Inorganic-organic composite solid electrolyte and preparation method thereof

Abstract

The present invention belongs to the field of solid electrolyte technology, and specifically discloses an inorganic-organic composite solid electrolyte and a preparation method thereof. The preparation method comprises the following steps: dissolving a polymer, a grafted monomer, and an initiator in a solvent 1 to obtain a polymer solution, coating the polymer solution into a film, and then performing ultraviolet light curing to obtain a polymer substrate; spraying a LiF aqueous solution on a surface of the polymer substrate, standing for reaction, and drying to obtain a modified polymer substrate; dissolving a sulfide solid electrolyte in a solvent 2 to obtain an electrolyte solution; spraying the electrolyte solution on the surface of the modified polymer substrate sprayed with LiF, and after ultrasonic treatment, drying to obtain an inorganic-organic composite solid electrolyte. The inorganic-organic composite solid electrolyte prepared by the present invention not only has a higher lithium ion transfer rate, but also can form a LiF-rich SEI film on the negative electrode surface, thereby greatly improving the cycle performance of the solid-state battery.

Description

Technical Field

[0001] The invention belongs to the technical field of solid electrolytes, and in particular relates to an inorganic-organic composite solid electrolyte and a preparation method thereof. Background Art

[0002] Traditional lithium batteries usually use flammable organic liquid electrolytes as the conductive medium for lithium ions, but liquid electrolytes have safety hazards such as leakage, combustion, and explosion. Replacing organic liquid electrolytes with solid electrolytes is expected to fundamentally solve its safety problems.

[0003] Solid electrolytes are mainly divided into two categories: inorganic solid electrolytes and polymer solid electrolytes. Inorganic solid electrolytes have high conductivity, high mechanical strength, and a lithium ion migration number close to 1, but they have poor stability in the air and poor solid-solid interface contact between the electrolyte and the electrode. Polymer solid electrolytes are relatively stable in the air, have strong plasticity, can wet the electrodes well, and have a simple battery assembly process, but they have poor thermal stability, are easy to crystallize, and have low room temperature conductivity. Therefore, it is difficult to meet the needs of practical applications using a single inorganic solid electrolyte or polymer solid electrolyte.

[0004] Based on this, inorganic-organic composite solid electrolytes came into being. The most common method for inorganic-organic composite solid electrolytes is to combine inorganic solid electrolytes with polymer solid electrolytes by mechanical mixing, and then prepare inorganic-organic composite electrolyte membranes by the preparation method of polymer solid electrolytes (casting method or coating method). Although the inorganic-organic composite electrolyte membrane prepared by the above method has good mechanical properties and thermal stability, and high conductivity, the dispersibility of inorganic solid electrolytes in organic polymers is poor. Therefore, more inorganic solid electrolytes need to be added to achieve better results. At present, the price of inorganic solid electrolytes is relatively high, which also greatly increases the cost of solid electrolytes. Furthermore, if too much inorganic solid electrolyte is added to the inorganic-organic composite solid electrolyte, the dispersibility is poor, and it is easy to form interface defects between the inorganic phase and the organic phase, which limits the transmission speed of lithium ions and affects the cycle performance of the assembled solid-state battery. Summary of the invention

[0005] The purpose of the present invention is to provide a low-cost inorganic-organic composite solid electrolyte and a preparation method thereof.

[0006] In a first aspect, the present invention provides a method for preparing an inorganic-organic composite solid electrolyte, using the following technical solution:

[0007] A method for preparing an inorganic-organic composite solid electrolyte comprises the following steps:

[0008] Step S1: dissolving a polymer, a grafting monomer, and an initiator in a solvent 1 to obtain a polymer solution, coating the polymer solution into a film, and then performing ultraviolet light curing to obtain a polymer substrate;

[0009] Step S2: spraying a LiF aqueous solution onto one surface of the polymer substrate, standing for reaction, and drying to obtain a modified polymer substrate;

[0010] Step S3: dissolving the sulfide solid electrolyte in solvent 2 to obtain an electrolyte solution; spraying the electrolyte solution on the surface of the modified polymer substrate sprayed with the LiF layer, ultrasonically treating, and drying to obtain an inorganic-organic composite solid electrolyte.

