Sulfide-based all-solid-state battery positive electrode binder and all-solid-state battery

Abstract

The invention belongs to the technical field of all-solid-state battery materials, and particularly relates to a sulfide-based all-solid-state battery positive electrode binder and an all-solid-state battery. The sulfide-based all-solid-state battery positive electrode binder comprises a polymer as shown in a structural formula 1: in the structural formula 1, R1 and R4 are selected from H or CH3; r2 is selected from a group consisting of C1-C3 fluoroalkyl groups; r3 is selected from a cyano group or an amide group; r5 is selected from alkyl with 1 to 4 carbon atoms or fluoroalkyl with 1 to 3 carbon atoms; x is an integer from 5 to 1000, and y and z are integers from 0 to 1000. The binder disclosed by the invention can be dissolved in a polar solvent, provides good binding power and ionic conductivity, and can be subjected to wet homogenization with each electrode active material to obtain a positive electrode system friendly to sulfide-based solid electrolyte, so that an all-solid-state battery with good long cycle performance is obtained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of all-solid-state battery materials, and particularly relates to a sulfide-based all-solid-state battery positive electrode binder and an all-solid-state battery. BACKGROUND

[0002] With the increasing requirements for energy density and safety of rechargeable batteries, the development of all-solid-state batteries (ASSB) has become an important direction for the development of next-generation batteries. All-solid-state batteries are lithium ion batteries in which both the electrolyte and the positive and negative electrodes are in solid state. All-solid-state batteries are composed of a positive electrode material, a solid electrolyte, and a negative electrode material, and do not contain any liquid components.

[0003] Currently, there are few corresponding research articles and patents in the field of sulfide-based solid-state battery positive electrode binders. The specific problem mainly lies in the incompatibility of sulfide-based solid electrolytes with polar solvents, which makes the traditional PVdF-NMP wet slurry system no longer applicable. In the existing research, most of the polymers with few polar groups are used as binders, such as nitrile rubber and styrene-butadiene rubber. And most of the positive electrode binders studied at present need to use strong polar solvents in the use process, which cannot be adapted to sulfide-based solid electrolytes. Such binders have the problems of low peeling force, poor adhesion performance, weak ability to inhibit electrode volume change, and are not conducive to the long-term cycling of all-solid-state batteries. SUMMARY

[0004] Based on this, the purpose of the present application is to provide a sulfide-based all-solid-state battery positive electrode binder and an all-solid-state battery to solve the problems of low peeling force, poor adhesion performance, weak ability to inhibit electrode volume change, and not conducive to the long-term cycling of all-solid-state batteries in the prior art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows.

[0006] In a first aspect, the present application provides a sulfide-based all-solid-state battery positive electrode binder, comprising a polymer represented by structural formula 1:

[0007]

[0008] Structural formula 1

[0009] wherein R1, R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl; R3 is selected from cyano or amide group; R5 is selected from C1-C4 alkyl or C1-C3 fluoroalkyl; x is an integer of 5-1000, and y, z are each independently selected from an integer of 0-1000.

[0010] The sulfide-based all-solid-state battery positive electrode binder provided in the present application can provide good adhesion and ionic conductivity due to the presence of ester bonds, and the overall polarity of the polymer is reduced due to the effect of fluorine substitution, so that the polymer can be dissolved in a low-polarity solvent friendly to sulfide-based solid-state electrolytes.

[0011] Specifically, as an embodiment of the present application, in the structural formula 1, R1 and R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl; R3 is selected from cyano or amide; R5 is selected from C1-C3 fluoroalkyl; x is an integer of 5-1000, y is an integer of 0-1000, and z is an integer of 1-1000.

[0012] Specifically, as an embodiment of the present application, the sulfide-based all-solid-state battery positive electrode binder is prepared from a fluorinated acrylate monomer, an acrylate monomer, an acrylonitrile monomer or an acrylamide monomer in a mass ratio of (1-5):(0-1):(0-1). Specifically, as an embodiment of the present application, the acrylonitrile monomer or the acrylamide monomer is alternatively used in the preparation of the binder.

[0013] More specifically, as an embodiment of the present application, the fluorinated acrylate monomer is selected from any one of trifluoroethyl acrylate monomer, trifluoromethyl acrylate monomer, 2,2,3,3-tetrafluoropropyl methyl acrylate monomer; and the acrylate monomer includes the fluorinated acrylate monomer.

