Method for manufacturing an electrode for a solid-state battery, electrode, solid-state battery

Abstract

A method for producing an electrode for a solid-state battery, wherein an electrode slurry (12) comprising at least one electrode active material is provided, and wherein an electrode active material layer (6,9) is formed from the electrode slurry (12) to produce the electrode (3,4), characterized in that an electrode slurry (12) is used which, in addition to the electrode active material, comprises at least one organic polymer electrolyte and / or polymerizable monomers for at least one organic polymer electrolyte as well as an electrolyte solvent (13), and that the electrode active material layer (6,9) is dried for a drying time of at most 1 min, such that the electrolyte solvent (13) is only partially removed from the electrode active material layer (6,9) and electrolyte solvent (13) is still present in the electrode active material layer (6,9) after drying.

Description

[0001] The invention relates to a method for producing an electrode for a solid-state battery, wherein an electrode slurry comprising at least one electrode active material is provided, and wherein an electrode active material layer is formed from the electrode slurry to produce the electrode.

[0002] Furthermore, the invention relates to an electrode.

[0003] Furthermore, the invention relates to a solid-state battery.

[0004] Electrical energy storage systems are considered a key technology, particularly in electromobility. Current developments aim to optimize these systems with regard to aspects such as manufacturing costs, weight, energy density, lifespan, and charging speed.

[0005] An electrical energy storage device has at least one positive electrode, or cathode, and at least one negative electrode, or anode, as electrodes. These electrodes typically have an electrode active material layer containing at least one electrode active material. Solid-state batteries, also known as solid-state accumulators or solid-state accumulators, are known from the prior art. They represent a specific type of electrical energy storage device in which both the electrodes and the electrolyte are made of solid material. Various classes of materials are used for the electrolyte in solid-state batteries: sulfide electrolytes, oxide electrolytes, or organic polymer electrolytes.The production of an electrode for a solid-state battery with an organic polymer electrolyte typically proceeds as follows: first, an electrode slurry containing at least one electrode active material is prepared. To produce the electrode, an electrode active material layer is then formed from the electrode slurry. In known processes, the electrode active material layer is usually subsequently dried and then impregnated with a liquid containing the organic polymer electrolyte, often at elevated temperatures. Due to the impregnation process, electrode production is time-consuming. Furthermore, the drying of the electrode active material layer limits the use of temperature-sensitive additives.Furthermore, German patent application JP 2021 057 205 A discloses a method in which the electrode active material layer is made so thin that impregnation with the organic polymer electrolyte is unnecessary. While impregnation can therefore be omitted, only electrodes with a thin electrode active material layer can be realized. German patent application CN 109216777 A discloses an electrical energy storage device with a semi-solid electrolyte.

[0006] German patent application DE 10 2016 217 702 A1 discloses a composite material for an electrode of a galvanic cell, comprising an electrochemical active material, a solid electrolyte, and a matrix, in particular an organic one, with polymer material, which are mixed in such a way that a multitude of particles of the electrochemical active material are electrically conductive and at least the solid electrolyte and the multitude of particles of the electrochemical active material are ionically conductively connected to one another. Further methods for producing composite electrodes are known from German patent applications DE 10 2018 218 486 A1 and DE 10 2018 218 414 A1.

[0007] The invention is based on the objective of improving a method for producing an electrode for a solid-state battery with an organic polymer electrolyte in such a way that the time required for producing the electrode is reduced.

