Preparation method of catalyst for metal-sulfur battery, catalyst and metal-sulfur battery

Abstract

The invention provides a preparation method of a catalyst for a metal-sulfur battery, the catalyst and the metal-sulfur battery. The preparation method comprises the following steps: carrying out a hydrothermal reaction on a biomass-based precursor, and carrying out first heat treatment in an inert atmosphere to obtain biomass carbon; mixing the biomass carbon and the indium-based chalcogenide, and performing second heat treatment in an inert atmosphere to obtain a catalyst precursor; and performing third heat treatment on the catalyst precursor in a reducing atmosphere. The preparation method is simple and low in cost, the carbon-loaded indium-based chalcogenide double-vacancy heterojunction catalyst with heterojunctions uniformly distributed in a carbon matrix can be prepared, the catalyst is used in a metal sulfur battery, an ion / electron transmission path can be effectively improved, adsorption and catalytic conversion of polysulfide are promoted, and the performance of the metal sulfur battery is improved. And the polysulfide shuttle problem in the metal-sulfur battery is effectively inhibited, so that the cycle performance of the metal-sulfur battery and the utilization efficiency of the sulfur positive electrode are improved.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and more particularly to a metal sulfur battery, and even more particularly to a method for preparing a catalyst for a metal sulfur battery and the catalyst thereof. Background Technology

[0002] With the rapid development of electric vehicles and large-scale energy storage grids, higher demands are being placed on the energy density of secondary batteries. Metal sulfur batteries, especially lithium-sulfur batteries, are considered strong candidates for next-generation high-energy-density energy storage systems due to their ultra-high theoretical specific capacity (1675 mAh / g) and theoretical energy density (2600 Wh / kg), as well as the abundant reserves, low cost, and environmental friendliness of sulfur as the positive electrode active material. However, the commercial application of lithium-sulfur batteries still faces a series of severe challenges: First, the intermediate product lithium polysulfides (LiPSs) easily dissolves and shuttles in the electrolyte, leading to irreversible loss of active material and rapid capacity decay; second, the electronic insulation of sulfur and its discharge end products Li2S / Li2S2 results in sluggish reaction kinetics; in addition, the volume expansion of the sulfur cathode and the growth of lithium dendrites during charging and discharging can easily lead to battery failure.

[0003] To address these issues, researchers typically focus on developing novel sulfur-based cathode host materials. Porous carbon materials can effectively anchor LiPSs through physical confinement, but their non-polar surface properties result in weak adsorption forces, failing to completely suppress the shuttle effect. While some polar materials (such as metal oxides and sulfides) can enhance LiPS adsorption as chemical anchoring centers, their intrinsic conductivity is generally low, and their catalytic activity for LiPS conversion still needs improvement. Single adsorption or catalytic strategies are insufficient for achieving efficient synergistic management of LiPSs. Therefore, there is an urgent need to develop a composite material with both strong adsorption capacity and efficient catalytic conversion function to simultaneously solve the two core challenges of the shuttle effect and kinetic sluggishness. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for preparing a catalyst for metal-sulfur batteries, the catalyst itself, and a metal-sulfur battery. This preparation method is simple and low-cost, and can produce a carbon-supported indium chalcogenide double-vacancy heterojunction catalyst with a heterojunction uniformly distributed in a carbon matrix. When used in metal-sulfur batteries, this catalyst can effectively improve ion / electron transport pathways, promote the adsorption and catalytic conversion of polysulfides, and effectively suppress polysulfide shuttle problems in metal-sulfur batteries, thereby improving the cycle performance of metal-sulfur batteries and the utilization efficiency of the sulfur cathode.

[0005] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a catalyst for metal-sulfur batteries, comprising the steps of: (1) Biomass carbon is obtained by hydrothermal reaction of biomass-based precursor and first heat treatment under an inert atmosphere; (2) The biomass carbon and indium-based oxo compounds are mixed and subjected to a second heat treatment under an inert atmosphere to obtain a catalyst precursor, wherein the indium-based oxo compounds are selected from at least one of indium sulfide, indium selenide and indium telluride; (3) The catalyst precursor is subjected to a third heat treatment in a reducing atmosphere.

