CN114361429B - Preparation method of sulfur positive electrode material and magnesium-sulfur battery assembly method thereof - Google Patents

Abstract

The invention relates to the technical field of energy, in particular to a preparation method of a sulfur positive electrode material and a magnesium-sulfur battery assembly method thereof. The preparation method of the sulfur positive electrode material comprises the steps of preparing a few-layer Ti ₃ C ₂ Suspension, preparation of Nitrogen doped Ti ₃ C ₂ (N‑Ti ₃ C ₂ ) Material, preparation of S- (N-Ti) ₃ C ₂ ) A composite material; the magnesium-sulfur battery assembling method comprises a preparation method of a sulfur positive electrode material, and further comprises the steps of preparing electrolyte and assembling the magnesium-sulfur battery; the assembled magnesium-sulfur battery has excellent electrochemical performance and S- (N-Ti) under the current density of 100mA g < -1 > ₃ C ₂ ) The positive electrode had 689mAh g ^‑1 The initial discharge specific capacity still has 380mAh g after 13 circles ^‑1 Is a specific discharge capacity of (a). Description of Nitrogen doped Ti ₃ C ₂ Is a good sulfur-sink material and can be practically applied to magnesium-sulfur batteries.

Description

Preparation method of sulfur cathode material and assembly method of magnesium-sulfur battery

Technical field

The present invention relates to the field of energy technology, and in particular to a method for preparing a sulfur cathode material and a method for assembling a magnesium-sulfur battery.

Background technique

The growing energy demand has promoted the widespread development of advanced electrical energy storage devices. As an important energy carrier, lithium-ion batteries have been widely used in daily life and modern industry. However, this type of battery is difficult to avoid some safety issues and needs to be prevented from overcharging or over-discharging. In addition, the difficulty in storing lithium resources and the problem of dendrites formed during battery operation hinder the sustainable development of lithium-ion batteries. Therefore, more and more research efforts are turning to the development of other rechargeable metal-ion batteries, including magnesium-ion batteries and magnesium metal batteries. Magnesium batteries are easy to prepare, have thermodynamic stability during charging and discharging, and can overcome various shortcomings of lithium batteries. On the one hand, magnesium is abundant in the earth's crust, and its content is 10,000 times that of lithium. This makes the cost of magnesium electrodes much lower than that of lithium electrodes. On the other hand, metallic magnesium itself has good chemical stability, and the magnesium anode is not affected by it during charging. Problems with SEI film formation. However, the low mobility of magnesium ions in the corresponding cathode materials is a major obstacle to the development of magnesium battery technology, and it also slows down the development of matching anode materials and electrolytes.

Sulfur is an ideal cathode material for magnesium-ion batteries due to its high theoretical volumetric capacity and can be used in magnesium-sulfur batteries. The commercial second-generation magnesium-ion battery electrolyte (APC) has strong nucleophilicity, so it can easily react with sulfur elements and is not suitable for magnesium-sulfur batteries. In order to solve this problem, J. Muldoon applied the non-nucleophilic MgHMDSCl/AlCl ₃ /THF electrolyte to the magnesium-sulfur battery for the first time in 2011. The battery only ran two charge and discharge cycles. Afterwards, the stable Mg(CB11H11) ₂ /tetraglyme electrolyte was applied to magnesium-sulfur batteries, and the electrochemical performance of the battery was improved. Zhao-Karger then used MgHMDS ₂ /AlCl ₃ /THF electrolyte to apply it to magnesium-sulfur batteries. The battery can still maintain 260mA hg ^-1 after 20 cycles. In addition, MgCl ₂ /AlCl ₃ /THF has also been used in magnesium-sulfur batteries, all of which have demonstrated excellent electrochemical activity. The commercial magnesium salt Mg(TFSI) ₂ has high solubility in ether solutions, and its ether solution is also non-nucleophilic, which has the prospect of being used in magnesium-sulfur batteries. Se-Young Ha first successfully applied Mg(TFSI) ₂ /glyme/diglyme electrolyte in magnesium ion batteries. It has relatively strong antioxidant capacity, relatively low viscosity, and allows reversible magnesium deposition/extraction. After that, Wang Chunsheng applied Mg(TFSI) ₂ /MgCl ₂ /DME to magnesium-sulfur batteries. The battery showed excellent electrochemical properties of high specific capacity and long cycle life. They also studied Mg(TFSI) ₂ /I ₂ /Application of DME electrolyte in magnesium-sulfur batteries.

