Layer g Layer h Layer Cathode a Negative terminal (external circuit) b Positive terminal (external circuit) a Discharge foil (anode side) b Discharge foil (cathode side) a First material b Second material 0 Aerosol deposition device 1 Vacuum pump 2 Deposition chamber 3 Nozzle assembly 3a Nozzle 3b Nozzle 3c Nozzle 3d Nozzle 3e Nozzle 4 Aerosol chamber 4a Aerosol chamber 4a Aerosol chamber 4b Aerosol chamber 4c Aerosol chamber Vibrating unit

[0145] T carrier gas a carrier gas chamber

[0146] valve

[0147] Aerosol jet and powder

[0148] Substrate guidance

[0149] substrate

[0150] Aerosol generation device

[0151] Battery cell

[0152] Housing

[0153] Lid

[0154] Connection

[0155] Overpressure valve

[0156] Proceedings

[0157] Providing the conductive foil

[0158] Aerosol deposition of the solid electrolyte separator on the discharge foil

[0159] Applying the cathode to the solid electrolyte separator

[0160] Attaching the cathode-side discharge foil a Manufacturing the cathode and cathode-side discharge foil a Assembling the anode-side discharge foil with separator and cathode

Claims

Patent claims 1. A multilayer solid electrolyte separator (3) for a battery cell (1, 30), comprising at least two layers (3a-h), wherein the at least two layers (3a-h) are deposited layer by layer by means of aerosol deposition, and wherein one (3a) of the at least two layers (3a-h) comprises an ion conduction function and a separation function.

2. The multilayer solid electrolyte separator (3) according to any of the preceding claims, wherein at least two layers (3a-h) have different material properties.

3. The multilayer solid electrolyte separator (3) according to one of the preceding claims, wherein at least one (3b) of the at least two layers (3a-h) serves as the armature layer for the cathode.

4. The multilayer solid electrolyte separator (3) according to one of the preceding claims, wherein at least one (3c) of the at least two layers (3a-h) is reduction-stable against an active material of the anode (1 , 30).

5. The multilayer solid electrolyte separator (3) according to one of the preceding claims, wherein at least one of the at least two layers is oxidation-stable (3e) against an active material of the cathode (1).

6. The multilayer solid electrolyte separator (3) according to one of the preceding claims, wherein at least one (3e) of the at least two layers has a contact angle of less than 100° relative to a metal anode.

7. The multilayer solid electrolyte separator (3) according to any of the preceding claims, wherein at least one (3f) of the at least two layers (3a-h) comprises tin, antimony, silver, indium, aluminium, silicon, nickel, iron, phosphorus or zinc.

8. The multilayer solid electrolyte separator (3) according to claim 6, wherein the layer (3e) comprising tin, antimony, silver or zinc further comprises metallic, alloying or non-alloying particles.

9. The multilayer solid electrolyte separator (3) according to any of the preceding claims, wherein at least two adjacent layers (3g, 3h) are configured as gradients.

10. Battery cell comprising the multilayer solid electrolyte separator (3) according to one of the preceding claims, an anode-side leakage foil (6a), a cathode (4) and a cathode-side leakage foil (6b), wherein the multilayer solid electrolyte separator (3) is deposited on the anode-side leakage foil (6a) by means of aerosol deposition.

11. Battery cell according to claim 9, in which at least one (3b) of the at least two layers (3a-h) of the multilayer solid electrolyte separator (3) serves as the armature layer for the cathode and the cathode is stacked directly on the multilayer solid electrolyte separator.

12. Method for producing the multilayer solid electrolyte separator (3) according to any one of claims 1 to 8 by means of aerosol deposition.

13. Method for manufacturing the battery cell according to claim 9 or 10, comprising the steps: Provision of the anode-side discharge foil (6a), and layer-by-layer deposition of the multilayer solid electrolysis separator (3) onto the anode-side discharge foil (6a) by means of aerosol deposition.

14. Aerosol deposition device for producing the multilayer solid electrolyte separator (3) according to any one of claims 1 to 8, comprising several nozzles (13, 13a-e) for ejecting an aerosol jet (18), and several separate aerosol chambers (14, 14a-c) for generating the aerosol from a powder (18a).

15. Aerosol deposition device according to claim 11, wherein at least two of the multiple nozzles (13a-c) are operated by an aerosol chamber (14a) of the multiple aerosol chambers (14, 14a-c).

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