CN115188928A - Preparation method of nitrogen-doped MXene sulfur positive electrode - Google Patents

Preparation method of nitrogen-doped MXene sulfur positive electrode Download PDF

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CN115188928A
CN115188928A CN202210882010.7A CN202210882010A CN115188928A CN 115188928 A CN115188928 A CN 115188928A CN 202210882010 A CN202210882010 A CN 202210882010A CN 115188928 A CN115188928 A CN 115188928A
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张苗
李迎春
魏葳
林珍华
常晶晶
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Xidian University
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Abstract

Preparation method of nitrogen-doped MXene sulfur positive electrode and Ti prepared by using method 3 C 2 T x MXene is heated to react with amino acid solution, hydroxyl on the surface of MXene and carboxyl of amino acid molecules are subjected to esterification reaction, and the self-supporting composite material modified by the amino acid is obtained by vacuum filtration; the material is thermally treated in an inert gas atmosphere to obtain nitrogen-doped Ti 3 C 2 T x MXene composite substrate; and finally depositing a sulfur simple substance on the composite substrate to obtain the nitrogen-doped MXene sulfur anode. The invention can effectively avoid amino acid and Ti in the subsequent processing process 3 C 2 T x Separation of MXene while avoiding Ti 3 C 2 T x MXene interlayer reconstructionSecondary stacking, simple manufacturing process and environmental protection. The invention obtains nitrogen-doped Ti through heat treatment 3 C 2 T x The MXene composite substrate can increase the number of nitrogen atoms on the composite substrate, efficiently anchor and activate lithium polysulfide, effectively avoid shuttle effect and improve the stability of battery circulation.

Description

Preparation method of nitrogen-doped MXene sulfur positive electrode
Technical Field
The invention belongs to the technical field of microelectronics, and particularly relates to a preparation method of a nitrogen-doped MXene sulfur anode, wherein the nitrogen-doped MXene sulfur anode can be used for electronic equipment.
Background
The high energy density battery system can realize light and small equipment, reduce the maintenance burden of operators, improve the guarantee capacity and greatly reduce the battery volume. Aiming at the development of energy storage devices, the realization of low cost, high mechanical performance and high energy density of batteries becomes a key technology in the field of flexible electronics. However, the conventional lithium ion battery system is close to its limit capacity, so the development of a battery system with higher energy density is a necessary choice for promoting the development of new electronic devices. Lithium-sulfur batteries (LSBs) are a novel battery system developed on the basis of Lithium ion batteries, and generally, a Lithium-sulfur battery is composed of a Lithium metal negative electrode, a sulfur positive electrode, an electrolyte and a diaphragm, and the conversion reaction between Lithium and sulfur is adopted to realize the high-efficiency storage of energy. The theoretical specific capacity and specific energy of the sulfur anode can reach 1675 mA.h.g -1 And 2600 Wh.kg -1 Therefore, a lithium sulfur battery using elemental sulfur as a positive electrode is an ideal choice for realizing a high energy density battery system in the future.
The commercial application of the lithium-sulfur battery is hindered during the use process because the advantages of the lithium-sulfur battery are not fully exerted due to the slow kinetics of the redox reaction at the positive electrode side and the "shuttle effect" caused by the dissolution of lithium polysulfide. The lithium-sulfur battery has multi-electron reaction of sulfur phase change in the reaction process, and the slow redox kinetics enable the positive electrode discharge product lithium polysulfide (Li) 2 S x ) The intermediate is dissolved in the organic electrolyte and shuttles and diffuses towards the negative electrode, and the occurrence of the shuttle effect can cause irreversible inactivation of partial sulfur and reduce the utilization rate of lithium, thereby seriously influencing the cycle stability and the coulombic efficiency of the lithium-sulfur battery. For this reason, how to solve the above problems is a focus of attention.
