Composite binder, preparation method and application in all-solid-state lithium battery

Abstract

The application belongs to the technical field of all-solid-state lithium batteries, and relates to a composite binder, a preparation method thereof and application of the composite binder in all-solid-state lithium batteries. The composite binder is that a surfactant is attached to the surface of a halogenated hydrocarbon polymer, and the mass fraction ratio of the surfactant and the halogenated hydrocarbon polymer is 1:9-99. Compared with the disclosed dry method, the adhesion of the binder is significantly improved, and the amount of the binder used in preparation of a polymer-sulfide flexible solid-state electrolyte (0.05%-3%) is reduced. The obtained sulfide composite solid-state electrolyte has excellent ductility, flexibility and relatively high ion conductivity (>=10 ‑3 S / cm), which is beneficial to large-scale production of high-load and high-capacity all-solid-state lithium batteries.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of all-solid-state lithium batteries, and relates to a composite binder, a preparation method thereof and application of the composite binder in all-solid-state lithium batteries. BACKGROUND

[0002] In recent years, lithium ion battery technology has developed rapidly and has had a profound impact on all walks of life. For example, the improvement of the energy density of lithium ion batteries provides support for high-energy high-performance wearable / portable devices, promotes their rapid progress, and changes the way of human life and production. As the core of new energy vehicles, the vigorous development of lithium ion power batteries also provides a favorable guarantee for the popularization of new energy vehicles, and is an important way to achieve energy saving, emission reduction and carbon neutrality. However, traditional commercial lithium ion batteries use organic electrolyte, which has a low flash point, is volatile and flammable, and has great safety hazards. At the same time, the growth of lithium dendrites, the dissolution and diffusion of by-products eventually lead to poor battery cycle performance, swelling and even short circuit. Solid-state electrolyte is non-volatile, non-flammable, has good high-temperature stability and high modulus to inhibit dendrite growth and diffusion of by-products. Therefore, the development of all-solid-state lithium batteries with stable performance and excellent performance has become the most important technical development direction at present.

[0003] Common solid-state electrolytes include polymer solid-state electrolytes, sulfide solid-state electrolytes and oxide solid-state electrolytes. Among them, sulfide solid-state electrolytes are considered to be the most revolutionary solid-state electrolyte material of the next generation due to their high ionic conductivity, wide electrochemical window and suitable modulus. However, sulfide solid-state electrolytes are extremely active in chemical properties, and will be greatly affected by water, oxygen or polar functional groups. Traditional blade coating and coating processes are difficult to use for sulfide solid-state electrolytes, because the polymer binders commonly used in the production of today's battery industry also generally have polar functional groups, and therefore their solvents are mostly high-polarity solvents. Therefore, there is an urgent need for a binder with low polarity and strong adhesion that is suitable for dry process to solve the industrialization problem of sulfide solid-state electrolytes. Chinese patent (CN202110141314.3) discloses a technical route for preparing a polymer-sulfide flexible solid-state electrolyte using a weakly polar solvent. Although the weak polarity alleviates the damage of the solvent to the structure of the sulfide solid-state electrolyte, the influence on ionic conductivity still exists. The ionic conductivity of the polymer-sulfide flexible solid-state electrolyte prepared by the technical route cannot be stabilized at more than 10 -3 S / cm. Chinese patent (CN202110829108.1) reports a process for filling sulfide solid-state electrolyte into a support film using a non-polar solvent dispersed in a porous support film by electrospinning. The amount of sulfide filled in the process is limited, and a continuous network cannot be formed, so the ionic conductivity of the polymer-sulfide flexible solid-state electrolyte prepared by the process is difficult to exceed 10 -3In addition, the binder is an ion transmission insulating phase, and the insufficient adhesion and large amount of use are important factors affecting the ion conductivity of the polymer-sulfide flexible solid-state electrolyte. A Chinese patent (CN202010603189.9) discloses a polymer-sulfide flexible solid-state electrolyte prepared by a dry process, wherein the amount of the binder is as high as 5-10%. Another bottleneck problem of the dry process is that the dry process generally has high requirements for the polymer, which must meet certain characteristics, greatly limiting the development. For example, a Chinese patent (CN202010725316.2) discloses a dry process, which requires that the polymer binder has the characteristics of fiberization under the action of external shear force, and sometimes high temperature above 210°C is needed. Based on the above analysis, it is urgent to develop a general binder for the dry process, which covers a variety of polymers, for the preparation of the polymer-sulfide flexible solid-state electrolyte. SUMMARY

[0004] The purpose of the present application is to provide a composite binder with low surface energy, strong adhesion, easy dispersion in the sulfide solid-state electrolyte dry process, a preparation method thereof and its application in all-solid-state lithium batteries.

