Positive plate, solid-state battery and preparation method of solid-state battery

Abstract

The invention provides a positive plate, a solid-state battery and a preparation method of the positive plate, the positive plate comprises a positive current collector, a conductive layer and an interface layer, the conductive layer is formed by compounding a positive active material and an LATP-based composite solid-state electrolyte, the LATP-based composite solid-state electrolyte comprises LATP powder and a sulfide layer, the sulfide layer comprises one or more sulfides, and the interface layer is formed by compounding a positive active material and an LATP-based composite solid-state electrolyte. The sulfide has a general formula of LixPSy, LixPSy alpha z or LixPSy alpha z beta k, 0 < x < = 10, 0 < y < = 12, 0 < z < = 2, 0 < k < = 2, alpha and beta are respectively selected from any one of Cl, Br, I, Ge, Si, Se, Sn, Al and Ga elements, the interface layer is formed by reversible covalent bond crosslinking, and the thickness of the interface layer is 10-50nm. LATP is coated with a sulfide layer, direct contact of positive active substances is effectively isolated, Ti < 4 + > reduction is inhibited, and an interface layer formed by reversible covalent bond crosslinking is combined, so that the deformation resistance and dynamic repair performance of a conductive layer are enhanced, stress between rigid structures is dispersed, and interface stripping is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid-state batteries, in particular to a positive electrode sheet, a solid-state battery and a preparation method thereof. BACKGROUND

[0002] With the increasing demand for commercialized solid-state batteries, solid-state electrolytes represented by NASICON-type lithium titanium aluminum phosphate (Li 1+ x Al x Ti 2-x (PO4)3, LATP) have attracted much attention due to their high ionic conductivity (~10 -3 S / cm), wide electrochemical window (>4.5V vs. Li + / Li) and low cost. However, LATP still faces the following key challenges in practical applications:

[0003] 1) Interfacial side reactions: When LATP directly contacts with positive electrode ternary materials, the residual lithium compounds (such as Li2O, LiOH) on the surface of the positive electrode ternary materials will react with Ti 4+ in LATP, resulting in a sharp increase in interfacial impedance and capacity decay. In addition, the reduction reaction of Ti 4+ at the interface between the lithium metal anode and LATP and the problem of lithium dendrite penetration further limit the application of LATP.

[0004] 2) Insufficient mechanical stability: When traditional LATP is compounded in the positive electrode sheet, the rigid contact between the LATP powder and the positive electrode active material is easily affected by the volume change during charging and discharging, resulting in cracks and broken ion transport paths.

[0005] 3) Poor process compatibility: The existing preparation of LATP composite electrolyte mainly relies on high-temperature sintering above 1000℃, and high temperature easily causes Li volatilization in LATP and generates inactive phases (such as AlPO4), reducing the ionic conductivity of the material. SUMMARY

[0006] To solve the above problems, a sulfide layer is coated on the surface of the LATP powder to form a core-shell material of LATP@sulfide to inhibit the interfacial side reaction, and a LATP-based composite solid-state electrolyte with a core-shell structure is prepared to form a conductive layer, and then an interface layer is formed through dynamic disulfide cross-linking, which can not only inhibit the side reaction, but also self-repair cracks and relieve interfacial fracture caused by stress, and improve the mechanical properties.

[0007] Based on this, the first aspect of the present application provides a positive electrode sheet, which comprises a positive electrode current collector, a conductive layer coated on the positive electrode current collector, and an interface layer covering the surface of the conductive layer, wherein the conductive layer is formed by compounding a positive electrode active material and a LATP-based composite solid electrolyte, the LATP-based composite solid electrolyte comprises a LATP powder and a sulfide layer coated on the surface of the LATP powder, the sulfide layer comprises one or more sulfides having a general formula: Li x PS y , Li x PS y α z or Li x PS y α z β k , wherein 0 < x ≤ 10, 0 < y ≤ 12, 0 < z ≤ 2, 0 < k ≤ 2, α and β are respectively selected from any one of Cl, Br, I, Ge, Si, Se, Sn, Al and Ga elements, the interface layer is formed by reversible covalent cross-linking, and the thickness is 10-50 nm.

[0008] In some optional embodiments, the interface layer has dynamic disulfide bonds cross-linked with each other, the cross-linking density of the disulfide bonds is 0.5-2.5 mmol / g; the interface layer comprises the following components in mass percentage: 30-60 wt% of a disulfide bond-containing compound, 30-70 wt% of a flexible block polymer, and 0-5 wt% of a cross-linking agent.

[0009] In some optional embodiments, the disulfide bond-containing compound has a molecular weight of 300-5000 Da and has a general formula P1-R1-S-S-R2-P2, P1 and P2 are respectively selected from one of carboxyl, hydroxyl and amino, R1 and R2 are respectively selected from one of an alkane chain of 1-12 carbons, an alkene chain of 1-12 carbons and an aromatic group containing at least one benzene ring, the flexible block polymer comprises polyethylene glycol diacrylate and / or polycaprolactone with a molecular weight of 500-2000 Da, and the cross-linking agent is ethylene glycol dimethacrylate.

[0010] In some optional embodiments, the feeding molar ratio of the disulfide bond-containing compound to the flexible block polymer is 3:7-6:4.

[0011] In some optional embodiments, the particle size of the LATP powder is 0.1-2 μm, the thickness of the sulfide layer is 50-200 nm, the coverage of the sulfide layer on the surface of the LATP powder is ≥95%, and the ionic conductivity of the LATP-based composite solid electrolyte at 25°C is (1.2-2.5) × 10 -3 S / cm, Li+ Migration number ≥ 0.6.

[0012] In some alternative embodiments, the mass ratio of the positive active material to the LATP-based composite solid electrolyte is (80-97):(3-20), and the compaction density of the positive electrode sheet is 3.2-3.8 g / cm 3 .

[0013] In some alternative embodiments, the positive active material is a high-nickel ternary material with a nickel element molar ratio ≥ 70%, and the chemical formula is Li a Ni x Co y Mn z M b O2; wherein 0.9 < a < 1.1, 0.7 < x ≤ 0.94, 0.1 ≤ y < 0.4, 0.05 ≤ z < 0.4, and 0 ≤ b ≤ 0.1; M is a combination of one or more of Al, Mg, Zr, Ti, W, Nb, Mo, and B.