Liang et al in sulfurfur CTi was first introduced into the aqueous solution of inorganic Based on Conductive MXene Nanosheets for High-Performance Lithium-Sulfur Batteries (Angew. Chem. Int. Ed.,2015,54,3907-3911) 2 C(OH) x MXene is introduced into a lithium-sulfur battery as a positive electrode carrier, and the discovery that lithium polysulfide has strong interaction and chemical adsorption with outer titanium atoms and hydroxyl groups effectively reduces the shuttle effect of the lithium polysulfide, but Ti is used alone 2 C(OH) x MXene is used as a substrate material of the sulfur anode, a layered structure is easy to be stacked again, interlayer atoms cannot be effectively utilized, doping of atoms is lacked, lithium polysulfide is slow in redox kinetics, and a shuttle effect is easy to cause.
Wei et al at Current conversion of dentine-free anode and high-loading cathode via3D printed N-Ti 3 C 2 MXene frame heated advanced Li-S full pellets (Energy Storage Material. 2021,41, 141-151) proposed preparation of melamine formaldehyde pellets by precipitation polymerization with Ti as template 3 C 2 MXene is compounded and annealed to generate nitrogen-doped porous Ti 3 C 2 T x The method successfully demonstrated nitrogen-doped Ti 3 C 2 T x MXene as sulfur anode carrier can accelerate the redox chemical power of lithium polysulfide and inhibit 'shuttle effect', but the processing steps are complex, and the template agent can cause environmental pollution.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a preparation method of a nitrogen-doped MXene sulfur positive electrode, so as to improve the carrier conductivity, reduce the processing difficulty, accelerate the lithium polysulfide catalytic conversion efficiency, avoid the formation of a shuttle effect and improve the cycle stability.
In order to achieve the purpose, the invention adopts the technical scheme that:
a preparation method of a nitrogen-doped MXene sulfur positive electrode comprises the following steps:
step (1), preparing Ti 3 C 2 T x MXene；
Step (2) of subjecting the Ti to 3 C 2 Tx MXene reacts with amino acid solution by heating, and carboxyl of amino acid molecule reacts with Ti 3 C 2 T x Performing esterification reaction on hydroxyl on the surface of MXene, and performing vacuum filtration to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting composite material;
step (3) of modifying the amino acid with Ti 3 C 2 T x Carrying out heat treatment on the MXene self-supporting composite material in the inert gas atmosphere to obtain nitrogen-doped Ti 3 C 2 T x MXene composite substrate;
step (4) of doping the nitrogen with Ti 3 C 2 T x And depositing a sulfur simple substance on the MXene composite substrate to obtain the nitrogen-doped MXene sulfur anode.
In one embodiment, step (1) is carried out by etching Ti with LiF/HCl 3 AlC 2 Preparation of Ti 3 C 2 Tx MXene, the method is as follows:
adding lithium fluoride into hydrochloric acid, and uniformly stirring to obtain a mixed solution of the lithium fluoride and the hydrochloric acid;
slowly adding Ti into a mixed solution of lithium fluoride and hydrochloric acid 3 AlC 2 Powder is heated to 60-100 ℃, continuously stirred for 12-48 h and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution;
a plurality of layers of Ti 3 C 2 T x Centrifuging MXene mixed solution, removing supernatant, adding hydrochloric acid solution, centrifuging, washing until pH value of the solution reaches 7, and freeze drying to obtain Ti 3 C 2 T x MXene。
In one embodiment, the concentration of the hydrochloric acid is 10 to 12mol/L, and the mass volume ratio of the lithium fluoride to the hydrochloric acid is 3.2g:40 mL-4.0 g:40mL of lithium fluoride and Ti 3 AlC 2 The mass ratio of the powder was 3.2g: 5-10 mg.
In one embodiment, in step (2), the amino acid is serine, arginine or lysine.
In one embodiment, in the step (2), the concentration of the amino acid solution is 2-4 mg/mL, and Ti is added 3 C 2 T x MXene andthe mass ratio of the amino acid solution was 2:1.
In one embodiment, in the step (2), the reaction is carried out at 60 to 100 ℃ for 3 to 5 hours by heating.
