CN106910883B - Preparation method of lithium-sulfur battery - Google Patents

Preparation method of lithium-sulfur battery Download PDF

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CN106910883B
CN106910883B CN201710256001.6A CN201710256001A CN106910883B CN 106910883 B CN106910883 B CN 106910883B CN 201710256001 A CN201710256001 A CN 201710256001A CN 106910883 B CN106910883 B CN 106910883B
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lithium
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sulfur
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CN106910883A (en
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洪泽平
姜小芳
其他发明人请求不公开姓名
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Shenzhen Guanghe Precision Equipment Co ltd
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    • H01M10/05—Accumulators with non-aqueous electrolyte
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    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
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    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
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    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract

The invention relates to a preparation method of a lithium-sulfur battery, wherein a negative electrode material comprises the following raw material compositions in parts by mass: 5-10 parts of stable lithium powder, 3-7 parts of carbon material, 1 part of binder and solvent. The invention particularly selects stable lithium powder, carbon nanospheres, carbon nanotubes and mesoporous carbon according to the mass ratio of 5: 2:1 as the carbon material in the negative electrode to prepare the negative electrode mixed slurry, so that the negative electrode material of the lithium-sulfur battery has more excellent performance.

Description

Preparation method of lithium-sulfur battery
Technical Field
The invention belongs to the field of electrode material preparation, and particularly relates to a lithium-sulfur battery electrode material and a method for preparing a lithium-sulfur battery by using the same.
Background
Lithium-ion batteries (LIBs), also known as Lithium secondary batteries, are a kind of mobile power devices that can be recharged cyclically. LIB has many advantages such as high energy density, high power density, long cycle life, cleanness, no toxicity and no memory effect, and has been rapidly and widely developed since the commercialization of LIB by sony corporation in the last 90 th century. LIBs have become the power source for most mobile electronic devices today. In recent years, LIB has been intensively and extensively studied. In the LIB, the negative electrode material has a great influence on the performance of the battery, and the development of an excellent negative electrode material is also one of the key factors for improving the performance of the LIB. The carbon material is the most important LIB cathode material, and at present, hundreds of carbon materials with different structures are used as the cathodes of lithium ion batteries, and the materials comprise natural graphite, artificial graphite, coke, carbon fiber, mesocarbon microbeads, carbon black and the like.
The elemental sulfur is non-toxic, the global reserves are abundant, and the theoretical specific capacity (1675 mAh/g) is higher. The lithium metal has low density (0.534 g/cm 3), low potential (-3.045 v) and high specific capacity (3861 mAh/g), so that the lithium-sulfur battery can achieve higher energy density, and can play an important role in the aspects of energy storage, renewable energy utilization and the like. However, there are many problems in the commercialization of lithium-sulfur batteries, such as unstable chemical properties of lithium metal and potential danger in use; when the negative electrode adopts the metal lithium foil, dendritic crystals are easily formed on the surface of the metal lithium foil after the battery is charged and discharged for many times. The continued growth of dendrites results in a decrease in battery capacity, and dendrite growth may puncture the separator, causing a short circuit in the battery, causing safety problems.
Hard carbon is pyrolytic carbon of a high molecular polymer and is difficult to graphitize even at high temperatures. The reversible capacity of hard carbon is high and the cycle performance is good. However, hard carbon also has the disadvantages of excessively high electrode potential, potential hysteresis (i.e., the lithium intercalation potential is smaller than the lithium deintercalation potential), large first cycle irreversible capacity, and the like.