Similar to lithium-sulfur batteries, the sulfur element used in magnesium-sulfur batteries requires a suitable host material, which can make up for the poor conductivity of sulfur element and promote the interconversion of polysulfides produced during the charge and discharge process of magnesium-sulfur batteries. In recent years, two-dimensional transition metal carbon/nitride (MXene) materials have become one of the most popular research topics in the field of electrochemical energy storage due to their excellent conductivity and high volume capacity. MXene is represented by the formula M _n+1 X _n T _x (n=1, 2, 3), where M is an early transition metal element, . Theoretical _calculations show that the typical MXene material _Ti3C2 has a high Mg2 ⁺ ion storage capacity. Min Xu et al. _{proposed a} simple strategy by pre-inserting a common cationic _surfactant cetyltrimethylammonium bromide ( CTAB), so that the layered (d)-Ti ₃ C ₂ T _x electrode has magnesium storage capacity, using APC solvent as the electrolyte, the current density of (d)-Ti ₃ C ₂ T _x /CTAB electrode at 50mA g ^-1 With a high reversible volume specific capacity of 300mAh cm ^-3 , (d)-Ti ₃ C ₂ T _x /CTAB has excellent rate performance and good cycle stability. However, the application of MXene two-dimensional materials in magnesium-sulfur batteries has not been studied.

Therefore, those skilled in the art are committed to developing a preparation method of sulfur cathode materials and a magnesium-sulfur battery assembly method.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to technologically realize the application of Ti ₃ C ₂ materials in magnesium ion batteries with higher quality and volumetric energy density. By realizing the process conditions for synthesizing Ti ₃ C ₂ suspension and further synthesizing N-Ti ₃ C ₂ using liquid-phase electrostatic self-assembly method, the prepared N-Ti ₃ C ₂ has a graphene-like nanosheet micromorphology. , and further melted it with sublimated sulfur to prepare S-(N-Ti ₃ C ₂ ) composite material. The composite material is combined with Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme electrolyte, and the assembled magnesium-sulfur battery has high charge-discharge specific capacity and good cycle performance.

In order to achieve the above object, the present invention provides a preparation method of sulfur cathode material, which includes the following steps:

Step 1. Prepare few-layer Ti ₃ C ₂ suspension:

Add 1, 2, 3g lithium fluoride to 20, 30, 40mL concentrated hydrochloric acid, stir for 5-20 minutes, then add 1g Ti ₃ AlC ₂ , react at 40-80°C for 24-48h; add the reaction product to deionized water and centrifuge Take the precipitate multiple times (4000rpm) until the pH value of the supernatant is close to 6.0, then add 100-200mL deionized water to the precipitate, stir at 0-20°C and _N2 atmosphere for 1-4h; then, after ultrasonic The obtained product is first centrifuged for 10-30min (4000rpm) to remove the substrate precipitate, then an appropriate amount of deionized water is added, and then centrifuged for 5-15min (10000rpm) to remove the substrate precipitate; finally a few-layer Ti ₃ C ₂ suspension (1-4 mg mL ^-1 ), and Ti ₃ C ₂ in the suspension exhibits a nanosheet morphology;

Step 2. Prepare nitrogen-doped Ti ₃ C ₂ (N-Ti ₃ C ₂ ) material:

Disperse 1-3g of melamine into 30mL of absolute ethanol, stir vigorously for 0.5-2h, then add 1-5mL of concentrated hydrochloric acid, continue stirring for 1-3h, and send it to the oven to dry the solvent; then, the obtained white Grind the solid particles into powder, and centrifuge them with water and absolute ethanol several times to obtain melamine powder with a positively charged surface; take 50 mL of few-layer Ti ₃ C ₂ suspension and dissolve it with 100 mg of melamine powder with a positively charged surface in In 50 mL of dilute hydrochloric acid, a large amount of floc appeared in the suspension. The product was centrifuged three times with deionized water (4000 rpm) and the supernatant was removed. The precipitate was freeze-dried and used as a precursor; finally, the precursor was Heating under N ₂ atmosphere for 1-4h (400-700℃) will obtain nitrogen-doped Ti ₃ C ₂ material;

Step 3. Preparation of S-(N-Ti ₃ C ₂ ) composite material:

Fully grind 0.6g of sublimated sulfur and 0.4g of nitrogen-doped Ti ₃ C ₂ for 20 minutes, then place it in a tube furnace and keep it at 155°C for 12 hours under an N ₂ atmosphere. After natural cooling, the sulfur cathode material S-(N-Ti ₃ C ₂ ) composite materials.