In one embodiment, step (2) is carried out by adding 1-ethyl- (3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine, 1-ethyl- (3-dimethylaminopropyl) carbodiimide and Ti in a mass ratio of 1:1 into the reaction 3 C 2 The mass ratio of Tx MXene is 1.
In one embodiment, the heat treatment parameters of step (3) are: the temperature rise rate is 1 min/DEG C, and the temperature is kept for 2 to 4 hours after the temperature rises to 400 to 800 ℃.
In one embodiment, the step (4) of doping Ti in nitrogen by a melting method 3 C 2 T x Depositing sulfur on the MXene composite substrate.
In one embodiment, nitrogen doped Ti at 1.1cm diameter 3 C 2 T x 1-3 mg of sulfur elementary substance is deposited on the MXene composite substrate wafer at 155 ℃.
Compared with the prior art, the invention has the beneficial effects that:
first, the present invention is based on the combination of amino acids and Ti 3 C 2 T x MXene solution is compounded through esterification reaction, and strong acting force exists between the MXene solution and the MXene solution, so that the MXene solution is effectively prevented from being separated in the subsequent processing process, and Ti is prevented from being generated at the same time 3 C 2 T x MXene layers are stacked again, and the manufacturing process is simple and environment-friendly.
Secondly, the present invention obtains nitrogen-doped Ti by heat treatment 3 C 2 T x The MXene composite substrate can effectively increase the number of nitrogen atoms on the composite substrate, efficiently anchor and activate lithium polysulfide, effectively avoid shuttle effect and improve the stability of battery circulation.
Drawings
Fig. 1 is the etched layered MXene.
FIG. 2 Nitrogen doped Ti 3 C 2 T x MXene composite base material.
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the drawings and examples.
The invention discloses a preparation method of a nitrogen-doped MXene sulfur anode, which mainly solves the problems of high processing difficulty, slow redox kinetics and shuttle effect of lithium polysulfide in the prior art, and has the implementation scheme that:
a preparation method of a nitrogen-doped MXene sulfur positive electrode comprises the following steps:
step 1, preparing Ti 3 C 2 T x MXene，T x In the present invention, the surface functional group, ti of the present invention 3 C 2 Tx MXene has high conductivity and has a large number of hydroxyl groups.
In the present invention, liF/HCl is used to etch Ti 3 AlC 2 Preparation of Ti 3 C 2 Tx MXene, the method is as follows:
and 11, adding lithium fluoride into hydrochloric acid, and uniformly stirring to obtain a mixed solution of the lithium fluoride and the hydrochloric acid.
Illustratively, one useful material dosage parameter is a concentration of 10 to 12mol/L hydrochloric acid, and a mass to volume ratio of lithium fluoride to hydrochloric acid is preferably 3.2g:40 mL-4.0 g:40mL. In the step, the uniform mixing can be realized after about 0.5h of stirring.
Step 12, slowly adding Ti into the mixed solution of lithium fluoride and hydrochloric acid 3 AlC 2 Powder is heated to 60-100 ℃, continuously stirred for 12-48 h and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution.
Illustratively, lithium fluoride and Ti 3 AlC 2 The mass ratio of the powders is preferably 3.2g: 5-10 mg
Step 13, forming a plurality of Ti layers 3 C 2 T x Centrifuging MXene mixed solution, removing supernatant, adding hydrochloric acid solution, centrifuging, washing until pH value of the solution reaches 7 to obtain Ti 3 C 2 T x MXene dispersion, freeze drying to obtain Ti 3 C 2 T x MXene。
Illustratively, the centrifugation speed in this step is 4000rmp, and the concentration of the hydrochloric acid solution added is 1mol/L.
Referring to FIG. 1, the present invention etches to obtain layered Ti 3 C 2 T x MXene, it can be seen that Ti 3 AlC 2 Al in the alloy is successfully etched and removed by LiF/HCl to obtain an obvious layered structure, which is beneficial to further reaction with amino acid in the subsequent steps.
