Battery electrode sheet and preparation method therefor, and solid-state battery and preparation method therefor

Abstract

A battery electrode sheet and a preparation method therefor, and a solid-state battery and a preparation method therefor. By using a rotary atomization spraying method, related process parameters are adjusted to realize the high-speed rotation and uniform atomization of a slurry containing a solid-state electrolyte, thereby realizing the uniform preparation of a solid-state electrolyte layer and enhancing interface contact between the solid-state electrolyte and a battery electrode sheet. In addition, by means of improving the efficiency of preparing an electrode sheet containing a solid-state electrolyte and reducing the device maintenance cost, the batch production of high-quality battery electrode sheets is realized.

Description

A battery pole piece and its preparation method and a solid-state battery and its preparation method

[0001] This application is based on the Chinese patent application with application number 202311007393.4 and application date August 10, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese application is hereby introduced into this application as a reference. Technical Field

[0002] The present invention belongs to the field of solid-state batteries and relates to a battery pole piece and a preparation method thereof, and a solid-state battery and a preparation method thereof. Background Art

[0003] Currently, commercial lithium-ion batteries use liquid organic electrolytes. These flammable and explosive liquid organic electrolytes, particularly in high-energy-density energy storage devices, can seriously impact the safety of lithium-ion batteries. Solid-state batteries, due to their use of thermally stable solid electrolytes, can effectively address safety issues during battery operation.

[0004] Solid-state electrolytes have attracted widespread attention from researchers due to their high thermal stability, high ionic conductivity, and stable electrochemical window. However, the application of both inorganic and polymer solid electrolytes in battery cells, as well as the scalable production process for solid electrolytes in battery electrodes, have hindered their large-scale commercialization. Therefore, developing methods that simultaneously meet the requirements for mass production of battery electrodes and address interface contact issues are crucial for the commercialization of solid-state batteries.

[0005] In the conventional production process of battery pole pieces, a coating method is usually used to prepare battery pole pieces containing solid electrolytes on the positive or negative electrode. However, the solid electrolyte layer obtained by directly coating the surface of the battery pole piece in the traditional coating method is unevenly distributed, the interface contact with the active material is not close, and the thickness of the coated solid electrolyte layer is difficult to control. The solid electrolyte coated on the surface is prone to agglomeration and sedimentation, which in turn causes process problems such as material sticking and clogging. It also affects the interface contact between the electrode active material and the solid electrolyte and the cycle stability of the solid-state battery, seriously affecting the performance and production efficiency of the solid-state battery.

[0006] Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In view of the above-mentioned process problems such as material jamming and blockage caused by agglomeration and sedimentation of solid electrolytes, and the problems that affect the interfacial contact between the electrode active material and the solid electrolyte and the cycle stability of the solid-state battery, it is necessary to improve the preparation process and significantly improve the production efficiency. It is also expected that battery electrodes and solid-state batteries containing solid electrolytes with controllable thickness, uniform dispersion of solid electrolytes and good interfacial contact can be prepared, thereby improving the performance of solid-state batteries.

[0009] Solutions for solving problems

[0010] The present invention provides a method for preparing a battery pole piece, a battery pole piece, and a solid-state battery, which solves the problems of uncontrollable thickness, uneven dispersion, and easy agglomeration of the solid electrolyte layer on the surface of the battery pole piece. At the same time, it is beneficial to increase the solid-solid contact interface, thereby achieving the goals of reducing interface impedance, improving the cycle stability of the solid-state battery, and improving production efficiency.

[0011] Specifically, the present invention provides a method for preparing a battery electrode, which comprises the following steps:

[0012] Step S2: spraying an organic polymer solid electrolyte slurry containing a composition of an organic polymer solid electrolyte, a lithium salt, and a binder onto the surface of the positive electrode sheet or the negative electrode sheet by a rotary atomization spraying method, thereby obtaining a positive electrode sheet or a negative electrode sheet having an organic polymer solid electrolyte layer.

[0013] The spraying pressure in the rotary atomization spraying is 0.6-3.5 MPa, preferably 1.0-2.0 MPa;

[0014] The preparation method may optionally include step Sx: hot pressing the finally prepared positive electrode sheet or negative electrode sheet.

[0015] According to the preparation method described above, it further comprises the following steps before step Sx:

[0016] Step S4: Spraying a slurry containing a second solid electrolyte onto the surface of the organic polymer solid electrolyte layer obtained in step S2 by rotary atomization spraying, thereby obtaining a positive electrode sheet or a negative electrode sheet having the organic polymer solid electrolyte layer and the second solid electrolyte layer.

[0017] According to the preparation method described above, in the step S2 and the step S4, the spraying conditions in the rotary atomization spraying are as follows: the rotation speed of the atomizing device is 2000-30000 rpm, and the liquid feed rate is 5-2000 kg / h;

[0018] Preferably, the spraying conditions in step S2 and step S4 are the same or different.

[0019] According to the preparation method described above, the solid content of the organic polymer solid electrolyte slurry containing the organic polymer solid electrolyte in step S2 is 10 to 70% by mass;

[0020] Preferably, the solid content of the second solid electrolyte slurry in step S4 is 10 to 70% by mass;

[0021] Preferably, in the step Sx, the hot pressing temperature is 40-60° C., the pressure is 0.1-0.5 MPa, and the hot pressing time is 5-20 minutes.

[0022] According to the preparation method described above, the organic polymer solid electrolyte slurry in step S2 further includes one or more of an inorganic ceramic material and a conductive agent;

[0023] Preferably, in the organic polymer solid electrolyte slurry in step S2, the mass ratio of the organic polymer solid electrolyte to the inorganic ceramic material is (100-1): (0.01-70);

[0024] Preferably, the second solid electrolyte in the second solid electrolyte slurry in step S4 includes one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte;

[0025] Preferably, when the second solid electrolyte comprises only an organic polymer solid electrolyte, the second solid electrolyte slurry in step S4 comprises a lithium salt;

[0026] Preferably, the second solid electrolyte slurry in step S4 further includes a binder.

[0027] According to the preparation method described above, the organic polymer solid electrolyte used in step S2 and the organic polymer solid electrolyte used in step S4 are selected from one or more of polyethylene oxide, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, polypentylene succinate, polyvinyl chloride, polyvinylene carbonate, polyvinyl pyrrolidone, polyimide, polyurethane, and polyacrylate;

[0028] Preferably, the organic polymer solid electrolyte used in step S2 and the organic polymer solid electrolyte used in step S4 are the same as or different from each other.

