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

Abstract

A composite electrode sheet and a preparation method therefor, a battery and a preparation method therefor, and a solid-state battery. By means of a high-pressure atomization spraying method, the agglomeration of tiny solute particles during the introduction of a slurry is prevented, thereby accurately controlling the thickness of a solid-state electrolyte layer while uniformly preparing a solid-state electrolyte-containing battery electrode sheet, and improving the energy density of a solid-state battery; in addition, the high-pressure atomization spraying method solves the problem of batch production of solid-state electrolyte-containing battery electrode sheets, thereby improving the production efficiency. In addition, the electrode sheet prepared by means of high-pressure atomization spraying can increase the contact area between a solid-state electrolyte and a battery electrode sheet, reduce the interfacial resistance, improve the lithium ion transmission rate, alleviate the solid-solid contact problem, construct a stable solid-state interface, realize the introduction of a continuous and compact solid-state electrolyte layer on an electrode sheet, and improve the electrochemical performance of solid-state batteries.

Description

Composite pole piece and preparation method thereof, battery and preparation method thereof, and solid-state battery

[0001] This application is based on the Chinese patent application with application number 202311007383.0 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 composite pole piece and a preparation method thereof, a battery and a preparation method thereof, and a solid-state battery. Background Art

[0003] With the rapid application and promotion of lithium-ion batteries in the new energy industry and the rapid growth of large-scale energy storage demand, the development of lithium-ion batteries with high energy density and high safety has become a common goal of academia and industry. Currently, commercial lithium-ion batteries use liquid organic electrolytes and polyolefin separators with poor thermal stability. In high-energy-density energy storage devices, as the operating temperature increases, the flammable and explosive liquid organic electrolytes and the separators that easily shrink and deform when heated will seriously affect the safety of lithium-ion batteries. In order to eliminate safety hazards such as fire and explosion caused by battery short circuits, replacing flammable liquid electrolytes and separators with thermodynamically stable solid electrolytes can effectively improve the safety of lithium-ion batteries while increasing their energy density. Therefore, the development and application of solid-state batteries have attracted much attention.

[0004] In the development of solid-state batteries, the preparation of battery pole pieces is crucial. Currently, new process paths for preparing solid-state battery pole pieces include magnetron sputtering and ultrasonic spraying. However, the magnetron sputtering process has low material utilization, extremely high costs, low production efficiency, and low yield, making it difficult to solve the problem of large-scale and uniform preparation of composite pole pieces. The ultrasonic atomization spraying process has a low liquid inlet flow rate, and in the actual production process, it is easy for tiny solute particles to agglomerate, resulting in blockage and sedimentation, resulting in poor interface contact between the solid electrolyte and the pole piece, increased interface impedance, and also resulting in excessively high maintenance costs during the production process and low coating efficiency. The front end of the ultrasonic generator has extremely high requirements for flow rate, frequency, and precision control, making it difficult to achieve continuous batch production.

[0005] Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Therefore, based on the current problems of particle clogging, sedimentation, difficulty in mass production, poor interface contact between solid electrolytes and battery electrodes, and high interface impedance in the production process, there is an urgent need to develop a method suitable for mass production of composite electrodes. While improving the effect and efficiency of the solid electrolyte introduction process, it is also necessary to improve the solid-solid contact interface, increase the lithium ion transmission rate, and construct a stable solid-state interface to achieve the goal of improving the electrochemical performance of solid-state batteries.

[0008] Solutions for solving problems

[0009] To address these issues, the present invention provides a method for preparing composite electrodes, which addresses the technical challenges of mass-producing solid-state battery electrodes and optimizes the integrated process for industrial solid-state battery production. While improving production efficiency, it also achieves the goal of improving the solid-solid interface between the solid electrolyte and the electrode, reducing interfacial impedance, and enhancing the electrochemical performance of solid-state batteries.

[0010] Specifically, the present invention provides a method for preparing a composite electrode, which comprises the following steps:

[0011] Step S1: preparing a solid electrolyte slurry containing a composition of a solid electrolyte and an optional lithium salt; and

[0012] Step S2: spraying the solid electrolyte slurry onto the surface of the positive electrode sheet or the negative electrode sheet by high-pressure atomization spraying and performing post-processing to obtain a positive electrode sheet or a negative electrode sheet having a solid electrolyte layer.

[0013] The atomization pressure in the high-pressure atomization spraying is 0.2-1.0 MPa, preferably 0.25-0.90 MPa.

[0014] According to the preparation method described above, in step S1, the solid content of the solid electrolyte slurry is 20-80% by mass, preferably 30-75% by mass;

[0015] Preferably, in step S2, the post-processing includes one or more of heating and curing, roller pressing, vacuum drying, and isostatic pressing.

[0016] According to the preparation method described above, in the high-pressure atomization spraying, the high-pressure pump pressure is 10-25 MPa, the nozzle diameter is 0.5-2.5 mm, the spray flow rate is 60-500 mL / min, the carrier gas flow rate is 50-350 L / min, the spraying distance is 50-300 mm, and the spraying angle is 80-90°.

[0017] According to the preparation method described above, the solid electrolyte is selected from one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte;

[0018] Preferably, the inorganic solid electrolyte is selected from one or more of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, borate solid electrolytes, and nitride solid electrolytes.