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

[0006] A composite binder, the composite binder is that a surfactant is attached to the surface of a halogenated hydrocarbon polymer, wherein the mass fraction ratio of the surfactant and the halogenated hydrocarbon polymer is 1:9-99.

[0007] The halogenated hydrocarbon polymer is in powder form, and the particle size is not greater than 20μm, so as to ensure that the binder has a larger specific surface area, generally in the range of 5-20μm.

[0008] Preferably, the halogenated hydrocarbon polymer is one or more of polyvinyl chloride, polytribromostyrene, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoroethylene, polyvinylidene fluoride-trifluoroethylene-trifluorochloroethylene, and chloromethyl polystyrene.

[0009] The surfactant is an anionic surfactant, a cationic surfactant, a non-ionic surfactant, or a zwitterionic surfactant.

[0010] The surfactant can be selected from stearic acid, quaternary ammonium, amine, sulfate, sulfonate derivative, alkyl ammonium salt, alkoxyl ether, alkoxyl alcohol, lecithin, amino acid, and fatty glyceride.

[0011] Preferably, the surfactant can be selected from one or more of ammonium 3,3,4,4,4-chlorobutyrate, ammonium perfluorooctanoate, sodium perfluorobutyrate, and perfluoropolyether carboxylic acid.

[0012] A method for preparing a composite binder

[0013] S1, add halogenated hydrocarbon polymer and surfactant into water according to the proportion; the mass of water is 30-80 times of the total mass of halogenated hydrocarbon polymer and surfactant, so that the polymer is fully dispersed and suspended in the system during subsequent high-speed shearing emulsification;

[0014] S2, after adding, high-speed shearing emulsification is carried out to make the surfactant adhere to the surface of the halogenated hydrocarbon polymer to form a stable suspended emulsion;

[0015] S3, remove all water to obtain a composite binder.

[0016] The shearing speed is not less than 10000 rpm, and high-speed shearing is used to ensure that the halogenated alkane polymer powder can be fully dispersed in water, avoid agglomeration, and promote the surfactant to adhere to the surface of the microparticles.

[0017] Further, by uniformly and stably dispersing the polymer small particles in water at a high emulsification speed under a specific particle size, and uniformly wrapping the surfactant dissolved in water on the particles to increase the specific surface area, the viscosity of the obtained binder is enhanced.

[0018] Application of a composite binder, the composite binder is used in the preparation of a polymer-sulfide flexible solid-state electrolyte film by a dry method.

[0019] A method for preparing a polymer-sulfide flexible solid-state electrolyte film, comprising the following steps:

[0020] S1, grind the sulfide solid-state electrolyte thoroughly;

[0021] S2, mix the composite binder and the sulfide solid-state electrolyte uniformly to obtain a flexible and ductile sulfide composite electrolyte precursor;

[0022] S3, extrude into a film.

[0023] The sulfide solid-state electrolyte is one of glass ceramic type, thio-LISICON type or argyrodite type.

[0024] Preferably, the sulfide solid-state electrolyte is 75Li2S : 25P2S5, 70Li2S : 30P2S5, Li3PS4, Li7P3P 11 , Li 10 GeP2S 12 , Li 10 SnP2S 12 , Li 9.54 Si 1.74 P 1.44 S11.7 Cl 0.3 Li6PS5Cl, Li6PS5Br, etc.

[0025] The mixing method is manual, rolling, screw extrusion, ball milling or internal mixing;

[0026] The extrusion method is manual extrusion, hot roller extrusion, flat hot pressing, isostatic pressing or blow molding.

[0027] A polymer-sulfide flexible solid-state electrolyte film is prepared by using the composite binder, and the obtained film thickness can be as low as 10 μm; wherein the composite binder accounts for 0.05%-3% of the mass of the polymer-sulfide flexible solid-state electrolyte film.

[0028] A full solid-state lithium battery comprises a positive electrode sheet, a negative electrode sheet and a solid-state electrolyte film, wherein the solid-state electrolyte film is the polymer-sulfide flexible solid-state electrolyte film.

