Solid sulfur positive electrode catalytic material, preparation method and application

Abstract

The invention relates to a solid sulfur positive electrode catalytic material, a preparation method and an application, the solid sulfur positive electrode catalytic material comprises a carrier, a first transition metal atom and a second transition metal atom, the first transition metal atom and the second transition metal atom are loaded on the carrier, the carrier is a nitrogen-doped carbon material, and the electronegativity difference value delta EN of the first transition metal atom and the second transition metal atom is more than or equal to 0.01 and less than or equal to 0.5. The solid sulfur positive electrode catalytic material disclosed by the invention can generate a dynamic electron buffer effect in a sulfur conversion reaction process of an all-solid-state battery, and is beneficial to adjusting the charge state of a metal center through reversible electron migration between diatoms during charging and discharging, so that the excessive oxidation or reduction of active sites is inhibited; the structural stability and the valence reversibility of the material in long-term circulation are improved. Meanwhile, the synergistic effect of double atoms can enhance the electron interaction with sulfur substances, so that the solid-solid interface reaction energy barrier can be reduced, and the sulfur conversion reaction kinetics can be improved.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a solid sulfur cathode catalytic material, its preparation method, and its application. Background Technology

[0002] With the development of sustainable energy systems and the increasing demand for high-safety energy storage, all-solid-state lithium-sulfur batteries have become an important research direction for the next generation of high-energy-density energy storage devices due to their advantages of not containing flammable liquid electrolytes and having high theoretical energy density.

[0003] However, in practical applications of all-solid-state lithium-sulfur batteries, sulfur and its discharge product, lithium sulfide, are both solid substances with low electronic and ionic conductivity. Their conversion reaction mainly occurs at the solid-solid interface region composed of the sulfur active material, the conductive phase, and the solid electrolyte. Due to the lack of mass transfer and interfacial wetting effects from the liquid electrolyte, the coordinated transport of electrons and ions during sulfur conversion is limited, leading to increased reaction polarization, reduced sulfur utilization, and rapid capacity decay during long-term cycling, severely restricting the practical application of all-solid-state lithium-sulfur batteries. Summary of the Invention

[0004] In view of this, in order to solve at least one of the above defects, it is necessary to propose a solid sulfur cathode catalyst material.

[0005] In addition, this application also provides a method for preparing the aforementioned solid sulfur cathode catalyst, as well as a cathode material and an all-solid-state lithium-sulfur battery using the aforementioned solid sulfur cathode catalyst.

[0006] In a first aspect, this application provides a solid sulfur cathode catalytic material, comprising: a support and a first transition metal atom and a second transition metal atom co-loaded on the support in an atomically dispersed form, wherein the support is a nitrogen-doped carbon material, and the electronegativity difference ΔEN between the first transition metal atom and the second transition metal atom satisfies: 0.01≤ΔEN≤0.5.

[0007] Based on the first aspect, in some embodiments of this application, the first transition metal atom and the second transition metal atom are each independently selected from one of copper, nickel, cobalt, iron and zinc; and the first transition metal atom and the second transition metal atom are different elements.

[0008] Based on the first aspect, in some embodiments of this application, the electronegativity difference ΔEN between the first transition metal atom and the second transition metal atom satisfies: 0.01≤ΔEN≤0.05.

[0009] Based on the first aspect, the first transition metal atom and the second transition metal atom are each independently selected from one of copper and nickel.

[0010] Based on the first aspect, in some embodiments of this application, the molar ratio of the first transition metal atom to the second transition metal atom is 0.7:1 to 1:0.7.

[0011] Based on the first aspect, in some embodiments of this application, the molar ratio of the first transition metal atom to the second transition metal atom is 1:1.

[0012] Based on the first aspect, in some embodiments of this application, the atomic spacing between the first transition metal atom and the second transition metal atom is 0.3 nm to 0.4 nm.

[0013] Secondly, this application provides a method for preparing the aforementioned solid sulfur cathode catalytic material, comprising: providing the support; mixing a first metal salt containing a first transition metal atom and a second metal salt containing a second transition metal atom with the support in a solvent to obtain a mixture; drying the mixture; and heat-treating the dried material under a protective atmosphere to obtain the solid sulfur cathode catalytic material.

[0014] Based on the second aspect, in some embodiments of this application, the first metal salt includes at least one of chloride, nitrate and acetate containing the first transition metal atom; the second metal salt includes at least one of chloride, nitrate and acetate containing the second transition metal atom.

[0015] Based on the second aspect, in some embodiments of this application, the heat treatment includes a first heat treatment stage and a second heat treatment stage; the first heat treatment stage is performed at 200°C to 350°C for 2 hours to 6 hours; the second heat treatment stage is performed at 500°C to 600°C for 2 hours to 6 hours; and / or, the mixed treatment is performed under ultrasonic conditions, the frequency of which is 50 kHz to 100 kHz, and the ultrasonic time is 20 minutes to 30 minutes; and / or, the drying treatment is performed at 50°C to 60°C by rotary evaporation for 30 minutes to 40 minutes. Based on the second aspect, in some embodiments of this application, the protective atmosphere includes hydrogen, argon, or a mixture thereof.

[0016] Thirdly, this application provides an all-solid-state lithium-sulfur battery cathode material, which includes the following: sulfur active material, conductive additive, solid electrolyte, and solid sulfur cathode catalyst as described above.

[0017] Based on a third aspect, in some embodiments of this application, the total mass of the solid sulfur cathode catalyst material accounts for 5% to 10% of the total mass of the all-solid-state lithium-sulfur battery cathode material.

[0018] Fourthly, this application provides an all-solid-state lithium-sulfur battery, comprising: a positive electrode, a negative electrode, and a solid electrolyte layer located between the positive electrode and the negative electrode, wherein the positive electrode is formed from the all-solid-state lithium-sulfur battery positive electrode material as described above.

