Lithium-sulfur battery positive electrode material as well as preparation method and application thereof

Abstract

The invention discloses a lithium-sulfur battery positive electrode material as well as a preparation method and application thereof, and belongs to the field of lithium-sulfur batteries. Dissolving an aluminum source, a zirconium source, a zinc source and a chelating agent in methanol or ethanol to obtain a precursor solution; the preparation method comprises the following steps: dispersing silicon dioxide nanospheres, benzimidazole and a surfactant in a precursor solution to carry out hydrothermal reaction, centrifuging and cleaning the obtained solid after the reaction is finished, then adding a hydrogen fluoride solution to carry out etching treatment, and drying to obtain a precursor; and putting the precursor and selenium powder into calcining equipment, and carrying out calcining reaction under inert gas to prepare the lithium-sulfur battery positive electrode material. The lithium-sulfur battery positive electrode material has a hydrophilic easily-infiltrated structure with ordered pore channels and a polar catalytic component, so that the lithium-sulfur battery positive electrode material can provide synergistic functions of physical constraint, chemical anchoring, excellent polysulfide redox reaction electrocatalysis and the like, and is especially suitable for a lithium-sulfur battery under the conditions of high sulfur loading and poor electrolyte; the electrochemical performance and the cycling stability of the battery can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of lithium-sulfur batteries, and in particular relates to a lithium-sulfur battery positive electrode material, a preparation method and application thereof. Background Art

[0002] Compared with traditional lithium-ion batteries, lithium-sulfur batteries have several advantages, including high energy density (2600 Wh / kg), low cost and good environmental compatibility. Therefore, it has been considered as one of the most promising energy storage systems. However, lithium-sulfur batteries still face the problem of "shuttle effect" in practical applications. This problem refers to the fact that polysulfides are easily dissolved in ether-based electrolytes and shuttle back and forth between the positive and negative electrodes, resulting in the loss of sulfur active species and side reactions of the lithium negative electrode. In order to deal with the "shuttle effect" problem in lithium-sulfur batteries, researchers have proposed a variety of strategies and achieved significant progress in electrochemical performance. However, these strategies usually require the use of excess electrolyte, that is, a high electrolyte / sulfur ratio (E / S). However, a high E / S ratio reduces the energy density and increases the cost of the electrolyte, thereby limiting the commercial application of lithium-sulfur batteries.

[0003] Therefore, for the commercial application of lithium-sulfur batteries, it is crucial to adopt a new positive electrode design to fully utilize the active material under low E / S conditions. The Chinese patent document with publication number CN115602811A discloses carbon nanofibers as self-supporting sulfur positive electrode host materials, preparation methods and applications. The carbon nanofibers are easy to infiltrate, and combined with their lightweight properties, they can effectively improve the energy density of lithium-sulfur batteries. However, one disadvantage under lean electrolyte conditions is that the solubility of sulfur is low, which leads to uneven deposition of undissolved polysulfides on the surface of carbon nanofibers, thereby affecting the battery's cycle performance and capacity decay rate. In addition, another disadvantage that carbon nanofibers may face as positive electrode materials under lean electrolytes is insufficient conductivity. The Chinese patent document with publication number CN118173767A discloses a three-dimensional ordered structure synthesized using polystyrene balls as templates. As a positive electrode material for lithium-sulfur batteries, the structure can effectively physically adsorb lithium polysulfide and improve battery performance. However, the material is prone to hollow structure collapse, reduced dispersibility, and damaged integrity under high temperature conditions. Therefore, it is necessary to study new hydrophilic and easily wettable carbon materials and develop a synthesis method with simple process steps and convenient operation. Summary of the invention

[0004] The purpose of the present invention is to provide a lithium-sulfur battery positive electrode material, a preparation method and application thereof. The positive electrode material has a hydrophilic and easily wettable structure with ordered pores and a polar catalytic component, which can provide synergistic functions such as physical confinement, chemical anchoring and excellent electrocatalysis of polysulfide redox reactions. It is particularly suitable for lithium-sulfur batteries under high sulfur loading and poor electrolyte conditions, and can improve the electrochemical performance and cycle stability of the battery.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for preparing the above-mentioned lithium-sulfur battery positive electrode material, comprising the following steps: (1) dissolving an aluminum source, a zirconium source, a zinc source and a chelating agent in methanol or ethanol to obtain a precursor solution; (2) dispersing silica nanospheres, benzimidazole and a surfactant in the precursor solution obtained in step (1) to carry out a hydrothermal reaction. After the reaction is completed, the obtained solid is centrifuged and washed, then a hydrogen fluoride solution is added for etching, and finally dried to obtain a precursor; (3) placing the precursor obtained in step (2) and selenium powder in a calcination device, and performing a calcination reaction under an inert gas to obtain a positive electrode material for a lithium-sulfur battery.