Further, the ultrasonic power described in step 1 of the preparation method of sulfur cathode material is 100W. Under this power condition, it can not only ensure that the product is obtained efficiently and quickly, avoid long waiting, reduce costs, but also prevent the breakage of nanosheets in the product.

Further, a method for preparing a sulfur cathode material as claimed in claim 1, characterized in that the stirring method in step 1 and step 2 is manual stirring, mechanical stirring, electromagnetic stirring, vibration stirring, or ultrasonic stirring. Any kind.

Further, the method for preparing a sulfur cathode material according to claim 1, wherein the drying time in step 2 is more than 2 hours. If the drying time is too short, the solvent cannot be fully volatilized, which affects the subsequent reaction efficiency.

Further, the method for preparing a sulfur cathode material according to claim 1, wherein the freeze-drying time in step 2 is more than 2 hours. If the drying time is too short, the solvent cannot be fully volatilized and the product with a specific morphology cannot be obtained, resulting in a reduction in the final experimental efficiency.

Further, the method for preparing sulfur cathode material according to claim 1, wherein the grinding method in step 3 is manual grinding or mechanical grinding.

The invention also relates to a magnesium-sulfur battery assembly method, which includes a preparation method using sulfur cathode materials and the following steps:

Step S1, prepare Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme electrolyte:

Take 292mg Mg(TFSI) ₂ , add 1mL diethylene glycol dimethyl ether, stir for 12h, then add 134mg AlCl ₃ , stir for another 12h, finally add 287mg of LiTFSI, stir for 12h to obtain Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI /diglyme electrolyte;

Step S2. Assemble Mg//Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme//S-(N-Ti ₃ C ₂ ) magnesium sulfur battery:

Take 0.7g of the sulfur cathode material S-(N-Ti ₃ C ₂ ) composite material, 0.2g nano carbon powder, and 0.1g PVDF in a mortar, grind it thoroughly for 20 minutes, add an appropriate amount of N-methylpyrrolidone, and prepare The uniform slurry is then coated on the carbon aluminum foil, baked at 80°C for 8 hours, sliced and placed in the glove box for later use; when assembling the magnesium sulfur secondary battery, place the cut positive electrode slices on the positive electrode shell and cover it. Glass fiber separator, electrolyte is added dropwise, and then covered with magnesium sheets, spring gaskets, spring sheets, and finally the negative electrode shell; the magnesium-sulfur battery is obtained by packaging under a press.

Further, the shape of the magnesium-sulfur battery in step S2 of the magnesium-sulfur battery assembly method is button-shaped.

Further, the press described in step S2 of the magnesium-sulfur battery assembly method is a servo press.

The invention also relates to a magnesium-sulfur battery, including a magnesium-sulfur battery produced using a magnesium-sulfur battery assembly method.

The beneficial effects of the present invention are: efficiently preparing nitrogen-doped Ti ₃ C ₂ (N-Ti ₃ C ₂ ) and S-(N-Ti ₃ C ₂ ) composite materials by etching the typical three-dimensional MAX phase Ti ₃ AlC ₂ The precise preparation of few-layer Ti ₃ C ₂ MXene was obtained, and N-Ti ₃ C ₂ was further synthesized using the liquid phase electrostatic self-assembly method. The prepared N-Ti ₃ C ₂ has a microscopic morphology similar to graphene nanosheets, which is further melted and compounded with sublimated sulfur to prepare an S-(N-Ti ₃ C ₂ ) composite material. The composite material is combined with Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme electrolyte, and the assembled magnesium-sulfur battery has a high charge-discharge specific capacity and good cycle performance, indicating that MXene materials have great potential in the field of magnesium-sulfur batteries. Great application potential and value.