[0019] According to the preparation method described above, the oxide solid electrolyte is selected from one or more of perovskite-type oxide solid electrolytes, garnet-type oxide solid electrolytes, and NASICON-type oxide solid electrolytes;

[0020] The sulfide solid electrolyte is selected from one or more of lithium germanium phosphorus sulfur, lithium phosphorus sulfur chlorine, lithium thiophosphate, lithium silicon phosphorus sulfur chlorine, lithium phosphorus sulfur bromine, lithium phosphorus sulfur iodine, and vitreous sulfide;

[0021] 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, and X″ is selected from O, Cl, F, or OH), Li 3-y Zr y M′ 1-y Cl6 (M′ is selected from one or more of Y, Er, Yb, Ho, Lu, and 0 < y < 1);

[0022] The borate solid electrolyte is selected from one or more of Li2B4O7 and Li2O - B2O3 - P2O5;

[0023] The nitride solid electrolyte is selected from one or more of LiPON, Li3N, Li7PN4, and LiSi2N3;

[0024] The organic polymer solid electrolyte is selected from one or more of polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride - hexafluoropropylene, polyvinylidene fluoride - chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, poly(ethylene succinate), polyvinyl chloride, poly(vinylidene carbonate), polyvinyl pyrrolidone, polyimide, polyacrylate, polyurethane;

[0025] Preferably, the perovskite-type oxide solid electrolyte is selected from lithium lanthanum titanium oxide;

[0026] 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 co-doped lithium lanthanum zirconium oxide;

[0027] The NASICON type oxide solid electrolyte is selected from one or more of lithium titanium aluminum phosphate, lithium yttrium titanium phosphate, and lithium germanium aluminum phosphate.

[0028] According to the preparation method described above, when the solid electrolyte is an organic polymer solid electrolyte, the composition in step S1 contains a lithium salt;

[0029] Preferably, the composition in step S1 contains a binder.

[0030] According to the preparation method described above, the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalatoborate; and the binder is 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.

[0031] According to the preparation method described above, the composition in step S1 further comprises a quasi-solid electrolyte; the quasi-solid electrolyte is selected from one or more of aluminum oxide, silicon dioxide, boron oxide, titanium dioxide, zirconium dioxide, magnesium oxide, aluminum silicate, silicon nitride, titanium nitride, aluminum nitride, boron nitride, magnesium nitride, silicon carbide, and boron carbide;

[0032] Preferably, the mass ratio of the quasi-solid electrolyte to the solid electrolyte is 1:99 to 8:92.

[0033] The present invention also provides a composite electrode, which includes at least one of the electrode sheets having a solid electrolyte layer prepared according to the preparation method described above.

[0034] According to the composite electrode sheet described above, the electrode sheet with a solid electrolyte layer comprises a positive electrode sheet or a negative electrode sheet and a solid electrolyte layer provided on the positive electrode sheet or the negative electrode sheet;

[0035] Preferably, the solid electrolyte layer includes a solid electrolyte and a quasi-solid electrolyte.

[0036] According to the composite pole piece described above, the thickness of the solid electrolyte layer is 2 to 50 μm.

[0037] According to the composite electrode sheet described above, the peel strength between the solid electrolyte layer and the positive electrode sheet or the negative electrode sheet is 60.0 to 90.0 N / m when the peeling speed is 60 mm / min and the peeling angle is 180°.

[0038] The present invention also provides a method for preparing a solid-state battery, which includes the steps of preparing a positive electrode sheet and / or a negative electrode sheet having a solid electrolyte layer by the preparation method described above.

[0039] The present invention further provides a solid-state battery, which includes at least one of the solid-state batteries prepared according to the preparation method described above.

[0040] Effects of the Invention

[0041] The above technical solution of the present invention has the following beneficial effects:

[0042] (1) The present invention solves the problem of mass production of battery pole pieces containing solid electrolytes through high-pressure atomization spraying, thereby improving production efficiency;

[0043] (2) The present invention uses a high-pressure atomization spraying method to prevent the agglomeration of tiny solute particles during the slurry introduction process, thereby achieving uniform preparation of battery electrodes containing solid electrolytes while precisely controlling the thickness of the solid electrolyte layer, thereby improving the energy density of solid-state batteries;

[0044] (3) The electrode prepared by the high-pressure atomization method of the present invention can increase the contact area between the solid electrolyte and the battery active material, reduce the interface resistance, improve the lithium ion transmission rate, build a stable solid interface, and realize the introduction of a continuous and dense solid electrolyte layer on the electrode, thereby improving the electrochemical performance of the solid-state battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG1 is a schematic diagram showing the structure of a composite electrode including a solid electrolyte layer according to the present invention.

[0046] FIG2 shows the first charge and discharge curve of the composite electrode prepared in Example 1 of the present invention.

[0047] FIG3 is a scanning electron microscope image showing the composite electrode in Example 1 of the present invention. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this specification, unless otherwise specified, "multiple" in "multiple", "multiple", "many" and the like means a numerical value of 2 or more.

[0052] 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.

[0053] In this specification, unless otherwise specified, "%" means percentage by mass.

[0054] In this specification, when "room temperature" or "normal temperature" appears, the temperature may generally be 10-37°C, or 15-35°C.

[0055] 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.

[0056] Throughout this specification, “optional” 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.

[0057] 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.

[0058] 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.

[0059] In solid-state batteries, solid electrolytes are the core components. The intrinsic ionic conductivity of the solid electrolyte and the interface contact between the solid electrolyte layer and the battery pole piece are the main factors affecting the performance of solid-state batteries. Therefore, while improving the ionic conductivity of the solid electrolyte, a suitable process method is used to prepare a composite battery pole piece containing a solid electrolyte, increase the contact area between the active material and the solid electrolyte, achieve the purpose of improving the solid-solid contact interface, enhance the transfer of lithium ions at the interface, and then reduce the interface impedance. Building a stable solid interface is the key to improving the performance of solid-state batteries. At the same time, the development of a process method that can be used to mass-produce composite pole pieces is the current technical difficulty that restricts the commercialization of solid-state batteries.

[0060] At present, the main methods for preparing composite electrodes are wet coating and dry pressing. Among them, the traditional wet coating method has different requirements for the selection of solvents for different solid electrolytes. Even in polar solvents or non-polar solvents where the solid electrolyte is relatively stable, long-term immersion will lead to a decrease in ionic conductivity, and energy consumption will increase during the drying process. At the same time, the volatilization of organic solvents will cause environmental pollution. Therefore, this process method is not suitable for batch preparation of composite electrodes. For dry pressing, it is necessary to use a mold to press the solid electrolyte powder into shape under high pressure, and then assemble the positive and negative electrodes and the solid electrolyte together for use. However, the solid electrolyte layer prepared by dry pressing is thicker, which will increase the internal resistance of the battery, and the contact with the electrode interface is poor, resulting in increased interface impedance. Continuous pressurization is required during the test process, which limits the use scenarios of solid-state batteries. Therefore, this process method is not suitable for batch preparation of solid-state batteries.