[0008] The problem underlying the invention is solved by a method with the features of claim 1. This method has the advantage that impregnation of the electrode active material layer with the organic polymer electrolyte is not necessary. This process step can therefore be omitted, resulting in time savings during electrode production. According to the invention, an electrode slurry is used which, in addition to the electrode active material, contains at least one organic polymer electrolyte and / or polymerizable monomers for at least one organic polymer electrolyte. The invention is based on the understanding that it is fundamentally possible to introduce the organic polymer electrolyte into the electrode active material layer as a component of the electrode slurry.In this process, the organic polymer electrolyte itself and / or polymerizable monomers for the polymer electrolyte are added to the electrode slurry. The electrode active material layer is then formed from this electrode slurry, so that the electrode active material layer already contains the organic polymer electrolyte or the monomers for the organic polymer electrolyte. This procedure allows even a thick electrode active material layer to be produced quickly. An organic polymer electrolyte is a polymer or macromolecule designed to complex a conductive ion of a conducting salt, thereby enabling the conduction of the ion. Preferably, a main chain and / or a side chain of the polymer has oxygen, nitrogen, phosphorus, and / or sulfur groups to complex the conductive ion.Depending on the cell chemistry, the ion to be conducted differs. For example, in lithium-ion cells, the ion to be conducted is the lithium ion, and in sodium-ion cells, it is the sodium ion. Preferably, an electrode slurry is used which, in addition to the electrode active material and the organic polymer electrolyte and / or the polymerizable monomers, also contains at least one conducting salt. Thus, the conducting salt is also introduced into the electrode active material layer by the electrode slurry. Preferably, a solid-state battery designed as a lithium-ion cell is produced by the process. If an anode for a lithium-ion cell is to be produced by the process, graphite, silicon, a mixture of graphite and silicon-containing materials, or lithium titanate is preferably used as the electrode active material.If the process is intended to produce a cathode for a lithium-ion cell, a lithium transition metal oxide such as NMC, lithium-rich NMC or LMNO, lithium iron phosphate or lithium manganese phosphate is preferably used as the electrode active material. The conducting salt is preferably a conducting salt from the group comprising LiAsF6, LiClO4, LiSbF6, LiPtCl6, LiAlCl4, LiGaCl4, LiSCN, LiAlO4, LiCF3CF2SO3, Li(CF3)SO3 (LiTf), LiC(SO2CF3)3, phosphate-based lithium salts, preferably LiPF6, LiPF3(CF3)3 (LiFAP) or LiPF4(C2O4) (LiTFOB), borate-based lithium salts, preferably LiBF4, LiB(C2O4)2 (LiBOB), LiBF2(C2O4) (LiDFOB), LiB(C2O4)(C3O4) (LiMOB), Li(C2F5BF3) (LiFAB) or Li2B12F12 (LiDFB), lithium salts of sulfonylimides, preferably LiN(SO2CF3)2 (LiTFSI), LiN(SO2F2) (LiFSI) or LiN(SO2C2F5)2 (LiBETI), or a mixture thereof.Preferably, the concentration of the lithium salt in the organic polymer electrolyte is greater than or equal to 0.5 M to less than or equal to 2.5 M, more preferably greater than or equal to 0.65 M to less than or equal to 2 M, more preferably greater than or equal to 0.8 M to less than or equal to 1.5 M, and particularly preferably greater than or equal to 0.9 M to less than or equal to 1.5 M. Preferably, the electrode slurry comprises, in addition to the organic polymer electrolyte, a ceramic or glass-ceramic solid electrolyte.

[0009] Preferably, an organic polymer electrolyte is used from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers, and mixtures thereof. By using one or more of these organic polymer electrolytes, an electrode active material layer with sufficiently high ionic conductivity can be obtained. When using polymerizable monomers, polymerizable monomers for an organic polymer electrolyte are preferably selected from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers, and mixtures thereof.

[0010] According to a preferred embodiment, the volume fraction of organic polymer electrolyte or polymerizable monomers in the electrode slurry is 10 vol% to 40 vol%, based on the total volume of the electrode slurry. Such a volume fraction allows for advantageous conductivity of the ions to be conducted in the finished electrode. Furthermore, at this volume fraction, the organic polymer electrolyte also provides an advantageous bonding effect, thus reducing the need for any polymeric binder that would otherwise be present. Preferably, the electrode slurry is polymer-free apart from the organic polymer electrolyte.