[0006] In the preparation method of this invention, the biomass-based precursor undergoes a hydrothermal reaction, followed by inert atmosphere. The first heat treatment yields biomass carbon. The biomass carbon and indium-based chalcogenides are mixed and calcined in an inert atmosphere. The oxygen in the biomass carbon oxidizes the indium-based chalcogenides, thus producing a carbon-supported indium oxide-indium sulfide / indium selenide / indium telluride heterojunction in one step, ensuring uniform distribution of the heterojunction within the carbon matrix. Further reduction treatment in a reducing atmosphere introduces dual vacancies, resulting in a vacancy-controlled heterojunction catalyst to improve electron transfer and enhance catalytic center activity. The preparation method of this invention features a simple production process, high production efficiency, and rapid sulfur reduction kinetics in the obtained catalyst. This catalyst promotes the conversion of polysulfides during charge and discharge, effectively suppresses their shuttle behavior, and significantly improves the cycle stability and rate performance of metal-sulfur batteries.

[0007] As a technical solution of the present invention, the metal sulfur battery is selected from lithium sulfur battery, sodium sulfur battery or potassium sulfur battery.

[0008] As one technical solution of the present invention, the biomass-based precursor is selected from at least one of cellulose, starch and glucose.

[0009] As one technical solution of the present invention, the hydrothermal reaction is carried out at a temperature of 120~180℃ for 4~12h, and the biomass-based precursor is prepared as an aqueous solution with a concentration of 0.5~3.0M.

[0010] As a technical solution of the present invention, the inert atmosphere in step (1) and step (2) is independently selected from at least one of argon, nitrogen and helium.

[0011] As one technical solution of the present invention, the temperature of the first heat treatment is 600~1000℃ and the time is 0.5~6.0h.

[0012] As one technical solution of the present invention, the temperature of the second heat treatment is 600~1000℃ and the time is 2~4h.

[0013] As one technical solution of the present invention, the temperature of the third heat treatment is 300~400℃ and the time is 2~4h.

[0014] As one technical solution of the present invention, the mass ratio of the biomass carbon to the indium-based oxometalate is 3 to 1:1.

[0015] As a technical solution of the present invention, the reducing atmosphere is a reducing gas or a mixture of reducing gas and inert gas.

[0016] As a technical solution of the present invention, the reducing atmosphere is selected from hydrogen, argon-hydrogen mixture or nitrogen-hydrogen mixture.

[0017] The second aspect of the present invention provides a catalyst prepared by the aforementioned method for preparing a catalyst for a metal sulfur battery, which is a carbon-supported indium-based oxometalate double-vacancy heterojunction catalyst.

[0018] In this carbon-supported indium-based chalcogenide dual-vacancy heterojunction catalyst, the indium oxide-indium sulfide / indium selenide / indium telluride dual-vacancy heterojunction exhibits strong adsorption and catalytic conversion capabilities for polysulfides, effectively suppressing the polysulfide shuttle problem in metal-sulfur batteries, thereby improving the cycle performance of metal-sulfur batteries and the utilization efficiency of the sulfur cathode. It is an ideal catalyst for promoting polysulfide conversion in metal-sulfur batteries. Simultaneously, the carbon matrix possesses good conductivity, which can effectively improve the ion / electron transport pathway and synergistically enhance the catalyst's ability to capture polysulfides through physical adsorption.

[0019] A third aspect of the present invention provides a metal-sulfur battery, comprising a sulfur positive electrode, a metal negative electrode, and a separator, wherein the aforementioned catalyst is loaded on the separator. This metal-sulfur battery exhibits superior cycle and rate performance. Attached Figure Description

[0020] Figure 1 These are contour plots of the cyclic voltammetry curves for Example 5 and Comparative Examples 1-2.

[0021] Figure 2 These are the cycle performance diagrams for Example 5 and Comparative Examples 1-2.

[0022] Figure 3 These are the rate performance diagrams for Example 5 and Comparative Examples 1-2.