[0029] According to the preparation method described above, the lithium salt used in step S2 and the lithium salt used in step S4 are respectively selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide) and lithium difluorooxalatoborate;

[0030] Preferably, the lithium salt used in step S2 and the lithium salt used in step S4 are the same or different.

[0031] According to the preparation method described above, the binder used in step S2 and the binder used in step S4 are respectively selected from one or more of polyvinylidene fluoride, polyvinyl alcohol, polytetrafluoroethylene, sodium hydroxymethyl cellulose, styrene-butadiene rubber, nitrile rubber, styrene-butadiene-styrene copolymer, polyacrylic acid, and lithium polyacrylate;

[0032] Preferably, the binder used in step S2 and the binder used in step S4 are the same or different.

[0033] According to the preparation method described above, the inorganic ceramic material used in step S2 is selected from one or more of nitrides, carbides, metal oxides, and non-metal oxides;

[0034] More preferably, the nitride is selected from one or more of silicon nitride, titanium nitride, aluminum nitride, boron nitride, and magnesium nitride; the carbide is selected from one or more of silicon carbide and boron carbide; the metal oxide is selected from one or more of aluminum oxide, titanium dioxide, zirconium dioxide, and magnesium oxide; and the non-metallic oxide is selected from one or more of silicon dioxide and boron oxide.

[0035] According to the preparation method described above, the conductive agent used in step S2 is selected from one or more of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes, Ketjen black, graphene, carbon nanofibers, polyethylene dioxythiophene, polystyrene sulfonic acid, sodium polystyrene sulfonate, and a polymer obtained by polymerization of ethylene dioxythiophene and styrene sulfonic acid.

[0036] According to the preparation method described above, in step S4, the inorganic solid electrolyte is selected from one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a borate solid electrolyte, and a nitride solid electrolyte.

[0037] According to the preparation method described above, the oxide solid electrolyte is selected from one or more of a perovskite oxide solid electrolyte, a garnet oxide solid electrolyte, and a NASICON oxide solid electrolyte;

[0038] The sulfide solid electrolyte is selected from one or more of lithium germanium phosphosulfur, lithium phosphosulfur chlorine, lithium silicon phosphosulfur chlorine, lithium phosphosulfur bromine, lithium phosphosulfur iodine, lithium thiophosphate, and glassy sulfide;

[0039] The halide solid electrolyte is selected from Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x(where 0 < x < 1), Li2XCl4 (X is selected from Cd and / or Mg), Li2X′I4 (X′ is selected from Cd and / or Zn), LiMCl5X″ (M is selected from one or more of La, Ta, Nb; X″ is selected from any one of O, Cl, F, OH), Li 3-x Zr x M′ 1-x Cl6 (M′ is selected from one or more of Y, Er, Yb, Ho, Lu, 0 ≤ x ≤ 1);

[0040] The borate solid electrolyte is selected from one or more of Li2B4O7, Li2O - B2O3 - P2O5;

[0041] The nitride solid electrolyte is selected from one or more of LiPON, Li3N, Li7PN4, LiSi2N3;

[0042] Preferably, the perovskite - type oxide solid electrolyte is selected from lithium lanthanum titanium oxide;

[0043] The garnet - type oxide solid electrolyte is selected from one or more of lithium lanthanum zirconium oxide, niobium - doped lithium lanthanum zirconium oxide, tantalum - doped lithium lanthanum zirconium oxide, niobium - tantalum co - doped lithium lanthanum zirconium oxide;

[0044] The NASICON - type oxide solid electrolyte is selected from one or more of lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, lithium germanium aluminum phosphate.

[0045] The present invention provides a battery electrode, and the battery electrode includes at least one prepared according to the above - mentioned preparation method.

[0046] According to the battery electrode described above, wherein the battery electrode includes a positive electrode or a negative electrode and an organic polymer solid electrolyte layer provided on the positive electrode or the negative electrode;

[0047] Preferably, the thickness of the organic polymer solid electrolyte layer is 5 - 25 μm;

[0048] Preferably, the organic polymer solid electrolyte layer further includes one or more of inorganic ceramic materials and conductive agents.

[0049] According to the battery electrode described above, wherein the battery electrode further includes a second solid electrolyte layer on the organic polymer solid electrolyte layer;

[0050] Preferably, the thickness of the second solid electrolyte layer is 10 - 50 μm;

[0051] Preferably, the second solid electrolyte layer includes one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte.

[0052] The present invention also provides a method for preparing a solid-state battery, which comprises:

[0053] The step of preparing the positive electrode sheet and / or the negative electrode sheet by the preparation method described above; and

[0054] The positive electrode sheet and the negative electrode sheet are rolled, dried, stacked, and then hot-pressed to integrate them.

[0055] According to the preparation method described above, the temperature of the hot pressing integration is 50-85° C., the pressure is 0.1-0.6 MPa, and the hot pressing time is 20-40 minutes.

[0056] The present invention further provides a solid-state battery, which includes at least one of the solid-state batteries prepared by the preparation method described above.

[0057] Effects of the Invention

[0058] The above technical solution of the present invention has the following beneficial effects:

[0059] 1. The present invention uses a rotary atomization spraying method to adjust relevant process parameters to achieve high-speed rotation and uniform atomization of the slurry containing the solid electrolyte, thereby achieving uniform preparation of the solid electrolyte layer and enhancing the interface contact between the solid electrolyte and the battery electrode;

[0060] 2. The present invention improves the efficiency of preparing solid electrolyte pole pieces and reduces equipment maintenance costs, thereby achieving mass production of high-quality battery pole pieces;

[0061] 3. The present invention improves the cycle stability of solid-state batteries by enhancing interface contact and reducing interface impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] FIG1 is a scanning electron microscope image showing a battery electrode prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0063] The following describes embodiments of the present invention, but the present invention is not limited thereto. The present invention is not limited to the various configurations described below; various modifications may be made within the scope of the invention claims, and embodiments obtained by appropriately combining different embodiments and appropriately combining the technical means disclosed in the examples are also included in the technical scope of the present invention. In addition, all documents listed in this specification are cited as references in this specification.

[0064] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0065] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0066] In this specification, unless otherwise specified, "multiple" in "multiple", "multiple", "many" and the like means a numerical value of 2 or more.

[0067] In this specification, the term “substantially”, “generally” or “essentially” means that the error is less than 5%, or less than 3%, or less than 1% compared with the relevant perfect standard or theoretical standard.

[0068] In this specification, unless otherwise specified, "%" means percentage by mass.