[0011] According to the invention, an electrode slurry is used which comprises at least one electrolyte solvent. An electrolyte solvent is a solvent suitable for use in a liquid electrolyte of an electrical energy storage device. Because an electrolyte solvent is used, the solvent does not necessarily have to be completely removed from the electrode active material layer before the electrode is installed in the solid-state battery. Preferably, an organic solvent from the group consisting of ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, ethyl propionate, propyl propionate, acetonitrile, glutaronitrile, adiponitrile, pimelonitrile, gamma-butyrolactone, gamma-valerolactone, dimethoxyethane, 1,3-dioxalane, methyl acetate, and / or a mixture thereof is used as the electrolyte solvent.Preferably, at least one organic solvent from the group consisting of cyclic carbonates such as ethylene carbonate and propylene carbonate and / or linear carbonates such as diethyl carbonate, dimethyl carbonate, and ethyl methyl carbonate is used as the electrolyte solvent. Particularly preferred is at least one organic solvent from the group consisting of ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, and / or mixtures thereof. Other preferred electrolyte solvents are ionic liquids, as these combine high thermal and electrochemical stability with high ionic conductivity.The ionic liquids preferably used as electrolyte solvents comprise a cation selected from the group comprising 1-ethyl-3-methylimidazolium (EMI+), 1,2-dimethyl-3-propylimidazolium (DMPI+), 1,2-diethyl-3,5-dimethylimidazolium (DEDMI+), trimethyl-n-hexylammonium (TMHA+), N-alkyl-N-methylpyrrolidinium (PYR1R+), N-alkyl-N-methylpiperidinium (PIP1R+) and / or N-alkyl-N-methylmorpholinium (MORP1R+) and an anion selected from the group comprising bis(trifluoromethanesulfonyl)imide (TFSI-), bis(pentafluoroethanesulfonyl)imide (BETI-), bis(fluorosulfonyl)imide (FSI-), 2,2,2-trifluoro-N-(trifluoromethanesulfonyl)acetamide (TSAC-), tetrafluoroborate (BF4-), Pentafluoroethanetrifluoroborates (C2F5BF3-), hexafluorophosphate (PF6-) and / or tri(pentafluoroethane)trifluorophosphate ((C2F5)3PF3-). Preferred N-alkyl-N-methylpyrrolidinium (PYR1R+) cations are selected from the group comprising N-butyl-N-methylpyrrolidinium (PYR14+) and N-methyl-N-propylpyrrolidinium (PYR13+).Particularly preferred is an ionic liquid from the group comprising N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) and N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR13TFSI).

[0012] Preferably, the mass fraction of electrolyte solvent in the electrode slurry, based on the total mass of the electrode slurry, is between 5% and 50%. This results in an electrode slurry with good processability. Particularly preferably, the mass fraction is between 10% and 30%. With such a low mass fraction, only a small amount of electrolyte solvent needs to be removed from the electrode active material layer after its formation.

[0013] According to a preferred embodiment, an electrode slurry with thixotropic behavior is used. The electrode slurry is thus composed in such a way that it is thixotropic. In particular, the thixotropic behavior of the electrode slurry is achieved by a suitable mass fraction of the organic polymer electrolyte contained in the electrode slurry. A composition with thixotropic behavior is characterized by the fact that its viscosity decreases under the influence of a shear force. Furthermore, in a composition with thixotropic behavior, the viscosity increases again after a period of inactivity. Consequently, an electrode slurry with thixotropic behavior has the advantage that it is easy to process because its viscosity decreases when the electrode slurry is stirred.Once the electrode active material layer has formed, the electrode slurry with its thixotropic behavior has the additional advantage that its viscosity increases again, thus preventing the electrode slurry from flowing away. In particular, the electrode slurry is stable at rest. Finally, the use of an electrode slurry with thixotropic behavior has the advantage that only minimal drying of the formed electrode active material layer is necessary to obtain a sufficiently viscous electrode active material layer. Preferably, an electrode slurry is used which, under the influence of a shear force, exhibits a viscosity of 100 mPas to 50,000 mPas, particularly preferably a shear force of 500 mPas to 25,000 mPas, and at rest a viscosity of more than 10⁶ mPas.