[0011] Preferably, in step S1, the polymer is one or more of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), and polyvinylidene fluoride-chlorotrifluoroethylene copolymer (PVDF-CTFE).

[0012] Preferably, in step S1, the grafting monomer is one or both of polyethylene glycol diacrylate (PEGDA) and hexafluorobutyl methacrylate (HFMA), and the mass ratio of the polymer to the grafting monomer is (90-120):(30-50).

[0013] Preferably, in step S1, the initiator is one or more of photoinitiator 369 (2-benzyl-2-dimethylamino-4'-morpholinobutyrophenone), photoinitiator 819 (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), photoinitiator 907 (2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholino)-1-propanone), and photoinitiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone), and the mass ratio of initiator to grafted monomer is (0.008~0.015):1.

[0014] Preferably, in step S1, solvent 1 is one or more of N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), tetrahydrofuran (THF), and the mass volume ratio of the polymer to the solvent 1 is (0.9-1.1) g: (9-11) mL.

[0015] Preferably, in step S1, the coating thickness is 150-250 μm; the intensity of the ultraviolet light is 90-120 mW / cm 2 , the curing time is 5~10min.

[0016] Preferably, in step S2, the concentration of the LiF aqueous solution is 0.05-0.1 g / L.

[0017] Preferably, in step S2, the spraying amount of the LiF aqueous solution is 30-50 μL / cm 2 .

[0018] Preferably, in step S2, the static reaction time is 10 to 30 minutes.

[0019] Preferably, in step S3, the sulfide solid electrolyte is Li6PS5Cl, Li7P3S 11 , Li 3.25 Ge 0.25 P 0.7 S4, Li 10 GeP2S 12 One of the above; the concentration of the electrolyte solution is 3~6g / L.

[0020] Preferably, in step S3, the solvent is one or more of toluene, 1,2-xylene, 1,3-xylene, and 1,4-xylene.

[0021] Preferably, in step S3, the spraying amount of the electrolyte solution is 0.08-0.15 mL / cm 2 ; The ultrasonic treatment time is 5~8min.

[0022] In a second aspect, the present invention provides an inorganic-organic composite solid electrolyte, which is prepared by the aforementioned preparation method.

[0023] The present invention first prepares a polymer substrate with a three-dimensional network structure of long and short chains interacting with each other; since the polymer substrate will shrink and expand with water, when the LiF aqueous solution is sprayed on the polymer substrate, a structure with pores will be formed in the polymer substrate; due to the existence of the pore structure, LiF particles will be introduced into the polymer substrate. When the sulfide solid electrolyte is sprayed into the polymer substrate containing LiF, the sulfide solid electrolyte will also be introduced into the polymer substrate due to the pore structure of the polymer substrate and ultrasonic action.

[0024] The above one or more technical solutions of the present invention can achieve at least one of the following beneficial effects:

[0025] (1) In the method of the present invention, LiF particles are first introduced into the polymer substrate, which is not only conducive to the formation of a LiF-rich SEI film on the negative electrode surface by the solid electrolyte, but also can improve the affinity of the polymer substrate, making it easier to introduce the sulfide solid electrolyte into the polymer substrate.

[0026] (2) By introducing the sulfide solid electrolyte into the polymer substrate using the method of the present invention, the dispersibility of the sulfide solid electrolyte will be better. Therefore, compared with directly adding the sulfide solid electrolyte into the polymer, under the condition of equivalent performance, the amount of sulfide solid electrolyte can be greatly reduced, thereby reducing the production cost.

[0027] (3) The inorganic-organic composite solid electrolyte prepared by the present invention has both ionic conductivity similar to that of sulfide solid electrolytes and mechanical properties of polymer electrolytes. It can improve the lithium ion transmission rate of the solid electrolyte and reduce polarization, thereby greatly improving the cycle performance of the battery.