[0069] In this specification, when "room temperature" or "normal temperature" appears, the temperature may generally be 10-37°C, or 15-35°C.

[0070] In this specification, the meanings of “may” or “can” include both existence and non-existence, and both performing a certain process and not performing a certain process.

[0071] Throughout this specification, “optionally,” “optionally,” and “optionally” mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0072] The term "comprises" and any variations thereof in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0073] In this specification, references to "some / certain / preferred embodiments," "embodiments," etc., mean that the specific elements (e.g., features, structures, properties, and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it should be understood that the elements may be combined in any suitable manner in various embodiments.

[0074] <First Aspect>

[0075] A first aspect of the present invention relates to a method for preparing a battery electrode, comprising the following steps:

[0076] Step S2: spraying an organic polymer solid electrolyte slurry containing a composition of an organic polymer solid electrolyte, a lithium salt and a binder onto the surface of the positive electrode sheet or the negative electrode sheet by a rotary atomization spraying method, thereby obtaining a positive electrode sheet or a negative electrode sheet having an organic polymer solid electrolyte layer.

[0077] In some preferred embodiments, the preparation method of the present invention may further comprise the following steps:

[0078] Step S4: spraying the second solid electrolyte slurry onto the surface of the organic polymer solid electrolyte layer obtained in step S2 by rotary atomization spraying, thereby obtaining a positive electrode sheet or a negative electrode sheet having the organic polymer solid electrolyte layer and the second solid electrolyte layer.

[0079] In some preferred embodiments, the preparation method of the present invention may further comprise the following homogenization step:

[0080] Step S1: homogenizing a composition containing an organic polymer solid electrolyte, a lithium salt and a binder in a solvent to prepare an organic polymer solid electrolyte slurry; and / or

[0081] Step S3: slurrying the composition containing the second solid electrolyte in a solvent to prepare a second solid electrolyte slurry.

[0082] In some preferred embodiments, the preparation method of the present invention may further comprise the following steps:

[0083] Step Sx: hot pressing the finally prepared positive electrode sheet or negative electrode sheet.

[0084] In the present invention, there is no particular limitation on the method for preparing the positive electrode sheet or the negative electrode sheet before spraying the organic polymer solid electrolyte slurry, and the positive electrode sheet can be prepared using common methods in the art such as conventional coating method, electrostatic spraying method, etc.

[0085] The following describes each step in detail.

[0086] Step S1

[0087] In step S1 , a composition containing an organic polymer solid electrolyte, a lithium salt, and a binder is slurried in a solvent to prepare an organic polymer solid electrolyte slurry.

[0088] In the present invention, the organic polymer solid electrolyte in the composition in step S1 can be selected from polyethylene oxide (PEO), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride-chlorotrifluoroethylene (PVDF-CTFE), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polypropylene carbonate (PPC), polyphenylene sulfide (PPS), polycyanoethyl acrylate (PCA), polypentylene succinate, polyvinyl chloride (PVC), polyvinyl carbonate, polyvinyl pyrrolidone (PVP), polyimide (PI), polyurethane, polyacrylate One or more. When two or more organic polymer solid electrolytes are used, the ratio between them is not particularly limited and can be adjusted according to actual needs.

[0089] In the present invention, the lithium salt and the binder are not particularly limited, and those commonly used in the art can be used. For example, the lithium salt can be selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), and lithium difluorooxalatoborate. The binder can be selected from one or more of polyvinylidene fluoride, polyvinyl alcohol, polytetrafluoroethylene, sodium hydroxymethyl cellulose, styrene-butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene-styrene copolymer, polyacrylic acid, and lithium polyacrylate.

[0090] In the composition in step S1 , the lithium salt content may be 20 mass % to 50 mass % and the binder content may be 1 mass % to 10 mass %.

[0091] In some preferred embodiments, the organic polymer solid electrolyte in step S1 is further doped with an inorganic ceramic material.

[0092] Adding inorganic ceramic particles to the organic polymer solid electrolyte layer can improve the interfacial contact with the positive or negative electrode active material, reduce the crystallization area of ​​the polymer and improve ion conduction, while reducing the interfacial impedance, improving the interfacial stability, and preventing the occurrence of interfacial side reactions, thereby increasing the cycle stability of the solid-state battery.

[0093] The inorganic ceramic particles may be selected from one or more of nitrides, carbides, metal oxides, and non-metal oxides. Specifically, the nitride may be selected from one or more of silicon nitride (Si3N4), titanium nitride (TiN), aluminum nitride (AlN), boron nitride (BN), and magnesium nitride (Mg3N2); the carbide may be selected from one or more of silicon carbide (SiC) and boron carbide (B4C); the metal oxide may be selected from one or more of aluminum oxide (Al2O3), titanium dioxide (TiO2), zirconium dioxide (ZrO2), and magnesium oxide (MgO); and the non-metal oxide may be selected from one or more of silicon dioxide (SiO2) and boron oxide (B2O3).

[0094] In some preferred embodiments, in the composition in step S1, the mass ratio of the organic polymer solid electrolyte to the inorganic ceramic particles is (100-1): (0.01-70), for example, it can be 99.9:0.01, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, etc., wherein, if the ratio of the inorganic ceramic particles exceeds this range, the particles will agglomerate, which is not conducive to dispersion, clogs the equipment, and affects production efficiency.

[0095] In some embodiments, the composition in step S1 further includes a conductive agent. There is no particular limitation on the conductive agent, and those commonly used in the art can be used. For example, the conductive agent can be selected from one or more of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes, Ketjen black, graphene, carbon nanofibers, polyethylene dioxythiophene, polystyrene sulfonic acid, sodium polystyrene sulfonate, and a polymer obtained by polymerization of ethylene dioxythiophene and styrene sulfonic acid. Among them, a polymer obtained by polymerization of ethylene dioxythiophene and styrene sulfonic acid is preferably used because the polymer, as a conductive agent, has better solubility in a solvent and better conductive agent performance.

[0096] When the composition in step S1 contains a conductive agent, the content thereof is not particularly limited and can be adjusted according to actual needs.

[0097] In the present invention, the solid content of the organic polymer solid electrolyte slurry is 10-70% by mass, for example, 10% by mass, 20% by mass, 30% by mass, 40% by mass, 50% by mass, 60% by mass, 70% by mass, etc.

[0098] In step S1, the organic solvent used in the homogenization can be selected from one or more of N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, butyrate, toluene, xylene, anisole, hexane, heptane, dibromomethane, dichloroethane, ethanol and glycol ether.