[0019] Compared with existing technologies, the solid sulfur cathode catalytic material provided in this application forms a bimetallic atom catalytic system with dynamic electron buffering capabilities by constructing atomically dispersed and electronegatively matched (ΔEN of 0.01 to 0.5) first and second transition metal atoms on a nitrogen-doped carbon support. During the redox process of sulfur, this catalytic material can buffer the accumulation or dissipation of electrons at a single metal site through reversible electron migration between the bimetallic atoms, thereby suppressing irreversible reconstruction of its electronic structure and helping to maintain the valence state and structural stability of the catalytic active sites during long-term cycling. Simultaneously, the orbital hybridization between the bimetallic atoms enhances the electronic interaction with sulfur and lithium sulfide intermediates, lowering the sulfur conversion reaction energy barrier at the solid-solid interface and improving the sulfur conversion reaction kinetics. Furthermore, the solid sulfur cathode catalytic material forms a three-phase composite structure in close contact with the sulfur active material and the solid electrolyte in the cathode, which helps to construct a continuous ion-electron conduction network and improve the charge transport efficiency inside the electrode. Based on the above mechanism, the solid sulfur cathode catalytic material provided in this application can improve the activity of sulfur conversion reaction while taking into account the long-term stability of catalytic sites and the reversibility of reaction, thereby providing effective support for achieving high rate performance, cycle stability and capacity retention of all-solid-state lithium-sulfur batteries. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of a method for preparing a solid sulfur cathode catalyst in one embodiment of this application.

[0021] Figure 2 This is a comparison of the infrared spectra of the PCN support, the single-atom catalysts Cu1-PCN and Ni1-PCN, and the bimetallic atom catalyst Cu1Ni1-PCN in one embodiment of this application.

[0022] Figure 3 This is a ring-shaped dark-field scanning transmission electron microscope image of the Cu1Ni1-PCN bimetallic atomic catalyst in one embodiment of this application.

[0023] Figure 4 This is an extended X-ray absorption fine structure spectrum of Cu1-PCN, Ni1-PCN and Cu1Ni1-PCN catalysts in one embodiment of this application.

[0024] Figure 5 The image shows the X-ray photoelectron spectra of copper and nickel in the all-solid-state lithium-sulfur battery prepared in Example 1 of this application under different charge and discharge potentials.

[0025] Figure 6 This is a comparison chart of the long-cycle performance of all-solid-state lithium-sulfur batteries prepared in Example 1 and Comparative Examples 1 to 3 of this application. Detailed Implementation

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this application pertain. The terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the embodiments of this application. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0027] The following describes some embodiments of this application in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] In all-solid-state lithium-sulfur battery systems, the extremely low electronic and ionic conductivity of sulfur and its discharge product, lithium sulfide, leads to slow sulfur conversion kinetics at the solid-solid interface, large battery polarization, and rapid capacity decay, severely restricting their practical application. To address these issues, catalytic strategies have been introduced to improve sulfur conversion efficiency. Single-atom catalysts have attracted attention due to their atomically dispersed active sites, which maximize the exposure of the catalytic interface and enhance interactions with sulfur species. However, in all-solid-state systems, isolated single-metal atoms lack effective electronic regulation mechanisms during continuous charge-discharge processes, making them prone to irreversible electronic structure reconstruction and catalytic activity decay. Furthermore, bimetallic atom catalysts have been investigated. While conventional bimetallic atom catalysts can modulate the electronic structure to some extent through the introduction of bimetallic sites, their effects are largely limited to static electronic control, making it difficult to adapt to the continuously changing electronic environment during solid-state sulfur conversion. Consequently, they still cannot maintain the structural and performance stability of the catalytic sites during long-term cycling.

[0029] Therefore, this application provides a solid sulfur cathode catalytic material with dynamic electron buffering function, which aims to achieve reversible electron migration and charge redistribution during sulfur conversion by constructing electronegativity-matched bimetallic atom pairs, thereby synergistically improving reaction kinetics and catalytic stability.

[0030] The solid sulfur cathode catalyst material includes a support and first and second transition metal atoms co-supported on the support in an atomically dispersed manner. The support can be a nitrogen-doped carbon material. The electronegativity difference ΔEN between the first and second transition metal atoms satisfies: 0.01 ≤ ΔEN ≤ 0.5.

[0031] This application ensures that the two transition metal atoms can form a stable electronic coupling relationship during the sulfur redox process by limiting ΔEN to the range of 0.01 to 0.5, and achieves dynamic charge redistribution through reversible electron migration. The solid sulfur cathode catalyst constructed in this way can achieve efficient and stable dynamic electron buffering during the sulfur redox process.

[0032] Specifically, in the electrochemical process, the aforementioned diatomic catalytic system regulates the electronic state of the metal center through reversible electron migration between bimetallic atoms during continuous charging and discharging. This suppresses excessive oxidation or reduction of a single active site due to continuous electron gain or loss, thereby inhibiting irreversible electronic structure reconstruction caused by excessive oxidation or reduction. It maintains the structural stability and reversible valence state of the catalytic site during long-term cycling (this stability stems from the strong coordination bond (MN bond) formed between the bimetallic atoms and the nitrogen atom in the support; this coordination firmly anchors the atomically dispersed metal center and synergistically regulates its electronic structure). Simultaneously, the electronegativity matching within this range promotes orbital hybridization between bimetallic atoms, enhancing electronic interactions with sulfur and its intermediates, effectively lowering the sulfur conversion reaction energy barrier at the solid-solid interface, and improving the sulfur conversion reaction kinetics. Furthermore, its close contact with the sulfur active material and solid electrolyte within the cathode forms a three-phase composite structure, which helps construct a continuous and efficient ion-electron conduction network, improving the charge transport efficiency within the electrode. Based on the above mechanism, the solid-state sulfur cathode catalytic material provided in this application can balance high catalytic activity and long cycle stability, effectively supporting the excellent rate performance, cycle life, and capacity retention of all-solid-state lithium-sulfur batteries. Furthermore, the atomically dispersed co-loading method facilitates the formation of spatially adjacent bimetallic atomic sites on the support surface, providing a structural basis for electron migration and avoiding the decrease in catalytic activity caused by metal atom aggregation. In addition, the inventors discovered during their research that if the electronegativity difference ΔEN between the first and second transition metal atoms exceeds 0.5, effective electronic coupling and synergistic effects are difficult to form between them, resulting in insufficient driving force for reversible electron migration. This leads to a significant weakening or even disappearance of the dynamic electron buffering effect, failing to effectively suppress the irreversible reconstruction of the electronic structure of the active sites. Simultaneously, excessively large electronegativity differences may also cause adverse changes in the loading behavior and coordination environment of the two metal atoms on the support, affecting the formation and stability of the bimetallic atomic structure. Therefore, this application limits ΔEN to the range of 0.01 to 0.5. For example, the electronegativity difference ΔEN can be 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, or any value within the range of any two of the above values.