[0029] The present application has the following advantages:

[0030] 1. The technical method adopted by the present application is to attach surfactants to the surface of polymer microparticles, which has the effect of reducing surface energy and enhancing adhesion. Various polymers can be dispersed in sulfide solid-state electrolyte to prepare polymer-sulfide flexible solid-state electrolyte film by dry method.

[0031] 2. The composite binder provided by the present application has excellent adhesion, and the mass fraction of the composite binder in the prepared polymer-sulfide flexible solid-state electrolyte is 0.05%-3%. The low content of the binder has low influence on the ionic conductivity of the sulfide solid-state electrolyte, so the present application provides a polymer-sulfide flexible solid-state electrolyte film with excellent ionic conductivity (≥10 -3 S / cm). The polymer-sulfide flexible solid-state electrolyte film has excellent flexibility and ductility, which reduces the difficulty of assembling the battery, is suitable for batteries of different sizes and shapes, and is suitable for various positive and negative electrode materials.

[0032] 3. The technical method for preparing the composite binder provided by the present application is suitable for large-scale production and simple operation.

[0033] 4. The method for preparing the polymer-sulfide flexible solid-state electrolyte film by dry method provided by the present application has no temperature requirement and can be carried out at room temperature. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Photos of polymer emulsion (left) and polymer emulsion (right) of the surfactant used in Example 1.

[0035] Figure 2 Cross-sectional morphology of the sulfide composite electrolyte film in Example 2.

[0036] Figure 3 Photo of the polymer-sulfide flexible solid-state electrolyte film in Example 2.

[0037] Figure 4 Charge-discharge long cycle graph (0.1C) of the battery assembled with the polymer-sulfide flexible solid-state electrolyte film in Example 2.

[0038] Figure 5 Ionic conductivity of the polymer-sulfide flexible solid-state electrolyte film at different temperatures in Example 4. DETAILED DESCRIPTION

[0039] The following examples are further illustrations of the present application, but the present application is not intended to be limited to the following examples.

[0040] The present application obtains stable emulsion suspension by high-speed shearing in the preparation of composite binder, and then removes all water. The stable emulsion suspension proves that the surfactant is wrapped around the halogenated hydrocarbon polymer powder particles. The surfactant wrapped around the surface of the powder particles increases the adhesion and reduces the surface tension, which is conducive to the dispersion of halogenated hydrocarbon polymers in sulfide solid-state electrolyte. Compared with the disclosed dry process technology, the present application significantly improves the adhesion of the binder and reduces the amount of the binder in the preparation of polymer-sulfide flexible solid-state electrolyte film (0.05%-3%). The obtained polymer-sulfide flexible solid-state electrolyte film has excellent ductility, flexibility and high ionic conductivity (≥10 -3 S / cm), which is conducive to the large-scale production of high-load and high-capacity all-solid-state lithium batteries.

[0041] Example 1

[0042] 97.5 g of polyvinyl chloride (PVC) with a particle size of 20 μm and 2.5 g of 3,3,4,4,4-ammonium chlorobutyrate were added to 5000 g of distilled water, and a high-speed emulsifier was used for shearing stirring at 15000 rpm for 3 hours to obtain a stable emulsion. About 20 g of the obtained emulsion was taken out and placed in a vial for 12 hours, and the photo thereof is as shown in Figure 1 Left. The emulsion was freeze-dried (water was removed) to obtain a composite PVC binder.

[0043] 4.975 g of Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3The sulfide solid electrolyte was prepared to a particle size of less than 15 μm, then 25 mg of PVC composite binder was added, and the mixture was manually mixed in a mortar. Finally, it was manually pressed into a 30 μm thick polymer-sulfide flexible solid electrolyte membrane using a polytetrafluoroethylene rod.

[0044] Comparative Example 1

[0045] 100g of polyvinyl chloride (PVC) with a particle size of 20μm was added to 5000g of distilled water. The mixture was sheared and stirred at 15000 rpm for 3 hours using a high-speed emulsifier. The dispersion was immediately removed and then allowed to stand for 12 hours. The resulting image is shown below. Figure 1 right.

[0046] This demonstrates that PVC itself cannot be stably dispersed in water. In Example 1, the surfactant was completely attached to the surface of the PVC particles, thus forming a stable suspended emulsion, achieving the goal of surfactant attachment to the polymer surface.

[0047] Example 2

[0048] 98.5 g of polytetrafluoroethylene (PTFE) powder with a particle size of 20 μm and 1.5 g of ammonium perfluorooctanoate were added to 5000 g of water, and the mixture was sheared and stirred at 12000 rpm for 3 hours using a high-speed emulsifier to obtain a stable emulsion. The emulsion was freeze-dried to obtain a composite PTFE binder.