[0099] Step S2

[0100] In step S2, the organic polymer solid electrolyte slurry prepared in step S1 is sprayed onto the surface of the positive electrode sheet or the negative electrode sheet by rotary atomization spraying, thereby obtaining a positive electrode sheet or a negative electrode sheet having an organic polymer solid electrolyte layer.

[0101] In the present invention, during the rotary atomization spraying in step S2, the spraying pressure can be 0.6-3.5 MPa, preferably 1.0 MPa-2.0 MPa, for example, 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, etc. The spraying pressure within the above range can effectively disperse the slurry, improve the atomization effect and the uniformity of the active material sprayed on the electrode surface. If the spraying pressure is too low, it is easy to cause agglomeration of the solid electrolyte, uneven particle size distribution after atomization, and other problems, affecting the interlayer interface contact.

[0102] In addition, the spraying conditions in the rotary atomization spraying of the present invention may also include the following:

[0103] The rotation speed of the atomizing device can be 2000-30000 rpm, for example, 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, 9000 rpm, 10000 rpm, 15000 rpm, 20000 rpm, 25000 rpm, 30000 rpm, etc.

[0104] The liquid intake rate can be 5-2000 kg / hour, for example, 5 kg / hour, 10 kg / hour, 50 kg / hour, 100 kg / hour, 200 kg / hour, 500 kg / hour, 1000 kg / hour, 1500 kg / hour, 2000 kg / hour, etc.

[0105] Controlling the rotation speed, liquid feed volume and pressure within the above range can more effectively disperse the slurry, improve the atomization effect and improve the spray uniformity; too low rotation speed and liquid feed volume can also easily cause problems such as agglomeration of solid electrolytes and uneven particle size distribution after atomization, affecting the interlayer interface contact.

[0106] In some embodiments of the present invention, the thickness of the organic polymer solid electrolyte layer may be 5-25 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, etc. An excessively thick organic polymer solid electrolyte layer may increase interfacial impedance and affect the rate performance of the battery.

[0107] Step S3

[0108] In some preferred embodiments, the preparation method of the present invention may further comprise the following steps:

[0109] The composition containing the second solid electrolyte is slurried in a solvent to prepare a second solid electrolyte slurry.

[0110] In the present invention, the second solid electrolyte in the composition in step S3 may include one or more of inorganic solid electrolytes and organic polymer solid electrolytes. When the second solid electrolyte includes both an inorganic solid electrolyte and an organic polymer solid electrolyte, the ratio between them is not particularly limited and can be adjusted according to actual needs. For example, the mass ratio between the inorganic solid electrolyte and the organic polymer solid electrolyte may be 0.2:1 to 40:1.

[0111] Specifically, the inorganic solid electrolyte may be selected from one or more of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, borate solid electrolytes, and nitride solid electrolytes.

[0112] More specifically, the oxide solid electrolyte may be selected from one or more of perovskite-type oxide solid electrolytes, garnet-type oxide solid electrolytes, and NASICON-type oxide solid electrolytes. Preferably, the perovskite-type oxide solid electrolyte may be selected from lithium lanthanum titanium oxide (LLTO); the garnet-type oxide solid electrolyte may be selected from one or more of lithium lanthanum zirconium oxide (LLZO), niobium-doped lithium lanthanum zirconium oxide (LLZNO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and niobium-tantalum co-doped lithium lanthanum zirconium oxide (LLZNTO); the NASICON-type oxide solid electrolyte may be selected from one or more of lithium aluminum titanium phosphate (LATP), lithium yttrium titanium phosphate (LYTP), and lithium germanium aluminum phosphate (LAGP).

[0113] The sulfide solid electrolyte may be selected from one or more of lithium germanium phosphorus sulfur (LGPS), lithium phosphorus sulfur chloride (LPSCl), lithium silicon phosphorus sulfur, lithium silicon phosphorus sulfur chloride, lithium phosphorus sulfur bromide (LPSBr), lithium phosphorus sulfur iodide (LPSI), lithium thiophosphate (LPS), and vitreous sulfides (Li2S-P2S5, Li2S-SiS2, Li2S-B2S3). The halide solid electrolyte may be selected from Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x (where 0 < x < 1), Li2XCl4 (X is selected from Cd and / or Mg), Li2X′I4 (X′ is selected from Cd and / or Zn), LiMCl5X″ (M is selected from one or more of La, Ta, and Nb; X″ is selected from any one of O, Cl, F, and OH), Li 3-x Zr x M′ 1-xOne or more of Cl6 (M' is selected from one or more of Y, Er, Yb, Ho, and Lu, 0≤x≤1). The borate solid electrolyte is selected from one or more of Li2B4O7 and Li2O-B2O3-P2O5. The nitride solid electrolyte can be selected from one or more of LiPON, Li3N, Li7PN4, and LiSi2N3.

[0114] Examples of organic polymer solid electrolytes are the same as those in step S1 and are not described in detail herein. In a specific embodiment, the organic polymer solid electrolyte used in step S3 is the same as or different from that used in S1.

[0115] The composition in step S3 optionally includes a lithium salt. When the second solid electrolyte in the composition in step S3 includes only an organic polymer solid electrolyte, the composition in step S3 must include a lithium salt. When the second solid electrolyte in the composition in step S3 includes an inorganic solid electrolyte or includes only an organic polymer solid electrolyte, the composition in step S3 may or may not include a lithium salt.

[0116] In some preferred embodiments, the composition in step S3 further comprises a binder. There are no particular limitations on the lithium salt and binder, and those commonly used in the art may be used. Examples of lithium salts and binders are the same as those listed in step S1. In specific implementations, the lithium salt and binder used in step S3 may be the same as or different from those used in step S1.

[0117] When the composition in step S3 contains a lithium salt and a binder, their contents are not particularly limited and can be adjusted according to actual needs, for example, 5% to 35% by mass, respectively.

[0118] In the present invention, the solid content of the second solid electrolyte slurry is 10-70 mass%, for example, 10 mass%, 20 mass%, 30 mass%, 40 mass%, 50 mass%, 60 mass%, 70 mass%, etc.

[0119] In step S3, examples of the organic solvent used in the homogenization are the same as those in step S1. In a specific embodiment, the organic solvent used in step S3 can be the same as or different from that in step S1.

[0120] Step S4

[0121] In step S4, the second solid electrolyte slurry prepared in step S3 is sprayed onto the surface of the organic polymer solid electrolyte layer obtained in step S2 by rotary atomization spraying, thereby obtaining a positive electrode sheet or a negative electrode sheet having an organic polymer solid electrolyte layer and a second solid electrolyte layer in sequence.