[0006] Preferably, in step (1), the aluminum source is one or more of aluminum acetate, aluminum nitrate, aluminum sulfate, and aluminum chloride; the zirconium source is one or more of zirconium acetate, zirconium nitrate, zirconium sulfate, and zirconium chloride; the zinc source is one or more of zinc acetate, zinc nitrate, zinc sulfate, and zinc chloride; and the chelating agent is one of gluconic acid, citric acid, and tartaric acid; the molar concentration of the zinc source in the precursor solution is 0.1 to 1 mol / L, the molar ratio of the sum of the aluminum source and the zirconium source to the zinc source is 1 to 5:100, and the molar ratio of the zinc source to the chelating agent is 5 to 10:1.

[0007] Preferably, in step (2), the surfactant is hexadecyltrimethylammonium bromide or polyvinylpyrrolidone, the mass ratio of silica nanospheres, benzimidazole and surfactant is 5-20:1-5:1; the dispersion time is 1-6 hours; the hydrothermal reaction temperature is 100-180°C, and the reaction time is 6-12 hours; the cleaning agent is one of water, methanol and ethanol; the mass fraction of hydrogen fluoride solution is 40-50wt.%; the drying temperature is 60-120°C, and the time is 4-12 hours.

[0008] Preferably, in step (3), the mass ratio of the precursor to the selenium powder is 1:1-5, the inert gas is nitrogen or argon, the calcination reaction is controlled at a heating rate of 2-5°C / min, a temperature of 600-1000°C, and a time of 6-15h.

[0009] In a second aspect, the present invention provides a lithium-sulfur battery positive electrode material consisting of a three-dimensional ordered macroporous structure of aluminum-zirconium doped zinc selenide, the pore size of the three-dimensional ordered macropores being 86 to 300 nm, the aluminum-zirconium elements accounting for 1.2 to 4.9% of the metal atomic ratio, and the zinc selenide accounting for 12.4 to 55.7% of the mass of the lithium-sulfur battery positive electrode material.

[0010] In a third aspect, there is provided an application of the lithium-sulfur battery positive electrode material prepared by the present invention for lithium-sulfur battery positive electrode.

[0011] In a fourth aspect, there is also provided an application of the lithium-sulfur battery positive electrode material prepared by the present invention for use in the positive electrode of a lithium-sulfur battery with high sulfur loading and poor electrolyte.

[0012] The beneficial effects of the present invention are as follows: 1. The present invention prepares positive electrode materials by combining hydrothermal reaction with hydrogen fluoride etching and calcination process. During the preparation process, the introduced specific chelating agent can form stable complexes with a variety of divalent and trivalent metal ions, and maintain a good chelating effect in a wide pH range, thereby effectively inhibiting the formation of precipitation and ensuring the uniform dispersion of metal ions. Subsequently, the 40-50wt.% hydrogen fluoride solution has a faster corrosion rate, which is suitable for rapid etching of the silica nanosphere template, leaving an ordered porous structure for the material. This ordered porous structure has excellent stability and dispersibility, effectively expands its specific surface area, and also creates more active sites for electrochemical reactions, thereby improving the electrochemical performance of the material. In the appropriate calcination process, the evaporation of selenium powder ensures sufficient contact between the reaction gas and the precursor material. This method promotes the uniform reaction of selenium powder, thereby further improving the electrochemical performance of the material. Through this series of optimization measures, the present invention successfully prepares lithium-sulfur battery positive electrode materials with excellent performance. These materials have high specific surface area and good electrochemical activity, and play an important role in improving battery specific capacity and cycle stability.

