A three-dimensional macroporous carbon doped carbon skeleton loaded zinc telluride modified diaphragm for lithium-sulfur batteries and a preparation method thereof

Abstract

The application discloses a three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified diaphragm for lithium-sulfur batteries and a preparation method thereof. The diaphragm is prepared by the following steps: styrene, polyvinylpyrrolidone and potassium persulfate are added into deionized water, and after reaction and polymerization, the mixture is extracted and filtered into a template; a mixed solution of zinc nitrate, 2-methylimidazole and methanol is poured into the template; methanol and ammonia water are used for inducing crystallization; after removing the template by using tetrahydrofuran, unsaturated tellurization reaction is carried out by annealing with tellurium powder; finally, the product is extracted and filtered onto a lithium-sulfur battery diaphragm to obtain the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified diaphragm. The lithium-sulfur battery diaphragm is modified by using an electrocatalytic material. Due to the three-dimensional ordered macroporous nitrogen-doped carbon skeleton introduced by the template method, the vacancy type zinc telluride obtained by subsequent unsaturated tellurization has higher catalytic capacity, and the synergistic effect of the two can effectively inhibit the shuttle of polysulfides and induce uniform deposition of Li2S, so that the reaction kinetics of the lithium-sulfur battery can be effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium-sulfur batteries, and particularly relates to a three-dimensional macroporous nitrogen-doped carbon framework loaded with zinc telluride modified diaphragm for lithium-sulfur batteries and a preparation method thereof. BACKGROUND

[0002] With the increasing dependence on non-renewable energy, especially fossil fuels, we are facing a series of severe environmental and social challenges, including resource depletion, increased greenhouse gas emissions, and global climate change. It is essential to develop safe, low-cost, high-energy-density, and long charge-discharge cycle life electrical energy storage devices. Lithium-sulfur batteries (LSB) as a promising energy storage device have attracted extensive research due to their excellent theoretical capacity, low cost, and environmental friendliness. However, its commercial application is restricted by a series of key problems, including sluggish reaction kinetics, shuttle effect, electrode structure damage caused by volume expansion, metal lithium corrosion, and safety issues. To address these challenges, the academic community has proposed a variety of innovative strategies, including the development of new sulfur host materials, optimization of electrolytes, metal lithium protection, and diaphragm modification. Among these strategies, diaphragm modification is considered a simple and efficient method, especially coating a layer of active material on the positive side of the commercial polypropylene (PP) diaphragm, which can effectively inhibit the migration of polysulfides (LiPSs).

[0003] Currently, the research of efficient, durable, and economical electrocatalysts has become the key to regulating the kinetics of redox reactions and accelerating the conversion of LiPSs. An ideal sulfur electrocatalyst should exhibit abundant active sites, strong LiPSs adsorption capacity, high conductivity, and excellent catalytic efficiency. Compared with metal oxides and sulfides, metal tellurides have attracted attention in recent years due to their higher conductivity and good electrocatalytic activity. Researchers have studied Co 0.9 Zn 0.1 Metal tellurides such as Te, NiTe2, CoTe2, ZnTe / ZnO, and VTe2 have been used as sulfur hosts or diaphragm modifiers for LSBs. However, due to the need for synthesis at high temperatures and for long periods, the pre-designed structure inevitably aggregates or collapses, and the exposure of active sites is severely reduced. In addition, single-component electrocatalysts cannot simultaneously achieve strong chemical adsorption of LiPSs, rapid ion diffusion, and excellent catalytic conversion. Therefore, the electrochemical performance of metal tellurides still needs to be improved. SUMMARY

[0004] To solve the problem of large pore size of lithium-sulfur battery diaphragm and the inability to capture polysulfides, the application provides a three-dimensional macroporous nitrogen-doped carbon framework loaded with zinc telluride electrocatalyst for lithium-sulfur batteries, which is applied to modify the lithium-sulfur battery diaphragm to obtain 3DOM-ZnTe 1-x@NC-PP, which is based on a commercial lithium-sulfur battery separator. A three-dimensional macroporous nitrogen-doped carbon skeleton loaded with zinc telluride is used to modify the lithium-sulfur battery separator to inhibit the shuttling of polysulfides, while simultaneously catalyzing the polysulfide redox reaction. The three-dimensional structure of the single-metal catalyst carrier skeleton is designed and the active substance ZnTe 1-x is modified, significantly improving the activity sites and catalytic ability of the material. Further, the long cycle stability, rate capability and capacity performance of the lithium-sulfur battery are significantly improved.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0006] A three-dimensional macroporous nitrogen-doped carbon skeleton loaded with zinc telluride modified separator for lithium-sulfur batteries, the preparation method comprising the following steps:

[0007] (1) Add styrene, polyvinylpyrrolidone and potassium persulfate into deionized water, heat and react until a milky white uniform emulsion is obtained, then filter the emulsion into a cake-shaped solid and dry overnight as a template for standby;

[0008] (2) Add a mixed concentrated solution of zinc nitrate hexahydrate and 2-methylimidazole in methanol into the template obtained in step (1) and soak thoroughly, then perform vacuum treatment and finally dry overnight;

[0009] (3) Perform crystallization reaction on the solid obtained in step (2), then use tetrahydrofuran to remove the template, centrifugally wash multiple times, and finally dry the washed product;

[0010] (4) Perform annealing reaction on the dried product of step (3) and a proper amount of tellurium powder in a tube furnace, and after the reaction, naturally cool it to room temperature to obtain the final electrocatalyst product three-dimensional macroporous nitrogen-doped carbon skeleton loaded with zinc telluride (3DOM-ZnTe 1-x @NC);

[0011] (5) Mix the dried product of step (4) with a conductive agent and a binder in an organic solvent, ultrasonically disperse uniformly, then use a lithium-sulfur battery separator as a filter membrane to filter the above mixture, and finally dry and cut to prepare the 3DOM-ZnTe 1-x @NC modified separator (3DOM-ZnTe 1-x @NC-PP).

[0012] Further, in step (1), the amount ratio of styrene, polyvinylpyrrolidone, potassium persulfate and deionized water is (2-20 mL):(0.1-2 g):(0.1-1 g):(50-200 mL).

[0013] Further, the amount ratio of zinc nitrate hexahydrate, 2-methylimidazole and methanol in step (2) is (0.5-5 g):(0.5-5 g):(2-15 mL).

[0014] Further, the solvent used in the crystallization reaction in step (3) is methanol and ammonia water, and the amount ratio of methanol and ammonia water is (10-30 mL):10-30 mL), and the crystallization time is 12-36 hours.

[0015] Further, the temperature of the annealing reaction in step (4) is 500-700 DEG C, and the time is 0.5-5 hours.

[0016] Further, the ratio of the dried product, conductive agent, binder and organic solvent used in step (5) is (1-10 mg):(0.2-1.5 mg):(0.3-3 mg):(3-30 mL).

[0017] Further, the conductive agent is any one of Ketjen black (KB) and Super P, the binder is polyvinylidene fluoride (PVDF), and the organic solvent is N-methyl pyrrolidone (NMP).

[0018] Further, the material of the lithium-sulfur battery diaphragm in step (5) is any one of polypropylene (PP) and polyethylene (PE).

[0019] The significant advantages of the present application are:

[0020] (1) The present application adopts a template method to modify the three-dimensional pore structure of the nitrogen-doped carbon skeleton of the zinc telluride active catalyst, and obtains a vacancy type zinc telluride active material through unsaturated tellurization, because the amount of tellurium powder is small, but the phase can be generated, so that a vacancy type ZnTe can be prepared. 1-x The micron-sized three-dimensional ordered macroporous nitrogen-doped carbon skeleton structure and the vacancy of zinc telluride greatly increase the active sites of the material, which shows stronger adsorption capacity and catalytic capacity.

[0021] (2) The present application uses the zinc telluride loaded by the three-dimensional macroporous nitrogen-doped carbon skeleton to modify the lithium-sulfur battery diaphragm, because it has adsorption and catalytic conversion capacity at the same time, so it can anchor LiPSs on the positive side of the battery, accelerate the conversion process and reduce the accumulation in the battery, and induce the uniform deposition of the final product Li2S.

[0022] (3) Metal tellurides have the advantage of high polarity and higher theoretical conductivity. Furthermore, the large interlayer spacing of metal tellurides can provide more active sites. Vacancy modification further enhances the catalytic ability of the material. Therefore, using metal tellurides to modify the membrane can take advantage of the strong polarity of metal tellurides to form polar covalent bonds with soluble polysulfides, thereby accelerating the reaction process of LiPSs and alleviating the shuttle effect of LiPSs. Attached Figure Description

[0023] Figure 1 3DOM-ZnTe prepared in Example 3 1-x @NC and ZnTe prepared in Comparative Example 1 1-x XRD diffraction pattern of @NC.

