Graphene intercalation Ti3CN MXene material as well as preparation method and application thereof

Abstract

The invention relates to a graphene intercalation Ti3CN MXene material as well as a preparation method and application thereof. The graphene intercalation Ti3CN MXene material is composed of Ti3CN MXene nanosheets and a graphene interlayer inserted between the Ti3CN MXene nanosheets. The preparation method of the graphene intercalation Ti3CN MXene material comprises the following steps: mixing the Ti3CN MXene nanosheets and the graphene nanosheets in dimethyl sulfoxide, and then putting the mixture in an inert atmosphere to carry out pulse ultrasonic treatment, thereby obtaining the graphene intercalation Ti3CN MXene material. The initial capacity and long-term cycle capacity of the graphene intercalation Ti3CN MXene material serving as a sodium ion battery material are increased to more than two times that of an original Ti3CN battery, and the graphene intercalation Ti3CN MXene material is obviously superior to similar carbide and carbonitride sodium ion batteries and has excellent sodium ion storage performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery materials, and particularly relates to a graphene intercalated Ti3CN MXene material and a preparation method and application thereof. BACKGROUND

[0002] Nowadays, sodium-ion and potassium-ion batteries are rapidly developing, and due to the high abundance, low cost and very suitable redox potential of sodium, they become a cheaper energy storage way than the commonly used lithium-ion batteries. They are suitable for most types of energy storage applications, especially stationary energy storage, such as grid storage, renewable energy storage, backup systems and automobiles. However, due to the large size of sodium, only a limited amount of sodium can be stored in the anode materials commonly used in lithium-ion batteries. Therefore, it is necessary to explore and develop new anode materials to meet the urgent needs of sodium-ion and potassium-ion batteries.

[0003] Existing research shows that Ti3CN has a certain application prospect as a potential anode material for sodium-ion batteries (SIBs). However, its electrochemical performance still has obvious deficiencies. Under the condition of a current density of 20 mA / g, the Ti3CN electrode only shows a discharge specific capacity of about 507 mAh / g and a charge specific capacity of 211.5 mAh / g in the first charge-discharge process, and when the current density is increased to 500 mA / g, its discharge specific capacity is even decreased to 98.9 mAh / g (see: Two-Dimensional Titanium Carbonitride MXene for High-Performance Sodium Ion Batteries), and the specific capacity, cycle stability and / or rate performance of Ti3CN material as an anode for sodium-ion batteries still need to be further improved. SUMMARY

[0004] In order to solve one or more technical problems in the prior art, the application provides a graphene intercalated Ti3CN MXene material (Gr-Ti3CN material) and a preparation method and application thereof. The Gr-Ti3CN material prepared by the application maintains the original crystal structure of the Ti3CN MXene nanosheet while showing excellent electrochemical performance.

[0005] In a first aspect, the application provides a graphene intercalated Ti3CN MXene material, which is composed of Ti3CN MXene nanosheets and graphene interlayers inserted between the Ti3CN MXene nanosheets.

[0006] Preferably, the Ti3CN MXene nanosheet maintains the original crystal structure.

[0007] Preferably, the mass ratio of the Ti3CN MXene nanosheet to the graphene is (5-30):1.

[0008] The application provides a preparation method of a graphene intercalated Ti3CN MXene material in a second aspect, which comprises the following steps: mixing Ti3CN MXene nanosheets and graphene nanosheets in dimethyl sulfoxide, and then performing pulse ultrasonic treatment in an inert atmosphere to obtain the graphene intercalated Ti3CN MXene material.

[0009] Preferably, the pulse ultrasonic treatment has a power density of 60-300 W / cm2, a pulse time of 20-30 s, and a duty cycle of 60-80%, and the pulse ultrasonic treatment is performed for 1-4 h. 2

[0010] Preferably, the mass ratio of the Ti3CN MXene nanosheet, the graphene nanosheet and the dimethyl sulfoxide is (5-30):1:(20-45).

[0011] Preferably, after the pulse ultrasonic treatment, post-treatment is further performed, which comprises the following steps: washing with ethanol and vacuum drying at 100-150 ℃ for 2-10 h.

[0012] Preferably, the Ti3CN MXene nanosheet is prepared by the following steps: mixing titanium powder, aluminum nitride and graphite powder, placing the mixture in a tube furnace to react under the protection of an inert gas, and then immersing in a hydrofluoric acid solution, washing, centrifuging and drying to obtain the Ti3CN MXene nanosheet; preferably, the molar ratio of the titanium powder, the aluminum nitride and the graphite powder is 3:1:1; preferably, the inert gas is argon and / or nitrogen, the reaction temperature is 1200-2000 ℃, and the reaction time is 2-10 h; preferably, the concentration of the hydrofluoric acid solution is 35-60 wt%, and the immersion time is 15-20 h; preferably, the washing is performed with deionized water until the pH is 6.5-7, and the drying is performed at 50-100 ℃ for 18-30 h.

[0013] The application provides a graphene intercalated Ti3CN MXene material prepared by the preparation method in the second aspect in a third aspect.