[0049] Grind 4.995g of Li by hand in a mortar. 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 The sulfide solid electrolyte is prepared to a particle size of less than 25 μm, and then 5 mg of the above-mentioned composite binder is added. The mixture is repeatedly rolled and mixed using a hot roller mill, and finally rolled into a polymer-sulfide flexible solid electrolyte membrane with a thickness of about 20 μm.

[0050] Depend on Figure 3 It can be seen that its thickness is about 20μm, reflecting that the polymer-sulfide flexible solid electrolyte membrane, containing only 0.1% composite binder, exhibits excellent ductility; Figure 2 The internal morphology is reflected. Due to its own characteristics, PTFE is fibrous, but it has very few fibers. It can be seen that a very small amount of binder can exhibit extremely strong adhesion.

[0051] The above polymer-sulfide flexible solid electrolyte membrane and ternary material NCM811 positive electrode sheet (load capacity 15mg / cm³) are combined. 2Both the lithium indium alloy sheet and the positive electrode sheet were cut into 10mm diameter discs and assembled into a battery using LIR2032 button cells. The battery was constructed by combining the negative electrode shell, lithium indium alloy sheet, polymer-sulfide flexible solid electrolyte membrane, positive electrode sheet, steel sheet, spring sheet, and positive electrode shell in an argon-protected glove box. The battery's charge-discharge long-cycle performance was tested at 50℃ and 0.2C, as shown in the attached figure. Figure 4 .

[0052] Depend on Figure 4 It is evident that the polymer-sulfide flexible solid electrolyte membrane has high ionic conductivity and extremely low binder content, which has little impact on ionic conductivity and interface, thus the battery exhibits good cycle stability.

[0053] Comparative Example 2

[0054] 4.985g of Li was simultaneously ground using a ball mill. 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 A mixture of sulfide solid electrolyte and 0.015g PTFE powder (i.e., PTFE and ammonium perfluorooctanoate were mixed according to the amount in Example 2) was repeatedly rolled by a hot roller press. The powder remained in fragments and could not be bonded into a film.

[0055] The rolling temperature is raised to 80°C, and the hot roller is used to repeatedly roll the product to obtain a polymer-sulfide solid electrolyte sheet that is brittle and easily bent.

[0056] It is evident that simply blending surfactant and PTFE fails to disperse the surfactant onto the polymer surface, resulting in minimal improvement in polymer adhesion, far inferior to the composite PTFE binder in Example 2. This comparative example, with a binder content of 0.3%, exhibits twice the adhesion of Example 2, yet requires heating to bond all the sulfides, demonstrating a significantly weaker film-forming effect compared to Example 2. This indicates that the structure of the composite binder from Example 2 provides better adhesion and promotes film flexibility.

[0057] Example 3

[0058] 98.8g of polyvinylidene fluoride (PVDF) with a particle size of 20μm and 1.2g of sodium perfluorobutyrate were added to 5000g of water. The mixture was sheared at 10000rpm for 5 hours using a high-speed emulsifier to obtain a PVDF emulsion. After thorough vacuum drying at 60℃, a PVDF composite binder was obtained.

[0059] 4.995g of Li6PS5Cl sulfide solid electrolyte was manually ground in a mortar until the particle size was below 25μm. After adding 5mg of composite binder, the mixture was repeatedly rolled and mixed at room temperature in a mixer to obtain a polymer-sulfide flexible solid electrolyte membrane with a thickness of about 19μm.

[0060] Example 4

[0061] 97.0g of polyvinylidene fluoride (PVDF) with a particle size of 10μm was used. co PVDF-HFP (poly(hexafluoroethylene)) and 3g of perfluoropolyether acetic acid were added to 5000g of double-distilled water, and a stable PVDF-HFP emulsion was obtained by shearing at 15000rpm for 3 hours using a high-speed emulsifier. After freeze-drying, a PVDF-HFP composite binder was obtained.

[0062] Take 15g of the above composite binder and add it to 2.5kg of Li with a particle size of less than 20μm. 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 In a drying room with a dew point ≤ -40℃, the powder is repeatedly rolled using a large rubber mixer to obtain a polymer-sulfide flexible solid electrolyte membrane with a thickness of about 40μm.