[0024] Figure 2 For the general ZnTe prepared in Comparative Example 1 1-x The scanning electron microscope image from @NC shows zinc telluride particles supported within a solid polyhedral nitrogen-doped carbon framework.

[0025] Figure 3 3DOM-ZnTe prepared in Example 3 1-x The scanning electron microscope (SEM) image from @NC shows that zinc telluride particles are uniformly distributed within a nitrogen-doped carbon framework with three-dimensional ordered macropores. Compared to the comparative example, the three-dimensional modified framework exposes more active sites, significantly increasing the specific surface area of ​​the material.

[0026] Figure 4 3DOM-ZnTe prepared in Example 3 1-x @NC-PP, ZnTe 1-x @NC-PP and pure PP membranes at 0.1 mV s -1 Cyclic voltammetry (CV) curves at scan rate. The size of the CV area encapsulated by the three components and the reaction potential directly show that 3DOM-ZnTe... 1-x The electrochemical performance of @NC-PP is better than that of pure PP and ZnTe. 1-x The NC-PP separator showed significant improvement. The cathode was tested using a standard carbon black-loaded sulfur material with a sulfur content of 75 wt.% and an areal loading of 1 mg / cm³. -2 .

[0027] Figure 5 3DOM-ZnTe prepared in Example 3 1-x @NC-PP, ZnTe 1-x Cycling performance curves of NC-PP and pure PP separators at different discharge rates. The discharge specific capacity performance of the three at different rates clearly shows that 3DOM-ZnTe... 1-xThe rate performance of NC-PP is significantly improved.

[0028] Figure 6 3DOM-ZnTe prepared for Example 3 1-x NC-PP, ZnTe 1-x The cycle performance curves of NC-PP and pure PP separators at 1C (1C = 1675 mAh g -1 The discharge specific capacity performance can intuitively show that the electrochemical performance of the three-dimensional macroporous framework loaded with zinc telluride modified separator is significantly improved compared with the pure PP separator.

[0029] Figure 7 3DOM-ZnTe prepared for Example 3 1-x The NC-PP is loaded on the surface of the sulfur active material at 6.5 mg cm -2 The cycle performance curves at 0.1C discharge rate. The discharge specific capacity performance can intuitively show that the electrochemical performance of the three-dimensional macroporous framework loaded with zinc telluride modified separator is significantly improved compared with the commercial lithium ion battery (dashed line part). DETAILED DESCRIPTION

[0030] A three-dimensional macroporous nitrogen-doped carbon framework loaded with zinc telluride modified separator for lithium-sulfur batteries, the preparation method comprising the following steps:

[0031] (1) 2-20 mL of styrene, 0.1-2 g of polyvinylpyrrolidone and 0.1-1 g of potassium persulfate are added to 50-200 mL of deionized water, heated to react at 50-100°C until a milky white uniform emulsion is obtained, then it is filtered into a cake-shaped solid, and dried overnight for standby as a template;

[0032] (2) A 2-15 mL methanol solution containing 0.5-5 g of zinc nitrate hexahydrate and 0.5-5 g of 2-methylimidazole is added to the template obtained in step (1) for soaking, then vacuum treatment at room temperature for 5-30 min, and finally dried at 70°C for 5-12 h;

[0033] (3) The solid obtained in step (2) is subjected to a crystallization reaction, the crystallization reaction uses 10-30 mL of methanol and 10-30 mL of 80wt% ammonia water (v:v = 1:1) as the solvent, the crystallization time is 12-36 hours, then the template is removed by centrifugal washing with tetrahydrofuran several times, and finally the washed product is dried at 70°C for 10 h;

[0034] (4) The dried product of step (3) is mixed with an appropriate amount of tellurium powder (mass ratio of 0.5-3:1), then subjected to an annealing reaction at 500-700°C for 0.5-5 h in a tube furnace, and then naturally cooled to room temperature to obtain the final electrocatalyst product.

[0035] (5) Weigh 1-10 mg of the product dried in step (4), mix with 0.2-1.5 mg of a conductive agent, 0.3-3 mg of a binder, and dissolve in 3-30 mL of an organic solvent, and ultrasonically disperse uniformly, then place the lithium-sulfur battery separator at the bottom of a glass sand core funnel, pour the above mixture into the glass sand core funnel for suction filtration, and then dry at 70°C for 10 h, cut, to prepare a bismuth sulfide modified separator for lithium-sulfur batteries.