[0013] 2. The lithium-sulfur battery positive electrode material provided by the present invention has an ordered three-dimensional macroporous structure (3DOM), which can promote the penetration of electrolyte and charge / mass transfer, thereby ensuring the uniform distribution of electrolyte; the considerable porosity of the 3DOM framework (86-300nm) is also conducive to the accommodation of sulfur and buffers the volume expansion during the sodium / desulfurization process; in addition, the 3DOM structure provides a high surface area and abundant active sites for the chemical reaction between aluminum-zirconium dual-doped zinc selenide and polysulfides, which plays a key role in improving the cycle life of high-sulfur-loaded lithium-sulfur batteries.

[0014] 3. In the lithium-sulfur battery positive electrode material prepared by the present invention, zinc selenide inhibits the shuttle effect through strong chemical adsorption, which helps to improve the electrochemical utilization and stability of the sulfur positive electrode; at the same time, zinc selenide can accelerate the electrocatalytic conversion of polysulfides, thereby improving the redox reaction kinetics of the battery; and aluminum-zirconium dual doping can improve the electronic structure of the sulfur main material, thereby improving its conductivity. This improvement in conductivity helps to promote the capture / diffusion of polysulfides and the deposition / oxidation process of Li2S, slowing down the volume expansion during the charge and discharge process, thereby enhancing the charge and discharge capacity and cycle stability of the battery under lean electrolyte conditions.

[0015] 4. In summary, the lithium-sulfur battery cathode material prepared by the method of the present invention performs outstandingly in the application of lithium-sulfur batteries. 2 Under the conditions of E / S=5μL / mg and 0.2C, the initial specific capacity is as high as 1248.1~1289.4mAh / g, and the capacity retention rate is 82.8%~85.9% in 100 cycle tests. Under the conditions of 1C, the initial specific capacity is as high as 972.6~986.2mAh / g, and the capacity retention rate is 82.2%~84.9% in 100 cycle tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a scanning electron microscope (SEM) image of the lithium-sulfur battery positive electrode material prepared in Example 1; Figure 2 The X-ray diffraction (XRD) pattern of the lithium-sulfur battery positive electrode material prepared in Example 1; Figure 3 The cycle stability of the lithium-sulfur battery positive electrode material prepared in Example 1 at 0.2C. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the embodiments and comparative examples, but the present invention is not limited thereto. Example 1

[0018] (1) dissolving aluminum acetate, zirconium chloride, zinc sulfate and gluconic acid in 100 mL of methanol to obtain a precursor solution; wherein the molar concentration of zinc sulfate in the precursor solution is 0.1 mol / L, the molar ratio of the sum of the aluminum source and the zirconium source to zinc sulfate is 1:20, and the molar ratio of zinc sulfate to gluconic acid is 5:1; (2) dispersing silica nanospheres, benzimidazole and polyvinyl pyrrolidone in the precursor solution obtained in step (1) for 4 hours, and then hydrothermally reacting at 100° C. for 6 hours. After the reaction, centrifuging the reaction solution, washing it with water, then removing the silica spheres with a 48 wt.% hydrogen fluoride solution and vacuum drying it at 70° C. for 6 hours to obtain a precursor; wherein the mass ratio of silica nanospheres, benzimidazole and surfactant is 15:5:1; (3) Take 100 mg of the precursor obtained in step (2) and 500 mg of selenium powder, heat the temperature to 800°C at a heating rate of 4°C / min under argon atmosphere and keep it at that temperature for 15 h to obtain a lithium-sulfur battery positive electrode material (3DOM Al / Zr-ZnSe).

[0019] The lithium-sulfur battery positive electrode material obtained in this embodiment has a three-dimensional ordered macropore diameter of 86-257 nm, aluminum and zirconium elements account for 4.9% of the metal atomic ratio, and zinc selenide accounts for 12.4% of the mass of the lithium-sulfur battery positive electrode material. Example 2

