CN111900403A - Sulfur/MXene/graphene composite material and preparation method and application thereof - Google Patents

Sulfur/MXene/graphene composite material and preparation method and application thereof Download PDF

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CN111900403A
CN111900403A CN202010753797.8A CN202010753797A CN111900403A CN 111900403 A CN111900403 A CN 111900403A CN 202010753797 A CN202010753797 A CN 202010753797A CN 111900403 A CN111900403 A CN 111900403A
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mxene
sulfur
composite material
graphene composite
graphene
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CN111900403B (en
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黄国家
李悦
尹香槟
杨波
李茂东
文芳
黎佩珊
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Guangzhou Special Pressure Equipment Inspection and Research Institute
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention relates to a sulfur/MXene/graphene composite material and a preparation method and application thereof, wherein the composite material is prepared from elemental sulfur, MXene and graphene, and the mass ratio of the elemental sulfur to the MXene to the graphene is 4-17: 1-6: 1. The preparation method of the sulfur/MXene/graphene composite material comprises the following steps: and mixing and grinding the elemental sulfur, MXene and graphene, and preparing the material by a vacuum melting diffusion method. The sulfur/MXene/graphene composite material is high in sulfur carrying capacity and good in conductivity, can improve the conductivity of the positive electrode material and the utilization rate of active substance sulfur by using the sulfur/MXene/graphene composite material as the positive electrode material of the lithium-sulfur battery, can adsorb intermediate polysulfide generated in the reaction process, can avoid shuttle effect caused by dissolution of the intermediate polysulfide, and can further improve the specific energy and coulombic efficiency of the lithium-sulfur battery.

Description

Sulfur/MXene/graphene composite material and preparation method and application thereof
Technical Field
The invention relates to the field of materials, in particular to a sulfur/MXene/graphene composite material and a preparation method and application thereof.
Background
With the continuous improvement of energy demand of people, the development of new energy storage systems is more and more important. Compared with a lithium ion battery with good performance, the lithium-sulfur battery taking metal lithium as a negative electrode and elemental sulfur as a positive electrode has obvious advantages, and the theoretical specific energy of the lithium-sulfur battery is high and can reach 2600Wh/kg (the theoretical specific capacities of lithium and sulfur are 3860mAh/g and 1675mAh/g respectively). In addition, the lithium-sulfur battery has the advantages of abundant raw material reserves, low cost, environmental friendliness and the like, so the lithium-sulfur battery is concerned by researchers and is considered to be one of the most potential research directions in an energy storage system capable of replacing a lithium-ion battery.
However, the development of the lithium-sulfur battery encounters a bottleneck and faces some technical difficulties, for example, the utilization rate of elemental sulfur of the cathode material cannot be increased due to poor fixation, so that the effective active material is reduced, the conductivity of the elemental sulfur at room temperature is poor, and furthermore, an intermediate state material in the reaction process is easily dissolved, so that a shuttle-threading effect is caused, and the like, and these factors cause that the actual specific energy (specific capacity) of the lithium-sulfur battery is not high and is far lower than the theoretical specific energy.
Through the development of the lithium-sulfur battery for many years, solutions have been developed for solving the technical barriers, for example, for solving the problem of low utilization rate of active materials of the positive electrode material of the lithium-sulfur battery, the current solution is to seek a carbon assembly with high specific surface area for compounding, or to adopt a continuous carbon coating and solution phase oxidation reaction method, and then to perform high-temperature calcination. The method has the advantages of complex flow, high energy consumption and high requirement on equipment. In another mode, porous carbon is used as a base material for compounding, and the good conductivity of the carbon-based material is utilized to improve the conductivity of the cathode material, but the capacity of adsorbing elemental sulfur by the method still cannot meet the requirement.
Therefore, at present, no effective solution exists for the problems of low actual specific energy caused by poor conductivity of the lithium-sulfur battery cathode material, easy dissolution of intermediate polysulfide, low utilization rate of active substance sulfur, and the like.