[0033] In this application, the type of support directly affects its effectiveness in loading atomically dispersed bimetallic atoms. Nitrogen-doped carbon material is used as the support, where nitrogen, due to its lone pair electrons, can form stable coordinate bonds with transition metal atoms, thus serving as an effective anchoring point to stably fix the first and second transition metal atoms on the support surface at the atomic level. This nitrogen-metal coordination not only inhibits the migration and aggregation of metal atoms during synthesis or operation but also modulates the local electronic structure of the metal center through electronic effects, enhancing electronic cooperation between the two atoms. This is a key structural basis for achieving a dynamic electronic buffering effect.

[0034] It is understandable that, in addition to nitrogen, other oxygen- and sulfur-containing functional groups on the support surface may also synergistically modulate the metal-support interaction through coordination or electrostatic interactions. Therefore, carbon materials containing one or more of the above functional groups can also be used as supports, ensuring that the support can achieve atomic-level dispersion and stable loading of bimetallic atoms. In the embodiments of this application, nitrogen-doped carbon materials are used as supports, which can achieve better metal dispersion, coordination stability, and catalytic performance.

[0035] Furthermore, the physicochemical properties of the support also have a certain influence on its effectiveness in loading atomically dispersed bimetallic atoms. Specifically, the size, specific surface area, and pore structure of the support affect the number and distribution of active sites that can be used to anchor metal atoms; a larger specific surface area and suitable pores help expose more nitrogen-doped sites. The surface morphology of the support (such as lamellar, porous, etc.) affects its interfacial contact with the reaction system, the mass transfer process, and the adsorption uniformity of the metal precursor during the preparation process. In addition, the type of nitrogen doping on the support surface and the nitrogen content in the compound also affect the anchoring effect on bimetallic atoms.

[0036] Therefore, by selecting or designing carbon-based supports with suitable size, high specific surface area, hierarchical channels, and abundant surface functional groups (especially nitrogen doping sites), such as high specific surface area porous nitrogen-doped carbon or two-dimensional nitrogen-doped carbon nanosheets, the dispersion, coordination environment, and interatomic spacing of bimetallic atoms can be optimized, thereby providing a better support platform for constructing efficient and stable biatomic catalytic systems.

[0037] In some embodiments, the nitrogen-doped carbon material may include at least one of polymeric carbonitride (PCN) and carbon-nitrogen 4 (CN4). The polymeric carbonitride (PCN) support used has the following physicochemical characteristics: its size (e.g., the lateral dimension of the sheet) can be selected from 50 nm to 100 nm, exemplarily, it can be 50 nm, 75 nm, 100 nm, or any value within the range of any two of the above values; its specific surface area is, for example, 150 m². 2 / g to 180m 2 / g, for example, can be 150m 2 / g、165m 2 / g、180m 2 / g or any value within the range of any two of the above values; the surface morphology exhibits a two-dimensional nanosheet or porous structure. These size and morphological characteristics facilitate the provision of abundant surface exposed areas and accessible active sites; the specific surface area range helps to load a sufficient number of bimetallic atoms per unit mass while maintaining good mass transfer and charge transport performance. These specific support parameters can be adjusted according to the needs of the actual catalytic system to achieve uniform and stable loading of the first and second transition metal atoms at the atomic scale, thereby providing a structural basis for constructing highly efficient biatomic catalytic active centers.

[0038] The nitrogen content in PCN can be controlled between 40% and 60%. Higher nitrogen content provides more active sites on the support surface for metal atom coordination, which is beneficial for increasing the loading of bimetallic atoms and promoting their uniform dispersion. However, excessively high nitrogen content may compromise the conductivity and stability of the carbon framework; therefore, the nitrogen doping level needs to be optimized while ensuring the integrity of the support structure.

[0039] The first and second transition metal atoms are each independently selected from one of the elements: copper, nickel, cobalt, iron, and zinc. Furthermore, the first and second transition metal atoms are distinct elements. The solid-state sulfur cathode catalytic material constructed based on this elemental combination achieves dynamic electron buffering through reversible electron migration between the bimetallic atoms during the electrochemical reaction. This mechanism helps suppress irreversible electronic structure reconstruction of the catalytic active sites during cycling, thereby maintaining its structural stability and catalytic activity. Simultaneously, the synergistic effect of the bimetallic atoms enhances the electronic interaction between them and sulfur, effectively lowering the reaction energy barrier at the solid-solid interface, thus improving the sulfur conversion reaction kinetics and providing effective support for improving the rate performance and cycle stability of all-solid-state lithium-sulfur batteries.

[0040] With in-depth research into the synergistic mechanism of bimetallic atoms, the inventors further discovered that controlling the electronegativity difference ΔEN between the first and second transition metal atoms within the range of 0.01 to 0.05 most effectively balances the electron migration driving force and orbital coupling strength between the bimetallic atoms. This preferred range helps to establish a more stable, efficient, and rapidly responsive reversible electron transfer channel, thereby further enhancing the dynamic electron buffering effect. Furthermore, within this range, the electronic synergistic effect between the bimetallic atoms is further optimized, which not only helps maintain the structural stability and valence reversibility of the catalytic site during long-term cycling, but also enhances the interaction with sulfur and its reaction intermediates (such as lithium sulfides, lithium polysulfides, etc.), reducing the solid-solid interface reaction energy barrier, thereby synergistically improving the sulfur conversion reaction kinetics and catalytic cycle stability. For example, ΔEN can be 0.01, 0.02, 0.03, 0.04, 0.05, or any value within the range of any two of the above values.

[0041] Furthermore, within the range of 0.01 to 0.05, when a copper-nickel combination is used, its ΔEN is approximately 0.01. This combination achieves high electronegativity matching while exhibiting excellent electronic synergistic response capabilities, providing a particularly effective catalytic material basis for achieving high rate performance and long cycle life in all-solid-state lithium-sulfur batteries.

[0042] In some embodiments, the molar ratio of the first transition metal atom to the second transition metal atom is from 0.7:1 to 1:0.7. This ratio range facilitates the coexistence of the two metal atoms on the support with a near-equilibrium loading, thereby increasing the likelihood of them being close to each other at the atomic scale and pairing to form heteronuclear diatomic active sites, providing a structural basis for subsequent effective electronic cooperation and dynamic buffering. Exemplarily, this molar ratio can be 0.7:1, 0.8:1, 0.9:1, 1:1, 1:0.9, 1:0.8, 1:0.7, or any value within the range of any two of the above values.