[0036] The conductive agent is any one of Ketjen black (KB) and Super P, the binder is polyvinylidene fluoride (PVDF), and the organic solvent is N-methyl pyrrolidone (NMP);

[0037] The lithium-sulfur battery separator is made of any one of polypropylene (PP) and polyethylene (PE).

[0038] In order to make the content of the application more convenient to understand, the technical solutions of the application will be further described below in combination with specific embodiments, but the application is not limited thereto.

[0039] Example 1

[0040] A three-dimensional macroporous framework loaded zinc telluride modified separator for lithium-sulfur batteries, the preparation method comprising the following steps:

[0041] (1) Add 5 mL of styrene, 0.2 g of polyvinylpyrrolidone and 0.15 g of potassium persulfate to 50 mL of deionized water, heat at 60°C until a milky white uniform emulsion is formed, then suction filter into a cake-shaped solid and dry overnight as a template for standby;

[0042] (2) Add a 7 mL methanol solution containing 2 g of zinc nitrate hexahydrate and 2 g of 2-methylimidazole to the template obtained in step (1) and soak thoroughly, then vacuum treat at room temperature for 5 min, and finally dry at 70°C for 5 h;

[0043] (3) Perform a crystallization reaction on the solid obtained in step (2), using 10 mL of methanol and 10 mL of 80wt% ammonia water (v:v=1:1) as the solvent, and crystallizing for 25 hours, then centrifugally wash with tetrahydrofuran to remove the template, and finally dry the washed product at 70°C for 10 h;

[0044] (4) Mix 15 mg of the product dried in step (3) with an appropriate amount of tellurium powder (mass ratio of 0.5:1), then perform an annealing reaction at 550°C in a tube furnace for 1 h, and then naturally cool to room temperature after the reaction to obtain the final electrocatalyst product;

[0045] (5) Take 1.9 mg of the product dried in step (4), mix with 0.3 mg of Ketjen black (KB), 0.2 mg of polyvinylidene fluoride (PVDF) and dissolve in 6 mL of N-methyl pyrrolidone (NMP), ultrasonic dispersion is uniform, then place the lithium-sulfur battery PP separator at the bottom of the glass sand core funnel, pour the above mixture into the glass sand core funnel for suction filtration, then dry at 70°C for 10 h, cut, and thus prepare the zinc telluride modified separator for lithium-sulfur batteries.

[0046] Example 2

[0047] A three-dimensional macroporous framework loaded zinc telluride modified separator for lithium-sulfur batteries, the preparation method comprising the following steps:

[0048] (1) Add 15 mL of styrene, 0.5 g of polyvinylpyrrolidone and 0.5 g of potassium persulfate to 150 mL of deionized water, heat at 85°C until a milky white uniform emulsion is formed, then suction filter into a cake-shaped solid and dry overnight as a template for standby;

[0049] (2) Add a solution containing 3.5 g of zinc nitrate hexahydrate and 5 g of 2-methyl imidazole in 12 mL of methanol to the template obtained in step (1) and soak thoroughly, then vacuum treat at room temperature for 10 min, and finally dry at 70°C for 7 h;

[0050] (3) Perform a crystallization reaction on the solid obtained in step (2), using 15 mL of methanol and 15 mL of 80wt% ammonia water (v:v=1:1) as the solvent, and crystallize for 30 hours, then use tetrahydrofuran to centrifugal wash multiple times to remove the template, and finally dry the washed product at 70°C for 10 h;

[0051] (4) Mix 60 mg of the product dried in step (3) with an appropriate amount of tellurium powder (mass ratio of 1:1), then perform an annealing reaction at 700°C for 2 h in a tube furnace, and then naturally cool to room temperature after the reaction, thus obtaining the final electrocatalyst product;

[0052] (5) Take 1.9 mg of the product dried in step (4), mix with 0.3 mg of Ketjen black (KB), 0.2 mg of polyvinylidene fluoride (PVDF) and dissolve in 6 mL of N-methyl pyrrolidone (NMP), ultrasonic dispersion is uniform, then place the lithium-sulfur battery PP separator at the bottom of the glass sand core funnel, pour the above mixture into the glass sand core funnel for suction filtration, then dry at 70°C for 10 h, cut, and thus prepare the zinc telluride modified separator for lithium-sulfur batteries.