[0014] The application provides an application of the graphene intercalated Ti3CN MXene material in the first aspect or the graphene intercalated Ti3CN MXene material prepared by the preparation method in the second aspect as a battery material in a fourth aspect; preferably, the battery material is an alkali metal cation battery material; more preferably, the battery material is a sodium ion battery material. ​

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention uses pulsed ultrasound and a suitable solvent, dimethyl sulfoxide (DMSO), to insert graphene (Gr) nanosheets into the interlayer voids of multilayer Ti3CN MXene nanosheets, forming a graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). This material combines the advantages of high charge capacity of Ti3CN nanosheets and high conductivity of graphene, improving its electronic conductivity and the capacity of MXene SIBs. Unlike previous reports of using graphene to encapsulate battery materials, in the Gr-Ti3CN material, Ti3CN MXene nanosheets and graphene nanosheets undergo intercalation, maintaining the original crystal structure and interlayer structure of the Ti3CN nanosheets, which is beneficial for ion adsorption and desorption. When the Gr-Ti3CN material is used as the anode of a sodium-ion battery, it exhibits excellent electrochemical performance, excellent cycle stability, and outstanding rate performance.

[0016] (2) The graphene intercalated Ti3CN MXene material in this invention can effectively promote the rapid transport and diffusion of electrolyte ions and improve the conductivity of the battery. The Gr-Ti3CN SIBs in this invention exhibit a rapid electrochemical kinetic process, and its charge transfer and Warburg impedance are reduced by nearly 90%, which is significantly lower than that of Ti3CN SIBs.

[0017] (3) The graphene-intercalated Ti3CN MXene material prepared in this invention improves the solid electrolyte interface (SEI) layer suitable for charge conduction and synergistically stabilizes the active material with Ti3CN containing negatively charged nitrogen, thereby enhancing the number of electrons and the active sites for sodium ion intercalation, thus achieving excellent sodium ion storage performance. The Gr-Ti3CN material prepared in this invention is used as the anode of sodium ion batteries, which exhibits excellent electrochemical performance, including high energy density, good cycle stability and excellent rate performance. After 500 cycles at a current density of 50 mA / g, the coulombic efficiency is still maintained at about 100%. The Gr-Ti3CN material prepared in this invention maintains the perfect crystal structure of Ti3CN through the intercalation of Ti3CN MXene nanosheets and graphene nanosheets. Its excellent sodium ion storage performance makes it a promising candidate material for advanced SIB energy storage devices. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The XRD patterns of the graphene-intercalated Ti3CN MXene material and Ti3CN MXene nanosheets prepared in Example 1 of this invention are shown. Figure 2 These are SEM images of the graphene-intercalated Ti3CN MXene material prepared in Example 1 of this invention and the Ti3CN / graphene mixed powder prepared in Comparative Example 1; in the figures, a is the SEM image of the Ti3CN / graphene mixed powder and b is the SEM image of the graphene-intercalated Ti3CN MXene material. Figure 3 This is the C and N element distribution energy spectrum of the graphene-intercalated Ti3CN MXene material prepared in Example 1 of this invention; Figure 4 This is a charge-discharge cycle curve of the graphene-intercalated Ti3CN MXene material prepared in Example 1 of this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] In a first aspect, the present invention provides a graphene-intercalated Ti3CN MXene material (abbreviated as Gr-Ti3CN material), wherein the graphene-intercalated Ti3CN MXene material is composed of Ti3CN MXene nanosheets and graphene intercalations inserted between the Ti3CN MXene nanosheets; in the present invention, the graphene intercalation is, for example, a graphene nanosheet intercalation; in the present invention, the Ti3CN nanosheets and graphene nanosheets are intercalated in the Gr-Ti3CN material, and the Ti3CN maintains its original crystal structure, that is, the introduction of graphene nanosheets into the Gr-Ti3CN material does not affect the original crystal structure of Ti3CN.

[0022] According to some preferred embodiments, the Ti3CN MXene nanosheets retain the original crystal structure, that is, the Ti3CN MXene nanosheets in the graphene-intercalated Ti3CN MXene material retain the original crystal structure.

[0023] According to some preferred embodiments, the mass ratio of the Ti3CN MXene nanosheets to the graphene is (5~30):1 (e.g., 5:1, 10:1, 15:1, 20:1, 25:1 or 30:1).

[0024] In a second aspect, this invention provides a method for preparing graphene-intercalated Ti3CN MXene material. The method involves mixing Ti3CN MXene nanosheets and graphene nanosheets in dimethyl sulfoxide and then subjecting the mixture to pulsed ultrasonic treatment in an inert atmosphere to obtain the graphene-intercalated Ti3CN MXene material. In this invention, the mixing is, for example, achieved by stirring, with a stirring speed of, for example, 200-500 r / min, a stirring temperature of, for example, room temperature (e.g., 10-38°C), and a stirring time of, for example, 1-2 h. This invention does not specifically limit the source of the Ti3CN MXene nanosheets and graphene nanosheets; either directly purchased products or products prepared using existing methods can be used. The inert atmosphere is, for example, argon and / or nitrogen.