[0043] Furthermore, when the first and second transition metal atoms are co-loaded on the support in nearly equal atomic-level dispersions (i.e., the molar ratio is controlled at approximately 1:1), the bimetallic atoms are more uniformly distributed on the support surface. Under these conditions, the probability of forming spatially adjacent heteronuclear diatomic pairs is higher, which is beneficial for constructing structurally uniform diatomic catalytic active sites, thus providing a good structural basis for achieving efficient and stable dynamic electronic buffering effects.

[0044] The interatomic distance between the first and second transition metal atoms is 0.3 nm to 0.4 nm. This distance range is closely related to the periodic arrangement of nitrogen-doped sites in the support: in a nitrogen-doped carbon support, nitrogen atoms are regularly embedded in the carbon framework at certain intervals. When the first and second transition metal atoms coordinate with adjacent nitrogen sites, their spatial distance is constrained by the intrinsic nitrogen distribution of the support, thus stably falling within the aforementioned nanoscale range. This distance is beneficial for the formation of effective d-orbital overlap and electronic coupling between the bimetallic atoms, and also prevents atoms from becoming too close together and agglomerating, providing the necessary structural basis for the dynamic electronic buffering effect.

[0045] Please see Figure 1 As shown in the embodiments of this application, a method for preparing the aforementioned solid sulfur cathode catalyst material is also provided, comprising the following steps: Step S1: Provide a support: The support can be a nitrogen-doped carbon material, such as at least one of polymeric carbonitride (PCN) and carbon-nitrogen 4 (CN4).

[0046] In some embodiments, the support may be a polymeric carbonitride (PCN), which has abundant nitrogen coordination sites, which is beneficial for the uniform anchoring and stable dispersion of subsequent metal atoms.

[0047] Step S2: Mixing the metal salt and the support: The first metal salt containing the first transition metal atom and the second metal salt containing the second transition metal atom are mixed with the support in a solvent to obtain a mixture. The solvent may be water, methanol, ethanol, or a mixture thereof.

[0048] The mixing treatment is carried out under ultrasonic conditions, with an ultrasonic frequency of 50 kHz to 100 kHz and an ultrasonic time of 20 min to 30 min. This promotes uniform wetting, dispersion, and initial adsorption of the metal salt on the carrier surface, avoiding local aggregation. For example, the ultrasonic time can be 20 min, 25 min, 30 min, or any value within the range of any two of the above values.

[0049] The first metal salt includes at least one of chloride, nitrate, and acetate containing the first transition metal atom; the second metal salt includes at least one of chloride, nitrate, and acetate containing the second transition metal atom. Exemplarily, the salt containing the transition metal atom can be at least one of nickel chloride, nickel nitrate, nickel acetate, copper chloride, copper nitrate, copper acetate, cobalt chloride, cobalt nitrate, cobalt acetate, ferric chloride, ferric nitrate, ferric acetate, zinc chloride, zinc nitrate, zinc acetate, manganese chloride, manganese nitrate, manganese acetate, chromium chloride, chromium nitrate, chromium acetate, vanadium chloride, vanadium nitrate, vanadium acetate, titanium chloride, titanium nitrate, titanium acetate, etc. These salts have good solubility in the selected solvent, facilitating uniform loading of atomic-level precursors.

[0050] Step S3: Drying Treatment: The mixture is dried, specifically by rotary evaporation at 50°C to 60°C for 30 to 40 minutes. This condition facilitates slow and uniform solvent removal, forming a homogeneous solid precursor and preventing metal salt migration or segregation due to excessively rapid drying. For example, the drying temperature can be 50°C, 55°C, 60°C, or any value within the range of any two of the above values. The drying time can be 30 minutes, 35 minutes, 40 minutes, or any value within the range of any two of the above values.

[0051] Step S4: Heat treatment: Under a protective atmosphere, the dried material is heat treated so that the first metal salt and the second metal salt react in situ on the support to generate the first transition metal atom and the second transition metal atom, respectively, thereby obtaining a solid sulfur cathode catalyst material.

[0052] In some embodiments, the protective atmosphere used during the heat treatment process includes hydrogen, argon, or a mixture thereof. Hydrogen helps reduce the metal salt and modulate the chemical state of the support surface; argon provides an inert environment to prevent oxidation of the support and metal at high temperatures.

[0053] The heat treatment process is divided into two stages: the first heat treatment stage and the second heat treatment stage.

[0054] The first heat treatment stage involves processing at 200℃ to 350℃ for 2 to 6 hours. This stage allows the metal salt to gradually decompose, initially anchoring metal atoms to the nitrogen sites on the support and preventing atomic migration and aggregation due to excessively high temperatures. For example, the temperature of the first stage can be 200℃, 250℃, 300℃, or 350℃; the treatment time can be 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours, or any value within the range of any two of the above values.

[0055] The second heat treatment stage involves processing at 500℃ to 600℃ for 2 to 6 hours. This stage further carbonizes the support, stabilizes the nitrogen sites, and promotes the formation of stable coordination structures of the bimetallic atoms at the nitrogen sites, thereby stabilizing the interatomic distance within the desired range of 0.3 nm to 0.4 nm and enhancing the electronic coupling between atoms. For example, the temperature of the second stage can be 500℃, 550℃, or 600℃; the processing time can be 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours, or any value within the range of any two of the above values. Through the above segmented heat treatment, the dispersion of metal atoms, the coordination environment, and the interatomic distance can be synergistically controlled, thus providing a structural basis for the realization of dynamic electronic buffering effects in subsequent electrochemical processes.

[0056] By coordinating and controlling the support type, metal salt ratio, and heat treatment conditions within the aforementioned suitable range, the interatomic distance between the first and second transition metal atoms can be stabilized at 0.3 nm to 0.4 nm. This distance range is conducive to the formation of effective d-orbital overlap and electronic interactions between the bimetallic atoms, while avoiding atomic aggregation due to excessive proximity or weakening of the synergistic catalytic effect due to excessive distance. Specifically, nitrogen atoms in the nitrogen-doped carbon support are embedded in the carbon framework with a specific periodicity and coordination configuration, providing relatively fixed anchoring points for the metal atoms. When the first and second transition metal atoms coordinate with adjacent nitrogen sites, their spatial distance is constrained and stabilized by the structure of the support itself, thus making it easy for the interatomic distance to fall within the aforementioned nanoscale range. By selecting a support with suitable nitrogen doping type and content, and in conjunction with the aforementioned preparation process, precise control of the interatomic distance between the bimetallic atoms can be achieved, laying a structural foundation for constructing a catalytically active center with highly efficient electronic synergistic effects. For example, the interatomic distance can be 0.30 nm, 0.34 nm, 0.38 nm, 0.40 nm, or any value within the range of any two of the aforementioned values.

