Preparation method and application of solid-state battery three-dimensional open structure composite sulfur positive electrode material
By preparing S@KB-Fe-NC composite sulfur cathode material, the problems of polysulfide migration and reaction kinetics in all-solid-state lithium-sulfur batteries were solved, and the battery performance was improved by achieving high efficiency, especially the discharge specific capacity and cycle stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEASTERN UNIV AT QINHUANGDAO
- Filing Date
- 2026-05-08
- Publication Date
- 2026-07-31
AI Technical Summary
All-solid-state lithium-sulfur batteries face challenges in practical applications, such as the shuttle effect of polysulfides and slow reaction kinetics, which limit their commercialization.
Fe-NC material was synthesized using MOF-5 as a precursor and then combined with Ketjen black to prepare S@KB-Fe-NC composite sulfur cathode material. By utilizing its porous structure and Fe-Nx active sites, the migration of polysulfides was inhibited through physical adsorption and chemical bonding, and the reaction kinetics were improved.
It effectively suppresses the shuttle effect of polysulfides, improves the discharge specific capacity and cycle stability of the battery, reduces the charge transfer impedance at the battery interface, and improves the coulombic efficiency and reaction rate of the battery.
Smart Images
Figure CN122494561A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of all-solid-state lithium-sulfur battery technology, specifically relating to a method for preparing and applying a three-dimensional open-structure composite sulfur cathode material for solid-state batteries. Background Technology
[0002] All-solid-state lithium-sulfur battery systems have shown great potential in next-generation energy storage technologies due to their significant theoretical capacity advantage, high specific energy, and abundant sulfur resources. However, this system still faces two key challenges in practical applications: the shuttle effect of polysulfides and the sluggish reaction kinetics, which severely limit its commercialization. To address these issues, researchers have proposed a solution strategy of adding functional materials to prepare sulfur composite electrodes, thus exploring different technical routes: on the one hand, introducing highly conductive carbon materials to improve the conductivity of the electrode, but these materials have limited chemical adsorption capacity for polysulfides; on the other hand, using highly polar materials such as metal nitrides, oxides, and sulfides to capture polysulfides and promote their conversion reactions, but the conductivity of these materials is generally inferior to that of carbon materials. Summary of the Invention
[0003] To overcome the shortcomings of existing technologies, this invention provides a method for preparing and applying a three-dimensional open-structure composite sulfur cathode material for solid-state batteries. Using MOF-5 as a precursor, this invention synthesizes a Fe-NC material with a porous open structure, and then combines it with Ketjenblack (KB), which has high ionic conductivity, to prepare an S@KB-Fe-NC composite sulfur cathode with a three-dimensional adsorption conductive network. The Fe-NC material, relying on its high specific surface area and abundant mesoporous structure, can achieve both physical adsorption and chemical bonding of polysulfides, adsorbing polysulfides in the cathode region and effectively suppressing the shuttle effect. Simultaneously, the uniformly distributed Fe-N... x The active sites and the Fe / Fe3C nanophase provide ample and efficient catalytic centers, significantly enhancing the reaction kinetics rate of polysulfide conversion. This series of adsorption and catalytic synergies effectively reduces the charge transfer impedance at the battery interface, alleviates the problem of intensified polarization during charge and discharge, allows for more complete utilization of the active material in the sulfur cathode, and thus ensures the battery's high discharge specific capacity and excellent cycle stability.
[0004] The present invention discloses a method for preparing a three-dimensional open structure composite sulfur cathode material for solid-state batteries. The method uses sulfur powder as a base, adds Ketjen black (KB) to prepare a sulfur cathode material S@KB, and adds Fe-NC material with a three-dimensional open structure to this cathode material to prepare a composite sulfur cathode material S@KB-Fe-NC.
[0005] The amount of sulfur powder and Ketjen black used is 730mg:300mg, and the mass of Fe-NC material is 3%-10% of the mass of S@KB.
[0006] The preparation method of Fe-NC material is as follows: after calcining metal-organic framework (MOF-5) particles, C material is obtained. After mixing C material with dicyandiamine (DCD) and calcining, NC material is obtained. After mixing NC material with acetone iron acetate and calcining, Fe-NC material with a three-dimensional open structure is obtained.
[0007] The calcination method was 2℃·min -1 The heating rate was increased from room temperature to 950℃ and held for 2 hours; the ratio of C material to dicyandiamine was 200mg: 600mg; the ratio of NC material to acetone iron was 200mg: 45mg.