[0014] The second aspect of the present application provides a solid-state battery, comprising a positive electrode sheet, a solid electrolyte layer, and a negative electrode sheet, wherein the positive electrode sheet is according to the above-mentioned positive electrode sheet, the solid electrolyte layer is formed by pressing the LATP-based composite solid electrolyte and the binder, and the thickness is 20-70 μm, wherein the particle size distribution of the LATP powder is 0.5-2 μm, the mass ratio of the sulfide layer to the solid electrolyte layer is 3-10%, and the thickness of the negative electrode sheet is 20-100 μm.

[0015] In addition, in order to avoid high temperature causing Li volatilization in LATP and generating an inactive phase, and reducing the ion conduction performance of the battery system, the third aspect of the present application provides a preparation method of a solid-state battery, comprising the following steps:

[0016] S1: mixing the positive active material, the LATP-based composite solid electrolyte, the conductive agent, and the binder, coating on the surface of the positive current collector, and rolling to obtain the conductive layer;

[0017] S2: coating a cross-linking reagent containing a disulfide bond on the surface of the conductive layer, and curing to form the interface layer, thereby obtaining the positive electrode sheet;

[0018] S3: weighing the LATP-based composite solid electrolyte and the binder, mixing, and then pressing to obtain the solid electrolyte layer;

[0019] S4: preparing a negative electrode sheet from a lithium metal sheet; and

[0020] S5: sequentially stacking the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet, packaging into a core, and wetting the interface between the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet with a liquid electrolyte at a dosage of 0.3-0.7 μL / cm 2 S5: sequentially stacking the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet, packaging into a core, and wetting the interface between the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet with a liquid electrolyte at a dosage of 0.3-0.7 μL / cm

[0021] In some optional embodiments, the sulfide is Li6PS5Cl and Li3PS4, and the preparation of the LATP-based composite solid-state electrolyte further comprises the following steps:

[0022] S11: placing the LATP powder in an atomic layer deposition reaction chamber, introducing a precursor of Li6PS5Cl, setting the deposition temperature to 200-400°C, the deposition rate to 0.1-0.5 nm / s, and the deposition thickness to 50-200 nm;

[0023] S12: annealing in an inert atmosphere at 300-500°C for 1-5 h to form a seed layer of the sulfide layer; and

[0024] S13: mixing the LATP powder coated with the seed layer and Li3PS4 at a mass ratio of (7-9):(1-3), ball milling at 400 rpm for 2 h to form the sulfide layer, thereby obtaining the LATP-based composite solid-state electrolyte.

[0025] In some optional embodiments, the conductive agent is carbon nanotubes, and the binder is polyvinylidene fluoride, and the preparation of the conductive layer further comprises the following steps:

[0026] S14: mixing the mixture of the positive electrode active material and the LATP-based composite solid-state electrolyte, carbon nanotubes, and polyvinylidene fluoride at a mass ratio of (85-95):(1-10):(1-5), wherein the mass ratio of the positive electrode active material to the LATP-based composite solid-state electrolyte in the mixture is (80-97):(3-20), adding a solvent and controlling the solid content to 60-80 wt%, and ball milling at 300 rpm for 4 h to obtain a conductive slurry; and

[0027] S15: coating the conductive slurry on the positive electrode current collector, vacuum drying at 100°C for 6 h, and rolling at a rolling pressure of 50-100 MPa to a compacted density of 3.2-3.8 g / cm 3 , thereby obtaining the conductive layer.

[0028] In some optional embodiments, the disulfide-containing compound is 4,4'-dithiodibenzoic acid, the flexible block polymer is polyethylene glycol diacrylate, and the crosslinking agent is ethylene glycol dimethacrylate, and the preparation of the interface layer further comprises the following steps:

[0029] S21: the feeding molar ratio of the disulfide bond-containing compound to the flexible block polymer is 3:7-6:4, and 1-5wt% of the crosslinking agent is added, and stirred for 1-2h to obtain a precursor solution; and

[0030] S22: the precursor solution is spin-coated on the surface of the conductive layer, and cured under 365nm ultraviolet light for 10-30min to form a 10-50nm dynamic buffer layer.

[0031] In some optional embodiments, the particle size of the LATP powder in the conductive layer is 0.1-1pm, and the particle size of the LATP powder in the solid-state electrolyte layer is 0.5-2pm.

[0032] The present application has at least the following technical effects:

[0033] 1) The first aspect of the present application provides a positive electrode sheet, which combines the particle interface modification of the LATP powder at the micro level and the formation of the interface layer of the dynamic buffer on the surface of the conductive layer at the macro level, to double inhibit the reduction side reaction of Ti 4+ , and the interface layer formed by the reversible covalent bond crosslinking naturally has the deformation resistance and dynamic repair performance, disperses the stress between the rigid structures, and improves the mechanical properties of the conductive layer. In addition, the particle interface modification of the LATP powder and the formation of the interface layer do not require high temperature conditions, avoiding the volatilization of active lithium of the LATP material, and ensuring the ion conduction performance of the battery system.

[0034] 2) The second aspect of the present application provides a solid-state battery, which combines the dynamic bond polymer and the LATP coated with a sulfide to realize the synergistic improvement of the interface stability and self-repairing ability, thereby improving the comprehensive performance of the battery.

[0035] 3) The third aspect of the present application provides a preparation method of a solid-state battery, which realizes the surface modification and interface engineering design of the LATP powder without high temperature conditions, avoids the volatilization of Li in the LATP and the generation of inactive phases caused by high temperature, and improves the ion conduction performance of the battery system. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Figure 1 The preparation flowchart of an optional embodiment of the solid-state battery of the present application;

[0038] Figure 2 Nyquist plots of Example 1, 6 and Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0039] In the description of the present embodiment, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, within, etc. are understood as including the number. If it is described as first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0040] In the description of the present embodiment, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood broadly, and those skilled in the art can reasonably determine the specific meaning of the above words in the present embodiment in combination with the specific content of the technical solution.

[0041] The common structure of the existing solid-state battery includes a shell, a battery core, and a cap, the battery core includes a positive electrode sheet, a solid-state electrolyte layer, a negative electrode sheet stacked in sequence, and a small amount of electrolyte between the contact interface of each layer structure. It can be understood that the solid-state battery can be a cylindrical battery or a square battery.