[0025] This invention utilizes pulsed ultrasound and a suitable solvent, dimethyl sulfoxide (DMSO), to insert graphene (Gr) nanosheets into the interlayer voids of multilayer Ti3CN MXene nanosheets, forming a graphene-intercalated Ti3CNMXene material (Gr-Ti3CN material). This material combines the high charge capacity of Ti3CN nanosheets with the high conductivity of graphene, improving both electronic conductivity and the capacity of MXene SiBs. Unlike previous reports of graphene-encapsulated battery materials, in the Gr-Ti3CN material, Ti3CN nanosheets intercalate with graphene nanosheets, maintaining the original crystal and interlayer structure of the Ti3CN nanosheets, which facilitates ion adsorption and desorption. When used as the anode in a sodium-ion battery, the Gr-Ti3CN material exhibits excellent electrochemical performance, superior cycle stability, and outstanding rate performance. In this invention, the strategy of inserting graphene interlayers between Ti3CN MXene nanosheets enables the production of SIBs with excellent conductivity, high specific capacity, and outstanding rate performance. Furthermore, by inserting graphene into Ti3CN MXene, the initial capacity and long-term cycling capacity of Gr-Ti3CN SIBs are increased to twice that of the original Ti3CN battery, significantly outperforming similar carbide and carbonitride sodium-ion batteries. In this invention, graphene improves the solid electrolyte interface (SEI) layer suitable for charge conduction and synergistically stabilizes the active material with negatively charged nitrogen-containing Ti3CN, enhancing the number of electrons and the active sites for sodium ion intercalation, thereby achieving excellent sodium-ion storage performance.

[0026] While existing technologies have reported methods to prepare MXene-carbon material three-dimensional composite carriers by ultrasonically dispersing Ti3CN MXene in a solvent to obtain an MXene dispersion, then ultrasonically dispersing graphene in the same solvent to obtain a carbon material dispersion, followed by mixing and further ultrasonic dispersion (see Chinese patent application CN113629265A), and by using ball milling to achieve intercalation of MXene and graphene to a certain extent to obtain MXene / Graphene composites (see Chinese patent application CN112876712A), these existing technologies, whether for three-dimensional composite carriers or MXene / Graphene composites obtained by ball milling, do not essentially achieve effective intercalation between Ti3CN MXene nanosheets and graphene. This is because conventional ultrasonic dispersion or ball milling methods are insufficient to drive graphene effectively into the interlayer voids of Ti3CN MXene, resulting in structures that are mostly disordered mixed powders or graphene coatings, failing to achieve a stable and ordered intercalation structure. Compared with existing technologies, this invention uses dimethyl sulfoxide (DMSO) as a solvent and combines it with pulsed ultrasound to effectively insert graphene nanosheets into the interlayer voids of Ti3CN MXene nanosheets under the synergistic effect of ultrasonic exfoliation and instantaneous energy pulses, thereby constructing a truly meaningful graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). This method not only avoids the problems of simple mixing or surface coating, but also achieves ordered interlayer assembly between graphene and Ti3CN MXene, significantly improving the interlayer structural stability and electrochemical performance of the material, exhibiting excellent sodium ion storage performance, making it a very promising candidate material for advanced SIB energy storage devices.

[0027] Compared to conventional continuous ultrasonic dispersion, the pulsed ultrasonic treatment employed in this invention can generate a stronger local cavitation effect and instantaneous impact force in a short time, while avoiding excessive temperature rise of the system during the intervals. This ensures both efficient energy utilization and prevents rapid solvent evaporation and material structure damage. This invention utilizes this characteristic of pulsed ultrasound to enable graphene to insert into the interlayer of Ti3CN MXene under instantaneous high-energy impact, achieving effective ordered intercalation. Furthermore, the selection of dimethyl sulfoxide (DMSO) as a solvent in this invention is also key to achieving effective graphene intercalation into the Ti3CN MXene interlayer. This is likely because DMSO has high polarity, enabling it to interact strongly with the polar groups on the Ti3CN MXene surface, promoting interlayer exfoliation, and simultaneously inhibiting graphene aggregation through polar -π interactions, thus achieving stable dispersion of both in the same solvent system. On the other hand, DMSO has a high boiling point, which avoids the attenuation of the cavitation effect due to premature vaporization during pulsed ultrasound, allowing ultrasonic energy to be continuously and effectively transferred to the material interface, thereby enhancing the graphene insertion into Ti3CN. The dynamics between MXene layers are crucial; furthermore, DMSO's small molecular size and strong dipole moment enable it to enter and expand the Ti3CN MXene interlayers, providing spatial channels and thermodynamic driving forces for the insertion of graphene interlayers. In contrast, commonly used low-boiling-point or insufficiently polar solvents (such as water, ethanol, acetone, etc.) are difficult to effectively drive graphene into the Ti3CN MXene interlayers; while other high-boiling-point solvents (such as N-methylpyrrolidone NMP, N,N-dimethylformamide DMF, etc.) can disperse graphene to some extent, but their dispersion and intercalation effects on Ti3CN MXene are significantly less than those of DMSO. The DMSO solvent used in this invention significantly promotes the ordered intercalation of graphene nanosheets between Ti3CN MXene layers under pulsed ultrasound. This invention reveals that effectively intercalated graphene-intercalated Ti3CN MXene materials exhibit superior electrochemical performance due to their unique interlayer structure and synergistic effects. During intercalation, graphene nanosheets are uniformly introduced into the Ti3CN MXene interlayer, forming an ordered and continuous conductive network, effectively improving ion diffusion and electron conduction. Simultaneously, the high conductivity and flexibility of graphene help mitigate the volume change of Ti3CN MXene during charge and discharge, improving cycle stability and rate performance. In contrast, unintercalated modified Ti3CN MXene materials lack an interlayer intercalation structure, resulting in insufficient contact between graphene and Ti3CN MXene, fragmented conductive paths, and limited ion channels, leading to low electrochemical reactivity and decreased cycle and rate performance.