[0061] Therefore, the present invention provides a method for preparing electrode sheets using high-pressure atomization. The electrode sheets obtained using this method can increase the contact area between the solid electrolyte and the battery active material, reduce interfacial resistance, establish a stable solid-state interface, and enhance the electrochemical performance of solid-state batteries. The preparation method of the composite electrode sheet of the present invention is described in detail below.

[0062] <First Aspect>

[0063] A first aspect of the present invention provides a method for preparing a composite electrode. The method comprises the following steps:

[0064] Step S1: preparing a solid electrolyte slurry containing a composition of a solid electrolyte and an optional lithium salt, and

[0065] Step S2: spraying the solid electrolyte slurry onto the surface of the positive electrode sheet or the negative electrode sheet by high-pressure atomization spraying and performing post-processing to obtain a positive electrode sheet or a negative electrode sheet having a solid electrolyte layer.

[0066] The atomization pressure in the high-pressure atomization spraying is 0.2-1.0 MPa, preferably 0.25-0.90 MPa.

[0067] The spray flow rate in high-pressure atomization spraying is 60-500 mL / min, preferably 100-300 mL / min.

[0068] In the present invention, there is no particular limitation on the method for preparing the positive electrode sheet or the negative electrode sheet, and the positive electrode sheet may be prepared using common methods in the art such as conventional coating methods, electrostatic spraying methods, and the like.

[0069] The following describes each step in detail.

[0070] Step S1

[0071] In step S1, a solid electrolyte slurry containing a composition of a solid electrolyte and an optional lithium salt can be purchased as an existing slurry or can be prepared. Therefore, preparing the solid electrolyte slurry includes purchasing a commercially available slurry or preparing the slurry.

[0072] When preparing the slurry, a composition containing the solid electrolyte and optionally a lithium salt is slurried in an organic solvent to prepare the solid electrolyte slurry.

[0073] In the present invention, there is no particular limitation on the solid electrolyte, and those commonly used in the art can be used.

[0074] In some embodiments of the present invention, the solid electrolyte may be selected from one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte. The inorganic solid electrolyte may be 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. When two or more solid electrolytes are used, the ratio between them is not particularly limited and can be adjusted according to actual needs.

[0075] The oxide solid electrolyte may be selected from one or more of a perovskite-type oxide solid electrolyte, a garnet-type oxide solid electrolyte, and a NASICON-type oxide solid electrolyte.

[0076] The perovskite oxide solid electrolyte may be selected from lithium lanthanum titanium oxide. The garnet oxide solid electrolyte may be 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 oxide solid electrolyte may be selected from one or more of lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, and lithium aluminum germanium phosphate.

[0077] The sulfide solid electrolyte can be selected from one or more of lithium germanium phosphorus sulfur (LGPS), lithium silicon phosphorus sulfur chlorine, lithium phosphorus sulfur bromine, lithium phosphorus sulfur iodine, lithium phosphorus sulfur chlorine (LPSCl), lithium thiophosphate (LPS), vitreous sulfides (Li2S-P2S5, Li2S-SiS2, Li2S-B2S3).

[0078] The halide solid electrolyte can be selected from Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x (where 0 < x < 1), Li2XCl4 (X = Cd and / or Mg), Li2X′I4 (X′ = Cd and / or Zn), LiMCl5X″ (M is selected from one or more of La, Ta, Nb, and X″ is selected from O, Cl, F or OH), Li<0​​​​​​​​​​​​​​​​In some preferred embodiments of the present invention, the composition in step S1 may further include a quasi-solid electrolyte as an inorganic filler. In the present invention, the quasi-solid electrolyte may be selected from one or more of aluminum oxide (Al2O3), silicon dioxide (SiO2), boron oxide (B2O3), titanium dioxide (TiO2), zirconium dioxide (ZrO2), magnesium oxide (MgO), aluminum silicate (Al2SiO5), silicon nitride (Si3N4), titanium nitride (TiN), aluminum nitride (AlN), boron nitride (BN), magnesium nitride (Mg3N2), silicon carbide (SiC), and boron carbide (B4C). In the present invention, the addition of inorganic fillers can improve the electrochemical stability window of the solid electrolyte, reduce the crystalline region of the polymer, induce ion transport behavior and form a new ion transport interface, improve ion conductivity, and increase the compatibility of the electrode and the solid electrolyte interface.

[0083] When a quasi-solid electrolyte is included in the composition in step S1, the mass ratio of the quasi-solid electrolyte to the solid electrolyte may be 1:99 to 8:92, for example, 1:99, 2:98, 3:97, 4:96, 5:95, 6:94, 7:93, 8:92, etc. The proportion of the quasi-solid electrolyte relative to the total mass of the composition may be 10% to 20% by mass, for example, 10% by mass, 12% by mass, 15% by mass, 18% by mass, 20% by mass, etc. If the quasi-solid electrolyte content is too low, the interface contact deteriorates, resulting in an increase in the interface impedance, affecting the rate performance of the solid-state battery. If the quasi-solid electrolyte content is too high, the ionic conductivity decreases, reducing the capacity and cycle stability of the solid-state battery.

[0084] The composition in step S1 preferably further comprises one or more of a lithium salt and a binder. When the solid electrolyte is only an organic polymer solid electrolyte, the composition must contain a lithium salt.

[0085] There is no particular limitation on lithium salts and binders, and those commonly used in the art can be used. In some embodiments of the present invention, examples of lithium salts can be any one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and lithium difluorooxalatoborate. Examples of binders can be one or more of polyvinylidene fluoride, polyvinyl alcohol, polytetrafluoroethylene, sodium hydroxymethylcellulose, and styrene-butadiene rubber.