[0014] According to a preferred embodiment, the electrode slurry comprises an organic polymer electrolyte, and the organic polymer electrolyte is post-crosslinked after the formation of the electrode active material layer. Preferably, the polymer electrolyte is post-crosslinked by a crosslinking initiator contained in the electrode slurry. An azo compound, particularly azo-bis(isobutyronitrile) (AIBN), or a peroxide, particularly dibenzoyl peroxide (DBPO) or a peroxide sulfate, is particularly preferred as the crosslinking initiator. Post-crosslinking the polymer electrolyte allows the viscosity of the electrode slurry to be increased after the formation of the electrode active material layer, independent of drying of the electrode active material layer. Therefore, drying of the electrode active material layer is either unnecessary or only required to a limited extent.

[0015] According to the invention, the electrode active material layer is dried for a drying time of at most 1 minute. The electrode active material layer is thus exposed to an elevated drying temperature, in particular a drying temperature of 120 °C, for a drying time of at most 1 minute. This comparatively short drying time makes it possible to add thermally unstable additives, such as electrolyte additives, to the electrode slurry. Due to the short drying time, the thermally unstable additives are decomposed only minimally, if at all. Preferably, the drying time is at most 30 seconds, and particularly preferably at most 20 seconds. Preferably, an electrode slurry is used which contains at least one additive from the group consisting of redox inhibitors, flame retardants, SEI formers, and CEI formers.

[0016] According to a preferred embodiment, the electrode slurry comprises polymerizable monomers for at least one organic polymer electrolyte, and the monomers are polymerized to form the organic polymer electrolyte after the formation of the electrode active material layer. In this embodiment of the process, the organic polymer electrolyte is thus obtained only after the formation of the electrode active material layer by polymerizing the monomers. This approach reduces the mass fraction of solvent or electrolyte solvent in the electrode slurry. Preferably, the monomers used in the electrode slurry are liquid. Particularly preferably, the electrode slurry contains no liquid components other than the liquid monomers. Preferably, the polymerization of the monomers is initiated by a temperature pulse or by UV radiation.

[0017] According to a preferred embodiment, a current collector is provided, and the electrode slurry is applied to the current collector as an electrode active material layer. This results in a mechanically robust electrode. If the process produces a positive electrode or cathode, an aluminum foil is preferably used as the current collector. However, if the process produces a negative electrode or anode, a copper foil is preferably used as the current collector when producing an anode for a lithium-ion cell, and an aluminum foil is preferably used when producing an anode for a sodium-ion cell.

[0018] Preferably, the electrode slurry is applied to both sides of the current collector. This results in the formation of an electrode active material layer on opposite end faces of the current collector. This produces an electrode with a high capacitance. Such a procedure is technically feasible because the electrode slurry, due to its organic polymer electrolyte, possesses suitable rheological properties.

[0019] According to a preferred embodiment, an adhesive layer is formed on the electrode active material layer. This adhesive layer improves the adhesion of the electrode to a separator of the solid-state battery. Preferably, a solution containing at least one polymeric binder is applied to the electrode active material layer to form the adhesive layer.

[0020] The electrode according to the invention is characterized by the features of claim 12 in that the electrode is manufactured using the method according to the invention. The advantages already mentioned also result from this. Further preferred features and combinations of features result from the foregoing and from the claims.

[0021] Preferably, the electrode active material layer of the electrode is polymer-free apart from the organic polymer electrolyte.

[0022] The solid-state battery according to the invention is characterized by the features of claim 14, namely at least one electrode designed according to the invention. The advantages already mentioned also result from this. Further preferred features and combinations of features result from the foregoing and from the claims. Preferably, the solid-state battery is designed as a lithium-ion cell.

[0023] The invention will be explained in more detail below with reference to the drawings. To this end, show Fig. 1 a solid-state battery in a schematic representation and Fig. 2 a method for manufacturing an electrode of the solid-state battery and Fig. 3 another method for manufacturing the electrode.

[0024] Fig. Figure 1 shows a simplified representation of a solid-state battery 1. In this case, the solid-state battery 1 is designed as a lithium-ion cell 1. The solid-state battery 1 has a housing 2. A positive electrode 3, or cathode 3, and a negative electrode 4, or anode 4, are arranged in the housing 2.