[0122] The range of each condition of the rotary atomization spraying in step S4 is the same as that in step S2 above, and will not be repeated here. In a specific embodiment, the conditions of the rotary atomization spraying adopted in step S4 can be the same as or different from those in step S2.

[0123] In some embodiments of the present invention, the thickness of the second solid electrolyte layer is 10-50 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. A thickness within the above range can effectively enhance interfacial stability and help improve the cycle stability of the solid-state battery. A thickness that is too high will increase the interfacial impedance and affect the rate performance of the battery. A thickness that is too low can easily cause a short circuit and affect the safety of the solid-state battery.

[0124] In the present invention, by regulating the physical properties of the solid electrolyte slurry and the process parameters of the rotary atomization spraying device, the solid electrolyte slurry meets the requirements of the rotary atomization spraying, improves the process problems such as material sticking and clogging caused by solid electrolyte agglomeration and sedimentation, greatly improves the production efficiency, and has a good atomization effect, so that the solid electrolyte layer can be uniformly prepared on the surface of the battery electrode, the interface contact between the electrode and the solid electrolyte layer is enhanced, and the interface impedance is reduced, thereby improving the electrochemical performance of the solid-state battery.

[0125] Step Sx

[0126] In some preferred embodiments, the preparation method of the present invention may further include step Sx: hot pressing the finally prepared positive electrode sheet or negative electrode sheet.

[0127] In the hot pressing of the present invention, the hot pressing temperature can be 40 to 60° C., for example, 40° C., 45° C., 50° C., 55° C., 60° C., etc., the pressure can be 0.1 to 0.5 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, etc., and the hot pressing time can be 5 to 20 minutes, for example, 5 minutes, 10 minutes, 15 minutes, 20 minutes, etc.

[0128] During the hot pressing process, the interface contact between the flexible interface of the organic polymer solid electrolyte layer and the solid electrolyte layer is increased, the crystallization area of ​​the polymer is reduced on the basis of reducing the process steps, ion transport behavior is induced and a new ion transport interface is formed, the electrochemical stability window of the solid electrolyte is improved, the ionic conductivity between the multilayer structure is improved, and the compatibility of the electrode and solid electrolyte interface is increased.

[0129] <Second Aspect>

[0130] The second aspect of the present invention relates to a battery pole piece, which includes at least one of the battery pole pieces prepared according to the preparation method described in the above <first aspect>.

[0131] In the present invention, the battery electrode sheet includes a positive electrode sheet or a negative electrode sheet and an organic polymer solid electrolyte layer provided on the positive electrode sheet or the negative electrode sheet.

[0132] In some preferred embodiments, the thickness of the organic polymer solid electrolyte layer is 5-25 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, etc. An excessively thick organic polymer solid electrolyte layer will increase interfacial impedance and affect the rate performance of the battery.

[0133] In some preferred embodiments, the organic polymer solid electrolyte layer further includes one or more of an inorganic ceramic material and a conductive agent.

[0134] In some preferred embodiments, the battery electrode further includes a second solid electrolyte layer on the organic polymer solid electrolyte layer.

[0135] In some more preferred embodiments, the thickness of the second solid electrolyte layer is 10-50 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. A thickness within the above range can effectively enhance interfacial stability, which is beneficial to improving the cycle stability of the solid-state battery. A thickness that is too high will increase the interfacial impedance and affect the rate performance of the battery. A thickness that is too low can easily cause a short circuit, affecting the safety of the solid-state battery.

[0136] In some more preferred embodiments, the second solid electrolyte layer includes one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte.

[0137] <Third Aspect>

[0138] The third aspect of the present invention relates to a method for preparing a solid-state battery, comprising: preparing a positive electrode sheet and / or a negative electrode sheet having an electrolyte layer by the preparation method described in the first aspect above; and

[0139] The steps of rolling the positive electrode sheet and / or the negative electrode sheet, drying the stacked sheets and packaging them, and then hot pressing them for integration.

[0140] The "hot pressing integration" here refers to integrating the positive and negative electrode sheets by hot pressing. The "hot pressing" in the above step Sx refers to hot pressing the positive electrode sheet or the negative electrode sheet.

[0141] In the hot pressing integration of the present invention, the hot pressing temperature is 50 to 85°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, etc., the pressure can be 0.1 to 0.6 MPa, for example, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, and the hot pressing time can be 20 to 40 minutes, for example, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.

[0142] Example

[0143] The present invention will be described in detail below by way of examples. The examples of the examples are intended to explain the present invention and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the examples, the methods were performed according to the techniques or conditions described in the literature in the art or according to the product specifications. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be obtained commercially.

[0144] Example 1

[0145] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0146] (1) Polyvinylene carbonate, boron oxide, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 6:1:2:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 50% by mass;

[0147] (2) By means of a rotary atomization spraying method, a stator and a rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 8000 rpm, the liquid feed rate is controlled at 20 kg / h, and the spraying pressure is 1.0 MPa. An organic polymer solid electrolyte slurry is sprayed on a lithium iron phosphate positive electrode sheet (purchased from Aladdin L-68230, the same below) to prepare an organic polymer solid electrolyte layer containing an inorganic ceramic material with a thickness of 10 μm;

[0148] (3) adding niobium-tantalum dual-doped lithium lanthanum zirconium oxide solid electrolyte and polypentane succinate to DMF solvent in a mass ratio of 23:1, stirring and mixing thoroughly to obtain a second solid electrolyte slurry with a solid content of 60% by mass;

[0149] (4) Using a rotary atomization spraying method, the rotation speed is set to 9000 rpm, the liquid feed rate is controlled at 30 kg / h, and the spraying pressure is 1.2 MPa. The second solid electrolyte slurry is sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0150] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0151] Example 2

[0152] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0153] (1) PVDF-HFP, alumina, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 6:1:2:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 50% by mass;

[0154] (2) By means of a rotary atomization spraying method, a stator and a rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 10,000 rpm, the liquid feed rate is controlled at 15 kg / h, and the spraying pressure is 1.0 MPa, and an organic polymer solid electrolyte slurry is sprayed on the lithium iron phosphate positive electrode sheet to prepare an organic polymer solid electrolyte layer containing inorganic ceramic material with a thickness of 10 μm;

[0155] (3) adding niobium-tantalum dual-doped lithium lanthanum zirconium oxide solid electrolyte and polyvinylidene fluoride to DMF solvent in a mass ratio of 19:1, stirring and mixing thoroughly to obtain a second solid electrolyte slurry with a solid content of 60% by mass;