[0086] When the composition in step S1 contains a lithium salt, the mass ratio of the lithium salt to the solid electrolyte can be 1:2 to 1:5, for example, 1:2, 1:3, 1:4, 1:5, etc. The proportion of the lithium salt relative to the total mass of the composition can be 20% to 30% by mass, for example, 20% by mass, 22% by mass, 25% by mass, 28% by mass, 30% by mass, etc. When the composition in step S1 contains a binder, its amount is not particularly limited and can be an amount commonly used in the art.

[0087] In the present invention, 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, acetone, dimethyl sulfoxide and glycol ether.

[0088] In some specific embodiments, the solid electrolyte, optional quasi-solid electrolyte, optional lithium salt, etc. can be ball-milled and sand-milled during homogenization, for example, at a rotation speed of 300-600 r / min for 4-8 hours to obtain a composition; the composition is added to an organic solvent in batches, and then a dispersant and a thickener are added, and the mixture is fully stirred for 8-15 hours to obtain a solid electrolyte slurry.

[0089] In the present invention, the dispersant is not particularly limited, and those commonly used in the art can be used.

[0090] In the present invention, the solid content of the solid electrolyte slurry can be 20% to 80% by mass, preferably 30% to 75% by mass, for example, 30%, 40%, 50%, 60%, 70%, 75%, 80% by mass, etc. A solid content within the above range is conducive to the spraying and uniform distribution of the solid electrolyte, preventing process problems such as material sticking during high-pressure atomization spraying due to excessively high concentration, and preventing process problems such as powder falling during high-pressure atomization spraying due to excessively low concentration, which affects the distribution of the solid electrolyte on the battery electrode.

[0091] Step S2

[0092] The solid electrolyte slurry prepared in step S1 is sprayed onto the surface of the positive electrode sheet or the negative electrode sheet by high-pressure atomization spraying and then post-processed to obtain a positive electrode sheet or a negative electrode sheet containing a solid electrolyte layer.

[0093] In the present invention, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material formed on the positive electrode current collector; the negative electrode sheet includes a negative electrode current collector and a negative electrode active material formed on the negative electrode current collector.

[0094] The positive electrode sheet or the negative electrode sheet can be commercially available or prepared. During the preparation, a positive electrode collector or a negative electrode collector can be provided, and then the positive electrode active material slurry or the positive electrode active material slurry is coated on the positive electrode collector or the negative electrode collector. Of course, other conventional drying, rolling and other steps may also be included, which will not be repeated here.

[0095] In the present invention, during the high-pressure atomization spraying in step S2, the atomization pressure can be 0.2-1.0 MPa, preferably 0.25-0.9 MPa, for example, 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, etc. When the pressure of the high-pressure atomization is within the above range, the slurry can be evenly sprayed on the surface of the battery electrode, which is beneficial for controlling the thickness of the obtained solid electrolyte layer and increasing the effective adsorption rate of the solid electrolyte slurry. If the atomization pressure is too low, the solid electrolyte sprayed on the surface of the battery electrode will be unevenly distributed and affect the interface contact between the solid electrolyte layer and the battery electrode. If the atomization pressure is too high, it will be detrimental to the dispersion of the slurry, and the thickness of the prepared solid electrolyte layer will be uneven.

[0096] In addition, the spraying conditions in the high-pressure atomization spraying of the present invention also include the following:

[0097] The high-pressure pump pressure is 10-25 MPa, for example, 10 MPa, 15 MPa, 20 MPa, 25 MPa, etc.;

[0098] The spraying flow rate is 60-500 mL / min, for example, 60 mL / min, 100 mL / min, 150 mL / min, 180 mL / min, 200 mL / min, 230 mL / min, 270 mL / min, 300 mL / min, 350 mL / min, 400 mL / min, 450 mL / min, 500 mL / min, etc.

[0099] The diameter of the nozzle is 0.5 to 2.5 mm, for example, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, etc.

[0100] The carrier gas flow rate is controlled to be 50-350 L / min, for example, 50 L / min, 100 L / min, 150 L / min, 200 L / min, 250 L / min, 300 L / min, 350 L / min, etc.;

[0101] The spraying distance between the target battery electrode and the high-pressure atomization equipment can be 50 to 300 mm, preferably 30 to 180 mm, for example, 50 mm, 60 mm, 80 mm, 100 mm, 120 mm, 150 mm, 180 mm, 200 mm, 230 mm, 260 mm, 300 mm, etc.

[0102] The spraying angle may be 80° to 90°, for example, 80°, 85°, 88°, 90°, etc.

[0103] Selecting a nozzle diameter and spray flow rate within the above range can reduce the problems of solid electrolyte particle agglomeration and slurry waste, improve the control accuracy and high-pressure atomization spraying effect during the spraying process, increase spraying efficiency and reduce equipment maintenance costs.

[0104] In addition, the high-pressure atomization spraying of the present invention is preferably carried out in a dry environment with a moisture content of less than 10 ppm, preferably 5 ppm, and more preferably less than 1 ppm.

[0105] In some preferred embodiments of the present invention, the positive electrode or negative electrode can be heated. The heating temperature can be 55-205°C, preferably 75-155°C, for example, 55°C, 60°C, 70°C, 75°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 155°C, 160°C, 170°C, 180°C, 190°C, 200°C, 205°C, etc. By heating the electrode, the electrolyte slurry can be evenly distributed on the surface of the electrode, reducing the agglomeration of the solid electrolyte during the mixing process, and improving the cycle stability of the battery.

[0106] In some embodiments, the positive electrode sheet or the negative electrode sheet is placed on a work plate for operation. Thus, both the heating of the positive electrode sheet or the negative electrode sheet and the drying after spraying can be achieved by the work plate, thereby reducing the process flow and achieving mass production.