Disclosure of Invention
Based on the above, the invention provides a sulfur/MXene/graphene composite material, which has high sulfur carrying capacity and good conductivity, and can be used as a positive electrode material of a lithium sulfur battery, improve the conductivity of the positive electrode material and the utilization rate of active substance sulfur, and adsorb intermediate polysulfide generated in the reaction process, so that the shuttle effect caused by the dissolution of the intermediate polysulfide can be avoided, and further the specific energy and the coulomb efficiency of the lithium sulfur battery can be improved.
The specific technical scheme is as follows:
a sulfur/MXene/graphene composite material is prepared from elemental sulfur, MXene and graphene, wherein the mass ratio of the elemental sulfur to the MXene to the graphene is 4-17: 1-6: 1.
In some embodiments, the elemental sulfur accounts for 60% to 80% of the total mass of the elemental sulfur, MXene, and graphene.
In some embodiments, the elemental sulfur accounts for 70-76% of the total mass of the elemental sulfur, MXene and graphene
In some embodiments, the mass ratio of the elemental sulfur, MXene and graphene is 14-16: 3-5: 1.
In some embodiments, the mass ratio of elemental sulfur, MXene, and graphene is 15:4:1, 8:1:1, 12:5:3, or 7:2: 1.
In some of these embodiments, the mass ratio of elemental sulfur, MXene, and graphene is 15:4: 1.
In some of the embodiments, the preparation method of MXene comprises the following steps: and etching the aluminum titanium carbide by using hydrofluoric acid to obtain MXene.
In some of the embodiments, the preparation method of MXene comprises the following steps: dissolving lithium fluoride in hydrochloric acid, stirring for 0.3-1 hour, adding aluminum titanium carbide, stirring, reacting at 20-30 ℃ for 20-30 hours, washing the obtained reaction product to be neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment, and then performing freeze drying treatment to obtain the MXene.
In some of the embodiments, the preparation method of MXene comprises the following steps: adding aluminum titanium carbide into hydrofluoric acid, stirring, reacting for 20-30 hours at the temperature of 20-30 ℃, washing the obtained reaction product to be neutral, then placing the reaction product into deionized water for ultrasonic dispersion treatment, and then performing freeze drying treatment to obtain the MXene.
In some embodiments, the ratio of the lithium fluoride, the hydrochloric acid and the aluminum titanium carbide is 0.8-1.2 g: 18-22 ml: 1g of the total weight of the composition.
In some embodiments, the ratio of the hydrofluoric acid to the aluminum titanium carbide is 18-22 ml: 1g of the total weight of the composition.
In some of these embodiments, the conditions of the ultrasonic dispersion treatment include: the temperature is 20-30 ℃, the power is 150-250W, and the time is 4-6 hours.
In some of these embodiments, the conditions of freeze-drying comprise: the temperature is lower than-40 ℃, the vacuum degree is lower than 10Pa, and the time is 16-20 h.
The invention also discloses a preparation method of the sulfur/MXene/graphene composite material.
The specific technical scheme is as follows:
a preparation method of a sulfur/MXene/graphene composite material comprises the following steps:
and mixing and grinding the elemental sulfur, MXene and graphene, and preparing the sulfur/MXene/graphene composite material by a melting diffusion method.
In some of these embodiments, the method for preparing the sulfur/MXene/graphene composite material comprises the following steps:
mixing and grinding the elemental sulfur, MXene and graphene, and then filling the obtained mixed powder into a closed container for carrying out a melting diffusion reaction to obtain the sulfur/MXene/graphene composite material; the oxygen value in the closed container is less than 0.1ppm, and the moisture in the closed container is less than 0.1 ppm.
In some of the embodiments, the temperature of the melt diffusion reaction is 140-170 ℃.
In some of the embodiments, the temperature of the melt diffusion reaction is 150-160 ℃.