[0156] (4) Using a rotary atomization spraying method, the rotation speed is set to 15,000 rpm, the liquid feed rate is controlled at 30 kg / h, and the spraying pressure is 1.2 MPa. The second solid electrolyte slurry is sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0157] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0158] Example 3

[0159] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0160] (1) Polyvinylene carbonate, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 3:1:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 40% by mass;

[0161] (2) Using a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 6000 rpm, the liquid feed rate is controlled at 15 kg / h, and the spraying pressure is 2.0 MPa. An organic polymer solid electrolyte slurry is sprayed on the lithium iron phosphate positive electrode sheet to prepare an organic polymer solid electrolyte layer with a thickness of 15 μm;

[0162] (3) adding tantalum-doped lithium lanthanum zirconium oxide solid electrolyte and polyvinylidene fluoride to DMF solvent in a mass ratio of 29:1, stirring and mixing them thoroughly to obtain a second solid electrolyte slurry with a solid content of 55% by mass;

[0163] (4) Using a rotary atomization spraying method, the rotation speed was set to 7000 rpm, the liquid feed rate was controlled at 20 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0164] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0165] Example 4

[0166] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0167] (1) Polyimide, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 3:1:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 45% by mass;

[0168] (2) By means of a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 6000 rpm, the liquid feed rate is controlled at 10 kg / h, and the spraying pressure is 2.0 MPa, and an organic polymer solid electrolyte slurry is sprayed on the lithium iron phosphate positive electrode sheet to prepare an organic polymer solid electrolyte layer with a thickness of 20 μm;

[0169] (3) adding tantalum-doped lithium lanthanum zirconium oxide solid electrolyte and polyvinylidene fluoride to DMF solvent in a mass ratio of 24:1, stirring and mixing them thoroughly to obtain a second solid electrolyte slurry with a solid content of 50% by mass;

[0170] (4) Using a rotary atomization spraying method, the rotation speed was set to 8000 rpm, the liquid feed rate was controlled at 20 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 25 μm;

[0171] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0172] Example 5

[0173] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0174] (1) Polyimide, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 5:2:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 45% by mass;

[0175] (2) Using a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 5000 rpm, the liquid feed rate is controlled at 10 kg / h, and the spraying pressure is 1.2 MPa. An organic polymer solid electrolyte slurry is sprayed on the lithium iron phosphate positive electrode sheet to prepare an organic polymer solid electrolyte layer with a thickness of 10 μm;

[0176] (3) adding niobium-doped lithium lanthanum zirconium oxide solid electrolyte, PVDF-HFP and LiTFSI into DMF solvent in a mass ratio of 3:5:2, stirring and mixing them thoroughly to obtain a second solid electrolyte slurry with a solid content of 60% by mass;

[0177] (4) Using a rotary atomization spraying method, the rotation speed was set to 8000 rpm, the liquid feed rate was controlled at 20 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 35 μm;

[0178] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0179] Example 6

[0180] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0181] (1) Polyvinylene carbonate, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 5:2:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 35% by mass;

[0182] (2) Using a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 5000 rpm, the liquid feed rate is controlled at 10 kg / h, and the spraying pressure is 1.2 MPa. An organic polymer solid electrolyte slurry is sprayed on the lithium iron phosphate positive electrode to prepare an organic polymer solid electrolyte layer with a thickness of 20 μm;

[0183] (3) adding niobium-doped lithium lanthanum zirconium oxide solid electrolyte, polyimide, and LiTFSI into DMF solvent in a mass ratio of 2:5:3, stirring and mixing thoroughly to obtain a second solid electrolyte slurry with a solid content of 65% by mass;

[0184] (4) Using a rotary atomization spraying method, the rotation speed was set to 8000 rpm, the liquid feed rate was controlled at 20 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 25 μm;

[0185] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0186] Example 7

[0187] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0188] (1) Polyvinylene carbonate, aluminum oxide, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 7:1:3:2 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 50% by mass;

[0189] (2) By means of a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 18,000 rpm, the liquid feed rate is controlled at 20 kg / h, and the spraying pressure is 1.2 MPa. An organic polymer solid electrolyte slurry is sprayed on the NCM622 positive electrode sheet to prepare an organic polymer solid electrolyte layer containing inorganic ceramic material with a thickness of 15 μm;

[0190] (3) adding niobium-tantalum dual-doped lithium lanthanum zirconium oxide solid electrolyte and polypentane succinate to DMF solvent in a mass ratio of 29:1, stirring and mixing thoroughly to obtain a second solid electrolyte slurry with a solid content of 60% by mass;

[0191] (4) Using a rotary atomization spraying method, the rotation speed is set to 20,000 rpm, the liquid feed rate is controlled at 30 kg / h, and the spraying pressure is 1.2 MPa. The second solid electrolyte slurry is sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0192] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0193] Example 8

[0194] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a positive electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0195] (1) Polyimide, aluminum oxide, LiTFSI, and polyvinylidene fluoride were selected and dissolved in DMF solvent in a mass ratio of 7:1:3:2, and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 35% by mass;

[0196] (2) By means of a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 16,000 rpm, the liquid feed rate is controlled at 20 kg / h, and the spraying pressure is 1.2 MPa. An organic polymer solid electrolyte slurry is sprayed on the NCM622 positive electrode sheet to prepare an organic polymer solid electrolyte layer containing inorganic ceramic material with a thickness of 20 μm;

[0197] (3) adding niobium-tantalum dual-doped lithium lanthanum zirconium oxide solid electrolyte and polypentane succinate to DMF solvent in a mass ratio of 29:1, stirring and mixing thoroughly to obtain a second solid electrolyte slurry with a solid content of 60% by mass;

[0198] (4) Using a rotary atomization spraying method, the rotation speed is set to 20,000 rpm, the liquid feed rate is controlled at 20 kg / h, and the spraying pressure is 1.2 MPa. The second solid electrolyte slurry is sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0199] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium metal negative electrode stacks, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0200] Example 9

[0201] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a negative electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0202] (1) Polyvinylene carbonate, LiTFSI, and styrene-butadiene rubber were selected and dissolved in DMF solvent in a mass ratio of 6:3:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 45% by mass;

[0203] (2) Using a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 5000 rpm, the liquid feed rate is controlled at 10 kg / h, and the spraying pressure is 1.2 MPa. The organic polymer solid electrolyte slurry is sprayed on the graphite negative electrode sheet to prepare an organic polymer solid electrolyte layer with a thickness of 25 μm;