Step 2, adding Ti 3 C 2 Tx MXene reacts with amino acid solution by heating, and the carboxyl of amino acid molecule reacts with Ti 3 C 2 T x The hydroxyl on the surface of MXene is subjected to esterification reaction to ensure that the MXene and the hydroxyl are tightly combined to realize the effect of forming Ti 3 C 2 Grafting and modifying Tx MXene, then carrying out vacuum filtration and drying to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting composites.
In the invention, the concentration of the amino acid solution is 2-4 mg/mL, and Ti 3 C 2 T x The mass ratio of MXene to amino acid solution is preferably 2:1, where the amino acid may be one or more of serine (Ser), arginine (Arg), and lysine (Lys). Illustratively, the heating reaction is preferably carried out at 60 to 100 ℃ for 3 to 5 hours.
Furthermore, the step can also add 1-ethyl- (3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine with the mass ratio of 1:1 in the reaction system to play a role of catalytic reaction, wherein the 1-ethyl- (3-dimethylaminopropyl) carbodiimide and the Ti 3 C 2 The mass ratio of Tx MXene is preferably 1.
Step 3, modifying amino acid modified Ti 3 C 2 T x The MXene self-supporting composite material is subjected to heat treatment in the inert gas atmosphere, the temperature is reduced, and the nitrogen-doped Ti is obtained 3 C 2 T x MXene composite substrate.
Illustratively, the heat treatment parameters of this step are: the temperature rise rate is 1 min/DEG C, and the temperature is kept for 2 to 4 hours after the temperature rises to 400 to 800 ℃. Argon gas may be preferably used as the inert gas.
Referring to FIG. 2, the nitrogen-doped Ti obtained by the present invention 3 C 2 T x The MXene composite substrate material can be used for observing the position and is treated at high temperatureThe nitrogen in the amino acid is successfully doped in the Ti 3 C 2 T x MXene surface and forming a fold structure.
Step 4, doping Ti in nitrogen 3 C 2 T x And depositing a sulfur simple substance on the MXene composite substrate by methods such as melting and the like to obtain the nitrogen-doped MXene sulfur anode.
Illustratively, in practical applications, ti may be doped with nitrogen at a diameter of 1.1cm 3 C 2 T x 1-3 mg of sulfur elementary substance is deposited on the MXene composite substrate wafer at 155 ℃.
The invention improves the ionic conductivity, reduces the processing difficulty, improves the circulating stability and can be used for electronic equipment.
The present invention provides several embodiments as follows.
Example 1
Step 1, preparing Ti with high conductivity and a large amount of hydroxyl 3 C 2 T x MXene。
1.1 40mL of 10mol/L hydrochloric acid is measured, 3.2g of lithium fluoride is added, and the mixture is stirred for 0.5h until the mixture is uniform, so that a mixed solution of the lithium fluoride and the hydrochloric acid is obtained;
1.2 To a mixed solution of lithium fluoride and hydrochloric acid, 5mg of Ti was slowly added 3 AlC 2 Powder is heated to 60 ℃, continuously stirred for 12 hours, and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution;
1.3 A plurality of layers of Ti 3 C 2 T x Centrifuging MXene mixed solution at 4000rmp rotation speed, removing supernatant, adding 1mol/L hydrochloric acid solution, continuously centrifuging, washing until pH value of the solution reaches 7, and freeze drying to obtain Ti 3 C 2 T x MXene。
Step 2, preparing amino acid modified Ti 3 C 2 T x MXene solution.
2.1 Preparing a 2mg/mL serine (Ser) (arginine (Arg) or lysine (Lys)) solution;
2.2 Weighing 0.5g of Ti 3 C 2 T x MXene powder, adding into amino acid solution, stirring, and adding 1-ethyl- (3-dimethylaminopropyl)Reacting carbonyl diimine and 4-dimethylamino pyridine (0.005 g, the mass ratio is 1:1) at 60 ℃ for 3 hours, carrying out vacuum filtration and drying to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting substrate.