[0107] In some specific embodiments, the positive electrode sheet or the negative electrode sheet is placed on a working plate, which is then heated and sprayed under the conditions. The electrolyte slurry is sprayed onto the surface of the sheet to the desired thickness. After standing for a period of time, the sheet is dried and cooled naturally to obtain a positive electrode sheet or a negative electrode sheet containing an electrolyte layer.

[0108] In some embodiments, during the standing period, the temperature of the working plate may be raised to a temperature slightly higher than the heating temperature during spraying, for example, 10 to 30° C. higher. The standing period may be, for example, 20 to 120 minutes.

[0109] After the solid electrolyte slurry is evenly applied to the surface of the positive or negative electrode sheet via high-pressure atomization spraying, post-processing is performed. This post-processing may include one or more of heat curing, roller pressing, vacuum drying, and isostatic pressing. The following uses heat curing as an example for illustration.

[0110] After the slurry is sprayed, a heat curing treatment can be performed, and drying can be performed before the heat curing treatment. In some embodiments of the present invention, the above-mentioned drying includes vacuum drying at a temperature of 50-100°C, preferably 60-90°C for 1-3 hours, and then vacuum drying at 50-100°C, preferably 50-80°C for 8-16 hours, preferably 9 to 12 hours. After drying is completed, a heat curing treatment is performed. In some embodiments of the present invention, the temperature of heat curing can be 50 to 80°C, preferably 60 to 80°C, the time of heat curing can be 10 to 60 minutes, 20 to 40 minutes, and the pressure of heat curing can be 0.2 to 1.0 MPa, preferably 0.3 to 0.8 MPa.

[0111] After thermal curing, the product is naturally cooled to obtain a positive electrode sheet or a negative electrode sheet having a solid electrolyte layer.

[0112] In some embodiments of the present invention, the thickness of the solid electrolyte layer may be 2 to 50 μm, for example, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. The thickness of the solid electrolyte layer within the above range can effectively separate the positive electrode and the negative electrode, and ensure the cycle stability of the solid-state battery while ensuring the battery energy density. If the thickness of the solid electrolyte layer is too low, it will lead to interface failure during the cycle and short circuit caused by contact between the positive and negative electrodes; if the thickness is too high, the internal resistance of the battery will increase, which will increase the cost and is not conducive to the design of high energy density battery cells.

[0113] In the preparation method of the present invention, by regulating the solid content of the solid electrolyte slurry and the process parameters of the high-pressure atomization spraying device, the slurry containing the solid electrolyte meets the high-pressure atomization spraying requirements, improves the process problems such as material sticking and clogging caused by solid electrolyte agglomeration and sedimentation, greatly improves production efficiency and reduces equipment maintenance costs, has good atomization effect and high control accuracy, and can realize the direct construction of a continuous and dense solid electrolyte layer on the battery electrode, enhances the interface contact between the electrode and the solid electrolyte layer, reduces the interface impedance, and thus improves the electrochemical performance of the solid-state battery.

[0114] The present invention uses a high-pressure atomization spraying method to prevent the agglomeration of tiny solute particles during the introduction of the slurry, thereby achieving uniform preparation of composite pole pieces while precisely controlling the thickness of the solid electrolyte layer and improving the energy density of the solid-state battery. The present invention solves the problem of mass production of battery pole pieces containing solid electrolytes through high-pressure atomization spraying, thereby improving production efficiency.

[0115] <Second Aspect>

[0116] The second aspect of the present invention relates to a composite electrode sheet, which includes at least one of the electrode sheets having a solid electrolyte layer obtained by the preparation method described in the above <first aspect>.

[0117] The composite electrode sheet of the present invention includes a positive electrode sheet or a negative electrode sheet and a solid electrolyte layer disposed on the positive electrode sheet or the negative electrode sheet. In some preferred embodiments, the solid electrolyte layer includes a solid electrolyte and a quasi-solid electrolyte. The thickness of the solid electrolyte layer can be 2-50 μm.

[0118] The electrode piece prepared by the high-pressure atomization method of the present invention can increase the contact area between the solid electrolyte and the battery electrode piece, reduce the interface resistance, increase the lithium ion transmission rate, build a stable solid interface, and improve the electrochemical performance of the solid-state battery.

[0119] FIG1 shows a schematic structural diagram of a composite electrode with a solid electrolyte layer according to the present invention.

[0120] The peel strength of the composite electrode sheet of the present invention at a peeling speed of 60 mm / min and a peeling angle of 180° (specifically, the peel strength between the current collector and the layer on the current collector) is 60.0 to 90.0 N / m, preferably 70.0 to 87.0 N / m, for example, 60.0 N / m, 65.0 N / m, 70.0 N / m, 72.0 N / m, 75.0 N / m, 78.0 N / m, 80.0 N / m, 82.0 N / m, 85.0 N / m, 87.0 N / m, 90.0 N / m, etc. The specific test method for the peel strength can be found in the method described in the examples below.

[0121] <Third Aspect>

[0122] The third aspect of the present invention relates to a method for preparing a solid-state battery, which includes the steps of preparing a positive electrode sheet having a solid electrolyte layer and / or a negative electrode sheet having a solid electrolyte layer by the preparation method described in the above <first aspect>.

[0123] Subsequent steps in the preparation of solid-state batteries can be performed using conventional procedures in the art. For example, the positive and / or negative electrode sheets prepared by the above-described preparation method can be processed by one or more of the following processes: roll pressing, vacuum drying, and isostatic pressing to obtain composite positive or negative electrode sheets. The resulting composite positive or negative electrode sheets are then laminated and packaged, and then integrated by hot pressing to obtain a solid-state battery.

[0124] The present invention also provides a solid-state battery, comprising at least one of the solid-state batteries obtained by the above-described method for preparing a solid-state battery. The solid-state battery described in the present invention includes a fully solid-state battery and a semi-solid-state battery.