[0063] The ionic conductivity of the aforementioned polymer-sulfide flexible solid electrolyte membrane was determined by measuring the AC impedance curves (EIS) of a stainless steel / electrolyte / stainless steel symmetrical cell, with a frequency range of 10 mHz to 7 MHz. This was then verified using the formula σ = L / (R). b S) Calculations show that the test temperature range is -40 ºC to 150 ºC. R b The measured bulk impedance value, where L and S refer to the thickness and area of ​​the electrolyte, respectively. See the test data for details. Figure 5 .like Figure 5 The ionic conductivity of the membranes obtained in the examples is greater than 10 at temperatures above 20°C. -3 S / cm.

[0064] Example 5

[0065] 98.0g of poly(vinylidene fluoride) with a particle size of 20μm was used. co -trifluoroethylene- co - Trifluorochloroethylene (P(VDF-TrFE-CTrFE)) and 2g of perfluoropolyether carboxylic acid activator FRD-901 were added to 5000g of water, and a stable P(VDF-TrFE-CTrFE) emulsion was obtained by shearing at 15000rpm for 3 hours using a high-speed emulsifier. After freeze-drying, P(VDF-TrFE-CTrFE) composite binder was obtained.

[0066] Take the above composite binder 0.01 g added to 0.99 g particle size within 20 μm Li7Ge3PS 12 The powder is mixed evenly in a mortar by hand grinding, and then rolled into a polymer-sulfide flexible solid electrolyte film with a thickness of about 40 μm using a polytetrafluoroethylene rod.

[0067] Comparative Example 3

[0068] Grind 4.9 g Li7Ge3PS 12 The sulfide solid electrolyte and 0.1 g P(VDF-TrFE-CTrFE) powder are mixed evenly, and the mixed powder is directly rolled repeatedly using a hot roller machine. The temperature of the hot roller is increased to 200°C, and the mixed powder is continuously rolled repeatedly using the hot roller machine. The polymer-sulfide solid electrolyte brittle sheet obtained is not flexible.

[0069] Since P(VDF-TrFE-CTrFE) itself has very poor creep resistance, high temperature is required to fully contact the sulfide powder and bond, and the bonding force is low, resulting in a polymer-sulfide solid electrolyte film with low mechanical strength. Comparative Example 5 further proves that the surfactant can reduce the surface activation energy and improve the bonding effect.

[0070] Example 6

[0071] 98.0 g of polyvinylidene chloride (PVDC) with a particle size of 20 μm and 2 g of 3,3,4,4,4-ammonium chlorobutyrate are added to 5000 g of water, and a stable PVDC emulsion is obtained by shearing at a speed of 12000 rpm for 4 hours using a high-speed emulsifier. After air drying, a PVDC composite binder is obtained.

[0072] Take the above composite binder 2 mg added to 0.998 g particle size within 20 μm Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 The powder is rolled into a film on a hot roller machine, and the thickness can be controlled by adjusting the roller gap to be between 35 μm and 200 μm.

[0073] Example 7

[0074] 98.5 g of polytetrafluoroethylene (PTFE) powder with a particle size of 10-20 μm and 1.5 g of sodium perfluorobutyl sulfonate are added to 5000 g of water, and a stable emulsion is obtained by shearing at a speed of 15000 rpm for 3 hours on a high-speed emulsifier. After drying, a PTFE composite binder is obtained.

[0075] Grind 4.9 g Li7Ge3PS9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 0.998g of sulfide solid electrolyte powder with a particle size of about 15μm was mixed with 2mg of the above-mentioned composite binder and manually ground and mixed evenly in a mortar. Then, the mixture was rolled into a polymer-sulfide flexible solid electrolyte membrane with a thickness of 40μm using a hot roller press.

[0076] Example 8

[0077] 98.8 g of polyhexafluoropropylene oxide (PFPO) powder with a particle size of 20 μm and 1.2 g of sodium perfluorobutyrate were added to 5000 g of water. The mixture was sheared at 10000 rpm for 5 hours in a high-speed emulsifier to obtain a stable emulsion. After thorough drying under vacuum at 60 °C, the PFPO composite binder was obtained.

[0078] Take 0.5 mg of the composite binder obtained above and add it to 0.9995 g of fully ground Li6PS5Cl powder. Then, use a hot roller press to roll it into a polymer-sulfide flexible solid electrolyte membrane. The thickness can be adjusted from 40 μm to 200 μm by the roller spacing.