The invention solves the shortcoming of current MXene materials that are rarely used in magnesium-sulfur batteries, and provides the synthesis process of N-Ti ₃ C ₂ and S-(N-Ti ₃ C ₂ ) as well as Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI /diglyme electrolyte preparation method, the magnesium-sulfur battery assembled with this solution has higher charge-discharge specific capacity and better cycle performance.

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, features and effects of the present invention.

Description of drawings

Figure 1 SEM image of Ti ₃ C ₂ suspension droplets after drying on a silicon wafer;

Figure 2 SEM image of Ti ₃ C ₂ suspension after freeze-drying;

Figure 3 XRD pattern of the powder obtained after freeze-drying the Ti ₃ C ₂ suspension;

Figure 4 SEM image of N-Ti ₃ C ₂ powder;

Figure 5 XRD pattern of N-Ti ₃ C ₂ powder;

Figure 6 SEM image of S-(N-Ti ₃ C ₂ );

Figure 7 Cycle performance of magnesium-sulfur battery at 100mA g ^-1 current density;

Figure 8 The charge-discharge voltage-specific capacity curve of the magnesium-sulfur battery in the first three cycles at a current density of 100mA g ^-1 .

Detailed ways

The following describes multiple preferred embodiments of the present invention with reference to the accompanying drawings to make the technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

In the drawings, components with the same structure are denoted by the same numerals, and components with similar structures or functions are denoted by similar numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustrations clearer, the thickness of components is exaggerated in some places in the drawings.

Example 1

The invention provides a method for preparing sulfur cathode materials, which includes the following steps:

Step 1. Prepare few-layer Ti ₃ C ₂ suspension:

Add 1, 2, 3g lithium fluoride to 20, 30, 40mL concentrated hydrochloric acid, stir for 5-20 minutes, then add 1g Ti ₃ AlC ₂ , react at 40-80°C for 24-48h; add the reaction product to deionized water Centrifuge several times (4000rpm) to collect the precipitate until the pH value of the supernatant is close to 6.0. Then add 100-200mL deionized water to the precipitate and stir for 1-4h under 0-20°C and _N2 atmosphere; then, ultrasonic The obtained product is first centrifuged for 10-30min (4000rpm) to remove the substrate precipitate, then an appropriate amount of deionized water is added, and then centrifuged for 5-15min (10000rpm) to remove the substrate precipitate; finally a few-layer Ti ₃ C ₂ suspension (1- 4mg mL ^-1 ), and Ti ₃ C ₂ in the suspension exhibits a nanosheet morphology;

Step 2. Prepare nitrogen-doped Ti ₃ C ₂ (N-Ti ₃ C ₂ ) material:

Disperse 1-3g of melamine into 30mL of absolute ethanol, stir vigorously for 0.5-2h, then add 1-5mL of concentrated hydrochloric acid, continue stirring for 1-3h, and send it to the oven to dry the solvent; then, the obtained white Grind the solid particles into powder, and centrifuge them with water and absolute ethanol several times to obtain melamine powder with a positively charged surface; take 50 mL of few-layer Ti ₃ C ₂ suspension and dissolve it with 100 mg of melamine powder with a positively charged surface in In 50 mL of dilute hydrochloric acid, a large amount of floc appeared in the suspension. The product was centrifuged three times with deionized water (4000 rpm) and the supernatant was removed. The precipitate was freeze-dried and used as a precursor; finally, the precursor was Heating under N ₂ atmosphere for 1-4h (400-700℃) will obtain nitrogen-doped Ti ₃ C ₂ material;

Step 3. Preparation of S-(N-Ti ₃ C ₂ ) composite material:

Fully grind 0.6g of sublimated sulfur and 0.4g of nitrogen-doped Ti ₃ C ₂ for 20 minutes, then place it in a tube furnace and keep it at 155°C for 12 hours under an N ₂ atmosphere. After natural cooling, the sulfur cathode material S-(N-Ti ₃ C ₂ ) composite materials.