In some of these embodiments, the temperature of the melt diffusion reaction is 155 ℃.
In some embodiments, the time of the melt diffusion reaction is 6-14 h.
In some embodiments, the time of the melt diffusion reaction is 8-11 h.
In some of these embodiments, the melt diffusion reaction time is 10 hours.
The invention also provides application of the sulfur/MXene/graphene composite material.
The specific technical scheme is as follows:
the sulfur/MXene/graphene composite material is applied to preparation of a battery anode material.
The invention also provides a lithium-sulfur battery.
The specific technical scheme is as follows:
a preparation material of a positive electrode of the lithium-sulfur battery comprises the sulfur/MXene/graphene composite material.
Compared with the prior art, the invention has the following beneficial effects:
the sulfur/MXene/graphene composite material is prepared by compounding elemental sulfur, MXene and graphene according to a specific ratio, can be used as a positive electrode material of a lithium-sulfur battery, and can solve the problems that in the prior art, the positive electrode material of the lithium-sulfur battery is poor in conductivity, low in sulfur content and utilization rate, and the actual specific energy of the lithium-sulfur battery is low due to the fact that intermediate polysulfide is easily dissolved. The MXene two-dimensional material has a high specific surface area similar to graphene, good conductivity and a rapid interlayer ion channel, a large amount of elemental sulfur active substances can be loaded on the extremely high surface area, the conductivity of the anode material can be improved by the excellent conductivity, ions can rapidly pass through the interlayer ion channel, and the efficiency of electrochemical reaction is improved. Meanwhile, the terminals of the two-dimensional layered surface of the MXene material prepared by the method are provided with a large amount of polar groups, so that a large amount of elemental sulfur active substances can be adsorbed, intermediate polysulfide can be adsorbed, and the MXene material is prevented from being fused into electrolyte, so that the loss of the active substances is reduced, and the consumption of a negative electrode lithium plate is reduced. The graphene has ultrahigh conductivity and good physical properties, and can increase the conductivity and buffer volume effect of the composite material and keep the structural integrity. MXene and graphene are matched in a specific ratio for use, so that a synergistic effect is achieved, the conductivity and comprehensive performance of the obtained sulfur/MXene/graphene composite material are greatly improved, a large amount of active substance elemental sulfur is adsorbed by MXene and graphene, and the density of the active substance elemental sulfur in the obtained sulfur/MXene/graphene composite material is greatly improved. Therefore, the sulfur/MXene/graphene composite material is moderate in sulfur carrying capacity and good in conductivity, can improve the conductivity of the positive electrode material and the utilization rate of active substance sulfur by using the composite material as the positive electrode material of the lithium-sulfur battery, can adsorb intermediate polysulfide generated in the reaction process, can avoid shuttle effect caused by dissolution of the intermediate polysulfide, can further greatly improve the actual specific energy of the lithium-sulfur battery, has the first discharge specific capacity of 1038-1211mAh/g at the multiplying power of 0.1A/g, and has higher coulombic efficiency and better long-term cycle performance of the battery.
The preparation method of the sulfur/MXene/graphene composite material is very simple, the elementary sulfur, the MXene and the graphene are physically and uniformly mixed according to a certain proportion, and the elementary sulfur can be fully combined with the MXene and the graphene through a melting diffusion method, so that the adsorption of active substance elementary sulfur is completed. The preparation of the MXene two-dimensional material takes hydrochloric acid (HCl) and lithium fluoride (LiF) or hydrofluoric acid as etching agents and simultaneously serves as an intercalating agent, the reaction can be carried out at room temperature to obtain the MXene two-dimensional material with few layers, the specific surface area of MXene is further improved, the loading capacity of elemental sulfur of active substances is increased, and therefore the comprehensive performance of the sulfur/MXene/graphene composite material as the lithium-sulfur battery anode material is further improved.
Drawings
Fig. 1 is an SEM image of a few-layer MXene two-dimensional material prepared in example 1.