currently, most lithium sulfur batteries employ metallic lithium as the negative electrode. Lithium as a negative electrode causes dendrite formation due to ten current density variations during multiple charging and discharging. Branches can cause the penetration of the diaphragm, so that the short circuit of the battery occurs, and the main source of potential safety hazard is obtained. If the graphene is added into the negative electrode, the specific surface area of the negative electrode is increased, the surface current density is reduced, and meanwhile, the loose graphene provides a lithium deposition space, so that the growth of lithium branches is more and more difficult. And aiming at the problems of the lithium negative electrode, the improvement and research performed by researchers are less. The summary mainly includes two aspects: firstly, the electrolyte additive is modified, and different additives such as LiNO3, PEO and the like are added to promote the surface of the lithium negative electrode to rapidly form a more stable SEI film in the charging and discharging processes, so that the lithium dendrite can be inhibited and the cycle performance can be improved. However, the additives are gradually consumed during charge and discharge, affecting the stability and continuity of the battery. And starting from the preparation process of the lithium electrode, the cycle efficiency and the cycle life are improved by using methods of coating lithium powder or electrodepositing metallic lithium by a lithium compound, increasing a protective layer on the surface of a lithium foil and the like, but the operation process is also complicated.
disclosure of Invention
in order to solve the problems in the prior art, the invention aims to provide a negative electrode slurry prepared from stable lithium powder and a carbon material with a special proportion, and a lithium-sulfur battery prepared from the slurry, which solve the technical defects caused by adopting hard carbon and other materials in the prior art, and solve the technical problems of poor stability and continuity, complex operation and the like in the improvement of a negative electrode of a lithium battery.
A lithium sulfur battery comprising a positive electrode and a negative electrode, characterized in that: the cathode comprises the following raw material compositions in parts by mass: 5-10 parts of stable lithium powder, 3-7 parts of carbon material, 1 part of binder and solvent; the binder is formed by mixing polyvinylpyrrolidone and polyethyleneimine according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1; the anode comprises the following materials: the positive electrode slurry includes: 9 parts of sublimed sulfur, 7 parts of conductive agent, 1 part of binder and solvent; the conductive agent is formed by combining carbon nanofibers and expanded graphite according to the mass ratio of 1:1, and the polyvinylpyrrolidone and the polyethyleneimine in the binder are mixed according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1;
a method of making a lithium sulfur battery comprising the steps of:
step 1, preparing a positive plate: taking a mixture formed by combining sublimed sulfur serving as a positive active material, nano carbon fibers and expanded graphite according to the mass ratio of 1:1 as a conductive agent, and a mixture system formed by mixing polyvinylpyrrolidone and polyethyleneimine according to the volume ratio of 2:1 as a mixture binder; the mass ratio of a conductive agent formed by combining sublimed sulfur, nano carbon fibers and expanded graphite in the sulfur-containing anode slurry according to the mass ratio of 1:1 to the binder is 9:7: 1; dissolving the mixed binder in a mixed solvent formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2:1 to prepare a solution, wherein the solvent is weighed according to the mass ratio of 30% of solid content, and the solid is sublimed sulfur, nano carbon fiber and expanded graphite; uniformly mixing the sublimed sulfur with a conductive agent formed by combining the carbon nanofibers and the expanded graphite according to the mass ratio of 1:1, and pouring the mixture into a solvent in which a binder is dissolved to prepare positive slurry;
Then uniformly coating the obtained slurry on a foamed nickel current collector; drying in a vacuum drying oven at 50 deg.C for 10-15 hr to remove solvent and water; scraping the slurry on the surface of the foamed nickel by using a blade, flattening the positive plate, and then placing the positive plate in a vacuum drying box for drying again;
Step 2, preparing the negative plate: weighing a mixed system binder formed by mixing stable lithium powder, a carbon material, polyvinylpyrrolidone and polyethyleneimine according to a volume ratio of 2:1, and taking a mixture formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to a volume ratio of 3:2:1 as a solvent, wherein the solvent is weighed according to a mass ratio of 30% of solid content, and the solid is the stable lithium powder and the carbon material; firstly, dissolving a binder in a solvent, then pouring stable lithium powder and a carbon material into the solution, uniformly mixing, and then coating the mixture on a foamed nickel current collector to obtain a negative plate; placing the negative plate on a heating plate, heating to volatilize the solvent, and flattening the negative plate; wherein the mass ratio of the stable lithium powder, the carbon material and the binder is 5-10: 3-7: 1; the heating temperature on the heating sheet is 70 ℃, and the heating time is 8-15 h;
Step 3, assembling the battery: and (3) assembling the positive plate prepared in the step (1) and the negative plate prepared in the step (2) into the lithium-sulfur battery.