[0204] (3) adding tantalum-doped lithium lanthanum zirconium oxide solid electrolyte, PVDF-HFP and LiTFSI into DMF solvent in a mass ratio of 2:2:1, stirring and mixing them thoroughly to obtain a second solid electrolyte slurry with a solid content of 65% by mass;

[0205] (4) Using a rotary atomization spraying method, the rotation speed was set to 17,000 rpm, the liquid feed rate was controlled at 15 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 25 μm;

[0206] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium iron phosphate positive electrode stack, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0207] Example 10

[0208] The present invention provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method on a negative electrode pole piece to obtain a battery pole piece with uniform distribution of solid electrolyte and good interlayer interface contact. The specific steps are as follows:

[0209] (1) PVDF-HFP, LiTFSI, and styrene-butadiene rubber were selected and dissolved in DMF solvent in a mass ratio of 5:2:1 and stirred for 6 hours to prepare an organic polymer solid electrolyte slurry with a solid content of 45% by mass;

[0210] (2) Using a rotary atomization spraying method, the stator and rotor are used to drive the atomizing device on the main shaft to rotate, the speed is set to 4000 rpm, the liquid feed rate is controlled at 10 kg / h, and the spraying pressure is 1.2 MPa. The organic polymer solid electrolyte slurry is sprayed on the graphite negative electrode sheet to prepare an organic polymer solid electrolyte layer with a thickness of 20 μm;

[0211] (3) adding niobium-doped lithium lanthanum zirconium oxide solid electrolyte, PVDF-HFP and LiTFSI into DMF solvent in a mass ratio of 5:3:2, stirring and mixing them thoroughly to obtain a second solid electrolyte slurry with a solid content of 65% by mass;

[0212] (4) Using a rotary atomization spraying method, the rotation speed was set to 20,000 rpm, the liquid feed rate was controlled at 15 kg / h, and the spraying pressure was 1.2 MPa. The second solid electrolyte slurry was sprayed on the composite battery electrode obtained in step 2 to prepare a second solid electrolyte layer with a thickness of 30 μm;

[0213] (5) Vacuum drying at 65°C for 8 hours, rolling and packaging with lithium iron phosphate positive electrode stack, and hot pressing integration at a temperature of 65°C and a pressure of 0.25 MPa for 30 minutes to obtain a solid-state battery.

[0214] Comparative Example 1

[0215] This comparative example provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method. The difference from Example 1 is that the applied rotation speed is 1000 revolutions per minute, which is lower than the limit range.

[0216] Comparative Example 2

[0217] This comparative example provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method. The difference from Example 1 is that the liquid feeding rate is 2 kg / hour.

[0218] Comparative Example 3

[0219] This comparative example provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method. The difference from Example 1 is that the spraying pressure is 0.1 MPa, which is lower than the limited range.

[0220] Comparative Example 4

[0221] This comparative example provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method. The difference from Example 1 is that the spraying pressure is 3.7 MPa, which is higher than the limited range.

[0222] Comparative Example 5

[0223] This comparative example provides a battery pole piece, a preparation method thereof, and a solid-state battery. The battery pole piece is prepared by a rotary atomization spraying method. The difference from Example 1 is that the applied rotation speed is 31,000 revolutions per minute, which is higher than the limited range.

[0224] Performance testing:

[0225] Interface impedance test: The prepared composite electrode and lithium metal sheet were assembled into a button cell. The AC impedance was tested in an electrochemical workstation using the AC impedance method. The voltage amplitude was set to 5 mV and the frequency range was 0.1 Hz to 1 MHz.

[0226] Cycling stability test: The positive electrode sheet and the negative electrode sheet, the positive electrode sheet containing a solid electrolyte, or the negative electrode sheet were cut and assembled into button batteries. The batteries were charged and discharged at a rate of 0.2C at 25°C for 300 cycles. The battery capacity before and after the cycle was recorded 300 times. The initial charge and discharge capacity was also recorded, and the initial coulombic efficiency was calculated.

[0227] Table 1

[0228] Analysis and comparison of the test results of Examples 1-10 and Comparative Examples 1-3 in Table 1 show that the battery electrodes prepared within the preferred process range of rotary atomization spraying have good first coulombic efficiency and cycle stability, which is attributed to the high-speed rotation and uniform atomization of the slurry containing the solid electrolyte, which effectively increases the solid-solid contact area and reduces the interfacial impedance. The flexible polymer solid electrolyte interface further improves the cycle stability and charge and discharge performance of the battery.

[0229] FIG1 is a scanning electron microscope image of the battery electrode prepared in Example 1. The solid electrolyte is evenly dispersed on the electrode surface by rotary spraying, forming a continuous and dense solid electrolyte layer without obvious agglomeration.

[0230] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0231] Industrial applicability

[0232] This invention utilizes a rotary atomization spray method and sets relevant process parameters to achieve high-speed rotation and uniform atomization of a solid electrolyte slurry, thereby achieving a uniform solid electrolyte layer and enhancing the interfacial contact between the solid electrolyte and the battery electrode. Furthermore, this invention improves the efficiency of preparing solid electrolyte electrode sheets and reduces equipment maintenance costs, enabling mass production of high-quality battery electrode sheets.

Claims

1. A method for preparing a battery electrode, characterized in that: It includes the following steps: Step S2: spraying an organic polymer solid electrolyte slurry containing a composition of an organic polymer solid electrolyte, a lithium salt and a binder onto the surface of the positive electrode sheet or the negative electrode sheet by a rotary atomization spraying method, thereby obtaining a positive electrode sheet or a negative electrode sheet having an organic polymer solid electrolyte layer. The spraying pressure in the rotary atomization spraying is 0.6-3.5MPa, preferably 1.0-2.0MPa; The preparation method may optionally include step Sx: hot pressing the finally prepared positive electrode sheet or negative electrode sheet.

2. The preparation method according to claim 1, further comprising the following steps before step Sx: Step S4: Spraying the slurry containing the second solid electrolyte onto the surface of the organic polymer solid electrolyte layer obtained in step S2 by rotary atomization spraying, thereby obtaining a positive electrode sheet or a negative electrode sheet having the organic polymer solid electrolyte layer and the second solid electrolyte layer.

3. The preparation method according to claim 2, wherein in the step S2 and the step S4, in the rotary atomization spraying, the spraying conditions are as follows: the rotation speed of the atomizing device is 2000-30000 rpm, and the liquid inlet amount is 5-2000 kg / hour; Preferably, the spraying conditions in step S2 and step S4 are the same or different.