The invention also relates to a magnesium-sulfur battery assembly method, which includes a preparation method using sulfur cathode materials and the following steps:

Step S1, prepare Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme electrolyte:

Take 292mg Mg(TFSI) ₂ , add 1mL diethylene glycol dimethyl ether, stir for 12h, then add 134mg AlCl ₃ , stir for another 12h, finally add 287mg of LiTFSI, stir for 12h to obtain Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI /diglyme electrolyte;

Step S2. Assemble Mg//Mg(TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme//S-(N-Ti ₃ C ₂ ) magnesium sulfur battery:

Take 0.7g of the sulfur cathode material S-(N-Ti ₃ C ₂ ) composite material, 0.2g nano carbon powder, and 0.1g PVDF in a mortar, grind it thoroughly for 20 minutes, add an appropriate amount of N-methylpyrrolidone, and prepare The uniform slurry is then coated on the carbon aluminum foil, baked at 80°C for 8 hours, sliced and placed in the glove box for later use; when assembling the magnesium sulfur secondary battery, place the cut positive electrode slices on the positive electrode shell and cover it. Glass fiber separator, electrolyte is added dropwise, and then covered with magnesium sheets, spring gaskets, spring sheets, and finally the negative electrode shell; the magnesium-sulfur battery is obtained by packaging under a press.

The invention also relates to a magnesium-sulfur battery, including a magnesium-sulfur battery produced using a magnesium-sulfur battery assembly method.

After the preparation of Ti ₃ C ₂ , the test results are shown in Figure 1, Figure 2, and Figure 3. Figure 1 shows the SEM image of Ti ₃ C ₂ suspension droplets after drying on a silicon wafer; Figure 2 shows the SEM image of Ti ₃ C ₂ suspension after freeze-drying; Figure 3 shows the SEM image of Ti ₃ C ₂ suspension after freezing The XRD pattern of the powder obtained after drying; Figure 1, Figure 2, and Figure 3 all prove the successful preparation of few layers of Ti ₃ C ₂ .

After the preparation of N-Ti ₃ C ₂ , the test results are shown in Figure 4 and Figure 5. Figure 4 shows the SEM image of N-Ti ₃ C ₂ powder, which shows that after nitrogen doping, the material has a graphene-like nanosheet morphology, showing Fluffy and porous structure; Figure 5 shows the XRD pattern of N-Ti ₃ C ₂ powder, proving that the successful introduction of N element into Ti ₃ C ₂ caused partial changes in the structure. After the preparation of S-(Ti ₃ C ₂ ), the detection results are shown in Figure 6. Figure 6 shows the SEM image of S-(N-Ti ₃ C ₂ ), showing that the Ti ₃ C ₂ nanosheets are loaded with sulfur and the surface becomes rough. .

The assembled magnesium-sulfur battery was placed in a blue battery test instrument for a constant current charge and discharge test. The test results are shown in Figures 7 and 8. Figure 7 shows the cycle performance of the magnesium-sulfur battery at a current density of 100mA g ^-1 ; Figure 8 shows the charge-discharge voltage-specific capacity curve of the magnesium-sulfur battery in the first three cycles at a current density of 100mA g ^-1 . The results in Figure 7 show that the S-(N-Ti3C2) cathode has an initial discharge specific capacity of 689mAh g ^-1 at a current density of 100mA g ^-1 and still has a discharge specific capacity of 380mAh g ^-1 after 13 cycles. The results in Figure 8 show that the magnesium-sulfur battery experienced an electrochemical reaction of polysulfide mutual conversion during the charge and discharge process. This shows that nitrogen-doped Ti3C2 is a good sink sulfur material and can be practically applied to magnesium-sulfur batteries.

The preferred embodiments of the present invention are described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention and on the basis of the prior art should be within the scope of protection determined by the claims.

Claims (10)

1. The preparation method of the sulfur cathode material is characterized by comprising the following steps:

step 1, preparing few-layer Ti ₃ C ₂ Suspension:

adding 1,2,3g lithium fluoride into 20,30,40, mL concentrated hydrochloric acid, stirring for 5-20min, and adding 1g Ti ₃ AlC ₂ Reacting 24-48h at 40-80 ℃; adding deionized water into the reaction product, centrifuging at 4000rpm for several times to obtain precipitate until the pH value of supernatant is close to 6.0, adding 100-200mL deionized water into the precipitate, and adding N at 0-20deg.C ₂ Stirring for 1-4h under the atmosphere; then, centrifuging the product obtained after ultrasonic treatment at 4000rpm for 10-30min to remove substrate precipitate, adding a proper amount of deionized water, and centrifuging at 10000rpm for 5-15min to remove substrate precipitate; finally, a few layers of 1-4mg mL are obtained ^-1 Ti ₃ C ₂ Suspension, and Ti in suspension ₃ C ₂ Presenting a nano sheet shape;