Step 3, preparing nitrogen-doped Ti 3 C 2 T x MXene substrate.
The obtained amino acid modified Ti 3 C 2 T x The MXene self-supporting composite membrane substrate is subjected to heat treatment for 2h at 400 ℃ in an inert gas atmosphere, the heating rate is 1 min/DEG C, the temperature is reduced, and the nitrogen-doped Ti is obtained 3 C 2 T x MXene self-supporting substrates.
Step 4, preparing Ti doped with nitrogen 3 C 2 T x MXene is the sulfur anode of the substrate.
In nitrogen doped Ti 3 C 2 T x MXene deposits sulfur simple substance on a self-supporting substrate, amino acid with the diameter of 1.1cm is cut to modify Ti 3 C 2 T x MXene self-supporting composite substrate wafer, 1mg of sulfur simple substance is deposited on amino acid modified Ti at 155 DEG C 3 C 2 T x MXene self-supporting composite substrate to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting composite substrate sulfur positive electrode.
Example 2
Step one, preparing Ti with high conductivity and a large amount of hydroxyl 3 C 2 T x MXene。
1.1 40mL of 11mol/L hydrochloric acid is measured, 4g of lithium fluoride is added, and the mixture is stirred for 0.5h until the mixture is uniform, so that a mixed solution of the lithium fluoride and the hydrochloric acid is obtained;
1.2 To a mixed solution of lithium fluoride and hydrochloric acid, 8mg of Ti was slowly added 3 AlC 2 Powder is heated to 80 ℃, continuously stirred for 24 hours, and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution;
1.3 A plurality of layers of Ti 3 C 2 T x Centrifuging MXene mixed solution at 4000rmp rotation speed, removing supernatant, adding 1mol/L hydrochloric acid solution, centrifuging continuously, washing until pH value of solution reaches7, freeze drying to obtain Ti 3 C 2 T x MXene。
Step 2, preparing amino acid modified Ti 3 C 2 T x MXene solution.
2.1 Preparing a 3mg/mL serine (Ser) (arginine (Arg) or lysine (Lys)) solution;
2.2 Weighing 0.5g of Ti 3 C 2 T x MXene powder is added into amino acid solution, stirred evenly, added with 1-ethyl- (3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine (0.005 g, the mass ratio of 1:1), reacted for 4 hours at 80 ℃, vacuum filtered and dried to obtain the amino acid modified Ti 3 C 2 T x MXene self-supporting substrate.
Step 3, preparing nitrogen-doped Ti 3 C 2 T x MXene substrate.
Modifying the obtained amino acid with Ti 3 C 2 T x The MXene self-supporting composite membrane substrate is subjected to heat treatment for 3h at the temperature of 600 ℃ under the inert gas atmosphere, the heating rate is 1 min/DEG C, the temperature is reduced, and the nitrogen-doped Ti is obtained 3 C 2 T x MXene self-supporting substrates.
Step 4, preparing Ti doped with nitrogen 3 C 2 T x MXene is the sulfur anode of the substrate.
Nitrogen doped Ti 3 C 2 T x MXene deposits sulfur simple substance on a self-supporting substrate, amino acid with the diameter of 1.1cm is cut to modify Ti 3 C 2 T x MXene self-supporting composite substrate wafer, 2mg of sulfur simple substance is deposited on amino acid modified Ti at 155 DEG C 3 C 2 T x MXene self-supporting composite substrate to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting composite substrate sulfur positive electrode.