[0014] Specifically, as an embodiment of the present application, the sulfide-based all-solid-state battery positive electrode binder is prepared by the following method: mixing a fluorinated acrylate monomer, an acrylate monomer, an acrylonitrile monomer or an acrylamide monomer with an emulsifier to form a pre-emulsion; then adding an initiator for emulsion polymerization, cooling, demulsifying, dissolving, washing and drying after the reaction is completed. Specifically, the acrylonitrile monomer or the acrylamide monomer is alternatively used in the preparation of the positive electrode binder. Residual emulsifiers in the polymer can be effectively removed through repeated washing, thereby improving the purity and electrochemical performance of the polymer.

[0015] Specifically, in some embodiments of the present application, the temperature of the polymerization reaction is 60-70°C, and the reaction time is 20-26h; the amount of the emulsifier is 2-3% of the total amount of the monomers; and the amount of the initiator is 0.1-0.5% of the total amount of the monomers.

[0016] Specifically, in some embodiments of the present application, the emulsifier includes one or more of sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether sodium sulfate, secondary alkyl sodium sulfate, nonylphenol polyoxyethylene ether, polyoxyethylene fatty acid ester or α-olefin sulfonate.

[0017] Specifically, in some embodiments of the present application, the initiator comprises one or more of potassium persulfate, ammonium persulfate, potassium sulfate-sodium bisulfite, hydrogen peroxide-ferrous salt, azobisisobutyronitrile or azobisisoheptyl nitrile.

[0018] In a second aspect, the present application also provides a full solid-state battery, comprising a positive electrode, wherein the positive electrode comprises a positive electrode current collector and a positive electrode material composition coated on the positive electrode current collector, and the positive electrode material composition comprises a positive electrode active material, a sulfide solid-state electrolyte, a conductive agent and the sulfide-based full solid-state battery positive electrode binder.

[0019] Specifically, in some embodiments of the present application, the mass ratio of the positive electrode active material, the sulfide solid-state electrolyte, the conductive agent and the sulfide-based full solid-state battery positive electrode binder is (75-85):(15-25):(0.5-3):(0.5-3).

[0020] In some embodiments of the present application, the sulfide solid-state electrolyte is Li6PS5Cl, Li6PS5Br or Li6PS5I.

[0021] In some embodiments of the present application, the positive electrode active material comprises one or more of transition metal oxides, lithium-rich manganese-based materials and sulfur-based materials.

[0022] Specifically, the transition metal oxides comprise one or more of LiCoO2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 1-x Mn x O2 or LiFePO4.

[0023] Specifically, the lithium-rich manganese-based material comprises Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O2.

[0024] Specifically, the sulfur-based material comprises elemental sulfur, Li2S or Li6PS5Cl.

[0025] In some embodiments of the present application, the conductive agent comprises one or more of carbon black, carbon nanotubes or graphene.

[0026] In the present application, the positive electrode of the full solid-state battery is prepared by uniformly dispersing the sulfide-based full solid-state battery positive electrode binder, the positive electrode active material, the sulfide solid-state electrolyte and the conductive agent into a solvent to form an electrode slurry, and then coating the electrode slurry onto a positive electrode substrate.

[0027] Further, the solvent is selected from the group consisting of tetrahydrofuran, dioxane, toluene, anisole, butyl butyrate, isobutyl isobutyrate, dipropylene glycol dimethyl ether in combination of one or more.

[0028] Based on the technical solutions of the present application, compared with the prior art, the present application has the following beneficial effects:

[0029] The sulfide-based full-solid-state battery positive electrode binder provided by the present application contains ester bonds, can provide good adhesion and ionic conductivity, and due to the effect of fluorine substitution, the polarity of the polymer as a whole is reduced, so that the polymer can be dissolved in a low-polarity solvent friendly to sulfide-based solid-state electrolyte.