Fig. 2 is an XRD pattern of the sulfur/MXene/graphene composite material prepared in example 1.
Fig. 3 is a first-order charge and discharge diagram of the sulfur/MXene/graphene composite material prepared in example 1.
Fig. 4 is a CV diagram of the sulfur/MXene/graphene composite material prepared in example 1.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, article, or apparatus that comprises a list of steps is not limited to only those steps or modules recited, but may alternatively include other steps not recited, or alternatively include other steps inherent to such process, method, article, or apparatus.
The "plurality" referred to in the present invention means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
The temperature range of the room temperature is 20-30 ℃.
The various chemicals and experimental materials used in the examples and comparative examples were commercially available.
Example 1
Preparing MXene materials: weighing 2g of lithium fluoride (LiF) and dissolving in 40ml of hydrochloric acid (HCl), continuously stirring, slowly adding 2g of aluminum titanium carbide (Ti) in batches one by one after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 20mg of MXene material, 5mg of graphene and 75mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 155 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
And (3) weighing and calculating the prepared sulfur/MXene/graphene composite material, and testing the electrochemical performance of the composite material which is used as a positive electrode material and assembled into a button type lithium-sulfur battery:
fig. 1 is an SEM image of MXene two-dimensional material prepared in example 1.
Fig. 2 is an XRD chart of the sulfur/MXene/graphene composite material prepared in example 1, the peaks of the composite material are generally consistent with those of elemental sulfur, and it can be seen from fig. 2 that elemental sulfur in the composite material is successfully adsorbed. Further, in a thermogravimetric analyzer, 10mg of a sample is taken, heated from room temperature to 600 ℃, and the sulfur-carrying capacity can be calculated to reach 74% from a weight loss curve.
Fig. 3 is a first cycle charge and discharge diagram of the button-type lithium-sulfur battery assembled by the sulfur/MXene/graphene composite material prepared in example 1 as the positive electrode material, and the test conditions are as follows: the voltage is 1.7-2.8 v, the current density is 0.1A/g, and the temperature is 25 ℃. From fig. 3, it can be seen that the initial specific discharge capacity of the sulfur/MXene/graphene composite material as the positive electrode material of the lithium-sulfur battery reaches 1203 mAh/g.
Fig. 4 is a CV diagram of the assembled button-type lithium-sulfur battery using the sulfur/MXene/graphene composite material prepared in example 1 as a positive electrode material, and the test conditions are as follows: the initial voltage is open circuit voltage, the scanning voltage range is 1.7V to 2.8V, and the scanning speed is 0.0001V/S. As can be seen from fig. 4, the stability of the battery was good.
Example 2
Preparing MXene materials: weighing 4g of lithium fluoride (LiF) and dissolving in 80ml of hydrochloric acid (HCl), continuously stirring, slowly adding 4g of aluminum titanium carbide (Ti) after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 10mg of MXene material, 10mg of graphene and 80mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, filling the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 160 ℃, taking out a sample after reacting for 8 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 79%, the first specific discharge capacity of the sulfur/MXene/graphene composite material is 1211mAh/g, and the stability of the battery is good.
Example 3
Preparing MXene materials: 40ml of hydrofluoric acid (HF) was measured and 2g of titanium aluminum carbide (Ti) was gradually added while stirring3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is below 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 25mg of MXene, 15mg of graphene and 60mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with oxygen of less than 0.1ppm and humidity of less than 0.1ppm, carrying out melt diffusion reaction at 150 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 60%, the first specific discharge capacity of the sulfur/MXene/graphene composite material is 1038mAh/g, and the stability of the battery is good.
Example 4
Preparing MXene materials: weighing 2g of lithium fluoride (LiF) and dissolving in 40ml of hydrochloric acid (HCl), continuously stirring, adding 2g of aluminum titanium carbide (Ti) after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is below 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 20mg of MXene, 10mg of graphene and 70mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, filling the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 160 ℃, taking out a sample after reacting for 8 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 70%, the first specific discharge capacity of the sulfur/MXene/graphene composite material is 1197mAh/g, and the stability of the battery is good.