[0020] (1) dissolving an aluminum source (aluminum acetate, aluminum nitrate, aluminum sulfate, aluminum chloride), a zirconium source (zirconium acetate, zirconium nitrate), zinc nitrate and tartaric acid in 100 mL of ethanol to obtain a precursor solution; wherein the molar concentration of zinc nitrate in the precursor solution is 1 mol / L, the molar ratio of the sum of the aluminum source and the zirconium source to zinc nitrate is 3:100, and the molar ratio of zinc nitrate to tartaric acid is 10:1; (2) dispersing silica nanospheres, benzimidazole and hexadecyltrimethylammonium bromide in the precursor solution obtained in step (1) for 1 hour, and then hydrothermally reacting at 130° C. for 12 hours. After the reaction, centrifuging the reaction solution, and then washing it with ethanol. Then, using 40wt.% hydrogen fluoride solution to remove the silica spheres and vacuum drying at 120° C. for 4 hours to obtain a precursor; wherein the mass ratio of silica nanospheres, benzimidazole and surfactant is 5:1:1; (3) Take 5 g of the precursor obtained in step (2) and 5 g of selenium powder, heat the temperature to 1000°C at a heating rate of 2°C / min under a nitrogen atmosphere and keep the temperature for 10 h to obtain 3DOM Al / Zr-ZnSe.

[0021] The lithium-sulfur battery positive electrode material obtained in this embodiment has a three-dimensional ordered macropore diameter of 100-300 nm, aluminum and zirconium elements account for 3.2% of the metal atomic ratio, and zinc selenide accounts for 55.7% of the mass of the lithium-sulfur battery positive electrode material. Example 3

[0022] (1) dissolving an aluminum source (aluminum nitrate, aluminum sulfate), a zirconium source (zirconium acetate, zirconium nitrate, zirconium sulfate, zirconium chloride), a zinc source (zinc acetate, zinc nitrate, zinc sulfate, zinc chloride) and citric acid in 100 mL of methanol to obtain a precursor solution; wherein the molar concentration of the zinc source in the precursor solution is 0.8 mol / L, the molar ratio of the sum of the aluminum source and the zirconium source to the zinc source is 1:100, and the molar ratio of the zinc source to the citric acid is 8:1; (2) dispersing silica nanospheres, benzimidazole and polyvinyl pyrrolidone in the precursor solution obtained in step (1) for 6 hours, and then hydrothermally reacting at 180° C. for 8 hours. After the reaction, centrifuging the reaction solution, and then washing it with methanol. Then, using 50wt.% hydrogen fluoride solution to remove the silica spheres and vacuum drying at 60° C. for 12 hours to obtain a precursor; wherein the mass ratio of silica nanospheres, benzimidazole and surfactant is 20:1:1; (3) Take 1 g of the precursor obtained in step (2) and 2 g of selenium powder, heat the temperature to 600 °C at a heating rate of 5 °C / min under a nitrogen atmosphere and keep the temperature for 6 h to obtain 3DOM Al / Zr-ZnSe.

[0023] The lithium-sulfur battery positive electrode material obtained in this embodiment has a three-dimensional ordered macropore diameter of 90 to 270 nm, aluminum and zirconium elements account for 1.1% of the metal atomic ratio, and zinc selenide accounts for 32.5% of the mass of the lithium-sulfur battery positive electrode material. Comparative Example 1

[0024] In this comparative example, no aluminum source and zirconium source were added, and the other processes were the same as those in Example 1.

[0025] The lithium-sulfur battery positive electrode material obtained in this comparative example has a three-dimensional ordered macropore diameter of 92 to 250 nm, and zinc selenide accounts for 16.4% of the mass of the lithium-sulfur battery positive electrode material. Comparative Example 2

[0026] In this comparative example, no aluminum source was added, and the other processes were consistent with those in Example 1.

[0027] The lithium-sulfur battery positive electrode material obtained in this comparative example has a three-dimensional ordered macropore diameter of 90 to 245 nm, and zinc selenide accounts for 16.2% of the mass of the lithium-sulfur battery positive electrode material. Comparative Example 3

[0028] In this comparative example, conventional carbon black is used as the positive electrode material, and the positive electrode preparation process and performance test are consistent with those in the embodiment. Comparative Example 4

[0029] This comparative example uses 800-1000 nm silicon dioxide nanospheres, and other steps are consistent with Example 1.

[0030] The lithium-sulfur battery positive electrode material obtained in this comparative example has a three-dimensional ordered macropore diameter of 763-981 nm, aluminum and zirconium elements account for 5.2% of the metal atomic ratio, and zinc selenide accounts for 13.3% of the mass of the lithium-sulfur battery positive electrode material.