[0030] The sulfide-based full-solid-state battery positive electrode binder provided by the present application can be used for wet homogenization of various electrode active materials to obtain a positive electrode system friendly to sulfide-based solid-state electrolyte, and the use of the positive electrode system can obtain a full-solid-state battery with good long cycle performance. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments or prior art of the present application, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0032] Figure 1 The peel strength test results of the binder in Example 1 and Comparative Example 1 are shown in the figure. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described in detail below, and obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0034] In a first aspect, the present application provides a sulfide-based full-solid-state battery positive electrode binder, comprising a polymer represented by structural formula 1:

[0035]

[0036] Structural formula 1

[0037] wherein R1, R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl; R3 is selected from cyano or amido; R5 is selected from C1-C4 alkyl or C1-C3 fluoroalkyl; x is an integer from 5 to 1000, and y, z are each independently selected from an integer from 0 to 1000.

[0038] Specifically, as an embodiment of the present application, in the structural formula 1, R1, R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl; R3 is selected from cyano or amido; R5 is selected from C1-C3 fluoroalkyl; x is an integer from 5 to 1000, y is an integer from 0 to 1000, and z is an integer from 1 to 1000.

[0039] More specifically, x in the above chemical formula can be 5, 10, 50, 100, 300, 400, 500, 600, 700, 800, 900 or 1000, etc.; z can be 1, 5, 30, 80, 120, 260, 320, 400, 410, 580, 680, 760, 800, 830, 920 or 1000, etc.; and y can be 1, 10, 25, 60, 75, 125, 260, 400, 600, 720, 800, 920 or 1000, etc. Further preferably, x, z are each independently selected from an integer from 400 to 800, and y is an integer from 10 to 600. In the present application, on the basis of the molecular structure determining the electrical properties, the greater the degree of polymerization, the higher the viscosity of the adhesive, and the adhesive performance will be slightly better.

[0040] More specifically, the polymer represented by the structural formula 1 in the present application can be selected from one of the chemical formulas shown in Table 1, wherein x is an integer from 5 to 1000, and y, z are each independently selected from an integer from 1 to 1000:

[0041] Table 1

[0042]

[0043]

[0044] The preparation method of the sulfide-based full-solid-state battery positive electrode adhesive comprises the following steps: mixing a fluoroacrylate monomer, an acrylate monomer, an acrylonitrile monomer or an acrylamide monomer with an emulsifier to form a pre-emulsion; then adding an initiator to perform emulsion polymerization reaction; after the reaction is completed, cooling, demulsification, dissolution, washing and drying are performed, and the sulfide-based full-solid-state battery positive electrode adhesive is obtained.

[0045] Preferably, the mass ratio of the fluorinated acrylate monomer, the acrylate monomer, the acrylonitrile monomer or the acrylamide monomer is (1-5):(0-1):(0-1). The amount of the emulsifier is 2%-3% of the total amount of the monomers; the amount of the initiator is 0.1%-0.5% of the total amount of the monomers. In the preparation of the adhesive, the acrylonitrile monomer or the acrylamide monomer is used alternatively.

[0046] In a second aspect, the present application provides a full solid-state battery, comprising a positive electrode, the positive electrode comprising a positive electrode current collector and a positive electrode material composition coated on the positive electrode current collector, the positive electrode material composition comprising a positive electrode active material, a sulfide solid-state electrolyte, a conductive agent and the above-mentioned sulfide-based full solid-state battery positive electrode binder.

[0047] Specifically, as an embodiment of the present application, the mass ratio of the positive electrode active material, the sulfide solid-state electrolyte, the conductive agent and the sulfide-based full solid-state battery positive electrode binder is (75-85):(15-25):(0.5-3):(0.5-3). More specifically, the mass ratio of the positive electrode active material, the sulfide solid-state electrolyte, the conductive agent and the sulfide-based full solid-state battery positive electrode binder is 75:15:0.5:0.5, 75:15:1:1, 75:15:1:2, 75:15:1:3, 75:15:2:3, 75:15:0.5:3, 75:15:3:3, 75:20:0.5:0.5, 75:20:1:1, 75:20:1:2, 75:20:0.5:3, 75:20:2:3, 75:20:1:3, 75:20:3:3, 80:20:0.5:0.5, 80:20:1:1, 80:20:1:2, 80:20:0.5:3, 80:20:1:3, 80:20:2:3, 80:25:2:3, 80:25:3:3, 80:25:0.5:0.5, 80:25:1:1, 80:25:1:2, 80:25:0.5:3, 80:25:2:3, 80:25:3:3, etc. More preferably, the mass ratio of the positive electrode active material, the sulfide solid-state electrolyte, the conductive agent and the sulfide-based full solid-state battery positive electrode binder is 80:20:1:(1-2).