[0053] Example 3

[0054] A three-dimensional macroporous framework loaded with zinc telluride modified diaphragm for lithium-sulfur battery, a preparation method thereof comprises the following steps:

[0055] (1) 20 mL of styrene, 1 g of polyvinylpyrrolidone and 0.5 g of potassium persulfate are added to 200 mL of deionized water, heated at 72°C until a milky white homogeneous emulsion is formed, then it is filtered into a cake and dried overnight as a template for standby;

[0056] (2) A solution containing 3.35 g of zinc nitrate hexahydrate and 3.37 g of 2-methylimidazole in 15 mL of methanol is added to the template obtained in step (1) and soaked, then vacuum treated at room temperature for 30 min, and finally dried at 70°C for 10 h;

[0057] (3) The solid obtained in step (2) is subjected to a crystallization reaction, the crystallization reaction uses 30 mL of methanol and 30 mL of 80wt% ammonia water (v:v=1:1) as the solvent, the crystallization time is 12 hours, then the template is removed by centrifugal washing with tetrahydrofuran several times, and finally the washed product is dried at 70°C for 10 h;

[0058] (4) 100 mg of the dried product obtained in step (3) is mixed with an appropriate amount of tellurium powder (the mass ratio of the two is 1:1), and then annealing reaction is carried out at 700°C for 2 h in a tube furnace, and the final electrocatalyst product is obtained after natural cooling to room temperature;

[0059] (5) 7 mg of the dried product obtained in step (4) is mixed with 1 mg of Ketjen black (KB) and 2 mg of polyvinylidene fluoride (PVDF) and dissolved in 20 mL of N-methylpyrrolidone (NMP), then ultrasonic dispersion is carried out, then a lithium-sulfur battery PP diaphragm is placed at the bottom of a glass sand core funnel, the above mixture is poured into the glass sand core funnel for filtration, and then the lithium-sulfur battery PP diaphragm is dried at 70°C for 10 h and cut to obtain the three-dimensional macroporous framework loaded with zinc telluride modified diaphragm for lithium-sulfur battery.

[0060] Comparative Example 1

[0061] (1) 0.810 g of Zn(NO3)2·6H2O is added to 40 mL of methanol and ultrasonically dissolved as A liquid; 0.526 g of 2-methylimidazole is added to 40 mL of methanol and dissolved as B liquid. Finally, B liquid is quickly poured into A liquid, stirred vigorously for 1 min and then left to stand for 12 h.

[0062] (2) The solvent precipitated powder is collected by centrifugation, washed with ethanol three times and then placed in a room temperature vacuum drying oven for drying for 12 h, and the white powder obtained after drying is ZIF-8.

[0063] (3) Carbonization and tellurization were carried out in the same way as described above in steps (4)-(5) of Example 3, and the filter membrane was extracted. ZnTe with a general bulk structure was obtained 1-x @NC-PP.

[0064] Electrochemical performance test

[0065] Battery assembly: 3DOM-ZnTe 1-x @NC-PP obtained in the example was cut into a disc with a diameter of 18 mm, and a CR2032 button cell was assembled in a glove box using a sulfur positive electrode, a lithium negative electrode, and a lithium-sulfur battery electrolyte (1.0 M LiTFSI, DME / DOL, volume ratio 1:1). Its electrochemical performance was tested by Neware test system.

[0066] The results show that the batteries assembled with 3DOM-ZnTe 1-x @NC-PP obtained in Examples 1, 2, and 3 have capacities of 940, 953, and 962 mAh / g at a current density of 1 C, respectively, and the electrochemical performance of Example 3 is the best.

[0067] The rate performance of the batteries using different separators shows that the 3DOM-ZnTe 1-x @NC-PP battery has average reversible capacities of 1396.6, 1192.2, 1058.9, 961.7, 849.7, 792.2, 728.7, and 699.6 mAh g −1 , respectively, at 0.1, 0.2, 0.5, 1, 2, 3, 4 C, and 5 C, and when the current density returns to 0.2 C, the capacity can recover to 1092.7 mAh g −1 , while the ZnTe 1-x @NC-PP battery has average reversible capacities of 1340.5, 1127.5, 985.2, 885.6, 784.7, 732.4, 650.4, and 580.6 mAh g −1 , respectively, at 0.1, 0.2, 0.5, 1, 2, 3, 4 C, and 5 C, and when the current density returns to 0.2 C, the capacity can recover to 989.8 mAh g −1 . Obviously, the rate performance of the 3DOM-ZnTe 1-x @NC-PP battery is significantly better than that of the ZnTe 1-x @NC-PP battery.