[0008] Specifically, it includes the following:
[0009] S1. Metal-organic framework (MOF-5) particles were subjected to an Ar atmosphere at 2 °C·min. -1 The heating rate was increased from room temperature to 950℃ and held for 2 hours to obtain precursor material C.
[0010] S2. Dissolve material C and dicyandiamine in methanol in a ratio of 200mg: 600mg: 80ml. Stir well at room temperature and dry at 70℃ for 12-16 hours. Then, calcine in the same way to obtain material NC.
[0011] S3. Dissolve the NC material and acetone iron in methanol in a ratio of 200mg: 45mg: 80ml. Stir well at room temperature, then wash with methanol by centrifugation at least 3 times to remove impurities. Dry under vacuum at 60℃ for 12h-16h, and finally obtain the Fe-NC material by the same calcination method.
[0012] The composite sulfur cathode material S@KB-Fe-NC of the present invention can be used to prepare solid-state battery cathodes. After assembling the solid-state battery cathode containing the composite sulfur cathode material S@KB-Fe-NC, the lithium metal anode, and the solid electrolyte, an all-solid-state lithium-sulfur battery is obtained.
[0013] The preparation method of the positive electrode of solid-state battery is as follows:
[0014] A1. Mix Fe-NC and S@KB powders and grind them in a mortar into black powder A;
[0015] A2. Dissolve powder A and binder in N,N-dimethylformamide (DMF) and stir to obtain a uniform slurry;
[0016] A3. The slurry is coated onto carbon-coated aluminum foil, vacuum dried, and then cut to obtain a solid-state battery cathode containing the composite sulfur cathode material S@KB-Fe-NC;
[0017] In A1, the mass of Fe-NC material is 3%-10% of the mass of S@KB; the grinding time is 30 min.
[0018] In A2, the ratio of powder A, binder, and DMF is 75mg:600mg:1ml; the stirring conditions are 35℃ and 650rpm for 8 hours.
[0019] In A3, the vacuum drying conditions are: vacuum drying at 60℃ for 12 hours.
[0020] The adhesive is prepared as follows: polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are added to DMF solvent, and the mixture is stirred at 60°C and 600 rpm for 12 h in a glove box. After standing at room temperature for 30 min, the adhesive is obtained.
[0021] The solid electrolyte is a PEO-based composite electrolyte membrane, which is prepared as follows: Polyethylene oxide (PEO), lithium aluminum germanium phosphate (LAGP), lithium germanium phosphorus sulfide (LGPS), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are added to acetonitrile and mixed. The mixture is first stirred at 60°C for 16 h, then stirred at room temperature for 30 min. After standing to defoam, it is shaped and dried to obtain the PEO-based composite electrolyte membrane.
[0022] This invention uses the composite of polar material Fe-NC and carbon-based material Ketjen Black (KB) as the key to improving the performance of the host material. This not only provides highly efficient ion and electron transport channels, but also, through the synergistic effect of strong chemisorption and catalytic activity, immobilizes polysulfides in the positive electrode region and accelerates their redox reaction kinetics. Compared with existing technologies, this invention has the following technical advantages:
[0023] 1. The Fe-NC material prepared by the MOF-5 pyrolysis method in this invention exhibits a typical three-dimensional porous cubic structure with micron-sized components. Its synthesis demonstrates good reproducibility and controllability, laying a solid foundation for subsequent research and application of material properties.
[0024] 2. The composite sulfur cathode S@KB-Fe-NC prepared in this invention is applied to all-solid-state lithium-sulfur batteries. The addition of Fe-NC provides a porous cubic structure, adsorbing polysulfides through physical confinement and chemical bonding. Simultaneously, uniformly distributed Fe-N... xThe active sites exhibit significant electrocatalytic activity in polysulfide conversion, effectively suppressing the shuttle effect of polysulfide migration to the negative electrode, improving sulfur utilization efficiency, and accelerating battery reaction kinetics. Furthermore, the combination with KB significantly enhances the conductivity of the composite material. This synergistic effect accelerates polysulfide conversion while constructing an efficient electron transport network, thereby improving the battery's coulombic efficiency and cycle stability.