[0057] Therefore, this preparation method achieves atomic-level dispersion, controllable proportion, and optimized spacing of dual transition metal atoms on a nitrogen-doped carbon support through multi-step synergistic control of support selection, solution dispersion, and segmented heat treatment. This method exhibits good process repeatability and mild conditions, which is conducive to the large-scale preparation of solid-state sulfur cathode catalysts with well-defined dual-atom structures, high dispersibility, and excellent electronic synergistic properties, laying a material foundation for their efficient catalytic and long-term stabilizing effects in all-solid-state lithium-sulfur batteries.

[0058] Compared with the prior art, the preparation method of the all-solid-state lithium-sulfur battery cathode material provided in this application has the following beneficial effects: 1. By limiting ΔEN to the range of 0.01 to 0.5, this application ensures that the two transition metal atoms can form a stable electronic coupling relationship during the sulfur oxidation-reduction process and achieve dynamic charge redistribution through reversible electron migration. The solid sulfur cathode catalyst constructed in this way can achieve efficient and stable dynamic electron buffering during the sulfur oxidation-reduction process.

[0059] Specifically, in the electrochemical process, the aforementioned diatomic catalytic system regulates the electronic state of the metal center through reversible electron migration between bimetallic atoms during continuous charge and discharge. This suppresses excessive oxidation or reduction of a single active site due to continuous electron gain or loss, thereby inhibiting irreversible electronic structure reconstruction caused by excessive oxidation or reduction and maintaining the structural stability and reversible valence state of the catalytic site during long-term cycling. Simultaneously, the electronegativity matching within this range promotes orbital hybridization between bimetallic atoms, enhancing electron interactions with sulfur and its intermediates, effectively lowering the sulfur conversion reaction energy barrier at the solid-solid interface, and improving the sulfur conversion reaction kinetics. Furthermore, its close contact with the sulfur active material and solid electrolyte within the cathode forms a three-phase composite structure, which helps to construct a continuous and efficient ion-electron conduction network, improving the charge transport efficiency within the electrode. Based on the above mechanisms, the solid-state sulfur cathode catalytic material provided in this application can balance high catalytic activity and long-term cycling stability, effectively supporting excellent rate performance, cycle life, and capacity retention in all-solid-state lithium-sulfur batteries. Furthermore, the use of a co-loading method in an atomically dispersed manner is beneficial for forming spatially adjacent bimetallic atomic sites on the support surface, providing a structural basis for electron migration and avoiding the decrease in catalytic activity caused by metal atom aggregation.

[0060] 2. The preparation method of the catalytic material, through the synergistic regulation of steps such as carrier selection, uniform dispersion of metal salt solution, and segmented heat treatment, can achieve atomic-level dispersion, ratio control, and spacing optimization of bimetallic atoms under mild conditions. This method has well-defined process conditions and high repeatability, and can reliably prepare highly efficient catalytic materials with a pre-defined biatomic structure, providing a feasible process basis for the controllable preparation and consistent performance of catalytic layers in all-solid-state lithium-sulfur batteries.

[0061] This application also provides an all-solid-state lithium-sulfur battery cathode material, which includes a sulfur active material, a conductive additive, a solid electrolyte, and the aforementioned solid-state sulfur cathode catalyst.

[0062] Among them, the sulfur active material is selected from lithium sulfide (Li2S), elemental sulfur, sulfur-organic complex (such as thioacrylonitrile); the conductive additive is selected from Ketjen black (KB), multi-walled carbon nanotubes, conductive carbon black, graphene, etc.; the solid electrolyte is selected from sulfide solid electrolyte LPSC, Li-Ge-PS type (such as LGPS), sulfide solid electrolyte, oxide solid electrolyte, polymer solid electrolyte, etc.

[0063] By introducing solid sulfur cathode catalytic material, this cathode material can form a three-phase composite structure with catalytic activity, electronic conductivity and ion transport synergistic effect inside the cathode, thereby helping to improve the utilization efficiency of sulfur active materials, improve the solid-solid interface reaction kinetics, and enhance the structural stability and electrochemical reversibility of the electrode during long-term cycling.

[0064] In some embodiments, the total mass of the solid sulfur cathode catalyst material accounts for 5% to 10% of the total mass of the all-solid-state lithium-sulfur battery cathode material. Exemplarily, the mass percentage of the catalyst material can be 5%, 6%, 7%, 8%, 9%, or 10%, or any value between any two of these. This range provides sufficient catalytic active sites to improve the sulfur conversion reaction efficiency while avoiding excessive crowding out of the volume fraction of sulfur active material or solid electrolyte due to excessive catalyst material. This facilitates a balance between catalytic activity and electrode structural integrity while ensuring high energy density.

[0065] This application also provides an all-solid-state lithium-sulfur battery, comprising: a positive electrode, a solid electrolyte layer, and a negative electrode, wherein the solid electrolyte layer is disposed between the positive electrode and the negative electrode. The positive electrode is formed from the aforementioned all-solid-state lithium-sulfur battery positive electrode material; the negative electrode is a Li-In alloy.

[0066] This all-solid-state lithium-sulfur battery utilizes a solid-state sulfur cathode catalytic material with dynamic electron buffering capabilities, enabling the construction of a highly efficient and synergistic solid-solid interface catalytic system within the battery. During charge and discharge, the bimetallic atom catalytic sites in the cathode effectively promote sulfur species conversion reactions and dynamically regulate charge, helping to suppress incomplete conversion and structural degradation of active materials, thereby improving the battery's sulfur utilization rate, rate performance, and long-cycle stability. Simultaneously, the combination of the solid electrolyte layer and the anode further ensures the battery's interfacial stability and safety characteristics under high temperature or high voltage conditions, providing a feasible device foundation for constructing high-energy-density, long-life all-solid-state energy storage systems.

[0067] The preparation process of the positive electrode includes the following steps: Step 1: Weigh out the sulfur active material, conductive additive, solid electrolyte, and solid sulfur cathode catalyst material according to a predetermined mass ratio. This mass ratio can be 70 to 75: 35 to 45: 75 to 85: 5 to 10.

[0068] For example, the mass ratio can be 70:40:80:5, 72:40:80:8, 75:45:85:10, or any value within the range of any two of the above values.

[0069] Step 2: Place the weighed components into a high-energy ball mill jar and add the ball milling media.