[0028] (4) The preparation method of the present invention is simple, the production conditions are green and clean, and the high-performance solid electrolyte for lithium-ion batteries can be efficiently prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The cycle performance diagram of the solid-state battery assembled with the inorganic-organic composite solid electrolyte prepared in Examples 1 to 7.

[0030] Figure 2 This is a cycle performance diagram of the solid-state battery assembled with the inorganic-organic composite solid electrolyte prepared in Comparative Examples 1 to 3.

[0031] Figure 3 This is an EIS test effect diagram of lithium-lithium batteries assembled with inorganic-organic composite solid electrolytes prepared in Examples 1 to 7 and Comparative Examples 1 to 3 at room temperature. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0034] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0035] Example 1

[0036] (1) 1.0 g PVDF-HFP, 0.4 g PEGDA, and 0.004 g photoinitiator 369 were added to 10 mL DMF and stirred to fully dissolve to obtain a polymer solution. The polymer solution was scraped onto a glass plate with a 200 μm thick scraper and then placed under 100 mW / cm 2 The polymer substrate was cured under ultraviolet light for 7 minutes to obtain a polymer substrate. In this step, the polymer substrate did not need to be removed from the glass plate.

[0037] (2) Add 0.007 g of LiF particles (average particle size of 500 nm) into 100 mL of water and stir thoroughly to dissolve to obtain a LiF solution. 2 The coating amount is evenly sprayed on the surface of the polymer substrate prepared in step (1), and after standing for reaction for 20 minutes, it is dried to obtain a LiF-modified polymer substrate.

[0038] (3) Add 0.04 g Li6PS5Cl to 10 mL toluene and stir thoroughly to dissolve to obtain a Li6PS5Cl solution. 2 The spray amount is evenly sprayed on the surface of the LiF-modified polymer substrate in step (2), ultrasonically applied for 7 minutes, and then dried. The mold is removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0039] Comparative Example 1

[0040] 1.0 g PVDF-HFP, 0.4 g PEGDA, 0.004 g photoinitiator 369, 0.05 g LiF particles (particle size of 500 nm), and 0.5 g Li6PS5Cl were added to 10 mL DMF and stirred to fully dissolve to obtain a polymer solution.

[0041] The polymer solution was coated on a glass plate using a doctor blade with a thickness of 200 μm and then placed under 100 mW / cm 2 The film was cured under ultraviolet light for 7 minutes, and then removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0042] Comparative Example 2

[0043] The method is basically the same as Example 1, except that: the LiF modification in step (2) is not performed; the Li6PS5Cl solution is directly sprayed on the surface of the polymer substrate prepared in step (1) according to the method in step (3) to prepare an inorganic-organic composite solid electrolyte.

[0044] Comparative Example 3

[0045] The same as Example 1, except that: in step (2), water is directly used for spraying without adding LiF particles; step (2) is as follows: water is sprayed at 40 μL / cm 2 The amount of the coating is uniformly sprayed on the surface of the polymer substrate prepared in step (1), allowed to react for 20 minutes, and then dried to obtain a modified polymer substrate.

[0046] Example 2

[0047] The method is basically the same as Example 1, except that the concentration and spraying amount of the Li6PS5Cl solution in step (3) are different. Step (3) is as follows: 0.06 g Li6PS5Cl is added to 10 mL toluene, and after sufficient stirring and dissolution, a Li6PS5Cl solution is obtained; the Li6PS5Cl solution is sprayed at 0.15 mL / cm 2 The spray amount is evenly sprayed on the surface of the LiF-modified polymer substrate in step (2), ultrasonically applied for 7 minutes, and then dried. The mold is removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0048] Example 3

[0049] The method is basically the same as Example 1, except that the concentration and spraying amount of the Li6PS5Cl solution in step (3) are different. Step (3) is as follows: 0.03 g Li6PS5Cl is added to 10 mL toluene, and after sufficient stirring and dissolution, a Li6PS5Cl solution is obtained; the Li6PS5Cl solution is sprayed at 0.08 mL / cm 2 The amount of the coating is uniformly sprayed on the surface of the LiF-modified polymer substrate in step (2), ultrasonicated for 7 minutes, and after drying, the mold is removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0050] Example 4