[0042] In the present embodiment, the solid-state battery includes a positive electrode sheet, a solid-state electrolyte layer, and a negative electrode sheet stacked and wound to form a cylindrical battery core, and a shell, the winding starts with the end of the electrode sheet at the cylindrical axis, and ends with the end of the electrode sheet at the outer surface of the cylinder, the shell is cylindrical, its interior is used to accommodate the battery core, the top is the positive electrode end, and the bottom is the negative electrode end, the shell can be a steel shell or an aluminum shell. The diameter of the solid-state battery ranges from 20 mm to 50 mm, and the height ranges from 60 mm to 180 mm, wherein the ratio of the diameter to the height of the battery is > 1.6.

[0043] The present application is aimed at the problems of LATP solid-state electrolyte in the existing solid-state battery industry, which is prone to side reactions with positive electrode ternary materials and lithium metal negative electrode sheets, and poor mechanical stability and easy peeling. A technical route for modifying LATP solid-state electrolyte is proposed, and a new positive electrode sheet structure is adaptively matched. Through the combination of microscopic interface modification of LATP powder particles and macroscopic surface coverage of dynamic buffer interface layer of conductive layer, Ti 4+The interface layer formed by reversible covalent bond crosslinking has natural anti-deformation ability and dynamic repair performance, disperses the stress between the rigid structures, and improves the mechanical properties of the conductive layer. In addition, the particle interface modification of the LATP powder and the formation of the interface layer do not require high temperature conditions, avoiding the volatilization of active lithium of the LATP material, and ensuring the ion conduction performance of the battery system.

[0044] Based on this, the first aspect of the present application provides a positive electrode sheet, comprising a positive electrode current collector, a conductive layer coated on the positive electrode current collector, and an interface layer covering the surface of the conductive layer, the conductive layer is formed by compounding a positive electrode active material and a LATP-based composite solid electrolyte, the LATP-based composite solid electrolyte comprises a LATP powder and a sulfide layer coated on the surface of the LATP powder, the sulfide layer contains one or more sulfides, the sulfide has a general formula: Li x PS y , Li x PS y α z or Li x PS y α z β k , wherein 0 < x ≤ 10, 0 < y ≤ 12, 0 < z ≤ 2, 0 < k ≤ 2, α and β are respectively selected from any one of Cl, Br, I, Ge, Si, Se, Sn, Al and Ga elements, the interface layer is formed by reversible covalent bond crosslinking, and the thickness is 10-50 nm.

[0045] Specifically, the reversible covalent bond can be a disulfide bond, an acylhydrazone bond, a diselenide bond, etc. For example, the polymerization monomer of the interface layer crosslinked by the disulfide bond can be 4,4'-dithiodibenzoic acid DTDB, dithiodiglycol DTDG, etc. The interface layer crosslinked by the acylhydrazone bond can be poly(formaldehyde-hydrazine), and the interface layer crosslinked by the diselenide bond can be poly(diseleno-bispropyl alcohol).

[0046] Further, the interface layer has dynamic disulfide bonds crosslinked with each other, the crosslinking density of the disulfide bond is 0.5-2.5 mmol / g; the interface layer comprises the following components in mass percentage: 30-60 wt% disulfide bond-containing compound, 30-70 wt% flexible block polymer, and 0-5 wt% crosslinking agent. The mass ratio of each component is determined to facilitate the feeding operation in actual production. By using the reversible breaking-recombination characteristics of the disulfide bond, the disulfide bond with a crosslinking density of 0.5-2.5 mmol / g can achieve a self-repairing efficiency ≥85% at 25°C, effectively relieving the interface peeling caused by stress.

[0047] In the specific implementation process, the crosslinking density of the interface layer is measured by the following method:

[0048] Using the FTIR method, the scanning range of the Fourier transform infrared spectrometer was 4000-4000 cm⁻¹. -1 4cm resolution -1 Through disulfide bonds (SS, 510 cm⁻¹) -1 Crosslinking density is calculated from the area of ​​characteristic peaks.

[0049] in

[0050] As-s: Characteristic peak of disulfide bond (510 cm⁻¹) -1 The integral area of ​​)

[0051] Reference peak (CH stretching vibration peak, 2850-2950 cm⁻¹) -1 The integral area of ​​)

[0052] Ms-s: Molar mass of the disulfide bond (64.12 g / mol).

[0053] Further, the interface layer comprises the following components by mass percentage: the disulfide-containing compound has a molecular weight of 300-5000 Da and has the general formula P1-R1-SS-R2-P2, where P1 and P2 are selected from one of carboxyl, hydroxyl, and amino groups, and R1 and R2 are selected from one of a 1-12 carbon alkane chain, a 1-12 carbon olefin chain, and an aromatic group containing at least one benzene ring, where the flexible block polymer comprises polyethylene glycol diacrylate (PEGDA) and / or polycaprolactone (PCL) with a molecular weight of 500-2000 Da, and the crosslinking agent is ethylene glycol dimethacrylate (EGDMA).

[0054] Compounds containing disulfide bonds provide disulfide bonds, and flexible block polymers are used to improve the flexibility of the interface layer, facilitating subsequent processes such as winding.

[0055] Furthermore, the molar ratio of the disulfide-containing compound to the flexible block polymer is 3:7-6:4.

[0056] By controlling the molar ratio of disulfide-containing compounds to flexible block polymers, the stoichiometric relationship of polymer monomers can be clarified, facilitating the calculation of the dynamic disulfide bond formation ratio.

[0057] In some optional embodiments, the LATP powder has a particle size of 0.1-2 μm, the sulfide layer has a thickness of 50-200 nm, the sulfide layer has a coverage of ≥95% on the surface of the LATP powder, and the LATP-based composite solid electrolyte has an ionic conductivity of (1.2-2.5) × 10⁻⁶. -3 S / cm (25℃), Li + Number of migrations ≥ 0.6.