A negative electrode material for a lithium-sulfur battery, comprising: the composition consists of the following raw material compositions in parts by mass: 5-10 parts of stable lithium powder, 3-7 parts of carbon material, 1 part of binder and solvent.
Further, the steady-state lithium powder is prepared by a Dropping Emulsification Technology (DET), and the diameter of the lithium powder is 60-90 μm.
further, the carbon material is carbon nanospheres, carbon nanotubes and mesoporous carbon according to a mass ratio of 5: 2:1, and mixing the components.
Further, the binder is formed by mixing polyvinylpyrrolidone and polyethyleneimine according to a volume ratio of 2: 1; the solvent is a mixed solvent formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1.
A preparation method of a lithium-sulfur battery adopts the cathode material as a cathode and is characterized by comprising the following steps:
(1) Coating sulfur-containing positive electrode slurry on a current collector to prepare a positive electrode plate;
(2) Weighing stable lithium powder, a carbon material and a binder according to a mass ratio, and taking a mixture of Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) in a volume ratio of 3:2:1 as a solvent; dissolving the binder in the solvent, then pouring the stable lithium powder and the carbon material into the solution, uniformly mixing, and then coating the mixture in the foamed nickel to obtain a negative plate; placing the negative plate on a heating plate and heating to volatilize the solvent; then flattening the negative plate for later use;
(3) And assembling the positive electrode, the negative electrode and the diaphragm into the button cell.
Further, the sulfur-containing cathode slurry in step (1) comprises: sublimed sulfur, a conductive agent, a binder and a solvent; the conductive agent is formed by combining carbon nanofibers and expanded graphite according to the mass ratio of 1:1, and the polyvinylpyrrolidone and the polyethyleneimine in the binder are mixed according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1; firstly, dissolving a binder in a mixed solvent, then uniformly mixing sublimed sulfur and a conductive agent according to a mass ratio, pouring the mixture into the solvent in which the binder is dissolved to prepare anode slurry, and then uniformly coating the anode slurry on a current collector to prepare an anode plate.
further, the positive plate needs to be heated in a vacuum drying oven to remove moisture and solvent, and then the surface of the positive plate is scraped, flattened and flattened; the temperature in the vacuum drying oven is 50 ℃, and the drying time is 10 hours.
Further, the mass ratio of the sublimed sulfur, the conductive agent and the binder in the sulfur-containing cathode slurry is 9:7: 1.
Further, in the step (2), the negative plate needs to be heated at 40-70 ℃ for 8-11 h to remove the solvent, and then is pressed flat for standby.
Further, the operations in steps (2) and (3) are all completed in a vacuum glove box filled with argon.
the lithium-sulfur battery cathode material and the lithium-sulfur battery prepared by the invention have the following beneficial effects:
(1) Compared with the common lithium foil electrode, the cathode made of the stable lithium powder and the carbon material with the specific proportion has larger specific surface area, higher porosity and more complete contact with the electrolyte, so that the lithium-sulfur battery cathode material has larger effective discharge area and smaller impedance, can effectively inhibit the growth of lithium dendrites, and can show better cycle performance and rate performance.
(2) The lithium-sulfur battery cathode material prepared by the invention adopts carbon nanosphere materials, the carbon nanospheres have unique morphology structures and have unique advantages in electrochemical performance: a. the spherical shape can realize the closest packing, so that the lithium ion battery has higher volume energy density; b. the spherical graphite lamellar structure enables Li < + > to be inserted and extracted from all directions of the sphere, and the problems of graphite lamellar swelling, collapse and incapability of quick charge and discharge caused by overhigh anisotropy of graphite are solved; c. the spherical particles are more convenient to process the electrode. The structure advantages of the carbon nano tube and the mesoporous carbon are fully combined, and the highly ordered mesoporous carbon has the characteristics of large specific surface area, uniform pore diameter, very high pore volume, interrelated porous structure, high conductivity and the like; the carbon nano tube has good orientation, can form good contact with a current collector and form a high-efficiency oriented conductive framework, effectively improves the conductivity of the framework in the electrode material of the lithium-sulfur battery, and the regular pore passage in the carbon nano tube is favorable for storing polysulfide. The invention fully utilizes the advantages of the three structures, can effectively weaken shuttle effect and dendritic crystal growth in the continuous charging and discharging process, and has better cycle performance and rate capability compared with the conventional electrode.