[0070] Step 3 involves high-energy ball milling under an inert atmosphere to ensure thorough mixing of the components and uniform dispersion of the catalyst. The inert atmosphere can be argon or nitrogen. The ball milling speed in this step is 450 rpm to 550 rpm, and the milling time is 6 to 10 hours. Exemplarily, the inert atmosphere can be either argon or nitrogen. Exemplarily, the ball milling speed can be 450 rpm, 480 rpm, 500 rpm, 520 rpm, or 550 rpm, or any value within the range of any two of the above values. Exemplarily, the ball milling time can be 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours, or any value within the range of any two of the above values.

[0071] Step 4 involves molding the composite powder obtained after ball milling into a positive electrode sheet with the required thickness and density under a certain pressure using a molding process. Through these steps, a composite positive electrode with uniform composition, dense structure, and well-dispersed catalytic sites can be obtained, laying the foundation for constructing a highly efficient ion-electron transport network and catalytic reaction interface within the positive electrode.

[0072] The preparation process of the negative electrode includes the following steps: Step 1: Select lithium-indium (Li-In) alloy as the negative electrode material.

[0073] Step 2 involves alternating stacking of lithium and indium sheets in a set ratio to form a multi-layered composite structure.

[0074] Step 3: Under the protection of an inert atmosphere, pressure is applied to the stacked composite structure to compress it, so that Li and In undergo an alloying reaction at the interface to form a uniform Li-In alloy anode.

[0075] Step 4 involves cutting or shaping the obtained Li-In alloy to obtain a negative electrode sheet that meets the battery size requirements. Through the aforementioned stacking-pressurization solid-state alloying process, uniform composite of Li and In can be achieved without introducing a liquid phase or high-temperature melting, which is beneficial for obtaining an alloy negative electrode with a dense structure, stable interface, and continuous lithium-ion transport path. This preparation method is simple, highly controllable, and suitable for the integration of high-stability negative electrodes in all-solid-state batteries.

[0076] The present application will be further described below with reference to specific embodiments and comparative examples.

[0077] Preparation Example 1 (Preparation of PCN) This preparation example provides a nitrogen-doped carbon material (PCN), and the preparation method includes the following steps: Step 1.1: Preparation of carbonitride carrier material by precursor calcination: Dicyandiamide was calcined at 550℃ (heating rate of 2.3℃ / min) for 4 hours, and then thermally exfoliated at 500℃ (heating rate of 5℃ / min) for 5 hours to obtain PCN nanosheets.

[0078] Preparation Example 2 (Preparation of Ni1-PCN Single-Atom Catalyst) Step 2.1: Disperse 200 mg of NiCl26H2O and 500 mg of PCN (prepared from Preparation Example 1) in 40 mL of ethanol solution, sonicate at 100 kHz for 30 minutes, and then remove the solvent by rotary evaporation to obtain solid material.

[0079] Step 2.2: The solid material obtained in step (2.1) is dried at 80°C, and then heated to 450°C in an argon atmosphere at a heating rate of 5°C / min, and held at this temperature for 5 hours to obtain powder.

[0080] Step 2.3: The powder obtained from step (2.2) is thoroughly washed with an ethanol / water mixture (ethanol and water in a 1:1 weight ratio) and dried again at 80°C. Finally, the sample is heated to 550°C at a heating rate of 2°C / min under argon protection and held at this temperature for 5 hours to obtain a single-atom catalyst (denoted as Ni1-PCN).

[0081] Preparation Example 3 (Preparation of Cu1-PCN Single-Atom Catalyst) Step 3.1: Disperse 200 mg of CuCl26H2O and 500 mg of PCN (prepared from Preparation Example 1) in 40 mL of ethanol solution, sonicate at 100 kHz for 30 minutes, and then remove the solvent by rotary evaporation to obtain solid material.

[0082] Step 3.2: The solid material obtained in step (3.1) is dried at 80°C, and then heated to 450°C in an argon atmosphere at a heating rate of 5°C / min, and held at this temperature for 5 hours to obtain powder.

[0083] Step 3.3: The powder obtained from step (3.2) is thoroughly washed with an ethanol / water mixture (ethanol and water in a 1:1 weight ratio) and dried again at 80°C. Finally, the sample is heated to 550°C at a heating rate of 2°C / min under argon protection and held at this temperature for 5 hours to obtain a single-atom catalyst (denoted as Cu1-PCN).

[0084] Preparation Example 4 (Preparation of Cu1Ni1-PCN bimetallic atom catalyst) Step 4.1: Disperse 200 mg of NiCl26H2O, 200 mg of CuCl26H2O and 500 mg of PCN (prepared from Preparation Example 1) in 60 mL of ethanol solution, sonicate at 100 kHz for 30 minutes, and then remove the solvent by rotary evaporation to obtain a solid material.

[0085] Step 4.2: The solid material obtained from (Step 4.1) is dried at 80°C, and then heated to 300°C in an argon atmosphere at a heating rate of 5°C / min, and held at this temperature for 5 hours to obtain powder.

[0086] Step 4.3: Thoroughly wash the powder obtained in Step 4.2 with an ethanol / water mixture (ethanol and water in a 1:1 weight ratio), and then heat it to 550°C at a heating rate of 2°C / min under argon protection for 5 hours to obtain a solid sulfur cathode catalyst material with bimetallic atomic electron buffer (denoted as Cu1Ni1-PCN).

[0087] Example 1 (All-solid-state lithium-sulfur battery cathode) This embodiment provides a solid-state lithium-sulfur battery cathode, the preparation method of which includes the following steps: Step 1: Weigh out the following components in a mass ratio of 72:40:8:80: lithium sulfide: conductive additive Ketjen black (KB): catalyst: solid electrolyte (LPSC). The catalyst is the Cu1Ni1-PCN bimetallic atom catalyst prepared in Preparation Example 4.

[0088] Step 2: Place all the components weighed in step S1 into a high-energy ball mill jar made of zirconia.

[0089] S3. Add 12g of zirconia grinding beads to the grinding jar.

[0090] S4. After sealing the ball mill jar, introduce inert argon gas to replace the atmosphere and maintain the inert atmosphere.

[0091] S5. The material in the ball mill is ball-milled at 550 rpm for 10 hours to ensure that the components are fully mixed and that the bimetallic atom catalyst is uniformly dispersed. After ball milling, a mixed powder is obtained.

[0092] S6. Take out the mixed powder to obtain the all-solid-state lithium-sulfur battery cathode material.

[0093] Comparative Example 1: The difference between this comparative example and Example 1 is that the catalyst in this comparative example is the Cu1-PCN catalyst prepared in Preparation Example 3.