[0025] The cathode 3 has a current collector 5, which in this case is an aluminum foil 5. A positive electrode active material layer 6 is formed on the current collector 5. The positive electrode active material layer 6 comprises a positive electrode active material such as a lithium transition metal oxide. The positive electrode active material layer 6 also comprises a conducting salt. Preferably, the conducting salt is a conducting salt from the group comprising LiAsF6, LiClO4, LiSbF6, LiPtCl6, LiAlCl4, LiGaCl4, LiSCN, LiAlO4, LiCF3CF2SO3, Li(CF3)SO3 (LiTf), LiC(SO2CF3)3, phosphate-based lithium salts, preferably LiPF6, LiPF3(CF3)3 (LiFAP) and LiPF4(C2O4) (LiTFOB), borate-based lithium salts, preferably LiBF4, LiB(C2O4)2 (LiBOB), LiBF2(C2O4) (LiDFOB), LiB(C2O4)(C3O4) (LiMOB), Li(C2F5BF3) (LiFAB) and Li2B12F12 (LiDFB) and lithium salts of sulfonylimides, preferably LiN(SO2CF3)2 (LiTFSI), LiN(SO2F2) (LiFSI) or LiN(SO2C2F5)2 (LiBETI).The positive electrode active material layer 6 also comprises an organic polymer electrolyte. The organic polymer electrolyte is configured to complex lithium ions, thereby ensuring the transport of lithium ions within the positive electrode active material layer 6. Preferably, the organic polymer electrolyte is a polymer from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers, and mixtures thereof.

[0026] Preferably, the positive electrode active material layer 6 comprises, in addition to the positive electrode active material, the conducting salt, and the organic polymer electrolyte, at least one further substance. In the present case, the positive electrode active material layer 6 also comprises at least one conductive additive such as conductive carbon black, graphene, or carbon nanotubes. In the present case, the positive electrode active material layer 6 also comprises at least one electrolyte additive such as a redox inhibitor, a flame retardant, an SEI former, or a CEI former. Preferably, the positive electrode active material layer 6 is polymer-free apart from the organic polymer electrolyte.

[0027] Preferably, the positive electrode active material layer 6 comprises, in addition to the positive electrode active material, the conducting salt, and the organic polymer electrolyte, a ceramic or glass-ceramic solid electrolyte. Preferably, the volume fraction of the ceramic or glass-ceramic solid electrolyte, based on the total volume of the positive electrode active material layer 6, is 0.1 vol% to 10 vol%, particularly preferably 0.5 vol% to 5 vol%. Preferably, the ceramic or glass-ceramic solid electrolyte is a sulfide solid electrolyte or an oxide solid electrolyte.The ceramic or glass-ceramic solid electrolyte particularly preferably comprises inorganic electrolyte particles with a NaSICon (sodium super-ion conductor) structure, in particular LATP (lithium aluminum titanium phosphate), LAGP (lithium aluminum germanium phosphate) or LAGTP (lithium aluminum germanium titanium phosphate), inorganic electrolyte particles with a garnet structure, in particular LLZO (lithium lanthanum zirconate), inorganic electrolyte particles with a LiSICon (lithium superion conductor) structure or inorganic electrolyte particles with an argyrodite structure.

[0028] An adhesive layer 7 is formed on the positive electrode active material layer 6. The adhesive layer 7 contains a polymeric binder.

[0029] The anode 4 has a current collector 8, which in this case is a copper foil 8. A negative electrode active material layer 9 is formed on the current collector 8. The negative electrode active material layer 9 comprises a negative electrode active material such as graphite. The negative electrode active material layer 9 also comprises a conducting salt. Preferably, the conducting salt is a conducting salt from the group comprising LiAsF6, LiClO4, LiSbF6, LiPtCl6, LiAlCl4, LiGaCl4, LiSCN, LiAlO4, LiCF3CF2SO3, Li(CF3)SO3 (LiTf), LiC(SO2CF3)3, phosphate-based lithium salts, preferably LiPF6, LiPF3(CF3)3 (LiFAP) and LiPF4(C2O4) (LiTFOB), borate-based lithium salts, preferably LiBF4, LiB(C2O4)2 (LiBOB), LiBF2(C2O4) (LiDFOB), LiB(C2O4)(C3O4) (LiMOB), Li(C2F5BF3) (LiFAB) and Li2B12F12 (LiDFB) and lithium salts of sulfonylimides, preferably LiN(SO2CF3)2 (LiTFSI), LiN(SO2F2) (LiFSI) or LiN(SO2C2F5)2 (LiBETI).The negative electrode active material layer 9 also comprises an organic polymer electrolyte. The organic polymer electrolyte is configured to complex lithium ions, thereby ensuring the transport of lithium ions within the negative electrode active material layer 9. Preferably, the organic polymer electrolyte is a polymer from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers, and mixtures thereof. Preferably, the positive electrode active material layer 6 and the negative electrode active material layer 9 comprise the same conducting salt and the same organic polymer electrolyte.