[0028] According to some preferred embodiments, the power density (sound intensity) of the pulsed ultrasound treatment is 60~300W / cm². 2The preferred value is 80~150W / cm 2 (e.g., 80, 90, 100, 110, 120, 130, 140 or 150 W / cm) 2 The pulse duration is 20-30 seconds (e.g., 20, 25, or 30 seconds), the duty cycle is 60-80% (e.g., 60%, 65%, 70%, 75%, or 80%), the pulse ultrasound treatment time is 1-4 hours (e.g., 1, 2, 3, or 4 hours), and the pulse ultrasound frequency is 15-40 kHz. In a specific embodiment of the present invention, for example, a probe-type pulse ultrasound is used. Specifically, during pulse ultrasound, the probe of a probe-type pulse ultrasound instrument is inserted into the system. The working time is 30 seconds, and the interval time is 10 seconds (75% duty cycle). That is, during pulse ultrasound, the pulse ultrasound is performed for 30 seconds with a 10-second interval.

[0029] In this invention, the power density, pulse time, duty cycle, and total processing time of the pulsed ultrasonic treatment are all optimized to ensure that graphene can effectively intercalate into the Ti3CN MXene interlayer. This invention also reveals that if the power density is too low, the cavitation effect is insufficient, making it difficult to provide enough instantaneous impact force to drive graphene into Ti3CN. Intercalation of MXene layers is crucial; excessive power density can lead to material structural damage, layer breakage, and even re-aggregation, thus affecting the intercalation effect. A pulse duration of 20-30 seconds can generate sufficient cavitation in each pulse cycle. If the pulse duration is too short, the impact will be insufficient; if it is too long, it can easily cause overall overheating of the system. A duty cycle of 60-80% ensures high instantaneous energy utilization of pulsed ultrasound, while allowing appropriate intervals for heat dissipation and solvent stability. If the duty cycle is too low, the energy density will be insufficient, which is not conducive to intercalation. If the duty cycle is too high, the system will continue to heat up, which can easily lead to solvent evaporation and material damage. The total pulsed ultrasound treatment time should be controlled within 1-4 hours to ensure that graphene is gradually intercalated and forms a stable structure. If the treatment time is too short, the intercalation will be incomplete; if it is too long, the ultrasound effect will be excessive, which can easily cause layer damage and a decrease in material properties. The preferred parameters of this invention can achieve a good balance between intercalation efficiency and material stability, ensuring the production of graphene-intercalated Ti3CN MXene materials with complete structure and ordered interlayer, which is beneficial to ensuring the preparation of graphene-intercalated Ti3CN MXene materials with excellent electrochemical performance.

[0030] According to some preferred embodiments, the mass ratio of the Ti3CN MXene nanosheets, the graphene nanosheets, and the dimethyl sulfoxide is (5~30):1:(20~45) (e.g., 5:1:20, 10:1:20, 15:1:20, 20:1:20, 25:1:20, 30:1:20, 5:1:30, 10:1:30, 15:1:30, 20:1:30, 25:1:30, 30:1:30, 5:1:40, 10:1:40, 15:1:40, 20:1:40, 25:1:40, 30:1:40, 5:1:45, 10:1:45, 15:1:45, 20:1:45, 25:1:45, or 30:1:45).

[0031] In this invention, the preferred mass ratio of the Ti3CN MXene nanosheets, graphene nanosheets, and dimethyl sulfoxide is (5~30):1:(20~45). This allows for effective graphene intercalation under pulsed ultrasound and enables the graphene-intercalated Ti3CN MXene material to achieve excellent electrochemical performance. This invention has found that excessive graphene nanosheets can lead to agglomeration on the Ti3CN MXene surface, resulting in uneven intercalation. Excessive Ti3CN MXene, on the other hand, reduces graphene intercalation efficiency, hindering the full utilization of the material's specific capacity and conductivity. Insufficient dimethyl sulfoxide results in high system viscosity, leading to uneven dispersion of Ti3CN MXene and graphene, making effective intercalation difficult. Excessive dimethyl sulfoxide causes over-dilution, reducing interlayer collisions and intercalation opportunities, also decreasing intercalation efficiency. This invention, through optimization within the above ranges, achieves a balance between effective graphene intercalation and Ti3CN MXene intercalation. The ordered structure between MXene layers yields graphene-intercalated Ti3CN MXene materials with stable structure, excellent conductivity, high specific capacity, and excellent electrochemical performance.