[0094] Comparative Example 2: The difference between this comparative example and Comparative Example 1 is that the catalyst in this comparative example is the Ni1-PCN catalyst prepared in Preparation Example 2.

[0095] Comparative Example 3: The difference between this comparative example and Example 1 is that the positive electrode component consists only of lithium sulfide, conductive additives, and solid electrolyte LPSC in a mass ratio of 80:40:80, with no catalyst added.

[0096] Preparation of all-solid-state batteries: The all-solid-state lithium-sulfur battery cathode materials obtained in Example 1 and Comparative Examples 1-3 were assembled into all-solid-state batteries. The specific operation steps are as follows: Step 1: Weigh 100mg of solid electrolyte LPSC powder, place it in a 10mm diameter mold, and press it into a dense electrolyte sheet under a pressure of 375MPa.

[0097] Step 2: The positive electrode powder (any all-solid-state lithium-sulfur battery positive electrode material prepared in Example 1 or Comparative Examples 1-3) is uniformly spread on the surface of the electrolyte sheet.

[0098] Step 3: Press the positive electrode material and electrolyte sheet together under a pressure of 625 MPa to form an integrated positive electrode-electrolyte structure.

[0099] Step 4: Using Li-In alloy as the negative electrode material, place it on the other side of the electrolyte sheet in the integrated positive electrode-electrolyte structure.

[0100] Step 5: Place the assembled battery assembly into the mold and apply an overall pressure of 200MPa to press it in place, thus completing the assembly of the all-solid-state lithium-sulfur battery.

[0101] Experimental tests on atomic-level catalysts: The atomic-level catalysts prepared in Preparation Examples 1 to 4 were subjected to the following tests: (1) Infrared spectroscopy test: The infrared stretching vibration signal of different catalysts was tested using Nicoletis 50 manufactured by Thermo Fisher Scientific.

[0102] (2) Annular dark field scanning transmission electron microscopy test: Annular dark field scanning transmission electron microscopy images of different catalysts were taken using a Spectra300 manufactured by Thermo Fisher Scientific. The test operating voltage was 200K.

[0103] (3) Results of Extended X-ray Absorption Fine Structure Measurements: Near-edge absorption X-ray structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements were performed on the XAFCA beamline of the Singapore Synchrotron Radiation Facility (SSLS). During the measurements, a silicon (111) dual-crystal monochromator was used to filter the X-ray beam, metal foil was used for energy calibration, and all samples were measured in transmission mode at room temperature. The EXAFS oscillation χ(k) was extracted and analyzed using the Demeter software package.

[0104] Infrared spectroscopy test results: See Figure 2 (Infrared spectrum) The abundant periodic NH functional groups in the PCN support provide suitable coordination sites for stabilizing isolated metal atoms. In both Cu1-PCN and Ni1-PCN single-atom catalysts, the characteristic vibrational intensities corresponding to the NH functional groups show a significant decrease, indicating that some NH sites are replaced by Cu or Ni single atoms, forming atomically dispersed single-atom catalysts. In the Cu1Ni1-PCN bimetallic atom catalyst, the NH-related vibrational intensities almost completely disappear, indicating that adjacent Cu and Ni atoms occupy more NH sites in the PCN through cooperative coordination. This demonstrates that the bimetallic atom configuration can more efficiently utilize the coordination sites on the support surface, improving the loading and dispersion efficiency of metal atoms.

[0105] Results of annular dark-field scanning transmission electron microscopy: See Figure 3 (Annular dark-field scanning transmission electron microscopy image) Observation results of the Cu1Ni1-PCN bimetallic atomic catalyst show that bright spots representing individual copper and nickel atoms are uniformly distributed on the support, with a considerable number of atoms spatially adjacent to each other, forming a clear paired structure. Statistical analysis indicates that the average distance between copper and nickel atoms is approximately 0.34 nm. This distance is within the range that favors direct electronic interactions between the two metal centers, while avoiding the formation of metal-metal bonds or atomic aggregates. Morphologically, this confirms the atomically dispersed and paired structural characteristics of the bimetallic atomic catalyst.

[0106] Extended X-ray absorption fine structure test results: See Figure 4(Extended X-ray absorption fine structure spectra) Extended X-ray absorption fine structure analysis was performed on the three atomic-level catalysts mentioned above. In the Cu1-PCN and Ni1-PCN catalysts, both Cu and Ni atoms formed a 4-coordinate structure with the surrounding N atoms, while in the Cu1Ni1-PCN catalyst, Cu formed a 2-coordinate structure with the surrounding N atoms, and Ni formed a 4-coordinate structure with the surrounding N atoms. No Cu-Cu, Ni-Ni, or Cu-Ni metal coordination peaks were observed in any of the three catalysts, further proving that the two metals exist in an atomically dispersed form. Furthermore, the close proximity of Cu and Ni atoms in the Cu1Ni1-PCN catalyst provides the necessary conditions for reversible electron migration between them, allowing the bimetallic atomic sites to collaboratively regulate the electronic state distribution during the reaction, rather than acting as isolated catalytic centers.

[0107] Testing and detection of all-solid-state lithium-sulfur battery cathode materials: All-solid-state batteries prepared from the cathode materials provided in Example 1 (Cu1Ni1-PCN bimetallic atomic catalyst), Comparative Example 1 (Cu1-PCN single-atom catalyst), Comparative Example 2 (Ni1-PCN single-atom catalyst), and Comparative Example 3 (no catalyst added) were tested in the following aspects: (a) XPS partial potential characterization analysis: The chemical state of the samples was investigated using K-Alpha++ (Thermo Fisher Scientific). The binding energy was calibrated by setting the measured C1s ionization energy to 284.8 eV.

[0108] (II) Electrochemical Cyclic Performance Test: The cyclic performance test was conducted using an electrochemical workstation CT-4008Tn-5V10mA-164j manufactured by Shenzhen Xinwei Co., Ltd., and a long-term cyclic test was performed at room temperature with a voltage range of 0.7V to 2.4V.