[0030] Preferably, the negative electrode active material layer 9 comprises at least one further substance in addition to the negative electrode active material, the conducting salt, and the organic polymer electrolyte. In the present case, the negative electrode active material layer 9 also comprises at least one conductive additive such as conductive carbon black, graphene, or carbon nanotubes. In the present case, the electrode active material layer 9 also comprises at least one electrolyte additive such as a redox inhibitor, a flame retardant, an SEI former, or a CEI former. Preferably, the negative electrode active material layer 9 is polymer-free except for the organic polymer electrolyte. Preferably, the negative electrode active material layer 9 also comprises a ceramic or glass-ceramic solid electrolyte, as described above with reference to the positive electrode active material layer 6.

[0031] An adhesive layer 10 is formed on the negative electrode active material layer 9. The adhesive layer 10 contains a polymeric binder.

[0032] The solid-state battery 1 also has a separator 11 arranged between the cathode 3 and the anode 4. Preferably, the separator 11 is a polymer separator 11 or a ceramic solid electrolyte 11. The adhesive layers 7 and 10 are in contact with the separator 11.

[0033] The following refers to Fig. 2 an advantageous method for producing the cathode 3 is explained in more detail. Fig. Figure 2 illustrates the procedure using a flowchart.

[0034] In a first step S1, an electrode slurry 12 is prepared. The electrode slurry 12 comprises the aforementioned materials for the positive electrode active material layer 6, namely at least the positive electrode active material, the conducting salt, and the organic polymer electrolyte. Preferably, the electrode slurry 12 exhibits thixotropic behavior. In this respect, the viscosity of the electrode slurry 12 decreases under the influence of a shear force and increases again after a period of rest. The thixotropic behavior of the electrode slurry 12 is caused in particular by the organic polymer electrolyte. Preferably, the electrode slurry 12 also comprises at least one conducting additive, at least one electrolyte additive, and / or a ceramic or glass-ceramic solid electrolyte. The electrode slurry 12 also comprises a solvent 13. The solvent 13 is an electrolyte solvent 13.Preferably, an organic solvent 13 is used from the group comprising ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, ethyl propionate, propyl propionate, acetonitrile, glutaronitrile, adiponitrile, pimelonitrile, gamma-butyrolactone, gamma-valerolactone, dimethoxyethane, 1,3-dioxalane, methyl acetate, and / or a mixture thereof. Preferably, at least one organic solvent 13 is used from the group comprising cyclic carbonates such as ethylene carbonate and propylene carbonate and / or linear carbonates such as diethyl carbonate, dimethyl carbonate, and ethyl methyl carbonate. Particularly preferably, an organic solvent 13 is used from the group comprising ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, and / or mixtures thereof.Other preferred electrolyte solvents 13 are ionic liquids, as these combine high thermal and electrochemical stability with high ionic conductivity. The ionic liquids preferably used as electrolyte solvents 13 comprise a cation selected from the group comprising 1-ethyl-3-methylimidazolium (EMI+), 1,2-dimethyl-3-propylimidazolium (DMPI+), 1,2-diethyl-3,5-dimethylimidazolium (DEDMI+), trimethyl-n-hexylammonium (TMHA+), N-alkyl-N-methylpyrrolidinium (PYR1R+), N-alkyl-N-methylpiperidinium (PIP1R+) and / or N-alkyl-N-methylmorpholinium (MORP1R+) and an anion selected from the group comprising bis(trifluoromethanesulfonyl)imide (TFSI-), bis(pentafluoroethanesulfonyl)imide (BETI-), bis(fluorosulfonyl)imide (FSI-), 2,2,2-trifluoro-N-(trifluoromethanesulfonyl)acetamide (TSAC-), tetrafluoroborate (BF4-), Pentafluoroethanetrifluoroborate (C2F5BF3-), hexafluorophosphate (PF6-) and / or tri(pentafluoroethane)trifluorophosphate ((C2F5)3PF3-).Preferred N-alkyl-N-methylpyrrolidinium (PYR1R+) cations are selected from the group comprising N-butyl-N-methylpyrrolidinium (PYR14+) and / or N-methyl-N-propylpyrrolidinium (PYR13+). Particularly preferred is an ionic liquid from the group comprising N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) and / or N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR13TFSI). The materials for the positive electrode active material layer 6 can be either dissolved or suspended in the electrolyte solvent 13.