[0032] According to some preferred embodiments, in step (2), after pulsed ultrasound treatment, a post-treatment is also included, which is washing with ethanol and vacuum drying at 100~150°C (e.g. 100°C, 110°C, 120°C, 130°C, 140°C or 150°C) for 2~10 hours (e.g. 2, 3, 4, 5, 6, 7, 8, 9 or 10 hours).

[0033] According to some preferred embodiments, when the amounts of Ti3CN MXene nanosheets and graphene nanosheets are 5-30g and 1g respectively, the amount of dimethyl sulfoxide is 20-40mL. Preferably, the mass ratio of Ti3CN MXene nanosheets to graphene nanosheets is (10-20):1, and the power density of the pulsed ultrasonic treatment is 100W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the pulse ultrasound treatment time is 2h.

[0034] According to some preferred embodiments, the Ti3CN MXene nanosheets are prepared as follows: titanium powder, aluminum nitride, and graphite powder are mixed and reacted in a tube furnace under inert gas protection, followed by soaking in hydrofluoric acid solution, washing, centrifugation, and drying to obtain Ti3CN MXene nanosheets; preferably, the molar ratio of titanium powder, aluminum nitride, and graphite powder is 3:1:1; preferably, the inert gas is argon and / or nitrogen, the reaction temperature is 1200℃~2000℃ (e.g., 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃, 1900℃, or 2000℃), and the reaction time is 2~10h (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10h); preferably, the concentration of the hydrofluoric acid solution is 35~60wt% (e.g., 35...). The concentrations are wt%, 40wt%, 45wt%, 50wt%, 55wt%, or 60wt%, and the soaking time is 15-20 hours (e.g., 15, 16, 17, 18, 19, or 20 hours). Preferably, the washing is with deionized water until the pH is 6.5-7 (e.g., 6.5, 6.6, 6.7, 6.8, 6.9, or 7.0), and the drying is vacuum drying at 50-100°C (e.g., 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C) for 18-30 hours (e.g., 18, 20, 22, 24, 26, 28, or 30 hours).

[0035] According to some preferred embodiments, in the preparation of Ti3CN MXene nanosheets, before soaking in hydrofluoric acid solution, the product obtained from the reaction is first sieved through a 325-mesh sieve to obtain powder with a particle size of <45μm.

[0036] According to some specific implementation methods, the Ti3CN MXene nanosheets are prepared as follows: titanium powder, aluminum nitride and graphite powder are weighed in a molar ratio of 3:1:1 and uniformly mixed and placed in a tube furnace for reaction (reaction at 1200℃~2000℃ for 2~10 hours under Ar atmosphere). The synthesized product (cermet precursor Ti3AlCN) is pulverized and sieved through a 325-mesh sieve to obtain powder with a particle size <45μm, which is then used for etching treatment. The etching treatment involves soaking in a 40wt% concentrated hydrofluoric acid (HF) solution for 15~20 hours, then washing with deionized water until neutral (e.g., washing multiple times with deionized water until pH 6.5~7) and centrifuging. Finally, the nanosheets are dried under vacuum at 50~100℃ for 24 hours to obtain Ti3CN MXene nanosheets.

[0037] According to some specific embodiments, the preparation of the graphene-intercalated Ti3CN MXene material is as follows: synthesized Ti3CN nanosheets and graphene nanosheets are mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 30:1 to 5:1 to obtain a precursor suspension. Then, a probe of a probe-type pulse ultrasonic instrument is inserted into the precursor suspension and pulse ultrasonic treatment is performed under an inert N2 atmosphere for 1 to 4 hours. After washing with ethanol, the material is dried at 100 to 150°C under vacuum for 2 to 10 hours. The graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material) is obtained while maintaining the Ti3CN crystal structure.

[0038] In a third aspect, the present invention provides a graphene-intercalated Ti3CN MXene material prepared by the preparation method described in the second aspect of the present invention.

[0039] In a fourth aspect, the present invention provides the application of the graphene-intercalated Ti3CN MXene material described in the first aspect or the graphene-intercalated Ti3CN MXene material prepared by the preparation method described in the second aspect of the present invention as a battery material.

[0040] According to some preferred embodiments, the battery material is an alkali metal cation battery material; more preferably, the battery material is a sodium-ion battery material; when the graphene intercalated Ti3CN MXene material prepared by the present invention is used as a battery material, in the alkali metal cation M + M + for Na + K + Or Li + Various energy storage devices exhibit reversible cation storage capabilities; the graphene intercalated Ti3CN MXene material described in this invention, as a sodium-ion battery material, has an initial capacity and long-term cycle capacity that are more than twice that of the original Ti3CN battery.

[0041] According to some preferred embodiments, when the graphene intercalated Ti3CN MXene material prepared by the present invention is used as an anode material for sodium-ion batteries, Gr-Ti3CN SIBs provides a specific capacity of 1020 mAh / g during the first discharge at a current density of 50 mA / g. As the current density increases from 20 mA / g to 500 mA / g, the rate performance is maintained from 403 mAh / g to 201 mAh / g. After 500 cycles at a current density of 50 mA / g, the coulombic efficiency remains at 100%.