[0048] Specifically, the sulfide solid-state electrolyte is Li6PS5Cl, Li6PS5Br or Li6PS5I.

[0049] Specifically, the positive electrode active material comprises one or more of transition metal oxides, lithium-rich manganese-based materials and sulfur-based materials.

[0050] The positive electrode of the all-solid-state battery described in the present application is prepared by the following method: uniformly dispersing a sulfide-based all-solid-state battery positive electrode binder, a positive electrode active material, a sulfide solid electrolyte, and a conductive agent into a solvent to prepare an electrode slurry, and coating the electrode slurry onto a positive electrode substrate to obtain the positive electrode.

[0051] The present application will be further explained and described below through specific examples.

[0052] The reagents, materials, and instruments used in the following description are conventional reagents, conventional materials, and conventional instruments, which are commercially available, and the reagents involved can also be synthesized by conventional synthesis methods. The methods in the examples are conventional methods in the art, unless otherwise specified. The monomers meeting the present application can be commercially available.

[0053] Example 1: Sulfide-based all-solid-state battery positive electrode binder, solid-state battery, and preparation method thereof

[0054] (1) Sulfide-based all-solid-state battery positive electrode binder:

[0055] 15 g of 2,2,2-trifluoroethyl acrylate monomer and 0.35 g of sodium dodecyl sulfate emulsifier were added to 15 g of water and stirred vigorously to form a pre-emulsion. The system was purged with nitrogen for 30 min, 0.05 g of potassium persulfate initiator was added, and the reaction was carried out at 65°C for 24 hours under magnetic stirring and nitrogen protection. After the reaction was completed, the system was cooled to room temperature, and the corresponding polymer was obtained by methanol demulsification, dissolution, washing, and drying. The polymer can be used as a sulfide-based solid-state battery positive electrode binder.

[0056] (2) Preparation of sulfide-based solid-state battery positive electrode:

[0057] Solid-state battery positive electrode and preparation thereof: The polymer prepared by the above method was used as a sulfide-based solid-state battery positive electrode binder, the polymer was dissolved in butyl butyrate and configured into a solution with a mass fraction of 5%. The sulfide-based solid-state battery negative electrode prepared according to the conventional method in the art and the sulfide-based solid-state battery positive electrode of the present application were assembled into a battery according to the general process for preparing a sulfide-based solid-state battery. 0.8 Co 0.1 Mn 0.1 O2: Li6PS5Cl: Super P: Binder = 80:20:1:1.

[0058] (3) Preparation of all-solid-state battery:

[0059] The sulfide-based solid-state battery negative electrode prepared according to the conventional method in the art and the sulfide-based solid-state battery positive electrode of the present application were assembled into a battery according to the general process for preparing a sulfide-based solid-state battery.

[0060] Examples 2-23

[0061] The sulfide-based all-solid-state battery cathode binder, the sulfide-based solid-state battery cathode and the all-solid-state battery were prepared according to the method of Example 1, and the main difference between Examples 2-23 and Example 1 is that the monomer used and its amount are different in the preparation of the sulfide-based all-solid-state battery cathode binder, and the chemical formula of the obtained polymer is different; the mass ratio of the cathode active material, the sulfide solid-state electrolyte, the conductive agent and the sulfide-based all-solid-state battery cathode binder is different in the preparation of the sulfide-based solid-state battery cathode. Specifically, as shown in Table 1.

[0062] The comparative examples are used to illustrate the sulfide-based all-solid-state battery cathode binder, the sulfide-based solid-state battery cathode and the all-solid-state battery disclosed in the present application, including most of the operation steps in Example 1, and the differences are shown in Table 2 and the following explanation.

[0063] Comparative Example 1:

[0064] Comparative Example 1 differs from Example 1 in that the sulfide-based all-solid-state battery cathode binder is polyvinylidene fluoride (PVdF), and the remaining steps are the same.