Example 3
Step one, preparing Ti with high conductivity and a large amount of hydroxyl 3 C 2 T x MXene。
1.1 40mL of 12mol/L hydrochloric acid is measured, 3.2g of lithium fluoride is added, and the mixture is stirred for 0.5h until the mixture is uniform, so that a mixed solution of the lithium fluoride and the hydrochloric acid is obtained;
1.2 To a mixed solution of lithium fluoride and hydrochloric acid, 10mg of Ti was slowly added 3 AlC 2 Powder is heated to 100 ℃, continuously stirred for 36 hours, and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution;
1.3 A plurality of layers of Ti 3 C 2 T x Centrifuging MXene mixed solution at 4000rmp rotation speed, removing supernatant, adding 1mol/L hydrochloric acid solution, continuously centrifuging, washing until pH value of the solution reaches 7, and freeze drying to obtain Ti 3 C 2 T x MXene。
Step 2, preparing amino acid modified Ti 3 C 2 T x MXene solution.
2.1 Preparing 4mg/mL serine (Ser) (arginine (Arg) or lysine (Lys)) solution;
2.2 Weighing 0.5g of Ti 3 C 2 T x MXene powder is added into amino acid solution, stirred evenly, added with 1-ethyl- (3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine (0.005 g, the mass ratio of 1:1), reacted for 5 hours at 100 ℃, vacuum filtered and dried to obtain the amino acid modified Ti 3 C 2 T x MXene self-supporting substrate.
Step 3, preparing nitrogen-doped Ti 3 C 2 T x MXene substrate.
Modifying the obtained amino acid with Ti 3 C 2 T x The MXene self-supporting composite membrane substrate is subjected to heat treatment for 4h at the temperature of 800 ℃ under the inert gas atmosphere, the heating rate is 1 min/DEG C, the temperature is reduced, and the nitrogen-doped Ti is obtained 3 C 2 T x MXene self-supporting substrates.
Step 4, preparing Ti doped with nitrogen 3 C 2 T x MXene is the sulfur anode of the substrate.
Nitrogen doped Ti 3 C 2 T x MXene deposits sulfur simple substance on a self-supporting substrate, amino acid with the diameter of 1.1cm is cut to modify Ti 3 C 2 T x MXene self-supporting composite substrate wafer, 3mg of sulfur simple substance is deposited on amino acid modified Ti at 155 DEG C 3 C 2 T x MXene self-supporting composite substrate to obtain amino acid modified Ti 3 C 2 T x MXene self-supporting composite substrate sulfur positive electrode.
According to Song et al, nitrogen-doped Ti is obtained by a sacrificial template method 3 C 2 MXene, to design a chemically active support for lithium-sulfur batteries, nitrogen-doped Ti was verified experimentally 3 C 2 MXene has good electronic conductivity, has strong interaction with lithium polysulfide, and can trigger the redox reaction on the surface. Furthermore, nitrogen is in Ti 3 C 2 The uniform doping on MXene enhances the interface interaction with lithium and reduces the dissociation barrier of lithium sulfide. Illustrating nitrogen doped Ti 3 C 2 MXene not only can effectively fix lithium polysulfide and avoid shuttle effect, but also can be used as an electrocatalyst to promote nucleation and decomposition of lithium sulfide in the charge-discharge process (Nano Energy,2022,70,104555).
Besides, according to the report of Bao et al, folded nitrogen-doped MXene nanosheets having strong physical and chemical co-adsorption effects on lithium polysulfide are synthesized by a one-step method and serve as sulfur hosts. Nitrogen doping introduces heteroatoms into MXene nanosheets, and good porous structure, high specific surface area and large pore volume are induced to form. The unique porous structure and physical constraints prevent the dissolution of lithium polysulfides, minimizing the "shuttle effect". In addition, the introduction of nitrogen atoms into MXene nanosheets can effectively increase Ti content 3 C 2 T x Electrochemical reaction performance of the nanosheet and sulfur composite electrode (adv. Energy mater, 2018,8,1702485).
The theory proves that the nitrogen-doped MXene sulfur anode provided by the invention is beneficial to improving the cycling stability of the battery.