[0051] The method is basically the same as Example 1, except that the concentration and spraying amount of the LiF solution in step (2) are different. Step (2) is as follows: 0.01 g of LiF particles (average particle size of 500 nm) are added to 100 mL of water and stirred thoroughly to dissolve to obtain a LiF solution; the LiF solution is sprayed at 50 μL / cm 2 The coating amount is evenly sprayed on the surface of the polymer substrate prepared in step (1), and after standing for reaction for 20 minutes, it is dried to obtain a LiF-modified polymer substrate.

[0052] Example 5

[0053] The method is basically the same as Example 1, except that the concentration and spraying amount of the LiF solution in step (2) are different. Step (2) is as follows: 0.005 g of LiF particles (average particle size of 500 nm) are added to 100 mL of water and stirred to dissolve to obtain a LiF solution; the LiF solution is sprayed at 30 μL / cm 2 The amount of the coating is evenly sprayed on the surface of the polymer substrate prepared in step (1), and after standing for reaction for 20 minutes, it is dried to obtain a LiF-modified polymer substrate.

[0054] Example 6

[0055] (1) 0.9 g PVDF-CTFE, 0.5 g HFMA, and 0.007 g photoinitiator 819 were added to 10 mL THF and stirred to fully dissolve to obtain a polymer solution. The polymer solution was scraped onto a glass plate with a 250 μm thick scraper and then placed under 120 mW / cm 2 The polymer substrate was cured under ultraviolet light for 8 minutes to obtain a polymer substrate. In this step, the polymer substrate does not need to be removed from the glass plate.

[0056] (2) Add 0.008 g of LiF particles (average particle size of 500 nm) into 100 mL of water and stir thoroughly to dissolve to obtain a LiF solution. 2 The coating amount is evenly sprayed on the surface of the polymer substrate prepared in step (1), and after standing for reaction for 30 minutes, it is dried to obtain a LiF-modified polymer substrate.

[0057] (3) 0.04gLi 10 GeP2S 12 Add 10mL 1,2-dimethylbenzene and stir thoroughly to dissolve to obtain Li 10 GeP2S 12 Solution; Li 10 GeP2S 12 The solution was 0.12mL / cm 2 The coating amount is evenly sprayed on the surface of the LiF-modified polymer substrate in step (2), and after ultrasonic treatment for 6 minutes, the film is dried and removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0058] Example 7

[0059] (1) 1.2 g PVDF, 0.3 g PEGDA, and 0.0027 g photoinitiator 907 were added to 10 mL DMF and stirred to fully dissolve to obtain a polymer solution. The polymer solution was scraped onto a glass plate with a 150 μm thick scraper and then placed under 90 mW / cm 2The polymer substrate was cured under ultraviolet light for 10 minutes to obtain a polymer substrate. In this step, the polymer substrate did not need to be removed from the glass plate.

[0060] (2) Add 0.006 g of LiF particles (average particle size of 500 nm) into 100 mL of water and stir thoroughly to dissolve to obtain a LiF solution. 2 The coating amount is evenly sprayed on the surface of the polymer substrate prepared in step (1), and after standing for reaction for 15 minutes, it is dried to obtain a LiF-modified polymer substrate.

[0061] (3) 0.05gLi7P3S 11 Add 10 mL of 1,3-dimethylbenzene and stir thoroughly to dissolve to obtain Li7P3S 11 Solution; Li7P3S 11 The solution was 0.14 mL / cm 2 The coating amount is evenly sprayed on the surface of the LiF-modified polymer substrate in step (2), ultrasonicated for 8 minutes, and after drying, the film is removed from the glass plate to obtain an inorganic-organic composite solid electrolyte.