[0023] Figure 4 The image shows the XRD pattern of the metal sulfur battery catalyst prepared in Example 5. Detailed Implementation

[0024] The catalyst of this invention is a carbon-supported indium-based chalcogenide dual-vacancy heterojunction catalyst, which is a carbon-supported dual-vacancy heterojunction with indium oxide-indium sulfide, indium oxide-indium selenide, or indium oxide-indium telluride heterojunctions. Among these, the indium oxide-indium sulfide, indium oxide-indium selenide, or indium oxide-indium telluride dual-vacancy heterojunctions exhibit strong adsorption and catalytic conversion capabilities for polysulfides. Simultaneously, the carbon matrix possesses good electrical conductivity, effectively improving ion / electron transport pathways and synergistically enhancing the catalyst's polysulfide capture ability through physical adsorption. Therefore, this carbon-supported indium-based chalcogenide dual-vacancy heterojunction catalyst can effectively suppress the polysulfide shuttle problem in metal sulfur batteries, thus improving the cycle and rate performance of metal sulfur batteries.

[0025] The catalyst of this invention can be used in metal-sulfur batteries, which are selected from lithium-sulfur, sodium-sulfur, or potassium-sulfur batteries. A metal-sulfur battery includes a sulfur cathode, a metal anode, and a separator. When the anode is lithium, the corresponding metal-sulfur battery is a lithium-sulfur battery; when the anode is sodium, the corresponding metal-sulfur battery is a sodium-sulfur battery; and when the anode is potassium, the corresponding metal-sulfur battery is a potassium-sulfur battery. The catalyst can be used on the sulfur cathode, the metal anode, and the separator, preferably on the separator. Furthermore, the catalyst is loaded onto the separator, which acts as a "catalytic barrier," blocking lithium polysulfides from shutting down while catalyzing their reverse conversion to sulfur. The separator can be a polypropylene separator, a polyethylene separator, a fiber separator, or other separators known in the industry for use in metal-sulfur batteries. The catalyst can be mixed with conductive carbon and a binder in a certain proportion to form a slurry, which is then coated onto one or both sides of the separator. After vacuum drying, a catalytically modified separator is obtained. This catalytically modified separator can directly replace a conventional separator and be assembled with a pure sulfur cathode and a metal anode to form a metal-sulfur battery.

[0026] The method for preparing the catalyst for metal sulfur batteries of the present invention may include the following steps: (1) Biomass carbon is obtained by hydrothermal reaction of biomass-based precursor and first heat treatment under an inert atmosphere; (2) After mixing biomass carbon and indium-based oxalate compounds, a second heat treatment is carried out under an inert atmosphere to obtain a catalyst precursor. The indium-based oxalate compounds are selected from at least one of indium sulfide, indium selenide and indium telluride. (3) The catalyst precursor is subjected to a third heat treatment in a reducing atmosphere.

[0027] The biomass-based precursor is selected from at least one of cellulose, starch, and glucose. The hydrothermal reaction temperature is 120~180℃, and the time is 4~12h. The biomass-based precursor is prepared as an aqueous solution with a concentration of 0.5~3.0M. The first heat treatment temperature is 600~1000℃, and the time is 0.5~6.0h. The second heat treatment temperature is 600~1000℃, and the time is 2~4h. The third heat treatment temperature is 300~400℃, and the time is 2~4h. The inert atmosphere in steps (1) and (2) is independently selected from at least one of argon, nitrogen, and helium. The mass ratio of biomass carbon to indium oxalate is 3~1:1. The reducing atmosphere is a reducing gas or a mixture of reducing gas and inert gas. The volume ratio of reducing gas to inert gas in the mixed atmosphere can be 5~20:95~80. The reducing gas can be hydrogen, and the inert gas can be nitrogen, argon, nitrogen, or helium. Furthermore, the reducing atmosphere is selected from hydrogen, an argon-hydrogen mixture, or a nitrogen-hydrogen mixture.

[0028] To better illustrate the purpose, technical solution, and beneficial effects of this invention, the invention will be further described below with reference to specific embodiments. It should be noted that the methods described below are further explanations of this invention and should not be construed as limiting it.

[0029] Example 1 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0030] (1) Prepare a 0.5M aqueous solution of glucose, react at 120℃ for 4h, and then heat-treat at 800℃ under nitrogen atmosphere for 2h to obtain biomass carbon.