step 2, preparing nitrogen doped Ti ₃ C ₂ Material N-Ti ₃ C ₂ ：

Dispersing 1-3g melamine into 30mL absolute ethyl alcohol, vigorously stirring for 0.5-2h, then adding 1-5mL concentrated hydrochloric acid, continuously stirring for 1-3h, and sending into an oven to dry the solvent; grinding the obtained white solid particles into powder, and centrifugally washing for many times by using water and absolute ethyl alcohol to obtain melamine powder with positive polarity on the surface; taking 50mL few layers of Ti ₃ C ₂ The suspension and melamine powder with the surface of 100mg being electropositive are dissolved in dilute hydrochloric acid of 50mL together, a large amount of floccules appear in the suspension, the product is centrifuged for 3 times at 4000rpm with deionized water, the supernatant is removed, and the precipitate is freeze-dried to be used as a precursor; finally, the precursor is at N ₂ Heating at 400-700 deg.c for 1-4 hr to obtain nitrogen doped Ti ₃ C ₂ A material;

step 3, preparing S- (N-Ti) ₃ C ₂ ) Composite material:

sublimating sulfur 0.6g and doping Ti with nitrogen 0.4g ₃ C ₂ Grinding for 20min, placing in a tube furnace, and adding N ₂ Preserving heat at 155 ℃ under atmosphere for 12h, and naturally cooling to obtain S- (N-Ti) sulfur anode material ₃ C ₂ ) A composite material.

2. The method for preparing a sulfur cathode material as claimed in claim 1, wherein the ultrasonic power in the step 1 is 100W.

3. The method for preparing a sulfur cathode material according to claim 1, wherein the stirring in step 1 and step 2 is performed by any one of manual stirring, mechanical stirring, electromagnetic stirring, vibration stirring and ultrasonic stirring.

4. The method for producing a sulfur cathode material as defined in claim 1, wherein said drying time in step 2 is 2 hours or more.

5. The method for producing a sulfur cathode material according to claim 1, wherein the time for freeze-drying in step 2 is 2 hours or longer.

6. The method for producing a sulfur cathode material as claimed in claim 1, wherein the grinding in step 3 is manual grinding or mechanical grinding.

7. A method for assembling a magnesium-sulfur battery, comprising the steps of:

step S1, preparation of Mg (TFSI) ₂ /2AlCl ₃ 2LiTFSI/diglyme electrolyte:

292Mg Mg (TFSI) ₂ 1mL of diethylene glycol dimethyl ether was added, stirred 12h, and 134mg of AlCl was added ₃ Stirring 12 to h, adding 287 to Mg LiTFSI, and stirring 12 to h to obtain Mg (TFSI) ₂ /2AlCl ₃ 2LiTFSI/diglyme electrolyte;

step S2, assembling Mg// Mg (TFSI) ₂ /2AlCl ₃ /2LiTFSI/diglyme//S-(N-Ti ₃ C ₂ ) Magnesium-sulfur battery:

taking 0.7 of g of S- (N-Ti) sulfur anode material ₃ C ₂ ) Composite material, 0.2. 0.2g nmGrinding rice carbon powder and 0.1g PVDF in a mortar for 20min, adding proper amount of N-methyl pyrrolidone to prepare uniform slurry, coating the slurry on carbon aluminum foil, baking the slurry at 80 ℃ for 8h, slicing the slurry and placing the sliced slurry in a glove box for later use; when the magnesium-sulfur secondary battery is assembled, the cut positive plate is placed on the positive plate shell, the glass fiber diaphragm is covered, the electrolyte is dripped, then the magnesium plate, the spring gasket and the spring piece are covered, and finally the negative plate shell is covered; and packaging under a press to obtain the magnesium-sulfur battery.

8. The method of assembling a magnesium sulfur battery according to claim 7, wherein the shape of the magnesium sulfur battery in step S2 is button-shaped.

9. The method of assembling a magnesium sulfur battery according to claim 7, wherein the press in step S2 is a servo press.

10. A magnesium-sulfur battery fabricated by the method of assembling a magnesium-sulfur battery according to claim 7.