4. The preparation method according to claim 1 or 2, wherein the solid content of the organic polymer solid electrolyte slurry containing the organic polymer solid electrolyte in step S2 is 10 to 70% by mass; Preferably, the solid content of the second solid electrolyte slurry in step S4 is 10 to 70% by mass; Preferably, in the step Sx, the hot pressing temperature is 40-60° C., the pressure is 0.1-0.5 MPa, and the hot pressing time is 5-20 minutes.

5. The preparation method according to claim 1, wherein the organic polymer solid electrolyte slurry in step S2 further comprises one or more of an inorganic ceramic material and a conductive agent; Preferably, in the organic polymer solid electrolyte slurry in step S2, the mass ratio of the organic polymer solid electrolyte to the inorganic ceramic material is (100-1): (0.01-70); Preferably, the second solid electrolyte in the second solid electrolyte slurry in step S4 includes one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte; Preferably, when the second solid electrolyte comprises only an organic polymer solid electrolyte, the second solid electrolyte slurry in step S4 comprises a lithium salt; Preferably, the second solid electrolyte slurry in step S4 further includes a binder.

6. The preparation method according to claim 5, wherein the organic polymer solid electrolyte used in step S2 and the organic polymer solid electrolyte used in step S4 are selected from one or more of polyethylene oxide, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, polypentylene succinate, polyvinyl chloride, polyvinyl carbonate, polyvinyl pyrrolidone, polyimide, polyurethane, and polyacrylate; Preferably, the organic polymer solid electrolyte used in step S2 and the organic polymer solid electrolyte used in step S4 are the same as or different from each other.

7. The preparation method according to claim 5, wherein the lithium salt used in step S2 and the lithium salt used in step S4 are respectively selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide) and lithium difluorooxalatoborate; Preferably, the lithium salt used in step S2 and the lithium salt used in step S4 are the same or different.

8. The preparation method according to claim 5, wherein the binder used in step S2 and the binder used in step S4 are respectively selected from one or more of polyvinylidene fluoride, polyvinyl alcohol, polytetrafluoroethylene, sodium hydroxymethyl cellulose, styrene-butadiene rubber, nitrile rubber, styrene-butadiene-styrene copolymer, polyacrylic acid, and lithium polyacrylate; Preferably, the binder used in step S2 and the binder used in step S4 are the same or different.

9. The preparation method according to claim 5, wherein the inorganic ceramic material used in step S2 is selected from one or more of nitrides, carbides, metal oxides, and non-metal oxides; More preferably, the nitride is selected from one or more of silicon nitride, titanium nitride, aluminum nitride, boron nitride, and magnesium nitride; the carbide is selected from one or more of silicon carbide and boron carbide; The metal oxide is selected from one or more of aluminum oxide, titanium dioxide, zirconium dioxide, and magnesium oxide; the non-metal oxide is selected from one or more of silicon dioxide and boron oxide.

10. The preparation method according to claim 5, wherein the conductive agent used in step S2 is selected from one or more of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes, Ketjen black, graphene, carbon nanofibers, polyethylene dioxythiophene, polystyrene sulfonic acid, sodium polystyrene sulfonate, and a polymer obtained by polymerization of ethylene dioxythiophene and styrene sulfonic acid.

11. The preparation method according to claim 5, wherein in step S4, the inorganic solid electrolyte is selected from one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a borate solid electrolyte, and a nitride solid electrolyte.

12. The preparation method according to claim 11, wherein the oxide solid electrolyte is selected from one or more of a perovskite oxide solid electrolyte, a garnet oxide solid electrolyte, and a NASICON oxide solid electrolyte; The sulfide solid electrolyte is selected from one or more of lithium germanium phosphosulfur, lithium phosphosulfuryl chloride, lithium silicon phosphosulfuryl chloride, lithium phosphosulfuryl bromine, lithium phosphosulfuryl iodide, lithium thiophosphate, and glassy sulfide; The halide solid electrolyte is selected from Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x (where 0 < x < 1), Li2XCl4 (X is selected from Cd and / or Mg), Li2X′I4 (X′ is selected from Cd and / or Zn), LiMCl5X″ (M is selected from one or more of La, Ta, Nb; X″ is selected from any one of O, Cl, F, OH), Li 3-x Zr x M′ 1-x Cl6 (M′ is selected from one or more of Y, Er, Yb, Ho, Lu, 0 ≤ x ≤ 1); The borate solid electrolyte is selected from one or more of Li2B4O7, Li2O-B2O3-P2O5; The nitride solid electrolyte is selected from one or more of LiPON, Li3N, Li7PN4, and LiSi2N3; Preferably, the perovskite-type oxide solid electrolyte is selected from lithium lanthanum titanium oxide; The garnet-type oxide solid electrolyte is selected from one or more of lithium lanthanum zirconium oxide, niobium-doped lithium lanthanum zirconium oxide, tantalum-doped lithium lanthanum zirconium oxide, and niobium-tantalum dual-doped lithium lanthanum zirconium oxide; The NASICON type oxide solid electrolyte is selected from lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, One or more of lithium aluminum germanium oxide.

13. A battery pole piece, characterized in that: The battery pole piece includes at least one of the battery pole pieces prepared by the preparation method according to any one of claims 1 to 12.

14. The battery electrode sheet according to claim 13, wherein the battery electrode sheet comprises a positive electrode sheet or a negative electrode sheet and an organic polymer solid electrolyte layer disposed on the positive electrode sheet or the negative electrode sheet; Preferably, the thickness of the organic polymer solid electrolyte layer is 5-25 μm; Preferably, the organic polymer solid electrolyte layer further comprises one or more of an inorganic ceramic material and a conductive agent.

15. The battery pole piece according to claim 14, wherein the battery pole piece further comprises a second solid electrolyte layer on the organic polymer solid electrolyte layer; Preferably, the thickness of the second solid electrolyte layer is 10-50 μm; Preferably, the second solid electrolyte layer includes one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte.

16. A method for preparing a solid-state battery, comprising: A step of preparing a positive electrode sheet and / or a negative electrode sheet by the preparation method according to any one of claims 1 to 12; and The positive electrode sheet and the negative electrode sheet are rolled, dried, stacked, and then hot-pressed for integration. 17 . The preparation method according to claim 16 , wherein the temperature of the hot pressing integration is 50 to 85° C., the pressure is 0.1 to 0.6 MPa, and the hot pressing time is 20 to 40 minutes.

18. A solid-state battery, comprising at least one of the solid-state batteries prepared according to the preparation method according to claim 16 or 17.

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