[0042] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments. The present invention may have many other embodiments, and those skilled in the art can make various corresponding changes and modifications based on the present invention without departing from its spirit and essence; however, all such corresponding changes and modifications should fall within the scope of protection of the appended claims.

[0043] Example 1 ① Weigh out titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1200℃ for 2 hours under Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 40wt% hydrofluoric acid solution for 18 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Then dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0044] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 10:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 30 times the mass of the graphene nanosheets. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0045] The XRD pattern of the graphene-intercalated Ti3CN MXene material prepared in this embodiment is as follows: Figure 1 As shown, from Figure 1As can be seen from the image, when graphene is inserted, the peak positions of Gr-Ti3CN are the same as those of Ti3CN (Ti3CN MXene nanosheets), indicating that the crystal structure of Ti3CN remains unchanged. The SEM image of the graphene-intercalated Ti3CN MXene material prepared in this embodiment is shown below. Figure 2 As shown, from Figure 2 As can be seen from b, the prepared Gr-Ti3CN consists of tightly bonded nanosheets with a smooth and clean surface; the C and N elemental distribution energy spectrum of the graphene-intercalated Ti3CN MXene material prepared in this embodiment is shown in the figure. Figure 3 As shown, the C element distribution perpendicular to the nanosheet cross-section is significantly higher than the C element distribution parallel to the nanosheet plane, indicating that graphene is embedded between Ti3CN MXene nanosheets. The charge-discharge cycle curves of the graphene-intercalated Ti3CN MXene material prepared in this embodiment, measured under constant current charge-discharge conditions with a current density of 50 mA / g and a charge-discharge cutoff voltage range of 0.1-3.0 V, are shown below. Figure 4 As shown, from Figure 4 As can be seen, Gr-Ti3CN exhibits excellent SIB electrochemical performance at a current density of 50 mA / g and a cutoff voltage of 0.1-3.0 V, providing high discharge specific capacity and high coulombic efficiency, indicating that graphene intercalation into Ti3CN MXene nanosheets greatly improves the capacity and reversibility of SIB.

[0046] The electrochemical testing method in this embodiment is as follows: 50 wt% Gr-Ti3CN, 20 wt% acetylene black, and 10 wt% polyvinylidene fluoride (PVDF) binder are mixed evenly in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which is then coated onto a copper foil current collector. After drying, a working electrode is obtained. Subsequently, this electrode, a sodium metal sheet (counter electrode), a polyolefin separator, and a sodium salt electrolyte (1M NaClO4 / EC:DEC) are assembled into a CR2032 half-cell for electrochemical performance testing. The 1M NaClO4 / EC:DEC sodium salt electrolyte indicates that NaClO4 is dissolved in a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) with a volume ratio of 1:1, and the concentration of NaClO4 is 1 mol / L.

[0047] The CR2032 half-cell assembled according to the above method in this embodiment is Gr-Ti3CN SIBs. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The Gr-Ti3CN SIBs provided a discharge specific capacity of 1020mAh / g during the first discharge at a current density of 50mA / g. As the current density increased from 20mA / g to 500mA / g, the reversible specific capacity remained at 201mAh / g, showing excellent rate performance. After 500 cycles at a current density of 50mA / g, the coulombic efficiency remained at 100%.

[0048] Example 2 ① Weigh out titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1500℃ for 2 hours under Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 60wt% hydrofluoric acid solution for 12 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Then dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0049] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 30:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 30 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0050] Example 3 ① Weigh out titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1500℃ for 2 hours under Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 60wt% hydrofluoric acid solution for 12 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Then dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0051] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 20:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 30 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0052] Example 4 ① Weigh titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1800℃ for 2 hours under an Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 40wt% hydrofluoric acid solution for 16 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Then dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0053] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 20:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 40 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0054] Example 5 ① Weigh titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1800℃ for 2 hours under an Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 40wt% hydrofluoric acid solution for 16 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Then dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0055] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 5:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 30 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0056] Example 6 ① Weigh titanium powder, aluminum nitride and graphite powder in a molar ratio of 3:1:1 and mix them evenly in a tube furnace. React at 1200℃ for 4 hours under an Ar atmosphere. Crush the synthesized product and sieve it through a 325-mesh sieve. Soak it in a 40wt% hydrofluoric acid solution for 16 hours. Then wash it with deionized water until pH≥6.8 and centrifuge it. Finally, dry it under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0057] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 20:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-intercalated Ti3CN MXene material (Gr-Ti3CN material). The amount of dimethyl sulfoxide used was 40 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0058] Comparative Example 1 ①The steps are the same as in Example 1.

[0059] ② The synthesized Ti3CN Mxene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide at a mass ratio of 10:1 at room temperature and a speed of 400 r / min for 1 h to obtain a mixture. The mixture was washed with ethanol and dried at 100 °C under vacuum for 8 h to obtain Ti3CN / graphene mixed powder. The amount of dimethyl sulfoxide used was 30 times the mass of graphene.