[0031] (2) Biomass carbon and indium sulfide are thoroughly mixed in a mass ratio of 3:1 and treated at 800°C for 2 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0032] (4) The catalyst precursor was treated at 300°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 2:8) to obtain a carbon-supported indium oxide and indium sulfide double vacancy heterojunction catalyst.

[0033] Example 2 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0034] (1) Prepare a 2.0M aqueous solution of glucose, react at 180℃ for 8h, and then heat-treat at 800℃ for 2h under an argon atmosphere to obtain biomass carbon.

[0035] (2) Biomass carbon and indium selenide are thoroughly mixed at a mass ratio of 2:1 and treated at 1000°C for 4 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0036] (4) The catalyst precursor was treated at 350°C for 2 h in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 2:8) to obtain a carbon-supported indium oxide and indium selenide double vacancy heterojunction catalyst.

[0037] Example 3 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0038] (1) Cellulose was prepared into a 1.0M aqueous solution, reacted at 180℃ for 12h, and then heat-treated at 900℃ under nitrogen atmosphere for 2h to obtain biomass carbon.

[0039] (2) Biomass carbon and indium telluride are thoroughly mixed in a mass ratio of 1.5:1 and treated at 800°C for 3 hours in an argon atmosphere to obtain a catalyst precursor.

[0040] (4) The catalyst precursor was treated at 400°C for 4 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 2:8) to obtain a carbon-supported indium oxide and indium telluride double vacancy heterojunction catalyst.

[0041] Example 4 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0042] (1) Prepare starch into a 1.0M aqueous solution, react at 180℃ for 8h, and then heat-treat at 900℃ for 3h under nitrogen atmosphere to obtain biomass carbon.

[0043] (2) Biomass carbon and indium sulfide are thoroughly mixed at a mass ratio of 2.5:1 and treated at 700°C for 3 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0044] (4) The catalyst precursor was treated at 300°C for 3 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 14:86) to obtain a carbon-supported indium oxide and indium sulfide double vacancy heterojunction catalyst.

[0045] Example 5 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0046] (1) Prepare a 0.5M aqueous solution of glucose, react at 180℃ for 6h, and then heat-treat at 800℃ for 2h under nitrogen atmosphere to obtain biomass carbon.

[0047] (2) Biomass carbon and indium telluride are thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0048] (4) The catalyst precursor was treated at 400°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 1:9) to obtain a carbon-supported indium oxide and indium telluride double vacancy heterojunction catalyst.

[0049] The catalyst used in the prepared metal-sulfur battery was subjected to XRD analysis. The figure shows the catalyst labeled "C@In2Te". 3-x -In2O 3-x The results are shown below. Figure 4 As shown in the figure, an indium telluride-indium oxide heterojunction is distributed in the carbon matrix.

[0050] Example 6 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0051] (1) Prepare a 0.5M aqueous solution of glucose, react at 180℃ for 6h, and then heat-treat at 800℃ for 2h under nitrogen atmosphere to obtain biomass carbon.

[0052] (2) Biomass carbon and indium selenide are thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0053] (4) The catalyst precursor was treated at 400°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 1:9) to obtain a carbon-supported indium oxide and indium selenide double vacancy heterojunction catalyst.

[0054] Example 7 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0055] (1) Prepare a 0.5M aqueous solution of glucose, react at 180℃ for 6h, and then heat-treat at 800℃ for 2h under nitrogen atmosphere to obtain biomass carbon.

[0056] (2) The biomass carbon and indium sulfide were thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain the catalyst precursor.

[0057] (4) The catalyst precursor was treated at 400°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 1:9) to obtain a carbon-supported indium oxide and indium telluride double vacancy heterojunction catalyst.

[0058] Example 8 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0059] (1) Prepare a 0.5M aqueous solution of starch, react it at 180℃ for 6h, and then heat it at 800℃ for 2h under a nitrogen atmosphere to obtain biomass carbon.

[0060] (2) Biomass carbon and indium telluride are thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0061] (4) The catalyst precursor was treated at 400°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 1:9) to obtain a carbon-supported indium oxide and indium sulfide double vacancy heterojunction catalyst.