[0125] Example

[0126] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0127] Example 1

[0128] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0129] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added in batches to DMF organic solvent and a dispersant (purchased from Aladdin S-17650, the same below) was added and stirred thoroughly for 12 hours to obtain a slurry with a solid content of 60% by mass;

[0130] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry was evenly sprayed onto the surface of a lithium iron phosphate positive electrode sheet (purchased from Aladdin L-68230, the same below) by a high-pressure atomization spraying method, wherein the nozzle diameter was 1.8 mm, the spraying distance was 230 mm, the spraying angle was 89°, the carrier gas flow rate was 150 L / min, the high-pressure pump pressure was 20 MPa, the atomization pressure was set to 0.6 MPa, and the spraying flow rate was controlled at 120 mL / min to obtain a composite electrode sheet with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0131] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0132] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0133] Example 2

[0134] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0135] (1) B2O3 and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 65% by mass was obtained;

[0136] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 240 mm, the spraying angle is 89°, the carrier gas flow rate is 100 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.5 MPa, and the spraying flow rate is controlled at 150 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0137] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0138] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0139] Example 3

[0140] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0141] (1) SiO2 and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 55% by mass was obtained;

[0142] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 250 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 15 MPa, the atomization pressure is set to 0.5 MPa, and the spraying flow rate is controlled at 150 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0143] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0144] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0145] Example 4

[0146] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0147] (1) B2O3, PVDF-HFP, and LiTFSI were mixed in a mass ratio of 1:6:3 by ball milling at a speed of 300 r / min for 2 hours, and then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 70% by mass was obtained;

[0148] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 2.0 mm, the spraying distance is 200 mm, the spraying angle is 90°, the carrier gas flow rate is 200 L / min, the high-pressure pump pressure is 25 MPa, the atomization pressure is set to 0.3 MPa, and the spraying flow rate is controlled at 230 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a polymer solid electrolyte with a thickness of 40 μm;

[0149] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 10 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0150] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0151] Example 5

[0152] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0153] (1) BN, PVDF-HFP, and LiTFSI were mixed in a mass ratio of 1:6:3 by ball milling at a speed of 300 r / min for 2 hours, and then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 70% by mass was obtained;

[0154] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry was evenly sprayed onto the surface of the NCM622 positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter was 2.0 mm, the spraying distance was 200 mm, the spraying angle was 90°, the carrier gas flow rate was 150 L / min, the high-pressure pump pressure was 25 MPa, the atomization pressure was set to 0.4 MPa, and the spraying flow rate was controlled at 260 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a polymer solid electrolyte with a thickness of 40 μm;

[0155] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 10 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0156] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0157] Example 6

[0158] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0159] (1) BN, polypentane succinate, and LiTFSI were mixed in a mass ratio of 2:5:3 by ball milling at a speed of 300 r / min for 2 hours, and then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 70% by mass was obtained;

[0160] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 2.0 mm, the spraying distance is 210 mm, the spraying angle is 90°, the carrier gas flow rate is 180 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.3 MPa, and the spraying flow rate is controlled at 240 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a polymer solid electrolyte with a thickness of 40 μm;

[0161] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0162] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0163] Example 7

[0164] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0165] (1) B2O3, Li 6.75 La3Zr 1.75 Nb 0.25 O 12 PVDF-HFP and LiTFSI were mixed at a mass ratio of 1:3:4:2 by ball milling at a speed of 500 r / min for 6 hours, then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 65% by mass was obtained;

[0166] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 200 mm, the spraying angle is 89°, the carrier gas flow rate is 180 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.5 MPa, and the spraying flow rate is controlled at 260 mL / min to obtain a composite electrode sheet with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0167] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0168] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0169] Example 8

[0170] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0171] (1) BN, Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , polypentylene succinate and LiTFSI were mixed in a mass ratio of 1:5:2:2 by ball milling at a speed of 500 r / min for 6 hours, then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 65% by mass was obtained;

[0172] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry was evenly sprayed onto the surface of the NCM622 positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter was 1.8 mm, the spraying distance was 200 mm, the spraying angle was 89°, the carrier gas flow rate was 180 L / min, the high-pressure pump pressure was 25 MPa, the atomization pressure was set to 0.5 MPa, and the spraying flow rate was controlled at 200 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0173] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0174] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0175] Example 9

[0176] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0177] (1) SiO2, Li 6.75 La3Zr 1.75 Nb 0.25 O 12PVDF-HFP and LiTFSI were mixed at a mass ratio of 1:5:2:2 by ball milling at a speed of 500 r / min for 6 hours, then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 65% by mass was obtained;

[0178] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry was evenly sprayed onto the surface of the NCM622 positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter was 1.8 mm, the spraying distance was 200 mm, the spraying angle was 89°, the carrier gas flow rate was 180 L / min, the high-pressure pump pressure was 25 MPa, the atomization pressure was set to 0.5 MPa, and the spraying flow rate was controlled at 200 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0179] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0180] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0181] Example 10

[0182] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0183] (1) Li 6.75 La3Zr 1.75 Nb 0.25 O 12 PVDF-HFP, polypentylene succinate and LiTFSI were mixed at a mass ratio of 5:2:1:2 by ball milling at a speed of 500 r / min for 3 hours, then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 75% by mass was obtained;

[0184] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 200 mm, the spraying angle is 89°, the carrier gas flow rate is 210 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 200 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0185] (3) The obtained composite positive electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0186] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0187] Example 11

[0188] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0189] (1) Li 6.75 La3Zr 1.75 Nb 0.25 O 12 PVDF-HFP, polypentylene succinate and LiTFSI were mixed at a mass ratio of 5:2:1:2 by ball milling at a speed of 300 r / min for 3 hours, and then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 75% by mass was obtained;

[0190] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the graphite negative electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 200 mm, the spraying angle is 89°, the carrier gas flow rate is 210 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.5 MPa, and the spraying flow rate is controlled at 200 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0191] (3) The obtained composite negative electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0192] (4) Assembling the composite negative electrode sheet obtained in the above steps with the lithium iron phosphate positive electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0193] Example 12