[0065] Comparative Example 2:

[0066] Comparative Example 1 differs from Example 1 in that the sulfide-based all-solid-state battery cathode binder is PVdF-HFP, and the remaining steps are the same.

[0067] Comparative Examples 3-6:

[0068] Comparative Examples 3-5 differ from Example 1 in that the polymer structure in the sulfide-based all-solid-state battery cathode binder is different.

[0069] Performance test:

[0070] After the sulfide-based solid-state battery cathode prepared in the above examples and comparative examples was dried, a 180° peeling force test was performed; the sulfide-based solid-state battery cathode prepared in the above examples and comparative examples was used to prepare a sulfide mold half-cell in a glove box, and a long cycle test was performed, and the capacity retention rate of the battery was tested after 300 cycles.

[0071] 1. Cycle test method:

[0072] At 25°C, charge at a charge rate of 1C to 4.25V, then charge at a charge rate of 0.05C to 4.25V, then discharge at a discharge rate of 1C to 3.0V, and repeat for 300 cycles. The discharge capacity Q1 at the first cycle and the discharge capacity Q300 at the 300th cycle were measured. 300 The capacity retention rate Q after 500 cycles was calculated according to the following formula:

[0073] Capacity retention rate Q = Q 300 / Q1×100%.

[0074] 2. 180° peel force

[0075] The peel strength test was conducted using GB / T2790 to test the 180° peel resistance of the sulfide-based all-solid-state battery cathode binder on the cathode substrate.

[0076] The peel force test results of Example 1 and Comparative Example 1 are as follows: Figure 1 As shown in Table 2, the polymer (PTFEA) prepared in Example 1 has significantly better peel strength than PVdF as an adhesive.

[0077] Table 2 shows the parameters required for preparing all-solid-state batteries in Examples 1 to 12 and Comparative Examples 1 to 6. The difference between Examples 1 to 12 and Comparative Examples 1 to 6 lies in the relevant parameters shown in Table 2. The other parameters are the same as those in Example 1. The specific differences are: the structural formula of the sulfide-based all-solid-state battery cathode binder, the mass ratio of polymer monomers, and the mass ratio of the cathode material composition.

[0078] Table 2 also shows the cycle test and 180° peel force test results of the all-solid-state batteries prepared in Examples 1 to 12 and Comparative Examples 1 to 6.

[0079] Table 2

[0080]

[0081] As shown in Table 2, the test results of Examples 1-12 and Comparative Examples 1-6 indicate that the sulfide-based all-solid-state battery cathode binder provided by this invention, due to the presence of ester bonds, provides excellent adhesion and ionic conductivity. Simultaneously, the fluorine substitution reduces the overall polarity of the polymer, allowing it to dissolve in low-polarity solvents friendly to sulfide-based solid electrolytes. This enables wet homogenization with various electrode active materials to obtain a cathode system friendly to sulfide-based solid electrolytes. Using this cathode system, sulfide-based solid-state batteries with excellent long-cycle performance can be obtained.

[0082] Table 3 shows the parameters required for preparing all-solid-state batteries in Examples 8, 13 to 16. The difference between Examples 8 and 13 to 16 lies in the relevant parameters shown in Table 3. All other parameters are the same as those in Example 8. The specific difference is the mass ratio of polymer monomers.

[0083] Table 3 shows the cycle test and 180° peel force test results of the all-solid-state batteries prepared in Examples 8, 13 to 16.

[0084] Table 3

[0085]

[0086] As can be seen from the test results of Example 8, Example 13 to Example 16 in Table 3, in the present application, when the mass ratio of the polymerization monomers is within a certain range, the positive electrode binder of the sulfide-based all-solid-state battery provided by the present application can be prepared, and the wet homogenate can be performed on each electrode active material to obtain a positive electrode system friendly to the sulfide-based solid electrolyte. The all-solid-state battery with good long cycle performance can be obtained by using the positive electrode system.

[0087] As shown in Table 4, each parameter required for preparing the all-solid-state battery in Example 8, Example 17 to Example 20 is shown, and the difference between Example 8, Example 17 to Example 20 is the relevant parameters shown in Table 4, and the rest of the parameters are the same as Example 8, and the specific difference is: the mass ratio of the positive electrode material composition.

[0088] Table 4 shows the test results of the cycle test and the 180° peeling force test of the all-solid-state battery prepared in Example 8, Example 17 to Example 20.