(3) In the aspect of the conductive additive of the positive electrode, the nano carbon fiber and the expanded graphite are added, the nano carbon fiber and the expanded graphite can form a three-dimensional conductive network, the long-distance conductive capability in the pole piece can be improved, the nano carbon fiber and the expanded graphite are not easily and completely covered by a product formed in the discharge process, and therefore the surface structure of the pole piece is improved, and the expanded graphite can improve the utilization rate and the cycle performance of elemental sulfur by utilizing the rich network gap structure and the good adsorption performance of the expanded graphite.
(4) the invention also particularly selects a mixed system of polyvinylpyrrolidone and polyethyleneimine as a binder, thereby keeping the porous structure of the sulfur anode in the circulating process forcefully.
(5) According to the invention, a mixed system of three substances is selected as a solvent, and through experiments, the solvent can better maintain the structural characteristics and advantages of the raw materials of various pole pieces, so that the finally prepared product has better stability and higher quality.
Detailed Description
The first embodiment is as follows:
A lithium sulfur battery and a preparation method thereof are as follows:
1. Preparing a positive plate: the mixture of sublimed sulfur as a positive active material, nano carbon fibers and expanded graphite in a mass ratio of 1:1 is used as a conductive agent, and the mixture of polyvinylpyrrolidone and polyethyleneimine in a volume ratio of 2:1 is used as a binder.
the mass ratio of the conductive agent and the binder, which are formed by combining the sublimed sulfur, the carbon nanofibers and the expanded graphite in the sulfur-containing cathode slurry according to the mass ratio of 1:1, is 9:7: 1. Dissolving the mixed binder in a mixed solvent formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2:1 to prepare a solution, wherein the solvent is weighed according to the proportion of 30 percent of solid content by mass. And then uniformly mixing the sublimed sulfur with a conductive agent formed by combining the carbon nanofibers and the expanded graphite according to the mass ratio of 1:1, and pouring the mixture into a solvent in which the binder is dissolved to prepare the anode slurry.
and then uniformly coating the obtained slurry on a foamed nickel current collector. And then placing the nickel foam into a vacuum drying oven for drying, removing the solvent and moisture, wherein the temperature in the vacuum drying oven is 50 ℃, the drying time is 10 hours, scraping the slurry on the surface of the nickel foam by using a blade, and flattening the positive plate at a certain pressure. And then the positive plate is placed in a vacuum drying box for drying again. The above operations are all completed in a vacuum glove box.
2. Preparing a negative plate: weighing a mixed system binder formed by mixing stable lithium powder, a carbon material, polyvinylpyrrolidone and polyethyleneimine according to a volume ratio of 2:1 according to a mass ratio, and taking a mixture formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to a volume ratio of 3:2:1 as a solvent, wherein the solvent is weighed according to a solid content of 30% by mass.
Firstly, dissolving a binder in a solvent, then pouring stable lithium powder and a carbon material into the solution, uniformly mixing, and then coating the mixture on a foamed nickel current collector to obtain a negative plate; placing the negative plate on a heating plate and heating to volatilize the solvent; then flattening the negative plate for later use; wherein the mass ratio of the stable lithium powder to the carbon material to the binder is 10:7: 1; the heating temperature on the heating plate is 70 ℃, and the heating time is 8 h. The above operations are all completed in a vacuum glove box.
3. assembling the battery: and assembling the positive plate and the negative plate into a battery.