[0025] 3. The Fe-NC material synthesized in this invention contains a large number of Fe and Fe3C nanoparticles, which not only have high conductivity but also catalyze the graphitization of amorphous carbon, thereby enhancing the material's conductivity. Furthermore, Fe-NC has a large specific surface area, and its abundant mesoporous structure provides more electron transport channels, effectively reducing the charge transfer impedance at the battery interface and accelerating the reaction process.
[0026] 4. A simple slurry coating method is used to prepare the composite sulfur cathode. The active material, binder, and catalyst are mixed and stirred to facilitate uniform dispersion of the components at the molecular or nanoscale. This mixture is then uniformly coated onto the surface of carbon-coated aluminum foil, resulting in an electrode sheet with uniform thickness and quality. This is crucial for obtaining uniform battery capacity and stable electrochemical performance.
[0027] 5. The all-solid-state lithium-sulfur battery prepared using the composite sulfur cathode synthesized in this invention can exhibit high discharge specific capacity, stable cycle performance and good rate performance. Attached Figure Description
[0028] Figure 1 This is a process flow diagram illustrating the preparation method and application of the composite sulfur cathode material of the present invention.
[0029] Figure 2 SEM images of the precursor MOF-5 used in this invention and the C, NC, and Fe-NC materials prepared in Example 1; wherein, (a) is MOF-5, (b) is C material, (c) is NC material, (d) is Fe-NC material, and (e) is the elemental distribution diagram of Fe-NC material;
[0030] Figure 3 The graph shows the rate performance of the prepared solid-state lithium-ion battery; where (a) is 1 # Battery, (b) is 4 # Battery, (c) is 5 # Battery, (d) is 6 # Battery;
[0031] Figure 4 The circuit diagram shows the cycle performance of the prepared solid-state lithium-ion battery (0.5C); where (a) is 1. # Battery, (b) is 4 #Battery, (c) is 5 # Battery, (d) is 6 # Battery;
[0032] Figure 5 The electrochemical impedance spectroscopy diagram of the prepared solid-state lithium-ion battery is shown. Detailed Implementation
[0033] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. It should be noted that the embodiments described in this invention are only for further explanation and illustration, and not for limiting their application scope. Based on this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.
[0034] The present invention provides a method for preparing and applying a three-dimensional open-structure composite sulfur cathode material for solid-state batteries, the process flow of which is as follows: Figure 1 As shown, a sulfur cathode material (S@KB) was prepared by adding Ketjenblack (KB) to sulfur powder as a base. Fe-NC material with a three-dimensional open structure was then added to this cathode material, resulting in an electrode containing the composite sulfur cathode material S@KB-Fe-NC, which can be used in all-solid-state lithium-sulfur batteries. Metal-organic framework (MOF-5) particles were prepared using the method described in CN120978175A. The sulfur powder was manufactured by Aladdin, model S106611; the Ketjenblack was manufactured by AkzoNobel, model KETJENBLACK EC600JD.
[0035] Example 1
[0036] Fe-NC material preparation:
[0037] (1) Metal-organic framework (MOF-5) particles were placed in an Ar atmosphere at 2 °C·min -1 The temperature was increased from room temperature to 950℃ and held for 2 hours to obtain the carbonized precursor C material. SEM images of MOF-5 are shown below. Figure 2 As shown in (a), the SEM image of material C is as follows: Figure 2 As shown in (b).
[0038] (2) Dissolve 200 mg of C material and 600 mg of dicyandiamine in 80 ml of methanol, stir evenly at 750 rpm at room temperature, and then dry in a 70°C forced-air drying oven. Subsequently, obtain NC material using the same calcination method, such as... Figure 2 As shown in (c).
[0039] (3) Dissolve 200 mg of NC material and 45 mg of acetone iron in 80 ml of methanol. Stir evenly at 750 rpm at room temperature, centrifuge multiple times with methanol, and dry in a vacuum drying oven at 60 °C for 12 hours. Then, obtain Fe-NC material by calcination in the same manner. Figure 2 As shown in (d).
[0040] By mixing sulfur powder, Ketjen black, and Fe-NC material, the composite sulfur cathode material S@KB-Fe-NC is obtained.
[0041] Solid-state battery cathodes containing composite sulfur cathode materials were prepared using a slurry coating method.
[0042] (1) Take 5 mg of Fe-NC material and mix it with 70 mg of S@KB powder. Grind the mixture in a mortar for 30 min to obtain a black powder.