[0058] In the implementation process, the thickness testing calibration method of the sulfide layer is:

[0059] The cross section of the LATP-based composite solid electrolyte (i.e. LATP@ sulfide core-shell material) is polished using a field emission scanning electron microscope, an acceleration voltage of 5 kV is set, a backscattered electron mode (BSE) is used to observe the interface layer thickness, and an EDS line scan is used to analyze the S element distribution to calculate the thickness of the sulfide layer.

[0060] Specifically, the ionic conductivity is obtained by alternating current impedance spectroscopy (EIS) test, and the lithium ion transference number is obtained by direct current polarization method.

[0061] Further, the ionic conductivity test method of the solid electrolyte layer is as follows: a 2032 type button cell is prepared using the LATP-based composite solid electrolyte. The LATP-based composite solid electrolyte is pressed into a disc with a diameter of 10 mm and a thickness of 1 mm, the disc is placed in a symmetric electrode (SS|Electrolyte|SS), SS is a stainless steel gasket, and a Nyquist diagram is recorded. A typical impedance spectrum includes a high-frequency region semicircle (bulk phase impedance) and a low-frequency region inclined line (interface impedance). The semicircle diameter is fitted to obtain the bulk resistance (Rb).

[0062] Ionic conductivity L: electrolyte thickness (cm); Rb: bulk resistance (Ω); A: effective contact area of electrode (cm 2 ), i.e. the single-sided area of the stainless steel gasket.

[0063] The test method of the lithium ion transference number is as follows: a 2032 type button cell is prepared using the LATP-based composite solid electrolyte. The positive electrode sheet and lithium sheet are combined to form a Li|positive electrode sheet|Li symmetric cell, a direct current voltage V of 10 mV is applied, the initial current (I0) is recorded, the polarization is continued until the current is stable, which takes about 1-2 hours, the current is stable, and the judgment standard is that the current value does not change for 1 min continuously, the steady-state current (I1) is recorded, and the EIS test is performed on the polarized cell to obtain the total resistance R.

[0064] The lithium ion transference number t+ = I1*V / I0*R.

[0065] In some optional embodiments, the mass ratio of the positive electrode active material to the LATP-based composite solid electrolyte is (80-97):(3-20), and the compaction density of the positive electrode sheet is 3.2-3.8 g / cm 3 .

[0066] Further, the positive electrode active material is a high-nickel ternary material with a nickel content of ≥70%, and its chemical formula is Li a Nix Co y Mn z M b O2; wherein 0.9 < a < 1.1, 0.7 < x < 0.94, 0.1 < y < 0.4, 0.05 < z < 0.4, 0 < b < 0.1; the M element is a combination of one or more of Al, Mg, Zr, Ti, W, Nb, Mo and B.

[0067] The second aspect of the present application provides a solid-state battery, comprising a positive electrode sheet, a solid-state electrolyte layer and a negative electrode sheet, wherein the positive electrode sheet is any one of the above-mentioned positive electrode sheets, the solid-state electrolyte layer is formed by pressing the LATP-based composite solid-state electrolyte and a binder, and the thickness is 20-70 μm, wherein the particle size distribution of the LATP powder is 0.5-2 μm, the mass ratio of the sulfide layer in the solid-state electrolyte layer is 3-10%, and the negative electrode sheet adopts a lithium metal sheet or a lithium alloy sheet, and the thickness is 20-100 μm.

[0068] Referring to Figure 1 , the third aspect of the present application provides a preparation method of a solid-state battery, which is used to prepare the above-mentioned solid-state battery, comprising the following steps:

[0069] S1: mixing the positive electrode active material, the LATP-based composite solid-state electrolyte, a conductive agent and a binder, coating on the surface of the positive electrode current collector, and rolling to obtain the conductive layer;

[0070] S2: coating a cross-linking reagent containing a disulfide bond on the surface of the conductive layer, and curing to form the interface layer, thereby preparing the positive electrode sheet;

[0071] S3: weighing the LATP-based composite solid-state electrolyte and the binder, mixing and then pressing to form the solid-state electrolyte layer;

[0072] S4: preparing a negative electrode sheet by taking a lithium metal sheet; and

[0073] S5: sequentially stacking the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet to form a roll core, and adding a liquid electrolyte in an amount of 0.3-0.7 μL / cm 2 to wet the interface between the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet.

[0074] Specifically, the sulfide is Li6PS5Cl and Li3PS4, and the preparation of the LATP-based composite solid-state electrolyte further comprises the following steps:

[0075] S11: placing the LATP powder into an atomic layer deposition reaction chamber, introducing a Li6PS5Cl precursor, setting a deposition temperature of 200-400°C, a deposition rate of 0.1-0.5 nm / s, and a deposition thickness of 50-200 nm;

[0076] S12: annealing in an inert atmosphere (nitrogen or argon) at 300-500°C for 1-5 h to form a seed layer of the sulfide layer; and

[0077] S13: mixing the LATP powder coated with the seed layer and Li3PS4 at a mass ratio of 9:1, ball milling at 400 rpm for 2 h to form the sulfide layer, thereby obtaining the LATP-based composite solid-state electrolyte.

[0078] Specifically, the Li6PS5Cl precursor can be a mixture of Li2S-P2S5 and LiCl.

[0079] In some optional embodiments, the conductive agent is a carbon nanotube, the binder is polyvinylidene fluoride (PVDF), and the preparation of the conductive layer further comprises the following steps:

[0080] S14: mixing the mixture of the positive electrode active material and the LATP-based composite solid-state electrolyte, the carbon nanotube, and the polyvinylidene fluoride (PVDF) at a mass ratio of (85-95):(1-10):(1-5), wherein the mass ratio of the positive electrode active material to the LATP-based composite solid-state electrolyte in the mixture is (80-97):(3-20), adding a solvent and controlling the solid content to be 60-80 wt%, and ball milling at 300 rpm for 4 h to obtain a conductive slurry; and

[0081] S15: coating the conductive slurry on a positive electrode current collector, vacuum drying at 100°C for 6 h, and rolling at a rolling pressure of 50-100 MPa to a compacted density of 3.2-3.8 g / cm 3 , thereby obtaining the conductive layer.