Assembling and testing the battery: the button cell was assembled in a glove box filled with argon. The negative plate is used as a negative electrode, and a Celgard2400 diaphragm and a 2025 button cell are adopted. The electrolyte is 1MLiClO4, 0.15MLiNO3 dissolved in DOL: DME (volume ratio 1: 1). The cell was placed in a blue test system (CT 2001A) for constant current testing. The charging and discharging voltage range is 1.5-3.0V, and the testing temperature is room temperature.
example two:
Compared with the first embodiment, in the second embodiment, in the preparation process of the negative electrode plate, the mass ratio of the stable lithium powder, the carbon material and the binder is changed to be 7: 4: 1, the heating temperature on the heating plate is 40 ℃, and the heating time is 11 h. The rest of the operation and the description are the same as the first embodiment.
Example three:
Compared with the first embodiment, in the second embodiment, in the preparation process of the negative electrode plate, the mass ratio of the stable lithium powder, the carbon material and the binder is changed to be 5: 5: 1, the heating temperature on the heating plate is 60 ℃, and the heating time is 9 h. The rest of the operation and the description are the same as the first embodiment.
Compared with the common lithium foil electrode, when the stable-state lithium powder and the mixed carbon material are used in the negative electrodes of the first, second and third embodiments, the lithium-sulfur battery can show better first charge-discharge specific capacity, and the capacity retention rate is over 95.2% after 100 cycles.
The button cells of the examples were left to stand for 24 hours before comparative experiments on the AC impedance were carried out. Experimental results show that when the stable lithium powder and the mixed carbon material are used in examples one, two and three, the impedance of the lithium-sulfur battery of the present invention is greatly reduced compared to a conventional lithium foil electrode because the stable lithium powder has a large specific surface area and is completely in contact with an electrolyte, and thus, faster electron transfer and transfer can be exhibited.
Meanwhile, the lithium-sulfur battery cathode material prepared by the invention adopts carbon nanosphere materials, and the carbon nanospheres have unique morphology structures and have unique advantages in electrochemical performance: (a) the spherical shape can realize the closest packing, so that the lithium ion battery has higher volume energy density; (b) the spherical graphite lamellar structure enables Li < + > to be inserted and extracted from all directions of the sphere, and the problems of graphite lamellar swelling, collapse and incapability of quick charge and discharge caused by overhigh anisotropy of graphite are solved; (c) the spherical particles are more convenient to process the electrode.
furthermore, the invention fully combines the structural advantages of the carbon nano tube and the mesoporous carbon, and the highly ordered mesoporous carbon has the characteristics of large specific surface, uniform aperture, very high pore volume, interrelated porous structure, high conductivity and the like; the carbon nano tube has good orientation, can form good contact with a current collector and form a high-efficiency oriented conductive framework, effectively improves the conductivity of the framework in the electrode material of the lithium-sulfur battery, and the regular pore passage in the carbon nano tube is favorable for storing polysulfide. The invention fully utilizes the advantages of the three structures, can effectively weaken shuttle effect and dendritic crystal growth in the continuous charging and discharging process, and has better cycle performance and rate capability compared with the conventional electrode.
Comparative charge and discharge experiments were performed at different rates when using the electrodes of the respective examples and a common lithium foil electrode. Experimental results show that lithium sulfur batteries can exhibit higher specific capacities at different rates when the electrode of the present invention is used. Particularly, under the condition of high current density, the specific capacity of the lithium-sulfur battery prepared by adopting the stable-state lithium powder and the mixed carbon material is obviously improved compared with that of the common lithium foil electrode battery.
In the aspect of a conductive additive of a positive electrode, nano carbon fiber and expanded graphite are added, the nano carbon fiber and the expanded graphite can form a three-dimensional conductive network, the long-distance conductive capability in a pole piece can be improved, the nano carbon fiber and the expanded graphite are not easily and completely covered by a product formed in a discharge allowing process, the surface structure of the pole piece is improved, and the expanded graphite can improve the utilization rate and the cycle performance of elemental sulfur by utilizing the rich network gap structure and the good adsorption performance of the expanded graphite.