[0062] Example 9 This embodiment describes a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0063] (1) Cellulose was prepared into a 0.5M aqueous solution, reacted at 180℃ for 6h, and then heat-treated at 800℃ for 2h under nitrogen atmosphere to obtain biomass carbon.

[0064] (2) Biomass carbon and indium telluride are thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain a catalyst precursor.

[0065] (4) The catalyst precursor was treated at 400°C for 2 hours in an argon-hydrogen atmosphere (volume ratio of hydrogen to argon was 1:9) to obtain a carbon-supported indium oxide and indium sulfide double vacancy heterojunction catalyst.

[0066] Comparative Example 1 This comparative example illustrates a method for preparing a catalyst for metal sulfur batteries, which includes the following steps.

[0067] (1) Prepare a 0.5M aqueous solution of glucose, react at 180℃ for 6h, and then heat-treat at 800℃ for 2h under nitrogen atmosphere to obtain biomass carbon.

[0068] (2) Biomass carbon and indium telluride are thoroughly mixed in a mass ratio of 3:1 and treated at 700°C for 2 hours in a nitrogen atmosphere to obtain carbon-supported indium oxide and indium telluride heterojunction catalyst.

[0069] The catalysts from Examples 1-9 and Comparative Example 1, along with SP and PVDF, were mixed in NMP at a mass ratio of 8:1:1 to obtain a slurry with a solid content of 10-15%. The slurry was coated onto one side of a polypropylene membrane and vacuum dried to obtain catalytically modified separators #1-10. Sulfur positive electrode sheets, catalytically modified separators, lithium negative electrode sheets, and electrolyte (LiTFSI / DOL-DME system with LiNO3 additive) were stacked in an argon glove box in the same order: positive electrode shell - positive electrode sheet - electrolyte - catalytically modified separator - electrolyte - lithium sheet - gasket - spring sheet - negative electrode shell. The sheets were then pressed using a button cell sealing machine at a sealing pressure of 500 kg to obtain lithium-sulfur button cells #1-10.

[0070] The sulfur positive electrode, polypropylene film, lithium negative electrode, and electrolyte (LiTFSI / DOL-DME system with LiNO3 additive) were stacked in an argon glove box in the following order: "positive electrode shell - positive electrode sheet - electrolyte - polypropylene film - electrolyte - lithium sheet - gasket - spring sheet - negative electrode shell". The stacks were then pressed using a button cell sealing machine to produce lithium-sulfur button cell battery #11.

[0071] Electrochemical performance tests were conducted on lithium-sulfur button cells #1 to #11, and the results are shown in Table 1. The test conditions are as follows.

[0072] Cyclic performance test: The electrode loading was 0.9 mg. After activating at 0.1 C for 3 cycles, the initial cycle test was started at a current density of 1 C, and the number of cycles was 500.

[0073] Rate performance test: The electrode loading is 0.9mg. The rate test is carried out in sequence at 0.1C, 0.3C, 0.5C, 1C, 2C, 3C and 0.2C, with each current density cycled 5 times.

[0074] Table 1 Electrochemical performance test results of lithium-sulfur button cells #1 to #11

[0075] As shown in Table 1, in the preparation method of the present invention, biomass carbon and indium-based oxalate compounds are mixed in an inert atmosphere and subjected to heat treatment and calcination, and then subjected to reduction treatment in a reducing atmosphere to introduce double vacancies to obtain a vacancy-controlled heterojunction catalyst, which can significantly improve cycle and rate performance when used in lithium-sulfur batteries.

[0076] Furthermore, comparing lithium-sulfur coin cells #5 and #6-7, it is evident that indium telluride (ITT) exhibits superior performance. This is because Te, within the same group, possesses stronger metallicity, resulting in a heterojunction with better electronic conductivity and catalytic activity. This allows for more effective catalysis of polysulfide conversion, thereby enhancing the performance of lithium-sulfur batteries. Comparing lithium-sulfur coin cells #5 and #8-9, it is clear that glucose, selected as the biomass-based precursor, demonstrates superior performance. This is because glucose, during hydrothermal processes, can form porous microspheres with smaller particle sizes and more uniform pore size distribution. After mixing with indium compounds, this results in a more uniform C@In2Te3 / In2O3 heterojunction.