[0082] In some optional embodiments, the disulfide bond-containing compound is 4,4'-dithiodibenzoic acid (DTDB), the flexible block polymer is polyethylene glycol diacrylate (PEGDA), and the crosslinking agent is ethylene glycol dimethacrylate (EGDMA), and the preparation of the interfacial layer further comprises the following steps:

[0083] S21: adding the disulfide bond-containing compound and the flexible block polymer according to a feeding molar ratio of 3:7-6:4, adding the crosslinking agent in an amount of 1-5 wt%, adding pure water as a solvent, stirring at 30 rpm for 1-2 h, and copolymerizing the dynamic disulfide bond (-S-S-) and the C=C double bond to generate microgel particles dispersed in the solution, thereby obtaining a precursor solution.

[0084] S22: spin-coating the precursor solution on the surface of the conductive layer, curing under 365nm ultraviolet light for 10-30min to form a 10-50nm dynamic buffer layer.

[0085] It should be noted that the molar ratio of the disulfide bond-containing compound to the flexible block polymer is set to 3:7-6:4. If the proportion of the disulfide bond-containing compound is too low, the disulfide bond crosslinking point will also decrease accordingly, and the target crosslinking density of 0.5-2.5mmol / g cannot be reached. On the contrary, excessive crosslinking of the disulfide bond will lead to increased brittleness. The ultraviolet curing time is set to 10-30min. When the curing time is less than 10min, the crosslinking reaction is insufficient, the disulfide bond conversion rate is low, and the crosslinking density decreases. When the curing time is greater than 30min, the C=C double bond is fully reacted, the network structure is densified, and the crosslinking density increases, but excessive crosslinking may lead to increased brittleness. In addition, the mass percentage measurement method of the crosslinking agent refers to the composition ratio of the aforementioned interface layer, that is, the mass of the crosslinking agent accounts for 1-5wt% of the sum of the mass of the disulfide bond-containing compound, the flexible block polymer, and the crosslinking agent.

[0086] The sulfide layer is constructed by a low-temperature atomic layer deposition process (annealing temperature <500), combined with the ultraviolet curing technology (365nm, 10-30min) of the interface layer, to reduce the process temperature to below 500℃, reduce Li loss, and improve interface uniformity. In the specific implementation process, the sulfide layer can also be constructed by a magnetron sputtering method.

[0087] Further, the particle size of the LATP powder in the conductive layer is 0.1-1μm, and the particle size of the LATP powder in the solid-state electrolyte layer is 0.5-2μm.

[0088] The LATP powder with a smaller particle size range is used to prepare the solid-state electrolyte layer. The high specific surface area characteristics of the small particle size LATP are utilized to improve its contact performance, and the close fit of the solid-state electrolyte layer with the electrode or the interface layer is improved, thereby reducing the interface impedance. The LATP powder with a smaller particle size range is used to prepare the solid-state electrolyte layer, wherein the large particle size particles form a skeleton, and the small particle size particles fill the pores, forming a hierarchical filling effect, and the total porosity is lower, thereby improving the compaction density of the subsequent tabletting, and the high density structure further enhances the mechanical strength and ion conduction continuity of the solid-state electrolyte layer.

[0089] In some optional embodiments, the diameter of the battery ranges from 20mm to 50mm, and the height ranges from 60mm to 180mm, wherein the ratio of the diameter to the height of the battery is >1.6.

[0090] On this basis, the disclosure provides a preparation method of a battery, comprising:

[0091] Preparation of positive electrode sheet: mixing positive electrode coating material, coating on at least one side surface of aluminum foil, drying and cold pressing to obtain positive electrode sheet;

[0092] Lithium metal as negative electrode sheet;

[0093] Assemble a full battery with Li metal as negative electrode, composite positive electrode (such as Ni93 / LATP@Li3PS4) and solid electrolyte layer, interface wetting 0.5 μL / cm 2 Liquid electrolyte, to obtain a battery roll core;

[0094] Assemble the battery: weld the tab of the battery roll core with the electrical connection sheet, put it into the battery shell, seal and formation process to obtain the battery.

[0095] The technical solutions of the present application are described below in combination with Examples 1-10 and Comparative Examples 1-10

[0096] Example 1

[0097] Example 1 provides a battery prepared by the following method:

[0098] 1. Preparation of LATP-based composite solid electrolyte (LATP@ sulfide core-shell material)

[0099] S11: Put the LATP powder with a particle size of 0.5 μm into the atomic layer deposition (ALD) reaction cavity, introduce the precursor of Li6PS5Cl, the deposition temperature is 300℃, the deposition rate is 0.3 nm / s, and the deposition thickness is 100 nm.

[0100] S12: Anneal at 400℃ for 3h in an argon atmosphere to form a seed layer of the sulfide layer.

[0101] S13: Mix the LATP powder coated with the seed layer with Li3PS4 at a mass ratio of 9:1, ball mill at 400 rpm for 2h to form the sulfide layer, to obtain the LATP-based composite solid electrolyte, i.e. the LATP@ sulfide core-shell material.

[0102] 2. Preparation of interface layer

[0103] S21: The monomer molar ratio of DTDB:PEGDA is 1:1, the molecular weight of PEGDA is 500-2000 Da, the reactant: crosslinking agent EGDMA is 97:3, and 0.5wt% initiator azobisisobutyronitrile (AIBN) is additionally added to configure a precursor solution;

[0104] S22: spin-coating the precursor solution on the surface of the conductive layer, and curing it under 365 nm ultraviolet light for 20 min to form a 30 nm dynamic buffer layer, and the cross-linking density of the disulfide bond is 2 mmol / g.

[0105] 3. Positive electrode sheet preparation

[0106] S14: mixing the high-nickel ternary material with the LATP-based composite solid-state electrolyte at a mass ratio of 90:10, taking the mixture of the high-nickel ternary material and the LATP-based composite solid-state electrolyte, the carbon nanotubes and the PVDF at a mass ratio of 95:2:3, adding NMP solvent and controlling the solid content to be 70%, and ball milling at 300 rpm for 4 h to obtain a conductive slurry; and S15: coating the conductive slurry on a 12 μm thick aluminum foil current collector, vacuum drying at 100°C for 6 h, and rolling at a rolling pressure of 50-100 MPa to a compacted density of 3.5 g / cm 3 , to obtain the conductive layer.