[0079] Example 9

[0080] 98.4 g of polytribromostyrene (PTBS) powder with a particle size of 10 μm and 1.6 g of perfluoropolyether carboxylic acid activator FRD-901 were added to 5000 g of double-distilled water. The mixture was sheared at 15000 rpm for 5 hours on a high-speed emulsifier to obtain a stable emulsion. After removing all water by vacuum drying at 60 °C, the PTBS composite binder was obtained.

[0081] Take 15g of the composite binder obtained above and add it to 1kg of fully ground Li6PS5Cl powder. In a drying room with a dew point ≤-40℃, repeatedly roll the mixture using a large rubber mixer to obtain a polymer-sulfide flexible solid electrolyte membrane with a thickness of 40μm or more.

[0082] Example 10

[0083] 98.0g of poly(vinylidene fluoride) with a particle size of 20μm was used. co co co co co co co co co co co co co co co co co co co P(VDF-TrFE) powder and 2g of perfluoropolyether carboxylic acid activator FRD-901 were added to 5000g of water. The mixture was sheared at 15000rpm for 5 hours on a high-speed emulsifier to obtain a stable emulsion. The emulsion was then freeze-dried to obtain the P(VDF-TrFE) composite binder.

[0084] Take 3 mg of the above-obtained composite binder and add it to 1 g of thoroughly ground Li. 10 GeP2S12 The powder was mixed evenly by hand in a mortar, and then pressed into a polymer-sulfide flexible solid-state electrolyte film by hand using a polytetrafluoroethylene rod, and the thickness thereof was controlled by the roller gap to be 50 μm to 200 μm.

[0085] The above is only a preferred embodiment of the present application, and of course cannot limit the scope of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, can make a number of improvements and changes, these improvements and changes are also considered to be within the scope of the present application.

Claims

1. An application of a composite adhesive, characterized in that, The composite binder is used in the dry preparation of polymer-sulfide flexible solid electrolyte membranes. The composite binder is a surfactant that adheres to the surface of a halogenated hydrocarbon polymer, wherein the mass ratio of the surfactant to the halogenated hydrocarbon polymer is 1:9-99.

2. The application of the composite adhesive according to claim 1, characterized in that, The halogenated hydrocarbon polymer is in powder form with a particle size of no more than 20 μm.

3. The application of the composite adhesive according to claim 1, characterized in that, The surfactant is an anionic surfactant, a cationic surfactant, a nonionic surfactant, or an amphoteric surfactant.

4. The application of the composite adhesive according to claim 1, characterized in that, The preparation method of the composite adhesive is as follows: S1, adding the halogenated hydrocarbon polymer and the surfactant to water according to the mass ratio of claim 1; S2, after addition, high-speed shear emulsification is performed to allow the surfactant to adhere to the surface of the halogenated hydrocarbon polymer to form a stable suspension emulsion; S3, removing all water to obtain the composite adhesive.

5. The application of the composite adhesive according to claim 4, characterized in that, The shearing speed is not less than 10,000 rpm.

6. A method for preparing a polymer-sulfide flexible solid electrolyte membrane, characterized in that, The process includes the following steps: S1, thoroughly grinding the sulfide solid electrolyte; S2, uniformly mixing the composite binder and the sulfide solid electrolyte as described in claim 1 to obtain a flexible and stretchable sulfide composite electrolyte precursor; S3, extruding into a film.

7. The method for preparing a polymer-sulfide flexible solid electrolyte membrane according to claim 6, characterized in that, The sulfide solid electrolyte is one of the following: glass-ceramic type, thio-LISICON type, or argyrodite type.

8. The method for preparing a polymer-sulfide flexible solid electrolyte membrane according to claim 6, characterized in that, The mixing method is manual, roller pressing, screw extrusion, ball milling or internal mixing; the extrusion method is manual extrusion, hot roller extrusion, flat plate hot pressing, isostatic pressing or blow molding.

9. A polymer-sulfide flexible solid electrolyte membrane, characterized in that, The polymer-sulfide flexible solid electrolyte membrane is prepared using the composite binder described in claim 1; wherein the composite binder accounts for 0.05%-3% of the mass of the polymer-sulfide flexible solid electrolyte membrane.

10. An all-solid-state lithium battery, characterized in that, The all-solid-state lithium battery includes a positive electrode, a negative electrode, and a solid electrolyte membrane, wherein the solid electrolyte membrane is the polymer-sulfide flexible solid electrolyte membrane as described in claim 9.

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