[0077] Additionally, lithium-sulfur coin cell battery #5 (referred to as "C@In2Te" in the figure) was obtained. 3-x -In2O 3-x The cyclic voltaic voltage curve contour plot, cycle performance plot, and rate performance plot of lithium-sulfur coin cells 10# (shown as "C@In2Te3-In2O3@PP" in the figure) and 11# (shown as "PP" in the figure) are shown below. The results are as follows: Figures 1-3 As shown. Figure 1 As shown, the two cathode peaks at 2.30V and 1.94V correspond to the reduction product Li₂S, respectively. x The anodic peak at 2.37V corresponds to the conversion of Li₂S to S. (The text then abruptly shifts to a seemingly unrelated topic: "C@In₂Te...") 3-x -In2O 3-x The cell in Figure c shown by @PP” exhibits a higher current response and smaller peak shift than other cells, especially in the anode peak region, fully demonstrating the promoting effect of the carbon-supported indium oxide / indium telluride dual-vacancy heterojunction catalyst on sulfur reduction kinetics. Figure 2 The results show that the battery using a carbon-supported indium oxide and indium telluride dual-vacancy heterojunction catalyst separator exhibits a high initial discharge capacity of 896.2 mAh / g at 1C rate. After 500 cycles, the capacity remains at 572.8 mAh / g, with a capacity retention of 63.9%, and an average capacity decay rate of only 0.072% per cycle. Furthermore, the coulombic efficiency remains above 99% throughout the entire cycle. Figure 3 As shown, the discharge capacities of the battery using a carbon-supported indium oxide and indium telluride dual-vacancy heterojunction catalyst at different rates (0.1C to 3C) were 1433.3 mAh / g, 1093.8 mAh / g, 1007.2 mAh / g, 938.9 mAh / g, 874.4 mAh / g, and 785.3 mAh / g, respectively. When the rate returned to 0.2C, the reversible capacity of the battery still reached 1023 mAh / g, demonstrating good electrochemical reversibility.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a catalyst for metal-sulfur batteries, characterized in that, Including the following steps: (1) Biomass carbon is obtained by hydrothermal reaction of biomass-based precursor and first heat treatment under an inert atmosphere; (2) The biomass carbon and indium-based oxo compounds are mixed and subjected to a second heat treatment under an inert atmosphere to obtain a catalyst precursor, wherein the indium-based oxo compounds are selected from at least one of indium sulfide, indium selenide and indium telluride; (3) The catalyst precursor is subjected to a third heat treatment in a reducing atmosphere.

2. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, The metal sulfur battery is selected from lithium sulfur batteries, sodium sulfur batteries, or potassium sulfur batteries.

3. The method for preparing the catalyst for polymetallic sulfur batteries according to claim 1, characterized in that, The biomass-based precursor is selected from at least one of cellulose, starch, and glucose.

4. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 120-180°C for 4-12 hours, and the biomass-based precursor is prepared as an aqueous solution with a concentration of 0.5-3.0 M.

5. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, The inert atmospheres in steps (1) and (2) are each independently selected from at least one of argon, nitrogen, and helium.

6. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, Includes at least one of the following features (I) to (III): (I) The temperature of the first heat treatment is 600~1000℃, and the time is 0.5~6.0h; (III) The temperature of the second heat treatment is 600~1000℃ and the time is 2~4h; (III) The temperature of the third heat treatment is 300~400℃ and the time is 2~4h.

7. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, The mass ratio of the biomass carbon to the indium oxalate compound is 3 to 1:

1.

8. The method for preparing the catalyst for metal-sulfur batteries according to claim 1, characterized in that, The reducing atmosphere is a reducing gas or a mixture of a reducing gas and an inert gas.

9. The catalyst prepared by the method for preparing a metal-sulfur battery catalyst according to any one of claims 1 to 8, characterized in that, It is a carbon-supported indium-based chalcogenide double-vacancy heterojunction catalyst.

10. A metal sulfur battery, characterized in that, It includes a sulfur cathode, a metal anode, and a membrane, wherein the catalyst of claim 9 is loaded on the membrane.

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