[0107] 4. Battery assembly

[0108] S5: sequentially stacking the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet to form a roll core, and adding liquid electrolyte at a dosage of 0.5 μL / cm 2 to wet the interface between the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet. The composition of the liquid electrolyte is: LiPF6 / EC:DEC=1:1, wherein the EC solution of LiPF6 has a lithium ion concentration of 1 mol / L.

[0109] The roll core is cut and folded to form positive and negative tabs, and is welded with a steel shell, and then sealed to obtain the battery of the present embodiment 1.

[0110]

[0111] Example 2

[0112] Example 2 provides a solid-state battery, and the difference between the present embodiment 2 and Example 1 is that the particle size of the LATP-based composite solid-state electrolyte is 1 μm, and the others are the same as those of Example 1.

[0113] Example 3

[0114] Example 3 provides a solid-state battery, and the difference between the present embodiment 3 and Example 1 is that the mass ratio of the high-nickel ternary material to the LATP-based composite solid-state electrolyte is 85:15, and the others are the same as those of Example 1.

[0115] Example 4

[0116] Example 4 provides a solid-state battery, the difference between this Example 4 and Example 1 is that the sulfide layer deposition thickness is 50 nm, and the others are the same as Example 1.

[0117] Example 5

[0118] Example 5 provides a solid-state battery, the difference between this Example 5 and Example 1 is that the sulfide layer deposition thickness is 200 nm, and the others are the same as Example 1.

[0119] Example 6

[0120] Example 6 provides a solid-state battery, the difference between this Example 6 and Example 1 is that the interface layer covalent bond crosslinking density is 1.5 mmol / g, and the others are the same as Example 1.

[0121] Example 7

[0122] Example 7 provides a solid-state battery, the difference between this Example 7 and Example 1 is that the interface layer covalent bond crosslinking density is 2.5 mmol / g, and the others are the same as Example 1.

[0123] Example 8

[0124] Example 8 provides a solid-state battery, the difference between this Example 8 and Example 1 is that the interface layer thickness is 10 nm, and the others are the same as Example 1.

[0125] Example 9

[0126] Example 9 provides a solid-state battery, the difference between this Example 9 and Example 1 is that the interface layer thickness is 30 nm, and the others are the same as Example 1.

[0127] Example 10

[0128] Example 10 provides a solid-state battery, the difference between this Example 10 and Example 1 is that the conductive paste formula of the positive electrode sheet is a mixture of high-nickel ternary material and LATP-based composite solid electrolyte, carbon nanotubes, and PVDF in a mass ratio of 92:5:3, and the others are the same as Example 1.

[0129] Comparative Example 1

[0130] Comparative Example 1 provides a solid-state battery, the difference between this Comparative Example 1 and Example 1 is that the LATP particle size is 2 μm, and the others are the same as Example 1.

[0131] Comparative Example 2

[0132] Comparative Example 2 provides a solid-state battery, which is different from Example 1 in that the mass ratio of high-nickel ternary material / LATP-based composite solid electrolyte = 70:30, and the other conditions are the same as those in Example 1.

[0133] Comparative Example 3

[0134] Comparative Example 3 provides a solid-state battery, which is different from Example 1 in that the sulfide layer deposition thickness is 20 nm, and the other conditions are the same as those in Example 1.

[0135] Comparative Example 4

[0136] Comparative Example 4 provides a solid-state battery, which is different from Example 1 in that the sulfide layer deposition thickness is 300 nm, and the other conditions are the same as those in Example 1.

[0137] Comparative Example 5

[0138] Comparative Example 5 provides a solid-state battery, which is different from Example 1 in that the covalent bond cross-linking density of the interface layer is 0.5 mmol / g, and the other conditions are the same as those in Example 1.

[0139] Comparative Example 6

[0140] Comparative Example 6 provides a solid-state battery, which is different from Example 1 in that the covalent bond cross-linking density of the interface layer is 3 mmol / g, and the other conditions are the same as those in Example 1.

[0141] Comparative Example 7

[0142] Comparative Example 7 provides a solid-state battery, which is different from Example 1 in that the interface layer thickness is 5 nm, and the other conditions are the same as those in Example 1.

[0143] Comparative Example 8

[0144] Comparative Example 8 provides a solid-state battery, which is different from Example 1 in that the interface layer thickness is 50 nm, and the other conditions are the same as those in Example 1.

[0145] Comparative Example 9

[0146] Comparative Example 9 provides a solid-state battery, which is different from Example 1 in that the positive electrode sheet formula is a mixture of high-nickel ternary material and LATP-based composite solid electrolyte, carbon nanotube conductive agent, and PVDF in a mass ratio of 96.5:0.5:3, and the other conditions are the same as those in Example 1.

[0147] Comparative Example 10

[0148] Comparative Example 10 provides a solid-state battery, which is different from Example 1 of Comparative Example 10 in that the positive electrode sheet formula is a mixture of high-nickel ternary material and LATP-based composite solid electrolyte, carbon nanotube conductive agent, and PVDF in a mass ratio of 87:10:3, and the others are the same as Example 1.

[0149] The cylindrical batteries of Examples 1-10 and Comparative Examples 1-10 were subjected to capacity performance evaluation, and the evaluation method was as follows:

[0150] Test the capacity retention rate (capacity retention rate after 600 cycles at 1C rate):

[0151] Take one solid-state battery, place it in a 25°C constant temperature box for more than 4h, and test according to the following steps:

[0152] Step 1: charge the battery to 4.2V at 0.1C, and 0.01C constant current to 4.2V cutoff, and stand for 5min;

[0153] Step 2: discharge the battery to 2.5V cutoff at 0.1C, and stand for 5min;

[0154] Step 3: charge the battery to 4.2V at 1C, and 0.01C constant current to 4.2V cutoff, and stand for 5min;

[0155] Step 4: discharge the battery to 2.5V cutoff at 1C, stand for 5min, read the capacity value C0 at this time, and stand for 5min;

[0156] Step 5: repeat steps 3 and 4 for 600 times, and measure the discharge capacity C1 at the 600th time;

[0157] Step 6: obtain the cycle performance of a single battery, i.e. the capacity retention rate, by the ratio of the discharge capacity C1 at the 600th time and the discharge capacity C0 at the 1st time of steps 5 and 4.