[0068] The 3DOM-ZnTe 1-x @NC-PP battery also exhibits ultra-long cycle performance under high current density conditions. After 900 cycles at a current density of 1 C, the capacity still maintains at 461.1 mAh g −1The capacity attenuation of each circle is only 0.06%.

[0069] The present application introduces metal telluride electrocatalytic materials with adsorption and catalytic conversion capacity for LiPSs, which can slow down the shuttle of LiPSs in electrolyte to the negative electrode and accelerate the deposition conversion process of LiPSs in the positive electrode. Because metal telluride has the advantages of high polarity, higher theoretical conductivity, and the large interlayer spacing of metal telluride can provide more active sites, and the catalytic capacity of the material is further enhanced by vacancy modification, so it has better electrochemical performance than commercial pure PP separator. The three-dimensional structure of the nitrogen-doped carbon skeleton of the active catalyst of zinc telluride is modified by using a template method, which significantly improves the effective contact area of the material with polysulfides. The combination of three-dimensional ordered pore structure and vacancy greatly increases the active sites of the material, which shows stronger adsorption capacity and catalytic capacity.

[0070] The above only describes the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the patent application of the present application shall be included in the scope of the present application.

Claims

1. A method for preparing a three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries, characterized in that, The three-dimensional ordered macroporous nitrogen-doped carbon framework and the vacancy characteristics of the active material zinc telluride greatly enhance the adsorption and catalytic capacity of the material, including the following steps: (1) styrene, polyvinylpyrrolidone, potassium persulfate are added to deionized water, heated to a white uniform emulsion, then filtered into a cake-shaped solid, dried overnight, as a template for standby; (2) a mixed solution of zinc nitrate hexahydrate, 2-methyl imidazole and methanol is added to the template obtained in step (1) for soaking, then vacuum treatment, and finally dried overnight; (3) the solid obtained in step (2) is subjected to a crystallization reaction, then the template is removed using tetrahydrofuran, centrifugal washing is performed multiple times, and finally the washed product is dried; (4) the dried product of step (3) is subjected to an annealing reaction with a proper amount of tellurium powder in a tube furnace, and after the reaction, it is naturally cooled to room temperature to obtain the final electrocatalyst product; (5) the dried product of step (4) is mixed with a conductive agent and a binder and dissolved in an organic solvent, then ultrasonic dispersion is performed, then a lithium-sulfur battery separator is used as a filter membrane for filtration, and finally drying and cutting are performed to obtain a three-dimensional macroporous nitrogen-doped carbon framework loaded with zinc telluride modified separator for lithium-sulfur batteries.

2. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (1), the amount ratio of styrene, polyvinylpyrrolidone, potassium persulfate and deionized water is (2-20 mL):(0.1-2 g):(0.1-1 g):(50-200 mL).

3. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (2), the amount ratio of zinc nitrate hexahydrate, 2-methyl imidazole and methanol is (0.5-5 g):(0.5-5 g):(2-15 mL).

4. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (3), the crystallization reaction uses methanol and ammonia water as solvents, the amount ratio of methanol and ammonia water is (10-30 mL):(10-30 mL), and the crystallization time is 12-36 hours.

5. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (4), the annealing reaction temperature is 500-700℃, and the time is 0.5-5 hours.

6. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (5), the ratio of the dried product, conductive agent, binder and organic solvent is (1-10 mg):(0.2-1.5 mg):(0.3-3 mg):(3-30 mL).

7. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: The conductive agent is any one of Ketjen black and Super P, the binder is polyvinylidene fluoride, and the organic solvent is N-methyl pyrrolidone.

8. The preparation method of the three-dimensional macroporous nitrogen-doped carbon skeleton loaded zinc telluride modified separator for lithium-sulfur batteries according to claim 1, characterized in that: In step (5), the material of the lithium-sulfur battery separator is any one of polypropylene and polyethylene.

9. A three-dimensional macroporous nitrogen-doped carbon framework loaded with zinc telluride modified separator for lithium-sulfur batteries prepared by the method of any one of claims 1-8.

Images