Example 5
Preparing MXene materials: 2g of lithium fluoride (LiF) are dissolved in 10ml of hydrochloric acid (HCl) and stirred continuously, and after 0.1h, 4g of lithium fluoride (LiF) are slowly added in portionsAluminum titanium carbide (Ti)3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, and the time is 1 hour), and finally performing freeze drying treatment for 18 hours under the conditions that the temperature is lower than-40 ℃ and the vacuum degree is less than 10Pa to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 20mg of MXene material, 5mg of graphene and 75mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 155 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 68%, and the first release specific capacity of the sulfur/MXene/graphene composite material is 1121 mAh/g.
Comparative example 1
Preparing MXene materials: weighing 2g of lithium fluoride (LiF) and dissolving in 40ml of hydrochloric acid (HCl), continuously stirring, slowly adding 2g of aluminum titanium carbide (Ti) in batches one by one after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 40mg of MXene material, 60mg of graphene and 100mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 155 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 49%, and the first specific discharge capacity of the sulfur/MXene/graphene composite material is 875 mAh/g.
Comparative example 2
Preparing MXene materials: weighing 2g of lithium fluoride (LiF) and dissolving in 40ml of hydrochloric acid (HCl), continuously stirring, slowly adding 2g of aluminum titanium carbide (Ti) in batches one by one after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene/graphene composite material: weighing 20mg of MXene material, 5mg of graphene and 75mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 120 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene/graphene composite material.
The prepared sulfur/MXene/graphene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene/graphene composite material is 73%, the initial specific discharge capacity of the sulfur/MXene/graphene composite material is 903mAh/g, and the stability of the battery is poorer than that of the battery in example 1.
Comparative example 3
Preparing MXene materials: weighing 2g of lithium fluoride (LiF) and dissolving in 40ml of hydrochloric acid (HCl), continuously stirring, slowly adding 2g of aluminum titanium carbide (Ti) in batches one by one after 0.5h3AlC2) And continuously stirring, reacting for 25 hours at room temperature, washing the obtained reaction product with deionized water and ethanol respectively until the solution is neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment (the temperature is 25 ℃, the power is 200W, the time is 5 hours), and finally performing freeze drying treatment (the condensation temperature is lower than-40 ℃, the vacuum degree is less than 10Pa, and the time is 18 hours) to obtain the MXene material.
Preparing a sulfur/MXene composite material: weighing 25mg of MXene material and 75mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, putting the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 155 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/MXene composite material.
The prepared sulfur/MXene composite material is subjected to weighing calculation and electrochemical performance test by the same method as the example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/MXene composite material is 74 percent, and the first specific discharge capacity of the sulfur/MXene composite material is 1176 mAh/g.
Comparative example 4
Preparing a sulfur/graphene composite material: weighing 25mg of graphene and 75mg of elemental sulfur, mixing and grinding, sieving the obtained mixed powder, then loading the sieved mixed powder into a closed container with an oxygen value of less than 0.1ppm and water content of less than 0.1ppm, carrying out melt diffusion reaction at 155 ℃, taking out a sample after reaction for 10 hours, and grinding to obtain the sulfur/graphene composite material.
The prepared sulfur/graphene composite material is subjected to weighing calculation and electrochemical performance test, the method is the same as that of example 1, and the test results are as follows: the sulfur carrying capacity of the sulfur/graphene composite material is 72%, and the first discharge specific capacity of the sulfur/graphene composite material is 1132 mAh/g.
The results of the electrochemical performance test of the sulfur/MXene/graphene composite material prepared in each example and comparative example are summarized in table 1 below.
TABLE 1 electrochemical Properties of Sulfur/MXene/graphene composites
Figure BDA0002610864060000111
Wherein, coulombic efficiency reveals the side reaction degree of the battery, which is the mark of the long-term cycling performance of the battery, and the higher the coulombic efficiency is, the better the long-term cycling performance of the battery is.