[0043] (2) Weigh 11.4g of DMF solvent, then weigh 0.44g of PEO and 0.16g of LiTFSI and add them to the DMF solvent. Stir the mixture at 60℃ and 600rpm for 12h in a glove box, and let it stand at room temperature for 30min to obtain the binder. Weigh 600mg of the binder into a 5ml beaker, add the ground powder to the beaker, add 1ml of DMF and stir to obtain a uniform slurry. (3) Coat the slurry onto a carbon-coated aluminum foil, vacuum dry it and cut it into electrode sheets to obtain a solid-state battery cathode containing the composite sulfur cathode material S@KB-Fe-NC.
[0044] Using S@KB-Fe-NC as the composite sulfur cathode, lithium metal sheet as the anode, and PEO-based composite electrolyte as the solid electrolyte membrane, a CR2032 coin-type solid-state lithium-ion battery was assembled in an argon-filled glove box, denoted as 1. # Battery.
[0045] The PEO-based composite electrolyte was prepared using a simple casting method. First, a cleaned and dried polytetrafluoroethylene (PTFE) mold was placed in a glove box. Inside the glove box, 0.768 g PEO, 0.1048 g LAGP, 0.1048 g LGPS, and 0.28 g LiTFSI were weighed and added sequentially to a glass bottle, followed by 15 mL of acetonitrile as a solvent. The mixture was stirred continuously at 60°C and 600 rpm for 16 hours, then stirred at 250 rpm for 30 minutes at room temperature. After stirring, the mixture was allowed to stand for 30 minutes to eliminate air bubbles. Finally, the well-mixed solution was poured onto the PTFE mold and allowed to air dry in the glove box for 12 hours to obtain the PEO-based composite electrolyte membrane.
[0046] 1 #The battery was charged and discharged at 60℃ within a potential range of 1.5V-2.8V at different rates. When 1 # The battery operates at 0.3C (1C = 1600mAh·g). -1 During charging and discharging, the discharge specific capacity is 1484.1 mAh·g. -1 At discharge rates of 0.5C, 1C, 2C, and 5C, the specific discharge capacity was 1361.6 mAh·g. -1 1104.3mAh·g -1 725.1mAh·g -1 and 433.3 mAh·g -1 When the discharge rate returns to 0.3C, the discharge specific capacity remains at 1530.8 mAh·g. -1 It is almost identical to the initial value, confirming that 1 # The battery has good reversibility, such as Figure 3 As shown in (a). During charge-discharge cycle testing at 0.5C, due to incomplete reaction in the first cycle, statistics were collected starting from the second cycle. The initial discharge specific capacity of S@KB-Fe-NC reached 1187.6 mAh·g. -1 It exhibited good cycle stability and high coulombic efficiency, maintaining a discharge specific capacity of 1135.3 mAh·g after 100 cycles. -1 It boasts an ultra-high capacity retention rate of 95.6%, such as Figure 4 As shown in (a). For 1 # The battery underwent electrochemical impedance spectroscopy (EIS) testing, and the ohmic resistance R of S@KB-Fe-NC was measured. s =10.49 Ω, charge transfer resistance R ct =16.97 Ω, indicating that the addition of Fe-NC catalyst can significantly reduce the charge transfer internal resistance of the battery, such as Figure 5 As shown in S@KB-Fe-NC.
[0047] Example 2
[0048] The difference from Example 1 is that sulfur powder, Ketjen black, and 3.5 mg of Fe-NC material (5% wt) were mixed to prepare a solid-state battery cathode containing S@KB-Fe-NC-5% cathode material, which was then assembled into a CR2032 type coin cell solid-state lithium-ion battery, denoted as 2. # The battery was prepared using the same methods as in Example 1. Two... # The battery was charged and discharged at 60°C within a potential range of 1.5V-2.8V at different rates.
[0049] Example 3
[0050] The difference from Example 1 is that sulfur powder, Ketjen black, and 7 mg of Fe-NC material (10% wt) were mixed to prepare a solid-state battery cathode containing 10% S@KB-Fe-NC-1, which was then assembled into a CR2032 type coin cell solid-state lithium-ion battery, denoted as 3. # The battery was prepared using the same methods as in Example 1. 3 # The battery was charged and discharged at 60°C within a potential range of 1.5V-2.8V at different rates.
[0051] Comparative Example 1
[0052] The difference from Example 1 is that NC material was prepared by mixing sulfur powder, Ketjen black, and NC material to prepare a solid-state battery cathode containing the cathode material S@KB-NC, which was then assembled into a CR2032 type coin cell solid-state lithium-ion battery, denoted as 4. # The battery is prepared using the same methods as in Example 1.