[0060] The SEM image of the Ti3CN / graphene hybrid powder prepared in this comparative example is shown below. Figure 2 As shown in a, from Figure 2 In the study, it was observed that in the mixture of graphene and Ti3CN nanosheets, the Ti3CN nanosheets were in a loose state, while the graphene nanosheets were dispersed on the outside.

[0061] In this comparative example, 50 wt% of Ti3CN / graphene mixed powder, 20 wt% of acetylene black, and 10 wt% of polyvinylidene fluoride (PVDF) binder were mixed evenly in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of Ti3CN / graphene SIBs during the first discharge process at a current density of 50 mA / g was measured to be 550 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was measured to be 221 mAh / g.

[0062] Comparative Example 2 ①The steps are the same as in Example 1.

[0063] ② The synthesized Ti3CN Mxene nanosheets and graphene nanosheets were mixed in a ball mill at a mass ratio of 10:1 for 2 hours at a speed of 300 r / min to obtain the MXene / Graphene composite with MXene and graphene intercalation.

[0064] In this comparative example, 50 wt% of MXene / Graphene composite, 20 wt% of acetylene black, and 10 wt% of polyvinylidene fluoride (PVDF) binder were mixed evenly in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of the MXene / Graphene composite SIBs during the first discharge process at a current density of 50 mA / g was measured to be 520 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was 214 mAh / g.

[0065] Comparative Example 3 ①The steps are the same as in Example 1.

[0066] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in deionized water at a mass ratio of 10:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-modified Ti3CN MXene material. The amount of deionized water used was 30 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0067] The graphene-modified Ti3CN MXene material prepared in this comparative example contains a considerable number of graphene nanosheets dispersed on the outside.

[0068] In this comparative example, 50 wt% of graphene-modified Ti3CN MXene material was mixed with 20 wt% acetylene black and 10 wt% polyvinylidene fluoride (PVDF) binder in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of graphene-modified Ti3CN SIBs during the first discharge process at a current density of 50 mA / g was measured to be 810 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was measured to be 290 mAh / g.

[0069] Comparative Example 4 ①The steps are the same as in Example 1.

[0070] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in N-methylpyrrolidone at a mass ratio of 10:1 at room temperature and a speed of 400 r / min for 1 h. The mixture was then subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-modified Ti3CN MXene material. The amount of N-methylpyrrolidone used was 30 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 100 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0071] The graphene-modified Ti3CN MXene material prepared in this comparative example contains a considerable number of graphene nanosheets dispersed on the outside.

[0072] In this comparative example, 50 wt% of graphene-modified Ti3CN MXene material was mixed with 20 wt% acetylene black and 10 wt% polyvinylidene fluoride (PVDF) binder in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of graphene-modified Ti3CN SIBs during the first discharge process at a current density of 50 mA / g was measured to be 840 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was measured to be 321 mAh / g.

[0073] Comparative Example 5 Titanium powder, aluminum nitride, and graphite powder were weighed out in a molar ratio of 3:1:1 and mixed evenly in a tube furnace. The mixture was reacted at 1200℃ for 2 hours under an Ar atmosphere. The synthesized product was pulverized and sieved through a 325-mesh sieve. It was then soaked in a 40wt% hydrofluoric acid solution for 18 hours, washed with deionized water until the pH reached 6.8, centrifuged, and then dried under vacuum at 80℃ for 24 hours to obtain Ti3CN Mxene nanosheets.

[0074] In this comparative example, 50 wt% Ti3CN Mxene, 20 wt% acetylene black, and 10 wt% polyvinylidene fluoride (PVDF) binder were mixed evenly in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of Ti3CN SIBs during the first discharge process at a current density of 50 mA / g was measured to be 502 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was measured to be 210 mAh / g.

[0075] Comparative Example 6 ①The steps are the same as in Example 1.

[0076] ② The synthesized Ti3CN Mxene nanosheets and graphene nanosheets were mixed in deionized water at a mass ratio of 10:1 at room temperature and a stirring speed of 400 r / min for 1 h to obtain a mixture. The container containing the mixture was then purged with nitrogen to remove oxygen and placed in an ultrasonic cleaning tank under nitrogen protection for conventional ultrasonic dispersion continuous treatment for 2 hours. Afterwards, it was washed with ethanol and dried at 100℃ under vacuum for 8 hours to obtain Ti3CN / graphene mixed powder. The amount of dimethyl sulfoxide used was 30 times the mass of graphene. The power density of the ultrasonic dispersion continuous treatment was 5 W / cm³. 2The frequency of the ultrasonic dispersion continuous processing is 40 kHz.

[0077] In this comparative example, 50 wt% of Ti3CN / graphene mixed powder, 20 wt% of acetylene black, and 10 wt% of polyvinylidene fluoride (PVDF) binder were mixed evenly in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of Ti3CN / graphene SIBs during the first discharge process at a current density of 50 mA / g was measured to be 535 mAh / g, and the reversible specific capacity at a current density of 20 mA / g was measured to be 218 mAh / g.

[0078] Comparative Example 7 ①The steps are the same as in Example 1.