[0031] Cathode preparation: 0.1 g of sulfur powder was dissolved in 10 mL of carbon disulfide under heating and stirring at 40°C until a uniform solution (i.e., a sulfur-containing solution) was obtained. Then, 150 μL of the above solution was added dropwise to the positive electrode materials prepared in the embodiment and the comparative example, and then these materials were placed on a heating table and dried at 60°C. The sulfur loading was weighed and confirmed to be 3.5 mg / cm by a 1 / 10,000 balance. 2 .

[0032] Performance Testing: 1cm 2The C2032 button cell was assembled with a positive electrode sheet, Celgard2300 separator and lithium foil negative electrode and 17.5μL electrolyte (a mixed solution of 1.0mol / LLiTFSI and 0.2mol / LLiN03 with 1,3-dioxolane and 1,2-dimethoxyethane (w / w, 1 / 1)). On the CT-4008-5A6V system, the battery was tested at a fixed potential range (1.7-2.8Vvs.Li + The battery was cycled at different current densities of 1.5V / Li. The test current density was 0.2C, the test voltage range was 1.7-2.8V, and the test results are shown in Table 1:

[0033] Figure 1 This is a SEM image of the positive electrode material of the lithium-sulfur battery prepared in Example 1. It can be observed from the figure that the 3DOM structure in the positive electrode material is constructed by using silicon dioxide nanospheres as a template. After removing the silicon spheres with hydrogen fluoride solution, a large interconnected pore structure is formed, in which the diameter of the three-dimensional ordered macropores is 86 to 257 nm. The hydrophilic surface in the 3DOM structure has a strong affinity for the electrolyte, which can improve the surface wettability and the permeability of the electrolyte to the positive electrode material structure. The enhancement of the electrolyte permeability can strengthen the contact between sulfur and lithium ions, promote the conversion of polysulfides and improve the overall reaction. In addition, the considerable porosity of the 3DOM framework is also conducive to the accommodation of sulfur and buffers the volume expansion during the sodium sulfur / desulfurization process; in addition, the 3DOM structure provides a high surface area and abundant active sites for the chemical reaction between aluminum zirconium doped zinc selenide and polysulfides. The above structural advantages are particularly suitable for high sulfur loading and low electrolyte concentration conditions, and play a vital role in improving the electrochemical performance and cycle stability of lithium-sulfur batteries.

[0034] The lithium-sulfur battery cathode material obtained in Example 1 was subjected to XRD test. Figure 2 As shown. Figure 2 It can be seen that the sharp peak displayed is consistent with the PDF standard card number, indicating that the synthesized material is ZnSe. In addition, the dual doping of Al and Zr did not change the crystal form of ZnSe, and the corresponding diffraction peaks of Al2O3 and ZrO2 were not observed, proving that the synthesized material was successfully doped with Al and Zr.

[0035] The prepared lithium-sulfur battery cathode material was assembled into a lithium-sulfur battery in a glove box and electrochemically tested at 1.7-2.8V, 0.2C and 1C current densities, as shown in Figure 2. Figure 3As shown. The lithium-sulfur battery prepared in Example 1 has an initial specific capacity of 1289.4 mAh / g at 0.2C, and a capacity retention rate of 85.9% after 100 cycles. The initial specific capacity at 1C is 986.2 mAh / g, and the capacity retention rate after 100 cycles is 84.9%, indicating that it exhibits excellent charge and discharge performance and cycle stability under high sulfur loading and lean electrolyte. The materials of Examples 2 to 3 were tested in the same way, and the results were similar to those of Example 1 (Table 1).

[0036] Compared with the sample in Comparative Example 2, the sample in Example 1 has a higher initial specific capacity and a stronger cycle capacity, which indicates that dual doping is more conducive to promoting the diffusion of polysulfides and reducing the charge transfer resistance.

[0037] Compared with the sample in Comparative Example 1, the embodiment shows better performance under the charge and discharge condition of 0.2C. This result confirms that the dual-element doping of Al and Zr optimizes the electronic structure of the sulfur main material and improves the conductivity of ZnSe. This improvement helps to accelerate the conversion process of polysulfides and promote their electrochemical reactions, thereby effectively improving the utilization rate of sulfur, accelerating the speed of redox reactions, and thus enhancing the charge and discharge capacity and cycle stability of the battery. Compared with the sample in Comparative Example 2, the embodiment not only has a higher initial specific capacity, but also shows a stronger cycle capacity. This phenomenon shows that dual doping of Al and Zr is more advantageous than single doping.