[0158] The cylindrical batteries of Examples 1-10 and Comparative Examples 1-10 were subjected to electrochemical performance testing according to the aforementioned measurement method of ionic conductivity of solid-state electrolyte layer and the test method of lithium ion transference number, and the results are shown in the following table.

[0159]

[0160]

[0161] Compared with Comparative Examples 1, 2 and Comparative Example 1, it can be seen that the large particle size of LATP leads to poor interface contact between the positive electrode conductive layer and the solid electrolyte layer, the ion transmission path is lengthened, the interface impedance is increased, and thus the ionic conductivity is reduced (0.8 x 10 -3 vs 2.3 x 10 -3 ). Small particle size LATP (0.5 pm) can optimize the Li + diffusion channel, but there is a problem of difficult dispersion in actual processing. Compared with Comparative Examples 1, 3 and Comparative Example 2, it can be seen that too high a proportion of LATP will occupy the space of high-nickel active material, reduce the lithium storage site, and lead to a decrease in capacity retention rate.

[0162] Compared with Comparative Examples 1, 4, 5 and Comparative Examples 3, 4, it can be seen that a too thin sulfide layer (20 nm) cannot effectively inhibit the interface side reaction (such as Ti 4+ reduction) between LATP and high-nickel material, leading to a decrease in Li + migration number (0.68 vs 0.85), but a too thick sulfide layer will increase the ion transmission path, thereby affecting the battery performance. The 100 nm thick sulfide layer (Li6PS5Cl) in Example 1 can provide a stable interface and does not affect the ion transmission.

[0163] Compared with Comparative Examples 1, 6, 7 and Comparative Examples 5, 6, it can be seen that when the dynamic bond density of the interface buffer layer is too low (0.5 mmol / g), the self-repairing ability of the dynamic disulfide bond of the interface layer is insufficient, the interface cracks cannot be closed in the cycle, and the capacity attenuation is intensified (65% vs 92%). When the dynamic bond density is too high, on the one hand, the production cost is increased, and on the other hand, the conductivity of the positive electrode sheet is reduced. After comprehensive comparison, the dynamic bond density of 2.0 mmol / g in Example 1 can achieve efficient self-repairing while maintaining relatively optimal sheet performance. Meanwhile, compared with Comparative Examples 1, 8, 9 and Comparative Examples 7, 8, it can be seen that when the interface layer is too thin (such as 5 nm), it cannot relieve the volume expansion stress in the charging and discharging process, and is easy to lead to electrode pulverization, and the capacity retention rate is reduced to 72%, but a too thick interface layer will hinder the Li + transport, leading to a decrease in lithium ion migration number, about 0.76, and a suitable buffer layer thickness (such as 20 nm) can buffer the stress and avoid hindering the Li + transport.

[0164] Compared with Comparative Examples 1, 10 and Comparative Examples 9, 10, it can be seen that too little conductive agent (0.5 wt%) will lead to discontinuous electronic conduction network, increased polarization, and a sharp decrease in capacity retention rate (60% vs 92%). A certain suitable amount of carbon nanotubes (CNT) can construct a three-dimensional conductive network and improve the rate performance. However, when the amount is too high, the CNT is difficult to disperse and is easy to agglomerate, and cannot form an efficient conductive network.

[0165] Further combining the drawings Figure 2 , Figure 2 The Nyquist plots of Example 1, Example 6 and Comparative Example 1 are depicted respectively, the Nyquist plot takes the impedance real part (Z', Ω) as the abscissa and the impedance imaginary part (Z", Ω) as the ordinate, reflecting the impedance response of the battery / electrode at different frequencies (ω), the starting points of the three curves in the high frequency region almost coincide, indicating that the ohmic resistance of Example 1, Example 6 and Comparative Example 1 is similar. The diameter of the semicircle in the medium frequency region directly reflects the size of the charge transfer resistance, the diameter of the semicircle of Example 6 is the smallest, indicating that the charge transfer resistance is the smallest, the charge transfer rate is the fastest, Example 1 is inferior to Example 6, and the charge transfer rate of Comparative Example is the slowest, proving that the interface contact of Example 6 using the interface layer with a crosslinking density of 1.5 mmol / g is optimal. The curve slope in the low frequency region reflects the size of the diffusion resistance, the closer the slope is to 45°, the smaller the diffusion resistance is, the curve slope of Example 6 is the largest (≈40°), and Z" decreases the fastest with the increase of Z', indicating that the diffusion resistance is the smallest; the curve slope of Example 1 is moderate (≈30°), and the curve slope of Comparative Example 1 is the smallest (≈20°), Z" decreases the slowest, indicating that the diffusion resistance is the largest, indicating that the diffusion path of Example 6 is optimal.

[0166] In summary, through the LATP solid-state battery based on the composite interface design of the sulfide layer and the dynamic bond polymer provided in the present application, the dynamic bond polymer is combined with the sulfide coated LATP to realize the synergistic improvement of the interface stability and self-repairing ability, thereby improving the comprehensive performance of the battery, and filling the technical blank of the LATP-based solid-state battery in the field of dynamic interface design. Through material composite innovation and process parameter differentiation design, a high-performance and high-stability solid-state battery is realized. The ionic conductivity can reach 2.3×10 -3 S / cm, the Li + transference number reaches 0.85, and the capacity retention rate is 92% after 600 cycles.

[0167] Although the embodiments of the present embodiment have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present embodiment, and the scope of the present embodiment is defined by the claims and their equivalents.

Claims

1. A positive electrode sheet characterized by comprising: The positive electrode sheet comprises a positive electrode current collector, a conductive layer coated on the positive electrode current collector, and an interface layer covering the surface of the conductive layer, wherein the conductive layer is formed by compounding a positive electrode active material and a LATP-based composite solid electrolyte, the LATP-based composite solid electrolyte comprises LATP powder and a sulfide layer coated on the surface of the LATP powder, the sulfide layer comprises one or more sulfides, and the sulfides have a general formula: Li x PS y , Li x PS y α z or Li x PS y α z β k , wherein 0 The interface layer is formed by reversible covalent cross-linking and has a thickness of 10-50 nm.

2. The positive electrode sheet according to claim 1, characterized by The interface layer has dynamic disulfide bonds crosslinked with each other, the crosslinking density of the disulfide bonds is 0.5-2.5 mmol / g; the interface layer comprises the following mass percentage of components: 30-60 wt% disulfide bond-containing compound, 30-70 wt% flexible block polymer and 0-5 wt% crosslinking agent.