[0109] I. XPS partial potential characterization analysis results: such as Figure 5As shown, the all-solid-state lithium-sulfur cathode material prepared in Example 1 was assembled into a battery and subjected to potential-wise X-ray photoelectron spectroscopy (XPS). The binding energy positions of copper (Cu) and nickel (Ni) at different potentials were statistically analyzed. In the initial stage of charging, a strong interaction occurs between sulfur and nickel sites in lithium sulfide (Li₂S), promoting electron transfer from sulfur to nickel. During this process, copper sites act as electron buffers, receiving excess electrons from nickel and thus inhibiting excessive nickel oxidation. As the charging voltage rises to 2.4V, the 2p peak of nickel shifts towards lower binding energies, indicating that nickel is in an electron-rich state; simultaneously, the 2p peak of copper shifts towards higher binding energies, indicating that copper is in an electron-deficient state. During discharge, nickel transfers electrons back to copper, and subsequently, the two metal sites synergistically participate in the electron transfer process of sulfur species, thereby accelerating the sulfur reduction reaction. When the discharge reaches 0.7V, the reaction products desorb, and the binding energy of copper and nickel essentially returns to its initial state. The above results indicate that Cu-Ni bimetallic atom catalysts can achieve reversible charge redistribution through dynamic electron migration between Cu and Ni during the charge-discharge cycle of all-solid-state lithium-sulfur batteries.

[0110] During the charging phase, Cu acts as an electron acceptor, buffering the electron accumulation at Ni sites and inhibiting their excessive oxidation. During the discharging phase, Ni acts as an electron donor, returning electrons to Cu and synergistically promoting sulfur reduction. This dynamic electron transfer mechanism allows the electronic structures of the two metal sites to remain reversibly altered during cycling. This not only reduces energy loss caused by the irreversible reconstruction of the electronic structure of a single metal site but also optimizes the adsorption-conversion process of sulfur species through the synergistic effect of the two metal atoms. Thus, it achieves a simultaneous improvement in catalytic activity and structural stability at the atomic scale, thereby maintaining the catalyst's high activity and long-term cycling stability.

[0111] II. Electrochemical Cycling Performance Test Results: The all-solid-state lithium-sulfur batteries assembled in Example 1 (Cu1Ni1-PCN), Comparative Example 1 (Cu1-PCN), Comparative Example 2 (Ni1-PCN), and Comparative Example 3 (without catalyst) were tested at 30°C with a current of 1 mA / cm². 2 Charge-discharge tests were conducted at current densities and within a voltage range of 0.7V to 2.4V to evaluate the impact of different catalysts on battery performance. Long-cycle test results are as follows: Figure 6 As shown.

[0112] See Figure 6It can be seen that the battery capacity of Comparative Example 3 (without catalyst) decayed rapidly, resulting in the shortest cycle life. Comparative Examples 1 (Cu1-PCN) and 2 (Ni1-PCN) showed improved battery performance, but still exhibited significant capacity decay after approximately 500 cycles, indicating that traditional single-atom catalysts, lacking a sustained electron buffering mechanism, gradually passivate and deactivate the single metal sites. In contrast, Example 1 (Cu1Ni1-PCN) demonstrated excellent cycle stability, maintaining 946.4 mAh g⁻¹ after 2500 cycles. -1 The high reversible capacity and extremely low capacity decay rate directly confirm the effectiveness of the adaptive electron redistribution mechanism in the copper-nickel bimetallic atom catalyst. This mechanism suppresses excessive reduction or oxidation of active sites through dynamic electron buffering, thereby significantly improving the long-cycle performance of the all-solid-state lithium-sulfur battery.

[0113] The above description describes some specific embodiments of this application, but in actual applications, the application should not be limited to these embodiments. For those skilled in the art, other modifications and alterations made based on the technical concept of this application should fall within the protection scope of this application.

Claims

1. A solid sulfur cathode catalyst material, characterized in that, include: The carrier and a first transition metal atom and a second transition metal atom co-loaded on the carrier in an atomically dispersed form, wherein the carrier comprises a nitrogen-doped carbon material, and the electronegativity difference ΔEN between the first transition metal atom and the second transition metal atom satisfies: 0.01≤ΔEN≤0.

5.

2. The solid sulfur cathode catalyst material according to claim 1, characterized in that, The first transition metal atom and the second transition metal atom are each independently selected from one of the elements copper, nickel, cobalt, iron, and zinc; Furthermore, the first transition metal atom and the second transition metal atom are different elements.

3. The solid sulfur cathode catalyst material according to claim 1, characterized in that, The electronegativity difference ΔEN between the first transition metal atom and the second transition metal atom satisfies: 0.01≤ΔEN≤0.

05.

4. The solid sulfur cathode catalyst material according to claim 1, characterized in that, The molar ratio of the first transition metal atom to the second transition metal atom is 0.7:1 to 1:0.

7.

5. The solid sulfur cathode catalyst material according to any one of claims 1 to 4, characterized in that, The interatomic distance between the first transition metal atom and the second transition metal atom is 0.3 nm to 0.4 nm.

6. A method for preparing a solid sulfur cathode catalyst material according to any one of claims 1 to 5, characterized in that, include: Provide the carrier; A first metal salt containing a first transition metal atom and a second metal salt containing a second transition metal atom are mixed with the support in a solvent to obtain a mixture. The mixture is then dried. as well as Under a protective atmosphere, the dried mixture is heat-treated to cause the first metal salt and the second metal salt to react in situ on the support to generate the first transition metal atom and the second transition metal atom, respectively, thereby obtaining the solid sulfur cathode catalyst material.

7. The method for preparing the solid sulfur cathode catalyst material according to claim 6, characterized in that, The first metal salt includes at least one of chloride, nitrate and acetate containing the first transition metal atom; The second metal salt includes at least one of chloride, nitrate and acetate containing the second transition metal atom.

8. The method for preparing the solid sulfur cathode catalyst material according to claim 6, characterized in that, The heat treatment includes a first heat treatment stage and a second heat treatment stage, wherein the first heat treatment stage is performed at 200°C to 350°C for 2 hours to 6 hours, and the second heat treatment stage is performed at 500°C to 600°C for 2 hours to 6 hours; and / or, The mixing treatment is performed under ultrasonic conditions, wherein the ultrasonic frequency is 50 kHz to 100 kHz and the ultrasonic time is 20 min to 30 min; and / or, The drying process is carried out by rotary evaporation at 50°C to 60°C for 30 to 40 minutes.

9. A positive electrode material for an all-solid-state lithium-sulfur battery, characterized in that, The cathode material includes: sulfur active material, conductive additive, solid electrolyte, and solid sulfur cathode catalyst as described in any one of claims 1 to 4.

10. An all-solid-state lithium-sulfur battery, characterized in that, include: A positive electrode, a negative electrode, and a solid electrolyte layer located between the positive electrode and the negative electrode, wherein the positive electrode is made of the positive electrode material as described in claim 9.

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