[0038] Comparison shows that the capacity difference between Comparative Example 3 and Example 1 exceeds 830 mAh / g, which indicates that under the conditions of high sulfur loading and low electrolyte concentration, the carbon black material has no catalytic component and cannot effectively inhibit the shuttle effect, and the limited voids are not conducive to the accommodation of sulfur. Its non-hydrophilic properties fail to improve the surface wettability and the permeability of the electrolyte to the positive electrode structure, resulting in low specific capacity. Compared with Example 1, the capacity retention rate of Comparative Example 4 is more than 38% lower, which indicates that excessive pore size will damage the structural stability of the material and reduce the mass transfer efficiency, thereby significantly reducing the cycle stability.

[0039] The above-described specific embodiments further illustrate the present invention in detail, but these descriptions cannot be understood as limiting the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a positive electrode material for a lithium-sulfur battery, comprising the following steps: (1) dissolving an aluminum source, a zirconium source, a zinc source and a chelating agent in methanol or ethanol to obtain a precursor solution; (2) dispersing silica nanospheres, benzimidazole and a surfactant in the precursor solution obtained in step (1) to carry out a hydrothermal reaction. After the reaction is completed, the obtained solid is centrifuged and washed, then a hydrogen fluoride solution is added for etching, and finally dried to obtain a precursor; (3) placing the precursor obtained in step (2) and selenium powder in a calcination device, and performing a calcination reaction under an inert gas to obtain a lithium-sulfur battery positive electrode material.

2. The method for preparing a positive electrode material for a lithium-sulfur battery according to claim 1, characterized in that: In the step (1), the aluminum source is one or more of aluminum acetate, aluminum nitrate, aluminum sulfate, and aluminum chloride; the zirconium source is one or more of zirconium acetate, zirconium nitrate, zirconium sulfate, and zirconium chloride; the zinc source is one or more of zinc acetate, zinc nitrate, zinc sulfate, and zinc chloride; and the chelating agent is one of gluconic acid, citric acid, and tartaric acid; the molar concentration of the zinc source in the precursor solution is 0.1 to 1 mol / L, the molar ratio of the sum of the aluminum source and the zirconium source to the zinc source is 1 to 5:100, and the molar ratio of the zinc source to the chelating agent is 5 to 10:

1.

3. The method for preparing a positive electrode material for a lithium-sulfur battery according to claim 1, characterized in that: In the step (2), the surfactant is hexadecyltrimethylammonium bromide or polyvinylpyrrolidone, the mass ratio of silica nanospheres, benzimidazole and surfactant is 5-20:1-5:1; the dispersion time is 1-6 hours; the hydrothermal reaction temperature is 100-180°C, and the reaction time is 6-12 hours; the cleaning agent is one of water, methanol and ethanol; the mass fraction of hydrogen fluoride solution is 40-50wt.%; the drying temperature is 60-120°C, and the drying time is 4-12 hours.

4. The method for preparing a positive electrode material for a lithium-sulfur battery according to claim 1, characterized in that: In the step (3), the mass ratio of the precursor to the selenium powder is 1:1-5, the inert gas is nitrogen or argon, the calcination reaction is controlled at a heating rate of 2-5°C / min, a temperature of 600-1000°C, and a time of 6-15h.

5. A lithium-sulfur battery positive electrode material prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The lithium-sulfur battery positive electrode material is composed of a three-dimensional ordered macroporous structure of aluminum-zirconium dual-doped zinc selenide, the pore size of the three-dimensional ordered macropores is 86-300nm, the aluminum-zirconium elements account for 1.2-4.9% of the metal atomic ratio, and the zinc selenide accounts for 12.4-55.7% of the mass of the lithium-sulfur battery positive electrode material.

6. An application of the positive electrode material for lithium-sulfur batteries as claimed in claim 5, characterized in that: The lithium-sulfur battery positive electrode material is used for the positive electrode of the lithium-sulfur battery.

7. The use of the positive electrode material for lithium-sulfur batteries according to claim 6, characterized in that: The lithium-sulfur battery positive electrode material is used for the positive electrode of a lithium-sulfur battery with high sulfur loading and poor electrolyte.

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