[0035] In a second step S2, the current collector 5 is provided.

[0036] In a third step S3, the electrode slurry 12 is applied to the current collector 5 to create the positive electrode active material layer 6. Various methods are possible for applying the electrode slurry 12 to the current collector 5. For example, the electrode slurry 12 can be applied to the current collector 5 using a slot nozzle.

[0037] In an optional fourth step S4, the positive electrode active material layer 6 obtained in step S3 is post-cured.

[0038] Preferably, in step S4, the positive electrode active material layer 6 is dried for a drying time of 20 s at a drying temperature of 120°C. This short drying time results in only a partial removal of the electrolyte solvent 13 from the positive electrode active material layer 6, so that some electrolyte solvent 13 remains in the electrode active material layer 6 even after drying. However, this partial removal of the electrolyte solvent 13 increases the viscosity of the positive electrode active material layer 6, ensuring that the positive electrode active material layer 6 exhibits sufficient mechanical strength. Furthermore, due to the short drying time, thermally unstable materials within the positive electrode active material layer 6 are only minimally degraded.

[0039] Alternatively or additionally to drying, the positive electrode active material layer 6 is preferably post-cured in step S4 by post-crosslinking the organic polymer electrolyte. For example, post-crosslinking of the organic polymer electrolyte is initiated by a temperature pulse or by UV radiation. Post-crosslinking of the organic polymer electrolyte can also achieve a sufficient increase in the viscosity of the positive electrode active material layer 6.

[0040] In particular, the optional step S4 is omitted. As mentioned previously, the electrode slurry 12 preferably exhibits thixotropic behavior. If this thixotropic behavior is sufficiently pronounced, the electrode slurry 12 becomes sufficiently hard at rest, so that active post-curing of the positive electrode active material layer 6 is not necessary.

[0041] In a fifth step S5, a solution containing the polymeric binder is applied to the positive electrode active material layer 6 to form the adhesive layer 7.

[0042] Fig. Figure 3 shows another method for producing the cathode 3. Also in Fig. The procedure is illustrated in section 3 using a flowchart.

[0043] Even in the Fig.In the process described in Figure 3, an electrode slurry 12 is provided in a first step V1. The electrode slurry 12 comprises the positive electrode active material and the conducting salt. Preferably, the electrode slurry 12 also comprises at least one conducting additive, at least one electrolyte additive, and / or a ceramic or glass-ceramic solid electrolyte. However, the electrode slurry 12 provided in step V1 differs from the electrode slurry 12 provided in step S1 in that the electrode slurry 12 provided in step V1 comprises polymerizable monomers for the organic polymer electrolyte instead of the organic polymer electrolyte itself. Preferably, the polymerizable monomers are liquid. In the present case, one of the previously mentioned electrolyte solvents 13 is also used in the electrode slurry 12 provided in step V1.Alternatively, the use of a solvent 13 or electrolyte solvent 13 is omitted.

[0044] In a second step V2, the current collector 5 is provided.

[0045] In a third step V3, the electrode slurry 12 is applied to the current collector 5 to create the positive electrode active material layer 6. Various methods are possible for applying the electrode slurry 12 to the current collector 5. For example, the electrode slurry 12 can be applied to the current collector 5 using a slot nozzle.