The foregoing description is only three specific examples of the present invention and is not intended to limit the invention, so that it will be apparent to those skilled in the art that various changes and modifications in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. The preparation method of the nitrogen-doped MXene sulfur positive electrode is characterized by comprising the following steps of:
step (1), preparing Ti 3 C 2 T x MXene；
Step (2) of subjecting the Ti to 3 C 2 Tx MXene reacts with amino acid solution by heating, and the carboxyl of amino acid molecule reacts with Ti 3 C 2 T x Hydroxyl on the surface of MXene undergoes esterification reaction, and the Ti modified by amino acid is obtained by vacuum filtration 3 C 2 T x MXene self-supporting composite material;
step (3) of modifying the amino acid with Ti 3 C 2 T x Carrying out heat treatment on the MXene self-supporting composite material in the inert gas atmosphere to obtain nitrogen-doped Ti 3 C 2 T x An MXene composite substrate;
step (4) of doping the nitrogen with Ti 3 C 2 T x And depositing a sulfur simple substance on the MXene composite substrate to obtain the nitrogen-doped MXene sulfur anode.
2. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein in the step (1), the Ti is etched by LiF/HCl 3 AlC 2 Preparation of Ti 3 C 2 Tx MXene, the method is as follows:
adding lithium fluoride into hydrochloric acid, and uniformly stirring to obtain a mixed solution of the lithium fluoride and the hydrochloric acid;
slowly adding Ti into a mixed solution of lithium fluoride and hydrochloric acid 3 AlC 2 Powder is heated to 60-100 ℃, continuously stirred for 12-48 h and finally etched to obtain multilayer Ti 3 C 2 T x MXene mixed solution;
a plurality of layers of Ti 3 C 2 T x Centrifuging MXene mixed solution, removing supernatant, adding hydrochloric acid solution, centrifuging, washing until pH value of the solution reaches 7, and freeze drying to obtain Ti 3 C 2 T x MXene。
3. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 2, wherein the concentration of the hydrochloric acid is 10-12 mol/L, and the mass volume ratio of the lithium fluoride to the hydrochloric acid is 3.2g:40 mL-4.0 g:40mL of lithium fluoride and Ti 3 AlC 2 The mass ratio of the powder was 3.2g: 5-10 mg.
4. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein in the step (2), the amino acid is serine, arginine or lysine.
5. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1 or 4, wherein in the step (2), the concentration of the amino acid solution is 2-4 mg/mL, and Ti is added 3 C 2 T x The mass ratio of MXene to amino acid solution was 2:1.
6. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein the step (2) is carried out by heating at 60-100 ℃ for 3-5 hours.
7. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein the step (2) is further adding 1-ethyl- (3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine, 1-ethyl- (3-dimethylaminopropyl) carbodiimide and Ti in a mass ratio of 1:1 into the reaction 3 C 2 The mass ratio of Tx MXene is 1.
8. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein the heat treatment parameters of the step (3) are as follows: the temperature rise rate is 1 min/DEG C, and the temperature is kept for 2 to 4 hours after the temperature rises to 400 to 800 ℃.
9. The method for preparing the nitrogen-doped MXene sulfur positive electrode according to claim 1, wherein the method comprises the step of mixing the nitrogen-doped MXene sulfur positive electrode with the nitrogen-doped MXene sulfur positive electrodeThe step (4) is to dope Ti in nitrogen by a melting method 3 C 2 T x Depositing sulfur on the MXene composite substrate.
10. The method of claim 9, wherein the Ti is doped into nitrogen with a diameter of 1.1cm 3 C 2 T x On MXene composite substrate wafer, deposit 1-3 mg sulfur elementary substance at 155 ℃.
CN202210882010.7A 2022-07-26 2022-07-26 Preparation method of nitrogen-doped MXene sulfur positive electrode Active CN115188928B (en)

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CN110386602A (en) * 2019-07-25 2019-10-29 常州工学院 A kind of preparation method of titanium carbide/azepine graphene hydrogel photoelectric conversion material

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WO2024036560A1 (en) * 2022-08-18 2024-02-22 中国科学院深圳先进技术研究院 Mxene modification method and use thereof

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