3. The positive electrode sheet according to claim 2, characterized by The disulfide bond-containing compound has a molecular weight of 300-5000 Da and has a general formula P1-R1-S-S-R2-P2, P1 and P2 are each selected from one of carboxyl, hydroxyl and amino, R1 and R2 are each selected from one of alkane chain of 1-12 carbons, olefin chain of 1-12 carbons and aromatic group containing at least one benzene ring, the flexible block polymer comprises polyethylene glycol diacrylate and / or polycaprolactone, and has a molecular weight of 500-2000 Da, and the crosslinking agent is ethylene glycol dimethacrylate.

4. The positive electrode sheet according to claim 2, characterized by The feeding molar ratio of the disulfide bond-containing compound to the flexible block polymer is 3:7-6:

4.

5. The positive electrode sheet according to claim 1, characterized by The particle size of the LATP powder is 0.1-2 μm, the thickness of the sulfide layer is 50-200 nm, the coverage of the sulfide layer on the surface of the LATP powder is ≥95%, the ionic conductivity of the LATP-based composite solid-state electrolyte at 25°C is (1.2-2.5)×10-3 S / cm, and the Li+ migration number is ≥0.

6.

6. The positive electrode sheet according to claim 1, characterized by The mass ratio of the positive electrode active material to the LATP-based composite solid electrolyte is (80-97):(3-20), and the compaction density of the positive electrode sheet is 3.2-3.8 g / cm 3 .

7. The positive electrode sheet according to claim 1, characterized by The positive electrode active material is a high-nickel ternary material with a nickel element molar ratio of > 70%, and its chemical formula is Li a Ni x Co y Mn z M b O2; wherein 0.9 < a < 1.1, 0.7 < x < 0.94, 0.1 < y < 0.4, 0.05 < z < 0.4, 0 < b < 0.1; the M element is a combination of one or more of Al, Mg, Zr, Ti, W, Nb, Mo and B.

8. A solid-state battery comprising a positive electrode sheet, a solid-state electrolyte layer, and a negative electrode sheet, characterized by, The positive electrode sheet is the positive electrode sheet according to any one of claims 1-7, the solid-state electrolyte layer is formed by pressing the LATP-based composite solid-state electrolyte and a binder, and has a thickness of 20-70 μm, wherein the particle size distribution of the LATP powder is 0.5-2 μm, the mass percentage of the sulfide layer in the solid-state electrolyte layer is 3-10%, and the negative electrode sheet is a lithium metal sheet or a lithium alloy sheet and has a thickness of 20-100 μm.

9. A method of producing a solid-state battery, characterized by, The solid-state battery is the solid-state battery according to claim 8, comprising the following steps: S1: mixing the positive electrode active material, the LATP-based composite solid-state electrolyte, a conductive agent and a binder, coating on the surface of a positive electrode current collector, and roll pressing to obtain the conductive layer; S2: coating a disulfide bond-containing crosslinking agent on the surface of the conductive layer, and curing to form the interface layer, thereby obtaining the positive electrode sheet; S3: weighing the LATP-based composite solid-state electrolyte and a binder, mixing and then pressing to form the solid-state electrolyte layer; S4: taking a lithium metal sheet to prepare a negative electrode sheet; and S5: sequentially stacking the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet, and packaging into a jelly-roll core, at 0.3-0.7 μL / cm 2 adding a liquid electrolyte solution in an amount of 0.3-0.7 μL / cm to wet the interface between the positive electrode sheet, the solid-state electrolyte layer, and the negative electrode sheet.

10. The method of producing a solid-state battery according to claim 9, characterized by, The sulfide is Li6PS5Cl and Li3PS4, and the preparation of the LATP-based composite solid-state electrolyte further comprises the following steps: S11: placing the LATP powder in an atomic layer deposition reaction chamber, introducing a precursor of Li6PS5Cl, setting the deposition temperature to 200-400°C, the deposition rate to 0.1-0.5 nm / s, and the deposition thickness to 50-200 nm; S12: annealing in an inert atmosphere at 300-500°C for 1-5 h to form a seed layer of the sulfide layer; and S13: mixing the LATP powder coated with the seed layer and Li3PS4 in a mass ratio of (7-9):(1-3), ball milling at 400 rpm for 2 h to form the sulfide layer, thereby obtaining the LATP-based composite solid electrolyte.

11. The method of producing a solid-state battery according to claim 9, wherein The conductive agent is a carbon nanotube, the binder is polyvinylidene fluoride, and the preparation of the conductive layer further comprises the following steps: S14: mixing the mixture of the positive active material and the LATP-based composite solid electrolyte, the carbon nanotube and the polyvinylidene fluoride in a mass ratio of (85-95):(1-10):(1-5), wherein the mass ratio of the positive active material to the LATP-based composite solid electrolyte in the mixture is (80-97):(3-20), adding a solvent and controlling the solid content to be 60-80 wt%, and ball milling at 300 rpm for 4 h to obtain a conductive slurry; and S15: The conductive paste is coated on the positive current collector, vacuum dried at 100°C for 6h, and rolled at a pressure of 50-100MPa to a compacted density of 3.2-3.8g / cm 3 , to obtain the conductive layer.

12. The method of producing a solid-state battery according to claim 9, wherein The disulfide bond-containing compound is 4,4'-dithiodibenzoic acid, the flexible block polymer is polyethylene glycol diacrylate, and the crosslinking agent is ethylene glycol dimethacrylate, and the preparation of the interface layer further comprises the following steps: S21: feeding according to a feed molar ratio of the disulfide bond-containing compound to the flexible block polymer of 3:7-6:4, adding 1-5 wt% of the crosslinking agent, stirring for 1-2 h to obtain a precursor solution; and S22: spin coating the precursor solution on the surface of the conductive layer, and curing for 10-30 min under ultraviolet light of 365 nm wavelength to form a 10-50 nm dynamic buffer layer.

13. The method of producing a solid-state battery according to claim 9, wherein The particle size of the LATP powder in the conductive layer is 0.1-1 μm, and the particle size of the LATP powder in the solid electrolyte layer is 0.5-2 μm.

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