[0053] 4 # The battery was charged and discharged at 60℃ within a potential range of 1.5V-2.8V at different rates. When 4 # The battery exhibits a discharge specific capacity of 1330.62 mAh·g at discharge rates of 0.3C, 0.5C, 1C, 2C, and 5C. -1 1166.59mAh·g -1 947.04mAh·g -1 610.07mAh·g -1 and 382.45mAh·g -1 When the discharge rate returns to 0.3C, the discharge specific capacity remains at 1340.45 mAh·g. -1 It is almost identical to the initial value, confirming that 4 # The battery has good reversibility, such as Figure 3 As shown in (b). During charge-discharge cycle testing at 0.5C, due to incomplete reaction in the first cycle, statistics were collected starting from the second cycle. The initial discharge specific capacity of S@KB-NC reached 825.4 mAh·g. -1 It exhibited good cycle stability and high coulombic efficiency, and the discharge specific capacity remained at 797.7 mAh·g after 100 cycles. -1 It can be observed that the trend of capacity change is a gradual increase followed by a period of stabilization, such as... Figure 4 As shown in (b). For 4 # The battery underwent electrochemical impedance spectroscopy (EIS) testing, and the ohmic resistance R of S@KB-NC was measured. s =14.74Ω, charge transfer resistance R ct =28.55 Ω, such as Figure 5 As shown in S@KB-NC.
[0054] Comparative Example 2
[0055] The difference from Example 1 is that, in this case, C material was prepared by mixing sulfur powder, Ketjen black, and C material to prepare a solid-state battery cathode containing the cathode material S@KB-C, which was then assembled into a CR2032 type coin cell solid-state lithium-ion battery, denoted as 5. # The battery is prepared using the same methods as in Example 1.
[0056] 5 # The battery was charged and discharged at 60℃ within a potential range of 1.5V-2.8V at different rates. When 5 # The battery exhibits a discharge specific capacity of 875.24 mAh·g at discharge rates of 0.3C, 0.5C, 1C, 2C, and 5C. -1 715.23mAh·g -1 480.29mAh·g -1 330.58mAh·g -1 and 215.6 mAh·g -1 When the discharge rate returns to 0.3C, the discharge specific capacity remains at 922.86 mAh·g. -1 It is almost identical to the initial value, confirming that 5 # The battery has good reversibility, such as Figure 3 As shown in (c). During charge-discharge cycle testing at 0.5C, due to incomplete reaction in the first cycle, statistics were collected starting from the second cycle. The initial discharge specific capacity of S@KB-C reached 757.1 mAh·g. -1 It exhibited good cycle stability and high coulombic efficiency, and the discharge specific capacity remained at 845.4 mAh·g after 100 cycles. -1 It can be observed that the trend of capacity change is a gradual increase followed by a period of stabilization, such as... Figure 4 As shown in (c). For 5 # The battery underwent electrochemical impedance spectroscopy (EIS) testing, and the ohmic resistance R of S@KB-C was measured. s =16.31 Ω, charge transfer resistance R ct =33.63 Ω, such as Figure 5 As shown in S@KB-C.
[0057] Comparative Example 3
[0058] The difference from Example 1 is that the cathode material does not contain MOF-5 particle derivatives. Instead, sulfur powder and Ketjen black are mixed to prepare a solid-state battery cathode containing cathode material S@KB, which is then assembled into a CR2032 type coin cell solid-state lithium-ion battery, designated as 6. # The battery is prepared using the same methods as in Example 1.
[0059] 6 # The battery was charged and discharged at 60℃ within a potential range of 1.5V-2.8V at different rates. When 6... # The battery exhibits a discharge specific capacity of 738.8 mAh·g at discharge rates of 0.3C, 0.5C, 1C, 2C, and 5C. -1 648.7mAh·g -1 410.1mAh·g -1 264.2 mAh·g -1 and 157.7mAh·g -1 ,like Figure 3 As shown in (d), the capacitance is significantly lower than that of the composite sulfur cathode in Examples 1-3. During charge-discharge cycle testing at 0.5C, due to incomplete reaction in the first cycle, the initial discharge specific capacity of S@KB reached 711.8 mAh·g starting from the second cycle. -1 ,like Figure 4 As shown in (d), the sulfur content is significantly lower than that of the composite sulfur cathodes in Examples 1-3. For 6 # The battery underwent electrochemical impedance spectroscopy (EIS) testing, and the ohmic resistance R of S@KB was measured. s =19.14 Ω, charge transfer resistance R ct =37.82 Ω, such as Figure 5 As shown in S@KB, it is far superior to the composite sulfur cathode in Examples 1-3.