[0194] The present invention provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The specific steps are as follows:

[0195] (1) Li 6.75 La3Zr 1.75Nb 0.25 O 12 PVDF-HFP and LiTFSI were mixed at a mass ratio of 5:3:2 by ball milling at a speed of 300 r / min for 3 hours, then added to DMF organic solvent in batches and a dispersant was added. After being fully stirred for 8 hours, a slurry with a solid content of 75% by mass was obtained;

[0196] (2) In a dry environment with a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the silicon-carbon negative electrode by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 200 mm, the spraying angle is 89°, the carrier gas flow rate is 200 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.5 MPa, and the spraying flow rate is controlled at 200 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a composite solid electrolyte with a thickness of 35 μm;

[0197] (3) The obtained composite negative electrode sheet was vacuum dried at 65° C. for 12 hours, and then heat-cured at 60° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0198] (4) Assembling the composite negative electrode sheet obtained in the above steps with the lithium iron phosphate positive electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0199] Comparative Example 1

[0200] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the atomization pressure applied is different. The specific process is as follows:

[0201] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0202] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.15 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0203] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0204] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0205] Comparative Example 2

[0206] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the spray flow rate applied is different. The specific process is as follows:

[0207] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0208] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 10 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0209] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0210] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0211] Comparative Example 3

[0212] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the spray flow rate applied is different. The specific process is as follows:

[0213] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0214] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 600 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0215] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0216] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0217] Comparative Example 4

[0218] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the solid content of the prepared slurry is different. The specific process is as follows:

[0219] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12, after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 5% by mass was obtained;

[0220] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0221] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0222] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0223] Comparative Example 5

[0224] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the solid content of the prepared slurry is different. The specific process is as follows:

[0225] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 90% by mass was obtained;

[0226] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0227] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0228] (4) Assemble the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrate them into a solid-state battery through hot pressing.

[0229] Comparative Example 6

[0230] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the diameter of the nozzle is different. The specific process is as follows:

[0231] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0232] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 0.3 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0233] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0234] (4) Assemble the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrate them into a solid-state battery through hot pressing.

[0235] Comparative Example 7

[0236] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the diameter of the nozzle is different. The specific process is as follows:

[0237] (1) BN and Li 6.75 La3Zr1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0238] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode sheet by a high-pressure atomization spraying method, wherein the nozzle diameter is 4.0 mm, the spraying distance is 230 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0239] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0240] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0241] Comparative Example 8

[0242] This comparative example provides a solid electrolyte introduction method, which uses high-pressure atomization spraying to prepare a composite electrode containing a solid electrolyte. The difference from Example 1 is that the spraying distance is adjusted differently. The specific process is as follows:

[0243] (1) BN and Li 6.75 La3Zr 1.75 Nb 0.25 O 12 , after mixing the materials in a mass ratio of 2:98 by ball milling and sand milling at a speed of 500 r / min for 6 hours, they were added to DMF organic solvent in batches and a dispersant was added, and after being fully stirred for 12 hours, a slurry with a solid content of 60% by mass was obtained;

[0244] (2) In a dry environment with an oxygen content and a moisture content of less than 1 ppm, the prepared slurry is evenly sprayed onto the surface of the lithium iron phosphate positive electrode plate by a high-pressure atomization spraying method, wherein the nozzle diameter is 1.8 mm, the spraying distance is 600 mm, the spraying angle is 89°, the carrier gas flow rate is 150 L / min, the high-pressure pump pressure is 20 MPa, the atomization pressure is set to 0.6 MPa, and the spraying flow rate is controlled at 120 mL / min to obtain a composite electrode with a solid electrolyte layer containing a quasi-solid electrolyte and a solid electrolyte with a thickness of 35 μm;

[0245] (3) The obtained composite positive electrode sheet was vacuum dried at 80° C. for 10 hours, and then heat-cured at 80° C. for 30 minutes at a pressure of 0.5 MPa. After cooling, the composite electrode sheet was obtained.

[0246] (4) Assembling the composite positive electrode sheet obtained in the above steps with the lithium metal negative electrode into a battery, and then integrating them through hot pressing to obtain a solid-state battery.

[0247] Performance testing:

[0248] Interfacial impedance testing: The prepared composite electrode and lithium metal sheet were assembled into a button cell. The AC impedance was measured using an electrochemical workstation with a voltage amplitude of 5 mV and a frequency range of 0.1 Hz to 1 MHz. The results are shown in Table 1.

[0249] Cycling stability test: The solid-state batteries obtained by hot pressing were charged and discharged at a rate of 0.2C at 30°C for 200 cycles for each example. The battery capacity before and after the 200 cycles was recorded. The initial charge and discharge capacity was also recorded, and the initial coulombic efficiency was calculated. The results are shown in Table 1.

[0250] Peel strength testing was conducted in a peel force tester at 25°C (room temperature) and a -40°C (dew point) humidity. One side of the prepared battery electrode current collector was adhered to a work surface using double-sided adhesive tape. Test tape was then used to connect the sample surface to the peel force tester. The test was performed at a speed of 60 mm / min and a peel angle of 180°. The peel force was recorded. The results are shown in Table 2.

[0251] Table 1

[0252] Table 2

[0253] Summarizing the test data in Table 1 and Table 2, by comparing and analyzing the test results of Examples 1-12 and Comparative Examples 1-10, when the applied process conditions are within the preferred range of high-pressure atomization spraying, the composite pole pieces prepared in Examples 1-12 have higher peel strength, the adhesion between the active substances of the composite pole pieces containing solid electrolytes is stronger, and the contact with the current collector is closer, which effectively reduces the interfacial impedance, and the first coulombic efficiency of the obtained solid-state battery is much higher than that of Comparative Examples 1-10, and it can be stably cycled for more than 200 times at a rate of 0.2C, showing good cycle stability. While significantly improving production efficiency, the electrochemical performance of the solid-state battery is further optimized.