As can be seen from the results of table 1: the sulfur/MXene/graphene composite material has higher specific discharge capacity and coulombic efficiency, and the long-term cycle performance of the battery is good. When the sulfur carrying amount is too high, the conductive performance of the material is reduced, and the overall performance of the electrode material is poor; when the sulfur carrying capacity is too low, the specific capacity of the electrode material is not high, and the integral performance is not good. The raw materials in the embodiment 1 and the embodiment 4 are better in proportion, and the sulfur carrying amount is moderate, so that the sulfur/MXene/graphene electrode material has better comprehensive performance, and the comprehensive performance of the embodiment 1 is optimal.
Compared with example 1, the conditions for preparing the MXene material are different, the number of the obtained MXene material layers is more, the sulfur carrying capacity of the sulfur/MXene/graphene composite material is reduced, and the specific discharge capacity and the coulombic efficiency of the sulfur/MXene/graphene composite material are lower than those of example 1.
Compared with the example 1, the amount of elemental sulfur added in the preparation process of the sulfur/MXene/graphene composite material is small, so that the sulfur carrying amount of the prepared sulfur/MXene/graphene composite material is only 49%, and the MXene and the graphene are not properly proportioned, so that the specific discharge capacity and the coulombic efficiency of the sulfur/MXene/graphene composite material are far lower than those of the example 1.
Compared with the example 1, in the preparation process of the sulfur/MXene/graphene composite material, the temperature of the melt diffusion reaction is lower, so that the sulfur carrying capacity, the specific discharge capacity and the coulombic efficiency of the sulfur/MXene/graphene composite material are lower than those of the example 1, and the temperature of the melt diffusion reaction also has certain influence on the comprehensive performance of the obtained material.
Compared with the example 1, the prepared sulfur/MXene composite material or sulfur/graphene composite material has the specific discharge capacity and the coulombic efficiency lower than those of the example 1, so that MXene and graphene have the synergistic effect, and the combination of the MXene and the graphene in a certain proportion can effectively improve the comprehensive performance of the obtained material as the lithium-sulfur battery cathode material.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The sulfur/MXene/graphene composite material is characterized by being prepared from elemental sulfur, MXene and graphene, wherein the mass ratio of the elemental sulfur to the MXene to the graphene is 4-17: 1-6: 1.
2. The sulfur/MXene/graphene composite according to claim 1, wherein the elemental sulfur accounts for 60% to 80%, more preferably 70% to 76% of the total mass of the elemental sulfur, MXene and graphene.
3. The sulfur/MXene/graphene composite material according to claim 1, wherein the mass ratio of elemental sulfur, MXene and graphene is 14-16: 3-5: 1, and more preferably 15:4: 1.
4. The sulfur/MXene/graphene composite according to any one of claims 1-3, wherein the MXene preparation method comprises the steps of: and etching the aluminum titanium carbide by using hydrofluoric acid to obtain MXene.
5. The sulfur/MXene/graphene composite according to claim 4, wherein the MXene preparation method comprises the following steps: dissolving lithium fluoride in hydrochloric acid, stirring for 0.3-1 hour, adding aluminum titanium carbide, stirring, reacting at the temperature of 20-30 ℃ for 20-30 hours, washing the obtained reaction product to be neutral, then placing the reaction product in deionized water for ultrasonic dispersion treatment, and then performing freeze drying treatment to obtain MXene; alternatively, the first and second electrodes may be,
the preparation method of MXene comprises the following steps: adding aluminum titanium carbide into hydrofluoric acid, stirring, reacting for 20-30 hours at the temperature of 20-30 ℃, washing the obtained reaction product to be neutral, then placing the reaction product into deionized water for ultrasonic dispersion treatment, and then performing freeze drying treatment to obtain the MXene.