[0089] Table 4

[0090]

[0091] As can be seen from the test results of Example 8, Example 17 to Example 20 in Table 4, when the mass ratio of the positive electrode material composition is controlled within a certain range, a positive electrode system friendly to the sulfide-based solid electrolyte can be obtained, thereby obtaining an all-solid-state battery with good long cycle performance.

[0092] As shown in Table 5, each parameter required for preparing the all-solid-state battery in Example 8, Example 21 to Example 23 is shown, and the difference between Example 8, Example 21 to Example 23 is the relevant parameters shown in Table 5, and the rest of the parameters are the same as Example 8, and the specific difference is: the sulfide solid electrolyte.

[0093] Table 5 shows the test results of the cycle test and the 180° peeling force test of the all-solid-state battery prepared in Example 8, Example 21 to Example 23.

[0094] Table 5

[0095]

[0096] As can be seen from the test results in Table 5, Examples 8, 21-23, in the positive electrode system, using the positive electrode binder provided by the present application, using different sulfide solid electrolytes, still can obtain a full solid-state battery with good long cycle performance, which shows that the positive electrode binder and the positive electrode system provided by the present application have universality for different sulfide solid electrolytes.

[0097] The above embodiments only express several embodiments of the present application, which are described in more detail and in more detail, but cannot be understood as limiting the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A sulfide-based all-solid-state battery cathode binder, characterized in that, Including the polymer shown in structural formula 1: ； Structural Formula 1 Wherein, R1 and R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl groups; R3 is selected from cyano or amide groups; R5 is selected from C1-C4 alkyl groups or C1-C3 fluoroalkyl groups; x is an integer from 5 to 1000, and y and z are each independently selected from integers from 0 to 1000.

2. The sulfide-based all-solid-state battery cathode binder according to claim 1, characterized in that, In the structural formula 1, R1 and R4 are each independently selected from H or CH3; R2 is selected from C1-C3 fluoroalkyl groups; R3 is selected from cyano or amide groups; R5 is selected from C1-C3 fluoroalkyl groups; x is an integer from 5 to 1000, y is an integer from 0 to 1000, and z is an integer from 1 to 1000.

3. The sulfide-based all-solid-state battery cathode binder according to claim 1, characterized in that, The sulfide-based all-solid-state battery cathode binder is prepared from fluorinated acrylate monomers, acrylate monomers, acrylonitrile monomers, or acrylamide monomers in a mass ratio of (1~5):(0~1):(0~1).

4. The sulfide-based all-solid-state battery cathode binder according to claim 3, characterized in that, The following method is used to prepare the product: Fluoroacrylate monomers, acrylate monomers, acrylonitrile monomers or acrylamide monomers are mixed with an emulsifier to form a pre-emulsion; then an initiator is added to carry out an emulsion polymerization reaction. After the reaction is completed, the product is cooled, demulsified, dissolved, washed and dried to obtain the final product.

5. The sulfide-based all-solid-state battery cathode binder according to claim 4, characterized in that, The amount of emulsifier used is 2% to 3% of the total monomer.

6. The sulfide-based all-solid-state battery cathode binder according to claim 4, characterized in that, The amount of initiator used is 0.1% to 0.5% of the total monomer amount.

7. An all-solid-state battery, characterized in that, The cathode includes a positive electrode current collector and a positive electrode material composition coated on the positive electrode current collector. The positive electrode material composition includes a positive electrode active material, a sulfide solid electrolyte, a conductive agent, and a sulfide-based all-solid-state battery positive electrode binder as described in any one of claims 1 to 6.

8. The all-solid-state battery according to claim 7, characterized in that, The mass ratio of the positive electrode active material, sulfide solid electrolyte, conductive agent and sulfide-based all-solid-state battery positive electrode binder is (75~85):(15~25):(0.5~3):(0.5~3).

9. The all-solid-state battery according to claim 7, characterized in that, The sulfide solid electrolyte is Li6PS5Cl, Li6PS5Br, or Li6PS5I.

10. The all-solid-state battery according to claim 7, characterized in that, The positive electrode active material includes one or more of the following: transition metal oxides, lithium-rich manganese-based materials, and sulfur-based materials.

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