[0046] In a fourth step V4, the polymerizable monomers are polymerized to obtain the organic polymer electrolyte. Preferably, the polymerization of the monomers is initiated by a temperature pulse or by UV radiation. The polymerization of the monomers increases the viscosity of the positive electrode active material layer 6, ensuring that the positive electrode active material layer 6 is sufficiently rigid. Optionally, a drying step is performed after the polymerization of the monomers.

[0047] In a fifth step V5, the solution containing the polymeric binder is applied to the positive electrode active material layer 6 to form the adhesive layer 7.

[0048] The formation of an electrode with an organic polymer electrolyte has been explained above using the positive electrode 3 as an example. However, the negative electrode 4 can also be produced using this method, in which case the negative electrode active material is used instead of the positive electrode active material. Reference symbol list 1 solid state battery 2 cases 3 Cathode 4 Anode 5 current collectors 6 Positive electrode active material layer 7 adhesive layer 8 current collectors 9 Negative electrode active material layer 10 Adhesive layer 11 Separator 12 Electrode slurry 13 Electrolyte solvents

Claims

[1] Method for producing an electrode for a solid-state battery, wherein an electrode slurry (12) comprising at least one electrode active material is provided, and wherein an electrode active material layer (6,9) is formed from the electrode slurry (12) to produce the electrode (3,4), characterized by , that an electrode slurry (12) is used which, in addition to the electrode active material, has at least one organic polymer electrolyte and / or polymerizable monomers for at least one organic polymer electrolyte as well as an electrolyte solvent (13), and that the electrode active material layer (6,9) is dried for a drying time of at most 1 min, so that the electrolyte solvent (13) is only partially removed from the electrode active material layer (6,9) and electrolyte solvent (13) is still present in the electrode active material layer (6,9) after drying. [2] Method according to claim 1, characterized by , that an organic polymer electrolyte from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers and mixtures thereof is used, or that monomers for an organic polymer electrolyte from the group comprising polyethylene oxide, polyethylene glycol, polyphosphazenes, polysiloxanes, polysulfones, polyphosphonates, polysulfides, thioethers and mixtures thereof are used. [3] Method according to any one of the preceding claims, characterized by , that the volume fraction of organic polymer electrolyte or of polymerizable monomers in the electrode slurry (12) is 10 vol% to 40 vol% in relation to the total volume of the electrode slurry (12). [4] Method according to any one of the preceding claims, characterized by, that the mass fraction of electrolyte solvent (13) in the electrode slurry (12) is between 5% and 50% based on the total mass of the electrode slurry (12), particularly preferably between 10% and 30%. [5] Method according to any one of the preceding claims, characterized by , that an electrode slurry (12) with thixotropic behavior is used. [6] Method according to any one of the preceding claims, characterized by , that the electrode slurry (12) has an organic polymer electrolyte, and that the organic polymer electrolyte is crosslinked after formation of the electrode active material layer (6,9). [7] Method according to any one of the preceding claims, characterized by that the drying time is at most 30 s, particularly preferably at most 20 s. [8] Method according to any one of the preceding claims, characterized by, that the electrode slurry (12) contains polymerizable monomers for at least one organic polymer electrolyte, and that the monomers are polymerized to form the organic polymer electrolyte after formation of the electrode active material layer (6,9). [9] Method according to any one of the preceding claims, characterized by , that a current collector (5,8) is provided, and that the electrode slurry (12) is applied to the current collector (5,8) as an electrode active material layer (6,9). [10] Method according to claim 9, characterized by , that the electrode slurry (12) is applied to both sides of the current collector (5,8). [11] Method according to any one of the preceding claims, characterized by , that an adhesive layer (7,10) is formed on the electrode active material layer (6,9). [12] Electrode produced by a method according to any one of the preceding claims. [13] Electrode according to claim 12, characterized by , that the electrode active material layer (6,9) of the electrode (3,4) is polymer-free apart from the organic polymer electrolyte. [14] Solid-state battery comprising at least one electrode (3,4) according to one of claims 12 and 13.

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