Claims
1. A method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries, characterized in that, The process includes the following: mixing sulfur powder and Ketjen black to form sulfur cathode material S@KB, adding Fe-NC material, and mixing to form composite sulfur cathode material S@KB-Fe-NC.
2. The method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries according to claim 1, characterized in that, The amount of sulfur powder and Ketjen black used is 730mg:300mg, and the mass of the Fe-NC material is 3%-10% of the mass of the S@KB.
3. The method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries according to claim 1, characterized in that, The preparation method of the Fe-NC material includes the following: calcining metal-organic framework (MOF-5) particles to obtain C material, mixing the C material with dicyandiamine and calcining to obtain NC material, and mixing the NC material with ferric acetone and calcining to obtain Fe-NC material with a three-dimensional open structure.
4. The method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries according to claim 3, characterized in that, The calcination is carried out at 2℃·min -1 The heating rate was increased from room temperature to 950℃, and the temperature was maintained for 2 hours.
5. The method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries according to claim 3, characterized in that, The ratio of material C to dicyandiamine is 200mg: 600mg, and the ratio of material NC to acetone iron is 200mg: 45mg.
6. The method for preparing a three-dimensional open-structure composite sulfur cathode material for solid-state batteries according to claim 3, characterized in that, The preparation method of the Fe-NC material includes the following: S1. The metal-organic framework MOF-5 particles were subjected to an Ar atmosphere at 2 °C·min. -1 The temperature was increased from room temperature to 950°C and held for 2 hours to obtain the precursor of material C. S2. Dissolve the C material and dicyandiamine in methanol in a ratio of 200 mg: 600 mg: 80 ml. Stir well at room temperature, then dry at 70°C for 12-16 hours. Then, in an Ar atmosphere, dry at 2°C / min. -1 The temperature was increased from room temperature to 950°C and held for 2 hours to obtain the NC material. S3. Dissolve the NC material and acetone iron in methanol in a ratio of 200 mg: 45 mg: 80 ml. After stirring evenly at room temperature, wash away impurities with methanol, and then vacuum dry at 60 °C for 12-16 h. Finally, dry under an Ar atmosphere at 2 °C / min. -1 The temperature was increased from room temperature to 950°C and held for 2 hours to obtain the Fe-NC material.
7. The application of the cathode material obtained by the preparation method according to claim 1, characterized in that, The cathode material is used to prepare the cathode of a solid-state battery; after assembling the solid-state battery cathode containing the composite sulfur cathode material S@KB-Fe-NC, the lithium metal sheet anode, and the solid electrolyte, an all-solid-state lithium-sulfur battery is obtained.
8. The application of the cathode material according to claim 7, characterized in that, The preparation method of the solid-state battery cathode includes the following steps: mixing and grinding Fe-NC material and S@KB powder to obtain black powder A; mixing powder A and binder in N,N-dimethylformamide to obtain a slurry; coating the slurry onto carbon-coated aluminum foil and vacuum drying to obtain a solid-state battery cathode containing composite sulfur cathode material S@KB-Fe-NC.
9. The application of the cathode material according to claim 8, characterized in that, The mass of the Fe-NC material is 3%-10% of the mass of S@KB; the ratio of powder A, binder, and N,N-dimethylformamide is 75mg:600mg:1ml; vacuum drying at 60℃ for 12h; The adhesive is prepared as follows: polyethylene oxide and lithium bis(trifluoromethanesulfonyl)imide are added to N,N-dimethylformamide and stirred at 60°C for 12 hours to obtain the adhesive.
10. The application of the cathode material according to claim 7, characterized in that, The solid electrolyte is a PEO-based composite electrolyte membrane, which is prepared as follows: polyethylene oxide, lithium aluminum germanium phosphate, lithium germanium phosphorus sulfide and lithium bis(trifluoromethanesulfonyl)imide are added to acetonitrile and mixed. The mixture is first stirred at 60°C for 16 h, then stirred at room temperature for 30 min. After standing to defoam, it is shaped and dried to obtain the PEO-based composite electrolyte membrane.