[0062] Charge and discharge test performance test:

[0063] The solid-state battery was assembled by the following method: the inorganic-organic composite solid electrolyte prepared in Examples 1 to 7 and Comparative Examples 1 to 3 was cut into round pieces with a diameter of 16 mm to serve as the battery electrolyte. The commercial NCM622 material was mixed with the conductive agent acetylene black (AB), Li6PS5Cl (Li 10 GeP2S 12 and Li7P3S 11 ) are mixed in a mass ratio of 7:1:2, and stirred to obtain a mixed powder; the mixed powder is pressed at a pressure of 100MPa on the side of the inorganic-organic composite solid electrolyte membrane sprayed with a sulfide solid electrolyte to obtain an inorganic-organic composite solid electrolyte sheet containing a positive electrode material. The lithium-indium alloy sheet is cut into a circular sheet with a diameter of 16mm to serve as the negative electrode of the battery. In a glove box filled with argon atmosphere with a water content and an oxygen content of less than 0.1ppm, the inorganic-organic composite solid electrolyte sheet containing the positive electrode material and the battery negative electrode are assembled into a CR2032 button battery in the glove box. After the battery assembly is completed and aged for 12h, a charge and discharge test is performed. The test parameters are: 100 cycles at a voltage of 2.8~4.5V and a current density of 0.5C.

[0064] Ionic conductivity performance test:

[0065] Solid electrolyte assembly of lithium-lithium battery: A lithium sheet with a diameter of 16 mm is used as the negative electrode of the battery, a stainless lithium sheet with a diameter of 15.6 mm is used as the positive electrode of the battery, and the prepared inorganic-organic composite solid electrolyte is used as the filler between the positive and negative electrodes (the side of the inorganic-organic composite solid electrolyte sprayed with sulfide solid electrolyte is in contact with the positive electrode), and assembled into a CR2032 button battery in a glove box filled with argon atmosphere with a water content and oxygen content of less than 0.1 ppm. EIS curve of the test battery at a frequency of 1-100000 Hz.

[0066] Table 1

[0067]

[0068] The cycle performance diagrams and cycle performance data of the solid-state batteries assembled with inorganic-organic composite solid electrolytes prepared in Examples 1 to 7 and Comparative Examples 1 to 3 can be seen respectively. Figure 1~2 From Table 1, it can be seen that the solid-state battery assembled with the inorganic-organic composite solid electrolyte prepared in Example 1 has good specific capacity and cycle performance. In Comparative Example 1, the inorganic-organic solid electrolyte membrane is prepared by directly mixing a conventional sulfide solid electrolyte with a polymer. When the added LiF and Li6PS5Cl are significantly higher than those in Example 1, the specific capacity and cycle stability of the solid-state battery assembled with the inorganic-organic composite solid electrolyte are not as good as those in Example 1. In Comparative Example 2, no LiF solution is sprayed, and the specific capacity and cycle performance of the solid-state battery assembled with the corresponding inorganic-organic solid electrolyte are significantly decreased compared with those in Example 1. In Comparative Example 3, pure water is used instead of LiF solution, and the specific capacity and cycle performance of the solid-state battery assembled with the corresponding inorganic-organic composite solid electrolyte are improved compared with Comparative Example 2, and decreased compared with Example 1.

[0069] In Examples 1 to 3, the spraying amount of Li6PS5Cl is mainly different, and the specific capacity and cycle performance of the solid-state batteries assembled with the corresponding prepared inorganic-organic composite solid electrolytes will fluctuate to a certain extent, but all have good electrochemical properties.

[0070] The main difference between Example 1 and Examples 4-5 is the spraying amount of the LiF solution. The specific capacity and cycle performance of the solid-state batteries assembled with the corresponding prepared inorganic-organic composite solid electrolytes will fluctuate to a certain extent, but all have good electrochemical properties.

[0071] In Example 6 and Example 7, the process parameters of the preparation method of the inorganic-organic composite solid electrolyte were adjusted. The specific capacity and cycle stability of the solid-state batteries assembled with the corresponding inorganic-organic composite solid electrolytes will fluctuate to a certain extent, but both have good electrochemical properties.