The invention also particularly selects a mixed system of polyvinylpyrrolidone and polyethyleneimine as a binder, thereby keeping the porous structure of the sulfur anode in the circulating process forcefully. According to the invention, a mixed system of three substances is selected as a solvent, and through experiments, the solvent can better maintain the structural characteristics and advantages of the raw materials of various pole pieces, so that the finally prepared product has better stability and higher quality.
The foregoing embodiments illustrate and describe the general principles, principal features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited by the embodiments described above, which are given by way of illustration of the principles of the invention and are not to be taken as limiting the scope of the invention in any way, and that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims (7)

1. a preparation method of a lithium-sulfur battery comprises a positive electrode and a negative electrode, and is characterized in that: the cathode comprises the following raw material compositions in parts by mass: 5-10 parts of stable lithium powder, 3-7 parts of carbon material, 1 part of binder and solvent; the binder is formed by mixing polyvinylpyrrolidone and polyethyleneimine according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1; the anode comprises the following materials: the positive electrode slurry includes: 9 parts of sublimed sulfur, 7 parts of conductive agent, 1 part of binder and solvent; the conductive agent is formed by combining carbon nanofibers and expanded graphite according to the mass ratio of 1:1, and the polyvinylpyrrolidone and the polyethyleneimine in the binder are mixed according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1;
The carbon material is carbon nanospheres, carbon nanotubes and mesoporous carbon according to a mass ratio of 5: 2:1, and mixing the components.
2. A method of making a lithium sulfur battery, comprising: the method comprises the following steps:
(1) Coating sulfur-containing positive electrode slurry on a current collector to prepare a positive electrode plate;
(2) Weighing stable lithium powder, a carbon material and a binder according to a mass ratio, and taking a mixture of Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) in a volume ratio of 3:2:1 as a solvent; dissolving the binder in the solvent, then pouring the stable lithium powder and the carbon material into the solvent, uniformly mixing, and then coating the mixture in the foamed nickel to obtain a negative plate; placing the negative plate on a heating plate and heating to volatilize the solvent; then flattening the negative plate for later use;
(3) Assembling the positive electrode, the negative electrode and the diaphragm into a button cell;
The carbon material is carbon nanospheres, carbon nanotubes and mesoporous carbon according to a mass ratio of 5: 2:1, and mixing the components.
3. the method of manufacturing a lithium sulfur battery according to claim 2, characterized in that: the sulfur-containing cathode slurry in the step (1) comprises: sublimed sulfur, a conductive agent, a binder and a solvent; the conductive agent is formed by combining carbon nanofibers and expanded graphite according to the mass ratio of 1:1, and the polyvinylpyrrolidone and the polyethyleneimine in the binder are mixed according to the volume ratio of 2: 1; the solvent is formed by mixing Propylene Carbonate (PC), Ethyl Methyl Carbonate (EMC) and polyether sulfone (PES) according to the volume ratio of 3:2: 1; firstly, dissolving a binder in a mixed solvent, then uniformly mixing sublimed sulfur and a conductive agent according to a mass ratio, pouring the mixture into the solvent in which the binder is dissolved to prepare anode slurry, and then uniformly coating the anode slurry on a current collector to prepare an anode plate.
4. The method of manufacturing a lithium sulfur battery according to claim 2, characterized in that: heating the positive plate in a vacuum drying box to remove moisture and solvent, and then flattening and flattening the surface of the positive plate; the temperature in the vacuum drying oven is 50 ℃, and the drying time is 10 hours.
5. the method of manufacturing a lithium sulfur battery according to claim 2, characterized in that: the mass ratio of the sublimed sulfur to the conductive agent to the binder in the sulfur-containing cathode slurry is 9:7: 1.
6. The method of manufacturing a lithium sulfur battery according to claim 2, characterized in that: in the step (2), the negative plate is heated at 40-70 ℃ for 8-11 h to remove the solvent, and then is pressed flatly for standby.
7. The method of manufacturing a lithium sulfur battery according to claim 2, characterized in that: and (3) finishing the operations in the steps (2) and (3) in a vacuum glove box filled with argon.
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