6. The sulfur/MXene/graphene composite material according to claim 5, wherein the ratio of the lithium fluoride, hydrochloric acid and titanium aluminum carbide is 0.8-1.2 g: 18-22 ml: 1g, the proportion of hydrofluoric acid to aluminum titanium carbide is 18-22 ml: 1g of a compound; and/or the presence of a gas in the gas,
the conditions of the ultrasonic dispersion treatment include: the temperature is 20-30 ℃, the power is 150-250W, and the time is 4-6 hours; and/or the presence of a gas in the gas,
the conditions for freeze-drying include: the temperature is lower than-40 ℃, the vacuum degree is lower than 10Pa, and the time is 16-20 h.
7. A method for preparing the sulfur/MXene/graphene composite material according to any one of claims 1 to 6, comprising the steps of: mixing and grinding the elemental sulfur, MXene and graphene, and preparing the sulfur/MXene/graphene composite material by a melting diffusion method;
preferably, the preparation method of the sulfur/MXene/graphene composite material comprises the following steps: mixing and grinding the elemental sulfur, MXene and graphene, and then filling the obtained mixed powder into a closed container for carrying out a melt diffusion reaction to obtain the sulfur/MXene/graphene composite material; the oxygen in the closed container is less than 0.1ppm, and the moisture is less than 0.1 ppm.
8. The preparation method of the sulfur/MXene/graphene composite material according to claim 7, wherein the temperature of the melt diffusion reaction is 140-170 ℃, preferably 150-160 ℃; and/or the presence of a catalyst in the reaction mixture,
the time of the melt diffusion reaction is 6-14 h, preferably 8-11 h.
9. Use of the sulfur/MXene/graphene composite material according to any one of claims 1 to 6 in the preparation of a battery positive electrode material.
10. A lithium-sulfur battery, characterized in that the positive electrode is made of a material comprising the sulfur/MXene/graphene composite material according to any one of claims 1 to 6.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115000410A (en) * 2022-07-07 2022-09-02 桂林理工大学 Carbon nano tube-titanium carbide composite porous microsphere, preparation thereof and application thereof in lithium-sulfur battery

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106058173A (en) * 2016-06-14 2016-10-26 中南大学 Graphene-like carbon material/sulphur composite cathode material for lithium-sulphur battery, and preparation method and application thereof
CN106220180A (en) * 2016-07-08 2016-12-14 中国科学院上海硅酸盐研究所 A kind of preparation method of two dimensional crystal MXene nano material
KR20170106857A (en) * 2016-03-14 2017-09-22 한국에너지기술연구원 Preparing method of the 3D porous structured graphene/Mxene composite by ice-templating method and 3D porous structured graphene/Mxene composite by the same method
CN111342009A (en) * 2020-03-02 2020-06-26 肇庆市华师大光电产业研究院 Novel high-performance lithium-sulfur battery positive electrode material and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20170106857A (en) * 2016-03-14 2017-09-22 한국에너지기술연구원 Preparing method of the 3D porous structured graphene/Mxene composite by ice-templating method and 3D porous structured graphene/Mxene composite by the same method
CN106058173A (en) * 2016-06-14 2016-10-26 中南大学 Graphene-like carbon material/sulphur composite cathode material for lithium-sulphur battery, and preparation method and application thereof
CN106220180A (en) * 2016-07-08 2016-12-14 中国科学院上海硅酸盐研究所 A kind of preparation method of two dimensional crystal MXene nano material
CN111342009A (en) * 2020-03-02 2020-06-26 肇庆市华师大光电产业研究院 Novel high-performance lithium-sulfur battery positive electrode material and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115000410A (en) * 2022-07-07 2022-09-02 桂林理工大学 Carbon nano tube-titanium carbide composite porous microsphere, preparation thereof and application thereof in lithium-sulfur battery
CN115000410B (en) * 2022-07-07 2023-12-26 桂林理工大学 Positive electrode material of lithium-sulfur battery

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