[0072] The EIS curves of the lithium-lithium batteries assembled with inorganic-organic composite solid electrolytes prepared in Examples 1 to 7 and Comparative Examples 1 to 3 show Figure 3 , the ionic conductivity data calculated by fitting the EIS curve can be seen in Table 1, and it can be seen that the ionic conductivity of the inorganic-organic composite solid electrolyte in Example 1 is significantly better than that of Comparative Examples 1 to 3. In Example 2, the spraying amount of Li6PS5Cl is increased, and the ionic conductivity of the corresponding prepared inorganic-organic composite solid electrolyte is slightly increased compared with that in Example 1; in Example 3, the spraying amount of Li6PS5Cl is reduced, and the ionic conductivity of the corresponding prepared inorganic-organic composite solid electrolyte is slightly reduced compared with that in Example 1; the change in the spraying amount of LiF in Examples 4 and 5 does not have a great effect on the ionic conductivity of the inorganic-organic composite solid electrolyte.

[0073] The process parameters of the preparation method of the inorganic-organic composite solid electrolyte in Example 6 and Example 7 were adjusted, and the ionic conductivity of the corresponding prepared inorganic-organic composite solid electrolyte would change to a certain extent.

[0074] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an inorganic-organic composite solid electrolyte, characterized in that: The following steps are involved: Step S1: dissolving a polymer, a grafting monomer, and an initiator in a solvent 1 to obtain a polymer solution, coating the polymer solution into a film, and then performing ultraviolet light curing to obtain a polymer substrate; wherein: the polymer is one or more of PVDF, PVDF-HFP, and PVDF-CTFE; and the grafting monomer is one or two of PEGDA and HFMA; Step S2: spraying a LiF aqueous solution on one surface of the polymer substrate, standing for reaction, and drying to obtain a modified polymer substrate; wherein: the concentration of the LiF aqueous solution is 0.05-0.1 g / L; the spraying amount of the LiF aqueous solution is 30-50 μL / cm 2 ; Step S3: dissolving the sulfide solid electrolyte in solvent 2 to obtain an electrolyte solution; spraying the electrolyte solution on the surface of the modified polymer substrate sprayed with LiF, ultrasonically treating, and drying to obtain an inorganic-organic composite solid electrolyte; wherein: the concentration of the electrolyte solution is 3-6 g / L; the spraying amount of the electrolyte solution is 0.08-0.15 mL / cm 2 ; Solvent 2 is one or more of toluene, 1,2-dimethylbenzene, 1,3-dimethylbenzene, and 1,4-dimethylbenzene.

2. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1, characterized in that: In the step S1, the mass ratio of the polymer to the grafting monomer is (90-120):(30-50).

3. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1 or 2, characterized in that: In the step S1, the initiator is one or more of photoinitiator 369, photoinitiator 819, photoinitiator 907, and photoinitiator 1173, and the mass ratio of the initiator to the grafted monomer is (0.008-0.015):

1.

4. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1 or 2, characterized in that: In the step S1, the solvent 1 is one or more of N,N-dimethylformamide, N-methylpyrrolidone, and tetrahydrofuran, and the mass volume ratio of the polymer to the solvent 1 is (0.9-1.1) g: (9-11) mL.

5. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1 or 2, characterized in that: In step S1, the coating thickness is 150-250 μm; the intensity of the ultraviolet light is 90-120 mW / cm 2 ; The UV curing time is 5~10min.

6. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1, characterized in that: In step S2, the static reaction time is 10 to 30 minutes.

7. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1, characterized in that: In step S3, the sulfide solid electrolyte is Li6PS5Cl, Li7P3S 11 , Li 3.25 Ge 0.25 P 0.7 S4, Li 10 GeP2S 12 One of them.

8. The method for preparing the inorganic-organic composite solid electrolyte according to claim 1 or 7, characterized in that: In step S3, the ultrasonic treatment time is 5 to 8 minutes.

9. An inorganic-organic composite solid electrolyte, characterized in that: The method is prepared according to any one of claims 1 to 8.

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