[0254] FIG2 is the first charge and discharge curve of the composite electrode in Example 1. The first charge and discharge efficiency thereof is as high as 98.83%, which is significantly better than that of Comparative Example 1.

[0255] FIG3 is a scanning electron microscope characterization of the composite electrode prepared in Example 1. No agglomeration of solid electrolyte particles was found, and the solid electrolyte was evenly dispersed, successfully achieving the introduction of a continuous and dense solid electrolyte layer on the electrode.

[0256] 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.

[0257] Industrial applicability

[0258] The present invention uses a high-pressure atomization spraying method to prevent the agglomeration of tiny solute particles during the slurry introduction process, thereby achieving uniform preparation of battery pole pieces containing solid electrolytes while precisely controlling the thickness of the solid electrolyte layer, thereby improving the energy density of solid-state batteries. Furthermore, the high-pressure atomization spraying method of the present invention solves the problem of mass production of battery pole pieces containing solid electrolytes, thereby improving production efficiency. Furthermore, the pole pieces prepared by the present invention using high-pressure atomization can increase the contact area between the solid electrolyte and the battery pole piece, reduce interfacial resistance, increase the lithium ion transfer rate, construct a stable solid-state interface, and improve the electrochemical performance of solid-state batteries.

Claims

1. A method for preparing a composite pole piece, characterized in that: It includes the following steps: Step S1: preparing a solid electrolyte slurry containing a composition of a solid electrolyte and an optional lithium salt; and Step S2: spraying the solid electrolyte slurry onto the surface of the positive electrode sheet or the negative electrode sheet by high-pressure atomization spraying and performing post-treatment to obtain a positive electrode sheet or a negative electrode sheet having a solid electrolyte layer. The atomization pressure in the high-pressure atomization spraying is 0.2-1.0 MPa, preferably 0.25-0.90 MPa.

2. The preparation method according to claim 1, wherein in step S1, the solid content of the solid electrolyte slurry is 20-80 mass %, preferably 30-75 mass %; Preferably, in step S2, the post-treatment includes one or more of heating and curing, roller pressing, vacuum drying, and isostatic pressing.

3. The preparation method according to claim 1 or 2, wherein in the high-pressure atomization spraying, the high-pressure pump pressure is 10-25 MPa, the nozzle diameter is 0.5-2.5 mm, the spraying flow rate is 60-500 mL / min, the carrier gas flow rate is 50-350 L / min, the spraying distance is 50-300 mm, and the spraying angle is 80-90°.

4. The preparation method according to any one of claims 1 to 3, wherein the solid electrolyte is selected from one or more of an inorganic solid electrolyte and an organic polymer solid electrolyte; Preferably, 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.

5. The preparation method according to claim 4, 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 thiophosphate, lithium silicon phosphosulfuryl chloride, lithium phosphosulfuryl bromine, lithium phosphosulfuryl iodine, and glassy sulfide; The halide solid electrolyte is selected from Li3OCl, LiI, Li5ZnI4, Li3OCl 1-x Br x (in 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, and X'' is selected from O, Cl, F, or OH), Li 3-y Zr y M′ 1-y Cl6 (M′ is selected from one or more of Y, Er, Yb, Ho, Lu, 0 < y < 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; The organic polymer solid electrolyte is selected from one or more of polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyacrylonitrile, polymethyl methacrylate, polypropylene carbonate, polyphenylene sulfide, polyethyl cyanoacrylate, polypentylene succinate, polyvinyl chloride, polyvinyl carbonate, polyvinyl pyrrolidone, polyimide, polyacrylate, and polyurethane; 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 one or more of lithium aluminum titanium phosphate, lithium yttrium titanium phosphate, and lithium aluminum germanium phosphate.

6. The preparation method according to claim 4 or 5, wherein when the solid electrolyte is an organic polymer solid electrolyte, the composition in step S1 comprises a lithium salt; Preferably, the composition in step S1 contains a binder.

7. The preparation method according to claim 6, wherein the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalatoborate; and the binder is selected from one or more of polyvinylidene fluoride, polyvinyl alcohol, polytetrafluoroethylene, sodium hydroxymethylcellulose, styrene-butadiene rubber, nitrile rubber, styrene-butadiene-styrene copolymer, polyacrylic acid and lithium polyacrylate.

8. The preparation method according to any one of claims 1 to 7, wherein the composition in step S1 further comprises a quasi-solid electrolyte; the quasi-solid electrolyte is selected from one or more of aluminum oxide, silicon dioxide, boron oxide, titanium dioxide, zirconium dioxide, magnesium oxide, aluminum silicate, silicon nitride, titanium nitride, aluminum nitride, boron nitride, magnesium nitride, silicon carbide, and boron carbide; Preferably, the mass ratio of the quasi-solid electrolyte to the solid electrolyte is 1:99 to 8:

92.

9. According to the preparation method according to any one of claims 1 to 8, the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material formed on the positive electrode current collector; the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material formed on the negative electrode current collector.

10. A composite pole piece, characterized in that: The pole piece with a solid electrolyte layer includes at least one of the pole pieces with a solid electrolyte layer prepared by the preparation method according to any one of claims 1 to 9.

11. The composite electrode sheet according to claim 10, wherein the electrode sheet having a solid electrolyte layer comprises a positive electrode sheet or a negative electrode sheet and a solid electrolyte layer disposed on the positive electrode sheet or the negative electrode sheet; Preferably, the solid electrolyte layer includes a solid electrolyte and a quasi-solid electrolyte. 12 . The composite pole piece according to claim 10 , wherein the thickness of the solid electrolyte layer is 2 to 50 μm.

13. A method for preparing a battery, comprising the step of preparing a positive electrode sheet and / or a negative electrode sheet having a solid electrolyte layer by the preparation method according to any one of claims 1 to 9.

14. A solid-state battery comprising at least one of the batteries prepared according to the preparation method of claim 13.

15. A battery comprising at least one of the batteries prepared by the preparation method according to claim 13.

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