[0079] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 10:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-modified Ti3CN MXene material. The amount of dimethyl sulfoxide used was 90 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 20 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0080] In this comparative example, 50 wt% of graphene-modified Ti3CN MXene material was mixed with 20 wt% acetylene black and 10 wt% polyvinylidene fluoride (PVDF) binder in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of the graphene-modified Ti3CN SIBs during the first discharge process at a current density of 50 mA / g was measured to be 715 mAh / g. As the current density increased from 20 mA / g to 500 mA / g, the reversible specific capacity decreased from 280 mAh / g to 140 mAh / g. After 500 cycles at a current density of 50 mA / g, the coulombic efficiency was 92%.

[0081] Comparative Example 8 ①The steps are the same as in Example 1.

[0082] ② The synthesized Ti3CN MXene nanosheets and graphene nanosheets were mixed in dimethyl sulfoxide (DMSO) solvent at a mass ratio of 10:1 at room temperature and a stirring speed of 400 r / min for 1 h. Then, the mixture was subjected to pulsed ultrasonic treatment under an inert N2 atmosphere for 2 h. After washing with ethanol, the mixture was dried at 100 °C under vacuum for 8 h to obtain graphene-modified Ti3CN MXene material. The amount of dimethyl sulfoxide used was 15 times the mass of graphene. The power density of the pulsed ultrasonic treatment was 400 W / cm². 2 The pulse duration is 30s, the duty cycle is 75% (i.e., 10s interval pulse ultrasound for 30s), and the frequency of the pulse ultrasound processing is 20kHz.

[0083] In this comparative example, 50 wt% of graphene-modified Ti3CN MXene material was mixed with 20 wt% acetylene black and 10 wt% polyvinylidene fluoride (PVDF) binder in 20 wt% N-methylpyrrolidone (NMP) solvent to prepare a slurry, which was then coated onto a copper foil current collector. After drying, the working electrode was obtained. The same electrochemical testing method as in Example 1 was used for testing. Charge-discharge tests were conducted in the potential range of 0.1~3.0V. The discharge specific capacity of the graphene-modified Ti3CN SIBs during the first discharge process at a current density of 50 mA / g was measured to be 760 mAh / g. As the current density increased from 20 mA / g to 500 mA / g, the reversible specific capacity decreased from 302 mAh / g to 152 mAh / g. After 500 cycles at a current density of 50 mA / g, the coulombic efficiency was 93%.

[0084] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A graphene-intercalated Ti3CN MXene material, characterized in that, The graphene-intercalated Ti3CN MXene material consists of Ti3CN MXene nanosheets and graphene interlayers inserted between the Ti3CN MXene nanosheets.

2. The graphene-intercalated Ti3CN MXene material according to claim 1, characterized in that: The Ti3CN MXene nanosheets maintained their original crystal structure.

3. The graphene-intercalated Ti3CN MXene material according to claim 1, characterized in that: The mass ratio of the Ti3CN MXene nanosheets to the graphene is (5~30):

1.

4. A method for preparing a graphene-intercalated Ti3CN MXene material, characterized in that, The preparation method is as follows: Ti3CN MXene nanosheets and graphene nanosheets are mixed in dimethyl sulfoxide and then subjected to pulsed ultrasonic treatment in an inert atmosphere to obtain graphene intercalated Ti3CN MXene material.

5. The preparation method according to claim 4, characterized in that: The power density of the pulsed ultrasound treatment is 60~300W / cm². 2 The pulse duration is 20-30 seconds, the duty cycle is 60-80%, and the pulse ultrasound treatment time is 1-4 hours.

6. The preparation method according to claim 4, characterized in that: The mass ratio of the Ti3CN MXene nanosheets, the graphene nanosheets and the dimethyl sulfoxide is (5~30):1:(20~45).

7. The preparation method according to claim 4, characterized in that: After pulsed ultrasound treatment, post-treatment is also included, which involves washing with ethanol and vacuum drying at 100~150℃ for 2~10h.

8. The preparation method according to claim 4, characterized in that, The Ti3CN MXene nanosheets were prepared as follows: Titanium powder, aluminum nitride and graphite powder were mixed and reacted in a tube furnace under inert gas protection. Then, the mixture was soaked in hydrofluoric acid solution, washed, centrifuged and dried to obtain Ti3CN MXene nanosheets. Preferably, the molar ratio of the titanium powder, aluminum nitride, and graphite powder is 3:1:1; Preferably, the inert gas is argon and / or nitrogen, the reaction temperature is 1200℃~2000℃, and the reaction time is 2~10h; Preferably, the concentration of the hydrofluoric acid solution is 35-60 wt%, and the soaking time is 15-20 h; Preferably, the washing is performed with deionized water until the pH reaches 6.5-7, and the drying is performed under vacuum at 50-100°C for 18-30 hours.

9. The graphene-intercalated Ti3CN MXene material prepared by any one of claims 4 to 8.

10. The application of the graphene-intercalated Ti3CN MXene material according to any one of claims 1 to 3 or the graphene-intercalated Ti3CN MXene material prepared by the preparation method according to any one of claims 4 to 8 as a battery material; preferably, the battery material is an alkali metal cation battery material; more preferably, the battery material is a sodium ion battery material.

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